Balancing Adsorption and Catalysis via Interfacial Electronic Coupling for High-Performance Room-Temperature Na-S...

Room-temperature sodium-sulfur (RT Na-S) batteries face critical challenges from polysulfide shuttling effects and sluggish redox kinetics, requiring an optimal balance between adsorption and catalysis as dictated by the Sabatier principle. Herein, we designed a carbon-supported ruthenium (C-Ru) structure with interfacial electronic coupling to resolve this adsorption-catalysis conundrum. Comprehensive density functional theory (DFT) calculations were first conducted to investigate the atomic-level impact of the C-Ru composite on polysulfide conversion. The substantial charge transfer from Ru to carbon optimally tunes polysulfide adsorption, facilitating sulfur redox kinetics while dramatically lowering the Na₂S decomposition barrier. Geometric and electronic analyses confirm that interfacial charge redistribution systematically weakens Na─S bonds. Guided by these insights, we designed a sponge-like porous carbon-Ru nanocomposite as sulfur host (SPC-Ru) with exceptional electrochemical performance: 924.3 mAh g^{- 1} after 100 cycles at 0.2 A g^{- 1} and ultralow capacity decay of 0.097% per cycle over 500 cycles at 2 A g^{- 1}. This work establishes interfacial electronic coupling as an effective strategy to reconcile adsorption-catalysis conflicts in metal-sulfur batteries, offering a rational pathway toward high-energy-density and long-lifespan RT Na-S energy storage systems.