The Oxide-Forming Role of Water in Aluminum Electrolytic Capacitors
The effect of the water content of several electrolytic solutions on their ability to form dielectric oxide films on aluminum was examined. Anhydrous electrolytes were found to be incapable of forming such films, but the addition of small amounts of water made it possible for these solutions to perform as normal oxide-film formers. The anodizing behavior of an anhydrous electrolyte composed of methyl cellosolve and ammonium picrate was investigated in detail in both experimental aluminum anodizations and in finished capacitors, in an attempt to correlate the behavior of the electrolyte as an anodizer of bare foil with the aging and life test characteristics of capacitors containing that electrolyte. The results tend to support the conclusion that water is essential to the proper performance of electrolytic capacitors.
Copyright © 1984 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.