KR20130123901A - Battery module with excellent cooling efficiency and compact structure - Google Patents

Abstract

The present invention provides a battery module which comprises: a battery cell lamination in which battery cells are laminated in an up and down direction; upper and lower plates which surround the lower and upper surfaces of the battery cell lamination; cooling pins placed on the interface of the battery cells in which end parts are protruded to one or both sides of the battery cell lamination; a heat transfer pad which is adjacent to the end part of cooling pin protrusions; and a cooling part which is adjacent to the heat transfer pad, is mounted on one or both sides of the battery cell lamination, and is equipped with a refrigerant channel inside.

Description

Battery Module with Excellent Cooling Efficiency and Compact Structure

The present invention is a battery module including a plurality of battery cells, specifically, a battery cell stack in which the battery cells are stacked in the vertical direction, an upper plate surrounding the bottom and top surfaces of the battery cell stack and A lower plate, cooling fins interposed at an interface between the battery cells and protruding end portions of one or both sides of the battery cell stack, a heat transfer pad in close contact with the protruding ends of the cooling fins, and the heat transfer pad. The present invention relates to a battery module including a cooling member mounted on one side or both side sides of a battery cell stack in a state of being in a state and having a refrigerant passage formed therein.

BACKGROUND ART [0002] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. In addition, the secondary battery is an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (HEV), and the like, which are proposed as solutions for air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels (Plug-In HEV) and the like.

In a small mobile device, one or two or more battery cells are used per device, while a middle- or large-sized battery module such as an automobile is used as a middle- or large-sized battery module in which a plurality of battery cells are electrically connected due to the necessity of a large-

Since the middle- or large-sized battery module is preferably manufactured in a small size and weight, a prismatic battery, a pouch-shaped battery, or the like, which can be charged with a high degree of integration and has a small weight to capacity, is mainly used as a battery cell have. In particular, a pouch-shaped battery using an aluminum laminate sheet or the like as an exterior member has recently attracted a lot of attention due to its advantages such as small weight, low manufacturing cost, and easy shape deformation.

Since the battery cells constituting the medium-large battery module are composed of secondary batteries capable of charging and discharging, such a high output large capacity secondary battery generates a large amount of heat during the charging and discharging process. Particularly, since the laminate sheet of the pouch-type battery widely used for the battery module has a surface coated with a polymer material having low thermal conductivity, it is difficult to effectively cool the temperature of the entire battery cell.

If the heat of the battery module generated during the charging and discharging process can not be effectively removed, heat accumulation may occur, thereby accelerating the deterioration of the battery module and possibly causing ignition or explosion. Therefore, a cooling system for cooling the battery cells built in the high-power, large-capacity battery pack is required.

A battery module mounted in a medium-large battery pack is generally manufactured by stacking a plurality of battery cells with high density, and stacking adjacent battery cells at regular intervals to remove heat generated during charging and discharging. For example, the battery cells themselves may be sequentially stacked without a separate member at predetermined intervals, or in the case of battery cells having low mechanical rigidity, one or more combinations may be embedded in a cartridge or the like, and a plurality of such cartridges may be stacked. The battery module can be configured. The stacked battery cells or the battery modules are structured such that a flow path of the coolant is formed between the battery cells or the battery modules so as to effectively remove accumulated heat.

However, this structure has a problem that the total size of the battery module is increased because a plurality of refrigerant flow paths must be secured corresponding to a plurality of battery cells.

In addition, as the stacking of many battery cells increases the volume of the battery module due to the addition of a large number of components in relation to the cooling structure, the manufacturing process is complicated, resulting in a significant increase in the manufacturing cost.

Accordingly, there is a high demand for a battery module having excellent life characteristics and safety due to high cooling efficiency while being able to be manufactured in a simple and compact structure while providing a high output large capacity power.

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

Specifically, it is an object of the present invention to provide a battery module having a compact structure that can be effectively removed from the battery cell without using many members.

Still another object of the present invention is to provide a battery module having excellent safety and excellent manufacturing process while providing high output large capacity power.

According to an aspect of the present invention,

A battery cell stack in which battery cells are stacked in a vertical direction;

An upper plate and a lower plate surrounding lower and upper surfaces of the battery cell stack;

Cooling fins interposed at the interface of the battery cells, the protruding end portion to one side or both sides of the battery cell stack;

A heat transfer pad in close contact with the protruding ends of the cooling fins; And

A cooling member mounted to one side or both sides of the battery cell stack in a state of being in close contact with the heat transfer pad and having a refrigerant passage formed therein;

As shown in FIG.

In general, the battery module is configured by stacking the battery cells spaced apart by a predetermined distance to form a coolant flow path, and prevents overheating of the battery cells by flowing a coolant such as air into the spaced space. In addition, the inlet and outlet of the refrigerant is located on one surface of the battery module and the duct is configured so that the flow of the refrigerant can be made smoothly, a cooling fan for the flow of the refrigerant is additionally installed as necessary.

On the other hand, the battery module of the present invention has a structure in which cooling fins are interposed between the battery cells and the ends of the cooling fins protrude toward the side of the battery cell stack to transfer heat to the cooling member through the heat transfer pad to perform cooling. Because of this, it is possible to exhibit a high cooling efficiency without using many members.

In addition, since heat generated from the battery cells can be effectively removed to the outside without being based on the conventional cooling system, as a result, the assembly processability can be improved, and a very compact battery module can be configured.

The battery cell is preferably made of a plate-shaped battery cell to provide a high stacking rate in a limited space, the plate-shaped battery cell has a structure in which the positive and negative terminals protrude on one side of the main body of the battery cell, or one electrode The terminal protrudes toward one side of the main body of the battery cell, and the other electrode terminal may have a structure protruding on the opposite side of the battery cell.

Among them, in order to connect the positive terminals and the negative terminals of the battery cells using a bus bar having a simple structure, a structure in which the electrode terminals are formed to protrude on one side may be more preferably used.

The plate-shaped battery cell may be, for example, a pouch-type battery cell having a structure in which an electrode assembly is built in a battery case of a laminate sheet including a resin layer and a metal layer.

Specifically, the plate-shaped battery cell is a pouch-type battery cell in which an electrode assembly having a positive electrode, a separator, and a negative electrode structure is sealed inside the battery case together with an electrolyte. The plate-shaped battery cell has a plate-shaped shape having a substantially rectangular parallelepiped structure having a thin thickness to width. . Such a pouch-shaped battery cell is generally composed of a battery case of a pouch type, and the battery case is composed of an outer coating layer made of a polymer resin having excellent durability; A barrier layer made of a metal material exhibiting barrier properties against moisture, air, and the like; And an inner sealant layer composed of a polymer resin that can be thermally fused, are laminated in this order.

The case of the pouch-type battery cell may have a variety of structures. For example, the case may be a two-unit member, which houses the electrode assembly in the housing portion formed on the upper and / or lower inner surface, And a structure for sealing by heat fusion. A pouch-shaped battery cell having such a structure is disclosed in PCT International Application No. PCT / KR2004 / 003312 of the present applicant, which application is incorporated herein by reference.

In one preferred example, the battery cells may be of a structure that is fixed to the battery cartridges. That is, each of the battery cells can be fixed by each battery cartridge of the frame structure for fixing their outer peripheral surface.

These battery cartridges are preferably fastened with fasteners therein, and fastened by the fastening members coupled to the upper plate and the lower plate through the fasteners, whereby the battery cells fixed by the battery cartridge are fixed to the upper plate and the lower plate. The stacked structure in between can be fixed.

The cooling fins interposed at the interface of the battery cells are not particularly limited in structure as long as they are thin members having thermal conductivity. For example, a metal plate may be preferably used. As the metal material, aluminum or an aluminum alloy having high thermal conductivity and light weight may be preferably used, but the metal material is not limited thereto.

In one preferred example, the end of the cooling fin can be bent vertically to surround the end of the cartridge. In this case, when the battery cartridges to which the battery cells are fixed are stacked, the ends of the vertically bent cooling fins are aligned in a straight line in the vertical direction.

In addition, the cooling fin may be bent into a shape corresponding to the outer surface of the battery cell and the cartridge so as to be in close contact with the outer surface of the battery cell and the cartridge outer surface. That is, the cooling fins may be bent in accordance with the outer structure of the battery cells so that the cooling fins may be in close contact with the battery cells in correspondence with the outer structure of the battery cells. In addition, it may be bent in a shape corresponding to the outer surface of the cartridge for fixing the outer peripheral surface of the battery cell, for example, the cooling fins are in close contact with the battery cell, the end of the battery cell from the outside of the cartridge It may be made of a structure that is bent and adhered along the outer surface.

On the other hand, the cooling fin may be made of a structure including a first cooling fin in contact with the upper surface of the battery cell, and a second cooling fin in contact with the lower surface of the battery cell. The first cooling fin and the second cooling fin may be formed in a structure of mutual symmetry according to the shape of the battery cell.

The cartridge may be a structure in which a step is formed in one end direction so that the cooling member is accommodated in a plane and fixed at a fixed position.

The heat transfer pad is positioned between the end of the cooling fin and the cooling member, and efficiently transfers heat of the cooling fin to the cooling member. The heat transfer pad is formed of an elastic material to improve adhesion between the end of the cooling fin and the cooling member. Can be done. As an example, the heat transfer pad may be manufactured by combining a heat conductive material with silicon, and thus may have a structure in which elasticity and heat conductivity are simultaneously exhibited.

The cooling member is an air-cooled or water-cooled member, and may have a structure in which air or cooling water flows through the refrigerant passage. Preferably, the structure is a water-cooled structure in which the cooling water flows in the refrigerant passage, and the heat generated from the battery cell may be configured as an indirect water cooling structure in which the heat generated by the cooling cell is cooled by the cooling water flowing in the refrigerant passage of the cooling member.

On the other hand, as mentioned above, the battery cell has a structure in which the positive and negative terminals protrude on one side of the body of the battery cell, or one electrode terminal protrudes on one side of the body of the battery cell, the other electrode terminal is opposite It may be made of a structure protruding on the opposite side. Among them, a battery cell having a structure in which positive and negative terminals protrude from one side of a battery cell body may be preferably used, and a bus bar assembly for electrically connecting electrode terminals of the battery cells may have one end of the battery cell stack. Can be mounted in addition.

In addition, an electrically insulating bus bar cover may be further included to insulate the electrical connection portion of the bus bar assembly from the outside.

In one preferred embodiment, the battery module includes a means for detecting the temperature and voltage in order to prevent overheating, malfunction, etc. and improve the safety, the temperature information and voltage information measured by these means is transmitted to a separate control unit do. A temperature connector and a voltage connector may be mounted on opposite surfaces of the bus bar cover on which the bus bar assembly is located. The temperature connector, the voltage connector and the controller are electrically connected by wires. The controller may be, for example, a battery management system (BMS).

In addition, a wire cover may be further included to insulate and protect a member such as a temperature connector, a voltage connector, and a wire located on an outer surface of the bus bar cover from the outside.

The present invention also provides a battery pack including the battery module as a unit module.

The battery pack can be manufactured by combining the battery module as a unit module according to the desired output and capacity, and considering the mounting efficiency, structural stability, electric vehicle, hybrid electric vehicle, plug-in hybrid electric vehicle, electric power Although it can be preferably used as a power supply such as a storage device, the scope of application is not limited to these.

Accordingly, the present invention provides a device including the battery pack as a power source, and the device may specifically be an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Since the structure and fabrication method of such a device are known in the art, detailed description thereof will be omitted herein.

As described above, in the battery module according to the present invention, the cooling fins are interposed between the battery cells, the ends of the cooling fins protrude to the side of the battery cell stack body, heat is transferred to the cooling member through the heat transfer pads, So that high cooling efficiency can be achieved without using many members.

In addition, since the heat generated from the battery cells can be effectively removed to the outside without being based on the conventional cooling system, as a result, the assembly processability can be improved, and a very compact battery module can be constructed.

1 is a perspective view of a battery cell mounted to a battery module;
Figure 2 is an exploded perspective view of Figure 1;
3 is a perspective view of a battery module according to an embodiment of the present invention;
4 is an exploded perspective view of FIG. 3;
5 is a top view of FIG. 3;
6 is a cross-sectional view showing an AA portion of FIG. 5;
7 is a cross-sectional view showing a BB portion of FIG. 5;
8 is an enlarged view of a portion C of FIG. 7.

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.

1 is a schematic perspective view of one exemplary battery cell mounted to the battery module of the present invention, Figure 2 schematically shows an exploded perspective view of FIG.

Referring to these drawings, the pouch-type battery cell 100, inside the pouch-type battery case 110, the electrode assembly 120 made of a positive electrode, a negative electrode and a separator disposed between the positive and negative electrode tabs ( Two electrode terminals 132 and 134 electrically connected to the 122 and 124 are sealed to be exposed to the outside of one side.

The battery case 110 includes an upper case 114 and a lower case 116 including a recess 112 having a concave shape in which the electrode assembly 120 may be seated.

The electrode assembly 120 having a folding or stacking type or a stacking / folding type structure has a plurality of positive electrode tabs 122 and a plurality of negative electrode tabs 124 bonded to the electrode terminals 132 and 134, respectively. have. In addition, when the outer circumferential surfaces of the upper case 114 and the lower case 116 are heat-sealed by the heat welder, the short circuit between the heat welder and the electrode terminals 132 and 134 is prevented and the electrode terminals 132 and 134 are prevented. And an insulating film 140 are attached to upper and lower surfaces of the electrode terminals 132 and 134 to secure the sealing property with the battery case 110.

The upper case 114 and the lower case 116 are composed of an outer resin layer 117, a barrier metal layer 118, and an inner resin layer 119, and the inner resin layer 119 is a heat sealer (not shown). It can be tightly fixed by the heat and pressure from the).

When the electrode assembly 110 impregnated with the electrolyte is seated on the accommodating part 112, the sealing part is formed by heat-sealing the outer circumferential contact portions of the upper case 114 and the lower case 116.

3 is a perspective view of a battery module according to an embodiment of the present invention, Figure 4 is an exploded perspective view of FIG.

Referring to these drawings, the battery module 200 has a battery cell stack 400 in which a plurality of structures in which the battery cells 410 are mounted on the cartridge 430 is stacked up and down, and an interface between the battery cells 410. Cooling fins 420 interposed therebetween, the upper plate 310 and lower plate 320 surrounding the lower surface and the upper surface of the battery cell stack 400, and is mounted on both sides of the battery cell stack 400 It consists of a structure comprising a cooling member (800).

The cooling fins 420 are made of a metal plate having high thermal conductivity, and are in close contact with the battery cells 410 to conduct heat generated from the battery cells 410, and then the cooling member through the end of the cooling fins 420. Conduct heat to (800).

The battery cartridge 430 has a structure for fixing the outer circumferential surface of each battery cell 410, the cooling member 800 is accommodated in a plane, the step 432 in one side end direction to be fixed in place Formed.

In addition, a bus bar assembly 700 is mounted at one end of the battery cell stack 400, and the protruding positive and negative terminals of the battery cells 410 are electrically connected by the bus bar assembly 700. Connected. An electrically insulating bus bar cover 800 is mounted on the outside of the bus bar assembly 700 so as to insulate the electrical connection portion of the bus bar assembly 700 from the outside.

The temperature connector 810 and the voltage connector 820 are mounted on the opposite side of the bus bar cover 800 where the bus bar assembly 700 is located. Therefore, the temperature connector 810 and the voltage connector 820 form a structure that is connected to a separate control unit by, for example, a wire.

In addition, the outside of the bus bar cover 800 has a structure in which a temperature cover 810, a voltage connector 820, and a wire cover 900 for insulating the wires connected thereto from the outside are mounted.

FIG. 5 is a plan view of FIG. 3, FIG. 6 is a cross-sectional view of part A-A of FIG. 5, and FIG. 7 is a cross-sectional view of part B-B of FIG. 5.

Referring to these drawings, the battery cells 410 are stacked and the outer circumferential surface of each of the battery cells 410 is fixed by the battery cartridge 430. Fasteners are formed at the corners of the battery cartridge 430 so that the battery cell 410 is a cartridge 430 by a fastening member penetrating the fastener and coupled to the upper plate 310 and the lower plate 320. The stack (electron cell stack: 400) having a structure fixed by () is fixed between the upper plate 310 and the lower plate 320.

FIG. 8 schematically shows an enlarged structure of a portion C of FIG. 7.

Referring to FIG. 8 together with FIG. 7, the outer circumferential surface of the battery cell 410 is pressed by the cartridge 430 and has a structure in which the battery cell 410 is fixed to the cartridge 430. The cooling fin 420 is positioned between the cartridge 430 and the battery cell 410 and is bent into a shape corresponding to the outer surface of the battery cell 410 and the cartridge 430, and the end of the cooling fin 420 is a cartridge. It is bent vertically to surround the end of 430. Therefore, when the cartridges 430 to which the battery cells 410 are fixed are stacked, the ends of the cooling fins 420 vertically bent are arranged in a straight line in the vertical direction.

The cooling fins 420 are divided into a first cooling fin 422 in contact with the top surface of the battery cell 410 and a second cooling fin 424 in contact with the bottom surface of the battery cell 410, respectively. It consists of a bent structure corresponding to the shape of the upper and lower surfaces of the.

The heat transfer pad 500 is a member positioned between the ends of the cooling fins 422 and 424 and the cooling member 800 to efficiently transfer the heat of the cooling fins 422 and 424 to the cooling member 800. It is made of a material having elasticity and restoring force to improve adhesion between the ends of the fins 422 and 424 and the cooling member 800. Therefore, when the cooling member 800 is mounted on the side surface of the battery cell stack 400, the cooling member 800 presses the side surface of the battery cell stack 400 through the heat transfer pad 500. It consists of a structure to improve the structural stability and thermal conductivity of the battery cell stack 400.

The cooling member 800 has a refrigerant passage 610 formed therein, and the cooling water flows through the refrigerant passage 610 to perform cooling. That is, the heat generated from the battery cell 410 is conducted to the cooling member 800 through the cooling fin 420, and the temperature of the battery module 200 is removed by removing heat by indirect water cooling cooling of the cooling member 800. It consists of a regulating structure.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Claims (21)

A battery cell stack in which battery cells are stacked in a vertical direction;
An upper plate and a lower plate surrounding lower and upper surfaces of the battery cell stack;
Cooling fins interposed at the interface of the battery cells, the protruding end portion to one side or both sides of the battery cell stack;
A heat transfer pad in close contact with the protruding ends of the cooling fins; And
A cooling member mounted to one side or both sides of the battery cell stack in a state of being in close contact with the heat transfer pad and having a refrigerant passage formed therein;
The battery module comprising: The battery module according to claim 1, wherein the battery cell is a plate-shaped battery cell in which electrode terminals are formed on one side or both sides. The battery module according to claim 2, wherein the plate-shaped battery cell is a pouch-type battery cell manufactured by embedding an electrode assembly in a case of a laminate sheet including a resin layer and a metal layer, and sealing an outer circumferential surface of the case. The battery module according to claim 2, wherein the plate-shaped battery cell has a structure in which a positive electrode terminal and a negative electrode terminal are formed at one side. The battery module according to claim 1, wherein the cooling fin is made of a metal plate having thermal conductivity. The battery module according to claim 5, wherein the cooling fin is made of aluminum or an aluminum alloy. The battery module according to claim 1, further comprising battery cartridges having a frame structure for fixing outer peripheral surfaces of the battery cells. 8. The battery module according to claim 7, wherein each of the battery cartridges further comprises a fastening member having a fastener, and further comprising a fastening member penetrating the fastener and coupled to the upper plate and the lower plate. 8. The battery module according to claim 7, wherein an end of the cooling fin is bent vertically to surround the end of the cartridge. The battery module according to claim 9, wherein the cooling fin is bent into a shape corresponding to the outer surface of the battery cell and the cartridge so as to closely contact the outer surface of the battery cell and the outer surface of the cartridge. The battery module of claim 10, further comprising a first cooling fin contacting an upper surface of the battery cell based on the battery cell, and a second cooling fin contacting a lower surface of the battery cell. 8. The battery module according to claim 7, wherein the cartridge has a step formed in one end direction such that the cooling member is accommodated in a plane. The battery module according to claim 1, wherein the heat transfer pad is made of an elastic material. The battery module according to claim 1, wherein the refrigerant member is a water cooling member and has a structure in which cooling water flows in the refrigerant passage. The battery cell of claim 1, wherein the battery cells have a structure in which a positive electrode terminal and a negative electrode terminal are formed at one end thereof, and for electrical connection of the battery cells at one end of the battery cell stack in which the positive electrode terminal and the negative electrode terminal are positioned. Battery module characterized in that the bus bar assembly is further mounted. 16. The battery module of claim 15, further comprising an electrically insulating bus bar cover mounted on the bus bar assembly. 17. The battery module according to claim 16, wherein a temperature connector and a voltage connector are mounted on opposite surfaces of the bus bar cover on which the bus bar assembly is located. 17. The battery module of claim 16, wherein a wire cover is additionally mounted on an outer surface of the bus bar cover. A battery pack comprising the battery module according to any one of claims 1 to 18 as a unit module. A device comprising a battery pack according to claim 19. The device of claim 20, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

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