Hybrid Co ₃ O ₄ /Al ₂ O ₃ nanofiller reinforced PEO/HPMC nanocomposite electrolytes for high-performance microcapacitors and optoelectronic devices

In this study, we present a novel dual-filler polymer-based solid electrolyte by incorporating cobalt oxide/aluminium oxide (Co3O4/Al2O3) nanoparticles into a blend of polyethylene oxide (PEO) and hydroxypropyl methylcellulose (HPMC). The electrolytes were synthesized via solution casting. XRD confirmed the reduction in crystallinity upon nanofiller addition, enhancing ionic mobility. UV-Vis analysis revealed a marked decrease in both direct and indirect optical band gaps indicating improved charge carrier transport. Dielectric studies further demonstrated enhanced permittivity and polarization effects, while AC conductivity exhibited strong frequency-dependent enhancement. The novelty of this work lies in the synergistic use of Co3O4 and Al2O3 within a blend matrix, leading to simultaneous improvements in ionic mobility, optical tunability, and dielectric response. These advancements make the material a promising candidate for next-generation energy storage systems and optoelectronic devices, contributing to the development of sustainable and efficient technologies for society.