GB2032679A - Improvements in or relating to electrical button cells - Google Patents
Improvements in or relating to electrical button cells Download PDFInfo
- Publication number
- GB2032679A GB2032679A GB7841972A GB7841972A GB2032679A GB 2032679 A GB2032679 A GB 2032679A GB 7841972 A GB7841972 A GB 7841972A GB 7841972 A GB7841972 A GB 7841972A GB 2032679 A GB2032679 A GB 2032679A
- Authority
- GB
- United Kingdom
- Prior art keywords
- cap
- channel
- cell
- casing
- sealing ring
- 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.)
- Granted
Links
- 238000007789 sealing Methods 0.000 claims abstract description 48
- 239000003792 electrolyte Substances 0.000 claims abstract description 22
- 239000010406 cathode material Substances 0.000 claims abstract description 7
- 239000010405 anode material Substances 0.000 claims abstract description 5
- 238000002788 crimping Methods 0.000 claims description 22
- 239000000463 material Substances 0.000 claims description 15
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 7
- 229910001923 silver oxide Inorganic materials 0.000 claims description 7
- 239000004020 conductor Substances 0.000 claims description 5
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052748 manganese Inorganic materials 0.000 claims description 2
- 239000011572 manganese Substances 0.000 claims description 2
- 229940101209 mercuric oxide Drugs 0.000 claims description 2
- UKWHYYKOEPRTIC-UHFFFAOYSA-N mercury(II) oxide Inorganic materials [Hg]=O UKWHYYKOEPRTIC-UHFFFAOYSA-N 0.000 claims description 2
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 230000006835 compression Effects 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 239000004677 Nylon Substances 0.000 description 3
- 238000011109 contamination Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229920001778 nylon Polymers 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 229920003023 plastic Polymers 0.000 description 3
- 239000003566 sealing material Substances 0.000 description 3
- 229910000497 Amalgam Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 2
- 239000002250 absorbent Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000000806 elastomer Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- OTCVAHKKMMUFAY-UHFFFAOYSA-N oxosilver Chemical compound [Ag]=O OTCVAHKKMMUFAY-UHFFFAOYSA-N 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- HQQADJVZYDDRJT-UHFFFAOYSA-N ethene;prop-1-ene Chemical group C=C.CC=C HQQADJVZYDDRJT-UHFFFAOYSA-N 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 229920000554 ionomer Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/10—Primary casings; Jackets or wrappings
- H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
- H01M50/109—Primary casings; Jackets or wrappings characterised by their shape or physical structure of button or coin shape
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/10—Primary casings; Jackets or wrappings
- H01M50/183—Sealing members
- H01M50/184—Sealing members characterised by their shape or structure
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/10—Primary casings; Jackets or wrappings
- H01M50/183—Sealing members
- H01M50/186—Sealing members characterised by the disposition of the sealing members
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/10—Primary casings; Jackets or wrappings
- H01M50/183—Sealing members
- H01M50/19—Sealing members characterised by the material
- H01M50/193—Organic material
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Primary Cells (AREA)
- Sealing Battery Cases Or Jackets (AREA)
Abstract
An electrical button type cell comprises a casing 11 and a cap 15. The cap 15 has an annular channel 18 which is crimped to grip a non-conducting sealing ring 19, while leaving a narrow opening around the channel, before assembly in the casing. The cap 15 is then sealed into position in the casing with a further non-conducting sealing device 22. The casing contains cathode material 12, anode material 16 and an alkaline electrolyte. <IMAGE>
Description
SPECIFICATION
Improvements in or relating to electrical button cells
The invention relates to electrical cells of the button type and particularly to such cells incorporating an alkaline electrolyte.
Electrical cells of the button type comprise an electrical casing into which is sealed an electrically conducting cap member. A common manufacturing problem is to prevent leakage between the casing and the cap.
Commonly, the cap provides the anode current collector of the cell and the casing provides the cathode current collector. The leakage which is most difficult to prevent is that which occurs by creepage along the metal surface of the anode current collector. It has previously been proposed to compress a pliant gasket between the cap and the casing but it is particularly difficult to obtain a satisfactory seal which remains effective over a long period of time. Difficulties in providing an effective seal arise from several reasons. If the areas to be sealed are contaminated with electrolyte during the battery assembly process before crimping to apply sealing pressure occurs, creepage of the electrolyte is likely to remain continuous regardless of the crimping load due to the tendency of electrolyte to leak along the conducting surface of the anode current collector.Furthermore, variations in the position of the sealing edge of the cap relative to the casing due to manufacturing tolerances can affect the sealing load during a crimping operation and thereby restrict the sealing force that can be applied. Furthermore, difficulties occur in selecting suitable sealing material for the pliable gasket. The gasket should be sufficiently pliable to flow and fill any surface irregularities but unless flow of the material can be constrained, compression stresses remaining after a crimping operation will be low. Increase of the compression during crimping will simply increase the flow of the material until rupture occurs.
Furthermore, creepage of the gasket material will occur over a period of time reducing the compression and thereby the efficiency of the seal. If materials are used which are harder and creep resistant, they are capable of maintaining a high compression stress over a longer period but they are less pliable and therefore less able to flow and fill surface irregularities to achieve a good static seal.
It is an object of the present invention to provide an improved seal between a cap and casing of such a button type electrical cell.
The present invention provides an electrical button type cell comprising an electrically conducting casing containing cathode material, a cap containing anode material and an alkaline electrolyte, the cap being sealed in position in the casing and including an annular channel around the cap, the channel containing a sealing ring of deformable non-conducting material resistant to the electrolyte and the channel being crimped to compress the sealing ring, while leaving a narrow opening in the channel, to form a seal within the channel before assembly of the cap in position in the casing.
The invention also includes a method of providing a seal between a cap and casing of an electrical button type cell incorporating an alkaline electrolyte, which method comprises forming an annular channel around the cap, locating within said channel a sealing ring of deformable non-conducting material resistant to the alkaline electrolyte, applying crimping pressure to the channel to compress the sealing ring within the channel and thereby form a seal within the channel while leaving an opening between an outer edge of the channel and the remainder of the cap, and subsequently locating the cap in a casing for the cell and forming a seal between the cap and the casing.
By locating the sealing ring in a channel around the cap and applying crimping pressure before assembling the cap in the casing, it is possible to provide a good seal within the channel without risk of electrolyte contamination of the seal areas. Furthermore, by crimping the cell cap as a separate operation before assembly, close control of the crimping operation is possible resulting in a tight effective seal and the sealing material to which the crimping pressure is applied is captured within the channel so that a high compressive stress may be retained without substantial loss of sealing pressure with time.
The sealing ring may be formed of circular cross section. Alternatively the sealing ring may be formed with a rectangular cross section.
The sealing ring may be formed of an elastomer or a non-resilient plastics material.
The invention is particularly applicable to button cells of the silver oxide type. It is also applicable to mercuric oxide cells or alkaline manganese cells.
Conveniently, he casing may be formed of nickel plated steel. The cap may conveniently be made of stainless steel with a copper laminate on an inside surface of the cap.
In a silver oxide cell, the casing may contain silver oxide cathode material. Conveniently, the electrolyte is contained in an absorbent pad impregnated with potassium hydroxide or sodium hydroxide as the electrolyte.
In a preferred embodiment, a separator is located between the cathode material and the pad containing the electrolyte.
In a silver oxide cell, the anode material may conveniently comprise zinc together with mercury amalgam.
Preferably the channel surrounding the cap is formed integrally with the cap and com prises a U-shape channel prior to crimping.
Preferably the crimping operation is arranged to deform the outer wall of the channel so that it projects towards the remainder of the cap compressing the sealing ring without touching the remainder of the cap.
When assembled in the casing, a further non-conducting sealing means is located between the cap and the casing. This further sealing means may comprise a material, such as nylon, which is harder than the material used for the aforesaid sealing ring. Preferably the casing has an upper wall which is crimped in the assembled cell to apply sealing pressure to the sealing means between the cap and the casing.
One embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which Figure 1 shows a section through one embodiment of a button cell in accordance with the present invention,
Figure 2 is a section through a second embodiment of a button cell in accordance with the present invention,
Figure 3 shows a cap and sealing member used in the embodiment of Fig. 2,
Figure 4 shows a cap member prior to assembly with a sealing ring,
Figure 5 is a section through one embodiment of a sealing ring for use in the invention,
Figure 6 is a similar section through an alternative sealing ring for use in accordance with the invention, and
Figure 7 is a section through a cap member having a sealing ring secured in position prior to assembly into a battery casing.
The button cell shown in Figs. 1 and 2 comprises a silver oxide alkaline button cell.
In each case, the cell comprises an outer casing 11 formed of nickel plated steel and containing silver oxide cathode material 12. A separator 13 separates the cathode material 12 from an absorbent pad 14 impregnated with electrolyte in the form of potassium hydroxide or sodium hydroxide. The cell includes a cap 15 containing anode material 16 in the form of zinc together with some mercury amalgam. The cap 15 is formed of stainless steel with a copper laminate on the inner surface of the cap.
The manner of forming the cap will now be described with reference to Figs. 4 to 7. The cap 15 is pressed to the shape shown in Fig.
4 such that it is surrounded by an annular channel 18 of U-shape. A sealing ring 19 which may be of circular cross-section as shown in Fig. 5 or rectangular cross section as shown in Fig. 6 is located in the annular channel 18. A crimping operation is then carried out to deform the channel as shown in
Fig. 7 so as to apply a compressive stress to the sealing ring 19. The outer wall 9 of the channel is bent to a position where it projects towards the remainder of the cap 15 while retaining a small gap 20 between the outer wall 9 and the remainder of the cap. In this way, any electrolyte which tends to creep along the wall of the cap has to pass around the interior of the channel 19 if it is to reach the exterior of the cap while remaining in contact with the electrically conducting surface.The sealing ring 19 is formed of a pliable non-conducting material which is resistant to the electrolyte used in the cell and suitable materials include polythene, ionomer
E.V.A., P.V.C. and polypropylene. The crimping operation is arranged to apply a high compressive stress to the sealing ring and yet the gap 20 is sufficiently narrow to prevent extrusion of the sealing ring. As the crimping operation is carried out against the metal surface of the remainder of the cap, it is possible to achieve close dimensional control of the crimped dimensions in profile. By carrying out the crimping operation prior to assembly in the remainder of the cell, there is no risk of any electrolyte contamination in the seal areas between the ring 19 and the metal of the cap.
Once the crimping operation has been carried out to achieve the product shown in Fig.
7, the cap together with the sealing ring is sealed into position in the casing in two alternative ways which will now be discussed with reference to Figs. 1 and 2.
In the arrangement shown in Fig. 1, the cap assembly shown in Fig. 7 is fitted into an
L-shaped gasket 22 formed of creep resistant non-conducting material such as nylon. The upper wall of the casing is then crimped so as to apply high compressive stress to the gasket 22 which covers the opening 20 in the channel around the cap 15 and thereby prevents long term creepage of the sealing ring 19 through the opening 20. As the gasket 22 is formed of material having long term resistance to creep, it is capable of maintaining this high compressive stress for long periods of battery life.
In the alternative arrangement shown in
Figs. 2 and 3, the assembly shown in Fig. 7 is overmoulded with a creep resistant gasket formed of material such as nylon and indicated by the reference numeral 25 in Fig. 3.
This overmoulded assembly shown in Fig. 3 is then located into the battery casing as previously described with reference to Fig. 1 and the outer wall of the casing is crimped to produce the results shown in Fig. 2. A spacer 26 is located in the casing prior to location of the cap assembly so as to achieve the desired battery height. The effect of crimping the casing onto the gasket 25 is similar to that already described with reference to Fig. 1.
In the particular examples described above, the sealing ring 19 may conveniently be formed of an elastomer such as nitrile rubber or ethylene propylene or of a plastics material.
In all cases, the crimping of the cap channel 18 onto the sealing ring 19 is carried out as a separate operation prior to assembly with the rest of the cell so that this sealing operation is carried out without risk of contamination or wetting by the electrolyte or other constituents of the cell.
Furthermore, in the completed cell, the overall seal between the cap and the casing is achieved by use of two different sealing materials, one forming the sealing ring and the other forming the gasket 22 or 25. By the use of two plastic materials which may have different resilience or creep properties, the best overall seal may be achieved.
The invention is not limited to the details of the foregoing example.
Claims (12)
1. An electrical button type cell comprising an electrically conducting casing containing cathode material, an electrically conducting cap, anode material and an alkaline electrolyte, the cap being sealed in position in the casing and including an annular channel around the cap, the channel containing a sealing ring of deformable non-electrically conducting material resistant to the electrolyte and the channel being crimped to compress the sealing ring and thereby form a seal within the channel, while leaving a narrow opening in the channel, between an outer edge of the channel and the remainder of the cap.
2. A cell according to claim 1 in which the channel surrounding the cap is formed integrally with the cap and comprises a U-shape channel prior to crimping.
3. A cell according to claim 2 in which the outer wall of the channel is deformed by crimping so that it projects towards the remainder of the cap compressing the sealing ring without touching the remainder of the cap.
4. A cell according to any one of claims 1 to 3 in which a further non-electrically conducting sealing means is located between the cap and the casing.
5. A cell according to claim 4 in which said further sealing means comprises a material which is harder than the material used for the said sealing ring.
6. A cell according to claim 4 or claim 5 in which the casing has an upper wall which is crimped in the assembled cell to apply sealing pressure to the sealing means between the cap and the casing.
7. A cell according to any one of the preceding claims in which the cell is of the silver oxide type.
8. A cell according to any one of claims 1 to 7 in which the cell is a mercuric oxide cell.
9. A cell according to any one of claims 1 to 7 in which the cell is an alkaline manganese cell.
10. A method of providing a seal between a cap and casing of an electrical button type cell incorporating an alkaline electrolyte, which method comprises forming an annular channel around the cap, locating within said channel a sealing ring of deformable nonconducting material resistant to the alkaline electrolyte, applying crimping pressure to the channel to compress the sealing ring within the channel and thereby form a seal within the channel while leaving an opening between an outer edge of the channel and the remainder of the cap, and subsequently locating the cap in a casing for the cell and forming a seal between the cap and the casing.
11. An electrical button type cell substantially as hereinbefore described with reference to Fig. 1 or Figs. 2 and 3, of the accompanying drawings.
12. A method of sealing an electrical button type cell which method is substantially as hereinbefore described with reference to Fig.
1 or Figs. 2 and 3, and Fig. 4 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7841972A GB2032679B (en) | 1978-10-26 | 1978-10-26 | Electrical button cells |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7841972A GB2032679B (en) | 1978-10-26 | 1978-10-26 | Electrical button cells |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2032679A true GB2032679A (en) | 1980-05-08 |
| GB2032679B GB2032679B (en) | 1982-08-18 |
Family
ID=10500587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7841972A Expired GB2032679B (en) | 1978-10-26 | 1978-10-26 | Electrical button cells |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2032679B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2154049A (en) * | 1984-02-09 | 1985-08-29 | Venture Tech Ltd | Electrochemical cell |
| GB2154786A (en) * | 1984-02-20 | 1985-09-11 | Renata Ag | Single-cell gas-tight primary battery |
-
1978
- 1978-10-26 GB GB7841972A patent/GB2032679B/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2154049A (en) * | 1984-02-09 | 1985-08-29 | Venture Tech Ltd | Electrochemical cell |
| GB2154786A (en) * | 1984-02-20 | 1985-09-11 | Renata Ag | Single-cell gas-tight primary battery |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2032679B (en) | 1982-08-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |