Preparation and characterization of superionic conducting Li7P3S11 crystal from glassy liquids

Superionic Li+ ion conducting Li7P3S11 crystal was prepared by crystallization of the 70Li(2)S center dot 30P(2)S(5) (mol %) glass and melt. In the case of crystallization of the 70Li(2)S center dot 30P(2)S(5) glass. the crystallized electrolyte heated at 360 degrees C for 1 h showed a conductivity of 4.1 x 10(-3) S cm(-1) at room temperature. In the case of crystallization from the 70Li(2)S center dot 30P(2)S(5) melt, a single phase of the Li7P3S11 crystal was obtained by crystallization of the melt at 700 degrees C for 48 h and then quenching in ice water. The crystallized electrolyte showed the conductivity of 2.9 x 10(-3) S cm(-1) at room temperature. The precipitated crystal depended on the heat treatment. temperature. holding time, and cooling rate. In both crystallization processes front the glass and melt, the Li7P3S11 crystal was precipitated as a primary phase from supercooled liquids and thus the superionic conducting Li7P3S11 crystal is a high temperature phase at the composition 70Li(2)S center dot 30P(2)S(5). (C) 2010 The Ceramic Society of Japan All rights reserved