Effect of quinoline-8-sulfonic acid and CaO as hybrid electrolyte additives on microstructure and property of AA5052 alloy anode for aluminum-air battery

Background: This work aims at developing hybrid corrosion inhibitors for AA5052 alloy anode of Al-air battery in alkaline solution. Methods: Inhibition of quinoline-8-sulfonic acid (8-QS) and calcium oxide (CaO) as hybrid additives on the self-corrosion of AA5052 alloy anode for alkaline Al-air battery is studied by H2 evolution test, electrochemical measurement and surface characterization. It shows that 8-QS and CaO have a good protection effect for Al anode and the best protection efficiency is 82.11%. The hybrid additive increases the utilization rate of AA5052 alloy anode to 81.9%. The formation of deposition layer of Ca(OH) 2 promotes adsorption of 8-QS. Chelation of 8-QS with Al3+ renders the uniform distribution on Al alloy surface and retards self-dissolution of AA5052 alloy. Fluorescence emission is observed after the discharging test, making it possible for on-line detection of self-dissolution of AA5052 anode. DFT (Density Functional Theory) calculations are used to clarify the synergistic mechanism of the hybrid additives. Significant finds: The adsorption and synergistic mechanism of 8-QS and CaO in alkaline solution is proposed, which could provide theoretical guidance for development of hybrid additives for alkaline electrolyte additives. (C) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study developed hybrid corrosion inhibitors for the AA5052 alloy anode of Al-air battery in alkaline solution, finding that the combination of 8-QS and CaO significantly improved the protection efficiency and utilization rate of the alloy anode. The proposed synergistic mechanism between the two additives provides theoretical guidance for the development of hybrid additives in alkaline electrolytes.