N/S codoped carbon microboxes with expanded interlayer distance toward excellent potassium storage

作者：Li, Youpeng; Zhong, Wentao; Yang, Chenghao^*; Zheng, Fenghua; Pan, Qichang; Liu, Yanzhen; Wang, Gang; Xiong, Xunhui; Liu, Meilin

来源：Chemical Engineering Journal, 2019, 358: 1147-1154.

DOI：10.1016/j.cej.2018.10.135

• Carbonaceous anode materials
• Potassium-ion batteries
• Metal-organic frameworks
• Electrochemical performance

Carbonaceous materials for potassium-ion batteries (PIBs) are quite attractive for the cost-effective feature. However, the cycle stability and rate performance of carbonaceous anode materials based on PIBs are limited, for the difficulty of accommodating large K ions (1.38 angstrom). Thus, the nitrogen (N) and sulfur (S) codoped carbon microboxes (NSC) with increased interlayer spacing is prepared via a carbonization-etching process. Unlike the traditional graphite, in which the K ions are difficult to insert into the restricted interlayer spacing, the NSC displays extremely large interlayer spacing of 0.412 nm, making the K ions more flexible during the insertion/extraction process in NSC. Moreover, ex-situ TEM study reveals that the layer structure of NSC is well-remained during the potassiation/depotassiation process. As a result, the NSC delivers super-long cycle life (180.5 mAh g(-1) at 500 mA g(-1) after 1000 cycles) and extraordinary rate ability (155.6 mAh g(-1) at 2 A g(-1)), which makes the NSC a promising anode material for PIBs.

• 出版日期2019-2-15
• 单位华南理工大学