Ionic Liquids Anchored on Carbon Synchronize Ion-Electron Transport in Liquid- and Solid-State Sulfur Batteries

Sulfur-based batteries hold great promise for next-generation energy storage owing to their high capacity and low cost, yet their performance is limited by sluggish ion transport and insulating discharge products. Here, we construct a continuous mixed ion-electron conductor network by anchoring imidazolium-based ionic liquids onto carbon nanotubes via strong π-π interactions. The ionic liquid layers provide fast Li+ pathways along the conductive framework, enabling synchronized ion–electron transport and reducing the Li2S nucleation overpotential to 28.2 mV. This interfacial design accelerates sulfur conversion and delivers outstanding cycling stability over 1000 cycles with only 0.045% capacity decay per cycle. In addition, PEO-based solid-state cells can also exhibit high sulfur utilization (>80%) and robust durability. Ah-level pouch cells achieve 1.7 Ah and 379 Wh kg–1 demonstrating that ionic liquid-anchored carbons offer a scalable strategy toward practical, high-energy lithium–sulfur batteries.