Process for the production of electrolyte capacitors of high nominal voltage
View Patent ↗The invention relates to a process for the production of electrolyte capacitors having a low equivalent series resistance and low residual current for high nominal voltages, electrolyte capacitors produced by this process and the use of such electrolyte capacitors.
1. An electrolyte capacitor produced with the process comprising process steps:
Subjecting a porous electrode body of an electrode material to anodic oxidation for formation of a dielectric which covers the surface of the electrode material,
Applying a dispersion A) on to the porous body wherein the porous body comprises the porous electrode body of the electrode material and the dielectric,
wherein said dispersion A) comprises at least particles B) of an electrically conductive polymer and a dispersing agent D), and
forming a solid electrolyte which completely or partly covers the dielectric surface, and the dispersing agent D) is at least partly removed and/or cured,
wherein the maximum anodizing voltage during the anodic oxidation of the porous electrode body is greater than 30 V and the particles B) of the conductive polymer in the dispersion A) have an average diameter of from 1 to 100 nm, wherein the particles B) comprise a cationic polythiophene and a polymeric anion as a counter-ion, the cationic polythiophene and the polymeric anion being present on the form of a polythiophene/polymeric anion complex.
2. The electrolyte capacitor according to claim 1 , wherein the electrolyte capacitor has a specific charge of from 100 to 100,000 μC/g, based on the weight of the electrode body covered with a dielectric.
3. The electrolyte capacitor according to claim 1 , wherein the electrolyte capacitor has a nominal voltage of greater than 15 V.
4. The electrolyte capacitor according to claim 1 , wherein electrolyte capacitor has a break-through voltage of greater than 150% of the nominal voltage.
5. The electrolyte capacitor according to claim 1 , wherein the electrolyte capacitor has a break-through voltage of greater than 40% of the anodizing voltage.
6. The electrolyte capacitor according to claim 1 , wherein the electrode material is based on aluminium and the thickness of the dielectric is greater than 30 nm.
7. The electrolyte capacitor according to claim 1 , wherein the electrode material is based on tantalum and the thickness of the dielectric is greater than 50 nm.
8. The electrolyte capacitor according to claim 1 , wherein the electrode material is based on niobium or niobium oxide and the thickness of the dielectric is greater than 80 nm.
9. An electronic circuit comprising an electrolyte capacitor as claimed in claim 1 .
10. The electrolyte capacitor according to claim 1 , wherein forming a solid electrolyte which completely or partly covers the dielectric surface, and the dispersing agent D) is at least partly removed and/or cured, is in the absence of chemical in situ oxidative polymerization.
11. An electrolyte capacitor produced with a process comprising process steps:
Subjecting a porous electrode body of an electrode material to anodic oxidation for formation of a dielectric which covers the surface of the electrode material,
applying a dispersion A) on to the porous body wherein the porous body comprises the porous electrode body of the electrode materials and the dielectric,
wherein said dispersion A) comprises at least particle B) of an electrically conductive polymer and a dispersing agent D), and
forming a solid electrolyte which completely or partly covers the dielectric surface, and the dispersing agent D) is at least partly removed and/or cured,
wherein the maximum anodizing voltage during the anodic oxidation of the porous electrode body is greater than 30 V and the particles B) of the conductive polymer in the dispersion A) have an average diameter of from 1 to 100 nm, and wherein the particles B) comprise at least one polythiophene carrying positive charges in the polythiophene main chain, wherein the polythiophene has recurring units of the general formula (I) or the formula (II) or recurring units of the general formulae (I and (II)
wherein
A represents an optionally substituted C 2 -C 3 -alkylene radical,
x represents 1 and indicates that 1 substituent R is bonded to A, and
R represents a sulfonate- or carboxylate substituted, negatively charged radical,
wherein the positive charges of the polythiophene main chain are partly or completely satisfied by the negative charges present on the radicals R.
12. The electrolyte capacitor according to claim 11 , wherein the electrolye capacitor has a specific charge of from 100 to 100,000 μC/g based on the weight of the electrode body covered with a dielectric.
13. The electrolye capacitor according to claim 11 , wherein the electrolyte capacitor has a nominal voltage of greater than 15 V.
14. The electrolyte capacitor according to claim 11 , wherein electrolyte capacitor has a break-through voltage of greater than 150% of the nominal voltage.
15. The electrolyte capacitor according to claim 11 , wherein the electrolyte capacitor has a break-through voltage of greater than 40% of the anodizing voltage.
16. The electrolyte capacitor according to claim 11 , wherein the electrode material is based on aluminum and the thickness of the dielectric is grater and 30 nm.
17. The electrolyte capacitor according to claim 11 , wherein the electrode material is based on tantalum and the thickness of the dielectric is greater than 50 nm.
18. The electrolyte capacitor according to claim 11 , wherein the electrode material is based on niobium or niobium oxide and the thickness of the dielectric is greater than 80 nm.
19. An electronic circuit comprising an electrolyte capacitor as claimed in claim 11 .
20. The electrolyte capacitor according to claim 11 , wherein forming a solid electrolyte which completely or partly covers the dielectric surface, and the dispersing agent D) is at least partly removed and/or cured, is in the absence of chemical in situ oxidative polymerization.