JPH04301360A - Manufacture for battery connecting collecting plate to pole plate - Google Patents

Abstract

PURPOSE:To prevent generation of a short-circuit due to a protrusion in a collecting plate by providing a foaming resin film in a non-foaming condition in a surface of the collecting plate opposed to an element cell. CONSTITUTION:A foaming resin film 5 is laminated in a non-foaming condition on a surface of a collecting plate 4 opposed to an element cell, and after a protrusion 8 of the plate 11 is connected to a pole plate of the element cell, the film 5 is foamed and expanded between the element cell and the plate 4. Since a space between the element cell and the plate 4 is filled with foamed synthetic resin, even when an interpole earth piece temporarily falls off, a short-circuit is prevented from being generated. That is, the plate 4 is insulated from an interpole plate, and the short-circuit, which is a fatal defect of the element cell, between the plate 4 and the pole plate can be almost clearly eliminated. Since the non-foaming film 5 is provided in the plate 4 and foamed after connecting the plate 4 to the pole plate, the pole plate can be easily connected to the plate 4 similarly to the past and also foaming between the plate 4 and the pole plate to provide complete isolation thereof by the inflated synthetic resin, so that insulation can be effectively attained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a battery in which an electrode plate insulated with a separator is connected to a current collector plate.

0002

[Prior Art] Sealed alkaline storage batteries with positive and negative electrode plates insulated by separators are generally constructed by winding both the positive and negative electrode plates in a spiral shape through the separator. It is. As a method for collecting current from a unit cell having such a configuration, the following structure is often adopted in order to be advantageous in extracting a large current.

[0003] A band-shaped electrode plate is wound into a spiral shape with a separator in between to form a unit cell. ■ The core metal of the electrode plate is made to protrude from the end face in the axial direction of the unit cell wound into a cylindrical shape. To achieve this, the strip-shaped electrode plate is not coated with active material on one edge. ■
A current collector plate is disposed opposite the protruding surface of the electrode plate, and the current collector plate and the core metal of the electrode plate are connected by a method such as welding.

[0004] The method of connecting the electrode plate to the current collector plate using the above method is disclosed in Japanese Utility Model Application Publication No. 127667/1983 and Japanese Utility Model Application Publication No. 1987-127667.
-41667. In the methods described in these publications, irregularities are provided on the surface of the current collector plate. The unevenness improves weldability and welding strength between the current collector plate and the electrode plate. This is because it is possible to weld by making the electrode plate bite into the unevenness. To provide irregularities on the current collector plate, for example, a common metal plate is burred to provide a plurality of protrusions, or a material with many irregularities, such as a lath plate, is welded to the surface of the metal plate.

[0005]

This method has the advantage that the electrode plates can be reliably connected due to the unevenness of the current collector plate. However, batteries manufactured by this method have the drawback that the electrode plates swell due to repeated charging and discharging cycles, or a portion of the electrode plates easily fall off, causing a short circuit. The reason for this is that the protruding portion of the current collector plate digs deeply into the electrode plate when welding the electrode plate, reaching close to the edge of the opposite electrode.

[0006] The present invention was developed with the aim of solving this drawback, and an important object of the present invention is to provide a current collector plate to an electrode plate that can prevent the occurrence of short circuits caused by protrusions on the current collector plate. The purpose of the present invention is to provide a method for manufacturing a battery that connects the

[0007]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the method of manufacturing a battery in which a current collector plate is connected to an electrode plate of the present invention involves manufacturing the battery through the following steps. That is, the method of the present invention includes the steps of obtaining a unit cell 2 in which positive and negative electrode plates 3A and 3B are disposed at opposite positions with a separator 1 interposed therebetween, and a step of obtaining a unit cell 2 in which positive and negative electrode plates 3A and 3B are arranged at opposite positions with a separator 1 interposed therebetween; This is an improved method of manufacturing a battery, which includes the step of connecting to the protrusions of the plate 4.

In the manufacturing method of the present invention, a foamed resin film 5 is laminated in an unfoamed state on the surface of the current collector plate 4 facing the unit cell 2, and the protrusions of the current collector plate 4 are connected to the electrode plate of the unit cell 2. 3A, 3B
This is characterized in that the resin film 5 is foamed to expand between the unit cell 2 and the current collector plate 4 after the battery is connected to the current collector plate 4.

The easiest way to provide the resin film 5 that foams on the current collector plate 4 is to adhere a synthetic resin sheet that foams when heated, or to apply a liquid or paste synthetic resin that foams when heated. be. As the resin film that foams, it is also possible to use a resin film that foams over time, for example, without depending on heating. The easiest way to provide protrusions on the surface of the current collector plate is to burr the current collector plate provided with a resin film.

0010

[Function] In the battery manufacturing method of the present invention, since the foamed synthetic resin fills the space between the unit cell 2 and the current collector plate 4,
Even if the counter electrode plate piece were to fall off, it would not cause a short circuit.

[0011]

[Embodiments] Examples of the present invention will be described below. however,
The examples shown below illustrate a manufacturing method for embodying the technical idea of this invention, and the method of this invention includes:
The following does not specify manufacturing conditions, materials used, or the structure of each part of the battery. The method of this invention is
Various changes can be made within the scope of the claims.

[Example] In the following steps, the electrode plate of a unit cell is connected to a current collector plate. (2) The band-shaped positive and negative electrode plates 3A and 3B are wound up in a spiral shape with the separator 1 in between, to form a unit cell 2 of a nickel-cadmium battery as shown in FIG. The positive and negative electrode plates have a core metal 7 exposed along one edge connected to the current collector plate 4. The exposed portion of the core bar 7 is not coated with active material on the surface of the core bar 7. The unit cell 2 has one end connected to the current collector plate 4 on the anode side and the other end connected to the current collector plate 4 on the negative electrode side. Therefore, in the unit cell, for example, a positive electrode plate projects from the upper end of the unit cell 2, and a negative electrode plate projects from the lower side. For this reason, the positive and negative electrode plates with the core bar 7 exposed on one side are stacked on the anode side and the negative electrode side with the protruding side of the core bar 7 on the opposite side, and are wound up in a spiral to form the unit cell 2. do.

(2) Processing the current collector plate 4 connected to the positive and negative electrode plates of the unit cell 2. For the current collector plate 4, a metal plate such as a nickel plate with a thickness of 0.2 mm is used. A metal plate is cut into the shape shown in FIG. 1, that is, a shape in which lead wires protrude from the outer periphery of a disk to obtain a current collector plate 4.

(2) A resin film 5 that foams when heated is adhered to one side of the current collector plate 4. For the resin film 5, a polyolefin resin sheet is used. The resin sheet used has a material thickness of 0.1 mm and a foaming rate of 10 times, that is, the thickness after foaming is 10 times the thickness of the material in an unfoamed state.

[0015] ■ A current collector plate 4 with a resin sheet adhered to it,
A burring process is performed to provide a plurality of protrusions 8 on one side as shown in FIG. The protrusion 8 is cylindrical and protrudes from the surface to which the resin sheet is adhered. The inner diameter of the protrusion 8 is 4 mmφ, and the protrusion height is 0.5 mm.

■ As shown in FIG. 2, the obtained current collector plate 4 is placed facing the end of the unit cell 2, and resistance welded to the core bar 7 of the positive and negative electrode plates of the unit cell 2. Weld by.

■ Thereafter, the resin film 5 adhered to the current collector plate 4 is foamed by placing it in an atmosphere of 100° C. for 10 minutes, as shown in FIG. Synthetic resin 6 is used. After that, they are assembled in the usual way to complete the battery.

[Comparative Example] In order to compare the characteristics of the battery manufactured in the example, a comparative battery was completed in the same manner as in the example except that the foamable resin sheet was not used.

Batteries of 100 cells each were manufactured using the methods of the above-mentioned Examples and Comparative Examples. After charging and discharging the manufactured batteries, they were subjected to a vibration test to investigate the failure rate. However, in this test, the battery was charged at 0.1C for 16 hours and discharged at 1C to give a final voltage of 1.0V.

The results are shown in Table 1. As shown in this table, the nickel-cadmium battery manufactured by the method of the present invention was able to eliminate all short-circuits in the above tests, whereas the nickel-cadmium battery prototyped in the comparative example 1% of cases resulted in a short circuit due to complete contact with the electrode plate, and 3% of cases resulted in an abnormal voltage drop due to contact between the electrode plate and current collector plate, that is, a slight short circuit.

[0021]

[Table 1]

[0022] Although the above embodiment describes a method for manufacturing a nickel-cadmium battery, the method of the present invention can be effectively used for manufacturing any battery having a structure in which the electrode plate of a unit cell is connected to a current collector plate. It goes without saying that it can be done.

[0023]

[Effect] The battery manufacturing method of the present invention has the excellent feature of almost completely eliminating the short circuit between the current collector plate and the electrode plate, which was a fatal defect in batteries, by adding simple processes and inexpensive materials. be. This is because a synthetic resin foam is filled between the current collector plate and the electrode plate, thereby insulating the current collector plate and the counter electrode plate.

Furthermore, the battery manufacturing method of the present invention is so simple that it is almost as simple as the conventional method, since an unfoamed resin film is provided on the current collector plate and foamed after the current collector plate and the electrode plate are connected. The electrode plate can be connected to the current collector plate, and the gap between the current collector plate and the electrode plate can be completely isolated and effectively insulated by the foamed and expanded synthetic resin.

[Brief explanation of drawings]

[Figure 1] Perspective view of a current collector plate provided with an unfoamed resin film

[Figure 2
】Cross-sectional view of the main parts of the battery showing the state where the current collector plate is connected to the electrode plate and there is an unfoamed resin film.

[Figure 3] Cross-sectional view of the main parts of the battery showing the foamed resin film

[Explanation of symbols]

1...Separator
2...Battery 3A...Positive electrode plate
3B...Cathode plate 4...Current collector plate
5... Resin film 6... Foamed synthetic resin
7...Core metal 8...Protrusion

Claims (1)

[Claims] Claim 1: A battery comprising the steps of obtaining a unit cell in which positive and negative electrode plates are disposed at opposite positions with a separator interposed therebetween, and connecting the electrode plates of this unit cell to protrusions of a current collector plate. In the manufacturing method, a foaming resin film is provided in an unfoamed state on the surface of the current collector plate facing the unit cell, and after connecting the protrusions of the current collector plate to the electrode plate of the unit cell, the resin film is foamed to form the unit cell. A method for manufacturing a battery in which a current collector plate is connected to an electrode plate, which is expanded between the battery and the current collector plate.