CA1086047A - Electrolyte for electrical device - Google Patents
Electrolyte for electrical deviceInfo
- Publication number
- CA1086047A CA1086047A CA262,135A CA262135A CA1086047A CA 1086047 A CA1086047 A CA 1086047A CA 262135 A CA262135 A CA 262135A CA 1086047 A CA1086047 A CA 1086047A
- Authority
- CA
- Canada
- Prior art keywords
- electrolyte
- azeotropic composition
- capacitors
- present
- dimethylformamide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000003792 electrolyte Substances 0.000 title claims abstract description 48
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims abstract description 46
- 239000000203 mixture Substances 0.000 claims abstract description 27
- 239000003990 capacitor Substances 0.000 claims abstract description 26
- 239000002904 solvent Substances 0.000 claims abstract description 13
- 238000009835 boiling Methods 0.000 claims abstract description 5
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical group CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 claims description 18
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 12
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 239000000306 component Substances 0.000 abstract description 7
- 239000000126 substance Substances 0.000 description 3
- ATHHXGZTWNVVOU-UHFFFAOYSA-N N-methylformamide Chemical compound CNC=O ATHHXGZTWNVVOU-UHFFFAOYSA-N 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- PMDCZENCAXMSOU-UHFFFAOYSA-N N-ethylacetamide Chemical compound CCNC(C)=O PMDCZENCAXMSOU-UHFFFAOYSA-N 0.000 description 1
- ZWZCDSDLYBMYLO-UHFFFAOYSA-N OB(O)O.OB(O)O.OB(O)O.OB(O)O.OB(O)O.OCCO.N.N.N.N.N.N.N.N.N.N.N.N.N.N.N.O Chemical compound OB(O)O.OB(O)O.OB(O)O.OB(O)O.OB(O)O.OCCO.N.N.N.N.N.N.N.N.N.N.N.N.N.N.N.O ZWZCDSDLYBMYLO-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000012442 inert solvent Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- INHDSJSGMCZSHA-UHFFFAOYSA-N n,n-bis(5-methyl-2-propan-2-ylcyclohexyl)formamide Chemical compound CC(C)C1CCC(C)CC1N(C=O)C1C(C(C)C)CCC(C)C1 INHDSJSGMCZSHA-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
- H01G9/004—Details
- H01G9/022—Electrolytes; Absorbents
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Electric Double-Layer Capacitors Or The Like (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
Abstract
Abstract of the Disclosure An electrolyte adapted for use in an electrical device such as a capacitor comprising an azeotropic composition of at least two com-ponents, the azeotropic composition having a boiling point higher than the pure components, and a solvent of dimethylformamide or its homo-logues.
Description
~ 60~7 : ' The present invention relates to el ectrolytes for electrolytic devices such as electrolytic aluminum capacitors, and more particularly to electrolytes containing an azeotropic composition of at least two components with a solvent of dimethylformamide or its homologues.
- In applicant's prior patents, U. S. 3,539,881, U. S. 3,670,212 and U. S. 3,812,038, it was recognized that zerotropic compositions having a boiling point higher than the pure components, alone or in a certain inert solvent, were useful as capacitor electrolytes because of their operability over a wide temperature range and good shelf li-fe.
In patents 3,670,212 and 3,812,038, the solvents disclosed for the azeotropic compositions included ketones, ethers, alcohols, esters and mixtures thereof. It was considered during the course oF work concerning the above electrolytes that dimethylformamide and its homoloyues would be unsuitable as a solvent for these azeotropic compositions because the polar and basic nature of dimethylformamide and its homologues would make the electrolyte unstable.
Surprisingly, however, it has been found that electrolytes of ~ an azeotropic composition in a solvent of dimethylformamide or its ; analogs have good life test stability and improved capacitor character-istics at low temperatures, that is, below 0C.
It is, therefore, a feature of the present invention to provide an electrolyte of an azeotropic composition and a solvent of dimethyl-formamide or its homologues. Another feature of the present invention ls that the electrolyte has good life test stability. Yet another Feature is that the electrolyte has improved characteristics at low temperatures. These and various other features of this invention will become more fully apparent -from a detailed consideration of the remainder of this disclosure including the examples and the appended claims.
~` 30 ~' ~
`~,`?
According to the aforementioned feature, from a broad aspect, the present invention provides an electrolyte consisting essentially of about 5 wt.% to about 95 wt.% of an azeotropic composition of a liquid organic acidic material and a liquid organic basic material. The azeotropic composi-tion has a boiling point higher than that of its pure compo-nents. The electrolyte also comprises a solvent consisting essentially of dimethylformamide.
- la -,,,~,i~ ,. :
.
Generally, the present invention relates to an electrolyte adapted for use in electrical devices such as electrolytic capacitors, the electrolyte containing an azeotropic composition of at least two components, the composition having a boiling point higher than the pure components, and a solvent of dimethylformamide or one of its homologues.
Suitable azeotropic compositions are given in U. S. patents 3,539,881, 3,670,212 and 3,812,038. The azeotropic composition may be binary or ternary. The solvent is selected from dimethylformamide or one of its homologues which include dimethylacetamide, N-methylformamide, di-10 ethylacetamide and the like. Mixtures of these solvents may also be used.The electrolyte of the present invention may contain from about 5 wt. %
to about 95 wt. ~ azeotropic composition, the remainder solvent. The preferred electrolyte contains the azeotropic composition in amounts from about 5 wt. % to about 50 wt. % of the electrolyte. The presently QGa;~
preferred electrolyte contains an azeotropic composition of ;ICi~iC ~cl~
and triethylamine and a solvent of dimethylformamide. The most pre-Ferred electrolyte contains about 25 wt. % of the azeotrope oF ~ acid and triethylamine and the remainder dimethylformamide.
While the electrolyte of the present invention primarily consists 20 of the above constituents, the electrolyte may also contain certain other substances, for example, water in small amounts, without adversely aFfecting the characteristics of the electrolyte. These other substances may be present as impurities in the major constituents of the electrolyte and thus the present lnvention comprehends the presence of such substances in the electrolyte.
The electrolyte of the present invention is particularly adapted For use in aluminum type electrolytic capacitors although its use is not limi ted thereto. Aluminum type capacitors generally comprise aluminum electrode foils in a rolled or stacked configuration enclosed
- In applicant's prior patents, U. S. 3,539,881, U. S. 3,670,212 and U. S. 3,812,038, it was recognized that zerotropic compositions having a boiling point higher than the pure components, alone or in a certain inert solvent, were useful as capacitor electrolytes because of their operability over a wide temperature range and good shelf li-fe.
In patents 3,670,212 and 3,812,038, the solvents disclosed for the azeotropic compositions included ketones, ethers, alcohols, esters and mixtures thereof. It was considered during the course oF work concerning the above electrolytes that dimethylformamide and its homoloyues would be unsuitable as a solvent for these azeotropic compositions because the polar and basic nature of dimethylformamide and its homologues would make the electrolyte unstable.
Surprisingly, however, it has been found that electrolytes of ~ an azeotropic composition in a solvent of dimethylformamide or its ; analogs have good life test stability and improved capacitor character-istics at low temperatures, that is, below 0C.
It is, therefore, a feature of the present invention to provide an electrolyte of an azeotropic composition and a solvent of dimethyl-formamide or its homologues. Another feature of the present invention ls that the electrolyte has good life test stability. Yet another Feature is that the electrolyte has improved characteristics at low temperatures. These and various other features of this invention will become more fully apparent -from a detailed consideration of the remainder of this disclosure including the examples and the appended claims.
~` 30 ~' ~
`~,`?
According to the aforementioned feature, from a broad aspect, the present invention provides an electrolyte consisting essentially of about 5 wt.% to about 95 wt.% of an azeotropic composition of a liquid organic acidic material and a liquid organic basic material. The azeotropic composi-tion has a boiling point higher than that of its pure compo-nents. The electrolyte also comprises a solvent consisting essentially of dimethylformamide.
- la -,,,~,i~ ,. :
.
Generally, the present invention relates to an electrolyte adapted for use in electrical devices such as electrolytic capacitors, the electrolyte containing an azeotropic composition of at least two components, the composition having a boiling point higher than the pure components, and a solvent of dimethylformamide or one of its homologues.
Suitable azeotropic compositions are given in U. S. patents 3,539,881, 3,670,212 and 3,812,038. The azeotropic composition may be binary or ternary. The solvent is selected from dimethylformamide or one of its homologues which include dimethylacetamide, N-methylformamide, di-10 ethylacetamide and the like. Mixtures of these solvents may also be used.The electrolyte of the present invention may contain from about 5 wt. %
to about 95 wt. ~ azeotropic composition, the remainder solvent. The preferred electrolyte contains the azeotropic composition in amounts from about 5 wt. % to about 50 wt. % of the electrolyte. The presently QGa;~
preferred electrolyte contains an azeotropic composition of ;ICi~iC ~cl~
and triethylamine and a solvent of dimethylformamide. The most pre-Ferred electrolyte contains about 25 wt. % of the azeotrope oF ~ acid and triethylamine and the remainder dimethylformamide.
While the electrolyte of the present invention primarily consists 20 of the above constituents, the electrolyte may also contain certain other substances, for example, water in small amounts, without adversely aFfecting the characteristics of the electrolyte. These other substances may be present as impurities in the major constituents of the electrolyte and thus the present lnvention comprehends the presence of such substances in the electrolyte.
The electrolyte of the present invention is particularly adapted For use in aluminum type electrolytic capacitors although its use is not limi ted thereto. Aluminum type capacitors generally comprise aluminum electrode foils in a rolled or stacked configuration enclosed
-2-'. ' . ..
: in a housing and contacted by an electrolyte.
Aluminum electrolytic capacitors containing electrolytes of the present invention are characterized as having good life test sta-bility and improved characteristics at low temperatures as compared to a conventional electrolyte as the test data presented in the following example will illustrate. `'It should be understood that the example is given for the purposes of illustration only and the example is not intended to limit the invention as has heretofore been described.
EXAMPLE
Five three inch, twenty-five volt computer grade capacitors are assembled, each capacitor having a different electrolyte. One capacitor contains a conventional ammonium pentaborate ethylene glycol-water electrolyte, another an electrolyte of the azeotropic composition of triethylamine and acetic acid, and three containing the electrolyte of the present invention which includes the azeotropic composition of triethylamine and acetic acid in varying amounts of dimenthylformamide.
(DMF). For these electrolytes, the vol. % DMF is approximately equal to the wt.% DMF. The five capacitors are tested at about 85C For about 1500 hrs to determine life characteristics. The quantities measured are capacity of the capacitor in microfarads (uf), the equivalent series resistance (ESR) in ohms and the leakage current (IDC) in milliamperes.
The results are as follows;
Electrolyte Initial Final DMF Capacity ESR IDcCapacity ESR IDc Type (vol %) (~f) (~L) (milliamps) (,uf) (n) (milliamps~
Glycol-borate ---- 57250 .0088 .27 56230 .0098 .12 A~eotrope O 56250 .0132 .26 57230 .0108 .15 " 5 55150 .0098 .55 54630 .0104 .15 54900 .0092 .39 54550 .0093 .14 Il 20 55200 .0090 .38 5~325 .0086 .12 As the above table indicates, capacitors containing the electrolytes of the present invention did not experience significant ~ 6;04~7 degradation of electrical character;stics after about 1500 hrs at about 85C and give comparable results with conventional electrolytes in the same type of capacitors.
In another test, the same type of capacitors are tested for stability of electrical characteristics when subjected to low tempera-tures. The electrical characteristics of the capacitors are measured at room temperature (about 22C) and again at about -30C. The quantities measured at each temperature are capacity of the capacitor in microfarads (uf) and the equivalent series resistance in ohms. The results are as follows:
Electrol te 22C -30C
Y
DMF Capacity ESR Capacity ESR ~ Capacity (vol %) (~f) (Q) (~f) ~) (%) Glycol-borate ---- 56750 .008836250 .089 36 Azeotrope 0 55920 .011834250 .157 39 " . 5 54230 .010041900 .087 23 ". 10 54930 .009345830 .066 17 " 20 55800 .009048600 .040 13 As the above table indicates, capacitors contaihing the.
electrolyte of the present invention have significantly better elec-trical.characteristics at low temperatures than capacitors containingconventional elect.rolytes. The average loss of capacity at a low temperature for capacitors containing electrolytes of the present in-vention is approximately half that experienced by the capacitors con-taining conventional electrolytes.
Thus, the electrolytes of the present invention, when utilized in capacitors, provide comparable life test performance when compared with conventional type electrolytes and have significantly better elec-trical characteristics at low temperatures.
. While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous 604~7 modifica~ions may be made by those skilled in the art without actually departing from the spirit and scope of the invention as defined in the appended claims.
, ; ~.
: in a housing and contacted by an electrolyte.
Aluminum electrolytic capacitors containing electrolytes of the present invention are characterized as having good life test sta-bility and improved characteristics at low temperatures as compared to a conventional electrolyte as the test data presented in the following example will illustrate. `'It should be understood that the example is given for the purposes of illustration only and the example is not intended to limit the invention as has heretofore been described.
EXAMPLE
Five three inch, twenty-five volt computer grade capacitors are assembled, each capacitor having a different electrolyte. One capacitor contains a conventional ammonium pentaborate ethylene glycol-water electrolyte, another an electrolyte of the azeotropic composition of triethylamine and acetic acid, and three containing the electrolyte of the present invention which includes the azeotropic composition of triethylamine and acetic acid in varying amounts of dimenthylformamide.
(DMF). For these electrolytes, the vol. % DMF is approximately equal to the wt.% DMF. The five capacitors are tested at about 85C For about 1500 hrs to determine life characteristics. The quantities measured are capacity of the capacitor in microfarads (uf), the equivalent series resistance (ESR) in ohms and the leakage current (IDC) in milliamperes.
The results are as follows;
Electrolyte Initial Final DMF Capacity ESR IDcCapacity ESR IDc Type (vol %) (~f) (~L) (milliamps) (,uf) (n) (milliamps~
Glycol-borate ---- 57250 .0088 .27 56230 .0098 .12 A~eotrope O 56250 .0132 .26 57230 .0108 .15 " 5 55150 .0098 .55 54630 .0104 .15 54900 .0092 .39 54550 .0093 .14 Il 20 55200 .0090 .38 5~325 .0086 .12 As the above table indicates, capacitors containing the electrolytes of the present invention did not experience significant ~ 6;04~7 degradation of electrical character;stics after about 1500 hrs at about 85C and give comparable results with conventional electrolytes in the same type of capacitors.
In another test, the same type of capacitors are tested for stability of electrical characteristics when subjected to low tempera-tures. The electrical characteristics of the capacitors are measured at room temperature (about 22C) and again at about -30C. The quantities measured at each temperature are capacity of the capacitor in microfarads (uf) and the equivalent series resistance in ohms. The results are as follows:
Electrol te 22C -30C
Y
DMF Capacity ESR Capacity ESR ~ Capacity (vol %) (~f) (Q) (~f) ~) (%) Glycol-borate ---- 56750 .008836250 .089 36 Azeotrope 0 55920 .011834250 .157 39 " . 5 54230 .010041900 .087 23 ". 10 54930 .009345830 .066 17 " 20 55800 .009048600 .040 13 As the above table indicates, capacitors contaihing the.
electrolyte of the present invention have significantly better elec-trical.characteristics at low temperatures than capacitors containingconventional elect.rolytes. The average loss of capacity at a low temperature for capacitors containing electrolytes of the present in-vention is approximately half that experienced by the capacitors con-taining conventional electrolytes.
Thus, the electrolytes of the present invention, when utilized in capacitors, provide comparable life test performance when compared with conventional type electrolytes and have significantly better elec-trical characteristics at low temperatures.
. While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous 604~7 modifica~ions may be made by those skilled in the art without actually departing from the spirit and scope of the invention as defined in the appended claims.
, ; ~.
Claims (6)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electrolyte consisting essentially of about 5 wt. % to about 95 wt. % of an azeotropic composition of triethylamine and acetic acid, the azeotropic composition having a boiling point higher than that of its pure components, and a solvent consisting essentially of dimethylformamide.
2. An electrolyte according to claim 1 wherein said azeotropic composition is in an amount of about 5 wt. % to 50 wt. % of said electrolyte.
3. An electrolyte according to claim 2 wherein said azeotropic composition is an amount of about 25 wt. % of said electrolyte.
4. An electrolytic capacitor containing aluminum electrodes and the electrolyte of claim 1.
5. The electrolytic capacitor of claim 4 wherein said azeotropic composition is triethylamine and acetic acid.
6. The electrolytic capacitor of claim 5 wherein said azeotropic composition is in an amount of from about 5 wt. % to about 50 wt. %
of said electrolyte.
of said electrolyte.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62178875A | 1975-10-14 | 1975-10-14 | |
| US621,788 | 1975-10-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1086047A true CA1086047A (en) | 1980-09-23 |
Family
ID=24491644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA262,135A Expired CA1086047A (en) | 1975-10-14 | 1976-09-27 | Electrolyte for electrical device |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5250556A (en) |
| BR (1) | BR7606761A (en) |
| CA (1) | CA1086047A (en) |
| DE (1) | DE2646500A1 (en) |
| GB (1) | GB1526878A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4479167A (en) * | 1983-08-01 | 1984-10-23 | Sprague Electric Company | Electrolytic capacitor |
-
1976
- 1976-09-27 CA CA262,135A patent/CA1086047A/en not_active Expired
- 1976-10-08 BR BR7606761A patent/BR7606761A/en unknown
- 1976-10-12 GB GB4238776A patent/GB1526878A/en not_active Expired
- 1976-10-14 JP JP12339976A patent/JPS5250556A/en active Pending
- 1976-10-14 DE DE19762646500 patent/DE2646500A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| BR7606761A (en) | 1977-08-30 |
| DE2646500A1 (en) | 1977-04-21 |
| GB1526878A (en) | 1978-10-04 |
| JPS5250556A (en) | 1977-04-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |