WO2013018150A1

WO2013018150A1 - Battery pack and sealed prismatic battery

Info

Publication number: WO2013018150A1
Application number: PCT/JP2011/006918
Authority: WO
Inventors: 益徳濱口; 浩文山村; 晋志大田; 和也前川
Original assignee: パナソニック株式会社
Priority date: 2011-08-03
Filing date: 2011-12-12
Publication date: 2013-02-07

Abstract

A battery pack (100) has a sealed prismatic battery (10) and an electronic component (50) which are integrally formed. The sealed prismatic battery (10) includes a metal jacket (11), an electrode set (1) accommodated in the metal jacket (11), and a substantially rectangular sealing plate (20) for sealing an opening (12) of the metal jacket (11). The boundary portion between the periphery of the opening (12) of the metal jacket (11) and the periphery of the sealing plate (20) is welded. The sealing plate (20) has a recessed portion (21) formed in the longitudinal direction of the sealing plate (20), with a thinned portion of the sealing plate (20) in a region inwardly apart in the width direction from a long side portion (20a) of the sealing plate (20), and at least a part of the electronic component (50) is embedded in the recessed portion (21).

Description

Battery pack and sealed rectangular battery

The present invention relates to a battery pack in which a protective element or the like is integrated with a sealed prismatic battery, and a sealed prismatic battery.

As battery packs become thinner and smaller, battery packs that integrate protection elements and protection circuits connected to electrode terminals on the battery are becoming mainstream.

Such a battery pack has a configuration in which an exterior cover is mounted on a sealing plate that seals an opening of an exterior can that accommodates an electrode group, and a circuit board or the like on which a protection element or a protection circuit is mounted is disposed in the exterior cover. It has become.

As a method for attaching the exterior cover to the battery body, Patent Document 1 discloses that when the exterior cover and the battery body are laser-welded, the surface roughness of the joint surface of the battery body is set to a predetermined size or more, thereby increasing the bonding strength. Techniques for improving the performance are described.

Patent Document 2 describes a technique in which a protective element, a circuit board, and the like are arranged on a battery sealing plate without using an exterior cover, and these and the battery are resin-molded with an insert resin. At this time, by providing an undercut recess in the sealing plate, the connection between the insert resin and the sealing plate is strengthened.

JP 2009-87554 A JP 2006-12589 A

In the technique described in Patent Document 1, the outer cover and the battery main body are joined with the protective element and the circuit board held on the inner surface of the outer cover. At that time, a protective element, a circuit board, etc. are disposed on the sealing plate, but a certain space is provided so that the sealing plate does not contact the protective element, the circuit board, etc. It is necessary to join. Therefore, there is a problem that it is difficult to reduce the size of the battery pack.

On the other hand, the technique described in Patent Document 2 requires a molding die or the like to increase the manufacturing cost of the battery pack in order to mold the protective element, the circuit board, etc. and the battery with the insert resin. There is.

An object of the present invention is to provide a battery pack including a sealing plate that can be downsized in a battery pack in which a battery and an electronic component such as a protection element are integrated.

A battery pack according to the present invention is a battery pack in which a sealed prismatic battery and an electronic component connected to an electrode terminal of the sealed prismatic battery are integrated, and the sealed prismatic battery includes an outer can and an inner portion of the outer can. The electrode group housed in the container and a substantially rectangular sealing plate that seals the opening of the outer can, the boundary between the outer periphery of the opening of the outer can and the peripheral edge of the sealing plate is welded, Has a concave portion with a reduced thickness of the sealing plate in a region spaced inward in the width direction from the long side portion of the sealing plate in the longitudinal direction of the sealing plate, and at least a part of the electronic component is in the concave portion. It is embedded in.

In a preferred embodiment of the battery pack, at the boundary between the periphery of the opening of the outer can and the periphery of the sealing plate, the end surface of the outer periphery of the opening of the outer can and the flat surface of the outer periphery of the sealing plate are flush with each other. It has become.

Further, in a preferred aspect of the battery pack, the concave portion is formed in a region separated from the long side portion of the sealing plate inward in the width direction by a distance larger than the thickness of the sealing plate.

Further, in a preferred aspect of the battery pack, the recess is formed in a central region in the longitudinal direction of the sealing plate. At this time, an electrode terminal connected to one electrode plate of the electrode group is attached to the sealing plate via an insulating member, and the electrode terminal is a recess formed in a central region in the longitudinal direction of the sealing plate. To the short side of the sealing plate.

Also, in a preferred aspect of the battery pack, the electronic component is covered with an exterior cover, and the exterior cover is joined to the exterior can at the open end of the exterior can.

The sealed prismatic battery according to the present invention is a sealed prismatic battery in which the opening of the outer can is sealed with a sealing plate, and the sealing plate has a substantially rectangular shape, the periphery of the opening of the outer can, and the sealing The boundary portion with the peripheral edge of the plate is welded, and the sealing plate has a reduced thickness in the longitudinal direction of the sealing plate in a region away from the long side portion of the sealing plate inward in the width direction. There is a recess, and when the electronic component connected to the electrode terminal of the sealed rectangular battery is disposed outside the sealing plate, at least a part of the electronic component is embedded in the recess. It is characterized by having.

According to the present invention, it is possible to realize a battery pack that can be miniaturized by providing a recess in which at least a part of the electronic component is embedded in a predetermined region of the sealing plate.

It is a disassembled perspective view of the sealed square battery used for the battery pack in one Embodiment of this invention. It is a perspective view of the sealed square battery after assembly in one embodiment of the present invention. FIG. 3 is a partial sectional view taken along line III-III in FIG. 2. (A) is a partial cross-sectional view taken along line IVa-IVa in FIG. 2, (b) is a partial cross-sectional view taken along line IVb-IVb in FIG. 2, and (c) is a cross-sectional view taken along line C in FIG. It is an enlarged view of the part shown by. It is a top view of the sealing board in one Embodiment of this invention. It is the fragmentary sectional view which showed the structure of the battery pack in one Embodiment of this invention. It is a perspective view of the battery pack in one Embodiment of this invention. It is the fragmentary sectional view which showed the structure of the conventional battery pack. It is the fragmentary sectional view which showed the modification of the sealed square battery in one Embodiment of this invention.

In a sealed prismatic battery, after the electrode group is accommodated in the outer can, a sealing plate is attached to the opening of the outer can, and then the sealing plate is welded to the periphery of the opening, thereby opening the opening of the outer can with the sealing plate. It has a sealed configuration.

Usually, the positive electrode lead connected to the positive electrode of the electrode group is connected to the sealing plate, whereby the sealing plate functions as a positive electrode terminal. On the other hand, a negative electrode terminal is attached to the sealing plate via an insulating member, and a negative electrode lead connected to the negative electrode of the electrode group is connected to the negative electrode terminal. Further, the sealing plate is provided with a safety valve composed of a thin portion for releasing the internal pressure when the internal pressure of the outer can increases, and an injection hole for injecting an electrolyte into the outer can. The negative electrode terminal is usually provided in the center of the sealing plate for reasons such as ease of attachment of the negative electrode lead and ease of connecting a plurality of batteries in parallel, and a safety valve and an injection hole ( Sealing plug).

By the way, as the size of the battery pack is reduced, the proportion of the circuit board or the like (hereinafter simply referred to as “electronic component”) on which a battery protection element or protection circuit is mounted increases in the planar space in the exterior cover. For this reason, when an electronic component is disposed on the sealing plate, it is difficult to dispose the electronic component by removing the negative electrode terminal provided at the central portion of the sealing plate.

Since the negative electrode terminal is provided so as to protrude upward from the surface of the sealing plate, when an electronic component is disposed on the negative electrode terminal, the size of the battery pack in the vertical direction (perpendicular to the sealing plate) is It is rate-limited in the area | region where a terminal is arrange | positioned, ie, the center area | region of a sealing board.

Therefore, the inventors of the present application remove the conventional regulation and attach the negative electrode terminal at a position away from the central region of the sealing plate in the longitudinal direction, whereby a flat portion having a certain area is provided in the central region of the sealing plate. Focused on the fact that it can be secured. That is, by providing a flat portion secured in the central region of the sealing plate with a concave portion with a reduced thickness of the sealing plate, and embedding at least a part of the electronic component in the concave portion, the vertical dimension of the battery pack is reduced. I thought it was possible.

By the way, in the sealed prismatic battery, the boundary portion between the peripheral edge of the opening of the outer can and the peripheral edge of the sealing plate is welded. At this boundary portion, the end surface at the peripheral edge of the opening of the outer can and the sealing plate If the position of the peripheral edge of the metal plate is shifted and not flush with the flat surface, welding failure may occur. For this reason, when the recess is formed by pressing the sealing plate, there is a concern that if the flatness of the sealing plate is impaired, the misalignment may occur at the boundary between the periphery of the opening of the outer can and the periphery of the sealing plate. Is done.

However, in the central region of the sealing plate, if the concave portion is formed only in the region away from the long side portion of the sealing plate to the inner side in the width direction, the ratio of the concave portion in the width direction can be relatively reduced. The influence on the degree can be reduced. In particular, if the concave portion is formed in the region separated from the long side portion of the sealing plate in the width direction by a distance larger than the thickness of the sealing plate, the influence on the flatness of the sealing plate can be minimized.

DETAILED DESCRIPTION OF THE INVENTION The present invention has been made on the basis of such knowledge. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention. Furthermore, combinations with other embodiments are possible.

FIG. 1 is an exploded perspective view of a sealed prismatic battery 10 used in a battery pack according to an embodiment of the present invention, and FIG. 2 is a perspective view of the sealed prismatic battery 10 after assembly. 3 is a partial cross-sectional view taken along line III-III in FIG. 2, FIG. 4A is a partial cross-sectional view taken along line IVa-IVa in FIG. 2, and FIG. FIG. 4C is a partial cross-sectional view taken along line IVb-IVb of FIG. 4A, and is an enlarged view of a portion indicated by C in FIG. FIG. 5 is a plan view of the sealing plate 20 in one embodiment of the present invention.

As shown in FIG. 1, the sealed prismatic battery 10 according to the present embodiment has an electrode group (not shown) accommodated in an outer can 11, and then a substantially rectangular sealing plate 20 is attached to the opening 12 of the outer can 11. Next, the opening 12 of the outer can 11 was sealed with the sealing plate 20 as shown in FIG. 2 by welding the boundary portion between the peripheral edge 13 of the opening 12 of the outer can 11 and the peripheral edge of the sealing plate 20. It is configured. Here, the long side part of the outer can 11 is 11a, the short side part is 11b, the long side part of the sealing plate 20 is 20a, and the short side part is 20b.

It should be noted that “substantially rectangular” means that the shape of the sealing plate 20 is not necessarily limited to a rectangle, and includes, for example, a shape in which four corners of the rectangle have a curvature.

As shown in FIGS. 3 and 5, the sealing plate 20 has a reduced thickness in the longitudinal direction of the sealing plate 20 in a region away from the long side portion 20 a of the sealing plate 20 inward in the width direction. A recess 21 is provided. When the electronic component connected to the electrode terminal of the sealed prismatic battery 10 is disposed outside the sealing plate 20 in the battery pack in which the electronic component described later is integrated, the concave portion 21 is at least part of the electronic component. However, it has a size embedded in the recess 21.

Also, as shown in FIGS. 4A to 4C, at the boundary portion between the peripheral edge 13 of the opening 12 of the outer can 11 and the peripheral edge of the sealing plate 20, at the peripheral edge 13 of the opening 12 of the outer can 11 The end surface and the flat surface 26 at the periphery of the sealing plate 20 are preferably flush with each other. Thereby, when welding the boundary part of the periphery 13 of the opening part 12 of the armored can 11 and the periphery of the sealing board 20, a welding defect can be prevented.

In addition, welding can be performed using methods, such as laser welding, for example.

Further, as shown in FIG. 4C, it is preferable to provide a step 14 on the end face of the opening 12 of the outer can 11. Thereby, when attaching the sealing board 20 to the opening part 12 of the armored can 11, positioning can be performed easily.

Next, a specific configuration of the sealing plate 20 will be described with reference to FIG.

The positive electrode lead (not shown) connected to the positive electrode of the electrode group 1 housed in the outer can 11 is connected to the sealing plate 20, whereby the sealing plate 20 functions as a positive electrode terminal. On the other hand, a negative electrode terminal 22 is attached to the sealing plate 20 via an insulating member 25, and a negative electrode lead (not shown) connected to the negative electrode of the electrode group 1 is connected to the negative electrode terminal 22.

Here, since the concave portion 21 is formed in the central region in the longitudinal direction of the sealing plate 20, the negative electrode terminal 22 extends from the concave portion 21 formed in the central region in the longitudinal direction of the sealing plate 20 to the short side of the sealing plate 20. It is attached at a position distant from the part 20b.

Further, the sealing plate 20 is provided with a safety valve 23 composed of a thin portion for releasing the internal pressure when the internal pressure of the outer can 11 rises, and an injection hole for injecting an electrolyte into the outer can 11. Is sealed with a sealing plug 24 after the electrolyte is injected.

In this way, in the central region of the sealing plate 20, the concave portion 21 is formed in the region away from the long side portion 20 a of the sealing plate 20 in the width direction, thereby reducing the influence on the flatness of the sealing plate 20. Can do. In particular, if the concave portion 21 is formed in a region separated from the long side portion 20a of the sealing plate 20 in the width direction by a distance larger than the thickness of the sealing plate 20, the influence on the flatness of the sealing plate 20 is minimized. Can do.

Here, if the recessed part 21 in this invention is formed using the method of press work, for example, since the stress added to the whole sealing board 20 can be reduced, the influence which acts on the flatness of the sealing board 20 is decreased. be able to.

In the present embodiment, the sealing plate 20 is used as a positive electrode terminal, and the negative electrode terminal 22 is attached to the sealing plate 20 via an insulating member 25. However, the sealing plate 20 is used as a negative electrode terminal, Of course, it may be configured to be attached to the sealing plate 20 via the insulating member 25.

In addition, the configuration of the electrode group 1 in the present embodiment is not particularly limited. For example, the electrode group 1 has a structure in which a positive electrode and a negative electrode are wound in a flat shape via a separator, or a positive electrode and a negative electrode are stacked via a separator. It may be of a different structure.

In addition, the type of the sealed rectangular battery in the present embodiment is not particularly limited, and for example, a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery or a nickel hydride secondary battery, or other secondary batteries can be used. .

FIG. 6 is a partial cross-sectional view showing the configuration of the battery pack 100 according to an embodiment of the present invention, and FIG. 7 is a perspective view of the battery pack 100. The battery pack 100 according to the present embodiment is characterized in that the sealed rectangular battery 10 having the configuration shown in FIG. 3 and the like and the

electronic components

42 and 50 connected to the electrode terminals of the sealed rectangular battery 10 are integrated. To do.

As shown in FIGS. 6 and 7, the

electronic components

42 and 50 are covered with an exterior cover 30, and the exterior cover 30 is joined to the exterior can 11 at the end of the opening of the exterior can 11. .

Here, the

electronic parts

42 and 50 may be of any type and form as long as they are connected to the electrode terminals of the sealed prismatic battery 10 and have a function of controlling and monitoring the sealed prismatic battery 10. For example, examples of the

electronic components

42 and 50 include a protective element (for example, a PCT element) of the sealed prismatic battery 10 and a circuit board on which a protective circuit is mounted. Further, the protective element includes not only a single element but also an integrated circuit device such as an IC.

As shown in FIG. 6, the sealing plate 20 has a recess 21 in which the thickness of the sealing plate 20 is reduced in a region away from the long side portion of the sealing plate 20 in the width direction in the longitudinal direction of the sealing plate 20. In addition, a part of the electronic component 50 is embedded in the recess 21.

Here, the concave portion 21 is formed in the central region in the longitudinal direction of the sealing plate 20, and the negative electrode terminal 22 is provided with the insulating member 25 at a position away from the concave portion 21 toward the short side portion 11 b of the sealing plate 20. Is attached through.

The sealing plate 20 is provided with a safety valve 23 composed of a thin portion for releasing the internal pressure when the internal pressure of the outer can 11 is increased, and an injection hole for injecting an electrolyte into the outer can 11. After injecting the electrolyte, it is sealed with a sealing plug 24.

The electronic component 42 is disposed inside the exterior cover 30, and the sealing plate 20 that also serves as the positive electrode terminal and the negative electrode terminal 22 are connected to the electronic component 42 via the connection terminal 40 and the connection terminal 41, respectively. Yes. Further, for example, when the electronic component 42 is configured by a circuit board, the sealing plate 20 that also serves as a positive terminal and the negative terminal 22 are the connection terminal 40 and the connection terminal 41, and wiring formed on the circuit board, respectively. And is connected to another electronic component 50.

Three windows are formed on the upper wall of the exterior cover 30, and external connection terminals (positive terminal, negative terminal, ground terminal) 60, 61, 62 connected to the electronic component 42 from the three windows. Is exposed.

In the present embodiment, a part of the electronic component 50 arranged in the central region of the sealing plate 20 is embedded in the recess 21 formed in the central region of the sealing plate 20, so that the electronic component 50 is embedded. Only the portion can reduce the vertical dimension of the battery pack. In addition, since the electronic component 50 is not disposed in the region where the negative electrode terminal 22 is provided, the negative electrode terminal 22 and another electronic component 42 are connected via the connection terminal 41 provided immediately above the negative electrode terminal 22. can do.

On the other hand, FIG. 8 shows a configuration of a conventional battery pack in which the negative electrode terminal 22 is provided in the central region of the sealing plate 20.

As shown in FIG. 8, since the electronic component 50 arranged in the central region of the sealing plate 20 is arranged on the negative electrode terminal 22, the vertical dimension of the battery pack is that the negative electrode terminal 22 is arranged. The speed is limited in the area, that is, in the central area of the sealing plate 20. Further, when the connection terminal 41 is provided toward the end away from the central region, the negative electrode terminal 22 is connected in the longitudinal direction of the sealing plate 20 in order to connect the negative electrode terminal 22 and the other electronic component 42. It is necessary to connect to the connection terminal 41 through the extending lead plate 41a. In this case, the vertical dimension of the battery pack in the central region of the sealing plate 20 is further expanded.

That is, the battery pack according to the present invention has a certain area in the central region of the sealing plate 20 by attaching the negative electrode terminal 22 to a position away from the central region of the sealing plate 20 in the longitudinal direction by removing the conventional restriction. The concave portion 21 in which the thickness of the sealing plate 20 is reduced is provided in the flat portion, and at least a part of the electronic component 50 is embedded in the concave portion 21, thereby The dimensions can be reduced.

In the present invention, the size, shape, and the like of the recess 21 may be appropriately determined according to the size, shape, etc. of the electronic component 50 embedded in the recess 21. Further, the number of electronic components embedded in the recess 21 is not limited to one and may be plural. In addition, it is sufficient that at least a part of the electronic component is embedded in the concave portion 21, and it is needless to say that all the electronic components are embedded.

9 (a) and 9 (b) are partial cross-sectional views showing modifications of the sealed prismatic battery according to the present embodiment, FIG. 9 (a) is a diagram corresponding to FIG. 4 (a), and FIG. 9 (b). These are figures corresponding to FIG.4 (b).

In the above embodiment, when the sealing plate 20 is attached to the opening 12 of the outer can 11, as shown in FIG. 4C, the end surface of the peripheral edge 13 of the opening 12 of the outer can 11, and the sealing plate 20 It was mounted so that the flat surface 26 at the periphery was flush.

On the other hand, in this modification, as shown in FIGS. 9A and 9B, the opening 12 of the outer can 11 has a flat surface in the long side portion 11 a of the outer can 11 and the length of the sealing plate 20. The sealing plate 20 is mounted so that the end surface of the side portion 20a is flush with the end surface. And the boundary part of the periphery of the opening part of the armored can 11 and the periphery of the sealing board 20 is welded. Thereby, when welding the boundary part of the periphery 13 of the opening part 12 of the armored can 11 and the periphery of the sealing board 20, a welding defect can be prevented.

As mentioned above, although this invention has been demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible. For example, in the above-described embodiment, an example in which a part of the electronic component is embedded in the recess 21 is shown, but it is needless to say that all the electronic component may be embedded.

The present invention is useful as a power source for various electric and electronic devices.

1 Electrode group 10 Sealed prismatic battery
11 Exterior can
11a Long side of the outer can 11b Short side of the outer can
12 opening
13 Perimeter of opening
14 steps
20 Sealing plate
20a Long side of the sealing plate
20b Short side of the sealing plate
21 recess
22 Negative terminal (electrode terminal)
23 Safety valve
24 Sealing stopper
25 Insulating material
30 Exterior cover
40, 41 connection terminal
41a Lead plate
42, 50 electronic components
60, 61, 62 External connection terminal 100 Battery pack

Claims

A battery pack in which a sealed prismatic battery and an electronic component connected to an electrode terminal of the sealed prismatic battery are integrated,
The sealed prismatic battery includes an outer can, an electrode group accommodated in the outer can, and a substantially rectangular sealing plate that seals an opening of the outer can,
The boundary portion between the peripheral edge of the opening of the outer can and the peripheral edge of the sealing plate is welded,
In the longitudinal direction of the sealing plate, the sealing plate has a recess in which the thickness of the sealing plate is reduced in a region away from the long side portion of the sealing plate inward in the width direction,
A battery pack in which at least a part of the electronic component is embedded in the recess.
In the boundary portion between the periphery of the opening of the outer can and the periphery of the sealing plate, the end surface of the outer periphery of the opening of the outer can and the flat surface of the outer periphery of the sealing plate are flush with each other. The battery pack according to claim 1.
2. The battery pack according to claim 1, wherein the concave portion is formed in a region separated from the long side portion of the sealing plate in the width direction by a distance larger than the thickness of the sealing plate.
The battery pack according to claim 1, wherein the recess is formed in a central region in a longitudinal direction of the sealing plate.
An electrode terminal connected to one electrode plate of the electrode group is attached to the sealing plate via an insulating member,
5. The battery pack according to claim 4, wherein the electrode terminal is attached to a position away from the concave portion formed in a central region in a longitudinal direction of the sealing plate toward a short side portion of the sealing plate.
The electronic component is covered with an exterior cover,
The battery pack according to claim 1, wherein the exterior cover is joined to the exterior can at an end of the open portion of the exterior can.
The battery pack according to claim 1, wherein the electronic component is formed of a circuit board on which a battery protection element and / or a protection circuit is mounted.
A sealed prismatic battery in which the opening of the outer can is sealed with a sealing plate,
The sealing plate has a substantially rectangular shape,
The boundary portion between the peripheral edge of the opening of the outer can and the peripheral edge of the sealing plate is welded,
In the longitudinal direction of the sealing plate, the sealing plate has a recess in which the thickness of the sealing plate is reduced in a region away from the long side portion of the sealing plate inward in the width direction,
The recess has a size such that at least a part of the electronic component is embedded in the recess when the electronic component connected to the electrode terminal of the sealed prismatic battery is disposed outside the sealing plate. A sealed prismatic battery.
In the boundary portion between the periphery of the opening of the outer can and the periphery of the sealing plate, the end surface of the outer periphery of the opening of the outer can and the flat surface of the outer periphery of the sealing plate are flush with each other. The sealed prismatic battery according to claim 8.
The sealed prismatic battery according to claim 8, wherein the concave portion is formed in a region separated from the long side portion of the sealing plate inward in the width direction by a distance larger than the thickness of the sealing plate.
The sealed rectangular battery according to claim 8, wherein the recess is formed in a central region in a longitudinal direction of the sealing plate.
An electrode terminal connected to one electrode plate of the electrode group is attached to the sealing plate via an insulating member,
The sealed rectangular battery according to claim 11, wherein the electrode terminal is attached to a position away from the concave portion formed in a central region in a longitudinal direction of the sealing plate toward a short side portion of the sealing plate.