Membranes with novel highly-delocalized sulfonylimide anions for lithium-ion batteries

Abstract

Cation-exchange membranes containing sulfo R–SO3M and sulfonylimide functional groups [R–SO2NSO2–X]M, where X=CCl3, CF3, Ph, p-NO2Ph, p-CF3Ph and M+=Li/Na/H, have been synthesized by the Hinsberg reaction from the polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene block copolymer. The obtained membranes have been characterized using ATR IR spectroscopy, CHNS elemental analysis, TGA, DSC, SEM and X-ray diffraction analysis, as well as mechanical properties were determined. Ionic conductivity of plasticized polymer electrolytes, containing mixtures of ethylene carbonate, propylene carbonate and ethylene carbonate, dimethylacetamide were investigated by impedance spectroscopy. It was demonstrated that membranes containing trifluorosulfonylimide functional groups have the highest ionic conductivity. The maximum ionic conductivity at 25 °C was observed for the membrane in contact with an ethylene carbonate – dimethylacetamide mixture.