Nanofluidic Interfaces Accelerating Sulfur Redox Kinetics toward High-Areal-Capacity Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries are promising for high-energy storage, yet practical devices are constrained by the coupled challenges of polysulfide shuttle and slow sulfur conversion, which become particularly severe at high sulfur loading and lean electrolyte. Here we report a vermiculite-derived nanofluidic separator interface that couples ion-selective transport with conversion regulation to accelerate sulfur electrochemistry and enhance sulfur utilization. Li-intercalated vermiculite nanosheets (VMT-Li) are assembled onto a commercial polypropylene (PP) separator to form a laminated coating with negatively charged, interlayer-confined galleries. This nanofluidic interface preferentially conducts Li + while rejecting anionic polysulfides, and simultaneously creates a confined reaction microenvironment that enriches intermediates and promotes Li 2 S formation, thereby reconciling shuttle suppression with accelerated sulfur redox kinetics. Consequently, Li-S cells using VMT-Li/PP exhibit markedly reduced interfacial impedance (81.9 Ω vs 227.1 Ω for PP) and stable long-term cycling (retaining 581.4 mAh g -1 after 500 cycles at 2 C). Importantly, the benefits persist under practical conditions (sulfur loading ∼9 mg cm -2 , E/S = 6 μL mg -1 ) and extend to a 1 Ah-class pouch cell delivering ∼200 Wh kg -1 based on total pouch-cell mass. This work establishes nanofluidic interface engineering as a scalable strategy to enable fast sulfur conversion and realize long-life, high-areal-capacity Li-S batteries.