脈沖電流對AZ21鎂電極電壓滯后的影響

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

摘要: AZ21鎂合金在硫酸鎂溶液中會產生表面膜,導致嚴重的電壓滯后問題.加載脈沖電流可以減少AZ21鎂合金的滯后時間,縮短放電初期時的電壓降,降低平衡電壓,提高放電平穩性等,有利于AZ21鎂合金在電池中的應用.本文利用恒電流法、多電流階躍法、電化學阻抗、掃描電鏡等多種方法對AZ21鎂合金在2 mol·L^-1的MgSO₄溶液的電壓滯后問題進行實驗研究.結果表明,經50 m A脈沖電流1 s后,AZ21的電壓滯后時間可從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).