High-Entropy Metal Single-Atom Catalysts Anchored in Hierarchically Porous Carbon for Accelerated Sulfur Conversion in Lithium–Sulfur Batteries

To mitigate the severe shuttle effect in lithium–sulfur batteries, single-atom catalysts (SACs) have emerged as one of the most effective strategies. Herein, a multimetal high-entropy single-atom catalyst (HEM-SA/NC), featuring atomically dispersed Fe, Co, Ni, Cu, and Mn anchored within a porous carbon framework, is rationally designed and synthesized using a silica aerogel confinement strategy. The rigid aerogel network restricts metal migration during pyrolysis, enabling high metal loading while preserving atomic dispersion. Meanwhile, the high-entropy incorporation introduces abundant defect sites and substantially modulates the electronic structure of the carbon matrix, thereby enhancing the chemisorption capability toward lithium polysulfides and promoting catalytic reaction activity. The synergistic interactions among the five metal centers effectively accelerate the redox kinetics of polysulfides, facilitating both Li₂S nucleation and decomposition. Benefiting from these collective advantages, lithium–sulfur batteries fabricated with HEM-SA/NC-modified separators exhibit markedly improved electrochemical performance, delivering an initial discharge capacity of 1215.1 mAh g^–1 at 0.2 C and retains 962.18 mAh g^–1 after 100 cycles. Even at 1 C, it provides an initial capacity of 1003.74 mAh g^–1 with 473.51 mAh g^–1 remaining after 1000 cycles. The coexistence of multiple transition-metal centers induces electronic interactions among neighboring metal atoms, thereby modulating the electronic structure of catalytic sites and accelerating polysulfide redox kinetics. This work provides new insights into the design of high-entropy, high-loading single-atom catalysts for high-performance lithium–sulfur batteries.