Aluminum Electrolytic Capacitor

An aluminum electrolytic capacitor consists of two electrically conductive aluminum layers, separated by a dielectric layer. One of the electrodes (the aluminum foil called anode) undergoes a Process called ‘forming’, by which a dielectric layer of aluminum oxide (Al2O3) is electrochemically coated on it. The other electrode is a conductive liquid, called the electrolyte. The second aluminum foil, the cathode, acts as a large surfaced contact area for passing current to the electrolyte.