脉冲电流对AZ21镁电极电压滞后的影响

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

摘要: AZ21镁合金在硫酸镁溶液中会产生表面膜,导致严重的电压滞后问题.加载脉冲电流可以减少AZ21镁合金的滞后时间,缩短放电初期时的电压降,降低平衡电压,提高放电平稳性等,有利于AZ21镁合金在电池中的应用.本文利用恒电流法、多电流阶跃法、电化学阻抗、扫描电镜等多种方法对AZ21镁合金在2 mol·L^-1的MgSO₄溶液的电压滞后问题进行实验研究.结果表明,经50 m A脉冲电流1 s后,AZ21的电压滞后时间可从6.35 s(3.23 V)降至0.59 s(0.034 V).

Abstract: 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).