Orbital‐Tailoring Strategy via Dual‐Defect Engineering in P‐FeTe _2‐x @NC Synergizes Polysulfide Adsorption‐Conversion for Lithium‐Sulfur Batteries

Abstract

Abstract The polysulfide shuttling and sluggish sulfur redox kinetics hinder the commercialization of lithium‐sulfur (Li‐S) batteries. Herein, the fabrication of phosphorus (P)‐doped iron telluride (FeTe 2 ) nanoparticles with engineered Te vacancies anchored on nitrogen (N)‐doped carbon (C) (P‐FeTe 2‐x @NC) is presented as a multifunctional sulfur host. Theoretical and experimental analyses show that Te vacancies create electron‐deficient Fe sites, which chemically anchor polysulfides through enhanced Fe─S covalent interactions. Additionally, P doping shifts the Fe d‐band center toward the Fermi level, increasing the affinity for polysulfide intermediates through d‐p orbital hybridization. This dual modulation strengthens the built‐in electric field at the P‐FeTe 2‐x /NC interface, effectively suppressing the shuttle effect and accelerating redox kinetics. The optimized P‐FeTe 2‐x @NC host enables Li‐S batteries to achieve an initial capacity of 1475.6 mAh g −1 at 0.1 C and remarkable cycling stability, exhibiting only a 0.031% capacity decay per cycle over 1000 cycles at 1 C. High sulfur utilization is evidenced by attaining 6.51 mAh cm −2 areal capacity under a loading of 7.80 mg cm −2 , while a 2.67 Ah pouch cell delivers an energy density of 326.6 Wh kg −1 . This work establishes a vacancy‐doping synergy strategy for coordinating adsorption and conversion processes in sulfur electrochemistry, offering new insights into the design of high‐energy‐density batteries.