Hydrothermal synthesis and characterization of α-Fe2O3/C using acid-pickled iron oxide red for Li-ion batteries.

To recycle the waste and meet the demand for anode materials for Li-ion battery, α-Fe2O3/C for use as anode material is successfully prepared via a simple hydrothermal process using acid-pickled iron oxide red as raw material. The techniques of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy are used to characterize the product. The synthesis conditions, including temperature and time, are optimized by orthogonal experimental design. The optimal reaction temperature, reaction time, Fe2O3/SO42- ratio, Fe2O3/glucose ratio are 120 °C, 30 h, 20:2 and 1:1, respectively. The sample prepared at optimal conditions exhibits a high initial specific capacity of 1144/1535 mA h g-1 at 100 mA g-1 and a superior cycling performance of ˜800 mA h g-1 after 200 cycles. Accordingly, this method provides information for the synthesis of α-Fe2O3/C with acid-pickled iron oxide red for the first time, which may help alleviate the problem of energy shortage and environmental pollution through the rational use of resources.