Hierarchical biomass-derived carbon framework with asymmetric ZnCo dual-atom pairs for synergistic polysulfide adsorption and catalysis in Lithium-sulfur batteries

Lithium‑sulfur (Li S) batteries have recently attracted ever-increasing attention owing to their ultrahigh specific energy and substantial cost benefits of sulfur. However, the sluggish redox kinetics from the critical conversion of soluble long-chain lithium polysulfide to solid-state Li 2 S remains a fundamental challenge. Herein, hierarchical porous nitrogen-doped carbon frameworks with asymmetric Zn Co dual-atom pairs (Zn-Co/NC) were successfully constructed using biomass-derived porous carbon as structural matrix through in situ growth and assisted pyrolysis strategy. The resulting hierarchical porous structure offers abundant electrochemically active interface and facilitates ultrafast electron/ion transport. In addition, the well-constructed Zn Co dual-atom pairs demonstrates strong adsorption and catalysis effect for sulfur species. Consequently, Li S cells incorporating Zn-Co/NC@PP deliver a 0.2C initial discharge capacity of 1263.5 mAh g −1 , coupled with exceptional 500-cycle durability at 1C. Furthermore, when the battery is under the conditions of high sulfur loading (6.6 mg cm −2 ) and low electrolyte (E/S = 5.0 μL mg −1 ), a satisfying surface capacity of 4.9 mAh cm −2 can still be achieved. Such a precise design of versatile dual-atom pairs catalysts involving synergistic adsorption and catalysis provides valuable insights for multistage sulfur conversion reactions.