Preparation of Fe₂O₃/Fe foils by anodic oxidation in saturated NaF solution and calcination

Abstract

Fe₂O₃/Fe foils were prepared by anodic oxidation of Fe foils in saturated NaF solution kept at 70°C and subsequent calcination at 400°C. The morphology of anodised Fe foils was affected remarkably by anodic voltage and time. When pulse anodisation was applied, clusters that consisted of nanograins were formed on the Fe foils. The X-ray diffraction and Fourier transform infrared data suggested that the cluster products transformed to Fe₂O₃ after calcining at 400°C for 2 h. According to thermogravimetry–differential scanning calorimetry data, the transformation began at ∼350°C. The Fe₂O₃/Fe anodes for Li ion batteries were analysed by means of cyclic voltammograms, electrochemical impedance spectroscopies and discharge/charge curves.

Keywords:

• Oxidation
• Anode
• Iron
• Morphology
• Foil

This work was financially supported by the National Natural Science Foundation of China (grant nos. 51062018 and 51262031), the Natural Science Foundation of Yunnan (grant nos. 2010FXW004), Program for Innovative Research Team (in Science and Technology) in University of Yunnan Province (grant nos. 2010UY08 and 2011UY09) and Yunnan Provincial Innovation Team (grant no. 2011HC008).