KR20070105115A - Battery module - Google Patents

Abstract

A battery module is provided to efficiently and easily pressurize unit cells or electrode assemblies in the module, thereby facilitating driving of the unit cells and improving the overall charge/discharge efficiency. A battery module(100) comprises: a plurality of unit cells(11); and partitions(12) disposed between one unit cell and another unit cell, wherein the partition is smaller in dimension than the unit cell. The unit cell comprises a case, and an electrode assembly received in the case, wherein the partition is the same in dimension as the electrode assembly. The partition is coupled to the case in such a manner that the center of the partition coincides with the center of the case.

Description

Battery module {BATTERY MODULE}

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

2 is a front view illustrating a unit cell and a partition wall according to the first embodiment of the present invention.

3 is a perspective view illustrating a unit cell and a partition wall according to the first embodiment of the present invention.

4 is a front view illustrating a unit cell and a partition wall according to a second exemplary embodiment of the present invention.

The present invention relates to a battery module configured by connecting a plurality of unit cells, and more particularly, to a battery module having an improved structure of a partition interposed between batteries.

The battery module may be configured as a rechargeable battery, which is a battery that can be charged and discharged, unlike a primary battery that is not rechargeable. Low-capacity secondary batteries consisting of one cell are used in portable electronic devices such as mobile phones, notebook computers, and camcorders. A large capacity secondary battery in which a plurality of cells are connected in a pack form is widely used as a power source for driving a motor of a hybrid vehicle.

Such secondary batteries are manufactured in various shapes, and typical shapes include cylindrical and rectangular shapes.

In addition, the secondary battery is connected in series to constitute a large capacity battery module so that the secondary battery can be used to drive a motor such as an electric vehicle requiring a large power.

The battery module generally includes a plurality of secondary batteries (hereinafter, referred to as "unit cells" for convenience of description throughout the specification).

Each unit cell includes an electrode group in which a positive electrode and a negative electrode are positioned with a separator interposed therebetween, a case having a space in which the electrode group is embedded, and a case coupled to the case to be sealed and electrically connected to the electrode group. It includes a cap assembly having an electrode terminal connected to the.

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

Here, the battery module includes a partition wall disposed between the unit cells for cooling the unit cells to form a flow path of the cooling medium.

The battery module has a structure in which a plurality of unit cells are fastened into one module for stability. That is, end plates are disposed at the outermost sides of the unit cells, and the end plates are assembled with the unit cells by a plurality of connection rods to support the unit cells.

Through this, the end plate presses and fixes the unit cells. The purpose of pressurizing the unit cells through the end plate is to fix the unit cells integrally, and press the case through the partition wall to reduce the thickness of the electrode group. As such, when the thickness of the electrode group is reduced, the moving distance of the active material ions in the electrode group is shortened, thereby improving charging and discharging efficiency.

However, when the partition wall has the same width as that of the unit cell and the edges of the partition wall and the case come into contact with each other as in the related art, the partition wall is supported by the corners of the case so that the surface of the case cannot be properly pressed. This is because the electrode group usually disposed in the case has a smaller size than the case.

Therefore, in this case, in order to pressurize the case properly, a large pressing force is required. When excessive pressing force is applied to the unit cell, a problem arises in that the unit cells are unnecessarily deformed.

In addition, even if a large pressing force is applied to the case, since most of the force is applied to the edge of the case, the force applied to the surface of the case is not so large that it is difficult to expect the reduction of the ion distance and the output of the unit cell.

In the case of high-power secondary batteries used in hybrid electric vehicles (HEVs), electric bicycles, and electric scooters, instantaneous power consumption is required. Therefore, an improvement in unit battery power determines the characteristics of the battery module. It is necessary to apply an appropriate fastening force in between.

Accordingly, the present invention has been made to meet the above needs, an object of the present invention is to provide a battery module that can pressurize the unit cells efficiently.

In order to achieve the above object, a battery module according to an embodiment of the present invention includes a plurality of unit cells, and partition walls disposed between the unit cells, and the partition walls are smaller than a surface of the unit battery contacting the partition walls. It has an area.

The unit cell may include a case and an electrode group embedded in the case, and may have the same size as that of the barrier rib and the electrode group.

The partition wall may be coupled to the case by matching its center to the center of the case.

The unit cell may include a case and an electrode group embedded in the case, and the partition wall may be coupled to the case by separating an edge thereof from an edge of the case.

When the width of the case in contact with the partition wall is W1, and the distance between the end of the partition wall from the widthwise edge of the case is W2, W2 may be formed larger than 0.05 times W1 and smaller than 0.2 times W1. have.

When the height of the case in contact with the partition wall is H1, and the distance of the end of the partition wall from the height direction edge of the case is H2, H2 is formed to be larger than 0.05 times of H1 and smaller than 0.2 times of H1. Can be.

The partition wall may include a plate-shaped base, and a protrusion formed to protrude from the base.

Chamfering portions may be provided at corner portions of the base.

The battery module may be for driving a motor.

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 can 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 an exploded perspective view illustrating a battery module according to a first embodiment of the present invention.

Referring to the drawings described above, the battery module 100 according to the first exemplary embodiment includes a partition wall disposed between the plurality of unit cells 11 and the unit cells 11 to provide a flow passage of a cooling medium ( 12) and an end plate 36 for supporting the unit cells 11.

In the following embodiment, a case where a rectangular unit cell is used as the unit cell 11 will be described. Of course, the present invention is not limited thereto, and the unit cell may have various shapes such as a cylindrical shape.

Each unit cell 11 includes a case 11a forming an outer shape and an electrode terminal 11b protruding outward from the case 11a. An inside of the case 11a is provided with an electrode group (not shown) stacked between a positive electrode and a negative electrode via a separator, and is configured as a secondary battery having a structure for charging and discharging a set amount of electricity.

The partition walls 12 are formed between the unit cells 11 to form a space in which the heat transfer medium is distributed, and the unit cells 11 and the partition walls 12 are alternately positioned and arranged in a line.

The outermost side of the unit cells 11 is provided with a pair of end plates 36 to press the unit cells 11 in close contact. Each of the end plates 36 has a through hole 36a formed at its edge, and a connecting member 30 supporting the end plates 36 is inserted into the through hole 36a.

The connection member 30 includes a rod portion 32 and a flange portion 31 formed at one end of the rod portion 32. A thread 34 is formed at the end of the rod 32 facing the flange 31 so that the nut 33 can be engaged.

The connecting member 30 is coupled to the thread 34 after the end plate 36 is inserted into the through hole 36a of the end plate 36 in a state where the end plate 36 is disposed at the outermost side of the unit cells 11. The end plates 36 are fixed to each other by the nuts 33, and the end plates 36 press the unit cells 11 by the fastening force of the nuts 33 to fix the unit cells 11. Be sure to

The partition wall 12 is composed of a plate-shaped base 12a and a plurality of protrusions 12b protruding from the base 12a, and the protrusions 12b are evenly arranged at regular intervals on the base 12a. .

The structure of the partition 12 is only one example of the present invention, and the present invention is not limited thereto. Therefore, the distribution space (the space between the protrusions 12b in the present embodiment) of the cooling medium by the partition 12 may be formed in various forms.

The partition 12 is formed by making the size smaller than the unit cell 11. Specifically, in the present embodiment, the partition wall 12 is formed such that the width of the base 12a is smaller than that of the case 11a of the unit cell 11. More specifically, the partition 12 has a size substantially the same as that of the electrode group 43 of the unit cell 11 (see FIG. 3). Of course, this is only one example of the size of the partition wall 12 is sufficient if the size of the partition wall 12 is smaller than the size of the case (11a) of the unit cell (11).

Substantially, when the partition 12 constitutes the battery module 100, the base 12a is in close contact with the unit cell 11 so that the center of the base 12a is aligned with the center of the case 11a of the unit cell 11.

Accordingly, the partition wall 12 spaces the left and right ends of the base 12a from the left and right ends of the case 11a of the unit cell 11 at equal intervals. Similarly, the upper and lower ends of the base 12a of the partition 12 are also spaced apart at equal intervals from the left and right ends of the case 11a of the unit cell 11 (see FIG. 2).

Such a coupling relationship of the partition wall 12 to the unit cell 11 is, when the configuration of the battery module, as described above, when the unit cells 11 are pressed by the end plate 36, the partition wall 12 Instead of dispersing the force toward the edges of the unit cells 11, the force is concentrated inside the unit cells 11 to pressurize the unit cells 11.

Thus, in the present embodiment, the partition wall 12 constitutes that the electrode group 43 accommodated in the case 11a of the unit cells 11 by the partition wall 12 is the partition wall 12 and the end plate 36. This is to reduce the moving distance of ions by receiving a lot of force applied by).

In a specific embodiment, the width of the unit cell 11 (the length in the X direction of the unit cell in FIG. 2) is referred to as W1, and the side end of the partition wall 12 (the end in the X direction of the partition in FIG. 2) and the unit cell 11. If the interval between the edges of W2 is W2, W2 is made 0.05 times to 0.2 times W1.

When W2 is smaller than 0.05 times W1, the distance between the partition 12 and the edge of the unit cell 11 is too close, and the force acting by the partition 12 is biased toward the edge of the case 11a, and the case 11a There is a problem that can not be properly pressurized. On the contrary, when W2 is larger than 0.2 times W1, the size of the partition wall 12 is too small compared to the size of the electrode group 43 installed inside the unit cell 11, so that the partition wall 12 makes the electrode group 43 as a whole. There is a problem that cannot be pressurized.

Further, the height of the unit cell 11 (the length in the Y direction of the unit cell in FIG. 2) is referred to as H1, and between the upper end of the partition 12 (the Y-direction end of the partition in FIG. 2) and the edge of the unit cell 11. When the interval of is referred to as H2, H2 is made 0.05 to 0.2 times H1.

When H2 is smaller than 0.05 times H1, the distance between the partition 12 and the edge of the unit cell 11 is too close, so that the force acting by the partition 12 is biased toward the edge of the case 11a. There is a problem that can not be properly pressurized. On the contrary, when H2 is larger than 0.2 times H1, the size of the partition wall 12 is too small compared with the size of the electrode group 43 provided inside the unit cell 11, so that the partition wall 12 is used to close the electrode group 43. There is a problem that cannot be pressed as a whole.

4 is a front view illustrating a unit cell and a partition wall according to a second exemplary embodiment of the present invention.

The structure of the unit cell and the partition wall of this second embodiment is basically the same as that of the unit cell and the partition wall of the first embodiment described above.

Hereinafter, referring to FIG. 4, the unit cell 50 according to the second embodiment of the present invention protrudes outward from the case 52 and the case 52 forming an external shape. The electrode terminal 53 is included. The partition wall 56 provided in contact with the unit cell 50 forms a chamfered portion 56a by inclining the portion of the base 56a adjacent to the corner of the case 52.

The chamfer 56b disperses the force acting on the corner of the case 52 that requires the maximum pressing force to the inside of the partition 56 when the partition wall 56 is pressed against the unit cell 50. It plays a role.

By the chamfering portion 53b, the partition wall 56 can press the case 52 evenly with a small force, so that the thickness of the electrode group can be reduced more easily.

In this embodiment, the chamfer 56b is illustrated as being inclined in a straight line, but the present invention is not limited thereto, and the chamfer may be formed in a rounded shape or a recessed recessed groove.

The battery module of the present invention is a device for operating by using a motor such as a hybrid electric vehicle, an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like for driving energy of the motor of the device. Can be used as a circle.

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.

As described above, according to the present invention, since the end portions of the partition walls are spaced apart at predetermined intervals from the corners of the unit cells, the electrode groups can be easily pressurized without causing excessive pressure on the partition walls. Accordingly, the charging and discharging efficiency can be improved.

Claims (9)

A plurality of unit cells; And Barrier ribs disposed between the unit cells; Including, A battery module having a size smaller than that of the unit cell. According to claim 1, The unit cell is case; And An electrode group embedded in the case; Including, And a battery module having the same size as that of the partition wall. The method of claim 2, The barrier rib is coupled to the case by matching the center thereof with the center of the case. According to claim 1, The unit cell is case; And Electrode group embedded in the case Including, The barrier rib is coupled to the case by separating the corner from the edge of the case. According to claim 1, The width of the case in contact with the partition wall is W1, A battery module that satisfies the following equation when the distance between the end of the partition wall and the widthwise edge of the case is W2. 0.05 × W1≤W2≤0.2 × W1 According to claim 1, The height of the case in contact with the partition is called H1, A battery module satisfying the following formula when the distance between the end of the partition wall and the distance from the height direction edge of the case is H2. 0.05 × H1≤H2≤0.2 × H2 According to claim 1, The partition wall Plate-shaped base; And Protrusions protruding from the base; Battery module comprising a. The method of claim 7, wherein Battery module is provided with a chamfered portion in the corner of the base. According to claim 1, The battery module is a battery module for driving a motor.

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