Studies of Circuit Design, Structural, Relaxation and Potential Stability of Polymer Blend Electrolyte Membranes Based on PVA:MC Impregnated with NH4I Salt

Muaffaq M Nofal; Shujahadeen B Aziz; Mohamad A Brza; Sozan N Abdullah; Elham M A Dannoun; Jihad M Hadi; Ary R Murad; Sameerah I Al-Saeedi; Mohd F Z Kadir

doi:10.3390/membranes12030284

Studies of Circuit Design, Structural, Relaxation and Potential Stability of Polymer Blend Electrolyte Membranes Based on PVA:MC Impregnated with NH₄I Salt

Membranes (Basel). 2022 Feb 28;12(3):284. doi: 10.3390/membranes12030284.

Authors

Muaffaq M Nofal¹, Shujahadeen B Aziz^{2

3}, Mohamad A Brza⁴, Sozan N Abdullah⁵, Elham M A Dannoun⁶, Jihad M Hadi⁷, Ary R Murad⁸, Sameerah I Al-Saeedi⁹, Mohd F Z Kadir¹⁰

Affiliations

¹ Department of Mathematics and General Sciences, Prince Sultan University, P.O. Box 66833, Riyadh 11586, Saudi Arabia.
² Hameed Majid Advanced Polymeric Materials Research Lab., Physics Department, College of Science, University of Sulaimani, Qlyasan Street, Sulaimani 46001, Iraq.
³ Department of Civil Engineering, College of Engineering, Komar University of Science and Technology, Sulaimani 46001, Iraq.
⁴ Medical Physics Department, College of Medicals & Applied Science, Charmo University, Sulaimani 46023, Iraq.
⁵ Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Sulaimani 46001, Iraq.
⁶ General Science Department, Woman Campus, Prince Sultan University, P.O. Box 66833, Riyadh 11586, Saudi Arabia.
⁷ Department of Medical Laboratory of Science, College of Health Sciences, University of Human Development, Sulaimani 46001, Iraq.
⁸ Department of Pharmaceutical Chemistry, College of Medical and Applied Sciences, Charmo University, Sulaimani 46023, Iraq.
⁹ Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh 11671, Saudi Arabia.
¹⁰ Centre for Foundation Studies in Science, University of Malaya, Kuala Lumpur 50603, Malaysia.

Abstract

This work presents the fabrication of polymer electrolyte membranes (PEMs) that are made of polyvinyl alcohol-methylcellulose (PVA-MC) doped with various amounts of ammonium iodide (NH₄I). The structural and electrical properties of the polymer blend electrolyte were performed via the acquisition of Fourier Transform Infrared (FTIR) and electrical impedance spectroscopy (EIS), respectively. The interaction among the components of the electrolyte was confirmed via the FTIR approach. Electrical impedance spectroscopy (EIS) showed that the whole conductivity of complexes of PVA-MC was increased beyond the addition of NH₄I. The application of EEC modeling on experimental data of EIS was helpful to calculate the ion transport parameters and detect the circuit elements of the films. The sample containing 40 wt.% of NH₄I salt exhibited maximum ionic conductivity (7.01 × 10^-8) S cm^-1 at room temperature. The conductivity behaviors were further emphasized from the dielectric study. The dielectric constant, ε' and loss, ε'' values were recorded at high values within the low-frequency region. The peak appearance of the dielectric relaxation analysis verified the non-Debye type of relaxation mechanism was clarified via the peak appearance of the dielectric relaxation. For further confirmation, the transference number measurement (TNM) of the PVA-MC-NH₄I electrolyte was analyzed in which ions were primarily entities for the charge transfer process. The linear sweep voltammetry (LSV) shows a relatively electrochemically stable electrolyte where the voltage was swept linearly up to 1.6 V. Finally, the sample with maximum conductivity, ion dominance of t_ion and relatively wide breakdown voltage were found to be 0.88 and 1.6 V, respectively. As the ions are the majority charge carrier, this polymer electrolyte could be considered as a promising candidate to be used in electrochemical energy storage devices for example electrochemical double-layer capacitor (EDLC) device.

Keywords: FTIR; TNM and LSV; circuit modeling; dielectric properties; impedance; polymer electrolyte; relaxation process.