Partition member equipped with a fire extinguishing pad and pack case containing the same

Abstract

The disclosed invention relates to a partition member installed between multiple battery modules mounted in a battery pack, and in one example, at least one side of the partition member has a plurality of regularly aligned groove structures, and fire extinguishing pads containing a fire extinguishing agent are installed within the plurality of groove structures.

Description

Technical Field

[0001] The present invention relates to a lightweight partition member including a fire extinguishing pad that automatically discharges a fire extinguishing agent in response to a fire occurring inside a pack case, and a pack case including the same.

[0002] This application claims the benefit of Korean Application No. 10-2023-0029893, filed on Mar. 7, 2023, which is hereby incorporated by reference in its entirety.

Background Art

[0003] Unlike primary batteries, secondary batteries are rechargeable and have been actively researched and developed in recent years due to the possibility of being miniaturized and having a large capacity. With the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in line with the contemporary demands of environmental protection, the demand for secondary batteries as an energy source has been increasing even more rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. An electrode assembly mounted inside the battery case in a secondary battery is a power generation element capable of charge and discharge, which has a laminated structure of electrodes and a separator.

[0005] Since secondary batteries are required to be used continuously for a long period of time, it is necessary to effectively control the heat generated during the charge and discharge process. If the cooling of the secondary battery is not smoothly performed, an increase in temperature causes an increase in current, and the increase in current causes a positive feedback chain reaction that again causes an increase in temperature, and as a result, a catastrophic state of thermal runaway occurs.

[0006] Furthermore, when secondary batteries are arranged in a group in the form of modules or packs, a thermal runaway in one secondary battery can cause a thermal propagation phenomenon in which surrounding secondary batteries continuously overheat. In other words, when a thermal runaway occurs in a battery module within a battery pack, a large amount of conductive dust, gas, and flames are ejected from the high-voltage terminals of the battery module. This causes dust to accumulate on the high-voltage terminals of adjacent battery modules, and the heat transfer from the gas and flames triggers the thermal propagation phenomenon.

[0007] Designs to prevent or delay the transfer of high heat and / or flames from a thermally runaway battery cell or module to adjacent battery cells or modules include thermal insulation designs that use insulating materials to prevent or delay heat transfer from a thermally runaway battery module to adjacent battery modules, heat dissipation designs that quickly and initially release heat from a thermally runaway battery module to the outside of the battery pack to reduce heat transfer to adjacent battery modules, and fire extinguishing designs that discharge fire extinguishing agents when a thermal runaway occurs to actively suppress the spread of fire.

[0008] Suppressing and delaying heat transfer is a particularly important consideration in electric vehicles, where it directly impacts human life, and related regulations are being strengthened daily. Specifically, sufficient delay time is required before heat transfer dissipates to ensure there is enough time for emergency evacuation and safety measures after a thermal runaway occurs. However, applying various designs to prevent heat transfer reduces the space utilization rate of the pack case, decreases the capacity per unit volume of the battery pack, and necessitates a change in the battery pack design. Therefore, an effective solution that takes these problems into account is needed. [Overview of the project] [Problems that the invention aims to solve]

[0009] The object of this invention is to provide a partition member that can prevent, suppress, or delay heat propagation phenomena in a battery pack.

[0010] However, the technical problems that the present invention aims to solve are not limited to those described above, and other problems not mentioned can be clearly understood by an ordinary person of the art from the description of the invention below. [Means for solving the problem]

[0011] The present invention relates to a partition member installed between multiple battery modules mounted on a battery pack, wherein, in one example, at least one side of the partition member is provided with a plurality of regularly aligned groove structures, and a fire extinguishing pad containing a fire extinguishing agent is fitted within the plurality of groove structures.

[0012] In one embodiment of the present invention, the fire extinguishing pad may include a porous pad, a plurality of capsules embedded within the pad, and a liquid fire extinguishing agent sealed within the capsules.

[0013] For example, the above-mentioned liquid fire extinguishing agent may be a fluorinated ketone.

[0014] The above capsule can melt or rupture due to internal vapor pressure when the temperature of the fire extinguishing pad is in the temperature range of 120 to 220°C, thereby releasing the fire extinguishing agent.

[0015] The fire extinguishing agent released from the capsule can be released to the outside through the pores of the porous pad.

[0016] In one embodiment of the present invention, the plurality of groove structures may form a honeycomb structure in which a plurality of hexagonal grooves are regularly aligned.

[0017] Here, the honeycomb structure may be provided on both sides of the partition wall member.

[0018] Furthermore, the honeycomb structures provided on both sides of the partition wall member may be arranged alternately along the vertical and / or horizontal directions at half-pitch intervals, without communicating with each other.

[0019] On the other hand, the present invention may provide a pack case comprising a base plate, side plates surrounding the outer casing of the base plate, partition members having the above configuration arranged vertically and / or horizontally to partition a storage space limited to the side plates, and a lid that closes the upper surface of the storage space.

[0020] In one example, the partition member described above could be a crossbeam. [Effects of the Invention]

[0021] According to the partition member of the present invention having the above configuration, the fire extinguishing pad exposed on one side reacts to the abnormally high temperature of the battery module experiencing thermal runaway and discharges the built-in fire extinguishing agent. By discharging the fire extinguishing agent, the high-temperature gases, particles, and flames caused by the thermal runaway are cooled or extinguished, thereby thermally protecting other surrounding battery modules and suppressing or delaying heat propagation.

[0022] Furthermore, the partition member of the present invention incorporates a fire extinguishing pad containing a fire extinguishing agent, eliminating the need for the pack case to have a separate space and device for storing and discharging the fire extinguishing agent. Therefore, by applying the partition member of the present invention, the heat transfer problem can be effectively addressed without a general redesign of the pack case and without sacrificing the capacity of the battery pack.

[0023] Furthermore, the partition member of the present invention ensures sufficient rigidity while simultaneously reducing weight by constructing the space for housing the fire extinguishing pad with a honeycomb structure, thereby contributing to a reduction in the weight of the pack case.

[0024] However, the technical effects that can be obtained by the present invention are not limited to the above-described effects, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

Brief Description of the Drawings

[0026] [Figure 1] It is a drawing showing an installation example of a partition member according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view obtained by cutting open the partition member of FIG. 1 along the line "A - A". [Figure 3] It is a drawing showing a cross-section of a fire extinguishing pad. [Figure 4] It is a drawing showing another embodiment of the partition member. [Figure 5] It is a drawing showing an embodiment in which a fire extinguishing pad is attached to a partition member. [Figure 6] It is a drawing showing another embodiment in which a fire extinguishing pad is attached to a partition member. [Figure 7] It is a drawing showing a pack case including a partition member according to an embodiment of the present invention. [Figure 8] It is a drawing showing an embodiment of a battery pack in which a battery module is mounted on the pack case of FIG. 7. [Figure 9] It is a drawing showing another embodiment of a battery pack in which a battery module is mounted on the pack case of FIG. 7.

Modes for Carrying Out the Invention

[0027] Since the present invention can be subjected to various modifications and can have various embodiments, specific embodiments will be described in detail below.

[0028] However, this is not intended to limit the present invention to any particular embodiment, but rather should be understood to include all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0029] In the present invention, terms such as "includes" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof as described in the specification, and do not preemptively exclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0030] Furthermore, in this invention, when a part such as a layer, film, region, or plate is described as being "on top" of another part, this includes not only the case where it is "directly on top" of the other part, but also the case where another part is located in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "directly below" the other part, but also the case where another part is located in between. Also, in this application, being "on top" may include being located not only at the top but also at the bottom.

[0031] The present invention relates to a partition member installed between multiple battery modules mounted on a battery pack, wherein, in one example, at least one side of the partition member is provided with a plurality of regularly aligned groove structures, and a fire extinguishing pad containing a fire extinguishing agent is fitted within the plurality of groove structures.

[0032] In one embodiment of the present invention, the fire extinguishing pad may include a porous pad, a plurality of capsules embedded within the pad, and a liquid fire extinguishing agent sealed within the capsules.

[0033] According to the partition member of the present invention having the above configuration, the fire extinguishing pad exposed on one side reacts to the abnormally high temperature of the battery module experiencing thermal runaway and discharges the built-in fire extinguishing agent. By discharging the fire extinguishing agent, the high-temperature gases, particles, and flames caused by the thermal runaway are cooled or extinguished, thereby thermally protecting other surrounding battery modules and suppressing or delaying heat propagation.

[0034] Furthermore, the partition member of the present invention incorporates a fire extinguishing pad containing a fire extinguishing agent, eliminating the need for the pack case to have a separate space and device for storing and discharging the fire extinguishing agent. This means that by applying the partition member of the present invention, the heat transfer problem can be effectively addressed without any overall redesign of the pack case or at the expense of the battery pack capacity.

[0035] Furthermore, by constructing the space for housing the fire extinguishing pad in the partition member of the present invention with a honeycomb structure, sufficient rigidity can be ensured while simultaneously achieving weight reduction, thereby contributing to a reduction in the weight of the pack case.

[0036] Hereinafter, specific embodiments of the pack case partition member 130 according to the present invention will be described in detail with reference to the attached drawings. For reference, the front-to-back and up-down-left-right directions used in the following description to specify relative positions are for the purpose of aiding the understanding of the invention, and unless otherwise defined, the directions shown in the drawings are used as the reference.

[0037] (First Embodiment) Figure 1 is a diagram showing an example of the installation of the partition member 130 according to the present invention, and Figure 2 is a cross-sectional view obtained by cutting the partition member 130 of Figure 1 along the line "AA".

[0038] Figure 1 is a diagram showing that the partition member 130 (hereinafter simply referred to as "partition member") of the battery pack according to the present invention can be applied as the center beam 140 and / or cross beam 150 of the pack case 100. Here, the center beam 140 refers to the vertical partition member 130 that crosses the center of the pack case 100 and divides the internal storage space into left and right halves, and the cross beam 150 refers to the horizontal partition member 130 that forms a grid shape with respect to the center beam 140.

[0039] The partition member 130 of the present invention is a member that forms multiple storage spaces by being installed between multiple battery modules 200 mounted on a battery pack 10, with one battery module 200 installed in each divided storage space. Therefore, the partition member 130 functions as a wall that separates or isolates the battery modules 200, and the partition member 130 is inevitably involved in heat transfer between the battery modules 200.

[0040] Figure 2 is a drawing showing a cross-section of a crossbeam 150 separated from the pack case 100 of Figure 1. For reference, Figure 2 is one example of a partition member 130, and the same structure as in Figure 2 can be applied to the center beam 140. Referring to Figure 2, the crossbeam 150, which is a partition member 130, is equipped with a fire extinguishing pad 170 exposed on one surface, and the fire extinguishing pad 170 contains a fire extinguishing agent 176.

[0041] The fire extinguishing pad 170, exposed on one side of the crossbeam 150, contacts the battery modules 200, which are installed in multiple containment spaces provided in the pack case 100 shown in Figure 1. In other words, the fire extinguishing pad 170 receives heat from the battery modules 200 primarily through conductive heat transfer. If a battery cell 210 constituting the battery module 200 experiences thermal runaway and reaches an abnormally high temperature, the fire extinguishing pad 170 provided on the partition member 130 will receive an abnormally large amount of heat, and in response to this heat, it will discharge the built-in fire extinguishing agent 176. The discharge of the fire extinguishing agent 176 cools or extinguishes the high-temperature gases, particles, and flames caused by the thermal runaway, thereby thermally protecting the surrounding battery modules 200 and suppressing or delaying heat propagation.

[0042] The partition member 130 of the present invention incorporates a fire extinguishing pad 170 containing a fire extinguishing agent 176, thereby eliminating the need for the pack case 100 to provide a separate space and device for storing and discharging the fire extinguishing agent 176. This means that by applying the partition member 130 of the present invention, the heat transfer problem can be effectively addressed without any overall redesign of the pack case 100 and without sacrificing the capacity of the battery pack 10.

[0043] Figure 3 is a cross-sectional view of a fire extinguishing pad 170 according to one embodiment. Referring to the figure, the fire extinguishing pad 170 includes a porous pad 172, a plurality of capsules 174 embedded within the porous pad 172, and a liquid fire extinguishing agent 176 sealed within the capsules 174. Sealing the liquid fire extinguishing agent 176 within the capsules 174 is a method that allows the fire extinguishing agent 176 to be stably stored within the fire extinguishing pad 170 until a thermal runaway incident occurs. In particular, the use of a liquid fire extinguishing agent 176 is expected to provide effective fire extinguishing functionality while occupying a small space despite its volume expanding explosively upon vaporization. Furthermore, the porous pad 172, which serves as a kind of container for housing the capsules 174, contains a large number of pores and is suitable for the discharge of vaporized fire extinguishing agent 176.

[0044] For example, a preferred liquid fire extinguishing agent 176 may be a fluorinated ketone. A fluorinated ketone is a substance artificially created by substituting hydrogen atoms with fluorine in a ketone. It is colorless and odorless, has a viscosity almost the same as water, and is easy to contain in a capsule 174. Due to the stable properties of fluorine, its dielectric strength is more than twice that of nitrogen, so it does not conduct electricity and does not react with substances it comes into contact with, such as oxidation. It has a very low surface tension and spreads well without forming droplets when it comes into contact with an object, making it very suitable for fire extinguishing. Furthermore, fluorinated ketone is non-toxic and harmless to humans, and it evaporates rapidly upon contact with fire or smoke, making it an effective fire retardant that quickly removes heat. Since it leaves no residue after evaporation, it is more environmentally friendly than existing fire extinguishing materials. In particular, the non-conductivity due to the stable properties of fluorine is suitable for dealing with fires in battery packs 10 caused by thermal runaway of secondary batteries.

[0045] However, since fluorinated ketones have a boiling point of 49°C, which is much lower than that of water, they exist in a liquid state at room temperature but rapidly vaporize when the temperature rises. Therefore, it is necessary to design the material and thickness of the capsule 174 containing the liquid fluorinated ketone and the porous pad 172 surrounding the capsule 174 so that they function properly as insulating materials. For example, the capsule 174 may be designed to melt or rupture due to the vapor pressure of the extinguishing agent 176 vaporized inside when the temperature of the fire extinguishing pad 170 in contact with the battery module 200 is in the temperature range of 120 to 220°C, releasing the extinguishing agent 176. The extinguishing agent 176 released from the capsule 174 is released to the outside through the pores of the porous pad 172, thereby enabling an early response to a fire occurring in the battery module 200.

[0046] Referring again to Figure 1, the partition member 130 has a plurality of regularly aligned groove structures 132 on its surface, and the fire extinguishing pad 170 is fixed within these groove structures 132. Here, the form of the regular groove structure 132 shown in Figure 1 is a honeycomb structure 134 in which a plurality of hexagonal grooves are regularly aligned. The honeycomb structure 134 is a dense structure in which one side of one hexagon (for example, a regular hexagon) overlaps with one side of another hexagon, and excluding the corners, it forms a regular arrangement in which one hexagon is surrounded by six other hexagons.

[0047] The honeycomb structure 134 is a representative structure that is particularly rigid relative to its volume. By providing the honeycomb structure 134 on the surface of the partition member 130 of the present invention, it becomes possible to secure space for housing a large number of fire extinguishing pads 170 while simultaneously maintaining the rigidity of the partition member 130 in an excellent state. This means that it is no longer necessary to make the partition member 130 thick in order to maintain mechanical rigidity while sufficiently mounting the fire extinguishing pads 170, and as a result, it becomes possible to make the weight of the partition member 130 and the pack case 100 containing it lighter while effectively suppressing and delaying heat propagation.

[0048] Figure 4 is a drawing showing another embodiment of the partition member 130, in which the groove structure 132 is provided as a honeycomb structure 134 on both sides of the partition member 130. Since weight reduction is possible via the honeycomb structure 134, by making the thickness of the partition member 130 slightly thicker and forming a honeycomb structure 134 on both sides to which the fire extinguishing pads 170 are attached, it is possible to respond more effectively to fires occurring in the battery module 200.

[0049] Here, the honeycomb structures 134 provided on each side of the partition member 130 may not communicate with each other. In this case, the honeycomb structures 134 on both sides of the partition member 130 may be arranged alternately by half a pitch P along the vertical and / or horizontal directions. Pitch refers to the vertical or horizontal spacing between hexagons that are regularly arranged to form the honeycomb structure 134. By offsetting the honeycomb structures 134 on both sides of the partition member 130 by half a pitch P along the vertical and / or horizontal directions so that they do not overlap, the overall rigidity of the partition member 130 is further enhanced by the offset honeycomb structures 134, which resemble a net. The partition member 130 shown exemplifies in Figure 4, which shows an embodiment in which the honeycomb structures 134 on both sides are arranged alternately by half a pitch P in both the vertical and horizontal directions.

[0050] (Second Embodiment) Figures 5 and 6 show embodiments in which the fire extinguishing pad 170 is attached to the partition wall member 130, respectively.

[0051] The embodiment shown in Figure 5 relates to a method in which a fire extinguishing pad 170 is separately provided that conforms to the shape of the groove structure 132 provided in the partition wall member 130, and then the fire extinguishing pad 170 is inserted into the groove structure 132 by means of adhesive or fitting.

[0052] For example, the fire extinguishing pad 170 can be manufactured using foam molding technology. That is, a porous pad 172 containing numerous pores can be manufactured by mixing a foaming agent with a thermoplastic resin or by injecting a gas such as nitrogen during the molding process. In this case, a fire extinguishing pad 170 with the structure shown in Figure 3 can be manufactured by mixing a capsule 174 containing a liquid fire extinguishing agent 176 into the resin used for molding and performing foam molding. By making the mold used for foam molding in the shape of the groove structure 132 provided in the partition member 130, the fire extinguishing pad 170 can be manufactured with the correct size and shape.

[0053] Figure 6 schematically shows an embodiment in which the partition member 130, which has the groove structure 132 formed on it, is used as a mold to attach the fire extinguishing pad 170, without the need to prepare a separate mold. By using the partition member 130 as a mold, mold costs are saved, and a partition member 130 with an integrated fire extinguishing pad 170 that fits perfectly into the groove structure 132 of the partition member 130 can be made without the need for a separate assembly process. In particular, the embodiment in Figure 6 is also advantageous when multiple groove structures 132 are provided by ribs 134, or when the shape of the groove structure 132 is complex, or when the shapes of the multiple groove structures 132 are not identical.

[0054] (Third embodiment) Figure 7 is a drawing showing a pack case 100 including a partition member 130 according to the first embodiment of the present invention.

[0055] The illustrated pack case 100 includes a base plate 110 forming the bottom surface, side plates 120 surrounding the outer casing of the base plate 110, partition members 130 of the first embodiment arranged vertically and / or horizontally to partition the storage space limited to the side plates 120, and a lid 180 that closes the top surface of the storage space.

[0056] The partition member 130, described in detail above, can be joined to the upper surface of the base plate 110 by laser welding, brazing, or bolting, etc., at its bottom surface. In the embodiment shown in Figure 7, the partition member 130 of the first embodiment forms the cross beam 150 of the pack case 100. Of course, as mentioned above, the partition member 130 of the first embodiment can also be used as the center beam 140.

[0057] Figure 8 is a diagram showing one embodiment of a battery pack 10 in which battery modules 200 are mounted in the pack case 100 of Figure 7. The crossbeam 150 equipped with fire extinguishing pads 170 is aligned so that the fire extinguishing pads 170 face the same direction, so that each battery module 200 is assigned one fire extinguishing pad 170 (see Figures 7 and 8). By assigning one fire extinguishing pad 170 to each battery module 200, if thermal runaway occurs in a battery module 200, the fire extinguishing pad 170 assigned to that battery module 200 reacts thermally and ejects vaporized fire extinguishing agent 176, thereby actively suppressing the thermal runaway. The ejection of the fire extinguishing agent 176 lowers the temperature of the battery module 200, delaying the thermal runaway, and when viewed as a whole battery pack 10, the fire extinguishing pads 170 that react to the heat propagation sequentially along the direction of heat propagation are activated, so that the heat propagation delay effect can be maintained for as long as possible.

[0058] Figure 9 is a drawing showing another embodiment of the battery pack 10 in which the battery module 200 is mounted in the pack case 100 of Figure 7. The difference from the embodiment in Figure 8 is that fire extinguishing pads 170 are provided on both sides of the crossbeam 150. By placing fire extinguishing pads 170 on both sides of the battery module 200, the amount of fire extinguishing agent 176 that solves the problem when a fire occurs in a battery module 200 is doubled, making it possible to suppress the fire more effectively. Here, Figure 9 is shown as an embodiment in which two partition members 130, each equipped with a fire extinguishing pad 170 on one side, overlap to form one crossbeam 150. However, it can be seen that the embodiment in Figure 9 can be realized by using one partition member 130 equipped with fire extinguishing pads 170 on both sides, as described in the embodiment in Figure 4, to construct the crossbeam 150.

[0059] The present invention has been described in more detail above through the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be various equivalents and modifications that can substitute for them at the time of filing. [Explanation of symbols]

[0060] 10: Battery Pack 100: Pack Case 110: Base plate 120: Side Plate 130: Partition member 132:Groove structure 134: Honeycomb structure 140: Center beam 150: Crossbeam 180: Lid 170: Fire extinguishing pad 172: Porous pad 174: Capsule 176: Fire extinguishing agent 200: Battery Module 210: Battery cell P: Pitch

Claims

1. A partition member installed between multiple battery modules mounted on a battery pack, At least one side surface of the partition wall member is provided with a plurality of regularly aligned groove structures, Fire extinguishing pads containing fire extinguishing agents are installed within the aforementioned multiple groove structures. The aforementioned fire extinguishing pad is It comprises a porous pad, a plurality of capsules embedded within the pad, and a liquid fire extinguishing agent sealed within the capsules. The aforementioned liquid fire extinguishing agent is It is a fluorinated ketone, The aforementioned capsule is When the temperature of the fire extinguishing pad is in the temperature range of 120 to 220°C, it ruptures due to melting or internal vapor pressure, releasing the fire extinguishing agent. The aforementioned multiple groove structures are A partition member having a honeycomb structure in which multiple hexagonal grooves are regularly arranged.

2. The fire extinguishing agent released from the aforementioned capsule is The partition member according to claim 1, wherein the material is released to the outside through the pores of the porous pad.

3. The aforementioned honeycomb structure is The partition member according to claim 1, which is provided on both sides of the partition member.

4. The honeycomb structures provided on both sides of the partition wall member are, Without communicating with each other, The partition wall members according to claim 3, which are arranged alternately at half-pitch intervals along the vertical and / or horizontal directions.

5. base plate and Side plates surrounding the outer casing of the base plate, A partition member according to any one of claims 1 to 4, which is arranged vertically and / or horizontally to partition the storage space limited to the side plate, A pack case, including a lid that closes the top surface of the aforementioned storage space.

6. The partition wall member is The pack case according to claim 5, which is a crossbeam.

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