Synergistic functionalization and descriptor-driven screening of MBene electrocatalysts for high-performance Li–S batteries

Identifying effective catalysts is vital for inhibiting the shuttling of polysulfides and enhancing reaction kinetics, thereby improving the cycling stability of lithium-sulfur batteries (Li-S batteries). Therefore, we systematically investigated the influence of surface functionalization (T = O, F, N, Cl, and S) on electrocatalytic and anchoring behavior on MBenes in Li-S batteries via density functional theory calculations. The study shows that O-functionalized MBenes possess optimal binding strength toward polysulfides, leading to effective suppression of the shuttle effect. Meanwhile, Mo₂B₂O₂ and W₂B₂O₂ exhibit excellent electrocatalytic activity alongside low Li₂S decomposition (0.44 and 0.74 eV) and Li⁺ diffusion barriers (0.09 and 0.11 eV). Further mechanism analysis indicates that the formation of T-Li bonds enables effective anchoring of lithium polysulfides (LiPSs), while the weakening of Li-S bonds promotes the decomposition of Li₂S. Notably, as shown in the Pearson correlation heatmap, the adsorption energy of LiS and the bond length of T-Li can be used as the key parameters for rapidly screening high-performance catalytic materials for sulfur cathodes. We propose that functionalized MBenes represent a promising class of anchoring and catalytic materials for lithium-sulfur batteries, and our work offers valuable guidance for the rapid and rational design of high-efficient cathodes for Li-S batteries.