Title Page
Contents
ABSTRACT 16
Chapter 1. Introduction of LIB and Fuel cell 20
1.1. Lithium-ion batteries (LIB) 20
1.1.1. Fundamentals of LIB 20
1.1.2. Electrolyte in LIB 23
1.1.3. Polymer electrolytes for LIB 24
1.1.4. Gel polymer electrolytes 27
1.1.5. GPEs preparation methods 28
1.1.6. Lithium salts 30
1.1.7. The research aims of this thesis for LIB 32
1.2. Fuel cell 33
1.2.1. Background of the Fuel cell (FC) 33
1.2.2. Proton exchange membrane (PEM) 36
1.2.3. Hydrocarbon Membranes 39
1.2.4. The research aims of this thesis for PEMFC 43
Chapter 2. Highly Conductive and Flexible Gel Polymer Electrolyte with Bis(Fluorosulfonyl)imide Lithium Salt via UV Curing for Li-Ion Batteries 44
2.1. Introduction 44
2.2. Experimental section 47
2.2.1. Materials 47
2.2.2. Fabrication of Self-Standing Gel Polymer Electrolytes 48
2.2.3. Characterization of Self-Standing Gel Polymer Electrolytes 49
2.3. Results and Discussion 50
2.4. Conclusion 58
Chapter 3. An in situ polymeric electrolyte with low interfacial resistance on electrodes for lithium-ion batteries 60
3.1. Introduction 60
3.2. Experiments 63
3.2.1. Materials 63
3.2.2. Synthesis of diepoxide tetramethyldisiloxane (DETMDS) 63
3.2.3. Preparation of the poly(siloxane-epoxy) based polymer electrolyte (PSEPE) 64
3.2.4. Assembly of the symmetrical Swagelock cell. 65
3.2.5. Characterization 65
3.3. Results and discussion 67
3.3.1. Characterization 67
3.3.2. Thermal stability 71
3.3.3. Ionic conductivity and transference number 72
3.3.4. FE-SEM and XRD 75
3.3.5. Electrochemical stability 78
3.4. Conclusions 80
Chapter 4. Comparative study of chemically different structured sulfonic acid and sulfonimide acid of Poly(isatine-phenylene) electrolyte for PEMFC 81
4.1. Introduction 81
4.2. Materials and Methods 84
4.2.1. Materials 84
4.2.2. Synthesis of N-methyl isatin 84
4.2.3. Synthesis of sulfamoyl fluoride 85
4.2.4. Polymerization of PiP and sulfonation 85
4.2.5. Chlorination and imidation of SPiP 86
4.2.6. Preparation of polymer and blending membranes 87
4.2.7. Characterization of monomer and polymers 88
4.3. Results and Discussion 91
4.4. Conclusions 103
Chapter 5. Sulfonyl imide acid-functionalized membranes via Ni (0) cata-lyzed carbon-carbon coupling polymerization for fuel cells 105
5.1. Introduction 105
5.2. Materials and Methods 107
5.2.1. Materials 107
5.2.2. Synthesis of poly(benzophenone) polymers (PBP) 107
5.2.3. Sulfonation of the PBP polymer (SPBP) 108
5.2.4. Synthesis of sulfonyl imide poly(benzophenone)s polymers (SI-PBP) 108
5.2.5. Characterizations and measurement of membranes properties 109
5.3. Results and Discussion 112
5.3.1. Preparation of monomer (DCBP) 112
5.3.2. Preparation of Polymers (SI-PBP) 113
5.3.3. IEC, Water uptake and dimensional stability of membranes 116
5.3.4. Proton conductivity of the SI-PBP membranes 117
5.3.5. Thermo-oxidative stability of membranes 118
5.3.6. Chemical stability of membranes 119
5.3.7. Morphology of the membranes 120
5.3.8. Cell performance of the SI-PBP membranes 121
5.4. Conclusions. 122
Chapter 6. Conclusion and outlook 124
6.1. General conclusions 124
6.2. Outlook 127
References 129
Appendix 190
Abstract (in Korean) 194
Table 1-1. Classification and characteristics of the fuel cell. 35
Table 5-1. Properties of membranes. 117
Figure 1-1. Comparison of energy density for different battery technologies. 21
Figure 1-2. The schematic of a typical LIB consists of a cathode, anode, separator and electrolyte. 22
Figure 1-3. Schematical illustration of the reaction equation in typical LIB. 22
Figure 1-4. Typical Polymer Electrolytes for Li-Based Batteries (left: SPEs, right: GPEs). 25
Figure 1-5. Chemical structures of common polymer matrices. 26
Figure 1-6. Illustrate the mechanism of lithium-ion transport in PEO-based polymer electrolytes. 26
Figure 1-7. LiPF₆ decomposition pathway (a) and reaction with SEI layer (b). 30
Figure 1-8. Schematic a typical single fuel cell. 33
Figure 1-9. Scheme of some typical applications of the fuel cell. 36
Figure 1-10. Illustration of a fuel cell stack and a single PEMFC 37
Figure 1-11. Chemical common structures of PFSA membranes. 38
Figure 1-12. Typical chemical structures of hydrocarbon-based polymer electrolyte membranes. 40
Figure 1-13. Microstructures of Nafion® and SPEEK illustrating the hydrophobic/hydrophilic separation.[이미지참조] 41
Figure 2-1. The process of fabricating a self-standing gel polymer electrolyte (SGPE) by UV curing. 48
Figure 2-2. Illustration of the homemade cell assembly. 50
Figure 2-3. The physical appearance of the SGPEs at room temperature. 51
Figure 2-4. FT–IR spectra of (a) SGPEs before/ after UV curing and (b) acrylic C=C bonds in the SGPEs before/ after UV curing. 52
Figure 2-5. (a) Thermal stability of pure PEGDMA, SGPEs, and 1M LiPF₆ in ethylene carbonate and dimethyl carbonate (EC/DMC), (b) Glass transition temperatures of SGPEs. 53
Figure 2-6. X-ray diffraction (XRD) pattern of pure PEGDMA, PEGDMA film, and SGPEs. 54
Figure 2-7. Nyquist plots of (a) SGPE20, (b) SGPE30 and (c) SGPE40. 55
Figure 2-8. Temperature-dependent ionic conductivity of SGPEs. 56
Figure 2-9. TLi⁺ values for (a) SGPE20, (b) SGPE30 and (c) SGPE40.[이미지참조] 57
Figure 2-10. LSV plots of SGPEs at room temperature with a scan rate of 0.1 mV s⁻¹. 58
Figure 3-1. (a) ¹H-NMR spectra of DETMDS, (b) FT-IR spectra of TMDS, AGE, and DETMDS. 69
Figure 3-2. (a) The image of PSEPEs precursor solution, (b) The image of PSEPEs after cationic ring-opening polymerization, (c) The mechanism of the LiFSI used as... 70
Figure 3-3. (a) FTIR spectra of DETMDS and PSEPEs after ring-opening cationic polymerization (b) FTIR spectra of DETMDS and PSEPEs (from 1350 to 500 cm⁻¹ wavenumber). 71
Figure 3-4. (a) TGA curves of DETMDS and PSEPEs, (b) DSC curves of DETMDS and PSEPEs 72
Figure 3-5. Ionic conductivity versus temperature plots of PSEPEs 74
Figure 3-6. The chronoamperometry curve of the symmetrical Swagelock cell Li/PSEPEs /Li at a polarization voltage of 10 mV, and in the inset shows the Nyquist... 75
Figure 3-7. (a) The cross-sectional FE-SEM images with an interface of the PSEPE-1.5 and LiFePO₄, (b) EDS analysis, (c) elemental mapping of C, N, O, F, Si, and F of... 77
Figure 3-8. (a) LSV plots of PSEPEs at room temperature with a scan rate of 0.1 mV s⁻¹, (b) CV plots of PSEPE-1.5 at room temperature with a scan rate of 1 mV s⁻¹, (c)... 79
Figure 4-1. ¹H-NMR spectra of methyl isatin 92
Figure 4-2. ¹H-NMR (a) and ¹⁹F-NMR (b) spectra of sulfamoyl fluoride. 92
Figure 4-3. ¹H-NMR spectra of (a) PiP, (b) SPiP and (c) SIPiP. 95
Figure 4-4. FT-IR spectrum of PiP and SIPiP. 96
Figure 4-5. Thermogravimetric analysis of PiP, SPiP, SIPiP, and blending membrane. 97
Figure 4-6. Ion exchange capacities and water uptakes for the SPiP, SIPiP, and blending membrane. 98
Figure 4-7. Proton conductivity for the SPiP, SIPiP, and blending membrane at 40-80 ℃ under 90% RH and (b) 30-90% RH under 80 ℃. 99
Figure 4-8. (a) Fenton's reagent test of sulfonated polymer membranes and Nafion 211®. (b) Tensile stress and elongation break of the membranes at room temperature...[이미지참조] 101
Figure 4-9. Atomic force microscopy images of (a) SPiP, (b) SIPiP, and (c) blending membrane. 102
Figure 4-10. Cell performance of membranes. 103
Figure 5-1. FT-IR spectra of PBP, S-PBP and SI-PBP. 114
Figure 5-2. ¹H-NMR of (a) PBP (b) S-PBP and (c) SI- PBP polymers (d) ¹⁹F-NMR of the SI-PBP polymers. 115
Figure 5-3. Ion exchange capacity (IEC) and Water uptake (WU) for the SI-PBP polymers membranes. 116
Figure 5-4. Proton conductivity for the SI-PBP polymer membranes in (a) different temperatures at 90% RH (b) different relative humidity at 90 ℃. 118
Figure 5-5. Thermo-oxidative stabilities of PBP and SI-PBP polymers. 119
Figure 5-6. Fenton's reagent (3 ppm Fe²⁺) test for the SI-PBP polymer membranes. 120
Figure 5-7. Atomic force microscopy images for (a) SI-PBP 1, (b) SI-PBP 2 and (c) SI-PBP 3 polymer membranes 121
Figure 5-8. Cell performance for the SI-PBP polymer membranes. 122
Scheme 3-1. Schematic reaction steps for the synthesis of PSEPEs. 64
Scheme 4-1. Synthesis procedures and the molecular chemical structures of monomer and polymer. 87
Scheme 5-1. Synthesis route towards sulfonyl imide poly(benzophenone) polymers(SI-PBP). 109