<p>This study examines the effects of glycerol as a plasticizer on the properties of CS-MC-Sorbitol-CH3COONa-TiO₂ nanocomposite polymer electrolytes developed via solution casting. By adding glycerol at varying concentrations (8–40 wt%), the research aimed to enhance ionic transport within the polymer structure. Structural analysis using X-ray diffraction (XRD) showed a decline in crystallinity from 38.97 to 25.87%, signifying increased amorphousness and chain flexibility. Fourier-transform infrared (FTIR) spectroscopy highlighted interactions between glycerol and the polymer’s functional groups. Electrochemical impedance spectroscopy (EIS) revealed a significant reduction in bulk resistance (Rb) from 4675 Ω to 66 Ω, while DC ionic conductivity surged from 4.2 × 10⁻⁷ S cm⁻¹ to 7.427 × 10⁻⁵ S cm⁻¹, marking a remarkable 177-fold increase. Higher glycerol content corresponded with increases in dielectric constant (ε′) and dielectric loss (ε″), which suggested enhanced dipolar polarization and mobility of charge carriers. The relaxation time (τ) decreased from 16.72 to 0.22 µs, reflecting expedited ion dynamics. Concurrently, charge carrier density (N) escalated from 1.25 × 10¹⁸ cm⁻³ to 1.71 × 10²³ cm⁻³. This study is original due to the unique combination of CS/MC/sorbitol/CH₃COONa/TiO₂ in a controlled glycerol concentration series, supplemented by FTIR deconvolution, dielectric, and impedance analyses. It presents clear evidence of glycerol’s impact on ion dissociation and transport mechanisms. Distinguishing itself from prior research on CS/MC/glycerol/TiO₂, this study innovatively integrates the plasticizers sorbitol and glycerol with sodium acetate salts, enhancing Na⁺ ion availability, and utilizes TiO₂ nanofillers to establish a link between ion transport and elevated Na⁺ conduction in biodegradable polymer electrolytes.</p>