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:
Feb. 17, 2015
Filed:
Jul. 29, 2011
Ryuichi Kasahara, Tokyo, JP;
Jiro Iriyama, Tokyo, JP;
Tetsuya Kajita, Tokyo, JP;
Hiroo Takahashi, Tokyo, JP;
Tatsuji Numata, Tokyo, JP;
Daisuke Kawasaki, Tokyo, JP;
Ryuichi Kasahara, Tokyo, JP;
Jiro Iriyama, Tokyo, JP;
Tetsuya Kajita, Tokyo, JP;
Hiroo Takahashi, Tokyo, JP;
Tatsuji Numata, Tokyo, JP;
Daisuke Kawasaki, Tokyo, JP;
NEC Corporation, Tokyo, JP;
NEC Energy Devices, Ltd., Kanagawa, JP;
Abstract
In a lithium ion secondary battery including a positive electrode, a separator, a negative electrode, and a package body, the negative electrode includes simple substance silicon as a negative electrode active material, and a negative electrode binder, and is doped with lithium, and the following formulas (1) and (2) are satisfied:1.2≦≦1.9  (1)1.0</()<1.6  (2)wherein an amount of lithium inserted into the negative electrode until the negative electrode reaches a potential of 0.02 V with respect to metal lithium is M(a number of atoms), an amount of lithium released from the positive electrode until the positive electrode reaches a potential of 4.3 V with respect to metal lithium is M(a number of atoms), and an amount of lithium with which the negative electrode is doped is M(a number of atoms).