Recent advances in carbon-based non-noble single-atom catalysts for rechargeable zinc–air batteries

Rechargeable zinc–air batteries (ZABs) have been considered as highly competitive candidates for next-generation sustainable electrochemical energy conversion and storage devices due to their high theoretical specific energy density, low cost, high safety, and high metal abundance. However, the sluggish reaction kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in the air cathode lead to high polarization, low efficiency, and nondurability circulation of rechargeable ZABs. Carbon-based non-noble single-atom catalysts (SACs) have been identified as promising bifunctional ORR/OER catalysts due to their maximum metal atom utilization efficiency, well-defined atomic geometry, high electrical conductivity, and flexibility. In this review, we reveal the advantages of carbon-based SACs on constructing non-novel ORR/OER bifunctional catalysts and present their application in ZABs. Finally, the summary and outlook are discussed with the aim of providing an essential guide for the development of rechargeable ZABs.