Action mechanisms, critical challenges and advanced optimization strategies of bionic-structured materials in catalysts for zinc-air batteries

Zinc-air batteries are promising next-generation energy storage systems owing to their high theoretical energy density, intrinsic safety, and sustainability. However, their practical performance is limited by sluggish ORR/OER kinetics, inefficient gas–liquid–solid mass transport, and insufficient utilization of catalytic active sites at air cathodes. Recently, bionic-structured materials have emerged as an effective strategy to address these issues by mimicking the hierarchical transport networks, interfacial regulation, and catalytic microenvironments found in natural systems. This review systematically summarizes recent advances in bio-inspired air cathode catalysts for zinc-air batteries from macroscopic, mesoscopic, and microscopic perspectives, including hierarchical transport pathways, interfacial wettability regulation, and active-site engineering. Plant-, animal-, and biomolecule-inspired structures are comprehensively discussed, emphasizing their structure–performance relationships. Finally, current challenges and future opportunities in scalable fabrication, structural controllability, and long-term durability are highlighted to guide the development of high-performance zinc-air batteries.