Abstract: A capacitor includes a cathode having a porous coating including an oxide of one of ruthenium, iridium, nickel, rhodium, platinum, palladium, and osmium, an anode including a metal selected from the group consisting of tantalum, aluminum, niobium, zirconium, and titanium, spaced from the porous coating, and an electrolyte in contact with the porous coating and the anode.

Abstract: An electrolytic capacitor including a metal container having an inside surface and an outside surface and functioning as a cathode of the capacitor, a porous coating including an oxide of one of ruthenium, iridium, nickel, rhodium, platinum, palladium, and osmium disposed at the inside surface of the container in electrical communication with the container, an anode selected from the group consisting of tantalum, aluminum, niobium, zirconium, and titanium, disposed within and spaced from the porous coating, and an electrolyte within the container in contact with the porous coating and the electrode.