Boron-doped Sb/SbO 2 @rGO composites with tunable components and enlarged lattice spacing for high-rate sodium-ion batteries

Abstract Antimony (Sb) and its oxides, as promising electrode materials, have attracted much attention because of their low cost, environmental friendliness, and high theoretical capacity. Herein, boron doped flower-cluster-like Sb/SbO 2 @reduced graphene oxide (rGO) composites are synthesized for use as sodium-ion battery anode materials using a solvothermal strategy. The contents of Sb and antimony oxide (SbO 2 ) are controlled by adding different contents of NaBH 4 . Meanwhile, the introduction of NaBH 4 successfully realizes boron doping and enlarges the lattice spacing of the SbO 2 , improving its conductivity and Na + transport. As a result, optimal Sb/SbO 2 @rGO-10 composites display a desirable capacity of 346 mAh g −1 at 50 mA g −1 after 100 cycles with a capacity retention of 106%. Even at high current densities, a capacity of 236 mAh g −1 is achieved, demonstrating a satisfactory rate capacity. Moreover, the Sb/SbO 2 @rGO-10 electrode shows satisfactory Na storage performance at low temperatures. In addition, sodium-ion full cells are assembled using an Sb/SbO 2 @rGO-10 anode and a Na 3 V 2 (PO 4 ) 2 O 2 F cathode, with which a satisfactory electrochemical performance of 102 mAh g −1 after 50 cycles at 50 mA g −1 is achieved, showing their high practical potential.