Xu Fei, Zhai Yixuan, Zhang En, Liu Qianhui, Jiang Guangshen, Xu Xiaosa, Qiu Yuqian, Liu Xiaoming, Wang Hongqiang, Kaskel Stefan
State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an, 710072, P. R. China.
Inorganic Chemistry, Technische Universität Dresden, Bergstrasse 66, 01062, Dresden, Germany.
Angew Chem Int Ed Engl. 2020 Oct 26;59(44):19460-19467. doi: 10.1002/anie.202005118. Epub 2020 Jun 8.
The development of ultrastable carbon materials for potassium storage poses key limitations caused by the huge volume variation and sluggish kinetics. Nitrogen-enriched porous carbons have recently emerged as promising candidates for this application; however, rational control over nitrogen doping is needed to further suppress the long-term capacity fading. Here we propose a strategy based on pyrolysis-etching of a pyridine-coordinated polymer for deliberate manipulation of edge-nitrogen doping and specific spatial distribution in amorphous high-surface-area carbons; the obtained material shows an edge-nitrogen content of up to 9.34 at %, richer N distribution inside the material, and high surface area of 616 m g under a cost-effective low-temperature carbonization. The optimized carbon delivers unprecedented K-storage stability over 6000 cycles with negligible capacity decay (252 mA h g after 4 months at 1 A g ), rarely reported for potassium storage.
用于钾存储的超稳定碳材料的开发存在关键限制，这是由巨大的体积变化和缓慢的动力学引起的。富含氮的多孔碳最近已成为该应用的有前途的候选材料；然而，需要对氮掺杂进行合理控制，以进一步抑制长期容量衰减。在此，我们提出了一种基于吡啶配位聚合物热解蚀刻的策略，用于在非晶态高比表面积碳中有意控制边缘氮掺杂和特定空间分布；所获得的材料在具有成本效益的低温碳化条件下，边缘氮含量高达9.34 at%，材料内部氮分布更丰富，比表面积高达616 m²/g。优化后的碳在6000次循环中提供了前所未有的钾存储稳定性，容量衰减可忽略不计（在1 A/g下4个月后为252 mA h/g），这在钾存储方面鲜有报道。
