Sb ₂ S ₃ Nanorods Anchored on Lignite‐Derived Carbon With Strong C‐S Interfacial Coupling Enabling High Initial Coulombic Efficiency Sodium‐Ion Batt

ABSTRACT

Sb ₂ S ₃ is regarded as a promising anode for sodium‐ion batteries (SIBs) because of its high theoretical capacity and moderate working potential. However, it suffers from huge volume changes, poor conductivity, and excessive side reactions, leading to severe capacity decay and a low initial Coulombic efficiency (ICE), thus limiting its practical use in SIBs. Herein, an Sb ₂ S ₃ /CS composite was synthesized solvothermally by anchoring Sb ₂ S ₃ nanorods onto lignite‐derived porous C and in situ doping the C with S. Specifically, lignite‐derived porous C simultaneously realizes the anchoring of Sb ₂ S ₃ nanorods and in situ S doping, constructing a strong C–S interfacial coupling structure that effectively buffers volume expansion and increases defect sites. This strategy optimizes surface chemistry to suppress polysulfide shuttling and induce a thin, uniform solid electrolyte interphase (SEI) film, thereby minimizing irreversible Na ⁺ consumption. Moreover, the hierarchical pores shorten ion transport pathways and enhance conductivity and active sites, thereby facilitating charge transfer kinetics. Consequently, the obtained Sb ₂ S ₃ /CS achieves an ICE of 88.9% at 0.1 A g ⁻¹ , retains 86.1% of its capacity when the current density is increased by 50‐fold, and maintains a capacity of 443.8 mAh g ⁻¹ after 2000 cycles at 5.0 A g ⁻¹ without significant capacity degradation.