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

Abstract

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 .

Keywords

• batteries–li-ion
• metal polysulfides positive electrodes
• all-solid-state lithium batteries
• sulfide solid electrolytes
• mechanochemical treatment