A comparative study of lithium-storage performances of hematite: Nanotubes vs. nanorods.

Abstract: α-Fe2O3 nanotubes and nanorods are obtained via a hydrothermal method without further annealing. Both of them are characterized by X-ray powder diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The lithium-storage performances of the nanostructures are measured and compared in terms of reversible capacity, cycling stability, and rate capability. The electrode based on the nanotubes delivers the reversible capacities of 1200 mAh g−1 at 100 mA g−1, 1000 mAh g−1 at 500 mA g−1, and 810 mAh g−1 at 1000 mA g−1 after 60 cycles, much higher than those based on the nanorods. The better performances of the nanotubes could be assigned to their tubular morphology that tolerates the huge volume change during the discharge/charge processes and possesses the large surface area to increase the contact between the electrode and the electrolyte. These insights will be of benefits in the design of other anode materials for lithium ion batteries. [Copyright &y& Elsevier]