Tong Huigang, Wang Changlai, Lu Jian, Chen Shi, Yang Kang, Huang Minxue, Yuan Qing, Chen Qianwang
Hefei National Laboratory for Physical Science at Microscale, Department of Materials Science & Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Center of Super-Diamond and Advanced Films (COSDAF), Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
Small. 2020 Oct;16(43):e2002771. doi: 10.1002/smll.202002771. Epub 2020 Oct 4.
The carbonaceous materials with low cost and high safety have been considered as promising anodes for potassium-ion batteries (PIBs). However, it is still a challenge to design a carbonaceous material with long cycle life and high rate performance due to the poor K reaction kinetics. Herein, this article reports a N-doped porous carbon framework (NPCF) with a high nitrogen content of 13.57 at% within high doping level of the pyrrolic N and pyridinic N, which exhibits a high reversible capacity of 327 mA h g over 100 cycles at a current density of 100 mA g , excellent rate capability (144 and 105 mA h g at 10 and 20 A g , respectively) and great cyclability of 258.9 mA h g after 2000 cycles at 1 A g . Such a high rate performance and excellent cycling stability anode material is seldom reported in PIBs. Density functional theory (DFT) calculations reveal that the pyrrolic and pyridinic N-doping are helpful to enhance the K adsorption ability, thereby increasing the specific capacity.
低成本且高安全性的碳质材料被认为是钾离子电池（PIBs）很有前景的阳极材料。然而，由于钾反应动力学较差，设计一种具有长循环寿命和高倍率性能的碳质材料仍然是一项挑战。在此，本文报道了一种氮掺杂多孔碳骨架（NPCF），在吡咯氮和吡啶氮的高掺杂水平下，氮含量高达13.57原子%，在100 mA g的电流密度下100次循环中表现出327 mA h g的高可逆容量、优异的倍率性能（在10和20 A g时分别为144和105 mA h g）以及在1 A g下2000次循环后258.9 mA h g的良好循环稳定性。这种高倍率性能和优异循环稳定性的阳极材料在钾离子电池中鲜有报道。密度泛函理论（DFT）计算表明，吡咯氮和吡啶氮掺杂有助于增强钾吸附能力，从而提高比容量。
