Green interface optimization strategy based on allium mongolicum regel extract for enhanced alkaline Al-air battery performance.

Abstract

Aqueous aluminum (Al)-air batteries (AABs) are gaining significant attention due to their excellent theoretical performance. However, the self-corrosion of the aluminum anode reduces anodic efficiency and battery capacity, limiting the broad commercial application of AABs. Herein, we propose the utilizing Allium Mongolicum Regel (AMR) extract as a green electrolyte additive to optimize the Al anode/electrolyte interface in alkaline AABs. Our findings indicate that the incorporation of AMR into NaOH electrolyte offers an effective strategy for preventing the self-corrosion of the Al anode, leading to significant enhancements in battery performance. Electrochemical experiments demonstrate that AMR achieves an inhibition efficiency of 53.9%. Through in-situ optical microscopy and in-situ attenuated total reflection Fourier-transform infrared spectroscopy, it is observed that the introduction of AMR can retard pitting corrosion by adsorbing onto the Al surface. This leads to a significant increase in specific capacity, from 1096 to 1667 mAh g^-1, compared with the electrolyte without AMR for AABs. Further analysis utilizing X-ray photoelectron spectroscopy, quantum chemical calculations, and ab-initio molecular dynamics determine that 4-hydroxycinnamamide (4-HCAA) and flavone molecules, which are the most active components of AMR, can bind with Al atoms through the carbonyl O functional group, forming an O-Al-O bond, thus suppressing the self-corrosion of the Al anode. The incorporation of the AMR extract into the electrolyte of AABs represents a sustainable approach for optimizing battery performance. This innovative strategy addresses a critical issue in the development of AABs, potentially creating new opportunities for their commercialization and widespread utilization as a reliable energy storage technology.