Anchoring Multi-Coordinated Bismuth Metal Atom Sites on Honeycomb-Like Carbon Rods Achieving Advanced Potassium Storage

Carbonaceous materials are recognized for their high conductivity and adaptable structures, making them potential candidates for potassium-ion batteries (PIBs). Yet, their application has been restricted due to challenges like limited potassium storage and slow kinetics. Addressing these issues, this study presents a novel method by anchoring nitrogen-oxygen-coordinated bismuth metal atom sites onto honeycomb-like carbon rods, termed Bi-N-4-O-2@HCR. This aims to enhance PIB performance by exploiting carbonaceous materials' strengths and mitigating their limitations. Through comprehensive experiments and theoretical simulations, it is found that Bi-N-4-O-2 sites enrich potassium storage and facilitate potassium ion migration, thus improving transport efficiency and reaction kinetics. The resulting anode showcased rapid and durable potassium storage, with a remarkable capacity of 190.7 mAh g(-1) at 30 A g(-1) and maintaining 192.2 mAh g(-1) over 4200 cycles at 5 A g(-1), outperforming many existing carbon anodes. Additionally, in full cell tests, it exhibited excellent rate performance and ultra-long cycle life, sustaining up to 8000 cycles with a stable capacity of 88.9 mAh g(-1) at 5 A g(-1). This research underscores the significance of incorporating unique metal sites on carbon substrates to advance battery technology.