Electrolytic capacitor
An electrolytic capacitor includes a capacitor element and an electrolytic solution. The capacitor element includes: an anode body including a dielectric layer; a cathode body; and a solid electrolyte in contact with the dielectric layer. The electrolytic solution includes a solvent, a solute, and a polymer component. The solvent includes an ethylene glycol compound. The polymer component includes polyalkylene glycol. The polyalkylene glycol includes at least one of (i) a mixture of polyoxyethylene and polyoxypropylene and (ii) an oxyethylene-oxypropylene copolymer. In the polyalkylene glycol, a molar ratio m/n of oxyethylene units to oxypropylene units is greater than 1.
1. An electrolytic capacitor comprising a capacitor element and an electrolytic solution, the capacitor element including: an anode body including a dielectric layer; a cathode body; and a solid electrolyte in contact with the dielectric layer, wherein:
the electrolytic solution includes a solvent, a solute, and a polymer component,
the solvent includes an ethylene glycol compound,
the polymer component includes polyalkylene glycol,
the polyalkylene glycol includes a mixture of polyoxyethylene and polyoxypropylene, and
a molar ratio m/n of oxyethylene units to oxypropylene units in the polyalkylene glycol is greater than 1.
2. The electrolytic capacitor according to claim 1 , wherein a proportion of the ethylene glycol compound in the solvent is more than or equal to 10% by mass.
3. The electrolytic capacitor according to claim 1 , wherein the ethylene glycol compound is at least one selected from a group consisting of ethylene glycol and polyethylene glycol, the polyethylene glycol including oxyethylene units at repeating number ranging from 2 to 8, inclusive.
4. The electrolytic capacitor according to claim 1 , wherein:
a number-average molecular weight of the polyoxyethylene ranges from 200 to 5,000, inclusive, and
a number-average molecular weight of the polyoxypropylene ranges from 200 to 5,000, inclusive.
5. The electrolytic capacitor according to claim 1 , wherein:
a concentration of the polyoxyethylene in the electrolytic solution is less than or equal to 50% by mass, and
a concentration of the polyoxypropylene in the electrolytic solution is less than or equal to 50% by mass.
6. The electrolytic capacitor according to claim 1 , wherein the solute includes an acid component and a base component.
7. The electrolytic capacitor according to claim 1 , wherein the electrolytic solution further includes at least one kind of ester compound selected from a group consisting of (i) a condensation product of a boric acid and a hydroxy compound and (ii) a condensation product of a phosphoric acid and a hydroxy compound.
8. An electrolytic capacitor comprising a capacitor element and an electrolytic solution, the capacitor element including: an anode body including a dielectric layer; a cathode body; and a solid electrolyte in contact with the dielectric layer, wherein:
the electrolytic solution includes a solvent, a solute, and a polymer component,
the solvent includes an ethylene glycol compound,
the polymer component includes polyalkylene glycol,
the polyalkylene glycol includes an oxyethylene-oxypropylene copolymer, and
a molar ratio m/n of oxyethylene units to oxypropylene units in the polyalkylene glycol is greater than 1 and less than or equal to 2.
9. The electrolytic capacitor according to claim 8 , wherein a proportion of the ethylene glycol compound in the solvent is more than or equal to 10% by mass.
10. The electrolytic capacitor according to claim 8 , wherein the ethylene glycol compound is at least one selected from a group consisting of ethylene glycol and polyethylene glycol, the polyethylene glycol including oxyethylene units at repeating number ranging from 2 to 8, inclusive.
11. The electrolytic capacitor according to claim 8 , wherein a number-average molecular weight of the oxyethylene-oxypropylene copolymer ranges from 200 to 5,000, inclusive.
12. The electrolytic capacitor according to claim 8 , wherein a concentration of the oxyethylene-oxypropylene copolymer in the electrolytic solution is less than or equal to 50% by mass.
13. The electrolytic capacitor according to claim 8 , wherein the solute includes an acid component and a base component.
14. The electrolytic capacitor according to claim 8 , wherein the electrolytic solution further includes at least one kind of ester compound selected from a group consisting of (i) a condensation product of a boric acid and a hydroxy compound and (ii) a condensation product of a phosphoric acid and a hydroxy compound.