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
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.