Patent ID: 7718315

Claim:
An alkaline battery comprising a positive electrode material mixture, a negative electrode, a separator interposed between said positive electrode material mixture and said negative electrode, and an alkaline electrolyte, wherein said positive electrode material mixture includes a first active material comprising nickel oxyhydroxide and a second active material comprising manganese dioxide, and the content of said manganese dioxide in said positive electrode material mixture is 20 to 90 wt %, said nickel oxyhydroxide is a solid solution in which both manganese and cobalt are dissolved as an additive element, the amount of each of manganese and cobalt dissolved in said solid solution is 1 to 7 mol % of the total of all of metallic elements included in said solid solution, and a content of nickel in said nickel oxyhydroxide is not less than 45 wt %, an average particle diameter on a volume basis of said nickel oxyhydroxide measured with a laser diffraction particle size distribution analyzer is 3 to 20 μm, and said nickel oxyhydroxide includes a γ-type crystal structure and a β-type crystal structure, and a powder X-ray diffraction pattern of said nickel oxyhydroxide includes a diffraction peak P γ attributed to the (003) plane of a γ-type crystal having an interplanar spacing of 6.8 to 7.1 angstroms (Å) and a diffraction peak P β attributed to the (001) plane of a β-type crystal having an interplanar spacing of 4.5 to 5 angstroms (Å), an integrated intensity I γ of said diffraction peak P γ and an integrated intensity I β of said diffraction peak P β satisfy 0.5≦I γ /(I γ +I β ) and average valence of nickel included in said nickel oxyhydroxide is not less than 3.3.