Ionic conductivity and dielectric behavior of PEO-based silver ion conducting nanocomposite polymer electrolytes

Abstract

Solid nanocomposite polymer electrolytes based on polyethylene oxide (PEO), AgNO3 as salt, and nanosized Fe2O3 (less than 50 nm size) as filler are prepared by hot press method. In (100-x) PEO:xAgNO3 system (where x = 5 ≤ x ≤ 50 wt%), the solid polymer electrolyte 90PEO:10AgNO3 gives highest ionic conductivity. This composition is further used as host matrix and Fe2O3 as filler for the preparation of solid nanocomposite polymer electrolytes (100-x) (90PEO:10AgNO3):xFe2O3 (where x = 5 ≤ x ≤ 30 wt%). The real impedance (Z') and imaginary impedance (Z") of the samples are analysed using LCR meter. The maximum ionic conductivity is observed for 10 wt% of filler Fe2O3. The optimum conducting composition 90(90PEO:10AgNO3):10Fe2O3 is used for further study. The dielectric response of the samples is analysed using dielectric constant (e'), dielectric loss (e"), loss tangent (tanδ), and real and imaginary part of electric modulus (M' and M"). The ionic conductivity and dielectric response of the solid nanocomposite polymer electrolytes are studied within the frequency range of 100 Hz–5 MHz and within the temperature range of 300–323 K. It is observed that the dielectric constant rises sharply towards low frequencies due to electrode polarization effects. The maxima of the loss tangent (tan δ) shift towards higher frequencies with increasing temperature. The enhancement in ionic conductivity is observed when nanosized Fe2O3 filler is added into the solid polymer electrolyte.