Mechanochemical Synthesis and Electrochemical Properties of Li _x VS _y Positive Electrodes for All-Solid-State Batteries

To enhance the energy density of all-solid-state batteries, polysulfide positive electrodes have a great advantage of their high capacity. In this study, we developed Li x VS y ( x = 5–9, y = 4–6) comprised Li 2 S and LiVS 2 . Although Li 2 S is an insulator, Li x VS y shows a high electronic conductivity (∼10 −1 –10 −2 S cm −1 ) because it contains LiVS 2 with a high electronic conductivity. The theoretical capacity of Li x VS y is 626–789 mAh g −1 when all the Li in Li x VS y reacts. Li x VS y positive electrodes achieve a high energy density because they show high capacity with no conductive additives and high loading of Li x VS y .