Decomposition mechanisms of some lithium ionic conductors

The decomposition reactions of some lithium ionic conductors are investigated. With many ternary lithium oxides as e.g. LiREO₂ (RE: rare-earth metal) or Li₃InO₃, hydrolysis in air is observed. The very steep increase in conductivity at temperatures of ≈380°C is due to the presence of impurities at the surface of the grains. These impurities are generated by hydrolysis. An investigation of the stability of LiAlO phases against molten lithium showed that all these compounds except Li₅AlO₄ exhibited a severe reaction with the molten alkali metal. LiAl may be identified as a reaction product.