Reducing material accumulation and designing reasonable sizes are critical strategies for increasing the rate and cycling stability of electrode materials. Herein, we presented a double-walled hollow carbon spheres (DWHCSs) loading strategy for achieving ultrafine SnS2 nanosheet adhesion by utilizing three-sided active sites of the interior/exterior carbon walls. The structure effectively shortened the electron/ion transport path, increased the effective contact between electrolyte and electrode material, and promoted ion diffusion kinetics. Furthermore, the hollow structure can adapt to the volume change of the electrode during the cycle, preventing active substances from draining. Based on the above advantages, SnS2@DWHCSs as an anode material for sodium ion batteries (SIBs) exhibited a distinguished reversible capacity of 665.7 mA h g-1 at 2 A g-1 after 1000 cycles, and a superior rate ability of 377.6 mA h g-1 at an ultrahigh rate of 10 A g-1. The outstanding electrochemical performance revealed that the structure exhibited a broad application prospect in the field of energy storage and provided a reference for the rational design of other 2D materials.
Keywords: double-walled hollow carbon spheres; high volume energy density; sodium-ion batteries; three-sided active sites; ultrafine SnS2 nanosheets.