Busbar assembly and battery pack including said busbar assembly

Abstract

A bus bar assembly according to an embodiment of the present invention includes a bus bar including a body portion and end portions extending from both ends of the body portion and having through holes formed therein, an insulating layer surrounding the body portion, and a cover plate covering the insulating layer and the end portions and having an integral shape.

Description

Technical Field

[0001] The present invention relates to a bus bar assembly and a battery pack including the bus bar assembly, and more specifically, to a bus bar assembly in which carbon gas is easily discharged and a cap is unnecessary, and a battery pack including the bus bar assembly.

Background Art

[0002] In modern society, as the use of portable devices such as mobile phones, notebook computers, video cameras, and digital cameras has become common, technological development in fields related to such mobile devices has become active. In addition, rechargeable secondary batteries are a measure for solving air pollution such as existing gasoline vehicles that use fossil fuels, and are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc. Therefore, the need for development of secondary batteries is increasing.

[0003] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among these, lithium secondary batteries are attracting attention because they hardly cause a memory effect compared to nickel-based secondary batteries, can be freely charged and discharged, have a very low self-discharge rate, and have a high energy density.

[0004] Such lithium secondary batteries mainly use a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate coated with such positive electrode active material and negative electrode active material are arranged with a separator interposed therebetween, and a battery case that hermetically stores the electrode assembly together with an electrolytic solution.

[0005] Generally, lithium secondary batteries are classified into can-type secondary batteries in which an electrode assembly is built into a metal can and pouch-type secondary batteries in which an electrode assembly is built into a pouch of an aluminum laminate sheet according to the shape of the exterior material.

[0006] In the case of secondary batteries used in small devices, two or three battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module is used in which multiple battery cells are electrically connected. In such battery modules, the capacity and output are improved by connecting multiple battery cells in series or parallel to each other to form a stack of battery cells. Furthermore, one or more battery modules can be mounted together with various control and protection systems such as a BDU (Battery Disconnect Unit), a BMS (Battery Management System), and a cooling system to form a battery pack.

[0007] In battery packs, where multiple battery modules are combined, the heat generated by the multiple battery cells can combine in a confined space, causing the temperature to rise rapidly and drastically. In other words, while battery modules with stacked battery cells and battery packs equipped with such modules can achieve high output, if the heat dissipation of the battery cells is not properly carried out and thermal runaway occurs, there is a high possibility of continuous ignition and subsequent explosion.

[0008] On the other hand, the battery pack contains busbars that connect to the battery modules.

[0009] Figure 1 shows exploded perspective and assembled perspective views of a conventional busbar assembly.

[0010] Referring to Figure 1, a conventional busbar assembly 10 includes a busbar 20, a covering 20C surrounding the busbar 20, a cap CP, and tape AL for securing the cap CP. The busbar 20 is a rod-shaped metal member extending along its longitudinal direction. Through-holes HH are formed at both ends of the busbar 20 for connection to the terminal busbars of the battery module. Such a busbar 20 is configured to handle HV (High Voltage) connections in a battery pack. HV connections refer to the connection of power sources for supplying power, and the busbar 20 is configured to guide the electrical connections of the battery module and generally contains a metal material with excellent electrical conductivity. As an example, the busbar 20 may contain copper (Cu) material.

[0011] The covering 20C can surround the busbar 20. The covering 20C may contain an electrically insulating material, such as silicone or epoxy. Because the covering 20C surrounds the busbar 20 through which high current flows, it prevents the busbar 20 from coming into contact with the terminal busbar of the battery module, as well as other electrical components or conductive materials, which could cause a short circuit.

[0012] A fastening member is inserted into the through-hole HH of the busbar 20, allowing the busbar 20 to be connected to the terminal busbar of the battery module. For insulation, caps CP are attached to both ends of the busbar 20. The caps CP may be, for example, rubber caps. The caps CP can be attached to the covering 20C using tape AL.

[0013] However, when a flame occurs inside the battery pack, the flame's temperature is extremely high, around 1000°C. This can cause the covering 20C surrounding the busbar 20 to melt, or the cap CP and tape AL to melt, exposing the busbar 20. If the exposed busbar 20 comes into contact with other conductive materials and causes a short circuit, the internal flame can spread further, potentially reaching the outside of the battery pack. Ultimately, this can lead to the explosion of the battery pack or the vehicle in which it is installed.

[0014] Therefore, there is a need for technological development of busbar assemblies that can maintain electrical insulation even if a flame occurs inside the battery pack. [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] The problem that the present invention aims to solve is to provide a busbar assembly that can maintain electrical insulation without melting even if a flame is generated inside the battery pack, and a battery pack including said busbar assembly.

[0016] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly extended within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0017] A busbar assembly according to one embodiment of the present invention includes a body portion, busbars extending from both ends of the body portion and having through holes formed therein, an insulating layer surrounding the body portion, and a cover plate covering the insulating layer and the ends and having an integral shape.

[0018] The cover plate can expose one surface of the insulating layer.

[0019] The shape of the cover plate on a plane is provided along the outer perimeter of the insulating layer and the edge.

[0020] The shape of the cover plate on the side surface is provided along the outer casing of the insulating layer and the end.

[0021] The cover plate may include a top surface, two short sides positioned in the direction of the short side of the busbar, and two long sides positioned in the direction of the long side of the busbar and formed in accordance with the shape of the insulating layer and the end.

[0022] The cover plate may include an upper surface formed in accordance with the shape of the insulating layer and the end, two short sides arranged in the direction of the short side of the busbar, one long side arranged in the direction of the long side of the busbar, and a lower surface facing the upper surface and formed in accordance with the shape of the insulating layer.

[0023] The insulating layer may be one that is ceramicized at high temperatures.

[0024] A battery pack according to one embodiment of the present invention includes the busbar assembly, battery modules, a BDU (battery disconnect unit) module for controlling the electrical connections of the battery modules, and a BMS (Battery Management System) module for monitoring and controlling the operation of the battery modules, wherein at least one of the busbar assemblies electrically connects at least one of the following: between the battery modules, between the battery modules and the BDU module, between the battery modules and the BMS module, and between the BDU module and the BMS module.

[0025] The present invention further includes fastening portions that are coupled to the through-holes of the at least one busbar assembly, and the cover plate can cover the fastening portions.

[0026] The battery module includes a first battery module, a second battery module adjacent to the first battery module, a third battery module facing the first battery module, and a fourth battery module adjacent to the third battery module and facing the second battery module. At least one busbar assembly includes a first busbar assembly connecting the first battery module and the second battery module, and a second busbar assembly connecting the third battery module and the fourth battery module and facing the first busbar. The lower surface of the first busbar assembly is exposed from the cover plate, and one side of the second busbar assembly can be exposed from the cover plate.

[0027] The exposed lower surface of the first busbar assembly faces the first battery module and the second battery module, and the exposed one side surface of the second busbar assembly can face the third battery module and the fourth battery module.

Advantages of the Invention

[0028] The busbar assembly of the present invention includes a cover plate that can replace the cap, thereby improving insulation and fire resistance.

[0029] When the busbar assembly of the present invention is exposed to flames, the gas generated inside can be easily discharged to the outside.

[0030] The effects of the present invention are not limited to the effects described above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Brief Description of the Drawings

[0031] [Figure 1] Exploded perspective view and assembled perspective view of a conventional busbar assembly. [Figure 2] Plan view of a battery pack of an embodiment. [Figure 3] Perspective view of one of the battery modules included in the battery pack of FIG. 2. [Figure 4] Partial perspective view showing the state where the module frame and end plate are removed with respect to the battery module of FIG. 3. [Figure 5] Perspective view of a busbar of an embodiment. [Figure 6] Perspective view of a busbar provided with an insulating layer of an embodiment. [Figure 7] Exploded perspective view of a busbar assembly of an embodiment. [Figure 8] Plan view of a busbar assembly of an embodiment. [Figure 9] Side view of a busbar assembly of an embodiment. [Figure 10] This is a cross-sectional view of a busbar assembly in one embodiment. [Figure 11] This is a cross-sectional view of a busbar assembly in one embodiment. [Figure 12] This is an exploded perspective view of a busbar assembly in one embodiment. [Figure 13] This is a plan view of a busbar assembly in one embodiment. [Figure 14] This is a side view of a busbar assembly in one embodiment. [Figure 15] This is a cross-sectional view of a busbar assembly in one embodiment. [Figure 16] This is a cross-sectional view of a busbar assembly in one embodiment. [Figure 17] This is a side view of a busbar assembly connecting battery modules according to one embodiment. [Figure 18] This is a side view of a busbar assembly connecting battery modules according to one embodiment. [Figure 19] This is a plan view of a busbar assembly connecting battery modules according to one embodiment. [Modes for carrying out the invention]

[0032] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be realized in a variety of different forms and is not limited to the embodiments described herein.

[0033] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0034] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for the sake of explanation, and therefore the present invention is not necessarily limited to those shown. In the drawings, the thicknesses are shown enlarged to clearly represent various layers and regions. Also, in the drawings, the thicknesses of some layers and regions are shown exaggerated for the sake of explanation.

[0035] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on top" of another part, this includes not only the case where it is "directly above" the other part, but also the case where the other part is in between. When we say that one part is "directly above" another part, it means that there is no other part in between. Note that being "on top" of a reference part means being located above or below the reference part, and does not necessarily mean being located "up" in the opposite direction of gravity.

[0036] Furthermore, when a specification as a whole states that a certain part "includes" a certain component, this means, unless otherwise stated, that it can further include other components rather than excluding them.

[0037] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0038] Furthermore, throughout the specification, the first direction DR1, the second direction DR2, and the third direction DR3 are used as relative concepts. The first direction DR1, the second direction DR2, and the third direction DR3 can intersect perpendicularly to each other.

[0039] Throughout the specification, the concepts of top and bottom are explained as being defined along the third direction DR3. Therefore, "thickness" in the specification refers to the length measured along the third direction DR3.

[0040] Figure 2 is a plan view of a battery pack according to one embodiment.

[0041] Referring to Figure 2, a battery pack 1000 according to one embodiment includes a busbar assembly 100, a pack frame 1100, battery modules 1200, a BDU (battery disconnect unit) module 1300 for controlling the electrical connections of the battery modules 1200, and a BMS (Battery Management System) module 1400 for monitoring and controlling the operation of the battery modules 1200. In this embodiment, at least one busbar assembly 100 electrically connects at least one of the following: between battery modules 1200, between battery modules 1200 and BDU modules 1300, between battery modules 1200 and BMS modules 1400, and between BDU modules 1300 and BMS modules 1400. Specifically, multiple battery modules 1200 are housed in the pack frame 1100, and the electric connections between the battery modules 1200 and between battery modules 1200 and BDU modules 1300 are made by the busbar assembly 100. In other words, the busbar assembly 100 according to this embodiment can handle HV (High Voltage) connections. Here, HV connection refers to a connection of power sources that supply power requiring high voltage, and means connections between battery cells or connections between battery modules.

[0042] On the other hand, the BDU module 1300 is a component for controlling the electrical connection of the battery module 1200, and can interrupt the power supply between the power converter and the battery module 1200. The BDU module 1300 can ensure the safety of the battery pack 1000 by interrupting the power supply to the battery pack 1000 when conditions occur in which the current exceeds a set range.

[0043] On the other hand, the LV connecting member 100' according to this embodiment can handle the electrical connection between the battery module 1200 and the BMS module 1400. Here, the electrical connection refers to an LV (Low voltage) connection, meaning a sensing connection for detecting and controlling the voltage and temperature of the battery module 1200. Specifically, sensors such as those inside the battery module 1200 are arranged, and real-time temperature and voltage information of the battery module 1200 is transmitted to the BMS module 1400 via the LV connecting member 100'. The real-time operating state of the battery module 1200 can be monitored and controlled via the BMS module 1400. Although not specifically shown, an HV current sensor may be integrated into the BMS module 1400. In this case, the busbar assembly according to this embodiment can handle the electrical connection between the battery module 1200 and the BMS module 1400, or between the BDU module 1300 and the BMS module 1400.

[0044] The battery module 1200 according to this embodiment will be described below with reference to Figures 3 and 4. However, the battery module 1200 described below is one exemplary structure of a battery module including multiple battery cells 11, and various forms of battery modules including multiple battery cells are applicable.

[0045] Figure 3 is a perspective view showing one of the battery modules included in the battery pack shown in Figure 2.

[0046] Figure 4 is a partial perspective view showing the battery module from Figure 3 with the module frame and end plate removed.

[0047] Referring to Figures 3 and 4, the battery module 1200 according to this embodiment may include a battery cell stack 11A in which multiple battery cells 11 are stacked. The battery cell stack 11A is shown in Figure 4. Such a battery cell stack 11A is housed in a module frame 30 and an end plate 40.

[0048] The battery cell 11 may be a pouch-type battery cell. Such a pouch-type battery cell is formed by housing an electrode assembly in a pouch case made of a laminate sheet containing a resin layer and a metal layer, and then fusing the outer periphery of the pouch case. Such a battery cell 11 is formed in a rectangular sheet structure. The electrode leads 11L connected to the electrode assembly protrude to the outside of the pouch case, but the electrode leads 11L of each battery cell 11 are electrically connected to each other via a lead busbar 21. On the other hand, at least one electrode lead 11L is connected to a terminal busbar 22. A portion of the terminal busbar 22 can be exposed to the outside of the battery module 1200, as shown in Figure 3. Both the lead busbar 21 and the terminal busbar 22 can include a metal material with excellent electrical conductivity.

[0049] The busbar assembly 100 according to this embodiment is electrically connected to such a terminal busbar 22, and the above-described HV connection is made. In other words, the battery module 1200 is electrically connected to other battery modules 1200, BDU modules 1300, or BMS modules 1400 via the busbar assembly 100 connected to the terminal busbar 22.

[0050] The following describes a busbar assembly according to one embodiment, with reference to Figures 5 to 11.

[0051] Figure 5 is a perspective view of a busbar in one embodiment.

[0052] Referring to Figure 5, the busbar 200 guides the electrical connections within the battery pack 1000 (see Figure 2). The busbar 200 is configured to guide the electrical connections, i.e., HV connections, of the battery module 1200 (see Figure 2), and may include a metal material with excellent electrical conductivity. For example, the busbar 200 may be made of copper (Cu). The body portion 210 may have a rod shape extending in one direction. Figure 2 shows, as an example, the busbar 200 having a rod shape extending in the first direction DR1.

[0053] In one embodiment, the busbar 200 includes a body portion 210 and end portions 220. The body portion 210 may correspond to the central part of the busbar 200. The end portions 220 extend from both ends of the body portion 210. For example, the end portions 220 may extend from both ends of the body portion 210 in a first direction DR1 and in the opposite direction to the first direction DR1. For convenience, in this specification, the busbar 200 has been described as including a body portion 210 and end portions 220, but the body portion 210 and end portions 220 have a single, integrated shape.

[0054] A through-hole HH is formed in the end portion 220. A fastening member is inserted into the through-hole HH to connect the busbar 200 to an external electrical device. For example, a bolt can be inserted into the through-hole HH of the end portion 220 to connect the busbar 20 and the terminal busbar 22 (see Figure 3) of the battery module 1200 (see Figure 3).

[0055] Figure 6 is a perspective view of a busbar provided with an insulating layer according to one embodiment.

[0056] Referring to Figure 6, the insulating layer 300 surrounds the body portion 210 of the busbar 200 (see Figure 5). In other words, the insulating layer 300 can surround the outer surface of the busbar 200, excluding the end portion 220. The end portion 220 is exposed from the insulating layer 300 and is electrically connected to the terminal busbar 22 of the battery module 1200 (see Figure 4).

[0057] The insulating layer 300 may contain refractory silicone. For example, the insulating layer 300 is formed by molding refractory silicone onto the outer surface of the body portion 210 (Figure 5) of the busbar 200. Unlike general silicone materials that are exposed to flames or burn at high temperatures, refractory silicone is ceramicized at high temperatures. Therefore, when exposed to flames, refractory silicone can be ceramicized without burning, maintaining its insulating properties to the busbar 200. For example, refractory silicone is ceramicized at temperatures between 500 degrees Celsius and 1700 degrees Celsius. However, the temperature range in which refractory silicone is ceramicized is not limited to this.

[0058] Refractory silicones can contain silicone polymers and silica. For example, the silicone polymer used may be a polysiloxane compound having a vinyl group as a functional group, and can serve as the base material for the refractory silicone material. For example, the silica used may be a reinforcing filler contained in the silicone polymer, and may be fumed silica. High-purity silicon chloride (SiCl4) compounds can be produced by reaction with hydrochloric acid and purification processes using metallic silicon as the main raw material, and fumed silica can be obtained by reacting this high-purity silicon chloride (SiCl4) compound with hydrogen and oxygen in a high-temperature flame. Refractory silicones can also contain platinum (Pt) as a catalyst.

[0059] When refractory silicone is exposed to flames or high temperatures, the silicone polymer decomposes and the silica (SiO2) crosslinks, forming a ceramic material. In one embodiment, the insulating layer 300 containing refractory silicone can maintain its electrical insulation properties by ceramicizing rather than burning or melting, even when exposed to flames or placed in a high-temperature environment.

[0060] Therefore, the insulating layer 300 insulates the body portion 210 (see Figure 5) of the busbar 200 even from flames and high temperatures, preventing the busbar 200 from coming into contact with other electrical components or conductive members and causing a short circuit.

[0061] Figure 7 is an exploded perspective view of a busbar assembly in one embodiment.

[0062] Referring to Figure 7, one embodiment of the busbar assembly 100 may include a busbar 200, an insulating layer 300, and a cover plate 400. For convenience of explanation, Figure 7 also shows fastening members BT that connect to the end 220 of the busbar 200. A bolt is shown as an example of a fastening member BT.

[0063] The cover plate 400 of the present invention covers the insulating layer 300 and the end portion 220 and has a single, integrated shape.

[0064] The cover plate 400 of the present invention may contain mica. The cover plate 400 may be a thermoformed mica plate formed by heat-pressing with a high-temperature press. The cover plate 400 is provided in an assembly manner without a separate adhesive layer by being thermoformed to match the outer shape of the busbar 200 and the insulating layer 300. Furthermore, compared to soft mica tape or sheet-shaped mica, the cover plate 400 of the present invention can maintain a rigid outer shape and physically protect the internal structure.

[0065] The cover plate 400 has excellent fire resistance, heat resistance, high temperature resistance, and electrical insulation properties, and can maintain the insulation of the busbar assembly 100 without burning in flames or high temperatures. Therefore, the cover plate 400 can block the insulating layer 300 from being directly exposed to flames when flames occur. In addition, the cover plate 400 can physically protect and insulate the end 220 and the fastening member BT connected to the end 220. The cover plate 400 can replace the cap CP (see Figure 1) and tape AL included in the conventional busbar assembly 10.

[0066] In one embodiment, the cover plate 400 may include a top surface TF, two short sides SF1 and SF2, and two long sides SF3 and SF4. In one embodiment, the cover plate 400 may not include another bottom surface. This allows the cover plate 400 to be assembled to the busbars 200 and the insulating layer 300 in the planar direction. The shape of the cover plate 400 in the planar direction can match the shape of the insulating layer 300 and the end 220.

[0067] In one embodiment of the cover plate 400, the top surface TF may have a planar shape. For example, the top surface TF may be a plane parallel to the plane formed by the first direction DR1 and the second direction DR2. Two short sides SF1 and SF2 are arranged in the direction of the short side of the bus bar 200. Two long sides SF3 and SF4 are arranged in the direction of the long side of the bus bar 200. The two long sides SF3 and SF4 may be formed along the shape of the insulating layer 300 and the end 220. The cover plate 400 is assembled to the bus bar 200 and the insulating layer 300 by thermoforming the two long sides SF3 and SF4 to match the outer shape of the bus bar 200 and the insulating layer 300 without the need for another adhesive layer.

[0068] Since the third height t3 of the cover plate 400 is greater than the first height t1 of the busbar 200 and the second height t2 of the insulating layer 300, the insulating layer 300 and the end 220 can be adequately accommodated in the third direction DR3.

[0069] The underside of the assembled busbar assembly 100 can be exposed from the cover plate 400. The underside of the busbar assembly 100 can contact the terminal busbar 22 of the battery module 1200 (see Figure 3). A further explanation of this will follow later.

[0070] Figure 8 is a plan view of a busbar assembly according to one embodiment.

[0071] Referring to Figure 8, the shape of the busbar assembly 100 in a plane may be the shape of the cover plate 400 in a plane. The shape of the cover plate 400 in a plane may be provided along the outer perimeter of the insulating layer 300 and the end 220. The cover plate 400 may have a first width L1 and a second width L2 in a plane. The first width L1 may be the length to cover the end 220 (see Figure 7). The second width L2 may be the length to cover the insulating layer 300 (see Figure 7). The second width L2 may be greater than the first width L1. On the other hand, in this specification, the width may be the length measured in a second direction DR2.

[0072] Figure 9 is a side view of a busbar assembly according to one embodiment.

[0073] Referring to Figure 9, the shape of the busbar assembly 100 on the side surface may be the shape of the cover plate 400 on the side surface. On the side surface, the cover plate 400 in one embodiment may have a rectangular shape. The thickness of the cover plate 400 may be a third thickness t3. Specifically, the cover plate 400 may have a constant thickness along the first direction DR1, which is the longitudinal direction.

[0074] Referring together to Figures 7, 8, and 9, the busbar assembly 100 in one embodiment may be assembled by fitting the cover plate 400 on a flat surface to match the shape of the insulating layer 300 and the end portion 220.

[0075] Figure 10 is a cross-sectional view of a busbar assembly according to one embodiment.

[0076] Referring to Figure 10, in the cross-section corresponding to the A-A' cutting line, the inner surface of the cover plate 400 can contact the end portion 220. Specifically, the cover plate 400 can contact the side surface of the end portion 220. Because the third height t3 of the cover plate 400 is greater than the first height t1 of the end portion 220, the cover plate 400 can adequately accommodate the end portion 220 and the bolt BT inside. The terminal busbar 22 (see Figure 3) of the battery module 1200 (see Figure 3) is connected to the lower part of the end portion 220 and the bolt BT.

[0077] Figure 11 is a cross-sectional view of a busbar assembly according to one embodiment.

[0078] Referring to Figure 11, in the cross-section corresponding to the B-B' cutting line, the inner surface of the cover plate 400 can contact the insulating layer 300. Specifically, the inner surface of the cover plate 400 can contact the side surface of the insulating layer 300. Because the third height t3 of the cover plate 400 is greater than the second height t2 of the insulating layer 300, the cover plate 400 can adequately accommodate the busbar 200 and the insulating layer 300 inside.

[0079] Referring together to Figures 10 and 11, the cover plate 400 of the present invention has a first width L1 and a second width L2 that are different from each other on a plane. The first width L1 is a width that takes into account the outer shape of the end 220 of the bus bar 200, and the second width L2 is a width that takes into account the outer shape of the insulating layer 300. As a result, the cover plate 400 is fitted and bonded to the bus bar 200 and the insulating layer 300 on a plane without the need for another adhesive layer.

[0080] On the other hand, the embodiments of the cover plate 400 are not limited thereto.

[0081] Figure 12 is an exploded perspective view of a busbar assembly in one embodiment.

[0082] Referring to Figure 12, the busbar assembly 100-a of one embodiment may include a busbar 200, an insulating layer 300, and a cover plate 400-a. For convenience of explanation, Figure 12 also shows fastening members BT that connect to the end 220 of the busbar 200. A bolt is shown as an example of a fastening member BT.

[0083] The cover plate 400-a shown in Figure 12 may have a different shape from the cover plate 400 shown in Figure 7. Specifically, in one embodiment, the cover plate 400-a may match the shape of the insulating layer 300 and the end portion 220 on its side surface.

[0084] In one embodiment, the cover plate 400-a may include a top surface TF, two short sides SF1 and SF2, one long side SF3, and a bottom surface BF. That is, compared to the cover plate 400 shown in Figure 7, the cover plate 400-a may omit one long side SF4 (see Figure 7) and further include a bottom surface BF. In this way, the cover plate 400-a is assembled to the busbar 200 and the insulating layer 300 in the lateral direction. The shape of the cover plate 400 in plan can match the shape of the insulating layer 300 and the end 220.

[0085] In one embodiment of the cover plate 400-a, the upper surface TF is formed along the shape of the insulating layer 300 and the end portion 220. Specifically, the upper surface TF is formed along the upper surface of the insulating layer 300 and the upper surface of the end portion 220, including a step. Two short sides SF1 and SF2 are arranged in the direction of the short side of the bus bar 200. One long side SF3 is arranged in the direction of the long side of the bus bar 200. In one embodiment, the one long side SF3 may cover one side of the insulating layer 300 and the end portion 220. The lower surface BF may cover the lower surface of the insulating layer 300. The lower surface of the end portion 220 of the bus bar 200 is exposed from the cover plate 400 and can contact the terminal bus bar 22 of the battery module 1200 (see Figure 3).

[0086] In one embodiment, the cover plate 400-a has one side omitted, and the top surface TF is thermoformed to match the outer shape of the bus bar 200 and insulating layer 300, thereby assembling and joining it to the bus bar 200 and insulating layer 300 in the lateral direction. In other words, the cover plate 400-a is fastened to the bus bar 200 and insulating layer 300 without the need for another adhesive layer.

[0087] Furthermore, the material, forming method, insulation properties, and heat resistance properties of the cover plate 400-a are the same as those described above for the cover plate 400 in Figure 7.

[0088] Figure 13 is a plan view of a busbar assembly according to one embodiment.

[0089] Referring to Figure 13, the shape of the busbar assembly 100-a on a plane may be the shape of the cover plate 400-a on a plane. On a plane, the cover plate 400-a may have a rectangular shape. In this case, the cover plate 400-a may have a third width L3. Specifically, the cover plate 400-a may have a constant width along the first direction DR1, which is the longitudinal direction.

[0090] Figure 14 is a side view of a busbar assembly according to one embodiment.

[0091] Referring to Figure 14, the shape of the busbar assembly 100-a on the side may be the shape of the cover plate 400-a on the side. The shape of the cover plate 400-a on the side may be provided along the outer perimeter of the insulating layer 300 and the end 220. The cover plate 400-a may have a fourth thickness t4 and a fifth thickness t5 on the side. The fourth thickness t4 may be the thickness necessary to cover the end 220 (see Figure 12) and the bolt BT. The fifth thickness t5 may be the length necessary to cover the insulating layer 300 (see Figure 12). The fifth thickness t5 may be greater than the fourth thickness t4.

[0092] Figure 15 is a cross-sectional view of a busbar assembly according to one embodiment.

[0093] Referring to Figure 15, in the cross-section corresponding to the C-C' cutting line, the inner surface of the cover plate 400-a can be separated from the end 220 by a predetermined gap GP in the second direction DR2. Since the cover plate 400-a includes only one long side surface SF3 (see Figure 12), one side of the end 220 can be exposed from the cover plate 400-a. On the other hand, the exposed side of the end 220 is assembled to face the battery module 1200 (see Figure 3), so it can be physically protected from external flames.

[0094] The end portion 220 and bolt BT are housed inside the cover plate 400-a. Since the fourth height t4 of the cover plate 400-a is greater than the first height t1 of the end portion 220, the cover plate 400-a can adequately accommodate the end portion 220 and bolt BT inside. The terminal busbar 22 (see Figure 3) of the battery module 1200 (see Figure 3) is connected to the lower part of the end portion 220 and bolt BT.

[0095] Figure 16 is a cross-sectional view of a busbar assembly according to one embodiment.

[0096] Referring to Figure 16, in the cross-section corresponding to the D-D' cutting line, the inner surface of the cover plate 400-a can contact the insulating layer 300. Specifically, the inner surface of the cover plate 400-a can contact one side of the insulating layer 300. Since the cover plate 400-a includes only one long side SF3 (see Figure 12), one side 300-SF of the insulating layer 300 can be exposed from the cover plate 400-a. As one side 300-SF of the insulating layer 300 is exposed, if a flame occurs inside, the gas generated from the insulating layer 300 can be easily discharged to the outside.

[0097] On the other hand, since the cover plate 400-a is fitted onto the insulating layer 300 and the busbar 200 on its side, the inner surface of the cover plate 400-a can contact the insulating layer 300 in the third direction DR3. Therefore, the fifth thickness t5 of the cover plate 400-a can be set taking into account the second thickness t2 of the insulating layer 300.

[0098] Referring together to Figures 12, 15, and 16, the cover plate 400-a of the present invention includes only one long side SF3 (see Figure 12), with the other long side being omitted, and is fitted onto the insulating layer 300 and busbar 200 in the lateral direction. The cover plate 400-a also has a fourth thickness t4 and a fifth thickness t5 that are different from each other on the side. The fourth thickness t4 is the thickness for accommodating the end 220 and bolt BT of the busbar 200, and the fifth thickness t5 is the thickness that takes into account the outer shape of the insulating layer 300. As a result, the cover plate 400-a is fitted and bonded to the busbar 200 and insulating layer 300 on the side without any additional adhesive layer.

[0099] The cover plate 400-a of the present invention can improve the fire resistance and insulation of the busbar assembly 100 without a separate cap by extending and covering from the insulating layer 300 to the end 220 of the busbar 200.

[0100] Figure 17 is a side view of a busbar assembly connecting battery modules in one embodiment.

[0101] Referring to Figure 17, the busbar assembly 100 of one embodiment can electrically connect adjacent first battery module 1200-a and second battery module 1200-b. The busbar assembly 100 includes a cover plate 400 (see Figure 7) of one embodiment. As described above in Figures 7 to 11, the lower surface of the busbar assembly 100 is exposed from the cover plate 400 (see Figure 7) and electrically connected to the first battery module 1200-a and the second battery module 1200-b.

[0102] When the busbar assembly 100 is exposed to flames and becomes hot, gas may be generated in the insulating layer 300 (see Figure 7). The gas generated in the insulating layer 300 can accelerate internal flames, impede the structural stability of the busbar assembly 100, and adversely affect the insulation performance of the busbar 200. In addition, the gas generated in the insulating layer 300 contains carbonized components, and if these carbonized components accumulate internally, they can adversely affect electrical insulation. In the busbar assembly 100 of the present invention, the lower surface is exposed from the cover plate 400 (see Figure 7), so the gas generated in the insulating layer 300 can be easily discharged to the outside.

[0103] Figure 18 is a side view of a busbar assembly connecting battery modules in one embodiment.

[0104] Referring to Figure 18, the busbar assembly 100-a of one embodiment can electrically connect the adjacent third battery module 1200-c and fourth battery module 1200-d. The busbar assembly 100-a includes the cover plate 400-a of one embodiment (see Figure 12), so that its lower surface is electrically connected to the third battery module 1200-c and fourth battery module 1200-d.

[0105] As described above in Figures 12 to 16, one side of the busbar assembly 100-a can be exposed from the cover plate 400-a (see Figure 12). The exposed side of the busbar assembly 100-a is assembled to face the third battery module 1200-c and the fourth battery module 1200-d, providing physical protection from external flames. Furthermore, while the exposed side of the busbar assembly 100-a is protected from external flames, gases generated inside the busbar assembly 100-a can be vented to the outside.

[0106] Figure 19 is a plan view of a busbar assembly connecting battery modules in one embodiment.

[0107] Figure 19 shows the first to fourth battery modules 1200-a, 1200-b, 1200-c, and 1200-d, the first busbar assembly 100, and the second busbar assembly 100-a. Figure 19 shows the first battery module 1200-a and the second battery module 1200-b, described above in Figure 17, arranged opposite the third battery module 1200-c and the fourth battery module 1200-d, described above in Figure 18. The first busbar assembly 100 is the same busbar assembly 100 described above in Figure 17. The second busbar assembly 100-a is the same busbar assembly 100-a described above in Figure 18.

[0108] Referring to Figure 19, when two busbar assemblies 100 and 100-a are placed adjacent to each other, one of the two will be the busbar assembly 100 shown in Figure 7, and the other will be the busbar assembly 100-a shown in Figure 12. In other words, the first busbar assembly 100 has a structure in which its lower surface is exposed from the cover plate 400 (see Figure 7), and the second busbar assembly 100-a has a structure in which one side surface is exposed from the cover plate 400-a (see Figure 12). As a result, one side surface of the cover plate 400 (see Figure 7) is positioned between the two busbar assemblies 100 and 100-a, preventing short circuits from occurring between them.

[0109] Furthermore, the exposed lower surface of the first busbar assembly 100 faces the first battery module 1200-a and the second battery module 1200-b. Therefore, during flame, the gas emitted from the first busbar assembly 100 does not directly affect the second busbar assembly 100-a. Also, one exposed side of the second busbar assembly 100-a is positioned to face the third battery module 1200-c and the fourth battery module 1200-d. Therefore, during flame, the gas emitted from the second busbar assembly 100-a does not directly affect the first busbar assembly 100.

[0110] The busbar assembly of the present invention can improve insulation and fire resistance by including a cover plate that can replace the cap. Furthermore, when exposed to flames, the busbar assembly of the present invention can easily discharge gases generated inside to the outside while maintaining the fire resistance, insulation, and stability of adjacent busbar assemblies and preventing the propagation of flames.

[0111] In this embodiment, terms indicating direction such as front, back, left, right, up, and down were used, but such terms are merely for the convenience of explanation and will differ depending on the position of the object being examined, the observer's position, etc.

[0112] One or more battery modules according to the above-described embodiment can be mounted together with various control and protection systems such as a BMS (Battery Management System), a BDU (Battery Disconnect Unit), and a cooling system to form a battery pack.

[0113] The aforementioned battery modules and battery packs can be applied to a variety of devices. Specifically, they can be applied to transportation methods such as electric bicycles, electric vehicles, and hybrids, as well as ESS (Energy Storage Systems), but are not limited to these, and can be applied to a variety of devices that can use secondary batteries.

[0114] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art that utilize the basic concepts of the present invention as defined in the following claims also fall within the scope of the present invention. [Explanation of Symbols]

[0115] 100, 100-a: Busbar assembly 200: Bus bar 300: Insulating layer 400, 400-a: Cover plate 1000: Battery pack 1100: Pack Frame 1200: Battery module 1300: BDU Module 1400: BMS module

Claims

1. A busbar assembly for attachment to a battery module, A busbar comprising a body portion and ends extending from both ends of the body portion, each having a through-hole for inserting a fastening member, An insulating layer surrounding the aforementioned body portion, A single cover plate that covers the insulating layer and the end portion, and forms a space that houses the insulating layer, the end portion, and the fastening member inside, In a busbar assembly including, The cover plate is a busbar assembly that exposes one side of the insulating layer facing the battery module.

2. The busbar assembly according to claim 1, wherein the shape of the cover plate on a plane is provided along the outer casing of the insulating layer and the end.

3. The busbar assembly according to claim 1, wherein the shape of the cover plate on the side surface is provided along the outer casing of the insulating layer and the end.

4. The aforementioned cover plate is Top surface and, The two short sides of the busbar are arranged in the direction of the short side, The busbar assembly according to claim 1, comprising: two long sides arranged in the longitudinal direction of the busbar and formed in accordance with the shape of the insulating layer and the end.

5. The aforementioned cover plate is The insulating layer and the upper surface formed in accordance with the shape of the end, The two short sides of the busbar are arranged in the direction of the short side, One long side of the busbar is positioned in the direction of its long side, The busbar assembly according to claim 1, further comprising: a lower surface facing the upper surface and formed in accordance with the shape of the insulating layer.

6. The busbar assembly according to claim 1, wherein the insulating layer has the property of being ceramicized at high temperatures.

7. A busbar assembly according to any one of claims 1 to 6, Battery module and A BDU (battery disconnect unit) module for controlling the electrical connection of the battery module, It includes a BMS (Battery Management System) module that monitors and controls the operation of the battery module, A battery pack in which at least one of the busbar assemblies electrically connects at least one of the following: between the battery modules, between the battery modules and the BDU module, between the battery modules and the BMS module, and between the BDU module and the BMS module.

8. It further includes fastening portions that are coupled to the through-holes of at least one of the busbar assemblies, The battery pack according to claim 7, wherein the cover plate covers the fastening portion.

9. The battery module includes a first battery module, a second battery module adjacent to the first battery module, a third battery module facing the first battery module, and a fourth battery module adjacent to the third battery module and facing the second battery module. At least one of the busbar assemblies includes a first busbar assembly connecting the first battery module and the second battery module, and a second busbar assembly connecting the third battery module and the fourth battery module and facing the first busbar assembly, The first busbar assembly has its lower surface exposed from the cover plate, The battery pack according to claim 7, wherein one side of the second busbar assembly is exposed from the cover plate.

10. The exposed lower surface of the first busbar assembly faces the first battery module and the second battery module, The battery pack according to claim 9, wherein the exposed side of the second busbar assembly faces the third battery module and the fourth battery module.

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