Effect of grain size on the electrochemical behavior of pure magnesium anode

Three kinds of pure magnesium anode materials with different grain sizes were prepared by extrusion at different temperatures. The grain size of each sample was calculated, then the effect of grain size on the electrochemical properties of pure magnesium anode was investigated by chemical immersion hydrogen test, potentiodynamic polarization scanning, constant current discharge and electrochemical impedance spectroscopy. As the extrusion temperature increases from 180 °C to 250 °C, the average grain size of pure magnesium increases from 20 µm to 30 µm, and the pure magnesium extruded at 250 °C has the best electrochemical performance as magnesium anode, with the discharge potential of −1.571 V (vs. SCE). Plastic deformation process is a convenient method that can change the microstructure and improve the electrochemical behavior of magnesium anode.