Development of Coating Technology for Cathode Material to Improve Durability of Sulfide-Based All-Solid-State Battery

Abstract

Development of all-solid-state lithium-ion batteries (ASSLBs) has rapidly progressed in the recent years. In the case of sulfide-based ASSLBs, interfacial reaction between the cathode material and solid electrolyte is considered as a major reason for the decrease in capacity, while surface coating of the cathode material is employed to mitigate the interfacial reaction. In SOLiD-EV project, we established a new coating process reducing the time for coating, and also developed a new coating material being more chemically stable at high electric potentials and high temperatures than LiNbO₃, which is one of the most representative coating materials. In addition, the thicker new coating-layer can further improve the battery durability.