Effect of tin alloying on the corrosion behavior and discharge performance of aluminum anodes for aluminum-air batteries

Aluminum-air batteries (AAB) are alternative to common commercial batteries like lithium-ion batteries due to their high theoretical energy density, low cost, and environmental friendliness. However, the formation of a protective oxide layer and side corrosion reactions on aluminum anodes limit the efficiency and decreases energy density. Effect of tin (Sn) alloying on the corrosion rate and discharge behavior of aluminum alloys for AABs in an alkaline solution was investigated in this study. Al-0.5Mg-0.05Ga-0.05In base alloy having three different Sn compositions were used during immersion and electrochemical tests performed in 4 M NaOH solution. The results show that addition of Sn significantly affects the self-corrosion rate and discharge performance of alloy. The alloy containing 0.1 wt% Sn exhibited the lowest corrosion rate and the highest energy density, highlighting the optimal Sn concentration for enhanced AAB performance. Microstructural analysis using SEM (Scanning Electron Microscope) and EDS (Energy Dispersive Spectroscopy) confirmed the presence of Sn-rich precipitates, which influence the electrochemical behavior of the alloys.