Wei Shiwei, Li Wei, Ma Zizai, Deng Xiaoyang, Li Yongfeng, Wang Xiaoguang
Laboratory of Advanced Materials and Energy Electrochemistry, Institute of New Carbon Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024, China.
Small. 2023 Nov;19(46):e2304265. doi: 10.1002/smll.202304265. Epub 2023 Jul 19.
Bismuth (Bi) has attracted attention as a promising anode for sodium-ion batteries (SIBs) owing to its suitable potential and high theoretical capacity. However, the large volumetric changes during cycling leads to severe degradation of electrochemical performance and limits its practical application. Herein, Bi nanoflowers are encapsulated in N-doped carbon frameworks to construct a novel Bi@NC composite via a facile solvothermal method and carbonization strategy. The well-designed composite structure endows the Bi@NC with uniformly dispersed Bi nanoflowers to alleviate the attenuation while the N-doped carbon frameworks improve the conductivity and ion transport of the whole electrode. As for sodium-ion half-cell, the electrode exhibits a high specific capacity (384.8 mAh g at 0.1 A g ) and excellent rate performance (341.5 mAh g at 10 A g ), and the capacity retention rate still remains at 94.9% after 5000 cycles at 10 A g . Furthermore, the assembled full-cell with Na V (PO ) cathode and Bi@NC anode can deliver a high capacity of 251.5 mAh g at 0.1 A g , and its capacity attenuates only 0.009% in each cycle after 2000 times at 5.0 A g . This work offers a convenient, low-cost, and eco-friendliness approach for high-performance electrodes in the field of sodium ion electrochemical storage technology.
铋（Bi）因其合适的电位和高理论容量，作为一种有前景的钠离子电池（SIBs）负极材料受到关注。然而，循环过程中的大体积变化导致其电化学性能严重退化，并限制了其实际应用。在此，通过简便的溶剂热法和碳化策略，将铋纳米花封装在氮掺杂碳框架中，构建了一种新型的Bi@NC复合材料。精心设计的复合结构使Bi@NC中的铋纳米花均匀分散，从而减轻衰减，同时氮掺杂碳框架提高了整个电极的导电性和离子传输能力。对于钠离子半电池，该电极在0.1 A g时表现出高比容量（384.8 mAh g）和优异的倍率性能（在10 A g时为341.5 mAh g），在10 A g下循环5000次后容量保持率仍为94.9%。此外，组装的以Na V(PO) 为正极、Bi@NC为负极的全电池在0.1 A g时可提供251.5 mAh g的高容量，在5.0 A g下循环2000次后，其容量每循环仅衰减0.009%。这项工作为钠离子电化学储能技术领域的高性能电极提供了一种便捷、低成本且环保的方法。
