Seawater activated battery magnesium alloy anode materials
|School||Central South University|
|Keywords||Magnesium Battery Magnesium alloy anode materials Electrochemical behavior Corrosion morphology Microstructure Alloying elements|
The the magnesium electrode material has low-cost, non-toxic, non-polluting, stable discharge voltage, high specific energy, high specific power, rich in natural resources, renewable and many other advantages, widespread concern by the people. But has not been widely used, one of the main reasons is that magnesium in the electrolyte polarization, corrosion, and other serious cases, making it impossible to achieve the application of the standard, it is difficult to meet the requirements. Therefore, the study of the high activity of alloying elements on the activation of the magnesium alloy anode materials, the second phase of the study, the alloy composition and the microstructure of the material properties of magnesium alloy anode has important theoretical significance and practical value. Firstly, by hydrogen evolution, weight loss, cyclic voltammetry, AC impedance, constant current potential, potentiodynamic polarization, constant pressure discharge a variety of methods to study the existing AP65, Mg-3% Hg-2% of Ga and AZ31 since the corrosion and electrochemical behavior of the kinds of magnesium alloy in 3.5% NaCl solution, and their performance as magnesium battery anode material. Hydrogen evolution and soak results show that the corrosion activity of the Mg-3% Hg-2% of Ga than AZ31 and AP65. Constant current potential, the electrochemical activity of the Mg-3% Hg-2% Ga and AP65 better than AZ31, anodic polarization, open circuit potential negative. AC impedance results show that the Mg-3% Hg-2% Ga AP65.AZ31 the RCT value is gradually increased. The potentiodynamic polarization results show that the Mg-3% Hg-2% Ga.AP65.AZ31 corrosion current density values ??are sequentially gradually decreases. , Mg-3% Hg-2% Ga and AP65 current density is greater than in the constant-voltage discharge the AZ31 is more stable, more magnesium anode battery application value. Second surface morphology by scanning electron microscopy magnesium alloy anode material for corrosion, types of corrosion and corrosion mechanism of magnesium alloy anode materials. By the results of the scan photo shows the types of corrosion of magnesium alloy in 3.5% NaCl solution for pitting. Corrosion first start from the local area, through the the pitting holes of extended and developed into a comprehensive corrosion. In combination with EDS analysis shows that the main corrosion product such as Mg (OH) 2 compound. Has magnesium alloy anode materials research, the paper further seawater activated battery without harmful alloying elements magnesium alloy anode materials-Mg-Al-Sn series magnesium alloy design. Adding different alloying elements and the content of alloying elements from corrosion and electrochemical properties of magnesium alloy anode materials were investigated through a series of design six different components of Mg-Al-Sn alloy. The self-corrosion rate of hydrogen evolution and soak method magnesium alloy. The results show that with the increase of Al and Sn content, magnesium alloys from corrosion activity gradually increased; six ingredients magnesium alloy Mg-6% Al-10% Sn alloy from corrosion activity optimal. The operating voltage of the constant current and voltage of Mg-AI-Sn series magnesium alloy. The study results showed that the working voltage of the Mg-Al-Sn series of magnesium alloy is more negative with increasing the content of Al and Sn, and more stable. AC impedance results show that, the magnesium Mg-Al-Sn series alloy electrode system containing adsorbent impedance of the electrode system. The study found that the adsorption capacity of the electrode reaction of the intermediate product and its effect on the impedance value of the charge transfer in the electrode reaction is reduced with the increasing content of Al, Sn and. Simultaneously from the numerical analysis of the passivation layer of the magnesium alloy of Mg-Al-Sn series block the ability of the metal dissolution reaction is weak, magnesium alloy having a strong corrosion activity. By scanning electron microscopy and energy dispersive analysis of Mg-Al-Sn series magnesium alloy corrosion product composition and morphology of corrosion. The results show that the corrosion products are mainly of the magnesium alloy of Mg-Al-Sn series of Mg (OH) 2, MgO and other compounds. More uniform corrosion, corrosion product is easy to fall off. Comprehensive Mg-Al-Sn series magnesium alloy from corrosion and electrochemical performance, optimal Mg-Al-Sn series magnesium alloy composition: Mg-6% Al-10% Sn.