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:
Jul. 09, 2019
Filed:
Nov. 25, 2015
Hitachi, Ltd., Tokyo, JP;
HITACHI, LTD., Tokyo, JP;
Abstract
A lithium ion secondary battery having a negative electrode includes a negative electrode active material containing at least one of two material of silicon and a silicon compound and carbon, a weight mixing ratio of at least one of two material of the silicon and the silicon compound and the carbon is 20:80 to 50:50, when Dof particles of at least one of two material of the silicon and the silicon compound is x, Dof particles of the carbon is y, and the weight mixing ratio of the carbon is z, y≤−1.17x+0.45z is satisfied, the x is between 2 μm and 10 μm, the y is between 10 μm and 23 μm, and the z is between 50% and 80% by weight, and a coefficient of expansion when the negative electrode is fully charged is 110% or more and 140% or less.