An electrolytic capacitor includes a capacitor element and electrolytic solution. The capacitor element includes an anode body with an oxide film, and a solid electrolyte contacting the oxide film. The electrolytic solution contains a solvent and a solute. The solvent contains at least one selected from the group consisting of a lactone compound, a glycol compound, and a sulfone compound. The solute includes a first acid component and a base component. The first acid component includes at least one of a benzenedicarboxylic acid and a derivative of the benzenedicarboxylic acid. The base component includes at least one of an amine and an amidine. A concentration of the solute in the electrolytic solution ranges from 15% by mass to 40% by mass, inclusive. A ratio (V/Vw) of a formation voltage V of the oxide film to a rated voltage Vw of the electrolytic capacitor is less than or equal to 1.7.

A capacitor manufacturing method is disclosed herein that includes a process for the isolation of electrode tabs attached to the capacitors' electrodes from other elements in the capacitor. An isolation patch or layer may be deposited over the tabs by a machine or a device after the tab is attached and before the electrodes are wound into a cylindrical internal element of a capacitor. The device may coat the tabs and surrounding regions with an isolating material. Electrode tabs may be provided with an isolating material pre-deposited at least in part over the tabs.

A method of manufacturing a winding capacitor package structure is provided. The method of manufacturing the winding capacitor package structure includes: forming a base layer on an inner bottom surface of a casing structure; placing a winding assembly and a part of a conductive assembly inside an accommodating space of the casing structure; sequentially forming a plurality of filling layers between the winding assembly and the casing structure; and then placing a bottom carrier frame on a bottom portion of the casing structure so as to match with the casing structure. The casing structure includes a rough inner surface, and the base layer and the filling layer are limited inside the casing structure through a friction provided by the rough inner surface of the casing structure.

A method of manufacturing a winding capacitor package structure is provided. The method of manufacturing the winding capacitor package structure includes: forming a base layer on an inner bottom surface of a casing structure; placing a winding assembly and a part of a conductive assembly inside an accommodating space of the casing structure; sequentially forming a plurality of filling layers between the winding assembly and the casing structure; and then placing a bottom carrier frame on a bottom portion of the casing structure so as to match with the casing structure. The casing structure includes a main casing for enclosing the base layer and the filling layer and a retaining body inwardly bent from a bottom side of the main casing, and the base layer and the filling layer are retained and limited inside the casing structure by the retaining body.

An electrolytic capacitor includes a capacitor element, a solid electrolyte layer, an electrolyte solution. The capacitor element has an anode foil with a dielectric layer, and a cathode foil. The solid electrolyte layer is provided between the anode foil and the cathode foil. And the capacitor element is impregnated with the electrolyte solution. The cathode foil includes a covering layer that contains at least one metal selected from titanium and nickel or a compound of the at least one metal. And the solid electrolyte layer contains a conductive polymer, a polymer dopant, and a base component.

In an electrolytic capacitor having a capacitor element housed inside a body case where the capacitor element has a first electrode member and a second electrode member wound up with a separator in between and where the capacitor element holding an electrolyte solution, there is provided, between the first and second electrode members, a conductive polymer particle band in which conductive polymer particles of a conductive polymer in a dense state are disposed to extend in the longitudinal direction of the separator, the conductive polymer particle band contains a cellulose derivative, and the conductive polymer particle band is provided to cover, within at least one of regions on opposite sides of the center line of the separator in its lateral direction, one half or more of the region in the lateral direction.

Provide is an electrolytic capacitor for a middle-to-high voltage application that is equal to or higher than 100 V which suppresses the total amount of gas to be produced in the electrolytic capacitor. The anode foil of the electrolytic capacitor includes an enlarged surface portion provided with tunnel-shape pits formed from the foil surface in the thickness direction of the foil, and a dielectric oxide film formed on the surface of the enlarged surface portion. The cathode body of the electrolytic capacitor includes a cathode foil formed of a valve acting metal, and a carbon layer formed on the cathode foil.

A method for producing an electrolytic capacitor, the electrolytic capacitor including a capacitor element including an anode body and a cathode body each having a foil shape. The anode body includes a dielectric layer on a surface of the anode body. The method includes a step of forming a capacitor element precursor by winding or stacking a separator, the anode body, and the cathode body with the separator interposed between the anode body and the cathode body, a step of impregnating the capacitor element precursor with a treatment liquid containing an acid component, a solvent, and a conductive polymer component, a step of impregnating the capacitor element precursor with a liquid component after the step of impregnating the capacitor element precursor with the treatment liquid, and a step of forming the capacitor element by eluting the acid component into the liquid component.

A method for producing an electrolytic capacitor, the electrolytic capacitor including a capacitor element including an anode body and a cathode body each having a foil shape. The anode body includes a dielectric layer on a surface of the anode body. The method includes a step of forming a capacitor element precursor by winding or stacking a separator, the anode body, and the cathode body with the separator interposed between the anode body and the cathode body, a step of impregnating the capacitor element precursor with a treatment liquid containing a polyhydric alcohol, a solvent, and a conductive polymer component, a step of impregnating the capacitor element precursor with a liquid component after the step of impregnating the capacitor element precursor with the treatment liquid, and a step of forming the capacitor element by eluting the polyhydric alcohol into the liquid component.

An electrolytic capacitor includes a capacitor element. The capacitor element includes an electrode group including an anode body, a cathode body, a separator, and an electrolyte layer. The anode body and the cathode body each has a foil shape. The anode body has a dielectric layer on a surface of the anode body. The electrolyte layer is in contact with the anode body, the cathode body, and the separator. The electrolyte layer contains a conductive polymer and a hydroxyl group-containing compound having a melting point of 50° C. or higher. The hydroxyl group-containing compound is at least one compound selected from the group consisting of a sugar and a polyhydric alcohol. The hydroxyl group-containing compound is unevenly distributed more in a peripheral portion of the capacitor element than in a central portion of the capacitor element.