Hierarchical SnO2-Fe2O3 heterostructures as lithium-ion battery anodes

We report a facile, two-step hydrothermal growth method to synthesize a novel hierarchical SnO2-Fe2O3 heterostructure, consisting of a micron-sized primary SnO2 nanosheet base and sub-10 nm diameter Fe2O3 nanorod branches grown on the nanosheet surface. In addition to the high theoretical lithium storage capacities of both oxide components, the two-dimensional SnO2 nanosheets offer a high surface area and fast charge transport pathways, and the one-dimensional alpha-Fe2O3 nanorods serve as structural spacers between individual SnO2 nanosheets, thus leading to an excellent anode material for lithium-ion batteries with enhanced capacity and cycling property. As a proof-of-concept, lithium-ion battery anodes made of these hierarchical SnO2-Fe2O3 heterostructures have shown a high initial discharge capacity of 1632 mA h g(-1) at 400 mA g(-1), which is retained at 325 mA h g(-1) after 50 cycles, better than the anodes made of pure SnO2 nanosheets and alpha-Fe2O3 nanorods grown under similar conditions.