IONIC LIQUID ELECTROLYTE FOR LITHIUM-ION BATTERIES

Described herein is a method of preparing an ionic liquid comprising a nitrogen or phosphorus cation and a bis(fluorosulfonyl)imidate (FSI) counter anion; the method comprising contacting a precursor selected from the group consisting of a tertiary amine, a tertiary phosphine, and an aromatic nitrogen heterocycle, with an alkyl bis(fluorosulfonyl)imidate in an aprotic solvent to alkylate the nitrogen or phosphorus of the precursor, and directly form a nitrogen or phosphorus cation with an FSI counter anion.