| Project/Area Number |
01550600
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機工業化学
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| Research Institution | Kyoto University |
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Principal Investigator |
NAKAJIMA Tsuyoshi Kyoto University Faculty of Engineering Associate Professor, 工学部, 助教授 (50026233)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1989: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Graphite Oxide / Lithium Battery / Intercalation / Fluorination |
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| Research Abstract |
Graphite oxide has been synthesized by Hummers, Staudenmeier and Brodie methods and fluorinated by fluorine gas and mixtures of VF_5+F_2 and SbF_5+F_2 at temperatures between 20 ^ﾟC and 200^ﾟC. Optimum fluorination temperature increased from 50^ﾟC to 100^ﾟC for graphite oxide prepared by Hummers, Staudenmeier and Brodie methods in that order. Perfect fluorination was difficult, but X-ray diffraction showed that the repeat distance along c-axis of fluorinated graphite oxide was 8.5-9 A, almost the same as that of stage 2 type graphite fluoride (c_2F)_n. At the same time the lattice parameter along a-axis increased from 2.48 A to 2.50 A consistent with that for (C_2F)_n. IR spectrum indicated a strong absorption at 1200 cm corresponding to C-F bonding. These data coincide with the stage 2 type structure model of graphite oxide.
The cathodic behavior of fluorinated graphite oxide has been investigated in propylene carbonate-1 M LiCLO_4 solution with Li negative electrode. With increasing crystallinity of graphite oxide, the capacities and flatness of the discharge potentials of fluorinated graphite oxide were impro ved.
Comparison of the structures of ionic intercalation compounds of transition metal fluorides and oxide fluorides with that of graphite oxide suggested that the covalency of C-O bond in graphite oxide is not as high as that of graphite fluoride.
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