Enhanced K-storage kinetics for N-doped carbon via controllable dedoping strategy.

As a potential alternative to next-generation LIBs, carbonous materials have garnered significant attention as anode materials for potassium-ion batteries due to their low cost and environmental friendliness. However, carbonaceous materials cannot fulfill the demand of anode for PIBs, due to volume expansion and poor stability during charging/discharging process. It is well-known that N doping can provide active sites for K-storage, and expand the layer distance between graphite layers. Therefore, a simple one-step pyrolysis strategy was proposed to synthesize different nitrogen-doped carbon to investigate the effects of N-doping and dedoping on K-storage performance. Through the synergistic action of N-doping and the carbon vacancy defects formed during the de-doping process, which alleviated volume expansion and promoted K+ transport rate. As a result, the PNC demonstrate excellent electrochemical performance, showing good long-term cycling stability (with a capacity of 195 mAh/g after 300 cycles at a current density of 200 mA/g) and outstanding rate performance. These findings provide valuable insights for the design and development of advanced anode materials with efficient potassium ion storage capabilities.