3d‐Orbital High‐Spin Configuration Driven From Electronic Modulation of Fe₃O₄/FeP Heterostructures Empowering Efficient Electrocatalyst for Lithium−Sulfur Batteries

Abstract The intricate lithium polysulfides (LiPSs) shuttle and uncontrollable lithium dendrite growth critically hinder the commercialization of lithium−sulfur (Li−S) batteries. The rational and orderly assignment of multi‐electron induced flow is the critical link in sulfer redox reaction. Herein, the yolk‐shell Fe 3 O 4 /FeP@C heterostructure nanoreactors are fabricated to modulate electronic structure, including spin‐related charge behavior and orbital orientation control, which can demonstrate the interaction between catalytic activity and spin‐state conformation. The orbital spin splitting of Fe 3 O 4 /FeP@C induces the electron transition from low‐spin to high‐spin, where the non‐degenerate orbitals contribute to energy level up‐shift, guiding electron migration from FeP to Fe 3 O 4 , and activating more electronic states in 3 d orbitals. Spin polarization guides electron flow and induces sulfur closed‐loop conversion, which are confirmed by DFT simulations and in situ Raman. Hence, the electrochemical performances are remarkable at ultra‐high current density and sulfur loading. Even an initial specific capacity of 928.5 mAh g −1 of a Li−S pouch cell reveals the practical prospect of Fe 3 O 4 /FeP@C/PP separator. The Li//Li symmetric cell cycles steadily for 4000 h, confirming the interlayer simultaneously promotes sulfur evolution kinetics and sieves lithium ions. This work deciphers the principles of spin‐orbit coupling, achieving the topological modulation of “charge−spin−orbit” toward electrocatalysts.