Self‐Sacrificial Copper Cluster‐Catalyzed Oxygen Reduction: A Paradigm Shift in Zinc‐Air Battery Technology

Metal‐ion decorated covalent organic frameworks (M‐COFs) are prepared by reacting aldehyde‐terminated Cu(I) clustered monomers and amine‐terminated triazine monomers through imine linkages, and the as‐prepared Cu(I) cluster‐based COF is analyzed and tested for its electrocatalytic activity toward oxygen reduction reactions. These M‐COFs are more stable and active under adverse conditions. The annealed sample (ACu‐COF) displays an increased surface area of 120 m 2 g −1 compared to the pristine sample Cu‐COF (19 m 2 g −1 ). Because of its larger specific surface area, and active nitrogen content, the annealed counterpart with flower morphology exhibits exceptional oxygen reduction reaction (ORR) capabilities. The ACu‐COF sample demonstrates a nearly four‐electron ORR process, an onset potential of 0.92 V versus reversible hydrogen electrode (RHE), and a diffusion limiting current density of 3.85 mA cm −2 . It also reached a half‐wave potential of 0.78 V versus RHE. After 2000 cycles, the onset potential of the ACu‐COF only dips by 28 mV, demonstrating its remarkable long‐term durability. Additionally, the homemade primary zinc‐air battery employing ACu‐COF produces a specific capacity of 747 mAh g −1 and a maximum peak power density of 133 mW cm −2 .