Phase-segregation induced growth of core-shell α-Fe2O3/SnO2 heterostructures for lithium-ion battery

In this paper, novel core-shell alpha-Fe2O3/SnO2 heterostructures (HSs) are successfully prepared by a one-step flame-assisted spray copyrolysis of iron and tin precursor. The effect of SnO2 component is investigated for the evolution of phase composition and morphology in detail. For the first time, it is noted that SnO2 as a dopant can effectively promote the phase transition of gamma-Fe2O3 to alpha-Fe2O3 during flame synthesis. A phase-segregation induced growth mechanism is proposed to explain the formation of a unique core-shell structure. Such core-shell HSs as LIB anode materials exhibit an enhanced lithium storage capacity in comparison to pure Fe2O3 and SnO2. This enhancement could be ascribed to the synergetic effect of both single components as well as the unique core-shell HSs.