Wet electrolytic capacitor comprising a copolymer of a polythiophene and at least one of a polypyrrole and a polyaniline

摘要

A wet electrolytic capacitor that contains an anodically oxidized porous anode body, a cathode containing a metal substrate coated with a conductive polymer coating, and a working fluid electrolyte in communication with the anode and the cathode; the conductive coating contains a conductive copolymer having at least one thiophene repeating unit, as well as a pyrrole repeating unit and/or aniline repeating unit, wherein each of the repeating units have a specific general structure. Also disclosed is a method for forming a cathode of a wet electrolytic capacitor, comprising applying a colloidal suspension of the monomer precursors of the above polymer repeating units, placing an electrode in contact with the metal substrate; and supplying a current to the electrode to induce electrolysis and polymerization of the monomers to form a conductive copolymer coating. Wherein the liquid electrolyte may be aqueous, specifically it may include sulphuric acid.