JPH0594835A - Sealed type lead-acid battery - Google Patents

Abstract

PURPOSE:To provide a sealed type lead-acid battery in which the form of electrode plates is reformed in order to prevent an internal short circuit owing to an active material. CONSTITUTION:An inclination is given to a grid frame skeleton 4 at the side surface of an electrode plate which consists of a grid and an active material 5, and a sealed type lead storage battery is composed of an electrode plate group made by grouping positive electrode plates 6 and negative electrode plates 7 placing separators 8 between them. By such a constitution, the distance that the active material removed from an electrode plate comes to contact with a neighboring electrode plate can be increased, and a generation of internal short circuit can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed lead acid battery in which electrode plates are arranged so as to prevent an internal short circuit between the electrode plates.

[0002]

2. Description of the Related Art In recent years, applications of sealed lead-acid batteries have been expanded in order to promote maintenance-free operation.

The structure of a conventional sealed lead-acid battery will be described below with reference to the drawings. FIG. 5 shows the structure of a conventional electrode plate. As shown in the figure, the active material portion 11 is inside the lattice frame skeleton portion 10 of the electrode plate, and the ear portion 9 of the electrode plate is above. As shown in FIG. 6, this electrode plate has a positive electrode plate 12 placed in a U-shaped separator 14 and a negative electrode plate 1 between the U-shaped separators 14.
It becomes the structure which sandwiched 3. As shown in FIG. 5, the positive electrode 12 and the negative electrode plate 13 have a rectangular cross section.

In such a conventional structure, an internal short circuit of the battery often occurs after the battery is assembled. The cause of this short circuit is often due to the dropping of the active material in the electrode plate.
This is because the active material particles that have fallen off adhere to the adjacent electrode plates and bridge the electrode plates to cause a short circuit. FIG. 7 shows the configuration of a conventional electrode plate group viewed from above, and the electrode plates that should originally be housed in the separator like the positive and negative electrode plates A in FIG.
Like the positive and negative plates a, both plates are offset from the center of the separator and are offset in the same direction. If the active material falls off in such a configuration, the probability of causing an internal short circuit increases. This is because the distance between the electrode plates becomes shorter due to the deviation of the electrode plates. As shown in FIG. 6, the shortest distance between the electrode plates is only X.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem. Even if the electrodes are laterally or vertically displaced after assembling the batteries by assembling the electrodes. It is an object of the present invention to provide a sealed lead-acid battery that does not cause an internal short circuit due to a dropped active material.

[0006]

In order to solve this problem, according to the present invention, both the positive electrode plate and the negative electrode plate have a shape in which the lattice frame skeleton on the side surface of the electrode plate has an inclination, and the cross-sectional shape of the electrode plate. Has a trapezoid. An electrode plate group obtained by grouping such an electrode plate and a U-shaped separator is used.

[0007] Further, all surfaces of the front side of the electrode plate are orientated in the same direction with the surface having the inclined portion of the electrode plate as the front, or a center line is provided in the central portion of the both electrode plates so that This is to use an electrode plate group which is grouped with all the surfaces facing the center line.

[0008]

According to this construction, since the lattice frame frame on the side surface of the electrode plate is inclined, the shortest distance between the positive electrode plate 6 and the negative electrode plate 7 adjacent thereto via the separator 8 as shown in FIG. The distance is increased by the inclined portion 4 of the frame portion of the lattice frame. That is, as can be seen from FIG. 4, the conventional shortest distance is X +
x, and becomes longer by x. Therefore, it is impossible to short-circuit both electrodes across the distance X + x with the size of the dropped active material particles, and it is possible to prevent an internal short-circuit of the battery.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sealed lead acid battery according to an embodiment of the present invention will be described below with reference to the drawings.

1A and 1B show the structure of the sealed lead-acid battery of this embodiment. As shown in the figure, an electrode plate is used in which the four sides of the lattice frame skeleton 4 are inclined. The electrode plate manufacturing method is
The lattice frame skeleton 4 having an inclined side surface is produced by casting, and the ear 3 is attached. The inclined surface was designated as the front surface 1 and the reflective side was designated as the back surface 2. This was filled with a paste prepared by kneading sulfuric acid, water and lead powder to prepare an electrode plate so that the positive electrode plate 6 had a thickness of about 3.65 mm and the negative electrode plate 7 had a thickness of about 1.9 mm.

Then, as shown in FIG. 2, the front surface 1 of the electrode plate
Are grouped with a U-shaped separator 8 sandwiched therebetween so that all of them face the same direction. Alternatively, as shown in FIG. 3, a center line AA is provided at the center of the electrode plate group, and the electrode plate group is sandwiched with a U-shaped separator 8 so that all the electrode plates face the center line AA. Constitute. 1000 6V1.3Ah batteries were trial-produced in this group, and the relationship between the defect rate based on an internal short circuit caused by the dropping of the active material after charging and the distance between the electrode plates was compared with the conventional battery. The result is shown in FIG. Figure 8
As can be seen from the result, the battery using the electrode plate of this example has a shortest distance (X + x) between electrode plates of 2.3 to 2.8 mm,
The occurrence rate of internal short circuit decreased from 0.6% to 0.2%, and the occurrence of defective rate was reduced as compared with the case of using the conventional electrode plate.

[0012]

As is apparent from the above description of the embodiments, according to the present invention, the active material of the electrode plate is prevented from falling off by inclining the frame portion of the lattice frame and increasing the distance between the electrode plates. The defective rate due to an internal short circuit caused by the cause can be reduced, and the quality of the battery can be improved.

[Brief description of drawings]

FIG. 1A is a plan view of positive and negative electrode plates of the present invention, and FIG. 1B is a side view of the same.

FIG. 2 is a cross-sectional view showing a configuration of a homopolar plate group.

FIG. 3 is a cross-sectional view showing another configuration of the homopolar plate group.

FIG. 4 is a sectional view showing the shortest distance between the same polar plates.

5A is a plan view of a conventional positive and negative electrode plate, and FIG. 5B is a side view of the same.

FIG. 6 is a vertical cross-sectional view showing the configuration of a homopolar plate group.

FIG. 7 is a horizontal cross-sectional view showing the configuration of an electrode plate group having the same positional deviation.

FIG. 8 is a diagram showing the relationship between the occurrence rate of internal short circuits and the shortest distance between electrode plates.

[Explanation of symbols]

 1 Front Surface of Electrode Plate 2 Back Surface of Electrode Plate 3 Ear Part 4 Lattice Frame Bone Part 5 Active Material Part 6 Positive Electrode Plate 7 Negative Electrode Plate 8 Separator X Shortest Distance between Electrode Plates x Increased by using the electrode plate of the present invention Distance between pole plates

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Tadashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A positive electrode plate and a negative electrode plate, each of which has an inclination in the thickness direction on a grid frame on four sides of an electrode plate, and an electrode plate group in which a separator is sandwiched between the positive and negative electrode plates to perform grouping. Sealed lead acid battery. 2. A positive electrode and a negative electrode that are inclined in the thickness direction on the lattice frame skeletons on the two sides of the electrode plate, and an electrode plate group that is grouped by sandwiching a separator between the positive and negative electrode plates. Sealed lead acid battery. 3. An electrode plate group in which the surfaces of the positive and negative electrode plates are grouped so that all the surface faces of the positive and negative electrode plates face the same direction. The sealed lead-acid battery described. 4. A center line is provided in the central portion of the electrode plate group in which positive and negative electrode plates are grouped, and grouping is performed so that all the front surfaces of the positive and negative electrode plates face the center line. The sealed lead-acid battery according to claim 1 or 2, wherein the sealed lead-acid battery comprises an electrode group.