A comparative study of ionic liquid and organic solvent based porous polymer electrolytes

Gel polymer electrolyte membranes are prepared by immobilizing two different liquid electrolytes of NaBF4 salt in porous Poly(vinylidene fluoride) PVdF membrane. The liquid electrolytes are prepared in two different solvents, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) ionic liquid and binary mixture of ethylene carbonate (EC) and diethyl carbonate (DEC). The effect of solvents is investigated using electrochemical impedance spectroscopy, linear sweep voltammetry and dc polarization technique. The ionic conductivity of the electrolyte membrane with ionic liquid solvent is observed better (similar to 4.1 x 10(-4) S cm(-1)) with better electrochemical stability window of similar to 4.8 V.