Ibrahim Luqman Salih, Ibrahim Nazem Qader, Karukh Ali Babakr, Shujahadeen Bakr Aziz, Peshawa H. Mahmood, Pshdar Ahmed Ibrahim, Abubakr Wsu Muhammed, Hazhar Hamad Rasul, S. Mohammed, Dlshad Aziz Hamid, Bala Talib Ali, Peyman Aspoukeh, Hossein Khojasteh, Samir M. Hamad
ABSTRACT This study systematically examines the influence of glycerol (9–45 wt%) as a plasticizer on the structural, physicochemical, and electrochemical properties of chitosan–dextran–LiClO 4 –Al 2 O 3 nanocomposite polymer electrolytes prepared by solution casting. Electrochemical impedance spectroscopy revealed a pronounced reduction in bulk resistance from 64,310 Ω to 160 Ω and an increase in ionic conductivity from 0.04 to 18.10 μS cm −1 (over 450‐fold). The relaxation time ( τ ) decreased from 1441.49 to 4.18 μs, indicating accelerated ion reorientation and enhanced charge‐carrier mobility at higher glycerol content. FTIR analysis evidences strong hydrogen‐bonding interactions among polymer hydroxyl/amine groups, Li + ions, and Al 2 O 3 nanoparticles, which promote salt dissociation and complex formation. Increasing glycerol content also elevated the dielectric constant ( ε ′) and dielectric loss ( ε ″), reflecting intensified dipolar and interfacial polarization and a higher mobile charge density. Glycerol augmented the amorphous fraction and segmental mobility, thereby facilitating ion transport. The optimized CS–Dextran–LiClO 4 –Al 2 O 3 –glycerol film demonstrates significantly improved ionic and dielectric performance, making it a promising solid polymer electrolyte for advanced electrochemical and energy‐storage applications.