Electrodeposition of iron oxide nanorods on carbon nanofiber scaffolds as an anode material for lithium-ion batteries

Iron oxide film with spaced radial nanorods is formed on the VGCF (vapor-grown carbon nanofiber) scaffolds by means of anodic electrodeposition. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy show that the iron oxide film deposited on the VGCF surface is α-Fe₂O₃ and consists of spaced radial nanorods having 16-21 nm in diameter after annealing at 400 °C. Galvanostatic charge/discharge results indicate that the α-Fe₂O₃/VGCF anode (970 mAh g⁻¹) has higher capacity than bare α-Fe₂O₃ anode (680 mAh g⁻¹) at 10 C current discharge. VGCF scaffolds fabricated by electrophoretic deposition favor the electron conduction, and the spaced radial nanorods on VGCFs facilitate the migration of lithium ion from the electrolyte. Electrochemical reactions between α-Fe₂O₃ and lithium ion are therefore improved significantly by this tailored architecture.