Non-aqueous polymer electrolytes containing room temperature ionic liquid: 2,3-dimethyl-1-octylimidazolium tetrafluoroborate

Ionic liquid: 2,3-dimethyl-1-octylimidazolium tetrafluoroborate (DMOImBF4) has been synthesized and found to be liquid at room temperature (25 °C). This room temperature ionic liquid (DMOImBF4) was incorporated in poly (vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) to obtain films of polymer electrolytes. The addition of ionic liquid, salt (ammonium tetrafluoroborate) and plasticizer (propylene carbonate, PC) has been found to increase the conductivity of polymer electrolytes to 10− 4 S/cm at 25 °C. Line narrowing observed in variable temperature 1H and 19F NMR line width suggests that cations and anions are mobile in these electrolytes. These polymer electrolytes have been found to be thermally stable up to 200–250 °C and hence can be used in various applications at temperature above 100 °C.