KR100590049B1 - Secondary battery module and end-plate - Google Patents

Abstract

The present invention is to penetrate between a plurality of unit cells, a pair of end plates placed on the outermost side of the stacked unit cells and in contact with the unit cells, protruding from the end plates to minimize weight. A connecting rod for fastening and fixing a pair of end plates, the end plate provides a secondary battery module whose thickness is thinner than the thickness of the fastening member.

End plate, fastening member, flat plate member, thickness

Description

Secondary battery module and unit plate fixing end plate {SECONDARY BATTERY MODULE AND END-PLATE}

1 is a perspective view illustrating a configuration of a rechargeable battery module according to an embodiment of the present invention.

2 is a schematic side cross-sectional view of a rechargeable battery module according to an embodiment of the present invention.

3 is a cross-sectional view showing in detail the end plate configuration of the secondary battery module according to an embodiment of the present invention.

The present invention relates to a secondary battery, and more particularly, to a battery module configured by connecting a plurality of unit cells.

In general, a secondary battery is a battery that can be charged and discharged unlike a primary battery that cannot be charged. In the case of a low capacity battery, a secondary battery is used in portable electronic devices such as a phone, a notebook computer, and a camcorder. It is widely used as a power source for driving motors of hybrid vehicles.

The secondary batteries are manufactured in various shapes, and typical shapes include cylindrical and rectangular shapes. The secondary batteries may be used for driving a motor requiring a large power, for example, an electric vehicle. A plurality of secondary batteries are connected in series to form a large capacity secondary battery.

As described above, one high capacity secondary battery (hereinafter, referred to as a battery module for convenience of description throughout) is made of a plurality of secondary batteries (hereinafter, referred to as unit cells for convenience of description throughout the specification) connected in series. Each unit cell includes an electrode assembly having a positive electrode plate and a negative electrode plate interposed therebetween, a case having a space portion in which the electrode assembly is embedded, a cap assembly coupled to the case and sealing the protrusion, and protruding from the cap assembly. And positive and negative terminals electrically connected to the positive and negative current collectors provided in the electrode assembly.

In the case of the rectangular battery, each of the unit cells cross-aligns each of the unit cells such that the positive electrode terminal and the negative electrode terminal protruding from the top of the cap assembly alternate with the positive electrode terminal and the negative electrode terminal of the neighboring unit cell, and the threaded negative electrode terminal The battery module is constructed by connecting and installing a conductor between the anode terminals via a nut.

In this case, the end plate is used to fix the unit cells stacked as the battery module forms a single battery module by connecting several to many tens of unit cells.

Accordingly, the end plate may be positioned at the outermost side of the stacked unit cells, and the end plates may be fastened by tightening each end plate with a connecting rod and a nut to tightly fix the unit cells between the end plates.

However, the conventional end plate has a disadvantage in that the weight is heavy, thereby reducing the output per weight of the battery module.

Furthermore, in the case of a vehicle such as a hybrid electric vehicle (HEV), the weight of the vehicle body is directly connected to fuel efficiency, and thus, when the conventional battery module having a heavy weight is applied to the HEV, a serious problem such as output reduction and fuel economy decreases. .

Accordingly, the present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a battery module capable of minimizing weight and an end plate for fixing unit cells applied thereto.

In order to achieve the above object, the present invention includes a plurality of unit cells, a pair of end plates placed on the outermost side of the stacked unit cells and in contact with the unit cells, and fastening members protruding from the end plates. And a connecting rod for fastening and fixing the pair of end plates, and the end plate has a structure whose thickness is thinner than that of the fastening member.

Accordingly, it is possible to minimize the weight of the battery module by reducing the thickness of the end plate.

Preferably, the end plate is formed to a minimum thickness that satisfies the allowable stress in press-contacting the unit cells.

The unit battery is preferably a rectangular secondary battery.

In addition, a battery partition wall may be further installed between the unit cells to maintain a gap between the unit cells and distribute the cooling medium.

In addition, the end plate is formed with a fastening member protruding from both ends opposite to each other, the formation position of the fastening member may be a central portion or both ends of the end plate and the front surface of the end plate can be uniformly pressed on the unit cell. If it exists, it will not specifically limit in the formation position and the formation number.

In addition, the fastening member is formed with a hole through which the connecting rod passes through.

The connecting rod is formed in the form of a bolt and is fastened by a nut to a thread formed at the tip.

In addition, in the present invention, the connecting portion between the end plate and the fastening member may have a circular cross-sectional structure.

Accordingly, it is possible to evenly distribute the stress applied to the connecting portion to prevent the fastening member from being damaged from the end plate in accordance with the stress concentration.

On the other hand, the end plate according to the present invention comprises a flat plate member which is formed in a size corresponding to the side of the rectangular unit cell contacting the side of the unit cell, and the fastening member formed to protrude in the upper and lower ends of the flat plate member and the hole formed in the front The flat plate member is thinner than the fastening member.

In addition, the end plate may be formed in a circular cross-sectional structure of the connecting portion between the plate member and the fastening member.

Here, the secondary battery module is an energy source for driving a motor of the device in a device operated using a motor such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like. Can be used as

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

1 is a perspective view illustrating a configuration of a rechargeable battery module according to an embodiment of the present invention.

Referring to the drawings, the battery module 10 according to the present embodiment is a large-capacity battery module, and includes a plurality of unit cells 11 continuously arranged at a predetermined interval.

In the following embodiment, a case where a rectangular unit cell is used as the unit cell 11 will be described.

Each of the unit cells 11 includes an electrode assembly having a positive electrode plate and a negative electrode plate disposed on both sides thereof with a separator interposed therebetween, and constitutes a secondary battery having a conventional structure for charging and discharging a predetermined amount of power. A battery partition wall 12 is provided between the unit cells 11 to maintain a gap between the unit cells 11 and to distribute a cooling medium between the unit cells 11.

Therefore, the battery module 100 according to the present exemplary embodiment may be arranged in a series of battery cells in which a plurality of unit cells 11 are stacked and continuously spaced apart at regular intervals by a battery partition wall 15 disposed between the unit cells.

The above-described battery string is closely contacted by a pair of end plates 20 in close contact with the outer surface of the unit cell 11 positioned at the outermost side of the battery string among the unit cells 11 constituting the battery string. ) Is fixed by the connecting rod 30 to connect the one to form a module (10).

As shown in FIG. 2, the end plate 20 has a size corresponding to the front surface of the unit cell 11 and is in close contact with the front surface of the unit cell, and an upper end of the flat plate member 22. And a fastening member 21 which is formed integrally with each other and protrudes outward.

Here, looking at the installation structure of the fastening member 21 and the connecting rod 30 in more detail, the front of the fastening member 21 is formed with a hole 24 is fitted with a connecting rod 30 and the connecting rod 30 is formed in the form of a bolt, the screw thread is processed at the front end is passed through the hole 24 of the fastening member 21 is fastened through the nut 31.

Accordingly, when the connecting rod 30 is inserted through the hole 24 formed in the fastening member 21, and the nut 31 is fastened, the end plates 20 placed on both sides of the cell row may be tightened to fix the unit cells. It will be possible.

Meanwhile, according to the present embodiment, the flat plate member 22 and the fastening member 21 of the end plate 20 are fastened in comparison with the thickness d of the flat plate member 22 as shown in FIG. 3. The thickness D of the member 21 is a relatively large structure.

This ensures the rigidity against stress by increasing the thickness D of the fastening member 21 in which the connection rod 30 is mounted, thereby minimizing the thickness d of the flat plate member 22. This is to reduce the weight of the plate 20 and thus minimize the weight of the battery module 10.

Accordingly, the fastening force of the unit cell 11 can be increased and the weight of the battery module 10 can be realized.

In addition, as shown in FIG. 3, the connecting portion 23 between the flat plate member 22 and the fastening member 21 of the end plate 20 is processed in an arcuate cross-sectional shape inward in the thickness direction. It is.

Accordingly, regardless of the thickness difference between the end plate 20 and the fastening member 21, the end plate 20 and the fastening member 21 are smoothly connected, and stress is distributed throughout the arc-shaped connection part 23. It is possible to prevent cutting between the end plate 20 and the fastening member 21 due to the stress concentration.

Looking at the operation of the battery module 10 according to the present embodiment configured as described above, the battery partition wall 12 placed between the plurality of unit cells 11 and the unit cells 11 are arranged in a state of being stacked in a row The end plates 20 according to the present embodiment are placed in the outermost unit cells 11 of the unit cells 11.

In this state, the connection rod 30 passes through the hole 24 of the fastening member 21 protruding from the end plate 20, and the fastening member 21 of the one end plate 20 passes through the hole 24. When the nut 31 is fastened by tightening the nut 31 at the distal end of the connecting rod 30 protruding outward, the plurality of unit cells 11 and the battery partition wall may be fixed to one.

Here, as the fastening member 21 assembled as described above is tightened inwardly by the connecting rod 30, stress is generated in the connecting portion 23 between the end plate 20 and the fastening member 21. The stress is dispersed throughout the formed connection portion 23 in the form of an arc so that the stress is not concentrated at any one place.

The above-described battery module of the present invention can be effectively used as a battery for HEV requiring high output / large capacity, but its use is not necessarily limited to HEV.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

As described above, according to the present invention, an effect of increasing the output by reducing the weight of the battery module is obtained.

In addition, by dispersing the stress generated when the unit cell is fastened, it is possible to prevent module damage due to stress concentration and to increase the reliability of the battery module.

Claims (9)

With a plurality of unit cells, A pair of end plates placed on the outermost side of the stacked unit cells and in contact with the unit cells, And a connecting rod penetrating between the fastening members protruding from the end plate to fasten and fix the pair of end plates. The end plate has a thickness smaller than that of the fastening member. The secondary battery module of claim 1, wherein a battery partition wall is disposed between the unit cells. The rechargeable battery of claim 1, wherein the end plate has a size corresponding to a side surface of the unit cell, and includes a flat plate member contacting the unit cell, and a fastening member protruding from the upper and lower ends of the flat plate member and through-holes formed on the front surface thereof. module. The secondary battery module of claim 1, wherein the end plate has a fastening member protruding from both ends of the end plate. The secondary battery module of claim 1, wherein the connection rod has a bolt shape and is fastened by a nut to a screw thread formed at a front end thereof. The secondary battery module of claim 1, wherein a connection portion between the end plate and the fastening member has an arc cross section. The secondary battery module of claim 1, wherein the battery module is for driving a motor. A flat plate member having a size corresponding to the side surface of the unit cell, the flat plate member contacting the unit cell, and a fastening member protruding from the upper and lower ends of the flat plate member, and having a hole penetrating through the front surface thereof. End plate of the secondary battery module thinner than the thickness. The end plate of claim 8, wherein the connection portion between the plate member and the fastening member has an arc-shaped cross-sectional structure.

Images