Mass Transportation Facilitated Porous Fe/Co Dual-Site Catalytic Cathodes for Ultrahigh-Power-Density Al–Air Fuel Cells

Abstract

The development of oxygen-dependent fuel cells is frequently hindered by the high cost of cathode materials and the sluggish kinetics of the oxygen reduction reaction (ORR). It is thus crucial to explore low-cost and high-activity catalysts with accelerated mass transport. Here, a high-throughput screening method is developed by integrating an explicit solvation model with machine learning potential-based molecular dynamics simulations, which enables the efficient evaluation of a vast array of diverse diatomic combinations and ultimately identifying Fe–Co dual-atomic sites as the optimal ORR electrocatalysts. The superior electrocatalytic performance of the diatomic Fe/Co sites loaded on 3D-interconnected ordered macroporous carbon (FeCo-3DMNC) is experimentally verified, achieving high ORR activity with half-wave potentials of 0.806 V in acidic and 0.905 V in alkaline environments. Additionally, innovative hybrid acid/alkali aluminum–air fuel cells (hA/A-AAFCs) incorporating FeCo-3DMNC as the cathode catalyst demonstrate a notably high open-circuit voltage of 2.72 V and a record-breaking power density of 827 mW cm⁻², significantly outperforming conventional alkaline aluminum–air fuel cells. This work marks a significant advancement by combining cutting-edge computational screening with rigorous experimental validation to develop promising electrocatalysts, potentially paving the way for the advanced energy storage and conversion technologies.