Figure 1. Chemistry classes, status, and R&D needs 95

Figure 2. Potential for Future Battery Technology Cost Reductions 95

Figure 3. Battery R&D Program Structure 97

Figure 4. Cell capacity (blue) and the energy (red) of a 2.5Ah pouch cell as a function of cycling. The cell energy was measured based on the weight of the whole pouch cell... 100

Figure 5. (Top) Battery cycle life for cells formed using a fluorinated electrolyte (FE-3), Gen2 electrolyte, or pristine graphite (baseline) showing better retention for FE-3... 101

Figure 6. (a) Capacity retention and Coulombic efficiency of NMC532/graphite cells with Gen 2 and FE-3 electrolyte, and (b) TM (Ni, Co, Mn) dissolution at various testing... 102

Figure 7. GX12 exhibiting excellent cycle stability with over 2,000 cycles at 40℃ 102

Figure 8. Dischargeable specific energy at 33Ah size and total charge time of each extreme fast charging cycle. The cell is charged at 6C to 80% state of charge in each cycle 103

Figure 9. Cycling performance in carbonate electrolyte and study of failure mechanisms. (A) Coulombic efficiency versus cycle number plots of Cu, HCS, and ALD Al₂O₃/HCS... 103

Figure 10. Demonstration of life extension for Si/graphite pouch cell using passive/internal release from Li reservoir 104

Figure 11. Energy density of generation 1 (Gen #1) proprietary, LiNi1-xMxO₂ ultralow-cobalt material compared with state-of-the-art commercial LiNi0.8Co0.1Mn0.1O₂... 104

Figure 12. (a) Cyclability of the cells fabricated with the carbon-paper cathodes with a sulfur loading, sulfur content, and E/S ratio of, respectively, (a) 13mg/cm², 75wt.%, and... 105

Figure 13. Capacity retention of NMC 811/graphite pouch cells (11.3-11.6mg-NMC/cm²) cycled at 0.33C/-0.33C up to 4.2V. Comparison between standard processing (dark red... 106

Figure 14. Results from 1Ah cells made with recycled cathode NMC111 shown in red, green and blue. Results from control cells made with commercial NMC111 shown in purple 106

Figure I.1.A.1. Current and projected cell development progression throughout the USABC program 109

Figure I.1.A.2. Cycle life performance for various high-energy build #3 cell designs 110

Figure I.1.A.3. Schematic of cell foot prints used in final cell build #4 111

Figure I.1.A.4. Normalized capacity versus cycles for large 50Ah and standard 11Ah capacity footprint cells 112

Figure I.1.B.1. Full cell voltage drop and anode potential drop during discharge at different rates 115

Figure I.1.B.2. Discharge rate capability of R&D full cell using cathode with modified slurry composition 116

Figure I.1.C.1. DST Cycle life for nickle rich NCM with Si/C composite 120

Figure I.1.C.2. DCR for the Gen 1 deliverable chemistry & 2b) Rate capability 120

Figure I.1.C.3. Cycle life for Gen 1 deliverable chemistry 120

Figure I.1.C.4. Cycle life for the different electrolyte formulations 121

Figure I.1.C.5. Calendar life DCR for the Gen 1 deliverable chemistry & 4b) Capacity retention at 100%SOC @ 30° and 45℃ 121

Figure I.1.C.6. a) Capacity of C1.1 with different amount of sacrificial Li source b) Cycle life of Ni rich NCM(C1.1) with 5% SLSM for Si (500mAh/g) and c) Si composite with capacity... 122

Figure I.1.D.1. 90°peel test result of PPG coating with different binder and mixing procedure 124

Figure I.1.D.2. Long term cycling of pouch cells with baseline thickness, 93/3/4 and with NMC622 cycled under C/3 125

Figure I.1.D.3. Nyquist Plot of EIS measurement on pouch cells fabricated at PSU 125

Figure I.1.D.4. Peel strength of the thick cathode coatings 126

Figure I.1.E.1. Electrolyte formulation was optimized for better Calendar and Cycle Life in Si/NCM (70% Ni) cells 129

Figure I.1.E.2. CAD drawing and prototype 40Ah cell with silicon nanowire anode 130

Figure I.1.E.3. Silicon nanowire cells with NCM811 and in large form factor achieve 375Wh/kg 131

Figure I.1.F.1. Si anode failure mechanisms (left), SiNode graphene-wrapped advanced silicon anode architecture (right) 133

Figure I.1.F.2. 1st cycle efficiency (FCE) and capacity for a series of surface-treated SiOx materials 134

Figure I.1.F.3. Normalized full cell capacity versus cycles for SiNode-graphite blended anodes (1000mAh/g) with NCA 134

Figure I.1.F.4. SiNode production and production capacity (left) and particle size distribution (PSD) measurements demonstrating consistent material production quality (right) 135

Figure I.1.F.5. 10 Ah prototype cell with SiNode anode and NCA cathode. Commercial 18650 cell for comparison 135

Figure I.1.G.1. Cycling performance comparison between cells stored for 25 days at 4.6V and a cell tested without storage 139

Figure I.1.G.2. SEM Images of PMP-coated separator produced under various trial conditions 140

Figure I.1.G.3. Residual capacity during OCV stand at 100% SOC vs. total thickness of AlOx deposited on the experimental separators 141

Figure I.1.G.4. Discharging capacity of experimental and control separators in NCM523/Graphite 1.35Ah pouch cells cycled at 45℃, between 3.5 and 4.4V 141

Figure I.1.H.1. Pictorial representation of the direct recycling process which largely relies on physical separation processes; compared to other recycling technologies, the positive... 144

Figure I.1.H.2. (a) Material recovery from positive electrode scrap, and (b) reversible electrochemical capacity of recycled NMC111, recovered using different process parameters... 146

Figure I.1.H.3. Raman spectra and SEM images of NMC111 recovered from electrode scrap using a range of thermal treatment conditions 147

Figure I.1.I.1. Hardware Strategy of the Program 150

Figure I.1.I.2. Cycling of 1Ah cells with WPI cathode and control between 4.15V and 2.7V, 100% DOD, 45℃, +1C/-2C 151

Figure I.1.I.3. 1-second DCR, 5C discharge, 45℃, 70%, 50%, and 20% SOC after 1 month of cycling 151

Figure I.1.I.4. Cycling of 10Ah cells with WPI cathode and control cathode between 4.15V and 2.7V, 100% DOD, 45℃, +1C/-2C 152

Figure I.1.I.5. HPPC of 10Ah cells with WPI cathode at 25℃ and 0℃ at 10s (a) and 1s (b) 153

Figure I.1.I.6. Rate performance of 10Ah cells with WPI cathode powder and a reference cell at 25℃ 153

Figure I.1.J.1. High-voltage measurement schematic (left). Power electronics breakout for voltage and current measurement (right) 156

Figure I.1.J.2. OBD e-PID messages have been deciphered 156

Figure I.1.K.1. 2C/-2C, 100%DOD cycle life tests on D0.1 (1 Ah LMO-LTO cells) at 30℃, 45℃, and 55℃. Capacity Retention (left), impedance retention (right) 159

Figure I.1.K.2. 5C/-5C, 100%DOD cycle life tests on 1 Ah LMO-LTO cells at 30℃. Capacity Retention (left), impedance retention (right) 160

Figure I.1.K.3. Charge and discharge power calculated from HPPC test at 30℃ on 1Ah LMO-LTO cells and scaled to the 12V module using the appropriate BSF 160

Figure I.1.K.4. (Left): (a) -30℃ impedance growth rate during the pulse cycle life test. (-●-) denote values from 0.5s, 6KW pulse test, (-○-) denote values from 4s 4KW pulse... 161

Figure I.1.K.5. Capacity fade of D0.1 (1Ah LMO-LTO cells) during calendar life testing at 100% SOC and 70% SOC, at both 30℃ and 45℃ 161

Figure I.1.K.6. Impedance growth on D0.1 (1Ah LMO-LTO cells) during calendar life testing at 100% SOC and 70% SOC. (a) Impedance growth measured at 30℃ from HPPC... 162

Figure I.1.K.7. Voltage profile during cold crank test at 50% SOC on 1 Ah LMO-LTO cell 163

Figure I.2.A.1. Volumetric energy density in full cell coin cells for Si-C produced at lab-pilot scale 166

Figure I.2.A.2. Gravimetric energy density in full cell coin cells for Si-C produced at lab-pilot scale 166

Figure I.2.A.3. Example of device-level enhancement: cycle stability of pre-lithiated Si-C 167

Figure I.2.A.4. Homogeneity within the Si-C composite as determined by SEM in combination with EDS 167

Figure I.2.A.5. Raman (left) and XRD spectra (right) consistent with amorphous silicon and carbon within Si-C 168

Figure I.2.B.1. 3-D Microscope images of as-printed and dried (a) and post-calendered (b) cathode electrodes produced via CoEx. Images illustrate the corrugated topography... 172

Figure I.2.B.2. Comparison of the electrochemical rate performance of one-layer and two-layer thick graphite anodes (~6mAh/cm²) in half coin cells. Three cycles were run at... 174

Figure I.2.B.3. Representative surface profile of CoEx cathode both before (blue) and after (red) calendering 175

Figure I.2.B.4. Electrochemical Performance of 1 Ah pouch cells, comparing thin and thick baselines vs. CoEx cathodes. Error bars represent +/- 1 standard deviation. Quadratic... 176

Figure I.2.C.1. (a) Optical photograph of a 20 foot roll coated continuously on the mini-coater system at a line speed of 0.5m/min. (b) A comparison of half-cell coin-cell performance... 180

Figure I.2.C.2. Film deposition rate increases proportionally to the increase in electric field strength demonstrated by (a) increasing voltage and (b) decreasing separation between... 180

Figure I.2.C.3. Aerial capacity measurements of electrode coatings fabricated by simultaneously coating both sides of the current collector foil on the mini-coater system and... 181

Figure I.2.C.4. (a) Residual water content of PPG electrocoated cathodes and ORNL NMP-processed NCM 333 cathodes subjected to different secondary drying conditions. Each data... 182

Figure I.2.C.5. Cycling performance of electrocoated cathodes fabricated using bench-scale equipment compared to baseline cells assembled using conventional binders and drawdown... 183

Figure I.2.D.1. Developed UV Web and Slot Die Process 185

Figure I.2.D.2. Layer on Layer Cathode Coatings are not a problem, but the solution. Double layer coatings always retain capacity as well or better than single layer coatings 186

Figure I.2.D.3. Layer on layer UV Slot-Die Processing works with no loss in capacity. 94-4-3-NMC532-C-UV 7, 14, and 21mg/cm² 186

Figure I.2.D.4. Power cathode (82-12-6: NMC(532)-C-UV, 4mg/cm²) shows 75% capacity retention at 10C race. UV cathode withstands high temperature (120℃), where a PVDF... 187

Figure I.2.D.5. UV LTO Anode (93-4-3: LTO-C-UV) with 3mg/cm² loading. Three curves show tight consistency between cells 187

Figure I.2.E.1. Voltage curves of the 1.5Ah cells prepared from baseline sample (PVDF/NMP processing), sample B (acrylate polyurethane resin binder and EB cured at 500fpm) and... 192

Figure I.2.E.2. Cycling performance of 1.5 Ah cells prepared from baseline sample (PVDF/NMP processing), sample B (acrylate polyurethane resin binder and EB cured at 500fpm) and... 192

Figure I.2.E.3. Representative photos of the electrostatic sprayed samples after receiving from Keyland polymer 194

Figure I.2.E.4. Areal loading of the electrode prepared by electrostatic spraying method versus the spraying time 194

Figure I.2.F.1. Capacity retention of five different cosolvent systems cycled in full pouch cells at 0.33C/-0.33C 198

Figure I.2.F.2. Comparison of crack formation for three different solvent systems showing a crack-free coating for the 90/10wt% water/methyl acetate cosolvent dispersion 198

Figure I.2.F.3. SEM micrographs of laser-structured NMC 532 cathodes with different pitches (left and center) and schematic of a bilayer NMC 532 cathode with a porosity gradient... 199

Figure I.2.F.4. Rate performance from 0.05C to 10C discharge rates of full graphite/NMC 532 pouch cells comparing laser structured cathodes and a structured bilayer cathode to... 199

Figure I.2.F.5. NMC 811 rate performance comparison between aqueous processed cathodes, NMP processing with water exposed cathodes, and NMP processed baseline charged... 200

Figure I.2.F.6. XRD (left) and Raman spectroscopy (right) data of NMC 333 and NMC 811 pristine active material and after one week of water exposure showing no difference in bulk... 200

Figure I.2.F.7. TEM images of pristine NMC 811 (top) and NMC 811 exposed to water for one week (bottom) 201

Figure I.2.F.8. Comparison of 0.33C/-0.33C cycle life between aqueous processed NMC 811, NMC 811 exposed to water for one week, and the NMP processed baseline showing that... 201

Figure I.2.F.9. Surface energy of various NMC 532 cathodes with different porosities compared to Conoco Phillips A12 graphite surface energy; surface energies not including the effect... 202

Figure I.2.G.1. Thermal stability comparison between commercial NMC811 and 811 core-gradient using time resolved XRD 206

Figure I.2.G.2. Oxygen release comparison of normal NMC and core-gradient materials 206

Figure I.2.G.3. New synthesis approach toward Core-Multi Shell particle structure 207

Figure I.2.G.4. Electrochemical performance of synthesized core-multi shell materials 207

Figure I.2.G.5. Cycling comparison between commercial NMC and core-multi shell materials 208

Figure I.2.G.6. DSC comparison at 5C/min rate 208

Figure I.2.G.7. Impedance analysis of core-multi shell materials 209

Figure I.2.G.8. Normalized average discharge capacities of commercial NMC811 and core-multi shell materials 209

Figure I.2.G.9. Average discharge capacity retention of commercial NMC811 and core-multi shell materials 210

Figure I.2.H.1. Mean particle diameter versus solids production rate for FSP synthesis of LLZO. All points except Sol40 are based on the LLZO-UM recipe. Sol40 is based on the LLZO-ANL... 213

Figure I.2.H.2. (SEM digital image of LLZO-ANL before and after annealing for 12 hours at 800℃) 213

Figure I.2.H.3. XRD patterns for LLZO-ANL green and annealed powder. The material was annealed in oxygen for 12 hours at the temperatures noted 214

Figure I.2.H.4. XRD patterns for LNMO following annealing in Ar for 12 hours at 1000oC 214

Figure I.2.I.1. SEM images of NMC (111) powders made at different temperatures: Left-a winkled morphology at low temperature (500℃), and Right-a spherical morphology at high... 216

Figure I.2.I.2. SEM images of NMC (111) powders made with two different precursors: Left-powders showing better spherical morphologies; Right-powders show "perfect" spheres,... 216

Figure I.2.I.3. Cycling tests (a) rate capability at various C rates, and (b) cycling performance at 1C 217

Figure I.2.I.4. XRD patterns of the as-prepared LR1 and LR2 showing typical diffraction peaks of Li-rich materials 217

Figure I.2.I.5. SEM image of a Ni-rich NMC powders and a mapping of the Al element on a particle surface, showing Al was uniform on the surface of the particle 218

Figure I.2.I.6. Charge-discharge profiles on bare (previously presented) and Al₂O₃ coated NMC powders (new results). The coated NMC shows improved stability 218

Figure I.2.J.1. (a) Cycling results (discharge curve) for a Li-ion half-cell with anode prepared from a dual fiber Si-PAA/C-PAN mat. The first 5 cycles were carried out at 0.1C and the... 222

Figure I.2.J.2. Cycling results for Li-ion half-cells with anodes prepared from the same C-PAN/Si-PAA dual fiber mat. Both cells were subjected to one charge/discharge cycle at 0.1C... 223

Figure I.2.J.3. (a) Surface SEM image of the raw mat obtained by concurrent electrospinning of Si-PAA and electrospraying of C-PVDF, (b) Surface SEM of the compacted/welded mat... 224

Figure I.2.J.4. (a) Surface SEM image of an as-spun mat of Si/PAA nanofibers (40wt.% PAA in Si-PAA fibers), (b) Surface SEM of the welded/compacted mat from Figure 4a, and (c)... 225

Figure I.2.K.1. Batch synthesis of ethyl and propyl trifluoroethyl sulfones 227

Figure I.2.K.2. Screening of flow synthesis conditions for propyl trifluoromethyl sulfone 228

Figure I.2.K.3. Batch Conditions for the Synthesis of H-TDI 228

Figure I.2.K.4. Conversion data for H-TDI as a function of time and temperature 228

Figure I.2.K.5. Reaction calorimetry data 229

Figure I.2.K.6. Structure of literature FSP precursors synthesized at MERF 229

Figure I.2.K.7. Route for novel disilylcarbonate electrolyte solvents invented and developed at MERF 230

Figure I.2.K.8. Conversion dependence on reaction conditions for Me₃SiCH₂SiMe₂CH₂OC(O)OMe 230

Figure I.2.K.9. 10% w/w TMSMSMMC and TMSMSMEC in Gen2, graphite//NCM523, 3.0-4.4V cycling (Ch/DCh at C/3), 30ºC 231

Figure I.2.K.10. Synthesis of Si-containing carbonate solvents 231

Figure I.2.K.11. Cell performance of BTMSMC and DEGBTMSMC additives to Gen2 electrolyte 232

Figure I.2.L.1. Cycling of 400 mAh Si pouch cells at C/3 and room temperature with and without relithiation. The blue circles represent cycling with no relithiation. The green and red... 237

Figure I.2.L.2. Cycling of 400 mAh Si pouch cells at C/3 and room temperature with and without continuous relithiation using passive control 237

Figure I.2.L.3. Comparison of cell resistance during cycling of 400 mAh Si pouch cells at C/3 and room temperature with and without continuous relithiation using passive control 238

Figure I.2.L.4. Measured lithium concentration within LFP/graphite 18650 cells after high-rate relithiation. Three coin cells were extracted from each of location of the cells' jellyrolls... 239

Figure I.2.L.5. Simulated lithium concentration within NMC/graphite 18650 cell relithiated at different rates. 20% of capacity can be recovered over 6 months or slower without concern... 239

Figure I.2.L.6. Loss mechanisms for SOA high energy (5% Si-85%Gr/NMC811) LG MJ1 cell 240

Figure I.3.A.1. Approach for microstructure characterization and modeling 243

Figure I.3.A.2. (a) Five layers of 114μm thick graphite electrode individually resolved in beamline XRD study. (b) Li concentration layer-by-layer during 1C charge and discharge, data... 244

Figure I.3.A.3. Comparison of experimentally measured stress-strain response of a 3Ah pouch format cell against model predictions at various strain rates 245

Figure I.3.A.4. Comparison of the experimentally observed rise in temperature within a 5S1P module comprised of 3Ah pouch format cells charged to 100% SOC 245

Figure I.3.A.5. Force vs displacement of fully charged 5-Ah pouch cells. Little changed is observed up to 60℃, however a dramatic softening of the cell is observed at 120℃ 246

Figure I.3.A.6. Electrode microstructural variations concurrently affect (a) electrochemical, (b) thermal and (c) chemical interactions. The electrode capacities are kept unchanged to... 247

Figure I.3.A.7. Through-plane tortuosity factors of 7 positive NMC532 and 7 negative A12 graphite ANL CAMP electrodes, obtained with microstructure numerical homogenization (blue),... 248

Figure I.3.A.8. Lithiation of anode with Superior graphite SLC1506T at 5C rate with snapshot taken at approximately 60% SOC. The 3D direct numerical electrochemical model solves for... 249

Figure I.3.B.1. (a) Load vs. Displacement plots of 3-point bend tests of 4 cells (b) XCT results of Li-ion cells after 3-point bending 253

Figure I.3.B.2. Cross-sectional SEM images of an anode from a used cell after indentation (a) Low magnification image showing the Cu and fragmentation, (b) higher magnification of... 254

Figure I.3.B.3. (a) XPS depth profiles of elements in a pristine collect collector, (b) XPS depth profiles of elements in a stressed current collector 254

Figure I.3.B.4. Drucker-Prager criterion in deviatoric stress-pressure coordinates 255

Figure I.3.B.5. Unconstrained compression of battery electrode material. (a) experimental setup with die-set; and sample (b) axial compression; (c) lateral compression (Brazilian test) 255

Figure I.3.B.6. FIB-SEM cross-sectioning of positive electrodes. (a) SEM image of the cross-section; (b) EDS map showing carbon as signature for binder location 256

Figure I.3.B.7. (a)1C charge and discharge capacity curves, 1C dQ/dV curves. (b) concentration profiles at the end of CC and CV charging conditions (c) CC charging for various C rates... 257

Figure I.3.B.8. Equivalent circuit model for lithium ion battery 258

Figure I.3.B.9. Battery cell HPPC voltage data compared to ECM at ambient temperature of 25℃. Data from HPPC test shown as solid red line, ECM as dashed black line. Right plot is... 258

Figure I.3.B.10. Comparison of the module ECM (purple line) to the module US06 drive cycle data (red line). The voltage profile represents three modules connected in series 259

Figure I.3.C.1. Enhanced workflow for converting 3D tomography to mesh including the CBD phase 262

Figure I.3.C.2. Convergence and mesh refinement study for image-based mesoscale simulations for various effective properties 263

Figure I.3.C.3. Pore space tortuosity calculated for dense and nanoporous CBD phases using the binder morphologies from the next figure 264

Figure I.3.C.4. Binder morphologies generated from multiple approaches 264

Figure I.3.C.5. Snapshot of a coupled electrochemical-mechanical discharge simulation of an NMC cathode 265

Figure I.3.C.6. (left) A CDFEM mesostructure including active material particles and CBD created from DEM simulations of electrode drying and compression. (right) Tortuosity versus... 265

Figure I.3.D.1. Tomography scan times overlaid on potential-time curve. (LBNL, ANL) 268

Figure I.3.D.2. Image postprocessing pipeline. Left to right: reconstruction, slice after edge detection, detection of central plane, detection of bounding planes, rotated and cropped... 269

Figure I.3.D.3. Upper left: Raw slice averages as a function of slice position. Upper right: Slice average curves aligned on current collector edge. Lower left: Slice average curves... 270

Figure I.3.E.1. X-ray radiograph of the cell (a transverse cross section), showing the various components. The X-ray beams penetrate the cell from the left. Gaussian-shaped colored... 275

Figure I.3.E.2. Voltage-capacity plots for cycling of Gr/NCM523 cell at C/20 and 1C rates (cycles 2 and 5, respectively). Specific capacities of the graphite electrode are shown at the... 275

Figure I.3.E.3. Experimental d-spacing (filled circles, axis to the left) for LixC6 phases present in layer L0, observed during cycling at 1C rate and plotted as a function of the cell average... 276

Figure I.3.E.4. Layer average lithium content x in the ordered LixC6 phases estimated using eq. 1 plotted as a function of the cell average lithium content x of the graphite matrix... 277

Figure I.3.E.5. Layer average Li content x in the ordered phases (filled circles, to the bottom) plotted vs. the median depth of these layers (to the left). Panel a is for charge and panel b... 277

Figure I.3.F.1. Force vs displacement of fully charged 5 AH pouch cells. Little changed is observed up to 60℃, however a dramatic softening of the cell is observed at 120℃ 280

Figure I.3.F.2. Drop tower commissioning 281

Figure I.3.F.3. Example propagation data provided to NREL for multi-cell modeling activities 281

Figure I.3.G.1. Project schematic showing major constituents and progression of Alpha and Beta versions 283

Figure I.3.G.2. Two models for the battery impact simulation. These models have the same settings except that different elements, (a) solid elements and (b) composite t-shell... 285

Figure I.3.G.3. Comparison of (a) voltage and (b) state of charge evolution in two types of models 285

Figure I.3.G.4. Comparison of temperature distribution at 41 seconds in (a) the composite t-shell element model and (b) macro model 285

Figure I.3.G.5. Both (a) composite tshell models and (b) macro models can use a small number of elements in the cell thickness direction. The difference is that in the former, the EM... 286

Figure I.3.G.6. Comparison of the cell stresses in the (a) layered solid and (b, d) solid element assembly. In (b), the four top unit cells are resolved, and in (d) all unit cells are resolved... 287

Figure I.3.G.7. X-ray tomography of deformed cells (a) cell sectioning, and (b) scanning 288

Figure I.3.G.8. X-ray tomography of the internal damage in a sheared cell 288

Figure I.3.G.9. Experimental test for lateral compression of active material specimen 289

Figure I.3.G.10. Experimental results for uniaxial and lateral compression test of active material specimens 290

Figure I.3.G.11. The uniaxial compression test response for LS-DYNA materials 145 and 193 290

Figure I.3.G.12. Characterization of microstructure characteristics based on image analysis 291

Figure I.3.G.13. Stochastic reconstruction of 3D microstructures. The reconstructed "porous phase" is shown in green pixel. The lamellae phase is not shown 292

Figure I.3.G.14. Solid-beam hybrid model. Tension along the machine direction 292

Figure I.3.G.15. Solid-beam hybrid model. Tension along the transverse direction 293

Figure I.3.G.16. Simulation results: stress-strain curves on machine direction (MD) and transverse direction (TD) 293

Figure I.4.A.1. Process for NMC precursor production via co-precipitation 296

Figure I.4.A.2. Process for production of NMC cathode powder via calcination 297

Figure I.4.A.3. Share of total energy of Li-S cell production (excluding energy use for cell assembly) 298

Figure I.4.A.4. Cradle-to-gate LCA comparison of Li-S battery and conventional LIB on a per kWh basis 298

Figure I.4.B.1. Reduction in virgin material demand due to recycling 301

Figure I.4.B.2. Inter-relationship of recycling processes 304

Figure I.4.C.1. Schematic of ReCell model 307

Figure I.4.C.2. Potential cost savings of per kg cell production via battery recycling for different chemistries 308

Figure I.4.C.3. Potential SOx emission savings from recycling NMC111 batteries 309

Figure I.4.C.4. Total energy reductions from recycling of Li-S batteries 310

Figure I.4.E.1. Process and Timeline for the Battery Recycling Prize 318

Figure I.5.A.1. Discharge capacity as a function of electrode loading and charge rate (left) and photos of lithium deposits on representative graphite electrodes (right).These results... 321

Figure I.5.A.2. Discharge capacity retention for the graphite materials selected in the coin-cell prescreening study under 6C charge and C/2 discharge between 3-4.1V at 30℃... 324

Figure I.5.A.3. Discharge capacity for the MAG-E3 graphite using CMC-SBR binder versus NMP-based PVDF binder in the coin-cell prescreening study under 6C charge and C/2 discharge... 326

Figure I.5.A.4. Discharge capacities for the 2nd Round coin cells (purple and blue) compared to the 1st Round coin cells (green) cycled under 6C (and 4C) charge rates (Superior... 328

Figure I.5.A.5. Averaged and normalized capacities (based on NMC532) for the 2nd Round coin cells (purple and blue) compared to the 1st Round coin cells (green) cycled under 6C... 328

Figure I.5.A.6. Normalized capacities (based on NMC532) for the 2nd Round coin cells at increasing charge rates (Superior Graphite SLC1506T vs. NMC532) 329

Figure I.5.A.7. Discharge capacities from formation cycles for 24 single-sided single-layer 2nd Round pouch cells (Superior Graphite SLC1506T vs. NMC532) delivered to INL 329

Figure I.5.A.8. Raman spectrum of MAG E3. All spectrum displayed the same bands with different intensity ratios, including the band at ~2700cm-¹ (overtone/harmonic of D band... 330

Figure I.5.A.9. XRD patterns of the selected graphites in the 2θ range of 40 to 60° 331

Figure I.5.A.10. Relaxation time (τδ) vs. state of charge (SOC) for the discharge subcycle for MCMB graphite. The discharge voltage limits were 1.5V to 5mV and represented the... 332

Figure I.5.A.11. Relaxation time (τδ) vs. state of charge (SOC) for the charge subcycle for MCMB graphite. The discharge voltage limits were 5mV to 1.5V and represented the... 333

Figure I.5.A.12. Discharge A12 graphite half-cell GITT data and simulation in the LiC32 single-phase region (left) and the LiC6-LiC12 two-phase region (right) 333

Figure I.5.A.13. Left: graphite electrode voltage compared to model simulation using indicated parameters for 10s 3C discharge and charge pulses on reference electrode cell. Right:... 334

Figure I.5.A.14. Left: graphite electrode voltage compared to model simulation from reference electrode cell for 1C discharge. Right: NMC electrode voltage compared to model simulation... 335

Figure I.5.A.15. Comparison of cell cost estimates with material prices in 2017 and 2018 336

Figure I.5.B.1. The respective C/1 and C/20 capacity fade results from the aging experiment (right) using the different charge protocols defined in Table I.5.B.1 341

Figure I.5.B.2. Increased graphite capacity in stage 1 following over lithiation in a half-cell (left) and compared coulombic efficiency and Li stripping efficiency (right) 342

Figure I.5.B.3. Preliminary data showing acoustic signal for Li plating for cells cycled at 0.2C. LCO pouch cell at 8℃ (a, with Li plating) and 21℃ (b, no plating). Circles on the left show... 343

Figure I.5.B.4. Capacity over cycles, Right: Visual Lithium Confirmation 343

Figure I.5.C.1. Schematic of the various transport limitations during XFC that can result in poor charge acceptance, heat generation, lithium plating and capacity loss 347

Figure I.5.C.2. Comparison of high rate charging performance of graphite/NMC 532 cells having a low loading of 1.5mAh/cm2-NMC. Model results are shown as solid lines and... 347

Figure I.5.C.3. Comparison of high rate charging performance of graphite/NMC 532 cells having a low loading of 1.5mAh/cm2-NMC. Model results are shown as solid lines and... 348

Figure I.5.C.4. Comparison of high rate charging performance of graphite/NMC 532 cells having a low loading of 1.5mAh/cm2-NMC. Model results are shown as solid lines and... 349

Figure I.5.C.5. Cell potential and intercalation fraction within A12 graphite anode during 1C in-situ XRD experiments performed by ANL. Experimental results are squares and model... 349

Figure I.5.C.6. Macro-homogeneous model predictions for useable SOC (left) and driving potential for lithium plating (right) as function of cell/cathode level loading at 4 and 6C. For... 350

Figure I.5.C.7. Macro-homogeneous model predictions for useable SOC (left) and driving potential for lithium plating (right) as function of cell/cathode level loading at 4 and 6C. For... 351

Figure I.5.C.8. Model predictions for lithium plating during XFC as function of electrode thickness/loading for current electrodes & electrolyte (dot-dash lines) and next generation (NG)... 351

Figure I.5.C.9. (a) Microstructure-predicted tortuosity for several different electrodes. (b) Correlation of tortuosity with capacity at cycle number 500 for 6C charge, C/2 discharge of... 352

Figure I.5.C.10. Model predictions for lithium plating during XFC as function of electrode thickness/loading for current electrodes & electrolyte (dot-dash lines) and next generation (NG)... 352

Figure I.5.C.11. Model predictions for lithium plating during XFC as function of electrode thickness/loading for current electrodes & electrolyte (dot-dash lines) and next generation (NG)... 353

Figure I.5.C.12. Model predictions for lithium plating during XFC as function of electrode thickness/loading for current electrodes & electrolyte (dot-dash lines) and next generation (NG)... 354

Figure I.5.D.1. (a) slurry mixture in a planetary mixer; (b) wet anode slurry coated onto Cu foil; (c) wet cathode slurry coated onto Al foil; (d) electrode coating densified through... 357

Figure I.5.D.2. Left, the first three cycles of superior graphite 1520T electrodes; right, the first three cycles of NMC622 electrodes 357

Figure I.5.D.3. Normalized cell voltage vs. capacity curves with different loadings charging at different C rates and discharging at 1C 358

Figure I.5.D.4. Left, capacity & voltage versus cycling number when the cells are cycled at +1C/-1C and +6C/-1C, respectively. Right, voltage versus capacity curves during cycling 358

Figure I.5.D.5. Temperature rises inside a 600 mAh pouch cells during a 5A charge (through collaboration with Prof Guangsheng Zhang at University of Alabama in Huntsville) 359

Figure I.5.D.6. 1H NMR spectra of Sty-TFSI-K+ 359

Figure I.5.D.7. Synthesis of single Li-ion conducting oligomer (compound 5) 360

Figure I.5.D.8. 1H NMR spectrum of single Li-ion monomer (compound 4) 360

Figure I.5.E.1. Charge/discharge capacities and coulombic efficiencies of TNO at different current rates 364

Figure I.5.E.2. Normalized capacity of NMC622 half coin cells at various charge protocols and areal loadings 365

Figure I.5.F.1. Cooling plate fixture 367

Figure I.5.F.2. Cell temperature (Kokam 5Ah pouch) during 6C charge, 2C discharge cycling, inside the cooling fixture 368

Figure I.5.F.3. Baseline cell rate capability performance 368

Figure I.5.F.4. Figure 4: dQdV vs V for various cycles in baseline rate capability 369

Figure I.5.F.5. Figure 5: dQdV vs V for 1C discharge steps after each charge rate increase 369

Figure I.5.G.1. Conceptual graphic describing the connections between fast charging and the related energy systems that can be bridged by behind the meter storage 372

Figure I.7.A.1. Cost of cells and packs as a function of the production volume. See Table 1 for specifications 381

Figure I.7.A.2. Cost of cells and packs as a function of the maximum allowable current density to avoid lithium deposition during charging. Production volume = 100,000 packs/year... 382

Figure I.7.A.3. Cost of cells and packs as a function of the production volume, showing the effects of cathode price and pack size. See Table 1 for specifications 382

Figure I.7.A.4. Specific energy density as a function of the upper cutoff voltage (UCV) 383

Figure I.7.A.5. Pack costs vs. upper cutoff voltages (UCV vs Li/Li+) for BEV and PHEV batteries. The ASI of all the cathode materials is held constant 12Ω-cm² (at 20% SOC). Production... 383

Figure I.7.A.6. Schematic of a process for the production of LiPF6 384

Figure I.7.A.7. Impact of the cost of LiPF6 on the cost of a 60kWh lithium ion battery pack. (NMC622-Graphite electrodes, plant capacity of 100,000 packs per year) 385

Figure I.7.B.1. Schematic representations of the HPPC and Peak Power test profiles 388

Figure I.7.B.2. (a) Relative resistance at 80% DOD from the peak power test from the calendar life test. The numbers in the legend represent the test temperature in ℃. The best-fit... 389

Figure I.7.B.3. (a) Relative resistance at 80% DOD vs. time. The numbers in the legend are the test temperatures. The best-fit line was forced to have a have a y-intercept of 1. The... 389

Figure I.7.D.1. Results of increasing SOC within 18650 cells 398

Figure I.7.D.2. Comarison for two cell sizes 399

Figure I.7.D.3. Failure SOC during overcharge testing 399

Figure I.7.D.4. Failure temperature during overcharge 399

Figure I.7.D.5. Failure temperature during thermal ramp 400

Figure I.7.D.6. dQ/dV vs SOC for cells charged at 1C and 1.5C 400

Figure I.7.E.1. Efficiency summary of cells tested at 30℃ in NREL's calorimeters 404

Figure I.7.E.2. Efficiency of silicon blended cells tested at 30℃ in NREL's calorimeters under various charge/discharge currents 405

Figure I.7.E.3. Entropic response to NCM-1:1:1 and high nickel content NCM cathodes paired with a graphite anode 406

Figure I.7.E.4. Efficiency comparison of a single cell compared to a 10-cell module at 30℃ 406

Figure I.7.E.5. Infrared image of lithium battery cell at the end of a 2C discharge 407

Figure I.7.F.1. a) Voltage profile comparison and b) cycle performance comparison of NCM523/SiO and NCM523-LFO/SiO. The capacity of SiO/NCM523-LFO full cells are calculated... 411

Figure I.7.F.2. Punched electrodes of ceramic-coated graphite anode 413

Figure I.7.F.3. Cycle Life (left) and HPPC ASI at 50% SOC (right) for the ceramic-coated graphite electrodes evaluated in xx3450 single-layer pouch cells 413

Figure I.7.F.4. Cycle Life (left) and HPPC ASI at 50% SOC (right) for the ceramic-coated graphite electrodes evaluated in coin cells in separator-free study for 3-4.1V window 414

Figure I.7.F.5. Cycle Life (left) and HPPC ASI at 50% SOC (right) for the ceramic-coated graphite electrodes evaluated in coin cells in separator-free study for 3-4.4V window 415

Figure I.7.F.6. White light images of the (a) pristine and (b) aged (400 cycles) electrode cross-sections; Raman maps were obtained in the portions indicated by the dashed red boxes... 42

Figure I.7.F.7. Sequence of steps for the quantitation of gas evolution by the Archimedes method 417

Figure I.7.F.8. Volume change of pouch bags containing (a) deionized water and NMP slurries, with and without 2.5wt% PAA and (b) aqueous slurries with PAA and LiPAA (the extent of... 418

Figure I.7.F.9. Gas evolution from aqueous slurries containing LiPAA80% and silicon particles from Paraclete Energy with different surface coatings: graphene for nSi/Cg, silicon oxide for... 419

Figure I.7.F.10. (Left) Cathode dimensions, interfaces, area, and perimeter information of the xx3450 and xx6395 pouch cells fabricated at the CAMP Facility. (Right) Image of the partially... 419

Figure I.7.F.11. Cycle life performance (Left) and area specific impedance performance at 50% depth of discharge (DOD) which were acquired every 50 cycles (Right) for both the xx3450... 420

Figure I.7.G.1. Schematic diagram of (left) core-gradient nickel rich cathode material, and (right) charge and discharge voltage profiles of NMC811 and NMC811-CG 424

Figure I.7.G.2. Cycling performance of conventional NMC811 and NMC-CG full cell 424

Figure I.7.G.3. ASI results of full cells containing (left) NMC811 and (right) NMC811-CG cathode during cycling test 425

Figure I.7.G.4. FSEM images from graphite raw materials: a) CPreme A12; b) XL40; c) XL20. Note the slightly different scale bars 426

Figure I.7.G.5. Gr/NMC532 full-cell electrochemical cycling data following standard cycling protocols; filled points indicate discharge capacity while open points indicate Coulombic Efficiency... 427

Figure I.7.G.6. Gr/NMC532 full-cell electrochemical cycling data following Fast-Charge protocols. (left) Charge capacity during Formation (C/10) and Fast-Charge studies (discharge rate... 428

Figure I.7.G.7. SEM images of graphite electrode containing (a) XL40 and (b) A12 graphite recovered after 100 cycles with 6C charge, C/3 discharge. The insets include photographs of the... 429

Figure I.7.H.1. SEM images of the anode surfaces from cells charged to 140% SOC. Figure (a) is from a cell containing a NMC532 cathode, and (b), from a cell containing an LFP cathode 432

Figure II.1.A.1. Temperature versus time for laminates dried at different oven temperatures 437

Figure II.1.A.2. Drying time versus oven temperature 437

Figure II.1.A.3. Photos of laminates dried at different temperatures 438

Figure II.1.A.4. Adhesion (green) and cohesion (orange) of the laminates dried at different temperatures as measured on a peel tester in N/m and N/m², respectively 438

Figure II.1.A.5. Area specific resistance as a function discharge % for laminates dried at different temperatures 438

Figure II.1.A.6. Nyquist plot of EIS data of electrodes dried at various temperatures 439

Figure II.1.A.7. The atomic percentage of C and F measured on the surface of electrodes dried at different temperatures as measured by EELS 439

Figure II.1.A.8. X-ray data of PVDF films formed by drying from solutions at different drying temperatures 439

Figure II.1.A.9. Ionic conductivity of electrolyte in PVDF films prepared by drying from solutions at different temperatures 440

Figure II.1.B.1. (a) Chemical structures of the polymer coatings used in this study. Coloring of the label corresponds to the chemical functionality of the polymer. (b) Diagram of the... 442

Figure II.1.B.2. (a) Chemical structures of the dynamic crosslinking of the dynamic crosslinking of the SHP and covalent crosslinking of the SHE. SEM images of 0.1mAh/cm² of lithium... 443

Figure II.1.B.3. SEM images of 0.1mAh/cm² of lithium electrodeposited on copper with (a) no polymer coating, (b) PEO coating, (c) PVDF coating, (d) SHP coating, (e) PU coating, and... 443

Figure II.1.B.4. (a) Exchange current density plotted against dielectric constant for various polymer coatings measured via microelectrode. (b) The average diameter of the Li deposited... 445

Figure II.1.B.5. Schematic of the factors influencing Li metal deposition through a polymer coating. Low surface energy coatings give rise to higher interfacial energies and encourage the... 446

Figure II.2.A.1. Battery Performance and Cost (BatPaC) model utilized to establish relevance by connecting pack to anode targets 447

Figure II.2.A.2. Program participants including Laboratories, research facilities, and individual contributors 448

Figure II.2.A.3. Electrochemical results of an experimental silicon electrodes fabricated by the CAMP Facility. These cells were cycled between 0.05 to 1.5V vs. Li+/Li. Graphite was not used... 450

Figure II.2.A.4. Full cell results using the silicon deep dive protocol of the high-silicon graphite-free anode and 15wt.% Si in graphite composite. Both cells were tested against a common... 451

Figure II.2.A.5. Electrochemical results of the A-A017 high-silicon graphite-free electrode fabricated by the CAMP Facility. These cells were cycled between various lower cutoff voltages (LCV)... 452

Figure II.2.A.6. Installed 4L hydro/solvothermal reaction system (a) and FT-IR result comparison of pristine NanoAmor Si particles and their hydrothermally treated product 453

Figure II.2.A.7. a) cycling performance of NMC532|| Si/Gr cells with a) modified silicon anode with and without carbon coating in baseline electrolyte. b) modified silicon anode with carbon... 454

Figure II.2.A.8. (a) XRD patterns of Si films along with Cu foil reference, and (b) content of Si and O detected by EDS for Si films 455

Figure II.2.A.9. CV curves of (a) Si-5, (b) Si-10, (c) Si-20, and (d) Si-30 films during the first two cycles. Insets are enlarged CV curves between 0.45 and 1.5V 455

Figure II.2.A.10. (a) Voltage profiles, (b) CV curves of Si-Sn film, (c) enlarged CV curves at 0.14-1.5V, (d) capacity, (e) capacity retention, and (f) CE of Si-Sn and Si films of similar thickness 456

Figure II.2.A.11. 1L of 15% Si-graphite aqueous based slurry after 1-week storage. Gassing from the slurry caused foaming and subsequent drying as the slurry "snaked" out of the open... 457

Figure II.2.A.12. a) The change in pressure vs time of W2-water based nano Si/CB slurry (blue trace, circles), W5-water based 325 mesh Si slurry (black trace, diamonds), W4-water... 458

Figure II.2.A.13. a) Mass spectrum of gas collected from head space of mixing vessel for W2 (blue trace), W4 (green trace), and N1 (red trace), normalized to the N₂ signal of ambient air... 459

Figure II.2.A.14. XPS of Si 2p orbitals, Normalized to Si4+at 103.6 eV, of various dried Si samples (untreated nano Si-brown trace, N1-red trace, W1-purple trace (overlapping with N1),... 460

Figure II.2.A.15. Voltage profile of Si-Li metal half cells comparing short-processed NA 70-130 Si (brown trace) and W2 (blue trace). Cycled at C/10 (0.25A g-¹) from 1.5 to 0.05V vs Li metal 461

Figure II.2.A.16. A representative schematic of several reactions that occur during processing of water based Si/CB slurry 462

Figure II.2.A.17. Raman maps of the distribution of carbon black, c-Si, graphite, and a-Si in Si-Gr composite anodes after 1 full cycle (lithiation and delithiation). The top row maps an anode... 463

Figure II.2.A.18. (a) Raman map of the intensity of the main band from crystalline silicon at 520cm-¹ in a silicon-graphite composite electrode after 1 charge-discharge cycle. The fraction of... 463

Figure II.2.A.19. SEM images of the different Cu-coated silicon electrodes obtained by applying the 6 different electrodeposition protocols collected in Table 2 464

Figure II.2.A.20. Raman spectra of the different Cu-coated silicon electrodes obtained by applying the 6 different electrodeposition protocols collected in Table 2 465

Figure II.2.A.21. XRD of as-synthesized Li7Si3, with a small amount of the slightly oxidized phase Li12Si7 465

Figure II.2.A.22. (a) 7Li NMR, (b) 29Si NMR, and (c) XRD results of pristine LS samples and their mixture with 10 wt% PVDF or LiPAA 466

Figure II.2.A.23. (a) 1H, (b) 13C, and (c) 19F MAS NMR spectra of pristine LS samples and their mixture with 10 wt% PVDF 466

Figure II.2.A.24. Images of gas-cathcing setup before, immediately after, and 1 day after the mixing of PVDF and Li7Si3 467

Figure II.2.A.25. (a) 7Li and (b) 29Si solid state MAS NMR for Li7Si3 and its mixture with different electrolyte solvents 468

Figure II.2.A.26. (a) 7Li and (b) 29Si in-situ solid state MAS NMR for Li21Si5 and different electrolyte solvents. ANL, unpublished results 469

Figure II.2.A.27. Electrochemical profiles of Paraclete baseline silicon powder and carbon SP electrodes vs. Li metal half cells comparing Gen2 + 10% FEC and 1M LiTFSI in Trigylme electrolytes 470

Figure II.2.A.28. (a) 7Li and (b) 13C solid state MAS NMR for post-electrochemistry Si loose-powder anodes after cycling between 0.01-1.5 and 0.05-1.5V vs. Li respectively for 15 cycles,... 471

Figure II.2.A.29. Electrode potential vs. capacity during lithiation (a) and delithiation (b) of a Gr-only electrode (grey line) and of a Si/Gr (15/73w/w, red line) blended electrode cycled vs. Li... 472

Figure II.2.A.30. Capacity (a) and specific capacity (b) of the Gr and Si components in a Si-Gr electrode during lithiation and delithiation. Note that the capacity increases during lithiation and... 473

Figure II.2.A.31. Changes in the positive electrode potential during (a) cycle-life aging and (b) calendar-life aging of a NCM523/Si-Gr (10wt% FEC) cell. The inset in (b) shows the top 50mV... 474

Figure II.2.A.32. Synthesis of surface-functionalized SiNPs with methyl and epoxy terminal groups 476

Figure II.2.A.33. (a) FT-IR spectra and (b) TGA thermograms of pristine SiNPs, silanol-enriched SiNPs, and epoxy-SiNPs 477

Figure II.2.A.34. Initial capacity and Coulombic efficiency of Si/Li cells: (a) three C/20 formation cycles and (b) one-hundred C/3 cycles 478

Figure II.2.A.35. EDX elemental mapping (Si, C, O, F, P) for Si/PAA electrodes with (a) pristine SiNPs, (b) Si-OH SiNPs and (c) epoxy-SiNPs after 100 cycles 478

Figure II.2.A.36. Si2p XPS spectra of the Si electrodes based on pristine SiNPs and epoxy-SiNPs before and after one formation cycle: (a) fresh Si electrode before cycling and (b) Si electrode... 479

Figure II.2.A.37. (a) Adhesion strength of the Si anodes with pristine SiNPs, Si-OH SiNPs, epoxy-SiNPs, and CH3-SiNPs as active materials, and (b) summarized data of average load per unit width 480

Figure II.2.A.38. The voltage profiles of the functionalized electrodes. Cut-off: 2 hours lithiation, 1.5V delithiation. Current density: 27.3μA/cm² 481

Figure II.2.A.39. Impedances of the surface treated electrodes, measured at the end of lithiation. The same electrolyte, Gen2 with 10% FEC, was used for all of electrochemical testing 482

Figure II.2.A.40. (a) A representative voltage profile of Si wafer electrode. (b) (c) Nyquist plots of SEI-CH3 and SEI-COOH. EIS measurements were conducted at specific state of lithiation and... 483

Figure II.2.A.41. Bode plots of silicon electrodes fictionalized by (a) -COOH and (b) -CH₃ 484

Figure II.2.A.42. Surface coating effects on the electronic conductivity. Resistivity depth profile in (a) was plotted as a function of depth. All of the measurements end at the point where the... 485

Figure II.2.A.43. Diagram for the synthesis of Li₂SiO₃-coated silicon nanoparticles 486

Figure II.2.A.44. XRD patterns of silicate-coated Si with starting Si nanoparticles of different oxide layer thicknesses 486

Figure II.2.A.45. Electrochemical performance of formation cycles for silicate-coated Si with different silicate layer thicknesses 487

Figure II.2.A.46. SEM of silicate-coated Si with starting Si nanoparticles of different oxide layer thicknesses 488

Figure II.2.A.47. Electrochemical performance of formation cycles for high-energy-ball-milled silicate-coated Si with a) a thinner silicate layer and b) a thicker silicate layer 488

Figure II.2.A.48. (a) Generic synthesis of poly(1-pyrenemethyl methacrylate-co-dopamine methacrylamide) (PPyMADMA). (b) Wide angle X-ray scattering (WAXS) of PPyMA and PPyMADMA... 490

Figure II.2.A.49. (a) Synthetic scheme, (b, c) physical appearance of PBzM, PNaM and P(AnMx-co-BuMy) polymer emulsions 491

Figure II.2.A.50. a. A schematic of bi-functional additives. b. Formation of surface layer on the Si surface. c. Formation of bulk polymer. d. An example of vinylenecarbonate polymerization to... 492

Figure II.2.A.51. The bi-functional additives and their performance as an additive in a graphite or Si electrode with EC/DMC LiPF6 electrolyte and lithium metal counter electrode. There is no... 493

Figure II.2.A.52. A plot of pH vs. LiOH/COOH molar ratio (a) and the apparent viscosity vs. the shear rate (b) for 10wt% aqueous solutions of PAA. The pH of the aqueous solutions is color... 495

Figure II.2.A.53. A viscosity plot for the PAA polymers at two different pHs 496

Figure II.2.A.54. Specific delithiation capacity (a and c) and Coulombic efficiency profiles (b and d) of half cells assembled using lithiated PAA during formation cycles at a C/3 rate (a, b) and... 496

Figure II.2.A.55. Specific discharge capacity (left) and Columbic efficiency (right) for full cells. The pH of PAA solutions in Figure II.2.A.52 is indicated in the plot 497

Figure II.2.A.56. The 180˚ peeling test for the Si-Gr electrode composed using different PAA binders (left). The load/width ratios averaged over a range of 50 mm for different electrodes... 497

Figure II.2.A.57. Synthesis of P4VBA and Methylation for GPC Analysis 498

Figure II.2.A.58. MOPAC Computed Conformations of PAA and P4VBA Dimers 498

Figure II.2.A.59. (a) Size exclusion chromatograms for synthesized P4VBA polymers; (b) The apparent viscosity vs. shear rate for 30wt% P4VBA solutions in NMP. See the color coding in the plot 499

Figure II.2.A.60. Specific discharge capacity (left) and Coulomb efficiency (right) for different half-cells (100 cycles at a constant C/3 rate) 499

Figure II.2.A.61. (a) The load/width ratio plotted vs. the extension and (b) the average ratio over the extension range for different S-Gr electrodes 500

Figure II.2.A.62. Specific discharge capacity (to the left) and Coulombic efficiency (to the right) for different full-cells 500

Figure II.2.A.63. Specific discharge capacity (to the left) and Coulombic efficiency (to the right) for half cells using non-lithiated PAA binders during formation (a) and normal cycling (b) 501

Figure II.2.A.64. Cathode capacity versus cycle number plot of two LFO weight percent blended NMC532 electrodes (as labeled) together with the non LFO-containing Si-graphite full cells. In... 502

Figure II.2.A.65. Cathode capacity versus cycle number plot (Si DD protocol) of three over-lithiated Li1+xNMC532O₂/Si-graphite full cells, and one black baseline cell. The x value represents... 503

Figure II.2.A.66. Full cell potential profiles for the (a) first and (b) second charge and discharge of LiNi0.5Mn1.5O4 and chemically lithiated Li1.62Ni0.5Mn1.5O4 versus a Si-graphite composite... 504

Figure II.2.B.1. Pouch cells designed for gassing studies. The pouch has two wells-one for electrolyte and the other for material-to control initial mixing 517

Figure II.2.B.2. Buoyancy apparatus with a water bucket, indium wire to hang the pouch from the balance, and a bob (20g dry) 517

Figure II.2.B.3. IR gas cell used for kinetic measurements from two different angles. The path length through the cell is 11 cm, and the KBr windows are 25 mm in diameter by 2mm thick... 518

Figure II.2.B.4. Plot of change in volume (calculated through buoyancy) of the nanostructured silicon compounds reacting with various electrolytes in pouches. The left plot is of the PECVD Si... 519

Figure II.2.B.5. Characterization data for the gases produced in the reaction between the PECVD silicon LiPF6 electrolyte. A. Kinetic IR (black = 14 min, red = 752 min, blue = 1,278 min), insets... 520

Figure II.2.B.6. Characterization data for the gases produced in the reaction between the nanoamor silicon and the electrolyte. A. Kinetic IR (black = 0.936 min, red = 126 min, blue = 559 min,... 521

Figure II.2.B.7. Characterization data for the gases produced in the reaction between the fumed silica and the electrolyte. A. Kinetic IR (black = 0.3 min, red = 184 min, blue = 1,019 min,... 522

Figure II.2.B.8. Characterization data for the gases produced in the reaction between the Stöber silica and the electrolyte. A. IR data as a function of time (black = 0.936 min, red = 126 min,... 523

Figure II.2.B.9. Characterization data for the gases produced in the reaction between the Li₂SiO₃ and the electrolyte. A. IR data as a function of time (black = 0.936 min, red = 126 min, blue... 524

Figure II.2.B.10. Characterization data for the gases produced in the reaction between the Li4¬SiO4 and the electrolyte. A. Kinetic IR data as a function of time (black = 0.936 min, red... 525

Figure II.2.B.11. FTIR data showing the proton-termination region of several representative materials 526

Figure II.2.B.12. Left: Example FTIR data on chemical reactivity of plasma-grown Si nanoparticles (black) with 1.2M LiPF6 in EC (blue) or (red) electrolyte. Right: Cartoons showing various... 527

Figure II.2.B.13. DRIFTS spectra showing fumed SiO₂ (top), nanoamor 30-50nm particles (middle), and Stober SiO₂ (bottom) before (black) and after (red) exposure to electrolyte 528

Figure II.2.B.14. DRIFTS spectra showing Li₂SiO₃ and Li4SiO4 before (black) and after (red) exposure to electrolyte 528

Figure II.2.B.15. ATR IR spectra over exposure time for a) SiO₂, b) Li₂Si₂O5, c) Li₂SiO₃, and d) Li₃SiOx 529

Figure II.2.B.16. FIB cross sections of Li₃SiOx samples soaked for (a) 0 hour, (b) 3 hours, (c) 24 hours, and (d) 72 hours 530

Figure II.2.B.17. Illustration of thickness and compositional changes of (a) SiO₂, (b) Li₂Si₂O5, (c) Li₂SiO₃, and (d) Li₃SiOx films soaked in electrolyte over time 531

Figure II.2.B.18. XPS depth profile of Li₃SiOx thin film 531

Figure II.2.B.19. XPS sputter depth profiles for SiO₂ (a) F 1s and (b) Li 1s; Li₂Si₂O5 (c) F1s and (d) Li 1s; Li₂SiO₃ (e) F 1s and (f) Li 1s; and Li₃SiOx (g) F 1s and (h) Li 1s 532

Figure II.2.B.20. XPS Si 2p, O 1s, F 1s, and C 1s binding energies with depth for SiO₂ soaked for 0 hours (a-d), 30 minutes (e-h), 24 hours (i-l), and 72 hours (m-p) 533

Figure II.2.B.21. XPS Si 2p, O 1s, F 1s, and C 1s binding energies with depth for Li₃SiOx soaked for 0 hours (a-d), 30 minutes (e-h), 24 hours (i-l), and 72 hours (m-p) 534

Figure II.2.B.22. 1×1μm AFM images from left to right: Native oxide pristine surface, after soaking in electrolyte, thermally grown 50-nm SiOx wafer pristine surface, after soaking in... 538

Figure II.2.B.23. SSRM depth profiling on 15-nm SiO₂ on c-Si sample after soaking in electrolyte for 7 days. Height image is shown at left, and resistivity image is shown at right. Electronic... 538

Figure II.2.B.24. Calculated radial distribution functions g(r) and the corresponding integrals N(r) of Li-O(EC), Li-F(PF6−), Li-Li, Li-P(PF6−) pairs of (a) (b) 1.0M LiPF6 in EC, and Li-O (EC),... 539

Figure II.2.B.25. (a) The calculated total coordination number for Li+ in 1.0M LiPF6 in EC with 0/5/10% FEC and 1.2M LiPF6 in EC with 0/5/10% FEC with specifications of the contributions... 539

Figure II.2.B.26. (a) Self-diffusion coefficients computed from MD simulations as compared with NMR experiments (1.0M LiPF6 in EC) (b) Transference numbers for Li+ and PF6− from MD... 540

Figure II.2.B.27. Measured FTIR spectra of the C=O breathing band of (a) pure EC and 1.0M LiPF6 in EC, and (b) EC with 10% FEC and 1.0M LiPF6 in EC with 10% FEC. (c-d) The... 541

Figure II.2.B.28. Measured FTIR spectra of the P−F bond stretching band of (a) 1.0M LiPF6 in EC, and (b) 1.0M LiPF6 in EC with 10% FEC. (c) The corresponding calculated IR spectra for... 542

Figure II.2.B.29. Structures of EC molecules around a Li ion (a) in bulk and (b) at interface 543

Figure II.2.B.30. (a) The model Si anode interface, and (b) the voltage profile in the electrolyte region between the electrodes. The electric potentials are -0.47V and +0.7V at the negative... 544

Figure II.2.B.31. Contact ion pair (CIP) ratio in the bulk electrolyte and at SiO₂ interface at temperatures of 400K, 350K, and 313K. The CIP ratio increases from the bulk to interface. The... 544

Figure II.2.B.32. Li-Si phase diagram 545

Figure II.2.B.33. (a) 7Li and (b) 29Si solid-state in-situ MAS NMR for Li7Si3 and its physical with different electrolyte solvents 546

Figure II.2.B.34. (a) 7Li and (b) 29Si in-situ solid-state MAS NMR for Li22Si5 and different electrolyte solvents. ANL, unpublished results 547

Figure II.2.B.35. Inset photo: Electrolyte drop on lithium silicide thin film on silicon wafer. Main plot: ATR-FTIR spectra of the FEC and Gen2-treated lithium silicide surface 547

Figure II.2.B.36. Bulk modulus of lithium silicates and lithium silicides 548

Figure II.2.B.37. a) Photo of sputter targets, and b) diagram of sputter conditions in the process chamber of Lesker PVD75 system 549

Figure II.2.B.38. Substrate holders used for sputter deposition. Left: Holder for Si chips, Right: Holder for KCl chemical test samples 550

Figure II.2.B.39. Sputter system and sample transfer process 550

Figure II.2.B.40. ICP-OES results for Li/Si ratio in each thin film at each power setting 551

Figure II.2.B.41. FTIR spectra of all five sputtered lithium silicate compositions 552

Figure II.2.B.42. Gaussian-peak deconvolution of Li/Si = 7.7 film 553

Figure II.2.B.43. Gaussian-peak deconvolution of a) Li/Si = 4.8 film, b) Li/Si = 2.9 film, c) Li/Si = 1.9 film, and d) Li/Si = 1.4 film 554

Figure II.2.B.44. Percent of vibration modes relevant to lithium silicate film with for each composition 555

Figure II.2.B.45. XPS a) O1s, b) Si 2p, and c) C 1s binding energy regions with depth profiling of Li/Si = 1.4 sample 556

Figure II.2.B.46. XPS a) O1s, b) Si 2p, and c) C 1s binding-energy regions with depth profiling of Li/Si = 2.9 sample 557

Figure II.2.B.47. XPS a) O1s, b) Si 2p and c) C 1s binding-energy regions with depth profiling of Li/Si = 4.8 sample 558

Figure II.2.B.48. XPS a) O1s, b) Si 2p, and c) C 1s binding-energy regions with depth profiling of Li/Si = 7.7 sample 559

Figure II.2.B.49. TOF-SIMS analysis of Li/Si = 1.4 thin film 561

Figure II.2.B.50. TOF-SIMS analysis of a) Li/Si = 1.9 thin film, b) Li/Si = 2.9 thin film, c) Li/Si = 4.8 thin film, and d) Li/Si = 7.7 thin film 562

Figure II.2.B.51. TOF-SIMS depth profiling of Li2O (left), Li₃SiOx (middle), and Li₂SiO₃ (right) 563

Figure II.2.B.52. XPS depth profile analysis of LiF thin films on a Li foil (left) and a Pt-coated Si wafer (right) 563

Figure II.2.B.53. Morphologies and RMS roughness of individual SiEI components deposited on Pt-coated Si wafers 564

Figure II.2.B.54. Ionic conductivity of individual SiEI components with varying temperature (left) and binding energy variation of a LiF thin film on a Li foil obtained from operando XPS (right) 565

Figure II.2.B.55. Average surface electronic resistivity (left) and nanoindentation depth (right) of individual SiE 566

Figure II.2.B.56. 500×500-nm AFM images of the LiF surfaces before and after nanoindentation was performed, illustrating the AFM-based nanoindentation technique. Hardness results for... 566

Figure II.2.B.57. 1×1-μm SSRM images of the LiF surface showing resistance and height channels after SSRM resistivity vs. depth profiling was performed. Resistivity vs. depth profiles for... 567

Figure II.2.B.58. EELS spectrum images of Li2O film deposited on Pt on c-Si showing the Li K edge and O K edge maps 567

Figure II.2.B.59. EELS spectrum images of Li₂SiO₃ film deposited on Pt on crystalline Si showing O K edge, Si L edge, and C K edge maps 568

Figure II.2.B.60. XPS data showing little to no variation in chemical states present on the surface of the Si thin-film samples 569

Figure II.2.B.61. TOF-SIMS profile data showing the apparent change in sputter rate of Si thin-film samples that have been aged in different gloveboxes across the five national laboratories;... 570

Figure II.2.B.62. (left) Photo of the silicon-supported electrodes; (right) Schematic of the electrode cross section 571

Figure II.2.B.63. TOF-SIMS data collected on the as-prepared electrode 572

Figure II.2.B.64. TOF-SIMS data collected for 18O labeled electrodes aged for three hours in wet and dry electrolyte 572

Figure II.2.B.65. NR data collected for Li₂Si₂O5/Si films as a function of time aging in electrolyte 573

Figure II.2.B.66. Cyclic voltammetric response of 70-nm-thick amorphous Li₂Si₂O5 films on a Si wafer in 1M LiPF6 1:1 EC: DMC at scan rate of 0.1mV/s. Markers indicate the potential... 574

Figure II.2.B.67. Operando AFM images on 70-nm-thick Li₂Si₂O5: Si electrodes undergoing lithiation and substrate alloying. Topography and effective elastic modulus a, b) prior to the Li-Si... 575

Figure II.2.B.68. Scanning electron micrographs of a Li₂Si₂O5: Si electrode alloyed to 50 mC/cm2 at 90mV (vs. Li0/+). a) Silicate film disruption (localized cracking and delamination) is... 576

Figure II.2.B.69. TOF-SIMS depth profiles (25-keV Bi+ for analysis, 1-keV Xe+ for milling) of Li₂Si₂O5: Si electrodes at various stages of LiSi alloying. a) 72-nm-thick silicate alloyed to... 577

Figure II.2.B.70. Uncoated amorphous silicon galvanostatically cycled with 0.05V cutoff voltage at C/100 rate 578

Figure II.2.B.71. a) First-cycle CV for silicon anodes with silicate coatings and b) discharge profiles 579

Figure II.2.B.72. First lithiation of silicate-coated silicon anodes at C/100 with replicates for each coating composition 580

Figure II.2.B.73. CV plots for the a) second, b) seventh, and c) fourteenth cycle for each silicate coating cycling at a C/50 cycle rate 581

Figure II.2.B.74. Discharge capacity per cycle calculated using area under CV curve with 0.08V cutoff voltage 582

Figure II.2.B.75. Discharge capacity per cycle calculated using area under CV curve with 0.26V cutoff voltage 583

Figure II.2.B.76. Discharge capacity per cycle for cycling data with a 0.26V cutoff voltage 583

Figure II.2.B.77. Discharge capacity change from the first to second and second to fourteenth cycle for cyclic voltammetry and constant current samples 584

Figure II.2.B.78. XPS depth profile analysis of LixSiOy composite thin film on copper foil for a) Si-rich region and b) Li-rich region. The top panels show binding-energy depth profile of O 1s... 585

Figure II.2.B.79. a) Voltage profile of lithium-rich LixSiOy composite film and silicon-rich LixSiOy composite film; b) Impedance evolution of lithium-rich LixSiOy composite and silicon-rich LixSiOy... 586

Figure II.2.B.80. a) Charge and discharge profile of Si and LixSiOy /Si, with inset showing the schematic of double-layer thin film; b) Cycle performance and coulombic efficiency of double-layer... 587

Figure II.2.B.81. a) Evolution of XPS core-level spectra during in-situ lithiation of 50-nm SiO₂/Si(001) wafer. b) AES depth profile of the lithiated sample reveals that the entire SiO₂ layer has... 588

Figure II.2.B.82. Evolution of XPS core-level spectra during in-situ lithiation of an: a) sputter-cleaned Si(001) wafer, b) wafer with a native oxide, and c) Si (001) wafer with a 50-nm-thick... 588

Figure II.2.B.83. Overpotential variations for the three different Si wafers tested: a) 50-nm SiO₂/Si (001) b) native oxide on Si (001) and c) sputter-cleaned Si (001). The black curve was... 589

Figure II.2.B.84. XPS core-level spectral evolution monitored as a function of lithiation time for three samples: bare Si(001), native oxide SiOx/Si(001), and 5-nm thermal-oxide SiO₂/Si (001)... 590

Figure II.2.B.85. XPS O 1s (upper left) and Si 2p (upper right) core levels recorded on the 5-nm SiO₂/Si(001) sample before the Li ion gun was turned on and immediately after. The shifts in... 591

Figure II.2.B.86. Measured (symbols) and calculated (solid lines) ARXPS angular profiles of detected chemical states highlighting near-surface, intermediate, and buried phases (upper panels)... 591

Figure II.2.B.87. Structures of EC molecules around a Li ion (a) in the bulk and (b) at the interface 593

Figure II.2.B.88. (a) The model Si anode interface, and (b) the voltage profile in the electrolyte region between the electrodes. The electric potentials are -0.47V and +0.7V at the negative... 594

Figure II.2.B.89. Contact ion-pair (CIP) ratio in the bulk electrolyte and at SiO₂ interface at temperatures of 400, 350, and 313 K. The CIP ratio increases from the bulk to interface. The neutral... 594

Figure II.2.B.90. (a) The voltage profile and (b) differential capacity profile when lithiation to 60mV. (c) The voltage profile and (d) differential capacity profile when using a cut-off voltage of... 595

Figure II.2.B.91. The SEM morphology of es-SEI on the Si surface after cathodic cycling with the cut-off potential of (a) 400mV and no rest, (b) 115mV and no rest, as well as (c) 115mV... 596

Figure II.2.B.92. The XPS spectra obtained from the es-SEI with the cut-off potential of 400mV. The spectra show that the LiEDC starts to form at the potential higher than 400mV 597

Figure II.2.B.93. The XPS spectra obtained from the es-SEI after HVIST cycling with the cut-off potential of 115mV and no rest. The spectra show that the SiOx was reduced to LixSiOy during... 598

Figure II.2.B.94. The XPS spectra obtained from es-SEI after HVIST cycling with the cut-off potential of 115mV and long rest. During the long rest, the spectra show that the LiEDC was... 599

Figure II.2.B.95. (a) Cyclic voltammetry of 50-nm Si thin film in Gen 2 electrolyte (1.2M LiPF6 in EC: EMC 3:7wt.%). Inset represents the comparison of the first-cycle voltage profile of the Si... 600

Figure II.2.B.96. Schematic representation of the electrode recovery and ATR-FTIR testing of unwashed (a) and washed (c) Si thin-film model electrodes. Cells have been cycled at 5μA cm-²... 601

Figure II.2.B.97. (a) 3-D schematic of aNSOM experimental setup and operational principle. aNSOM 1-μm × 1-μm image of 50-nm silicon thin-film electrode cycled up to 0.05V after the first... 603

Figure II.2.B.98. Ex-situ ATR-FTIR analysis of cycled Si thin films at different states of charge during the first (de)lithiation process in the 1,000-700cm-¹ spectral region of unwashed (a) and... 604

Figure II.2.B.99. Ex-situ ATR-FTIR analysis of cycled Si thin films in the fully lithiated and delithiated state upon the 1st and 2nd cycle in the 1,900-1,000cm-¹ (a) and 1,000-700cm-¹ (b)... 605

Figure II.2.B.100. Ex-situ XAS analysis at the Si L-edge collected in TEY (a) and TFY (b) mode for the 50-nm Si thin film with native oxide 605

Figure II.2.B.101. Ex-situ ATR-FTIR analysis of unwashed cycled 50-nm Si thin films with 10-nm SiO₂ at different states of charge during the first (de)lithiation process (a) and following 2nd... 606

Figure II.2.B.102. A comparison of the EQCM-D data for a silicon film cycled in (a) Gen2, and (b) Gen2 +10wt.% FEC 607

Figure II.2.B.103. AFM topography (blue box), TERS mapping of an individual band (orange box) and composite TERS map (grey box) of 1X, 5X, and 20X cycled a-Si samples. The topography... 608

Figure II.2.B.104. TERS spectra collected from various locations of (a) 1X sample, (b) 5X sample, and (c) 20X sample. The assignment for bands of interest are at the top of each plot. The... 610

Figure II.2.B.105. SSRM resistivity vs. depth profiles of SEI formed on 15-nm SiO₂ and native oxide on Si wafers after one cycle 611

Figure II.2.B.106. STEM EELS areal density maps on SEI formed on two model Si systems. SEI formed on native oxide is comparably thicker and less laterally homogenous when compared to... 611

Figure II.2.B.107. An example of 3-D resistance mapping of SEI. (a) SSRM schematic, where spreading resistance (Rsp) 〉〉 sample and back-contact resistance (Rsb). By using appropriately... 612

Figure II.2.B.108. SIMS and SSRM data for doped α-Si: H on c-Si reference sample. (a) Dynamic SIMS P-concentrations measured with cesium and oxygen sputtering at 15 keV and 2 keV,... 613

Figure II.2.B.109. (Left) Scheme for lithium binding by HPNO fluorophore. (b) UV-vis spectra of 0.05mM HPNO in propylene carbonate without lithium (purple) and increasing amounts of LiBr... 614

Figure II.2.B.110. Synthesis of Li ion fluorescent sensors with tunable absorbance spectra. R groups represent strong electron withdrawing groups. n 614

Figure II.2.B.111. (top) Three new monomeric Li-ion fluorescent sensors developed in this program with "tunable" absorbance spectra over a range of ~100nm. (Bottom) Sensitivity of the... 615

Figure II.2.C.1. Voltage profile (a) and cycling performance (b) of the NMC532|| Si/Gr (CAMP electrodes) in TEPa-based LHCE 623

Figure II.2.C.2. a) Cycling performance of NMC532|| Si/Gr cells with a) modified silicon anode with and without carbon coating in baseline electrolyte. b) Modified silicon anode with carbon... 624

Figure II.2.C.3. Cycling performance of NMC532|| Si/Gr full cell with different additives 625

Figure II.2.C.4. In situ TEM characterization of the lithiation process of a typical CNT@Si microsphere. a) Si/MWNT composite particle before lithiation; b) partially lithiated particle; c, fully... 625

Figure II.2.C.5. In-situ SEM-AFM indentation of a CNT@Si@C particle. a) SEM image of the AFM Tip; b) high resolution of the CNT@Si@C particle; c) SEM image of the contact between AFM... 626

Figure II.2.C.6. (a) Long-term cycling performance of the CNT@Si @C and Comm-Si electrodes. (b) Cycling performance of CNT@Si @C-Graphite electrodes with 30wt% CNT@Si @C in the... 626

Figure II.2.D.1. Stability of the LixSi/graphene foil. (a) Photographs of the Li metal and LixSi/graphene foil exposed to ambient air for different durations. (b) The areal capacity retention of a... 629

Figure II.2.D.2. Electrochemical performance of the LixSi/graphene foil. Half-cell cycling performance of LixSi/graphene foils with thicknesses of 12 and 19μm at 0.1mAcm−². The Coulombic... 630

Figure II.2.D.3. Electrochemical performance of the LixSi/graphene foil. a, The voltage profiles of LixSi/graphene foil-LiFePO4 full cell and Li-LiFePO4 half cell (LiFePO4: Super P: PVDF... 631

Figure II.2.D.4. Characterization of the sulfur electrode and the sulfur batteries. a, SEM image of the graphitic carbon-encapsulated sulfur composites. b, TEM image of the graphitic carbon... 632

Figure II.2.D.5. Photographs of the (a) LixSn/graphene foil and (b) LixAl/graphene foil. XRD patterns of the (c) LixSn/graphene foil and (d) LixAl/graphene foil 633

Figure II.3.A.1. (Left Panel) Change in volume of NMC-811//Gr pouch cells due to gas evolution measured using Archimedes method. Gassing is significant in cells charged to 4.4V with... 636

Figure II.3.A.2. (Left Panel) Gases sampled from symmetric pouch cells (anode//anode and cathode//cathode) and full pouch cells after cycling. The gases were measured ex situ with GC-MS... 636

Figure II.3.A.3. (Left) AEGIS reactor capable of continuously probing gas phase species without loss of solvent. (Right) Change in concentration of CO and CO₂ with state of charge measured... 637

Figure II.3.A.4. (Left Panel)-Voltage and electrode potential data from cells containing the (a) NMC811/LTO and (b) NMC811/Gr couples. For both couples, the profiles to the left show the... 638

Figure II.3.A.5. (Left Panel) HAADF-STEM micrograph (5nm scale bar) from a NMC-532 particles cycled in FE-3 electrolyte. (Right Panel) EELS analysis results from the oxides cycled with... 639

Figure II.3.A.6. (a) Capacity vs. cycle number for cells containing pristine graphite/F-Gr/G-Gr anodes, pristine cathodes, and Gen2 electrolyte. (b) Average CE for the final 5 C/3 cycles of each... 640

Figure II.3.B.1. SEM images of a) platelet-shaped and b) truncated-octahedron-shaped NMC crystals 644

Figure II.3.B.2. (a, b) Hard XAS spectra of pristine, delithiated, and aged NMC-333 particles, and (c) The relationship between Ni-K edge energy and aging time 645

Figure II.3.B.3. K-edge energy shift of a) Ni, b) Mn and c) Co as a function of aging time in chemically-delithiated NMCs 645

Figure II.3.B.4. (Right) 27Al NMR spectra of 5wt.% Al₂O₃-coated NMC-622 and 811 annealed at 800℃ for 8h, compared to Co-rich NCA, Ni-rich NCA and NCMA, and Co-rich NCMA. (Left)... 646

Figure II.3.B.5. Summary of effects of different surface treatment conditions on electrochemical performance 646

Figure II.3.B.6. Electrochemical performance of baseline NMC-532 with optimized coatings as per Figure II.3.B.5 647

Figure II.3.B.7. Electrochemical performance comparison of baseline with optimized cathodes 648

Figure II.3.C.1. (a) Segregation trend for dopants in NMC-111. (b) Reactivity trend for dopants in NMC-111 651

Figure II.3.C.2. (a) Dissolution concentrations in the electrolyte for different additives, electrolytes, and states of charge 652

Figure II.3.C.3. Formation energy as a function of c-direction expansion for pinned (a) Li₂Ni₂O₄ and (b) Li₂Co₂O₄ spinels on a NMC-111 (012) facet 652

Figure II.3.C.4. Adsorption configuration on partially delithiated NMC-111 of (a) TMSPi and (b) TMSPi decomposed by Si-O bond breaking pathway. Silver, blue, purple, green, light blue, gray,... 653

Figure II.3.C.5. Change of NMC/LiAlO₂ interface formation energy with the thickness of α-LiAlO₂ layer sandwiched between NMC and a disordered LiAlO₂ phase 656

Figure II.3.C.6. (a) Model slab for the (012) NMC-111 surface coated with 2 layers of α-LiAlO₂. Light blue spheres represent Al, green-Li, purple-Mn, blue-Co, silver-Ni, and red-O. (b) TM layer... 656

Figure II.3.C.7. Positive SEI growth model compared to a 4.6V hold on NMC//Gr coin cell at room temperature 657

Figure II.3.C.8. Left: Proposed side reaction mechanism from reference 1. Right: Full electrochemical model compared to 4.6V hold on NMC//Gr coin cell at room temperature 657

Figure II.3.D.1. (a) Neutron diffraction and Rietveld refinement of a Mo-NMC composite cathode with x = 0.15. (b) Charge/discharge curves and (c) cycling stability of NMC compared with a... 662

Figure II.3.D.2. Half-cell electrochemical characterization of Li₂MoO₃ thin film cathodes cycled in a liquid carbonate electrolyte. (a) Galvanostatic charge/discharge profiles and (b) differential... 663

Figure II.3.D.3. Ex-situ XPS spectra of pristine (i.e., uncycled) and cycled thin film Li₂MoO₃ thin film cathodes collected after 1 and 20 charge/discharge cycles showing core-level scans... 664

Figure II.3.D.4. Electrochemical characterization at room temperature for an all-solid-state Li₂MoO₃/Lipon/Li thin film battery showing (a) galvanostatic charge/discharge curves, (b)... 665

Figure II.3.D.5. Li+ diffusion coefficient in Li2MoO3 at 80℃ at various states of charge for a Li₂MoO₃/Lipon/Li thin film battery as determined from EIS using the method reported by Ho... 665

Figure II.3.D.6. Characterization of LiNi0.5Mn0.5O₂ (LNMO)-based cathodes with and without 1 at % Mo (LiNi0.495Mn0.495Mo0.01O₂). (a) X-ray diffraction (XRD) patterns and galvanostatic... 666

Figure II.3.D.7. (a) Cycling stability at 20mA/g and (b) rate capabilities at 10-200mA/g for LNMO cathodes which were modified by doping with 1 at% Mo and/or coating with 2wt% MnPO₄... 667

Figure II.3.E.1. The cycling behaviors of Sn-Fe-C anode composite synthesized with mechano-chemical synthesis 671

Figure II.3.E.2. The cycling and rate performance of modified polyol approach synthesized SnyFe anode material 671

Figure II.3.E.3. (left) The first cycle, (middle) the 1st three cycles showing the rapid decay and (right) the ex-situ XAS showing the oxidation and reduction of Cu during the conversion and... 672

Figure II.3.E.4. The rate capability on 1st discharge of (left) a Li//CuF₂ cell and (right) a Li//CuF₂-VOPO₄ cell 672

Figure II.3.E.5. The behavior of a Cu0.5Fe0.5F₂ electrode. From left to right: the first two cycles (and also indicating where the XAS measurements were made; the fade of the Cu²+ peak;... 672

Figure II.3.E.6. The cycling and rate performance of solid-state synthesized LixVOPO₄ cathode with high energy ball milling with carbon and then annealed with different hours 673

Figure II.3.E.7. Comparison of (a) the capacity and (b) the energy density of the SnyFe//LixVOPO₄ cell vs. the baseline SnyFe//LiFePO₄ cell 674

Figure II.3.E.8. (a) Comparison of the cycling performance of a SnyFe//LixVOPO₄ cell with different capacity ratios of cathode to anode; (b) comparison of the performance of... 675

Figure II.3.F.1. Electrochemical behavior of Li||NMC76 cells using two different carbonate-based electrolytes at 0.33C current rate after three formation cycles at 0.1C rate. Comparison of... 679

Figure II.3.F.2. Comparison of the cycling performance of Li||NMC76 cells using two electrolytes under high charging/discharging current rates (A) 1C/1C, (B) 2C/2C, and (C) 5C/5C. (D) Rate... 680

Figure II.3.F.3. (a, d) Cycling performance of Ni-rich LiNi0.76Mn0.14Co0.10O₂ cathode in (a) E-baseline (1M LiPF6/EC-EMC) and (d) E-optimized (0.6M LiTFSI, 0.4M LiBOB, and 0.05M LiPF6... 681

Figure II.3.F.4. (a) First cycle charge-discharge voltage profiles and (b) cycling performance of Li||NMC76 cells using E-baseline and four LiBOB-added electrolytes (E-n%LiBOB). (c) Comparison... 682

Figure II.3.G.1. Schematic illustration of the experimental setup for in situ probing of local elemental diffusion, oxidation and ordering of cations during synthesis of Ni-Mn-Co (NMC) layered... 685

Figure II.3.G.2. Structural transformation during synthesis of the layered LiNi0.73Mn0.13Co0.10O₂ (NMC771310) from the hydroxide precursor. (a) Schematic of the transformation from layered... 686

Figure II.3.G.3. Dynamic process of local structural ordering within TMO6 octahedra during synthesis of NMC771310. (a) Temperature-resolved in situ PDF patterns in a wide r range, showing... 687

Figure II.3.G.4. Oxidation dynamics of the constituent cations during synthesis of NMC771310. (a) Schematics of the transformation of the octahedra associated with the hydroxides, namely,... 688

Figure II.3.G.5. Reaction pathway, with cationic ordering coupled with reconstruction of NiO6 octahedra, during synthesis of NMC771310, at the three sequential stages: I (below 250℃); II... 689

Figure II.3.G.6. In situ tracking of local cationic oxidation/ordering during synthesis of Ni-rich NMC with compositional heterogeneity. (a) RGB images reproduced from XRF maps of multiple... 690

Figure II.3.H.1. (Left) Estimated cathode-oxide specific capacity and voltage requirements for next-gen EV targets (K. Gallagher). (Right) Pack-level cost for useable energy as a... 692

Figure II.3.H.2. (a) Cycle-life of NMC-532//Li and LLS//Li cells cycled between 4.45-2.5V; the LLS//Li cells included a first-cycle activation between 4.6-2.0V. All cycling was carried out at... 693

Figure II.3.H.3. LLS//Li cell cycling data for baseline and surface-treated LLS samples under various cycling conditions (a) 1st cycle: 4.6-2.0V ; All others: 4.45-2.5V at 15mA/g. (b) Capacity... 695

Figure II.3.H.4. (a) Cycle-life performance of an untreated LLS//Li baseline cell in traditional EC: EMC electrolyte (Gen2, red) and a high-voltage, fluorinated electrolyte (DFEC: FEMC, blue). All... 696

Figure II.3.H.5. (a) LLS//Gr cell data for various treated and untreated samples collected using the HE/HV protocol. Each of the cells underwent an activation cycle between 4.5-2.0V followed... 697

Figure II.3.I.1. In-situ heating XRD patterns of (a) 75% chemically delithiated NMC-622, (b) zoomed in sections of (a), and (c) 75% chemically delithiated NMC-811 701

Figure II.3.I.2. Transition metal L-edge of thermal exposed to various temperatures of 75% chemically delithiated NMC 622 (a: Ni, b: Co, c: Mn) and NMC-811 ( d: Ni, e: Co, f: Mn) 702

Figure II.3.I.3. (a) soft XAS O K-edge in TEY mode which probes 5 nm of the surface and (b) X-ray Raman spectroscopy which probes the bulk of the NMC-811. Both analysis were done at... 703

Figure II.3.I.4. (a) In-situ heating experiments on 75% chemically delithiated NMC-811, probing the Ni oxidation changes using TXM. (b) Post heating TXM analysis on small 75% chemically... 703

Figure II.3.J.1. Charge/discharge voltage curves of the bare and graphene-coated Cu current collectors at 0.5mA cm-² (discharge for 2 h, charge up to 2V; 5th cycle) 706

Figure II.3.J.2. SEM images of Li deposit on the bare and graphene-coated Cu current collectors. Li deposition was performed at 1mA cm-² for 6h at room temperature 706

Figure II.3.J.3. Charge/discharge voltage curves of the Li//Li symmetric cells with the Al₂O₃- and LiZr₂(PO₄)₃-filled LiTFSI: PEO membranes at the10th cycle and 60℃ 707

Figure II.3.J.4. Charge/discharge cycle performance of the Li//Li symmetric cells with the (a) Al₂O₃- and (b) LiZr₂(PO₄)₃-filled LiTFSI: PEO membranes at 60℃ 707

Figure II.3.J.5. Charge/discharge voltage curves of the Cu/Al₂O₃-filled LiTFSI: PEO membrane/Li cell at the 5 (blue), 50 (green), and 100th (red) cycles and 60℃ 708

Figure II.3.J.6. (a) Charge/discharge voltage curves of the LiTFSI/Cu(ClO₄)₂-dissolved in PEG inside PVDF-HFP in contact with Cu foil. (Current: 20μA). (b) Charge/discharge voltage curves... 708

Figure II.3.K.1. CV plot of (a) LNMO, (b) LNRO, (c) LNRO-C, and (d) LNRO-BM. Cells were cycled between 4.8 and 2.0V at 0.5mV/s 711

Figure II.3.K.2. In situ XRD patterns of LNRO during the 1st cycle and 2nd charge. Black curve on the bottom indicates the background from in situ pouch cell. In situ cell was cycled between... 712

Figure II.3.K.3. Structural characterization upon chemical delithiation and electrochemical cycling. (a) XRD patterns, Rietveld refinement of (b) x = 1.2, and (c) x = 0, (d, e) lattice parameters... 713

Figure II.3.K.4. Structural evolution during the first cycle. HAADF-STEM images of LNRO (a) at pristine state, (b) after 4.8V charge, and (c) after 2.0V discharge, scale bar in (a-c) is 1nm;... 714

Figure II.3.K.5. Microstructural evolution upon cycling. HAADF-STEM images of LNRO (a) at pristine state, (b) after 4.8V charge, (c) after 2.0V discharge, (d) after 10 cycles, (e, f) after... 715

Figure II.3.K.6. (a) sXRD patterns, (b) voltage profiles, and (c) dQ/dV plots of Li1.2Ni0.8-xRuxO₂ (x = 0.2, 0.4, 0.6). Cells were cycled between 4.8 and 2.5V at 5 mA/g 716

Figure II.3.K.7. (a) In situ sXRD patterns of Li1.2Ni0.4Ru0.4O₂ during the first cycle between 4.8 and 2.5V at C/10, and (a) ex situ sXRD patterns of LixNi0.4Ru0.4O₂ (x = 1.2, 0.5, 0.2, and 0)... 717

Figure II.3.L.1. Cyclic voltammograms of Li1.3Nb0.3Mn0.4O₂ half-cells cycled between 1.5V and various upper cut off voltages of: a) 4.2V, b) 4.4V, c) 4.6V and d) 4.8V. The scan rate was... 719

Figure II.3.L.2. Voltage profiles of Li1.3Nb0.3Mn0.4O₂ half-cells cycled at 10mA/g between the voltage window of: a) 1.5-4.2V and b) 1.5-4.8V, and c) Specific discharge capacity and average... 720

Figure II.3.L.3. Diffusion coefficient and dQ/dV profile during: a) first charge and b) first discharge. Relationship between diffusion coefficient and cell voltage during the first 4 cycles of... 721

Figure II.3.L.4. O K-edge (a-f) and Mn L-edge (g-l) XAS profiles of chemically delithiated Li0Nb0.3Mn0.4O₂ a), b), g), h) and Li1.3Nb0.3Mn0.4O₂ cathodes charged to 4.8V after various cycle... 722

Figure II.3.L.5. SEM images a) and d) and Rietveld refinement of b) and e) synchrotron XRD patterns, c) and f) neutron diffraction patterns of as-synthesized Li1.2Nb0.2Mn0.6O₂ and... 723

Figure II.3.L.6. Voltage profiles a), c), e) and f) and incremental capacity (dQ/dV) profiles b), d), f) and h) of the half-cells cycled at 10mA/g. a) and b) were collected during the first cycle,... 725

Figure II.4.A.1. (Stationary Probe Rotating Disk Electrode (SPRDE) System Coupled to Inductively Coupled Plasma Mass Spectrometry (ICP−MS) 729

Figure II.4.A.2. (a) In situ dissolution currents for Co ion dissolution (magenta) from LiCoO₂ in 1.2M LiPF6 in 3:7 EC/EMC at increasing upper potential values during electrochemical... 730

Figure II.4.B.1. Representative synthesis route for the proposed solvent and electrolyte based on fluorinated pyrrolidinium bis(fluorosulfonyl)imide (FDESFSI). (The proposed new synthesis is... 734

Figure II.4.B.2. Capacity and capacity retention of 1M LiFSI PMpipFSI for LiFP/Li cells (left) and charge/discharge voltage profiles (Cutoff voltage: 3.0-3.8V; C/20 for 3 formation cycles and... 735

Figure II.4.B.3. Capacity and capacity retention of 1M LiFSI PMpipFSI for NMC532/Li cells (left) and Coulombic efficiency profiles (Cutoff voltage: 3.0-4.3V; C/20 for 3 formation cycle and C/10... 735

Figure II.4.B.4. Capacity and capacity retention of 5M LiFSI PMpipFSI for NMC532/Li cells (left) and Coulombic efficiency profiles (Cutoff voltage: 3.0-4.3V; C/20 for 3 formation cycle and C/10... 736

Figure II.4.B.5. Cyclic voltammograms of the FDES/LiFSI electrolytes with 1M, 2M, 3M, 4M and 5M LiFSI concentration. (Al electrode as working electrode and lithium as both counter and... 736

Figure II.4.B.6. Cyclic voltammograms of the FDES/LiFSI electrolytes with 1M, 2M, 3M, 4M and 5M LiFSI concentration. (SS electrode as working electrode and lithium as both counter and... 737

Figure II.4.C.1. AES survey scan of an uncycled (left) and cycled (right) NMC622 cathode before (black) and after (red) a depth profile experiment 741

Figure II.4.C.2. TOF-SIMS maps of positive ions in a cycled NMC622 cathode at 4.6V with the hydrocarbon electrolyte. A) TIC B) Ni+ C) Mn+ D) Co+ E) Al+ 742

Figure II.4.C.3. TOF-SIMS maps of negative ions in a cycled NMC622 cathode with the hydrocarbon electrolyte. A) TIC B) LiF- and LiF2- C) O- D) PF6- E) F- 742

Figure II.4.C.4. TOF-SIMS maps of positive ions in a cycled NMC622 cathode at 4.6V with a highly fluorinated electrolyte (1.2M LiPF6, 60% EMC, 20% HFE, 20% FEC, 1% w/w PS). A) TIC... 742

Figure II.4.C.5. TOF-SIMS maps of negative ions in a cycled NMC622 cathode with the fluorinated electrolyte. A) TIC B) CxHyOzFw C) CxHyOz D) CxHyFzPw E) F- 743

Figure II.4.C.6. SEM images of amorphous carbon films A) 1000 Å B) 5000 Å 744

Figure II.4.C.7. Elemental profiles of different spots on an NMC622 cathode (left). Solid lines represent that from a cycled cathode (4.6V, fluorinated electrolyte), dashed lines from an... 744

Figure II.4.C.8. Keyence thickness gauges have a linear voltage response to thickness changes in devices, up to 5 mm. These have a sub-millimeter resolution, and are capable of operating... 745

Figure II.4.C.9. 200 mAh NCA cells cycled at .7C at r.t. as a function of FEC concentration (0-20% v/v) and voltage (4.2, 4.5, and 4.6) 746

Figure II.4.C.10. Calendar life test (△OCV and △gas volume) at 55℃ with 20% FEC at an OCV of 4.2 (left) and 4.6V (right) 747

Figure II.5.A.1. (a) AFM image, (b) XRD and (c) Raman spectrum of the NMC thin film electrode made by PLD 751

Figure II.5.A.2. (a) Voltammogram trace of the NMC thin film electrode and (b) FTIR-ATR spectrum of the pristine and 3 cycled NMC thin film electrode, tetraethylene glycol and ployethylene... 751

Figure II.5.A.3. (a) CV profile of NMC thin film electrode. Scan rate: 0.2mV s-¹ Inserted plot presents a typical CV of NMC composite electrodes reported in, (b) ex situ Raman of NMC thin film... 752

Figure II.5.A.4. FTIR spectrum of cycled thin film electrode with different washing time. (a) after 3 cycles (discharge end), (b) after 1, 2 and 3 cycles, and (c) after 3 cycles vs. Li or MCMB anode 752

Figure II.5.A.5. (a, d) AFM morphology image of the pristine NMC thin film electrode, (b) AFM morphology image and (c) near-field IR absorbance image of cycled NMC thin film after 5s washing... 753

Figure II.5.A.6. Experimental setup for impedance measurements of the NMC electrode under Ar atmosphere 754

Figure II.5.A.7. (a) Real-part AC impedance at 0.1Hz (b) ATR-FTIR spectra of thin-film NMC532 electrodes: pristine and after 3 and 10 cycles 754

Figure II.5.B.1. The minority phases identified by our data-mining approach. Panels (a) and (c) show the transmission images of the field-of-views covering particles (P37 and P46), which... 759

Figure II.5.B.2. (a) Electrochemical profile of LiCoO₂ charged to 4.6V followed by a discharge to 3V. The lower-left and the right insert show the structures of the pristine sample and the... 760

Figure II.5.B.3. (a) xPDF data of pristine sample (symbol) and the O-O pair contribution (solid line) (b) nPDF data of both pristine and charged sample (symbol) and the O-O pair contribution... 761

Figure II.5.B.4. (a) Figure 1. Spatially resolved EELS mapping of concealed pore and exposed pore. (a) STEM-EELS mapping of a concealed pore. (i) ADF-STEM image of a concealed pore... 762

Figure II.5.C.1. STEM/ABF images of (a) uncoated LRLO and (b) LRLO material coated with 1wt% LLTO. (c) EELS Ti-L edge spectra at surface regions of LRLO sample coated with LLTO... 766

Figure II.5.C.2. First charging comparison of (a) electrochemical performance and (b) strain generation for LRLO electrode under different rate. (c, d) The strain distribution along the [003]... 767

Figure II.5.C.3. Operando evolution of a LRLO nanoparticle during electrochemical charge at different rates including the changes in the displacement field along q003 and the strain along the... 767

Figure II.5.C.4. HRTEM image, ED, and intensity of reciprocal lattice from line-scanning on single particle for the LRLO sample after 50 cycles (a) and after heat treatment at 300℃ (b). Models... 768

Figure II.5.C.5. Correlation between voltage decay and defects generation. a. Schematic illustration of free energy differences due to different oxygen stacking sequences (green, Li; red, O;... 769

Figure II.5.C.6. Cryo-TEM images (a, b, d, e) with their corresponding area FFT analysis (c, f) of the deposited Li metal using electrolytes containing Cs+ (a-c) and Zn2+ (d-f) additives at... 769

Figure II.5.C.7. Compared XPS spectra of the survey (a), C 1s (b), F 1s (c), Li 1s (d), Cs 3d (e) and Zn 2p (f) with the deposited Li metal from the pristine, Cs+ and Zn2+ containing electrolytes 770

Figure II.5.D.1. HAADF-STEM images of layered-to-disordered rock salt phase transition at the low cycling rate. (a) HAADF-STEM image of thepristine sample showing the majority of the bulk... 774

Figure II.5.D.2. Infusion of Li3PO4 into secondary particles eliminates structural degradation. The structural degradations are evaluated by a combination of SAED a-c, bright-field TEM... 775

Figure II.5.D.3. In situ heating-induced crack nucleation and propagation. The LiNi0.6Mn0.2Co0.2O₂ (NMC622) was delithiated by charging to 4.7V vs. Li metal. a and b High angle annular dark... 776

Figure II.5.E.1. Design of 3-omega thermal sensors and how they are incorporated into an electrochemical battery pouch cell for in-operando measurements 780

Figure II.5.E.2. Raw 3-omega data for an in-operando measurement of a full Li-ion battery showing the extended frequency range of our upgraded system 780

Figure II.5.E.3. Newly built Cut Bar system that uses linear heat flow to accurately measure the thermal conductivity of isolated battery components ex-situ. Bottom-right: data from Cut Bar... 781

Figure II.5.F.1. Reversible redox and phase behavior of Li₂-xIrO₃. (a) Capacity-voltage curves of Li₂-xIrO₃ galvanostatically measured at a C/12 rate (17.58mA g-¹) in 4.50-2.50V for... 785

Figure II.5.F.2. Hybridized Ir-O redox in Li₂-xIrO₃. (a) sXAS fluorescence yield spectra (solid lines) and STXM (scanning transmission X-ray microscopy)-XAS spectra (dashed lines) of O K... 786

Figure II.5.F.3. (a) Charge/discharge profiles of Li2-xIr1-ySnyO3 (y=0, 0.25, 0.5) under a constant current density (C/10 rate) for a full cycle (black) and for an approximately 1.5 electron per... 787

Figure II.5.G.1. Stress-thickness response during plating sequence and OCV hold of 5 consecutive symmetric cycles. a: -265uA/cm² for 5hrs; b: -265uA/cm² for 10hrs 790

Figure II.5.G.2. Schematic of Li flow between the conductive paths and Li metal surface during plating/stripping cycles 791

Figure II.5.G.3. Stress-thickness evolution predicted from the kinetic model 791

Figure II.5.G.4. (a-c) Finite element modeling of morphological evolution of SEI on Li metal anode (a) before 1st Li plating half-cycle; (b) after the 1st Li plating half-cycle; (c) after the 1st Li... 792

Figure II.5.G.5. A phase diagram of wrinkling and delamination of a thin film protective coating on a Li metal electrode 793

Figure II.5.G.6. (a) The distribution of von Mises stress in bulk Li after nanoindentation. (b) Microstructure of an indent in a Li foil after it is stored inside an Ar-filled glovebox for 30 days at... 793

Figure II.5.G.7. (a) The schematic diagram of a Swagelok cell. Microstructure of mossy Li plated under (b) 4.85MPa and (c) 19.39MPa 794

Figure II.5.G.8. XPS depth profiling spectra of plated Li surfaces after a half cycle (0.5mA cm-², 4mAh cm-²) in 4 different electrolytes (4M LiFSI DME, 0.4 LiTFSI + 0.6M LiNO DOL-DME, 1M... 795

Figure II.5.G.9. Self-forming nanocomposite has a unique nanostructure where LiF nanocrystals embedded in polymeric matrix (a); The cross-section image showing the coating is dense and... 797

Figure II.5.G.10. The combination of the protective coating with high concentration LiFSi in DME enables the long cycle stability 797

Figure II.5.H.1. XAS results of various elements in Li1.2Ni0.15Co0.1Mn0.55O₂ at different cycles. Transmission mode transition metal K-edge XAS spectra for Mn, Co and Ni, and fluorescence... 803

Figure II.5.H.2. Three-dimensional electron tomography reconstruction of Li1.2Ni0.15Co0.1Mn0.55O₂ materials. (a and b) volume rendition and progressive cross-sectional view of cathode... 803

Figure II.5.H.3. (a) CV scan (black) of the fresh graphite electrode in 1 mol/L LiPF6 EC/DMC at 1mV/s from OCP (3.0V) to 0.0V, and the simultaneous EQCM responses (blue) recorded; (b)... 805

Figure II.5.H.4. the thermal stability of the PET-based separator 806

Figure II.5.H.5. Thermal runaway characterization of 25-Ah SC-NMC532/graphite cell 806

Figure II.6.A.1. (a) One dimensional model geometry for the electrode-electrolyte interfacial region; (b) phase field model converts the sharp interface into a continuous interfacial region by a... 811

Figure II.6.A.2. (a) Demonstration of inhomogeneous SEI resistance, which may have a sharp variation (black line) or a wide drop (red line). (b) Initial lithium-electrolyte interface, which is flat... 812

Figure II.6.A.3. (a) Increase in height of dendritic protrusions with time for sharp and wide drop in SEI resistance. Growth of dendrites decrease with time because of increase in surface area... 812

Figure II.6.A.4. (a) Computational mesh used to understand the growth of dendritic protrusions under the presence of SEI layer. Internal heterogeneity of the SEI at the left boundary leads to... 813

Figure II.6.A.5. (a) Growth of dendritic protrusions with time under applied current density of 100A/m². Increasing thickness of a stiff SEI layer helps to prevent dendrite growth. (b) Height of... 813

Figure II.6.A.6. (a) Modeled Li₂S film growth on the active carbon surface in the discharge, and Li₂S film removal in the charge; (b) Li₂S film thickness growth under different discharge... 814

Figure II.6.A.7. Effect of the S₄²- solubility on the evolution of Li₂S film thickness on top of carbon substrate. (a) During discharge, decreasing the solubility of S₄²- helps to delay the surface... 814

Figure II.6.B.1. Experimentally measured conductivity as a function of salt concentration for LiAsF6 and LiPF6 in dimethyl carbonate (DMC). The bottom rectangles (left to right) illustrate the... 817

Figure II.6.B.2. Free energy of dissociation for LiAsF6 (black) and LiPF6 (blue) into their respective free ions as computed from first principles using the polarizable continuum model (PCM) 817

Figure II.6.B.3. Formation energy of crystalline and amorphous a) lithium silicides and b) lithium silicates, following lithiation path from Si and SiO₂, respectively, as seen on the c) phase diagram 818

Figure II.6.B.4. Predicted potential profiles for a) Si and b) SiO₂ as referenced to the phase diagram in Figure II.6.B.3 819

Figure II.6.B.5. Li self-diffusivity diffusion coefficients in lithium silicides and lithium silicates as a function of voltage vs Li/Li+ 819

Figure II.6.C.1. LiCoO₂-LiF phase diagram 822

Figure II.6.C.2. (a) Local fluorine environments present in Li1.125M0.875O1.75F0.25 disordered rocksalt phases. (b) Superposition of the low fluorine region of the phase diagrams obtained for... 823

Figure II.6.C.3. (a) XRD, (b) STEM-EDS mapping from Li₁Mn₂/₃Nb₁/₃O₂F, (c) SEM 823

Figure II.6.C.4. (a) Electrochemical performance of LMNOF. (b) A schematic band structure of Li₁Mn₂/₃Nb₁/₃O₂F 824

Figure II.6.C.5. Computed phase diagram of MnO-Li₂VO₃-LiF 824

Figure II.6.C.6. Computed voltage profile and evolution of Mn andV oxidation states (from DFT) 825

Figure II.6.C.7. Comparison between observed and theoretical capacities for ST-LMVF20, ST-LMVO, MR-LMVF20, and LR-LMVF20 compounds 826

Figure II.6.C.8. Distribution of (a) F-cation and (b) Li-anion environments by coordination number, among simulated partially charged structures derived from ST-LMVF20, according to the... 826

Figure II.6.D.1. Large-format Shapeoko CNC stage produced by Carbide 3D, with a custom made N-line probe attachment 829

Figure II.6.D.2. Measured bulk conductivity and contact resistance values (with 95% confidence intervals) on ANL AC006 cathode film using both large-format ("Big Red") and high-resolution... 830

Figure II.6.D.3. Converted Carbide 3D CNC stage with custom rolling N-line probe attachment 830

Figure II.6.D.4. Conductance measurements over a 40-mm segment of battery electrode film, showing areas of no, minimal, and good contact. The measurement is repeated eight times with... 831

Figure II.6.D.5. The experimental setup of a microprobe in contact with a sample of delaminated cathode 832

Figure II.6.D.6. Nyquist spectra of different electrolyte samples with conductivities varying from 82 to 443μS/cm 832

Figure II.6.D.7. Average MacMullin number versus localized ionic resistance for 7 different electrode films 832

Figure II.6.D.8. Optical microscope images of probe surface (a) before durability tests, (b) after a total of 3,000 sampling points, (c) after a total of 7,000 points, and (d) after a total of... 833

Figure II.6.E.1. A sandwich system with Li-S and Mn hexaaminobenzene system with the maximum lithiation of 20 Li per 8 S atoms. The top view and side view. The green ball is Li and yellow... 836

Figure II.6.E.2. The energy landscape by pulling one Li through the system. One can use such landscape to estimate the barrier height 836

Figure II.6.E.3. The Li polysulphides free energies calculated with solvent model (Sol), compared with the results in vacuum (Vac), and the reference curve derived from experiment (Ref) 836

Figure II.6.E.4. A sandwich system with Li-S and Mn hexaaminobenzene system with the maximum lithiation of 20 Li per 8 S atoms. The top view and side view. The green ball is Li and yellow... 837

Figure II.6.E.5. The energy landscape by pulling one Li through the system. One can use such landscape to estimate the barrier height 837

Figure II.6.E.6. The mixing of the Li10(GeS₄)(PS₄)₂ structure and the Li10(GeO₄)(PO₄)₂ structure to form the Li10(GeS₄)(PO₄)₂ structure 837

Figure II.6.E.7. The chemical decomposition energy of Li10GeP2S12-xOx system (green), and the moisture caused reaction energy (purple). Negative energy indicates the instability, while... 838

Figure II.6.E.8. Mean square displacements (MSD) of Li-ions along three different crystallographic directions as well as the overall value, obtained from the ab initio molecular dynamics... 839

Figure II.6.F.1. Upper panel, the observed Li (left) and Mg (right) plating morphology from Yoo et al. Lower panel, the simulated morphology difference of Li and Mg plating 841

Figure II.6.F.2. Improved cycle life with carbon coated Li-electrode 842

Figure II.6.F.3. Compare the total density of states between bulk and slabs of (a) c-LLZO and (b) LIPON and (c) the solid electrolyte properties that relate to Li-dendrite resistance 843

Figure II.6.F.4. Phase-field simulation results of Li dendrite growth and nucleation at straight grain boundaries with different widths under constant voltage condition at 100s: (a) Li dendrite... 843

Figure II.6.F.5. (a) Voltage profiles of Li-Li symmetrical cells cycled in baseline electrolyte (1M LiPF6 in a mixture of ethylene carbonate and diethyl carbonate with a mass ratio of 1:2) with... 844

Figure II.7.A.1. Indentation of Li thin films. Plots at left are typical the load displacement curves to a maximum of 250μN, followed by 60 sec hold and unload. At right are average values for the... 848

Figure II.7.A.2. Instron and sample setup for Li adhesion test (left). The area specific resistance of the Li/LLZO/Li determined by electrical impedance correlates with the Li-LLZO adhesion (right) 849

Figure II.7.A.3. Average CCD for our recent studies compared to earlier published results. Most of the studies showed little change with increasing temperatures (left). The Arrhenius plot (right)... 849

Figure II.7.A.4. Indentation of Lipon thin films showing creep behavior for constant load at different displacements from the surface (left). The stress exponent (right) was determined for the... 850

Figure II.7.B.1. XPS analysis of LLZO before and after heat treatment at 400 and 500℃. a) C: (La+Zr) atomic ratio as a function of heat treatment temperature, b) O 1s and c) C 1s core levels,... 853

Figure II.7.B.2. Contact angle measurements of molten metallic Li on a) Li2CO3, b) DP-LLZO, c) WP-LLZO, d) WP-LLZO after heat treatment at 500℃ 854

Figure II.7.B.3. Calculated work of adhesion (Wad), contact angle (θ), and atomic structure for the a) Li-Li2CO3 and b) Li-LLZO interfaces 855

Figure II.7.B.4. a) Schematic of the all solid-state Li-LLZO-Li cell, b) the equivalent circuit used for modeling the EIS data c) representative Nyquist plot of the Li-LLZO-Li cell (for LLZO heat-treated... 855

Figure II.7.B.5. a) DC cycling of Li-LLZO-Li cells (LLZO HT to 500℃ after WP) at room temperature, stepping the current density from 0.01 to 1mA.cm-², b) the critical current density versus... 856

Figure II.7.C.1. Tri-layer sample configuration (left). Comparison of area specific resistance dry and with DMC additive (center). Extracted resistance attributed to polymer-ceramic interface (right) 860

Figure II.7.C.2. Cycling of batteries comparing performance with PE-only with a bilayer electrolyte of PE coated CPE. Cycling capacities at 75℃ (left). Voltage profiles for cycle 15 (right)... 861

Figure II.7.C.3. Ionic conductivity comparing dry and plasticized electrolytes of different compositions (left). DC symmetric cycling at +/- 50μA/cm² for plasticized ceramic-free polymer gel versus... 862

Figure II.7.D.1. Characterization of garnet fibrous membrane: left, Reconstructed model of garnet membrane flatness generated by 3D laser scanning; right, Focus ion beam analysis of... 865

Figure II.7.D.2. Characterization of hybrid electrolyte membrane: left, AFM scanning of the hybrid electrolyte membrane; right, Thermal properties of the hybrid electrolyte membrane 866

Figure II.7.D.3. Sintered garnet nanofiber membrane from PAN fiber template. Sample was impregnated with epoxy 866

Figure II.7.D.4. Hybrid electrolyte membrane with ~11μm thickness 866

Figure II.7.D.5. Electrochemical impedance of the Li/electrolyte/Li symmetrical cell at room temperature (left); Cycling of the cell at different current densities of 0.1mA/cm², 0.5mA/cm²... 867

Figure II.7.D.6. Formation energy of point defects in LLZO (left) and Li ion diffusion in LLZO grain boundary (right) from atomistic modeling 868

Figure II.7.D.7. Hot map of Li dendrite formation in SSE with various microstructure features 868

Figure II.7.D.8. Electrochemical cycling of the Li/electrolyte/Li symmetrical cell, including low current density stabilization at 0.1mA/cm² and high current density cycling at 3mA/cm² (top);... 869

Figure II.7.E.1. (a) Cross-sectional views of Li metal anodes retrieved from Li∥NMC cells after 100 cycles at 1.75mA cm−² using different dual-salt electrolytes. (b) cycling performances of... 872

Figure II.7.E.2. (a) The average Li CE values of the LiTFSI-LiBOB/EC-EMC (7:3 by wt) electrolytes with single additive of LiPF6, VC, and FEC, and the combinational additives of LiPF6 + VC, LiPF6... 873

Figure II.7.E.3. (a) Average CE values of Li metal in electrolytes with LiDFP additive from 0 to 0.15M.(b) Cycling stability of Li||Li symmetric cells in the electrolytes without and with various... 874

Figure II.7.E.4. (a) Cyclic voltammogram curves of Li∣Li∣Pt three-electrode cell containing HPISE at a scan rate of 0.5mV s-¹ in the voltage window of -0.2V to 5.0V at room temperature. (b)... 875

Figure II.7.F.1. Charge density difference profile when a Li ion is deposited on top of a defective Li surface. Yellow: charge density accumulation. Light blue: Charge density depletion 879

Figure II.7.F.2. Atomic configuration and energy profile of a knocked-off Li atom entering the gap site. Panels (A) through (E) show atomic configurations of the diffusion pathway of the Li... 880

Figure II.7.F.3. (a) MD simulation setting (side views): anode surface (blue) covered by SEI (LiF, yellow). The SEI has a crack (shown as a blue spot in (a)). In green the electrolyte phase... 881

Figure II.7.F.4. (a) Electrodeposition morphology phase map for Li deposition as a function of Damkohler number. Yellow zone corresponds to Da≫1 (dendrite morphology), green zone... 882

Figure II.7.F.5. Effect of the Li surface diffusion rate kf on the electrodeposition rate and morphology of the deposited film; kf0is the rate of diffusion calculated using activation energy of Li... 882

Figure II.7.G.1. a) Coulombic Efficiency of Li plating on MPF with organic coating, without coating, and on an unmodified copper foil. b) Nucleation overpotential for Cu foil, Cu foam, and organic... 885

Figure II.7.G.2. SEM images of (a) pristine lithium foil, (b) lithium foil imprinted with 300 grit sandpaper, and (c) 2500 grit 886

Figure II.7.G.3. a) Nucleation potential for various surface modified lithium-metal foils at different current densities. Sand's time experiment showing potential vs time for symmetric Li/Li cells for... 886

Figure II.7.G.4. SEM images of a) surface engineered Lithium, b) Li plating on SE-Li and c) cycled SE-Li. d) Cycling behavior of LiMn2O4 cathode tested against P-Li and SE-Li 887

Figure II.7.G.5. Voltage-time curve for symmetric Li/Li cells using composite polymer electrolytes a) CPE-III and b) CPE-VI (~200 cycles). SEM images of lithium-metal after cycling in symmetric... 888

Figure II.7.G.6. a) Variation of heterogeneous nucleation barrier with contact angle, b) Plating/ stripping behavior of an efficient electrode showing zero nucleation underpotential and invariant... 890

Figure II.7.H.1. (a) Linear sweep voltammetry curve of the PEO/LiTFSI andPEO/LiTFSI/LLTO 15wt% solid composite electrolytes. (b) Voltage profile of the continued lithium plating/stripping... 893

Figure II.7.H.2. (a) Schematic illustration showing the structure with and without Li₃PO₄ coating on the LLATO nanofibers. (b) Voltage profile of Li|PVDF-HFP/LiTFSI/LLATO/Li₃PO₄|Li... 894

Figure II.7.H.3. The procedure for synthesis of cross-linked poly(ethylene oxide) solid-state electrolyte (CLPSE) 895

Figure II.7.H.4. Schematic illustration of the CNF/S-PEO/LLTO bilayer structure: the top thin PEO/LLTO solid composite electrolyte layer acts as the Li-ion conductor, enabling fast ion transport... 896

Figure II.7.I.1. Possible molecular conformation of aromatic-based Li organosulfide (a) and Li organopolysulfide (b) originating from PSD polymer; alkyl amine-based Li organosulfide (c) and Li... 899

Figure II.7.I.2. The photos of PSD-90-Ely before cycling (a) and after 1st cycle of Li plating/stripping: (b) with separator covering on stainless steel, (c) separator was peeled off 899

Figure II.7.I.3. Cycling performance of 2wt% PSDs containing different sulfur contents as additives 899

Figure II.7.I.4. Cycling performance of cells using electrolytes containing different contents of SCPs 900

Figure II.7.I.5. Morphologies of Li metal deposited onto stainless steel substrates. SEM images of Li metal deposited onto bare stainless steel substrates in the control electrolyte (a-c), and the... 900

Figure II.7.I.6. SEM images of the deposited Li after 100 cycles at a current density of 2mA cm-² and a deposition capacity of 2mA h cm-². (a, b) Top view and cross-section view of deposited... 901

Figure II.7.I.7. The XPS spectra of SEI layers formed from the electrolytes containing different additives. S 2p XPS spectra (a), C 1s XPS spectra (b), and F 1s XPS spectra (c) of the SEI layers... 901

Figure II.7.I.8. FT-IR of SEI layers obtained from the C-Ely (C-SEI) and the PSD-90-Ely (PSD-90-SEI) 902

Figure II.7.I.9. AFM images and indentation study of SEI layers obtained from C-Ely (a, c) and PSD-90-Ely (b, d). SEM images of SEI layers obtained from C-Ely (e) and PSD-90-Ely (f). The scan... 902

Figure II.7.I.10. Cycling performances of Li deposition/dissolution using the PSD-90-Ely and C-Ely at a current density of 2mA cm-² and a deposition capacity of 2 (a) and 3mA h cm-² (b). (c)... 903

Figure II.7.I.11. Li deposition/dissolution cycling performances of the cells using PSD-90-Ely at a current density of 4mA cm-² with a deposition capacity of 4mA h cm-² 904

Figure II.7.I.12. Cycling performance of cells using PSD-90-Ely electrolyte 904

Figure II.7.I.13. Schematic illustration for the fabrication of polymer-PxSy protective layer on substrates 904

Figure II.7.I.14. SEM images of the as prepared polymer-PxSy film on SS foil 904

Figure II.7.J.1. Synthesis scheme for PEO-POSS block copolymers 907

Figure II.7.J.2. Chemical structure of the POSS-PEO-POSS triblock copolymer. The triblock synthesized during this study has a molecular weight of 5-35-5 908

Figure II.7.J.3. Ionic conductivity of PEO-POSS. Conductivity is plotted for organic-inorganic diblock copolymer electrolytes with PEO molecular weight 5kg mol-1 and POSS 1, 1.9, 2.7, and 18kg... 908

Figure II.7.J.4. Ionic conductivity of a POSS-PEO-POSS (5-35-5) electrolyte with LiTFSI salt concentration r = [Li]/[EO] = 0.04. The ionic conductivity is similar to previously studied polystyrene... 908

Figure II.7.J.5. Diffusion coefficient and transference number of the POSS-PEO-POSS (5-35-5) electrolyte. The values, marked by a star, are superimposed for comparison on a plot of previously... 909

Figure II.7.J.6. Transference number measurements of PEO-POSS(5-6) as a function of salt concentration 909

Figure II.7.J.7. Comparison of charge passed before failure, Cd, between Li symmetric cells fabricated from a POSS-PEO-POSS (5-35-5) electrolyte and a polystyrene-b-poly(ethylene... 910

Figure II.7.J.8. Slice through a reconstructed volume imaged using X-ray tomography. This Li/POSS-PEO-POSS/Li cell was cycled at 0.175mA cm-² and failed after 17 cycles 910

Figure II.7.J.9. Example of a routine used to test the limiting current of POSS-PEO-POSS (5-35-5). This 30 micron thick solid organic-inorganic polymer electrolyte was sandwiched between... 911

Figure II.7.J.10. A schematic showing the three types of defects observed in this study: (a) a void defect, (b) a protruding lithium globule, and (c) a protruding non-globular dendrite. In each... 912

Figure II.7.J.11. Examples of defective lithium deposition observed by X-ray tomography. The top row shows an orthogonal cross-section through the defect. The bottom row shows a 3D... 912

Figure II.7.J.12. Representative cross section of cell polarized at i = 0.04mA cm-² for t = 900 h acquired using X-ray tomography. Lithium was deposited downward through the polymer... 913

Figure II.7.J.13. Correlation between current density and defect density in failed cells. The areal density of protruding defects, P, increases with current density 913

Figure II.7.J.14. Nature of observed lithium protrusions as a function of current density, i, and charge passed before failure, Cd. Observation of no protrusion nucleation at low current densities... 914

Figure II.8.A.1. Cycle performance of a Li/S cell in two different electrolytes at C/10 within 1.0-3.0V voltage window at room temperature: (a) novel concentrated siloxane-based electrolyte... 917

Figure II.8.A.2. SEM images of Li metal before (a) and after 20 cycles in (b) common ether-based electrolyte and (c) concentrated siloxane-based electrolyte. SEM images of S cathode before... 918

Figure II.8.A.3. SEM elemental mapping of Li metal after 20 cycles in (a) common ether-based electrolyte and (b) concentrated siloxane-based electrolyte. SEM elemental mapping of separator... 919

Figure II.8.A.4. (a) 2D contour plot of in-operando Se K-edge XANES of Li/Se cell in concentrated siloxane-based electrolyte at C/10 within 1.0-3.0V voltage window at room temperature and... 919

Figure II.8.A.5. In-operando Se K-edge EXAFS measurement of Li/Se cell in concentrated siloxane-based electrolyte at C/10 within 1.0-3.0V voltage window at room temperature 920

Figure II.8.A.6. Snapshot of simulated structure of Li₂S6 in the concentrated siloxane-based electrolyte determined by ab initio molecular dynamics simulation 920

Figure II.8.B.1. (a) Comparison of BET surface areas of pristine IKB/CNF carbon materials and those mixed with 10wt% of different types of binders and (b) corresponding pore volume. (c)... 925

Figure II.8.B.2. (a) Cross-section view of the hybrid cell design, (b) electrochemical impedance of In-SE-In and In-SE-LE-Li (5mv, 105-10-¹Hz). (c) charge/discharge curves of LiIn-SE-LE-S... 926

Figure II.8.B.3. Electrochemical impedance spectra (EIS) evolution in the first 20 hrs of In-SE-LE-SS cell with electrolytes (a) 1M LiTFSI/DME and (b) 1M LiTFSI/DOL. (c) EIS evolution of... 927

Figure II.8.B.4. (a) Cross-sectional SEM image of double-side coated Celgard 2500, (b) digital photographs of the static contact angles of the coated separators with electrolyte 1M... 928

Figure II.8.C.1. ICP-AES data of S to Li atoms concentration ratio (a) remaining in supernatant solutions and (b) adsorbed onto candidate materials, after 3mM Li₂S6 adsorption test 931

Figure II.8.C.2. (a) Commercially available APP used as fertilizer. (b) Digital image of the Li₂S6 (0.005M) captured by PVDF and APP in DOL/DME solution. (c) UV/Vis absorption spectra of... 933

Figure II.8.C.3. The specific burning time test of sulfur electrodes with (a) S-PVDF electrode and (b) S-APP electrode. The time indicated in the pictures are counted as soon as the electrodes... 934

Figure II.8.C.4. (a) Chemical reaction for flame-retardant mechanism. (b) XPS spectra of the surface chemical composition of the S-APP electrode before and after burning. (c) S 2p XPS... 935

Figure II.8.C.5. (a) Schematic of the electrochemical cell design that allows in-operando dark field light microscopy (DFLM) observation. (b and c) DFLM images of the metal grid (50nm thick,... 936

Figure II.8.D.1. (a) Effects of porosity, sulfur loading, and morphology on cell performance. (b) Evolution of resistance modes during discharge: Surface passivation resistance (red), pore block... 938

Figure II.8.D.2. Anode chemical reactions and electrochemical interactions at 1C. (a) With chemical redox reactions at Li anode, capacity decreases as well as qualitative nature of the potential... 939

Figure II.8.D.3. (a) Charge-discharge hysteresis is composed of dissimilar potential profiles and unequal capacities (b) Dissolution of Li₂S does not often proceed to completion as freshly... 939

Figure II.8.D.4. (a) Lithium-sulfur bonding and lithium-carbon interaction at low lithium contents, (b) electronic charge distribution at low lithium contents. Color code: C grey, S yellow, Li... 940

Figure II.8.D.5. Multilayer graphene structure showing the incorporation of N into the C rings in pyridinic (not shown), graphitic (blue circle), and pyrrolic (green circle) positions and... 940

Figure II.8.E.1. The relative ratios of (RS5R+RS6R+RS7R+RS8R+S8)/(RS3R+RS4R) for electrolytes (containing 16mM Li₂S6) without and with additives before and after contacted with Li metal... 945

Figure II.8.E.2. Comparison of the reaction between dissolved polysulfide ions with metallic Li, Li-phosphorus and a proprietary Li containing anode (Li-XX). The HPLC peak on the far right (in... 946

Figure II.8.E.3. The photograph of the synthesized S/Xant co-polymer with different sulfur contents (top); the cycle and rate performance of the co-polymer with 70% sulfur. The tests were... 947

Figure II.8.F.1. Scanning electron microscope (SEM) images of Li deposits using Li-Cu cells (a) with and (b) without the KW-stabilization layer at 3mA cm-² for 3 hours. Overpotential of Li-Li... 950

Figure II.8.F.2. Cyclability (a) with various E/L ratios from 45 to 9μL mg-¹ at a fixed Li₂S loading of 8mg cm-² and (b) with various Li₂S loadings from 2 to 8mg cm-² at a fixed E/L ratio of 9μL... 951

Figure II.8.F.3. (a) Cyclability of the cells fabricated with the carbon-paper cathodes with a sulfur loading, sulfur content, and E/S ratio of, respectively, (a) 13mg cm-², 75wt.%, and 4.0μL mg-¹... 952

Figure II.8.F.4. (a) Sulfur cathodes fabricated for pouch-type Li-S cells. Electrochemical performance of the pouch-type Li-S cells: (b) voltage profiles and (c) cycling performance 952

Figure II.8.G.1. Silver-lithium/iodine solid state dual function battery 957

Figure II.8.G.2. Conductivity effects of additive 958

Figure II.8.G.3. (a) Cycling of cells containing addtive with and without Li metal added, b) Coulombic efficiency 958

Figure II.8.G.4. (a) Intermittent charging and (b) AC impedance results for LiI electrolyte based cell 959

Figure II.8.G.5. AC impedance of LiI cells with and without polymer 959

Figure II.8.G.6. (a) Discharge curves, (b) AC impedance, and (c) impedance results for LiI composite containing cell 960

Figure II.8.G.7. Schematic of cell as assembled and after charge 960

Figure II.8.G.8. X-ray diffraction of negative and positive electrodes after charge of AgI cell 961

Figure II.8.G.9. X-ray diffraction of negative and positive electrodes after charge of LiI cell 961

Figure II.8.G.10. X-ray diffraction of positive electrode after charge of LiI cell 961

Figure II.8.H.1. Ti 2p core level HAXPES spectra after Li deposition demonstrating orientation-dependent reactivity of epitaxial LLTO thin films 964

Figure II.8.H.2. (a) C1s and (b) O 1s XPS core level before (labeled RT) and after heating to 500℃ to remove surface contamination species. (c) XRD patterns of LLZO heated to 200℃ (green)... 965

Figure II.8.H.3. XPS core level spectra after Li deposition on clean LLZO surface. Reduction of (a) Nb and Zr in Nb: LLZO; (b) Zr in Al: LLZO; and (c) Zr in Ta: LLZO 965

Figure II.8.H.4. EIS spectra of Li-Li symmetric cells with (a) Nb- and (b) Ta-doped LLZO at room temperature demonstrating the change in impedance over 72 hours due to reaction with... 966

Figure II.8.H.5. Examples of DFT optimized structures with Nb dopants (a) distributed in the bulk and (b) segregated towards the surface for Nb-doped LLZO in contact with Li. (c) Bar chart... 967

Figure II.8.H.6. Survey (left), S 2p (middle) and P 2p (right) core level XPS spectra before (red) and after (black) Li sputtering show clear reaction of LPS with Li metal 967

Figure II.8.H.7. The impedance spectrum of unpolished (left) and polished (right) Li-LPS-Li symmetric cells at room temperature 968

Figure II.8.I.1. a) Molecular structure of SIG components with their abbreviated names. b) Cycling data (0.1mA/cm²) for Li|Li symmetric cells with SIG separators, along with Li(G4)TFSI/glass... 973

Figure II.8.I.2. a) Self-healing efficiency based on maximum tensile strength and, b) recovery of Young's modulus upon self-healing of composite films after heat treatment at different... 974

Figure II.8.I.3. a) Self-healing efficiency based on maximum tensile strength and, b) recovery of Young's modulus upon self-healing of composite films after heat treatment at different... 974

Figure II.8.I.4. (a) The discharge/charge voltage profiles of the MJ430-S and the 20% SH-MJ430-S electrodes based on S loading of 1mg cm-² at initial activation cycle (0.05 C) and 10th... 976

Figure II.8.I.5. (a) 7Li MAS NMR spectra of the Li₂S8 solution interacting with MJ430 and the 20% SH-MJ430. (b) 7Li MAS NMR spectra of the cathode materials with MJ430-S and 20%... 977

Figure II.8.J.1. Constant voltage charge (red)/constant current discharge (blue) profile representative of multicomponent structured architecture cells cycled between 1.75 and 3.5V 980

Figure II.8.J.2. Impact of transport additive composition on discharge capacities of solid state multicomponent nanolayered structured architecture cells in the 1st, 2nd and 5th cycles... 980

Figure II.8.J.3. Impact of electrode design, including electrode thickness and width, on the positive electrode utilization of 12V in-situ cells. Cells were cycled between 7.5 and 13.5V. By... 981

Figure II.8.J.4. First cycle voltage profile for self-formed 12V cell with improved transport pathways due to cell design modifications and increased reactive electrolyte thickness. The cell was... 982

Figure II.8.K.1. a) Crystal structure of Li₃PO₄ and Li₃PS₄ with hopping pathways of Li-ions; 1b) potential energy for migration paths of Li-ions along c-axis interstitial channels in... 986

Figure II.8.K.2. a) Nyquist plot from lithium ion conductivity measurements performed on the LIC membranes. b) Mechanical property analysis of the LIC membranes c) Electrochemical cycling... 987

Figure II.8.K.3. a) Crystal structure of the cubic garnet-type Li7La₃Zr₂O12 with partially occupied Li-ion sites denoted by arrows, 3b) potential energy for the migration paths of Li-ions... 988

Figure II.8.K.4. a&b) TEM images of S-C4FM-1 at two different magnifications along with the corresponding SAED pattern (inset) and c&d) TEM images of S-C4FM-1 at two different... 989

Figure II.8.K.5. a) Cycling performance of S-C4FM-1 and S-C4FM-2 cycled at 0.2C rate, b) rate capability plot of S-C4FM-1 and S-C4FM, c) charge-discharge plot of S-C4FM-1 and d)... 990

Figure II.8.K.6. a&b) TEM images of C4FM-3 at two different magnifications and c&d) TEM images of S-C4FM-3 at two different magnifications along with the corresponding SAED pattern 991

Figure II.8.K.7. a) Cycling and rate capability plot of the S-C4FM-3 and b) Specific capacity plot of the S-C4FM-3 992

Figure II.9.A.1. (a) Schematic of the operation principle of the simple one-step electrochemical pre-charging treatment process for CNTs air electrode and Li metal anode. (b) TEM image... 996

Figure II.9.A.2. (a) Cycling performance of Li-O₂ cells with optimized RuO₂/CNT air electrode and LiFePO4 (LFP) counter electrode cycled at 0.1mA cm-² in 1M LiTf-Tetraglyme electrolyte... 997

Figure II.9.A.3. (a, b) Optical images of as-prepared free-standing thin composite LiTFSI-LLZTO-PVDF (LLP) membrane with good flexibility. Cycling performance of Li-O₂ cells composed of... 998

Figure II.9.A.4. (a) Schematic of high energy-density Li-O₂ cell design. (b) Cycling performance of Li-O₂ cells containing optimal RuO₂/CNTs air electrodes (high loading: 4mg cm-²) and Li... 999

Figure II.9.B.1. Schematic of Pt modified MOF-derived catalysts. BND−Co@G = biphasic N-doped cobalt@graphene, Pt−SC−BND−Co@G = Pt surface-coating BND−Co@G, and... 1003

Figure II.9.B.2. HRTEM image of annealed Ir8 clusters on an rGO cathode showing crystalline facets of the Ir nanoparticles 1003

Figure II.9.B.3. Density functional calculation of the barrier for dissolution of O₂ into the TEGDME 1004

Figure II.10.A.1. Na-driven structural behavior on cycling. (a) In situ XRD patterns collected during the first charge-discharge cycle for NaCrS₂, corresponding time vs. voltage profile is... 1007

Figure II.10.A.2. Ex situ XAS Studies of Cr (b) and S (g) valance state during various charge-discharge stages 1008

Figure II.10.A.3. X-ray diffraction patterns of LixNa₃-xVP₃O9N collected before starting and after each ion exchange (IE) process. The zooming (111) reflections are shown on the right side,... 1008

Figure II.10.A.4. In-situ X-ray diffraction patterns collected during the first charge/discharge and the second charge of Na/ Na0.66Mn0.6Ni0.2Mg0.2O₂ cells at a current rate of 0.2C in the... 1009

Figure II.10.A.5. Charge compensation mechanism of MNM-2 during charge and discharge processes. a), b) and c) Mn and d), e) and f) Ni K-edge XANES of MNM-2 at various stages during the... 1010

Figure II.11.A.1. (a) 1st cycle charge/discharge voltage profiles of LiNi0.94M0.06O₂ at fresh and after exposure to a moist atmosphere for 14 and 30 days. (b) Cycling performance of... 1014

Figure II.11.A.2. DSC profiles of (a) NMC 811 and (b) NCA charged to different cut-off voltages. (c) Capacity retention of a graphite/NMC 811 cell, compared with a Li||NMC 811 cell 1015

Figure II.11.A.3. Electrochemical performance of Li||NMC811 with investigated electrolytes (a) cycling performance at C/3 charge/discharge processes (b) Different charge rate performance... 1016

Figure II.11.A.4. Cross-section of cycled Li (100 cycles) collected form Li||NMC811 cells with (a) baseline and (b) ED1123 electrolytes 1016

Figure II.11.A.5. SEM images of NMC811 electrodes fabricated with two different binders, PVDF-HFP copolymer and PVDF-HSV 900 homopolymer 1017

Figure II.11.A.6. Schematics (top) of LiF deposition on h-BN to heal the defects. This approach enables dense, void-free Li metal cycling (bottom, A). In contract, Li deposits on bare Cu surface... 1018

Figure II.11.A.7. Cycle life of cells (as specified by the cycle number at completely no capacity) as a function of electrolyte content to illustrate the impact of electrolyte quantity on... 1018

Figure II.11.A.8. Cryo FIB-SEM images of the plated lithium at the first cycle and the corresponding cross-section images when the cells are cycled in (a, c) 1M LiPF6 EC: DMC, and (b, d) 0.1M... 1020

Figure II.11.A.9. Discharge curves at ~6mA/cm² to understand cathode utilization (right). Current density variation computations (left) cathode chemistries 1020

Figure II.11.A.10. Final deliverable cell for FY2018. The Li||NMC pouch cell was still cycling at the end of FY2018 1021

Figure II.11.B.1. Potential vs. time (bottom right), capacity vs. cycle number (bottom left), and columbic efficiency (top) plots of SPAN/LATSP+LiPON/Li half cells at 0.25C rate 1031

Figure II.11.B.2. (a, d) Computer generated schematics, (b, e) stereomicroscope images of as-printed structures, and (c, f) SEM images of sintered structures for the (a-c) columns and (d-f)... 1032

Figure II.11.B.3. (Top)-High performance of Directly Derived Doped Sulfur Architectures (DDSA) with polysulfide trapping agents (PTA); (Bottom)-weight analysis and cost analysis for large... 1034

Figure II.11.B.4. Schematic of direct alternating deposition of S/carbon and graphene by layer-on-layer via air-controlled electrospray (ACES) and enhanced cell performance (rate capability... 1035

Figure II.11.B.5. Schematic of direct coating of PEDOT: PSS-rGO coating on a separator and enhanced cell performance due to the separator coating 1035

Figure II.11.B.6. Electrodeposition of solvated Li (green) at constant potential. Top left: High density DME solvent (low LiTFSI salt concentration). Top right: Low density DME solvent (high... 1036

Figure II.11.B.7. Preliminarily electrochemical results of the as-prepared 3-D MnO₂ based cathode materials: (a) First three cycle charge-discharge profiles; (b) Capacity vs. cycle number plots... 1037

Figure II.11.B.8. First three cycles of galvanostatic charge and discharge (GCD) profiles of surface tuned Li₂S@graphene at A. E/S ratio of 2 with mass loading of 6.8mg/cm² B. A TEM image... 1037

Figure II.11.B.9. MoS₂ nanosheet-carbon nanotube-sulfur composites. Left: conceptual figure, Right: scanning electron micrograph 1038

Figure II.11.B.10. Synchrotron tomographic images of aqueous freeze-cast LLZO scaffolds (subvolume view 1046x1403x128μm). Left to right: 7.5% LLZO, 12.5% LLZO, and 17.5% LLZO... 1039