A phase transformation route to Fe2O3-Mn3O4 nanocomposite with improved electrode performance

Intimately mixed nanocomposite of Fe2O3 and Mn3O4 is synthesized by an electrostatically-derived self-assembly between exfoliated MnO2 nanosheets and Fe cations, which is followed by heat-treatment at elevated temperature. The as-prepared Fe-layered MnO2 nanocomposite experiences phase transformations into Fe-substituted Mn3−xFexO4 nanoparticle at 450 °C and Fe2O3-Mn3O4 nanocomposite at 650 °C. The Fe2O3−Mn3O4 nanocomposite shows better performance as anode material for lithium ion batteries than the Fe-substituted Mn3−xFexO4 nanoparticle, indicating the beneficial effect of composite formation on the electrode performance of 3d metal oxide. The present finding underscores that a self-assembly between exfoliated metal oxide nanosheets and metal cations can provide useful precursor for efficient composite electrode materials.