Ionic transport and structural analysis of zinc chloride doped ί-carrageenan solid polymer electrolytes for energy storage devices

This study aims to develop a solid polymer electrolyte (SPE) with high ionic conductivity using ί-Carrageenan (iC) suitable for zinc-ion batteries. The SPEs are prepared through a straightforward solution-casting technique that employs ί-Carrageenan and zinc chloride, with deionized water as the solvent. Fourier-transform infrared (FTIR) spectroscopy is conducted to analyze the interactions between the polymer chains and ions, while X-ray diffraction (XRD) patterns are evaluated to determine crystallinity and confirm salt dissociation. Ionic conductivity is measured using impedance spectroscopy, achieving a maximum conductivity of ∼10⁻⁴ S cm⁻¹. The contribution of cations to this conductivity is assessed using the Bruce-Vincent method, using a custom LabVIEW program on a sourcemeter and an LCR meter. A primary cell incorporating the SPE was fabricated and characterized to evaluate its feasibility, leading to the conclusion that, with some minor improvements, this SPE could serve effectively in zinc-ion batteries.