The d-Orbital High-Spin State of Fe Single Atomic Sites via Asymmetric Axial Ligand Effect of Cu Clusters for an Ultralow Δ E in Rechargeable Zinc–Air Batteries

作者：Yuehao Zhong, Xiaoliang Yuan, X. Z. Chen, Yuhao Wu, Hailong Liu, Zheng Li, Jiling L Li, Jiajun Gu, Jianbo Ma, Lin Gu, Dingxin Cancer Liu · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.5c16672 · 被引用次数：4 · 研究领域：Electrocatalysts for Energy Conversion、Advanced battery technologies research、Advanced Battery Materials and Technologies

The development of bifunctional catalysts to diminish the kinetic barriers associated with the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is regarded as a viable approach to augmenting the efficacy of zinc–air batteries (ZABs). This research presents a methodology that integrates metal clusters and single atoms, employing ZIF-7-NH 2 as the foundational material to affix metals onto derivatives, resulting in the creation of g-SAFe-Cu n . Aberration-corrected transmission electron microscopy (AC-TEM) revealed discrete bright spots corresponding to iron atoms and copper cluster sites, with their bonding interactions substantiated by extended X-ray absorption fine structure (EXAFS) analysis. Electrochemical assessments indicated that g-SAFe-Cu n possesses outstanding bifunctional catalytic capabilities, as evidenced by a Δ E value of 0.578 V. When integrated into a liquid-phase zinc–air battery with g-SAFe-Cu n serving as the air cathode, the system exhibited remarkable long-term stability, enduring over 2100 cycles at a current density of 10 mA·cm –2, which equates to an operational duration surpassing 350 h. Density functional theory (DFT) computations elucidated that the incorporation of Cu clusters induces substantial spin polarization of the Fe 3d orbitals, thereby increasing the quantity of unpaired electrons and facilitating the transition of Fe to a high-spin state, which aids in the activation of triplet O 2 to generate active intermediates. Furt...