Electrochemical Investigations on AZ Series Magnesium Alloys as Anode Materials in a Sodium Chloride Solution

Electrochemical and discharge properties of Mg-air battery based on 3N5 Mg, AZ31, AZ61, AZ91 alloys were studied in a 0.6M NaCl electrolyte, with the aim of selecting a common commercial Mg alloy to decrease passivation and self-corrosion of Mg anode for Mg-air battery. Results obtained indicate that self-corrosion and passivation decrease, and anodic utilization increases gradually with increasing Al content. This is associated with the double effect of Al on discharge performance of Mg anode. Al with high hydrogen overvoltage decreases self-corrosion of Mg anode and passivation of Mg anode by peeling off Mg(OH)(2) discharge products. Results of electrochemical impedance spectroscopy and discharge morphology relate wellwith the results of electrochemical and discharge performances. It is concluded that solution-treated AZ91 alloy has a better discharge performance as anode of Mg-air battery in 0.6M NaCl electrolyte.