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. 11, 2014
Filed:
Aug. 22, 2011
Shunsuke Yamada, Ibaraki, JP;
Keita Yamaguchi, Kagawa, JP;
Taisuke Nose, Kagawa, JP;
Hideharu Sato, Ibaraki, JP;
Shunsuke Yamada, Ibaraki, JP;
Keita Yamaguchi, Kagawa, JP;
Taisuke Nose, Kagawa, JP;
Hideharu Sato, Ibaraki, JP;
Mitsubishi Chemical Corporation, Tokyo, JP;
Abstract
To provide a negative electrode material capable of giving a lithium ion secondary battery that is sufficiently small in the charge/discharge irreversible capacity observed at the initial cycle stage, has excellent high-temperature storage characteristics, and reduced in the gas generation at the initial cycle stage as well as during high-temperature storage. A carbon material for lithium ion secondary battery, wherein the surface functional group amount O/C value represented by the following formula 1 is from 1 to 4% and the sum (Cl/C+S/C) of the surface functional group amount Cl/C value represented by the following formula 2 and the surface functional group amount S/C value represented by the following formula 3 is from 0.05 to 0.5%:O/C value (%)=O atom concentration determined based on the peak area of the spectrum of O1s in X-ray photoelectron spectroscopy (XPS) analysis/C atom concentration determined based on the peak area of the spectrum of C1s in XPS analysis×100  Formula 1:Cl/C value (%)=Cl atom concentration determined based on the peak area of the spectrum of Cl2p in XPS analysis/C atom concentration determined based on the peak area of the spectrum of C1s in XPS analysis×100  Formula 2:S/C value (%)=Satom concentration based on the peak area of the peak near 165 eV in the spectrum corresponding to S2p in XPS analysis/C atom concentration determined based on the peak area of the spectrum of C1s in XPS analysis×100  Formula 3.