Panasonic Corporation

Tomonori Nakaguchi

Yoshiki Osawa

Junya Nishimori

Teruhisa Ishikawa

Mitsuru Funaki

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.

Growing community of inventors

Hirakata, Japan

Tomonori Nakaguchi