Constructing hierarchical SnS2 hollow micron cages anchored on S-doped graphene as anodes for superior performance alkali-ion batteries

Abstract

Two-dimensional layered metal sulfides have been regarded as worthwhile anodes for Lithium/Sodium-ion batteries (LIBs/SIBs) due to their extraordinary specific capacity and outstanding cyclic stability. Nevertheless, the sluggish reaction kinetics of alkali ions and pulverization in the process of discharging/ charging still restrict further development of layered metal sulfides. Therefore, reasonable structure design and surface optimization become efficacious ways to solve this issue. Herein, a hollow micron cage with a hierarchical structure composed of SnS2 nanosheets anchoring on S-doped reduced graphene oxide (H-SnS2@rGO) was prepared by a two-step hydrothermal method. The layered SnS2 nanosheets provide remarkable kinetic conditions for the rapidly diffusion of alkali ions. Moreover, the synergistic effect of hollow structure and rGO makes H-SnS2@rGO exhibit satisfactory electrochemical performance. Which displays a prominent rate capacity (874.1 mA h g−1 at 5 A g−1) in LIBs and an admirable specific capacity (613.3 mA h g−1 at 0.1 A g−1 after 100 cycles) in SIBs. This work opens up a new route for the use of two-dimensional layered sulfides as anode materials for new-type alkali-ion batteries.