CPC H01M 10/0567 (2013.01) [H01M 10/0525 (2013.01); H01M 10/0568 (2013.01); H01M 10/4235 (2013.01); H01M 2300/0025 (2013.01)] | 12 Claims |
1. A flame retardant lithium secondary battery electrolyte comprising at least one compound of a fluoro carbonate compound represented by the following chemical formula 1 or a fluoro ester compound represented by the following chemical formula 2, and further comprising a cyclic carbonate compound represented by the following chemical formula 3, and a lithium salt including any one or mixtures of two or more selected from the group consisting of LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAlO4, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2, LiN(CxF2x+1SO2)(CyF2y+1SO2)(provided that x and y are 0 or natural number), LiCl, LiI, LiSCN, LiB(C2O4)2, LiF2BC2O4, LiPF4(C2O4), LiPF2(C2O4)2, and LiP(C2O4)3:
In chemical formula 1, R1 and R2 are each independently hydrogen, fluoro or CHxF(3-x) (x is 0, 1, 2, or 3), hydrogens connected to the carbon Ca and carbon Cb can be independently substituted with fluoro, an C1-C3 alkyl group, or a C1-C3 fluoroalkyl group, and n is 1, 2, or 3, and includes at least one fluoro;
In chemical formula 2, R1 is hydrogen, R2 is hydrogen, fluoro or CHxF(3-x) (x is 0, 1, 2, or 3), n of Ca is 1, hydrogens connected to the carbon Cb are each independently substituted with fluoro, an C1-C3 alkyl group, or a C1-C3 fluoroalkyl group, and n of Cb is 1, 2, or 3, and includes at least one fluoro; and
In chemical formula 3, R1 and R2 are each independently hydrogen or a C1-C4 alkyl group,
wherein, when the flame retardant lithium secondary battery electrolyte comprises the fluoro carbonate compound represented by the above-mentioned chemical formula 1 and the cyclic carbonate compound represented by the above-mentioned chemical formula 3, the fluoro carbonate compound represented by the above-mentioned chemical formula 1 and the cyclic carbonate compound represented by the above-mentioned chemical formula 3 are mixed at a volume ratio of 0.5:9.5 to 9.5:0.5,
when the flame retardant lithium secondary battery electrolyte comprises the fluoro ester compound represented by the above-mentioned chemical formula 2 and the cyclic carbonate compound represented by the above-mentioned chemical formula 3, the fluoro ester compound represented by the above-mentioned chemical formula 2 and the cyclic carbonate compound represented by the above-mentioned chemical formula 3 are mixed at a volume ratio of 0.5:9.5 to 9.5:0.5.
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