Electrospun poly[(vinylidene fluoride)-co-hexafluoropropylene]/silica (PVdF-HFP/SiO2) nanocomposite polymer membranes (esCPMs) were prepared by incorporating different weight percentages of SiO2 nanoparticles onto electrospun PVdF-HFP by electrospinning technique. The surface morphology of electrospun PVdF-HFP nanocomposite membranes was characterized by scanning electron microscopy. The effect of SiO2 nanoparticles incorporation onto electrospun PVdF-HFP polymer membranes (esPMs) has been studied by XRD, DSC, TGA, and tensile analysis. The electrospun PVdF-HFP/SiO2 based nanocomposite membrane electrolytes (esCPMEs) were prepared by soaking the corresponding esCPMs into 1 M LiPF6 in EC:DMC (1:1 vol/vol %). The ionic conductivity of the esCPMEs was studied by AC-impedance studies and it was found that the incorporation of SiO2 nanoparticles into PVdF-HFP membrane has improved the ionic conductivity from 1.320 x 10(-3) S cm(-1) to 2.259 x 10(-3) S cm(-1). The electrochemical stability of the esCPME was studied by linear sweep voltammetry studies and it was found to be 2.87 V. Finally, a prototype LiCo0.2Mn1.8O4//C Li-ion capacitor (LIC) cell was fabricated with esCPME, which delivered a discharge capacitance of 128 F g(-1) at the current density of 1 A g(-1) and retained 86% of its discharge capacitance even after 10,000 cycles. These results demonstrated that the esCPMEs could be used as promising polymer membrane electrolyte for LICs. (C) 2017 Wiley Periodicals, Inc.