JPH08203493A - Lead-acid battery - Google Patents

Abstract

PURPOSE: To prevent breakage of a separator caused by corrosion extension of a grid of a positive plate, and suppress oxidation deterioration of the separator by preventing the contact of the separator with the positive plate. CONSTITUTION: An insulating resin 3 is applied to right and left edges of at least one surface of a microporous synthetic resin sheet la to the position of bones 2a at both edges of an electrode plate 2. The resin sheet la is folded in almost a U shape to form an envelope, then used as a separator 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead acid battery for an automobile, and more particularly to improvement of a bag-like separator that wraps the electrode plate.

[0002]

2. Description of the Related Art In a lead-acid battery for an automobile, a positive electrode plate or a negative electrode plate obtained by filling an expanded grid or a cast grid with a paste of a predetermined active material is housed in a bag-shaped separator made of a microporous synthetic resin sheet. Is used. And
The bag-shaped separator separates the positive and negative electrodes from each other and prevents an electrical short circuit between the positive and negative electrodes due to the active material that has fallen off from the positive electrode plate due to the corrosion and expansion of the lattice when the battery is used.

Further, in order to prevent oxidative deterioration at the bottom end or side of the grid body due to contact between the positive electrode plate and the separator, a glass fiber mat made of ultrafine glass fibers is formed on one entire surface of the microporous synthetic resin sheet. A separator is used which is laminated and folded in a U-shape to form a bag.

[0004]

However, due to the high performance of automobile engines and the increase of electric components inside the automobile in recent years, the ambient temperature of automobile batteries has become extremely high. If used, corrosion of the grid of the positive electrode plate is promoted, and the grid expands greatly. Then, the ends of the bones of the elongated and deformed lattice pierce both ends of the bag-shaped separator, and the ends of the positive electrode plate and the negative electrode plate come into contact with each other, causing an internal short circuit.

Further, a positive electrode plate or a negative electrode plate is housed in a bag-shaped separator formed by laminating a glass fiber mat on one entire surface of a microporous synthetic resin sheet and bending the glass fiber mat so as to contact the positive electrode plate. In this case, since a large amount of electrolytic solution is present in the lead acid battery for automobiles, this electrolytic solution fills the voids in the glass fiber mat. The voids in the glass fiber mat were blocked by the electrolytic solution, so that oxygen gas generated from the positive electrode plate during use of the battery could not smoothly reach the negative electrode plate through the voids. For this reason, oxygen gas accumulates inside the glass fiber mat as air bubbles, increasing the internal resistance of the battery and lowering the voltage characteristics of the battery.

The present invention solves these problems, and prevents the separator from being broken by the corrosion extension of the lattice of the positive electrode plate, and also allows the oxygen gas generated from the positive electrode plate during charging to be efficiently transferred to the separator. It is intended to provide a lead storage battery that can reach the negative electrode plate through the lead storage battery.

[0007]

In order to solve the above-mentioned problems, the lead-acid battery of the present invention has a position of bones at both ends of an electrode plate along the left and right ends of at least one surface of a microporous synthetic resin sheet. An insulating resin was applied to the sheet, and the sheet was bent into a substantially U shape to form a bag-shaped separator.

It is preferable that the side of the synthetic resin sheet coated with the insulating resin faces the side in contact with the positive electrode plate.

[0009]

In the lead-acid battery of the present invention, the insulating resin is applied to the bone positions at both ends of the electrode plate along the left and right ends of at least one surface of the microporous synthetic resin sheet, and the sheet is formed into a substantially U-shape. Since the positive electrode plate or the negative electrode plate is accommodated by the bag-shaped separator that is bent in the shape of, the grid of the positive electrode plate corrodes and expands when the battery is used, and the bone of the grid tries to break through the bag-shaped separator. It can be prevented by the insulating resin.

Among them, particularly when the surface coated with the insulating resin faces the side in contact with the positive electrode plate, it is possible to prevent the separator from breaking through and suppress the deterioration due to the contact between the separator and the positive electrode plate. large. Furthermore, since the left and right ends are insulated, it also has the effect of suppressing the longitudinal extension of both side parts of the positive electrode plate.

Further, the side surface of the bag-shaped separator which is in contact with the center of the lattice is a microporous synthetic resin sheet, and the oxygen gas generated from the positive electrode plate during charging is smoothly retained from the positive electrode plate to the negative electrode without being retained in the separator. It is possible to reach the plate, and it is possible to prevent an increase in internal resistance due to the gas remaining in the separator.

[0012]

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

In the illustrated embodiment, an epoxy resin is applied to both left and right ends of one surface of a microporous synthetic resin sheet, and the positive electrode is applied to a bag-shaped separator formed by bending the application surface inward into a substantially U shape. It shows an example in the case of accommodating a plate.

FIG. 1 shows a state in which a positive electrode plate is housed in a separator in the lead acid battery of this embodiment.
Indicates a bag-shaped separator made of a microporous synthetic resin sheet 1a containing polyethylene resin and silica as main components, and the positive electrode plate 2 is housed in the separator 1. The bag-shaped separator 1 is coated with an epoxy-based insulating resin 3 with a width of 20 mm from the edges on both left and right ends of the synthetic resin sheet 1a, and is bent into a substantially U shape with the side coated with the insulating resin 3 being the inside. The insulating resin 3 is formed into a bag shape by being attached to each other. In this embodiment, the insulating resin 3 is applied beyond the positions of the bones 2a at both ends of the positive electrode plate 2, so that the bones 2a at both ends of the positive electrode plate 2 come into contact with the bag-shaped separator 1. I tried to prevent it surely.

Using the positive electrode plate and the predetermined negative electrode plate housed in the bag-shaped separator 1 as described above, a nominal specification of 2V,
A 48 Ah lead acid battery was prepared and designated as lead acid battery A of the present invention.

Further, as a comparative example, a bag-shaped separator made of a microporous synthetic resin sheet containing polyethylene resin and silica as a main component was used as a separator, and a lead storage battery containing a positive electrode plate therein was designated as a conventional battery B. . Further, a glass fiber mat is attached to the entire one surface of the microporous synthetic resin sheet, and the glass fiber mat is placed so that the glass fiber mat is on the inside.
A battery using a bag-shaped separator formed by bending it into a letter shape was referred to as a conventional battery C. Then, the batteries A, B, and C were continuously charged in a 60 ° C. atmosphere with a charging voltage of 14.0 V.
The battery was charged for 00 hours, discharged as 300 cycles per cycle for 30 seconds, and an overcharge test was conducted with the terminal voltage at the 30th second being 7.2 V or less as the life. The result is shown in FIG.

As shown in FIG. 2, in the conventional battery B, the bag-shaped separator made of polyethylene is broken by the bone of the positive electrode grid due to the corrosion extension of the positive electrode grid, and the positive electrode plate and the negative electrode plate are short-circuited to reach the end of service life early. Was there. On the other hand, the battery A of the present invention
In the conventional battery C, the grid did not break through the bag-shaped separator, but the battery voltage of the battery A was higher than that of the battery C and the life could be improved. This is because in the battery A of the present invention, the oxygen gas generated from the positive electrode plate can be smoothly absorbed by the negative electrode plate through the separator in comparison with the conventional battery C, and bubbles of oxygen gas accumulate in the separator. It is considered that this is because the internal resistance of the battery can be reduced by preventing this.

Further, as the constitutions other than the above-mentioned embodiment of the present invention, the same effect as that of the above-mentioned embodiment was observed in the constitutions shown below. A structure in which a negative electrode plate is housed inside a bag-shaped separator formed by applying an epoxy resin to the left and right ends of one side of a microporous synthetic resin sheet and bending it into a substantially U shape with the applied surface inside. . A positive electrode plate or a negative electrode plate is provided inside a bag-shaped separator formed by applying an epoxy resin to the left and right ends of one side of a microporous synthetic resin sheet and bending it in a substantially U shape with the application surface facing outward. Housed configuration. A structure in which a positive electrode plate or a negative electrode plate is housed inside a bag-shaped separator formed by applying an epoxy resin to both left and right ends of both sides of a microporous synthetic resin sheet and bending it into a substantially U shape.

In any of the above constitutions, the life is improved as compared with the battery of the conventional constitution, but among them, the battery D of the present invention having a constitution in which the surface coated with the epoxy resin faces the side in contact with the positive electrode plate. The above-described overcharge test was performed on the battery E of the present invention having a structure facing the side not contacting with. However, as an evaluation, the test was conducted until the terminal voltage at 30 seconds became 0V. The result is shown in FIG.

As shown in FIG. 3, the battery D of the present invention and the battery E of the present invention did not break through the separator due to the corrosion extension of the lattice, but the battery D did not have a short circuit and had a long life as compared with the battery E. there were. It is considered that this is because, in the battery D, the bones at both end portions of the positive electrode plate were not in direct contact with the separator in the battery D, so that the separator was less susceptible to oxidative deterioration.

[0021]

As described above, in the lead acid battery of the present invention, the insulating resin is applied along the left and right ends of at least one side of the microporous synthetic resin sheet to the bone positions at both ends of the electrode plate, and the sheet is formed. Is used to form a bag-shaped separator by bending the battery into a substantially U shape. When the battery is used, the grid of the positive electrode plate is corroded and expanded, and the bone of the grid tries to break through the bag-shaped separator. In addition, when the insulating resin-coated side of the synthetic resin sheet is directed to the side in contact with the positive electrode plate, it also suppresses oxidative deterioration due to contact between the separator and the positive electrode plate. . Furthermore, since the side portions of the electrode plate can be in an insulating state, the lattice of the side portions can be prevented from extending.

The side surface of the bag-shaped separator in contact with the central portion of the lattice is a microporous synthetic resin sheet, which allows the generated oxygen gas to smoothly reach the negative electrode plate without being retained in the separator. Therefore, it is possible to prevent the internal resistance from increasing due to the gas remaining in the separator.

[Brief description of drawings]

FIG. 1 is a diagram showing a state where a positive electrode plate is accommodated in a separator in an embodiment of the lead acid battery of the present invention.

FIG. 2 is a characteristic diagram showing results of an overcharge test of the present invention and a conventional battery.

FIG. 3 is a characteristic diagram showing the results of an overcharge test depending on the positional relationship between the surface coated with the insulating resin and the positive electrode plate of the battery of the present invention.

[Explanation of symbols]

 1 Bag Separator 1a Microporous Synthetic Resin Sheet 2 Positive Electrode Plate 2a Bone 3 Insulating Resin

Front page continuation (72) Inventor Hiroshi Yasuda 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A microporous synthetic resin sheet is coated with an insulating resin along the left and right ends of at least one side up to the bone positions at both ends of the electrode plate, and the sheet is bent into a substantially U shape to form a bag shape. A lead-acid battery characterized by using a separator formed on. 2. The lead acid battery according to claim 1, wherein the side of the synthetic resin sheet coated with the insulating resin faces the side in contact with the positive electrode plate.