Advanced dual-atom catalysts for rechargeable zinc-air batteries

Rechargeable zinc-air batteries (ZABs) have gained extensive research attention as a promising sustainable energy technology due to their considerable theoretical specific energy density, low toxicity, abundant availability, and robust safety features. However, the practical implementation of ZABs still faces challenges, primarily attributed to the sluggish kinetics of oxygen-involved reactions, including oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) during the discharge and charge process. Therefore, searching for efficient bifunctional oxygen electrocatalysts is crucial to address these challenges. Dual-atom catalysts (DACs), an extension of single-atom catalysts (SACs), exhibit flexible architectures that allow for the combination of homogeneous and/or heterogeneous active sites, making them highly attractive for improving bifunctional activity. In this review, we first introduce the basic framework of ZABs and the structural characteristics of DACs. Subsequently, we organize the research progress on applying DACs in liquid and solid-state ZABs and elaborate on their unique catalytic mechanism. Finally, we highlight the challenges and future research directions for further innovation of DACs in ZABs. In summary, this review highlights the advantages of DACs compared with SACs used as bifunctional oxygen electrocatalysts and provides a reference for the broad applications of DACs in energy conversion and storage.