Three-dimensionally interconnected nickel-antimony intermetallic hollow nanospheres as anode material for high-rate sodium-ion batteries

Three-dimensionally interconnected NiSb intermetallic hollow nanospheres for Na-ion batteries are prepared by a facile and low-temperature approach involving crystallized 3D interconnected Ni nanospheres precursor and subsequent galvanic replacement reaction involving Sb ions. The 3D interconnected hollow structure and Ni matrix encapsulation contribute significantly to the excellent structure stability and high electrochemical performance of the Sb-based anode. They exhibit highly stable and substantial discharge capacities of 400, 372, 230mAhg^-1 after 150 cycles at 1C, 5C, 10C, respectively. Moreover, a full Na_0.4Mn_0.54Co_0.46O₂//NiSb battery shows at a current density of 300mA/g_Sb a charge and discharge capacity of 451 and 301mAhg^-1, respectively, and also displayed relatively good stability, retaining 75% of the initial discharge capacity after 20 cycles.