触媒‐溶媒界面における剥離型触媒とデュアル活性サイトによる貧電解液リチウム硫黄電池のための多硫化物脱溶媒和速度論の強化

Humdrum catalyst-polysulfide interactions in sulfur cathodes of lithium-sulfur (Li-S) batteries show limited effectiveness to further accelerate the sluggish conversion reaction kinetics under lean electrolyte conditions. Herein, we design an electrode/electrolyte interface coupled with W₂N nanoparticles and single-atom W (SA-W) on ultrathin carbon nanosheets for improving the conversion reaction kinetics of Li-S batteries from the perspective of accelerating the desolvation of lithium polysulfides (LiPSs). The desolvation kinetics near the electrode/electrolyte interface are enhanced by the excoriation-type effect of SA-W, first exfoliating the solvation sheath of LiPSs through d-2p hybridization, and then by W₂N nanoparticles adsorbing LiPSs and catalyzing their reduction reaction. Structurally, these carbon nanosheets are self-assembled into hollow microspheres, which reinforce the spatial confinement effect and accommodate the volume change during lithiation/delithiation under high sulfur loading. Such optimized catalyst-reactant/-solvent interactions have elicited superb rate capability (with reversible capability of 702 mAh/g at 5C) and remarkable cycling stability (with capacity degradation rate as small as 0.05% per cycle at 1C over 600 cycles). Benefiting from the rapid desolvation process of LiPSs, a high areal capacity of 13.5 mAh/cm² can be achieved even under high sulfur loading (11.4 mg/cm²) and low electrolyte/sulfur ratio (5 µL/mg). The proposed catalyst/solvent interface engineering has the potential to inspire sustainable liquid-solid interconversion electrochemical energy storage.