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

• Published in: Advanced functional materials Vol. 34; no. 49
• Main Authors: Wang, Zhengyi, Huang, Wenzhi, Wu, Hao, Wu, Yujie, Shi, Kaixiang, Li, Junhao, Zhang, Weigang, Liu, Quanbing
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 02.12.2024
• Subjects: bifunctional catalysis; Catalytic activity; Commercialization; Electrocatalysts; Electron spin; Electron states; Electron transitions; Electronic structure; Energy levels; Heterostructures; High spin‐state configuration; Interlayers; Iron oxides; Lithium; Lithium ions; Lithium sulfur batteries; lithium−sulfur batteries; Modulation; orbital orientation; Orbitals; Polarization (spin alignment); Redox reactions; Sulfur; sulfur redox kinetics
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202409303

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 Fe3O4/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 Fe3O4/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 Fe3O4, and activating more electronic states in 3d 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 Fe3O4/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. The sulfur redox reaction needs to sort out the multi‐electron orientation of polysulfides, the rational and orderly assignment of electron induced flow is the critical link. Herein, the yolk‐shell Fe3O4/FeP@C heterostructure nanoreactors are fabricated to modulate electronic structure, concerning the orbital spin splitting and electron transition from low‐spin to high‐spin, which activates more electronic states in 3d orbitals.