Single-Atom Chromium-Embedded N-Doped Graphene as a Multifunctional Separator Coating for Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries offer a promising alternative to traditional lithium-ion batteries due to their high energy density, large capacity, cost advantages, and environmental benefits. However, their commercialization is impeded by challenges like the lithium polysulfide (LiPS) shuttle effect, necessitating advanced sulfur host materials and separator coatings for the effective trapping of LiPSs and enhancing the ion transfer. In this research, single-atom chromium-incorporated nitrogen-doped graphene (Cr@NG) is introduced as a novel separator coating, synthesized by an NaCl soft-template method. This material, as an efficient and economic alternative to other existing single-atom catalysts-based materials, combines high conductivity and catalytic activity, effectively suppressing the shuttle effect and enhancing sulfur conversion. First-principles calculations and electrochemical studies further demonstrate that Cr@NG significantly improves adsorption capabilities, capacity retention, rate capability, and cycling stability. The incorporation of chromium offers substantial benefits in electron transport and catalytic efficiency, establishing Cr@NG as a promising multifunctional separator coating for high-performance Li–S batteries.