Sieve Tube-Inspired Polysulfide Cathode with Long-Range Ordered Channels and Localized Capture-Catalysis Microenvironments for Efficient Li-S Batteries

Accelerating the conversion of soluble lithium polysulfides (LiPSs) to solid Li2S2/Li2S through single-atom cathodes has emerged as a promising strategy for realizing high-performance lithium-sulfur batteries. However, rationally optimizing the conversion effects and spatial capture abilities of LiPSs intermediates on the atomic catalytic sites is extremely required but still faces enormous challenges. Here, inspired by the delicate structure of sieve tubes in plants, Fe single-atom cathode (channel-FeSAC) equipped with long-range ordered channels and localized capture-catalysis microenvironments towards efficient LiPSs conversion is reported on designing. Benefiting from the individual and stable catalytic areal for localized capture and migration inhibition abilities on LiPSs and fully confined triple-phase boundaries between atomic catalytic centers, conductive carbon, and electrolytes, the channel-FeSAC can effectively convert polysulfides, thus eliminating the shuttle effects and generation of inactive LiPSs. It is also elucidated that the channel-FeSAC exhibits superior migration inhibition of polysulfide and accelerates Li2S deposition/conversion kinetics compared with bowl-FeSAC and flat-FeSAC. The outstanding areal capacity and cycling stability under high sulfur loading and low electrolyte/sulfur ratio verify that the channel-FeSAC holds great potential as cathodes for high-performance cathodes. This work offers vital insights into the essential roles of bioinspired fully confined channels and catalytic microenvironments in polysulfide catalysis for efficient lithium-sulfur batteries. Sieve tube-inspired polysulfide cathode with long-range ordered channels and localized capture-catalysis microenvironments is designed for Li-S batteries. Benefiting from the spatial geometry optimization, including ordered channels and fully confined triple-phase boundaries between catalytic centers, conductive carbon, and electrolytes, the cathode can effectively convert polysulfides via sulfur redox reactions, thus eliminating their shuttle effects and generation of inactive intermediates.image