Ionic Conductivity and Phase Transition of the Spinel System Li2 − 2x M 1 + x Cl4 ( M = Mg , Mn , Cd )

The spinel systems with has been studied by means of impedance measurement, differential thermal analysis, and x‐ray diffraction analysis. The ionic conductivity increases and the activation energy for conduction decreases with increasing within the solid solution range, in , in , and in . The highest conductivity is found to be in at room temperature and 0.35 Scm −1 in at 400°C. The three chloride spinels exhibit a first‐order phase transition and a diffuse transition. The diffuse transition temperatures decrease with increasing .