Title Page
Abstract
Contents
Ⅰ. Introduction 11
Ⅱ. Research Background 15
2.1. Transmission-line model for measurement of inner particle impedance 15
2.2. Variation of TLM for measurement of inter-layer impedance 15
Ⅲ. Experimental 17
3.1. Electrode preparation 17
3.2. Electrochemical characterization 17
Ⅳ. Results and Discussion 20
4.1. EIS analysis based on the TLM 20
4.1.1. Measurement of inner particle impedance in the cathode composites 20
4.1.2. Measurement of inter-layer impedance between the cathode composites and SE layer 23
4.1.3. Effects of inter-layer formation between cathode composites and SE layer 24
4.2. Effects of the fabrication process on the inter-layer formation 29
4.2.1. Effects of the cathode composites fabrication process on the inter-layer formation 29
4.2.2. Effects of the solid electrolyte fabrication process on the inter-layer formation 35
Ⅴ. Conclusion 38
Ⅵ. References 40
Table 1. Characteristics of cathode composites with various electrode compositions calculated from the ion-blocking cells. 22
Table 2. Characteristics of cathode composites with various electrode compositions calculated from the electron-blocking cells. 26
Figure 1. Comparison of ionic conductivity of solid electrolytes and liquid electrolyte. 12
Figure 2. Schematic diagrams of (a) the hindrance of the conduction pathway due to the void formation for ASSBs, (b) inner particle contact of the cathode composites, and (b) inter-layer contact between the... 12
Figure 3. Illustration of fabrication process chain for conventional LIB and reference ASSB based on the conventional production chain of LIB. 14
Figure 4. (a) Schematics of electronic and ionic conduction pathways in cathode composites for ASSBs. (b) The impedance components corresponding to the conduction pathways and interfacial response for... 16
Figure 5. A variation type of TLM which represent the connection of an external circuit elements. 16
Figure 6. Schematics of (a) mold cell for cell fabrication and (b) configurations of sample prepared for the ion-blocking cell and for the electron-blocking cell to measure the inner particle and inter-layer impedance. 19
Figure 7. (a) Nyquist plot and (b) Bode plot for ion-blocking cells with various electrode compositions. (c) Schematic diagram of an ion-blocking cell and its equivalent circuit. (d) Fitting result of... 22
Figure 8. (a) Schematic diagram of conduction pathways at the inter-layer between the cathode composites and the SE layer. (b) The impedance elements of inter-layer corresponding to the contact... 26
Figure 9. (a) Nyquist plot and (b) Bode plot for electron-blocking cells with various electrode compositions. (c) Fitting result of experimental EIS data. 27
Figure 10. (a) Effective ionic conductivity and (b) tortuosity for the ion-blocking cell (absence of interlayer) and the electron-blocking cell (presence of inter-layer) with various electrode compositions. (c)... 27
Figure 11. (a) The inter-layer CPE component (Qint), (b) contact resistance (Rcont), and (c) contact CPE component (Qcont) for the electron-blocking cells with various electrodes compositions.[이미지참조] 28
Figure 12. Illustration of the fabrication process for the cathode composites and the SE layer. The solid electrolyte fabrication process was carried out (a) before and (b) after the cathode compaction process. 30
Figure 13. Cross-section SEM image of (a) cathode composites without compaction, (b) SE layer after the SE fabrication process, and (c) inter-layer between cathode composites and SE layer after the... 30
Figure 14. (a) Nyquist plot of the electron-blocking cell and its resulting data of (b) contact resistance (Rcont) and (c) contact CPE component (Qcont) in case 1 and 2.[이미지참조] 33
Figure 15. (a) First-cycle voltage profiles, (b) DCIR at 50 % of SOC, and (c) rate capabilities for case 1 and 2. 33
Figure 16. (a) Transient charge voltage profiles and (b) their polarization for case 1 and 2. 34
Figure 17. Illustration of the fabrication process for the cathode composites and the SE layer. (a) The compaction process of SE layer and (b) both the compaction processes of cathode composites and SE... 36
Figure 18. Cross-section SEM image of the SE layer pressed at (a) 164 MPa and (b) 492 MPa. 36
Figure 19. (a) Nyquist plot of the electron-blocking cells and (b) the discharge profiles at 0.1 C for case 1,2,3, and 4. 37