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.

Date of Patent:
Jan. 12, 2021

Filed:

Sep. 10, 2018
Applicant:

Toyota Jidosha Kabushiki Kaisha, Toyota, JP;

Inventor:

Ippei Goto, Toyota, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01M 4/36 (2006.01); H01M 10/0525 (2010.01); H01M 4/505 (2010.01); H01M 4/525 (2010.01); H01M 4/38 (2006.01); H01M 10/052 (2010.01); H01M 4/02 (2006.01);
U.S. Cl.
CPC ...
H01M 4/366 (2013.01); H01M 4/382 (2013.01); H01M 4/505 (2013.01); H01M 4/525 (2013.01); H01M 10/0525 (2013.01); H01M 10/052 (2013.01); H01M 2004/028 (2013.01);
Abstract

The present invention provides a positive electrode material for lithium secondary batteries, having: a positive electrode active material containing Li; and a cover disposed on the positive electrode active material, and containing Li and F, and further containing one or two or more cover elements from among Al, Ti, Zr, Ta and Nb. With a Point a as an arbitrary point of the cover in contact with the positive electrode active material, a Point c as a point on the surface of the cover at a shortest distance from the Point a, and a Point b as a midpoint between the Point a and the Point c, an analysis of the Point a, the Point b and the Point c by X-ray photoelectron spectroscopy yields a ratio of Li concentration at the Point a with respect to the Li concentration at the Point b is 1.1 or higher and lower than 10.8, and a ratio of F concentration at the Point c with respect to F concentration at the Point b is 1.1 or higher and lower than 51.1.


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