Orbital Coupling Driven Band Remodeling Enables Durable Oxygen Electrocatalysis

ABSTRACT Binary alloys are promising bifunctional electrocatalysts for rechargeable zinc‐air batteries (ZABs). However, their activity and durability remain constrained by sluggish kinetics in both oxygen reduction and oxygen evolution reactions (ORR/OER). To overcome these challenges, modulating the d ‐orbital electronic structure via orbital coupling provides an effective approach to optimize the chemisorption of oxygen intermediates. Herein, a face‐centered cubic Co _0.5 Ni _0.5 alloy encapsulated within a honeycomb‐like porous N‐doped carbon framework (denoted as fcc ‐Co _0.5 Ni _0.5 @HPNC) was rationally constructed via a ligand‐assisted self‐assembly strategy. Theoretical and experimental analyses reveal that strong Co─Ni orbital coupling induces significant electronic band reorganization, downshifts the d ‐band center, and optimizes the oxygen intermediate adsorption. This electronic modulation facilitates the formation of *OOH and the desorption of *OH, thereby accelerating the kinetics of both ORR and OER. Consequently, fcc ‐Co _0.5 Ni _0.5 @HPNC delivers an ultralow potential gap (Δ E ) of 0.63 V, excellent durability, and superior performance. The assembled aqueous and flexible ZABs achieve open‐circuit voltages of 1.49 and 1.43 V, as well as peak power densities of 187.3 and 76.2 mW cm ⁻² , respectively. These findings underscore the crucial role of orbital coupling in modulating electronic structures and provide fundamental insights for designing high‐performance alloy‐based bifunctional electrocatalysts.