Tripod-Linked Molecular Armor for Low-Overpotential Al–Air Batteries

The self-corrosion of aluminum poses a critical challenge to the development of aluminum–air batteries. We herein propose a novel approach to suppress aluminum self-corrosion by utilizing ultrashort tripod-linked cyanuric acid as molecular armor. Cyanuric acid featuring a planar triacid group adsorbs onto the aluminum surface in an armor-like configuration, forming a protective layer that effectively mitigates the self-corrosion of the aluminum anode. This closed face-to-face cyanuric acid/Al structure, with its minimized interfacial distance, could reduce the overpotential by maintaining ion pathways, reducing water reacting with Al, facilitating hydrogen bubble detachment, and minimizing bubble retention. Electrochemical results demonstrated that the aluminum anode achieved a high utilization efficiency of 89.9%, delivering a capacity of 2680 mAh g–1 at 50 mA cm–2. These findings underscore the potential of cyanuric acid as an effective inhibitor additive, offering a promising pathway to enhance the performance and durability of aluminum–air batteries.