Upcycling Post-Consumer Plastic Waste into Electrospun Nanofibrous Separators for Sustainable Energy Storage

The global economy is confronted by two parallel grand challenges: the unsustainable accumulation of plastic waste and the escalating demand for high-performance, sustainable energy storage technologies. This perspective operates at the nexus of these challenges and establishes a conceptual roadmap for upcycling post-consumer plastics into functional battery components. In particular, the potential of four widely available waste polymers, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA), is examined for the fabrication of nanofibrous separator membranes through electrospinning. The distinct physicochemical characteristics of these polymers are analyzed in relation to key separator requirements, including porosity, electrolyte wettability, thermal stability, and ionic transport. Because studies employing waste-derived polymers remain limited, relevant research based on commercial polymers and alternative membrane fabrication approaches is also discussed to provide broader insight into structure-property-performance relationships. Environmental aspects related to recycling pathways, solvent systems, and life cycle considerations are also evaluated. Finally, major challenges such as feedstock variability, limited electrochemical validation, and scale-up limitations are identified, and future research directions are proposed. By integrating plastic waste upcycling with separator engineering, this perspective outlines a pathway toward circular and sustainable materials for next-generation energy storage systems.