JP2001093504A - Battery and manufacturing method thereof - Google Patents

Abstract

(57) [Problem] To provide a battery and a method of manufacturing the same, which achieve an increase in battery capacity and an improvement in current collecting performance by improving a current collecting structure. SOLUTION: A plurality of positive plates 2 and negative plates 3 are laminated via a separator 4 and are arranged and accommodated in a battery case 5 so that the ends of the positive plates 2 protrude. The negative electrode plate 3 contacts the inner surface of the battery case 5 and is connected to the battery case 5 serving as a negative electrode terminal of the battery 1. The end of each positive electrode plate 2 is in contact with the current collector plate 6, and the contact portions are joined by laser welding at a plurality of positions.
Connected to 0. Since each positive electrode plate 2 is joined to the current collecting plate 6 at multiple points, current collecting efficiency is increased and the internal resistance of the battery is reduced. Further, since the space for the current collecting connection is reduced, the area of each electrode plate can be increased to increase the battery capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery and a method for manufacturing the same, which increase the battery capacity and the current collection efficiency.

[0002]

2. Description of the Related Art In a battery in which a plurality of positive plates and negative plates are stacked with a separator interposed therebetween, each positive plate and each negative plate are joined between the same electrodes, and are respectively connected to the positive terminal and the negative terminal of the battery. Connected. FIG. 8 shows a conventional structure of a battery in which electrode plates are formed in a laminated structure, and shows an example of a nickel-metal hydride battery formed in a rectangular shape.

In FIG. 8, a positive electrode plate 21 and a negative electrode plate 22 are laminated with a separator 23 interposed therebetween to form an electrode plate group 3.
0 is formed. As shown in FIG. 9 (a), the electrode group 30 is enclosed in a bag-shaped separator 23.
Positive plates 21 and the positive plates 21 on both sides during folding
And the negative electrode plate 22 sandwiching it. By inserting the electrode plate group 30 into the battery case 25, the negative electrode plate 22 comes into contact with the battery case 25 and is connected to the battery case 25 serving as a negative electrode terminal of the battery. On the other hand, as shown in FIG. 9 (b), the positive electrode plate 21 bundles lead terminals 24 protrudingly formed on the respective positive electrode plates 21, and performs laser welding together with the relay lead 26, and connects the other end of the relay lead 26 to the positive electrode terminal 28. Is connected by current collection.

[0004] The current collecting structure configured as described above and a manufacturing method thereof are disclosed in Japanese Patent Application Laid-Open No. 7-220715.

[0005]

If the batteries have the same standard size, it is desirable that the batteries have a larger battery capacity. To realize this, a larger case of electrode plates is accommodated in a battery case of the same size. There is a need to. However, in the structure in which the lead terminals 24 are bundled in order to pull out the relay lead 26 from each lead terminal 24 and joined to the relay lead 26 as in the above-described conventional configuration, the battery case 25 is connected to the battery case 25 for current collection connection. And the size of the positive electrode plate 21 and the negative electrode plate 22 as power generating elements is limited. In addition, since the current collection from each positive electrode plate 21 is performed from one lead terminal 24, the current collection efficiency is low and there is a problem that it is difficult to reduce the internal resistance of the battery.

An object of the present invention is to provide a battery and a method of manufacturing the same, in which the volume of the power generating element is increased and the current collection efficiency is improved by a lead bonding structure for reducing the space required for lead bonding. To provide.

[0007]

According to a first aspect of the present invention, there is provided a battery in which a positive electrode plate and a negative electrode plate are disposed in a battery case with a separator interposed therebetween, and the positive electrode plate is connected to the battery. In a battery in which each negative electrode plate is connected to the positive electrode terminal and each negative electrode plate is connected to the negative electrode terminal of the battery, the positive electrode plate and / or the negative electrode plate are arranged such that their ends protrude in a predetermined direction from the other electrode plate. The end of each electrode plate and the current collector plate arranged so as to be in contact with the end surface of the protruding electrode plate are joined at a plurality of positions by melting and resolidification by scanning with a laser beam. It is characterized by comprising a plate connected to a positive electrode terminal and / or a negative electrode terminal.

In the battery having the above structure, the positive electrode plate and / or the negative electrode plate are laser-welded to the current collector plate at a plurality of positions.
The current collection efficiency from the electrode plate is improved, and the internal resistance of the battery can be reduced. In addition, since the space for the current collecting connection can be reduced, the capacity for accommodating the electrode plates is increased by the reduction, and the battery capacity of batteries of the same standard size can be increased by increasing the area of the electrode plates.

According to a second aspect of the present invention, there is provided a method of manufacturing a battery, wherein a positive electrode plate and a negative electrode plate are disposed in a battery case with a separator interposed therebetween, and the positive electrode plate is connected to a positive electrode of the battery. In a method for manufacturing a battery, wherein a negative electrode plate is connected to a negative electrode terminal of a battery by current collection at a terminal, the positive electrode plate and / or the negative electrode plate are arranged such that their ends project in a predetermined direction from the other electrode plate. Then, a current collecting plate is disposed so as to abut on the end surface of the protruding electrode plate, and the end surface of the current collecting plate and the electrode plate is scanned by scanning a contact position of the current collecting plate with the electrode plate with a laser beam. It is characterized in that the current collector plate and the end of each electrode plate are joined at a plurality of positions by melting and resolidifying the melted portion.

According to the above-described battery manufacturing method, when the current collector in contact with the end face of the protruding electrode plate is scanned with the laser beam, the current collector at the portion irradiated with the beam is melted. The end face of the electrode plate in contact with the electrode also melts, and when the melted portion re-solidifies, the electrode plate is joined to the current collector plate. Since the current collecting connection by the current collecting plate is made at a plurality of positions, the current collecting efficiency from the electrode plate can be improved. Further, in this current collection connection structure, the space can be reduced, so that the area of the electrode plate can be increased, and the battery capacity of batteries of the same standard size can be increased.

In the above manufacturing method, the protruding end portion of the electrode plate is bent in the direction in which the electrode plates are arranged, and the current collector plate is pressed against the bent end surface, whereby the end portion of the electrode plate is bent. The part can be brought into elastic contact with the current collector plate, and the contact with the current collector plate can be ensured.

Further, when the current collector plate is melted and opened by the laser beam, the laser beam transmitted through the opening is formed by making the position of the bent end face overlap with the surface position of the same polar plate in the bending direction. Irradiation of the beam to a location other than the welding site can be blocked by the overlap portion.

[0013] Further, by irradiating the laser beam from an angle direction inclined at a predetermined angle from the plate surface direction of the electrode plate, the reflection of the laser beam does not return to the laser head, and the laser beam is collected by the reflected beam. Damage to the optical lens and the like can be prevented.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.

FIG. 1 shows the configuration of a battery 1 according to this embodiment with a part of a battery case 5 opened.
Battery 1 is configured as a square nickel-metal hydride battery. The battery 1 is formed by inserting an electrode plate group 8 in which a plurality of positive electrode plates 2 and negative electrode plates 3 are laminated via a separator 4 into a battery case 5 and closing an opening of the battery case 5 with a sealing plate 9. Is done. When the negative electrode plate 3 contacts the inner surface of the battery case 5, the negative electrode plate 3 is connected to the battery case 5 serving as a negative electrode terminal of the battery 1. Further, each positive electrode plate 2 is joined to a current collector plate 6, and a lead 7 joined to the current collector plate 6 is joined to a positive electrode terminal 10 provided on a sealing plate 9, so that each positive electrode plate 2
Is connected to the positive electrode terminal 10.

The electrode group 8 is formed as shown in FIG. As shown in FIG. 2 (a), the positive electrode plate 2 holds the positive electrode active material 14 on both sides of the positive electrode core material 12 with the ends thereof left.
It is constituted by painting. As shown in FIG. 2B, the positive electrode plate 2 is inserted into a bag-shaped separator 4 in a state where an end portion on which the positive electrode active material is not applied is exposed. Further, the negative electrode plate 3 is configured by applying a negative electrode active material to both surfaces of a negative electrode core material. This negative electrode plate 3 is folded in half as shown in FIG. 2 (c), and the positive electrode plate 2 inserted in the separator 4 is sandwiched. As shown in FIG. 2 (d), the positive electrode plate 2 is sandwiched between the negative electrode plates 3. With both ends
By arranging the positive electrode plate 2 inserted in the separator 4 in the meantime, the positive electrode plate 2 and the negative electrode plate 3 are formed in the electrode group 8 alternately arranged with the separator 4 interposed therebetween. The electrode plate group 8 is inserted into the battery case 5 in a state where the end of the positive electrode core material 12 of the positive electrode plate 2 is arranged so as to protrude from the end of the negative electrode plate 3.

The electrode group 8 inserted into the battery case 5
Since each negative electrode plate 3 comes into contact with the inner surface of the battery case 5 and is connected to the current collector, the battery case 5 serves as a negative electrode terminal of the battery 1. On the other hand, each positive electrode plate 2 is connected by a current collecting plate 6 for current collection, and this current collecting plate 6 is lead-connected to a positive electrode terminal 10 provided on a sealing plate 9 for closing the opening of the battery case 5. The connection structure and connection method of the positive electrode plate 2 to the positive electrode terminal 10 will be described below.

As shown in FIG. 3, the current collecting plate 6 has a plurality of projections 11 formed by V-shaped or U-shaped grooves in cross section. The direction in which the protrusions 11 are formed is formed in a direction that intersects the surface direction of the positive electrode plate 2. As shown in FIG. 4, the current collecting plate 6 is provided on the electrode group 8 with the protrusions 11.
Are arranged so that the bottom surface of each of them abuts on each positive electrode plate 2. next,
The upper surface of the current collector plate 6 is irradiated with a laser beam from a laser head 13 to melt and open the current collector plate 6 and simultaneously melt the positive electrode core material 12 in contact with the projection 11 of the positive electrode plate 2. Since the laser beam is moved at a predetermined speed, the molten portion of the trace of the movement of the laser beam closes the opened hole and solidifies. In the embodiment, the thickness of the positive electrode core material 12 is as follows:
0.025 mm, thickness of current collector 6: 0.2 mm, protrusion 1
The positive electrode core material 12 and the current collector plate 6 are securely welded under the conditions of the height of 1: 0.4 mm, laser output: 50 W, laser pulse width: 3 to 10 ms, and moving speed of the laser beam: 3 mm / sec. As a result, the portion of the protrusion 11 where the inside of the groove was melted and opened was also closed with solidification.

As described above, one end of the lead 7 is joined to the current collector plate 6 connected to each positive electrode plate 2 at multiple points by laser welding, and the other end of the lead 7 is joined to the positive electrode terminal 10. Then, each positive electrode plate 2 is in a state of being connected to the positive electrode terminal 10 by current collection. With the above connection structure, each positive electrode plate 2 is connected to the current collector plate 6
, The current collection efficiency from the positive electrode plate 2 is improved, and the internal resistance of the battery can be reduced.
In addition, the connection structure allows the space formed above the battery case 5 for the current collection connection to be smaller than that of the conventional current collection connection structure. The size of the negative electrode plate can be increased, and the battery capacity of batteries having the same standard size can be increased.

As shown in FIG. 5, the current collecting connection between each positive electrode plate 2 and the current collecting plate 6 is made so that the end of each positive electrode plate 2 is bent so as to exceed the plate surface position of the adjacent negative electrode plate 3. By forming in a wrapped state, the current collector plate 6 is irradiated by laser.
Can be shielded by the bent portion from irradiating the laser beam to a portion other than the negative electrode plate 3 and the welding portion when the opening is formed.

When the laser beam is irradiated from a direction inclined with respect to a direction perpendicular to the upper surface of the current collector 6, the reflected laser beam does not return to the laser head 13, It is possible to prevent the condenser lens from being damaged by the reflected beam.

The method of joining the electrode plate and the current collector plate described above can also be applied to a cylindrical battery as shown in FIG. In this case, as shown in FIG. 7, a disk-shaped current collector plate 6a is used to join to the electrode plate.

Although the embodiment described above is applied to a relatively small battery, the electrode plate group is accommodated in a resin battery case like a relatively large nickel hydride secondary battery. In such a case, the above-described current collecting connection structure can be adopted also for the negative electrode plate. In this case,
The positive electrode plate and the negative electrode plate are arranged so as to protrude from the other electrodes in different directions, respectively, and each of the positive electrode plate and the negative electrode plate is laser-welded to the current collector plate.

[0024]

As described above, according to the present invention, since the positive electrode plate and / or the negative electrode plate are joined to the current collecting plate at a plurality of positions by laser welding, the current collecting efficiency is improved and the internal resistance of the battery is improved. Can be reduced. In addition, since the space formed in the battery case for current collection connection can be reduced, the area of the electrode plate in a battery of the same standard size can be increased, and a higher capacity battery can be configured. Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a battery according to an embodiment.

FIG. 2 shows the configuration of an electrode group of the battery (a) a positive electrode plate, and (b)
Insertion into a separator, (c) combination with a negative electrode plate,
(D) Schematic diagram showing the arrangement as an electrode plate group.

FIG. 3 is a perspective view showing a configuration of a current collecting plate.

FIG. 4 shows a current collecting connection structure between a positive electrode plate and a current collecting plate (a).
Is a side view, and (b) is a front view.

FIG. 5 is a schematic view showing a variation of a connection structure between a positive electrode plate and a current collector plate.

FIG. 6 is a perspective view showing a configuration applied to a cylindrical battery.

FIG. 7 is a perspective view showing a configuration example of a current collector plate in the case of a cylindrical battery.

FIG. 8 is a perspective view showing a configuration of a battery according to a conventional configuration.

9A is a side view and FIG. 9B is a front view showing a configuration of an electrode group of a conventional battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Positive electrode plate 3 Negative electrode plate 4 Separator 5 Battery case 6 Current collecting plate 8 Electrode plate group 9 Sealing plate 10 Positive electrode terminal 11 Projection 12 Positive electrode core material 13 Laser head

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazumi Shimizu 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 5H022 AA04 BB02 BB17 CC08 CC12 CC13 CC16

Claims (5)

[Claims] 1. A positive electrode plate and a negative electrode plate are arranged in a battery case via a separator, and the positive electrode plate is connected to a positive electrode terminal of the battery.
In a battery in which a negative electrode plate is collectively connected to a negative electrode terminal of the battery, the positive electrode plate and / or the negative electrode plate are arranged and arranged such that their ends protrude in a predetermined direction from the other electrode plate, and protrude. Between the current collector plate and the end of the electrode plate arranged to be in contact with the end surface of the electrode plate is fused at a plurality of positions by melting and re-solidification by scanning with a laser beam, and the current collector plate is connected to a positive electrode terminal and And / or a battery connected to the negative electrode terminal. 2. A positive electrode plate and a negative electrode plate are arranged in a battery case via a separator, and the positive electrode plate is connected to a positive electrode terminal of the battery.
In a method for manufacturing a battery, wherein a negative electrode plate is collectively connected to a negative electrode terminal of a battery, the positive electrode plate and / or the negative electrode plate are arranged such that ends thereof project in a predetermined direction from the other electrode plate. A current collector is disposed so as to contact the end face of the electrode plate, and the end faces of the current collector and the electrode plate are melted by scanning a contact position of the current collector with the electrode plate with a laser beam, A method for manufacturing a battery, comprising joining a current collector plate and an end of each electrode plate at a plurality of positions by re-solidifying a molten portion. 3. The method for manufacturing a battery according to claim 2, wherein the protruding end portion of the electrode plate is bent in the arrangement direction of the electrode plate, and the current collector plate is pressed against the bent end surface. 4. The method for manufacturing a battery according to claim 2, wherein the position of the bent end face is overlapped with a plate surface position of the same pole plate in the bending direction. 5. The method for manufacturing a battery according to claim 2, wherein the laser beam is emitted from an angle direction inclined at a predetermined angle from a direction perpendicular to the plate surface direction of the electrode plate. .