Co₃O₄/C-NFs Induced 3D Electric Field Enhancement for Dual-Regulation of Polysulfides and Li⁺ Transport in Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are promising next-generation energy storage systems, yet their practical application is hindered by sluggish and uncontrolled mass transport of Li⁺ and lithium polysulfides (LiPSs). Here, a Co₃O₄-based nano-framework catalyst (Co₃O₄/C-NFs) is designed featuring a highly symmetric 3D sharp-edged architecture that induces strong 3D electric field enhancement. This unique structural design promotes the directional migration and enrichment of negatively charged species, thereby accelerating the sulfur reduction reaction (SRR) kinetics, suppressing LiPSs shuttling, and improving Li⁺ transport. Moreover, by monitoring the real-time conversion of LiPSs during the reaction using integrated in situ techniques, a universal method for quantitatively evaluating LiPSs conversion kinetics is proposed. Both experimental and theoretical results confirm that the 3D electric field enhancement governs mass transfer at multiple scales, achieving efficient ion regulation and interfacial stability. Benefiting from this effect, the assembled double-layer pouch cell with a high sulfur loading of 6.5 mg cm⁻² and a lean electrolyte ratio (E/S = 4 µL mg⁻¹) maintains stable cycling for over 100 cycles at 0.1C, delivering a specific capacity of 1200 mAh g⁻¹. This work introduces a new paradigm of 3D electric field–driven mass transfer modulation for designing high-performance and practical LSBs.