Battery module components

Abstract

The disclosed invention relates to a battery module component, which in one example includes a body made of a synthetic resin material and a mesh made of a metal material embedded in the body, the body having a lower melting point than the mesh.

Description

Technical Field

[0001] The present invention relates to battery module components, and more particularly, to battery module components capable of suppressing the spread of secondary damage such as external fires and explosions by preventing flames from being exposed outside the module frame even when the battery cells mounted inside the module frame overheat and generate flames.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0083860, filed on July 7, 2022, and all the contents disclosed in the document of the Korean Patent Application are incorporated herein by reference.

Background Art

[0003] Unlike primary batteries, secondary batteries can be recharged and have been extensively researched and developed in recent years due to their potential for miniaturization and high capacity. With the increasing development of technology and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in line with the contemporary requirements 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. The 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 carried out smoothly, the temperature rise will cause an increase in current, and the increase in current will cause a positive feedback chain reaction that causes the temperature to rise again, eventually leading to a catastrophic state of thermal runaway.

[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 thermal propagation, leading to continuous overheating of surrounding secondary batteries. Moreover, if flames generated by an overheated secondary battery are exposed to the outside, they can not only damage surrounding equipment but also spread to cause secondary damage such as fires and explosions. Therefore, measures must be taken to address such fire hazards. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Korean Published Patent No. 2020-0078344 (Published July 1, 2020) [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a battery module component that can suppress the spread of secondary damage such as fires and explosions to the outside by preventing flames from being exposed to the outside of the frame even if the battery cells mounted inside overheat and generate flames.

[0009] However, the technical problems that this 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]

[0010] The present invention relates to a battery module component, and in one example includes a body made of synthetic resin material and a mesh made of metal material embedded within the body, wherein the body has a lower melting point than the mesh.

[0011] In one embodiment of the present invention, the mesh is embedded in the main body by insert injection molding to form an integral part, and at least a portion of the mesh is exposed on the inner surface of the main body.

[0012] According to the embodiment, the main body may form an end plate for a battery module frame.

[0013] Furthermore, a portion of the outer surface of the main body may be provided with a weaker area that has less heat resistance than the surrounding area.

[0014] The aforementioned fragile portion may be made of a different type of synthetic resin material with a lower melting point than the main body, or it may be formed to be thinner than the surrounding area.

[0015] Furthermore, it is preferable that the metal material of the mesh described above be heat-resistant stainless steel.

[0016] According to another embodiment of the present invention, the mesh is embedded in the main body by insert injection molding to form an integral part, and the mesh is not exposed to the outside of the main body.

[0017] Here, the inner surface of the main body is provided with a first weak point that has weaker heat resistance than the surrounding area, and furthermore, a part of the outer surface of the main body is provided with a second weak point that has weaker heat resistance than the surrounding area.

[0018] The first and second weak parts described above may each be made of a different synthetic resin material with a lower melting point than the main body, or they may be formed to be thinner than the surrounding area.

[0019] Furthermore, the above-mentioned first vulnerable part is provided in multiple locations. The second vulnerable portion may be provided as a single entity, thereby being positioned at equal distances from the plurality of first vulnerable portions.

[0020] Furthermore, the second vulnerable portion may be equipped with a filter having a denser dimension than the mesh described above. [Effects of the Invention]

[0021] The battery module component of the present invention having the above-described configuration is made of a composite material in which a mesh of a metal material is embedded in a main body made of a synthetic resin material. When a flame occurs in the battery module, it has an anti-inflammatory effect through the mesh structure. On the other hand, even if the main body made of a resin material with a low melting point melts to form a discharge port, only the high-temperature gas is discharged and the flame is not discharged to the outside.

[0022] And by forming a vulnerable part in the main body and limiting the discharge position of the high-temperature gas to the vulnerable part, the risk of an external fire can be further reduced.

[0023] 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 will be clearly understood by those skilled in the art from the description of the invention described below.

Brief Description of the Drawings

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention and play a role in further understanding 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. [Figure 1] It is a drawing illustrating an example of a battery module including the battery module component of the present invention. [Figure 2] It is a drawing illustrating a cross-sectional structure of an end plate according to an embodiment of the present invention. [Figure 3] It is a drawing illustrating an example of joining a mesh to the inside of the main body of the end plate by insert injection. [Figure 4] It is a drawing illustrating an example of the end plate of FIG. 2 being joined to a battery module frame. [Figure 5] It is a drawing illustrating examples of forming vulnerable parts in the main bodies respectively. [ [Figure 6]These are diagrams illustrating examples of how weak points are formed in the main body. [Figure 7] This drawing illustrates the cross-sectional structure of an end plate according to another embodiment of the present invention. [Figure 8] This diagram illustrates the relative positional relationship between the first and second vulnerable areas. [Figure 9] Figure 7 is a diagram illustrating an example in which a filter is provided in the second vulnerable portion formed in the end plate. [Modes for carrying out the invention]

[0025] The present invention can be modified in various ways and may have a variety of embodiments; therefore, specific embodiments are described in detail below.

[0026] However, this should not be understood as limiting the present invention to any particular embodiment, but rather as including all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0027] In the present invention, terms such as "includes" and "have" are intended to specify the presence of features, numbers, stages, operations, components, parts, or combinations thereof as described in the specification, and should be understood as not preemptively excluding the presence or possibility of adding one or more other features, numbers, stages, operations, components, parts, or combinations thereof.

[0028] 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.

[0029] The present invention relates to a battery module component, and in one example includes a body made of synthetic resin material and a mesh made of metal material embedded within the body, wherein the body has a lower melting point than the mesh.

[0030] The battery module component of the present invention, having the above configuration, is made of a composite material in which a metal mesh is embedded in a synthetic resin body. This allows for flame suppression through the mesh structure when a flame occurs inside the battery module, while even if the resin body, which has a low melting point, melts and forms an outlet, only high-temperature gas is discharged, and the flame is not discharged to the outside.

[0031] Specific embodiments of the battery module components of the present invention will be described in detail below with reference to the attached drawings. For reference, the forward / backward and up / down / left / right directions used to specify relative positions in the following description 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.

[0032] (First Embodiment) Figure 1 is a diagram illustrating an example of a battery module 10 including the battery module component 200 of the present invention. The battery module 10 refers to a battery assembly in which a certain number of battery cells 410 are bundled together and placed in a frame to protect them from external shocks, heat, vibrations, etc. The battery module 10 consists of a number of battery cells 410 connected to each other in series and / or parallel, and is embedded in a mechanical structure, i.e., a battery module frame 100.

[0033] Each battery cell 410 plays a vital role in storing energy and supplying it to the outside when needed. However, since a single battery cell 410 has a small capacity, modules are created by combining them, and then larger modules are combined to form a battery pack.

[0034] The present invention relates to a battery module component 200 applied to a battery module 10 that protects a number of battery cells 410. The battery module 10, illustrated as an example in Figure 1, includes a battery cell assembly 400 in which a number of battery cells 410 are connected in series and / or parallel to form a single assembly.

[0035] The battery module frame 100, a mechanical structure protecting numerous battery cells 410, includes a main frame 102 having a "U"-shaped cross-section and forming a space inside which to house the battery cell assembly 400, and an upper plate 104 covering the open upper surface of the main frame 102. Here, end plates 200' are attached to both open sides of the battery module frame 100 to seal the battery module 10, and the end plate 200' is an example of a battery module component 200 that the present invention would like to illustrate.

[0036] The battery module 10 has a polyhedron shape, a hexahedron shape in Figure 1, that houses multiple battery cells 410, with end plates 200' attached to both sides. Here, the end plates 200' are connected to the electrode lead side of the battery cell assembly 400, and as a result, the end plates 200' may be equipped with busbars that are electrically connected to the battery cell assembly 400.

[0037] In this respect, if the end plate 200' includes a busbar, it can also be called a busbar frame. Therefore, the end plate 200' as referred to in the specification of the present invention should be broadly understood as a battery module component 200 that seals both sides of the battery module 10, without being bound by the examples of its usage.

[0038] Figure 2 illustrates the cross-sectional structure of a battery module component 200, specifically an end plate 200', according to a first embodiment of the present invention. The end plate 200' includes a body 210 made of synthetic resin and a metal mesh 230 embedded within the body 210. In particular, the body 210 made of synthetic resin has a lower melting point than the metal mesh 230.

[0039] In other words, the end plate 200' of the present invention is made of a composite material formed by combining a body 210 made of synthetic resin material and a metal mesh 230 embedded within the body 210. Here, the body 210 made of synthetic resin material plays the role of a structure that maintains the mechanical structure of the end plate 200'. From this point of view, a synthetic resin with excellent mechanical strength, such as polycarbonate, can be used as the body 210.

[0040] Furthermore, the mesh 230 contained within the synthetic resin body 210 can be understood, in a broad sense, as a porous metal body. For example, a metal mesh, wire mesh 230, or a thin metal film with numerous through-holes can be used as the mesh 230. Alternatively, a flat bundle of wires, formed by spirally winding thin metal threads, can be inserted into the metal mesh 230.

[0041] The end plate 200' of the present invention, while using a synthetic resin body 210 as its structure, includes a porous mesh 230 within it. Therefore, the lightweight design achieved by the synthetic resin material and the weight reduction provided by the mesh 230 structure makes it possible to realize a lightweight battery module component 200.

[0042] Furthermore, the end plate 200' of the present invention not only finely crushes the metal mesh 230 embedded in the main body 210 while allowing the flame generated during thermal runaway of the battery cell 410 to pass through, but also causes an endothermic reaction that absorbs the energy of the flame, resulting in a temperature reduction and flame extinguishing effect.

[0043] More specifically, since the metal mesh 230 has many small holes, gases such as gases and vapors can easily pass through the mesh 230, but flames are relatively difficult to pass through.

[0044] When the flammable gas and air mixture inside the battery cell 410 is ignited, the mesh 230 inside the end plate 200' absorbs and dissipates the heat generated from the burning gas mixture, thereby lowering the combustion temperature and preventing the surrounding gas from rising to its autoignition temperature. This is because the high-temperature gas absorbs heat as it passes through the mesh 230, due to the porous structure of the metal material. In other words, the mesh 230 is made of a metal material containing numerous holes and functions as a flame arrester with a very large cross-sectional area.

[0045] Therefore, the flame generated by the thermal runaway of the battery cell 410 passes through the battery module component 200 of the present invention, and as it passes through, it loses so much heat that it can no longer sustain the flame. This effectively suppresses heat propagation phenomena and external fires.

[0046] Furthermore, because the synthetic resin body 210 has a lower melting point than the metal mesh 230, flames passing through the mesh 230 can melt a portion of the outer surface of the body 210 as heat is removed, creating a perforated hole. However, since the mesh 230, which functions as a fire prevention screen, removes most of the flames, high-temperature gases are mainly discharged through the perforations in the body 210 created by the melting flames, and very little of the flame is discharged.

[0047] On the other hand, the metal mesh 230 needs to have heat resistance to maintain its flame-extinguishing function for a long period of time. Furthermore, it is preferable to select a material for the mesh 230 that not only has the ability to stop flames but also possesses mechanical properties that can withstand explosive pressure. From this perspective, steel or stainless steel, which are heat-resistant and have excellent mechanical strength, can be selected as the material for the mesh 230.

[0048] For example, mesh 230 can be made of heat-resistant stainless steel. Heat-resistant stainless steel can be ferritic stainless steel alloys such as X10CrAlSi7, X10CrAl13, X10CrAl18 and X18CrN28, austenitic stainless steel alloys such as X15CrNiSi20-12, X15CrNiSi25-20, X15CrNiSi25-21 and X12CrNiTi18-10, or nickel-chromium stainless steel alloys such as NiCr15Fe, NiCr23Fe, NiCr22Mo9Nb, NiCr21Mo and NiCr28FeSiCe.

[0049] Furthermore, since the mesh 230 embedded in the main body 210 is a thin plate, it can suppress an increase in the size of the battery module frame 10. Also, since the mesh 230 has many holes, it can suppress an increase in weight.Therefore, the battery module component 200 of the present invention improves the safety of the battery module 10 by suppressing an increase in the size and weight of the battery module 10 and the battery pack into which the battery modules 10 are assembled, while also preventing the outward emission of flames in the event that flames erupt from the battery cell 410.

[0050] In one embodiment of the present invention, the mesh 230 can be embedded in the main body 210 by insert injection molding to form an integral part. Figure 3 illustrates an exemplary process in which molten synthetic resin is injected with the mesh 230 fixed in the upper mold UM and the lower mold BM to manufacture a battery pack component.

[0051] Furthermore, according to the embodiment shown in Figure 3, since the mesh 230 is fixed in close contact with the bottom surface of the lower mold, at least a portion of the mesh 230 is exposed on the inner surface of the main body 210 of the end plate 200', as shown in Figure 2. In order to embed and fix the mesh 230 within the main body 210, a step is formed in a portion of the mesh 230 to allow molten synthetic resin to penetrate, but the portion of the mesh 230 that is in close contact with the bottom surface of the lower mold forms an exposed surface against the inner surface of the main body 210.

[0052] An example of the end plate 200' in Figure 2 being connected to the battery module frame 100 is illustrated in Figure 4. In the battery module 10 of Figure 4, if a fire occurs in the battery cell 410, the mesh 230 of the end plate 200' is exposed to the inner surface of the main body 210, and when the expanding flame reaches the mesh 230, it will exhibit flame-extinguishing capabilities that block the flame. Therefore, even if a perforation is created on the outer surface of the main body 210 due to high heat, only high-temperature gas will be mainly discharged, and the flame will not be ejected outside the end plate 200'.

[0053] However, the location of the through-hole in the end plate 200' is random. In other words, the through-hole will occur in a heat-vulnerable area depending on the location where the flame originates and the shape of the end plate 200'. Even if flames do not erupt through the through-hole, high-temperature gases will be released, so if there are devices or components that are vulnerable to high-temperature gases or are flammable located around the through-hole, this could cause an external fire or secondary damage.

[0054] Therefore, according to one embodiment of the present invention, by providing a weak portion 220 on a part of the outer surface of the main body 210 that has weaker heat resistance than the surrounding area, it is possible to induce the formation of a through hole on the side of the weak portion 220. In other words, the preferred location of the through hole from which high-temperature gas is discharged can be limited to the weak portion 220.

[0055] The weak point 220 can be designed in various ways. For example, as shown in Figure 5, the weak point 220 can be formed by inserting a different type of synthetic resin material with a lower melting point than the main body 210 into the main body 210, or as shown in Figure 6, the weak point 220 can be made thinner than the surrounding area so that it melts faster even when subjected to the same heat. However, since Figures 5 and 6 are illustrative examples of how to form the weak point 220, these illustrative examples do not limit the specific configuration of the weak point 220.

[0056] (Second Embodiment) Figure 7 is a drawing illustrating an end plate 200' according to a second embodiment of the present invention. According to the second embodiment in Figure 7, the mesh 230 is embedded integrally within the main body 210 by insert injection molding, and the mesh 230 is not exposed to the outside of the main body 210.

[0057] In other words, the end plate 200' of the second embodiment has a structure in which the mesh 230 is completely embedded within the main body 210, and the mesh 230 is not exposed from anywhere on the outer surface of the main body 210, as well as from the inner surface. Therefore, if a fire occurs inside the battery module 10, when the high-temperature flames melt the inner surface of the main body 210 and the mesh 230 is exposed, the flames will flow into the mesh 230, and then the flame-extinguishing function of the mesh 230 will take effect, preventing the flames from spreading.

[0058] The end plate 200' of the second embodiment has the advantage of being structurally stronger because it does not have an incision surface that exposes the mesh 230 on the main body 210. Therefore, the second embodiment can be said to be a more suitable embodiment when the size and weight of the battery module 10 are large.

[0059] However, in the second embodiment, since the mesh 230 is exposed after the high-temperature flame melts the inner surface of the main body 210, the flame extinguishing function does not act immediately, and the location of the through-holes on the inner surface of the main body 210 is random. Therefore, as shown in Figure 7, it is preferable to provide a first weak point 221 on the inner surface of the main body 210, which has weaker heat resistance than the surrounding area, in order to guide the formation of through-holes in the first weak point 221.

[0060] Furthermore, as described in the first embodiment, by forming a second weak portion 222 on a part of the outer surface of the main body 210, which has weaker heat resistance than the surrounding area, the preferred location of the through hole from which high-temperature gas is discharged can be limited to the second weak portion 222. The first weak portion 221 and the second weak portion 222 may each be made of a different synthetic resin material with a lower melting point than the main body 210, or may be formed with a thinner thickness than the surrounding area. Figure 7 illustrates an embodiment in which the first weak portion 221 and the second weak portion 222 are made of a different synthetic resin material with an even lower melting point than the main body 210.

[0061] Figure 8 is a diagram illustrating the relative arrangement of the first vulnerable section 221 and the second vulnerable section 222. Multiple first vulnerable sections 221 are provided, and one second vulnerable section 222 is provided, arranged at equal distances from the multiple first vulnerable sections 221. This is to ensure that flames entering each first vulnerable section 221 travel as long a distance as possible before being discharged from the second vulnerable section 222, thereby allowing the flame-extinguishing effect of the mesh 230 to be fully exerted.

[0062] Figure 9 shows a configuration in the end plate 200' of the second embodiment, in which a filter 300 with dimensions denser than the mesh 230 inside the main body 210 is provided in the second vulnerable section 222. When flames that have passed through the mesh 230 are ejected through the second vulnerable section 222, almost no flame remains and they are discharged as high-temperature gas, but the high-temperature gas may contain high-temperature particles that act as an ignition source for an external fire.

[0063] The embodiment shown in Figure 9 is for preventing fires caused by high-temperature particles. By providing a filter 300 in the second vulnerable part 222, and in particular a filter 300 that is denser than the mesh 230 so as to filter out particles of a size that would pass through the mesh 230, the risk of external fire can be prevented more effectively.

[0064] The present invention has been described in more detail above with reference to 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. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application. [Explanation of Symbols]

[0065] 10: Battery Module 100: Battery module frame 102: Mainframe 104: Top plate 200: Battery module components 200': End Plate 210: Main unit 220: Vulnerable parts 221: First Vulnerable Part 222: Second Vulnerable Area 230: Mesh 300: Filter 400: Battery cell assembly 410: Battery cell UM: Upper mold M: Lower mold

Claims

1. The main body is made of synthetic resin, A metal mesh embedded within the main body, Includes, The main body has a lower melting point than the mesh. The aforementioned main body is It forms the end plate of the battery module frame, A battery module component having a weaker area on a portion of the outer surface of the main body, which has weaker heat resistance than the surrounding area.

2. The main body is made of synthetic resin, A metal mesh embedded within the main body, Includes, The main body has a lower melting point than the mesh. The aforementioned main body is It forms the end plate of the battery module frame, A battery module component, wherein the inner surface of the main body is provided with a first vulnerable area that has weaker heat resistance than the surrounding area.

3. The mesh is embedded in the main body by insert injection to form an integral part. The battery module component according to claim 1, wherein at least a portion of the mesh is exposed on the inner surface of the main body.

4. The aforementioned vulnerable part is The battery module component according to claim 3, wherein it is made of a different synthetic resin material with a lower melting point than the main body, or is formed to be thinner than the surrounding area.

5. The battery module component according to claim 1 or 2, wherein the metal material of the mesh is heat-resistant stainless steel.

6. The mesh is embedded in the main body by insert injection to form an integral part. The battery module component according to claim 2, wherein the mesh is not exposed to the outside of the main body.

7. The battery module component according to claim 6, wherein a second vulnerable portion is provided on a part of the outer surface of the main body, which has weaker heat resistance than the surrounding area.

8. The first and second vulnerable parts are, respectively, The battery module component according to claim 7, wherein it is made of a different synthetic resin material with a lower melting point than the main body, or is formed to be thinner than the surrounding area.

9. The first vulnerable part is provided in multiple locations, The battery module component according to claim 7, wherein the second vulnerable portion is provided as a single portion, and is arranged such that it is at equal distances from a plurality of first vulnerable portions.

10. The second vulnerable part is, The battery module component according to claim 7, comprising a filter having dimensions denser than the mesh.

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