Selenium Doping and Vacancy Engineering to Regulate the P-Band Center of Sulfur in Zinc Sulfide for High-Performance...

Zinc-based sulfides are promising anodes for sodium-ion batteries (SIBs) due to their high theoretical capacities and low costs. However, inferior structural stability under high current densities leads to severe volume expansion and rapid capacity fading. Herein, a series of Se-doped, carbon-coated ZnS (ZnS_1-xSe_x@C) anodes with various vacancy levels are designed. Se doping and vacancy engineering modulate the band structure of ZnS and lift the p-band center of sulfur, thereby weakening Zn-S bonds, strengthening Na-S interactions, and accelerating reaction kinetics. The optimized ZnS_0.80Se_0.09@C anode delivers an exceptional rate capability of 328.7 mAh g^-1 at 30 A g^-1 and maintains a remarkable capacity of 372.4 mAh g^-1 over 2200 cycles at 10 A g^-1. Particularly, the sodium-ion full cell exhibits superior rate capacity and long-term cycling stability. These findings provide new insights into enhancing sodium-ion storage performance through controlled doping and vacancy engineering to regulate the p-band center of sulfur.