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

Zhao, Shibo; Lu, Wenqiang; Dai, Weiteng; Hou, Zhichao; Li, Shanshan; Tang, Jimin; Zhang, Dong; Wang, Ying et al. · Adv Mater · 2026

basic_science · Level V

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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<sub>2</sub>-tolerant and anode-friendly near-neutral electrolytes. Here, a feasible catalyst design strategy is reported by introducing Mn<sup>2+</sup> into aqueous electrolytes to enable in situ formation of MnO<sub>2</sub>. Notably, this electrodeposited MnO<sub>2</sub> exhibits a unique 3% lattice contraction, which upshifts the d-band center and significantly accelerates oxygen evolution reactions. The lattice distortion optimizes the <sup>*</sup>OOH intermediate formation energy, reducing the potential-determining step barrier by ≈17.0% compared to conventional MnO<sub>2</sub>. 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<sub>2</sub>-tolerant AMABs.