JPH05121058A - Closed type battery - Google Patents

Abstract

PURPOSE:To prevent the leakage of an electrolyte and gas from a closed type battery. CONSTITUTION:For an insulating packing being interposed in a portion for sealing an opening in a battery, there is used a material prepared by forming a second resin layer, made of polypara-xylylene resin or the like being more flexible than a first resin 1 forming a basic body, on the surface of the first resin 1 through a process of chemical vapor deposition. This can form the second resin layer 2 of uniform thickness and flexibility on the surface of the first resin 1, and consequently can as reliably as possible prevent causing a gap in the portion for sealing the opening in the battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery in which an insulating packing is interposed between the opening of a battery outer can and a sealing lid for closing the opening, and the sealing of the battery. It is a thing.

[0002]

2. Description of the Related Art As a battery often used conventionally,
There are nickel-cadmium batteries and lithium batteries,
In these batteries, usually, an insulating packing is interposed between the opening of the battery outer can that also serves as one polarity terminal and the sealing body that also serves as the other polarity terminal, and the opening of the outer can is crimped to the sealing body. The battery is attached and sealed to hermetically seal the inside of the battery. Further, when the sealing body is welded to the opening of the outer can, the sealing is performed by interposing an insulating packing between the through hole provided in the sealing body and the terminal pin inserted into the through hole.

As described above, in the sealed type battery in which the inside of the battery is hermetically sealed, the insulating packing for insulating the positive electrode terminal and the negative electrode terminal is arranged in the sealing portion of the battery, and the material of the insulating packing is , Various resins such as polyamide and polypropylene are used.

However, when an insulating packing made of any of these materials is used and the battery is hermetically sealed by caulking or the like by interposing it in the sealing portion, a small gap in the sealing portion causes
Gas or electrolyte generated by the chemical reaction of the battery leaks,
Battery performance may be reduced or safety may be impaired.

For this reason, Japanese Utility Model Publication No. 37-119 proposes to coat the surface of the resin as the base of the insulating packing with a thin layer of a pitch material such as asphalt made of a soft material. .. By doing so, leakage of the electrolytic solution can be slightly suppressed, but when such a pitch agent is used, the leakage of the electrolytic solution and various gases can be completely sealed when the battery is left at high temperature for a long time. It is not possible.

Further, when the surface of the insulating packing is covered with a sealing agent such as chlorosulfonated polyethylene having a good gas sealing property, the sealing agent has fluidity at a high temperature, so that the sealing part is exposed to heat or impact. There is a problem that gaps are easily created. On the other hand, it is possible to improve the sealing performance by making the resin itself, which is the base of the insulating packing, a highly flexible material, but when mechanically sealing by caulking, etc., the insulating packing is crushed and the sealing part There is a gap.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealed battery which prevents leakage of electrolyte solution or gas in the battery.

[0008]

The sealed battery of the present invention comprises:
The positive electrode terminal member and the negative electrode terminal member are liquid-tightly sealed via an insulating packing, and the insulating packing has a surface of a first resin, which is a base, and is more flexible than the first resin. Further, the second resin layer formed by chemical vapor deposition is coated, and the outer resin layer is made of a polyparaxylylene resin, so that further effects can be obtained.

[0009]

When the insulating packing is formed by forming a second resin layer having a higher flexibility than this resin on the surface of the first resin as a base by chemical vapor deposition, even if the battery is sealed by caulking or the like, Since the strength of the resin inside is high, it is possible to prevent the insulation packing itself from collapsing, and because the resin layer on the surface has flexibility, between the insulation packing in the sealing part and the battery outer can or sealing body, etc. It is possible to prevent a gap from being generated.

When a resin layer having high flexibility is formed on the surface of the first resin, which is the base of the insulating packing, by coating or the like, as shown in FIG. The second resin layer 2 cannot be formed on the surface with a uniform thickness, and in particular, the edge portion of the insulating packing is rounded by forming the resin layer 2.

On the other hand, when the resin layer on the surface is formed by chemical vapor deposition like the insulating packing in the battery of the present invention, as shown in FIG. 1, the thickness of the resin layer 2 on the surface of the resin 1 serving as the substrate is increased. Can be controlled uniformly, and the shape of the insulating packing hardly changes even when the resin layer 2 is formed on the surface. Therefore, by designing the insulating packing in consideration of the shape of the sealing portion in which the insulating packing is arranged, the sealing property can be sufficiently improved.

When the resin layer on the surface is formed by chemical vapor deposition of a polyparaxylylene resin such as polyparaxylylene, polymonochloroparaxylylene or polydichloroparaxylylene, the surface of the insulating packing is more uniform. Since the resin layer can be arranged in various thicknesses and these resins have excellent thermal stability, chemical resistance, and gas barrier property, stable sealing performance can be obtained for a long period of time.

[0013]

【Example】

Example 1 An insulating packing in which polyparaxylylene was coated on the surface of 6-nylon by chemical vapor deposition to a thickness of 20 μm was prepared, and the insulating packing was provided between the opening of the battery outer can and the sealing body. Was interposed and the opening of the battery outer can was caulked and sealed to produce an AA size sealed battery (the power generating element is not housed in the battery) shown in FIG. The battery thus produced is referred to as Battery A of the invention.
And

Incidentally, in FIG. 3, 3 is an insulating packing,
Reference numeral 4 denotes a battery outer can, 5 denotes a sealing body, and the sealing body 5 is composed of a lid body 6, a terminal plate 7, an elastic sheet 8 and a spring 9.

Example 2 A battery B of the present invention was manufactured under the same conditions as in Example 1 except that the resin to be chemically vapor deposited on the surface of the insulating packing was replaced with polymonochloroparaxylylene.

Example 3 A battery C of the present invention was manufactured under the same conditions as in Example 1 except that the resin chemically deposited on the surface of the insulating packing was replaced by polydichloroparaxylylene.

Comparative Example 1 A comparative battery D was prepared in the same manner as in Example 1, except that 6-nylon was used as the insulating packing, the surface was not coated, and the other conditions were the same.

Comparative Example 2 A comparative battery E was prepared in the same manner as in Example 1, except that 6-nylon surface coated with asphalt as a pitch agent was used as the insulating packing and the other conditions were the same.

[Comparative Example 3] A comparative battery F was prepared in the same manner as in Example 1, except that 6-nylon surface coated with chloropolysulfonated polyethylene as a sealant was used as the insulating packing and other conditions were the same. It was made.

[Comparative Example 4] In Comparative Example 4, a comparative battery G was prepared in the same manner as in Example 1 except that ethylene propylene rubber, which itself had a large elastic force, was used as the insulating packing, nothing was applied to the surface, and the other conditions were the same. did.

[Comparative Example 5] A comparative battery H was prepared in the same manner as in Example 1 except that 6-nylon surface coated with polyethylene resin was used as the insulating packing and the other conditions were the same.

Each of the batteries A to H was inserted into a hydrogen gas leak test gas case shown in FIG. 4, and the amount of gas leak was measured. In FIG. 4, 10 is a closed case, and the battery 11 is accommodated inside this. Reference numeral 12 is a pressure sensor for measuring the internal pressure of the battery, which is attached to a through hole formed in the bottom of the battery 11. In addition, 13 is a gas sampling port. In addition, the test method, after inserting the battery into the gas case,
Inject hydrogen gas into the battery and maintain the pressure at 5 kg / cm ² 1
It is left for a day and the amount of hydrogen gas leak during that time is measured. The results are shown in Table 1.

[0023]

[Table 1]

As is clear from Table 1, the battery A of the present invention,
It can be seen that B and C have a lower hydrogen leak amount than the comparative batteries D to H. Further, the comparative battery C has a lower hydrogen leak amount than the other comparative batteries.

In the batteries A, B and C of the present invention, a resin layer which is more flexible than the base resin is formed on the surface of the base resin inside the insulating packing by chemical vapor deposition to have a uniform thickness. The resin layer having this flexibility and a uniform thickness improves the sealing property, and the strength of the insulating packing itself is maintained by the resin inside, and the insulating packing may be largely deformed by caulking at the time of sealing. It is thought that it was possible to suppress it.

On the other hand, in Comparative Battery D, since nothing was applied to the surface of the insulating packing, gas leaked from the gap in the sealing portion, and in Comparative Battery E, leakage of the alkaline electrolyte was prevented. However, it is not effective for sealing hydrogen gas having a small molecular radius. Further, in the comparative battery G, since the insulating packing itself is soft, the insulating packing was crushed during crimping, and a gap was formed in the sealing portion. In Comparative Battery H, the surface of the resin inside the insulating packing could not be coated with the polyethylene resin to a uniform thickness, so the surface shape deteriorated, and the effect of preventing the leak amount could not be obtained.

Then, in order to confirm the thermal stability of the sealing portion, each of the batteries was left at 60 ° C. for 3 days and then subjected to a hydrogen gas leak test under the same conditions as described above. The results are shown in Table 2.

[0028]

[Table 2]

It can be seen from Table 2 that the comparative battery F, which had the effect of preventing leaks in Table 1, had its sealing property deteriorated when left at high temperature. It is considered that this is because the chloropolysulfonated polyethylene, which is the sealant, flowed when left at high temperature. On the other hand, the batteries A, B and C of the present invention maintain high sealing property even after being left at high temperature.

[0030]

As described above, the sealed battery of the present invention is
An insulating packing formed by coating the surface of the first resin, which is the base, with a second resin layer, which is more flexible than the first resin and formed by chemical vapor deposition, is interposed in the sealing portion of the battery. Since the strength of the first resin, which is the base, is high even when the battery is sealed by caulking or the like, the insulating packing itself can be prevented from collapsing and the second resin layer on the surface is flexible. Since it has a gap, it is possible to prevent a gap from being formed between the insulating packing in the sealing part and the battery outer can or the sealing body, which can effectively improve the sealing property and improve the reliability of the battery. The nature is enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an insulating packing according to the present invention.

FIG. 2 is a sectional view of a main part of an insulating packing of a comparative battery.

FIG. 3 is a sectional view of a main part of the battery of the present invention.

FIG. 4 is a schematic diagram of a hydrogen gas leak test apparatus.

[Explanation of symbols]

 1 Internal resin 2 External resin layer 3 Insulating packing 4 Battery outer can 5 Sealing body

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[Procedure amendment]

[Submission date] November 13, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023]

[Table 1]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

As is clear from Table 1, the battery A of the present invention,
It can be seen that B and C have a lower hydrogen leak amount than the comparative batteries D to H. Further, the comparative battery F has a lower hydrogen leak amount than the other comparative batteries.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

[0028]

[Table 2]

Claims (2)

[Claims] 1. A hermetically sealed battery in which a positive electrode terminal member and a negative electrode terminal member are liquid-tightly sealed via an insulating packing, wherein the insulating packing has a surface of a first resin serving as a base, A sealed battery, which is more flexible than the first resin and is covered with a second resin layer formed by chemical vapor deposition. 2. The sealed battery according to claim 1, wherein the outer resin layer is a polyparaxylylene resin.