Preparation of α-Fe2O3 submicro-flowers by a hydrothermal approach and their electrochemical performance in lithium-ion batteries

Uniform α-Fe2O3 submicron-sized flowers have been synthesized by a simple hydrothermal process conducted at 160 °C for 24 h. The crystalline structure and morphology of the as-synthesized powder have been characterized by using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and field emission scanning electron microscopy (FE-SEM). The results revealed that the highly crystalline α-Fe2O3 submicro-flowers were composed of nanospheres with an average size of 20–30 nm. The electrochemical performance as anode material for lithium-ion batteries was further evaluated by cyclic voltammetry (CV) and by electrochemical impedance and charge–discharge measurements. It was demonstrated that the material could provide an initial reversible capacity of 959.6 mAh/g at a current density of 20 mA/g over the voltage range from 0.01 to 3.0 V. The capacity retention upon the 50th cycle was 44.4 and 35.9% at 60 and 100 mA/g, respectively. The superior electrochemical performance may be resulted from the high surface area and the small and uniform grain size.