Composition optimization and electrochemical properties of Mg-Al-Pb-Ga-Y alloys as anodes for seawater activated battery

Magnesium alloy anode materials for Mg-Al-Pb-Ga-0.9Y seawater battery were prepared by metallurgy method. The effects of Pb、Ga additions on the microstructures and electrochemical properties of this alloy were investigated by optical microscopy(OM), scanning electronic microscopy(SEM), X-ray diffraction(XRD) and Electrochemical test. The results show that the discharge voltage and corrosion resistance of the alloy increase with the growth of Pb content. Moreover, the optimum effect of discharge voltage is achieved with 5 wt% Pb and 1 wt% Ga additions. The alloy has a high discharge voltage at 20 mA/cm² and 100 mA/cm² current densities. The Mg-3Al-5Pb-1Ga-0.9Y alloy has more excellent comprehensive performance than the other alloys, which also has the most negative discharge potential. The working potentials at current densities of 20 mA/cm² and 100 mA/cm² are -1.723 V and -1.680 V respectively. In addition, the Mg-3Al-5Pb-1Ga-0.9Y alloy has a low self-corrosion rate, and its corrosion current density is 5.1164×10^-5 A/cm².