Electrochemical Performance of Mg-3Al Modified with Ga, In and Sn as Anodes for Mg-Air Battery

Mg-3wt%Al anodes with Sn, Ga and In were prepared by melting and heat-treatment in electric resistance furnace. The electrochemical discharge behavior of these anodes in 3.5wt% NaCl solutions was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The microstructures and the corroded surfaces of the anodes were investigated by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Finally, Mg-air batteries based on Mg-3Al-1Sn (AS31), Mg-3Al-1Ga (AG31), Mg-3Al-1In (AI31) alloys were prepared and battery properties were studied by constant current discharge test. Mg-3Al (A3) and Mg-3Al-1Zn (AZ31) were also prepared to be used for contrast test. The results show AI31 behaves good comprehensive properties, the battery based on AI31 anode possesses the highest capacity density (1382 mAhg −1 ) and power density (18.5 mWcm −2 ). Compared with A3 and AZ31, AS31 and AG31 show higher corrosion resistance. In addition, The paper also researches on the modification mechanism of Ga, In and Sn on Mg-3Al.