Influence Of Zinc Oxide Corrosion Inhibitors With The Cooperation Of Amide Group On The Performance Of Al Anode And Electrolyte Properties After Discharging

The aluminum-air battery using aluminum as the energy storage medium possesses excessive safety and high specific energy density,which also can realize the recycling of aluminum.It is a green and sustainable electrochemical energy storage system with huge potential.However,it still holds the development bottleneck of hydrogen evolution corrosion of Al anode.Although the effect of corrosion inhibition could be obviously improved by adding the ZnO into the electrolytes,which is also a simple operation.It is still challenging to maintain the stable electrochemical performance of Al anode for a long time.The paper proposes to adopt the organic compound containing amide groups to improve the effect of ZnO,and further improve the performance of Al anode via the mutual synergy of the hybrid inhibitors.Meanwhile,the effect of corrosion inhibitors on hydrogen evolution corrosion and electrochemical performance of aluminum anode was investigated.On the basis,the influence of discharge conditions and the hybrid inhibitors on the composition,structure and properties of the electrolytes was explored to realize the realize the recovery of aluminum.The main outcomes are as follows:（1）A loose,porous and easily peeled Zn/ZnO protective layer could be constructed on the Al anode surface after adding zinc oxide to the alkaline electrolyte.And the corresponding corrosion inhibition efficiency held 68.13%.When further adding acrylamide（AM）and polyacrylamide（PAM）respectively,a more stable composite protective layer was formed with the cooperation of amide groups.The corrosion inhibition of aluminum was upgraded to 78.03%and 83.50%,separately.For the ZnO-AM and ZnO-PAM composite corrosion inhibitors,the discharge specific capacities were 1240.6 mAh g^-1 and 1185.6 mAh g^-1 at a discharge current density of 25 mA cm^-2.While the specific capacity reached 2444.1 mAh g^-1 and 2561.0 mAh g^-1 at a discharge current density of 100 mA cm^-2.Furthermore,the power densities of Al-air batteries were 63.7 m W cm^-2and 60.5 m W cm^-2,respectively.（2）The Al（Ⅲ）in the electrolytes of Al-air batteries after discharge mainly exists in the tetrahedral structure of Al（OH）₄^-under different conditions.And there is also a small amount of aluminate with bridging oxygen-containing structure produced by the polymerization of Al（OH）₄^-and the aluminate ion with high coordination number obtained by further reaction with OH^-.The content of Al（III）and viscosity of the electrolyte increased,while the electrical conductivity decreased with the extend of discharge current density,discharge time and temperature.Meanwhile,the composition and properties of the electrolyte after discharging were mainly affected by the discharge time and temperature when the current density increased to a certain level.When adding the inhibitors into the electrolytes,single corrosion inhibitor of ZnO shows little effect on the composition and properties of the electrolyte,while organic AM and PAM enlarge the viscosity of the electrolyte and decrease its ionic conductivity.The amide groups of AM molecules would induce the polymerization of aluminates,while the steric hindrance effect of macromolecular polymer of PAM inhibits the polymerization process to a certain extent.