New Li-ion electrolytes for low temperature applications

Ethyl acetate and methyl butyrate have been tested as new solvents for Li-ion liquid electrolytes. Specific ternary mixtures have been investigated, containing cyclic carbonate and linear carbonate solvents in addition to the esters. Thanks to their high conductivities, these electrolytes make it possible to obtain very good performances below −30°C, in different LiCoO2graphite cells. Moreover, these electrolyte compositions do not affect cyclability, charge retention of safety of the LiCoO2 cells, behaving as pure carbonate electrolytes.