Optimized electronic structure of N-doped carbon@FeCo alloys: Remarkable bifunctional oxygen catalyst for rechargeable zinc-air batteries

Rationally designing effective bifunctional electrocatalysts for both oxygen reduction and evolution is key to enhancing rechargeable Zn-air batteries (ZAB). In this work, a 'dynamic hot dipping-high temperature carbonization' strategy was presented to create a nitrogen-doped carbon coated FeCo alloy core catalysts (Fe1Co1@NC) with an average particle size of 13.11 nm. Benefiting from an optimized electronic structure, the Fe1Co1@NC displays remarkable bifunctional performance, achieving a high half-wave potential of 0.85 V in the oxygen reduction reaction and requiring only 334 mV overpotential at 10 mA cm-2 for the oxygen evolution reaction. Additionally, the Fe1Co1@NC-based ZAB exhibits superb cycling stability and an ultra-high peak power density 165.3 mW cm-2, functioning steadily for over 350 h. This work sheds light on the structure-activity relationship of bimetallic alloy catalysts and their potential for superior-performance ZAB applications.