Solid Biopolymer Electrolytes Based Carboxymethyl Cellulose Doped with Ammonium Fluoride: Ionic Transport and Conduction Mechanism

Abstract

A series of solid biopolymer electrolytes (SBEs) based carboxymethyl cellulose doped with different weight percentage of ammonium fluoride, NH₄F were prepared by the solution cast technique. The ionic conductivity was investigated using electrical impedance spectroscopy in the frequency range of 5 0Hz – 1 MHz. The highest ionic conductivity of 2.68 × 10⁻⁷ Scm⁻¹ (9 wt.% NH₄F) was obtained at ambient temperature. The ionic mobility and diffusion coefficient of charge carriers were identified to influence the enhancement of ionic conductivity in SBE samples. The exponent s of SBE samples were determined using Joncher's Universal Power Law. The conduction mechanism of the most conductive SBE sample can be represented by quantum mechanical tunnelling model.