Title Page
Abstract
Contents
Chapter 1. Introduction 10
1-1. Lithium ion batteries 10
1-1-1. Composition of lithium secondary batteries 10
1-1-2. Principle of lithium secondary batteries. 11
1-1-3. Properties and limitation of organic liquid electrolyte 12
1-2. Solid electrolytes 15
1-2-1. Oxide solid electrolyte 15
1-2-2. Sulfide solid electrolyte 20
1-2-3. Lithium rich anti-perovskite 23
Reference 31
Chapter 2. General experimental 40
2-1. Physical characterization 40
2-1-1. X-ray diffraction (XRD) 40
2-1-2. Filed emission scanning electron microscopy (FE-SEM) 42
2-1-3. Laser Raman spectroscopy 43
2-2. Electrochemical analysis 44
2-2-1. Electrochemical impedance spectroscopy (EIS) 44
2-2-2. Cyclic voltammetry 45
2-2-3. Direct current cycling (DC-cycling) 45
2-2-4. Galvanostatic charge-discharge measurements (CD) 46
Reference 47
Chapter 3. Electrochemical performance of the mixed solid electrolyte (100-x)Li₃SI-xLi6PS5Cl (x=0, 10, 20 and 30) for all solid state lithium batteries[이미지참조] 48
3-1. Introduction 48
3-2. Experimental 50
3-3. Results and discussion 52
3-3-1. Characterization 52
3-3-2. Electrochemical measurements 55
3-4. Conclusions 64
References 65
Chapter 4. Summary 69
Figure 1.1. Illustration of operating principle of lithium secondary batteries. 14
Figure 1.2. Schematic open-circuit energy diagram of a lithium cell. 14
Figure 1.3. Structural schematic of perovskite (LLTO). 17
Figure 1.4. Structural schematic of (a) garnet and (b) garnet-related Li5La₃M₂O₁₂.[이미지참조] 19
Figure 1.5. Structural schematic of LISICON 20
Figure 1.6. Crystal structures of Li7P3S11 metastable crystal projected onto the a-c...[이미지참조] 22
Figure 1.7. Section of the crystal structure Li6PS5I[이미지참조] 23
Figure 1.8. Schematic illustration of structure of lithium rich anti-perovskites. 25
Figure 1.9. Schematic illustration of lithium diffusion mechanism in the structure of... 26
Figure 1.10. Schematic illustration of lithium diffusion mechanism of by... 27
Figure 1.11. Schematic illustration of lithium diffusion mechanism of solid electrolyte. 28
Fiaure 1.12. Calculated electrochemical stability window of the solid. 29
Figure 1.13. Example DC-cycling data of Li₃OCl. 30
Figure 1.14. SEM images of Li/Li₂OHCl/Li cell after 160 charge/discharge cycles. 30
Figure 2.1. Bragg reflection on a set of atomic planes. 41
Figure 2.2. Seven crystal system and 14 Bravais lattice. 42
Figure 2.3. (a) The Li+ diffusion mechanism of lithium ion batteries, (b) Nyquist plot of an...[이미지참조] 46
Figure 3.1. XRD for (100-x)Li₃SI -xLi6PS5Cl (x=0, 10, 20, and 30).[이미지참조] 53
Figure 3.2. XRD comparison of Li6PS5Cl and Li6PS5Cl-ballmill process after annealing.[이미지참조] 54
Figure 3.3. SEM image for Li₃SI, 10Li₃SI -90Li6PS5Cl, 20Li₃SI -80Li6PS5Cl, 30Li₃SI-...[이미지참조] 55
Figure 3.4. Impedance profiles of (a) Nyquist plot of In │Li6PS5Cl│ In symmetric cell and...[이미지참조] 57
Figure 3.5. Cyclic-voltammetry curve of (100-x)Li₃SI-x Li6PS5Cl materials.[이미지참조] 59
Figure 3.6. DC cycling of (100-x)Li₃SI-x Li6PS5Cl materials.[이미지참조] 60
Figure 3.7. Impedance profiles of Nyquist plot of Li-In alloy │(100-x)Li₃SI-xLi6PS5Cl...[이미지참조] 61
Figure 3.8. Initial cycle curve of Li-In alloy │(100-x)Li₃SI-xLi6PS5Cl │ Li(Ni0.8Co0.1₁Mn0.1)O₂ASSLB.[이미지참조] 62
Figure 3.9. (a) Cycle performance, (b) capacity retention, and (c) Coulombic efficiency of... 63