High-efficiency recycling of papermaking wastes for synthesizing carbon/calcium terephthalate composite anodes for potassium-ion batteries

Because of the large ion radius of potassium and sluggish kinetics, high-performance anodes are required to release the horsepower of potassium-ion batteries. Calcium terephthalate emerges as an outstanding anode for potassium-ion batteries, due to its impressive combination of high discharge capacity and cycle stability. However, challenges arise from its intrinsic low conductivity and the reported high cost of calcium terephthalate. To address these issues, this study introduces a novel approach where carbon/calcium terephthalate composite anodes were synthesized to elevate electrochemical performance of potassium-ion batteries, where carbon and calcium terephthalate were completely derived and synthesized from waste polyethylene terephthalate and deinking sludge from a waste paper mill. The composite anodes exhibit remarkable potential as superior materials for potassium-ion batteries, demonstrating comparable performance to lithium-ion batteries using similar anodes as reported in literature. Furthermore, economic analysis underscores cost effectiveness of the proposed synthesis method. Ultimately, this research not only addresses the challenges associated with calcium terephthalate but also opens up the gate to directly utilize papermaking wastes to develop high-performance anode materials for potassium-ion batteries.