Highly nitrogen doped carbon nanofibers with superior rate capability and cyclability for potassium ion batteries

• Published in: Nature communications Vol. 9; no. 1; pp. 1720 - 11
• Main Authors: Xu, Yang, Zhang, Chenglin, Zhou, Min, Fu, Qun, Zhao, Chengxi, Wu, Minghong, Lei, Yong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.04.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 140/146; 147/135; 147/143; 639/301/299/891; 639/638/161/891; 639/638/675; 639/925/357/537; Anodes; Batteries; Carbon; Carbon fibers; Electrode materials; Humanities and Social Sciences; Kinetics; Lithium; Lithium-ion batteries; multidisciplinary; Nanofibers; Nitrogen; Pigments; Potassium; Rechargeable batteries; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04190-z

Potassium-ion batteries are a promising alternative to lithium-ion batteries. However, it is challenging to achieve fast charging/discharging and long cycle life with the current electrode materials because of the sluggish potassiation kinetics. Here we report a soft carbon anode, namely highly nitrogen-doped carbon nanofibers, with superior rate capability and cyclability. The anode delivers reversible capacities of 248 mAh g –1 at 25 mA g –1 and 101 mAh g –1 at 20 A g –1 , and retains 146 mAh g –1 at 2 A g –1 after 4000 cycles. Surface-dominated K-storage is verified by quantitative kinetics analysis and theoretical investigation. A full cell coupling the anode and Prussian blue cathode delivers a reversible capacity of 195 mAh g –1 at 0.2 A g –1 . Considering the cost-effectiveness and material sustainability, our work may shed some light on searching for K-storage materials with high performance. The development of potassium ion batteries calls for cheap, sustainable, and high-performance electrode materials. Here, the authors report a highly nitrogen-doped soft carbon anode that exhibits superior rate capability and cyclability based on a surface dominated charge storage mechanism.