1-Ethyl-1-methyl piperidinium bis(trifluoromethanesulfonyl)imide as a co-solvent in Li-ion batteries

► A solid ionic liquid (EMP-TFSI) was used as a new co-solvent for Li batteries. ► EMP-TFSI performed better as a co-solvent than MPP-TFSI. ► The 50 wt% EMP-TFSI electrolyte performed as well as a carbonate electrolyte.