Ionic conductivity in Li5AlO4 and LiOH

The ionic conductivity and thermal properties of Li5AlO4 and LiOH have been measured in wet and dry environments. Results show that an endothermic reaction at ∼ 415°C and an associated large increase in conductivity is observed both in Li5AlO4 in a wet environment and in LiOH. These features are not observed in Li5AlO4 prepared and examined in a dry environment. This suggests that the large conductivity increase in Li5AlO4 results from LiOH retained within the material. The reaction(s) for formation of LiOH within Li5AlO4 and the associated electrical changes appear to be reversible as the environment switches from wet to dry at high temperatures (≳ 450°C). There is a significant (> 1%) electronic contribution to the conductivity in these materials.