Electrochemical corrosion behavior of Mg-Al-Sn alloys with different morphologies of β-Mg17Al12 phase as the anodes for Mg-air batteries

The morphologies of β-Mg17Al12 phase in Mg-Al-Sn alloys are tailored by using different molds during the casting of liquid alloys. The electrochemical corrosion behavior of these alloys is investigated; the finer β-Mg17Al12 induced by a thick-walled copper mold facilitates the spalling of oxidation products and mitigates the self-corrosion during galvanostatic discharge. All these features lead to the superior anode performance when used for Mg-air batteries, as compared with the coarser β-Mg17Al12 prepared via a flat iron mold. Furthermore, the intrinsic linkage between electrochemical corrosion behavior and β-Mg17Al12 morphologies in Mg-Al-Sn specimens is unraveled according to electrochemical response and microstructural characterization.