Preparation of alpha-Fe2O3 submicro-flowers by a hydrothermal approach and their electrochemical performance in lithium-ion batteries
Uniform alpha-Fe2O3 submicron-sized flowers have been synthesized by a simple hydrothermal process conducted at 160 degrees C for 024 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 alpha-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 0.0 1 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.