Invention Grant
- Patent Title: Negative electrode material for lithium ion secondary battery and method for producing the same
- Patent Title (中): 锂离子二次电池用负极材料及其制造方法
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Application No.: US12311675Application Date: 2007-11-08
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Publication No.: US08153303B2Publication Date: 2012-04-10
- Inventor: Kenta Ishii
- Applicant: Kenta Ishii
- Applicant Address: JP Tokyo
- Assignee: Tokai Carbon Co., Ltd.
- Current Assignee: Tokai Carbon Co., Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Flynn, Thiel, Boutell & Tanis, P.C.
- Priority: JP2006-305018 20061110
- International Application: PCT/JP2007/072139 WO 20071108
- International Announcement: WO2008/056820 WO 20080515
- Main IPC: H01M4/38
- IPC: H01M4/38

Abstract:
A negative electrode material for lithium ion secondary batteries includes core-shell composite particles prepared by covering the surface of a graphite powder with an amorphous carbon powder via a carbide of binder pitch, the graphite powder having an average particle diameter of 5 to 30 μm and an average lattice spacing d(002) of less than 0.3360 nm, and the amorphous carbon powder having an average particle diameter of 0.05 to 2 μm and an average lattice spacing d(002) of 0.3360 nm or more. A method to produce the negative electrode material includes mixing a graphite powder with pitch having a softening point of 70 to 250° C., adding an amorphous carbon powder to the resulting product, kneading the mixture while applying a mechanical impact to soften the pitch and carbonizing the pitch by heat treatment of the mixture at 750 to 2250° C. in a non-oxidizing atmosphere.
Public/Granted literature
- US20100021820A1 Negative electrode material for lithium ion secondary battery and method for producing the same Public/Granted day:2010-01-28
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