Electrostatic spray deposition of porous Fe2O3 thin films as anode material with improved electrochemical performance for lithium–ion batteries

Iron oxide materials are attractive anode materials for lithium–ion batteries for their high capacity and low cost compared with graphite and most of other transition metal oxides. Porous carbon-free α-Fe2O3 films with two types of pore size distribution were prepared by electrostatic spray deposition, and they were characterized by X-ray diffraction, scanning electron microscopy and X-ray absorption near-edge spectroscopy. The 200 °C-deposited thin film exhibits a high reversible capacity of up to 1080 mAh g−1, while the initial capacity loss is at a remarkable low level (19.8%). Besides, the energy efficiency and energy specific average potential (Eav) of the Fe2O3 films during charge/discharge process were also investigated. The results indicate that the porous α-Fe2O3 films have significantly higher energy density than Li4Ti5O12 while it has a similar Eav of about 1.5 V. Due to the porous structure that can buffer the volume changes during lithium intercalation/de-intercalation, the films exhibit stable cycling performance. As a potential anode material for high performance lithium–ion batteries that can be applied on electric vehicle and energy storage, rate capability and electrochemical performance under high-low temperatures were also investigated.