Cobalt Single Atoms Anchored on Nitrogen-Doped Porous Carbon as an Interlayer for Capture and Catalysis of Polysulfides in Lithium-Sulfur Batteries

The shuttle effect of lithium polysulfides (LiPSs) is one of the main challenges impeding the practical application of lithium-sulfur batteries (LSBs). In this study, we develop an innovative approach involving the creation of cobalt single atoms anchored on nitrogen-doped porous carbon (CoSAC-NPC) as an interlayer for LSBs. This exceptional functional interlayer possesses a porous skeleton and abundant active sites, facilitating the adsorption and catalysis of LiPSs. Furthermore, due to its excellent electrical conductivity, the interlayer also serves as a secondary collector. Electrochemical results confirm the presence of single atom Co sites, which contribute to reducing the polarization voltage and expediting polysulfide conversion. LSBs equipped with the Co-SAC-NPC interlayer exhibit a high specific capacity (1457.9 mA h g(-1) at 0.1C) and maintain a remarkable capacity of 788.7 mA h g(-1) even after 400 cycles at 0.5C, with a minimal capacity decay rate of only 0.045% per cycle.