Studies on structural, dielectric and charge transport properties of PVA:LiBr solid polymer electrolyte films

In the present study, solid polymer electrolytes (SPEs) based on poly (vinyl alcohol) (PVA) doped with lithium bromide (LiBr) were prepared by solution casting method. Fourier transform infrared spectroscopy results affirm the complexation of LiBr with PVA. X-ray diffraction results exhibit the increase of amorphous nature of the polymer electrolytes, which is also observed in scanning electron microscopy images and atomic force microscopy topographs. Thermogravimetric analysis thermographs endorse the increase of thermal stability of the polymer due to doping. Dielectric studies exhibit non-Debye nature of the polymer electrolytes. Conductivity spectra reveal the maximum ionic conductivity (1.15 × 10⁻⁴ S/cm) for 20 wt% LiBr/PVA electrolyte at ambient temperature. Impedance analysis reveals the decrease of ionic relaxation in the polymer electrolytes and the studied transport properties of the electrolyte show that the major contribution to the conduction in this polymer electrolyte is ions.