Electrolytic capacitor to a smooth surface of the same area or the same volume. By applying a positive voltage to the above-mentioned anode material in an electrolytic bath an oxide barrier layer with a thickness corresponding to the applied voltage will be formed (formation). This oxide layer acts as dielectric in an electrolytic capacitor. The properties of this oxide layers are given in the following table: After forming a dielectric oxide on the rough anode structure, a counter electrode has to match the rough insulating oxide surface. This is accomplished by the electrolyte, which acts as the cathode electrode of an electrolytic
Aluminum electrolytic capacitor sensitive to voltages spikes or current surges. The anodic generated insulating oxide layer is destroyed if the polarity of the applied voltage changes. Every electrolytic capacitor in principle forms a "plate capacitor" whose capacitance is greater the larger the electrode area A and the permittivity ε, and the thinner the thickness (d) of the dielectric. The capacitance is proportional to the product of the area of one plate multiplied with the permittivity, divided by the thickness of the dielectric. Electrolytic capacitors obtain their large capacitance values by a large area and small dielectric thickness. The dielectric thickness of electrolytic capacitors