| The aluminum-air battery has excellent prospect by its advantages, such as high energy, environmental and inexpensive. In order to further promote the development and application of the battery, it is very important to develope new aluminum anode alloys with higher electrochemical properties and lower self-corrosion rate.In this paper, by adding the alloy element magnesium into the Al-0.1Ga-0.2Mn ternary alloy respectively, the series of Al-0.1Ga-0.2Mn-x Mg(x is 0.0, 0.05, 0.10, 0.15 and 0.20) quaternary anode alloys were prepared. In order to study the effect of magnesium contents on the microstructure and electrochemical performances of AlGa-Mn anode alloy by testing alloy performances in 40℃, 4mol/L NaOH solution. Moreover, the effect of heat treatment, solution termperatures and electrolyte additives on microstructures and electrochemical performances of aluminum anode alloy are studied.The results show that after adding magnesium elements into Al-Ga-Mn ternary alloy, the number of the second phase in alloys increased, along with open circuit potential and galvanostatic discharge potential negatively shifted, at the same time the hydrogen evolution rate of alloys are decreased and surface corrosion morphologies are improved. The Al-Ga-Mn-Mg has good comprehensive performances. Which have the open cricuit potential of-1.848V(vs Hg/Hg O), discharge potential of-1.549V(vs Hg/HgO), hydrogen evolution rate of 0.403 ml·cm-2·min-1 and uniform corrosion morphology.The second phase quantity of Al-Ga-Mn-Mg anode alloy reduces significantly after the solution treatment with the temperature from 450 to 5℃ 40℃, which the open circuit potential and galvanostatic discharge potential negatively shifted, moreover, the hydrogen evolution rate of alloys obviously decreased. The open circuit potential of alloy is-l.861 V, the discharge potential is-1.576 V at the current density of 100 mA·cm-2 and the hydrogen evolution rate is 0.313 ml·cm-2·min-1 when the solution temperature was 480℃. The hydrogen evolution rate is reduced after the annealing treatment with the temperature from 450 to 5℃ 10℃, but the open circuit potential and discharge potential shift positive. It shows that annealing treatment reduces the activity of aluminum alloy and the polarization phenomenon disappear at the time of discharge.The electrolyte temperatures have a greater effect on the performances of Al-Ga-Mn-Mg anode alloy. The electrochemical activity of alloys are improved and the hydrogen evolution rate also increase in line with increased electrolyte temperatures. Comprehensive consideration, the aluminum anode alloy should have good electrochemical properties and low rate of hydrogen evolution, Therefore, the alloy have relatively good comprehensive performances at the electrolyte temperature of 40℃, with the open circuit potentia of-l.774 V, the discharge potential of-1.475 V and the hydrogen evolution rate of 0.382 ml·cm-2·min-1.After adding sodium stannate or sodium citrate into pure NaOH solution, the hydrogen evolution rate of the anode alloy is decreased obviously. The hydrogen evolution rate of alloy drops to 0.247 ml·cm-2·min-1 when sodium stannate is 0.04 mol/L and the hydrogen evolution rate drops to 0.170 ml·cm-2·min-1 when sodium citrate is 0.4 mol/L. Although the sodium stannate or sodium citrate all reduces the discharge potential of aluminum anode alloy, but sodium stannate obviously improve the stability of discharge process while the sodium citrate is reducing the stability of the alloy at discharge, and shows some polarization phenomenon. The hydrogen evolution rate significantly increase with the alloying addition of potassium permanganate, when its concentration is 0.02 mol/L, the hydrogen evolution rate can reach to 1.071 ml·cm-2·min-1, the discharge potential of alloy moves positive as well as the stability of discharge is also reduced compared with the pure NaOH solution. |
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