Patent ID: 7335445
Filing Date: 2008-02-26
Classification: H01M,Y02E

Abstract:
1. A particulate positive electrode active material for an alkaline storage battery comprising: (a) solid solution nickel hydroxide particles containing at least magnesium, the amount of magnesium contained in said solid solution nickel hydroxide particles being not smaller than 2 mol % and not larger than 15 mol % of the total amount of metal elements contained in said solid solution nickel hydroxide particles, BET specific surface area of said solid solution nickel hydroxide particles measured by nitrogen gas adsorption being not smaller than 5 m (b) a coating layer comprising cobalt oxide formed on the surface of said solid solution nickel hydroxide particles, said coating layer further comprising at least one element “Xs” selected from the group consisting of yttrium, ytterbium, and lutetium, wherein an amount of said element “Xs” contained in said coating layer (b) is not smaller than 2 mol % and not larger than 20 mol % of the total amount of metal elements contained in said coating layer (b).