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:
Nov. 08, 2011
Filed:
Mar. 27, 2008
Kenji Nakai, Hitachinaka, JP;
Akinori Tada, Hitachinaka, JP;
Kinya Aota, Hitachi, JP;
Hitachi Vehicle Energy, Ltd., Ibaraki, JP;
Abstract
The present invention provides a lithium-ion secondary battery which can suppress internal resistance to a small value. The lithium-ion secondary battery includes a winding group obtained by winding a positive electrode plate and a negative electrode plate via a separator. An end portion of a positive electrode mixture non-application portionprojects at an upper portion of the winding group, while an end portion of a negative electrode mixture non-application portion projects at a lower portion of the winding group. Current collecting disksare disposed on both end faces of the winding group so as to face them, respectively, and materials for the current collecting disks are the same materials as those for a positive electrode current collector and a negative electrode current collector. An end portion of the positive electrode mixture non-application portionis joined to a face of the current collecting diskpositioned on the side of the winding group at a plurality of joint portions on the positive electrode side, while an end portion of the negative electrode mixture non-application portion is joined to a face of the current collecting diskpositioned on the side of the winding group at a plurality of joint portions on the negative electrode side. Some of the joint portions form joint portions taking on a width expansion shape gradually expanding from a joint end portion with the positive electrode mixture non-application portiontoward the current collecting disk. A volume of the joint portionis increased.