Mechanochemical synthesis of high lithium ion conducting solid electrolytes in a Li2S-P2S5-Li3N system

High lithium ion conducting Li2S-P2S5-Li3N glasses and glass-ceramics were prepared using mechanical milling. Glasses of (75-1.5x)Li2S·25P2S5·xLi3N (mol%) were obtained in the composition range of 0 ≤ x ≤ 20. The glass conductivity increased with an increase in the Li3N content. Glass with 20 mol% of Li3N showed the highest conductivity of 5.8 × 10− 4 S cm− 1 at room temperature. For glass-ceramics, the conductivity also increased with an increase in the Li3N content up to 20 mol%. A new crystal phase was precipitated in the glass-ceramics. The glass-ceramic with 10 mol% of Li3N showed the highest conductivity of 1.4 × 10− 3 S cm− 1 at room temperature. Moreover, the glass-ceramic had a wide electrochemical window and high chemical stability to moisture. An all-solid-state In/LiCoO2 cell using the glass-ceramic electrolyte operated as a rechargeable battery. The addition of nitrogen to the Li2S-P2S5 system improved electrolyte properties.