(C) Electrolyte capacitors of various shapes and sizes . Aluminum electrolytic capacitors are made of two aluminum foils and a paper soaked in electrolyte.
An electrolytic capacitor is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor. A solid, liquid, or gel electrolyte covers the surface of this oxide layer, serving as the cathode or negative plate of the capacitor.
1. General Description of Aluminum Electrolytic Capacitors An aluminum electrolytic capacitor consists of cathode aluminum foil, capacitor paper (electrolytic paper), electrolyte, and an aluminum oxide layer, which acts as the dielectric, formed on the anode foil surface.
There are three families of electrolytic capacitor: aluminium electrolytic capacitors, tantalum electrolytic capacitors, and niobium electrolytic capacitors. The large capacitance of electrolytic capacitors makes them particularly suitable for passing or bypassing low-frequency signals, and for storing large amounts of energy.
Electrolytic capacitors use a chemical feature of some special metals, previously called "valve metals", which on contact with a particular electrolyte form a very thin insulating oxide layer on their surface by anodic oxidation which can function as a dielectric. There are three different anode metals in use for electrolytic capacitors:
66 Electrolytic capacitors consist of two electrodes (anode and cathode), a film oxide layer acting as a 67 dielectric and an electrolyte. The electrolyte brings the negative potential of the cathode closer to the 68 dielectric via ionic transport in the electrolyte (see Figure 2). The electrolyte is either a liquid or a 3