Electrolytic capacitor and method for producing the same

Patent metadata

Field	Value
Publication number	US-2022102082-A1
Application number	US-202017427534-A
Country	US
Kind code	A1
Filing date	Jan 29, 2020
Priority date	Jan 31, 2019
Publication date	Mar 31, 2022
Grant date	—

Abstract

A method for producing an electrolytic capacitor, the method including steps of: preparing an electrode foil; preparing a first conductive polymer dispersion containing a first conductive polymer component and a first dispersion medium; forming a first conductive polymer layer containing the first conductive polymer component, by applying the first conductive polymer dispersion to a surface of the electrode foil by a coating method, and then at least partially removing the first dispersion medium; and fabricating a capacitor element, using the electrode foil having the first conductive polymer layer.

First claim

1 . A method for producing an electrolytic capacitor, the method comprising steps of:
preparing an electrode foil; preparing a first conductive polymer dispersion containing a first conductive polymer component and a first dispersion medium; forming a first conductive polymer layer containing the first conductive polymer component, by applying the first conductive polymer dispersion to a surface of the electrode foil by a coating method, and then at least partially removing the first dispersion medium; and fabricating a capacitor element, using the electrode foil having the first conductive polymer layer.

2 . The method for producing an electrolytic capacitor according to claim 1 , wherein
a content of the first conductive polymer component in the first conductive polymer dispersion is 1 mass % or more and 15 mass % or less, and a viscosity of the first conductive polymer dispersion as measured at room temperature using a vibration-type viscometer is 10 mPa·s or more.

3 . The method for producing an electrolytic capacitor according to claim 1 , wherein
the first conductive polymer component includes a first polyanion, and the first polyanion has a weight average molecular weight of 1,000 or more and 70,000 or less.

4 . The method for producing an electrolytic capacitor according to claim 1 , wherein the method includes a step of impregnating the fabricated capacitor element with an electrolyte.

5 . The method for producing an electrolytic capacitor according to claim 4 , wherein the electrolyte contains a solvent and an acid component.

6 . The method for producing an electrolytic capacitor according to claim 4 , wherein the electrolyte contains a solvent having two or more hydroxy groups.

7 . The method for producing an electrolytic capacitor according to claim 1 , wherein
the method includes a step of impregnating the fabricated capacitor element with a second conductive polymer dispersion, the second conductive polymer dispersion contains a second conductive polymer component and a second dispersion medium, a content of the second conductive polymer component is smaller than the content of the first conductive polymer component in the first conductive polymer dispersion, and a viscosity of the second conductive polymer dispersion as measured at room temperature using a vibration-type viscometer is lower than a viscosity of the first conductive polymer dispersion as measured under the same conditions.

8 . The method for producing an electrolytic capacitor according to claim 1 , wherein in the step of forming a first conductive polymer layer, the first dispersion medium is partially removed, to form the first conductive polymer layer containing the first conductive polymer component and the first dispersion medium.

9 . The method for producing an electrolytic capacitor according to claim 1 , wherein
the electrode foil is a continuous body, and the method includes, after the step of forming a first conductive polymer layer, a step of cutting the electrode foil.

10 . The method for producing an electrolytic capacitor according to claim 1 , wherein the electrode foil is an anode foil having a dielectric layer.

11 . The method for producing an electrolytic capacitor according to claim 10 , wherein
the anode foil is a continuous body, and the method includes, after the step of forming a first conductive polymer layer, a step of cutting the anode foil, and forming a dielectric layer on a cut face formed by cutting.

12 . The method for producing an electrolytic capacitor according to claim 1 , wherein the electrode foil is a cathode foil.

13 . The method for producing an electrolytic capacitor according to claim 12 , wherein
the cathode foil prepared in the step of preparing a cathode foil has a metal foil and a coating layer with electrical conductivity formed on the metal foil, the metal foil containing a valve action metal, and the coating layer contains at least one selected from the group consisting of a carbon and a metal having an ionization tendency lower than the valve action metal.

14 . An electrolytic capacitor, comprising:
a capacitor element including an electrode foil, wherein a conductive polymer layer is formed on the electrode foil, 90% or more area of one principal surface of the electrode foil is covered with the conductive polymer layer, and the conductive polymer layer incudes a first conductive polymer layer containing a first conductive polymer component, and a second conductive polymer layer partially covering the first conductive polymer layer and containing a second conductive polymer component.

15 . The electrolytic capacitor according to claim 14 , wherein
the first conductive polymer component contains a first polyanion, the second conductive polymer component contains a second polyanion, and a weight average molecular weight of the second polyanion is higher than a weight average molecular weight of the first polyanion.

16 . The electrolytic capacitor according to claim 14 , wherein the first conductive polymer layer has a mass per unit area of 0.1 mg/cm 2 or more.

17 . The electrolytic capacitor according to claim 14 , wherein the first conductive polymer layer has an electrical conductivity of 170 S/cm or less.

18 . The electrolytic capacitor according to claim 14 , wherein the first conductive polymer layer is not formed on an edge face of the electrode foil.

19 . The electrolytic capacitor according to claim 14 , wherein the electrode foil is an anode foil having a dielectric layer.

20 . The electrolytic capacitor according to claim 19 , wherein the dielectric layer is further formed on an edge face of the anode foil.

21 . The electrolytic capacitor according to claim 14 , wherein the electrode foil is a cathode foil.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Kubo Daisuke
• Matsushita Shumpei
• CHASHIRO Kenta
• Arima Hiroyuki

Classifications

• H01G9/0036

  Formation of the solid electrolyte layer · CPC title

• H01G9/145

  Liquid electrolytic capacitors (H01G11/00 takes precedence) · CPC title

• H01G9/028

  Organic semiconducting electrolytes, e.g. TCNQ · CPC title

• H01G9/035 Primary

  Liquid electrolytes, e.g. impregnating materials (H01G11/54 takes precedence) · CPC title

• H01G9/151

  with wound foil electrodes · CPC title