Like any other capacitor, the (aluminum) electrolytic capacitor consists of two conductive layers (capacitor plates) and a dielectric between them. One speaks of capacitor plates only symbolically, since today only wound capacitors are used in practice.
An aluminum electrolytic capacitor is usually made of very thin aluminum foil. Between the metal surfaces, there is the electrolyte or also a polymer, which determined the name of these capacitor categories.To prevent a short circuit in the capacitor, one of the foils is covered with an insulating (oxide) layer (Al2O3). The oxidation takes place during the manufacturing process and is also called forming. The oxidation gives the surface a very rough structure and thus a very large surface area. This in turn influences the capacity of the aluminum electrolytic capacitor.
Conductive Polymer Hybrid
As in many other technical areas, attempts are made to combine different properties of materials or components and so-called hybrids are developed. This has also been done with electrolytic hybrid capacitors. Polymer-hybrid capacitors contain a liquid electrolyte in addition to the polymer and are therefore ideally suited for applications with higher temperature stability.
With the hybrid electrolyte technology, high reliability and, compared to the pure polymer technology, relatively higher voltage ranges are achieved. Voltage levels of up to 63 volts are possible with a low internal resistance. They also have a very good service life and become highly resistive in the event of a fault.
Conductive polymer electrolytic capacitor
In polymer capacitors, a polymer is added to the electrolyte. As a result, the internal resistance ESR is lower and thus the current carrying capacity of the capacitor is higher. Due to the high polymer content, the electrolyte contains hardly any liquid and can therefore hardly dry out. The capacitor temperature has little effect on the aging of these capacitors, so the life expectancy is significantly higher than with other capacitors. Due to the added polymer the possible operating voltage (max. 35V) decreases. However, in case of faults, permanent short circuits can occur in the capacitor.
SMD - Aluminium electrolytic capacitors are designed for surface mounting on a printed circuit board. Sense and purpose of the SMT technology is the fast, automatic assembly with space-saving printed circuit board design. Ultimately, this reduces system costs. In the adjoining data sheets you will find capacitors for a wide range of applications and technical requirements.
Miniature aluminum electrolytic capacitors
Large aluminium electrolytic capacitors