High-performance α-Fe2O3/C composite anodes for lithium-ion batteries synthesized by hydrothermal carbonization glucose method used pickled iron oxide red as raw material

The alpha-Fe2O3/C composites have been successfully synthesized by a facile hydrothermal carbonization glucose method using pickled iron oxide red as raw materials, which is the recycled product after treating the pickling wastewater. The NaOH is used as an additive to assist carbonization of glucose to obtain the high-quality carbon coating layer. X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscope are used to characterize the structure and morphology of the samples. To characterize the surface chemical composition and bonding configuration of alpha-Fe2O3/C, X-ray photoelectron spectroscopy is detected. The Electrochemical properties are optimized by the orthogonal tests, revealing that the hydrothermal reaction time has the most significant influence on the electrode capacity, followed by the hydrothermal reaction temperature, the amount of glucose added and the concentration of NaOH. As anode material for lithium ion battery, the initial discharge/charge capacity of alpha-Fe2O3/C electrode can reach 2640.1/2151.4 mAh g(-1) with initial coulomb efficiency of 81.49% at a current density of 100 mA g(-1), and even after 80 cycles maintain the capacity of 1529.5 mAh g(-1), which far exceeds the theoretical capacity (1007 mAh g(-1)) of alpha-Fe2O3 electrode.