A Unique Quadruple-Site System Integrating Fe-N4 Sites and Zn Atomic Clusters for Oxygen Reduction Reaction and Wide-Temperature Zn–Air Batteries

Fe-N-C single-atom catalysts (SACs) featuring Fe-N₄ configurations face challenges in the simultaneous enhancement of intrinsic oxygen reduction reaction (ORR) activity and long-term stability. Herein, we developed a unique quadruple-site cooperative system through a 90 s ultrafast thermal shock strategy, where most Zn atomic clusters are surrounded by two closely neighboring and a further Fe-N₄ sites (Fe_SA/Zn_AC-N-C). Density functional theory and molecular dynamics simulations jointly reveal that proximal Fe-N₄-modified Zn atomic clusters mediate O₂ adsorption/activation/hydrogenation, while distal Fe-N₄ sites facilitate H₂O formation/desorption. This synergistic dual-active-center configuration achieves a positive half-wave potential of 0.90 V and superb durability. The constructed aqueous Fe_SA/Zn_AC-N-C-based Zn-air batteries demonstrate a large maximum power density of 161.5 mW cm^-2, a high specific discharge capacity of 792.7 mAh g^-1, and stable operation over 1500 cycles. In addition, the fabricated quasi-solid-state Zn-air batteries also maintain favorable operation across a wide temperature range (-30 to 60 °C) and at the ampere scale.