Impact of KNO₃ Concentration on Structural Properties, Dielectric and AC Conductivity Response of 80 PEO:20 PVDF Blend Polymer Electrolytes

Due to the limited availability and unequal distribution of lithium resources, a thorough investigation into the viability and financial feasibility of using lithium as a long-term, sustainable solution has been initiated. Our work was focused to prepare the solid polymer electrolyte systems using solvent cast technique and the ionic conductivity, dielectric properties were studied using impedance spectroscopy from 1 Hz to 10 MHz at various temperatures. XRD (X-ray diffractogram) and FTIR (Fourier transform infrared) characterization techniques have been carried out to confirm the electrolytes' complexation and functional groups, respectively. Morphological study and thermal analysis have been studied using SEM (scanning electron microscopy) and DSC (differential scanning calorimetry). The dielectric response of the samples was examined through dielectric constant (ε′), dielectric loss (ε″), modulus (M′ and M″) and relaxation time (τ). The electrical properties of polymer electrolytes complexed with salt concentration were changed remarkably. The ionic conductivity of KNO₃-complexed polymer electrolytes has been enhanced and the maximum ionic conductivity (3.19 × 10^–5 S/cm) was noticed for 3 wt% of KNO₃ which could be attributed to high dissociation and maximum movement of ions.