Hierarchical microspheres constructed by SnS2 nanosheets and S-doped graphene for high performance lithium/sodium-ion batteries

Abstract

SnS2 with a two-step conversion and alloying mechanism, has now regarded as potential anode materials in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, significant capacity attenuation caused by the tremendous volumetric change inhibits its practical application. Herein, the hierarchical microspheres constructed by SnS2 nanosheets and S-doped graphene (SnS2-rGO) are synthesized via coprecipitation and hydrothermal methods. After 400 cycles at a current density of 1 A g−1, hierarchical SnS2-rGO microspheres can receive a superb reversible capacity of 1177.2mAhg−1 in LIBs. After 400 cycles in SIBs, hierarchical SnS2-rGO microspheres can perform a charge capacity of 483.1mAhg−1 at 0.5 A g−1. The single SnS2 nanosheet with a thickness of 20 nm can facilitate the insertion/extraction of lithium/sodium-ion, which is helpful to improve the lithium/sodium storage capacity. In addition, a conductive network constructed by the S-doped graphene can boost electron migration. Sufficient volume expansion space can be offered by the hierarchical structure, which can as well as strengthen the contact with electrolytes. Thus, the hierarchical SnS2-rGO microspheres can be inferred as an ideal anode for LIBs and SIBs.