Fe/Fe3C modification to effectively achieve high-performance Si–C anode materials

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2022-11, Vol.10 (43), p.23103-23112
• Main Authors: Lin, Xuqi, Gao, Jingguo, Zhong, Kehua, Huang, Yongcong, Yao, Hurong, Lin, Yingbin, Zheng, Yongping, Huang, Zhigao, Li, Jiaxin
• Format: Article
• Language: English
• Subjects: Anodes; Batteries; Carbon; Carbon fibers; Catalytic activity; Cementite; Compatibility; Composite materials; Conductivity; Electrode materials; Electrodes; Iron carbides; Lithium; Lithium-ion batteries; Low conductivity; Nanofibers; Nanoparticles; Rechargeable batteries; Room temperature; Silicon; Solid electrolytes; Stability
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d2ta06008f

For high-performance silicon–carbon (Si–C)-based anode materials used in high-energy-density lithium-ion batteries (LIBs), there is an urgent need to rationally construct a stable solid electrolyte interface (SEI) film and load a high proportion of silicon content, which is closely related to the capacity and cycling stability of the electrode. Herein, composites of Fe/Fe3C-modified carbon nanofiber–coated Si nanoparticles (Fe/Fe3C–Si@CNFs) were synthesized via a simple electrospinning method. These composites effectively overcome the volume change effect, poor interfacial compatibility and low conductivity, delivering excellent LIB performance. Tested at 2.0 A g−1, Fe/Fe3C–Si@CNFs provides a high reversible capacity of 956.5 mA h g−1 with a coulombic efficiency of more than 99.5% even after 4000 ultra-long stable cycles. The high conductivity of the Fe/Fe3C embedded in the CNF framework can promote e− transfer and boost the Li+ diffusion kinetics in the electrode. The catalytic activity of Fe/Fe3C helps to enhance the interfacial compatibility, grow a balanced stable SEI film and promote the long-cycle stability of the electrode at room temperature.