Capacitor including serially connected capacitor cells employing a solid electrolyte

• US 5,559,667 A
• Filed: 08/11/1995
• Issued: 09/24/1996
• Est. Priority Date: 03/22/1993
• Status: Expired due to Term

• Current Assignee: Evans Capacitor Co.
• Original Assignee: The Evans Finding Company, Incorporated
• Inventors: Evans, David A.
• Primary Examiner(s): Walberg, Teresa J.
• Assistant Examiner(s): Mills, Gregory L.
• Application Number:
  US08/514,145
• Time in Patent Office: 410 Days
• Field of Search: 361/523, 361/524, 361/525, 361/526, 361/528, 361/529, 361/532, 361/535, 361/540, 361/541, 361/522
• US Class Current: 361/526
• CPC Class Codes: H01G 9/00 Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
• CPC Class Codes: H01G 9/042 characterised by the material H01G11/22 takes precedence
• CPC Class Codes: H01G 9/0425 specially adapted for cathode

Abstract

A capacitor includes a cathode having a porous coating including an oxide of one of ruthenium, iridium, nickel, rhodiumm 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.

Claims

1. A capacitor comprising:

a plurality of capacitor cells, each cell including;

a first metal body having opposed first and second surfaces;

a cathode comprising a porous coating including an oxide of at least one metal selected from the group consisting of ruthenium, iridium, nickel, rhodium, platinum, palladium, and osmium disposed on the first surface of said first metal body;

an electrically insulating oxide disposed on the second surface of the first metal body; and

a solid electrolyte in contact with the cathode opposite the first metal body wherein the plurality of capacitor cells are disposed in a serial arrangement, the electrolyte of one cell contacting the electrically insulating oxide on the second surface of the first metal body of an adjacent cell;

a second metal body having first and second opposed surfaces, disposed at one end of the serial arrangement, and including a cathode comprising a porous coating including an oxide of at least one metal selected from the group consisting of ruthenium, iridium, nickel, rhodium, platinum, palladium, and osmium, disposed on one side of the second metal body, opposite an electrically insulating film in the serial arrangement and functioning as a cathode of the capacitor, and a solid electrolyte disposed between and contacting the porous coating of the second metal body and the electrically insulating oxide of the opposite first metal body in the serial arrangement;

a third metal body having first and second opposed surfaces, disposed at the other end of the serial arrangement, and including an electrically insulating oxide disposed on one side of the third metal body, opposite a porous coating of a first metal body in the serial arrangement, but no porous coating, and functioning as an anode of the capacitor, and a solid electrolyte disposed between and contacting the electrically insulating oxide of the third metal body and the porous coating of the opposite first metal body in the serial arrangement.

2. The capacitor of claim 1 wherein the first, second, and third metal bodies are aluminum and the electrically insulating oxide is an oxide of aluminum.

3. The capacitor of claim 1 wherein the electrolyte is a solid selected from the group consisting of polypyrrole, NAFION, polyaniline, and a gel of an aqueous electrolyte and silica.