New lithium ion conductors based on Li2S-SiS2 system

There is great interest in sulfide glasses because of their high lithium ion conductivity. We have synthesized a new lithium ion conductive solid electrolyte based on Li2S-SiS2 glass with the composition: 0.03Li3PO4-0.59Li2S-0.38SiS2 at ambient pressure by quenching in liquid nitrogen. Its conductivity at room temperature was 6.9×10−4 S cm−1. The stability of the glass towards electrochemical reduction was dramatically improved compared with SiS2-Li2S-LiI glass. The glass synthesized with Li2SO4 instead of Li3PO4 also indicated good conductivity and stability against electrochemical reduction.