JPH07240199A - Manufacturing method of battery electrode plate and cylindrical battery using the electrode plate - Google Patents

Abstract

(57) [Abstract] [Purpose] When welding a strip-shaped lead plate to the exposed portion of the core body where the active material layer is not formed in the expanded metal or net-shaped electrode plate core body, the lead of the exposed core body portion Prevents the vicinity of the plate welded portion from being deformed and distorted. [Structure] A surface of the electrode plate core body on which the lead plate is not installed is contacted and supported by a concave portion of a concave welding electrode, and the other welding electrode is pressed against the lead plate installed on the exposed portion. The electrode plate core and the lead plate are welded by bringing them into contact with each other and conducting electricity between these electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery electrode plate, and more particularly to a core body formed by removing a part of the active material while allowing the expanded metal or net-shaped core body to hold the active material. The present invention relates to a method for manufacturing an electrode plate in which a strip-shaped lead plate is welded to an exposed portion and a battery using the electrode plate.

[0002]

2. Description of the Related Art Conventionally, in a lithium battery, an active metal is held by an expanded metal, punching metal or net-shaped elongated core, and a part of the active material layer is removed to form an exposed core. The electrode plate that is welded to the strip-shaped lead plate is used.

A method of manufacturing the electrode plate will be described with reference to FIGS. 4, 5 and 6. First, the active material is held on one surface of the expanded metal core 1 as shown in FIG. 4, and the active material layer 2 is formed on the core 1 as shown in FIG. By removing the portion, the exposed core portion 3 is formed.

Then, as shown in FIG. 6, a strip-shaped lead plate 4 is provided on one surface of the exposed portion 3, and a pair of welding electrodes 5 are pressure-contacted on both sides of these strips to energize between the two electrodes. Weld the exposed portion of the core and the lead plate.

[0005]

However, in the electrode plate manufactured as described above, as shown in FIG. 7, the exposed core body portion 3 in the gap between the active material layer 2 and the lead plate 4 is distorted. It may be deformed and the core mesh portion of this portion may be projected from the plane of the electrode plate.

This is because when the lead plate is welded to the exposed portion of the core body, pressure is applied to the exposed portion of the core body and the lead plate between the welding planes of the pair of welding electrodes. As described above, since stress is applied to the core body in an oblique direction at the time of this pressurization, it is considered that the core body tends to stretch unevenly and the vicinity of the lead plate welded portion of the core body projects distortedly.

In the case where a battery is constructed by spirally winding the electrode plate in which the vicinity of the lead plate welded portion of the exposed portion of the core body is distorted in this manner and the electrode plate of the other electrode through the separator in a spiral shape. In some cases, the protruding portion of the core body broke through the separator and came into contact with the electrode plate of the other pole to cause an internal short circuit.

The present invention is intended to solve such a problem, and a strip-shaped lead plate is welded to an exposed portion of the core body of the expanded metal or net-shaped electrode plate where the active material layer is not formed. At this time, the vicinity of the welded portion of the lead plate in the exposed portion of the core body is prevented from being deformed into a distorted shape and protruding.

[0009]

In order to solve the above-mentioned problems, in the method of manufacturing a battery electrode plate of the present invention, the surface of the electrode plate core body on which the lead plate is not installed is exposed by concave welding. The electrode plate is abutted and supported by the recessed portion of the electrode, the other welding electrode is brought into pressure contact with the lead plate provided on one surface of the exposed portion, and the electrode plate core body and the lead plate are welded by energization between these electrodes. It is a thing.

[0010]

In the method of manufacturing a battery electrode plate of the present invention, when the exposed portion of the core body and the lead plate are welded under pressure by a pair of welding electrodes, one of the welding electrodes is formed into a concave shape and It supports the surface of the exposed core where the lead plate does not exist. Therefore, at the time of welding, it is possible to prevent the vicinity of the lead plate welded portion of the core body exposed portion from being deformed to be distorted and protruding on the side surface of the recess of the welding electrode. Therefore, when this electrode plate is used, the work at the time of forming the spiral electrode body is facilitated, and it is possible to prevent the separator from breaking in the electrode body to cause an internal short circuit.

[0011]

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

A method of manufacturing the electrode plate of the present invention will be described with reference to FIG. As shown in the cross-sectional view of FIG. 1, manganese dioxide is used as a main constituent material of manganese dioxide on one surface of an expanded metal-like nickel core 1 having a thickness of 0.10 mm and a thickness of 0.31.
The active material layer 2 having a thickness of 2 mm was formed, and the exposed portion 3 of the core was formed by removing a part of the active material layer 2.

Then, a strip-shaped lead plate 4 having a thickness of 0.15 mm was placed on one surface of the exposed core portion 3 on the same side as the surface on which the active material layer was formed. Then, the surface where the lead plate was not present in the exposed portion of the core was contacted with and supported by the concave copper-cobalt-beryllium alloy welding electrode 5.

Here, the recessed welding electrode 5 has a trapezoidal cross-sectional shape in which the upper side is longer than the lower side, and the inclination angles of both side surfaces are about 5 ° from the bottom surface.

Then, a convex welding electrode 5 is brought into pressure contact with the upper surface of the lead plate 4 installed on the exposed portion of the core, and an electric current is applied between these welding electrodes to separate the exposed portion of the core and the lead plate. Spot welded. The welding conditions at this time are:
kg and accumulated energy 30 w · s. In this way, a positive electrode plate 6 having a cross section as shown in FIG. 2 was produced, which was designated as a positive electrode plate A of the present invention. The positive electrode plate 6 and the negative electrode plate 7 using metallic lithium were spirally wound via a separator 8 made of a polypropylene microporous film to obtain a spiral electrode body. At this time, since the exposed portion of the core body is curved in a substantially convex shape toward the surface where the lead plate does not exist, the spiral electrode body can be easily formed by winding with the welded surface of the lead plate inside. I was able to get it. Further, since the thickness of the lead plate was smaller than that of the active material layer, the separator was not broken by the lead plate.

Then, as shown in FIG. 3, the positive electrode lead plate 4 protruding upward from the electrode body is bent inward, and the lead portion 9 of the negative electrode plate 7 is connected to the lower insulating plate 10.
After bending through the inside of the electrode body via, the electrode body was inserted into the battery case, and the upper insulating plate 12 was attached to the upper portion of the electrode body.

Then, an organic electrolytic solution in which lithium perchlorate was dissolved in a solvent such as polypropylene carbonate was injected from the upper part of the battery case 11, and then a sealing plate 13 was attached and the opening of the case 11 was caulked and sealed. . The thus produced cylindrical lithium battery having a nominal capacity of 1300 mAh was designated as Battery A of the present invention.

Further, in the above concave welding electrode, batteries similar to the present invention were prepared except that the inclination angles of both side surfaces were 10 °, 15 ° and 20 ° from the bottom surface, and the batteries B, C and C of the present invention were produced, respectively. D.

Further, as a comparison, a battery similar to the present invention was manufactured except that a flat welding electrode was used instead of the concave welding electrode, and this was used as a conventional battery E.

Using each of these batteries, 5000 batteries were dropped onto concrete from a height of 1 m 50 times, and the occurrence of internal short circuit of the batteries was examined. The results are shown in (Table 1).

[0021]

[Table 1]

As can be seen from Table 1, in the conventional battery E, the vicinity of the welded portion of the lead plate in the exposed portion of the core of the positive electrode plate was deformed into protrusions and protruded. Was broken and an internal short circuit occurred. On the other hand, in the batteries A to D of the present invention, no protrusion was formed on the exposed portion of the core body of the positive electrode plate, and no internal short circuit occurred.

[0023]

As described above, according to the method for producing a battery electrode plate of the present invention, the active material is held in the electrode plate core, and a part of the active material is removed to form the core exposed part. After that, a strip-shaped lead plate is installed on one surface of the exposed part of the core body and these are welded by a pair of welding electrodes, and no lead plate is installed in the exposed part of the electrode plate core body. The surface is abutted and supported by the concave portion of the concave welding electrode, the other welding electrode is brought into pressure contact with the lead plate installed on the exposed portion, and the electrode plate core body and the lead plate are caused by energization between these electrodes. Is to be welded.

Therefore, even when the exposed portion of the core body and the lead plate are welded under pressure, it is possible to prevent the vicinity of the welded portion of the lead plate from being deformed into protrusions and protruding at the side surface inclined portion of the concave welding electrode. Therefore, the structure of the spiral electrode body is facilitated, and the occurrence of internal short circuit of the battery can be prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing a method for manufacturing an electrode plate of the present invention.

FIG. 2 is a sectional view of an electrode plate obtained by the manufacturing method of the present invention.

FIG. 3 is a sectional view of a cylindrical battery.

FIG. 4 is a plan view of an expanded metal core body.

FIG. 5 is a view showing a state in which an expanded metal-like core body holds an active material, and a part of the active material is removed to form an exposed portion of the core body.

FIG. 6 is a diagram showing a conventional method for manufacturing an electrode plate.

FIG. 7 is a sectional view of an electrode plate obtained by a conventional manufacturing method.

[Explanation of symbols]

 1 core 2 active material layer 3 core exposed part 4 strip-shaped lead plate 5 welding electrode 6 positive electrode plate 7 negative electrode plate 8 separator 9 negative electrode lead portion 10 lower insulating plate 11 battery case 12 upper insulating plate 13 sealing plate

Claims (3)

[Claims] 1. An active material is held by an electrode plate core, and
After removing a part of the active material to form a core exposed part, a strip-shaped lead plate is installed on one surface of the core exposed part and these are welded with a pair of welding electrodes. In the manufacturing method, a surface of the electrode plate core on which the lead plate is not installed is supported in contact with a recess of a concave welding electrode, and the other welding electrode is attached to the lead plate installed on the exposed part. A method for manufacturing a battery electrode plate, in which the electrode plate core body and the lead plate are welded by applying pressure to each other and energizing the electrodes. 2. The method for producing a battery electrode plate according to claim 1, wherein the recessed welding electrode has a trapezoidal cross section in which the upper side is longer than the lower side. 3. An active material layer is formed on one surface of an electrode plate core, and a part of the active material is removed to form an exposed part of the core, which is on the same side as the surface on which the active material layer is present. On one surface of the exposed part, a strip-shaped lead plate thinner than the thickness of the active material layer is welded, and the electrode plate in which the exposed part is curved in a substantially convex shape toward the surface where the lead plate does not exist is welded to the lead plate. Cylindrical battery wound in a spiral shape with the opposite side inside and a polar plate of the other polarity through a separator.