Ion transport mechanism and dielectric relaxation behavior of PVA-imidazolium ionic liquid-based polymer electrolytes

Abstract

Solid polymer electrolytes based on poly(vinyl alcohol) (PVA) with different wt% ionic liquid (IL), 1-Butyl-2, 3-dimethylimidazolium tetraflouroborate [BDMITFB] were prepared using the solution cast technique. Prepared samples were characterized using the AC impedance spectroscopic technique. AC conductivity spectra of a PVA-IL-based system at different concentrations/temperatures have been discussed. The fitted AC conductivity spectra using Jonscher's power law (JPL) exhibits the correlated barrier hopping (CBH) type conduction mechanism. The scaled AC conductivity spectra of PVA-IL-based films with temperature/concentrations collapsed into a single master curve indicating the ion conduction mechanism have the same origin. For higher IL loaded samples (20 and 25 wt%) mobility, μ dc conductivity, σ dc as well as total number density of charge carriers, N increases with increasing IL content in PVA. Dielectric permittivity (ϵ′ and ϵ″) and electric modulus (M′ and M″) study of prepared samples has been done. Temperature-dependent dc conductivity for prepared polymeric films follows the Arrhenius type thermally activated process. © 2019 IOP Publishing Ltd.