Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering , Beijing Institute of Technology , Beijing 100081 , P. R. China.
Collaborative Innovation Center of Electric Vehicles in Beijing , Beijing 100081 , P. R. China.
ACS Appl Mater Interfaces. 2018 Jun 27;10(25):21335-21342. doi: 10.1021/acsami.8b05618. Epub 2018 Jun 13.
Phosphorus-doped hard carbon nanofibers with macroporous structure were successfully synthesized by electrospinning followed by a thermal treatment process using polyacrylonitrile and HPO as carbon and phosphorus precursors, respectively. X-ray photoelectron spectroscopy analysis reveals that the doped phosphorus atoms can incorporate into the carbon framework and most of them are connecting with carbon atoms to form P-C bond. The (002) plane interlayer spacing was taken from the X-ray diffraction pattern, which shows a large spacing of 3.83 Å for the obtained P-doped hard carbon nanofibers. When used as an anode in sodium-ion batteries, the as-prepared P-doped hard carbon nanofibers can deliver a reversible capacity of 288 and 103 mAh g at a current density of 50 mA g and 2 A g, respectively. After 200 cycles at 50 mA g, the capacity retention of P-doped hard carbon nanofibers still reaches 87.8%, demonstrating good cycling durability. These excellent electrochemical performances of P-doped hard carbon nanofibers can be attributed to the macroporous structure, large interlayer spacing, and the formation of P-C bond.
通过静电纺丝和随后的热处理工艺，成功地合成了具有大孔结构的磷掺杂硬碳纳米纤维，分别使用聚丙烯腈和 HPO 作为碳和磷前体。X 射线光电子能谱分析表明，掺杂的磷原子可以掺入碳骨架中，并且大部分与碳原子结合形成 P-C 键。从 X 射线衍射图谱中可以得到（002）面的层间距，对于得到的磷掺杂硬碳纳米纤维，其间距较大，为 3.83 Å。当用作钠离子电池的阳极时，所制备的磷掺杂硬碳纳米纤维在电流密度为 50 mA g 和 2 A g 时，分别可以提供 288 和 103 mAh g 的可逆容量。在 50 mA g 下循环 200 次后，磷掺杂硬碳纳米纤维的容量保持率仍达到 87.8%，表现出良好的循环耐久性。磷掺杂硬碳纳米纤维的这些优异电化学性能可归因于大孔结构、较大的层间距和 P-C 键的形成。
