Electrolytic capacitor and method for producing same
An electrolytic capacitor includes an anode body, a dielectric layer covering the anode body, a first solid electrolyte layer covering the dielectric layer, and a second solid electrolyte layer covering the first solid electrolyte layer. The first solid electrolyte layer contains a first conductive polymer including polythiophene as a basic skeleton. The second solid electrolyte layer contains a second conductive polymer including polypyrrole as a basic skeleton. A conductivity of the first solid electrolyte layer is less than or equal to 2 S/cm.
1 . An electrolytic capacitor comprising:
an anode body;
a dielectric layer covering the anode body;
a first solid electrolyte layer covering the dielectric layer; and
a second solid electrolyte layer covering the first solid electrolyte layer,
wherein:
the first solid electrolyte layer contains a first conductive polymer being a self-doped type conductive polymer including polythiophene as a basic skeleton and having a conductivity of less than or equal to 2 S/cm,
the second solid electrolyte layer contains a second conductive polymer including polypyrrole as a basic skeleton, and
a conductivity of the first solid electrolyte layer is less than or equal to 2 S/cm.
2 . The electrolytic capacitor according to claim 1 , wherein the conductivity of the first solid electrolyte layer ranges from 0.1 S/cm to 0.5 S/cm, inclusive.
3 . The electrolytic capacitor according to claim 1 , wherein a thickness of the first solid electrolyte layer is less than or equal to 10 nm.
4 . The electrolytic capacitor according to claim 1 , wherein a thickness of the second solid electrolyte layer ranges from 50 nm to 100 nm, inclusive.
5 . The electrolytic capacitor according to claim 1 , wherein a conductivity of the second solid electrolyte layer is higher than the conductivity of the first solid electrolyte layer.
6 . The electrolytic capacitor according to claim 5 , wherein the conductivity of the second solid electrolyte layer ranges from 30 S/cm to 300 S/cm, inclusive.
7 . The electrolytic capacitor according to claim 1 , wherein the second solid electrolyte layer contains the second conductive polymer that is a non-self-doped type conductive polymer.
8 . A method for producing an electrolytic capacitor, the method comprising:
a first step of preparing an anode body on which a dielectric layer is formed;
a second step of forming a first solid electrolyte layer containing a first conductive polymer on the dielectric layer, the first conductive polymer being a self-doped type conductive polymer including polythiophene as a basic skeleton and having a conductivity of less than or equal to 2 S/cm; and
a third step of forming a second solid electrolyte layer containing a second conductive polymer by performing electrolytic polymerization of a precursor of the second conductive polymer on the first solid electrolyte layer, the second conductive polymer including polypyrrole as a basic skeleton,
wherein a conductivity of the first solid electrolyte layer is less than or equal to 2 S/cm.
9 . The method for producing an electrolytic capacitor according to claim 8 , wherein the second step includes:
a step of preparing a first treatment liquid containing the first conductive polymer; and
a step of forming the first solid electrolyte layer containing the first conductive polymer by attaching the first treatment liquid to the dielectric layer.