A cathode foil for a solid electrolytic capacitor is designed to increase capacitance, reduce ESR and leakage current, enhance heat resistance, and reduce production costs, while enhancing a power density, realizing rapid charging-discharging, and improving a life property, in an electric energy storage element such as a secondary battery, an electric double layer capacitor and a hybrid capacitor. A cathode foil or a current collector may include a metal foil, a metal layer, a mixed layer containing carbon and a substance composing the metal layer in a mixed state, and a carbon layer consisting substantially of carbon, each formed on the metal foil. The mixed layer is configured to have a composition changing from a state containing substantially only the substance composing the metal layer to a state containing substantially only carbon, in a direction from the metal layer to the carbon layer.

Electrode foil, current collector, electrode, and electric energy storage element using same

A solid electrolytic capacitor includes an anode foil, a solid electrolyte provided on the anode foil and made of conductive polymer, and a cathode foil provided on the solid electrolyte and facing the anode foil across the solid electrolyte. The anode foil includes an anode base made of aluminum, a rough surface layer made of aluminum and provided on a surface of the anode base, and a dielectric oxide layer provided on the rough surface layer and contacting the solid electrolyte. The cathode foil includes a cathode base made of aluminum, and a nickel layer provided on a surface of the cathode base and contacting the solid electrolyte. The nickel layer faces the dielectric oxide layer of the anode foil across the solid electrolyte. The nickel layer is made of nickel and nickel oxide. This solid electrolytic capacitor has a large capacitance and a low equivalent series resistance while being inexpensive and highly reliable.

Solid electrolytic capacitor and method for manufacturing the same

A method of manufacturing an electrolytic capacitor includes preparing a dielectric film formed on a surface of an anode foil, forming a first conductive polymer layer on a surface of the dielectric film by immersing the anode foil in first dispersion solution including conductive polymer particles and forming a second conductive polymer layer covering the first conductive polymer layer solvent by immersing the anode foil in second dispersion solution including second conductive polymer particles and second solvent. The surface of the anode foil has plural pits formed therein. The second dispersion solution has a pH value farther from 7 than the first dispersion solution does. This configuration can suppress damages to the dielectric film.

Method of manufacturing electrolytic capacitor

In the present invention, microcapsules of a fire retardant are produced by encapsulating the fire retardant, which comprises a phosphate ester or a condensate thereof, in a resin that melts at or above 150°C, and the microcapsules of the fire retardant are added into a capacitor element. The resin that configures the microcapsule shells comprises at least one resin selected from: epoxy resin, phenol resin, polyphenylene sulfide, polyimide, polyaramide, melamine resin, polyruea, or polyurethane. As the fire retardant, for example, trimethyl phosphate, tritolyl phosphate, or cresyldiphenyl phosphate is used.

Flame-retardant electrolytic capacitor

Provided is a method for producing electrolytic capacitors that comprises: a step where a dielectric film, formed on the surface of an anode foil having multiple pores, is prepared; a step where the anode foil is impregnated with a first dispersion solution which contains conductive polymer particles and a solvent, and a first conductive polymer layer is formed on the surface of the dielectric film; and a step where the anode foil is impregnated with a second dispersion solution which contains conductive polymer particles and a solvent, and which has a pH further from 7 than the first dispersion solution, and a second conductive polymer layer, which covers the first conductive polymer layer, is formed. With the above steps, the present invention enables the suppression of damage to the dielectric film.

Method for producing electrolytic capacitor

An electrolytic capacitor includes a capacitor element and an electrolyte solution impregnated into the capacitor element. The capacitor element includes an anode foil, cathode foil, separator, and a solid electrolytic layer. The anode foil has a dielectric layer on its surface, and the cathode foil confronts the anode foil. The separator is interposed between the anode foil and the cathode foil. The solid electrolytic layer is formed on the surfaces of the anode foil, cathode foil, and separator as an aggregate of fine particles of conductive polymer. The separator has an air-tightness not greater than 2.0 s/100 ml. Sizes of the fine particles measure not greater than 100 nm in diameter, and the fine particles are contained in an amount ranging from 0.3 mg/cm2 to 1.2 mg/cm2 converted to amounts per unit area of the anode foil.

Electrolytic capacitor and method of manufacturing the same

A solid electrolytic capacitor that includes a cathode foil and solid electrolyte made of conductive polymer. This cathode foil is made by providing a nickel layer on a surface of a base material made of valve metal. This nickel layer includes a layer containing only nickel and a layer containing nickel oxide. Both large capacitance and low equivalent series resistance are achievable at the same time with this simple structure at low cost.

Electrode foil for capacitors and solid electrolytic capacitor

A capacitor element includes an anode foil, the first oxide film on a surface of the anode foil, a solid electrolyte layer formed using π-conjugated conductive polymer dispersing material on the first oxide film, and a cathode foil on the solid electrolyte layer. The cathode foil faces the first oxide film across the solid electrolyte layer. An electrolytic capacitor includes the capacitor element, an anode terminal connected to the anode foil, and a second oxide film on a surface of the anode terminal. The second oxide film provided on the anode terminal has higher water repellency than the first oxide film provided on the anode foil. This electrolytic capacitor can reduce a leakage current.

Electrolytic capacitor and method for manufacturing same

PROBLEM TO BE SOLVED: To acquire a high capacity winding-type solid-state electrolytic capacitor excellent in an impedance characteristic and a leakage current at high-frequency zone. SOLUTION: The solid-state electrolytic capacitor comprises: a capacitive element 10 formed by winding an positive electrode foil 1 with a dielectric oxide layer formed and a negative electrode foil 2 of an aluminum foil through a separator 3 comprising an unwoven cloth of a synthetic fiber; and a conductive polymer 4 provided between the positive electrode foil 1 and the negative electrode foil 2 by impregnating a polymerizable monomer and an oxidant to the capacitive element 10 and by chemically polymerizing. The separator 3 having affinity with the polymerizable monomer can provide the solid-state electrolytic capacitor excellent in a low ESR characteristic and a leakage current characteristic. COPYRIGHT: (C)2010,JPO&INPIT

Solid-state electrolytic capacitor and method of manufacturing the same

A method for manufacturing an electrolytic capacitor includes: a first step of preparing a capacitor element including an anode having a dielectric layer; a second step of impregnating the capacitor element with a first processing solution including at least a conductive polymer and a first solvent; and a third step of swelling the conductive polymer after the second step, by impregnating the capacitor element with a second processing solution including a swelling agent while at least part of the first solvent remains in the capacitor element.

Yukiya Shimoyama

Papers

Electrolytic capacitor and method of manufacturing the same

Electrode foil for capacitors and solid electrolytic capacitor

Electrolytic capacitor and method for manufacturing same

Solid-state electrolytic capacitor and method of manufacturing the same

Method for manufacturing electrolytic capacitor