Graphene Decorated by Indium Sulfide Nanoparticles as High-Performance Anode for Sodium-Ion Batteries

We report a highly performing anode material for sodium-ion batteries (SIBs) composed of graphene decorated by indium sulfide (In₂S₃). The composite is synthesized by a facile hydrothermal pathway with subsequent annealing and is characterized by defined structure and well-tailored morphology, as is indeed demonstrated by X-ray diffraction and spectroscopy as well as high-resolution microscopy. These optimal characteristics allow the electrode to perform remarkably in sodium cell by achieving a maximum specific capacity as high as 620 mAh g^-1 and the still-relevant value of 335 mAh g^-1 at an extremely high current (i.e., 5 A g^-1). The high storage capacity, the long cycle life, and the impressive rate capability of the composite may be attributed to the synergetic effect between uniform In₂S₃ nanoparticles and the graphene matrix. These features suggest that the In₂S₃-graphene is a viable choice for application as an anode material in high-performance SIBs.