Physical and Electrolytic Properties of Monofluorinated Ethyl Acetates and Their Application to Lithium Secondary Batteries

Abstract

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 LiPF 6 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|LiCoO 2 coin cell at high cycle numbers.

Fluorine and Lithium: Ideal Partners for High‐Performance Rechargeable Battery Electrolytes

“…Although acetate‐containing electrolytes decrease the internal resistance of LIBs, they suffer from a low oxidative stability compared to the SOTA counterparts . The effect of fluorination as well as the impact on the fluorination position in case of ethyl acetates (Scheme ) have been evaluated.…”

The effect of different organic solvents on sodium ion storage in carbon nanopores

“…and EMC, in different neutral and charged nanopores. The EMC solvent has a low dielectric constant (2.93) [39] and a low dipole moment in contrast to the EC and PC solvents. However, EMC viscosity is low (0.65 cP at 25 0 C [10]) thus leading to Na + transport number of 0.44 [11] same to that in PC solvent, and lower than that in EC solvent (0.49).…”

Physical and Electrochemical Properties of Fluorinated Dialkyl Ethers

“…3 We synthesized FETFEE from 2-fluoroethyl ptoluenesulfonate and 2-(2,2,2-trifluoroethoxy)ethanol in acetonitrile in the presence of sodium hydroxide in a yield of about 23%. 2-fluoroethyl p-toluenesulfonate was prepared by reaction of 2-fluoroethanol with p-toluensulfonyl chloride in pyridine in a yield of about 70%.…”

“…3,[5][6][7] We measured relative permittivities (¾ r ) or relative dielectric constants by the use of a LF impedance analyzer (Hewlett Packard, 4192A) that was connected to a thermostat (Ando Denki, TO-9). The electrostatic capacitances of air (C 0 ) and a sample (C sample ) were measured separately at a frequency of 1 MHz.…”

“…Partially fluorinated solvents exert the polar effect on the physical and electrochemical properties such as relative permittivity, viscosity, electrolytic conductivity, and electrochemical stability. 3 In contrast, polyfluorinated and perfluorinated organic solvents show low polarity. The individual dipole moments of the C-F bonds are canceled in the molecule resulting in low relative permittivity.…”