Role of Glycerol Content in Modulating Structural and Electrochemical Properties of Chitosan –Dextran–KSCN–TiO ₂ Polymer Electrolytes

ABSTRACT Polymer electrolytes are promising for future energy storage devices due to their safety, flexibility, and processability, but their low ionic conductivity remains a limitation. In this study, a chitosan (CS)–dextran (DN) blend electrolyte was modified with potassium thiocyanate (KSCN), TiO 2 nanoparticles, and varying glycerol concentrations (9–45 wt.%) to enhance ionic conductivity. Five films (EV1–EV5) were prepared using solution casting and extensively characterized. X‐ray diffraction confirmed a largely amorphous structure with reduced crystallinity at higher glycerol content, while FTIR verified strong molecular interactions and complexation among components. Electrochemical impedance spectroscopy (EIS) showed a remarkable decrease in resistance from 143.5 kΩ (EV1) to 60 Ω (EV5), resulting in a conductivity increase from 2.55 × 10 − 8 to 7.00 × 10 − 5 S cm − 1 , an enhancement of about 2,750‐fold. Dielectric analysis indicated higher permittivity and loss, consistent with enhanced ion dissociation and polarization. Moreover, relaxation time decreased from 26.11 to 0.288 µs, with significant improvements in ionic mobility and diffusivity, evidencing faster ion transport. These findings highlight glycerol's role as an effective plasticizer in improving structural flexibility and electrochemical performance, establishing the CS‐based electrolyte system as a strong candidate for next‐generation solid‐state energy storage applications.