Electrolyte for electrolytic capacitor, electrolytic capacitor and process for producing tetrafluoroaluminate salt of organic onium
View Patent ↗There are provided an aluminum electrolytic capacitor comprising an anode, a cathode comprising aluminum and an electrolytic solution containing an onium salt of fluorine-containing anion, wherein the electrolytic solution has a water concentration of 1% by weight or less, or wherein the cathode has a peak top of Al2p spectrum of 74.0 to 75.8 eV as measured by a method in which the surface of the cathode in the aluminum electrolytic capacitor heated at 125° C. for 50 hours is analyzed by X-ray photoelectron spectroscopy (XPS); an electrolytic solution for electrolytic capacitor comprising a quaternary cyclic amidinium tetrafluoroaluminate and a solvent and containing specific impurity compounds in a total amount of 0.6% by weight or less, and an electrolytic capacitor using the electrolytic solution; and a method for preparing an organic onium tetrafluoroaluminate which is advantageously used in an aluminum electrolytic capacitor.
1. An aluminum electrolytic capacitor comprising an anode, a cathode comprising aluminum and an electrolytic solution containing an onium salt of fluorine-containing anion, wherein the cathode has a peak top of Al2p spectrum of 74.0 to 75.8 eV as measured by a method in which the surface of the cathode in the aluminum electrolytic capacitor heated at 125° C. for 50 hours is analyzed by X-ray photoelectron spectroscopy (XPS).
2. The aluminum electrolytic capacitor according to claim 1 , wherein the electrolytic solution has a water concentration of 1% by weight or less.
3. The aluminum electrolytic capacitor of claim 2 , wherein the fluorine-containing anion is an anion represented by the following formula (a):
MFn − (a)
wherein:
M represents an element selected from the group consisting of B, Al, P, Nb, Sb and Ta; and
n represents a number of 4 or 6.
4. The aluminum electrolytic capacitor of claim 3 , wherein the onium salt is at least one member selected from the group consisting of a quaternary ammonium salt, a quaternary phosphonium salt, a quaternary imidazolium salt, a quaternary amidinium salt and an ammonium salt.
5. The aluminum electrolytic capacitor of claim 4 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
6. The aluminum electrolytic capacitor of claim 3 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
7. The aluminum electrolytic capacitor of claim 2 , wherein the onium salt is at least one member selected from the group consisting of a quaternary ammonium salt, a quaternary phosphonium salt, a quaternary imidazolium salt, a quaternary amidinium salt and an ammonium salt.
8. The aluminum electrolytic capacitor of claim 7 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
9. The aluminum electrolytic capacitor of claim 2 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
10. The aluminum electrolytic capacitor of claim 1 , wherein the fluorine-containing anion is an anion represented by the following formula (a):
MFn − (a)
wherein:
M represents an element selected from the group consisting of B, Al, P, Nb, Sb and Ta; and
n represents a number of 4 or 6.
11. The aluminum electrolytic capacitor of claim 10 , wherein the onium salt is at least one member selected from the group consisting of a quaternary ammonium salt, a quaternary phosphonium salt, a quaternary imidazolium salt, a quaternary amidinium salt and an ammonium salt.
12. The aluminum electrolytic capacitor of claim 11 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
13. The aluminum electrolytic capacitor of claim 10 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
14. The aluminum electrolytic capacitor of claim 1 , wherein the onium salt is at least one member selected from the group consisting of a quaternary ammonium salt, a quaternary phosphonium salt, a quaternary imidazolium salt, a quaternary amidinium salt and an ammonium salt.
15. The aluminum electrolytic capacitor of claim 14 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.
16. The aluminum electrolytic capacitor of claim 1 , wherein the aluminum electrolytic capacitor is assembled in an atmosphere having a moisture content of 50% or less in terms of a relative humidity.