High lithium ion conducting Li2S-P2S5-Li3N glasses and glass-ceramics were prepared using mechanical milling. Glasses of (75-1.5x)Li2S center dot 25P(2)S(5)center dot xLi(3)N (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 x 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 x 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. (C) 2017 Elsevier B.V. All rights reserved.