Magnesium-based solid electrolyte with polysaccharides pectin complexed electrodes for electrochemical applications

Abstract

Biopolymer electrolytes are growing as a popular alternative to synthetic polymer electrolytes in electrochemical systems due to their carbon neutrality, sustainability, and ease-of-use biodegradability. Recent research on applying an electrochemical system concentrates on polysaccharides like pectin, cellulose, chitosan, agar–agar, xanthum gum, and starch as electrolytes. This project focuses on the synthesis and the characterization of biopolymer electrolyte pectin with magnesium chloride (MgCl₂) salt, with two different concentrations of pectin (1g):MgCl₂ (0.5g) and pectin (1g):MgCl₂ (0.7g). Biopolymer electrolytes are produced through solution casting method and studied using X-ray diffraction (XRD), Fourier-transform infrared (FTIR), differential scanning calorimetry (DSC), SEM-EDAX, AC impedance spectroscopy, and linear sweep voltammetry. Integration of salt strengthens the non-crystalline nature of the membranes as confirmed by XRD. FTIR analysis has been employed to verify interlinkage and coordination bonding of host biopolymer and Mg salt. Thermal analysis is used to affirm the glass transition temperature of obtained electrolytes. In AC impedance investigation, the ionic conductivity value for PP (1 g) with (0.7 g) MgCl₂ is found to be 1.92 × 10^–3 S/cm. Dielectric permittivity (ε*) is employed to study the dielectric behavior of electrolytes. As the MgCl₂ content rises, ε′ and ε″ increase as well and prove that they are ionic conductors. Electrochemical and cyclic stability of prepared electrolytes is analyzed by LSV studies. A basic magnesium battery has been fabricated using PMg2 biopolymer electrolyte and the functioning of the battery has been examined.

Graphical abstract