Enhanced cycling performance of an Fe0/Fe3O4 nanocomposite electrode for lithium-ion batteries.

We demonstrate the formation of a highly conductive, Fe0/Fe3O4 nanocomposite electrode by the hydrogen reduction process. Fe2O3 nanobundles composed of one-dimensional nanowires were initially prepared through thermal dehydrogenation of hydrothermally synthesized FeOOH. The systematic phase and morphological evolutions from Fe2O3 to Fe2O3/Fe3O4, Fe3O4, and finally to Fe/Fe3O4 by the controlled thermochemical reduction at 300 degrees C in H2 were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM). The Fe/Fe3O4 nanocomposite electrode shows excellent capacity retention ( approximately 540 mA h g(-1) after 100 cycles at a rate of 185 mA g(-1)), compared to that of Fe2O3 nanobundles. This enhanced electrochemical performance in Fe/Fe3O4 composites was attributed to the formation of unique, core-shell nanostructures offering an efficient electron transport path to the current collector.