Refurbished Carbon Materials from Waste Supercapacitors as Industrial-Grade Electrodes: Empowering Electronic Waste

Abstract

Reinstallation of industrial-grade electrode materials by recycling waste electrochemical energy storage devices is the best practice to bring excellent economic and environmental benefits. Here, we have repaired active carbon materials from the end-of-life supercapacitors using simple thermal activation and back-integrated them in high-voltage and super-stable supercapacitors. The preliminary characterizations revealed that the recovered carbon materials retained their excellent surface and structural features including large specific surface area (~1716 m2/g) with tailored pore-size distribution and a high degree of graphitization with well-oriented graphitic layers. Later, the repaired carbon was re-instated in an innovative water-in-salt electrolyte, which can easily be cycled in an extended working voltage range (2 V). Benefiting from the maintained structural and surface characteristics, the renovated supercapacitor delivered exceptional cycling stability over 300,000 cycles with 99% capacitance retention. Such a ground-breaking performance of recovered materials from waste-supercapacitor will encourage future waste-recovery initiatives, aiding the sustainable practices and circular economy.

Keywords: Spent Supercapacitor, Recovered carbons, Water-in-salt, cycling stability, cost.