Ion Transport and Dielectric Studies on [PEO:TiO₂]:NH₄SCN Nanocomposite Polymer Electrolytes

Abstract

An improvement in ion transport behavior and dielectric properties of polyethylene oxide based polymer electrolytes have been investigated upon the dispersal of TiO 2 nanoparticles. TiO 2 nanoparticle is synthesized with the help of well-known sol-gel technique. The different compositions of polymer electrolyte systems are prepared by the solution cast technique. Nanocomposite polymer electrolytes (NCPEs) films are synthesized by loading of nanoTiO 2 particle in a pristine polymer electrolyte matrix. The structural and morphological behaviors of nanocomposite polymer electrolytes (NCPEs) have been subsequently characterized by XRD and SEM studies. The ionic behavior of synthesized NCPEs is ascertained by Wagner's polarization technique. AC and DC conductivity of polymer electrolyte films have been carried out using impedance spectroscopic techniques. Dielectric relaxation studies of polymer electrolytes are examined using impedance spectroscopic data. The conductivity relaxation mechanism of NCPEs has been concluded with the help of modulus formalism. DC conductivity of best ion-conducting NCPEs at room temperature has been found to 𝝈 = 2.5 × 10 −5 S cm −1 . The electrode polarization effect has completely vanished in the dielectric and modulus formalism and the conductivity scaling data show a single master curve observed in ion dynamics. The change in ionic conductivity with frequency and temperature is studied by impedance spectroscopic investigations. The effect of salt on dielectric parameters of NCPEs is also extracted from impedance spectroscopic data to explore underlying ion dynamics.Recently, nanocomposite polymer electrolytes (NCPEs) have received very much attention, owing to their potential application in advanced electrochemical devices such as high-performance solid-state ionic batteries, efficient energy conversion devices, [1][2][3][4][5] etc. NCPEs have several advantages over liquid electrolytes such as good mechanical properties, better thermal stability, less corrosion, lightweight, flexibility and ease of fabrication, easy to processibility as thin films of suitable size, and it can perform a