In order to develop high performance Ni-MH batteries, new methods for activation of the active material of the negative electrodes and for synthesis of the high-power density active material of the positive electrodes were investigated. The activation of the negative electrodes was promoted largely by the addition of fine crystallite nickel hydroxide-loaded carbon powder. The power density of the paste-type positive electrodes was improved to about three times that of conventional electrodes by optimizing the diameter of the active material.

Ni-MH batteries employing these new techniques exhibited greater discharge capacity, higher power density, and higher charge efficiency at 60°C in comparison with those on the market.