Intermodule busbars containing fire extinguishing fluid

Abstract

The present invention relates to an intermodule bus bar for connecting battery modules, comprising: a metal bar made of an electrically conductive metal material; and an insulator located in a portion of the metal bar excluding both ends, the insulator containing a fire-extinguishing liquid.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0101747 filed on August 16, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an intermodule bus bar that connects battery modules, and more particularly to an intermodule bus bar that has an insulating structure for protecting a metal bar made of an electrically conductive metal material from the outside and a structure containing a fire-extinguishing liquid that can extinguish a fire in the event of a fire. [Background technology]

[0003] Recently, the demand for secondary batteries that can store electrical energy produced by the development of alternative energy sources due to air pollution caused by the use of fossil fuels and energy depletion has increased. Rechargeable secondary batteries are widely used in everyday life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Secondary batteries are used as energy sources for various electronic devices that are essential in modern society, and the required capacity is increasing due to the increasing use and complexity of mobile devices and the development of electric vehicles, etc. To meet user demands, small devices are equipped with multiple battery cells, while automobiles and the like use battery modules that electrically connect multiple battery cells or battery packs equipped with multiple such battery modules.

[0005] Meanwhile, bus bars are widely used as an electrical connection means for the battery modules, and are useful as a large current carrying means because they can stably pass a large current even with a relatively small diameter compared to cables.

[0006] Generally, the bus bar is provided in the form of a metal bar made of copper or aluminum, which has good electrical conductivity, and for safety reasons, the remaining portion of the metal bar, except for both ends connected to the terminals, is covered with a tube or extrusion.

[0007] However, if a fire occurs inside the battery pack, the tube or projectile may be dislodged, exposing the metal bar to the outside and causing contact with surrounding metal objects, resulting in a short circuit.

[0008] Furthermore, there is currently no way to actively deal with fire using only bus bars equipped with heat-resistant insulators that are resistant to fire.

[0009] To solve this problem, the following patent document discloses a bandage means that prevents contact with surrounding metal objects by including an insulating tube 20 that surrounds a ring-shaped or band-shaped metal wire and a bandage member 30A, with the remaining portion of the metal bar 10, excluding both ends, coated with an insulating and fire-resistant material, as shown in Figure 1. However, this is merely a structure that prevents an electrical short circuit caused by a fire, and does not disclose or suggest any fire extinguishing means that can fundamentally extinguish a fire. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2021-0141095 Summary of the Invention [Problem to be solved by the invention]

[0011] In order to solve the above problems, an object of the present invention is to provide an inter-module bus bar that has a fire extinguishing liquid inside an insulator surrounding a metal bar, so that in the event of a fire, the fire extinguishing liquid can leak out and directly extinguish the flames. [Means for solving the problem]

[0012] To achieve the above object, an intermodule busbar according to the present invention includes a metal bar made of an electrically conductive metal material, and an insulator located on the metal bar excluding both ends, and the insulator contains a fire-extinguishing liquid.

[0013] In the intermodule busbar according to the present invention, the insulator has a hole for fitting to the metal bar, and at least one hole is fitted to the metal bar in the length direction.

[0014] In the intermodule bus bar according to the present invention, the plurality of insulators fitted to the metal bar are fixed by being bonded with an adhesive.

[0015] In addition, in the inter-module bus bar according to the present invention, the insulator includes an inner insulating portion surrounding the metal bar and an outer insulating portion surrounding the outer surface of the inner insulating portion excluding the side surfaces, and the inner insulating portion has a space into which the fire-extinguishing liquid is poured.

[0016] In addition, in the intermodule busbar according to the present invention, the space into which the fire-extinguishing liquid is poured is formed between a first insulating layer that is in close contact with the metal bar and a second insulating layer that is in close contact with the outer insulating portion.

[0017] In the inter-module bus bar according to the present invention, the space into which the fire-extinguishing liquid is poured surrounds the entire metal bar.

[0018] In the inter-module busbar according to the present invention, the internal insulating portion may include a first injection hole for injecting the fire-extinguishing liquid, and a first sealing cap for sealing the first injection hole.

[0019] In addition, in the inter-module busbar according to the present invention, the internal insulating part includes a first injection hole for injecting the fire-extinguishing liquid, the external insulating part includes a second injection hole communicating with the first injection hole, and the inter-module busbar further includes a second sealing cap sealing the first injection hole and the second injection hole.

[0020] In the inter-module bus bar according to the present invention, the first insulating layer is thicker than the second insulating layer.

[0021] In the inter-module busbar according to the present invention, the outer insulating portion surrounds an outer surface including a side surface of the inner insulating portion.

[0022] In the inter-module bus bar according to the present invention, the internal insulating portion is made of an expandable heat-resistant silicone material.

[0023] In the inter-module bus bar according to the present invention, the outer insulating portion is made of a heat-resistant silicon material that is ceramicized by heat.

[0024] In the intermodule bus bar according to the present invention, the fire-extinguishing liquid is made of an insulating material. [Effects of the Invention]

[0025] As described above, the intermodule bus bar according to the present invention has the advantage that the fire-extinguishing liquid is contained inside the bus bar, and therefore in the event of a fire, the fire-extinguishing liquid leaks out, allowing the fire to be extinguished quickly.

[0026] Furthermore, according to the intermodule bus bar of the present invention, the insulator for protecting the bus bar from external impact and preventing electrical contact can be manufactured in blocks and fitted to the metal bar according to its length, which has the advantage of reducing the bus bar manufacturing cost and simplifying the manufacturing process.

[0027] Furthermore, the intermodule busbar according to the present invention can effectively deal with various fire causes and environments by injecting different fire extinguishing liquids provided inside the bus depending on the cause and type of fire. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a cross-sectional view of an inter-module bus bar according to the prior art. [Figure 2] 1 is an exploded perspective view of an inter-module bus bar according to a first preferred embodiment of the present invention. [Figure 3] FIG. 3 is a perspective view of the assembly of FIG. 2. [Figure 4] 1 is a perspective view of an inter-module bus bar according to a first preferred embodiment of the present invention. [Figure 5] FIG. 2 is a vertical cross-sectional view of a JJ line of an insulator according to a first preferred embodiment of the present invention. [Figure 6] 1 is a vertical cross-sectional view of a KK line of an insulator according to a first preferred embodiment of the present invention. [Figure 7] FIG. 10 is a perspective view of an inter-module bus bar according to a second preferred embodiment of the present invention. [Figure 8] FIG. 10 is a vertical cross-sectional view of a KK line of an insulator according to a second preferred embodiment of the present invention. [Figure 9] FIG. 10 is a vertical cross-sectional view of a KK line of an insulator according to a third preferred embodiment of the present invention. [Figure 10] FIG. 10 is a vertical cross-sectional view of a KK line of an insulator according to a fourth preferred embodiment of the present invention. [Figure 11] 1 is a cross-sectional view showing a deformed shape in the event of a fire at the lower part of an inter-module bus bar according to a preferred embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0030] Furthermore, the same reference numerals are used throughout the drawings for parts that have similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element between them. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0031] Hereinafter, an inter-module bus bar according to the present invention will be described in detail with reference to the accompanying drawings.

[0032] FIG. 2 is an exploded perspective view of an intermodule bus bar according to a first preferred embodiment of the present invention, FIG. 3 is an example of combining the exploded perspective views of FIG. 2, and FIG. 4 is a perspective view of the intermodule bus bar according to the first preferred embodiment of the present invention.

[0033] 2 to 4, the inter-module bus bar of the present invention comprises a metal bar 100 made of an electrically conductive metal material having fastening holes H at both ends for connecting battery modules, and an insulator 200 fitted to the metal bar 100 except for both ends.

[0034] One end of the metal bar 100 may be connected to the (+) terminal of one battery module, and the other end may be connected to the (-) terminal of the other battery module. For example, the terminals of the battery modules may be configured as bolts, and may be inserted into holes H provided at both ends of the metal bar 100 and then tightened with nuts to firmly secure the connection portions.

[0035] Furthermore, the thickness and width can be determined depending on the magnitude of the current flowing through the electrode, and the electrode can be manufactured in various sizes depending on the installation location or installation conditions.

[0036] On the other hand, the insulator 200 has a structure surrounding the outside of the metal bar 100 and plays a role in protecting the metal bar 100 while maintaining electrical insulation.

[0037] 2 and 3, the insulator 200 has an insertion space B into which the metal bar 100 is inserted, and is fitted in the length direction of the metal bar 100. The insulator 200 is configured in the form of a unit block so that it can be easily fitted to the metal bar 100. This has the advantage that the number of insulators 200 to be fitted can be flexibly adjusted according to the length of the metal bar 100.

[0038] FIG. 4 shows an example in which a plurality of insulators 200 are fitted over the length of the metal bar 100.

[0039] The metal bar 100 can have various sizes and lengths, and therefore, a new bus bar must be designed and manufactured accordingly. However, the insulator 200 of the present invention allows additional insertion of the metal bar 100 by the length thereof, and the shape and size of the metal bar insertion space B of the insulator 200 can be changed, so bus bars of various sizes can be manufactured effectively.

[0040] As shown in FIG. 4, the mated insulators 200 can be fixed in close contact with each other via adhesive 230 at the contacting areas, thereby preventing loose movement and deformation in advance.

[0041] The internal structure of the insulator 200 will now be described in detail with reference to FIGS.

[0042] FIG. 5 is a vertical cross-sectional view of an insulator 200 according to a first preferred embodiment of the present invention taken along line JJ, and FIG. 6 is a vertical cross-sectional view of the insulator 200 taken along line KK.

[0043] 5 and 6, the insulator 200 includes a hole B for fitting onto the metal bar 100, an inner insulating portion 210 surrounding the metal bar, and an outer insulating portion 220 surrounding the inner insulating portion 210.

[0044] The inner insulating part 210 has a doughnut-shaped structure and includes a first insulating layer 211 which is the inner surface surrounding the metal bar insertion space B, a fire-extinguishing liquid injection space S which is shaped to surround the metal bar, and a second insulating layer 212 which is the outer surface.

[0045] 5, the first insulating layer 211 and the second insulating layer 212 are seen as being separated from each other, but are actually formed as a single body as shown in FIG.

[0046] Here, the first insulating layer 211 and the second insulating layer 212 may be configured to have the same thickness, but the second insulating layer 212 may also be configured to be thinner than the first insulating layer 211 in order to maintain the metal bar insertion space B stable and to easily leak the fire-extinguishing liquid to the outside in the event of a flame, as will be described later.

[0047] The second insulating layer 212 has a first injection part 214 including a first injection hole 215 for injecting the extinguishing liquid and a first sealing cap 216 for sealing the first injection hole 215, so that the extinguishing liquid 213 can be injected through the first injection hole 215. After the extinguishing liquid is injected, it is sealed with the first sealing cap 216 to prevent the extinguishing liquid from leaking out.

[0048] Here, the size and shape of the first injection hole are not particularly limited and can be adjusted in consideration of the injection efficiency of the fire-extinguishing liquid, and may be, for example, circular, elliptical, polygonal, such as triangular, rectangular, or amorphous.

[0049] Meanwhile, it is clear that the first insulating layer 211 and the second insulating layer 212 constituting the inner insulating part 210 must be made of a material capable of storing the fire-extinguishing liquid for a long period of time. Preferably, the material is an expandable flame-retardant silicone material that has chemical resistance and expands and melts when heated above a certain temperature by a flame, allowing the internal fire-extinguishing liquid to easily leak out.

[0050] The outer insulating part 220 has a structure surrounding the outer surface of the inner insulating part 210, and according to the first embodiment of the present invention, it has a shape surrounding the outer surface of the inner insulating part 210 except for both side surfaces as shown in FIGS. 5 and 6.

[0051] The material of the outer insulating part 220 is not particularly limited as long as it is preferably refractory silicon that undergoes small cracks while being ceramized when exposed to flames.

[0052] For example, ceramized refractory silicone exhibits the properties of ordinary silicone resin at room temperature, but at high temperatures it transforms into a ceramized structure and exhibits ceramic properties, allowing it to withstand impact while maintaining a certain level of strength.

[0053] The detailed shape change of the insulator 200 due to the flame will be described in detail later with reference to FIG.

[0054] FIG. 7 is a perspective view of an inter-module bus bar according to a second preferred embodiment of the present invention, and FIG. 8 is a vertical cross-sectional view of an insulator 200 according to the second preferred embodiment of the present invention taken along line KK.

[0055] In the first embodiment described above, the fire extinguishing liquid is injected into the inner insulating part 210, sealed with the first sealing cap, and then the outer insulating part 220 is added, so as shown in FIG. 4, it is not possible to inject additional fire extinguishing liquid.

[0056] Meanwhile, as shown in FIGS. 7 and 8, the inter-module busbar according to the second embodiment of the present invention includes a second injection part 224 in which a first injection hole 215 provided in the inner insulating part for injecting a fire-extinguishing liquid and a second injection hole 225 provided in the outer insulating part 220 are integrally connected and sealed by a second sealing cap 226.

[0057] In particular, in the second embodiment, the second injection part 224 can be formed in a post-process after the inner insulating part 210 and the outer insulating part 220, which do not have an injection space for the extinguishing liquid, are manufactured, and therefore the work process can be relatively simplified compared to the first embodiment. In addition, there is an advantage that the insulator 200 can be manufactured without injecting the extinguishing liquid, and the extinguishing liquid can be selectively injected through the second injection part 224 depending on the subsequent use.

[0058] FIG. 9 is a vertical cross-sectional view taken along the line KK of an insulator 200 according to a third preferred embodiment of the present invention, and FIG. 10 is a vertical cross-sectional view taken along the line KK of an insulator 200 according to a fourth preferred embodiment of the present invention.

[0059] As shown in FIGS. 9 and 10, the insulator 200 has a structure in which the outer insulating part 220 completely surrounds the outer surface of the inner insulating part 210, including the side surface (excluding the inner surface of the metal bar insertion space B).

[0060] FIG. 9 shows a third embodiment, which is a modification of the first embodiment, in which the first injection portion 214 is provided only in the inner insulating portion 210, and FIG. 10 shows a fourth embodiment, which is a modification of the second embodiment, in which the second injection portion 224 is provided.

[0061] In particular, when a busbar is constructed using only one insulator 200, in the first and second embodiments, the side of the inner insulating portion 210 is directly exposed to the flame, or if a gap occurs between adjacent insulators 200 bonded by the adhesive 230, they may also be exposed to the flame. Therefore, the third and fourth embodiments have the advantage of being able to compensate for this.

[0062] FIG. 11 is a cross-sectional view showing a deformed shape when a fire occurs below an inter-module bus bar according to a preferred embodiment of the present invention.

[0063] Generally, when a fire occurs inside a battery pack, a large amount of heat and flames are generated, which can cause the insulation of the inter-module bus bar to be lost, resulting in an electrical short circuit with the surrounding area. In particular, the electrical short circuit can form an electrical closed circuit inside the battery pack, which can accelerate thermal runaway inside the pack.

[0064] As shown in Figure 11, Figure 11(a) shows the shape before deformation when a flame breaks out at the bottom of the inter-module bus bar connecting the battery modules, and Figure 11(b) shows the deformed shape of the bus bar after a certain time has passed since the flame broke out.

[0065] 11(b), when a flame occurs and the temperature rises above a certain level, the surface of the outer insulating part 220 forming the exterior of the insulator 200 is ceramicized. At the same time, the inner insulating part 210 expands due to the heat and applies pressure to the ceramicized outer insulating part 220, causing cracks 240 to form on the underside of the outer insulating part 220.

[0066] At this time, the inner insulating part 210, which receives heat through the crack gap 240, melts, and the fire-extinguishing liquid 213 inside flows out through the crack gap 240 of the outer insulating part 220, thereby quickly extinguishing the fire.

[0067] Generally, fire extinguishing is divided into physical fire extinguishing (removal or blocking of oxygen supply sources, ignition energy, combustible materials, etc.) and chemical fire extinguishing, which suppresses the chain reaction of combustion through chemical control. Since the purpose of the present invention is to extinguish a fire inside a sealed battery pack, the fire extinguishing liquid 213 of the present invention preferably has insulating properties and can be a halogen compound fire extinguishing liquid that corresponds to chemical fire extinguishing using a secondary catalytic effect to suppress the chain reaction caused by the fire and extinguish the fire.

[0068] However, since bus bars can be used in a variety of ways depending on the application, and there are various causes of fires, and the fire extinguishing liquid 213 can be easily adopted by an ordinary engineer at the level of an ordinary engineer, the type of fire extinguishing liquid 213 is not limited.

[0069] Hereinafter, a process for manufacturing the inter-module bus bar according to the first embodiment of the present invention will be described.

[0070] First, the method of manufacturing the insulator 200 includes a first step of manufacturing the inner insulating part 210 including the first insulating layer 211, the second insulating layer 212, and the first injection hole 215 by a method such as injection molding; a second step of injecting the fire-extinguishing liquid 213 through the first injection hole 215; a third step of sealing the fire-extinguishing liquid 213 with the first sealing cap 216 to prevent leakage after the injection of the fire-extinguishing liquid 213 is completed; and a fourth step of forming the outer insulating part 220 that surrounds the inner insulating part 210 from the outside.

[0071] The method further includes a fifth step of fitting a plurality of insulators 200 corresponding to the length of the metal bar 100 excluding both ends, and fixing each insulator with an adhesive 230 to fabricate an inter-module bus bar.

[0072] Meanwhile, in the process of manufacturing an inter-module busbar according to the second embodiment of the present invention, the fourth step of forming the outer insulating part 220 is carried out immediately after the first step in the first embodiment, and then the step of injecting and sealing the fire-extinguishing liquid 213 through the second injection part 224 is carried out. The inter-module busbar can also be manufactured by the fifth step.

[0073] Although the present invention has been described above with reference to specific examples, it will be apparent to those skilled in the art that various modifications and variations within the scope of the present invention may be made based on the above teachings. [Explanation of symbols]

[0074] 10, 100 metal bars 20 Insulating tubing 30A Bandage material 200 Insulator 210 Internal insulation 211 First insulating layer 212 Second insulating layer 213 Fire extinguishing liquid 214 1st injection section 215 First injection hole 216 First sealing cap 220 Outer insulation 224 2nd injection section 225 Second injection hole 226 Second sealing cap 230 Adhesive 240 Cracks and Gaps H bolt fastening hole S Fire extinguishing liquid injection space B Metal bar insertion space

Claims

1. a metal bar formed of an electrically conductive metal material; an insulator located on the metal bar except for both ends; An inter-module bus bar for a battery module, comprising: A liquid fire extinguishing agent is contained within the insulator; the insulator includes an inner insulating portion surrounding the metal bar and an outer insulating portion surrounding an outer surface of the inner insulating portion excluding side surfaces, an inter-module bus bar, wherein a space into which the fire extinguishing agent is introduced is provided inside the internal insulating portion.

2. The inter-module bus bar according to claim 1 , wherein the insulator has at least one hole for fitting onto the metal bar in a longitudinal direction of the metal bar.

3. The inter-module bus bar according to claim 2 , wherein the plurality of insulators fitted to the metal bar are fixed by being bonded with an adhesive.

4. 2. The inter-module bus bar according to claim 1, wherein the space into which the fire extinguishing agent is introduced is formed between a first insulating layer that is in close contact with the metal bar and a second insulating layer that is in close contact with the outer insulating portion.

5. The inter-module bus bar according to claim 4 , wherein the space into which the fire extinguishing agent is introduced surrounds the entire metal bar.

6. The inter-module busbar according to claim 1 , wherein the internal insulating portion includes a first injection hole for injecting the fire extinguishing agent, and a first sealing cap for sealing the first injection hole.

7. 2. The inter-module busbar of claim 1, wherein the internal insulating portion includes a first injection hole for injecting the fire extinguishing agent, the external insulating portion includes a second injection hole communicating with the first injection hole, and the inter-module busbar further includes a second sealing cap sealing the first injection hole and the second injection hole.

8. The inter-module busbar of claim 4 , wherein the first insulating layer is thicker than the second insulating layer.

9. The inter-module busbar according to claim 1 , wherein the outer insulation also surrounds sides of the inner insulation.

10. The inter-module busbar of claim 1 , wherein the inner insulation is an expandable heat resistant silicone material.

11. The inter-module busbar according to claim 1 , wherein the outer insulating portion is made of a heat-resistant silicon material that is ceramicized by heat.

12. The inter-module busbar according to claim 1 , wherein the fire extinguishing agent is an insulating material.

13. A battery pack comprising an inter-module busbar according to any one of claims 1 to 12.

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