Simulation of the compaction of an all-solid-state battery cathode with coated particles using the discrete element method

Abstract

The simulation of a cold-pressed electrode, which consists of active material (AM) particles coated with a solid electrolyte (SE), of an all-solid-state battery (ASSB), is presented. The aim of this study is to elucidate the effect of the SE coating structure on the performance of the ASSB. The new method we developed to simulate the SE-coated AM particles is based on a discrete element method. This approach enables us to simulate mold compaction as well as the delamination of SE from the AM particles. Simulation of the AM as clustered particles held together by fusion bonding allows the mechanical damage to the AM to be reproduced simultaneously. For a ductile SE material, new fusion bonding contacts with other particles could develop when pressure is applied. Our simulations suggest that the SE coating promotes more effective ionic transport, in contrast to conventional particle mixture, owing to the superior percolating network. At low mold pressures, electron transport between the AM particles is disrupted because of the shielding effect of the SE coating. This effect vanishes at higher mold pressures. Both types of electrodes (particle mixture and SE coating) have similar damage profiles, with damage concentrated near the current collector.