Porous peony-like α-Fe2O3 hierarchical micro/nanostructures: synthesis, characterization and its lithium storage properties

In this work, hierarchical peony-like FeCO3 structures of 3-5 mm diameter assembled from nanosheet layers were successfully prepared through a facile and well controlled hydrothermal method in the presence of an anionic surfactant sodium dodecyl sulfate (SDS). The factors influencing the morphology of the hierarchical FeCO3 structures were investigated. Hierarchical peony-like alpha-Fe2O3 structures assembled from nanoparticles were also fabricated by a thermal treatment of the as-obtained FeCO3 at 700 degrees C for 3 h in air. Tested as anode materials of Li-ion batteries, the hierarchical porous peony-like alpha-Fe2O3 structures exhibited an excellent reversible capacity of 1721 mA h g(-1) at a current density of 50 mA g(-1) and a high cyclic stability at 100 mA h g(-1) over 30 cycles. These results demonstrate the hierarchical porous alpha-Fe2O3 is a promising anode candidate for lithium ion batteries.