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 CoSAC-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.