Effect of partial substitution of Ta2O5 by ZrO2 on the structure and ionic conductivity of Li2O-Ta2O5-2 SiO2 glass and glass-ceramics

Abstract

LiTaSiO5 system is considered as type of solid electrolyte with great potential for application as ionic conductor. It is well-known that it is difficult to obtain pure dense LiTaSiO5 phase by traditional synthesis methods, because dielectric LiTaO3 phase easily precipitates during synthesis, which affects ionic conductivity. In this work, a glass-ceramic electrolyte with main LiTaSiO5 phase was obtained by controlled crystallization of Li2OTa 2O5-2 SiO2 glass without porosity. The precipitation of LiTaO3 phase at the grain boundary was effectively inhibited by adding an appropriate amount of ZrO2. Among all the glass-ceramic samples, the glass containing 4.76mol% ZrO2 had the maximum ionic conductivity of 8.40 × 10−6 S/cm at 25°C, which is two order of magnitude greater than the ionic conductivity of the matrix glass. These glass-ceramic samples have the potential to be used as solid electrolytes in electrochemical applications.

Keywords

• glass ceramics
• silicate
• ionic conductivity
• ir spectroscopy
• impedance