Interfacial Water Orientation in Neutral Oxygen Catalysis for Reversible Ampere-scale Zinc-air Batteries.

The neutral oxygen catalysis is an electrochemical reaction of the utmost importance in energy generation, storage application, and chemical synthesis. However, the restricted availability of protons poses a challenge to achieving kinetically favorable oxygen catalytic reactions. Here, we alter the interfacial water orientation by adjusting the Brønsted acidity at the catalyst surface, to break the proton transfer limitation of neutral oxygen electrocatalysis. An unexpected role of water molecules in improving the activity of neutral oxygen catalysis is revealed, namely, increasing the H-down configuration water in electric double layers rather than merely affecting the energy barriers for reaction limiting steps. The proposed porous nanofibers with atomically dispersed MnN3 exhibit record-breaking activity (EORR@1/2/EOER@10 mA = 0.85/1.65 V vs. RHE) and reversibility (2500 h), outperforming all previously reported neutral catalysts and rivaling conventional alkaline systems. In particular, practical ampere-scale zinc-air batteries (ZABs) stack are constructed with a capacity of 5.93 Ah and can stably operate under 1.0 A and 1.0 Ah conditions, demonstrating broad application prospects. This work provides a novel and feasible perspective for designing neutral oxygen electrocatalysts and reveals the future commercial potential in mobile power supply and large-scale energy storage.