Synergistic effect of processing and composition x on conductivity of xLi2S-(100 − x)P2S5 electrolytes

Abstract

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 xLi2S·(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 70Li2S·30P2S5 sample showed a highest conductivity of 1.58×10−3Scm−1 and an activation energy of 39kJmol−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 70Li2S·30P2S5 glass ceramic as electrolyte was prepared. First discharge capacity of 1055mAhg−1, high capacity retention of 57.2% after ten cycle and excellent coulombic efficiency were achieved.