Impedance and Dielectric Properties of PVC:NH4I Solid Polymer Electrolytes (SPEs): Steps toward the Fabrication of SPEs with High Resistivity

In the present article, a simple technique is provided for the fabrication of a polymer electrolyte system composed of polyvinyl chloride (PVC) and doped with varying content of ammonium iodide (NH₄I) salt using solution-casting methodology. The influences of NH₄I on the structural, electrochemical, and electrical properties of PVC have been investigated using X-ray diffraction, electrochemical impedance spectroscopy (EIS), and dielectric properties. The X-ray study reveals the amorphous nature of the polymer-salt complex. The EIS measurement revealed an ionic conductivity of 5.57 × 10^-10 S/cm for the electrolyte containing 10 wt.% of salt. Our hypothesis is provided, which demonstrated the likelihood of designing highly resistive solid electrolytes using the concept of a polymer electrolyte. Here, the results showed that the resistivity of the studied samples is not dramatically decreased with increasing NH₄I. Bode plots distinguish the decrease in resistance or impedance with increasing salt contents. Dielectric measurements revealed a decrease in the dielectric constant with the increase of NH₄I content in the PVC polymer. The relaxation time and dielectric properties of the electrolytes confirmed their non-Debye type behavior. This pattern has been validated by the existence of an incomplete semicircle in the Argand plot. Insulation materials with low ε_r have found widespread applications in electronic devices due to the reduction in delay, power dissipation, and crosstalk. In addition, an investigation of real and imaginary parts of electric modulus leads to the minimized electrode polarization being reached.