Synergistic Cu/Se Substitution and Dual Carbon Encapsulation in ZnS Enabling High‐Rate Sodium Storage

ABSTRACT

ZnS possesses an elevated theoretical capacity, a feature that makes it an exceptionally promising anode option for sodium‐ion batteries (SIBs), yet its electrochemical performance is severely hindered by sluggish electron and ion migration kinetics, along with structural deterioration upon repeated cycling. Here, a synergistic Cu/Se dual‐doped and dual carbon encapsulated ZnS (CuZnSSe@DC) anode is rationally designed. The incorporated Cu cation and Se anion not only boost charge transfer kinetics but also create rapid Na ⁺ diffusion channels. Meanwhile, the conductive dual carbon encapsulation efficiently accommodates volume variation during electrochemical processes. As expected, CuZnSSe@DC demonstrates excellent sodium storage properties, delivering a high‐rate capability (193.1 mAh g ⁻¹ at 100 A g ⁻¹ ) and a long lifespan of 2500 cycles at 20 A g ⁻¹ . This work highlights the great potential of cation/anion dual‐doping engineering in developing high‐capacity, durable anodes suitable for SIBs.