14th International Conference on Shot Peening

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

Manabu Kodama, Kai Takashima, Shuichiro Hirai

Tokyo Institute of Technology, School of Engineering, 2-12-1 Oookayama Meguro-ku, Tokyo, Japan – tanaka.m.ay@m.titech.ac.jp

Introduction

To reduce the CO2 emission, gasoline vehicles should be changed to electrical vehicles (EV). However, conventional EV’s cruising distance is only about 400 km and is much shorter than that of a gasoline vehicle (~1000 km) due to lithium-ion batteries’ volumetric energy density limitation. Moreover, there is an ignition risk of organic electrolyte in the lithium-ion battery, and some cases are reported of fire accidents of EV. An all-solid-state lithium-metal battery (ASSLiMB) is proposed to increase the battery volumetric energy density and as high safety battery. The ASSLiMB’s anode is a lithium metal, and the energy density is ten times higher than that of a conventional lithium-ion battery anode. Moreover, the inorganic solid electrolyte (SE) that is fire-resisting material is used as the electrolyte; thus, the ignition risk of the battery is negligibly small. However, the charging speed of ASSLiMB is slow, and it takes more than 20 hours to charge. The reason for the slow charging speed is lithium dendrite. If the ASSLiMB is in high-speed charging, the lithium dendrite grows into the SE that separates the anode and cathode by developing a clack, and the lithium dendrite connects the anode and cathode, then the battery is in an internal short circuit. For high-speed charging ASSLiMB, the lithium dendrite growth with clack propagation should be suppressed. The shot peening (SP) is one of the methods to suppress the clack generation by making compressive residual stress. Therefore, there is a possibility to suppress the lithium dendrite growth by the shot peening to the SE.

Objectives

In this study, the characteristics of SP processed ASSLiMB is demonstrated with experiments to elucidate the influence of the SP for battery charging speed and electrochemical and mechanical characteristics of the ASSLiMB.