A densely packed Sb₂O₃ nanosheet-graphene aerogel toward advanced sodium-ion batteries

As a promising anodic material for rechargeable batteries, Sb₂O₃ has drawn increasing attention due to its high theoretical capacity and abundant natural deposits. However, poor cyclability and rate performance of Sb₂O₃ derived from a large volume change during insertion/desertion reactions as well as a sluggish kinetic process restrict its practical application. Herein, we report a facile amorphous-to-crystalline strategy to synthesize a densely packed Sb₂O₃ nanosheet-graphene aerogel as a novel anode for sodium ion batteries (SIBs). This Sb₂O₃/graphene composite displays a reversible capacity as high as 657.9 mA h g^-1 even after 100 cycles at 0.1 A g^-1, along with an excellent rate capacity of 356.8 mA h g^-1 at 5.0 A g^-1. The superior electrochemical performance is attributed to the synergistic effects of densely packed Sb₂O₃ nanosheets and graphene aerogel, which serves as both a robust support and stable buffer layer to maintain the structural stability of the nanocomposite, and enhances the electrode kinetics of electrolyte diffusion and electron transfer simultaneously. Hence, this densely-packed two-dimensional Sb₂O₃ nanosheet-graphene aerogel can be a promising anode material for rechargeable SIBs due to its facile synthesis process and outstanding electrochemical performance.