KR800001600B1 - Terminal assembley for an electrochemical device - Google Patents

Abstract

Connecting piece for an electrochemical device having a metallic container contg. an alkaline electolyte, has an electrically conducting part lying on the inner surface of a wall of the container over an opening(14), an electrical insulation with an opening(36) between the contacting part and the inner surface of the wall. The opening (36) is aligned with the opening(14) in the wall and thin layers of an adhesive sealing material, witch is not wetted by the alkaline electrolyte, placed between the conducting part and the electrical insulation, and between this insulation and the inner surface of the wall.

Description

Terminal assembly for electrochemical device

1 is a cross-sectional view of a terminal assembly of the present invention.

2 is a cross-sectional view of another embodiment of a terminal assembly.

The present invention relates generally to the installation of a sealed alkaline electrochemical device and in particular an improved terminal assembly on one wall of a sealed metal container used in such a device.

Electrochemical devices refer to electrochemical devices that use electrodes in physical contact with an alkaline electrolyte and include devices such as electrochemical current generating cells, electrolytes, capacitors, meters, and electrolytic cells.

Alkaline electrolytes are well known for their ability to easily wet most metal and plastic surfaces, resulting in the prevention of liquid leakage of metal containers in electrochemical devices using seals made of metal or plastic parts. It was a very difficult problem.

Alkaline electrolytes that wet these parts actually leak through the seals and eventually leak out from inside the metal container.

The installation of terminal assemblies on the walls of sealed metal containers to prevent leakage of alkaline electrolytes has been a particularly embarrassing problem. In US Pat. No. 3,871,376, one flat electrochemical current generating cell is described, wherein an electrode assembly comprising antipolar flat electrode elements having a porous separator containing an alkaline electrolyte positioned between them is sealed. Enclosed in a plastic membrane shell, it is also equipped with one terminal connection by installing a current collector adjacent one end of the electrode assembly exposed through a hole in the shell wall. The current collector is tightly attached to the coating wall around the hole and sealed by a thin layer of an adhesive sealant which is not wetted by the alkaline electrolyte. Adhesive sealants are preferably constructed from compounds known as “fatty polyamides”.

In US Pat. No. 4,044,200, one flat electrochemical current generating cell is described, wherein the electrode assembly is also enclosed in a sealed plastic film sheath and also in the same thin layer of non-wetting adhesive seal around the hole in the wall. Terminal connections are provided by using internal and external current collectors sealed to the outer wall by means of which the current collectors are electrically connected to each other through holes by suitable methods such as spot welds.

The present invention relates to improvements to terminal assemblies in metal containers of electrochemical devices using alkaline electrolytes.

By implementing the present invention, it is possible to install an improved terminal assembly on one wall of a metal container used in an electrochemical device that is sealed so that liquid does not leak against electrolyte leakage.

According to the present invention, there is provided a terminal assembly composed of an internal electrically conductive element which is located adjacent to an inner surface of one wall of a metal container and placed on a hole in such a container wall, in combination with a metal container of a chemical apparatus having an alkaline electrolyte. And the first electrical insulator has a hole into the insulator located between the inner electrical conductor and the inner surface of the vessel wall, the aperture coinciding with the hole in the vessel wall described above, the outer electrical conductor adjacent to the outer surface of the vessel wall. A second electrical insulator having a hole into the insulator located between the outer electrical conductor and the outer surface of the vessel wall, the aperture being a hole in the vessel wall described above. And the thin layer of adhesive sealant is not wetted by alkaline electrolyte And at each interface between the first and second electrical insulators and between the inner and outer electrical conductors and between the first and second electrical insulators and the inner and outer surfaces of the vessel wall. The conductor is spot welded through the hole in the vessel wall.

The electrical insulator may be a flat washer made of an organic plastic composition, for example polypropylene.

The inner and outer electrical conductors may be metal plates or foils and are electrically connected to one or more electrodes in the electrochemical device.

The adhesive sealant substantially each of the electrical insulators at each interface between the first and second electrical insulators and between the inner and outer electrical conductors and between the inner and outer surfaces of the first and second electrical insulators and the metal vessel wall. It is good to cover the surface of the. The present invention will be described below with reference to the accompanying drawings. Referring to the drawings, reference numeral 10 denotes one wall of a metal container used in an electrochemical device using an alkaline electrolyte, such as, for example, a nickel plated steel container used in a conventional nickel-cadmium battery. In the device of the invention, the wall 10 is polarized, ie the wall is electrically connected to an electrode of one polarity while the terminal assembly is electrically connected to an electrode of the opposite polarity.

The terminal assembly includes an internal current collector 26 and an external current collector 28, respectively, which are metal foils such as nickel foil, for example. The inner selector 26 is located adjacent to the inner surface of the wall 10 lying on the hole 14 but separated by a first polypropylene washer 30 whose hole 32 is a hole 14. ) The outer selector 28 is located adjacent to the outer surface of the wall 10 overlying the hole 14 but is separated by a second propylene washer 34 whose hole 36 is also a hole 14. Matches A thin layer 38 of adhesive sealant, such as an aliphatic polyamide sealant that is non-wetting to the alkaline electrolyte, is located at the interface between the first polypropylene washer 30 and the inner selector 26 and of the same adhesive sealant. Another thin layer 40 is located between the first polypropylene washer 30 and the inner surface of the wall 10. In an essentially the same way, the outer selector 28 is by means of a thin layer 42 of adhesive sealant located at the interface between the second polypropylene washer 34 and the outer selector 28 and the second polypropylene washer ( It is firmly attached and sealed to the outer surface of the wall 10 by a thin layer 44 of adhesive sealant located at the interface between the outer surface of the wall 10 and 34.

Both the collectors 26 and 28 are recessed centrally and are electrically connected to each other by a suitable method such as spot welding 46.

The electrical insulator used in the terminal assembly of the present invention is made of polypropylene film or sheet. In addition to polypropylene, the insulator consists of one of the following materials: For use with vinyl polymers and copolymers, polyvinylidene chloride, polyethylene, nylon, polysulfone, polystyrene, and fluoropolymer aliphatic polyamide adhesives, films made of polyethylene, polypropylene and vinyl polymers and copolymers The sheet is good. Suitable fatty polyamide sealants are described in US Pat. No. 3,922,178. As described in US Pat. No. 3,922,178, fatty polyamides are produced by reaction of polybasic acids with polyamines. In general, fatty polyamides used in the present invention are those having an amine number of about 9 or more. The amine number is the number of milligrams of KOH equivalent to 1 gram of fatty polyamide and is determined by a known method. Fatty polyamide sealants may be mixed with potentiators and modifiers to modify the physical properties of the fatty polyamide. The aliphatic polyamide sealant can be applied in hot melted form or as a solution in a solvent such as an alcohol and aromatic hydrocarbon mixture.

Examples of the Invention Specific commercially available aliphatic polyamides that are particularly useful are the Swift Z-610, Swift's Z-610, Swift and Company trademarks, and Versalon and Gen Bond, General Mills, GneBond, Produced under the trademarks of Generalal Mills, Inc.).

It is known that liquid seals between plastic insulators and metal parts of the terminal assembly are often difficult to achieve because adhesive sealants such as fatty polyamides are not easily wetted.

This problem can be overcome if the plastic film or sheet from which the insulator is made is initially subjected to continuous heat treatment or corona discharge treatment and the coupling between the plastic insulator and the metal parts is substantially improved. Methods of treating plastic films or sheets are described in US Pat. No. 3,914,521.

In this method, the plastic film or sheet is heated to a high temperature of about 120 ° C. for polypropylene for about 30 seconds, optionally cooling the plastic film or sheet to room temperature and then adhering the film or sheet to the metal parts. At the site, high intensity corona discharge is applied.

Claims (1)

A terminal assembly comprising an internal electrical conducting element coupled to a metal vessel of an electrochemical device having an alkaline electrolyte and positioned adjacent to an inner surface of one wall of the metal vessel and lying on a hole in the vessel wall, wherein the first electrical insulator is internal. It has a hole into the insulator located between the electrical conductor and the inner surface of the vessel wall, which coincides with the hole in the vessel wall, and the external electrical conductor is located adjacent to the outer surface of the vessel wall and placed on the hole in the vessel wall. The second electrical insulator has a hole into the insulator located between the external electrical conductor and the outer surface of the container wall, which coincides with the hole in the container wall and is a thin layer of adhesive sealant that is not wetted by alkaline electrolyte. Silver between the first and second electrical insulators and between the inner and outer electrical conductors, A terminal assembly for electrochemical devices, wherein the inner and outer electrical conductors are spot welded to each other through holes in the vessel wall, the insulation being located at each interface between the interior and exterior surfaces of the vessel wall.

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