The effects of Ca addition on corrosion and discharge performance of commercial pure aluminum alloy 1070 as anode for Aluminum-air battery

The effects of calcium addition on the commercial pure aluminum alloy anode for Al-air battery in alkaline electrolyte were examined by potentiodynamic polarization, AC impedance, corrosion rate and discharge measurements. The results show that calcium addition can increase the polarization resistance, discharge voltage and restrain the corrosion rate in 4 M KOH. Electrodes with calcium addition have the superior anode efficiency and higher capacity density. Microstructure observations show that calcium addition refines the grain structure, redistributes the impurity elements Fe and Si, and leads to more intermetallic phases formed along the inter-dendritic region and grain boundary and dispersed in the matrix. These characteristics are responsible for the improved electrochemical performance of the Al- air battery.