All-Plastic Supercapacitors from Poly(ethylene terephthalate) Waste

Document Type

Article

Publication Date

9-7-2025

Department

Department of Materials Science and Engineering

Abstract

The increased accumulation of plastic waste presents a major environmental challenge, underscoring the urgent need for sustainable upcycling strategies. In this work, we report the first approach for utilizing plastic waste for the fabrication of an all-plastic supercapacitor. Specifically, waste poly(ethylene terephthalate) (PET) bottles were employed not only as separators but also as precursors for porous carbon electrodes. The PET waste was converted into porous carbon for the electrodes using Ca(OH)2to assist pyrolysis and KOH for final activation. Electrochemical characterization showed that surface area governs capacitance at low current densities, whereas meso/macroporosity improves ion diffusion and enhances high-rate performance. The resulting all-plastic supercapacitor delivered a gravimetric capacitance of 197.2 F/g at 0.5 A/g and retained 79% of its capacitance at high rates, outperforming analogous devices based on glass fiber separator (190.3 F/g at 0.5 A/g). Moreover, the PET separator exhibited excellent mechanical strength (57 MPa), superior thermal resistance, and tunable ionic conductivity (up to 2.79 × 10–2S/cm) with increased porosity, demonstrating its wide suitability for supercapacitor applications. This study offers a comprehensive and scalable strategy for valorizing plastic waste into high-performance supercapacitor components, opening new opportunities for circular energy storage technologies.

Publication Title

Energy and Fuels

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