Electrolytic capacitor Electrolytic capacitor An electrolytic capacitor (abbreviated e-cap) 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. Due to their very thin dielectric oxide layer and enlarged anode surface, electrolytic capacitors have a much higher capacitance-voltage (CV) product per unit volume compared to ceramic capacitors or film capacitors, and so can have large capacitance values.
Aluminum electrolytic capacitor as "Z". In this sense the impedance is a measure of the capacitor's ability to pass alternating currents. Impedance can be calculated using the idealized components of a capacitor's series-equivalent circuit, including an ideal capacitor formula_4, a resistor formula_5, and an inductance formula_6. In this case the impedance at the angular frequency formula_7 is therefore given by the geometric (complex) addition of ESR, by a capacitive reactance (Capacitance) and by an inductive reactance (Inductance) Then formula_10 is given by Aluminum electrolytic capacitor Aluminum electrolytic capacitors are polarized electrolytic capacitors whose anode electrode (+) is made of a pure aluminum foil