Influence of pulse current on the voltage delay of AZ21 magnesium electrode

A surface film generates on AZ21 magnesium alloy in magnesium sulfate solutions,resulting in serious voltage delay.Pulse current is conducive to the application of AZ21 magnesium alloy in a battery,for it can shorten the lag time,reduce the initial discharge voltage drop and increase the discharge stability. The voltage delay of AZ21 magnesium alloy in a 2 mol·L^-1 MgSO₄ solution was investigated by chronopotentiometry,multi-current steps,electrochemical impedance measurement,and scanning electron microscopy. After a 50 mA pulse current was applied for 1 s,the voltage lag time of AZ21 magnesium alloy decreased from 6.35 s(3.23 V) to 0.59 s(0.034 V).