Performance Optimization of All-Solid-State Lithium Ion Batteries Using a Li2S-P2S5 Solid Electrolyte and LiCoO2 Cathode

In order to improve the performance of all-solid-state batteries, 78Li(2)S.22P(2)S(5) glass-ceramics with an enhanced ionic conductivity of 8.5 x 10(-4) S cm(-1) were developed using a two-step heat treatment after mechanical milling. The two-step heat treatment process consists of a nucleation step at 160 degrees C and a crystal growth step at 230 degrees C, where the nucleation temperature was determined using previously performed thermal analyses. Moreover, the wet mixing method, which is identified as an effective method of obtaining more homogeneous distributions of composite particles, was applied in order to prepare the composite cathode. As a result, the cell prepared using the wet mixing method exhibited significantly improved capacity retention.