KR20160040167A - Stacking Type Battery Pack Having Connecting Member Made of Different Metals - Google Patents

Abstract

The present invention relates to a battery pack which has stacked unit cells to be electrically connected, and has two or more battery modules having an external input/output terminal connected to a side. The two or more battery modules are connected in series or in parallel to an adjacent battery module by a connection member. The connection member has a structure formed by combining different metals with different melting points. So the safety of the battery pack can be improved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery pack including a battery module connecting member made of different metals,

The present invention relates to a battery pack including a battery module connecting member of dissimilar metals, and more particularly, to a battery pack comprising two or more battery modules in which unit cells are stacked and electrically connected and an external input / The battery pack according to claim 1, wherein the at least two battery modules are connected in series or in parallel with an adjacent battery module by a connecting member, and the connecting member is formed in a structure in which dissimilar metals having different melting points are combined .

BACKGROUND ART [0002] In recent years, a rechargeable secondary battery has been widely used as an energy source for wireless mobile devices, and has been widely used as an energy source for electric vehicles EV, a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (Plug-In HEV), and the like.

In addition, technologies related to a power storage device that stores electricity and supplies it to a power system in a stable manner at a required time are being developed. Power storage devices are devices that store energy when power demand is low, and supply power in the event of an overload or an emergency, thereby providing an effect of improving power quality and energy use efficiency. In particular, residential power storage devices and industrial or commercial medium power storage devices are rapidly gaining market share in conjunction with Smart Grid technology.

On the other hand, in order for the battery pack to provide the output and capacity required by a predetermined device or device, a plurality of unit cells or battery modules equipped with unit cells are electrically connected in series or parallel manner to form a battery pack , As the capacity of the battery pack becomes larger, it is required to be able to maintain a stable structure with ease.

Particularly, when a battery pack is constructed using a plurality of battery modules, a large number of members are generally required for mechanical fastening and electrical connection thereof, such as a bus bar or a power connection cable, , If the battery pack needs to be expanded, it is not easy to change the structure, and addition of many components is required, which increases the manufacturing cost.

In addition, since the battery pack has a structure in which a plurality of battery modules are combined, when the battery module is over-voltage, over-current or overheated, the safety and operation efficiency of the battery pack become significant. Therefore, need. Accordingly, a BMS (Battery Management System), which is a safety system, is included to detect overvoltage, overcurrent, overheat, and the like to block the current of the battery pack or to operate the cooling device. However, such a BMS, various sensors, The wiring structure and the like also increase the manufacturing cost and cause the manufacturing process to be complicated by the addition of parts.

Therefore, there is a high need for a technique for improving safety in preparation for abnormal operation of a battery pack by adding or changing simple parts.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery pack in which when the temperature of the battery pack rises due to abnormal operation such as overcharge, overdischarge, overcurrent, or the like, And to provide a battery pack with a structure that improves the safety of the pack.

It is a further object of the present invention to provide a battery pack having a simple structure without using a plurality of members to reduce the manufacturing cost by forming a current blocking structure according to the temperature rise of the battery pack, And a battery pack.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a battery pack in which two or more unit cells are stacked and electrically connected, and two or more battery modules each having an external input / The modules are connected in series or in parallel with the adjacent battery modules by a connecting member, and the connecting members are formed in a structure in which dissimilar metals having different melting points are combined.

That is, in the battery pack according to the present invention, when a short circuit occurs in an abnormal state of the battery modules, a momentarily high current flows, and when the temperature of the connecting member rises, the metal having a low melting point in the dissimilar metal melts first, Structure, so that it is structured to ensure safety against short circuit.

In addition, in the conventional battery pack, a structure for cutting off electric power at a high temperature by using a fuse or the like is used, but a separate space for installing the fuse is required, Did not do it. However, according to the present invention, by using a connecting member having a structure in which dissimilar metals having different melting points are used, it is possible to secure safety against short circuit by a simple process, and further, Or a separate installation space is not required, thereby providing an effect of improving manufacturing cost and productivity.

Furthermore, the present invention provides a battery pack having a compact overall structure and excellent stability.

In one specific example, the connecting member may be formed in a structure including a first connecting portion and a second connecting portion, which are respectively engaged with the input / output terminals of the battery modules to be electrically connected. That is, the connection member may be manufactured in a structure in which the first connection portion and the second connection portion are coupled.

The first connection portion and the second connection portion may be formed of plate-shaped members of dissimilar metals, and the coupling of the first connection portion and the second connection portion may be performed by various methods such as laser welding and resistance welding. The first connection part and the second connection part of the plate-like structure are brought into contact with each other while being in contact with each other, and in some cases, one end of the first connection part and the second connection part are positioned to overlap with each other, It is possible. In this case, the clad metal structure is formed by rolling.

On the other hand, the cross-sectional area of the joint portion of the first connection portion and the second connection portion may be formed to be smaller than the cross-sectional area of the first connection portion and the cross-sectional area of the second connection portion, so that the first connection portion and the second connection portion are appropriately separated under high-

Specifically, one or more through-holes may be drilled or a notch may be formed in the coupling portion of the first connection portion and the second connection portion to reduce the cross-sectional area of the coupling portion.

The first connection portion and the second connection portion are not particularly limited as long as they are electrically conductive and have mutually different melting points. For example, the first connection portion may be formed of copper, and the second connection portion may be formed of aluminum. Therefore, when the temperature of the connecting member rises above the melting point of aluminum, the second connecting portion formed of aluminum is melted and separated at the first connecting portion formed of copper, thereby inducing a disconnection at the connecting member.

In one specific example, the unit cell may be a plate-shaped battery cell structure, or may be a structure of a cell assembly in which two or more plate-shaped battery cells are mounted on a cell cover while electrode terminals are exposed.

The plate-shaped battery cell may be, for example, a prismatic secondary battery or a pouch-type secondary battery. The prismatic secondary battery may have a structure in which an electrode assembly is sealed in a rectangular metal case, and the pouch type secondary battery may have a structure in which an electrode assembly is sealed in a laminate sheet including a resin layer and a metal layer.

The battery cell is not particularly limited as long as it is capable of providing a high voltage and a high current when the battery module or the battery pack is constructed. For example, the battery cell may be a lithium secondary battery having a large energy storage amount per volume.

In the cell assembly, which is another example of the unit cell, the cell cover may be composed of a pair of sheath members mutually coupled to surround the outer surfaces of the battery cells except the electrode terminal portion. For example, two battery cells may be mounted on the cell cover, and the two battery cells may be stacked so that the electrode terminals of the same polarity are connected to each other while being in contact with each other.

In one specific example, the battery module includes:

The unit cells having electrode terminals formed on one side, the cartridges fixing the unit cells, and the bus bars coupled with the electrode terminals to electrically connect the unit cells;

Wherein the unit cells are mounted on the respective cartridges so that electrode terminals face each other, electrode terminals are connected in parallel by bus bars for parallel connection mounted on the respective cartridges, Form a structure;

Wherein the cartridges are stacked such that the unit cell parallel connection structures are arranged in a height direction from the ground, and the parallel connection bus bars of the unit cell parallel connection structures are connected in series or in parallel with each other. .

That is, since a plurality of unit cells are arranged in parallel to form a unit cell parallel connection structure, and the unit cells are stacked and connected in series or in parallel, it is easy to assemble and output or capacity can be expanded by a simple process .

The external input / output terminals of the battery module may be connected to the parallel connection bus bars, and may be electrically connected to an electrical connection member connecting the bus bar and the external input / output terminals.

The present invention also provides a device including the battery pack.

The device is particularly applicable to household power supply, utility power supply, large-scale store power supply, emergency power supply, computer room power supply, portable power supply, medical equipment power supply, fire extinguishing equipment power supply, A power supply, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

The structure and manufacturing method of such a device are well known in the art, so a detailed description thereof will be omitted herein.

As described above, according to the battery pack of the present invention, when the temperature of the battery pack rises due to abnormal operation such as overcharge, overdischarge, overcurrent, or deterioration due to long-term charge / discharge, So that the safety of the battery pack can be improved. In addition, the battery pack according to the present invention can reduce the manufacturing cost by forming a current blocking structure according to the temperature rise of the battery pack with a simple structure without using a plurality of members, and is excellent in compactness and structural stability, There is an effect that can be improved.

1 is a perspective view of a battery cell constituting a unit cell in the battery module of the present invention;
2 is a perspective view of a unit cell having a structure in which the battery cells of FIG. 1 are mounted on a cell cover;
3 is an exploded perspective view of a battery pack according to one embodiment of the present invention;
Fig. 4 is an enlarged view of a portion where the battery modules in Fig. 3 are connected by a connecting member; Fig.
5 is a schematic view of the connection member of Fig. 3;
6 is a schematic view of a connecting member according to another embodiment of the present invention;
FIG. 7 is a schematic view showing a side view of FIG. 3; FIG.
8 is a schematic view showing a side surface of a connecting member according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

FIG. 1 is a perspective view of a battery cell constituting a unit cell in the battery module of the present invention, and FIG. 2 is a perspective view of a unit cell (cell assembly) having a structure in which the battery cells of FIG. 1 are mounted on a cell cover have.

1 and 2, the battery cell 10 has a plate-like structure in which electrode terminals (a positive electrode terminal 11 and a negative electrode terminal 12) are formed at one end. Specifically, the plate-shaped battery cell 10 includes an electrode assembly (not shown) in a pouch case 13 of a laminate sheet including a metal layer (not shown) and a resin layer (not shown) , And a sealing part 14 is formed by thermal fusion, and this is commonly referred to as a 'pouch type battery cell'.

The unit cell 110 has a structure in which two plate-shaped battery cells are mounted on the cell cover 116 while the electrode terminals 112 and 114 are exposed on one side. The cell cover 116 of the unit cell 110 is composed of a pair of exterior members that are mutually coupled to surround the outer surface of the battery cell except for the electrode terminals 112 and 114, And the electrode terminals 112 and 114 of the battery cells are connected in parallel and exposed to the outside of the cell cover with the same polarity being in contact with each other.

FIG. 3 is an exploded perspective view of a battery pack according to an embodiment of the present invention, and FIG. 4 is an enlarged view of a portion where the battery modules of FIG. 3 are connected by a connecting member.

3 and 4, the battery pack 100 includes two battery modules 200, the battery modules 200 are mounted on the base plate 300, the battery modules 200 are mounted on the base plate 300, The upper plate 400, the side plates 500, and the front plate 600 are mounted on the upper surface, the side surface, and the front surface of the battery module 200 to protect the battery modules 200.

The battery module 200 includes unit cells having electrode terminals formed on one side, cartridges 210 for fixing the unit cells, and bus bars electrically coupled with the electrode terminals to electrically connect the unit cells. And a bus bar cover 222 for protecting the bus bar is attached to the outside of the bus bar. Outer input / output terminals 242 and 244 are formed on one side of the battery module 200 and are connected to the bus bar through electrical connecting members 252 and 254.

The unit cells are mounted on the respective cartridges 210 so that the electrode terminals face each other, and the electrode terminals are connected in parallel by the bus bars mounted on the respective cartridges 210, A unit cell forms a parallel connection structure. The cartridges 210 are stacked such that the unit cell parallel connection structures are arranged in the height direction from the ground, and the parallel connection bus bars of the unit cell parallel connection structures are connected to each other in series or in parallel.

The battery modules 200 are connected to each other in series and this connection is achieved by fastening the connecting member 260 between the external input / output terminals 242 and 248 formed on the outside of the battery module 200. When the temperature of the battery pack 100 rises, the metal having a relatively low melting point first melts to separate the connecting member 260, And thus the current between the battery modules 200 is cut off.

Fig. 5 is a schematic view of the connection member of Fig.

Referring to FIG. 5 together with FIG. 3, the connecting member 260 is formed in a structure in which a first connecting portion 262 and a second connecting portion 266 made of metal having different melting points are combined. The first connecting part 262 and the second connecting part 266 are formed with fastening grooves 263 and 267 so that the external input and output terminals 242 and 248 of the battery modules 200 and the bolts Respectively.

A through hole 269 is formed in the connection portion of the first connection portion 262 and the second connection portion 266 of the connection member 260. This structure provides an effect of reducing the cross-sectional area of the joining portion and appropriately separating the first connecting portion 262 and the second connecting portion 266 in a high-temperature condition of the battery pack 100. [

Fig. 6 shows a schematic view of a connecting member having another structure.

6, a notch 279 is formed on both sides of a joining portion of the first connecting portion 272 and the second connecting portion 276 in the connecting member 270. Accordingly, a structure for reducing the cross-sectional area of the coupling portion is formed, thereby providing the effect of properly separating the first connecting portion 272 and the second connecting portion 276 in a high temperature condition as shown in FIG.

The structure in which the cross-sectional area of the coupling portion is reduced is not limited to FIGS. 5 and 6, and may be formed in various structures. For example, a structure for perforating a plurality of through-holes or a structure for simultaneously forming a through-hole and a notch.

Fig. 7 is a schematic view showing a side surface of the connection member of Fig. 5, and Fig. 8 is a schematic view showing a side surface of a connection member according to yet another embodiment.

Referring to Figs. 7 and 8, the connecting member may be connected to one side end of the first connecting portion 262 and the second connecting portion 266 in contact with each other as shown in Fig. 7, Is formed as a coupled structure (265) with one side ends of the connection portion (262 ') and the second connection portion (266') being positioned to overlap with each other.

That is, the structure of the bonding site and the kind of the dissimilar metal are not particularly limited as far as the metal having a relatively low melting point among the dissimilar metals is melted at a predetermined temperature to separate the bonding sites. The coupling structure as shown in FIG. 7 is coupled by laser welding, resistance welding, or the like, and a structure in which one end portions are overlapped as shown in FIG. 8 is coupled with a clad metal structure through rolling.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

A battery pack in which two or more unit cells are stacked and electrically connected and two or more battery modules each having an external input / output terminal formed on one side thereof are connected,
Wherein the at least two battery modules are connected in series or in parallel with an adjacent battery module by a connecting member,
Wherein the connection member is formed in a structure in which dissimilar metals having different melting points are combined,
The connecting member includes a first connecting portion and a second connecting portion, respectively, coupled to the input / output terminals of the battery modules to be electrically connected,
Wherein the first connecting portion and the second connecting portion are coupled at one end thereof with a clad metal structure by rolling. The battery pack according to claim 1, wherein the first connecting portion and the second connecting portion are formed of plate-shaped members of dissimilar metals. The battery pack according to claim 1, wherein the cross-sectional area of the joint portion of the first connection portion and the second connection portion is smaller than the cross-sectional area of the first connection portion and the cross-sectional area of the second connection portion. 4. The battery pack according to claim 3, wherein at least one through hole is formed in the connection portion of the first connection portion and the second connection portion to reduce the cross-sectional area of the connection portion. The battery pack according to claim 3, wherein a notch for reducing a cross-sectional area of the coupling portion is formed at a joint portion of the first connection portion and the second connection portion. The battery pack according to claim 1, wherein the first connecting portion and the second connecting portion are made of copper and aluminum, respectively. The battery pack according to claim 1, wherein the unit cell is a plate-shaped battery cell structure or a structure in which two or more plate-shaped battery cells are mounted on a cell cover in a state that electrode terminals are exposed. The battery pack according to claim 7, wherein the cell cover is a pair of sheath members mutually coupled to cover the outer surfaces of the battery cells except the electrode terminal portion. The battery module according to claim 1,
The unit cells having electrode terminals formed on one side, the cartridges fixing the unit cells, and the bus bars coupled with the electrode terminals to electrically connect the unit cells;
Wherein the unit cells are mounted on the respective cartridges so that electrode terminals face each other, electrode terminals are connected in parallel by bus bars for parallel connection mounted on the respective cartridges, Form a structure;
Wherein the cartridges are stacked such that the unit cell parallel connection structures are arranged in a height direction from the ground, and the parallel connection bus bars of the unit cell parallel connection structures are connected to each other in series or in parallel. The battery pack according to claim 9, wherein the parallel connection bus bar and the external input / output terminals are connected by an electrical connection member.

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