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. 26, 2019
Filed:
Sep. 26, 2014
Tdk Corporation, Tokyo, JP;
Yasuhiro Ikeda, Tokyo, JP;
Atsushi Sano, Tokyo, JP;
Masaki Sobu, Tokyo, JP;
Akinobu Nojima, Tokyo, JP;
TDK CORPORATION, Tokyo, JP;
Abstract
A negative electrode active material is provided for a lithium ion secondary battery having high initial charging/discharging efficiency. The negative electrode active material containing silicon and silicon oxide has two phases with different compositions therein. One of the two phases has a lower silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of primary particle of the negative electrode active material. Use of the negative electrode active material enables a sufficient increase in initial charging/discharging efficiency.