Solid electrolytic capacitor assembly

1. A capacitor assembly comprising:

a solid electrolytic 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 termination that is in electrical connection with the anode body, wherein a first coating is disposed on at least a portion of the anode termination that contains an organometallic compound;

a cathode termination that is in electrical connection with the solid electrolyte wherein a second coating is disposed on at least a portion of the cathode termination that contains an organometallic compound; and

a casing material that encapsulates the capacitor element and leaves exposed a mounting surface of the anode termination and the cathode termination.

2. The capacitor assembly of claim 1 , wherein the organometallic compound of the first coating, the organometallic compound of the second coating, or both has the following general formula:

wherein,

M is an organometallic atom;

R 1 , R 2 , and R 3 are independently an alkyl or a hydroxyalkyl, wherein at least one of R 1 , R 2 , and R 3 is a hydroxyalkyl;

n is an integer from 0 to 8;

X is an organic or inorganic functional group.

3. The capacitor assembly of claim 2 , wherein M is silicon.

4. The capacitor assembly of claim 3 , wherein the hydroxyalkyl is OCH 3 .

5. The capacitor assembly of claim 2 , wherein R 1 , R 2 , and R 3 are a hydroxyalkyl.

6. The capacitor assembly of claim 1 , wherein the organometallic compound is 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, glycidoxymethyl-tripropoxysilane, glycidoxymethyltributoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, β-glycidoxyethyl-tripropoxysilane, β-glycidoxyethyl-tributoxysilane, β-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, α-glycidoxyethyltripropoxysilane, α-glycidoxyethyltributoxysilane, γ-glycidoxypropyl-trimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl-tripropoxysilane, γ-glycidoxypropyltributoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyl-triethoxysilane, β-glycidoxypropyltripropoxysilane, α-glycidoxypropyltributoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, α-glycidoxypropyl-tripropoxysilane, α-glycidoxypropyltributoxysilane, γ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltripropoxysilane, δ-glycidoxybutyl-tributoxysilane, δ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltripropoxysilane, γ-propoxybutyltributoxysilane, δ-glycidoxybutyl-trimethoxysilane, δ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltripropoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, α-glycidoxybutyl-tripropoxysilane, α-glycidoxybutyltributoxysilane, or a combination thereof.

7. The capacitor assembly of claim 1 , wherein each surface of the anode termination contains the first coating.

8. The capacitor assembly of claim 1 , wherein each surface of the cathode termination contains the second coating.

9. The capacitor assembly 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 dispersed within a resinous polymer matrix.

10. The capacitor assembly of claim 1 , wherein the anode body includes tantalum and the dielectric includes tantalum pentoxide.

11. The capacitor assembly of claim 1 , wherein the solid electrolyte includes a plurality of conductive polymer particles.

12. The capacitor assembly of claim 11 , wherein the conductive polymer particles contain an extrinsically conductive polymer having repeating units of the following formula (III):

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.

13. The capacitor assembly of claim 12 , wherein the extrinsically conductive polymer is poly(3,4-ethylenedioxythiophene).

14. The capacitor assembly of claim 12 , wherein the particles also contain a polymeric counterion.

15. The capacitor assembly of claim 11 , wherein the conductive polymer particles contain an intrinsically conductive polymer having repeating units of the following formula (IV):

wherein,

R is (CH 2 ) a —O—(CH 2 ) b ;

a is from 0 to 10;

b is from 1 to 18;

Z is an anion;

X is a cation.

16. The capacitor assembly 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.

17. The capacitor assembly of claim 1 , wherein the capacitor is in contact with an atmosphere having a relative humidity of about 40% or more.

18. The capacitor assembly of claim 1 , further comprising a moisture barrier layer that coats at least a portion of the casing material.

19. The capacitor assembly of claim 18 , wherein the moisture barrier layer includes a silicone elastomer.