Nanocomposite solid polymeric electrolyte of 49% poly(methyl methacrylate)-grafted natural rubber–titanium dioxide–lithium tetrafluoroborate (MG49-TiO2-LiBF4)

Abstract

A nanocomposite polymer electrolyte consisting of 49% poly(methyl methacrylate)-grafted natural rubber (MG49) as a polymer matrix, lithium tetrafluoroborate (LiBF4) as a dopant salt, and titanium dioxide (TiO2) as an inert ceramic filler was prepared by solution casting technique. The ceramic filler, TiO2, was synthesized in situ by a sol–gel process. The ionic conductivity was investigated by alternating current impedance spectroscopy. X-ray diffraction (XRD) was used to determine the structure of the electrolyte, and its morphology was examined by scanning electron microscopy (SEM). The highest conductivity, 1.4 × 10−5 S cm−1 was obtained at 30 wt.% of LiBF4 salt addition with 6 wt.% of TiO2 filler content. Ionic conductivity was found to increase with the increase of salt concentration. The optimum value of conductivity was found at 6 wt.% of TiO2. The XRD analysis revealed that the crystalline phase of the polymer host slightly decreased with the addition of salt and filler. The SEM analysis showed that the smoother the surface of the electrolyte, the higher its conductivity.