Nanoarchitectured Fe₃C@N-Doped C/FeVO₄ as High-Performance Anode for Sodium-Ion Batteries

Ferric vanadate exhibits potential as an attractive anode material for sodium-ion batteries (SIBs) due to the multiple oxidation states of vanadium and natural abundances of iron. However, the design and fabrication of high-performance ferric vanadate-based SIB anode materials with unique composite nanostructures are still challenging. Herein, a facile self-template method is reported to synthesize 1D nanostructured Fe₃C@N-doped C/FeVO₄ (Fe₃C@NC/FeVO₄) anode materials by the combination of morphology regulation with hybrid composite construction, for the first time. To this end, a 1D Fe, N-doped carbon nanotube (FeNC) is used as a template, followed by etching and re-growth to obtain the 1D Fe₃C@N-doped C/FeVO₄ nanostructure. The introduction of Fe₃C can improve its electronic conductivity and enhance capacitive behavior. Additionally, the 1D nanostructure can effectively shorten the ions transport path and alleviate volume expansion during the charge-discharge processes. With these advantages, the SIBs using such anodes show a remarkable rate performance with a capacity of 325.4 mAh g^-1 at 0.1 A g^-1, 150.6 mAh g^-1 at 5 A g^-1, and excellent cycling stability with a reversible capacity of 139.6 mAh g^-1 at 1 A g^-1 after 1500 cycles. This work offers a new strategy for the future development of SIBs with ferric vanadate-based anode.