Fe3O4-C open hollow sphere assembled by nanocrystals and its application in lithium ion battery

This article reports a solvothermal method to fabricate sub-micrometer hematite alpha-Fe2O3 hollow sphere, and Fe3O4-C sphere is obtained with further carbothermal reduction process. The key trick of the solvothermal method is to use crystal water of the raw material Fe(NO3)(3)center dot 9H(2)O as the water phase in the water/oil micro-reactor system. Interestingly, one hole is found on the surface of almost each alpha-Fe2O3/Fe3O4 hollow sphere. The obtained material is characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmer-Teller analysis, elemental analysis and its electrochemical properties are also studied. This Fe3O4-C composite material shows a high reversible capacity of 917.3 mAh g(-1) at 90 mA g(-1), 849.3 mAh g(-1) at 900 mA g(-1), and can be employed as excellent anode material for high energy-density lithium ion battery. (C) 2012 Elsevier B. V. All rights reserved.