Investigation of commercial aluminum alloys as anode materials for alkaline aluminum–air batteries

Abstract

Metal Al is an attractive energy carrier in Al-based batteries with promising recyclability and sustainability in alkaline solutions. However, finding applicable Al anode materials for alkaline Al–air batteries is difficult. In this study, commercial Al alloys are employed as anode materials for Al–air batteries. The self-corrosion behavior, electrochemical properties, composition, and microstructure of the alloys and their relationships are systematically investigated using a hydrogen collection method, electrochemical measurements, and multiple characterization studies. The results show that the 6061 Al alloy (A6061) presents a low hydrogen evolution rate and superior electrochemical performance. The hydrogen evolution reaction is found to be inhibited by increasing the current density. The A6061 anode presents a high anodic efficiency of 89.28%, a specific capacity of 2660.69 mA h g⁻¹, and an energy density of 2119.09 W h kg⁻¹ at 80 mA cm⁻². The exceptional performance is due to its crystallographic orientation which is beneficial for Al dissolution and promotes electrochemical activity. This study could provide a better understanding of commercial Al alloy anodes and is conducive to optimizing the Al anode structure.