MoS2/SnS@C Hollow Hierarchical Nanotubes as Superior Performance anode for Sodium-ion Batteries

Abstract As a two-dimensional layered material, SnS is considered a promising candidate anode material for sodium storage due to its high theoretical capacity (1022 mAh g-1) and large interlayer spacing (4.33 A). However, its application is hindered by its large volume expansion and low electronic conductivity. Herein, a unique MoS2/SnS@C hollow hierarchical nanotube with self-supporting structure was synthesized through a facile solvothermal reaction. The results indicate that the hollow nanotube structure can support the material structure and provide a large sodium-ion migration channel. In addition, the heterojunction that formed between SnS and MoS2 can effectively reduce the kinetic barrier of sodium-ion diffusion. Furthermore, the hollow hierarchical nanotube can effectively alleviate the radial and hoop stresses of the SnS sodiation process, inhibit the volume expansion of the material, and increase the capacitance contribution ratio of the material at a high rate. The MoS2/SnS@C composites used as anode materials in sodium-ion batteries (SIBs) delivered excellent rate and cycle performance. The discharge capacity was about 325 mAh g-1 at a high current density of 15 A g-1, and it remained at about 292 mAh g-1 after 2000 cycles at 5 A g-1 current density.