Silver–Manganese Oxide Mott–Schottky Catalyst for Dual-Function Oxygen and Potassium Iodate Reduction Reactions in Enhanced Aluminum–Air Batteries

Aluminum–air (Al–air) batteries offer exceptional theoretical energy density and utilize abundant aluminum, but their development is hindered primarily by the inherently sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode. Conventional methods focus on developing efficient nonplatinum catalysts with high catalytic activity and superior stability, but these approaches offer limited performance enhancement. To address this issue, we propose a strategy to improve sluggish cathodic kinetics in Al–-air batteries by introducing an extra reduction reaction associated with the ORR. These reactions provide more electrons during discharge, thereby breaking through the ORR activity limit at the cathode. Herein, a carbon-supported silver–manganese monoxide composite catalyst with a Mott–Schottky heterointerface (denoted as Ag–MnO/NC) is designed and prepared for bifunctional catalytic reactions. The engineered interface not only boosts the ORR performance but also catalyzes the reduction of potassium iodate (KIO3) to iodide ion (I–) through the construction of an efficient electron transportation pathway. Benefiting from the simultaneous oxygen reduction and KIO3 reduction reactions, the assembled Al–-air battery achieves a maximum power density of 150.2 mW cm–2, significantly surpassing that of a commercial 20% Pt/C-based counterpart (130.6 mW cm–2). This study not only provides deeper insights into the Mott–Schottky effect in catalytic systems but also demonstrates the potential of maximizing metal–air battery performance through introducing extra redox reactions.