Sanyo Electric Co., Ltd.

Kentaro Tsukamoto

Yoshifumi Magari

Kazuaki Tamura

Tomoyuki Yamada

Atsutoshi Ako

Akira Nishida

A secondary battery provided with: a belt-like positive electrode plate having a plurality of positive electrode tabs; and a positive electrode current collector which is connected so that the plurality of positive electrode tabs are stacked, wherein the positive electrode plate has a positive electrode core body and a positive electrode active material layer formed on the positive electrode core bodies. At one edge side of the positive electrode plate where the plurality of positive electrode tabs are provided, one surface of the positive electrode core body has formed thereon a first protrusion that protrudes from said surface of the positive electrode core body in the thickness direction of the positive electrode core body, whereas the other surface of the positive electrode core body has no protrusion formed to protrude from said other surface of the positive electrode core body in the thickness direction of the positive electrode core body.

Secondary battery

A positive electrode plate that has a positive electrode active material layer formed on a positive electrode core, wherein the positive electrode core has, on an edge side, a thick portion which has a thickness that is greater than the thickness of a portion of the positive electrode core that has the positive electrode active material layer formed on both sides, and the positive electrode plate has a first region that extends into the thick portion from the portion of the positive electrode core that has the positive electrode active material layer formed on both sides and a second region that is positioned outside the first region in the thick portion. The average maximum diameter of the metal crystal grains that compose the first region is smaller than those of the second region.

Growing community of inventors

Hyogo, Japan

Kentaro Tsukamoto