Solid Polymer Electrolyte Based on PVDF-HFP and Ionic Liquid Embedded with TiO2Nanoparticle for Electric Double Layer Capacitor (EDLC) Application

Solid polymer electrolytes based on PVDF-HFP polymer and 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and TiO 2 nanoparticle have been prepared for different concentrations of nanoparticles. It is observed that the electrolyte containing 5 wt% of TiO 2 nanoparticle exhibits highest ionic conductivity. Electric double layer capacitor (EDLC) cells have been fabricated with the prepared electrolytes and the activated carbon electrode. The cyclic voltammetric (CV) profiles of the prepared EDLC cells display nearly rectangular shape indicating their capacitive behavior. It is observed that the specific capacitance (147.66 Fg −1 at current density of 0.5 Ag −1 ) of the EDLC cell fabricated with 5 wt% of TiO 2 nanoparticle is higher than that (85.66 F g −1 at current density of 0.5 Ag −1 ) of the EDLC cell without TiO 2 nanoparticle. The specific energy density and power density of the EDLC cell containing 5 wt% of TiO 2 nanoparticle, obtained at a current density of 1 Ag −1 in the first cycle, are 145.82 Wh/Kg and 2.9 kW/Kg respectively with 100% coulomb efficiency. The specific capacitance of the EDLC cell obtained from cyclic voltammetry is in good agreement with the value obtained from the low frequency electrochemical impedance and galvanostatic measurements. The cyclic stability of 1500 cycles of charge-discharge processes has been observed for the EDLCs.