Heterostructured Mn–Sn Bimetallic Sulfide Nanocubes Confined in N, S-co-Doped Carbon Framework as High-Performance Anodes for Sodium-Ion Batteries

Benefiting from its high theoretical capacity, tin disulfide (SnS₂) draws abundant interest and attention for its promising practical prospect for sodium-ion batteries (SIBs). However, the huge volumetric variation in sodiation/desodiation reactions usually results in the fast decay of rate and cycling properties, which seriously obstructs its future applicable foregrounds. Herein, heterostructured Mn-Sn bimetallic sulfide nanocubes confined in N and S-codoped carbon (MSS@NSC) were rationally designed via a facile coprecipitation followed by a sulfurization strategy. When used as anodes for SIBs, the heterojunctions at the interfaces effectively accelerate the Na⁺ diffusion rate to promote the sodium-storage reaction kinetics. The N and S-codoped carbon provides a rapid conductive framework for the fast charge transport during the sodium-storage process. Moreover, the beneficial confinement effect of the NSC layer effectively guarantees a superb cycle property for the MSS@NSC anode. The favorable synergistic effects between the highly conductive framework of the NSC and MSS heterostructure endow the MSS@NSC anode with satisfactory electrochemical Na-storage properties.