Polymer electrolytes based on agarose dissolved in DMSO solvent complexed with different weight percentages of Mg(NO₃)₂ ranging from 0 to 35 wt% were prepared using a solution casting method. Electrochemical impedance spectroscopy (EIS) was applied to study the electrical properties of this polymer electrolyte, such as ionic conductivity at room and different temperatures, dielectric and modulus properties. The highest conducting film has been obtained at 1.48 × 10⁻⁵ S·cm⁻¹ by doping 30 wt% of Mg(NO₃)₂ into the polymer matrix at room temperature. This high ionic conductivity value is achieved due to the increase in the amorphous nature of the polymer electrolyte, as proven by X-ray diffractometry (XRD), where broadening of the amorphous peak can be observed. The intermolecular interactions between agarose and Mg(NO₃)₂ are studied by Fourier transform infrared (FTIR) spectroscopy by observing the presence of –OH, –CH, N–H, CH₃, C–O–C, C–OH, C–C and 3,6-anhydrogalactose bridges in the FTIR spectra. The electrochemical properties for the highest conducting agarose–Mg(NO₃)₂ polymer electrolyte are stable up to 3.57 V, which is determined by using linear sweep voltammetry (LSV) and supported by cyclic voltammetry (CV) that proves the presence of Mg²⁺ conduction.

Gel polymer electrolyte based on poly (vinyl alcohol)(PVA)–magnesium triflate (MgTf) incorporating with different weight percentage (wt.%) of ethylene carbonate (EC) as plasticizer has been prepared by using solution casting method. The ionic conductivity of PVA–MgTf–EC gel polymer electrolyte has been determined by using Electrochemical Impedance Spctroscopy (EIS) and has achieved an optimum value at 1.26 x 10-4 S.cm-1 when 50 wt.% of EC is added into the system. Fourier Transform Infrared Spectroscopy (FTIR) has been performed to study the molecular interaction between components in PVA-MgTf-EC gel polymer electrolyte. The complexations between the materials used in electrolyte system are observed based on shifting of the bands and changes in intensity of peaks in FTIR spectra. The morphological behaviour of electrolyte has been studied by using Field Emission Scanning Electron Spectroscopy (FESEM) to observe the changes of PVA based gel polymer electrolyte when EC is added to the system.

Electrochemical energy storage devices (EES) such as batteries and supercapacitors depend significantly on electrolytes, which have properties that significantly impact their energy capacity, rate performance, cyclability, and safety. Agarose–Mg(ClO4)2–based polymer electrolyte was prepared using the solution casting method by incorporating various amounts of Mg(ClO4)2 from 0 – 35 wt%. The presence of Mg(ClO4)2 as the dopant in agarose-matrix enhanced the ionic conductivity of the system from 1.796 × 10-8 S∙cm-1 to 6.247 × 10-4 S∙cm−1 in the composition of 30 wt% Mg(ClO4)2 due to the production of free ions. This system obeys the Arrhenius rule as it records the conductivity increment when temperature increases. This increment shows the amorphous nature of electrolytes, which XRD analyses by determining the crystallite size and degree of crystallinity of agarose–Mg(ClO4)2 polymer electrolyte. High ionic conductivity at room temperature has increased attention to this polymer electrolyte based on agarose–Mg(ClO4)2.