Synthesis and the comparative lithium storage properties of hematite: hollow structures vs. carbon composites

Abstract

In the present work, α-Fe₂O₃ hollow structures from nanotubes to nanorings, and α-Fe₂O₃/carbon composites composed of nanoparticles homogeneously dispersed on graphene sheets and carbon nanotubes were synthesized via self-assembly combined with a facile hydrothermal method, and their structure, morphology and electrochemical performance were characterized by XRD, XPS, SEM, TEM, CV, charge–discharge tests and EIS. The focus is elucidating how structural aspects, such as particle size and shape of the nanoparticles as well as the carbon matrix, influence the electrochemical properties of the α-Fe₂O₃ nanoparticles. The results revealed that the cycling performance of hollow structured α-Fe₂O₃ improves with the increase of aspect ratio, namely, the α-Fe₂O₃ nanotubes exhibit the best electrochemical performance in terms of reversible capacity, capacity retention and rate performance, which is comparable to that of α-Fe₂O₃ nanoparticle–carbon composites. It is expected that the synthesis of α-Fe₂O₃ nanotubes with high aspect ratio anchored on conducting graphene would be a potential anode material for high performance LIBs.