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. 08, 2022
Filed:
Jan. 15, 2020
Murata Manufacturing Co., Ltd., Nagaokakyo, JP;
Toru Kawai, Nagaokakyo, JP;
MURATA MANUFACTURING CO., LTD., Nagaokakyo, JP;
Abstract
A lithium ion secondary battery that includes a winding-type electrode assembly in which a positive electrode having a positive electrode active material layer, a negative electrode having a negative electrode active material layer, and a separator interposed therebetween are wound into a roll shape and have a charge cutoff voltage of 4.41 V to 4.47 V. In this lithium ion secondary battery, an area ratio of the entirety of the negative electrode active material layer to an area of a facing portion between the positive electrode active material layer and the negative electrode active material layer is 100.5% to 104.0%. A gap between the positive electrode and the negative electrode is 0.1 mm to 0.5 mm in an axial direction of the winding. A discharge capacity per unit weight of a positive electrode active material in the positive electrode active material layer is 169.0 mAh/g to 178.0 mAh/g.