Regeneration and usage of commercial activated carbon from the waste electrodes for the application of supercapacitors.

Currently, efficient and cost-effective recycling of waste capacitors is a pressing issue. In this study, the recovery of electrode powder from waste supercapacitors and enabling the reuse of the prepared samples are reported. The recovered powder is directly activated by mixing it with KOH using chemical activation to regenerate the waste-activated carbon. The regenerated activated carbon's specific surface area could be restored to a level similar to that of the original commercial powder, reaching 1803.15 m/g. The regenerated activated carbon has a high proportion of microporous, which played a crucial role in its electrochemical performance. The samples' capacity in the organic system reached 125.96 F/g at 0.2 A/g and 111.77 F/g at 20 A/g, with a retention rate of 88.74%. Furthermore, the capacitance was maintained at 91.18% after 10,000 cycles, showing good cycling performance. Additionally, the supercapacitor assembled from the regenerated activated carbon delivered a high energy density of 31.83 Wh/kg and a power density of 269.76 W/kg, indicating great application potential. Overall, this study offers a useful and low-cost approach for recycling activated carbon from waste electrodes, which would be possible for supercapacitors recycling.