The Structural and Electrical properties of Guar Gum based Green Electrolyte

Abstract Guar gum is an environmental tree-based natural polymer with a large molecular weight. Guar gum polymer electrolytes are new materials that are being developed for the applications of electrochemical devices such as supercapacitors, high energy density batteries, fuel cells, electrochromic displays, etc. The solution casting method has been employed to prepare solid-state composite Green-polymer electrolytes using Guar gum, Zinc Sulphate heptahydrate salt (ZnSO4.7H2O). These synthesized polymer electrolytes have been studied by using X-Ray Diffraction(XRD), Fourier Transformation Infrared (FTIR), Differential scanning calorimetry (DSC), Scanning Electron Microscope(SEM), and Electrical impedance Spectroscopy(ESI) techniques. The addition of the zinc (ZnSO4.7H2O) salt, to withstand the ion movement in composite guar gum matrix electrolyte was the main investigation in the present work. The complexation of polymer and salt was confirmed by the FTIR. The phase transition and amorphous nature were confirmed by X-Ray Diffraction (XRD). The glass transition temperature was calculated for all samples by using a DSC study. The scanning electron microscopy(SEM) technique investigated that the surface exhibited anisometric morphology (spherical and elongated)for pure guar gum and while in the composite polymer, bounded the salt ion within the guar gum matrix. The ionic conductivity was calculated using bulk resistance at room and different temperatures. The maximum ionic conductivity is 2.5x10− 5 S/cm at 100oC for a pure guar gum sample, while with the addition of the salt guar gum, a non-linear variation of the conductivity was found. The long tail in dielectric constant(εʹ(ω)) and loss (εʺ(ω) analysis was refect the bulk capacitance nature of the sample. The non-Deby behavior and relaxation process was studied by dielectric modulus parameters.