High-Rate Discharge Properties of Ni-MH Battery Using New Substrates for HEV Applications

摘要

Because of its open pore structure and high porosity, foam-type nickel substrate has been widely used for the positive electrodes of nickel-metal hydride (Ni-MH) batteries. In recent years, Ni-MH batteries are adopted as the hybrid electric vehicle (HEV) power sources. The market is rapidly expanding and further demand can be expected in the near future. While cost reduction of auto parts is strongly required, there is a limitation in cost reduction of foam type nickel substrate because it is made by a complex manufacturing method that involves many processes. The authors have developed a low-cost substrate for positive electrode application. The new substrate is similar to a foam-type nickel substrate in having an open pore structure and high porosity, but the amount of nickel used is reduced by half. Using the new substrate, the authors made positive electrodes and evaluated their charge-discharge property using cylindrical sealed batteries. It was found that the charge-discharge property of this new substrate is as good as or better than that of foam nickel substrates, although the amount of nickel had been decreased.