WO2013021592A1

WO2013021592A1 - Battery pack

Info

Publication number: WO2013021592A1
Application number: PCT/JP2012/004922
Authority: WO
Inventors: 慎也本川; 裕史高崎
Original assignee: パナソニック株式会社
Priority date: 2011-08-11
Filing date: 2012-08-02
Publication date: 2013-02-14
Also published as: JP2014199716A

Abstract

Provided is a battery pack (200), wherein a battery module (100) in which a plurality of batteries which is housed in a case (10) is stacked. The battery module has a positive electrode terminal (20) and a negative electrode terminal (21) disposed on one face (11) of the case. The positive electrode terminals and the negative electrode terminals of each of the plurality of battery modules (100a, 100b, 100c) are respectively connected via bus bars (70a, 70b) which are disposed along the one face of the case. The bus bars further comprise fixed ribs (75a, 75b) which extend along the battery module side. The fixed ribs are fixed sandwiched between battery modules which are adjacent in the stacking direction.

Description

Battery pack

The present invention relates to a battery pack in which battery modules provided with a plurality of batteries are stacked.

A battery pack in which a plurality of batteries are accommodated in a case so as to be able to output a predetermined voltage and capacity is widely used as a power source for various devices, vehicles and the like. Above all, a general-purpose battery is connected in parallel and in series, and a battery module that outputs a predetermined voltage and capacity is modularized, and by combining various battery modules, a technology capable of supporting various applications is adopted. I'm starting. With this modularization technology, the battery module itself can be reduced in size and weight by enhancing the performance of the battery housed in the battery module, so that the workability at the time of assembling the battery pack is improved and the limitation of the vehicle etc. It has various merits, such as the improvement of the degree of freedom when it is mounted in the space.

Generally, in a battery module, a plurality of batteries are accommodated in a battery case, and a wire connecting electrodes of each battery electrically in series or in parallel is connected to an electrode terminal attached to one side of the battery case It has a configuration (see, for example, Patent Document 1). Then, when a plurality of battery modules are arranged to constitute a battery pack, external terminals provided on one side of each battery module are electrically connected in series or in parallel, and provided with a predetermined voltage and capacity. The battery pack can be obtained.

JP 2007-026894 A

The battery module can be easily assembled by arranging the required number of battery modules, since the external dimensions and external terminals of the battery module are fixed at predetermined sizes and positions. At that time, by arranging the battery modules so that their electrode terminals (positive electrode terminal and negative electrode terminal) face the same direction (for example, laminating a plurality of battery modules), electrical connection between the battery modules can be facilitated as well. Become.

However, since the connecting members (for example, bus bars) connecting the respective battery modules are only fixed to the positive electrode terminal or the negative electrode terminal at both ends, when an external force such as an impact is applied to the battery pack, the connecting members The both ends become a fixed end and vibrate. Therefore, there is a possibility that the strength of the connecting member may be reduced by applying a large stress to the connecting member. And if generation of bending by vibration is repeated, there is a possibility that a connecting member may lead to fatigue failure. In particular, when the battery pack is mounted on a vehicle or the like, an external force such as vibration is frequently applied to the battery pack, so even with a relatively short connection member, the strength of the connection member is reduced due to the bending of the connection member, which results in fatigue failure. There is a fear of getting up.

Such a problem leads to a reduction in the reliability of the battery pack. In addition, since such a phenomenon such as fatigue failure depends on the length of the connecting member, the more the design freedom of the specification (particularly, the length) of the connecting member, the more the variation in the reliability of the battery pack occurs. It becomes difficult to produce stable quality battery packs.

The present invention has been made in view of such problems, and the main object thereof is to prevent a reduction in strength of bus bars connecting between battery modules in a battery pack in which battery modules are stacked, and to provide a highly reliable battery pack. It is to provide.

In the battery pack according to the present invention, in which battery modules in which a plurality of batteries are accommodated in a case are stacked, the present invention provides a fixing rib on a bus bar connecting between battery modules, and A configuration for supporting the bus bar is adopted by arranging and fixing between modules.

With such a configuration, bending of the bus bar can be prevented with a simple configuration by supporting the bus bar with the fixing rib provided on a part of the bus bar without using an extra support member. Thereby, since the strength reduction due to the vibration of the bus bar can be prevented, a highly reliable battery pack can be realized.

The battery pack according to the present invention is a battery pack in which a battery module in which a plurality of batteries are accommodated in a case is stacked, and the battery module is provided with a positive electrode terminal and a negative electrode terminal on one side of the case. The plurality of battery modules are connected to the positive electrode terminal and the negative electrode terminal of each battery module by the bus bars disposed along one side of the case, and the bus bars are fixed ribs extending to the battery module side The fixing rib is sandwiched and fixed between the adjacent battery modules in the stacking direction.

According to the present invention, in a battery pack in which a plurality of battery modules are stacked, bending of a bus bar connecting between battery modules can be prevented with a simple configuration, thereby realizing a highly reliable battery pack it can.

It is the perspective view which showed the structure of the battery module 100 used for the battery pack of one Embodiment of this invention. FIG. 1 is a perspective view showing a configuration of a battery pack in which a plurality of battery modules according to an embodiment of the present invention are stacked. It is the disassembled perspective view which showed the structure of the battery pack on which two or more battery modules in one Embodiment of this invention were laminated | stacked. It is the top view which showed the structure of the bus-bar used for the battery pack of one Embodiment of this invention. It is the figure which showed the structure of the battery pack by which the battery module in one Embodiment of this invention was laminated | stacked, (a) is a front view, (b) is a side view.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The present invention is not limited to the following embodiments. Moreover, changes can be made as appropriate without departing from the scope in which the effects of the present invention are exhibited. Furthermore, combinations with other embodiments are also possible.

FIG. 1 is a perspective view showing the configuration of a battery module 100 according to an embodiment of the present invention. In the battery module 100, a plurality of batteries (not shown) are accommodated in the case 10. The type of battery used in the battery module 100 is not particularly limited, and, for example, a lithium ion battery or a nickel hydrogen battery can be used. In addition, it may be a battery that can be used alone as a power source of a portable electronic device such as a notebook computer. In this case, since a high-performance general-purpose battery can be used as the battery of the battery module 100, it is possible to easily achieve high performance and cost reduction of the battery module 100.

As shown in FIG. 1, on a first side surface (one side surface) 11 of the case 10, a positive electrode terminal 20 and a negative electrode terminal 21 connected to respective electrodes of a plurality of batteries are disposed. The electrical connection between the batteries may be in series or in parallel. When the battery module 100 is stacked in the direction (stacking direction) perpendicular to the second side surface 12 of the case 10 by providing the connecting portions 40 on both side surfaces 13 in the width direction W of the case 10, Adjacent battery modules 100 can be connected by the connecting portion 40.

FIG. 2 is a perspective view showing the configuration of a battery pack 200 in which a plurality (three in the drawing) of battery modules 100 are stacked in the stacking direction X. FIG. 3 is an exploded perspective view showing the configuration of the battery pack 200. As shown in FIG.

As shown in FIGS. 2 and 3, the plurality of stacked

battery modules

100a, 100b and 100c are fixed to each other by aligning bolt holes of connecting portions 40 of adjacent battery modules with each other and tightening them with bolts. . The

positive terminals

20b and 20c and the

negative terminals

21a and 21b of the

battery modules

100a, 100b and 100c are connected by the

bus bars

70a and 70b disposed along the first side surface 11 of the case 10.

For example, in the example shown in FIGS. 2 and 3, the positive electrode terminal 20c of the lowermost battery module 100c is connected to the negative electrode terminal 21b of the middle battery module 100b by the bus bar 70b. The positive terminal 20b of the middle battery module 100b is connected to the negative terminal 21a of the uppermost battery module 100a by the bus bar 70a. Thus, the

battery modules

100a, 100b, and 100c are electrically connected in series, and the positive electrode terminal 20a of the uppermost battery module 100a and the negative electrode terminal 21c of the lowermost battery module 100c are respectively connected to the battery pack 200. It becomes an external terminal of positive and negative.

The attachment of the

bus bars

70a and 70b to the

positive electrode terminals

20b and 20c and the

negative electrode terminals

21a and 21b can be performed, for example, by aligning the bolt holes provided in each and tightening with bolts 50.

FIG. 4 is a plan view showing the configuration of the bus bar 70a in the present embodiment.

As shown in FIG. 4, the bus bar 70a includes a metal connector 71A connecting between the positive electrode terminal 20b of the battery module 100b and the negative electrode terminal 21a of the battery module 100a, and at least a positive electrode terminal 20b and a negative electrode terminal 21a of the metal connector 71A. And 73 A of insulating members which coat | cover the site | part except

connection part

72A, 72A. As described above, when the metal connector 71A is covered with the insulating member 73A, a short circuit is prevented, and the assembling workability of the battery pack is facilitated. The configuration of the bus bar 70b is the same as that of the bus bar 70a, so the drawing is omitted.

As shown in FIG. 3, the

bus bars

70a, 70b have

fixing ribs

75a, 75b extending to the side of the plurality of stacked

battery modules

100a, 100b, 100c. When the

bus bars

70a and 70b are disposed along the first side surface 11 of the case 10, as shown in FIG. 2, the fixing rib 75a of the bus bar 70a corresponds to the bottom surface of the battery module 100a and the battery module 100b. It is pinched and fixed to the upper surface. The fixing rib 75b of the bus bar 70b is sandwiched and fixed to the bottom surface of the battery module 100b and the top surface of the battery module 100c. Fixing of the fixing rib 75a and the fixing rib 75a is performed by fastening the

battery modules

100a and 100b and the

battery modules

100b and 100c at the connecting portion 40, respectively. At this time, the connecting portions 40 are fastened via the spacer 60 having the same thickness as the fixing rib 75 a and the fixing rib 75 a.

In general, the bus bars 70a and 70b merely fix the

connection portions

72A and 72A at both ends to the negative electrode terminal and the positive electrode terminal, and the other portions do not have a portion in contact with the case 10 . Therefore, in this state, the bus bars 70a and 70b vibrate with the

connection portions

72A and 72A as the fixed ends. However, as in the present embodiment, the fixing

ribs

75a and 75b extending toward the battery module are provided in the middle of the

connection portions

72A and 72A of the bus bars 70a and 70b, and the fixing

ribs

75a and 75b are adjacent in the stacking direction. Vibration between the bus bars 70a and 70b can be prevented by sandwiching and fixing the battery modules.

In addition, with such a structure, the bus bars 70a and 70b can be supported simply by fixing the fixing

ribs

75a and 75b with the stacked battery modules without using an extra support member or the like. Thus, bending of the bus bars 70a and 70b can be effectively prevented. Therefore, since the strength reduction due to the vibration of the bus bars 70a and 70b can be prevented, the highly reliable battery pack 200 can be realized.

Such bus bars

70a and 70b can be formed, for example, by integrally forming a metal connection body 71A provided with a fixing rib in a part with the same metal material. Also, as described above, the metal connector 71A may cover the portion excluding the connection portion 72A with the insulating member 73A. In addition, the fixing

ribs

75a and 75b provided on a part of the bus bars 70a and 70b may be made of only the insulating member. For example, when the metal connection body 71A of the bus bars 70a and 70b is integrally molded by resin insertion molding, the fixing

ribs

75a and 75b can be integrally molded of resin.

The positions, number, width, thickness, etc. of the fixing

ribs

75a, 75b formed on the

bus bars

70a, 70b are not limited, and it depends on the length of the bus bar, the application of the battery pack, the size of the battery module, etc. , Is set appropriately.

FIG. 5A is a front view of the battery pack 200 in which the

battery modules

100a, 100b, and 100c are stacked, as viewed from the first side 11. FIG. 5B shows the battery pack 200 in the case 10 FIG. 6 is a side view as viewed from a side surface 13 in the width direction W.

As shown in FIG. 5A, the

battery modules

100a, 100b, 100c are electrically connected by connecting the

positive electrode terminals

20b, 20c and the

negative electrode terminals

21a, 21b to the

connection parts

72A, 72A of the

bus bars

70a, 70b. It is connected in series. Here, as described above, the bus bars 70a and 70b have the fixing

ribs

75a and 75b extending to the battery module side, and are respectively sandwiched between the

battery modules

100a and 100b and the

battery modules

100b and 100c. The bus bar is supported by being fixed.

The fixing

ribs

75a and 75b disposed between the battery modules may be extended from one part of the bus bars 70a and 70b, and as shown in FIG. 3, a plurality of places (two places in FIG. 3) It may be extended and provided. Further, the fixing

ribs

75a and 75b are not limited to the case where the bus bars 70a and 70b extend from the position where the metal connection body 71A is positioned. For example, the insulating member 73A It may be made to project outward along side 11 and extend from the projection to the battery module side.

Here, as shown in FIG. 5A, at least a part of the fixing

ribs

75a and 75b extending from the bus bars 70a and 70b is the

positive electrode terminal

20b or 20c to which the bus bar is connected, or the

negative electrode terminal

21a , 21b are preferably formed at positions in the stacking direction X. Such a configuration can further reduce deflection due to vibration.

Further, as shown in FIG. 5A, the

bus bars

70a, 70b have portions extending in the width direction W of the

battery modules

100a, 100b, 100c, and the end portions 75D of the fixing

ribs

75a, 75b in the width direction W It is preferable to project and form the width direction outer side rather than the edge part 70D of the width direction W of bus-

bar

70a, 70b. Thereby,

bus bars

70a and 70b can be supported more stably.

In the present embodiment, the fixing

ribs

75a and 75b are formed only between the

connection portions

72A and 72A of the bus bars 70a and 70b, but the invention is not limited thereto. For example, the fixing

ribs

75a and 75b may be formed on both ends of each connection site 72A, and the upper and lower portions of the positive electrode terminal or the negative electrode terminal may be fixed by a plurality of fixing ribs.

Further, as shown in FIG. 5B, the fixing

ribs

75a and 75b are disposed in contact between the

battery modules

100a and 100b and the

battery modules

100b and 100c, respectively. It is appropriately set depending on the mounting application of the battery pack, the required fixing strength depending on the size, weight and the like of the battery module.

Further, as shown in FIG. 5, the adjacent battery modules can be fixed by arranging the spacers 60 having bolt holes between the connection parts 40 of each other and tightening them with bolts. According to such a configuration, the gap between the battery modules can be adjusted by appropriately adjusting the thickness of the spacer 60 and the fixing

ribs

75a and 75b, and the battery module can be caused to flow the refrigerant through the gap. Can be cooled more efficiently.

Further, the gap between the battery modules, that is, the thickness of the spacer 60 and the fixing

ribs

75a and 75b may be appropriately changed inside the battery pack. For example, when a large number of battery modules are stacked, if the thickness of the spacer 60 and the fixing

ribs

75a and 75b is set so that the gap between the battery modules stacked in the center becomes large, It is possible to cool more efficiently and uniformly cool the entire battery pack. Here, the spacer 60 may be disposed between the battery modules in addition to being disposed between the connection portions 40 of the adjacent battery modules.

Although the present invention has been described above by the preferred embodiments, such description is not a limitation and, of course, various modifications are possible.

For example, in the above embodiment, an example in which the battery packs 200 are electrically connected in series has been described. However, the present invention can be applied to the case in which the battery packs 200 are electrically connected in parallel.

Further, in the present embodiment, bus bars connecting adjacent battery modules are described, but the connection is not necessarily limited between adjacent battery modules, and battery modules having one or more battery modules interposed therebetween The present invention can be applied even to a bus bar connecting the two. In that case, the bus bar can be supported, for example, by forming and fixing the fixing rib corresponding to the number between the existing battery modules. Therefore, even when a long bus bar is used, bending is less likely to occur, a reduction in strength due to the vibration of the bus bar can be prevented, and a highly reliable battery pack can be obtained.

Further, in the present embodiment, although the bus bars 70a and 70b are obtained by bending the metal connection body 71A, the present invention is not limited thereto, and the positive electrode terminal and the negative electrode terminal are connected linearly without bending. You may

Moreover, in the present embodiment, the spacer 60 is disposed between the connection portions 40 of adjacent battery modules, but the spacer 60 is not necessarily required. For example, the thickness (length) corresponds to the thickness of the fixing

ribs

75a and 75b , And the fixing position of the connecting portion 40 may be extended in the stacking direction.

INDUSTRIAL APPLICABILITY The present invention is useful as a power supply for driving an automobile, an electric motorcycle, an electric toy or the like.

DESCRIPTION OF SYMBOLS 10 Case 11 1st side 12

2nd side

20, 20a, 20b, 20c

Positive electrode terminal

21, 21a, 21b, 21c Negative electrode terminal 40 Connection part 60

Spacer

70a, 70b Bus bar 71A Metal connection body

72A Connection part

73A Insulating member

70D ,

75D end

75a, 75b fixed

rib

100, 100a, 100b, 100c battery module 200 battery pack

Claims

A battery pack in which a battery module in which a plurality of batteries are accommodated in a case is stacked,
The battery module has a positive electrode terminal and a negative electrode terminal disposed on one side of the case,
In the plurality of battery modules, the positive electrode terminal and the negative electrode terminal of each battery module are respectively connected by a bus bar disposed along one side surface of the case.
The battery pack, wherein the bus bar has a fixing rib extending to the battery module side, and the fixing rib is sandwiched and fixed between the battery modules adjacent in the stacking direction.
The battery pack according to claim 1, wherein the fixing rib is formed at a position in a stacking direction with respect to the positive electrode terminal or the negative electrode terminal to which the bus bar is connected.
The bus bar has a portion extending in the width direction of the battery module,
The battery pack according to claim 1, wherein the widthwise end of the fixing rib protrudes outward in the widthwise direction than the widthwise end of the bus bar.
The bus bar is an insulating member covering a metal connection body connecting between the positive electrode terminal and the negative electrode terminal of each of the battery modules, and a portion excluding a connection portion between at least the positive electrode terminal and the negative electrode terminal of the metal connection body. The battery pack according to any one of claims 1 to 3, which is composed of:
The battery pack according to claim 4, wherein the fixing rib is configured only by the insulating member.
The battery pack according to claim 4, wherein the bus bar is integrally formed by insert molding the metal connection body into a resin.