An electrolytic capacitor includes at least one capacitor element. The at least one capacitor element includes: an anode body including an anode lead portion, and a cathode forming portion; a dielectric layer disposed on at least a surface of the cathode forming portion of the anode body; and a cathode part covering at least a part of the dielectric layer. The cathode part includes a solid electrolyte layer that contains a conductive polymer, and covers at least a part of the dielectric layer. A ratio T1/T2 of a thickness T1 of the solid electrolyte layer formed at a corner portion of the anode body to a thickness T2 of the solid electrolyte layer formed at a center portion of a principal surface of the anode body is in a range from 0.8 to 1.7, inclusive, in a cross section of the at least one capacitor element.

An electrolytic capacitor includes at least one capacitor element. The at least one capacitor element includes: an anode body including an anode lead portion, and a cathode forming portion; a dielectric layer disposed on at least a surface of the cathode forming portion of the anode body; and a cathode part covering at least a part of the dielectric layer. The cathode part includes a solid electrolyte layer that contains a conductive polymer, and covers at least a part of the dielectric layer. A ratio T1/T2 of a thickness T1 of the solid electrolyte layer formed at a corner portion of the anode body to a thickness T2 of the solid electrolyte layer formed at a center portion of a principal surface of the anode body is in a range from 0.8 to 1.7, inclusive, in a cross section of the at least one capacitor element.

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.

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.

A solid electrolyte capacitor includes a sintered body formed by sintering a molded body containing metal powder; and a conductive polymer layer disposed above the sintered body. A ratio (t2/t1) of a thickness (t2) of the conductive polymer layer in an edge portion of the sintered body to a thickness (t1) of the conductive polymer layer in a central portion of the sintered body satisfies 0.35≤t2/t1≤0.9.

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.

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.

An electrolytic capacitor includes an anode body having a dielectric layer; a solid electrolyte layer in contact with the dielectric layer of the anode body; and an electrolytic solution. The electrolytic solution contains a solvent and a solute. The solvent contains a glycol compound. The solute contains an acid component and a base component. A mass of the acid component in the solute is greater than a mass of the base component in the solute. The acid component contains a first aromatic compound having a hydroxyl group.

An electrolytic capacitor includes an anode body having a dielectric layer; a solid electrolyte layer in contact with the dielectric layer of the anode body; and an electrolytic solution. The electrolytic solution contains a solvent and a solute. The solvent contains a glycol compound. The solute contains an acid component and a base component. A mass of the acid component in the solute is greater than a mass of the base component in the solute. The acid component contains a first aromatic compound having a hydroxyl group.