Study on Ion Transport Properties of Solid Biopolymer Electrolyte based on Almond Gum with Ammonium Chloride

Abstract This study focused on the development of a solid biopolymer electrolyte (SBE) membrane based on almond gum (AG) as the polymer host and ammonium chloride (NH 4 Cl) as the ionic salt. The properties of the membranes were comprehensively investigated using various techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Electrochemical Impedance Spectroscopy (EIS), and transference number measurements (TNM). These findings reveal that the incorporation of NH 4 Cl into the solid biopolymer membrane resulted in enhanced properties. XRD analysis indicated an increase in the amorphous nature of the membrane upon the addition of NH 4 Cl. FTIR analysis proven the existence of diverse functional groups within the polymer and demonstrated the interaction between the polymer and the ammonium salt. EIS analysis revealed a decrease in bulk resistance in the SBE membrane when NH 4 Cl was introduced into the polymer matrix, resulting in enhancement of ionic conductivity from 1.38×10 − 8 S/cm to 1.04×10 − 4 S/cm at room temperature. The DC ionic conductivity is further verified from conduction spectra and dielectric properties. The TNM results emphasise the significant role of H + ions in ion transport. Finally, a primary battery was constructed using the utmost conducting membrane as the electrolyte, which displayed an open-circuit voltage (OCV) of 1.92 V.