Electrochemical performance of polymer blend electrolytes based on chitosan: dextran: impedance, dielectric properties, and energy storage study

A facile and efficient methodology was implemented in preparation of plasticized polymer electrolyte with polymer blend of chitosan and dextran from leuconostocmesenteroides impregnated with magnesium acetate using solution cast technique. A number of electrochemical techniques were applied in the characterization of the blend polymer electrolyte, such as cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and transference number measurement (TNM). Field emission scanning electron microscopy (FESEM) is used in morphological investigation of impact of plasticizer on films. The X-ray diffraction (XRD) patterns of the plasticized doped samples have shown a significant enhancement in their amorphous nature compared to the pure sample. From the CV, the capacitive behavior of the polymer blend electrolyte was proved. The decomposition potential of the polymer blend electrolyte is determined to be 1.5 V using LSV. The ion transference number (t(ion)) was calculated and found to be 0.979, confirming dominancy of ion conduction in the polymer blend electrolyte system. It is found that ionic conductivity can be enhanced via adding glycerol as plasticizer, which supported the obtained results from both FESEM and XRD studies. To evaluate the EDLC assembly, the specific capacitance was measured as 25.377 F/g using CV curve, with energy and power densities of 7.59 Wh/kg and 520.8 W/kg, respectively.