Electrochemical properties of iron oxide nanoparticles as an anode for Li-ion batteries

Abstract

The synthesis of iron oxide nano-particles by direct thermal decomposition was studied. Simultaneous thermal analysis and Fourier transform infrared spectroscopy results confirmed the formation of iron-urea complex, and disclosed iron oxide formation mechanism. Calcination of the iron-urea complex at 200°C and 250°C for 2 hrs. resulted in the formation of maghemite along with hematite as a second phase. X-ray diffraction results revealed that increment of iron-urea complex calcination temperature led to the augmentation of hematite to maghemite ratio. Field emission scanning electron microscopy and transmission electron microscopy results showed that the average particle size was around 38nm for sample calcined at 250°C for 2 hrs. The anode body was doctor bladed using primary powder with polyvinylidene difluoride and graphite. Galvanostatic charge–discharge cycling showed a reversible capacity of 483 mAh g-1 at 100 mA g−1 current density. The reason for this competent performance was thought to be dependent upon the particle sizes.