流体静高压下的锂离子导电性

本文改进实验方法,在0.0001—1.23GPa流体静高压下测量了整片非晶锂离子导体B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃(x=0.05;0.15)及其粉末压片的离子电导率及激活体积。发现粉末压片电导率峰值是由非晶微粒间的接触电导及非晶微粒体电导两者叠加;对整片非晶电导率的压力效应用离子迁移通道的物理图象给出初步的微观解释。此外,还观测到氧化铝组分减少使电导率的压力转变点明显降低;测量出不同温度热处理以及300℃等温热处理4—20h后离子电导率-压力曲线的变化规律,仍可归因于非晶态相分离及两种非晶相的先后晶化。 关键词：

LITHIUM IONIC CONDUCTIVITY AT HIGH HYDROSTATIC PRESSURE

Ionic conductivity and activation volume of bulk sample and comprssed powder disc of amorphous lithium ionic conductor B₂O₃-0.7Li₂O-0.7LiCl-xAl₂O₃ (x= 0.05, 0.15) in the hydros-tatie pressure range of 0.0001-1.23 GPa were investigated. We found that the peak of conductivity of compressed powder disc consisted of contact conductivity and bulk conductivity. For hydrostatic pressure dependence of ionic conductivity of the bulk sample, a preliminary microscopic explanation was obtained by considering the physical picture of ionic transport passages. In addition, we observed that decrease of the content of alumina lowers the pressure of conductivity maximum. Variation of ionic conductivity with pressure was measured after heating samples at different temperature or at 300℃ for 4-20 hours. The behaviors were due to the amorphous phase separation and successive crystallization process of the two amorphous phases.