Polymer capacitors belong to the group of aluminum electrolytic capacitors, but have ESR values many times lower than classic aluminum electrolytic capacitors. Instead of a liquid electrolyte, polymer capacitors use its namesake solid polymer compound. Compared to aluminum electrolytic capacitors, polymer capacitors have a considerably longer service life, a high current-carrying capacity and better low-temperature behavior. They are also used in many applications, for example, instead of tantalum electrolytic capacitors.