Effect of alkali-treatment of hydrogen storage alloy on the degradation of Ni/MH batteries

摘要

Alkali-treatment at high temperature ofthe hydrogen storage alloy which was used as thenegative electrode of nickel/metal-hydride batteriescould enhance the cycle life. Al dissolves from thealloy surface, rare earth metal hydroxides form on thealloy surface, while Ni and Co exist as metals nearthe surface. Mn dissolves first and then depositsagain as an oxide on the alloy surface. The corrosionreaction caused by alkali-treatment of the alloy stopsat a certain stage. The above three points can beconsidered as the main factors for the long cycle lifefor the alkali-treated alloys.