The electrochemical behaviors of Mg-5Li-3Al-1La and Mg-8Li-3Al-1La alloys in sodium chloride solution

The electrochemical behaviors of Mg-5Li-3Al-1La and Mg-8Li-3Al-1La electrodes in NaCl solution are investigated by means of potentiodynamic polarization, potentiostatic oxidation, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). It is found that the Mg-8Li-3Al-1La electrode is of higher discharge activity than the Mg-5Li-3Al-1La electrode in 0.7 mol L^?1 NaCl solution, which is consistent with the results observed from SEM images. The composition of the discharging products is also analyzed by means of XRD diffraction. This result shows that the Mg-8Li-3Al-1La alloy displays better compatibility with salt than the Mg-5Li-3Al-1La alloy, and the electrolyte can easily permeate the electrode, which enlarges the reaction zone and improves the activity of the electrode. The continuous discharging utilization efficiency of the Mg-5Li-3Al-1La and Mg-8Li-3Al-1La electrodes is 47.36 and 50.46%, respectively. The utilization of the Mg-Li-Al-La electrode is increased by 3.10% with the amount of Li increased from 5 to 8%. Meanwhile, the interval discharging utilization efficiency of the two electrodes is 46.13 and 49.88%, respectively, and the increase in the amount of Li in the electrode also brings a favorable effect on the interval electrochemical properties of the electrode.