Performance of Al-0.5In as Anode for Al–Air Battery in Inhibited Alkaline Solutions

Abstract

In this research, the performance of Al–air batteries based on pure Al and Al-0.5 wt%In anodes in 4M NaOH solutions with or without different concentrations of additives was investigated by galvanostatic discharge test. The characteristics of the anodes after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive analysis of X-ray (EDAX). The corrosion behavior of the anodes was researched by self-corrosion rate test and potentiodynamic polarization test. The results show that the Al–In alloy exhibits a low self-corrosion rate and high anodic efficiency when ZnO or Na2SnO3 is added to 4M NaOH. The results of galvanostatic discharge at 20 mAcm−2 indicate that the Al–air battery based on Al-0.5 wt%In anode shows excellent discharge performance. The Al–air battery based on the alloy anode has an operating voltage of 1.3 V and anodic efficiency of 75.2% in 4M NaOH with 0.02M Na2SnO3, and an operating voltage of 1.01 V and anodic efficiency of 82.5% in 4M NaOH with 0.2M ZnO. SEM and EDAX results prove that zinc oxide or sodium stannate could inhibit the corrosion of the Al–In anode by the deposition of zinc or tin on the anode surface.