Ionic liquid based polymer gel electrolyte membranes for lithium ion rechargeable batteries

Abstract

Li-ion conducting polymeric membranes containing 1-butyl-3-methylimidazolium tetrafluroborate (BMIMBF4), polymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), and Lithium bis(trifluoromethanesulfonyl)imide) (LiTFSI) salt have been synthesized and characterized by various techniques. The synthesized polymeric membrane have good free-standing characteristics, good thermal stability (300-400 °C) and also have a wide electrochemical window (ECW) ∼ 4.0 to 4.50V. The room temperature ionic conductivity of the membrane (PVdF-HFP+20 wt.% LiTFSI) + 60% BMIMBF4 was found to be 1.7mS.cm-1. © The Electrochemical Society.