Construction of uniform SnS2/ZnS heterostructure nanosheets embedded in graphene for advanced lithium-ion batteries

Abstract Lithium-ion batteries have been broadly used in energy storage systems and power batteries. However, the current research on LIBs anodes still faces key problems such as low specific capacity, limited cycle life and low initial coulombic efficiency, which limit its commercial applications. In order to solve these issues, SnS2/ZnS heterostructure nanosheets are synthesized on a reduced graphene oxide (expressed as SnS2/ZnS-rGO) derived from ZnSn(OH)6 through the solution sulfidation method. This composite has the features of two-dimensional ultrathin nanosheets and heterostructure, which can shorten Li+ diffusion distance, and provide additional charge transfer driving force. The three-dimensional (3D) SnS2/ZnS-rGO electrode represents high specific capacity (1458.3 mA h g−1 at 0.2 A g−1) and outstanding cycle stability of 4000 cycles (432.4 mA h g−1 at 10 A g−1). This unique lithium storage mechanism has been studied by in-situ and ex-situ XRD techniques in detail. This work not only provides a feasible method for the preparation of bimetallic sulfides, but also gives a novel application prospect for the new self-built high energy density anode.