Title Page
Contents
ABSTRACT 13
Ⅰ. Introduction 15
1.1. History of plastics 15
1.2. Carbonization: conversion of plastic materials into carbon materials for up-cycling 17
1.2.1. Anoxic carbonization 17
1.2.2. Catalytic carbonization 17
1.2.3. Pressure carbonization 18
1.3. Carbon micro structure 23
1.4. Sodium ion batteries 27
1.4.1. Effect of carbon microstructure on sodium ion storage 30
1.5. Objective 34
Ⅱ. Synthesis of soft and hard carbons from Polyethylene for anodes in SIB 36
2.1. Introduction 36
2.2. Experimental 40
2.2.1. Materials 40
2.2.2. Electron beam irradiation of PE 40
2.2.3. Stabilization of PE 40
2.2.4. Carbonization and graphitization 41
2.2.5. Characterizations 41
2.2.6. Laser desorption ionization mass spectrometry 42
2.2.7. Electrochemical measurements 43
2.3. Results and discussion 44
2.4. Summary 77
Ⅲ. Polypropylene-based into hard carbon for anodes in SIB 78
3.1. Introduction 78
3.2. Experimental 81
3.2.1. Synthesis of mask-derived hard carbon 81
3.2.2. Characterization 81
3.2.3. Electrochemical characterization 82
3.3. Result and discussion 84
3.4. Summary 112
Ⅳ. High-yield conversion of polystyrene into carbonaceous materials for anodes in SIB 113
4.1. Introduction 113
4.2. Experimental 117
4.2.1. Materials 117
4.2.2. Preparation of sulfonated PS 117
4.2.3. Carbonization of sulfonated polystyrene 117
4.2.4. Characterization 118
4.2.5. Electrochemical measurements 118
4.3. Results and discussion 120
4.3.1. Simultaneous sulfonation and condensation of PS 120
4.3.2. Carbonization of sulfonated PS 129
4.3.3. Carbonized PS at graphitization temperatures 136
4.3.4. Carbonization of other PS wastes 150
4.4. Summary 152
Ⅴ. Conclusion and future works 153
5.1. Conclusion 153
5.2. Future works 155
References 156
Appendix 171
Abstract (in Korean) 173
〈Table 1-1〉 Summary of carbonization method for plastic precursors 21
〈Table 2-1〉 Microstructural parameters of e-PE-derived carbons materials (e-TSCs and e-ASCs) with different HTT 59
〈Table 3-1〉 Atomic compositions of the mask sulfonated for 6 h and its heat treated ones at various temperatures of 1600, 2000, and 2400 °C. The values were obtained from... 95
〈Table 3-2〉 Textural and structural properties of the mask-derived carbons heat-treated at different temperatures of 1600, 2000, and 2400 °C 98
〈Table 3-3〉 The average Coulombic efficiencies of C16, C20, and C24 electrodes at various current rate from 0.05 to 1 A/g and ranges for diffusion coefficients of Na-ion... 107
〈Table 4-1〉 Number ratio of oxygen and sulfur atoms to carbon atoms on the surface of S-p-PS and annealed S-p-PS 132
〈Table 4-2〉 ID/IG and Lα values calculated from Raman data shown in Figure 4-6(b)[이미지참조] 140
〈Table 4-3〉 Positions and Lc values associated with signals identified in XRD diffractograms shown in Figure 4-6(a)[이미지참조] 143
〈Table 4-4〉 Atomic compositions of S-p-PS and thermally treated S-p-PS (Tf=1600, 2000, 2400, and 2700 ℃). The values were obtained from XPS spectra[이미지참조] 145
〈Table 4-5〉 BET surface area, total pore volume of C12, C16, and C20 149
〈Figure 1-1〉 Schematic structure of (a) soft carbon and (b) hard carbon. 24
〈Figure 1-2〉 Typical experimental behavior of graphitic crystal size as function of treatment temperature for graphitizable and non-graphitizable carbons. 26
〈Figure 1-3〉 Timeline of researches for sodium ion storage mechanism in hard carbon. 29
〈Figure 1-4〉 (a) Typical X-ray diffraction patterns indexed in 2H-graphite referential, (b) graphical representation of the fine structure, and (c) typical voltage-charge profiles... 32
〈Figure 1-5〉 Schematic illustration of the main active sites for sodium ion storage in hard carbon. 33
〈Figure 2-1〉 (a) Schematic of overall process for preparing PE-derived carbon materials. (b) ESR, (c) FT-IR spectra, and (d) XRD diffractograms of PE e-PE samples... 46
〈Figure 2-2〉 Effect of e-beam treatment to PEs; (a) crystallinity of pristine PE and PEs e-beam irradiated with 2000 and 4000 kGy. The crystallinity was calculated from XRD... 47
〈Figure 2-3〉 (a) TGA thermograms, (b) elemental analysis, (c) XRD diffractograms, and (d) Raman spectra of pristine and e-beam irradiated PE after different stabilization. 52
〈Figure 2-4〉 XPS characterization of (a) e-PE, (b) e-TS, and (c) e-AS. 53
〈Figure 2-5〉 (a) Raman spectra, (b) XRD diffractograms and (c) atomic contents of carbonized e-TS and e-AS at low temperature (400, 500, 600 °C). The atomic contents... 55
〈Figure 2-6〉 (a) XRD diffractograms and (b) Raman spectra of e-TSC and e-ASC 58
〈Figure 2-7〉 (a) XRD diffractograms and (b) Raman spectra of TS and AS-derived carbon (TSC and ASC) with different heat treatment temperatures. 61
〈Figure 2-8〉 TEM micrographs of PE-derived carbon with different stabilization. Insets are SAED patterns. 63
〈Figure 2-9〉 SEM micrographs of PE-derived carbon with different stabilization. 64
〈Figure 2-10〉 (a) LDI-TOF-MS spectra of PE-derived carbon materials prepared with different stabilization processes and (b) schematic illustration of conversion process of... 69
〈Figure 2-11〉 (a) Galvanostatic charge-discharge profiles of the first and second cycles, (b) contribution ratio of the slope and plateau capacities in the second cycle discharge... 71
〈Figure 2-12〉 Galvanostatic charge-discharge profiles of (a) e-TSC and (b) e-ASC with different heat treatment temperature. 73
〈Figure 2-13〉 Electrochemical performances of (a) e-TSCs, and (b) e-ASCs with different heat treatment temperatures. 75
〈Figure 3-1〉 (a) TGA thermograms, (b) the corresponding derivative mass loss, (c) DSC thermograms, and (d) FT-IR spectra of the pristine mask and samples sulfonated... 86
〈Figure 3-2〉 (a) XPS profiles of the mask sulfonated for 6 h, (b) XRD patterns and Raman spectra of the pristine mask and the mask sulfonated for 6 h (SM6h). 89
〈Figure 3-3〉 ¹³C-NMR spectra of the (a) pristine mask and masks sulfonated for (b) 2 h and (c) 6 h, and the proposed stabilization mechanism of PP during its sulfonation. 92
〈Figure 3-4〉 (a) XRD patterns, (b) Raman spectra, and (c) TEM micrographs of the mask-derived carbons heat-treated at different temperatures of 1600, 2000, and 2400 °C. 94
〈Figure 3-5〉 (a) N₂ adsorption-desorption isotherm and (b) pore size distribution of the mask-derived carbons heat treated at various temperatures of 1600, 2000, and 2400 °C. 97
〈Figure 3-6〉 Electrochemical properties of mask-derived carbons characterized by galvanostatic charge/discharge over the voltage window of 0.01-2.7 V vs. Na/Na⁺. (a)... 100
〈Figure 3-7〉 (a) Cyclic voltammetry of C16, C20, and C24 electrodes at various scan rates from 0.1 to 5 mV/s and (b) contribution of the surface process at scan rate of 0.1... 103
〈Figure 3-8〉 (a) GITT voltage profiles of C16, C20, and C24 electrodes. (b, d) Reaction resistance during discharge and charge process and (c, e) diffusion coefficients calculated... 105
〈Figure 3-9〉 Electrochemical properties of Na₀.₉[Li₀.₀₅(Ni₀.₂₅Fe₀.₂₅Mn₀.₂)₀.₉₅]O₂ cathode in an electrolyte of 1 M NaPF₆ dissolved in DEGDME over a voltage window of 2.5-4.2... 109
〈Figure 3-10〉 Electrochemical performance of the full cell composed of C16//Na₀.₉[Li₀.₀₅(Ni₀.₂₅Fe₀.₂₅Mn₀.₂)₀.₉₅]O₂ in an electrolyte of 1 M NaPF₆ in DEGDME... 111
〈Figure 4-1〉 Schematic of preparation of carbon powders from PS wastes. 121
〈Figure 4-2〉 (a) Photographs and (b) FT-IR spectra of PS, S-PS, and S-p-PS. (c) ¹H-NMR spectra of PS and intermediates of S-PS and S-p-PS. * and # denote peaks related... 125
〈Figure 4-3〉 (a) XRD diffractograms of PS, S-PS, and S-p-PS. (b) Raman spectra of PS and S-p-PS. 128
〈Figure 4-4〉 (a) TGA thermograms of PS, PCA-p-PS, S-PS and S-p-PS. (b) FT-IR spectra of S-p-PS, and (c) S2p narrow peaks in the XPS spectra of S-p-PS after annealing... 133
〈Figure 4-5〉 (a) XRD diffractograms, (b) Raman spectra of PS, (c) FT-IR spectra, and (d) TGA thermograms of PS treated with sulfuric acid for various periods. 135
〈Figure 4-6〉 (a) XRD diffractograms, (b) Raman spectra, and (c) TEM micrographs of carbonized S-p-PS for different Tf values (provided in the bottom right corner of each...[이미지참조] 139
〈Figure 4-7〉 HR-TEM micrographs of carbonized S-p-PS for different Tf values: (a) 2000, (b) 2400, and (c) 2700 °C. Intensity profiles along blue lines are presented at the...[이미지참조] 142
〈Figure 4-8〉 (a) 1st and 2nd cycles galvanostatic charge-discharge curves, (b) contribution of capacity at 2nd cycle, (c) rate capability, (d) and cycle stability at 25 mA/g...[이미지참조] 148
〈Figure 4-9〉 TGA thermograms of various PS wastes sulfonated in the presence of PFA. 151