3-D mesoporous nano/micro-structured Fe3O4/C as a superior anode material for lithium-ion batteries

Urchin-like nano/micro-structured Fe₃O₄/C composite has been successfully synthesized using inexpensive starting materials. The urchin-shaped nano/micro-structure consisted of several oriented nanorods. TEM analysis revealed that there is a large number of pores and uniform amorphous carbon distribution at a nanoscale in the nanorods walls. As used in lithium-ion batteries, the mesoporous Fe₃O₄/C anode delivered a higher reversible capacity of about 830?mAh?g^?1 at 0.1?C up to 50 cycles, as well as enhanced high-rate capability compared with urchin-like Fe₂O₃ and commercial Fe₃O₄. The improvements can be attributed to the combined effects of the nano/micro-architecture, the porosity, and the ultra-fine carbon matrix, where the three factors would contribute to possess both the merits of nanometer-sized building blocks and micro-sized assemblies and provide high electronic conductivity. It is believed that the results of this study offer new prospects for improving the lithium storage capacity of metal oxides by controlling both architecture and composition.