Electrolytic capacitance is a kind of capacitance. Metal foil is the cathode (aluminium or tantalum), and the oxide film (alumina or tantalum pentoxide) which is close to the metal is the dielectric. The cathode is composed of conductive material, electrolyte (electrolyte can be liquid or solid) and other materials. Because electrolyte is the main part of the cathode, electrolytic capacitance is named for it. At the same time, the positive and negative capacitors can not be misconnected. Aluminum electrolytic capacitors can be divided into four categories: lead-type aluminum electrolytic capacitors; horn-type aluminum electrolytic capacitors; bolt-type aluminum electrolytic capacitors; solid-state aluminum electrolytic capacitors.
