Conductivity, XRD, and FTIR Studies of New Mg2+-ion-conducting Solid Polymer Electrolytes: [PEG: Mg(CH3COO)2]

Solid polymer electrolytes based on poly (ethylene glycol) (PEG) doped with Mg(CH3COO)2 have been prepared by using the solution-casting method. The X-ray diffraction patterns of PEG with Mg(CH3COO)2 salt indicated a decrease in the degree of crystallinity with increasing concentration of the salt. The complexation of Mg(CH3COO)2 salt with the polymer was confirmed by using Fourier transform infrared spectroscopy (FTIR) studies. The ionic conductivity was measured for the [PEG: Mg(CH3COO)2] system in the frequency range 50 Hz - 1 MHz. The addition of Mg salt was found to improve the ionic conductivity significantly. The 15-wt-% Mg(CH3COO)2-doped system had a maximum conductivity of 1.07 ?10−6 S/cm at 303 K. The conductance spectrum shows two distinct regions: a dc plateau and a dispersive region. The temperature dependence of the ionic conductivity reveals the conduction mechanism to be an Arrhenius-type thermally activated process.