| Aluminum air battery has the advantages of high specific energy,low price of raw materials and environmentally friendliness,etc.It is the ideal power source for electric vehicles,so it has caused more and more attention in recent years.However,when the aluminum is used as the anode material in the battery media,some problems will come,such as self-corrosion and passivation,which not only lead to excessive consumption of aluminum,but also increase the internal electrical loss of the battery.This seriously hinders the commercial process of the aluminum air battery.The addition of appropriate amount of alloy element can decrease the corrosion rate of A1 alloy and improve its electrochemical activity.Therefore it becomes one of the hot research hotspots in the field of aluminum air battery in recent years.In this paper,the influences of the different contents of In and Zn on the properties of Al-Mg-Sn-In-Zn anode materials for aluminum air battery were explored on the basis of Al-Mg-Sn alloys.The proper alloy ratio was selected.The effect of heat treatment system on the properties of aluminum alloy was studied.Self-corrosion rate was measured by weight-loss method.The current discharge of aluminum anodic alloy was tested through chronopotentiometry.The microstructure and corrosion morphology of the alloys were observed by scanning electron microscope(SEM)and Metallurgical Microscopy.The effects of In and Zn on the electrochemical properties of the alloys were explored by electrochemical impedance spectroscopy(EIS).The results showed that the number of precipitates increases with the increase of In content.Compared with the basic alloys,the electrochemical performance and the discharge performance of the In alloy have been improved.But its corrosion rate increased.The comprehensive performance of Al-0.5Mg-0.1Sn-0.1In alloy was the best.The corrosion morphology of was uniform in 4 M KOH solution.The alloy of self-corrosion rate was 0.263 mg·cm-2·min-1 and open circuit potential was about-1.646 V(vs.Hg/HgO).The discharge potential was about-1.363 V(vs.Hg/HgO)at 100 mA·cm-2 of constant current.The discharge output voltage was 1.42 V with the current as 20 mA in monomer battery.Compared with the basic alloy,the high frequency capacitive reactance arc on EIS of Al-0.5Mg-0.1Sn-xIn alloy became smaller;activation energy of alloy enhanced;intermediate-frequency capacitive reactance arc and low-frequency impedance arc became larger.These indicated that dissolution and shedding rate of the corrosion products on the anode surface decreased.The addition of Zn could improve the electrochemical and discharge performance of Al-0.5Mg-0.1Sn-0.1In-xZn alloy.When the contents of Zn were-separately 0.5 wt%and 1 wt%,the corrosion rates of the alloy decreased and the output voltages of the monomer battery became larger.The capacitive arc on EIS of alloy became larger,and the enhances corrosion resistance alloy.It had the opposite results when the contents of Zn were separately 1.5 wt%and 2 wt%.In all alloys,the comprehensive performance of Al-0.5Mg-0.1 Sn-0.1In-lZn alloy was the best.The corrosion morphology was uniform in 4M KOH solution.The self-corrosion rate of anode alloy was 0.195 mg·cm-2·min-1 and open circuit potential was about-1.706 V(vs.Hg/HgO).The discharge potential was about-1.416 V with constant current as 100 mA·cm-2.The discharge output voltage was 1.51 V with the current as 20 mA in monomer battery.Although simple annealing treatment could make the self-corrosion rate of Al-0.5Mg-0.1 Sn-0.1 In-1 Zn alloy decreased.However it made the comprehensive electrochemical properties of alloy obvious deterioration.The solid solution treatment not only improved the self-corrosion performance of alloy,but also improved the comprehensive electrochemical performance of the alloy at the same time.The corrosion rate of Al-0.5Mg-0.1Sn-0.1In-1Zn alloy decreased to 0.152 mg·cm-2·min-1 after 4 h and 510 ℃ of solid solution treatment.The discharge potential was-1.452 V with 100 mA·cm-2 of constant current.While the open circuit potential remained essentially unchanged. |
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