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:
May. 07, 2013
Filed:
Apr. 19, 2007
Yutaka Bannai, Sendai, JP;
Tatsuji Numata, Sendai, JP;
Ryuichi Kasahara, Sendai, JP;
NEC Energy Devices, Ltd., Sagamihara-shi, JP;
Abstract
The invention provides a lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolysis solution containing an aprotic solvent having an electrolyte dissolved in it, wherein the negative electrodes uses an amorphous carbon material as a negative electrode active material. The amorphous carbon material has (A) an average particle diameter (median size) of 7 μm to 20 μm inclusive as measured by a laser diffraction scattering method and (B) a particle size distribution as measured by a laser diffraction scattering method, in which distribution the ratio of particles of less than 3 μm in diameter is 1% by mass to 10% mass inclusive, and is free of an electrical conducting material.