Robust Electronic Correlation of Co‐CoN4 Hybrid Active Sites for Durable Rechargeable Zn‐Air Batteries

Abstract The rational design of bifunctional catalysts with excellent activity and stability toward the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is essential for rechargeable Zn‐air batteries (ZABs). In this study, a facile coordination bridging strategy is proposed to construct bifunctional Co‐CoN 4 hybrid active sites embedded in porous N‐rich carbon nanolamellas (denoted as Co‐CoN 4 @NCNs) for both the ORR and OER. Synchrotron X‐ray absorption spectroscopy and density functional theory calculations reveal that the increased intrinsic ORR/OER activities can be attributed to the efficient interfacial charge transfer between the atomic CoN sites and metallic Co sites due to their robust electronic correlation. In situ Raman spectroscopy confirms that the OER activity depends on the CoOOH intermediates formed during the reaction. Co‐CoN 4 @NCNs exhibits superior bifunctional catalytic performance for the ORR ( E 1/2 = 0.83 V) and OER (η = 310 mV at 10 mA cm −2 ) conducted in alkaline media. The assembled rechargeable Co‐CoN 4 @NCNs‐based ZAB displays an open‐circuit voltage of 1.47 V, peak power density of 118.8 mW cm −2 , specific capacity of 776.7 mAh g −1 , and outstanding cycling stability over 1500 cycles. The regulation of the interfacial electronic properties can contribute to the rational design of bifunctional electrocatalysts used in rechargeable metal‐air batteries.