The 70Li(2)S center dot 30P(2)S(5) glass-ceramic showed high ion conductivity of 1.5 x 10(-3) S cm(-1) at room temperature. The 75Li(2)S center dot 25P(2)S(5) glass showed ion conductivity of 5.0 x 10(-4) S cm(-1) at room temperature and high chemical stability. All-solid-state C/LiCoO2 cells using those materials as solid electrolytes were assembled. Their cell performance were compared. The cell using the 70Li(2)S center dot 30P(2)S(5) glass-ceramic showed superior rate performance to the cell using the 75Li(2)S center dot 25P(2)S(5) glass. On the other hand, the cell using the 75Li(2)S center dot 25P(2)S(5) glass showed superior cycle performance to the cell using the 70Li(2)S center dot 30P(2)S(5) glass-ceramic. It was suggested that solid electrolytes in all-solid-state batteries preferably had both high ion conductivity and high chemical stability. (C) 2013 Elsevier B.V. All rights reserved.