发明名称 |
GRAPHITE POWDER SUITABLE FOR NEGATIVE ELECTRODE MATERIAL OF LITHIUM ION SECONDARY BATTERIES |
摘要 |
A graphite powder has surface closed-end structures in which the graphite c-plane layers of the graphite layer crystal lattices have closed-ends on the surface of the graphite powder by linking the ends of one or more pairs of the c-plane layers, leaving interstices which are open on the surface of the graphite. The number of open interstices is at least 100 and at most 1500 per micrometer in a c-axis direction of the graphite. Preferably, the graphite powder has a specific surface area of 1.0 m2/g or less. Such a graphite powder can be prepared either by graphitizing a carbon material, which has been pulverized at a high speed under well-controlled conditions before and/or after the carbonization, or by subjecting a carbon material, which has been pulverized under well-controlled conditions before and/or after the carbonization, to graphitization and then to oxidative heat treatment at a temperature of 600 - 800.degree.C and finally to heat treatment at a temperature of 800.degree.C or higher in an inert gas. The graphite powder can be used to produce negative electrodes of lithium ion secondary batteries having a high discharge capacity of at least 320 mAh/g and a high charge/discharge coulombic efficiency of at least 90%. |
申请公布号 |
CA2247319(C) |
申请公布日期 |
2002.12.24 |
申请号 |
CA19972247319 |
申请日期 |
1997.12.25 |
申请人 |
SUMITOMO METAL INDUSTRIES, LTD.;SONY CORPORATION |
发明人 |
KAMEI, KAZUHITO;KAMINAKA, HIDEYA;NEGI, NORIYUKI;ABE, MASARU;YONEMURA, MITSUHARU;MORIGUCHI, KOJI |
分类号 |
C01B31/04;H01M4/587;H01M4/62;H01M6/10;H01M10/05 |
主分类号 |
C01B31/04 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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