JPS6032246A - Alkaline battery - Google Patents

Abstract

PURPOSE:To enable internally generated gas of over a given level to be rapidly discharged outside and realize a good liquid-leakage resistance by coating a negative sealing plate with a sealing agent film layer extending at least over the entire inner surface of the negative sealing plate and over an area in which a current collector bar is attached to a gasket. CONSTITUTION:A sealing plate 8 is coated with a sealing agent film layer 9 extending over a gas exhaust hole 8a and the entire inner surface including its peripheral area as well as over the peripheral area of the outer surface and an area in which a current collector bar 6 is attached to a gasket 5. As a result, good liquid-leakage resistance is realized. Moreover, when the internal gas pressure of the battery abnormally increases, the thin section 56 of the gasket 5 is pressed and broken thereby allowing gas to pass through the ventilation hole 7a of a metallic supporter 7a before reaching the internal space of the sealing plate 8. Following that, the adhesive film layer 9 covering the gas exhaust hole 8a is pressed and broken thereby allowing gas to be discharged outside through the exhaust hole 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alkaline battery having a gas discharge function for internal gas generation, and particularly to an alkaline battery with improved leakage resistance.

It is known that alkaline batteries generate gas during discharge or storage.

In this case, Takaike himself, of course,
There is no problem with equipment using batteries, but abnormal gas may be generated if the battery is rapidly discharged, the positive and negative terminals of the battery are short-circuited, or the battery is charged due to incorrect insertion into the equipment. In the worst case scenario, there was a risk that the pond would burst.

Therefore, conventional alkaline batteries of this type used an insulating gasket with a detonation prevention valve and a cathode sealing plate with a gas discharge hole. Some devices have a so-called gas exhaust function in which when the explosion exceeds a predetermined level, the explosion prevention valve of the gasket is ruptured and the abnormal gas is discharged to the outside through the gas exhaust hole of the cathode sealing plate.

However, if this is done, the following inconvenience will occur. That is, generally alkaline batteries have I, 7.
The electrolyte creeps up along the current collector rod due to the electrocapillary action that occurs between the negative potential of the electrode and the surface tension at the electrolyte interface, and the electrochemical reaction in which oxygen gas in the air is reduced to α. There is a phenomenon.For this reason.

As mentioned above, the gas exhaust hole of the cathode sealing plate remains open, and the electrolyte moves along the inner surface of the sealing plate (l!:), and passes through the gas exhaust hole to the outside. This had the disadvantage of significantly deteriorating leakage properties due to leakage.Therefore, in the past, a sealing plate with through holes for gas discharge was fabricated with a breathable, alkali-resistant synthetic resin film such as polyethylene or polypropylene. One idea is to use an alkali-resistant adhesive to prevent the electrolyte from creeping up, and to prevent sudden gas generation, the film at the gas exhaust hole can be torn to allow the gas to escape.

However, in general, in Alka IJ batteries, the current collector rod is welded to the inner surface of the sealing plate, so the current collector rod gets in the way when pasting the film. There was a drawback that it could not be prevented reliably and a sufficient effect in terms of leakage resistance could not be obtained.

In addition, conventional gas exhaust holes are provided (!: By applying adhesive to the gas exhaust hole portion of the inner surface of the sealing plate to which the current collector rod is welded, and the fitting portion of the current collector rod to the gasket, respectively. There are also plans to prevent the electrolyte from creeping up and also to achieve good results in terms of gas discharge.

However, the speed of the electrolyte that tries to creep up along the current collector rod is suppressed by the adhesive layer formed on the part of the current collector rod that fits into the gasket, and further Although the adhesive layer can cut off the leakage path of the electrolyte to the gas exhaust hole, since no treatment has been taken on the periphery of the sealing plate, a leakage path still exists along this periphery. Therefore, there was a drawback that a sufficient leakage resistance effect could not be obtained.

This invention was made to eliminate the above-mentioned drawbacks.
By forming a sealant coating layer on at least the entire inner surface of the cathode sealing plate and the fitting part of the current collector rod welded to the clever plate to the gasket, internally generated gas that exceeds a predetermined pressure can be quickly released to the outside. It is an object of the present invention to provide an alkaline battery that not only can be used but also has good liquid resistance.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a cylindrical anode metal can, and this metal can 1 is made by drawing a nickel-plated steel plate.

The metal can 1 is filled with power generating elements. In this case, the center of the metal can 1 is filled with a gelled zinc cathode material 2, and around this cathode material 2, an anode mixture 3 mainly composed of manganese dioxide is filled through a synthetic fiber separator 4. ing.

An insulating gasket 5 is provided at the opening of the metal can 1.

This gasket 5 is made of nylon 6.6. Since the barrel is integrally molded from synthetic resin such as polypropylene, the circumference of the inner pipe part 51 of the inner part 51) is ~1.8 m.
An outer cylindrical portion 52 formed through a connecting portion 53 of about m
In addition, when forming a stepped portion 54 at the upper portion of the inner cylindrical portion ε 51 and the upper portion of the outer cylindrical portion 52, a folding projecting wall 55 is also formed along the upper opening end of the outer cylindrical portion 52. are doing. In addition, the connection part 53 of the gasket 5 has a battery internal pressure of 30 to 60 kg/
It has a thin wall portion 56 with a thickness of approximately 0.1 to 0.3 mm that will burst when the pressure abnormally increases to approximately Cm''.

A cathode sealing plate 8 is placed on the stepped portion 54 of the gasket 5 via a monkey-shaped metal support 7 having a ventilation hole 7a. This sealing plate 8 has a gas discharge hole Ba4.

Further, a current collector rod 6, which is drawn out from the cathode agent 2 and fitted into the hollow portion of the inner cylindrical portion 51 of the gasket, is fixed to the inner surface by welding or the like.

In this case, the sealing plate 8 forms a sealing agent N layer 9 from the entire inner surface including the gas discharge hole 8a portion and the inner peripheral edge portion to the outer peripheral edge portion and the fitting portion of the current collector rod 6 to the gasket 5. . This coating layer 9 is made of rubber adhesive or synthetic resin.

For example, polyisobutylene, aliphatic polyamide resin, chlorosulfonated polyethylene, haloprene rubber.

Chlorinated polyethylene, ethylene-ethyl acrylate copolymer, vulcanized or unvulcanized natural rubber, SB.

Adhesives such as neoprene, butyl rubber, nitri rubber, polybutadiene rubber, and fluorinated rubber are used as sealants.

Here, the gas exhaust hole 8a of the sealing plate 8 is made with a diameter of 0.4 to 0.
It has been confirmed that if the sealant is about 8nTn, not only can the gas be discharged, but also that it does not flow out from the discharge hole 8a during application due to the viscosity of the sealant. Further, the sealant is applied using a syringe or by brush coating, and then dried under pressure or reduced pressure to form a sealant coating 9. If the thickness of the coating 9 at this time is approximately 0.05 to 0.25 rrm, it will sufficiently rupture due to an abnormal increase in gas pressure.

In this state, the opening of the metal can 1 is tightened in the radial direction, and the opening is bent inward to form the folding projecting wall 5 of the gasket 5.
The opening is sealed by pressing the sealing plate 8 through the opening 5. In Figure 0, 10 is an insulating tube, and 11 is a metal jacket.

Therefore, according to such a purchase, the electrolyte that constantly creeps up along the current collecting rod 6 is prevented by the sealant coating layer 9 formed on the fitting part of the collecting tα rod 6 to the gasket 5. The creeping speed can be suppressed to a large rlJ, and the leakage path at the gas discharge port 8a can be cut off by the sealant coating layer 9 formed from the entire inner surface of the sealing plate 8 to the outer peripheral edge. Further, the inner peripheral edge of the sealing plate 8 is closely attached to the metal support plate 7 via the sealant coating layer 9, and the outer circumferential edge of the sealing plate 8 is also tightly attached to the folding protrusion 55 of the gasket 5 via the sealant coating layer 9. Since the sealing plate 8 is in close contact with the sealing plate 8 and the liquid leakage path at these parts can be cut off, a good liquid leakage resistance effect can be obtained from the entire inner surface to the outer peripheral edge of the sealing plate 8. Also, if the gas pressure inside the battery rises abnormally in this state, the thin parts 5 and 6 of the gasket 5 are first pressed and stretched to their fullest extent, and the gas leaks through the vent hole 7a of the metal support 7.
3'i reaches the inside of the sealing plate 8. Then, the adhesive coating layer 9 covering the gas exhaust hole 8a is pressed and ruptured, whereby the gas is discharged to the outside through the exhaust hole 8a. In other words, by doing this, it is possible to obtain good leakage resistance while suppressing the movement of the electrolyte that constantly tries to creep up along the current collector rod 6, and also to quickly prevent abnormal rises in the gas pressure inside the battery. It can also be released to the outside.

Furthermore, even when the current collector rod 6 is welded to the sealing plate 8, the sealant can be simply dropped or applied, so a better sealant coating layer can be obtained compared to pasting a conventional film-like material.

In this respect as well, good pain fluid resistance effects can be expected.

By the way, a La6 type alkalmanganese battery (A) to which this single blade was applied and a battery with a sealant coating applied to the gas exhaust hole part of the cathode sealing plate and the fitting part to the gasket of the U14 contact body [B] , a battery with a gas discharge hole in the cathode sealing plate but without a sealant coating layer [C], and a battery with no gas discharge hole in the cathode sealing plate (1)]
When 100 pieces of each were made and forcibly charged with a current of 600 mA for 1 hour to increase the internal pressure and a burst test was performed, the results shown in Table 1 were obtained.

Here, for each battery [:A] [B] [C] CD), the insulating gasket described in the above embodiment is used. In this case, the number of batteries that can be saved due to rupture is due to damage to the outside of the battery, such as a torn insulating tube, a protruding current collector rod, or a torn crimped part of the jacket. If the thin part of the gasket ruptures due to this, it will not cause an external nJ shell lagoon, so it is not considered as a battery rupture.

G 1 The table below shows the rate of leakage when 100 Id cells of each of these batteries [A) CI3] [C) [J)] were stored for a specified period in an atmosphere with a temperature of 60°C and a humidity of 60°C. Upon investigation, the results shown in Table 2 were obtained.

However, from the results of Table 4111 and Table 2, the battery [A] obtained by this invention is the conventional Shinike CB) [:C]
CD), it has been found that not only does it not rupture even when abnormal gas is generated during use of the a pond, but it also has excellent leakage resistance at all times.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.

For example, in the above description, the sealant liquid film layer 9 was formed from the entire inner surface of the sealing plate 8 to the peripheral portion of the outer surface and the fitting portion of the fruit aliment 6 to the gasket 5. By forming a sealant and a corrugated layer 9 on the part of the mandrel 6 that fits into the gasket 5, the same effects as described above can be expected.

[Brief explanation of the drawing]

The drawing is a schematic 4-7 diagram showing an embodiment of the present invention. 1... Metal can 2... L electrode material 3... Anode mixture 4... Separator 5... Gasket 51... Inner circular section 52... Outer circular section 5
3... Connecting part 54... Step part 55... Projection 56... Thin wall part 6... Current collector rod 7... Metal support 7a... Ventilation hole 8... Sealing plate 8a ...Gas exhaust hole 9...Sealant layer 1
0...Insulating tube 11...Metal jacket

Claims (3)

[Claims] (1) An insulating gasket provided at the opening of a cylindrical metal can filled with a power generation element and having a thin wall portion that ruptures due to gas pressure, and a gas exhaust hole placed on the gasket via a metal support. a current collecting bale that is led out from the power generation element, is fitted into the gasket, and is fixed to the sealing board, and a current collector that is fitted to at least the entire inner surface of the sealing board and the current collection stop to the gasket. 1. An alkaline battery comprising a sealant a film layer formed in a joint portion. (2) The alkaline battery according to claim 1, wherein the self-sealant coating layer is formed on the outer peripheral edge i53 of the sealing plate. (3) The alkaline battery according to claim 1 or 2, wherein the sealant coating layer is made of a rubber adhesive or a synthetic resin adhesive.