Synergistic Polymer–Ionic Liquid Nanofibrous Electrolytes for High-Efficiency Supercapacitor Devices

Electrospun polymer–ionic liquid composite nanofibers offer a versatile platform for high-performance electrochemical energy storage systems. In this study, poly (methyl methacrylate) (PMMA) nanofibers incorporated with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) were developed as flexible electrolyte/separator materials for supercapacitor applications. The incorporation of the ionic liquid improved charge transport characteristics by increasing ionic mobility and enhancing the amorphous structure of the polymer matrix. The resulting nanofibrous membrane exhibited a highly porous architecture, promoting efficient ion diffusion and large electrode–electrolyte interfacial contact. Electrochemical studies revealed enhanced ionic conductivity, improved specific capacitance, and stable charge–discharge performance compared to neat PMMA membranes. Additionally, the composite showed excellent thermal stability and mechanical flexibility, supporting its potential use in flexible and wearable supercapacitors. The synergistic interaction between PMMA and [BMIM]Cl demonstrates an effective strategy for designing advanced polymer electrolyte systems for high-performance supercapacitors.