Research On Al-Ga-Mn-Bi Series Anode Materials Of Mg, Sn Alloying

The aluminum/air battery has excellent prospect on account of its advantages,such as, high energy, environmental, and inexpensive. In order to promote thedevelopment of the battery technology, it is very important to exploit new aluminumanode materials with higher electrochemical property.In this paper, based on the Al-Ga-Mn-Bi alloy, two series of anode alloy weredesigned and prepared, these alloys were the Al-0.1Ga-0.5Mn-0.5Bi-xSn (x is0,0.05,0.1and0.13) and Al-0.1Ga-0.5Mn-0.5Bi-xMg(x is0,0.3,0.7,1.0and1.3) respectively.After composition optimization, the anode alloys were processed by heat treatment androlling deformation. The electrochemical properties and corrosion resistance weretested in4mol/L NaOH solution, the microstructure and corrosion morphology wereobserved. Effects of element content, heat treatment and rolling on the electrochemicalproperties were investigated.The results show that the addition of Sn element in the basic alloy improves theelectrochemical performance on the whole, enhances the constant-current dischargeperformance and increases the corrosion resistance. The comprehensive property ofAl-Ga-Mn-Bi-Sn shows the best when0.1%Sn element was added, the open circuitpotential is-1.719V(vs. Hg/HgO), the self-corrosion rate is0.237mg cm-2min-1, thegalvanostatic discharge voltage moves to-1.304V with100mA/cm2constant currentdischarge, and the discharge curve is stable. The addition of Mg element makes thedistribution of the second phase more uniform, enhances the activation, and improvesthe galvanostatic discharge. When0.1%Mg element was added, theAl-0.1Ga-0.5Mn-0.5Bi-Mg Shows the best comprehensive performance, its opencircuit potential is-1.769V, the self-corrosion rate is0.282mg cm-2min-1, and thegalvanostatic discharge voltage is the most negative (-1.454V at100mA/cm2constantcurrent discharge).The second phase quantity of Al-0.1Ga-0.5Mn-0.5Bi-0.1Sn anode alloy reduces significantly after the solution treatment with the temperature from460℃to500℃,the open circuit potential moves negative, but the mobile degree is small, the solutiontreatment enhances the constant-current discharge performance and increases thecorrosion resistance. The comparison of solid solution treatment at differenttemperatures showed that the best comprehensive property can be obtained when thesolution temperature was480℃, its self-corrosion rate is0.171mg cm-2min-1, and thegalvanostatic discharge voltage is the most negative (-1.487V at100mA/cm2constantcurrent discharge). The second phase quantity of Al-0.1Ga-0.5Mn-0.5Bi-0.1Sn anodealloy increases significantly after anneal treatment with the temperature from460℃to500℃, its distribution is more homogeneous, and the open circuit potential movespositive. The anneal treatment brings down the constant-current discharge performance,reduces the corrosion resistance, and deteriorate the corrosion morphology. The effectof solution treatment is superior to that of anneal treatment and therefore it is favorablefor engineering application of the alloy.After rolling deformation at room temperature the open circuit potentials of theAl-0.1Ga-0.5Mn-0.5Bi-Mg anode alloy change small. Along with the increase ofrolling deformation the galvanostatic discharge voltage moves negative, when thedeformation is80%, the discharge performance is the best, its discharge voltagereaches-1.517V, its self-corrosion rate is0.260mg cm-2min-1and its corrosionresistance changes small with the original sample. After rolling deformation at380℃the open circuit potentials of the Al-0.1Ga-0.5Mn-0.5Bi-Mg anode alloy also changesmall. Along with the increase of rolling deformation the self-corrosion rate decreasesgradually, as the deformation is80%, the self-corrosion rate islowest(0.196mg cm-2min-1). When the deformation is80%, the discharge performanceis the best, its discharge voltage reaches-1.440V.