Selenide‐driven electron delocalization in Co single‐atom@metal‐cluster sites on periodic macroporous carbon framework for synergistic oxygen/iodine electrocatalysis in zinc‐air/iodine hybrid batteries

Abstract Zinc‐air batteries are crucial for next‐generation energy storage; however, challenges related to energy efficiency persist owing to the kinetically sluggish oxygen evolution reaction in conventional cathodes. Groundbreaking zinc‐air/iodine hybrid batteries (ZAIHBs) incorporate reversible iodine redox reactions; however, the design of bifunctional catalysts capable of synergistically mediating oxygen and iodine redox reactions remains challenging. In this study, we achieve efficient and reversible oxygen/iodine catalysis using a pioneering hierarchical heterointerface‐engineered catalyst comprising single Co atoms coupled with Co/CoSe 2 nanoclusters within a three‐dimensionally ordered macroporous carbon framework (3DOM Co(Se)/NC). Spectroscopic analysis and density functional theory calculations reveal that CoSe 2 incorporation induces partial electron delocalization at the Co single‐atom@Co‐cluster interface, while preserving a locally enriched electron density. This electronic configuration balances the adsorption/desorption energetics of the oxygen and iodine intermediates, while the 3DOM architecture facilitates rapid mass transport and exposes abundant active sites. Consequently, ZAIHBs equipped with 3DOM Co(Se)/NC deliver a remarkably low voltage gap (ΔE = 0.40 V) and outstanding cycling stability over 400 h at 10 mA cm −2 . This study provides a novel approach to multi‐redox cathode design and facilitates the development of highly efficient hybrid batteries. image