Design Multifunctional Catalytic Interface: Toward Regulation of Polysulfide and Li₂S Redox Conversion in Li–S Batteries

The polysulfide shuttle effect and sluggish reaction kinetics hamper the practical applications of lithium–sulfur (Li–S) batteries. Incorporating a functional interlayer to trapping and binding polysulfides has been found effective to block polysulfide migration. Furthermore, surface chemistry at soluble polysulfides/electrolyte interface is a crucial step for Li–S battery in which stable cycling depends on adsorption and reutilization of blocked polysulfides in the electrolyte. A multifunctional catalytic interface composed of niobium nitride/N‐doped graphene (NbN/NG) along the soluble polysulfides/electrolyte is designed and constructed to regulate corresponding interface chemical reaction, which can afford long‐range electron transfer surfaces, numerous strong chemisorption, and catalytic sites in a working lithium–sulfur battery. Both experimental and theoretical calculation results suggest that a new catalytic interface enabled by metal‐like NbN with superb electrocatalysis anchored on NG is highly effective in regulating the blocked polysulfide redox reaction and tailoring the Li 2 S nucleation–growth–decomposition process. Therefore, the Li–S batteries with multifunctional NbN/NG barrier exhibit excellent rate performance (621.2 mAh g −1 at 3 C) and high stable cycling life (81.5% capacity retention after 400 cycles). This work provides new insights to promote Li–S batteries via multifunctional catalytic interface engineering.