Cooling component and battery pack containing the same

Abstract

A cooling member according to one embodiment of the present invention is attached to a battery cell stack in which a plurality of battery cells are stacked. The cooling member includes an upper plate, a lower plate, a refrigerant contained in an internal space between the upper plate and the lower plate, and at least one of an upper structure supporting the upper plate and a lower structure supporting the lower plate, wherein the upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell, and the upper structure and the lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0125134 filed on September 30, 2022, and all the contents disclosed in the document of the Korean patent application are included as part of this specification.

[0002] The present invention relates to a cooling member and a battery pack including the same, and more specifically, to a cooling member provided with a reinforcing structure and a battery pack including the same.

Background Art

[0003] In modern society, as the use of portable devices such as mobile phones, notebook computers, video cameras, and digital cameras has become common, the technological development in fields related to such mobile devices has become active. In addition, rechargeable secondary batteries are a solution for solving problems such as air pollution in existing gasoline vehicles that use fossil fuels, and are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug - in hybrid electric vehicles (P - HEVs), etc. Therefore, the need for development of secondary batteries is increasing.

[0004] Currently commercialized secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, lithium secondary batteries, etc. Among these, lithium secondary batteries have the advantages of free charge and discharge, low self - discharge rate, and high energy density, and are the most widely noted.

[0005] On the other hand, while secondary batteries used in small devices typically consist of two to three battery cells, secondary batteries used in medium- and large-sized devices such as automobiles utilize medium- and large-sized battery modules (Battery modules) that electrically connect numerous battery cells. Since medium- and large-sized battery modules are preferably manufactured to be as small and light as possible, prismatic batteries and pouch-type batteries, which can be stacked with a high degree of integration and have a small capacity-to-weight ratio, are mainly used as battery cells in medium- and large-sized battery modules.

[0006] On the other hand, battery cells mounted in battery modules can generate a large amount of heat during the charging and discharging process. If their temperature rises above the appropriate temperature due to overcharging or other reasons, their performance may deteriorate, and if the temperature rise is excessive, there is a risk of explosion or fire. If a fire occurs inside a battery module, high-temperature heat, gas, or flames may be released to the outside of the battery module. In this case, the heat, gas, sparks, or flames released from one battery module can be transmitted to other battery modules located at a narrow distance within the battery pack, potentially causing a continuous thermal runaway phenomenon within the battery pack.

[0007] To prevent such thermal runaway phenomena, attempts have recently been made to apply water-cooled cooling members or water-cooled heat dissipation members into which a refrigerant is injected. Figures 1 and 2 are perspective views showing a conventional cooling member and a part of a battery pack including the same, respectively. The cooling member 50 is provided to lower the internal temperature of a battery module or battery pack, including battery cells. The cooling member 50 may be a refrigerant or a water-cooled cooling member 50 into which a refrigerant is injected. By providing the cooling member 50 in a water-cooled manner, the cooling efficiency of the cooling member 50 can be maintained uniformly, and the battery cells in the battery module or battery pack can be cooled evenly. On the other hand, the conventional cooling member 50 is made of a metal material such as aluminum so that heat can be transferred. For example, the cooling member 50 is constructed by joining two plates of metal material using a brazing method or the like.

[0008] On the other hand, conventional cooling components 50 are made of metal, making them somewhat heavy, and their weight increases further when filled with refrigerant (cooling water). When a battery pack containing such a cooling component 50 is installed in, for example, an automobile, its fuel efficiency may decrease slightly. However, if the cooling component 50 is manufactured by injection molding of plastic or the like to reduce its weight, there is a problem in that its rigidity decreases.

[0009] Therefore, there is a need to develop cooling components that increase the rigidity of heat dissipation components while achieving weight reduction and cost savings, and that are also easy to manufacture. [Overview of the project] [Problems that the invention aims to solve]

[0010] The problem that this invention aims to solve is to provide a cooling element that can supply a coolant in the appropriate place at the appropriate time in the event of internal ignition of a battery module or battery pack, and a battery pack including the same. More specifically, the invention aims to provide a cooling element that achieves weight reduction and cost savings while further increasing rigidity, and is easy to manufacture, and a battery pack including the same.

[0011] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly extended within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0012] A cooling member mounted on a battery cell stack, in which a plurality of battery cells are stacked, according to one embodiment of the present invention, includes an upper plate, a lower plate, a coolant built into the internal space between the upper plate and the lower plate, and at least one of an upper structure supporting the upper plate and a lower structure supporting the lower plate, wherein the upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell, and the upper structure and the lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell.

[0013] The upper structure is attached to the outer surface of the upper plate, and the lower structure is attached to the outer surface of the lower plate.

[0014] The portion of the upper plate that does not come into contact with the upper structure forms a weak point, and the portion of the lower plate that does not come into contact with the lower structure also forms a weak point, and the weak point melts or ruptures when a thermal event occurs in the battery cell, allowing the refrigerant to be injected into the battery cell.

[0015] At least one of the upper plate and the lower plate is made of plastic, and at least one of the upper structure and the lower structure is made of metal.

[0016] At least one of the upper plate and the lower plate is made of PP or PE, and at least one of the upper structure and the lower structure is made of stainless steel, aluminum, copper, or an alloy containing these materials.

[0017] The superstructure may include at least one of the following: a vertical bar mounted vertically on the upper plate and arranged parallel to the long side; a horizontal bar mounted horizontally on the upper plate and arranged parallel to the short side; and a peripheral portion mounted along the periphery of the upper plate.

[0018] The upper plate includes a groove into which the upper structure is mounted, and a low step is formed along the periphery of the upper plate, so that the structure and shape of the upper structure and the structure and shape of the groove and periphery of the upper plate can interlock with each other.

[0019] The grooves in the upper plate may include a first groove formed in the middle portion of the upper plate and arranged parallel to the long side of the upper plate, a second groove formed on both sides of the first groove and arranged parallel to the long side of the upper plate, and a third groove that intersects the first and second grooves and is arranged parallel to the short side of the upper plate.

[0020] The vertical bar of the upper structure is mounted in the first groove and the second groove of the upper plate, and the horizontal bar of the upper structure is mounted in the third groove of the upper plate.

[0021] The cooling member further includes an inlet port and an outlet port through which the refrigerant flows in and out on the first short side of the two short sides of the cooling member. One end of the first groove of the upper plate is in contact with the first short side, and the other end of the first groove of the upper plate can be separated from the second short side of the cooling member by a predetermined distance so that the refrigerant can flow in a U shape in the internal space of the cooling member.

[0022] Both ends of the second groove of the upper plate can be separated from the first short side and the second short side by a predetermined distance so that the refrigerant can flow in the internal space of the cooling member.

[0023] The third groove of the upper plate and the horizontal bar of the upper structure are each composed of a plurality of elements.

[0024] The lower structure can include at least one of a vertical bar mounted in the longitudinal direction of the lower plate and arranged parallel to the long side, a horizontal bar mounted in the transverse direction of the lower plate and arranged parallel to the short side, and a peripheral portion mounted along the periphery of the lower plate.

[0025] The lower plate includes a groove for mounting the lower structure, and a step with a low height is formed along the periphery of the lower plate. The structure and shape of the lower structure and the structure and shape of the groove and the periphery of the lower plate can be meshed with each other correspondingly.

[0026] The groove of the lower plate can include a fourth groove arranged parallel to the long side of the lower plate and a fifth groove intersecting the fourth groove and arranged parallel to the short side of the lower plate.

[0027] The vertical bar of the lower structure is mounted in the fourth groove of the lower plate, and the horizontal bar of the lower structure is mounted in the fifth groove of the upper plate.

[0028] The fourth groove of the lower plate and the vertical bars of the lower structure are each composed of a plurality of them, or the fifth groove of the lower plate and the horizontal bars of the lower structure are each composed of a plurality of them.

[0029] In order to prevent the refrigerant from leaking outside the cooling member, a sealing pad disposed between the upper plate and the lower plate can be further included.

[0030] The upper plate, the lower plate, and the sealing pad can all be fastened by rivets or bolts.

[0031] The upper plate and the lower plate are integrally formed.

[0032] An inlet port through which the refrigerant flows into the inside of the cooling member and an outlet port through which the refrigerant flows out of the inside of the cooling member can be further included.

[0033] The cooling member is mounted on the upper surface of the battery cell laminate.

[0034] A battery pack according to another embodiment of the present invention includes the above-described cooling member.

Advantages of the Invention

[0035] The cooling member according to an embodiment of the present invention, when an internal ignition occurs in a battery module or a battery pack, releases a part thereof and injects a refrigerant at an appropriate time and place, thereby quickly suppressing an internal fire of the battery module or the battery pack and preventing a continuous thermal runaway phenomenon.

[0036] Furthermore, the cooling member according to an embodiment of the present invention has the advantages of achieving weight reduction and cost reduction while increasing rigidity, and being easy to manufacture.

[0037] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawing]

[0038] [Figure 1] This is a perspective view showing a conventional cooling component and a part of a battery pack containing it. [Figure 2] This is a perspective view showing a conventional cooling component and a part of a battery pack containing it. [Figure 3] This is an exploded perspective view showing a battery pack according to one embodiment of the present invention. [Figure 4] Figure 3 is a perspective view of the battery module included in the battery pack. [Figure 5] Figure 3 is a perspective view of the cooling component included in the battery pack and the battery module located below the cooling component. [Figure 6] This is a magnified view of a portion of Figure 5. [Figure 7] Figure 5 is an exploded perspective view of the cooling component. [Figure 8] Figure 5 is a perspective view of the upper plate of the cooling component. [Figure 9] Figure 5 is a perspective view of the lower plate of the cooling member. [Figure 10] Figure 5 is a perspective view of the superstructure of the cooling member. [Figure 11] Figure 5 is a perspective view of the lower structure of the cooling member. [Figure 12] Figure 5 is a perspective view of the sealing pad of the cooling component. [Figure 13] This diagram shows the method of injecting refrigerant into the cooling component when a thermal event occurs in a battery cell. [Figure 14] This diagram shows a magnified view of a portion of the refrigerant flow. [Figure 15] This figure shows the process of assembling the cooling component shown in Figure 5. [Figure 16] This figure shows the process of assembling the cooling component shown in Figure 5. [Figure 17] This figure shows the process of assembling the cooling component shown in Figure 5. [Figure 18] This figure shows the process of assembling the cooling component shown in Figure 5. [Figure 19] This figure shows the process of assembling the cooling component shown in Figure 5. [Modes for carrying out the invention]

[0039] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be realized in various other forms besides those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0040] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0041] Furthermore, the dimensions and thicknesses of each component shown in the drawings have been arbitrarily enlarged or reduced for the sake of explanation, so it is obvious that the content of the present invention is not limited to what is shown. In the following drawings, the thickness of each layer is shown enlarged in order to clearly represent the various layers and regions. Also, in the following drawings, the thickness of some layers and regions is shown in an exaggerated manner for the sake of explanation.

[0042] Furthermore, when describing a layer, membrane, region, or plate as being "above" another part, this must be interpreted to include not only cases where the corresponding layer, membrane, region, or plate is "directly above" the other part, but also cases where there are other parts in between. Conversely, when describing a corresponding layer, membrane, region, or plate as being "directly above" another part, it can mean that there are no other parts in between. Also, being "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "up" in the opposite direction of gravity. On the other hand, just as describing something as being "above" another part is understandable by referring to the above points, describing something as being "below" another part should also be understood by referring to the above points.

[0043] Furthermore, since the top / bottom surfaces of a particular component can be determined differently depending on the direction used as the reference, throughout this specification, "top surface" or "bottom surface" is defined as meaning two opposing surfaces on the z-axis of the component in question.

[0044] Furthermore, when a specification as a whole states that a certain part "includes" a certain component, this means, unless otherwise stated, that it can further include other components rather than excluding them.

[0045] Furthermore, throughout the specification, "on a plane" means when the part is viewed from above, and "on a cross-section" means when the part is viewed from the side of a cross-section obtained by cutting the part vertically.

[0046] A battery pack according to one embodiment of the present invention will be described below.

[0047] Figure 3 is an exploded perspective view showing a battery pack according to one embodiment of the present invention. Figure 4 is a perspective view of a battery module included in the battery pack according to Figure 3. Referring to Figure 3, the battery pack 1000 according to one embodiment of the present invention may include at least one battery module 100, a pack frame 200 housing the battery module 100, a resin layer 300 formed on the inner surface of the pack frame 200, an end plate 400 closing the open surface of the pack frame 200, a cooling member 500 disposed between the pack frame 200 and the battery cell stack 120, and cooling fins 600 that release heat from the battery cells 110 by contacting the battery cells 110. However, the components included in the battery pack 1000 are not limited thereto, and by design, the battery pack 1000 may be provided with some of the above-mentioned components omitted, or with other components not mentioned added.

[0048] Referring to Figures 3 and 4, the battery module 100 provided in this embodiment can have a module-less structure in which the module frame is omitted.

[0049] Conventional battery packs typically have a double-assembly structure where a battery module is formed by assembling a stack of battery cells and various connected components, and multiple battery modules are then housed back into the battery pack. In this case, since the battery module includes a module frame that forms its outer surface, conventional battery cells are double-protected by the module frame of the battery module and the pack frame of the battery pack. However, such a double-assembly structure not only increases the manufacturing cost and process of the battery pack, but also has the disadvantage of reducing reassembly capability if some battery cells become defective. Furthermore, if the cooling material is located outside the battery module, there is a problem in that the heat transfer path between the battery cells and the cooling material becomes somewhat complex.

[0050] Therefore, in this embodiment, the battery module 100 is provided in the form of a "cell block" with the module frame omitted, and the battery cell stack 120 contained in the cell block is directly coupled to the pack frame 200 of the battery pack 1000. This simplifies the structure of the battery pack 1000, provides advantages in terms of manufacturing cost and manufacturing process, and has the effect of achieving a lighter battery pack.

[0051] Hereinafter, a battery module 100 without a module frame will be referred to as a "cell block" to distinguish it from a battery module with a module frame. However, regardless of whether or not it has a module frame, the term "battery module 100" collectively refers to a battery cell stack 120 segmented into predetermined units for modularization, and the term "battery module 100" should be interpreted as including all ordinary battery modules with module frames and cell blocks.

[0052] Referring to Figure 4, the battery module 100 of this embodiment may include a battery cell stack 120 in which a plurality of battery cells 110 are stacked in one direction, side plates 130 located at both ends of the battery cell stack 120 in the stacking direction, holding straps 140 that surround the side plates 130 and the battery cell stack 120 to fix their shape, and busbar frames 150 that cover the front and rear surfaces of the battery cell stack 120.

[0053] On the other hand, Figure 4 shows a battery module 100 provided in the form of a cell block, but the contents of such drawings do not preclude the application of a sealed battery module 100 having a module frame to the battery pack 1000 of this embodiment.

[0054] Each battery cell 110 may include an electrode assembly, a cell case, and electrode leads protruding from the electrode assembly. The battery cells 110 are supplied in a pouch or prismatic form that maximizes the number of cells stacked per unit area. For example, a battery cell 110 supplied in a pouch can be manufactured by housing an electrode assembly, including a positive electrode, a negative electrode, and a separator membrane, in a laminate sheet cell case, and then heat-sealing the cell case. On the other hand, while Figures 3 and 4 show the positive and negative electrode leads of the battery cell 110 protruding in opposite directions, this is not necessarily the case, and the electrode leads of the battery cell 110 can also protrude in the same direction.

[0055] The battery cell stack 120 may be a stack of electrically connected battery cells 110 stacked in one direction. The direction in which the multiple battery cells 110 are stacked (hereinafter referred to as the "stack direction") may be the y-axis direction (or the -y-axis direction, and hereafter the expression "axis direction" can be interpreted to include all + / - directions), as shown in Figures 3 and 4.

[0056] On the other hand, because the battery cells 110 are arranged in one direction, the electrode leads of the battery cells 110 can be located on one surface of the battery cell stack 120, or on one surface and the other surface opposite to that surface. Thus, the surfaces on which the electrode leads are located in the battery cell stack 120 are referred to as the front surface or the rear surface of the battery cell stack 120, and in Figures 3 and 4, the front surface and the rear surface of the battery cell stack 120 are shown as two surfaces facing each other on the x-axis.

[0057] Furthermore, the surface on which the outermost corner battery cell 110 is located in the battery cell stack 120 is referred to as the side surface of the battery cell stack 120, and in Figures 3 and 4, the side surfaces of the battery cell stack 120 are shown as two surfaces facing each other on the y-axis.

[0058] The side plates 130 are provided to maintain the overall shape of the battery cell stack 120. The side plates 130 are plate-shaped members that can complement the rigidity of the cell block in place of the module frame. The side plates 130 are positioned at both ends of the battery cell stack 120 in the stacking direction and can contact the outermost corner battery cells 110 on both sides of the battery cell stack 120.

[0059] The side plate 130 can be manufactured from a variety of materials and provided by a variety of manufacturing methods. For example, the side plate 130 may be made of a plastic material manufactured by injection molding. As another example, the side plate 130 may be made of a plate spring material. As yet another example, the side plate 130 may be made of an elastic material so that its shape can be partially deformed in response to volume changes of the battery cell stack 120 due to swelling.

[0060] The holding straps 140 are for fixing the position and shape of the side plates 130 at both ends of the battery cell stack 120. The holding straps 140 may be members having length and width. Specifically, the battery cell stack 120 is located between two side plates 130 that are in contact with the outermost corner battery cells 110, and the holding straps 140 can connect the two side plates 130 across the battery cell stack 120. In this way, the holding straps 140 prevent the distance between the two side plates 130 from increasing beyond a certain range, thereby maintaining the overall shape of the cell block within a certain range.

[0061] The holding strap 140 may have hooks at both ends in the longitudinal direction for stable connection with the side plate 130. The hooks are formed by bending both ends of the holding strap 140 in the longitudinal direction. On the other hand, the side plate 130 has locking grooves formed at positions corresponding to the hooks, and the holding strap 140 and the side plate 130 can be stably connected by the connection between the hooks and the locking grooves.

[0062] The holding strap 140 can be provided in a variety of materials or by a variety of manufacturing methods. For example, the holding strap 140 may be made of an elastic material, which allows for volume changes of the battery cell stack 120 due to swelling to remain within a certain range.

[0063] On the other hand, the holding strap 140 is for fixing the relative position between the side plate 130 and the battery cell stack 120, and can be provided in a form different from that shown in the illustration, as long as its purpose as a “fixing member” is achieved. For example, the fixing member can be provided in the form of a long bolt that can traverse between the two side plates 130, i.e., a long bolt. The side plate 130 is provided with a groove into which the long bolt can be inserted, and the long bolt can fix the relative position of the two side plates 130 by simultaneously connecting the two side plates 130 through the groove. The long bolt is provided at the periphery of the side plate 130, preferably near the apex of the side plate 130. Depending on the design, the holding strap 140 may be replaced by the long bolt described above, but it may also be possible for both the holding strap 140 and the long bolt to be provided in the cell block.

[0064] The busbar frame 150 is positioned on one side of the battery cell stack 120, covering that side and guiding the connection between the battery cell stack 120 and external equipment. The busbar frame 150 can be positioned on the front or rear side of the battery cell stack 120. Two busbar frames 150 are provided, one for the front and one for the rear side of the battery cell stack 120. Busbars are mounted on the busbar frame 150, so that the electrode leads of the battery cell stack 120 are connected to the busbars, thereby enabling the battery cell stack 120 to be electrically connected to external equipment.

[0065] The busbar frame 150 may include electrically insulating material. The busbar frame 150 can restrict the busbars from contacting other parts of the battery cell 110 other than the portion connected to the electrode leads, thereby preventing electrical short circuits.

[0066] The pack frame 200 is for protecting the battery module 100 and the electrical components connected thereto from external physical shocks. The pack frame 200 can house the battery module 100 and the electrical components connected thereto within its internal space. Here, the pack frame 200 includes an internal surface and an external surface, and the internal space of the pack frame 200 is defined by the internal surface.

[0067] There may be multiple battery modules 100 housed within the pack frame 200. Multiple battery modules 100 are referred to as a "module assembly." The module assembly is arranged in rows and columns within the pack frame 200. Here, "row" can mean a set of battery modules 100 arranged in one direction, and "column" can mean a set of battery modules 100 arranged in a direction perpendicular to the aforementioned direction. For example, as shown in Figure 3, the battery modules 100 can be arranged along the stacking direction of the battery cell stack to form a module assembly in a single row or column.

[0068] The pack frame 200 is provided in a hollow form that is open along one direction. For example, as shown in Figure 3, if multiple battery modules 100 are continuously positioned along the stacking direction of the battery cells 110, the pack frame 200 may have a hollow form that is open along the aforementioned stacking direction.

[0069] The structure of the pack frame 200 can be diverse. As an example, as shown in Figure 3, the pack frame 200 may include a lower frame 210 and an upper frame 220. Here, the lower frame 210 is provided in a plate shape, and the upper frame 220 is provided in a U shape. At least one battery module 100 is arranged on the plate-shaped lower frame 210, and the U-shaped upper frame 220 is provided so as to surround the top surface and two surfaces along the x-axis of the module assembly.

[0070] The pack frame 200 may include portions with high thermal conductivity to rapidly dissipate heat generated from the internal space to the outside. For example, at least a portion of the pack frame 200 may be made of a metal with high thermal conductivity, such as aluminum, gold, silver, copper, platinum, or alloys containing these. The pack frame 200 may also be partially electrically insulating, and an insulating film may be provided or an insulating coating may be applied to locations where insulation is required. The portion of the pack frame 200 to which an insulating film or insulating coating is applied may be referred to as an insulating portion.

[0071] A resin layer 300 is provided between the battery module 100 and the inner surface of the pack frame 200. The resin layer 300 is provided between the bottom surface of the battery module 100 and the lower frame 210. The resin layer 300 is provided between the top surface of the battery module 100 and the upper frame 220. Specifically, the resin layer 300 is provided between the cooling member 500 (described later) and the upper frame 220.

[0072] The resin layer 300 may be formed by injecting resin between the battery cell laminate 120 and one side of the inner surface of the pack frame 200. However, this is not necessarily the case, and the resin layer 300 may be a component provided in the form of a plate.

[0073] The resin layer 300 is manufactured from a variety of materials, and its function differs depending on the material. For example, the resin layer 300 may be formed from an insulating material, which can prevent electron transfer between the battery module 100 and the pack frame 200. As another example, the resin layer 300 may be formed from a thermally conductive material. A resin layer 300 made from a thermally conductive material allows heat generated from the battery cell 110 to be transferred to the pack frame 200, thereby enabling heat to be released / transmitted to the outside. In yet another example, the resin layer 300 may contain an adhesive material, which can fix the battery module 100 and the pack frame 200 together. Specifically, the resin layer 300 is provided to include at least one of a silicone-based material, a urethane-based material, and an acrylic-based material.

[0074] The end plates 400 are designed to protect the battery module 100 and its connected electrical components from external physical shocks by sealing the open sides of the pack frame 200. Each corner of the end plate 400 can be joined to the corresponding corner of the pack frame 200 by means of welding or other methods. Two end plates 400 are provided to seal the two open sides of the pack frame 200 and are manufactured from a metallic material of a predetermined strength.

[0075] The end plate 400 has an opening 410 for exposing the inlet / outlet ports 530 of the cooling member 500, which will be described later, and a connector 420 for LV (Low voltage) connection or HV (High voltage) connection with external equipment is attached to it.

[0076] The cooling member 500 is intended to cool the inside of the battery pack 1000 by releasing the heat generated from the battery cells 110. Considering that hot air or gases released when the battery cells 110 ignite mainly move in the opposite direction to gravity, it is preferable that the cooling member 500 be located above the battery cells 110, as shown in Figure 3. However, this is not always the case, and for various design reasons, the cooling member 500 may also be located below the battery cells 110.

[0077] The cooling member 500 may be a refrigerant, for example, a water-cooled cooling member 500 into which a refrigerant is injected. In this case, any refrigerant can be used in the cooling member 500 as long as it can dissipate the heat from the battery cell 110 by moving along the flow path inside the cooling member 500.

[0078] Figure 5 is a perspective view of the cooling element included in the battery pack according to Figure 3 and the battery module located below the cooling element. Figure 6 is a partial enlargement of Figure 5. Figure 7 is an exploded perspective view of the cooling element in Figure 5. Figures 8 and 9 are perspective views of the upper and lower plates of the cooling element in Figure 5, respectively. Figures 10 and 11 are perspective views of the upper and lower structures of the cooling element in Figure 5, respectively. Figure 12 is a perspective view of the sealing pad of the cooling element in Figure 5. Figure 13 shows the refrigerant injection method of the cooling element when a thermal event occurs in the battery cell. Figure 14 shows a magnified view of a part of the refrigerant flow.

[0079] Referring to Figures 5 to 7, and more specifically to Figure 7, the cooling member 500 may include an upper plate 510, a lower plate 520, and an inlet / outlet port 530. The cooling member 500 is formed by joining the upper plate 510 and the lower plate 520. A gap is formed between the joined upper plate 510 and lower plate 520, into which a refrigerant is injected through the inlet / outlet port 530. The refrigerant is supplied through the inlet port 530 and discharged through the outlet port 530. The cooling member 500 also further includes a superstructure 540 that supports the upper plate 510 and a substructure 550 that supports the lower plate 520.

[0080] Referring to Figures 8 and 9, grooves 511 and 521 are formed on the outer surfaces of the upper plate 510 and the lower plate 520, respectively. Here, the outer surface refers to the outer surface of the cooling member 500 when the upper plate 510 and the lower plate 520 are joined together to form the cooling member 500.

[0081] The grooves 511 in the upper plate 510 and 521 in the lower plate 520 are fitted with the upper structure 540 shown in Figure 10 and the lower structure 550 shown in Figure 11, respectively, and the structure of the grooves 511 and 521 determines the flow of the refrigerant (cooling water). As an example of this, Figure 5 shows that the flow of the refrigerant (cooling water) is formed in a U shape by the grooves 511 and 521 formed in the cooling member 500.

[0082] For example, using the groove 511 of the upper plate 510 in Figure 7 as a reference, the groove 511 includes a first groove 511a located in the middle portion in the vertical direction (in the y-axis direction), and two second grooves 511b located on either side of the first groove 511a. The groove 511 also includes one or more third grooves 511c in the horizontal direction perpendicular to the vertical direction. The third grooves 511c intersect the first grooves 511a and the second grooves 511b.

[0083] The structure of the first groove 511a determines the flow of the refrigerant (cooling water). More specifically, the first groove 511a extends vertically from the first short side of the cooling member 500, where the inlet / outlet ports 530 are located, at an intermediate point between the inlet port 530 and the outlet port 530 of the cooling member 500. At this time, the first groove 511a extends only to a point a predetermined distance away from the second short side, which is the remaining short side of the cooling member 500. This forms a point where the refrigerant makes a detour (U-turn) (see Figure 14).

[0084] In short, one end of the first groove 511a is in contact with the first short side where the inlet / outlet port 530 is located, and the other end of the first groove 511a is separated from the second short side by a predetermined distance. As a result, the refrigerant flows into the inlet port 530, passes through the space between the end of the first groove 511a and the second short side, and flows out into the outlet port 530. This forms a U-shaped flow of refrigerant (cooling water) within the cooling member 500.

[0085] Furthermore, the bottom of the first groove 511a can come into contact with the lower plate 520. As a result, the inside of the cooling member 500 is divided into two main sections: a section in which the refrigerant flows into the inlet port 530 and then to a bypass point, and a section in which the refrigerant flows from the bypass point to the outlet port 530.

[0086] Of course, as will be described later, the superstructure 540 is fitted into the first groove 511a to complement the rigidity of the cooling member 500.

[0087] The second groove 511b is provided to complement the longitudinal rigidity of the cooling member 500. The two second grooves 511b are positioned longitudinally on both sides of the first groove 511a with respect to the cooling member 500, and both ends of the second grooves 511b are separated by a predetermined distance from the two short sides of the cooling member 500. This does not obstruct the U-shaped flow of refrigerant (cooling water) within the cooling member 500 as described above (see Figure 14). On the other hand, if the depth of the second groove 511b is relatively shallow and does not obstruct the flow of refrigerant in the internal space of the cooling member 500, that is, if it does not come into contact with the sealing pad 560 and / or lower plate 520 described later, then both ends of the second groove 511b may come into contact with the two short sides of the cooling member 500.

[0088] A third groove 511c is also provided for the rigidity of the cooling member 500. One or more third grooves 511c are provided in the lateral direction (in the x-axis direction) of the cooling member 500. The embodiments in Figures 5 to 7 show that multiple third grooves 511c are provided. The third grooves 511c are provided to complement the lateral rigidity of the cooling member 500. Both ends of the third groove 511c are in contact with the two long sides of the cooling member 500. At this time, the depth of the third groove 511c is shallower than the depth of the first groove 511a so that the U-shaped flow of refrigerant is not obstructed by the third groove 511c.

[0089] Furthermore, the peripheral edge 512 of the upper plate 510 has a step relative to the cross-section of the upper plate 510 in the height direction (relative to the z-axis). In other words, the height of the peripheral edge 512 along the periphery of the upper plate 510 is lower than the height of the portion of the upper plate 510 through which the refrigerant flows. As described later, the height of the peripheral edge 522 along the periphery of the lower plate 520 is lower than the height of the portion of the lower plate 520 through which the refrigerant flows. As a result, the peripheral edge 512 of the upper plate 510 and the peripheral edge 522 of the lower plate 520 abut and are joined together, and a channel through which the refrigerant flows is formed in the internal space between the upper plate 510 and the lower plate 520.

[0090] Referring to Figure 10, the superstructure 540 is fitted into a groove 511 formed on the outer surface of the upper plate 510. In this case, the outer surface of the upper plate 510 to which the superstructure 540 is attached may be substantially flat.

[0091] The superstructure 540 includes at least one of the following: vertical bars 541, 542 mounted vertically on the upper plate 510 and arranged parallel to the long side; horizontal bar 543 mounted horizontally on the upper plate 510 and arranged parallel to the short side; and peripheral portion 544 mounted on the peripheral portion 512 of the upper plate 510.

[0092] Furthermore, the shape and structure of the superstructure 540 can be entirely or partially consistent with the shape and structure of the groove 511 and / or the shape and structure of the periphery 512. To elaborate further, for example, the superstructure 540 includes portions that are consistent with the first groove 511a and at least one of the two second grooves 511b, and / or portions that are consistent with the third groove 511c, and / or portions that are consistent with the periphery 512 of the upper plate 510.

[0093] In the embodiment shown in Figure 10, for example, the superstructure 540 includes a first vertical bar 541 fitted into a first groove 511a in the middle portion of the upper plate 510, second vertical bars 542 fitted into two second grooves 511b of the upper plate 510, a horizontal bar 543 fitted into a third groove 511c of the upper plate 510, and a peripheral portion 544 fitted to the peripheral portion 512 of the upper plate 510.

[0094] The first vertical bar 541 and the second vertical bar 542 are arranged parallel to the two long sides of the cooling member 500 along the vertical direction (y-axis direction) of the cooling member 500. One end of the first vertical bar 541 is in contact with the first short side of the peripheral edge 544, which is provided with the inlet / outlet port 530, and the other end of the first vertical bar 541 is separated from the second short side by a predetermined distance. Both ends of the second vertical bar 542 are separated from the two short sides of the peripheral edge 544 by a predetermined distance. The horizontal bar 543 connects the two short sides of the cooling member 500 to each other along the horizontal direction (x-axis direction) of the cooling member 500.

[0095] On the other hand, the cooling member 500 may be a cooling tank type that does not have inlet / outlet ports 530. The ends of the first vertical bar 541 and the second vertical bar 542 may extend to the peripheral edge 544 and be in contact with each other. In other words, they may have the same shape and structure as the lower structure 550 described later. The present invention is not limited to those described above, and various modifications and changes are possible.

[0096] The groove 521 of the lower plate 520 in Figure 9 may have a grid-like structure that is generally rectangular (e.g., a rectangle or a square), which is slightly different from the groove 511 of the upper plate 510 in Figure 8. In other words, one or more fourth grooves 521a are formed along the vertical direction (y-axis direction) of the cooling member 500, connecting the two long sides of the cooling member 500 to each other. That is, both ends of the fourth groove 521a are in contact with the two long sides. In addition, one or more fifth grooves 521b are formed along the horizontal direction (x-axis direction) of the cooling member 500, connecting the two short sides of the cooling member 500 to each other. That is, both ends of the fifth groove 521b are in contact with the two short sides.

[0097] Referring to Figure 11, the substructure 550 is fitted into a groove 521 formed on the outer surface of the lower plate 520, and the shape and structure of the substructure 550 can be entirely or partially consistent with the shape and structure of the groove 521 and / or the shape and structure of the peripheral portion 522.

[0098] The lower structure 550 includes at least one of the following: a vertical bar 551 mounted longitudinally on the lower plate 520 and positioned parallel to the long side; a horizontal bar 552 mounted transversely on the lower plate 520 and positioned parallel to the short side; and a peripheral portion 553 mounted on the peripheral portion 522 of the lower plate 520.

[0099] In the embodiment shown in Figure 11, the lower structure 550 includes, as an example, a plurality of vertical bars 551, each mounted in a plurality of fourth grooves 521a of the lower plate 520, a plurality of horizontal bars 552, each mounted in a plurality of fifth grooves 521b of the lower plate 520, and a peripheral portion 553, mounted on the peripheral portion 522 of the lower plate 520. The vertical bars 551 connect the two long sides of the cooling member 500 to each other along the vertical direction (y-axis direction) of the cooling member 500. The horizontal bars 552 connect the two short sides of the cooling member 500 to each other along the lateral direction (x-axis direction) of the cooling member 500.

[0100] Referring to Figures 9 and 13, the area enclosed by the fourth groove 521a and the fifth groove 521b forms a weak point 523, which will be described later. A rigid substructure 550 is fitted into the groove 521 of the lower plate 520. However, the weak point 523 enclosed by the fourth groove 521a and the fifth groove 521b is only present in the lower plate 520, which is injection-molded from a material such as plastic. Therefore, when a thermal event occurs in a battery cell in contact with the lower part of the cooling member 500, the weak point 523, which is the part where the rigid substructure 550 is not fitted, melts, and the coolant from the cooling member 500 is injected into the battery module 100.

[0101] Referring to Figures 7 and 12, the sealing pad 560 is positioned between the upper plate 510 and the lower plate 520. This prevents the refrigerant from flowing out of the cooling member 500 when the refrigerant flows into the internal space between the upper plate 510 and the lower plate 520.

[0102] In the embodiment shown in Figure 12, the first vertical bar 561 of the sealing pad 560 matches the structure and shape of the first groove 511a of the upper plate 510 and is positioned between the bottom of the first groove 511a of the upper plate 510 and the top of the fourth groove 521a of the lower plate 520. The two second vertical bars 562 of the sealing pad 560 match the structure and shape of the two second grooves 511b of the upper plate 510 and are positioned between the bottom of the second grooves 511b of the upper plate 510 and the top of the fourth groove 521a of the lower plate 520. The peripheral edge 563 of the sealing pad 560 is positioned between the peripheral edge 512 of the upper plate 510 and the peripheral edge 522 of the lower plate 520.

[0103] On the other hand, the upper plate 510 and lower plate 520 are made of a material that has chemical resistance to cooling water and does not have a high heat resistance temperature so that they can melt when a thermal event occurs in the battery cell, for example, they are made of a plastic material such as PP or PE. The upper plate 510 and lower plate 520 are manufactured by injection molding and are capable of melting / breaking when a thermal event occurs in the battery cell. The upper structure 540 and lower structure 550 are made of a rigid metal material, for example, stainless steel, aluminum, copper, or an alloy containing these. The upper structure 540 and lower structure 550 allow the cooling member 500 to maintain its overall structure and shape. The sealing pad 560 is made of an elastic material such as a silicone foam pad, an acrylic foam pad, or a urethane foam pad.

[0104] The components of the cooling member 500 described above in relation to Figures 5 to 13 are merely examples, and the present invention is not limited thereto. In other words, the structure, shape, arrangement, etc., of the cooling member 500 and its components can be modified in various ways depending on the environment in which the present invention is implemented.

[0105] For example, the upper plate 510 and / or lower plate 520 may not have the grooves described above, and only the upper structure 540 and / or lower structure 550 may surround the upper plate 510 and / or lower plate 520, or be attached to the upper plate 510 and / or lower plate 520. Alternatively, the upper structure 540 and / or lower structure 550 may be attached to the inner surface of the upper plate 510 and / or lower plate 520, and various other modifications and changes are possible.

[0106] Figures 15 to 19 show the process of assembling the components of the cooling member 500 shown in Figure 5 to manufacture the cooling member 500. First, the lower plate 520 is provided (Figure 15). Next, the sealing pad 560 is placed on the inner surface (upper surface) of the lower plate 520 (Figure 16). Next, the upper plate 510 is placed on the sealing pad 560 (Figure 17). Here, the arrangement of the detailed components between the lower plate 520, the sealing pad 560, and the upper plate 510 is described above in Figures 7 to 12.

[0107] Next, the lower structure 550 is attached to the outer surface of the lower plate 520 (Figure 18). Alternatively, the assembly in which the lower plate 520, sealing pad 560, and upper plate 510 are connected, as described in Figures 15 to 17, may be inverted and attached to the lower structure 550, and then inverted again together with the lower structure 550. Alternatively, the assembly in which the lower plate 520, sealing pad 560, and upper plate 510 are connected may be attached directly to the lower structure 550. Alternatively, after attaching the lower plate 520 to the lower structure 550 as in Figure 15, the sealing pad 560 and upper plate 510 may be attached respectively in the manner described in Figures 16 and 17.

[0108] Finally, the upper structure 540 is attached to the outer surface (upper surface) of the upper plate 510, and the lower structure 550, lower plate 520, sealing pad 560, upper plate 510, and upper structure 540 are fastened together with rivets or bolts to complete the manufacturing of the cooling member 500.

[0109] On the other hand, the present invention is not limited to what has been described above, and various modifications and changes are possible, such as, in some cases, omitting the sealing pad 560, and integrally injection-molding the upper plate 510 and the lower plate 520, with the upper structure 540 and the lower structure 550 attached to the respective outer surfaces of the upper plate 510 and the lower plate 520.

[0110] On the other hand, although the above description has been based on the assumption that the cooling member 500 is provided outside the battery module 100, this is not necessarily the case, and it is also possible for the cooling member 500 to be placed inside the battery module 100. If the cooling member 500 is placed inside the battery module 100, heat transfer between the cooling member 500 and the battery cells 110 can be easily achieved even if the battery module 100 has a closed structure with a module frame.

[0111] Thus, by providing the cooling member 500 to the battery pack 1000 or battery module 100, the heat generated from the battery cells 110 is absorbed and released by the cooling member 500. However, since it is nearly impossible to design the cooling member 500 and the battery cells 110, which are joined together by assembly after being manufactured, to be in complete contact within the battery pack 1000 or battery module 100, a gap can usually occur between the cooling member 500 and the battery cells 110. As a result, an air gap or air pocket may form in the gap between the cooling member 500 and the battery cells 110, which can lead to less smooth heat transfer from the battery cells 110 to the cooling member 500 and a slight decrease in the cooling efficiency of the cooling member 500.

[0112] To overcome the reduction in cooling efficiency caused by air pockets and other factors, methods have been devised to fill the aforementioned separation space with a thermal interface material (TIM) to form a heat transfer passage. However, this increased the overall manufacturing cost of the battery pack 1000 due to the unit cost of the thermal interface material, and the additional process increased the manufacturing time of the battery pack 1000. Therefore, the battery module 100 or battery pack 1000 of this embodiment is provided with cooling fins 600 to minimize the reduction in cooling efficiency due to air gaps.

[0113] On the other hand, although not specifically mentioned above, a battery pack according to one embodiment of the present invention may additionally include a battery management system (BMS) and / or a cooling device for managing the temperature and voltage of the battery.

[0114] Furthermore, a battery pack according to one embodiment of the present invention is applicable to a variety of devices. For example, the device to which the battery pack is applied may be a means of transportation such as an electric bicycle, electric vehicle, or hybrid vehicle. However, the devices are not limited to those described above, and the battery pack according to this embodiment can be used in a variety of devices other than those exemplified above, and this also falls within the scope of the present invention.

[0115] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art that utilize the basic concepts of the present invention as defined in the following claims also fall within the scope of the present invention. [Explanation of Symbols]

[0116] 100: Battery Module 110: Battery cell 120: Battery cell stack 130: Side plate 140: Holding Strap 150: Busbar Frame 200: Pack Frame 300: Resin layer 400: End plate 500: Cooling component 510: Top plate 520: Lower plate 511, 521: Groove 512, 522: Peripheral area 523: Vulnerable parts 530: Inlet / Outlet Port 540:Superstructure 550: Substructure 560: Sealing pad 541, 542, 551, 561, 562: Vertical bars 543, 552: Horizontal bar 544, 553, 563: Peripheral area 600: Cooling fins

Claims

1. In a cooling member attached to a battery cell stack in which multiple battery cells are stacked, An upper plate, a lower plate, and a refrigerant built into the internal space between the upper plate and the lower plate, It includes at least one of the superstructure that supports the upper plate and the substructure that supports the lower plate, The upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell. The aforementioned upper structure and the aforementioned lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell. The portion of the upper plate that does not come into contact with the upper structure forms a weak point. The portion of the lower plate that does not come into contact with the lower structure forms the weak portion. The aforementioned fragile portion is a cooling member that melts or ruptures when a thermal event occurs in the battery cell, allowing the refrigerant to be injected into the battery cell.

2. The aforementioned superstructure is attached to the outer surface of the upper plate, The cooling member according to claim 1, wherein the lower structure is attached to the outer surface of the lower plate.

3. At least one of the upper plate and the lower plate is made of plastic. The cooling member according to claim 1 or 2, wherein at least one of the superstructure and the substructure is made of a metal material.

4. A cooling member to be attached to a battery cell stack in which a plurality of battery cells are stacked, An upper plate, a lower plate, and a refrigerant built into the internal space between the upper plate and the lower plate, It includes at least one of the superstructure that supports the upper plate and the substructure that supports the lower plate, The upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell. The aforementioned upper structure and the aforementioned lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell. At least one of the upper plate and the lower plate is made of plastic. At least one of the superstructure and the substructure is made of metal. At least one of the upper plate and the lower plate is made of PP or PE. A cooling member wherein at least one of the superstructure and the substructure is made of stainless steel, aluminum, copper, or an alloy containing these materials.

5. A cooling member to be attached to a battery cell stack in which a plurality of battery cells are stacked, An upper plate, a lower plate, and a refrigerant built into the internal space between the upper plate and the lower plate, It includes at least one of the superstructure that supports the upper plate and the substructure that supports the lower plate, The upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell. The aforementioned upper structure and the aforementioned lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell. The aforementioned superstructure is A vertical bar is attached to the upper plate in the vertical direction and is positioned parallel to the long side. A horizontal bar is attached to the upper plate in the lateral direction and is positioned parallel to the short side, and Peripheral portion attached along the periphery of the upper plate, A cooling member comprising at least one of the following.

6. The upper plate includes a groove into which the upper structure is mounted. A low step is formed along the periphery of the upper plate. The cooling member according to claim 5, wherein the structure and shape of the superstructure and the structure and shape of the groove and the periphery of the upper plate correspond to and interlock with each other.

7. The groove in the upper plate is A first groove is formed in the middle portion of the upper plate and is arranged parallel to the long side of the upper plate, A second groove is formed on both sides of the first groove and is arranged parallel to the long side of the upper plate, The cooling member according to claim 6, further comprising a third groove that intersects the first groove and the second groove and is arranged parallel to the short side of the upper plate.

8. The vertical bars of the superstructure are fitted into the first groove and the second groove of the upper plate. The cooling member according to claim 7, wherein the horizontal bar of the superstructure is mounted in the third groove of the upper plate.

9. The cooling member further includes an inlet port and an outlet port on the first short side of the two short sides through which the refrigerant flows in and out. One end of the first groove of the upper plate is in contact with the first short side, The cooling member according to claim 7, wherein the other end of the first groove of the upper plate is spaced a predetermined distance from the second short side of the cooling member so that the refrigerant can flow in a U-shape within the internal space of the cooling member.

10. The cooling member according to claim 9, wherein both ends of the second groove of the upper plate are spaced a predetermined distance from the first short side and the second short side, respectively, so that the refrigerant can flow in the internal space of the cooling member.

11. The cooling member according to claim 7, wherein the third groove of the upper plate and the horizontal bar of the upper structure are each composed of a plurality of units.

12. A cooling member attached to a battery cell stack in which a plurality of battery cells are stacked, An upper plate, a lower plate, and a refrigerant built into the internal space between the upper plate and the lower plate, It includes at least one of the superstructure that supports the upper plate and the substructure that supports the lower plate, The upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell. The aforementioned upper structure and the aforementioned lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell. The aforementioned substructure is A vertical bar is attached to the lower plate in the vertical direction and is positioned parallel to the long side. A horizontal bar is attached to the lower plate in the lateral direction and is positioned parallel to the short side, and Peripheral portion attached along the periphery of the lower plate, A cooling member comprising at least one of the following.

13. The lower plate includes a groove into which the lower structure is mounted. A low step is formed along the periphery of the lower plate. The cooling member according to claim 12, wherein the structure and shape of the lower structure and the structure and shape of the groove and the periphery of the lower plate correspond to and interlock with each other.

14. The groove in the lower plate is A fourth groove is arranged parallel to the long side of the lower plate, The cooling member according to claim 13, further comprising a fifth groove that intersects the fourth groove and is arranged parallel to the short side of the lower plate.

15. The vertical bar of the lower structure is fitted into the fourth groove of the lower plate. The cooling member according to claim 14, wherein the horizontal bar of the lower structure is mounted in the fifth groove of the upper plate.

16. The fourth groove of the lower plate and the vertical bar of the lower structure are each composed of multiple units, The cooling member according to claim 15, wherein the fifth groove of the lower plate and the horizontal bar of the lower structure are each composed of a plurality of units.

17. A cooling member to be attached to a battery cell stack in which a plurality of battery cells are stacked, An upper plate, a lower plate, and a refrigerant built into the internal space between the upper plate and the lower plate, It includes at least one of the superstructure that supports the upper plate and the substructure that supports the lower plate, The upper plate and the lower plate are made of a material that can melt or break when a thermal event occurs in the battery cell. The aforementioned upper structure and the aforementioned lower structure are made of a material that maintains rigidity when a thermal event occurs in the battery cell. A cooling member further comprising a sealing pad disposed between the upper plate and the lower plate so as to prevent the refrigerant from leaking to the outside of the cooling member.

18. The cooling member according to claim 17, wherein the upper plate, the lower plate, and the sealing pad are all fastened together with rivets or bolts.

19. The cooling member according to claim 1 or 2, wherein the upper plate and the lower plate are integrally formed.

20. The inlet port through which the refrigerant flows into the interior of the cooling member, The cooling member according to claim 1 or 2, further comprising an outlet port through which the refrigerant flows out to the outside of the cooling member.

21. The cooling member is mounted on the upper surface of the battery cell stack, as described in claim 1 or 2.

22. A battery pack comprising the cooling member according to claim 1 or 2.

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