Electrolytic Capacitors

Electrolytic Capacitors

"Electrolytic" means any capacitor that requires a conductive layer between the dielectric and one electrode.  In the original electrolytic capacitor, the layer was an actual electrolyte, a conductive salt in a solvent.  Some electrolytic capacitors today don´t actually use an electrolyte, but the word is still commonly used, to the annoyance of some.  Electrolytic capacitors are made by growing a oxide film, the dielectric, on a metal, the anode, by electrochemical means.  The films are very thin with fairly high Ks (roughly 10-25) which make for a lot of capacitance in a small package.  The resulting devices pass current much better in one direction than the other, making a rectifier of a sort.  Because of this, the metals are sometimes called "valve" metals.  The metals presently used are aluminum, tantalum, and niobium, Above about the Electrolytic Capacitors information content.

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