Effect of Mg content on discharge behavior of Al-0.05Ga-0.05Sn-0.05Pb-xMg alloy anode for aluminum-air battery

Al-0.05Ga-0.05Sn-0.05Pb-xMg alloys with different Mg content have been prepared. Electrochemical tests including constant current discharge test, current polarization test, electrochemical impedance spectroscopy (EIS) test, and Tafel test are performed. The surface states of the alloys after constant current discharge were analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS). X-ray diffraction (XRD) analysis was carried out. We find that different Mg contents have great influence on discharge performance of aluminum alloy anodes by changing the corrosion behavior. The SEM and XRD show that Mg can influence the distribution of corrosion and change the grain size to improve the discharge performance of aluminum anodes. Al-0.05Ga-0.05Sn-0.05Pb-0.1Mg shows the best electrochemical performance due to uniform corrosion and proper grain size. At 800 mA cm−2 constant current discharge, the potential of the aluminum anode can reach − 1.54 V (vs Hg/HgO), and the utilization ratio is over 98%.