Structural, thermal, and impedance properties of a gel polymer electrolyte containing ionic liquid

The gel polymer electrolytes composed of ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF(4)) and the copolymer of acrylonitrile (AN), methyl methacrylate (MMA), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) are synthesized and characterized by FT-IR spectra, TGA, DSC, and AC impedance measurements. IR spectra show that there is an interaction between PEO side chains of the copolymer and imidazolium cations. TGA measurements indicate that the gel polymer electrolytes are stable until 120 degrees C. By using the equivalent circuit proposed, the experimental data and the simulated data fit very well. The bulk resistance R-b is found to decrease with the increase in BMImBF(4) content. Copyright (C) 2009 John Wiley & Sons, Ltd.