Improving energy efficiency of commercial aluminum alloy as anodes for Al-air battery through introducing micro-nanoscale AlSb precipitates

The micro-nanoscale AlSb precipitates are introduced into selected commercial aluminum alloys as anode material for alkaline Al–air battery, and their corrosion behaviors, microstructure and discharge properties are investigated in details. It is found that such Sb addition can coexist in harmonization with already added other alloying elements in the Al alloys, and further bring out the improved microstructure and the electrochemical performance as the Al anodes. The energy density of 1080 alloy with Sb (1544 Wh•kg−1) is 30.9% higher than that without Sb at 10 mA•cm−2. The resulting electrochemical impedance spectroscopy (EIS) with Sb addition demonstrates that the diffusion resistance (RC) and inductance (L) reduce with decreasing thickness of passive film on the anode surface while increasing its discharge voltage. The improved refinement in microstructure can also restrain hydrogen evolution from the Al-based anode. The fundamental information obtained is useful for designing and fabricating the Al anode products from low-cost commercial alloys with added-on electrochemical performance.