2013 Fiscal Year Final Research Report
Physical and electrolytic properties of organofluorine compounds and their application to lithium secondary batteries
| Project/Area Number |
23750221
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Functional materials/Devices
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| Research Institution | Tokyo Polytechnic University |
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Principal Investigator |
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| Project Period (FY) |
2011 – 2013
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| Keywords | 有機フッ素化合物 / リチウム電池 |
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| Research Abstract |
A trifluoromethyl group (CF3-) is a strong electron-withdrawing substituent. The trifluoromethyl is much larger than a methyl group. We have investigated the physical and electrolytic properties of trifluorinated linear ethers as solvents and their application to lithium secondary batteries. We synthesized trifluorinated linear diether (TFEME) and trifluorinated linear triether (TFEMEE). The mass densities, relative permittivities, viscosities, and anodic stabilities of TFEME and TFEMEE were higher than those of the corresponding nonfluorinated linear ethers. The presence of the trifluomethyl group can weaken the attractive forces between molecules. The kinematic viscosities of TFEME and TFEMEE were as low as those of the corresponding nonfluorinated linear ethers especially at high temperatures. The use of an ethylene carbonate (EC)-TFEME or an EC-TFEMEE binary mixture improved the cycling efficiency of a lithium anode and the discharge capacity of a Li|LiCoO2 coin cell.
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