<p>In recent years, antimony trisulfide (Sb₂S₃) has been considered a promising anode material for sodium-ion batteries (SIBs) due to its high theoretical specific capacity of 946 mAh g⁻¹ and low electrochemical potential of around 0.5&#xa0;V vs. Na⁺/Na. However, the practical application of Sb₂S₃ is severely limited due to significant volume expansion during charge–discharge cycles and its poor conductivity, which affect the cycling stability and long-term usability of the battery. This study, based on theoretical calculations, proposes that cobalt (Co) can react with Sb₂S₃ through a redox reaction, transforming Sb₂S₃ into a more conductive product. CoSbS was synthesized by mixing Co and Sb₂S₃ in a 2:1 molar ratio and heating the mixture. To further enhance the reversible capacity and stability of the material, CoSbS was ball-milled with graphite to form a nanoscale layered CoSbS-G composite. This composite exhibited an initial reversible capacity of 590.9 mAh g⁻¹ at a current density of 1 A g⁻¹. At current densities of 0.1, 0.2, 0.5, 1.0, 2.0, and 4 A g⁻¹, the CoSbS-G composite achieved reversible capacities of 507.7, 453.2, 414.8, 369.2, 346.4, and 325.8 mAh g⁻¹, respectively, compared to bulk CoSbS, which exhibited reversible capacities of 684.4, 423, 317.2, 172.9, 110.7, and 82.1 mAh g⁻¹ under the same conditions. These results indicate that the exfoliated graphite greatly enhances the material’s practical performance. This study offers a novel approach for developing high-capacity, long-lifespan sodium-ion battery anode materials based on multi-metal sulfides.</p>