Dielectric Study of Gel Polymer Electrolyte Based on PVA-K2CO3-SiO2

Abstract

In this study, effect of filler (SiO2) on dielectric and electrical properties of gel polymer electrolyte (GPE) based on PVA-K2CO3 has been investigated and reported. The electrolyte were prepared by incorporating silica particle as a filler into the un-plasticized electrolyte (PVA-K2CO3). The prepared electrolyte were characterized physicochemically (FTIR) and electrochemically based on electrochemical impedance spectroscopy (EIS). Based on the impedance spectroscopy, complex permittivity (ε*) (dielectric constant and loss) and complex electrical modulus (M*) (real and imaginary modulus) were calculated. Characterization result indicate that SiO2 particles has successfully interacts with PVA-K2CO3 in the form of a three dimensional polymeric network. At low frequencies, high values of complex permittivity (dielectric constant and dielectric loss) were observed, which increased with increasing temperature, signifying an increase in ionic conductivity of the electrolyte. With the incorporation of filler, the peaks of both ε* and M* shifts towards higher frequency side suggesting the speed up the relaxation time. From the electrical modulus, the developed electrolyte is shown to be highly capacitive in nature. Based on the peak shape of the imaginary part of electric modulus, the non-Debye type relaxation predicted. Analysis of both dielectric permittivity and electrical modulus suggest that ionic and polymer segmental motions are strongly coupled. An optimum ionic conductivity of 3.25 × 104 mScm1 was achieved at ambient temperature at a composition of 15 wt.% SiO2 (PKS15).