摘要
The Al foil for high voltage Al electrolytic capacitor usage was immersed in 5.0%NaOH solution containing trace amount of Zn2＋and Zn was chemically plated on its surface through an immersion-reduction reaction. Such Zn-deposited Al foil was quickly transferred into HCl-H 2 SO 4 solution for DC-etching. The effects of Zn impurity on the surface and cross-section etching morphologies and electrochemical behavior of Al foil were investigated by SEM, polarization curve （PC） and electrochemical impedance spectroscopy （EIS）. The special capacitance of 100 V formation voltage of etched foil was measured. The results show that the chemical plating Zn on Al substrate in alkali solution can reduce the pitting corrosion resistance, enhance the pitting current density and improve the density and uniform distribution of pits and tunnels due to formation of the micro Zn-Al galvanic local cells. The special capacitance of etched foil grows with the increase of Zn2＋concentration.
将高压铝电解电容器用电子铝箔在含Zn2+的5.0%NaOH溶液中实施化学镀锌处理,然后在HCl+H2SO4电解液中进行直流电解扩面腐蚀得到腐蚀箔;采用极化曲线研究化学镀锌处理对扩面腐蚀时铝箔点蚀电流、点蚀电位的影响,利用电化学交流阻抗(EIS)研究化学镀锌处理对铝箔电解腐蚀时电化学特征的影响;使用扫描电镜(SEM)观察化学镀锌处理对腐蚀箔表面和横截面形貌的影响;测试100 V形成电压下腐蚀箔的比电容。结果表明:铝箔表面化学镀锌形成的Zn-Al微电偶有助于电蚀时降低点蚀电极反应的阻力,提高点蚀电流密度,增加铝箔表面蚀孔密度和蚀孔分布的均匀性;随着碱液中Zn2+浓度的提高,腐蚀箔的比电容逐渐增加。
基金
Project (51172102) supported by the National Natural Science Foundation of China
Project (BS2011CL011) supported by Promotive Research Fund for Young and Middle-aged Scientists of Shandong Province(doctor fund),China
