Investigation of State-of-charge Distributions for LiCoO2Composite Positive Electrodes in All-solid-state Lithium Batteries by Raman Imaging

Composite positive electrodes for all-solid-state lithium batteries were prepared by mixing LiCoO2 and Li2S-P2S5 solid electrolytes particles. Two different sizes of solid electrolyte particles were used. Raman mapping was conducted for each positive electrode before and after the charge–discharge tests to examine local state-of-charge (SOC) distribution. Mapping images indicated that the charge–discharge reaction proceeded uniformly in the positive electrode with smaller solid electrolyte particles.