Structural, thermal, and electrical studies on gel polymer electrolytes containing 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

Gel polymer electrolytes containing various concentrations of an ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide in an optimized composition of poly(epsilon-caprolactone) (PCL), and zinc triflate (ZnTr) were prepared by solution casting technique and characterized using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and AC impedance spectroscopic techniques. The occurrence of complexation of polymer host with dopant salt zinc triflate as well as ionic liquid has been confirmed from FTIR results whereas from the present DSC data, it is quite evident that with an increase in the content of ionic liquid, the degree of crystallinity decreases. Complex impedance studies have revealed the occurrence of a maximum electrical conductivity of 1.1 x 10(-4) S cm(-1) at 25 A degrees C in the case of the sample with a composition of 0.375 g PCL:0.125 g ZnTr:0.5 g IL.