Ethylene Carbonate (EC)-Propyl Acetate (PA) Based Electrolyte for Low Temperature Performance of Li-Ion Rechargeable Batteries

Abstract Charge-discharge performance at −30 °C was studied by using low-viscosity ester solvents (propyl acetate (PA), propyl propionate (PP), and ethyl propionate (EP)) as electrolyte for improving the low-temperature performance of lithium-ion rechargeable batteries. Among the studied ester, PA based electrolyte shows the most superior cycle stability, and it was found that EC-PA based electrolyte increased the discharge capacity of the cell at −30 °C by 6% compared to the EC-DEC based electrolyte. Although the cell capacity at low temperature was increased, favorable solid electrolyte interface (SEI) may not be formed and the cycle stability was decreased in the cell using PA component as the electrolyte. By using an electrolyte additive for SEI formation in combination with PA based electrolyte, the low temperature discharge capacity and cycle stability were much increased which is strongly demanded for electric vehicle application.