Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Junya Nishimori

Kenjin Masumoto

Akira Kakinuma

Keisuke Yoneda

Yoshiki Osawa

Teruhisa Ishikawa

Mitsuru Funaki

Tomonori Nakaguchi

A battery includes a first electrode plate, a second electrode plate, a separator interposed between the first and second electrode plates, a closed-end cylindrical metal case accommodating these three elements, and a sealing member sealing an opening of the metal case with an insulating member interposed therebetween. The first and second electrode plates are wound with the separator interposed therebetween to form a wound electrode group. A center axis portion of the wound electrode group is substantially the same as a center axis of a cylinder of the metal case, and contains no power-generating element. A first current collector lead coupled to the first electrode plate extends toward the opening of the metal case, and joined to an inner sidewall surface of the metal case. A second current collector lead coupled to the second electrode plate extends toward the opening of the metal case, and joined to the sealing member.

Battery and manufacturing method of the battery

A wound electrode group includes an electrode stack that is formed by laminating a strip of positive electrode plate, a strip of negative electrode plate, and a pair of separators interposed therebetween. When the electrode stack is wound, a difference L in length between an inner turn and an adjacent outer turn satisfies L=2t&#x3c0;+(W&#xd7;k), where t is a thickness of the electrode stack, W is a maximum diameter of a cross section of the wound electrode group, and k is a coefficient that is preset in accordance with expansion coefficients of active materials of the positive and negative electrode plates and is within a range from 0.005 to 0.05.

Battery and method for manufacturing spiral electrode group for use therein

Growing community of inventors

Osaka, Japan

Junya Nishimori