Study On Anodic Materials Of Aluminum-air Battery

As an environmental friendly new energy,aluminum air battery has advantages of high power density,working voltage stability and light weight.It is an ideal battery system.However,aluminum is very easy to passivate in the neutral solution,which reducing the output power,And it is easy to occur self-corrosion in the alkaline solution,which reduces the utilization of the anode.In this experiment,Aluminum anode was activated by micro-alloying to improved its electrochemical performance and the ultra-hydrogen per-potential element was added to inhibit hydrogen evolution corrosion.So it has improved the utilization of anodes.The anode material is Al-Mg-Zn-Ga-Sn and the orthogonal test was designed by four factors and three levels.In addition,Al(industrial aluminum)-0.2Sn-0.15 Ga-1.0Mg-1.5Sn alloy was added to study the influence of impurity Fe and Si elements,there are ten sets of alloying samples in total.The cathodes was composed of the catalytic layer,the conductive collector networks and the waterproof breathable layers.The catalytic layer was made of MnO2,acetylene black,activated carbon and PTFE in a ratio of 3:1:4:2 and the waterproof breathable layers was made of acetylene black,activated carbon,PTFE,anhydrous sodium sulfate in a ratio of 1:1:6:2.The electrolyte is 3mol/L NaOH.The effects of alloying elements,impurity elements and annealing treatment on the electrochemical performance of aluminum alloy anodes were studied by the open circuit potential,polarization curve,corrosion rate and corrosion morphology.Assemble aluminum air battery,monitoring the battery device discharge voltage,the current,electrolyte temperature and PH changes.In order to select the best anode material,the battery needs a comprehensive study of the discharge performance and stability.The experimental results show that:(1)Annealing is beneficial to promote the open circuit potential shift to the negative and improve the discharge capacity of the alloy;(2)The corrosion rate of the annealed aluminum alloy is less than the unannealed aluminum alloy;(3)Both annealed and unannealed aluminum anodes are relatively stable and the voltage is between 1.7V?1.85V and 1.8V?1.94V respectively;(4)Fe,Si aggravated the corrosion of the alloys to decreased the utilization of the anodes;(5)The open circuit potential(-1.883V)of the Al-0.05Ga-0.6Sn-1.5Zn-0.6Mg after annealing treatment was the most negative,which made it have a strong discharge ability.At the same time,it has small corrosion rate that is 0.003889 mg/(cm2·min),which increased anode utilization.The stable discharge voltage is between 1.75V?1.81V and the corrosion morphology is uniform.So it is the best anode material.