Effect of Glycerol as a Plasticizer on the Performance of PEO:NaNO3-Based Solid Polymer Electrolytes

Abstract
Polymer electrolytes (PEs) are promising materials for electrochemical energy devices like batteries and solar cells due to their safety, stability, cost efficiency, and compatibility. However, challenges such as low ionic conductivity and high interfacial resistance remain. This study develops polyethylene oxide (PEO)-NaNO3 polymer electrolyte films by incorporating varying concentrations of glycerol to enhance film-forming properties, transparency, and ionic conductivity. Characterization techniques, including x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and electrochemical impedance spectroscopy (EIS), are employed to evaluate the structural and electrical behavior of the films. The addition of glycerol significantly improves the properties of PEO-NaNO3 polymer electrolytes. XRD analysis reveals a reduction in crystallinity from 42.32% in the pure complex to 26.01% in glycerol-containing samples, indicating increased amorphous content and enhanced ionic mobility. FTIR results show a 32% increase in intensity at 3369 cm−1 due to strong hydrogen bonding from glycerol’s -OH groups, which enhances the local ionic environment. Ionic conductivity improves with glycerol concentration, supported by correlations with XRD and FTIR findings. Dielectric studies demonstrate increased dielectric constant and loss at low frequencies, attributed to heightened polarizability and dipole relaxation, while a frequency shift in relaxation processes suggests improved dipole mobility. Analysis of the electrical modulus shows decreased modulus values and a shift in relaxation peaks to higher frequencies, reflecting reduced ionic barriers. These results confirm that glycerol acts as an effective plasticizer, significantly enhancing ionic conductivity and dielectric properties. In summary, glycerol effectively enhances ionic conductivity and dielectric properties by acting as a plasticizer, demonstrating its potential to optimize polymer electrolytes for advanced energy storage applications.

Author
Dr. Ibrahim Nazem Qader

DOI
https://doi.org/10.1007/s11664-025-12025-z

Publisher

ISSN
03615235, 1543186X

Publish Date: