Abstract: A solid electrolytic capacitor (1) includes an anode foil (2a) having formed thereon an oxide film, a cathode foil (2c), and a separator (2d), and is equipped with a solid electrolyte (20) formed of an electroconductive polymer compound in a fine particle form, and a water-soluble compound solution (30) introduced to surround the solid electrolyte (20), the solid electrolyte (20) contains a polyol compound having a molecular weight of less than 200 and a number of hydroxy groups of 4 or more as a first water-soluble compound (2f1), the water-soluble compound solution (30) contains one kind or multiple kinds of a glycol compound in a liquid form as a second water-soluble compound (2f2), and the second water-soluble compound (2f2) has an average molecular weight of less than 400.

Abstract: A solid electrolytic capacitor (1) includes an anode foil (2a) having formed thereon an oxide film, a cathode foil (2c), and a separator (2d), and is equipped with a solid electrolyte (20) formed of an electroconductive polymer compound in a fine particle form, and a water-soluble compound solution (30) introduced to surround the solid electrolyte (20), the solid electrolyte (20) contains a polyol compound having a molecular weight of less than 200 and a number of hydroxy groups of 4 or more as a first water-soluble compound (2f1), the water-soluble compound solution (30) contains one kind or multiple kinds of a glycol compound in a liquid form as a second water-soluble compound (2f2), and the second water-soluble compound (2f2) has an average molecular weight of less than 400.

Abstract: To provide an electrolytic capacitor having a configuration that achieves a low impedance by increasing the content of water, satisfies a withstand voltage of 400 V or more, and is capable of enhancing the long-term reliability. Provided as a solution is an electrolytic capacitor (1) including an electrolytic solution (2e) containing ethylene glycol, 10 to 30% by mass of water, and 1 to 12% by mass of an amine salt of a carboxylic acid, having added thereto 0.01 to 2% by mass of one or more kind of ammonium hypophosphite, an amine salt of hypophosphorous acid, and hypophosphorous acid, the carboxylic acid being a polycarboxylic acid having a chain hydrocarbon skeleton and a molecular weight of 140 to 500.

Abstract: A solid electrolytic capacitor (1) includes an anode foil (2a) having formed thereon an oxide film, a cathode foil (2c), and a separator (2d), and is equipped with a solid electrolyte (20) formed of an electroconductive polymer compound in a fine particle form, and a water-soluble compound solution (30) introduced to surround the solid electrolyte (20), the solid electrolyte (20) contains a polyol compound having a molecular weight of less than 200 and a number of hydroxy groups of 4 or more as a first water-soluble compound (2f1), the water-soluble compound solution (30) contains one kind or multiple kinds of a glycol compound in a liquid form as a second water-soluble compound (2f2), and the second water-soluble compound (2f2) has an average molecular weight of less than 400.

Abstract: A solid electrolytic capacitor includes: an anode foil on which an oxide film is formed; a cathode foil; and a separator between the anode and cathode foils, wherein a solid electrolyte in a fine particle form made of a conductive high molecular weight compound and a water-soluble high-molecular weight compound in a liquid form are introduced into a gap between the anode and cathode foils in a state where the water-soluble high-molecular weight compound in a liquid form surrounds the solid electrolyte, and a ratio of an area that the solid electrolyte occupies in the gap is set to a value which falls within a range of 1 vol % to 30 vol %, and a ratio of an area that the water-soluble high-molecular weight compound in a liquid form occupies in the gap is set to a value which falls within a range of 10 vol % to 99 vol %.

Abstract: A solid electrolytic capacitor includes: an anode foil on which an oxide film is formed; a cathode foil; and a separator between the anode and cathode foils, wherein a solid electrolyte in a fine particle form made of a conductive high molecular weight compound and a water-soluble high-molecular weight compound in a liquid form are introduced into a gap between the anode and cathode foils in a state where the water-soluble high-molecular weight compound in a liquid form surrounds the solid electrolyte, and a ratio of an area that the solid electrolyte occupies in the gap is set to a value which falls within a range of 1 vol % to 30 vol %, and a ratio of an area that the water-soluble high-molecular weight compound in a liquid form occupies in the gap is set to a value which falls within a range of 10 vol % to 99 vol %.