Working electrolyte for electrolytic capacitors

1. An electrolyte for a capacitor comprising: up to about 85%, by weight, water; up to about 65%, by weight organic solvent; an acid consisting essentially of Formula I:

HOOC—(CH 2 ) x —COOH  Formula I

wherein x is 3, 5, 7 or 9; and ammonium hydroxide.

2. The electrolyte for a capacitor of claim 1 wherein said electrolyte has a pH of about 4 to amount 9.

3. The electrolyte for a capacitor of claim 2 wherein said electrolyte has a pH of about 6 to about 8.

4. The electrolyte for a capacitor of claim 1 wherein said x is 5 or 7.

5. The electrolyte for a capacitor of claim 4 wherein said x is 7.

6. The electrolyte for a capacitor of claim 1 wherein said water represents at least about 30 to no more than about 70%, by weight, of said electrolyte.

7. The electrolyte for a capacitor of claim 1 wherein said organic solvent represents at least about 30 to no more than about 65%, by weight, of said electrolyte.

8. A capacitor comprising the electrolyte of claim 1 .

9. An electrolyte for a capacitor comprising:

up to about 85%, by weight, water;

up to about 65%, by weight, organic solvent;

an acid defined by Formula I:

HOOC—(CH 2 ) x —COOH  Formula I

wherein x is 3, 5, 7 or 9; and

ammonium hydroxide wherein said ammonium hydroxide is present in a molar amount of at least about 0.9 to no more than about 2.1 times the molar amount of said Formula I.

10. The electrolyte for a capacitor of claim 9 wherein said ammonium hydroxide is present in a molar amount of at least about 1.9 to no more than about 2.1 times the molar amount of said Formula I.

11. An electrolyte for a capacitor comprising:

up to about 85%, by weight, water;

up to about 65%, by weight, organic solvent;

an acid defined by Formula I:

HOOC—(CH 2 ) x —COOM  Formula I

wherein x is 3, 5, 7 or 9; and

ammonium hydroxide wherein said organic solvent is selected from a diol, a N-alkyl substituted amide and a lacitone.

12. The electrolyte for a capacitor of claim 11 wherein said organic solvent is selected from ethylene glycol; propylene glycol; 2-methyl, 1,3-propane diol; 4-butyrolactone and dimethyl formamide.

13. An electrolyte for a capacitor comprising:

up to about 85%, by weight, water;

up to about 65%, by weight, organic solvent; and

NH 4 OOC—(CH 2 ) x —COONH 4 wherein x is 3, 5, 7 or 9;

wherein said electrolyte is at a pH of about 4 to about 9.

14. The electrolyte for a capacitor of claim 13 with a pH of about 6 to about 8.

15. The electrolyte for a capacitor of claim 13 wherein said x is 5 or 7.

16. The electrolyte for a capacitor of claim 15 wherein said x is 7.

17. The electrolyte for a capacitor of claim 13 wherein said organic solvent is selected from a dial, a N-alkyl substituted amide and a lactone.

18. The electrolyte for a capacitor of claim 17 wherein said organic solvent is selected from ethylene glycol; propylene glycol; 2-methyl, 1,3-propane diol; 4-butyrolactone and dimethyl formamide.

19. The electrolyte for a capacitor of claim 13 wherein said water represents at least about 30 to about 70%, by weight, of said electrolyte.

20. The electrolyte for a capacitor of claim 13 wherein said organic solvent represents at least about 30 to about 65%, by weight, of said electrolyte.

21. The electrolyte for a capacitor of claim 13 wherein said NH 4 OOC—(CH 2 ) x —COONH 4 is formed in-situ by the reaction of an acid of formula HOOC—(CH 2 ) x —COOH and ammonium hydroxide.

22. A capacitor comprising the electrolyte of claim 13 .

23. A capacitor comprising an electrolyte wherein said electrolyte comprises:

about 30 to about 85%, by weight, water;

an organic solvent;

an acid defined by Formula I:

HOOC—(CH 2 ) x —COOH  Formula I

wherein x is 3, 5, 7 or 9; and

ammoniurn hydroxide; and

wherein said electrolyte has a pH of about 4 to about 9.

24. The capacitor of claim 23 with a pH of about 6 to about 8.

25. The capacitor of claim 23 wherein said 4 is 5 or 7.

26. The capacitor of claim 25 wherein said x is 7.

27. The capacitor of claim 23 comprising about 15 to about 65%, by weight, said organic solvent.

28. The capacitor of claim 23 comprising about 30 to about 65%, by weight, said water.

29. A capacitor comprising an electrolyte wherein said electrolyte comprises:

about 30 to about 85%, by weight, water;

an organic solvent;

an acid defined by Formula I:

HOOC—(CH 2 ) x —COOH  Formula I

wherein x is 3, 5, 7 or 9; and

ammonium hydroxide; and

wherein said electrolyte has a pH of about 4 to about 9 wherein said ammonium hydroxide is present in a molar amount of at least about 0.9 to no more than about 2.1 times the molar amount of said Formula I.

30. The capacitor of claim 29 wherein said ammonium hydroxide is present in an molar amount of at least about 1.9 to no more than about 2.1 times the molar amount of said Formula I.

31. A capacitor comprising an electrolyte wherein said electrolyte comprises:

about 30 to about 85%, by weight, water;

an organic solvent;

an acid defined by Formula I:

HOOC— (CH 2 ) x —COOH  Formula I

wherein x is 3, 5, 7 or 9; and

ammonium hydroxide; and

wherein said electrolyte has a pH of about 4 to about 9 wherein said organic solvent is selected from a diol, a N-alkyl substituted amide and a lactone.

32. The capacitor of claim 31 wherein said organic solvent is selected from ethylene glycol; propylene glycol; 2-methyl, 1,3-propane diol; 4-butyrolactone and dimethyl formamide.

33. An electrolyte for a capacitor comprising:

up to about 85%, by weight, water;

up to about 65%, by weight organic solvent;

an acid defined by Formula I:

HOOC— (CH 2 ) x —COOH  Formula I

wherein x is 3, 5, 7 or 9; and

ammonium hydroxide; wherein said electrolyte does not expand upon freezing and no precipitate remains upon thawing.

34. The electrolyte for a capacitor of claim 33 wherein said electrolyte has a pH of about 4 to about 9.

35. The electrolyte for a capacitor of claim 34 wherein said electrolyte has a pH of about 6 to about 8.

36. The electrolyte for a capacitor of claim 33 wherein said x is 5 or 7.

37. The electrolyte for a capacitor of claim 36 wherein said x is 7.

38. The electrolyte for a capacitor of claim 33 wherein said ammonium hydroxide is present in a molar amount of at least about 0.9 to no more than about 2.1 times the molar amount of said Formula I.

39. The electrolyte for a capacitor of claim 38 wherein said ammonium hydroxide is present in a molar amount of at least about 1.9 to no more than about 2.1 times the molar amount of said Formula I.

40. The electrolyte for a capacitor of claim 33 wherein said organic solvent is selected from a diol, a N-alkyl substituted amide and a lactone.

41. The electrolyte for a capacitor of claim 40 wherein said organic solvent is selected from ethylene glycol; propylene glycol; 2-methyl, 1,3-propane diol; 4-butyrolactone and dimethyl formamide.

42. The electrolyte for a capacitor of claim 33 wherein said water represents at least about 30 to no more than about 70%, by weight, of said electrolyte.

43. The electrolyte for a capacitor of claim 33 wherein said organic solvent represents at least about 30 to no more than about 65%, by weight, of said electrolyte.

44. A capacitor comprising the electrolyte of claim 33 .

45. An electrolyte for a capacitor comprising:

from 30% up to about 85%, by weight, water; up to about 65%, by weight organic solvent; a compound defined by Formula I:

ROOC—(CH 2 ) x —COOR  Formula I

wherein R is selected from H + and NH 4 + ;

wherein x is 3, 5, 7 or 9;

wherein said electrolyte is at a pH Qf about 4 to about 9; and

said electrolyte does not contain benzoic acid.