Pt₁/MnO₂ Nanotip Inducing Local Electric Field Intensifies Oxygen Transport for High-Energy-Density Al-Air Battery...

Modulating the coordination environment of atomic site catalysts is a promising strategy to enhance the oxygen reduction reaction (ORR) of Al-air battery; however, its practical development is greatly hindered by inefficient oxygen transport across the air cathode. Herein, we design a branch-like MnO₂ support with exposed (100) facets anchoring Pt single atoms (B-Pt₁/MnO₂) to address the oxygen transport bottleneck. We demonstrate that the nanotips of branch-like MnO₂ can induce a localized electric field that significantly enhances mesoscale oxygen transport, as validated by finite element simulation, ab initio molecular dynamics, and oxygen diffusion experiments. Meanwhile, we show that the Pt-O₄ coordination stabilized by the (100) facet lowers the reaction energy barrier and hinders Pt leaching. This multiscale microenvironment regulation enables B-Pt₁/MnO₂ to achieve an ultrahigh energy density of 3690.6 Wh kg^-1 and remarkable stability for over 650 h at 50 mA cm^-2, outperforming all previously reported catalysts. The ensembled practical Al-air battery stack achieves an energy density of 480.2 Wh kg^-1, which is close to the United States Department of Energy requirements for power battery. Techno-economic analysis reveals a system cost per kW·h only 1/50 of the reported Al-air battery, highlighting its feasibility for sustainable energy applications.