Hollow Multishelled ZnS _0.8 Se _0.2 @HMCS Nanostructures as a High-Performance Anode for Sodium-Ion Batteries

The pursuit of electrode materials with reversible and stable electrochemical performance is pivotal for advancing energy storage technologies. Transition metal sulfides, such as ZnS, are promising anode materials for sodium-ion batteries (SIBs) but suffer from severe volume expansion and sluggish reaction kinetics. To address these issues, we designed and synthesized a hollow multishelled nanostructured carbon composite embedded with Se-doped ZnS (ZnS 0.8 Se 0.2 @HMCS) via a sequential templating and one-step hydrothermal method. Such a well-designed hollow multishelled nanostructure not only offers distinct structural advantages in enhancing material stability and reactivity but also provides internal void space to effectively buffer volume changes during cycling, while the selenium doping enlarges the interlayer spacing and modulates the electronic structure, thereby facilitating Na + diffusion and enhancing conductivity. Benefiting from this synergistic structural and compositional design, the ZnS 0.8 Se 0.2 @HMCS anode exhibits excellent electrochemical performance. It delivers a high reversible capacity of 423 mAh g –1 at 0.1 A g –1 after 200 cycles and maintains a stable capacity of 196 mAh g –1 at 2 A g –1 even after 580 cycles. This work demonstrates a viable strategy of combining structural engineering with anion doping for developing high-performance SIB anodes.