TITLE:
Physical and Electrolytic Properties of Monofluorinated Ethyl Acetates and Their Application to Lithium Secondary Batteries
AUTHORS:
Noritoshi Nambu, Yukio Sasaki
KEYWORDS:
Monofluorinated Organic Solvent, Carboxylate, Position Isomerism, Electrolytic Properties, Discharge Capacity, Lithium Secondary Battery
JOURNAL NAME:
Open Journal of Metal,
Vol.5 No.1,
April
30,
2015
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 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.