Morphology and Transport Properties of Polyethylene Oxide (PEO)-based Nanocomposite Polymer Electrolytes

Abstract

Magnesium Oxide (MgO) Nanoparticles (Nps) synthesized by microwave-assisted coprecipitation method was added as a nanoscale filler together with sodium thiocyanate (NaSCN) into poly (ethylene oxide) (PEO) to form PEO-MgO/NaSCN Nanocomposite Polymer Electrolytes (NCPEs). The MgO Nps were characterized by Scanning Electron Microscopy (SEM). The effect of the incorporation of MgO Nps and dispersion of NaSCN on the morphology and transport properties of Nanocomposite Polymer Electrolytes (NCPEs) were studied employing Fourier Transform Infra-Red (FTIR) Spectroscopy, Optical Microscopy (OM) and ionic conductivity measurement. The FTIR spectroscopy confirmed the existence of strong interfacial interaction between PEO and MgO Nps as the pristine polymer matrix are uniformly interspersed with MgO Nps showing strong absorption bands for the polymer and the MgO NPs. The optical microscopy results showed that the microstructural evolution of pristine PEO polymer is as a result of incorporation and intercalation of MgO Nps and NaSCN proton donor respectively. The temperature dependence of ionic conductivity of the NCPEs seems to follow an Arrhenius-type, thermally activated process with activation energies reducing with increase in nanosized filler content. This can be attributed to the smooth transport of Na+ along several crystalline grains and amorphous grain boundaries.