Dual-atom catalysts (DACs) are promising materials for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional electrocatalysts for rechargeable Zn-air batteries. Although there have been many theoretical studies of DACs, most of them assumed constant-charge conditions rather than the real electrochemical process of the constant-potential condition. In our work, we investigated Fe-based DACs for ORR and OER bifunctional catalytic performance by using constant-potential first-principles calculations. Among them, FeCo-N