Facile synthesis of monodispersed α-Fe2O3 cubes as a high-performance anode material for lithium-ion batteries

Monodispersed cubic α-Fe2O3 particles are prepared by a facile hydrothermal method with FeCl3•6H2O and CO(NH2)2 as raw materials. The structure and surface morphology of the sample are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performance of the sample is investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic discharge–charge tests. The results demonstrate that the cubic α-Fe2O3 has a superior high-rate capability and outstanding cycling stability. For example, the cubic α-Fe2O3 maintains a specific capacity of 377 mA h g−1 at 2.0 A g−1, and delivers a reversible capacity of 664 mA h g−1 after 500 cycles at 500 mA g−1. The lithium ions diffusion coefficient evaluated by galvanostatic intermittent titration technique (GITT) method ranges from 10−11 to 10−14 cm2 s−1. Ex-situ SEM and charge storage mechanism analysis reveal that the cubic α-Fe2O3 has good structural integrity and exhibits a pseudocapacitive-dominant charge storage behavior during discharge/charge processes, which account for the superior cycling stability and high-rate performance. Considering the merits of low-cost, easy preparation, non-toxicity, and superior lithium storage performance, the cubic α-Fe2O3 could be a promising candidate as an anode material for next-generation LIBs.