Research on low temperature electrolyte for Li-ion batteries

The solvent composition of electrolyte was a key factor in determining the low temperature performance of Li-ion batteries. To develop the high conductive electrolyte at low temperature,the binary and multicomponent solvent systems were studied based on the mixed solvent of cyclic ethyl carbonate (EC) and several aliphatic alkyl carbonates and the conduction behaviors of these electrolytes were also investigated. The results showed that the quaternary solvents consisting of ethylene carbonate(EC),dimethyl carbonate(DMC),ethyl methyl carbonate(EMC) and diethyl carbonate(DEC) had the highest ion conductivity below -30?℃, and the batteries using these quaternary electrolytes could deliver over 59% of the discharge capacity at room temperature at 0.1?C rate and -40?℃.