Design of Composite Catalysts for Rechargeable Zinc-Air Batteries: Design Strategies and Recent Advances

Rechargeable zinc-air batteries are highly promising next-generation electrochemical energy storage devices because of their advantages, such as high theoretical energy density, enhanced safety, and environmental friendliness. The development of efficient and stable bifunctional oxygen electrocatalysts is crucial for improving the performance of zinc-air batteries. This review systematically summarizes recent design strategies and research progress in composite catalysts developed to address this challenge. First, the working principles of zinc-air batteries and the key challenges faced by oxygen electrode catalysis are outlined, including the large voltage gap, the difficulty of single active sites in simultaneously meeting the requirements for both the OER and ORR, and conflicts between material hydrophilicity and hydrophobicity. On this basis, the design principles of composite catalysts are discussed, with a focus on optimizing the electronic structure through synergistic effects between components, achieving high dispersion of active sites, and constructing heterointerfaces to enhance charge transfer and intermediate adsorption/desorption capabilities. Finally, prospects and future directions for composite catalysts in zinc-air batteries are presented. Ongoing efforts are needed in areas such as precise regulation of active sites, elucidation of multicomponent synergistic mechanisms, and improvement of durability under practical operating conditions to advance the practical application of high-performance and low-cost zinc-air batteries.