Oxygen Bridge-Induced Spin-State Engineering Enables Solvation-Barrier-Free Sulfur Redox Kinetics in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are attractive for next-generation energy storage, yet practical deployment is impeded by the lithium polysulfides (LiPSs) shuttle effect and sluggish sulfur redox kinetics, which are further aggravated by solvent shielding that blocks LiPSs from accessing catalytic sites. Here, we develop a yolk-shell MoO3/Co3O4@C nanoreactor that leverages oxygen bridge-induced orbital oscillation to break the solvation barrier and accelerate interfacial conversion. We identify that the dynamic vibration of Mo-O-Co oxygen bridges facilitates a directional electron flow via a 4d-2p-3d orbital interaction pathway, which fundamentally triggers a low-spin to high-spin transition of Co centers, strengthening d-p orbital hybridization and enabling robust chemisorption/catalysis of LiPSs. Meanwhile, the modulation of solvation structure from solvent-separated ion pairs (SSIPs) to contact ion pairs (CIPs)/aggregates (AGGs) lowers the Li+ desolvation energy barrier and homogenizes the ion flux. Synergistically, the double-shelled architecture confines soluble intermediates and suppresses outward diffusion. Consequently, Li-S batteries deliver 352 mAh g-1 at an ultrahigh rate of 15 C, and an initial areal capacity of 11.95 mAh cm-2 is achieved at an ultrahigh sulfur loading of 13.03 mg cm-2. This work proposes a strategy of oxygen-bridge-induced high-spin state to realize desolvation and mass-transfer reaction of LiPSs within interface catalytic domain.