Bus bar assembly and battery pack including the bus bar 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 have almost no 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 lithium-based oxides and carbon materials as the positive electrode active material and the negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with such a positive electrode active material and a negative electrode active material, are arranged with a separator interposed therebetween, and a battery case that hermetically houses the electrode assembly together with an electrolytic solution.

[0005] Generally, lithium secondary batteries are classified into can-type secondary batteries in which the electrode assembly is built into a metal can and pouch-type secondary batteries in which the 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 a secondary battery used in a small device, two or three battery cells are arranged. However, in the case of a secondary battery used in a medium or large device such as an automobile, a battery module in which a plurality of battery cells are electrically connected is used. Such a battery module has improved capacity and output by forming a battery cell laminate in which a plurality of battery cells are connected in series or in parallel with each other. In addition, 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 a battery pack in which a plurality of battery modules are combined, the heat generated from the plurality of battery cells can be combined in a narrow space, and the temperature can rise rapidly and sharply. In other words, in the case of a battery module in which a plurality of battery cells are stacked and a battery pack in which such a battery module is mounted, high output can be obtained, but when the heat dissipation of the battery cells is not properly performed and a thermal runaway phenomenon of the battery cells occurs, there is a high possibility of continuous ignition and explosion due to it.

[0008] On the other hand, a bus bar connected to the battery module is provided inside the battery pack.

[0009] FIG. 1 is an exploded perspective view and an assembled perspective view of a conventional bus bar assembly.

[0010] Referring to FIG. 1, a conventional bus bar assembly 10 includes a bus bar 20, a coating 20C surrounding the bus bar 20, a cap CP, and a tape AL for fixing the cap CP. The bus bar 20 is a bar-shaped metal member extending along the longitudinal direction. Through holes HH for connection with the terminal bus bar of the battery module are formed at both ends of the bus bar 20. Such a bus bar 20 is configured to carry out HV (High voltage) connection in the battery pack. The HV connection means the connection of the power supply for supplying power, and the bus bar 20 is generally configured to guide the electrical connection of the battery module and includes a metal material with excellent electrical conductivity. As an example, the bus bar 20 can include a copper (Cu) material.

[0011] The coating 20C can surround the bus bar 20. The coating 20C can include an electrically insulating material, and as an example, can include a material such as silicone or epoxy. Since the coating 20C surrounds the bus bar 20 through which a high current flows, it is blocked that the bus bar 20 comes into contact with other electrical components or conductive members in addition to the terminal bus bar of the battery module and a short circuit occurs.

[0012] A fastening member is inserted into the through hole HH of the bus bar 20, and the bus bar 20 can be connected to the terminal bus bar of the battery module. Caps CP are attached to both ends of the bus bar 20 for insulation. The cap CP can be, for example, a rubber cap. The cap CP can be attached to the coating 20C using the tape AL.

[0013] However, when a flame occurs inside the battery pack, since the temperature of the flame is extremely high at about 1000°C, the coating 20C surrounding the bus bar 20 may melt, or the cap CP and the tape AL may melt, and the bus bar 20 may be exposed. If the exposed bus bar 20 comes into contact with other conductive members and a short circuit occurs, the internal flame may further spread, and such a flame may propagate to the outside of the battery pack. Eventually, this may lead to the explosion of the battery pack or the vehicle on which the battery pack is mounted.

[0014] Therefore, there is a demand for the development of a bus bar assembly that can maintain electrical insulation even if a flame occurs inside the battery pack.

Summary of the Invention

Problems to be Solved by the Invention

[0015] The problem to be solved by the present invention is to provide a bus bar assembly that can maintain electrical insulation without melting even if a flame occurs inside the battery pack, and a battery pack including the bus bar assembly.

[0016] However, the problems to be solved by the embodiments of the present invention are not limited to the above-described problems, and can be variously extended within the scope of the technical idea included in the present invention.

Means for Solving the Problems

[0017] 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.

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

[0019] The shape of the cover plate on the plane is provided along the outer contours of the insulating layer and the end portions.

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

[0021] The cover plate can include an upper surface, two short side surfaces arranged in the short side direction of the bus bar, and two long side surfaces arranged in the long side direction of the bus bar and formed along the shapes of the insulating layer and the end portions.

[0022] The cover plate may include an upper surface formed along the insulating layer and the shape of the end portion, two short side surfaces arranged in the short side direction of the bus bar, one long side surface arranged in the long side direction of the bus bar, and a lower surface facing the upper surface and formed along the shape of the insulating layer.

[0023] The insulating layer may be ceramified at high temperature.

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

[0025] The at least one bus bar assembly further includes a fastening portion coupled to the through hole, and the cover plate can cover the fastening portion.

[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 bus bar assembly includes a first bus bar assembly connecting the first battery module and the second battery module, and a second bus bar assembly connecting the third battery module and the fourth battery module and facing the first bus bar. The lower surface of the first bus bar assembly can be exposed from the cover plate, and one side surface of the second bus bar assembly can be exposed from the cover plate.

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

Advantages of the Invention

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

[0029] When the bus bar assembly of the present invention is exposed to a flame, 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]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0032] Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. The present invention can be realized in various different forms and is not limited to the embodiments described herein.

[0033] For the purpose of clearly explaining the present invention, parts that are unnecessary for the explanation are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0034] In addition, the sizes and thicknesses of the respective components 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. The thicknesses are enlarged in the drawings to clearly represent various layers and regions. And, in the drawings, for the convenience of explanation, the thicknesses of some layers and regions are exaggerated.

[0035] Also, when a part such as a layer, film, region, plate, etc. is said to be "above" another part, this includes not only the case where it is directly above the other part, but also the case where there are other parts in between. When a part is said to be "directly above" another part, it means that there are no other parts in between. Note that being "above" the reference part means being located above or below the reference part, and does not necessarily mean being located "above" in the opposite direction of gravity.

[0036] Furthermore, throughout the specification, when a part "includes" a certain component, this means that, unless otherwise stated to the contrary, it does not exclude other components, but can further include other components.

[0037] Also, throughout the specification, when it is said to be "on a plane", this means when looking at the target part from above, and when it is said to be "in a cross-section", this means when looking at the cross-section obtained by vertically cutting the target part from the side.

[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 be perpendicular to each other.

[0039] Throughout the specification, it was explained that the up / down concept is divided along the third direction DR3. Accordingly, the "thickness" in the specification means the length measured in the third direction DR3.

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

[0041] Referring to FIG. 2, a battery pack 1000 according to an embodiment includes a busbar assembly 100, a pack frame 1100, a battery module 1200, a BDU (battery disconnect unit) module 1300 for controlling the electrical connection of the battery module 1200, and a BMS (Battery Management System) module 1400 for monitoring and controlling the operation of the battery module 1200. At least one busbar assembly 100 according to this embodiment electrically connects at least one of between the battery modules 1200, between the battery module 1200 and the BDU module 1300, between the battery module 1200 and the BMS module 1400, and between the BDU module 1300 and the BMS module 1400. Specifically, a plurality of battery modules 1200 are housed in the pack frame 1100, and the electrical connection between the battery modules 1200 and the electrical connection between the battery module 1200 and the BDU module 1300 are performed by the busbar assembly 100. That is, the busbar assembly 100 according to this embodiment can undertake HV (High voltage) connection. Here, the HV connection is a connection serving as a power source for supplying power that requires a high voltage, and means a connection between battery cells or a connection between battery modules.

[0042] On the other hand, the BDU module 1300 is a member 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. When a condition where the current exceeds the set range occurs, the BDU module 1300 can cut off the power supply of the battery pack 1000 to ensure the safety of the battery pack 1000.

[0043] On the one hand, the LV connection member 100' according to this embodiment can be responsible for the electrical connection between the battery module 1200 and the BMS module 1400. Here, the electrical connection refers to an LV (Low voltage) connection, which means a sensing connection for detecting and controlling the voltage and temperature of the battery module 1200. Specifically, sensors inside the battery module 1200 are arranged, and the real-time temperature information and voltage information of the battery module 1200 are transmitted to the BMS module 1400 via the LV connection 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 be responsible for 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] Hereinafter, with reference to FIGS. 3 and 4, the battery module 1200 according to this embodiment will be described. However, the battery module 1200 described below is an exemplary structure of a battery module including a plurality of battery cells 11, and various forms of battery modules including a plurality of battery cells are applicable.

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

[0046] FIG. 4 is a partial perspective view showing the state where the module frame and the end plate are removed from the battery module of FIG. 3.

[0047] Referring to FIGS. 3 and 4, the battery module 1200 according to this embodiment can 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 is housed in the module frame 30 and the 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 of a laminate sheet including a resin layer and a metal layer, and then fusing the outer peripheral portion of the pouch case. Such a battery cell 11 is formed in a rectangular sheet structure. The electrode lead 11L connected to the electrode assembly protrudes outside the pouch case, but the electrode leads 11L of the respective battery cells 11 are electrically connected to each other via a lead bus bar 21. On the other hand, at least one electrode lead 11L is connected to a terminal bus bar 22. A part of the terminal bus bar 22 can be exposed outside the battery module 1200 as shown in FIG. 3. The lead bus bar 21 and the terminal bus bar 22 can both contain a metal material excellent in electrical conductivity.

[0049] The bus bar assembly 100 according to this embodiment is electrically connected to such a terminal bus bar 22, and the above-described HV connection is performed. That is, the battery module 1200 is electrically connected to another battery module 1200, the BDU module 1300, or the BMS module 1400 via the bus bar assembly 100 connected to the terminal bus bar 22.

[0050] Hereinafter, with reference to FIGS. 5 to 11, a bus bar assembly according to an embodiment will be described.

[0051] FIG. 5 is a perspective view of a bus bar according to an embodiment.

[0052] Referring to FIG. 5, the bus bar 200 guides electrical connection within the battery pack 1000 (see FIG. 2). The bus bar 200 is a configuration for guiding the electrical connection of the battery module 1200 (see FIG. 2), that is, the HV connection, and can contain a metal material excellent in electrical conductivity. As an example, the bus bar 200 can contain a copper (Cu) material. The body portion 210 can have a bar shape extending in one direction. In FIG. 2, as an example, the bus bar 200 is shown as having a bar shape extending in the first direction DR1.

[0053] A bus bar 200 of an embodiment includes a body portion 210 and end portions 220. The body portion 210 may correspond to the central portion of the bus bar 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 a direction opposite to the first direction DR1. In this specification, for the sake of convenience, the bus bar 200 has been described as including the body portion 210 and the end portions 220, but the body portion 210 and the end portions 220 have an integral shape.

[0054] A through hole HH is formed in the end portion 220. A fastening member can be inserted into the through hole HH to connect the bus bar 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 bus bar 20 and the terminal bus bar 22 (see FIG. 3) of the battery module 1200 (see FIG. 3).

[0055] FIG. 6 is a perspective view of a bus bar provided with an insulating layer according to an embodiment.

[0056] Referring to FIG. 6, an insulating layer 300 surrounds the body portion 210 (see FIG. 5) of the bus bar 200. That is, the insulating layer 300 can surround the outer peripheral surface of the bus bar 200 excluding the end portions 220 of the bus bar 200. The end portions 220 are exposed from the insulating layer 300 and are electrically connected to the terminal bus bar 22 (see FIG. 4) of the battery module 1200.

[0057] The insulating layer 300 may include refractory silicone. For example, the insulating layer 300 is formed by molding refractory silicone on the outer peripheral surface of the body portion 210 (FIG. 5) of the bus bar 200. Different from general silicone materials that are exposed to flames or burn at high temperatures, refractory silicone is ceramified at high temperatures. Therefore, when exposed to flames, refractory silicone can be ceramified without burning and maintain insulation for the bus bar 200. For example, refractory silicone is ceramified at a temperature of 500 degrees Celsius or higher and 1700 degrees Celsius or lower. However, the temperature range at which refractory silicone is ceramified is not limited to this.

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

[0059] When refractory silicone is exposed to flames or high heat, cross-linking of silica (SiO2) occurs along with decomposition of the silicone polymer, forming a ceramic substance. The insulating layer 300 of one embodiment containing refractory silicone is ceramified rather than burning or melting when exposed to flames or placed in a high-temperature environment, and can maintain electrical insulation.

[0060] Therefore, the insulating layer 300 can insulate the body portion 210 (see FIG. 5) of the bus bar 200 even from 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.

[0061] FIG. 7 is an exploded perspective view of a bus bar assembly according to an embodiment.

[0062] Referring to FIG. 7, a bus bar assembly 100 according to an embodiment can include a bus bar 200, an insulating layer 300, and a cover plate 400. In FIG. 7, for convenience of explanation, a fastening member BT coupled to the end portion 220 of the bus bar 200 is also shown. As an example of the fastening member BT, a bolt is shown.

[0063] The cover plate 400 of the present invention covers the insulating layer 300 and the end portion 220 and has an integral shape.

[0064] The cover plate 400 of the present invention can include mica. The cover plate 400 may be a thermoformed mica plate formed by thermocompression bonding with a high-temperature press. The cover plate 400 is thermoformed according to the outer contour shape of the bus bar 200 and the insulating layer 300, and is provided in an assembled manner without another adhesive layer. Also, compared with a soft mica tape or sheet-shaped mica, the cover plate 400 of the present invention can maintain a hard outer shape and physically protect the internal structure.

[0065] The cover plate 400 is excellent in fire resistance, heat resistance, high-temperature resistance, and electrical insulation, and can maintain the insulation of the bus bar assembly 100 without burning in the presence of flames or high heat. Therefore, the cover plate 400 can block the insulating layer 300 from being directly exposed to the flame when the flame occurs. Also, the cover plate 400 can physically protect and insulate the end portion 220 and the fastening member BT coupled to the end portion 220. The cover plate 400 can replace the cap CP (see FIG. 1) and the tape AL included in the conventional bus bar assembly 10.

[0066] In one embodiment, the cover plate 400 may include an upper surface TF, two short side surfaces SF1, SF2, and two long side surfaces SF3, SF4. The cover plate 400 of one embodiment may not include another lower surface. Accordingly, the cover plate 400 is assembled and coupled to the bus bar 200 and the insulating layer 300 in a planar direction. The shape of the cover plate 400 on the plane may match the shapes of the insulating layer 300 and the end portion 220.

[0067] In the cover plate 400 of one embodiment, the upper surface TF may have a planar shape. For example, the upper surface TF may be a surface parallel to the plane formed by the first direction DR1 and the second direction DR2. The two short side surfaces SF1, SF2 are arranged in the short side direction of the bus bar 200. The two long side surfaces SF3, SF4 are arranged in the long side direction of the bus bar 200. The two long side surfaces SF3, SF4 may be formed along the shapes of the insulating layer 300 and the end portion 220. By thermoforming the two long side surfaces SF3, SF4 in accordance with the outer shapes of the bus bar 200 and the insulating layer 300, the cover plate 400 is assembled and coupled to the bus bar 200 and the insulating layer 300 in an assembly manner without another adhesive layer.

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

[0069] The lower surface of the assembled bus bar assembly 100 can be exposed from the cover plate 400. The lower surface of the bus bar assembly 100 can contact the terminal bus bar 22 of the battery module 1200 (see FIG. 3). Related explanations will be described later.

[0070] FIG. 8 is a plan view of a bus bar assembly according to one embodiment.

[0071] Referring to FIG. 8, the shape of the bus bar assembly 100 on the plane may be the shape of the cover plate 400 on the plane. The shape of the cover plate 400 on the plane may be provided along the outlines of the insulating layer 300 and the end portion 220. The cover plate 400 can have a first width L1 and a second width L2 on the plane. The first width L1 may be a length for covering the end portion 220 (see FIG. 7). The second width L2 may be a length for covering the insulating layer 300 (see FIG. 7). The second width L2 may be larger than the first width L1. On the other hand, in this specification, the width may be a length measured in the second direction DR2.

[0072] FIG. 9 is a side view of a bus bar assembly according to an embodiment.

[0073] Referring to FIG. 9, the shape of the bus bar assembly 100 on the side may be the shape of the cover plate 400 on the side. On the side, the cover plate 400 of an embodiment can have a rectangular shape. The thickness of the cover plate 400 may be the third thickness t3. Specifically, the cover plate 400 can have a constant thickness along the first direction DR1 which is the longitudinal direction.

[0074] Referring to FIGS. 7, 8, and 9 together, the bus bar assembly 100 of an embodiment may be assembled by fitting the cover plate 400 on the plane according to the shapes of the insulating layer 300 and the end portion 220.

[0075] FIG. 10 is a cross-sectional view of a bus bar assembly according to an embodiment.

[0076] Referring to FIG. 10, in the cross section corresponding to the cutting line A-A', 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. Since 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 sufficiently accommodate the end portion 220 and the bolt BT therein. A terminal bus bar 22 (see FIG. 3) of the battery module 1200 (see FIG. 3) is coupled to the lower portions of the end portion 220 and the bolt BT.

[0077] FIG. 11 is a cross-sectional view of a bus bar assembly according to an embodiment.

[0078] Referring to FIG. 11, in the cross section corresponding to the cutting line B-B', 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. Since 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 sufficiently accommodate the bus bar 200 and the insulating layer 300 therein.

[0079] Referring to FIGS. 10 and 11 together, 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 considering the outer contour shape of the end portion 220 of the bus bar 200, and the second width L2 is a width considering the outer contour shape of the insulating layer 300. Accordingly, the cover plate 400 is fitted and coupled to the bus bar 200 and the insulating layer 300 on the plane without another adhesive layer.

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

[0081] FIG. 12 is an exploded perspective view of a bus bar assembly according to an embodiment.

[0082] Referring to FIG. 12, the bus bar assembly 100-a of one embodiment can include a bus bar 200, an insulating layer 300, and a cover plate 400-a. In FIG. 12, for convenience of explanation, a fastening member BT coupled to the end 220 of the bus bar 200 is also shown. As an example of the fastening member BT, a bolt is shown.

[0083] The cover plate 400-a shown in FIG. 12 can have a shape different from that of the cover plate 400 shown in FIG. 7. Specifically, the cover plate 400-a of one embodiment can conform to the shapes of the insulating layer 300 and the end 220 on the side surface.

[0084] The cover plate 400-a of one embodiment can include an upper surface TF, two short side surfaces SF1, SF2, one long side surface SF3, and a lower surface BF. That is, compared with the cover plate 400 shown in FIG. 7, one long side surface SF4 (see FIG. 7) of the cover plate 400-a is omitted, and the lower surface BF can be further included. Thereby, the cover plate 400-a is assembled and coupled to the bus bar 200 and the insulating layer 300 in the side surface direction. The shape of the cover plate 400 on the plane can conform to the shapes of the insulating layer 300 and the end 220.

[0085] In the cover plate 400-a of one embodiment, the upper surface TF is formed along the shapes of the insulating layer 300 and the end 220. Specifically, the upper surface TF is formed to include steps along the upper surface of the insulating layer 300 and the upper surface of the end 220. The two short side surfaces SF1, SF2 are arranged in the short side direction of the bus bar 200. One long side surface SF3 is arranged in the long side direction of the bus bar 200. In one embodiment, one long side surface SF3 may cover one side surface of the insulating layer 300 and the end 220. The lower surface BF may cover the lower surface of the insulating layer 300. The lower surface of the end 220 of the bus bar 200 can be exposed from the cover plate 400 and contact the terminal bus bar 22 of the battery module 1200 (see FIG. 3).

[0086] In one embodiment, one side of the cover plate 400-a is omitted, and the upper surface TF is thermoformed according to the outer contour shapes of the bus bar 200 and the insulating layer 300, so that it is assembled and coupled to the bus bar 200 and the insulating layer 300 in the side direction. That is, without another adhesive layer, the cover plate 400-a is fastened to the bus bar 200 and the insulating layer 300.

[0087] In addition, the material, forming method, insulation characteristics, and heat resistance characteristics of the cover plate 400-a are equally applicable to the description of the cover plate 400 described above with reference to FIG. 7.

[0088] FIG. 13 is a plan view of a bus bar assembly according to one embodiment.

[0089] Referring to FIG. 13, the shape of the bus bar assembly 100-a on the plane may be the same as the shape of the cover plate 400-a on the plane. On the plane, the cover plate 400-a can have a rectangular shape. At this time, the cover plate 400-a can have a third width L3. Specifically, the cover plate 400-a can have a constant width along the first direction DR1 which is the longitudinal direction.

[0090] FIG. 14 is a side view of a bus bar assembly according to one embodiment.

[0091] Referring to FIG. 14, the shape of the bus bar assembly 100-a on the side may be the same as 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 contours of the insulating layer 300 and the end portion 220. The cover plate 400-a can have a fourth thickness t4 and a fifth thickness t5 on the side. The fourth thickness t4 may be the thickness for covering the end portion 220 (see FIG. 12) and the bolt BT. The fifth thickness t5 may be the length for covering the insulating layer 300 (see FIG. 12). The fifth thickness t5 may be greater than the fourth thickness t4.

[0092] FIG. 15 is a cross-sectional view of a bus bar assembly according to one embodiment.

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

[0094] The end portion 220 and the bolt BT are accommodated inside the cover plate 400-a. Since the fourth height t4 of the cover plate 400-a is larger than the first height t1 of the end portion 220, the cover plate 400-a can sufficiently accommodate the end portion 220 and the bolt BT inside. The terminal bus bar 22 (see FIG. 3) of the battery module 1200 (see FIG. 3) is coupled to the lower portions of the end portion 220 and the bolt BT.

[0095] FIG. 16 is a cross-sectional view of a bus bar assembly according to an embodiment.

[0096] Referring to FIG. 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 surface of the insulating layer 300. Since the cover plate 400-a includes only one long side surface SF3 (see FIG. 12), one side surface 300-SF of the insulating layer 300 can be exposed from the cover plate 400-a. As one side surface 300-SF of the insulating layer 300 is exposed, when a flame occurs inside, the gas generated from the insulating layer 300 can be easily discharged to the outside.

[0097] On the one hand, since the cover plate 400-a is fitted into the insulating layer 300 and the bus bar 200 on the side surface, 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 in consideration of the second thickness t2 of the insulating layer 300.

[0098] Referring to FIGS. 12, 15, and 16 together, the cover plate 400-a of the present invention includes only one long side surface SF3 (see FIG. 12), the other long side surface is omitted, and it is fitted into the insulating layer 300 and the bus bar 200 in the side surface direction. Further, the cover plate 400-a has different fourth thickness t4 and fifth thickness t5 on the side surfaces. The fourth thickness t4 is the thickness for accommodating the end portion 220 of the bus bar 200 and the bolt BT, and the fifth thickness t5 is the thickness considering the outer contour shape of the insulating layer 300. Thereby, the cover plate 400-a is fitted and joined to the bus bar 200 and the insulating layer 300 on the side surface without another adhesive layer.

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

[0100] FIG. 17 is a side view of a bus bar assembly for connecting battery modules of an embodiment.

[0101] Referring to FIG. 17, a bus bar assembly 100 of an embodiment can electrically connect adjacent first battery module 1200-a and second battery module 1200-b. The bus bar assembly 100 includes a cover plate 400 (see FIG. 7) of an embodiment. As described above with reference to FIGS. 7 to 11, the lower surface of the bus bar assembly 100 is exposed from the cover plate 400 (see FIG. 7) and is electrically connected to the first battery module 1200-a and the second battery module 1200-b.

[0102] When the bus bar assembly 100 is exposed to a flame and becomes hot, gas may be generated in the insulating layer 300 (see FIG. 7). The gas generated in the insulating layer 300 may accelerate the internal flame, inhibit the structural stability of the bus bar assembly 100, and have an adverse effect on the insulation performance with respect to the bus bar 200. Further, the gas generated in the insulating layer 300 contains carbonized components, and when the carbonized components are internally accumulated, it may have an adverse effect on the electrical insulation. Since the lower surface of the bus bar assembly 100 of the present invention is exposed from the cover plate 400 (see FIG. 7), the gas generated in the insulating layer 300 can be easily discharged to the outside.

[0103] FIG. 18 is a side view of a bus bar assembly that connects battery modules according to an embodiment.

[0104] Referring to FIG. 18, a bus bar assembly 100-a according to an embodiment can electrically connect adjacent third battery modules 1200-c and fourth battery modules 1200-d. By including a cover plate 400-a (see FIG. 12) according to an embodiment, the lower surface of the bus bar assembly 100-a is electrically connected to the third battery module 1200-c and the fourth battery module 1200-d.

[0105] As described above with reference to FIGS. 12 to 16, one side surface of the bus bar assembly 100-a can be exposed from the cover plate 400-a (see FIG. 12). The exposed side surface of the bus bar assembly 100-a is assembled so as to face the third battery module 1200-c and the fourth battery module 1200-d, and can be physically protected from an external flame. Further, while the exposed side surface of the bus bar assembly 100-a is protected from an external flame, the gas generated inside the bus bar assembly 100-a can be discharged to the outside.

[0106] FIG. 19 is a plan view of a bus bar assembly that connects battery modules according to an embodiment.

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

[0108] Referring to FIG. 19, when the two bus bar assemblies 100, 100-a are arranged adjacent to each other, one of the two applies the bus bar assembly 100 shown in FIG. 7, and the other applies the bus bar assembly 100-a shown in FIG. 12. That is, the first bus bar assembly 100 has a structure in which the lower surface is exposed from the cover plate 400 (see FIG. 7), and the second bus bar assembly 100-a has a structure in which one side surface is exposed from the cover plate 400-a (see FIG. 12). Thereby, one side surface of the cover plate 400 (see FIG. 7) is arranged between the two bus bar assemblies 100, 100-a, and it is possible to prevent a short circuit from occurring between them.

[0109] Further, the exposed lower surface of the first bus bar assembly 100 faces the first battery module 1200-a and the second battery module 1200-b. Therefore, during a fire, the gas discharged from the first bus bar assembly 100 does not directly affect the second bus bar assembly 100-a. Note that the exposed one side surface of the second bus bar assembly 100-a is arranged to face the third battery module 1200-c and the fourth battery module 1200-d. Therefore, during a fire, the gas discharged from the second bus bar assembly 100-a does not directly affect the first bus bar assembly 100.

[0110] The bus bar assembly of the present invention includes a cover plate that can replace the cap, thereby improving insulation and fire resistance. In addition, when the bus bar assembly of the present invention is exposed to a flame, it can easily discharge the gas generated inside to the outside, while maintaining the fire resistance, insulation, and stability of adjacent bus bar assemblies, and preventing the propagation of the flame.

[0111] In this embodiment, terms indicating directions such as front, rear, left, right, up, and down are used, but such terms are only for convenience of explanation and vary depending on the position of the object and the position of the observer.

[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 battery module and the battery pack can be applied to various devices. Specifically, they can be applied to transportation means such as electric bicycles, electric vehicles, hybrids, and ESS (Energy Storage System), but are not limited thereto, and can be applied to various devices that can use secondary batteries.

[0114] As described above, the preferred embodiments of the present invention have been described in detail, but the scope of the rights of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concepts of the present invention defined in the following claims also belong to the scope of the rights of the present invention.

Description of Reference Numerals

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

Claims

1. 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. A cover plate covering the insulating layer and the end portions and having an integral shape. A bus bar assembly including the above.

2. The bus bar assembly according to Claim 1, wherein the cover plate exposes one surface of the insulating layer.

3. The bus bar assembly according to Claim 1, wherein the shape of the cover plate on a plane is provided along the outer contours of the insulating layer and the end portions.

4. The bus bar assembly according to Claim 1, wherein the shape of the cover plate on a side surface is provided along the outer contours of the insulating layer and the end portions.

5. The cover plate includes an upper surface, two short side surfaces arranged in the short side direction of the bus bar, and two long side surfaces arranged in the long side direction of the bus bar and formed along the shapes of the insulating layer and the end portions. The bus bar assembly according to Claim 1.

6. The cover plate includes an upper surface formed along the shapes of the insulating layer and the end portions, two short side surfaces arranged in the short side direction of the bus bar, one long side surface arranged in the long side direction of the bus bar, and a lower surface facing the upper surface and formed along the shape of the insulating layer. The bus bar assembly according to Claim 1.

7. The bus bar assembly according to Claim 1, wherein the insulating layer is ceramized at high temperature.

8. The bus bar assembly according to any one of Claims 1 to 7, a battery module, a BDU (battery disconnect unit) module for controlling the electrical connection of the battery module, and a BMS (Battery Management System) module for monitoring and controlling the operation of the battery module. At least one of the bus bar assemblies electrically connects at least one of between the battery modules, between the battery module and the BDU module, between the battery module and the BMS module, and between the BDU module and the BMS module. A battery pack.

9. The battery pack according to Claim 8, further including a fastening portion coupled to the through hole of at least one of the bus bar assemblies, wherein the cover plate covers the fastening portion.

10. The battery pack according to Claim 8, further including a fastening portion coupled to the through hole of at least one of the bus bar assemblies, wherein the cover plate covers the fastening portion.

10. 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 bus bar assemblies includes a first bus bar assembly connecting the first battery module and the second battery module, and a second bus bar assembly connecting the third battery module and the fourth battery module and facing the first bus bar assembly. The lower surface of the first bus bar assembly is exposed from the cover plate. The battery pack according to claim 8, wherein one side surface of the second bus bar assembly is exposed from the cover plate.

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

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