In Situ Formation of Lattice‐Distorted Mn‐Based Catalysts Boosting High Energy‐Efficiency Aqueous Metal‐Air Batteries

Abstract

Abstract Rechargeable aqueous metal‐air batteries (AMABs) offer sustainable energy storage solutions with inherent safety, cost‐effectiveness, and high theoretical energy density. However, their practical performance is limited by sluggish oxygen redox kinetics, especially in CO 2 ‐tolerant and anode‐friendly near‐neutral electrolytes. Here, a feasible catalyst design strategy is reported by introducing Mn 2+ into aqueous electrolytes to enable in situ formation of MnO 2 . Notably, this electrodeposited MnO 2 exhibits a unique 3% lattice contraction, which upshifts the d ‐band center and significantly accelerates oxygen evolution reactions. The lattice distortion optimizes the * OOH intermediate formation energy, reducing the potential‐determining step barrier by ≈17.0% compared to conventional MnO 2 . Consequently, Zn‐air batteries with near‐neutral electrolytes achieve a 35.9% reduction in OER/ORR overpotential (0.50 V) and elongated cycling stability (>1000 h). This approach further enables Mn‐air batteries to achieve a low overpotential (0.29 V) and high energy efficiency (84.2%), offering a universal strategy for efficient, durable, and CO 2 ‐tolerant AMABs.