Busbar assembly and battery pack including same

Abstract

A busbar assembly according to one embodiment of the present invention includes: a busbar that is connected to a battery module inside a battery pack and guides electrical connection of the battery module; a first insulating layer that surrounds the outer periphery of the busbar and has grooves formed on both ends; a second insulating layer that surrounds the first insulating layer; and caps that include a body that surrounds both ends of the busbar and fixing portions that are inserted into the grooves.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0105717, filed August 11, 2023, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a bus bar assembly and a battery pack including the same, and more particularly to a bus bar assembly with improved insulation stability and a battery pack including the same. [Background technology]

[0003] In modern society, the use of portable devices such as mobile phones, laptops, video cameras, and digital cameras has become commonplace, and the development of technologies related to these mobile devices is accelerating. Furthermore, rechargeable secondary batteries are a solution to address air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and are used as the power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc., which has led to an increased need for the development of secondary batteries.

[0004] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention due to their advantages over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, extremely low self-discharge rate, and high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively, and include an electrode assembly in which positive and negative electrode plates coated with the positive and negative electrode active materials are disposed with a separator between them, and a battery case that hermetically houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries can be classified into can-type secondary batteries, in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] While secondary batteries used in small devices typically have two or three battery cells, secondary batteries used in medium- to large-sized devices such as automobiles typically use a battery module in which multiple battery cells are electrically connected. Such a battery module improves capacity and output by connecting multiple battery cells in series or parallel to form a stack of battery cells. One or more battery modules can also be installed with various control and protection systems, such as a battery disconnect unit (BDU), battery management system (BMS), and cooling system, to form a battery pack.

[0008] In a battery pack made up of multiple battery modules, the heat generated from the multiple battery cells can be combined in a small space, causing a rapid temperature rise. In other words, a battery module in which multiple battery cells are stacked and a battery pack equipped with such a battery module can produce high output, but if the heat is not properly dissipated from the battery cells or if thermal runaway occurs in the battery cells, there is a high possibility of continuous fires and subsequent explosions.

[0009] Meanwhile, a bus bar connected to the battery module is provided inside the battery pack.

[0010] FIG. 1 is an exploded perspective view and a combined perspective view of a conventional busbar assembly.

[0011] Referring to FIG. 1, a conventional busbar assembly 10 includes a busbar 20, a covering 20C surrounding the busbar 20, a cap (CP), and a tape (AL) for fixing the cap (CP). The busbar 20 is a rod-shaped metal member extending longitudinally. Through-holes (HH) may be formed at both ends of the busbar 20 for connection to terminal busbars of a battery module. The busbar 20 serves as a high voltage (HV) connection in a battery pack. The HV connection refers to a connection that functions as a power source for supplying power. The busbar 20 guides the electrical connection of the battery modules and is generally made of a metal material with excellent electrical conductivity. For example, the busbar 20 may include copper (Cu).

[0012] The covering 20C can encase the bus bar 20. The covering 20C can include an electrically insulating material, such as silicone or epoxy. Because the covering 20C encases the bus bar 20, through which a high current flows, the bus bar 20 is prevented from coming into contact with other electrical components or conductive members other than the terminal bus bar of the battery module, thereby preventing a short circuit from occurring.

[0013] Fasteners can be inserted into the through holes (HH) of the busbar 20 to connect the busbar 20 to the terminal busbar of the battery module. Caps (CP) are attached to both ends of the busbar 20 for insulation. The caps (CP) may be, for example, rubber caps. The caps (CP) can be attached to the covering 20C using tape (AL).

[0014] However, if a fire breaks out inside the battery pack, the flame temperature will be as high as approximately 1000°C, which may melt the coating 20C surrounding the busbar 20 or the cap (CP) and tape (AL) and expose the busbar 20. If the exposed busbar 20 comes into contact with other conductive components and a short circuit occurs, the internal fire may spread further and even reach the outside of the battery pack. Ultimately, this may lead to an explosion of the battery pack or the vehicle in which the battery pack is installed.

[0015] Therefore, there is a need to develop technology for busbar assemblies that can maintain electrical insulation even if a flame occurs inside the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0016] An object of the present invention is to provide a bus bar assembly that can maintain excellent electrical insulation even if a flame occurs inside the battery pack, and a battery pack including the bus bar assembly.

[0017] However, the problems to be solved by the embodiments of the present invention are not limited to the above-mentioned problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0018] The busbar assembly of the present invention includes: a busbar that is connected to a battery module inside a battery pack and guides the electrical connection of the battery module; a first insulating layer that surrounds the outer periphery of the busbar and has grooves formed on both ends; a second insulating layer that surrounds the first insulating layer; and a cap that includes a body that surrounds both ends of the busbar and a fixing portion that is inserted into the groove.

[0019] In one embodiment, the thickness of the fixing portion may be greater than the thickness of the first insulating layer, the lower portion of the fixing portion may be coupled to the first insulating layer, and the second insulating layer may be in contact with the upper portion of the fixing portion.

[0020] In one embodiment, the second insulating layer may be disposed between the fixing portions disposed at both ends of the bus bar.

[0021] In one embodiment, the thickness of the fixing portion is the same as the thickness of the first insulating layer, the fixing portion and the first insulating layer are located on the same layer, and the second insulating layer can be disposed on the fixing portion and the first insulating layer.

[0022] In one embodiment, a tape may be disposed between the second insulating layer and the fixing portion.

[0023] In one embodiment, the second insulating layer may have a tube shape containing glass fiber.

[0024] In one embodiment, the outer surface of the second insulating layer may be coated with silicon.

[0025] In one embodiment, the second insulating layer does not include an adhesive material.

[0026] In one embodiment, the fixing portion may include a plurality of protrusions spaced apart from one another, and the groove may include a plurality of spaced apart recesses into which the protrusions can be inserted.

[0027] In one embodiment, the fixing portion may have a shape of an elongated block, and the groove may have a groove into which the block is inserted.

[0028] In one embodiment, the first insulating layer may comprise refractory silicon.

[0029] The battery pack of the present invention includes at least one busbar assembly; battery modules; a BDU (battery disconnect unit) module for controlling the electrical connection of the battery modules; and a BMS (Battery Management System) module for monitoring and controlling the operation of the battery modules, wherein the at least one busbar assembly electrically connects at least one of the battery modules, the battery modules and the BDU module, the battery modules and the BMS module, and the BDU module and the BMS module. [Effects of the Invention]

[0030] The bus bar assembly of the present invention minimizes the use of adhesives for bonding the cap and the insulating layer, and can maintain good insulation and fire resistance even when exposed to flames.

[0031] The effects of the present invention are not limited to those described above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0032] [Figure 1] 1A and 1B are exploded and assembled perspective views of a conventional busbar assembly; [Figure 2] FIG. 2 is a plan view of the battery pack according to the embodiment. [Figure 3] 3 is a perspective view of one of the battery modules included in the battery pack of FIG. 2. FIG. [Figure 4] 4 is a partial perspective view showing the battery module of FIG. 3 with a module frame and end plates removed. FIG. [Figure 5] FIG. 2 is a plan view of a bus bar provided with an insulating layer according to an embodiment. [Figure 6] FIG. 2 is a plan view of a cap according to an embodiment. [Figure 7] FIG. 1 is a plan view of a bus bar provided with a cap and an insulating layer according to an embodiment. [Figure 8] FIG. 2 is a plan view of a cap according to an embodiment. [Figure 9] FIG. 2 is a plan view of a bus bar provided with a cap and an insulating layer according to one embodiment. [Figure 10] 1 is a plan view showing a step in a manufacturing method of a busbar assembly according to an embodiment; [Figure 11] 1 is a plan view showing a step in a manufacturing method of a busbar assembly according to an embodiment; [Figure 12] 1 is a plan view showing a step in a manufacturing method of a busbar assembly according to an embodiment; [Figure 13] 1 is a plan view showing a step in a manufacturing method of a busbar assembly according to an embodiment; [Figure 14] FIG. 2 is a cross-sectional view of a busbar assembly according to an embodiment. [Figure 15] FIG. 2 is a cross-sectional view of a busbar assembly according to an embodiment. [Figure 16] FIG. 2 is a cross-sectional view of a busbar assembly according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0033] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement various embodiments of the present invention. The present invention can be embodied in several different forms and is not limited to the examples described herein.

[0034] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0035] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0036] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this does not only mean that it is "directly above" that part, but also that there is another part in between. When a part is "directly above" another part, it means that there is no other part in the middle. Furthermore, when a part is said to be "on" or "above" a reference part, it means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "above" the direction opposite to gravity.

[0037] Furthermore, throughout the specification, when a part "comprises" a certain element, it does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0038] Also, throughout the specification, "on a plane" means when the target part is viewed from above, and "on a cross section" means when the target part is cut vertically and viewed from the side.

[0039] 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 with each other. Throughout this specification, the concepts of up and down have been described as being distinguished along the third direction (DR3). Specifically, the up direction or upper direction refers to the third direction (DR3). The down direction or lower direction refers to the opposite direction of the third direction (DR3). In this specification, "thickness" refers to the length measured from the third direction (DR3).

[0040] FIG. 2 is a plan view of the battery pack of one embodiment.

[0041] 2 , a battery pack 1000 according to one embodiment includes a busbar assembly 100, a pack frame 1100, battery modules 1200, a battery disconnect unit (BDU) module 1300 for controlling electrical connection of the battery modules 1200, and a battery management system (BMS) module 1400 for monitoring and controlling operation of the battery modules 1200. At least one busbar assembly 100 according to this embodiment electrically connects at least one of the battery modules 1200 together, the battery modules 1200 and the BDU module 1300 together, the battery modules 1200 and the BMS module 1400 together, and the BDU module 1300 and the BMS module 1400 together. Specifically, a plurality of battery modules 1200 can be housed in the pack frame 1100, and electrical connection between the battery modules 1200 and the battery modules 1200 and the BDU module 1300 can be achieved by the busbar assembly 100. That is, the bus bar assembly 100 according to this embodiment can serve as an HV (High Voltage) connection. Here, the HV connection is a connection that serves as a power source for supplying power that requires high voltage, and refers to a connection between battery cells or between battery modules.

[0042] Meanwhile, the BDU module 1300 is a component for controlling the electrical connection of the battery module 1200, and can cut off the power supply between the power conversion device and the battery module 1200. The BDU module 1300 can ensure the safety of the battery pack 1000 by cutting off the power supply to the battery pack 1000 when a condition occurs in which the current exceeds a set range.

[0043] Meanwhile, the LV connecting member 100′ according to this embodiment may be responsible for electrical connection between the battery module 1200 and the BMS module 1400. The electrical connection here is a low voltage (LV) connection, which refers to a sensing connection for detecting and controlling the voltage and temperature of the battery module 1200. Specifically, sensors and the like are disposed inside the battery module 1200, and real-time temperature and voltage information of the battery module 1200 is transmitted to the BMS module 1400 through the LV connecting member 100′. The real-time operating status of the battery module 1200 can be monitored and controlled through the BMS module 1400. Although not specifically shown, an HV current sensor may be integrated into the BMS module 1400. In this case, the bus bar assembly according to this embodiment may be responsible for electrical connection between the battery module 1200 and the BMS module 1400 or between the BDU module 1300 and the BMS module 1400.

[0044] A battery module 1200 according to this embodiment will be described with reference to Figures 3 and 4. However, the battery module 1200 described below is one exemplary structure of a battery module including a plurality of battery cells 11, and various types of battery modules including a plurality of battery cells can be applied.

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

[0046] FIG. 4 is a partial perspective view showing the battery module of FIG. 3 with the module frame and end plates removed.

[0047] 3 and 4, a battery module 1200 according to this embodiment may include a battery cell stack 11A in which a plurality of battery cells 11 are stacked. The battery cell stack 11A is shown in FIG. 4. Such a battery cell stack 11A may be housed in a module frame 30 and end plates 40.

[0048] The battery cell 11 may be a pouch-type battery cell. Such a pouch-type battery cell can be formed by housing an electrode assembly in a pouch case made of a laminate sheet including a resin layer and a metal layer, and then fusing the outer periphery of the pouch case. However, the battery cell 11 of the present invention is not limited to a pouch-type battery cell.

[0049] In one embodiment, the battery cell 11 may be formed with a rectangular sheet structure. The electrode leads 11L connected to the electrode assembly protrude outside the pouch case, and the electrode leads 11L of each battery cell 11 may be electrically connected to each other via a lead bus bar 21. Meanwhile, at least one electrode lead 11L may be connected to a terminal bus bar 22. A portion of the terminal bus bar 22 may be exposed to the outside of the battery module 1200, as shown in FIG. 3. The lead bus bar 21 and the terminal bus bar 22 may both include a metal material with excellent electrical conductivity.

[0050] The busbar assembly 100 according to this embodiment can be electrically connected to the terminal busbar 22 to achieve the above-described HV connection. That is, the battery module 1200 can be electrically connected to another battery module 1200, a BDU module 1300, or a BMS module 1400 via the busbar assembly 100 connected to the terminal busbar 22.

[0051] A busbar assembly according to one embodiment will now be described.

[0052] FIG. 5 is a plan view of a busbar provided with an insulating layer according to one embodiment.

[0053] Referring to FIG. 5, the busbar 200 guides electrical connections within the battery pack 1000 (see FIG. 2). The busbar 200 is a component for guiding electrical connections, i.e., HV connections, of the battery modules 1200 (see FIG. 2), and may include a metal material with excellent electrical conductivity. For example, the busbar 200 may include a copper (Cu) material. The busbar 200 may have a rod shape extending in one direction. Through holes (HH) are defined at both ends of the busbar 200. Fastening members may be inserted into the through holes (HH) to connect the busbar 200 to the terminal busbar 22 (see FIG. 3) of the battery module 1200 (see FIG. 3).

[0054] The first insulating layer 300 is provided to encase the bus bar 200. At this time, the through holes (HH) of the bus bar 200 are exposed from the first insulating layer 300 and can be electrically connected to the terminal bus bar 22 (see FIG. 3) of the battery module 1200 (see FIG. 3).

[0055] The first insulating layer 300 may include a refractory material. Specifically, the first insulating layer 300 may include refractory silicone. For example, the first insulating layer 300 may be formed by molding refractory silicone on the outer circumferential surface of the bus bar 200. Unlike typical silicone materials that burn when exposed to flames or high heat, refractory silicone can be ceramified at high heat. Therefore, when exposed to flames, refractory silicone ceramifies without burning, thereby maintaining the insulation properties of the bus bar 200. For example, refractory silicone may be ceramified at temperatures between 500°C and 1700°C. However, the temperature range at which refractory silicone ceramizes is not limited thereto. The refractory silicone may include a silicone polymer and silica. For example, the silicone polymer used may be a polysiloxane-based compound having a vinyl group as a functional group, which may serve as a base material for the refractory silicone material. For example, the silica used may be fumed silica, which acts as a reinforcing filler in silicone polymers. High-purity silicon chloride (SiCl4) compounds can be produced from silicon metal as the main raw material through a reaction with hydrochloric acid and purification process, and then fumed silica can be obtained by reacting this with hydrogen and oxygen in a high-temperature flame. Refractory silicon can also contain platinum (Pt) as a catalyst.

[0056] When refractory silicone is exposed to flame or high heat, the silicone polymer decomposes and silica (SiO2) cross-links to form a ceramic material. In one embodiment, the first insulating layer 300 containing refractory silicone ceramifies and maintains its electrical insulation properties, rather than burning or melting, even when exposed to flame or in a high-heat environment. Therefore, the first insulating layer 300 insulates the bus bar 200 without burning even in flames or high temperatures, preventing the bus bar 200 from coming into contact with other electrical components or conductive members and causing a short circuit.

[0057] Grooves (GV) are formed on both ends of the first insulating layer 300. The GVs are recessed from both ends of the first insulating layer 300. In one embodiment, the GVs may include a plurality of recesses spaced apart from one another. The GVs are structures for coupling with the cap 400, which will be described later.

[0058] FIG. 6 is a plan view of the cap of one embodiment.

[0059] FIG. 7 is a plan view of a busbar provided with a cap and insulating layer according to one embodiment.

[0060] 6 and 7, cap 400 covers both ends of bus bar 200, particularly the through holes (HH). Although not shown, after fastening members are inserted into the through holes (HH), cap 400 covers both ends of bus bar 200 and the fastening members. Therefore, cap 400 has a space for accommodating the fastening members. For ease of explanation, these drawings omit the process of connecting bus bar 200 to terminal bus bar 22 (see FIG. 3) with fastening members. In addition, cap 400 is coupled to first insulating layer 300 to prevent bus bar 200 from being exposed to the outside and prevent short-circuiting of bus bar 200.

[0061] The cap 400 may include a fire-resistant material. In one embodiment, the cap 400 may include any one of fire-resistant plastic, mica, and fire-resistant silicone. This allows the cap 400 to exhibit excellent fire resistance.

[0062] Fire-resistant plastics can block the flames for a certain period of time without developing holes or drips when exposed to fire. Specifically, fire-resistant plastics can protect the internal structure by forming a carbonized layer in the flame. Fire-resistant plastics can include at least one of PPO (Polyphenylene Oxide)-based materials, PA (Polyamide)-based materials, and PBT (Polybutylene Terephthalate)-based materials.

[0063] Mica has excellent fire resistance, heat resistance, high temperature resistance and electrical insulation properties, and can act as a fire-resistant insulating layer without burning in flames or high heat.

[0064] For the refractory silicon, the same as described above for the first insulating layer 300 can be applied.

[0065] The cap 400 of the present invention includes a main body 410 and a fixing portion 420. As described above, the main body 410 covers both ends of the bus bar 200 and has a space for accommodating a fastening member. The fixing portion 420 is inserted into the groove (GV) of the first insulating layer 300 to connect the cap 400 to the first insulating layer 300. The fixing portion 420 may have a shape suitable for insertion into the groove (GV), and in one embodiment, the fixing portion 420 may include a plurality of protrusions spaced apart from one another. The fixing portion 420 may be provided integrally with the main body 410, but the embodiment is not limited thereto. The fixing portion 420, including a plurality of protrusions, is coupled to the groove (GV), including a plurality of recesses, thereby strengthening the bonding strength between the cap 400 and the first insulating layer 300.

[0066] FIG. 8 is a plan view of the cap of one embodiment.

[0067] FIG. 9 is a plan view of a bus bar provided with a cap and insulating layer according to one embodiment.

[0068] 8 and 9, the cap 400-1 includes a main body 410 and a fixing portion 420-1. In one embodiment, the fixing portion 420-1 may include a protrusion extending in one direction. In one embodiment, the first insulating layer 300-1 may include a recess extending in one direction to match the shape of the fixing portion 420-1. The fixing portion 420-1 having a shape extending in one direction increases the adhesive area between the cap 400-1 and a tape provided on the cap 400-1, thereby increasing adhesive strength.

[0069] Hereinafter, a busbar assembly 100 having the structure of the first insulating layer 300 and the cap 400 shown in Figures 6 and 7 will be described as an example. However, the contents described below can be equally applied to a busbar assembly having the structure of the first insulating layer 300-1 and the cap 400-1 shown in Figures 8 and 9.

[0070] FIG. 10 is a plan view showing a step in a method for manufacturing a busbar assembly according to one embodiment.

[0071] FIG. 11 is a plan view showing a step in a method for manufacturing a busbar assembly according to one embodiment.

[0072] FIG. 12 is a plan view showing a step in a method for manufacturing a busbar assembly according to one embodiment.

[0073] FIG. 13 is a plan view showing a step in a method for manufacturing a busbar assembly according to one embodiment.

[0074] An example of a method for manufacturing a busbar assembly will be described with reference to FIGS.

[0075] 10 , a method for manufacturing a busbar assembly according to an embodiment includes providing a second insulating layer 500 on a first insulating layer 300. The second insulating layer 500 is provided to encase the first insulating layer 300. Specifically, the cap 400 and the first insulating layer 300 may be joined at one end of the busbar 200, and then the second insulating layer 500 may be provided to encase the first insulating layer 300. The second insulating layer 500 may be provided in a tubular shape. Specifically, the tubular second insulating layer 500 may encase the first insulating layer 300 and fit in the length direction (Ld) of the busbar 200.

[0076] The second insulating layer 500 of the present invention may be free of a separate adhesive material. The adhesive material may include, for example, at least one of epoxy resin, silicone resin, and acrylic resin. The absence of an adhesive material in the second insulating layer 500 can prevent harmful gases from being generated from the adhesive material in the event of a fire, which could deteriorate the insulation of the busbar assembly.

[0077] 11, after providing the second insulating layer 500 on the first insulating layer 300, a step of providing a cap 400 on the other end of the first insulating layer 300 is performed. A fixing part 420 is inserted into a groove (GV) formed on the other end of the first insulating layer 300, and the cap 400 is fixed to the other end of the first insulating layer 300.

[0078] 12, after the caps 400 are coupled to both ends of the bus bar 200 (see FIG. 10), the second insulating layer 500 spreads to contact the fixing portions 420 at both ends. The second insulating layer 500 may not include an adhesive material, but may be fixed by being fitted between the fixing portions 420 of the caps 400 at both ends. This will be described in detail later with reference to FIGS. 15 and 16.

[0079] 12 and 13 , a tape 600 may be provided on the fixing portion 420 to form the busbar assembly 100 according to an embodiment. The tape 600 may be provided to cover the fixing portion 420 and a portion of the second insulating layer 500. The tape 600 may strengthen the bonding force between the cap 400 and the second insulating layer 500, thereby improving the insulation properties of the busbar assembly 100. The tape 600 may include, for example, a glass fiber layer. The glass fiber layer may physically protect the internal structure, for example, by preventing the first insulating layer 300 from being directly exposed to an external flame. If the first insulating layer 300 is ceramized in a flame or high-heat environment, the electrical insulation properties of the first insulating layer 300 may be maintained, but the strength may be weakened and the first insulating layer 300 may be damaged by an external force. The glass fiber layer may be provided to encase the first insulating layer 300, thereby preventing the first insulating layer 300 from being damaged by an external force. The busbar assembly 100 of one embodiment includes a tape 600 including a glass fiber layer, which improves structural rigidity and maintains good insulation performance even in the event of a fire. The tape 600 includes an adhesive layer in addition to the glass fiber layer to provide adhesive properties. However, the tape 600 is used in small amounts, and the second insulating layer 500, which previously used glass fiber tape, is replaced with a glass fiber tube containing no adhesive material, minimizing the generation of harmful gases due to ignition of the adhesive material when the busbar assembly 100 is exposed to fire.

[0080] FIG. 14 is a cross-sectional view of a busbar assembly according to one embodiment.

[0081] Fig. 14 is a cross-sectional view of an example of the bus bar assembly 100 taken along the line A-A' shown in Fig. 13. Referring to Fig. 14, the first insulating layer 300 covers the outer circumferential surface of the bus bar 200, and the second insulating layer 500 covers the outer circumferential surface of the first insulating layer 300.

[0082] In one embodiment, the second insulating layer 500 may include a glass fiber layer 510 and a coating layer 520. The glass fiber layer 510 is the glass fiber layer described above, and may be provided in a tubular shape without including a separate adhesive layer. The coating layer 520 may be formed by coating the outer surface of the glass fiber layer 510 with silicone. The second insulating layer 500 may include the coating layer 520 to further improve fire resistance.

[0083] FIG. 15 is a cross-sectional view of a busbar assembly according to one embodiment.

[0084] FIG. 15 is a cross-sectional view of an embodiment of the bus bar assembly 100 shown in FIG. 13 taken along line B-B'. Referring to FIG. 15, the thickness (H1) of the fixing portion 420 of the cap 400 may be greater than the thickness (T1) of the first insulating layer 300. Thus, when the fixing portion 420 is coupled to the first insulating layer 300, the first insulating layer 300 contacts the lower portion (PT1) of the fixing portion 420, and the remaining portion, the upper portion (PT2) of the fixing portion 420, may be exposed from the first insulating layer 300. The upper portion (PT2) of the fixing portion 420 may serve as a locking portion for fixing the second insulating layer 500. Specifically, the second insulating layer 500 is fitted and fixed between the upper portions (PT2) of the fixing portions 420.

[0085] 10 to 13 and 15, in FIGS. 10 and 11, the second insulating layer 500 is fitted to contact the upper part (PT2) of the fixing portion 420 provided at one end. In FIG. 12, the second insulating layer 500 is fitted and fixed between the upper parts (PT2) of the fixing portions 420 provided at both ends. Therefore, even if the second insulating layer 500 does not include a separate adhesive material, the second insulating layer 500 can be stably fixed without moving in the longitudinal direction of the bus bar 200 by the fixing portion 420 included in the cap 400. In addition, the tape 600 can improve the structural rigidity of the bus bar assembly 100 by re-bonding the fixing portion 420 and the second insulating layer 500. The tape 600 may be omitted if necessary.

[0086] However, the embodiment of the cap 400 is not limited to this.

[0087] FIG. 16 is a cross-sectional view of a busbar assembly according to one embodiment.

[0088] FIG. 16 is a cross-sectional view of an embodiment of the bus bar assembly 100 shown in FIG. 13 taken along the line B-B'. Referring to FIG. 16, in the cap 400-2 of the embodiment, the thickness (H2) of the fixing portion 420-2 may be the same as the thickness (T1) of the first insulating layer 300. Thus, when the fixing portion 420-2 is coupled to the first insulating layer 300, the first insulating layer 300 and the fixing portion 420-2 may be disposed on the same layer. To ensure the fixing force, a tape 600 may be provided to tape the cap 400-2 and the first insulating layer 300 together. Thereafter, a second insulating layer 500 may be provided to encase the fixing portion 420-2, the tape 600, and the first insulating layer 300. Specifically, the second insulating layer 500 having a tube shape may be fitted to encase the outer circumferential surfaces of the tape 600 and the first insulating layer 300. As a result, the tape 600 is disposed between the second insulating layer 500 and the fixing portion 420. In the embodiment of Fig. 16, the second insulating layer 500 is disposed and fixed between the bodies 410 of the caps 400-2 provided on both ends. Meanwhile, the tape 600 may be omitted if necessary.

[0089] The busbar assembly of the present invention includes a cap including a fixing portion and a first insulating layer including a groove into which the fixing portion can be inserted. This minimizes the amount of adhesive used to bond the cap and the first insulating layer, preventing the adhesive from emitting harmful gases during a fire, which could degrade the insulating properties. Furthermore, the second insulating layer disposed on the first insulating layer is provided in a tube shape without any adhesive, allowing the second insulating layer to be fixed by the caps on both ends without any adhesive. This allows the busbar assembly of the present invention to maintain good insulating properties and fire resistance even when exposed to a fire.

[0090] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are used for convenience of explanation and may differ depending on the position of the object of interest or the position of the observer.

[0091] One or more battery modules according to the above-described embodiments may 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.

[0092] The battery module or battery pack can be applied to various devices, specifically, but not limited to, transportation means such as electric bicycles, electric cars, and hybrids, and ESS (Energy Storage Systems).

[0093] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0094] 100 Busbar Assembly 200 Busbar 300 First insulating layer GV groove 400 caps 410 Main Unit 420 Fixed part 500 Second insulating layer 600 Tape

Claims

1. a bus bar connected to the battery module inside the battery pack and guiding the electrical connection of the battery module; a first insulating layer that wraps around the outer periphery of the bus bar and has grooves formed at both ends; a second insulating layer encasing the first insulating layer; and a cap including a body that encloses both ends of the bus bar and a fixing portion that is inserted into the groove; a busbar assembly including:

2. the thickness of the fixing portion is greater than the thickness of the first insulating layer; a lower portion of the fixing portion coupled to the first insulating layer; The busbar assembly according to claim 1 , wherein the second insulating layer contacts an upper portion of the fixing portion.

3. The busbar assembly according to claim 2 , wherein the second insulating layer is disposed between the fixing portions disposed at both ends of the busbar.

4. the thickness of the fixing portion is the same as the thickness of the first insulating layer; the fixing portion and the first insulating layer are located in the same layer, The busbar assembly according to any one of claims 1 to 3, wherein the second insulating layer is disposed on the fixing portion and the first insulating layer.

5. The busbar assembly according to claim 4 , wherein a tape is disposed between the second insulating layer and the fixing portion.

6. The busbar assembly of claim 1 , wherein the second insulating layer has a tubular shape containing glass fiber.

7. The busbar assembly according to claim 6 , wherein an outer surface of the second insulating layer is coated with silicon.

8. The busbar assembly of claim 1 , wherein the second insulating layer does not include an adhesive material.

9. the fixing portion includes a plurality of protrusions spaced apart from one another; The busbar assembly of claim 1 , wherein the groove includes a plurality of spaced apart recesses into which the protrusions can be inserted.

10. the fixing portion comprises an elongated block shape; The busbar assembly according to claim 1 , wherein the groove has a groove into which the block is inserted.

11. The busbar assembly of claim 1 , wherein the first insulating layer comprises a refractory silicone.

12. At least one busbar assembly according to claim 1; Battery module; a battery disconnect unit (BDU) module for controlling the electrical connection of the battery module; and a BMS (Battery Management System) module that monitors and controls the operation of the battery module; The at least one busbar assembly electrically connects at least one of the battery modules, the battery modules and the BDU module, the battery modules and the BMS module, and the BDU module and the BMS module.

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