Synergetic approach to achieve enhanced lithium ion storage performance in ternary phased SnO₂-Fe₂O₃/rGO composite nanostructures

We report here a study on the Li ion storage performance of binary phased SnO₂/rGO and ternary phased SnO₂-Fe₂O ₃/rGO composite nanostructures. The SnO₂/rGO and SnO ₂-Fe₂O₃/rGO were prepared by a facile wet-chemical approach. The Li storage performances of these samples were closely related to the weight ratio of SnO₂:rGO or SnO₂:Fe ₂O₃:rGO. It was found that ternary SnO₂-Fe ₂O₃/rGO composite nanostructures (e.g. with a weight ratio of SnO₂:Fe₂O₃:rGO = 11:1:13) showed significant enhancement of the specific capacities and cyclabilities as compared to that of SnO₂/rGO samples. For example, the SnO ₂-Fe₂O₃/rGO electrode depicted a specific capacity of 958 mA h g^-1 at a current density of 395 mA g ^-1 (0.5 C) during the 100^th cycle. Such Li storage performances of the SnO₂-Fe₂O₃/rGO electrodes, especially at high current densities (e.g. 530 mA h g^-1 at 5 C rate), were also much better than those reported for either SnO₂-based or Fe₂O₃-based electrodes. Such a synergetic effect in the SnO₂/Fe₂O₃/rGO composite nanostructures is promising for the development of advanced electrode materials for rechargeable Li-ion batteries.