Battery pack and device including the same

Abstract

A battery module according to one embodiment of the present invention comprises: battery modules comprising a plurality of battery cells; and a busbar assembly for electrically connecting the battery modules. The battery module comprises a terminal busbar electrically connected to the battery cell and having at least a portion exposed through an opening. The busbar assembly comprises: a pack busbar connected to the terminal busbar exposed through the opening; a first cover member covering the upper surface, lower surface, and sides of the pack busbar; and a second cover member covering the first cover member. The pack busbar has at least two connection areas that are in contact with the terminal busbar, and the first cover member has an upper exposed portion in which the upper surface of the connection area is exposed and a lower exposed portion in which the lower surface of the connection area is exposed. The second cover member includes a cap portion covering the upper exposed portion and a partition portion connected to the cap portion and extending downward to cover the portion of the terminal busbar exposed through the opening.

Description

Technology Field

[0001] The present invention relates to a battery pack and a device including the same, and more specifically, to a battery pack with improved fire resistance and a device including the same. Background Technology

[0002] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0004] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0005] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0006] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, battery modules in which multiple battery cells are electrically connected are used. In such battery modules, capacity and output are improved by connecting multiple battery cells in series or parallel to form a stack of battery cells. In addition, one or more battery modules can be mounted together with various control and protection systems, such as a Battery Disconnect Unit (BDU), a Battery Management System (BMS), and a cooling system, to form a battery pack.

[0007] In battery packs composed of multiple battery modules, the heat generated from numerous cells accumulates within a confined space, causing the temperature to rise rapidly and severely. In other words, while battery modules with stacked cells and battery packs equipped with such modules can achieve high output, there is a high risk of explosion or ignition if heat dissipation from the cells is inadequate or if thermal runaway occurs.

[0008] Meanwhile, a pack busbar connected to a battery module is provided inside the battery pack. Figure 1 is a drawing showing a conventional pack busbar.

[0009] Referring to FIG. 1, a conventional pack busbar (20) is a rod-shaped metal member extending along the longitudinal direction. The pack busbar (20) serves as a medium for electrically connecting terminal busbars (22) of a battery module (1200). For example, each of the two ends of the pack busbar (20) can be connected to a terminal busbar (22) of the battery module (1200). For example, the pack busbar (20) and the terminal busbar (22) can be physically and electrically connected in such a way that a bolt (60) passes through both the pack busbar (20) and the terminal busbar (22) and is coupled with a nut.

[0010] This pack busbar (20) is a component responsible for the HV (High voltage) connection in the battery pack. The HV connection refers to a connection that serves as a power source for supplying power, and the pack busbar (20) is a component that guides the electrical connection of the battery module, and it is common for it to include a metal material with excellent electrical conductivity. For example, the pack busbar (20) may include copper (Cu) material.

[0011] The covering member (20P) can wrap around the pack busbar (20). The covering member (20P) may include an electrically insulating material, for example, a silicone material or an epoxy material. Since the covering member (20P) wraps around the pack busbar (20) through which high current flows, it prevents the pack busbar (20) from coming into contact with other electrical components or conductive members other than the terminal busbar of the battery module, thereby preventing a short circuit. Additionally, a cap (20C) may be provided to cover the part where the pack busbar (20) and the terminal busbar (22) are connected, and the cap (20C) may be fixed to the covering member (20P) by a tape (20T).

[0012] Recently, battery packs are required to have a system in which flames do not spread to the outside of the battery pack even if ignition occurs inside the battery pack. Since the temperature of the flame generated inside the battery pack is very high, approximately 1000 degrees Celsius, the covering member (20P) surrounding the pack busbar (20) may melt, exposing the pack busbar (20). If the exposed pack busbar (20) comes into contact with other electrical components or conductive members and causes a short circuit, the internal flames may spread further and propagate to the outside of the battery pack. Ultimately, this can lead to an explosion of the battery pack or the vehicle equipped with the battery pack.

[0013] Additionally, in the case where the cap (20C) covers the portion where the pack busbar (20) and the terminal busbar (22) are connected, the portion of the pack busbar (20) is generally covered, but there is a concern that the terminal busbar (22) may be exposed from the side. A portion of the terminal busbar (22) is exposed through an opening (40H) formed in the battery module (1200), and the pack busbar (20) is connected to this exposed portion of the terminal busbar (22). Since the cap (20C) covers the portion where the pack busbar (20) and the terminal busbar (22) are connected, the portion of the pack busbar (20) is generally covered, but because the opening (40H) is not completely covered, the terminal busbar (22) is exposed from the side.

[0014] Dust (D) penetrates through the gap between the terminal busbar (22) and the opening (40H), and if this dust (D) accumulates on the exposed part of the terminal busbar (22), the risk of a short circuit with other electrical components inside the battery pack increases. In particular, in a situation where flames occur, dust accumulated on a conductor such as the terminal busbar (22) causes additional thermal runaway phenomena and ultimately causes fire or explosion.

[0015] Accordingly, there is a need for technological development regarding busbar assemblies capable of maintaining electrical insulation. The problem to be solved

[0016] The problem that the present invention aims to solve is to provide a battery pack with improved electrical insulation at the portion where the pack busbar and the terminal busbar are connected, and a device including the same.

[0017] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention. means of solving the problem

[0018] A battery module according to one embodiment of the present invention comprises: battery modules comprising a plurality of battery cells; and a busbar assembly for electrically connecting the battery modules. The battery module comprises a terminal busbar electrically connected to the battery cell and having at least a portion exposed through an opening. The busbar assembly comprises: a pack busbar connected to the terminal busbar exposed through the opening; a first cover member covering the upper surface, lower surface, and sides of the pack busbar; and a second cover member covering the first cover member. The pack busbar has at least two connection areas that are in contact with the terminal busbar, and the first cover member has an upper exposed portion in which the upper surface of the connection area is exposed and a lower exposed portion in which the lower surface of the connection area is exposed. The second cover member includes a cap portion covering the upper exposed portion and a partition portion connected to the cap portion and extending downward to cover the portion of the terminal busbar exposed through the opening.

[0019] Based on the height direction, the bulkhead portion may extend further down than the portion where the terminal busbar contacts the connection area of ​​the pack busbar.

[0020] At least a portion of the above cap portion may be inserted into the above upper exposed portion.

[0021] The portion between one side of the first cover member and the upper exposed portion among the first cover members can be fitted between the cap portion and the partition portion of the second cover member, thereby fixing the second cover member.

[0022] The above partition may be located in the space between one of the pack busbars connecting any two battery modules and another of the pack busbars connecting the other two battery modules.

[0023] The above partition may block the space between one of the pack busbars connecting any two battery modules and another of the pack busbars connecting the other two battery modules.

[0024] The above partition may be fitted between the first cover member that surrounds one of the pack busbars connecting any two battery modules and the first cover member that surrounds another of the pack busbars connecting the other two battery modules.

[0025] The second cover member includes a plurality of cap portions, and the partition portion may extend downward between the plurality of cap portions.

[0026] The first cover member and the second cover member may include an electrically insulating material.

[0027] The above cap portion and the above bulkhead portion can be injection molded as a single unit.

[0028] A pack busbar hole may be formed in the connection area of ​​the pack busbar, and a terminal busbar hole may be formed in the terminal busbar of the battery module. The pack busbar and the terminal busbar may be connected by a bolt passing through the pack busbar hole and the terminal busbar hole through the upper exposed portion and engaging with a nut.

[0029] The above cap portion can cover the part where the bolt is exposed to the upper exposed portion.

[0030] The above busbar assembly may further include an outer cover member that covers both the first cover member and the second cover member.

[0031] The above outer cover member may be a mica plate.

[0032] The outer surface of the above outer cover member can be wrapped with a fiberglass tape.

[0033] A device according to one embodiment of the present invention includes the battery pack. Effects of the invention

[0034] According to embodiments of the present invention, since the first cover member covers the pack busbar and the second cover member covers the portion of the first cover member where the pack busbar or the terminal busbar of the battery module is exposed, there is no risk of dust or the like accumulating on the pack busbar or the terminal busbar of the battery module. Accordingly, the risk of a short circuit occurring between the pack busbar or the terminal busbar and other electrical components inside the battery pack can be reduced.

[0035] In addition, the partition portion of the second cover member can increase the insulation distance because it covers the terminal busbar of the battery modules or the pack busbar connected thereto. Accordingly, the battery modules can be arranged more compactly, and ultimately, a high-output, high-capacity battery pack can be realized.

[0036] Meanwhile, tapes or adhesives have an adverse effect on maintaining electrical insulation because they emit carbonized gases in flame situations. In one embodiment of the present invention, the second cover member can be fixed by fitting the cap portion of the second cover member onto the first cover member. Since a separate tape or adhesive for fixation is unnecessary, the problem of carbonized gases being emitted in flame situations can be resolved.

[0037] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0038] Figure 1 is a drawing showing a conventional pack bus bar. FIG. 2 is a plan view showing a battery pack according to one embodiment of the present invention. FIG. 3 is a perspective view showing one of the battery modules included in the battery pack of FIG. 2. FIG. 4 is a partial perspective view showing the battery module of FIG. 3 with the module frame and end plate removed. FIG. 5 is a top view of a busbar assembly according to one embodiment of the present invention. FIG. 6 is a plan view showing the busbar assembly of FIG. 5 with the second cover member removed. Figure 7 is a bottom view of the busbar assembly of Figure 5 seen from below. Figure 8 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of Figure 5. FIG. 9 is a partial drawing showing an enlarged view of the connection portion between the busbar assembly and the battery modules according to one embodiment of the present invention. Figure 10 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of Figure 9. FIGS. 11 and FIGS. 12 are cross-sectional views illustrating the process of connecting a busbar assembly to a battery module. FIG. 13 is a top view of a busbar assembly according to another embodiment of the present invention. FIG. 14 is a plan view showing the busbar assembly of FIG. 13 with the second cover member removed. FIG. 15 is a bottom view of the busbar assembly of FIG. 13 seen from below. Figure 16 is a cross-sectional view showing a cross-section cut along the cutting line C-C' of Figure 13. FIG. 17 is a side view of the busbar assembly of FIG. 13. FIG. 18 is a partial drawing showing an enlarged view of the connection portion between the busbar assembly and the battery modules according to another embodiment of the present invention. FIG. 19 is a cross-sectional view showing a cross-section cut along the cutting line D-D' of FIG. 18. FIGS. 20 and FIGS. 21 are cross-sectional views illustrating the process of connecting a busbar assembly to a battery module. FIG. 22 is a perspective view showing an outer cover member according to one embodiment of the present invention. FIG. 23 is a perspective view showing an outer cover member and a glass fiber tape according to another embodiment of the present invention. Specific details for implementing the invention

[0039] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0040] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0041] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0042] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0043] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0044] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0045] FIG. 2 is a plan view showing a battery pack according to one embodiment of the present invention. Specifically, FIG. 2 is a plan view of the battery pack as seen from above.

[0046] Referring to FIG. 2, a battery pack (1000) according to one embodiment of the present invention includes battery modules (1200) comprising a plurality of battery cells; and a busbar assembly (100) for electrically connecting the battery modules (1200).

[0047] Additionally, the battery pack (1000) may include a Battery Disconnect Unit (BDU) module (1300) for controlling the electrical connection of battery modules (1200); and a Battery Management System (BMS) module (1400) for monitoring and controlling the operation of the battery modules (1200). At least one busbar assembly (100) according to the present embodiment may electrically connect at least one of the following: between battery modules (1200), between a battery module (1200) and a BDU module (1300), between a battery module (1200) and a BMS module (1400), or between a BDU module (1300) and a BMS module (1400). Specifically, a plurality of battery modules (1200) can be housed in a pack frame (1100), and electrical connections between battery modules (1200) or between battery modules (1200) and BDU modules (1300) can be made by a busbar assembly (100). That is, the busbar assembly (100) according to the present embodiment can be responsible for HV (High voltage) connections. Here, an HV connection is a connection that serves as a power source to supply power requiring high voltage, and refers to a connection between battery cells or between battery modules.

[0048] The BDU module (1300) is a component for controlling the electrical connection of the battery module (1200) and can cut off power between the power converter and the battery module (1200). The BDU module (1300) can ensure the safety of the battery pack (1000) by cutting off power to the battery pack (1000) when a condition occurs where the current exceeds a set range.

[0049] Meanwhile, the LV connection member (100') according to the present embodiment may be responsible for the electrical connection between the battery module (1200) and the BMS module (1400). The electrical connection here 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 placed, and real-time temperature information or voltage information of the battery module (1200) is transmitted to the BMS module (1400) through the LV connection 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 illustrated, there are cases where an HV current sensor is integrated into the BMS module (1400). In this case, the busbar assembly according to the present 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).

[0050] Hereinafter, a battery module (1200) according to the present embodiment will be described with reference to FIGS. 3 and 4. However, the battery module (1200) described below is an exemplary structure of a battery module including a plurality of battery cells (11). The present invention can be applied to various types of battery modules including a plurality of battery cells.

[0051] FIG. 3 is a perspective view showing one of the battery modules included in the battery pack of FIG. 2. FIG. 4 is a partial perspective view showing the battery module of FIG. 3 with the module frame and end plate removed.

[0052] Referring to FIGS. 3 and 4, the battery module (1200) according to the present embodiment includes a plurality of battery cells (11). For example, the battery module (1200) may include a battery cell stack (11A) in which a plurality of battery cells (11) are stacked. The battery cell stack (11A) is illustrated in FIG. 4. For example, the battery cells (11) may be stacked along one direction to form the battery cell stack (11A). This battery cell stack (11A) may be housed in an internal space formed by a module frame (30) and an end plate (40). The module frame (30) may be a box-shaped member with an open front and rear facing, and the end plate (40) may be a member that covers the open front and rear of the module frame (30) and is bonded to the module frame (30). There are no special restrictions on the joining method between the module frame (30) and the end plate (40), but for example, welding joints may be made on the mutually facing sides of the module frame (30) and the end plate (40).

[0053] The battery cell according to the present embodiment may be a pouch-type battery cell, a prismatic battery cell, or a cylindrical battery cell. However, in FIGS. 3 and 4, the battery cell (11) is described as a pouch-type battery cell as an example of the present invention. A pouch-type battery cell may be formed by housing an electrode assembly in a pouch case of a laminate sheet comprising a resin layer and a metal layer, and then fusing the outer periphery of the pouch case. Such a battery cell (11) may be formed in 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).

[0054] The battery module (1200) further includes a terminal busbar (22) that is electrically connected to the battery cell (11) and at least a portion of which is exposed through an opening (40H). Specifically, at least one electrode lead (11L) may be connected to the terminal busbar (22). At least a portion of the terminal busbar (22) may be exposed to the outside through an opening (40H) of the battery module (1200) as shown in FIG. 3. Both the lead busbar (21) and the terminal busbar (22) may comprise a metal material with excellent electrical conductivity.

[0055] There are no specific restrictions on the location of the opening (40H), but it may be formed on the end plate (40). For example, it may be formed on the corner portion of the end plate. In the present invention, the opening (40H) refers to a portion of the battery module that is open to expose a part of the terminal busbar (22) to the outside, without any restrictions on its shape or location.

[0056] The pack busbar (200) of the busbar assembly according to the present embodiment is electrically connected to the terminal busbar (22), so that the above-described HV connection can be made. That is, the battery module (1200) can be electrically connected to another battery module (1200), BDU module (1300), or BMS module (1400) through the pack busbar (200) connected to the terminal busbar (22). In FIG. 3, for convenience of explanation, only the appearance of the electrically conductive pack busbar (200) of the busbar assembly is shown.

[0057] Hereinafter, a busbar assembly according to an embodiment of the present invention will be described in detail with reference to FIGS. 5 to 8.

[0058] FIG. 5 is a top view of a busbar assembly according to an embodiment of the present invention. FIG. 6 is a top view of the busbar assembly of FIG. 5 with the second cover member removed. FIG. 7 is a bottom view of the busbar assembly of FIG. 5. FIG. 8 is a cross-sectional view taken along the cutting line A-A' of FIG. 5.

[0059] Referring to FIGS. 5 to 8, a busbar assembly (100) according to one embodiment of the present invention comprises: a pack busbar (200) connected to a terminal busbar (22, see FIG. 3) exposed at an opening (40H, see FIG. 3); a first cover member (300) covering the upper surface, lower surface and sides of the pack busbar (200); and a second cover member (400) covering the first cover member (300).

[0060] The pack busbar (200) is a component for guiding the electrical connection of the battery module, i.e., the HV connection, and may include a metal material with excellent electrical conductivity. For example, the pack busbar (200) may include a copper (Cu) material. The pack busbar (200) may be a metal rod extending along the longitudinal direction.

[0061] Meanwhile, the first cover member (300) and the second cover member (400) may include an electrically insulating material.

[0062] FIG. 9 is a partial view showing an enlarged view of the connection portion between the busbar assembly and the battery modules according to one embodiment of the present invention. FIG. 10 is a cross-sectional view showing a cross section cut along the cutting line B-B' of FIG. 9.

[0063] Referring together to FIGS. 5 to 10, the pack busbar (200) guides electrical connections within the battery pack (1000). FIGS. 9 and 10 illustrate, for example, that the pack busbar (200) electrically connects the terminal busbars (22) of the battery modules (1200a, 1200b, 1200c, 1200d). Specifically, four battery modules, namely the first to fourth battery modules (1200a, 1200b, 1200c, 1200d), can be arranged so that two of them face each other. One pack busbar (200) can connect the terminal busbar (22) of the first battery module (1200a) and the terminal busbar (22) of the third battery module (1200c), and another pack busbar (200) can connect the terminal busbar (22) of the second battery module (1200b) and the terminal busbar (22) of the fourth battery module (1200d).

[0064] Looking at the connection type, each connection area provided at both ends of the pack busbar (200) can be connected to the terminal busbar (22) of the battery module (1200). For example, the pack busbar (200) has at least two connection areas that are in contact with the terminal busbar (22) of the battery module (1200). For example, one connection area of ​​the pack busbar (200) can be connected by contacting the terminal busbar (22) of a first battery module (1200a), and another connection area of ​​the pack busbar (200) can be connected by contacting the terminal busbar (22) of a third battery module (1200c). Likewise, one connection area of ​​another pack busbar (200) may be connected by contacting the terminal busbar (22) of one second battery module (1200b), and another connection area of ​​the other pack busbar (200) may be connected by contacting the terminal busbar (22) of the fourth battery module (1200d).

[0065] Accordingly, the pack busbar (200) can electrically connect the terminal busbars (22) of the battery modules (1200a, 1200b, 1200c, 1200d) to each other. As long as physical and electrical connections are possible, there are no special restrictions on the method of connection between the pack busbar (200) and the terminal busbar (22). For example, the connection area of ​​the pack busbar (200) can be connected to the terminal busbar (22) of the battery module (1200) by bolting. Specifically, a pack busbar hole (200H) can be formed in the connection area of ​​the pack busbar (200), and a terminal busbar hole (22H) can be formed in the terminal busbar (22). The bolt (500) passes through the pack busbar hole (200H) and the terminal busbar hole (22H) via the upper exposed portion (310) described later and is coupled with the nut (600), thereby connecting the pack busbar (200) and the terminal busbar (22).

[0066] The first cover member (300) according to the present embodiment covers the upper surface, lower surface, and sides of the pack busbar (200). The first cover member (300) may be manufactured to cover the upper surface, lower surface, and sides of the pack busbar (200) by an insert molding method. However, not all sides of the pack busbar (200) are covered by the first cover member (300), and the first cover member (300) has an upper exposed portion (310) in which the upper surface of the connection area of ​​the pack busbar (200) is exposed, and a lower exposed portion (320) in which the lower surface of the connection area is exposed. That is, a portion of the connection area of ​​the pack busbar (200) is exposed at the upper exposed portion (310) and the lower exposed portion (320), and the remaining portion of the pack busbar (200) may be covered by the first cover member (300). In FIG. 6, viewed from above, the busbar assembly with the second cover member (400) removed can be seen with the connection area between the pack busbar hole (200H) and the pack busbar (200) exposed through the upper exposed portion (310) of the first cover member (300). Additionally, in FIG. 7, viewed from below, the connection area between the pack busbar hole (200H) and the pack busbar (200) exposed through the lower exposed portion (320) of the first cover member (300) can be seen.

[0067] As described above, the first cover member (300) and the second cover member (400) according to the present embodiment may include an electrically insulating material. The first cover member (300) and the second cover member (400) having electrical insulation function as an insulating layer that protects the pack busbar (200), thereby preventing the pack busbar (200) from coming into contact with other electrical components or conductive members and causing a short circuit.

[0068] For example, each of the first cover member (300) and the second cover member (400) according to the present embodiment may include a fire-resistant silicone material or a fire-resistant plastic material.

[0069] Unlike general silicone materials that burn when exposed to flames or high temperatures, the above-described refractory silicone material is a material that becomes ceramicized when exposed to flames or high temperatures. The above-described refractory silicone material may include a silicone polymer and silica. The silicone polymer applied may be a polysiloxane-based compound having a vinyl group as a functional group and corresponds to the substrate of the above-described refractory silicone material. The silica may be fumed silica, serving as a reinforcing filler included in the above-described silicone polymer. A high-purity silicon chloride (SiCl4) compound can be manufactured using metallic silicon as the main raw material through a reaction with hydrochloric acid and a purification process. Fumed silica can then be obtained by reacting this with hydrogen and oxygen in a high-temperature flame. Additionally, the refractory silicone material may include platinum (Pt) as a catalyst.

[0070] When the above-mentioned refractory silicone material is exposed to flame or high heat, the silicon polymer undergoes decomposition and the silica (SiO2) cross-links, thereby forming a ceramic material. The first cover member (300) according to the present embodiment can maintain electrical insulation properties by becoming ceramicized rather than burning or melting away, even when exposed to an internal flame or placed in a high-temperature environment.

[0071] Accordingly, even if a flame is generated due to thermal runaway in the battery pack (1000), the first cover member (300) is not burned or melted away but is ceramicized to maintain electrical insulation. Consequently, the electrical insulation of the busbar assembly (100) is maintained, and additional short circuits from the busbar assembly (100) are prevented, thereby preventing the flame from leading to an explosion of the battery pack or the vehicle equipped with the battery pack.

[0072] Additionally, the above-mentioned fireproof plastic material may include a flame-blocking plastic material that does not produce holes or drips even when exposed to flames or high heat. For example, the above-mentioned fireproof plastic material is a material that forms a carbonized layer that blocks flames when exposed to flames, and the first cover member (300) or the second cover member (400) containing the above-mentioned fireproof plastic material can protect internal electrical components from flames.

[0073] However, as described above, not all sides of the pack busbar (200) are covered by the first cover member (300), and the first cover member (300) has an upper exposed portion (310) in which the upper surface of the connection area of ​​the pack busbar (200) is exposed, and a lower exposed portion (320) in which the lower surface of the connection area is exposed. The upper exposed portion (310) and the lower exposed portion (320) are provided in the first cover member (300) to guide the connection between the pack busbar (200) and the terminal busbar (22). Hereinafter, with reference to FIGS. 11 and 12, the connection between the pack busbar (200) and the terminal busbar (22) and the placement of the second cover member (400) on the first cover member (300) will be described.

[0074] FIGS. 11 and FIGS. 12 are cross-sectional views illustrating the process of connecting a busbar assembly to a battery module.

[0075] Referring together to FIGS. 9, 10, 11 and 12, a busbar assembly (100) may be provided to connect any two battery modules. One pack busbar (200) may connect the terminal busbar (22) of the first battery module (1200a) and the terminal busbar (22) of the third battery module (1200c), and another pack busbar (200) may connect the terminal busbar (22) of the second battery module (1200b) and the terminal busbar (22) of the fourth battery module (1200d).

[0076] The first cover member (300) can be manufactured to wrap the upper, lower, and side surfaces of the pack busbar (200) by an insert molding method. That is, as shown in FIG. 11, the pack busbar (200) can be placed on the terminal busbar (22) while wrapped by the first cover member (300). At this time, since the lower exposed portion (320) is provided in the first cover member (300), the connection area of ​​the pack busbar (200) can come into contact with the terminal busbar (22) through the lower exposed portion (320). Additionally, the connection area of ​​the pack busbar (200) can be connected to the terminal busbar (22) of the battery module (1200) by a bolting connection. As illustrated in FIG. 11, the pack busbar (200) and the terminal busbar (22) can be connected by the bolt (500) passing through the pack busbar hole (200H) and the terminal busbar hole (22H) and joining with the nut (600). At this time, since the upper exposed portion (310) is provided in the first cover member (300), the bolt (500) can pass through the pack busbar hole (200H) and the terminal busbar hole (22H) in the connection area of ​​the pack busbar (200).

[0077] The second cover member (400) according to the present embodiment covers the first cover member (300) as described above. Specifically, the second cover member (400) includes a cap portion (410) covering the upper exposed portion (310) and a partition portion (420) that extends downward to cover a portion of the terminal bus bar (22) connected to the cap portion (410) and exposed through the opening (40H). Here, downward extension means extending in a direction toward the ground or the bottom of the pack frame (1100, see FIG. 2) from the point where the cap portion (410) is located. In addition, the bottom of the pack frame (1100) refers to the bottom of the pack frame (1100) where the battery modules (1200) are placed.

[0078] In the second cover member (400), the cap portion (410) and the partition portion (420) can be injection molded as a single unit. That is, the cap portion (410) and the partition portion (420) are not joined by a separate joining member, but can be in a form that is integrated with each other.

[0079] The side of the pack busbar (200) is covered by the first cover member (300), and the portion of the pack busbar (200) exposed through the lower exposed portion (320) is covered by being combined with the terminal busbar (22). The second cover member (400) according to the present embodiment can additionally cover the portion not covered by the first cover member (300). As shown in FIGS. 10 and 12, after the connection area of ​​the pack busbar (200) is connected to the terminal busbar (22) by bolting, the second cover member (400) can be placed on the first cover member (300). At this time, the cap portion (410) of the second cover member (400) covers the upper exposed portion (310). The cap portion (410) can cover the portion where the bolt (500) is exposed to the upper exposed portion (310) of the first cover member (300). Additionally, at least a portion of the cap portion (410) may be inserted into the upper exposed portion (310) of the first cover member (300). In other words, the cap portion (410) may cover the upper exposed portion (310) in a manner such that at least a portion of the cap portion (410) is inserted into the upper exposed portion (310) of the first cover member (300).

[0080] Additionally, the terminal busbar (22) exposed through the opening (40H) is covered by a partition (420) extending downward from the second cover member (400). In the height direction, the partition (420) may extend further down than the portion where the terminal busbar (22) contacts the connection area of ​​the pack busbar (200). Here, the height direction corresponds to a direction perpendicular to the ground and parallel to the z-axis.

[0081] As described above, the second cover member (400) can additionally cover a portion that the first cover member (300) cannot cover, and can also cover the portion of the terminal busbar (22) exposed through the opening (40H). That is, together with the first cover member (300), the second cover member (400) prevents the pack busbar (200) from coming into contact with other electrical components or conductive members and causing a short circuit. In particular, the partition portion (420) of the second cover member (400) can cover the portion of the pack busbar (200) and the terminal busbar (22) exposed from the battery module, and accordingly, the insulation distance between the pack busbar (200) and the terminal busbar (22), more specifically the clearance, is increased. Due to the demand for high-output, high-capacity battery modules and battery packs, the size of the pack busbar (200) or terminal busbar (22) increases, and the distance between battery modules is shortened for compact placement. Consequently, there is a risk of a short circuit occurring between adjacent pack busbars (200) or terminal busbars (22) in battery modules located close together. The partition portion (420) of the second cover member (400) according to the present embodiment extends downward and covers the pack busbar (200) and terminal busbar (22), thereby increasing the insulation distance and preventing a short circuit caused by a high voltage difference between adjacent pack busbars (200) or terminal busbars (22). Accordingly, in the case of a battery pack (1000) to which the busbar assembly (100) according to the present embodiment is applied, the battery modules (1200a, 1200b, 1200c, 1200d) can be arranged more compactly, and accordingly, the capacity or output of the battery pack (1000) can be increased.

[0082] In addition, in the conventional case illustrated in FIG. 1, dust (D) penetrates through the gap between the terminal busbar (22) and the opening (40H), and if this dust (D) accumulates on the exposed part of the terminal busbar (22), the risk of a short circuit with other electrical components inside the battery pack increases. On the other hand, the cap part (410) and the partition part (420) of the second cover member (400) according to the present embodiment can cover both the exposed part of the pack busbar (200) and the part of the terminal busbar (22) exposed through the opening (40H) so that they are not exposed. Accordingly, there is no risk of dust accumulating on the conductor, such as the terminal busbar (22), and consequently, it is possible to prevent additional short circuits caused by dust in a flame situation.

[0083] As described above, at least a portion of the cap portion (410) according to the present embodiment may be inserted into the upper exposed portion (310) of the first cover member (300). In particular, as at least a portion of the cap portion (410) is fitted into the upper exposed portion (310) of the first cover member (300), the second cover member (400) may be fixed to the first cover member (300). At this time, as in the conventional case shown in FIG. 1, a tape (20T) may be used to fix the cap (20C) to the covering member (20P). However, tape or adhesive releases carbonized gas in a flame situation. Carbonized gas generated in a flame situation can further accelerate the flame and have an adverse effect on maintaining electrical insulation. On the other hand, the second cover member (400) according to the present embodiment can be fixed to the first cover member (300) in the manner described above without a separate tape or adhesive, thus solving the problem of carbonized gas being released in a flame situation.

[0084] Meanwhile, in another embodiment of the present invention, the portion between one side of the first cover member (300) and the upper exposed portion (310) of the first cover member (300) can be fitted between the cap portion (410) and the partition portion (420) of the second cover member (400), thereby allowing the second cover member (400) to be fixed. That is, when the upper exposed portion (310) is provided on the first cover member (300), the portion between one side of the first cover member (300) and the upper exposed portion (310) can be utilized as a portion where the second cover member (400) can be fixed. However, this is an embodiment that can be applied additionally in addition to the fixing method by the cap portion (410) described above, and the present invention is not limited to this form.

[0085] The partition (420) according to the present embodiment may be located in the space (S, see FIG. 11) between one pack bus bar (200) connecting any two battery modules (1200a, 1200c) and another pack bus bar (200) connecting the other two battery modules (1200b, 1200d). Specifically, as described above, four first to fourth battery modules (1200a, 1200b, 1200c, 1200d) may be arranged so that two of them face each other. One pack busbar (200) may connect the terminal busbar (22) of the first battery module (1200a) and the terminal busbar (22) of the third battery module (1200c), and another pack busbar (200) may connect the terminal busbar (22) of the second battery module (1200b) and the terminal busbar (22) of the fourth battery module (1200d). At this time, the partition (420) according to the present embodiment may be located in the space (S) between the pack busbar (200) connecting the first battery module (1200a) and the third battery module (1200c) and the pack busbar (200) connecting the second battery module (1200b) and the fourth battery module (1200d).

[0086] Additionally, the partition (420) according to the present embodiment may block the space between one pack bus bar (200) connecting any two battery modules (1200a, 1200c) and another pack bus bar (200) connecting the other two battery modules (1200b, 1200d). The partition (420) according to the present embodiment may block the space between the pack bus bar (200) connecting the first battery module (1200a) and the third battery module (1200c) and the pack bus bar (200) connecting the second battery module (1200b) and the fourth battery module (1200d).

[0087] As in the present embodiment, the partition (420) is located in the space between the pack busbars (200) facing each other and can block the pack busbars (200). As previously described, the partition (420) according to the present embodiment allows the partition (420) of the second cover member (400) to cover the portion of the pack busbar (200) and the terminal busbar (22) exposed from the battery module, and accordingly, the insulation distance between the pack busbar (200) and the terminal busbar (22) can be increased. As an example of this, since the partition (420) blocks the space between the pack busbars (200) facing each other, the insulation distance between the pack busbars (200) is increased, thereby preventing a short circuit from occurring. The effect of increasing the insulation distance by this second cover member (400) may be more important in recent battery pack structures where the size of the pack busbar (200) or terminal busbar (22) increases and the distance between battery modules is shortened for a compact arrangement.

[0088] Additionally, the partition (420) according to the present embodiment can be fixed between pack busbars (200) facing each other. For example, as shown in FIGS. 10 and 12, the partition (420) can be fixed by being sandwiched between two pack busbars (200). More specifically, the partition (420) can be sandwiched between a first cover member (300) surrounding one pack busbar (200) and a first cover member (300) surrounding another pack busbar (200). Accordingly, when the second cover member (400) is fixed to the first cover member (300), an additional fixing effect can be achieved.

[0090] Hereinafter, with reference to FIGS. 13 to 21, the structure of a busbar assembly according to another embodiment of the present invention will be described in detail. However, parts similar to the structure of the busbar assembly described above will be omitted to avoid repetition of the description.

[0091] FIG. 13 is a top view of a busbar assembly according to another embodiment of the present invention. FIG. 14 is a top view showing the busbar assembly of FIG. 13 with the second cover member removed. FIG. 15 is a bottom view of the busbar assembly of FIG. 13. FIG. 16 is a cross-sectional view showing a section cut along the cutting line C-C' of FIG. 13. FIG. 17 is a side view of the busbar assembly of FIG. 13.

[0092] Referring to FIGS. 13 to 17, the busbar assembly (100) according to the present embodiment includes a pack busbar (200), a first cover member (300), and a second cover member (400). Since the pack busbar (200) and the first cover member (300) have the same structure as the busbar assembly described in FIGS. 5 to 8, a description thereof is omitted.

[0093] The second cover member (400) includes a cap portion (410) that covers the upper exposed portion (310) of the first cover member (300), and a partition portion (420) that is connected to the cap portion (410) and extends downward to cover a portion of the terminal busbar (22) exposed through an opening (40H). In this case, the second cover member (400) according to the present embodiment includes a plurality of cap portions (410), and the partition portion (420) may extend downward between the plurality of cap portions (410). The cap portions (410) and the partition portion (420) may be injection molded as a single unit. That is, the cap portions (410) and the partition portion (420) may not be joined by a separate joining member, but may be in a form that is integrated with each other.

[0094] FIG. 18 is a partial view showing an enlarged view of the connection portion between the busbar assembly and the battery modules according to another embodiment of the present invention. FIG. 19 is a cross-sectional view showing a cross section cut along the cutting line D-D' of FIG. 18.

[0095] Referring to FIGS. 13 to 19 together, four battery modules, namely the first to fourth battery modules (1200a, 1200b, 1200c, 1200d), can be arranged so that two of them face each other. One pack busbar (200) can connect the terminal busbar (22) of the first battery module (1200a) and the terminal busbar (22) of the third battery module (1200c), and another pack busbar (200) can connect the terminal busbar (22) of the second battery module (1200b) and the terminal busbar (22) of the fourth battery module (1200d). One connection area of ​​the pack busbar (200) may be connected by contacting the terminal busbar (22) of one first battery module (1200a), and another connection area of ​​the pack busbar (200) may be connected by contacting the terminal busbar (22) of the third battery module (1200c). Likewise, one connection area of ​​the other pack busbar (200) may be connected by contacting the terminal busbar (22) of one second battery module (1200b), and another connection area of ​​the other pack busbar (200) may be connected by contacting the terminal busbar (22) of the fourth battery module (1200d).

[0096] At this time, one of the plurality of cap portions (410) according to the present embodiment may cover the upper exposed portion (310) of the first cover member (300) that surrounds one pack busbar (200), and another of the plurality of cap portions (410) may cover the upper exposed portion (310) of the first cover member (300) that surrounds another pack busbar (200). That is, in the second cover member (400) according to the present embodiment, since the cap portions (410) are integrated and composed of multiple cap portions, the upper exposed portions (310) provided in each busbar assembly can be covered at once.

[0097] FIGS. 20 and FIGS. 21 are cross-sectional views illustrating the process of connecting a busbar assembly to a battery module.

[0098] Referring together to FIGS. 18 to 21, the first cover member (300) can be manufactured to wrap the upper, lower, and side surfaces of the pack busbar (200) by an insert molding method, and the connection area of ​​the pack busbar (200) can be connected to the terminal busbar (22) of the battery module (1200) by bolting. As shown in FIG. 20, the pack busbar (200) and the terminal busbar (22) can be connected by a bolt (500) passing through the pack busbar hole (200H) and the terminal busbar hole (22H) and being joined with a nut (600). At this time, since the upper exposed portion (310) is provided in the first cover member (300), the bolt (500) can pass through the pack busbar hole (200H) and the terminal busbar hole (22H) in the connection area of ​​the pack busbar (200).

[0099] After the connection area of ​​the pack busbar (200) is connected to the terminal busbar (22) by a bolting connection, the second cover member (400) can be placed on the first cover member. At this time, the cap portions (410) of the second cover member (400) can cover the upper exposed portions (310) provided on each of the busbar assemblies. In the second cover member (400) according to the present embodiment, since the cap portions (410) are integrated and composed of multiple parts, there is an advantage that the number of second cover members (400) required can be reduced.

[0100] The partition portion (420) of the second cover member (400) can cover the portion of the pack busbar (200) and the terminal busbar (22) exposed from the battery module, and accordingly, the insulation distance between the pack busbar (200) and the terminal busbar (22) is increased. In particular, the partition portion (420) can be located in the space (S) between the pack busbar (200) connecting the first battery module (1200a) and the third battery module (1200c) and the pack busbar (200) connecting the second battery module (1200b) and the fourth battery module (1200d). More specifically, the partition (420) can block the space between the pack busbar (200) connecting the first battery module (1200a) and the third battery module (1200c) and the pack busbar (200) connecting the second battery module (1200b) and the fourth battery module (1200d). The partition (420) can block the pack busbars (200) by being located in the space between the pack busbars (200) facing each other, and accordingly, the insulation distance between the pack busbars (200) and the terminal busbars (22) can be increased.

[0101] Additionally, the cap portions (410) and the partition portions (420) of the second cover member (400) can cover the entire portion of the exposed pack busbar (200) and the portion of the terminal busbar (22) exposed through the opening (40H) so that they are not exposed. Accordingly, there is no risk of dust accumulating on conductors such as the terminal busbar (22), and consequently, it is possible to prevent additional short circuits caused by dust in a flame situation.

[0102] Additionally, the portion between one side of the first cover member (300) and the upper exposed portion (310) of the first cover member (300) can be fitted between the cap portion (410) and the partition portion (420) of the second cover member (400), thereby fixing the second cover member (400). Since the second cover member (400) can be fixed to the first cover member (300) without separate tape or adhesive, the problem of carbonized gas being emitted in a flame situation can be resolved.

[0103] In particular, the partition member (420) according to the present embodiment can be sandwiched between a first cover member (300) that surrounds one pack bus bar (200) connecting any two battery modules (1200a, 1200c) and another first cover member (300) that surrounds another pack bus bar (200) connecting the other two battery modules (1200b, 1200d). Accordingly, when the second cover member (400) is fixed to the first cover member (300), an additional fixing effect can be achieved.

[0104] FIG. 22 is a perspective view showing an outer cover member according to one embodiment of the present invention. FIG. 23 is a perspective view showing an outer cover member and a glass fiber tape according to another embodiment of the present invention.

[0105] Referring to FIGS. 22 and 23, a busbar assembly according to one embodiment of the present invention may further include an outer cover member (700) that covers both a first cover member and a second cover member. An open area (700H) may be formed at the bottom of the outer cover member (700). Through the open area (700H) formed in the outer cover member (700), the pack busbar (200), the first cover member (300), and the second cover member (400) are fitted into the interior of the outer cover member (700). As shown in FIG. 22, the outer cover member (700) may have an empty space inside, and this empty space may be connected to the open area (700H) formed at the bottom. That is, the outer cover member (700) may include an upper surface and four side portions, and the internal space formed by the upper surface and the four side portions may be in communication with the open area (700H) formed at the bottom.

[0106] These outer cover members (700) may be mica plates containing mica material. The outer cover members (700) containing mica material can provide fire resistance and structural rigidity to the busbar assembly (100). Even if a flame occurs due to thermal runaway in the battery pack (1000), the outer cover members (700) do not melt and protect the internal pack busbar (200) from surrounding structures, thereby preventing additional short circuits from occurring.

[0107] In the busbar assembly according to the present embodiment, the outer surface of the outer cover member (700) may be wrapped by a glass fiber tape (800). The glass fiber tape (800) may include a substrate layer containing glass fibers and an adhesive layer formed on one side of the substrate layer. The substrate layer may be a fabric containing glass fibers, and the adhesive layer may include at least one of acrylic resin or silicone resin. The glass fiber tape (800) may be a rectangular tape having a long side and a short side. Although the glass fiber tape (800) is illustrated as wrapping only a portion of the outer surface of the outer cover member (700), this is for convenience of explanation, and the glass fiber tape (800) may wrap the entire outer surface of the outer cover member (700) so that the outer cover member (700) is not directly exposed.

[0108] This glass fiber tape (800) can serve as a primary fireproof wall. That is, by the glass fiber tape (800) directly protecting the pack busbar (200), the first cover member (300), and the second cover member (400) from flames, the fire resistance of the busbar assembly can be improved. In addition, structural rigidity can be increased because the outer surface of the outer cover member (700) is taped with the glass fiber tape (800).

[0109] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the observer.

[0110] One or more battery modules according to the embodiment described above can be mounted together with various control and protection systems, such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system, to form a battery pack.

[0111] The above battery module or battery pack can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, or to Energy Storage Systems (ESS), but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0112] 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 using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0113] 100: Busbar assembly 200: Pack busbar 300: First cover member 310: Upper exposed section 320: Lower exposed section 400: Second cover member 410: Cap 420: Bulkhead 1000: Battery pack 1100: Pack Frame 1200: Battery module 1300: BDU Module 1400: BMS Module

Claims

Claim 1 A battery pack comprising: battery modules including a plurality of battery cells; and a busbar assembly for electrically connecting the battery modules; wherein the battery module includes a terminal busbar electrically connected to the battery cell and having at least a portion exposed through an opening; the busbar assembly includes a pack busbar connected to the terminal busbar exposed through the opening; a first cover member covering the upper surface, lower surface, and sides of the pack busbar; and a second cover member covering the first cover member; wherein the pack busbar has at least two connection areas that are in contact with the terminal busbar; the first cover member has an upper exposure portion in which the upper surface of the connection area is exposed and a lower exposure portion in which the lower surface of the connection area is exposed; and the second cover member includes a cap portion covering the upper exposure portion and a partition portion extending downward to cover the portion of the terminal busbar exposed through the opening. Claim 2 In claim 1, the battery pack, based on the height direction, has a partition that extends further down than the portion where the terminal busbar contacts the connection area of ​​the pack busbar. Claim 3 A battery pack according to claim 1, wherein at least a portion of the cap portion is inserted into the upper exposed portion. Claim 4 A battery pack in which, in claim 1, the portion between one side of the first cover member and the upper exposed portion among the first cover members is fitted between the cap portion and the partition portion of the second cover member, thereby fixing the second cover member. Claim 5 In claim 1, the bulkhead portion is a battery pack located in the space between one of the pack busbars connecting any two battery modules and another of the pack busbars connecting the other two battery modules. Claim 6 A battery pack according to claim 1, wherein the partition section is a blocking section between one of the pack busbars connecting any two battery modules and another of the pack busbars connecting the other two battery modules. Claim 7 In claim 1, the above partition is a battery pack sandwiched between the first cover member surrounding one of the pack busbars connecting any two battery modules and the first cover member surrounding another of the pack busbars connecting the other two battery modules. Claim 8 In claim 1, the second cover member comprises a plurality of cap portions, and the partition portion is a battery pack extending downward between the plurality of cap portions. Claim 9 In claim 1, the first cover member and the second cover member comprise an electrically insulating material, forming a battery pack. Claim 10 A battery pack in which the cap portion and the partition portion are integrally injection molded in claim 1. Claim 11 A battery pack according to claim 1, wherein a pack busbar hole is formed in the connection area of ​​the pack busbar, a terminal busbar hole is formed in the terminal busbar of the battery module, and a bolt passes through the pack busbar hole and the terminal busbar hole through the upper exposed portion and is coupled with a nut, thereby connecting the pack busbar and the terminal busbar. Claim 12 In Clause 11, the above cap portion covers the part where the bolt is exposed to the upper exposed portion of the battery pack. Claim 13 In claim 1, the busbar assembly further comprises an outer cover member that covers both the first cover member and the second cover member, forming a battery pack. Claim 14 In paragraph 13, the outer cover member is a battery pack that is a mica plate. Claim 15 A battery pack in which the outer surface of the outer cover member is wrapped with glass fiber tape in Clause 13. Claim 16 A device including a battery pack according to paragraph 1.

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