2007 Fiscal Year Final Research Report Summary
Development of carbon nano composite for electrode of high capacity lithium secondary ion batteries
| Project/Area Number |
17560296
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Nagano National College of Technology |
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Principal Investigator |
OSHIDA Kyoichi Nagano National College of Technology, Department of Electronics and Computer Science, Professor (90224229)
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| Co-Investigator(Kenkyū-buntansha) |
OSAWA Kozo Nagano National College of Technology, Department of Electrical and Electronic Engineering, Professor (10176860)
NAKAZAWA Tatsuo Nagano National College of Technology, Department of Electronics and Computer Science, Professor (70126689)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Lithium ion secondary batteries / Negative carbon electrode / Composite / Microscopy / Image analysis |
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| Research Abstract |
In order to improve the capacity and performance of lithium ion secondary batteries (LIBs), we try to develop new carbon composites for negative electrode using high conductive carbon materials from nano carbon and low crystalline carbon which can be expected higher capacity than high crystalline carbons.
The textural and structural changes of each composite material for electrode were observed by optical microscopy and transmission electron microscopy. The structure of polyparaphenylene (PPP)-based carbons is analyzed by high energy X-ray diffraction at Spring-8 (Japan Synchrotron Radiation Research Institute (JASRI)). The results shows that the PPP-based carbon consists of basic structural units (BSUs) of which size is about 0.7 nm and the BSUs increase slightly up to over 1 nm with increasing of heat treat temperature from 600 to 900℃. The results show the PPP-based carbon is non graphitized carbon. Nano spaces are formed among the BSUs. Ii is estimated that Li ions are trapped in the nano spaced since the interlayer spacing of hexagonal layers not increase when LIBs are charge. While the nano spaces are contributed to high capacity of LIBs using PPP-based carbon, the discharge energy from the nano space reduces the performance of it. The composite of PPP-based carbon and nano carbons can reduce electric resistance with high capacity maintained.
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