Effects of Electrolyte Composition on the Electrochemical Properties of an Aluminum Alloy Electrode for Al-Air Batteries

Abstract

Aluminum-air batteries that use alkaline electrolytes have the advantage of a high operating voltage, but the aluminum alloy electrodes experience high corrosion rates. To address this issue, a promising solution is proposed, which involves mixing neutral electrolytes with the alkaline electrolyte. In this study, we analyzed the electrochemical characteristics of aluminum alloy electrodes in electrolyte solutions containing varying concentrations of NaCl added to a 1 M NaOH alkaline electrolyte solution to understand the effect of neutral electrolytes on the discharge performance of aluminum-air batteries. The results obtained from potentiodynamic polarization tests, electrochemical impedance spectroscopy, three-electrode discharge tests, and open-circuit potential tests confirmed that the corrosion reaction and discharge voltage of aluminum alloy electrodes are influenced by the concentration of NaCl in the alkaline electrolyte solution. The corrosion rates and discharge voltages decreased as the concentration of neutral electrolyte increased, indicating that the electrochemical properties of aluminum-air batteries are highly dependent on the electrolyte composition.