Achieving long cycle sodium-ion storage by an “top-down” size control strategy on Sn-based anode

Size control is one of the important strategies to improve the sodium-ion storage performance of Sn-based anode materials. However, the traditional control strategy of “bottom-up” methods still needs to be improved because of their complex processes to obtain nanostructures in Sn anodes. Herein, a simple “top-down” strategy is adopted to realize ultra-small Sn nanoparticles (∼25 nm). This strategy employs in-situ phase transformation technology of Sn nanoparticles, decreasing the size of Sn nanoparticles from 125 to 25 nm successfully. Benefiting from this nanostructure, these ultra-small Sn nanoparticles achieve long cycle sodium-ion storage performance during cycling. As an anode material for sodium-ion batteries, the electrode exhibits a reversible capacity of 387.2 mAh•g−1 after 500 cycles at a current density of 1 A•g−1. Further characterization shows that it has good kinetics performance and structural stability. This work can provide ideas toward the structural design of Sn-based anode to obtain high electrochemical performance in future.