CeN3O9.6H2O对镁空气电池负极性能的影响

Effect of CeN3O9.6H2O on the performance of magnesium air battery anode

摘要:

在镁空气电池中,镁负极的极化和腐蚀是衡量镁空气电池的重要指标。本文通过动电位极化法和电化学阻抗谱法,研究了在8% NaCl电解液中,六水合硝酸铈(CeN3O9.6H2O)对AZ31负极抗腐蚀性能的影响。结果表明：电解液中加入CeN3O9.6H2O,在AZ31镁合金表面形成Ce(OH)3保护膜,提高镁合金的耐腐蚀性。随着CeN3O9.6H2O浓度的增大,Ce(OH)3保护膜逐渐致密,AZ镁合金的腐蚀速率降低。当CeN3O9.6H2O浓度达到1.0g/L时,镁合金的腐蚀速率最低,其缓蚀率为70.4%。然而当加入的CeN3O9.6H2O浓度大于1.0g/L时,由于Ce(OH)3保护膜被溶解而导致镁合金的腐蚀速率增大。由浸泡50小时AZ合金的SEM图发现CeN3O9.6H2O在镁合金表面形成Ce(OH)3保护膜,抑制阳极反应。从等效电路图得到Mg2+电荷转移阻力增大了69.5Ω,改善了镁合金的耐腐蚀性能。通过放电测试得到加入CeN3O9.6H2O提高电池的放电性能,放电时间延长近1h。

Abstract:

In the magnesium air battery, the polarization and corrosion of the magnesium anode is an important index to measure the magnesium air battery. In this paper, by means of dynamic potential polarization method and electrochemical impedance spectroscopy (NaCl), the effect of six hydrated cerium (CeN₃O₉.6H₂O) on the corrosion resistance of AZ31 cathode was studied. The results showed that CeN₃O₉.6H₂O were added into the electrolyte to form Ce(OH)₃ protective film on the surface of AZ31 magnesium alloy to improve the corrosion resistance of the magnesium alloy. With the increase of the concentration of CeN₃O₉.6H₂O, the Ce(OH)₃ protective film became denser, and the corrosion rate of AZ magnesium alloy was decreased. When the concentration of CeN₃O₉.6H₂O reached 1.0g/L, the corrosion rate of the magnesium alloy was the lowest, and the corrosion inhibition rate was 70.4%. However, when the concentration of CeN₃O₉.6H₂O is greater than 1.0g/L, the corrosion rate of magnesium alloy is increased due to the dissolution of Ce(OH)₃ protective film. Ce(HO)₃ protective film formed on the surface of magnesium alloy CeN₃O₉.6H₂O was found by the SEM diagram of AZ alloy, which was found in the of 50h after immersion. The Mg₂₊ charge transfer resistance is increased by 69.5Ω from the equivalent circuit diagram, which improves the corrosion resistance of the magnesium alloy. The discharge performance of CeN₃O₉.6H₂O was improved by the discharge test, and the discharge time was prolonged by nearly 1h.