Chapter 1. Introduction 12

Figure 1-1. Representative scheme of secondary batteries. (a) vanadium redox flow battery (VRFB) (b) lithium-sulfur (Li-S) battery. 12

Figure 1-2. schematic description of Nafion under hydrated condition and their TEM images[내용없음] 8

Figure 1-3. Ternary phase diagram and SEM images of porous membranes generated by different demixing rates via phase inversion method. 13

Figure 1-4. Phase diagram of AB diblock copolymer, S, C, G, L, O70 implies bcc spherical (S), cylindrical (C), gyroid (G), lamellar (L), and Fddd (O70) morphologies. 14

Figure 1-5. Porous polymer generated from block copolymer precursor by selective etching. (a) schematic description of generation of porous polymer (b) porous polymer with different pore size by controlling the molar... 15

Figure 1-6. Schematic description of mesoporous polymer monolith prepared via PIMS method (a) homogeneous polymerization mixture at the beginning of PIMS (b) polymerization (c) cross linked microphase separated... 16

Chapter 2. The effect of the pore size and ionic groups on the ion transport in mesoporous membrane for VRFBs 22

Figure 2-1. The effect of pore size, pore size distribution, and the pore surface on the ion selectivity (a) SEM images of porous membranes with different pore size distributions by changing the evaporation time (b) selectivity... 22

Figure 2-2. Simulation study of effective pore size that suppress vanadium ions. 23

Figure 2-3. Schematic description of SMM synthesis. 29

Figure 2-4. (a) ¹H NMR spectra of PLA-CTAs. (b) SEC traces of PLA-CTAs. 30

Figure 2-5. FT-IR spectra of PLA-b-P(S-co-DVB), P(S-co-DVB) and sulfonated P(S-co-DVB). 32

Figure 2-6. Characterization of the mesoporous membranes synthesized with PLA-CTAs of different Mₙs. (a)-(d) SEM images of the mesoporous membranes. Samples were coated with Os prior to imaging (scale bar: 200 nm).... 34

Figure 2-7. Control of sulfonic acid contents by sulfonation time determined for SMMs synthesized with PLA-CTA-30. (a) Relationship between sulfonation time and xₛ determined by EA. (b) A plot between the xₛ and IEC... 36

Figure 2-8. SEM images of SMMs. (a) SMM(3.6, 0.04). (b) SMM (3.6, 1.74). (c) SMM (3.6, 2.14). (d) SMM (4.7, 0.03). (e) SMM (4.7, 1.89). (f) SMM (4.7, 2.33). (g) SMM (5.6, 0.04). (h) SMM (5.6, 1.77). (i) SMM (5.6, 2.14).... 39

Figure 2-9. Cross-sectioned SEM image of SMM(3.6, 1.74) used for EDS analysis. 40

Figure 2-10. SMM SAXS data. (a) SMMs derived from PLA-CTA-11 (D ＝ 3.6 nm). (b) SMMs derived from PLA-CTA-20 (D ＝ 4.7 nm). (c) SMMs derived from PLA-CTA-30 (D ＝ 5.4 nm). (d) SMMs derived from PLA-... 41

Figure 2-11. Strain-stress curves of SMM(5.4, 0.04) (black square) and (SMM, 2.14) (red square). 42

Figure 2-12. Water uptake of SMMs. Solid line corresponds to calculated amount of water that completely fills the pore volume in mesoporous membranes, which was estimated by nitrogen sorption measurements assuming... 44

Figure 2-13. Proton conductivity of SMMs. 44

Figure 2-14. Ion permeability through SMMs. Filled and open squares represent data obtained with NaCl and KCl, respectively. (a) Concentration changes through unsulfonated mesoporous membranes. (b) Concentration changes... 46

Figure 2-15. Calibration of molar concentration based on conductivity (LiCl, NaCl, KCl, and HCl). 46

Figure 2-16. Ion permeability through SMMs. Filled and open squares represent data obtained with NaCl and KCl, respectively. (a) SMM(D ＝ 3.6 nm). (b) SMM(D ＝ 4.7 nm). (c) SMM(D ＝ 5.4 nm) (same as Figure 6b). (d)SMM(D ＝ 6.1 nm). 47

Figure 2-17. Ion (H+, Li+, Na+, and K+) concentration changes according to time through SMM(D ＝ 5.4 nm). (a) SMM(5.4, 0.04). (b) SMM(5.4, 1.77). (c) SMM(5.4, 2.14). (d) Ion permeability overlay through SMM(D ＝ 5.4 nm). 48

Figure 2-18. Permeability of VOSO₄ through SMMs. (a) Concentration changes through unsulfonated mesoporous membranes. (b) Concentration changes through SMM(D ＝ 5.4 nm) with varying sulfonic acid content. (c) VOSO₄... 49

Figure 2-19. Calibration of VOSO₄ concentration based on absorbance at 765 nm. (a) UV-vis adsorption spectrum with different concentration of VO²⁺. (b) Calibration curves of VO²⁺. 50

Figure 2-20. VOSO₄ concentration changes according to time through SMMs. (a) SMM(D ＝ 3.6 nm). (b) SMM(D ＝ 4.7 nm). (c) SMM(D ＝ 5.4 nm) (same as Figure 7b). (d) SMM(D ＝ 6.1 nm). 51

Figure 2-21. VRFB performance of a single cell fabricated with SMM(3.6, 1.99) in comparison with Nation 212 as a reference. (a) voltage efficiency and current efficiency. (b) Discharge capacity retention during... 52

Chapter 3. Mesoporous composite membranes (MCMs) with uniform mesopores for a highly efficient VRFB 54

Figure 3-1. Photographs of SMMs during processing of vanadium redox flow battery. (a) cracks of SMMs during assembly of the cell (b) severe vanadium crossover within a few cycles. 54

Figure 3-2. Illustration of the high ion selectivity between protons and vanadium ion in sulfonated pore structure. 59

Figure 3-3. Schematic description of synthetic procedure for MCMs. 60

Figure 3-4. Characterization of PLA-CTA for generating 3.6 nm-pore size (a) ¹H NMR spectrum (b) SEC trace. 60

Figure 3-5. Characteristics of porous, sulfonated porous composites (a-c) SEM images of Lydall membrane MCM-40 before sulfonation and after sulfonation. Samples were coated with Os prior to imaging (d) Nitrogen sorption... 62

Figure 3-6. (a) Strain-stress curves of MCM and SMM without support membrane (b) uv-vis spectra of V5+ according to time. 64

Figure 3-7. (a) Concentration changes of vanadium ions through the membrane according to time (b) proton conductivity measured by measuring the ASR. 65

Figure 3-8. The results of VRFB with MCM-40 compared with Nafion 212 (a) voltage efficiency (VE) (b) coulombic efficiency (CE) (c) energy efficiency (EE) (d) discharge capacitance retention. 66

Figure 3-9. The results of VRFB with MCM-40, MCM-40 compared with Nafion 212 up to 100 cycles (a) voltage efficiency (VE) (b) coulombic efficiency (CE) (c) energy efficiency (EE) (d) discharge capacitance retention. 67

Chapter 4. Solid-state polymer electrolyte with 3D continuous channel for the high modulus and the high ion conductive supercapacitor 70

Figure 4-1. Modulus vs conductivity graphs of conventional electrolytes materials and multifunctional materials. 70

Figure 4-2. (a) Phase diagram of ternary system in PIPS process. (b) PIPS using acrylate based monomer (c) SEM image of the electrolyte obtained using (b). (c) PIPS using epoxy based monomer and cross-linker (c) SEM... 71

Figure 4-3. (a) Schematic description of electrolyte using block copolymer. (b) ion conductivity with different morphologies in block copolymer system. (c) alignment issue in block copolymer for high ion conductivity. 72

Figure 4-4. (a) Synthetic route to generate 3D continuous polymer electrolyte vis PIMS (b) ion conductivity (c) elastic modulus with different temperature. 73

Figure 4-5. Schematic illustration of (a) the fabrication procedure of the SSC and (b) the multi-functionality of the SSC. 81

Figure 4-6. Morphological and structural characterization of the electrode and SPE. Morphology of the electrode: (a) low-magnification and (b) high-magnification SEM images of CCNC Nws on carbon fabric. Morphology of... 83

Figure 4-7. Cross-section SEM image of the SSC. 83

Figure 4-8. electrochemical performances of structural electrode and SSC: (a) Cyclic voltammetry curves of bare carbon fabric electrode, NC Nws electrode, and CCNC Nws electrode; (b) Constant current charge-discharge... 85

Figure 4-9. Mechanical performances and multi-functionality of the SSC: (a) Set-up image of the mechano-electrochemical test, (b) Tensile stress-strain curves of the SSC, (c) Flexural stress-strain curves of the SSC, (d)... 86

Figure 4-10. (a) Tensile stress-strain curves of the structural electrolyte with various contents of BMITFSI; (b) Tensile strength and elastic modulus of the structural electrolyte with various contents of BMITFSI. 87

Figure 4-11. Mechanical performances of SSC: (a) Tensile strength and elastic modulus of the SSC; (b) Flexural strength and modulus of elasticity of the SSC. 88

Figure 4-12. (a) The relationship between ultimate tensile strength and power density of various SSC; (b) The relationship between ultimate tensile strength and energy density of various SSC. 90

Appendix. Synthesis of polyolefin containing block polymer via postpolymerization modification for the well-defined porous polyolefin membrane 94

Figure A-1. Elimination pathways in process of metal coordination polymerization. 94

Figure A-2. Borane-catalyzed deoxygenation reaction with hydosilane in small molecules (a) aldehyde, ketone (b) alcohol, ether (c) carboxylic acid. 95

Figure A-3. The representative scheme of synthesizing PP via deoxygenation reaction with borane catalyst. 96

Figure A-4. Architecture controlled polymer containing polyolefins generated via deoxygenation reaction[내용없음] 10

Figure A-5. SEC traces of PMA-containing polymer precursors. (a) S(8), SM(8-10), and SMS(8-10-4). (b) S(42) and SM(42-18). 100

Figure A-6. In situ ¹H NMR spectra of the B(C₆F₅)₃-catalyzed deoxygenation reactions of methyl 2-methyl-3-phenylpropanoate 1 with different amounts of TMDS. The spectra were obtained in CDCl₃ at RT after 24 h. 102

Figure A-7. Monitoring of the deoxygenation reaction by in situ ¹H NMR spectroscopy (CDCl₃, 400 MHz, RT). (a) Spectra in the range of 0.8-4 ppm showing progression of the reaction over time. (b) Representative spectra... 103

Figure A-8. Synthesis of PS-b-PP-b-PS by the deoxygenation.. (a) Reaction scheme. (b-d) ¹H NMR (b), SEC (c), and ¹³C NMR (d) data of SPS(8-4-4) (blue) compared with the parent SMS(8-10-4) (orange). 106

Figure A-9. ¹³C DEPT NMR spectra of (a) SMS(8-10-4) and (b) SPS(8-4-4) (CDCl₃, 100 MHz, RT). 107

Figure A-10. ¹³C NMR spectrum of SPS(8-4-4) obtained at 90 ℃ (1,2,4-trichlorobenzene-d₃, 800 MHz). The tacticity of the PP block was assigned based on the literature. 108

Figure A-11. Synthesis of PS-b-PP and PP (orange) by deoxygenation of parent PS-b-PMA and PMA (blue). Reaction scheme for PS-b-PP, and PP (a,c), and ¹H NMR spectra of SP(42-7) and P(4) in comparison with SM(42-... 110

Figure A-12. Partial deoxygenation to produce PS-b-PP-bearing functional groups. (a) Reaction scheme. (b) In situ ¹H NMR spectra of SM(42-18) treated with 1, 1.5 and 2 equiv TMDS. (c) ¹H NMR spectrum of isolated SP₀.₄₇(42-13). 111

Figure A-13. ¹H-¹H COSY NMR spectrum of SP₀.₄₇(42-13) (CDCl₃, 400 MHz, RT). 113

Figure A-14. HSQC NMR spectrum of SP₀.₄₇(42-13) (CDCl₃, 400 MHz, RT). 114

Figure A-15. FT-IR spectrum of SP₀.₄₇(42-13) (red). The spectra of SM(42-18) (black) and SP(42-7) (blue) are also shown as references. 114

Figure A-16. SEC trace of SP₀.₄₇(42-13). The traces of SM(42-18) and SP(42-7) are also shown as references. 115

Figure A-17. DSC thermograms of SMS(8-10-4) and SPS(8-4-4). 116

Figure A-18. Microphase separation behavior and mechanical properties of PS-b-PP-b-PS in comparison with PS-b-PMA-b-PS. (a) SAXS data of SMS(6-70-6) and SPS(6-28-6). (b) Representative strain-stress curves of SMS(6-... 117

Appendix. Synthesis of polyolefin containing block polymer via postpolymerization modification for the well-defined porous polyolefin membrane 99

Scheme A-1. The synthetic route to PS-b-PMA-b-PS (SMS). 99