Fe2 O3 nanoparticles wrapped in multi-walled carbon nanotubes with enhanced lithium storage capability

Abstract

We have designed a novel hybrid nanostructure by coating Fe 2O3 nanoparticles with multi-walled carbon nanotubes to enhance the lithium storage capability of Fe2O3. The strategy to prepare Fe2O3 @MWCNTs involves the synthesis of Fe nanoparticles wrapped in MWCNTs, followed by the oxidation of Fe nanoparticles under carbon dioxide. When used as the anode in a Li-ion battery, this hybrid material (70.32 wt% carbon nanotubes, 29.68 wt% Fe2O 3) showed a reversible discharge capacity of 515mAhg-1 after 50 cycles at a density of 100mAg-1 and the capacity based on Fe2O3 nanoparticles was calculated as 1147mAhg -1, Three factors are responsibile for the superior performance: (1) The hollow interiors of MWCNTs provide enough spaces for the accommodation of large volume expansion of inner Fe2O3 nanoparticles, which can improving the stability of electrode; (2) The MWCNTs increase the overall conductivity of the anode; (3) A stable solid electrolyte interface film formed on the surface of MWCNTs may reduce capacity fading.