Battery module and battery pack including cooling unit

Abstract

A battery pack according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a frame that houses the battery cell stack, and a cooling unit on the battery cell stack, the cooling unit including a refrigerant receiving member including an upper plate and a lower plate, an elastic member disposed in an internal space of the refrigerant receiving member, and a sealing member that seals at least one through-hole formed in the refrigerant receiving member and is meltable due to an increase in temperature of the battery cells, and a refrigerant is received inside the elastic member, and the elastic member expands as the refrigerant is received.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0088258, filed July 18, 2022, and Korean Patent Application No. 10-2023-0092580, filed July 17, 2023, and all contents disclosed in the documents of those Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including a cooling unit, and more specifically, to a battery module and a battery pack that contains a refrigerant inside a refrigerant receiving space and includes an elastic member that can contract and expand so as to prevent thermal runaway by quickly supplying a refrigerant when a battery cell ignites. [Background technology]

[0003] Secondary batteries are attracting attention as a power source for electric vehicles, hybrid electric vehicles, and plug-in hybrid electric vehicles, which have been proposed as a solution to air pollution caused by existing vehicles that use fossil fuels and diesel vehicles.

[0004] Small mobile devices use one, two, three, or four battery cells per device, whereas medium to large devices such as automobiles use medium to large battery modules in which multiple battery cells are electrically connected due to the need for high output and large capacity.

[0005] Since it is preferable that medium- to large-sized battery modules be manufactured as small in size and weight as possible, prismatic batteries and pouch-shaped batteries, which can be packed at a high density and have a small weight relative to their capacity, are mainly used as battery cells for medium- to large-sized battery modules.

[0006] The battery cells constituting such medium- to large-sized battery modules are composed of secondary batteries that can be charged and discharged, and such high-power, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process.

[0007] If the heat generated in the battery module during the charging and discharging process cannot be effectively removed, heat accumulation occurs, which accelerates deterioration of the battery module and, in some cases, may lead to fire or explosion. Therefore, medium- to large-sized battery packs for vehicles and medium- to large-sized battery packs for power storage devices, which include multiple medium- to large-sized battery modules and are high-output, large-capacity batteries, require a cooling system to cool the battery cells inside them.

[0008] 12 and 13 are vertical cross-sectional views of a battery module or battery pack 10 according to the prior art. Referring to Fig. 12, the refrigerant (cooling water) stored in the refrigerant receiving member 220 (water tank) is supplied to the ignited battery cell 103 through the through-hole 230, and the pressure of the refrigerant (water pressure) in the refrigerant receiving member 220 gradually decreases. Therefore, the rate at which the refrigerant is injected into the battery cell 103 slows down over time.

[0009] Furthermore, the pressure of the refrigerant inside the refrigerant receiving member 220 is roughly proportional to the height of the refrigerant, but since the refrigerant receiving member 220 (water tank) is usually formed along the direction in which the battery cell stack is housed, its height is shorter than its width, which means that the pressure of the refrigerant injected into the battery cells 103 is inevitably even lower. This is a factor that hinders rapid injection of the refrigerant.

[0010] Furthermore, if a vehicle equipped with a battery pack is positioned on an inclined surface, and the refrigerant receiving member 220 of the battery pack is also positioned at an incline, it may not be possible for all of the refrigerant in the refrigerant receiving member 220 to be supplied to the battery cell stack, as shown in Figure 13.

[0011] 12 and 13, the coolant is supplied by gravity from the upper coolant receiving member 220 to the lower battery cell stack along the open through-holes 230. Therefore, the coolant receiving member 220 can only be located at the top of the battery cell stack, and there is a restriction that a coolant receiving member 220 cannot be provided at the bottom. Figures 12 and 13 show a case where no coolant receiving space is provided at the bottom, and only a heat sink 211 is provided. Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention is intended to solve these problems and to provide a battery module and / or a battery pack including a cooling unit that can quickly and directly inject a refrigerant for the cooling unit provided inside the battery module and / or battery pack into the ignited battery cell to prevent thermal energy from being transferred to adjacent battery cells when a battery cell ignites or explodes, while overcoming the difficulty of injecting the refrigerant on a sloped path, minimizing the increase in the volume of the battery module and / or battery pack, and efficiently suppressing thermal runaway of the battery cells.

[0013] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0014] A battery pack according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a frame that houses the battery cell stack, and a cooling unit on the battery cell stack, wherein the cooling unit includes a refrigerant receiving member including an upper plate and a lower plate, an elastic member that is disposed in an internal space of the refrigerant receiving member, and a sealing member that seals at least one through-hole formed in the refrigerant receiving member and is meltable due to an increase in temperature of the battery cells, and a refrigerant is received inside the elastic member, and the elastic member can expand due to the reception of the refrigerant.

[0015] Before the elastic member melts, the elastic member accommodates the refrigerant therein and expands to the maximum extent, thereby covering the entire inner space of the refrigerant-receiving member.

[0016] When the temperature of the battery cells rises, the sealing member may melt due to high-temperature gas or sparks emitted from the battery cells, and simultaneously or subsequently, a portion of the elastic member adjacent to the sealing member may melt, causing the coolant inside the elastic member to flow out into the battery cell stack.

[0017] The refrigerant flows into the battery cell stack, and the pressure applied by the refrigerant to the elastic member gradually decreases, allowing the elastic member to gradually contract.

[0018] The refrigerant may not be received in the space between the refrigerant receiving member and the elastic member.

[0019] An adhesive for adhering the elastic member may be applied to a portion of the inner surface of the refrigerant receiving member including the periphery of the through hole.

[0020] The adhesive may be an acrylic adhesive, a silicone adhesive, a rubber adhesive, or a hot melt adhesive.

[0021] The refrigerant receiving member may be a water tank, and cooling water may be received inside the elastic member.

[0022] The coolant receiving member may include at least one partition wall disposed across the internal space to divide the internal space into a plurality of sections, the at least one partition wall being disposed perpendicular to the heat sink and in a longitudinal direction of the battery cell, and the elastic member may be provided in each of the plurality of sections.

[0023] A pressure member having elastic force is provided between the inner surface of the cooling section and the outer surface of the elastic member, and when a refrigerant is received inside the elastic member, the pressure of the refrigerant compresses the pressure member. When the refrigerant is supplied to the battery cell through the through hole and the elastic member gradually contracts, the restoring force of the compressed pressure member causes the pressure member to pressurize the outer surface of the elastic member, and the elastic member can adhere closely to the periphery of the through hole.

[0024] The pressure member may be a spring.

[0025] The sealing member may be made of a thermoplastic polymer resin.

[0026] The elastic member may be made of natural rubber, synthetic rubber (SBR), oil-resistant rubber (NBR), or polyurethane rubber.

[0027] The surface of the coolant receiving member adjacent to the battery cell stack may be a heat sink.

[0028] The frame may include an upper plate disposed on an upper portion of the battery cell stack, a lower plate disposed on a lower portion of the battery cell stack, and a side plate disposed on a side of the battery cell stack between the upper plate and the lower plate, the cooling unit may be disposed on at least one of the upper plate and the lower plate, and the heat dissipation plate of the refrigerant receiving member may be spaced a predetermined distance from the frame to form the refrigerant receiving member.

[0029] A battery pack according to another embodiment of the present invention may include a plurality of the battery cell stacks, and the cooling unit may be disposed on the plurality of battery cell stacks. [Effects of the Invention]

[0030] As described above, the battery module and / or battery pack according to the present invention can quickly cool a ignited battery cell by storing a refrigerant in the internal space of the cooling unit and including a contractible and expandable elastic member. Furthermore, even if the refrigerant-receiving space is tilted, all of the refrigerant in the refrigerant-receiving space can be supplied to the ignited battery cell. This minimizes the increase in the volume of the battery module and / or battery pack and efficiently suppresses thermal runaway in the battery cell.

[0031] Additionally, if the sealing member attached to the cooling unit melts due to high battery cell temperatures, the cooling unit injects coolant directly into the battery cells, thereby quickly lowering the temperature of the battery cells. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a schematic diagram of a battery module or a battery pack according to an embodiment of the present invention. [Figure 2] FIG. 2 is a vertical cross-sectional view of a battery module or battery pack according to an embodiment of the present invention. [Figure 3] FIG. 3 shows a case where the battery cell is cooled by the elastic member provided in the cooling section of FIG. 2 when the battery cell catches fire. [Figure 4] FIG. 4 shows a case where a pressure member is further included in the cooling section of FIG. [Figure 5] FIG. 5 is a vertical cross-sectional view of a battery module or a battery pack according to another embodiment of the present invention. [Figure 6] FIG. 6 is a plan view of an embodiment of a heat sink that can be applied to the cooling unit of FIGS. [Figure 7] FIG. 7 is a partially enlarged view of FIG. [Figure 8] FIG. 8 is an enlarged vertical cross-sectional view of a battery module or battery pack in which a sealing member is added to a heat sink having a groove formed therein. [Figure 9] FIG. 9 is a vertical cross-sectional view of a grooved heat sink with a sealing member added thereto. [Figure 10] FIG. 10 is a schematic diagram showing a battery pack according to an embodiment of the present invention in which a plurality of battery cell stacks (cell module assemblies) are housed. [Figure 11] FIG. 11 is a vertical cross-sectional view of the battery pack according to the embodiment of the present invention of FIG. 10, illustrating the case where a cooling section is included on the stack of multiple battery cells of FIG. [Figure 12] FIG. 12 is a vertical cross-sectional view of a battery module or battery pack according to the prior art. [Figure 13] FIG. 13 is a vertical cross-sectional view of a battery module or battery pack according to the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0033] DETAILED DESCRIPTION OF THE INVENTION The present invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

[0034] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. Thicknesses are exaggerated in the drawings to clearly show various layers and regions. Also, in the drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0035] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Furthermore, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" the direction opposite to gravity.

[0036] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0037] Furthermore, throughout the specification, the term "on a plane" means when the subject part is viewed from above, and the term "on a cross section" means when the subject part is cut vertically and viewed from the side.

[0038] Furthermore, since the upper / lower surfaces or top / bottom of a particular member can be determined differently depending on whether a certain direction is used as the reference, throughout this specification, "upper surface" and "lower surface" refer to two surfaces of the member that face each other on the z-axis, and "upper surface" and "lower surface" are defined as surfaces that are located in opposite directions on the z-axis of the member.

[0039] FIG. 1 is a schematic diagram of a battery module or a battery pack according to the present invention.

[0040] The battery module or battery pack referred to in the present specification is the same in that it has a cooling section, which will be described in detail below, on at least one surface of the upper and lower parts of the battery cell stack, except for the scale.

[0041] Referring to FIG. 1, a battery module or battery pack 100 according to the present invention includes a frame that houses a battery cell stack 101 in which a plurality of battery cells are stacked, and cooling units disposed on the upper and lower surfaces of the battery cell stack 101.

[0042] 1 shows bidirectional pouch-type battery cells in which the electrode leads 102 protrude in opposite directions, but it goes without saying that unidirectional pouch-type battery cells in which the positive and negative electrode leads protrude in the same direction can also be used. Furthermore, while the battery cells may be pouch-type battery cells, the present invention is not limited to the above and can be modified in various ways, such as being applicable to prismatic battery cells or cylindrical battery cells.

[0043] The battery module or battery pack frame (hereinafter referred to as "frame") includes an upper plate 110 arranged on the top of the battery cell stack 101, a lower plate 120 arranged on the bottom of the battery cell stack, and a side plate 130 arranged between the upper plate 110 and the lower plate 120 and arranged on the side of the battery cell stack 101.

[0044] In addition, an end plate (not shown) may be combined with the upper plate 110, the lower plate 120, and the side plate 130 on the outer side of the protruding electrode lead 102 of the battery cell to assemble a frame.

[0045] In addition, the shape of the frame is not limited to the structure shown in Fig. 1, and a mono-frame or U-frame may be used as the frame, unlike that shown in Fig. 1. That is, in some cases, the upper plate 110 may not be separately provided, and the upper surface of the cooling unit (described later) may replace the upper plate of the frame.

[0046] FIG. 2 is a vertical cross-sectional view of a battery module or battery pack according to an embodiment of the present invention.

[0047] Referring to FIG. 2, a battery module or a battery pack includes a battery cell stack 101 in which a plurality of battery cells are stacked, housed in a frame including an upper plate 110 and a lower plate 120 .

[0048] The cooling unit 200a includes a heat dissipation plate 210 and a coolant-receiving member 220 that accommodates a coolant. The heat dissipation plate 210 is coupled to the upper plate 110 with a gap therebetween, and the space formed by the gap constitutes the coolant-receiving member 220. Therefore, the upper plate 110, the heat dissipation plate 210, and the coolant-receiving member 220 form an integrated structure. The cooling unit 200a is coupled to the upper plate 110 as an integrated unit and is located above the battery cell stack 101.

[0049] However, the present invention is not limited to the above. For example, the upper plate 110 of the frame does not necessarily have to be a component of the coolant receiving member 220. As long as the coolant receiving member 220 itself has a shape that allows it to store a coolant, it is sufficient that the shape and structure allow it to be joined to the battery cell stack 101 across the heat sink 210, which includes through-holes 230 (described below).

[0050] The cooling unit 200a' also includes a heat sink 210 and a coolant-receiving member 220 that accommodates a coolant. The heat sink 210 is coupled to the lower plate 120 with a gap therebetween, and the space formed by the gap constitutes the coolant-receiving member 220. Therefore, the lower plate 120, the heat sink 210, and the coolant-receiving member 220 form an integrated structure.

[0051] In other words, the cooling section 200a' is integrally connected to the lower plate 120 and is located below the battery cell stack 101. Similarly, the lower plate 120 of the frame does not necessarily have to form the refrigerant receiving member 220. It is sufficient if the refrigerant receiving member 220 itself has a shape that allows it to store a refrigerant, and it is sufficient if it has a shape and structure that allows it to be connected to the battery cell stack via a heat sink 210 that includes through-holes 230, which will be described later. The heat sink 210 has through-holes 230 formed therein, and a sealing member 240 is attached to the through-holes 230.

[0052] The sealing member 240 is made of a material that melts when exposed to high-temperature gas or sparks emitted from the battery cells. That is, when the battery cells are in a normal state, the sealing member 240 keeps the through-hole 230 sealed. However, when the temperature rises or a fire occurs, as in the case of battery cell 103, the sealing member 240 melts and opens the through-hole 230. The coolant from the coolant receiving member is directly injected into the battery cell stack 101 through the opened through-hole 230. Through this process, the overheated or ignited battery cell can be quickly cooled, thereby quickly preventing the spread of thermal runaway.

[0053] Since the sealing member 240 is a material that melts in the high-temperature gas or sparks that are ejected due to venting of the battery cell when the temperature increases, a thermoplastic polymer resin with a melting point of about 200°C or less may be used. For example, the thermoplastic polymer resin may be a material with a melting point of about 100°C or more and 200°C or less, such as polyethylene or polypropylene.

[0054] Meanwhile, when coolant is used as the refrigerant and the coolant is directly injected into the battery cells, it is necessary to prevent the injection of the coolant from causing a fire or explosion in the battery cells. Therefore, it is preferable that the additive contained in the coolant does not contain a flammable substance. Alternatively, when a flammable substance is contained as the additive, the amount of the additive may be sufficient to prevent a secondary explosion in the battery cells and to act as an antifreeze to prevent the coolant from freezing.

[0055] Meanwhile, the refrigerant receiving member 220 is a structure (for example, a water tank) that stores a refrigerant therein. More specifically, the cooling unit 200a according to the present invention includes an elastic member 250 that can contract / expand in the internal space of the refrigerant receiving member 220, and stores the refrigerant inside the elastic member 250. The space between the elastic member 250 and the refrigerant receiving member 220 is empty space, and no refrigerant is stored therein. The embodiment of FIG. 2 shows a case where the refrigerant is stored to the maximum extent inside the elastic member 250, and the refrigerant expands to the maximum extent to cover the entire internal surface of the refrigerant receiving member 220.

[0056] The elastic member 250 is also made of a material that melts due to high-temperature gas or sparks emitted from the battery cell 101. To make it easier for the elastic member 250 to melt when the temperature of the battery cell 101 rises, a portion of the elastic member 250 adjacent to the through-hole 230 of the heat sink 210 may be formed relatively thinner than other portions of the elastic member 250 or may be formed of a material with a lower melting point. When the temperature of the battery cell 101 rises, the high-temperature gas or sparks emitted from the heated battery cell 101 melts the sealing member 240 attached to the through-hole 230 of the heat sink 210. Next, the high-temperature gas or sparks transmitted through the opened through-hole 230 also open the elastic member 250. Therefore, the coolant contained inside the elastic member 250 is supplied to the battery cell 103 through the opening 255 and the opened through-hole 230, which are opened when a portion of the elastic member 250 melts.

[0057] As shown in Fig. 2, the elastic member 250 expands to its maximum extent due to the internal pressure of the refrigerant, and as shown in Fig. 3, the refrigerant received inside the elastic member 250 is released, the pressure applied by the refrigerant to the elastic member 250 by the refrigerant gradually decreases, and the elastic member 250 gradually contracts. Unlike the prior art cases shown in Figs. 12 and 13, the pressure generated by the contraction of the elastic member 250 allows the refrigerant in the elastic member 250 located within the refrigerant receiving member 220 to be supplied to the battery cells 103 at a faster speed. In addition, the refrigerant can be supplied to the battery cells 103 without remaining in the elastic member 250.

[0058] The elastic member 250 is made of a material that melts when exposed to high-temperature gas or sparks emitted from the battery cell 101. The elastic member 250 is also made of a material that melts when exposed to high-temperature gas or sparks emitted by venting a battery cell whose temperature has increased, and is an elastic material that can contract and expand. For example, natural rubber, synthetic rubber (SBR), oil-resistant rubber (NBR), polyurethane rubber, etc. may be used as the elastic member 250. As an example, the elastic member 250 may be made of rubber and have a wind-line shape.

[0059] On the other hand, when the elastic member 250 contracts, the reaction force of the refrigerant escaping from the elastic member 250 may cause the elastic member 250 and the opening 255 of the elastic member 250 to move toward the upper plate 110, which is opposite the through hole 230.

[0060] To prevent this, an adhesive for adhering the elastic member 250 may be applied to the entire surface of the heat sink 210 facing the elastic member 250 or to the periphery of the through-hole 230. The adhesive may not be an adhesive that permanently adheres the elastic member 250, but may be an adhesive that allows the elastic member 250 to be peeled off from the heat sink 210 by contracting the elastic member 250. The adhesive may be, for example, an acrylic adhesive, a silicone adhesive, a rubber adhesive, or a hot-melt adhesive. Alternatively, as shown in FIG. 4, an elastic pressure member 260 may be provided between the inner surface of the cooling unit 200a and the outer surface of the elastic member 250. The pressure member 260 may be, for example, a spring. When a refrigerant is received inside the elastic member 250, the elastic member 250 expands into the cooling unit 200a due to the pressure of the refrigerant, thereby compressing the pressure member 260. Meanwhile, when the refrigerant is supplied to the battery cell 103 through the through-hole 230 and the elastic member 250 gradually contracts, the restoring force of the compressed pressure member 260 causes the pressure member 260 to pressurize the outer surface of the elastic member 250. This allows the elastic member 250 to adhere tightly to the periphery of the through-hole 230.

[0061] The present invention is not limited to the above, and various modifications and variations are possible, such as either the cooling unit 200a located on the upper side of the battery cell stack or the cooling unit 200a' located on the lower side of the battery cell stack including only the heat sink 210 and not including the refrigerant receiving member 220.

[0062] Fig. 5 is a vertical cross-sectional view of a battery module or battery pack according to another embodiment of the present invention, showing a cooling unit 200b which is a partial modification of the cooling unit 200a of Fig. 2. For an explanation of the components of the cooling unit 200b of Fig. 5 that overlap with those of the cooling unit 200a of Fig. 2, please refer to the explanation of Fig. 2.

[0063] 5, the partition wall 215 can vertically cross the coolant receiving member 220 to partition the internal space. The partition wall 215 may be, for example, in the form of a plate that connects the heat sink 210 and the upper plate and is arranged parallel to the side plate 130 (see FIG. 1). In this case, the partition wall 215 can be arranged parallel to the longitudinal direction of each battery cell in the battery cell stack 101.

[0064] The coolant receiving member 220 is divided into a plurality of sections arranged in a row in the horizontal direction based on the partition wall 215. An elastic member 250 is provided in each of the sections divided inside the coolant receiving member 220, and a coolant is contained in each of the elastic members 250. When the temperature of the battery cell 103 rises or a fire occurs, the coolant can be supplied in several divided portions.

[0065] The number of partitions 215 is not limited to that shown in FIG. 5 and may be one or more, and various modifications and variations are possible, such as a plurality of partitions 250a, to suit the environment in which the present invention is implemented.

[0066] The shape of the partition wall 215 is not necessarily flat, and various modifications and variations are possible as long as it can separate and partition the internal space of the refrigerant receiving member 220. Figure 6 shows a plan view of an embodiment of a heat sink 210 that can be applied to the cooling unit of Figures 2 to 5. Figure 6(a) shows a state in which a through hole 230 is formed in the heat sink 210.

[0067] The heat sink 210 has through-holes 230 each having a circular shape on a plane, which are arranged at regular intervals in the horizontal and vertical directions.

[0068] The through-holes must be formed at positions that allow cooling water to be supplied to any battery cell that catches fire. That is, it is preferable that at least one through-hole is provided for each battery cell so that cooling water can be supplied to all battery cells. Therefore, the number and spacing of the through-holes may be adjusted depending on the number and size of the battery cells.

[0069] 6(b) and 6(c) are plan views of embodiments in which the heat sink 210 of FIG. 6(a) is partially modified.

[0070] 6(b) and 6(c), the shape of the through holes 230' and 230'' formed in the heat sink 210 is different from the shape of the through hole 230 in FIG.

[0071] When the battery cells are arranged so that the minor axis direction of the heat sink 210 shown in Figures 6(b) and 6(c) is parallel to the longitudinal direction L of the battery cells, the through holes 230' are formed at an angle so that one through hole can cover two or more battery cells, and the through holes 230'' are formed in a direction perpendicular to the longitudinal direction L of the battery cells so that one through hole can cover two or more battery cells.

[0072] When a through hole of this type is formed, if the sealing member melts due to heat generation and explosion of one of the battery cells, the through hole is large enough to allow cooling water to be applied to the surface of the battery cells that are adjacent to the battery cell that has heated up and exploded, thereby lowering the temperature of the battery cells that have not heated up and exploded, thereby preventing thermal runaway.

[0073] Figure 7 is a partially enlarged view of Figure 2. Spaces may form between the battery cell stack 101 and the heat sink 210, which may result in variations in the distance between each individual battery cell and the heat sink 210. These spaces formed between the battery cell stack 101 and the heat sink 210 reduce the heat dissipation performance of the battery module and / or battery pack, which releases heat from within the battery module and / or battery pack to the outside.

[0074] To prevent such problems, the space between the battery cell stack 101 and the heat sink 210 can be filled with a thermal interface material (TIM) 390.

[0075] The thermal transfer material 390 spreads the thermal connection points between the battery cell stack and the heat sink, allowing the thermal energy generated in the battery cell stack to be quickly dissipated.

[0076] However, if the heat energy released from the battery cell does not directly contact the sealing member due to the heat transfer material 390, the sealing member may not reach its melting temperature. Therefore, the addition of the heat transfer material can be omitted.

[0077] Alternatively, the heat transfer material may not be formed under the through-hole of the heat sink, but may be applied only to other areas. In this case, even if the heat transfer material is applied, the thermal energy of the vented battery cell is not lost but is transferred directly to the sealing member, causing the sealing member to melt and allowing the coolant to be supplied to the vented battery cell.

[0078] Meanwhile, a sealing member 240 is attached to the through hole 230 that penetrates the heat sink 210, so that, for example, the sealing member 240 fills the through hole 230 and includes an extension portion 241 that extends further outward from around the through hole 230 on the inner surface 211 of the heat sink and the outer surface 212 of the heat sink.

[0079] Since the sealing member 240 has the extension portion 241, the sealing member 240 can be prevented from being removed by the pressure of the cooling water flowing through the refrigerant receiving member, thereby preventing the through-hole from being opened.

[0080] FIG. 8 is an enlarged vertical cross-sectional view of a battery module or battery pack in which a sealing member is added to a heat sink having a groove formed therein.

[0081] Referring to FIG. 8, a coolant receiving member 320 is formed between the upper plate 110 and the heat sink 310, and a sealing member 340 is attached to the through-hole of the heat sink 310.

[0082] The sealing member 340 includes an extension 341, and grooves 314 are formed in the inner surface 311 of the heat sink and the outer surface 312 of the heat sink where the extension 341 is formed.

[0083] A part of the sealing member constituting the extension part 341 is inserted into the groove 314 to form the insertion part 345, which more effectively prevents the sealing member from being removed by the water pressure of the cooling water and opening the through hole.

[0084] To manufacture a sealing member including such an extension, an insert injection method may be used, in which a sealing resin is injected into a heat sink plate having a groove formed therein. Alternatively, the portion of the sealing member that passes through the through hole may be formed by preparing a central portion of the sealing member having a shape and size corresponding to the shape and size of the through hole, and then attaching a separate member to the central portion of the sealing member to form the extension. The method of connecting the central portion of the sealing member and the separately attached extension may be, but is not limited to, adhesive bonding, screw fastening, or interference fitting. Furthermore, the central portion of the sealing member may be made of a thermoplastic polymer resin that melts at high temperatures, and the material of the separately attached extension may be made of a material that does not melt at high temperatures.

[0085] FIG. 9 is a vertical cross-sectional view of a grooved heat sink with a sealing member added thereto.

[0086] Referring to FIG. 9, heat sinks 410, 510, 610 each have a sealing member 440, 540, 640 attached thereto.

[0087] The heat sinks 410, 510, 610 are each formed with grooves 414, 514, 614 at the portions where they come into contact with the extensions, and the grooves 414, 514, 614 are each formed with insertion portions 445, 545, 645 inside.

[0088] The vertical cross section of the heat sink 410, 510, 610 where the grooves 414, 514, 614 are formed may be formed in one or more shapes selected from the group consisting of polygons including triangles and trapezoids, semicircles, and semi-ellipses, or may be formed in a mixture of these shapes.

[0089] 9(c), the thickness of center portion 641 of sealing member 640 is thinner than the thickness of center portion of sealing member 410 and the thickness of center portion of sealing member 510. When the thickness of the portion sealing the through hole is formed relatively thin in this manner, the time required for the sealing member to melt and open the through hole can be shortened, thereby enabling the coolant to be supplied to the battery cell more quickly.

[0090] In addition, the heat sink may form a water tank coupled to the upper and lower plates of the frame, and the heat sink may form one side of the water tank that faces the other side of the water tank that is coupled to the upper and lower plates.

[0091] The above description has been given with reference to the drawings, focusing on a battery module or battery pack including one battery cell stack 101 according to the present invention and the cooling unit included therein, but the cooling unit according to an embodiment of the present invention can also be applied in the same manner to a battery pack including multiple battery cell stacks 101 (cell module assemblies).

[0092] A battery pack formed by stacking multiple battery cell stacks 101 (cell module assemblies) will be described with reference to FIGS. 10 and 11. FIG. 10 schematically illustrates a battery pack 100' according to an embodiment of the present invention, in which multiple battery cell stacks 101 are accommodated. FIG. 11 is a vertical cross-sectional view of the battery pack according to the embodiment of the present invention of FIG. 10, illustrating a case in which a cooling unit 200 is included on the multiple battery cell stacks 101 of FIG. 10. The battery pack 100' of FIGS. 10 and 11 illustrates a case in which one cooling unit 200 is placed on the multiple battery cell stacks 101. The cooling units described above in FIGS. 1 to 9 can be applied in the same manner to a battery pack 100' in which multiple battery cell stacks 101 are stacked.

[0093] Referring to FIG. 11, a cooling unit 200 may be located on a plurality of battery cell stacks 101 (cell module assemblies).

[0094] The frame includes an upper plate 110 disposed on top of the plurality of battery cell stacks 101, a lower plate 120 disposed on the bottom of the plurality of battery cell stacks 101, and side plates (not shown) disposed between the upper plate 110 and the lower plate 120 and on both sides of the plurality of battery cell stacks 101. Additionally, a cross beam 140 may be included between the plurality of battery cell stacks 101. The shape of the frame including the upper plate 110, the lower plate 120, and the side plates is not limited to the structure shown in Figures 10 and 11, and can be modified and changed in various ways to suit the environment in which the present invention is embodied.

[0095] 11, the upper plate 110 and the lower plate 120 refer to the upper plate and the lower plate of the frame, respectively, and are simply referred to as the upper plate 110 and the lower plate 120 for convenience. This should be understood as a separate concept from the upper plate and the lower plate of the refrigerant receiving member 220, which are based on the refrigerant receiving member 220.

[0096] 11 , the cooling unit 200 includes a coolant receiving member 220 that receives a coolant. One surface of the coolant receiving member 220 is disposed on at least one surface of the plurality of battery cell stacks 101. One surface of the coolant receiving member 220 may be a heat sink 210. The other surface facing the one surface of the coolant receiving member 220 may be the upper plate 110 of the frame. In other words, when the coolant receiving member 220 is disposed on the upper surface of the plurality of battery cell stacks 101, the upper plate of the coolant receiving member 220 may be the upper plate 110 of the frame. The heat sink 210 includes a plurality of through holes 230. The through holes 230 are sealed with a sealing member 240.

[0097] 11 is disposed on a plurality of battery cell stacks 101, whereas the coolant receiving member 220a of the battery module or battery pack 100 of FIG. 2 is disposed on a single battery cell stack 101. However, the detailed components of the coolant receiving member 220 of FIG. 11 are the same as the detailed components of the coolant receiving member 220a of the battery module or battery pack 100 of FIG. 2.

[0098] Therefore, the description of the detailed components of the coolant receiving member 220 in Fig. 11 overlaps with the description of the detailed components of the coolant receiving member 220a of the battery module or battery pack 100 in Fig. 2, so for other descriptions, please refer to what has been described above with reference to Figs. 1 to 9. In addition, the description of the portion marked A in Fig. 11 also overlaps with the portion described above with reference to Fig. 7, so please refer to what has been described above with reference to that portion.

[0099] 11 shows the cooling unit 200 disposed above the plurality of battery cell stacks 101, various modifications and variations are possible, such as disposing the cooling unit 200 below the plurality of battery cell stacks 101. Of course, as described above in the embodiment of FIG. 5, the partition wall 215 can also be applied to the cooling unit 220.

[0100] As described above, when the battery module and / or battery pack and the cooling unit included therein according to the present invention are used, even if a battery cell catches fire, the battery cell can be cooled quickly. Furthermore, even if the refrigerant-receiving space is arranged at an angle, the entire refrigerant in the refrigerant-receiving space can be supplied to the ignited battery cell. This minimizes the increase in the volume of the battery module and / or battery pack, and efficiently suppresses the thermal runaway phenomenon of the battery cell.

[0101] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content.

[0102] Although the 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 made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0103] 101: Battery cell stack 110: Upper plate 120: Lower plate 130: Side plate 200a, 200a′, 200b, 200b′: Cooling section 210, 310, 410, 510, 610: Heat sink 215: Bulkhead 220, 320: refrigerant receiving member 230, 230′, 230″, 267, 267′, 330: Through holes 240, 268, 268′, 340, 440, 540, 640: sealing members 250: Elastic member 260: Pressure member

Claims

1. a battery cell stack in which a plurality of battery cells are stacked; a frame that houses the battery cell stack; a cooling section on the battery cell stack; A battery pack comprising: The cooling unit is a refrigerant receiving member including an upper plate and a lower plate; a plurality of elastic members disposed in the internal space of the refrigerant receiving member; a sealing member that seals at least one through-hole formed in the coolant receiving member and that is meltable by a temperature increase of the battery cell; A refrigerant is received inside the elastic member, and the elastic member expands due to the reception of the refrigerant, at least one partition wall disposed across the interior space of the refrigerant receiving member to separate the interior space into a plurality of sections; the at least one partition wall is disposed perpendicular to the heat sink adjacent to the battery cell stack and in the longitudinal direction of the battery cells; The battery pack includes the elastic member provided in each of the plurality of separated sections.

2. 2. The battery pack according to claim 1, wherein before the elastic member melts, the elastic member accommodates the refrigerant therein and expands to a maximum extent, covering the entire interior space of the refrigerant receiving member.

3. 2. The battery pack according to claim 1, wherein when the temperature of the battery cells rises, the sealing member melts due to high-temperature gas or sparks emitted from the battery cells, and simultaneously or subsequently, a portion of the elastic member adjacent to the sealing member melts, causing the coolant inside the elastic member to flow out into the battery cell stack.

4. 4. The battery pack according to claim 3, wherein the coolant flows out into the battery cell stack, and the pressure applied by the coolant to the elastic member gradually decreases, causing the elastic member to gradually contract.

5. The battery pack according to claim 1 , wherein no coolant is received in a space between the coolant receiving member and the elastic member.

6. 2. The battery pack according to claim 1, wherein an adhesive for adhering the elastic member is applied to a portion of the inner surface of the coolant receiving member including the periphery of the through hole.

7. 7. The battery pack according to claim 6, wherein the adhesive is an acrylic adhesive, a silicone adhesive, a rubber adhesive, or a hot melt adhesive.

8. 2. The battery pack according to claim 1, wherein the coolant receiving member is a water tank, and coolant is accommodated inside the elastic member.

9. a pressure member having elastic force is provided between an inner surface of the cooling portion and an outer surface of the elastic member, When a refrigerant is received inside the elastic member, the pressurizing member is compressed by the pressure of the refrigerant, 2. The battery pack according to claim 1, wherein when the refrigerant is supplied to the battery cells through the through holes and the elastic member gradually contracts, the restoring force of the compressed pressure member causes the pressure member to press against the outer surface of the elastic member, and the elastic member is in close contact with the periphery of the through holes.

10. The battery pack according to claim 9 , wherein the pressure member is a spring.

11. 2. The battery pack according to claim 1, wherein the sealing member is made of a thermoplastic polymer resin.

12. 2. The battery pack according to claim 1, wherein the elastic member is made of natural rubber, synthetic rubber (SBR), oil-resistant rubber (NBR), or polyurethane rubber.

13. The battery pack according to claim 1 , wherein a surface of the coolant receiving member adjacent to the battery cell stack is a heat sink.

14. The frame is an upper plate disposed on top of the battery cell stack; a lower plate disposed under the battery cell stack; a side plate disposed on a side of the battery cell stack between the upper plate and the lower plate, the cooling portion is disposed on at least one of the upper plate and the lower plate, The battery pack according to claim 13 , wherein the heat sink of the coolant receiving member is spaced a predetermined distance from the frame to form the coolant receiving member.

15. a plurality of the battery cell stacks; The battery pack according to claim 1 , wherein the cooling section is disposed on a plurality of the battery cell stacks.

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