Improved sodium storage properties of nickel sulfide nanoparticles decorated on reduced graphene oxide nanosheets as an advanced anode material

For sodium ion batteries, the fabrication of nanocrystal anode materials has been identified as a satisfactory strategy to improve electrochemical performance and maintain the structural integrity of electrodes. However, the issues of agglomeration and serious volume variation have always existed within the process of charging/discharging in anode materials. In this work, a series of composites of nickel sulfide nanoparticles decorated on reduced graphene oxide nanosheets (denoted as NiS2@rGO) were successfully synthesized via a simple one-step hydrothermal method under different temperatures. The strategy of confining nickel sulfide nanoparticles within the interlayer of graphene nanosheets can not only avoid the agglomeration, but also alleviate the volume change to some extent in electrode materials. For sodium ion storage, the NiS2@rGO synthesized at 160 °C exhibited a higher reversible capacity and better rate capability.