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. 29, 2014
Filed:
Feb. 03, 2009
Masami Makidera, Tsukuba, JP;
Taketsugu Yamamoto, Tsukuba, JP;
Masami Makidera, Tsukuba, JP;
Taketsugu Yamamoto, Tsukuba, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Abstract
The present invention provides a positive electrode active material that can suppress the necessity of performing sieving and is suitable for use in secondary batteries, particularly sodium secondary batteries. Also provided is a powder for a positive electrode active material as a raw material for the positive electrode active material. The powder for a positive electrode active material of the present invention comprises Mn-containing particles. In the cumulative particle size distribution on the volume basis of particles constituting the powder, D50, which is the particle diameter at a 50% cumulation measured from the smallest particle, is in the range of from 0.1 μm to 10 μm, and 90 vol % or more of the particles constituting the powder are in the range of from 0.3 times to 3 times D50. The powder for a positive electrode active material comprises Mn-containing particles, and 90 vol % or more of the particles constituting the powder are in the range of from 0.6 μm to 6 μm. The positive electrode active material is a powdery positive electrode active material obtained by calcining a mixture of the powder for positive electrode active material and a sodium compound. The positive electrode for sodium rechargeable batteries comprises the positive electrode active material.