Patent ID: 7166391

Claim:
An alkaline storage battery, comprising: a positive electrode plate comprising a conductive support and an active material paste supported by the support, the active material paste containing nickel hydroxide and cobalt compounds, and an alkaline electrolyte, wherein the cobalt compounds comprise a hardly-soluble cobalt compound having a solubility of not more than 1 μg/g in a potassium hydroxide aqueous solution with a specific gravity of 1.3, the hardly soluble cobalt compound is obtained by at least one process selected from the group consisting of mixing a cobalt hydroxide powder and a sodium hydroxide powder, and applying a heat treatment to the same in an atmosphere containing oxygen, or, adding a sodium hydroxide aqueous solution and an aqueous solution containing an oxidizing agent to a cobalt hydroxide power, or, baking a cobalt hydroxide powder in an atmosphere containing oxygen at a temperature in the range of 90° C. to 140° C., and an easily-soluble cobalt compound having a solubility in a range of 100 μg/g to 10000 μg/g in the potassium hydroxide solution with a specific gravity of 1.3, and the easily-soluble cobalt compound is at least one selected from cobalt metal, cobalt hydroxide, cobalt monoxide, and cobalt sulfate.