Schottky Barrier and Interfacial Oxygen Vacancies Engineering Enable Low-Barrier-Potential Electron Injection and...

Developing effective electrocatalysts to suppress lithium polysulfides (LiPSs) shuttling and accelerate the sluggish sulfur redox reaction (SRR) remains challenging for lithium-sulfur batteries (LSBs). The multistep 16-electron SRR requires not only strong polysulfides conversion capability but also sustained interfacial electron supply. Herein, we report a MOF-derived catalytic site and Schottky barrier dual-engineered semiconductor-metal heterostructure, denoted DSMH@C, to couple polysulfides catalysis with low-barrier-potential electron injection. In DSMH@C, oxygen-deficient semiconducting In₂O_3-x provides vacancy-associated catalytic sites that strengthen LiPSs chemisorption and d-p orbital hybridization with sulfur species, while metallic In serves as an electronically coupled transport domain. More importantly, the defect states in In₂O_3-x regulate the energy band and depletion region at the In/In₂O_3-x heterointerface, lowering the electron-injection barrier potential from metallic In to the semiconducting catalytic domain. This dual engineering enables efficient polysulfides conversion with timely electron supply, accelerating SRR kinetics and suppressing LiPSs shuttling. Consequently, DSMH@C delivers 998 mAh g^-1 at 1 C, a low capacity decay rate of 0.038% per cycle over 500 cycles, an areal capacity of 11.1 mAh cm^-2 at 10 mg cm^-2 sulfur loading, and a pouch-cell energy density of 507.5 Wh kg^-1.