Ethyl acetate (EA) shows low viscosity for its relative permittivity. Monofluorinated organic solvents exert the polar effect on the various properties. We have investigated the effect of position isomerism on the phy...Ethyl acetate (EA) shows low viscosity for its relative permittivity. Monofluorinated organic solvents exert the polar effect on the various properties. We have investigated the effect of position isomerism on the physical and electrochemical properties of two monofluorinated carboxylates: 2-fluoroethyl acetate (2FEA) and ethyl fluoroacetate (EFA). Relative permittivity of 2FEA was lower than that of EFA, whereas viscosity of 2FEA was higher. Electrolytic conductivity of a LiPF6 solution in 2FEA was lower than that in EFA, but higher than that in EA at high temperatures. The use of 2FEA as a co-solvent improved cycling efficiency and suppressed fading of discharge capacity of a Li|LiCoO2 coin cell at high cycle numbers.展开更多
文摘Ethyl acetate (EA) shows low viscosity for its relative permittivity. Monofluorinated organic solvents exert the polar effect on the various properties. We have investigated the effect of position isomerism on the physical and electrochemical properties of two monofluorinated carboxylates: 2-fluoroethyl acetate (2FEA) and ethyl fluoroacetate (EFA). Relative permittivity of 2FEA was lower than that of EFA, whereas viscosity of 2FEA was higher. Electrolytic conductivity of a LiPF6 solution in 2FEA was lower than that in EFA, but higher than that in EA at high temperatures. The use of 2FEA as a co-solvent improved cycling efficiency and suppressed fading of discharge capacity of a Li|LiCoO2 coin cell at high cycle numbers.
