Effects of l‐Cysteine Inhibitor on the Electrochemical Properties of an Aluminum Alloy Anode Used for an Aluminum‐Air Battery

Abstract Serious self‐corrosion and passivation film of Al‐air battery reduces the actual energy density and limits its commercial application. The corrosion inhibition effect of l ‐cysteine on low‐cost Al anode alloy and Al‐air battery was studied using hydrogen evolution and electrochemical tests. The results show that l ‐cysteine can significantly reduce the corrosion current density of the Al electrode in 4 M KOH and improve the activity of the Al electrode. The optimum amount of inhibitor (0.5 M) improved the performance of the Al battery. The anode utilization efficiency reached 82.73%, and the battery life was prolonged by nearly three times. The cell capacity, energy, and maximum power density increased from 1990.67 mAh·g −1 , 1672.16 Wh·kg −1 , and 34.62 mW·cm −2 in the system without inhibitor to 2465.33 mAh·g −1 , 2144.84 Wh·kg −1 , and 64.4 mW·cm −2 in the system with 0.5 M l ‐cysteine. The researchers also used X‐ray photoelectron spectroscopy (XPS) and other techniques combined with quantum chemistry calculation to obtain that ─COOH, ─NH 2 , ─SH in l ‐cysteine form physical adsorption films on Al surface, which improves the corrosion resistance of Al alloy anode.