Highly Li-ion conductive Li2S-P2S5 glass-ceramic electrolytes were prepared by controlling the compositions and heat treatment process of the glass. In the systems xLi(2)S center dot(100 - x)P2S5 (65 <= x <= 75,mol%) glass phase substrates were prepared by mechanical ball milling. After melting, rapidly quenching and tempering, glass-ceramic electrolytes were prepared. Among them, the 70Li(2)S center dot 30P(2)S(5) sample showed a highest conductivity of 1.58 x 10(-3) S cm(-1) and an activation energy of 39 kJ mol(-1). The outstanding property was attributed to both the precipitation of the high conductivity thio-LISICON III phase and the heat treatment, which reduces the grain boundary and improves the grain morphology. Moreover, ball milling method was applied to prepare the composite cathode. Significant high capacity all-solid-state cell with commercial Li2S as active material and 70Li(2)S center dot 30P(2)S(5) glass ceramic as electrolyte was prepared. First discharge capacity of 1055 mAh g(-1), high capacity retention of 57.2% after ten cycle and excellent coulombic efficiency were achieved. (C) 2017 Elsevier B.V. All rights reserved.