Properties of the perovskite-type oxide ceramic Ca1 − xLa2x3MnO3 − δ as the cathode active materials in alkaline batteries

The substituted complex oxides shown by Ca1 − xLa2x3MnO3 − δ, where the average valence of Ca-site is designed to always be double, have the perovskite-type structure in the range of x ≤ 0.90. These sintered oxides show high electronic conductivity of more than 101 S cm−1 at room temperature even in the porous state (porosity 50 to 60%). The sintered porous ceramics work as cathode active materials without any conductive additives in alkaline solutions. The discharge performance changes depending on the x value in Ca1 − xLa2x3MnO3 − δ and the kind of alkaline solution. The discharge capacity is 225 mAh g−1 (810 C g−1) for the x = 0.1 sample in 5% LiOH solution. This is comparable to that of the real cathode mixture composed of MnO2 and graphite in alkaline manganese batteries.