Performances of an Al-0.15 Bi-0.15 Pb-0.035 Ga alloy as an anode for Al-air batteries in neutral and alkaline electrolytes

Abstract

Aluminum is a very good candidate anode for metal-air batteries due to its negative electrode potential, high theoretical electrochemical equivalent value, abundant reserves and environmental friendliness. The corrosion behavior and electrochemical properties of the Al-1.5Bi-1.5Pb-0.035Ga alloy were investigated by self-corrosion tests and electrochemical techniques, and compared with that of pure Al and Al-Bi-Pb alloys. The performances of Al-air batteries based on these alloy anodes were studied by constant current discharge and I-V discharge tests. The corrosion morphology and discharge surface were also investigated by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. The results show that the Al-Bi-Pb-Ga alloy provides a more negative potential and exhibits an enhanced activity in NaCl solution compared with pure Al and Al-Bi-Pb alloys, and gives high power density (253.4 ± 2.5 mW cm-2) and desirable anode efficiency (85.4 ± 0.5%) when used as an anode for Al-air batteries in KOH solution. Moreover, the dissolution mechanism of the Al-Bi-Pb-Ga alloy is also characterized based on the electrochemical measurements and microstructure observations.