Solid electrolytic capacitors comprising a conductive layer made of a polymer of pyrrole or its derivative

• US 5,812,367 A
• Filed: 04/01/1997
• Issued: 09/22/1998
• Est. Priority Date: 04/04/1996
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Shimada, Hiroshi, Hayashi, Chiharu, Akami, Kenji, Kudoh, Yasuo, Matsuya, Yasue, Kojima, Toshikuni
• Primary Examiner(s): Kincaid, Kristine L.
• Assistant Examiner(s): Dinkins, Anthony
• Application Number:
  US08/840,445
• Time in Patent Office: 539 Days
• Field of Search: 29/25.03, 361/502, 361/503, 361/504, 361/531, 361/509, 361/524, 361/523, 361/525, 361/526, 361/529, 205/152, 205/103, 205/153, 205/166, 205/167, 204/414, 204/421, 429/192, 429/193, 429/209
• US Class Current: 361/523
• CPC Class Codes: H01G 11/48 Conductive polymers
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 9/0036 Formation of the solid electrolyte layer
• CPC Class Codes: H01G 9/025 Solid electrolytes H01G11/54 takes precedence
• CPC Class Codes: H01G 9/028 Organic semiconducting electrolytes, e.g. TCNQ
• CPC Class Codes: H01G 9/0425 specially adapted for cathode
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A solid electrolytic capacitor is composed of a pair of electrodes and a dielectric film therebetween, wherein one electrode includes a conducting polymer doped with a polyvalent anion and a monovalent anion. The conducting polymer layer may have a multi-layer structure wherein a second or third conductive polymer layer is made of doped thiophene or derivative thereof.

Claims

1. A solid electrolytic capacitor which comprises a first electrode and a second electrode, and a dielectric film provided therebetween wherein at least the first electrode comprises a first conductive polymer layer made of a polymer selected from the group consisting of pyrrole and derivatives thereof, said first conductive polymer layer being doped with a mixed dopant of a polyvalent anion and a monovalent anion comprising a sulfonate ion dissociated from an anionic surface active agent.

2. A solid electrolytic capacitor according to claim 1, wherein said polyvalent anion comprises a sulfate.

3. A solid electrolytic capacitor according to claim 1, wherein said dielectric film comprises an oxide of a valve metal and said second electrode comprises a valve metal.

4. A solid electrolytic capacitor according to claim 3, wherein said valve metal is selected form the group consisting of aluminium and tantalum.

5. A solid electrolytic capacitor according to claim 1, wherein said dielectric film comprises a polymer.

6. A solid electrolytic capacitor according to claim 5, wherein said polymer of said dielectric film comprises a polyimide.

7. A solid electrolytic capacitor according to claim 1, wherein said sulfonate comprises alkylnaphthalenesulfonate.

8. A solid electrolytic capacitor according to claim 1, wherein said sulfonate comprises dodecylbenzenesulfonate.

9. A solid electrolytic capacitor according to claim 1, wherein the second electrode comprises said first conductive polymer layer and said dielectric film comprises a polyimide.

10. A solid electrolytic capacitor according to claim 1, further comprising a second conductive polymer layer provided between said dielectric film and said first conductive polymer layer so that said first conductive polymer layer and said second conductive polymer layer comprise a built-up conductive polymer layer wherein said second conductive polymer layer comprises a polymer of a thiophene derivative of the following formula ##STR5## wherein A represents an unsubstituted or substituted alkylene group, O is oxygen and S is sulfur.

11. A solid electrolytic capacitor according to claim 10, wherein said second conductive polymer layer comprises a monovalent anion as a dopant.

12. A solid electrolytic capacitor according to claim 11, wherein said monovalent anion comprises a sulfonate dissociated from an anionic surface active agent.

13. A solid electrolytic capacitor according to claim 10, wherein said second conductive layer comprises a polyvalent anion as a dopant.

14. A solid electrolytic capacitor according to claim 13, wherein said polyvalent anion comprises a sulfate.

15. A solid electrolytic capacitor according to claim 10, wherein said second conductive polymer layer comprises a polystyrenesulfonate anion.

16. A solid electrolytic capacitor according to claim 10, further comprising a third conductive polymer layer in contact with said first conductive polymer layer on a side opposite a side where said second conductive layer is formed, said third conductive polymer layer comprises a polymer of a thiophene derivative of the following formula ##STR6## wherein A represents an unsubstituted or substituted alkylene group, O is oxygen and S is sulfur.

17. A solid electrolytic capacitor according to claim 16, wherein said third conductive polymer layer comprises a monovalent anion as a dopant.

18. A solid electrolytic capacitor according to claim 17, wherein said monovalent anion comprises a sulfonate dissociated from an anionic surface active agent.

19. A solid electrolytic capacitor according to claim 16, wherein said third conductive layer comprises a polyvalent anion as a dopant.

20. A solid electrolytic capacitor according to claim 19, wherein said polyvalent anion comprises a sulfate.

21. A solid electrolytic capacitor according to claim 16, wherein said third conductive polymer layer comprises a polystyrenesulfonate anion.