IMPROVEMENT OF HIGH-RATE DISCHARGE AND ST ORAGE CAPABILITY OF MERCURY-FREE ALKALINE MANGANESE BATTERIES - INFLUENCE OF DIAMETER OF GRAPHITEPARTICLE IN POSITIVE ACTIVE MATERIAL AND INDIUM MODIFICATION FOR NEGATIVE CURRENT COLLECTOR

Addition of graphite powder as a conductive material for the positive electrode, and modification of the negative current collector with ind ium have been examined to improve the high-rate discharge and storage capability of mercury-free alkaline manganese batteries, The graphite powder with a mean diameter of about 6.0 mu m effectively suppressed p olarization of the positive electrode during discharge. The modificati on with indium effectively decreased both the internal cell impedance and hydrogen gas evolution due to the self-discharging reaction of zin c. A mercury-free alkaline manganese battery using the graphite powder and the negative current collector exhibited the same high-rate disch arge and storage capability as a battery with 0.15wt% mercury in zinc powder.