Kabushiki Kaisha Toshiba

Toshiba Battery Co., Ltd.

Seiichi Hikata

Takashi Kobayashi

Hideaki Morishima

Natsuki Toyota

Takahisa Ohsaki

Yoshikazu Kobayashi

Haruchika Ishii

A non-aqueous electrolyte secondary battery includes an electrode body including a positive electrode and a negative electrode superimposed upon each other with a separator interposed therebetween. The negative electrode is superimposed upon the positive electrode in a state where a negative electrode active material layer, except the part on a proximal end part of a negative electrode tab, is positioned inside an outer edge of a positive electrode active material layer of the positive electrode. A width H1 of the negative electrode active material layer including the part on the proximal end part of the negative electrode tab, width H2 of the negative electrode active material layer or negative electrode current collector at a part other than the negative electrode tab, and width H3 of the positive electrode active material layer are formed to satisfy the relationships of H2&#x3c;H3, and (H1&#x2212;H2)&#x2267;(H3&#x2212;H2)&#xf7;2.

Non-aqueous electrolyte secondary battery, electrode used for secondary battery, and method of manufacturing electrode

A non-aqueous electrolyte secondary battery includes an electrode body including a positive electrode and a negative electrode superimposed upon each other with a separator interposed therebetween. The negative electrode is superimposed upon the positive electrode in a state where a negative electrode active material layer, except the part on a proximal end part of a negative electrode tab, is positioned inside an outer edge of a positive electrode active material layer of the positive electrode. A width Hof the negative electrode active material layer including the part on the proximal end part of the negative electrode tab, width Hof the negative electrode active material layer or negative electrode current collector at a part other than the negative electrode tab, and width Hof the positive electrode active material layer are formed to satisfy the relationships of H&#x3c;H, and (H&#x2212;H)&#x2267;(H&#x2212;H)&#xf7;2.

An electrode body of a secondary battery is formed by superimposing a positive electrode and a negative electrode upon each other with a belt-shaped separator interposed between the electrodes, and rolling up the positive and negative electrodes and the separator into a spiral shape. At least one side edge of a positive electrode current collector of the positive electrode in the longitudinal direction thereof includes a plurality of step parts discontinuously formed in the longitudinal direction at unequal intervals, and extends at both sides of each step part with a deviation of 0.2 mm or more. At least one side edge of a negative electrode current collector of the negative electrode in the longitudinal direction thereof includes a plurality of step parts discontinuously formed in the longitudinal direction at unequal intervals, and extends on both sides of each step part with a deviation of 0.2 mm or more.

Secondary battery

An object of the present invention is to improve the alkaline dry cell performance by modifying a positive cell case. An alkaline dry cell comprises a can as both of a terminal and a cell case 1 for accommodating a power generating element, prepared by drawing processing of a cold rolled steel material preliminarily applied with nickel-plating on both sides so as to form a can, having a conductive film formed in an inner surface portion contacting with a positive electrode compound, wherein the area of the portion with the conductive film is in the range of 75% to 90% with respect to the area of the whole portion contacting with the positive electrode compound in the inner surface. Since the conductive film is provided, the increase of the contact resistance can be prevented so as to improve the short-circuit current and the storage property. With less than 75% conductive film area, the above-mentioned effect cannot be achieved sufficiently. On the other hand, with more than 90% area, the filler compound can be separated in the dry cell production. Therefore, the above range is appropriate.

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Takasaki, Japan

Seiichi Hikata