Synthesis of new fluorinated imidazolium ionic liquids and their prospective function as the electrolytes for lithium-ion batteries

•Green pathway to prepare fluorinated ionic liquids.•1-(2,2,2-Trifluoroethyl)-3-methylimidazolium tosylate.•1-(2,2,2-Trifluoroethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.•Both will be prospective electrolytes for lithium batteries.•[CF3CH2MIm][Tf2N] even showed a wider electrochemical window.

Two fluorine-containing ionic liquids, 1-(2,2,2-trifluoroethyl)-3-methylimidazolium tosylate and 1-(2,2,2-trifluoroethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (TFSI anion), were obtained in good yields and high purity via a green pathway procedure free of solvent and hazardous catalyst. The incorporation of CF3 moieties in imidazolium structure decreases the ILs TFSI melting point. The preliminary electrochemical results are very promising, a wide electrochemical stability up to 5.7 V vs Li+/Li for the fluorinated imidazolium with TFSI anion.

Graphical abstractTwo fluorine-containing ionic liquids, 1-(2,2,2-trifluoroethyl)-3-methylimidazolium tosylate and 1-(2,2,2-trifluoroethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (TFSI anion), were obtained in good yields and high purity via a green pathway procedure free of solvent and hazardous catalyst. The incorporation of CF3 moieties in imidazolium structure decreases the ILs TFSI melting point. The preliminary electrochemical results are very promising, a wide electrochemical stability up to 5.7 V vs Li+/Li for the fluorinated imidazolium with TFSI anion.Figure optionsDownload full-size imageDownload as PowerPoint slide