电解电容器铝箔横向隧道孔的生长控制

Growth control of transverse tunnels for Al foil in electrolytic capacitor

在酸性介质中已经产生隧道孔的铝箔表面,继续在中性电解液中采取直流阳极溶解时,隧道孔密度及长度与二次侵蚀时电解质类别相关。在此基础上,通过二次侵蚀前铝箔表面的酸浸泡成膜处理,以及二次侵蚀过程中在中性氯化钠介质中添加复合有机物,达到控制此过程中隧道孔生长方向的目的,使其在原隧道孔的孔壁沿着与铝箔表面平行的方向产生新的隧道孔,这为提高铝箔表面积提出了新的途径,为进一步提高铝电解电容器比容提供了可能性。

The kind of electrolyte had effect on the density and length of tunnels in aluminum foil when the etched aluminum foil in acid solution continually was etched in neutral electrolyte. On the base of this conclusion, aluminum foil with transverse tunnels was fabricated by use of the two-step DC etching method. Experiments indicate that the pretreatment of immersing in an acid solution between the two steps DC etching and the composition of electrolyte has great effect on the two-step DC etching process, new tunnels would appear on the tunnels＇ wall during the second-step DC etching when appropriate conditions are chose. The special morphology tunnels increase the surface area of aluminum foil for electrolytic capacitor usage in a way.