JPH06243857A - Cylindrical secondary battery - Google Patents

Abstract

PURPOSE:To prevent an anode lead plate from being brought into contact with a cathode plate out of an electrode group, and thereby surely restrain the occurrence of internal shortcircuiting by disposing a circular insulating plate over the electrode group. CONSTITUTION:An impregnation hole and a ventilation hole are provided for a circular insulating plate 1 made of resin, and a lead insertion hole is provided for an anode lead plate 9 close to its installation section so as to be disposed over an electrode group 5. By this constitution, no electrolytic solution is prevented from being poured, and moreover, the anode plate 9 is prevented from being brought into contact with a cathode 6 by the insulating plate 1, so that the occurrence of internal shortcircuiting is surely restrained even if the insulating tape 10 of the anode leat plate is damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical secondary battery, and relates to improvement of an insulating member arranged on an electrode group.

[0002]

2. Description of the Related Art Conventionally, in a cylindrical secondary battery using a positive electrode plate with a lead, as shown in FIG. 4, an insulating tape 10 is attached to both the lead 9 and the lead mounting portion excluding the tip end from both sides of the positive electrode plate 8. Bond the leads 9 and the case 13 as shown in FIG.
In addition to preventing a short circuit with the negative electrode plate 6 in the electrode group 5, it is common to install an insulating ring 11 on the electrode group 5 to prevent a short circuit between the case 13 and the positive electrode plate 8 in the electrode group 5. It was target.

[0003]

However, in the above-mentioned conventional method, as shown in FIG. 3, when the positive electrode lead 9 is welded to the back surface of the sealing plate 12 to close the case 13, the bent portion of the lead 9 is bent. There is a drawback that 14 may come into contact with the edge portion of the negative electrode plate 6 in the electrode group 5 and the insulating tape 10 may be damaged to cause an internal short circuit. In addition, 7 in the figure
Indicates a separator.

An object of the present invention is to solve the above conventional problems and to provide a cylindrical secondary battery capable of reliably preventing an internal short circuit caused by contact between a positive electrode lead and a negative electrode in an electrode group. It is in.

[0005]

In the cylindrical secondary battery of the present invention, an electrode group in which a positive electrode plate, a negative electrode plate, and a separator interposed between these electrode plates are spirally wound, and this electrode In a cylindrical secondary battery provided with an insulating member arranged on a group, the insulating member is formed in a circular flat plate shape, and a lead insertion hole formed in a shape substantially corresponding to the cross-sectional shape of the lead, It is characterized in that it has a small diameter electrolyte injection hole through which the lead does not pass.

If necessary, at least one small-diameter vent hole through which the lead does not pass is provided in the flat plate-shaped insulating member.
It is preferable to provide one so that the replacement of the electrolytic solution with the air inside the battery can be promoted during the injection step.

[0007]

[Function] Even after the circular flat plate-shaped insulating plate is arranged on the electrode plate group, it is easy to inject the electrolytic solution by using the liquid injection hole.
Since the diameter of this liquid injection hole is such that the positive electrode lead plate does not pass through, an internal short circuit due to contact between the positive electrode lead and the negative electrode plate in the electrode group can be prevented.

Furthermore, even when a vent is provided,
Since the diameter of the vent hole is also a size through which the positive electrode lead does not pass, the same effect can be obtained.

Further, since the lead insertion hole is formed in a shape substantially corresponding to the cross-sectional shape of the lead, it is possible to completely prevent an internal short circuit even when the insulating tape in the bent portion of the lead is damaged.

[0010]

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

FIG. 1 shows a plan view of an insulating plate 1 which is an insulating member used in the present invention. This insulating plate 1 is made of resin and is formed in a circular flat plate shape. The liquid injection hole 2 having a diameter of 2 to 3 mm provided in the center and the electrolyte solution and the air inside the battery are replaced during the liquid injection process. Diameter 1 with a focus on promoting
Vent hole 3 of ~ 2 mm, long side 6-7 mm, short side 1-2 m
m rectangular lead insertion hole 4. In this embodiment, two ventilation holes 3 are provided.

The lead insertion hole 4 has a long side which is larger than the width of the insulating tape 10 by about 1 to 2 mm, and two of the insulating tape 10.
It is formed in a rectangular shape having a short side that is about twice the thickness of the positive electrode lead 9 plus the thickness of the positive electrode lead 9, and is located at an intermediate position between the straight line passing through the center of the insulating plate 1 and the outer edge of the insulating plate 1. The straight line passing through the center of 1 and the long side are arranged in parallel. That is, the lead insertion hole 4 is formed so as to be arranged on the electrode group in the vicinity of the mounting portion of the lead 9.

The ventilation hole 3 is provided in a region facing a region where the lead insertion hole 4 exists with respect to a straight line passing through the center of the insulating plate 1. These injection holes 2 and ventilation holes 3
The lead insertion hole 4 and the lead insertion hole 4 are arranged at positions where they do not interfere with each other and do not contact the outer edge of the insulating plate 1.

FIG. 2 is a vertical sectional view of a cylindrical secondary battery using the insulating plate 1 of FIG. The electrode group 5 is composed of a positive electrode plate 8, a negative electrode plate 6 and a separator 7 interposed between these electrode plates, and the insulating plate 1 is placed on the electrode group 5. The electrode group 5 is housed in the battery outer case 13, and after the outer case 13 is grooved, the positive electrode lead portion 9 is welded to the back surface of the sealing plate 12, and the case 13 is closed by the sealing plate 12.

[0015]

As described above, according to the present invention, the liquid can be injected easily as in the conventional case, and the internal short circuit can be completely prevented even when the insulating tape of the positive electrode lead is damaged. A secondary battery can be provided.

[Brief description of drawings]

FIG. 1 is a plan view of an insulating plate according to an embodiment of the present invention.

2 is a vertical cross-sectional view of a cylindrical secondary battery using the insulating plate of FIG.

FIG. 3 is a vertical cross-sectional view of a conventional cylindrical secondary battery.

FIG. 4 is a plan view of a positive electrode plate.

[Explanation of symbols]

 1 Insulation plate 2 Injection hole 3 Vent hole 4 Lead insertion hole 5 Electrode group 6 Negative electrode plate 7 Separator 8 Positive electrode plate 9 Positive electrode lead plate 10 Insulation tape 11 Insulation ring 12 Sealing plate 13 Exterior case 14 Lead bent part

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

Claims (2)

[Claims] 1. A cylindrical two-dimensional structure including an electrode group in which a positive electrode plate, a negative electrode plate, and a separator inserted between these electrode plates are spirally wound, and an insulating member disposed on the electrode group. In the secondary battery, the insulating member is formed in a circular flat plate shape, and has a lead insertion hole formed in a shape substantially corresponding to the cross-sectional shape of the lead, and a small diameter electrolyte injection hole through which the lead does not pass. A cylindrical secondary battery characterized in that 2. The cylindrical secondary battery according to claim 1, wherein the flat insulating member is provided with at least one small-diameter vent hole through which the lead does not pass.