Solid electrolytic capacitor

1. A solid electrolytic capacitor comprising:

a capacitor element that contains a sintered porous anode body, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric;

an anode lead extending from a surface of the capacitor element;

an anode termination that is in electrical connection with the anode lead and a cathode termination that is in electrical connection with the solid electrolyte,

a casing material that encapsulates the capacitor element and anode lead; and

a barrier coating that is disposed on at least a portion of the capacitor element and is in contact with the casing material, wherein the coating comprises a polymeric material that includes a fluorinated component and a non-fluorinated component, wherein the polymeric material has a glass transition temperature of from about 10° C. to about 120° C. and a thermal decomposition temperature of about 200° C. to about 300° C., and wherein the non-fluorinated component includes a (meth)acrylate.

2. The solid electrolytic capacitor of claim 1 , wherein the capacitor exhibits a Moisture Sensitive Level of at least 4 when tested in accordance with J-STD-020E (December 2014).

3. The solid electrolytic capacitor of claim 1 , wherein the fluorinated component includes a fluorocarbon having a fluoroalkyl group.

4. The solid electrolytic capacitor of claim 3 , wherein the fluoroalkyl group includes —CF 3 , —CF 2 CF 3 , —(CF 2 ) 2 CF 3 , —CF(CF 3 ) 2 , —(CF 2 ) 3 CF 3 , —CF 2 CF(CF 3 ) 2 , —C(CF 3 ) 3 , —(CF 2 ) 4 CF 3 , —(CF 2 ) 2 CF(CF 3 ) 2 , —CF 2 C(CF 3 ) 3 , —CF(CF 3 )CF 2 CF 2 CF 3 , —(CF 2 ) 5 CF 3 , —(CF 2 ) 3 CF(CF 3 ) 2 , or a combination thereof.

5. The solid electrolytic capacitor of claim 3 , wherein the fluorocarbon also contains a (meth)acrylate group.

6. The solid electrolytic capacitor of claim 1 , wherein the fluorinated component includes a fluoroalkyl-substituted (meth)acrylate.

7. The solid electrolytic capacitor of claim 6 , wherein the fluoroalkyl-substituted (meth)acrylate includes perfluorobutyl (meth)acrylate, perfluorohexyl (meth)acrylate, perfluoroheptyl (meth)acrylate, perfluorooctyl (meth)acrylate, perfluorononyl (meth)acrylate, perfluorodecyl (meth)acrylate, perfluoroundecyl (meth)acrylate, perfluorododecyl (meth)acrylate, or a combination thereof.

8. The solid electrolytic capacitor of claim 1 , wherein the fluorinated component and the non-fluorinated component are monomeric repeating units of a copolymer.

9. The solid electrolytic capacitor of claim 1 , wherein the fluorinated component is a separate material from the non-fluorinated component.

10. The solid electrolytic capacitor of claim 1 , wherein the non-fluorinated component includes n-stearyl methacrylate, n-stearyl acrylate, cyclohexyl methacrylate, behenyl methacrylate, or a combination thereof.

11. The solid electrolytic capacitor of claim 1 , wherein the barrier coating is in contact with at least a portion of the anode termination and/or cathode termination.

12. The solid electrolytic capacitor of claim 11 , wherein the barrier coating covers at least a portion of the anode termination.

13. The solid electrolytic capacitor of claim 1 , wherein the barrier coating covers at least a portion of the anode lead.

14. The solid electrolytic capacitor of claim 1 , wherein the barrier coating covers at least a portion of the surface of the capacitor element from which the anode lead extends.

15. The solid electrolytic capacitor of claim 1 , wherein the casing material is formed from a resinous matrix.

16. The solid electrolytic capacitor of claim 1 , wherein the capacitor element further comprises a cathode coating that contains a metal particle layer that overlies the solid electrolyte, wherein the metal particle layer includes a plurality of conductive metal particles.

17. The solid electrolytic capacitor of claim 1 , wherein the anode body includes tantalum.

18. The solid electrolytic capacitor of claim 1 , wherein the solid electrolyte includes a conductive polymer.

19. The solid electrolytic capacitor of claim 18 , wherein the conductive polymer has repeating units of the following formula:

wherein,

R 7 is a linear or branched, C 1 to C 18 alkyl radical, C 5 to C 12 cycloalkyl radical, C 6 to C 14 aryl radical, C 7 to C 18 aralkyl radical, or a combination thereof; and

q is an integer from 0 to 8.

20. The solid electrolytic capacitor of claim 19 , wherein the conductive polymer is poly(3,4-ethylenedioxythiophene).

21. The solid electrolytic capacitor of claim 19 , wherein the solid electrolyte also contains a polymeric counterion.

22. The solid electrolytic capacitor of claim 1 , further comprising an external polymer coating that overlies the solid electrolyte and contains pre-polymerized conductive polymer particles and a cross-linking agent.

23. A method for forming the solid electrolytic capacitor of claim 1 , the method comprising:

disposing a coating formulation on at least a portion of the anode termination, the coating formulation containing the polymeric material and a solvent; and

removing the solvent from the coating formulation to form the barrier coating.

24. The method of claim 23 , wherein the solvent includes a fluorinated hydrocarbon, fluorinated ketone, fluorinated aliphatic olefin, fluorinated aromatic olefin, or a combination thereof.