Shot Peening on All-solid-state Lithium Metal Battery for High-speed Charging

Author:  M. Kodama1, K. Takashima1 and S. Hirai1 1 School of Engineering, Tokyo Institute of Technology, Japan
Source:  ICSP14 Milan
Doc ID:  2022067
Year of Publication:  2022
Abstract:  
All-solid-state lithium metal battery is a candidate of the next generation electrical vehicle’s battery. However, lithium dendrite generated in the fast charging process penetrates the solid electrolyte layer and breaks the battery with an internal short circuit. With this problem, the charging speed of the all-solid-state lithium metal battery is limited. In this paper, the authors propose and demonstrate a shot peening processing on the solid electrolyte layer surface to increase the charging speed of the all-solid-state lithium metal battery. With the shot peening, crack generation on the solid electrolyte layer can be suppressed with the compressive residual stress, and the lithium dendrite penetration into the solid electrolyte layer should be suppressed. Moreover, the shot peening generates a roughness on the surface of the solid electrolyte layer, and the contact between the solid electrolyte layer to the lithium metal anode would be improved, and the electrochemical reaction should be enhanced. The experimental results show that the shot peening successfully increases the charging speed (critical current density). Moreover, there is a synergistic effect between shot peening and gold thin-film insertion, which is one of the electrochemical performance improvement methods. Shot peening with changing the shot size is also conducted. The results show that there is an optimum shot size that maximizes the charging speed. Keywords All-solid-state lithium metal battery, shot peening, charging speed, shot size.