Comparative study of the optical and dielectric properties of PVA and silver-doped PVA

Abstract

Electrolytes stand as essential components in electrochemical energy storage devices, with their physical and chemical characteristics significantly impacting device performance. Selecting the right electrolyte is pivotal for ensuring the safety and efficiency of super capacitive devices. This work explores the utilization of polyvinyl alcohol (PVA) as a host polymer in solid polymer electrolytes (SPEs) for supercapacitors and other energy storage devices. PVA based solid polymer electrolytes were synthesized by a simple casting method and investigated the effect on structural, optical and dielectric properties of polyvinyl alcohol (PVA) thin films with Ag doping. The XRD data confirms that silver-doped samples exhibit reduced crystallinity in comparison to PVA films that are pure. As a result of this decrease in crystallinity, silver-doped PVA samples exhibit improved electrical transport characteristics, making them excellent choices for Solid Polymer Electrolytes (SPE). An analysis of UV–VIS spectroscopy in silver-doped materials verifies SPR peaks at 424 nm. Exploration of the dielectric properties and frequency dependence was conducted at room temperature and silver doped samples shows higher dielectric constant values compare to pure PVA. The complex electric modulus M* of the prepared samples was also derived. The correlation between M' and M'' describes the nature of the relaxation process within the PVA/Ag NPs nanocomposite films, revealing a semicircular pattern that aligns with the Debye model.