PROPERTIES OF THE PEROVSKITE-TYPE OXIDE CERAMIC CA1-XLA2X 3MNO3-DELTAAS THE CATHODE ACTIVE MATERIALS IN ALKALINE BATTERIES/

The substituted complex oxides shown by Ca1-xLa2x/3MnO3-delta where th e 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 0.9 0. These sintered oxides show high electronic conductivity of more tha n 10(1) S cm(-1) at room temperature even in the porous state (porosit y 50 to 60%). The sintered porous ceramics work as cathode active mate rials without any conductive additives in alkaline solutions. The disc harge 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, T his is comparable to that of the real cathode mixture composed of MnO2 and graphite in alkaline manganese batteries. Copyright (C) 1997 Else vier Science Ltd.