Hierarchical Sb₂S₃/SnS₂/C heterostructure with improved performance for sodium-ion batteries

Metal sulfides are promising anode materials for sodium-ion batteries (SIBs) because of their high theoretical capacities. However, they are usually limited by their poor cycling performance and rate properties due to their large volume expansion and sluggish reaction kinetics. Herein, Sb₂S₃/SnS₂/C heterostructures were fabricated by directly growing SnS₂ nanoplates on Sb₂S₃ nanorods and then coating their surface with a carbon layer. Sodium-ion diffusion in several electrodes and different electrolytes was further evaluated to investigate the electrochemical performance of the heterostructures. Results revealed that the heterostructures greatly enhanced material stability and promoted ion and electron transport. Consequently, the Sb₂S₃/SnS₂/C composites displayed a high reversible capacity of 642 mA h g⁻¹ at a current density of 1 A g⁻¹ after 600 cycles and a good rate performance of 367.3 mA h g⁻¹ at 4 A g⁻¹ in a NaPF₆-diglyme electrolyte. Therefore, Sb₂S₃/SnS₂/C heterostructures are promising anode materials for SIBs.