Influences of Sodium Polyacrylate/ZnO Composite Corrosion Inhibitor on the Electrochemical Activity and Discharge Performance of 6061 Aluminum Alloy in Alkaline Electrolyte

Abstract

For suppressing the self-corrosion rate of the anode of aluminum-air battery and improving its discharge performance，the effects of adding sodium polyacrylate (PAAS) or zinc oxide (ZnO) alone or adding them both on the self-corrosion and discharge properties of aluminum alloy in 4mol/L NaOH solution were studied using 6061 aluminum alloy as anode material.Results showed that the effect of PAAS/ZnO composite corrosion inhibitor was better than that of single corrosion inhibitor.The composite corrosion inhibitor not only promoted the activation of the anode，but also formed a more stable composite protective film on the surface of aluminum anode，which effectively slowed down the selfcorrosion of hydrogen evolution and improved the utilization rate of the anode.In NaOH+PAAS+ZnO electrolytic liquid system，the dissolution of 6061 aluminum alloy was mainly controlled by the diffusion of charge in corrosion products or zinc salt deposition layer.After adding the composite corrosion inhibitor，the self - corrosion rate of 6061 aluminum alloy decreased from 0.496 4 mg/(cm2 ·min) to 0.275 0 mg/(cm2·min).Meanwhile，the inhibition rate reached 44.6%，the discharge voltage decreased from -1.381 V to -1.681 V，and the anode utilization rate increased by 13.5%.In general，the discharge performance of aluminum-air battery was obviously improved.

Keywords

• aluminum-air battery|6061 aluminum anode|paas/zno|composite corrosion inhibitor|electrochemical activity