KR20140039350A - Battery module of improved cooling efficiency - Google Patents

Abstract

The present invention provides a battery module comprising: battery cells of a structure where an electrode assembly including an anode, a cathode, and a separator is housed within a battery case, and an anode lead and a cathode lead connected to the electrode assembly protruded outside the battery case; cartridges to form a stacked battery cell structure by fixing the battery cells respectively; a cooling member mounted on at least one surface of a stacked battery cell body that is the stacked structure of the battery cells; and an electrically insulating heat conductive member interposed between the stacked battery cell structure and the cooling member, and being in contact with the end of at least one of the anode lead and the cathode lead of the battery cells.

Description

Battery Module of Improved Cooling Efficiency

The present invention relates to a battery module with improved cooling efficiency, and more particularly, an electrode assembly including a positive electrode, a negative electrode, and a separator is housed in a battery case, and a positive electrode lead and a negative electrode lead connected to the electrode assembly are connected to the battery case. Battery cells having a structure protruding to the outside, cartridges for fixing the battery cells to form a battery cell stacking structure, a cooling member mounted on at least one surface of the battery cell stack of the battery cells, and the The present invention relates to a battery module including an electrically insulating thermally conductive member interposed between a battery cell stack structure and a cooling member and in contact with an end portion of at least one of the positive electrode lead and the negative electrode lead of the battery cells.

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 medium and large devices such as automobiles, due to the necessity of high output and large capacity, medium and large battery modules electrically connecting a plurality of battery cells are used.

Since such a medium-large battery module is preferably manufactured in a small size and weight, a square battery, a pouch-type battery, etc., which can be charged with high integration and have a small weight to capacity, are mainly used as battery cells (unit cells) of a medium-large battery module. It is used. 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. In particular, the laminate sheet of the pouch-type battery widely used in the high-output large-capacity battery module is coated with a low thermal conductivity polymer material, 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.

The battery module mounted on the middle- or large-sized battery pack is generally manufactured by stacking a plurality of battery cells at a high density, and adjacent battery cells are stacked at a predetermined interval so as to remove heat generated during charging and discharging. For example, the battery cells themselves may be sequentially stacked while being spaced apart from each other by a predetermined space, or in the case of a battery cell having low mechanical rigidity, one or a combination of two or more batteries may be built in a cartridge or the like. 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, an object of the present invention is to provide a battery module that can reduce the temperature variation of the battery cell, and improve the cooling efficiency despite the compact structure without using many members.

According to an aspect of the present invention,

Battery cells having an electrode assembly including a positive electrode, a negative electrode, and a separator housed in a battery case, and the positive electrode lead and the negative electrode lead connected to the electrode assembly protrude out of the battery case;

Cartridges fixing the battery cells to form a battery cell stack structure;

A cooling member mounted on at least one surface of the battery cell stack having a stack structure of the battery cells; And

An electrically insulating thermally conductive member interposed between the battery cell stack structure and the cooling member and in contact with an end of at least one of the positive electrode lead and the negative electrode lead of the battery cells;

As shown in FIG.

In general, when the temperature inside the battery cell rises, the temperature rises rapidly in the electrode lead exposed to the outside of the battery case, which is connected to the electrode assembly inside the battery case, rather than the outer surface of the battery case, and cools the battery case of the battery cell. Since the cooling structure does not include a structure for directly cooling the electrode lead, the temperature variation of the battery cell is increased, resulting in a decrease in cooling efficiency.

However, the battery module according to the present invention includes a structure that cools the electrode lead portion in which the temperature rises particularly high when the battery cell is heated by the cooling member through the electrically insulating thermally conductive member, and thus the temperature deviation of the battery cell with a simple cooling structure. It has a structure that improves the safety against fire or explosion by lowering the temperature and improving the cooling efficiency.

In one specific example, the battery cells are preferably made of a plate-shaped battery cells to provide a high stacking rate in a limited space, the one or both sides are stacked to face the adjacent battery cells to form a battery cell stack It can be made of a structure. The plate-shaped battery cell has a structure in which the positive and negative terminals protrude from one side of the main body of the battery cell, or one electrode terminal protrudes from one side of the main body of the battery cell, and the other electrode terminal is opposite or adjacent to the opposite side thereof. It may also be made of a protruding structure.

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-type battery cell is generally composed of a pouch-type battery case, the battery case is an outer coating layer made of a polymer resin having excellent durability, a blocking layer made of a metal material exhibiting a barrier against moisture, air, etc., and heat It consists of a laminate sheet structure in which an inner sealant layer made of a polymer resin that can be fused is sequentially stacked.

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.

The pouch-type battery cells are stacked in a fixed state by a cartridge. Specifically, the heat-sealed outer circumferential sealing portion of the pouch-type battery cell is interposed between the cartridges to press the structure so that the pouch-type battery cells are fixed to the cartridge. Can be achieved.

An end of the electrode lead of the battery cell may be formed in a bent structure to be in close contact with the outer surface of the cartridge. In detail, an end portion of the electrode lead protruding out of the cartridge may be bent at an approximately 90 degree angle to be in close contact with the outer surface of the cartridge. This structure increases the contact area with the electrically insulating thermally conductive member, thereby enhancing the thermal conductivity and further improving the cooling effect.

In one specific example, a cooling fin may be further mounted between the electrically insulating thermally conductive member and the cooling member. As a specific example of the structure of the cooling fin, one side of the cooling fin is interposed between the battery cells, and the remaining portion of the cooling fin is disposed so as to face the end of the electrode lead in the state where the electrically insulating heat conductive member is interposed. It may be formed into a structure extending in a bent state from the site.

In this case, in order to prevent shorts generated while contacting the electrode lead, the bent portion may have a structure positioned between the electrically insulating thermally conductive member and the cooling member. That is, the end of the electrode lead is in close contact with the outer surface of the cartridge is located between the cartridge and the electrically insulating thermally conductive member, the end of the cooling fin is composed of a structure located between the electrically insulating thermally conductive member and the cooling member, their ends are electrically It may be made of a structure that is insulated without contacting the insulating heat conductive member.

If the cooling fin is a thin member having thermal conductivity, its structure is not particularly limited, and for example, a sheet of a metal material may be preferably used. The metal material may be aluminum or aluminum alloy having high thermal conductivity and light weight among metals, but is not limited thereto.

The electrically insulating thermally conductive member is positioned between the battery cell stack structure and the cooling member to efficiently transfer heat from the end portions of the battery cell stack structure and the electrode lead to the cooling member. It may be made of an elastic material to improve adhesion between the cooling members. As an example, the heat transfer pad may be manufactured by combining a heat conductive material with silicon, thereby forming a structure in which elasticity and heat conductivity are simultaneously exhibited.

The material is not particularly limited as long as the cooling member is a member having thermal conductivity. For example, a metal material may be preferably used. The metal material may be aluminum or aluminum alloy having high thermal conductivity and light weight among metals, but is not limited thereto.

In addition, the cooling member may be an air-cooled or water-cooled member, and may have a structure in which a contact surface with external air is maximized or a refrigerant flow path in which cooling water flows.

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

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.

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, the battery module according to the present invention includes a structure for cooling the electrode lead portion, in which the temperature rises particularly much when the battery cell is heated, by the cooling member through the electrically insulating heat conductive member, thereby providing a compact cooling structure. By lowering the temperature deviation of the battery cell and improving the cooling efficiency, there is an effect of improving the safety against fire or explosion.

1 is a perspective view of one exemplary battery cell mounted to a battery module;
2 is an exploded perspective view of a battery module according to an embodiment of the present invention;
3 is a schematic diagram showing a portion where cooling is performed in a structure in which the components of the battery module of FIG. 2 are combined;
4 is an exploded perspective view of a battery module according to another embodiment of the present invention;
5 is a schematic diagram showing a portion where cooling is performed in a structure in which the components of the battery module of FIG. 4 are combined.

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.

In the present specification, a housing, a cable, a protection circuit member, etc., which are generally included in the battery module, are omitted for convenience of description.

1 is a perspective view schematically showing one exemplary battery cell mounted to the battery module of the present invention.

Referring to FIG. 1, the pouch-type battery cell 110 is electrically connected to an electrode assembly (not shown) including an anode, a cathode, and a separator disposed therebetween inside the pouch-type battery case 112. The two electrode terminals 114 and 116 are sealed to be exposed to the outside.

The battery case 112 is composed of an upper case and a lower case including a concave shaped receiving portion into which the electrode assembly can be seated.

When the electrode assembly impregnated with the electrolyte is seated on the accommodating part 118, the sealing part is formed by heat-sealing the outer peripheral surface contact portion 113 of the upper case and the lower case. The sealing portion is vertically bent and closely attached to the side wall of the storage portion.

2 is an exploded perspective view of a battery module according to an embodiment of the present invention, Figure 3 is a schematic diagram showing a portion where cooling is performed in the structure in which the components of the battery module of Figure 2 combined. .

2 and 3, the battery module 100 includes pouch-type battery cells 110 and 110 ′, cartridges 120 and 120 ′, a cooling member 140, and an electrically insulating thermally conductive member 130. Consists of a structure that includes.

In the battery cells 110 and 110 ′, an electrode assembly (not shown) is housed inside a pouch-shaped battery case, and a cathode lead 114 and a cathode lead 116 connected to the electrode assembly are connected to the battery case 112. It is formed in a plate-like structure protruding to the outside, the cartridges (120, 120 ') is fixed to the battery cells (110, 110'), respectively, to form a stack structure of battery cells (110, 110 ').

The cooling member 140 is mounted on one surface of the stack of battery cells 110 and 110 ′ to conduct cooling by conducting heat from the battery cells 110 and 110 ′, and the electrically insulating thermal conductive member 130 is a battery cell. (110, 110 ') interposed between the stacked structure and the cooling member 140, and is in contact with the end 115 of the electrode lead of the battery cells (110, 110').

The end 115 of the electrode lead protruding from the battery cells 110 and 110 ′ is bent at an angle of 90 degrees to closely contact the outer surfaces of the cartridges 120 and 120 ′, thereby making contact with the electrically insulating thermally conductive member 130. Increasing the area improves the thermal conductivity efficiency. In addition, the end 115 of the electrode lead is formed by bending the end 115 of the electrode lead of the battery cells 110 and 110 ′ to prevent contact between the electrode leads of the adjacent battery cells 110 and 110 ′. It is bent in the opposite direction to form a symmetrical structure.

The electrically insulating thermally conductive member 130 efficiently transfers heat from the end cells 115 of the battery cells 110 and 110 ′ and the electrode lead to the cooling member 140. The electrically insulating thermally conductive member 130 is an electrically insulating and thermoelectric member. It is made of a material having excellent conductivity, and is manufactured by combining a thermally conductive material with silicon in order to improve adhesion between the battery cells 110 and 110 ′ and the electrode leads 114 and 116 and the cooling member 140.

In addition, the cooling member 140 may be an air-cooled structure that maximizes the contact surface with the outside air, or may include a water-cooled cooling structure formed with a refrigerant flow path through which the coolant flows, and although not shown in the drawings, the cooling structure is not limited thereto. Of course, various cooling structures can be used.

Figure 4 is an exploded perspective view of a battery module according to another embodiment of the present invention is shown in Figure 5 is a schematic diagram showing a portion where cooling is performed in the structure in which the components of the battery module of Figure 4 combined.

In FIGS. 4 and 5, except that cooling fins 150 and 150 ′ are added to the structures illustrated in FIGS. 2 and 3, other structures are the same, and thus redundant descriptions thereof will be omitted.

4 and 5, as a structure for further improving the cooling efficiency of the battery module, cooling fins 150 and 150 ′ are mounted between the electrically insulating thermally conductive member 130 and the cooling member 140. One side of the cooling fins 150 and 150 'is interposed between the battery cells 110 and 110', and the remaining portions of the cooling fins 150 and 150 'are interposed with the electrically insulating thermally conductive member 130. Is formed in a structure extending in a state bent to face the end 115 of the electrode lead.

The portion 155 extending in the bent state is positioned between the electrically insulating thermally conductive member 130 and the cooling member 140 to prevent shorts generated while contacting the electrode lead. That is, the end 115 of the electrode lead is in close contact with the outer surface of the cartridge (120, 120 ') and is located between the cartridge (120, 120') and the electrically insulating thermally conductive member 130, the cooling fins (150, 150 ') The bent end portion 155 of the structure has a structure positioned between the electrically insulating thermally conductive member 130 and the cooling member 140 so that their ends are insulated without being contacted by the electrically insulating thermally conductive member 130. It consists of a structure.

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 (17)

Battery cells having an electrode assembly including a positive electrode, a negative electrode, and a separator housed in a battery case, and the positive electrode lead and the negative electrode lead connected to the electrode assembly protrude out of the battery case;
Cartridges fixing the battery cells to form a battery cell stack structure;
A cooling member mounted on at least one surface of the battery cell stack having a stack structure of the battery cells; And
An electrically insulating thermally conductive member interposed between the battery cell stack structure and the cooling member and in contact with an end of at least one of the positive electrode lead and the negative electrode lead of the battery cells;
The battery module comprising: The battery module according to claim 1, wherein the battery cells are plate-shaped battery cells, and one or both surfaces thereof are stacked to face adjacent battery cells to form a battery cell stack. The battery cell of claim 2, wherein the plate-shaped battery cell is a pouch-type battery cell having a structure in which the outer circumferential surface of the cell case is heat-sealed and sealed in a state in which an electrode assembly is embedded in a cell case of a laminate sheet including a resin layer and a metal layer. Battery module. The battery module according to claim 3, wherein the heat-sealed outer circumferential surface of the pouch-type battery cell is fixed between cartridges. The battery module according to claim 1, wherein an end portion of the electrode lead of the battery cell is bent to be in close contact with an outer surface of the cartridge. The battery module according to claim 1, wherein a cooling fin is further mounted between the electrically insulating thermally conductive member and the cooling member. The method of claim 6, wherein one side of the cooling fin is interposed between the battery cells, and the remaining portion of the cooling fin is bent from the one side so as to face an end of the electrode lead with the electrically insulating thermally conductive member interposed therebetween. A battery module, characterized in that extending in the state. The battery module according to claim 6, wherein the cooling fin is a sheet of a metallic material. The battery module according to claim 8, wherein the metal material is aluminum or an aluminum alloy. The battery module according to claim 1, wherein the electrically insulating thermally conductive member is formed of a structure in which a thermally conductive material is combined with an elastic base material. The battery module according to claim 1, wherein the battery cell has a positive electrode and a negative electrode terminal protruding on one side of the outer circumferential surface, or a positive electrode terminal protruding on one side of the outer circumferential surface and a negative electrode terminal protruding on the opposite side of the battery cell. . The battery module according to claim 1, wherein the cooling member is formed of a metal material. The battery module according to claim 1, wherein the cooling member has a refrigerant passage through which a refrigerant flows. The battery module according to claim 1, wherein the battery cell is a lithium secondary battery. A battery pack comprising the battery module according to any one of claims 1 to 14 as a unit module. Device comprising the battery pack according to claim 15. 17. The device of claim 16, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Images