Discharge performance of Al-0.1Sn-0.1In-0.05Ga alloy for Al–air battery anodes

Abstract

The performance of Al-0.1Sn-0.1In-0.05Ga alloys as anodes for Al–air batteries is investigated for low carbon development needs. Low melting point elemental metals were added to high purity Al (99.9999 %) using micro alloying, either in a diffuse distribution or as a second phase, depending on their solid solubility in the Al. The correlation between the microstructure and electrochemical properties of Al-0.1Sn-0.1In-0.05Ga alloys was established. The experiments were conducted in a 4.0 mol/l NaOH solution. The electrochemical characteristics of the Al-0.1Sn-0.1In-0.05Ga anodes were assessed by using potentiodynamic polarization, electrochemical impedance spectroscopy, and galvanostatic discharge experiments. It is indicated that the inclusion of Sn, In, and Ga elements results in improved corrosion resistance and discharge activity in the anode composed of Al. This can be attributed to the presence of nano-scale second phase particles and a uniform microstructure in the Al-0.1Sn-0.1In-0.05Ga alloy, which effectively inhibits localized crystallographic corrosion. In comparison to pure Al, the Al-0.1Sn-0.1In-0.05Ga alloy exhibits a reduction in corrosion current density by 24.77 % and an increase in anode efficiency by 40 %. When discharged at a current density of 10 mA/cm2, an Al–air battery with an Al-0.1Sn-0.1In-0.05Ga anode exhibits a discharge voltage of 1.523 V, a discharge capacity of 2214 Ah/kg, and an anode efficiency of 74.31 %. The research has the potential to advance Al–air batteries' progress and significantly contribute to global sustainability efforts.