Abstract
The accelerating accumulation of plastic waste, together with the growing demand for sustainable electrochemical energy storage materials, calls for processing strategies that integrate environmental value with structural functionality. This perspective review proposes a methodological framework for converting commodity plastic wastes, including poly(ethylene terephthalate), polystyrene, polymethyl methacrylate, and poly(vinyl chloride), into hierarchical nanofibers through coaxial electrospinning with heat treatment, an approach for which experimental studies on waste plastics for energy storage applications are currently absent. Unlike conventional single-fluid electrospinning, this technique enables independent control of core and shell formulations, allowing the rational design of core-shell, hollow, and multicompartment fibers with tunable porosity, tailored surface chemistry, and enhanced mechanical stability. Particular emphasis is placed on process-structure relationships in waste-derived systems, including polymer compatibility, solvent selection, rheological windows for stable jet formation, and control of internal morphology. Post-treatment strategies such as carbonization, infiltration, and crosslinking are discussed as key routes for transforming polymeric precursors into functional fibrous architectures for electrodes, separators, and solid polymer electrolytes. By establishing design principles and future research priorities, this work provides a roadmap for advancing waste-derived hierarchical fibers toward practical and sustainable energy storage applications.