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

Abstract

In this paper, novel core–shell α-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 γ-Fe₂O₃ to α-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.