The study of impedance, ion transport properties, EEC modeling, dielectric and electrochemical characteristics of plasticized proton conducting PVA based electrolytes

Abstract

In this work, a facile and efficient way is presented for preparation of plasticized polymer electrolytes (PEs) of PVA with ammonium iodide (NH4I) using solution cast method. The impact of glycerol plasticizer on improving electrochemical and electrical properties of PVA:NH4I electrolyte is confirmed. The EIS measurement has shown a conductivity of 8.57 × 10−4 S cm−1 after plasticization. The EEC modeling was used to fit the EIS data and also to determine the circuit elements desired for each electrolyte. Both dielectric constant and DC conductivity have similar trend of variation when modifications have been performed. The shift in position of relaxation peaks to the higher frequency emphasizes decreasing of resistivity within the samples. The non-Debye behaviors of relaxation are identified from the asymmetric shape of Mi spectra. The ion transference number (tion) has a value of 0.868 for the maximum plasticized system, confirming ion conduction dominancy in the PE system. The decomposition potential of the PE starts at 1.35 V using LSV. From the CV measurement, the capacitive behavior of the PE are proved. The specific capacitance of the EDLC are measured using CV curve and found to be 72.25 F/g at 10 mV/s.

Keywords

• PVA electrolyte
• Ammonium salt
• Impedance
• Proton transport
• Relaxation processes
• TNM and LSV measurements