Corrosion Inhibition of PAAS/ZnO Complex Additive in Alkaline Al-Air Battery with SLM-Manufactured Anode

In order to improve the electrochemical activity and discharge performance of aluminum–air batteries and to reduce self-corrosion of the anode, an SLM-manufactured aluminum alloy was employed as the anode of the Al-air battery, and the influence of PAAS and ZnO inhibitors taken separately or together on the self-corrosion rate and discharge performance of the Al-air battery in a 4 M NaOH solution were investigated. The experimental result indicated that the effect of a composite corrosion inhibitor was stronger than that of a single corrosion inhibitor. The addition of the compound inhibitor not only promoted the activation of the anode but also formed a more stable composite protective film on the surface of the anode, which effectively slowed down the self-corrosion and improved the utilization rate of the anode. In NaOH/PAAS/ZnO electrolytes, the dissolution of the Al6061 alloy was mainly controlled by the diffusion of the electric charge in the corrosion products or the zinc salt deposition layer. Meanwhile, for the Al-air battery, the discharge voltage, specific capacity, and specific energy increased by 21.74%, 26.72%, and 54.20%, respectively. In addition, the inhibition mechanism of the composite corrosion inhibitor was also expounded. The excellent discharge performance was due to the addition of the composite corrosion inhibitor, which promoted the charge transfer of the anode reaction, improved the anode’s activity, and promoted the uniform corrosion of the anode. This study provides ideas for the application of aluminum–air batteries in the field of new energy.