Enhanced electrochemical performance of template-free carbon-coated iron(II, III) oxide hollow nanofibers as anode material for lithium-ion batteries

Carbon-coated Fe3O4 hollow nanofibers (Fe3O4/C hNFs) as a lithium ion battery anode material are prepared through electrospinning, annealing, and hydrothermal processing. At a high current density of 1000 mAg−1, the template-free Fe3O4/C hNFs exhibit high 1st- and 150th-cycle specific capacities of ∼963 and 978 mAhg−1, respectively. Moreover, Fe3O4/C hNFs have excellent and stable rate capability, compared to that of the Fe3O4 hNFs, and a capacity of 704 mAhg−1 at a current density of 2000 mAg−1. Owing to the carbon layer, the Li-ion diffusion coefficient of the Fe3O4/C hNFs, 8.10 × 10−14 cm2 s−1, is 60 times higher than that (1.33 × 10−15 cm2 s−1) of the Fe3O4 hNFs. These results indicate that Fe3O4/C hNFs may have important implications for developing high performance anodes for next-generation lithium ion batteries.