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:
Jan. 10, 2017
Filed:
Jun. 16, 2015
Hitachi, Ltd., Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A lithium ion secondary battery includes: a positive electrode including a positive electrode active material; a negative electrode formed by coating a negative electrode active material mixture onto a surface of a negative electrode collector, the negative electrode active material mixture including a negative electrode active material, a conductive additive, and a binder; a separator interposed between the positive electrode and the negative electrode; and an electrolyte, in which the negative electrode active material includes graphite and an Si alloy, inequities of 0.43≦x≦9.0 and 8≦y<18 are satisfied when a mass ratio of the graphite and the Si alloy is defined as x and a coating amount of the negative electrode active material mixture is defined as y (mg/cm). Thus, an initial capacity thereof can be increased and a capacity retention rate thereof can be improved in the lithium ion secondary battery which includes the Si alloy in the negative electrode.