Electrical Properties and the Structure of Glasses in the Li2SO4–LiPO3 System

Electrical characteristics, namely, the temperature–concentration dependence of the electrical conductivity and the concentration dependence of the transport numbers of lithium ions (determined with the use of the Tubandt method) are investigated for glasses in the Li2SO4–LiPO3 system. It is revealed that only lithium ions are involved in charge transfer. The IR absorption spectra, density, microhardness, and ultrasonic velocity are measured. An analysis of the experimental results obtained demonstrates that SO2-4 ions form terminal groups and can be incorporated into polyphosphate structural fragments. An increase in the electrical conductivity and a decrease in the activation energy for electrical conduction are interpreted in the framework of a crossover of the migration mechanism. In lithium metaphosphate, lithium ions predominantly migrate through the interstitial mechanism. However, an increase in the lithium sulfate content in the initial glass leads to an increase in the fraction of charge carriers that migrate according to the vacancy mechanism.