Guar gum based nanocomposite gel polymer electrolytes for energy storage applications

Abstract

The primary applications of polymeric electrolytes are in rechargeable lithium-ion batteries, offering an alternative to traditional liquid electrolytes. Their benefits, including prevention of electrolyte leakage, higher energy density, flexible geometry, and enhanced safety, have spurred significant research into lithium polymer batteries and other electrochemical devices such as supercapacitors, electrochromic windows, and sensors. This thesis focuses on the synthesis of nanocomposite gel polymer electrolytes (NCGPEs) of bio-polymer guar gum (GG) using TiO2, SiO2, and Al2O3as filler materials. The variation in the composition of nanofillers in polymer electrolytes noticeably affects characteristics such as ionic conductivity, surface morphology, electrochemical stability, and interfacial stability. newlineThis research involves synthesizing NCGPEs with GG as the base materials and nanofibers of TiO2, SiO2, and Al2O3 as fillers. The resulting nanocomposite polymer electrolytes are characterized by various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and universal testing machine (UTM).Additionally, the incorporation of nanofibers enhances the electrochemical and interfacial properties of the nanocomposite gel polymer electrolytes. Density functional theory (DFT) simulations are employed to investigate the ion transport paths in guar gum upon exposure to nanofibers. newline newlineChapter 1 provides an overview of different types of polymer electrolytes, including solid polymer electrolytes (SPEs), gel polymer electrolytes (GPEs), and composite polymer electrolytes (CPEs), along with their historical development. It also includes a brief description of ion transport models, concluding with the problem statement and objectives of the current work. newline