α-Fe 2 O 3 /SnO 2 heterostructure composites: A high stability anode for lithium-ion battery

Abstract α-Fe2O3 microoval structure decorated with SnO2 nanocrystals are fabricated by hydro-thermal process. The composite heterostructure has a uniform size of 310 nm in length and 110 nm in width, and SnO2 shell thickness is ∼10 nm. The SnO2 shell acts as a conductive layer to offer fast pathways for transport of electrons and ions. What is more, the SnO2 layer serves as an inactive matrix for α-Fe2O3 particles, avoiding agglomeration and keeping structural integrity. Benefiting from the smart design, the hierarchical α-Fe2O3/SnO2 composite as anode exhibits a higher specific capacity and a better rate performance than those of pristine α-Fe2O3 structures. The stability electrochemical performance of the hierarchical composite can be put down to the core-shell architecture, which improves the conductivity and stability of the electrodes. The heterostructure design in our work provides a possible approach to synthesis high stability materials for electrochemical energy storage.