<p>Polymer electrolytes are increasingly important for applications in energy storage devices owing to their safety, flexibility, and potential for enhanced ionic conductivity. Nonetheless, their effectiveness is often constrained by low ionic mobility at ambient conditions. This study focuses on improving ion generation in a methylcellulose (MC):dextran-based nanocomposite electrolyte by incorporating glycerol as a plasticizer at varying concentrations. Samples were prepared via solution casting with fixed amounts of MC, dextran, sorbitol, KNO₃, and TiO₂, while adjusting glycerol content from 9&#xa0;wt.% to 45 wt.%. Analytical techniques including x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy (EIS) were employed to assess the impact of glycerol on crystallinity, molecular interactions, and ionic transport behavior. Increasing the glycerol concentration induced a notable transition from semi-crystalline to amorphous morphology, as revealed by XRD, while FTIR spectra indicated enhanced hydrogen bonding and interaction between the polymer matrix and the plasticizer. EIS analysis showed a significant reduction in bulk resistance from 1172 kΩ at 9 wt.% glycerol to 3.28 kΩ at 45 wt.%, accompanied by a nearly 690-fold increase in ionic conductivity from 2.74 × 10^–9 to 1.89 × 10^–6 S/cm. These findings underscore the effectiveness of glycerol in promoting segmental polymer motion and ion dissociation, thereby enhancing the electrochemical performance of the biopolymer electrolyte system.</p>