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

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.