Sb2O3@Sb nanoparticles impregnated in N-doped carbon microcages for ultralong life and high-rate sodium ion batteries

Abstract

Antimony-based materials have been considered as highly competitive anodes for sodium-ion batteries (SIBs) because of their high theoretical capacity. However, the poor rate capability and fast capacity fading, originating from sluggish kinetics and volume expansion, greatly restrict their practical application. To address the above issues, an effective spraying method and one-step partial reduction process were utilized to synthesize Sb₂O₃@Sb nanoparticle impregnated in N-doped carbon microcages (Sb₂O₃@Sb@NC) offering extraordinary sodium storage capabilities and delivering an ultra-high rate performance of 175.1 mA h g⁻¹ at 20 A g⁻¹ and a superior capacity retention of 245.2 mA h g⁻¹ after 10 000 cycles under 10 A g⁻¹ for SIBs. Such unprecedented electrochemical properties of the Sb₂O₃@Sb@NC electrode can be ascribed to the comprehensive characteristics derived from multi-scale structural engineering: the fast electrochemical kinetics and tight packing of Sb₂O₃@Sb nanoparticles with carbon sheets, the strong Na⁺ adsorption ability of Sb₂O₃@Sb@NC enhanced by the synergistic effect of heterostructures and N-doping, the structural integrity strengthened by a robust interface bond of Sb–O–C, and the improved pseudocapacitive contribution. These distinct features enable the Sb₂O₃@Sb@NC anode to be a potential candidate for large-scale sodium ion storage.