Mg-3wt%Al anodes with Sn, Ga and In were prepared by melting and heat-treatment in electric resistance furnace. The electrochemical discharge behavior of these anodes in 3.5wt% NaCl solutions was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The microstructures and the corroded surfaces of the anodes were investigated by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Finally, Mg-air batteries based on Mg-3Al-1Sn (AS31), Mg-3Al-1Ga (AG31), Mg-3Al-1In (AI31) alloys were prepared and battery properties were studied by constant current discharge test. Mg-3Al (A3) and Mg-3Al-1Zn (AZ31) were also prepared to be used for contrast test. The results show AI31 behaves good comprehensive properties, the battery based on AI31 anode possesses the highest capacity density (1382 mAhg−1) and power density (18.5 mWcm−2). Compared with A3 and AZ31, AS31 and AG31 show higher corrosion resistance. In addition, The paper also researches on the modification mechanism of Ga, In and Sn on Mg-3Al.

In this research, the performance of Al-air batteries based on pure Al and Al-0.5 wt%In anodes in 4M NaOH solutions with or without different concentrations of additives was investigated by galvanostatic discharge test. The characteristics of the anodes after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive analysis of X-ray (EDAX). The corrosion behavior of the anodes was researched by self-corrosion rate test and potentiodynamic polarization test. The results show that the Al-In alloy exhibits a low self-corrosion rate and high anodic efficiency when ZnO or Na 2 SnO 3 is added to 4M NaOH. The results of galvanostatic discharge at 20 mAcm −2 indicate that the Al-air battery based on Al-0.5 wt%In anode shows excellent discharge performance. The Al-air battery based on the alloy anode has an operating voltage of 1.3 V and anodic efficiency of 75.2% in 4M NaOH with 0.02M Na 2 SnO 3 , and an operating voltage of 1.01 V and anodic efficiency of 82.5% in 4M NaOH with 0.2M ZnO. SEM and EDAX results prove that zinc oxide or sodium stannate could inhibit the corrosion of the Al-In anode by the deposition of zinc or tin on the anode surface.Aluminum is an excellent anode material for metal-air batteries because of its high theoretical electrochemical equivalent value (2980 mAh g -1 ), which is just lower than that of lithium (3860 mAh g -1 ) and higher than those of other metals such as magnesium (2200 mAh g -1 ) and zinc (820 mAh g -1 ). 1 As promising power and energy storage devices, Al-air batteries can be applied in fields such as electric vehicles, navigation and portable sources. In addition, the final reaction product can be recovered as aluminum during recycling. However, severe self-corrosion of the aluminum anode in alkaline electrolyte causes fuel loss during standby. A protective oxide film forms spontaneously on the aluminum surface in neutral electrolyte, which slows down the active dissolution of the aluminum anode. These problems have hindered the development and business applications of Al-air batteries. 2,3 Two main methods have been proposed to inhibit the self-corrosion of aluminum anodes in alkaline solution. The first method is to dope aluminum with active metal elements. The active metal elements mainly include Ga, In, Sn, Zn and Mg. 4 As they have high hydrogen evolution overpotential, these alloying elements can reduce hydrogen evolution. An Al-air battery based on Al-1 wt%Mg-1 wt%Zn-0.1 wt%Ga-0.1 wt%Sn anode in 4M NaOH solution showed excellent discharge performance. 5 However, the addition of excessive kinds of elements is harmful to the recovery of aluminum. What's more, the amount of active metal elements added into the aluminum should be as low as possible. Therefore, researchers preferred to study some binary aluminum alloys as anodes of Al-air batteries. 6-9 For instance, Wilhelmsen studied the corrosion rate of Al-0.1 wt%In anode in 4M KOH solution by the weight loss method and the result revealed that t...

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In this paper, the performance of Al-air batteries based on pure Al, Al-0.1 wt%Ga, Al-0.1 wt%In and Al-0.1 wt%Sn anodes in 1 M KOH solutions was investigated by galvanostatic discharge test. The electrochemical characteristics of the anodes were investigated by means of hydrogen collection, tafel polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM). The results reveal that compared with pure Al in 1 M KOH, Al-0.1 wt%In or Al-0.1 wt%Sn exhibits a lower self-corrosion rate and higher electrochemical activity because indium or tin with a high hydrogen evolution overpotential deposits on the aluminum surface. The Al-0.1 wt%Ga alloy is not an ideal anode of alkaline Al-air battery because the severe self-corrosion. The results of galvanostatic discharge at a current density from 1 to 40 mA cm −2 indicate that the Al-air batteries based on both Al-0.1 wt%In and Al-0.1 wt%Sn anodes in 1 M KOH show excellent discharge performance and high anodic efficiencies.Aluminum is considered an excellent anode material for metal-air batteries, because it is the most abundant crustal metal on the earth and has a high theoretical electrochemical equivalent value (2980 mAh g −1 ) and energy density (8100 Wh Kg −1 ). 1 However, Al-air batteries still encounter many challenges, which have hindered the development of Al-air battery and restrict its business applications. 2,3 For instance, in neutral salt electrolyte, pure aluminum supports a passive film on the surface with an operational potential of approximately −0.8 V (vs. SCE) and a greatly serious polarization during discharge, which makes it useless as a sacrificial anode for Al-air battery. To overcome the problem, many researchers have used high purity grade aluminum alloys doped with such elements as Mg, Ga, In, Sn, which act as corrosion inhibitors without enhancing the overvoltage for aluminum dissolution and can also shift the potential toward more negative values causing the so-called activation of aluminum which is helpful for Al-air battery. 4 According to the previous reports, the potential values of Al-In alloys in neutral salt solution changed from −1.4 V to −1.7 V (vs. SCE) and the corrosion rates of the alloys were decreased compared to pure aluminum. The electrochemical properties of the alloys in 2 M NaCl solution also were studied. The results indicated that the corrosion potentials were around −1.3 V (vs. SCE). 5 The performance of Al-Sn alloy was studied by El Shayeb. The potential value of the alloy in 0.6 M NaCl was around −0.98 V (vs. SCE). In 2 M NaCl solution, the potential value of the alloy shifted more toward the negative which was around −1.45 V (vs. SCE). 6 Some ternary Al alloys were also investigated in 2 M NaCl solution. The potential of Al-In-Sn alloy obtained in 2 M NaCl solution was around −1.46 V vs. SCE). 7 The Al-In-Ga alloy exhibited more negative potential than that of pure Al but slight lower than Al-In alloy. 7 But, these methods just can only resolve the passivation of aluminum limitedly. Addition...

Aluminum is attracting interest due to the good application prospect as anode for metal-air batteries in alkaline solutions. In this paper, the corrosion behavior and electrochemical properties of industrial aluminum alloy are investigated using hydrogen collection method, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 4 M NaOH and 4 M KOH. Battery performances are tested by constant current discharge at different current densities. The results show 8011 Al alloy has better electrochemical properties, discharge energy and power density. Considering the cost and performance, 8011 Al alloy is one of the most promising low-cost and high performance Al anode for Al-air batteries.

Aluminum (Al) is a candidate anode material for metal-air batteries. But low anode efficiency and power density hinder its commercial application. This paper reports a kind of Al alloy as the anode for Al-air batteries. The electrochemical properties of the anodes are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 4 M KOH. Battery performance is tested by constant current discharge at different current densities. The results show that the alloy as the anode has higher electrochemical activity and lower polarization. The new alloy anode provides higher energy density and power density for Al-air batteries.There is a growing interest in next generation energy that is sustainable, safe and does not pollute. Metal air batteries are one of the most promising new energy sources which produce electricity from the reaction of the anode with oxygen in the air. Aluminum, owing to its high energy density (8.1 kWhkg −1 ) and low cost, has emerged as one of the most promising anode candidates. 1-3 Many Al-air batteries utilize strongly alkaline electrolytes. 4 However, the commercial applications of Al-air batteries have not yet been realized due to the low anode efficiency and the large polarization, which reduce the energy density and limit the power output of the batteries. To solve those problems, researchers have added corrosion inhibitors 5,6 in electrolytes or alloy elements such as Mg, Ga, In, Sn, in Al anodes to reduce the corrosion and enhance the electrochemical activity. The optimal content of the alloying element is determined by the saturated solid solubility of the alloying element to form a single phase solid solution at room temperature. However, the reduction of self-corrosion may cause an increase of polarization resistance by increasing the charge transfer resistance. Thus, the energy density and power density of an Al-air battery is limited at high current densities, which restrict the application of aluminum air batteries in high power density machinery such as electric cars and airplanes. Therefore, increasing anode efficiency and reducing polarization are essential to allow development of high performance Al-air batteries for high power electric devices. [14][15][16] After testing several possibilities, an excellent Al alloy anode named LF1 was discovered in this paper. The alloy exhibits high electrochemical activity and low polarization resistance as the anode to produce high power and energy density for Al-air batteries, which would allow application as high performance power sources for electric vehicles and aircraft. ExperimentalMaterial preparation.-Alloys were prepared from pure metals, using the method of casting. Raw materials were pure aluminum (99.99%), magnesium (99.9%), gallium (99.999%), tin (99.99%) and indium (99.99%). The appropriate content of Mg is about 0.6%, Ga about 0.05%, and In and Sn are about 0.1% (wt), which is reported in the literature. 17 High purity Al (99.999%) and Al-0.5 Mg-0.07 Sn (EB50V) 18 were used as comparisons....

The performance of Al-air batteries in 4 M NaOH containing ZnO or ZnO/cetyl trimethyl ammonium bromide (CTAB) hybrid inhibitor is studied by constant current discharge test. The characteristics of aluminum anodes after discharge are investigated by scanning electron microscopy (SEM), and energy dispersive analysis of X-ray (EDAX). The corrosion behavior of aluminum electrodes in 4 M NaOH containing ZnO or ZnO/CTAB is studied by means of hydrogen collection and potentiodynamic polarization. SEM and EDAX results indicate that CTAB can greatly improve the deposition of zinc so that a uniform and compact zinc layer covers on the aluminum surface.Due to the low atomic mass and the negative electrode potential, aluminum potentially attracts as an outstanding anode material for Alair battery with a high theoretical energy density. 1-3 The electrolyte is one of the important components of Al-air battery. Al-air batteries in various electrolytes such as saline, alkaline, and non-aqueous have been studied by many researchers over the past few decades. 4-6 However, Al-air batteries still encounter many challenges. For instance, a protective oxide film forms spontaneously on the aluminum surface in neutral or non-aqueous electrolytes, which retards the active dissolution of aluminum anode. Additionally, severe self-corrosion of aluminum causes the fuel loss during standby in alkaline electrolytes. 7-9 So far, these problems are still not effectively resolved so that the business applications of Al-air batteries have been hindered. One effective method to mitigate the corrosion of aluminum in alkaline solutions is to add inhibitors to the electrolytes. 10-12 Many researchers found that zinc oxide can significantly inhibit the corrosion of aluminum anodes in alkaline solutions. 13 But, if the alkaline solution only contains zinc oxide inhibitor, the deposited zinc covering on the aluminum surface is loose and spongy, which means that the inhibition of the corrosion of aluminum anodes may not sustain for a long time. As a result, in order to obtain a better deposited zinc layer covering on the aluminum surface, numerous researchers tried to add another additive to improve the deposition of zinc. 14,15 Wang found that the addition of dimethyl amine epoxy propane (DE) to the zincate-containing alkaline solution can bring about a granular zinc on the aluminum surface. But Wang mainly paid attention to the electrochemical performance of aluminum anode in the alkaline solution containing ZnO/DE hybrid inhibitor but ignored the Al-air battery performance. 16 Zhu studied the influence of some surfactants on the electrochemical behavior of zinc electrodes in alkaline solution. The results revealed that the surfactant cetyl trimethyl ammonium bromide (CTAB) can bring about a significant improvement in the morphology of the deposition of zinc. 17 Besides, the addition of surfactant cetyl trimethyl ammonium bromide (CTAB) into alkaline solution can also inhibit the corrosion of aluminum anodes. 18 However, so far, the electrolyte system o...

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