Regulating Electron Filling and Orbital Occupancy of Anti‐Bonding States of Transition Metal Nitride Heterojunction for High Areal Capacity Lithium–Sulfur Full Batteries

Abstract

AbstractThe commercialization of lithium–sulfur (Li–S) battery is seriously hindered by the shuttle behavior of lithium (Li) polysulfide, slow conversion kinetics, and Li dendrite growth. Herein, a novel hierarchical p‐type iron nitride and n‐type vanadium nitride (p‐Fe2N/n‐VN) heterostructure with optimal electronic structure, confined in vesicle‐like N‐doped nanofibers (p‐Fe2N/n‐VN⊂PNCF), is meticulously constructed to work as “one stone two birds” dual‐functional hosts for both the sulfur cathode and Li anode. As demonstrated, the d‐band center of high‐spin Fe atom captures more electrons from V atom to realize more π* and moderate σ* bond electron filling and orbital occupation; thus, allowing moderate adsorption intensity for polysulfides and more effective d–p orbital hybridization to improve reaction kinetics. Meanwhile, this unique structure can dynamically balance the deposition and transport of Li on the anode; thereby, more effectively inhibiting Li dendrite growth and promoting the formation of a uniform solid electrolyte interface. The as‐assembled Li–S full batteries exhibit the conspicuous capacities and ultralong cycling lifespan over 2000 cycles at 5.0 C. Even at a higher S loading (20 mg cm−2) and lean electrolyte (2.5 µL mg−1), the full cells can still achieve an ultrahigh areal capacity of 16.1 mAh cm−2 after 500 cycles at 0.1 C.