Polymer-Cross-Linking-Guided Pyrolytic Engineering of FeCo@N-Doped Carbon with Defect Networks for High-Performance Oxygen Reduction and Zinc–Air Batteries

In the coregulation of bimetallic active centers, engineering the carbon support to achieve a balanced defect architecture is crucial for the rational design of high-performance oxygen reduction electrocatalysts. Herein, a polymer-cross-linking-guided pyrolytic approach is employed to construct a nitrogen-rich carbon nanosheet framework featuring well-distributed structural defects, while concurrently anchoring Fe–Co alloy nanoclusters within the carbon matrix. The optimized FeCo@NC-900 catalyst delivers a half-wave potential of 0.86 V with excellent electrochemical durability. When implemented as a hybrid air cathode composed of FeCo@NC-900 and RuO 2 in rechargeable Zn–air batteries, it delivers a high power density and long-term cycling stability. It achieves a peak power density of 110 mW cm –2 and a specific discharge capacity of 801.1 mAh g –1 . Notably, the assembled battery can operate stably for 1000 h at a current density of 5 mA cm –2, suggesting good structural stability of the catalyst architecture during long-term operation. Combined with its low-cost synthesis and structural tunability, these results indicate that the defect-balanced bimetallic carbon catalyst holds broad application prospects in high-energy metal-air systems.