A method of producing a capacitor electrode includes forming an oxide layer on a foil. The method also includes heating the foil to a target temperature so as to induce defects in the oxide layer. The target temperature is about 450° C. to 560° C. and the duration of heating the foil to the target temperature is less than 4 minutes. The oxide layer is reformed so as to generate a reformed oxide layer that is an aluminum oxide with a boehmite phase and a pseudo-boehmite phase.

An electrode foil for an electrolytic capacitor includes: an anode body including a first metal; a first dielectric layer covering at least a part of the anode body and including an oxide of the first metal; and a second dielectric layer covering at least a part of the first dielectric layer and including an oxide of a second metal. The first metal includes at least one selected from the group consisting of titanium, tantalum, niobium, and aluminum. And the second metal includes at least one selected from the group consisting of silicon, zirconium, hafnium, and tantalum. A thickness T2 of the second dielectric layer is smaller than a thickness T1 of the first dielectric layer.

A capacitor assembly that is capable of exhibiting good electrical properties even under a variety of conditions is provided. More particularly, the capacitor contains a capacitor element that includes a porous anode body that contains a valve metal compound, a dielectric that overlies the anode body and includes an oxide of the valve metal compound, a solid electrolyte that overlies the dielectric, wherein the solid electrolyte includes at least one conductive polymer layer that contains a sulfonyl ion, and an organofunctional silane that is bonded to the oxide of the dielectric and is capable of bonding to the sulfonyl ion of the conductive polymer layer.

Disclosed is a solid electrolytic capacitor 1 including capacitor elements 2A to 2C, an anode terminal 4, and a resin package body enclosing at least the capacitor elements, the capacitor elements 2A to 2C each including an anode body 6 having a porous portion as a surface layer, a dielectric layer 7, and a cathode part 8 covering at least part of the dielectric layer 7. The anode body 9 has a cathode forming portion and an anode thin-thickness portion adjacent to the cathode forming portion. The dielectric layer 7 covers at least part of a surface of the porous portion in the cathode forming portion. The porous portion is removed in the anode thin-thickness portion or is thinner in the anode thin-thickness portion than in the cathode forming portion. The anode body is connected to the anode terminal 4 at the anode thin-thickness portion.

A solid electrolytic capacitor comprising a capacitor element that contains a sintered porous anode body formed from a valve metal powder having a specific charge of about 50,000 μF*V/g or more, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric that includes a conductive polymer is provided. The capacitor exhibits an anomalous charging current of about 0.25 amps or less when charged at a constant voltage rate increase of 120 volts per second, determined at a temperature of 23° C. and voltage of 16 volts.

Provided herein is a method for forming a capacitor and an improved capacitor formed by the method. The method comprises providing an anode with an anode lead extending therefrom. A dielectric is formed on the anode thereby forming an anodized anode. A cathode layer is formed over the dielectric wherein the cathode layer is formed by applying a conductive polymer solution or dispersion and applying a primer solution or dispersion comprising a monophosphonium or monosulfonium cation.

The present invention if related to an improved electrolytic capacitor and a method of making the improved electrolytic capacitor. The electrolytic capacitor comprises an anode comprising a dielectric layer on the anode. A first mordant layer is on the dielectric wherein the first mordant layer comprises a mordant compound of Formula A:

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wherein: R.sub.1 and R.sub.2 is independently selected from H; cation, linear alkyl, cyclic alkyl or substituted alkyl of 1 to 10 carbons; R.sub.3 is selected from —CR.sub.4R.sub.5R.sub.6 wherein R.sub.4 represents a hydrogen, an alkyl of 1-20 carbons or an aryl of 6-20 carbons; R.sub.4 and R.sub.5 can be taken together to represent a cyclic alkyl or substituted cyclic alkyl or (—CR.sub.6OP(O)OR.sub.1OR.sub.2).sub.n; R.sub.5 represents an alkyl of 1-20 carbons or an aryl of 6-20 carbons; R.sub.4 and R.sub.5 can be taken together to represent a cyclic alkyl or substituted cyclic alkyl or (—CR.sub.6OP(O)OR.sub.1OR.sub.2).sub.n; R.sub.6 represents a hydrogen, an alkyl of 1-20 carbons or an aryl of 6-20 carbons; and n is an integer from 1 to 20; and a crosslinker. A primary conductive polymer layer is on the first mordant layer.

A cathode foil for electrolytic capacitors includes a metal porous part, a metal core part that is continuous with the metal porous part, and a coating film covering the metal porous part. Pores in the metal porous part are open at a first main surface of the cathode foil. The coating film is disposed in a region from the first main surface to a depth more than or equal to 10% of a thickness of the metal porous part in a thickness direction of the metal porous part.

A film production method for producing a layer containing a metal oxide, the film production method including: a heating step of heating a metal foil containing a first metal by bringing a part of the metal foil into contact with at least one heat generator; a first contact step of letting first gas containing a second metal to be in contact with both surfaces of the metal foil in a state where the part of the metal foil is supported; and a second contact step of letting second gas containing an oxidant to be in contact with the both surfaces of the metal foil in a state where the part of the metal foil is supported.

An electrolytic capacitor includes a capacitor element, a first current collector, and a case. The capacitor element includes a wound body in which a first electrode foil and a second electrode foil are wound. The first electrode foil and the second electrode foil face each other. The first current collector is connected to the first electrode foil. The case houses the capacitor element and the first current collector. The first electrode foil includes a first facing portion that faces the second electrode foil and a first non-facing portion that does not face the second electrode foil. The first non-facing portion is located at a first end portion in a winding axis of the wound body. The first current collector is disposed in a vicinity of the first end portion of the wound body to be connected to the first non-facing portion of the first electrode foil.