Co₂C-Decorated Sea-Anemone-Like Carbon Structure: Enhanced Polysulfide Immobilization and Conversion for Lithium–Sulfur Batteries

The critical challenge of suppressing the shuttle effect relies not only on efficient chemisorption but also on accelerating the reaction kinetics of polysulfides. Herein, cobalt carbide (Co₂C)-decorated sea-anemone-like reduced graphene oxide–carbon nanotube (Co₂C@RGO–CNT) is designed as an efficient sulfur host to suppress polysulfide shuttling. The conductive and polar Co₂C nanoparticles are employed as electrocatalysts to effectively entrap polysulfides and accelerate the redox kinetics of lithium polysulfides/sulfides, as revealed both theoretically and experimentally. Three-dimensional sea-anemone-like Co₂C@RGO–CNT architectures form continuous conductive networks and afford sufficient channels for electron transfer from RGO–CNT to Co₂C nanoparticle surface, which accelerates the polysulfide conversion. As a result, the cathode with Co₂C@RGO–CNT exhibits superior cycling stability with high capacity retention of 83.4% and 90.5% at a rate of 0.1C and 1C, respectively. This work highlights Co₂C as a new electrocatalyst to promote immobilization and conversion of polysulfides for high-performance lithium–sulfur batteries.