Enhanced Electrochemical Performance of Fe0.74Sn5@Reduced Graphene Oxide Nanocomposite Anodes for Both Li-Ion and Na-Ion Batteries.

The recently found intermetallic FeSn5 phase with defect structure Fe0.74Sn5 has shown promise as a high capacity anode for lithium-ion batteries (LIBs). The theoretical capacity is as high as 929 mAh g(-1) thanks to the high Sn/Fe ratio. However, despite being an alloy, the cycle life remains a great challenge. Here, by combining Fe0.74Sn5 nanospheres with reduced graphene oxide (RGO) nanosheets, the Fe0.74Sn5@RGO nanocomposite can achieve capacity retention 3 times that of the nanospheres alone, after 100 charge/discharge cycles. Moreover, the nanocomposite also displays its versatility as a high-capacity anode in sodium-ion batteries (SIBs). The enhanced cell performance in both battery systems indicates that the Fe0.74Sn5@RGO nanocomposite can be a potential anode candidate for the application of Li-ion and Na-ion battery.