Study Of Inhibitors Of Electrode In Containing Cl~-Solution And Inhibition Mechanism

The advantages of the aluminum-air battery, such as high specific energy, richmaterial source of aluminum anode and clean energy, make the battery have a goodprospects. However, the serious corrosion of aluminum restricts the aluminum-airbattery development.This dissertation uses the inhibitors of the aluminum in the3.5wt.%NaCl mediumas the research object. Study the inhibitor behavior of mixsd sodium oleate（SO） withsodium vanadate co-inhibitors and the inhibition mechanism. Mixed SO with sodiumvanadate, used as co-inhibitors for aluminum in3.5wt.%NaCl solution with totalconcentration of0.5g/L, were chosen by Open Circuit Potential-time（OCP） curves. WithTafel curves, the optimum technological conditions was studied. And it ws at roomtemperature, which can be expressed as follows: the3.5wt.%NaCl solution containstwo inhibitors of SO and sodium vanadium, and their mass concentration ratio is1:2with their total concentration of0.5g/L, solution pH value is8.0⁸.5. The Tafel and EIStest result showed that the co-inhibitor has a strong inhibition to cathodic process andanodic process, and especially to the cathodic process.The mechanism of the co-inhibitor was studied by the Electrochemical ImpedanceSpectroscopy（EIS） test, the result showed that the co-inhibitor has four corrosioninhibition stages. SO and sodium vanadate have played the major role of corrosioninhibition at different stage respectively, which can be attributed to the formation ofcontinuous phase on the surface of pure aluminum. Equivalent circuit, SEM-EDS testand XPS test have supported this kind of corrosion inhibition mechanism.Tafel test results showed that the appropriate concentration of co-inhibitor is that:0.4g/LC₁₇H₃₅COONa+0.4g/LNaVO₃. OCP and Tafel test results showed that add to opcan increase the inhibition efficiency of co-inhibitor to87.46%. Weight loss method andEIS test also showed that add to op can increase the inhibition efficiency.Electrochemical Noise（EN） result showed that add to op never change the inhibitionmechanism of the co-inhibitor. The EN result also proved that sodium vanadate inhibitcorrosion of aluminum electrode by oxidation-passivation mechanism.