Supercapacitor Separators from Upcycled Waste Paper with Functionalized Surfaces

This study presents a sustainable strategy for developing high-performance supercapacitor separators through the upcycling of waste newspapers into functional cellulose-based membranes. The intrinsic porous architecture of cellulose fibers was exploited as a robust scaffold, onto which Parylene C and polyaniline (PANI) layers were sequentially introduced to reinforce mechanical integrity and enhance electrochemical functionality. The resulting dual-layer configuration exhibited significantly improved interfacial stability and ion-transport characteristics compared with conventional polyethylene separators. Comprehensive structural and electrochemical analyses verified that the synergistic combination of Parylene C and PANI coatings effectively optimized separator-electrolyte interfacial properties and reduced impedance. Beyond performance enhancement, this work establishes an environmentally responsible route for valorizing paper waste, offering a viable pathway toward sustainable energy storage technologies.