High-Entropy Electrocatalytic Materials in Zn-Air Batteries: From Fundamentals to Applications

Rechargeable Zn-air batteries (ZABs) have garnered significant attention owing to their high energy density, low costs, and environmental sustainability by using air as the cathode and zinc as the anode. The critical bottlenecks in advancing rechargeable ZABs lie in the development of high-performance bifunctional air electrode catalysts that efficiently drive the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). High-entropy materials (HEMs), comprising four or more elements with distinctive structural characteristics, tailorable chemical compositions, and correspondingly tunable functional properties, have exhibited exceptional electrocatalytic activity toward ORR/OER in various catalytic systems. To further enhance HEMs' catalytic performance, systematic investigations into elemental interactions, precise identification of active sites, and elucidation of fundamental reaction mechanisms are imperative. This review first introduces the synthetic methods, design principles, and characterization technologies of HEM-based electrocatalysts and summarizes their applications in ZABs based on oxygen chemistry. This study endeavors to decode the complexity of active sites, elemental interactions, and the reaction mechanisms intrinsic to HEMs. Finally, the critical challenges, the significance of integrating both experimental and theoretical approaches, and the prospective applications of HEMs in ZABs are emphasized. This review is expected to facilitate the rational design and practical deployment of HEMs for next-generation ZAB systems.