Ion dynamics and dielectric relaxation behavior of PVA-PVP-NaI-SiO2 based nano-composites polymer blend electrolytes

Abstract

In this paper we have reported the loading effect of SiO2 nano-particles on the electrical transport properties and dielectric relaxation behavior of the PVA-PVP-NaI based nano composite polymer blend electrolytes (NCPBEs). Solution cast technique has been used for the preparation of PVA-PVP-NaI-SiO2 based NCPBE films. AC impedance spectroscopic technique is used for the study of electrical conductivity and dielectric properties. The frequency dependence of AC conductivity with different SiO2 concentration for all prepared NCPBEs obeys the Jonscher power law (JPL) with exponent, n ≥ 1. The dielectric permittivity (ε′&ε″), electric modulus (M′&M″) vs. frequency plots at different concentrations and temperatures were reported. Mobility (μ), dc conductivity (σdc) and total number of charge carriers (N) were estimated and found that mobility varies with the SiO2 concentration. Sample containing 0.6 wt% of SiO2 shows optimum dc conductivity, σdc ~5.07 × 10−6 S/cm with μ ~4.60 × 10−7 and N ~6.98 × 1021. Dielectric relaxation peaks have been observed for all samples and relaxation time (τ) is minimum for 0.6 wt%SiO2 based NCPBE film.