In situ grown graphitic carbon/Fe₂O₃/carbon nanofiber composites for high performance freestanding anodes in Li-ion batteries

Conductive carbon nanofiber electrodes containing graphitic carbon coated Fe₂O₃ nanoparticles are synthesized via facile, one-pot electrospinning. The catalytic effect of Fe allows in situ formation of onion-shaped graphene layers on Fe₃C nanoparticles upon carbonization, which are transformed into Fe₂O₃ by annealing. The graphene coating offers several important synergies: it not only prevents the Fe₂O₃ particles from peeling off from the carbon nanofiber substrate, but it also buffers the volume change of Fe ₂O₃ and improves the conductivity of the electrode. As a consequence, the freestanding composite anode delivers an excellent capacity of 826 mA h g^-1 after 105 charge/discharge cycles at 0.1 A g ^-1 for Li ion batteries.