JPS60146447A - Enclosed type lead storage battery - Google Patents

Abstract

PURPOSE:To prevent the transmission of steam and to obtain the high performance and the long life of a battery by providing sheets composed of metal layyer, surfaces of which are covered by synthetic resin with acid resistance, on the inner wall of a jar. CONSTITUTION:Sheets 5, 6 are stuck to one surface of collecting bodies 3, 4, and silicone rubber 7, 8 of hardening with the normal temperature are applied to the upper surfaces of the sheets 5, 6 and the peripheral portion at the other surfaces of the collecting bodies 3, 4, and the sheets 5, 6 and the collecting bodies 3, 4 of positive and negative electrodes are integratelly embedded in jars 1, 2 so as to cover the rubber portions 7, 8. A positive plate 9, a separator 10 and a negative plate 11 are piled up and housed between the collecting bodies 3, 4, and the positive jar 1 and the negative jar 2 are ultrasonic-welded after injecting given electrolyte. The sheets, for example, in which a vaporization film 13 of aluminium is formed on one surface of a polyester film 12 and adhesive 14 is applied to the other surface, are embedded in the jar 1, 2 in the state of permitting the vaporization film 13 of aluminium to oppose to the inner walls of the jars 1, 2.

Description

Detailed Description of the Invention B) Industrial Field of Application The present invention is directed to reducing the amount of water in the electrolyte due to permeation of the water in the electrolyte as water vapor from the wall of the cell; This relates to a sealed lead-acid battery with a limited amount of electrolyte that is affected by concentration.

(b) Conventional technology Sealed lead-acid batteries have a configuration in which the amount of sulfuric acid in the electrolyte is limited to limit the electrode reaction t'B in order to ensure a wider range of applications (particularly deep discharge, etc.). It is taken. In other words, if deep discharge is repeated many times until the active material in the battery case is completely used up, the battery life will be shortened.

Therefore, the amount of sulfuric acid is limited so that unused active material remains during discharge. (However, since charging and discharging proceed at the same time in automobile batteries, there is no problem even if the amount of sulfuric acid is large.

) Also, from the point of view of ensuring high energy density of the pond, it is designed to remove as much unnecessary water as possible from the surface of 1 volume and 1 weight of the storage element. Therefore, in a sealed lead-acid battery, under the above conditions, a sulfuric acid water bath solution with an optimum concentration of about 40% is used as the electrolyte solution by limiting the amount of the solution t.

Also, as a sealing mechanism, oxygen gas generated from the anode during charging is consumed at the cathode according to the reaction expressed by the following formula.
The method is being carried out.

2Pl)+02+2H[04→2PbBOa+2HtO
Since this reaction requires securing a three-phase interface (solid phase-Pb, liquid phase-electrolyte, gas phase-Of), the amount of electrolyte is limited. This is 0 if the amount of electrolyte is too large! But it is difficult to reach PB (
This is because the above reaction is delayed.

As mentioned above, in sealed lead-acid batteries.

ia) The amount of electrolyte is limited.

ibl The concentration of the electrolyte is set higher than that of Hibiki's general automotive lead-acid batteries (electrolyte concentration at the time of charging is around 35%) from the viewpoint of the energy density mentioned above.

Therefore, the value is close to the initial concentration limit value.

I have a technical background.

On the other hand, the material of the battery case is generally mechanical strength.

Resin such as BS resin is used for reasons such as dimensional stability, aesthetics, and cost. However, these resins have the property of permeating water vapor.

Therefore, as water in the electrolyte passes through and escapes through the cell wall as water vapor, the concentration of the electrolyte becomes higher than the allowable range.

This phenomenon of high concentration increases the rate of corrosion of the electrode plates, deteriorates the performance of the electrode plates, and reduces battery capacity life.
There is.

An example of a technique that focuses on this type of electrolyte retention problem is disclosed in Japanese Utility Model Application Publication No. 58-159166.

In this case, a flat current collector is housed inside a flat container, and an electrode plate and separator metal are held between the current collectors. A rising portion is formed at the peripheral edge of the current collector, and this rising portion (2) prevents water vapor and electrolyte from entering between the current collector and the inner wall of the battery case. However, at this rising part, the seal between the current collector and the inner wall of the battery case is not perfect (9). The disadvantage is that the liquid permeates through the container wall and escapes into the outside air.

Object of the Invention The present invention has been made in view of the problems of the prior art as described above. The purpose of this is to prevent high concentration of the electrolytic solution due to permeation and escape of C2 from the cell wall as water vapor in the layer solution, and to improve the performance and longevity of the battery.

(c) Structure of the Invention A sheet consisting of a metal layer whose surface is covered with an acid-resistant synthetic resin is placed on the inner wall surface of the battery case so that the synthetic resin surface is located on the center side of the inside of the battery case. The present invention is characterized by the presence of an electrolyte, which prevents the concentration of electrolyte from increasing due to a decrease in water content in the electrolyte.

More specifically, a sheet covered with a thin metal layer (C foil, vapor deposited film) on both sides is formed in an acid-resistant synthetic resin bath. This sheet is placed between one side of the sheet and the wall of the container so that gas (water vapor, oxygen, hydrogen) and liquid (electrolyte) do not enter. Since most of the surface area of the battery case is covered with a metal layer, water vapor cannot pass through the battery case because the water vapor is blocked by the metal layer.

When covering the wall surface of the battery case with metal, there are two methods: (1) covering the outer wall of the tank, and (1) covering the inner wall of the battery case. Generally, in lead-acid batteries, the electrolyte is sulfuric acid, so the components inside the battery are required to be acid resistant. Therefore, at first glance it seems easier to cover the outer walls.

There are two possible methods for covering the outer wall with metal:

(1) Paste a metal film on the outer wall of the battery case.

As a method, it is easy to think of, but to attach it to the outer wall,
The misalignment of the placement is directly linked to aesthetics.

This causes defects such as adhesive extrusion, making it difficult to obtain high-quality products, and secondly, there are problems in that the adhesive peels off during use.

(2) Apply a double coated film and a vapor deposited film to the outer wall of the battery case.

Since a metal film does not form inside the container, a complete mask is not required, and the process is time-consuming and involves masking, film formation, and mask removal.

On the other hand, if the inner wall is covered with a metal film, the above 111
Although there is no problem with 12), it is difficult to impart acid resistance to the metal.

It may seem difficult to create a sheet covered with a synthetic resin layer, which is the structure of the present invention, but the following structure can be produced in large quantities on a streamlined production line and is an inexpensive product. , that is, "Adhesive - Aluminum evaporated film -
Applying the manufacturing method for labels, etc., which has "resin film-printing-resin film".

It is possible to make a sheet with the structure of "resin film-aluminum vapor deposited film-resin film".

(E) Example 1 Example 1 shows an example in which the sheet of the present invention is applied to a flat lead-acid battery C2.
As shown in the figure.

111 is a positive electrode side battery case, and (2) is a negative electrode side battery case, both of which are made of CAES resin or As resin, (31,
(41 is the positive and negative electrode current collectors attached to the above-mentioned battery case +11 and 12), and sheets (5) and (6) are attached to one side of these current collectors (3L). this sea)
+51 (the upper surface of 61 and the surrounding area of the other surface of the assembly (31, +41 ≦2 Room temperature curable silicone rubber (7) (8)
t-1 cloth, and cover the rubber (71 (810) part of the battery case +11. (211″-the sheet (51F6)
1 and positive and negative electrode current collectors (31 (41 is integrally formed I: buried. And the battery case +11+21 made in this way
The positive electrode plate (9), separator aα, and negative electrode plate t111 are folded together and placed between the current collectors (3) and (4), and after injecting a predetermined electrolyte (10 co)', the current collector (31 (41 is brought into pressure contact with the electrode plate 19111+) (the two positive electrode batteries (11) and the negative electrode battery (21) are all ultrasonically melted to obtain a sealed lead-acid battery.

The sheet used in this example was made of a polyester film (or polypropylene film) with a Ni-aluminum evaporation film 3 placed on one side and an adhesive I on the other side, as shown in Figure 2C. It is coated with 1 said battery case (1) (
The aluminum vapor-deposited film αJ is buried in the battery containers (1) and (2) so as to face the inner wall surface of the container (2).

Prior to this embodiment, the inventors proposed a sealed lead storage pond as shown in Figure 3C (Japanese Patent Application No. 58-1856).
09 specification and drawings). In this figure, positive and negative electrode batteries α51. (Positive and negative electrode collectors are integrally buried in the inner wall area of 161, (181 is coated with silicone rubber (11),
The current collector α′fJtta is pressurized and compressed by the storage force during molding, and sealing ability is added to the assembly QDa&
This prevents the infiltration of liquid or water vapor from the surrounding area. However, in the case shown in FIG.
1. Although it is possible to almost prevent the electrolyte from entering the inner wall part, in the negative electrode current collector αa, the electrolyte may enter the interface between the assembly 0 barrel and the silicone rubber 2 and go around to the back side of the assembly. Ta. Although the principle behind this is unknown, it has been found that the electrolyte moves more easily along the negative electrode condensate, which is charged with a negative potential.

In this embodiment, in view of this point, the wall of the container is made of an electrically insulated metal layer. Therefore, in this example, the electrolyte is made of current collectors (31F41 and silicone rubber (7), (8)).
(51 (The interface between 61 and the battery case (11f2 + inner wall is silicone rubber 17) +
81, and no further infiltration is possible, resulting in infiltration at the interface between aggregate f31 (4) and sea) (51 (61). 1 decomposition.

Or even if water vapor enters this part G2, the sheet T5
The electrically insulated aluminum vapor deposited film that constitutes +161 (
131 and does not permeate from this surface, and the amount of water vapor permeated can be reduced to a fraction of that.

In addition, in this example, in order to increase the reliability of preventing water vapor permeation, a positive electrode assembly (3 eyes 2 seas) (51T) was pasted.

Even just the negative electrode side is sufficiently effective. In the case of this embodiment, it is only necessary to add a step of attaching a strip sheet to the strip lead plate before punching out the current collector (31) (manufacturing is also easy).

Second Example Next, an example in which the present invention is applied to a monobloc lead-acid battery.
Figure 4C: Shown.

(211 is a battery case, (23 is a battery case lid that closes the top opening of the battery case 1211, (c) is a positive electrode assembly, @ is a negative electrode current collector,
(251 (261 is a negative electrode plate located inside the electric N circle and connected to the negative electrode current collector C! C: is located between the negative electrode plates @ (to).

The positive electrode current collector (the positive electrode plate connected to Wl2, (2)) is a separator interposed between the negative electrode plate and the positive electrode plate.

The conventional monobloc lead-acid battery (see Figure 5) consists of only the above components and has a temperature of 9. The amount of decrease in electrolyte solution was large.

In this embodiment, the battery case c! CJll is pasted on the inner wall of D via a two-component epoxy resin.

This sea) CI4) has a thickness of 50 to 80 as shown in the m6 diagram.
A aluminum vapor-deposited film 1311 is formed on the polysilkworm stell film (2), and a polyester film (2) coated with an adhesive (2) is laminated thereon.

As described above, in this example, five sides of the battery case (2H) were covered by the aluminum vapor deposition error, and as a result, the amount of electrolyte solution decreased by about 176% compared to the conventional case due to permeation and escape of moisture in the electrolyte solution as water vapor. improve to.

(f) Effects of the Invention As explained above, the present invention provides a sheet consisting of a metal layer whose surface is covered with an acid-resistant synthetic resin.

The sheet is present on the inner wall surface of the battery case so that the synthetic resin surface is located on the center side (2) of the interior of the battery case. The amount of water vapor permeation from the battery can be reduced by a fraction of a second.As a result, the battery performance and life can be extended several times.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a flat lead-acid battery according to an embodiment of the present invention;
FIG. 3 is a sectional view of a conventional flat lead-acid battery corresponding to FIG. 1, FIG. 4 is a sectional view of a monobloc lead-acid battery according to another embodiment of the present invention, and FIG. FIG. 6 is a sectional view of a conventional monobloc battery corresponding to FIG. (13 (to) (to)...Synthetic resin, Sumitomo 1...Metal layer, +51 (61311...Sheet, (1) (21)
G11...Battery container. Figure 1

Claims (1)

[Claims] (1) A sheet consisting of a metal layer whose surface is covered with an acid-resistant synthetic resin bead is placed so that the synthetic resin surface is on the center side of the inside of the battery case. A sealed lead-acid battery characterized by the presence of a sheet.