Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Tadaya Okada

Shigeto Noya

Yasuo Mukai

Fumio Kato

Hidekatsu Izumi

Michiko Fujiwara

Yasuhiko Syoji

Katsuya Sawada

An alkaline battery including a negative electrode including zinc, a positive electrode including manganese dioxide, and an alkaline electrolyte, in which the positive electrode includes graphite particles each having a basal surface and an edge surface, and anatase titanium dioxide particles, and the anatase titanium dioxide particles have a mean particle size larger than a height of the edge surface of each graphite particle.

Alkaline battery

Provided is a cylindrical alkaline battery in which the packing density Dc of the manganese dioxide in the positive electrode is 2.8 to 3.0 g/cmand the packing density Da of zinc or a zinc alloy in the negative electrode is 2.0 to 2.3 g/cm. The packing density Dc of the manganese dioxide, the packing density Da of the zinc or zinc alloy, the thickness Tc of the positive electrode in a radial direction, and the thickness Ta of the negative electrode in a radial direction satisfy one of the following relational formulas (1) to (3):&#x2212;1.975&#xd7;()+2.745&#x3c;&#x3c;&#x2212;1.690&#xd7;()+2.734&#x2003;&#x2003;(1)&#x2212;11.652&#xd7;()+14.470&#xd7;()&#x2212;3.095&#x3c;&#x3c;11.652&#xd7;()&#x2212;18.420&#xd7;()+8.585&#x2003;&#x2003;(2)&#x2212;8.895&#xd7;()+12.864&#xd7;()&#x2212;3.258&#x3c;&#x3c;8.895&#xd7;()&#x2212;16.244&#xd7;()+8.726&#x2003;&#x2003;(3).

Cylindrical alkaline battery having specific electrode packing densities and electrode thickness

An alkaline dry battery of this invention includes: a cylindrical battery case with a bottom; a cylindrical positive electrode having a hollow, being in contact with an inner face of the battery case, and containing a manganese dioxide powder and a graphite powder; a negative electrode disposed in the hollow of the positive electrode; a separator interposed between the positive electrode and the negative electrode; and an alkaline electrolyte. The positive electrode has cracks therein, and the cracks are substantially arc-shaped in a cross-section perpendicular to the axial direction of the positive electrode and extend in the axial direction of the positive electrode. The positive electrode has a manganese dioxide density of 2.15 to 2.30 g/cm.

Alkaline dry battery and method for producing the same

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

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.

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Osaka, Japan

Tadaya Okada