KR20060099028A - Secondary battery module and end plate used in the same - Google Patents

Abstract

The present invention is not only to reduce the weight of the battery module by improving the fastening structure of the battery module, but also to enhance the rigidity of the fastening structure, the plurality of unit cells and the unit cell is disposed outside the battery assembly is stacked Provided is a secondary battery module including an end plate having a strength reinforcement at a stress concentration part and a connection rod and a nut installed between the end plate and fastening the end plate.

Battery module, end plate, connecting rod

Description

SECONDARY BATTERY MODULE AND END PLATE USED IN THE SAME}

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

2 is a plan view illustrating an end plate according to an exemplary embodiment of the present invention.

The present invention relates to a secondary battery module, and more particularly, to an end plate of a secondary battery module.

Recently, a high output secondary battery using a high energy density nonaqueous electrolyte has been developed, and a plurality of high output secondary batteries connected in series to drive a motor requiring a large power, for example, an electric vehicle, have a large capacity secondary battery. You need to configure

As described above, one large 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 in which a positive electrode plate and a negative electrode plate are positioned with a separator interposed therebetween, a case including a space part in which the electrode assembly is embedded, and a terminal coupled to the case to seal the terminal plate and electrically connected to the electrode plate. And a cap assembly provided.

Each unit cell is usually arranged in a housing at regular intervals and connects terminals of each unit cell to form a battery module.

Here, the battery module electrically connects a plurality of unit cells, and has a structure in which a plurality of unit cells are fastened to one battery module for stability of the battery module.

That is, a plurality of unit cells are arranged in a row, two end plates are arranged on the outermost sides of the unit cells, and the two end plates are arranged on the two end plates so that the end cells are arranged in close contact with each other. A plurality of unit bars are stably fixed by fixing a four rod-shaped connecting bar fixed to the end plate by a nut.

In this structure, when the connecting rod is inserted into the hole of the end plate and the nut is fastened to closely contact the unit cells inward, the periphery of the hole of the end plate is subjected to a large stress by the nut.

In this case, if the entire end plate is used to secure the rigidity, the manufacturing cost increases considerably, and thus, conventionally, the end plate is increased in order to secure the rigidity of the end plate and prevent deformation and damage.

However, if the thickness of the end plate is increased, the overall weight of the battery module is increased, which causes the performance of the device on which the battery module is mounted.

Particularly, in the case of a secondary battery for driving a motor used in a hybrid electric vehicle (HEV), an electric bicycle, an electric scooter, and the like, it is important to reduce the self load of the battery in order to improve the performance of the devices. The conventional structure has a problem that it is difficult to apply for driving the motor because the output is reduced relative to the weight due to the increase of the battery module.

Accordingly, the present invention has been made to solve the above problems, an object of the present invention is to improve the strength of the stress concentration portion in the end plate to reduce the self-weight of the battery module and the end by the stress An object of the present invention is to provide a battery module having an improved fastening structure and an end plate used therein, to prevent the plate from being deformed or broken.

In order to achieve the above object, the present invention uses a material having a high rigidity in a portion where stress is concentrated in the end plate.

To this end, the battery module of the present invention includes a plurality of unit cells, an end plate disposed at an outermost side of a row of battery assemblies in which the unit cells are stacked, a connection rod inserted into each end plate, and the connection rod to the end plate. And a nut for fastening.

In this case, the end plate is located at the periphery of the flat plate portion which presses the unit cell and at least two opposite ends of the flat plate portion, and the hole portion formed at the center of the protruding ring portion to insert the connecting rod and the hole portion. And the periphery of the hole where the force from the nut is acting directly.

In this case, the connecting rod is coupled to the nut to tighten the flat plate to press the unit cell heat. The nut directly acts on the periphery of the hole, and the force acting on the periphery of the hole is applied to the protruding ring part. When delivered, the protruding ring portion is also stressed into the cell row.

Therefore, a material having a higher tensile strength than the flat plate part is used for the protruding ring portion that is relatively stressed, and particularly, a material having a higher tensile strength than the flat plate part is used. It can be formed using a material having a stronger tensile strength than the protruding ring portion.

Here, the secondary battery module is used as an energy source for driving a motor of the device in a device that operates by 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

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

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

Referring to the drawings, a plurality of unit cells 11 are stacked to form a battery assembly, and end plates 20 are arranged on both side ends of the battery assembly, respectively, to form a structure for pressing and fixing the battery assembly. .

The battery assembly has a structure in which battery partition walls 12 are installed between unit cells 11 to maintain a gap between unit cells 11 and to distribute cooling air.

In addition, a connecting rod 25 connecting the end plates 20 is inserted into the end plate 20, and a nut 24 is coupled to an end of the connecting rod to fasten the end plate 20. The battery 11 is pressurized.

In addition, referring to FIG. 2, the end plate 20 is formed on two flat surfaces 21 contacting and in close contact with the unit cell 11, and face two surfaces of the flat plate 21 facing the hole 26. Protruding ring portion 22, including the hole formed in the center of the protruding ring portion 26 for inserting the connecting rod and the hole peripheral portion (23).

The entire thickness of the end plate 20 according to the present embodiment is smaller than that of the conventional end plate 20, but the protruding ring portion 22 is formed of a material having a greater strength than the flat plate portion 21, and the periphery of the hole. (23) It is also formed of a material of greater strength than the flat plate portion 21, and preferably of a material of greater strength than the protruding ring portion 22.

At this time, the coupling method between the different materials is not limited. For example, the coupling method may be combined by various methods well known in the art, such as composite steel or clad steel.

Therefore, according to the embodiment, even if the thickness of the end plate 20 is reduced by using a material having a higher strength than the end plate 20 formed of the conventional iron plate where the stress is concentrated, the nut 24 and the connecting rod 25 It is possible to withstand the stress acting by).

In a preferred embodiment of the present invention, when the material of the flat plate portion 21 of the end plate 20 is a steel plate having a low tensile strength of 100 MPa, the material of the protruding ring portion 22 preferably has a tensile strength of 150 MPa. It is formed using 3003 kinds of Japanese Industrial Standards (JIS) aluminum alloys, and the hole periphery 23 may be formed using 304 kinds of Korean Industrial Standards (KS) stainless steel having a tensile strength of 300 Mpa.

As in the above embodiment, when the stress concentration is concentrated where the tensile strength and the shear strength are formed using a strong material, the thickness of the end plate 20 may be reduced to about 1/3 to 1/2.

The protruding ring portion 22 may not only be formed in the vertical direction of the unit cell 11 when the terminal cell 11 is placed upright, but may also be formed on the left and right sides of the unit cell 11. Can be.

In addition, the number of protruding ring portions 22 is not limited, and a plurality of protruding ring portions 22 may be formed according to the size and shape of the protruding ring portion 22.

According to the above embodiment, the connecting rod 25 is inserted into the end plate 20, and the nut 24 is fastened to both ends of the connecting rod 25 so that the nut 24 unit the end plate 25. When pressed into the cells 11, the nut 24 fastened to both connecting rods 25 directly presses the hole periphery 23, wherein the hole periphery 23 is sufficient to withstand the pressing stress. Since it is formed of a material having a sufficient strength, it is not easily deformed or broken by the pressure stress.

In addition, since the stress acting on the hole periphery 23 is transmitted to the protruding ring portion 22, the stress acts toward the inside of the battery at the part contacting the hole periphery 22.

In this case, since the protruding ring portion 22 is made of a material having a greater strength than a general steel material, the protruding ring portion 22 can withstand the force, and transfers a stress to the plate portion 21 so that the plate portion 21 has unit cells inside. To pressurize sufficiently.

Accordingly, the secondary battery module 10 may be more stably coupled, and the end plate 20 may prevent deformation and breakage due to stress acting.

In addition, the weight of the end plate 20 may be reduced to improve performance of a device on which the battery module 10 is mounted.

The secondary battery of the present invention is a device that operates by using a motor such as a HEV (hybrid electric vehicle), an EV (electric vehicle), a wireless cleaner, an electric bicycle, an electric scooter, and the like to drive a motor of the device. It can be used as an energy source.

In the above description of the preferred embodiment of the present invention, 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 the range of.

According to the embodiment of the present invention as described above, since the thickness of the end plate can be reduced, the weight of the battery module can be reduced, and since a material with high rigidity is used at the portion where stress is concentrated, deformation and Breakage can be easily prevented.

Claims (13)

A plurality of unit cells; An end plate disposed outside the battery assembly in which the unit cells are stacked and having a strength reinforcement part at a stress concentration part; And A connection bar and a nut installed between the end plates to fasten the end plate; Secondary battery module comprising a. The secondary battery module of claim 1, wherein the strength reinforcing portion is made of a material having a greater strength than other portions. The secondary battery module of claim 1, wherein the strength reinforcement part is formed at a connection portion between the connection rod and the nut. According to claim 1, The end plate is a plurality of protruding ring portion and the protruding ring portion formed of a material having a tensile strength greater than the flat plate portion at the two ends facing the plate portion and the plate portion in close contact with the outside of the battery assembly Secondary battery module including a hole formed in the center through the connection rod. The secondary battery module of claim 4, wherein the end plate is formed around the hole and includes a hole periphery formed of a material having a greater strength than that of the flat plate. The secondary battery module of claim 4, wherein the periphery of the hole is formed of a material having a greater strength than the protruding ring portion. The secondary battery module of claim 4, wherein the protruding ring portion is formed of aluminum 3003. The secondary battery module of claim 4, wherein the hole periphery is formed of stainless steel 304. A flat plate contacted to the outside of the battery assembly; A plurality of protruding rings formed at a material having a strength greater than that of the flat plate at two opposite ends of the flat plate; An end plate of the secondary battery module is formed in the center of the protruding ring portion and comprises a hole through which the connection rod passes. 10. The end plate of claim 9, further comprising a hole periphery formed around the hole and formed of a material having a greater strength than that of the flat plate. The end plate of the secondary battery module of claim 10, wherein the hole periphery is formed of a material having a greater strength than the protruding ring portion. 10. The end plate of claim 9, wherein the protruding ring portion is made of aluminum 3003. The end plate of the secondary battery module of claim 10, wherein the hole periphery is formed of stainless steel 304.

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