Properties of the perovskite-type oxide ceramic Ca1-xLa2x/3MnO3-delta as the cathode active materials in alkaline batteries

The substituted complex oxides shown by Ca1-xLa2x/3MnO3-delta where the average valence of Ca-site is designed to always be double, have the perovskite-type structure in the range of x less than or equal to 0.90. These sintered oxides show high electronic conductivity of more than 10(1) 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-xLa2x/3MnO3-delta 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. Copyright (C) 1997 Elsevier Science Ltd.