Effects of erbium additions on high temperature performance of high power Ni-MH batteries

The Co（Ⅲ）-coated spherical nickel hydroxide powder is optimum as positive electrode of high power Ni-MH battery because of its excellent property. But the performances at high temperature （above 50 ℃） is still not satisfied. In the present paper, the effect of element erbium, used as additive by different methods to prepare positive electrode, on the high temperature performances of the Ni-MH batteries is studied. It is found that the charge acceptance ability of the spherical Ni（OH）2 electrode with element erbium as additive is improved. The discharge capacities of Ni（OH）2 coated with 1% （atomic fraction） Er（OH）3 and mechanically added with 1% （atomic fraction） Er203 at 1C are 12.6% and 11.7%, respectively, higher than those of the samples without erbium at 70 ℃.