Investigations of Zinc Ion Dissociation in Gel Polymer Electrolytes Based on Poly(vinyl chloride) and Poly(ethyl methacrylate) Blend on the Addition of Two Different Ceramic Nanofillers

Abstract

Two series of nanocomposite gel polymer electrolytes (NCGPEs) have been prepared by simple solution casting method comprising of chosen nano-sized ceramic fillers [Alumina (Al2O3), Titania (TiO2)] dispersed into [poly(vinyl chloride) (PVC)/poly(ethyl methacrylate) (PEMA)] blend-based gel doped and plasticized with zinc triflate [Zn(OTf)2] salt and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) ionic liquid. The role of various concentrations of two different inorganic nanofillers on the structural and complex formation of the gel polymer electrolytes (GPEs) were explored from X-ray diffraction (XRD), Attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetric (DSC) analyses, respectively. All the composite electrolyte films were subjected to ac impedance analysis and changes in the ionic conductivity as a function of the type of filler added was analyzed at ambient temperature. These electrolytes demonstrated superior electrochemical properties with an exceptional electrochemical window exceeding ~ 4 V versus Zn/Zn2+, good voltammetric reversibility and zinc ion transference number averaging above ~ 0.63. Thermal stability of the samples was examined using thermogravimetry (TG) analysis whereas the variations in the surface morphology of the preferred samples owing to the incorporation of two distinct nanofillers were analyzed using scanning electron microscopy (SEM) study.