Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Nissui Chemicals Co., Ltd.

Yasuo Mukai

Shigeto Noya

Fumio Kato

Hidekatsu Izumi

Michiko Fujiwara

Tadaya Okada

Hideki Misaki

Katsuya Sawada

Kenji Shiotani

Takeshi Okubo

Yasuko Hoshina

Shinichi Sumiyama

Shuji Fujiwara

There is disclosed an alkaline battery including a positive electrode material mixture, a negative electrode, a separator interposed between the positive electrode material mixture and the negative electrode, and an alkaline electrolyte, wherein the positive electrode material mixture includes a first active material comprising nickel oxyhydroxide and a second active material comprising manganese dioxide, the nickel oxyhydroxide includes a &#x3b3;-type crystal structure, the content of nickel in the nickel oxyhydroxide is not less than 45 wt %, and the average particle diameter on a volume basis of the nickel oxyhydroxide measured with a laser diffraction particle size distribution analyzer is 3 to 20 &#x3bc;m.

Alkaline battery and positive electrode material for alkaline battery comprising nickel oxyhydroxide and manganese dioxide

An alkaline battery of the present invention includes a positive electrode material mixture including nickel oxyhydroxide. The nickel oxyhydroxide includes a secondary particle with a crystal structure mainly composed of &#x3b3;-type at least a portion of the surface layer of the secondary particle, and with a crystal structure mainly composed of &#x3b2;-type in the inner portion of the secondary particle. Based on the present invention, the advantage of the alkaline battery, i.e., excellence in discharge performance under high-load, can be kept and the conventional problem of storage characteristics can be improved.

Alkaline battery and manufacturing method of positive electrode material therefor

In order to provide a method of producing a gel negative electrode for an alkaline battery for preparing a gel negative electrode in which a zinc powder, a gelling agent and an electrolyte are disposed uniformly, by an agitator including a cylindrical agitation container disposed so that the center axis X of the cylinder is parallel to the horizontal direction, the agitation container is rotated around the center axis X and the left and right portions of the agitation container are swung around an axis Y, which is orthogonal to the longitudinal direction of the agitation container, thereby agitating and mixing the alkaline electrolyte and the dry mixture.

Method of producing gel negative electrode for alkaline battery and apparatus for producing the same

Provided is an alkaline dry battery allowing suppression of polarization in pulse discharge under heavy load to improve discharge characteristics, and having high reliability in safety in case of short circuit. In the positive electrode, a calcium compound having a content of iron element of 150 ppm or less is added in an amount of 0.1 to 10 mol % with respect to a positive electrode active material, a nickel oxyhydroxide powder having 2.95 or more of an average nickel valence and 8 to 18 &#x3bc;m of an average particle diameter is used, the weight ratio of the nickel oxyhydroxide powder and a manganese dioxide powder is in the range of 20:80 to 90:10. A zinc or zinc alloy powder used as negative electrode active material includes a first powder having a particle diameter more than 75 &#x3bc;m and 425 &#x3bc;m or less, and a second powder having a particle diameter more than 5 &#x3bc;m and 75 &#x3bc;m or less, and the weight ratio of the first powder and the second powder is in the range of 65:35 to 75:25, and the concentration of a potassium hydroxide solution is 33 to 35% by weight.

Alkaline dry battery with a nickel oxyhydroxide and manganese oxide positive electrode including a calcium compound

In order to provide a method of producing a gel negative electrode for an alkaline battery for preparing a gel negative electrode in which a zinc powder, a gelling agent and an electrolyte are disposed uniformly, by means of an agitator comprising a cylindrical agitation container disposed so that the center axis X of the cylinder is parallel to the horizontal direction, the agitation container is rotated around the center axis X and the left and right portions of the agitation container are swung around an axis Y, which is orthogonal to the longitudinal direction of the agitation container, thereby agitating and mixing the alkaline electrolyte and the dry mixture.

In order to obtain an alkaline dry battery low in the possibility of electrolyte leakage and excellent in discharge performance as well as an alkaline dry battery which is not likely to cause an internal short circuit even with the use of a thin separator, as a zinc powder used is one including 65 to 75 wt % of first zinc particles having a particle size of larger than 75 &#x3bc;m and not larger than 425 &#x3bc;m, and 25 to 35 wt % of second zinc particles having a particle size of not larger than 75 &#x3bc;m.

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Moriguchi, Japan

Yasuo Mukai