Investigations On The Magnesium Alloy Anodic Materials Used For Seawater Batteries

With the continuous development of deep-sea exploration technology, sea water battery began to have drawn the attention of the researchers at home and abroad. The properties of sea water battery are not only affected by electrode materials but also related to seawater environmental factors(such as oxygen concentration, flow rate) and battery parameters(such as interelectrode distance) because of its open structure. As anode material, magnesium suffers the drawbacks of low current efficiency due to its severe parasitic corrosion reaction resulting in the evolution of hydrogen and the “negative difference effect”. In this dissertation, the self-corrosion and electrochemical behaviors of AZ31, AZ61 and AZ91 magnesium alloys in 3.5wt%Na C l solution were firstly investigated by chromatography hydrogen, weightlessness, AC impedance, dynamic potential polarization, constant current discharge and so on many kinds of method. Then, it examines them as magnesium battery cathode material performance. Secondly, the surface morphology of magnesium alloy anode materials was studied by scanning electron microscopy. Thirdly, it studies the influence of environmental factors on the corrosion performance of AZ31 magnesium alloy and battery voltage. At last, it investigate the effect of different Hg content to the corrosion and electrochemical properties of the magnesium alloy anode materials.Results show that the corrosion resistance of AZ61, AZ91 and AZ31 increase gradually. The types of corrosion and corrosion mechanism of magnesium alloy anode material were discussed. The scanning photos show that magnesium alloys for corrosive pitting corrosion types in 3.5wt%Na C l solution. Corrosion began by pitting corrosion expansion from the first local area and development into a hole comprehensive corrosion.This paper studies the influence of environmental factors on the corrosion performance of AZ31 magnesium alloy and battery voltage. As the water temperature rises, the water concentration is increased, the water flow increases, the corrosion rate of AZ31 magnesium alloy increases. And as sea temperatures rise, the concentration of sea water increases, the pitch of positive and negative is reduced, the battery voltage rises.Research results show that, with the increase of the content of Hg, magnesium alloy corrosion activity increase firstly, and then decrease. Research results show that with the increase of the content of Hg, the working voltage of Mg-Al-Hg series of magnesium allays become more positive firstly and then more negative. Comprehensive Mg-Al- Hg series of magnesium alloy corrosion and electrochemical performance, obtaining the best Mg-Al-Hg series of magnesium alloy composition: AZ31-1.0% Hg.