Enhanced cycling performances of hollow Sn compared to solid Sn in Na-ion battery

Hollow Sn nanostructures were obtained by simply controlling PVP addition in a solution-based reduction process. These nanostructures are assembled by many Sn nanoparticles with an inner void structure in the center. As an anode in Na-ion battery, the hollow Sn nanoparticles present improved cycling stability and capability in comparison with solid Sn nanoparticles, clearly indicating enhanced electrochemical properties for pure Sn anode in Na-ion battery. Moreover, their electrochemical impedance spectroscopy and charge/discharge profiles reveal the hollow structure not only maintains much higher capacity at large volumetric shrinkage process, but also provides structural stability and facilitated charge transfer in Sn anodes during the electrochemical reaction. Therefore, this hollow Sn nanostructure could provide new insight towards the exploration and design of alloy anode materials in Na-ion battery.