Bifunctional Catalysis Drives Efficient and Ethanol‐Producing Aqueous Zn‐CO 2 Batteries

Bifunctional electrocatalysts that simultaneously drive CO 2 reduction (CO 2 RR) and oxygen evolution (OER) in neutral electrolytes are essential for aqueous Zn‐CO 2 batteries (AZCBs), but conventional designs prioritize CO 2 RR and are often incompatible with OER, resulting in low energy efficiency, poor reversibility, and rapid degradation of batteries. Here, we introduce a unified catalyst architecture integrating Cu and Ni single atoms with boron‐, nitrogen‐co‐doped carbon (CuNi@BNC‐T). Heteroatom co‐doping stabilizes high single‐atom loadings, enhances metal‐support interactions, and suppresses carbon corrosion, while N‐coordinated Cu + and Ni 3+ sites cooperatively boost CO 2 RR‐OER, enabling ethanol formation and low‐overpotential OER. This strategy achieves a 0.7 V voltage gap at 5 mA cm −2 , 522 h cycling at 20 mA cm −2 , and first ethanol production via AZCBs with energy efficiency of 88% (flow‐cell). By elucidating previously unresolved degradation pathways, this work also correlates catalyst dynamics with battery failure, establishing design principles for durable bifunctional catalysts in aqueous Zn‐CO 2 systems.