Characterization of the cobalt component in the positive-electrode material of a nickel metal hydride battery using extended X-ray absorption fine structure

摘要

Recently a nickel metal hydride (Ni-MH) battery has been developed for an electric vehicle. In this development, the electrochemical function of the positive electrode is one of the most important issues. For example, the charge efficiency or memory effect depend on the component of the positive active material. Furthermore, the battery capacity is controlled by the volume of positive electrode orpositive-to-negative-electrode ratio. There-fore, development activity regarding the positive-electrode component has been accelerated [1,2].