Self‐Activating Integrated Carbon‐Based Air Cathodes With <i>In Situ</i> Oxygen Functionalization for Durable and High‐Performance Metal–Air Batteries

ABSTRACT Carbon‐based air cathodes offer low cost, high electrical conductivity, and structural tunability. However, they suffer from limited catalytic activity and inefficient gas transport, and they typically rely on noble metal additives or complex multilayer configurations. To tackle these issues, this study devised a self‐activated integrated carbon‐based air cathode. By integrating in situ catalytic site construction with structural optimization, the strategy not only induces the formation of oxygen functional groups (─C─OH, ─C═O, ─COOH), hierarchical pores, and uniformly distributed active sites, but also establishes a favorable electronic and mass‐transport environment. Furthermore, the roll‐pressing‐based integrated design streamlines electrode construction, reinforces interfacial bonding, and significantly enhances mechanical stability. Density functional theory (DFT) calculations show that oxygen functional groups initiate hydrogen bonding interaction and promote charge enrichment, which improves the activity of the cathode and facilitates intermediate adsorption/desorption in oxygen reduction and evolution reactions processes. As a result, the integrated air cathode‐based rechargeable zinc‐air batteries (RZABs) achieve a high specific capacity of 811 mAh g –1 . It also performs well in quasi‐solid‐state RZABs and silicon‐air batteries systems across a wide temperature range, demonstrating strong adaptability and application potential. This study provides a scalable and cost‐effective design strategy for high‐performance carbon‐based air cathodes, offering new insights into advancing durable and practical metal–air energy systems.