Ionic conductivity (σ) of the designed SPEs was measured by electrochemical impedance spectroscopy (EIS) analysis (MTZ-35 impedance analyser, Biologic). The measurements were performed over the temperature range of 30-50 °C in frequency from 0.1 Hz to 1 MHz. A SS|PCIL-SPEs|SS (stainless-steel) coin cell configuration was used. The bulk resistance was calculated from the impedance curve at high frequency, and the ionic conductivity was calculated by the equation: