Positive electrode active material for alkaline storage battery, positive electrode using the same and method of producing the same

A positive electrode active material for an alkaline storage battery comprising at least one selected from the group consisting of a nickel hydroxide powder and a nickel oxyhydroxide powder is disclosed, wherein the positive electrode active material has (1) a mean particle circularity from 0.95 to 1, (2) a mean particle size from 5 to 20 mu m on a volume basis, and (3) a specific surface area from 5 to 20 m/g, and (4) at least the nickel hydroxide powder has an X-ray diffraction pattern where a full width at half maximum of a peak attributed to (101) face is from 0.7 to 1.2 deg/2&thetas; and a peak intensity ratio of a peak attributed to (001) face to a peak attributed to (101) face is not less than 1.1.