Title Page
ABSTRACT
국문 초록
Contents
Chapter 1. Introduction 21
1.1. Motivation and background 21
1.2. Metal oxides/carbon composites for energy storage devices 24
1.3. Synthesis of metal oxides/carbon composites via self-propagated combustion waves 26
1.4. Thesis overview 28
Chapter 2. Metal oxides core-shell structure via SPCW for high-performance supercapacitors 31
2.1. Introduction 31
2.2. Experimental 36
2.2.1. Chemicals 36
2.2.2. Preparation of hybrid mixtures of TiO₂ NPs and NC. 36
2.2.3. Fabrication of tunable carbon templates using combustion waves. 36
2.2.4. Thermophysical analysis of combustion waves. 37
2.2.5. Substitution of the carbon layer by RuO₂ to yield TiO₂ /RuO₂ hybrid composites. 37
2.2.6. Physicochemical characterization of the transition from TiO₂ to TiO₂/carbon templates to TiO₂/RuO₂ hybrid composites. 38
2.2.7. Fabrication of supercapacitor electrodes using tunable TiO₂/RuO₂ hybrid composites and their electrochemical characterization. 39
2.3. Result and Discussion 40
2.3.1. Synthesis of tunable TiO₂/RuO₂ hybrid composites using combustion waves 40
2.3.2. Characterization of tunable TiO₂/RuO₂ hybrid composites 45
2.3.3. Electrochemical performance of tunable TiO₂/RuO₂ hybrid composites 55
2.4. Conclusion 64
Chapter 3. Nitrogen-doped porous carbon via SPCW for high-performance supercapacitors 66
3.1. Introduction 66
3.2. Experimental 72
3.2.1. Chemicals 72
3.2.2. Preparation of hybrid mixtures comprising NaCl and nitrocellulose 72
3.2.3. NaCl templates-assisted fabrication of nitrogen-doped porous carbon (N-PC) and nitrogen-doped cube-like hierarchically porous carbon shells (N-C-HPCS) 72
3.2.4. Characterization of N-PC and N-C-HPCS 73
3.2.5. Electrochemical characterization of supercapacitor electrodes employing N-PC and N-C-HPCS 74
3.3. Results and Discussion 76
3.3.1. NaCl-assisted fabrication of nitrogen-doped porous carbon (N-PC) using combustion waves 76
3.3.2. Characterization of N-C-HPCS 82
3.3.3. Electrochemical performance of N-C-HPCS electrodes 88
3.4. Conclusion 96
Chapter 4. Carbon nanotubes and metal oxide composites via SPCW for hybrid Li-ion batteries 98
4.1. Introduction 98
4.2. Experimental 101
4.2.1. Chemicals 101
4.2.2. Preparation of freestanding films of Fe(NO₃)₃·9H₂O, nitrocellulose, and MWCNTs 101
4.2.3. Fabrication of MWCNT–iron oxide hybrid composite by one-step combustion waves 101
4.2.4. Characterization of MWCNT–iron oxide hybrid composite 102
4.2.5. Electrochemical Measurements and Characterization 103
4.3. Results and Discussion 104
4.4. Conclusions 121
Chapter 5. Conclusions 122
5.1. Summary 122
5.2. Future work 125
REFERENCES 127
Fig. 1.1. Schematic diagram of thesis organization 30
Fig. 2.1. Schematic of the combustion-driven synthesis of tunable TiO₂/RuO₂ hybrid composites as high-performance electrode materials. 35
Fig. 2.2. Combustion-driven fabrication processes for two types of hybrids of TiO₂ and carbon templates achieved using different NC amounts. 44
Fig. 2.3. Morphological transformation of micro/nanostructures during synthesis routes for the tunable TiO₂ /RuO₂ composites. 47
Fig. 2.4. Physicochemical transition of elemental compositions during synthesis of tunable TiO₂/RuO₂ composites. 51
Fig. 2.5. Characterization of tunable TiO₂/RuO₂ composites formed by KRuO₄ reduction of TiO₂/C templates. 54
Fig. 2.6. Electrochemical performance of tunable TiO₂/RuO₂ hybrid composites. 60
Fig. 2.7. Electrochemical stability of supercapacitor electrodes using commercial hydrous RuO₂ NPs and tunable TiO₂/RuO₂ hybrid composites. 63
Fig. 3.1. Schematic of sodium-chloride-assisted synthesis route of nitrogen-doped cube-like hierarchically porous carbon shells (N-C-HPCS) via one-step combustion waves. 71
Fig. 3.2. NaCl-assisted synthesis of nitrogen-doped porous carbon (N-PC) enabled by combustion waves with different loadings of chemical fuels and screening of N-C-HPCS. 81
Fig. 3.3. Morphological and composition analysis of N-C-HPCS. 83
Fig. 3.4. Physicochemical characterization of N-C-HPCS. 87
Fig. 3.5. Electrochemical performances of supercapacitor electrodes using N-C-HPCS and N-PCs. 93
Fig. 3.6. Electrochemical performances of symmetric two electrode cell using N-C-HPCS. 95
Fig. 4.1. Combustion-driven synthesis of the MWCNT-FexOy composites for Li-ion battery anode.[이미지참조] 100
Fig. 4.2. Morphological and compositional variations of CFs depending on MWCNT load. 106
Fig. 4.3. Characterization of CF-200 with optimized iron oxide and MWCNT contents. 108
Fig. 4.4. Physicochemical properties of CFs. 111
Fig. 4.5. Electrochemical performance of CFs as anodes for LIBs. 117
Fig. 4.6. Characterization of CF-200 anode after long-term charge–discharge cycles. 120