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

Abstract

BackgroundThis work aims at developing hybrid corrosion inhibitors for AA5052 alloy anode of Al-air battery in alkaline solution. MethodsInhibition 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 findsThe 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.