Coupled Electronic-Catalytic Regulation in All-in-One VN/B₂O₃ Ceramic Enables Fast Polysulfides Conversion in Li-S...

Lithium-sulfur (Li-S) batteries hold great promise for next-generation high-energy storage but are challenged by sluggish lithium polysulfides (LiPSs) conversion, low sulfur utilization, and limited practical loading. Herein, we report an all-in-one ant-nest-like porous VN/B₂O₃ (VNBO) ceramic, constructed through a bottom-up sintering-diffusion process of VN nanoparticles coupled with the phase transition of B₂O₃. This integrated porous ceramic provides a continuous conductive framework with minimized interfacial resistance. The VN nano-units serve as highly active catalytic centers to accelerate LiPSs redox kinetics, while B₂O₃ component promotes the formation of the hierarchical ant-nest-like network and modulates the electronic structure of the VN/B₂O₃ heterointerface. This coupled electronic-catalytic regulation effectively suppresses LiPSs shuttling and enables fast, reversible LiPSs conversion. Benefiting from this synergistic architecture, the 2-VNBO@S cathode delivers outstanding electrochemical performances, achieving 1187.2 mAh g^-1 at 0.5 C after 200 cycles and retaining 944.3 mAh g^-1 over 300 cycles at 3 C with a capacity decay of only 0.054% per cycle. Even under a high sulfur loading of 4 mg cm^-2, it maintains 557.9 mAh g^-1 after 150 cycles. This work establishes a robust design strategy for high-energy and catalytically active sulfur cathodes.