Lin, C. S.C. S.LinLi, W. J.W. J.LiLinCS2008-12-242018-06-282008-12-242018-06-28200600134651http://ntur.lib.ntu.edu.tw//handle/246246/93305https://www.scopus.com/inward/record.uri?eid=2-s2.0-33645537782&doi=10.1149%2f1.2131830&partnerID=40&md5=04612a0243626a259efc1f1a57dd1684Sulfate ions in sodium chloride solutions effectively enhance the capacitance of aluminum foils etched with direct current. This study explored the effects of sulfate ions on pitting behavior of aluminum foils for low-voltage electrolytic capacitor during etching with alternating current. Experimental results indicate that the presence of sulfate ions in hydrochloric acid reduced the loss of aluminum due to undermining by the cubic pits. Furthermore, sulfate ions adsorbed on the aluminum surface increased the breakdown potential of the surface film and led to passivation of the existing pits. Consequently, the aluminum foil etched in the solution with the addition of sulfate ions displayed a more uniform pitted structure than that etched in the solution solely composed of hydrochloric acid. © 2005 The Electrochemical Society. All rights reserved.application/pdf851701 bytesapplication/pdfen-USBreakdown potential; Direct current; Low-voltage electrolytic capacitors; Sulfate ions; Capacitance; Electrolytic capacitors; Etching; Hydrochloric acid; Ions; Sodium chloride; Solutions; Sulfate minerals; Thin films; Aluminum foiljournal article2-s2.0-33645537782http://ntur.lib.ntu.edu.tw/bitstream/246246/93305/1/10.pdf