Patent ID: 8124281
Filing Date: 2012-02-28
Classification: H01M,Y02E

Abstract:
1. A hydrogen storage alloy electrode comprising: negative electrode active material constituted of a hydrogen storage alloy containing at least a rare earth element, magnesium and aluminum; a crystalline structure of the hydrogen storage alloy having a mixed phase made up of at least an A a surface layer of hydrogen storage alloy particles being so formed as to have a nickel content ratio greater than that of a bulk, a ratio X/Y of a nickel mass content ratio X of the surface layer to a nickel mass content ratio Y of the bulk being greater than 1.0 but no more than 1.2; wherein the surface layer corresponds to a region where the particles of the hydrogen storage alloy contact with an electrolyte, and a thickness of the surface layer extends 100 nm inward from the surface of the hydrogen storage alloy.