Effect of Ethyl Acetate on Low Temperature Property in Lithium-ion Battery

The commercialized lithium ion secondary batteries using binary mixtures as co-solvent of electrolyte ha O an excellent energy density and cycle performance at room temperature.However, one of disadvantages related to the use of the binary mixtures as co-solvents of electrolyte was capacity fade and cycle life loss of the battery at low tem perature.The effect of adding ethyl acetate as 3rd solvent having a low melting point and low viscosity to enhanced dis charge capacity and cycle life were examined at the low temperature.Studies on low-temperature properties of electrolyte were investigated by using chronpotentiometry, ionic conductivity, cyclic voltammetry, impedance spectroscopy, and lin ear sweep voltammetry.In 1 M LiPF/EC:DEC:EA(4:3:3, v/v) electrolyte added EA as 3rd solvent, the reaction with Li by forming the perfect film on the surface of the carbon anode during charging was restrained and the reduction of ionic conductivity due to low melting point at the low temperature was prevented.Therefore, the electrochemical experiments using this system proved that the electrolyte showed the excellent discharge capacity regardless of the temperature and ethyl acetate was good additives to improve the properties of low temperature in Li ion battery.