Cryogenic grinding of tantalum for use in capacitor manufacture

Patent metadata

Field	Value
Publication number	US-9583271-B1
Application number	US-201313932034-A
Country	US
Kind code	B1
Filing date	Jul 1, 2013
Priority date	Jun 29, 2012
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

An electrolytic capacitor comprising an anode comprised of cryogenically milled anode material is described. The cryogenic milling process prepares the active anode material for anode fabrication. The capacitor further comprises a casing of first and second casing members secured to each other to provide an enclosure. A feedthrough electrically insulated from the casing and from the casing and extending there from through a glass-to-metal seal, at least one anode electrically connected within the casing, a cathode, and an electrolyte. The cathode is of a cathode active material deposited on planar faces of the first and second casing members.

First claim

What is claimed is:

1. A capacitor, which comprises:
a) a casing comprising first and second casing members secured to each other;
b) at least a first anode comprising a plurality of tantalum particles, the tantalum particles having an average diameter that ranges from about 1.25 μm to about 3 μm, and an average length that ranges from about 5 μm to about 25 μm;
c) a cathode comprising a cathode active material;
d) a separator disposed between the anode and the cathode housed inside the casing; and
e) a working electrolyte contained within the casing and in physical contact with the cathode and the anode.

2. The capacitor of claim 1 wherein the first anode is electrically connected to a second anode, and wherein a cathode current collector is disposed between the first and second anodes, the cathode current collector having opposed first and second major faces supporting the cathode active material opposite a respective one of the first and second anodes.

3. The capacitor of claim 1 wherein the cathode active material is supported by an interior face wall of at least the first casing member.

4. The capacitor of claim 1 wherein the cathode active material is ruthenium oxide.

5. The capacitor of claim 1 , wherein the tantalum particles have an average particle diameter that ranges from about 1.25 μm to about 1.75 μm, and an average particle length that ranges from about 10 μm to about 20 μm.

6. The capacitor of claim 1 wherein the tantalum particles have an iron content of less than about 10 parts per million.

7. The capacitor of claim 1 , wherein the cathode active material comprises an oxide, a nitride, or a carbon nitride selected from the group of metals consisting of ruthenium, cobalt, manganese, molybdenum, tungsten, tantalum, iron, niobium, iridium, titanium, zirconium, hafnium, rhodium, vanadium, osmium, palladium, platinum, nickel, lead, alloys, and mixtures thereof.

8. The capacitor of claim 1 wherein the tantalum particles have a hydrogen content of less than about 50 parts per million.

9. The capacitor of claim 1 wherein the tantalum particles comprise tantalum pentoxide.

10. The capacitor of claim 1 wherein the tantalum particles have a bulk density that ranges from about 1 g/cc to about 3 g/cc.

11. The capacitor of claim 1 wherein the tantalum particles have a surface area that ranges from about 0.3 m 2 /g to about 0.6 m 2 /g.

12. The capacitor of claim 1 wherein the tantalum particles have a substantially cylindrical shape.

13. The capacitor of claim 1 wherein the tantalum particles have a substantially monomial particle size distribution.

14. The capacitor of claim 1 wherein the tantalum particles have an elongated length and a curved cross section oriented substantially perpendicular to the elongated length.

15. A capacitor, which comprises:
a) a casing comprising first and second casing members secured to each other;
b) an anode comprising a plurality of tantalum particles having a substantially monomial particle size distribution with an average diameter that ranges from about 1.25 μm to about 3 μm, and an average length that ranges from about 5 μm to about 25 μm;
c) a cathode comprising a cathode active material;
d) a separator disposed between the anode and the cathode housed inside the casing; and
e) a working electrolyte contained within the casing and in physical contact with the cathode and the anode.

16. The capacitor of claim 15 wherein the tantalum particles have a bulk density that ranges from about 1 g/cc to about 3 g/cc.

17. The capacitor of claim 15 wherein the cathode active material comprises an oxide, a nitride, or a carbon nitride selected from the group of metals consisting of ruthenium, cobalt, manganese, molybdenum, tungsten, tantalum, iron, niobium, iridium, titanium, zirconium, hafnium, rhodium, vanadium, osmium, palladium, platinum, nickel, lead, alloys, and mixtures thereof.

18. The capacitor of claim 15 wherein the tantalum particles comprise tantalum pentoxide.

19. The capacitor of claim 15 wherein the tantalum particles have a surface area that ranges from about 0.3 m 2 /g to about 0.6 m 2 /g.

20. The capacitor of claim 15 wherein the tantalum particles have an average particle diameter that ranges from about 1.25 μm to about 1.75 μm, and an average particle length that ranges from about 10 μm to about 20 μm.

21. The capacitor of claim 15 wherein the tantalum particles have a substantially cylindrical shape.

22. The capacitor of claim 15 wherein the tantalum particles have an iron content of less than about 10 parts per million.

23. The capacitor of claim 15 wherein the tantalum particles have a hydrogen content of less than about 50 parts per million.

24. The capacitor of claim 15 wherein the tantalum particles have a bulk density that ranges from about 1 g/cc to about 3 g/cc.

25. A capacitor, which comprises:
a) a casing comprising first and second casing members secured to each other;
b) an anode comprising a plurality of tantalum particles, the tantalum particles having:
i) an average diameter that ranges from about 1.25 μm to about 3 μm;
ii) an average length that ranges from about 5 μm to about 25 μm;
iii) an iron content of less than about 10 parts per million; and
iv) a hydrogen content of less than about 50 parts per million;

c) a cathode comprising a cathode active material;
d) a separator disposed between the anode and the cathode housed inside the casing; and
e) a working electrolyte contained within the casing and in physical contact with the cathode and the anode.

26. The capacitor of claim 25 wherein the tantalum particles comprise tantalum pentoxide.

27. The capacitor of claim 25 wherein the tantalum particles have a surface area that ranges from about 0.3 m 2 /g to about 0.6 m 2 /g.

28. The capacitor of claim 25 wherein the tantalum particles have an average particle diameter that ranges from about 1.25 μm to about 1.75 μm, and an average particle length that ranges from about 10 μm to about 20 μm.

29. The capacitor of claim 25 wherein the tantalum particles have a substantially cylindrical particle shape.

Assignees

• Greatbatch Ltd
• Greatbach Ltd

Inventors

• Kaiser Donald F
• Thiebolt William C
• Hahl Jason T

Classifications

• B02C19/186 Primary

  Use of cold or heat for disintegrating (B02C4/44, B02C7/17, B02C11/08 take precedence) · CPC title

• H01G9/0029 Primary

  Processes of manufacture · CPC title

• H01G9/08

  Housing; Encapsulation · CPC title

• H01G9/052

  Sintered electrodes · CPC title

• H01G9/06

  Mounting in containers · CPC title