Electrochemical behavior of Mg-Al-Zn-Ga-In alloy as the anode for seawater-activated battery

The effect of indium alloying on the corrosion and discharge behaviors of Mg-Al-Zn-Ga alloys is investigated via materials characterization, immersion test and electrochemical methods. The results indicate that indium alloying can effectively modify the distribution of intermetallic phases in Mg matrix via promoting the segregation of Al in the form of Mg;Al;in matrix. The addition of indium can effectively activate Mg-Al-Zn-Ga alloy evidenced by increased hydrogen evolution volume and weight loss, negative shift of corrosion and discharge potentials, increase of corrosion current density, decrease of polarization resistance and promoted Faradic efficiency. Nonetheless, excessive indium alloying（2.0 wt.%） would strikingly deteriorate the electrochemical performance of Mg-Al-Zn-Ga anode due to the exorbitant active effect. The Mg-6 wt.%Al-3 wt.%Zn-1 wt.%Ga-1 wt.%In in as-cast state with acceptable corrosion rate and desirable discharge performance is a low cost, non-toxic and well-performance magnesium alloy, which is a promising anode materials for seawater-activated batteries.