Well-ordered mesoporous Fe₂O₃/C composites as high performance anode materials for sodium-ion batteries

Sodium-ion batteries have attracted considerable attention in recent years. In order to promote the practical application of sodium-ion batteries, the electrochemical performances, such as specific capacity, reversibility, and rate capability of the anode materials, should be further improved. In this work, a Fe₂O₃/C composite with a well-ordered mesoporous structure is prepared via a facile co-impregnation method by using mesoporous silica SBA-15 as a hard template. When used as an anode material for sodium-ion batteries, the well-ordered mesoporous structure ensures fast mass transport kinetics. The presence of nano-sized Fe₂O₃ particles confined within the carbon walls significantly enhances the specific capacity of the composite. The carbon walls in the composite act not only as an active material contributing to the specific capacity, but also as a conductive matrix improving the cycling stability of Fe₂O₃ nanoparticles. As a result, the well-ordered mesoporous Fe₂O₃/C composite exhibits high specific capacity, excellent cycleability, and high rate capability. It is proposed that this simple co-impregnation method is applicable for the preparation of well-ordered mesoporous transition oxide/carbon composite electrode materials for high performance sodium-ion and lithium-ion batteries.