Studies on the effect of H + carrier toward ionic conduction properties in alginate-ammonium sulfate complexes–based polymer electrolytes system

The present work highlights the contribution of ammonium sulfate (NH₄)₂SO₄ as H⁺ carriers in alginate-based solid polymer electrolytes (SPEs) that were successfully prepared via a solution casting technique. The Fourier transform infrared analysis revealed that molecular interactions between the host polymer and the ionic dopant complexes occurred at the wavenumbers 3700–2500 cm⁻¹, 1800–1500 cm⁻¹, and 1200–900 cm⁻¹. These regions corresponded to the O-H stretching, COO⁻ and C-O-C, moieties of alginate, respectively, which coordinated with the H⁺ carrier from (NH₄)₂SO₄. At ambient temperature, the optimum ionic conductivity was obtained at 3.01 × 10⁻⁵ S cm⁻¹ for the sample containing 10 wt.% of (NH₄)₂SO₄. The IR-deconvolution approach shows that the ionic conduction enhancement is governed by the ionic mobility and the diffusion coefficient of H⁺ carriers, and the findings show that the present biopolymer, which is an alginate-based SPEs system, has an excellent possibility to be used as electrolytes for application in electrochemical devices.