The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 2009
Filed:
Mar. 11, 2003
Teruhisa Ishikawa, Kadoma, JP;
Yoshiki Osawa, Suita, JP;
Mitsuru Funaki, Moriguchi, JP;
Tomonori Nakaguchi, Hirakata, JP;
Junya Nishimori, Takatsuki, JP;
Teruhisa Ishikawa, Kadoma, JP;
Yoshiki Osawa, Suita, JP;
Mitsuru Funaki, Moriguchi, JP;
Tomonori Nakaguchi, Hirakata, JP;
Junya Nishimori, Takatsuki, JP;
Panasonic Corporation, Osaka, JP;
Abstract
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=2tπ+(W×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.