Busbar assembly and battery pack including same

Abstract

A busbar assembly according to one embodiment of the present invention comprises: a busbar connected to a terminal busbar of a plurality of battery modules so as to guide an electrical connection between two battery modules from among the plurality of battery modules; and expandable members, each arranged at both ends of the busbar, wherein, when the predetermined temperature is reached, the expandable members can increase in volume toward the terminal busbar so as to shield an open area formed by the terminal busbar on the battery module connected to the busbar.

Description

Busbar assembly and battery pack including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0093636, filed July 16, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a busbar assembly and a battery pack including the same, and more particularly, to a busbar assembly and a battery pack including the same, which can prevent a thermal event from spreading to other battery modules when a thermal event occurs in some of the battery modules included in the battery pack.

[0004] In modern society, the widespread use of portable devices like cell phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), has led to active development of related technologies. Furthermore, rechargeable secondary batteries are increasingly being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) to address air pollution issues caused by conventional gasoline-powered vehicles. This, in turn, heightens the need for further development of these batteries.

[0005] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0006] Secondary batteries used in small devices are configured with two to three battery cells, but secondary batteries used in medium to large devices such as automobiles utilize battery modules in which multiple battery cells are electrically connected. These battery modules enhance capacity and output by forming a battery cell stack by connecting multiple battery cells in series or parallel. In addition, one or more battery modules may 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] Battery packs comprised of multiple battery modules can experience rapid and severe temperature increases due to the accumulation of heat from the numerous battery cells within a confined space. In other words, while battery modules stacked with multiple battery cells and battery packs equipped with these modules can achieve high output, there is a high risk of explosion or fire if the battery cells fail to dissipate heat properly or if thermal runaway occurs.

[0008] Meanwhile, a bus bar connected to the battery module is provided inside the battery pack. Fig. 1 is a plan view showing a conventional bus bar, and Fig. 2 is a cross-sectional view taken along the cutting line A-A' of Fig. 1.

[0009] Referring to FIGS. 1 and 2, a conventional bus bar (20) is a metal member in the shape of a bar extending in the longitudinal direction, and a through hole may be formed at both ends of the bus bar (20) for connection with a terminal bus bar of a battery module. This bus bar (20) is a component that is responsible for HV (High voltage) connection in a battery pack. The HV connection refers to a connection that serves as a power source for supplying electric power, and the bus bar (20) is a component that guides the electrical connection of the battery module, and generally includes a metal material with excellent electrical conductivity. For example, the bus bar (20) may include a copper (Cu) material.

[0010] A covering member (20C) can wrap around the bus bar (20). The covering member (20C) can include an electrically insulating material, for example, a silicone material or an epoxy material. Since the covering member (20C) wraps around the bus bar (20) through which a high current flows, the bus bar (20) is prevented from coming into contact with other electrical components or conductive members other than the terminal bus bar of the battery module, thereby preventing a short circuit from occurring.

[0011] Recently, battery packs require a structure that prevents a thermal event from spreading to other battery modules even if it occurs in some of the battery modules contained within the battery pack. There is a high risk that a flame generated inside a battery module will spread to the outside through an open portion of the battery module. For example, the flame may initially erupt from an open portion, such as the terminal bus bar of the battery module. When a thermal event occurs, the temperature of the flame is very high, approximately 1000°C. Therefore, in the case of a conventional bus bar (20), the covering member (20C) may melt, exposing the bus bar (20). If the exposed bus bar (20) comes into contact with another electrical component or conductive member, causing a short circuit, the internal flame will further spread and may spread to the outside of the battery pack. Ultimately, this may lead to an explosion of the battery pack or the vehicle in which the battery pack is mounted.

[0012] Therefore, a configuration capable of primarily preventing the propagation of flames due to thermal events occurring inside the battery module is required.

[0013] The problem to be solved by the present invention is to provide a busbar assembly and a battery pack including the same that can prevent a thermal event from spreading to other battery modules when a thermal event occurs in some of the battery modules included in the battery pack.

[0014] However, the problems to be solved by the embodiments of the present invention 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.

[0015] A busbar assembly according to one embodiment of the present invention includes a busbar connected to terminal busbars of a plurality of battery modules to guide electrical connection between two battery modules among the plurality of battery modules, and an expandable member disposed on each end of the busbar, wherein the expandable member can increase in volume toward the terminal busbar when a predetermined temperature is reached to shield at least a portion of an open area formed when the terminal busbar is exposed to the outside on the battery module.

[0016] The above busbar assembly further includes a pair of cap members surrounding at least a portion of both ends of the busbar, wherein the cap members may include a pocket portion in which the expandable member is disposed.

[0017] The cap member includes a pillar portion extending upward from an end of the bus bar, and the pocket portion can be formed on the pillar portion.

[0018] The cap member further includes a plate-shaped portion formed on the upper side of the pillar portion, and the pocket portion can be formed between the end of the bus bar and the plate-shaped portion.

[0019] The above pocket portion can be formed by being sunken inward from the surface of the pillar portion.

[0020] The above pocket portion may be formed to surround at least a portion of the perimeter of the above pillar portion.

[0021] The above pocket portion can be formed to surround the entire circumference of the pillar portion.

[0022] The cap member further includes a through hole penetrating the pillar portion, and a fixing member for connecting the electrode and the bus bar can be inserted through the through hole.

[0023] The above inflatable member can be placed in the pocket portion by heterogeneous injection or spray application.

[0024] It further includes a connecting member integrated with the pair of cap members, and the pair of cap members and the connecting member can be formed of an insulating member.

[0025] The above insulating member may include a refractory silicone material.

[0026] The above inflatable member may include at least one of silica gel, foamed silicone, polyurethane, and polypropylene.

[0027] The above battery module includes an opening exposing the terminal bus bar to the outside, and the open area may be an area other than an area occupied by the terminal bus bar on the opening.

[0028] A battery pack according to one embodiment of the present invention includes at least one busbar assembly and a plurality of battery modules, wherein the at least one busbar assembly can electrically connect between the plurality of battery modules.

[0029] The battery pack further includes a BDU (Battery Disconnect Unit) module for controlling electrical connection of the battery modules and a BMS (Battery Management System) module for monitoring and controlling operation of the battery modules, and the at least one busbar assembly can electrically connect at least one of the plurality of 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.

[0030] The inflatable member may increase in volume to shield an open area of ​​at least one of the battery module, the BDU module, and the BMS module when the predetermined temperature is reached.

[0031] A busbar assembly according to embodiments of the present invention and a battery pack including the same can prevent an open area of ​​a battery module from being exposed to the outside by expansion of an expandable member when a thermal event occurs in some of the battery modules included in the battery pack, thereby preventing the thermal event from spreading to other battery modules.

[0032] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0033] Figure 1 is a plan view showing a conventional bus bar.

[0034] Fig. 2 is a cross-sectional view showing a cross-section taken along the cutting line A-A' of Fig. 1.

[0035] Figure 3 is a plan view showing a battery pack according to one embodiment of the present invention.

[0036] FIG. 4 is a perspective view showing one of the battery modules included in the battery pack of FIG. 3.

[0037] Fig. 5 is a partial perspective view showing the battery module of Fig. 4 with the module frame and end plate removed.

[0038] Figure 6 is a perspective view of a busbar assembly according to one embodiment of the present invention.

[0039] Figure 7 is a perspective view of the busbar assembly illustrated in Figure 6 from a different angle.

[0040] Fig. 8 is a cross-sectional view showing a cross-section taken along the cutting line B-B' of Fig. 6.

[0041] Fig. 9 is a cross-sectional view showing a cross-section taken along the cutting line C-C' of Fig. 8.

[0042] FIG. 10 is a perspective view of a busbar assembly according to another embodiment of the present invention.

[0043] FIG. 11 is a drawing exemplarily illustrating a state in which a plurality of battery modules are electrically connected by a busbar assembly according to one embodiment of the present invention.

[0044] FIG. 12 is a drawing exemplarily illustrating a state in which a cell event occurs in one of a plurality of battery modules electrically connected by a busbar assembly according to one embodiment of the present invention.

[0045] Fig. 13 is a drawing illustrating an example of an expanded form of an expandable member in the busbar assembly illustrated in Fig. 12.

[0046] 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 invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0047] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0048] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0049] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on" or "over" another part, this includes not only cases where it is "directly on" the other part, but also cases where there are other parts in between. Conversely, when we say that a part is "directly on" another part, it means that there are no other parts in between. Furthermore, saying that a part is "on" or "over" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "over" the direction opposite to gravity.

[0050] Additionally, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0051] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0052] Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

[0053] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0054] Figure 3 is a plan view showing a battery pack according to one embodiment of the present invention.

[0055] Referring to FIG. 3, a battery pack (1000) according to one embodiment of the present invention may include a busbar assembly (100), battery modules (1200), a BDU (battery disconnect unit) module (1300) for controlling electrical connection of the battery modules (1200), and a BMS (battery management system) 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 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 the battery modules (1200) or electrical connections between the battery modules (1200) and the BDU module (1300) can be made by the busbar assembly (100). That is, the busbar assembly (100) according to the present embodiment can be responsible for HV (High voltage) connections. Here, the HV connection is a connection that serves as a power source for supplying power requiring high voltage, and means a connection between battery cells or a connection between battery modules.

[0056] The BDU module (1300) is a member for controlling the electrical connection of the battery module (1200) and can cut off power between the power conversion device and the battery module (1200). The BDU module (1300) can cut off power to the battery pack (1000) when a condition occurs in which the current exceeds a set range, thereby ensuring the safety of the battery pack (1000).

[0057] Meanwhile, the LV connecting member (100') according to the present embodiment can be responsible for the electrical connection between the battery module (1200) and the BMS module (1400). The electrical connection here is a LV (Low voltage) connection, which means a sensing connection for detecting and controlling the voltage and temperature of the battery module (1200). Specifically, sensors, etc., are arranged inside the battery module (1200), and real-time temperature information or voltage information of the battery module (1200) can be transmitted to the BMS module (1400) through the LV connecting member (100'). The real-time operating status of the battery module (1200) can be monitored and controlled through the BMS module (1400). Although not specifically 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 may be responsible for electrical connection between the battery module (1200) and the BMS module (1400) or between the BDU module (1300) and the BMS module (1400).

[0058] Hereinafter, a battery module (1200) according to the present embodiment will be described with reference to FIGS. 4 and 5. However, the battery module (1200) described below is an exemplary structure of a battery module including a plurality of battery cells (11), and various types of battery modules including a plurality of battery cells may be applied.

[0059] Fig. 4 is a perspective view showing one of the battery modules included in the battery pack of Fig. 3. Fig. 5 is a partial perspective view showing the battery module of Fig. 4 with the module frame and end plate removed.

[0060] Referring to FIGS. 4 and 5, the battery module (1200) according to the present embodiment 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. 5. This battery cell stack (11A) may be accommodated in a module frame (30) and an end plate (40).

[0061] The battery cell (11) may be a pouch-type battery cell. Such a pouch-type battery cell may be formed by housing an electrode assembly in a pouch case made of a laminate sheet including a resin layer and a metal layer, and then fusing the outer periphery of the pouch case. Such a battery cell (11) may be formed in a rectangular sheet structure. An electrode lead (11L) connected to the electrode assembly protrudes to the outside of the pouch case, and the electrode leads (11L) of each battery cell (11) may be electrically connected to each other via a lead bus bar (21). Meanwhile, at least one electrode lead (11L) may be connected to a terminal bus bar (22). A portion of the terminal bus bar (22) may be exposed to the outside of the battery module (1200), as illustrated in FIG. 4. Both the lead bus bar (21) and the terminal bus bar (22) may include a metal material having excellent electrical conductivity.

[0062] The busbar assembly (200) 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) via the busbar assembly (200) connected to the terminal busbar (22).

[0063] As described above, the battery cells and battery modules described in FIGS. 4 and 5 are exemplary structures, and there is no particular limitation on the type or shape of the battery cells and battery modules included in the battery pack to which the busbar assembly according to the present embodiment is applied. That is, although a pouch-type battery cell has been described as an example, square battery cells or cylindrical battery cells can also be applied to the battery module according to the embodiment of the present invention. In addition, although a battery module in which the battery cells are housed in a module frame has been described as an example, a CTP (cell to pack) type battery module in which a plurality of battery cells are mounted in a battery pack without being housed in a module frame can also be applied as an example of the present invention.

[0064] Fig. 6 is a perspective view of a busbar assembly according to one embodiment of the present invention. Fig. 7 is a perspective view of the busbar assembly illustrated in Fig. 6 from a different angle. Fig. 8 is a cross-sectional view taken along the section line B-B' of Fig. 6. Fig. 9 is a cross-sectional view taken along the section line C-C' of Fig. 8.

[0065] Referring to FIGS. 6 to 9, a busbar assembly (200) according to one embodiment of the present invention may include a busbar (210) that is connected to terminal busbars (22) of a plurality of battery modules (1200) to guide electrical connection between two battery modules (1200) among the plurality of battery modules (1200), an expandable member (220) that is respectively disposed on both ends (212) of the busbar (210), and a pair of cap members (230) that surround at least a portion of both ends (212) of the busbar (210).

[0066] The bus bar (210) is a member for guiding the electrical connection, i.e., the HV connection, between internal components such as electrical components or battery modules (1200) accommodated inside the battery pack (1000). The bus bar (210) may include both ends (212) and a main body (211), and the both ends (212) of the bus bar and the main body (211) may be integrated with each other. For example, the bus bar (210) may have a shape like a metal bar extending in one direction. However, the shape of the bus bar (210) is not limited to the above-described shape, and may be variously modified or changed depending on the environment in which the present invention is implemented. For example, the bus bar (210) may be a flexible bus bar and may have a shape in which a portion is bent along an empty space inside the battery pack (1000).

[0067] As in the example illustrated in Fig. 7, the lower surfaces of both ends (212) of the bus bar (210) may be exposed to the outside. That is, the lower surfaces of both ends (212) of the bus bar (210) may not be covered by the cap member (230) and the connecting member (240) described later. Here, the lower surfaces of both ends (212) of the bus bar (210) may come into contact with internal components such as electrical components or battery modules (1200) accommodated inside the battery pack (1000) and may be electrically connected to the components.

[0068] The busbar (210) may include a metal material with excellent electrical conductivity to guide electrical connections. For example, the busbar (210) may include copper (Cu). However, the material of the busbar (210) is not limited to the above-described material and may be modified or altered in various ways depending on the environment in which the present invention is implemented.

[0069] The bus bar (210) may have at least two connecting portions that are in contact with the terminal bus bars (22) of the battery module (1200). For example, one connecting portion (e.g., one end (212)) of the bus bar (210) may be connected by making contact with the terminal bus bar (22) of one battery module (1200), and the other connecting portion (e.g., the other end (212)) of the bus bar (210) may be connected by making contact with the terminal bus bar (22) of another battery module (1200). Accordingly, the bus bar (210) may electrically connect the terminal bus bars (22) of the battery modules (1200) to each other. As long as physical and electrical connection is possible, there is no particular limitation on the connection method between the bus bar (210) and the terminal bus bar (22). For example, both ends (212) of the bus bar (210) can be connected to the terminal bus bar (22) of the battery module (1200) through a bus bar fastening member (213) described later, such as by bolting.

[0070] The expandable member (220) can increase in volume when a predetermined temperature is reached. For example, the expandable member can expand at a temperature of about 150°C or higher.

[0071] As described below, when a thermal event or thermal runaway occurs in one of a plurality of battery cells (11) within a battery module (1200), the expandable member (220) can prevent venting gas, particles, flames, etc. generated from the battery cell (11) in which the thermal event or thermal runaway occurred from leaking out from an open area formed in the battery module (1200) and spreading to an adjacent battery module (1200). That is, as described below, the expandable member (220) can expand in volume to shield the open area of ​​the battery module (1200).

[0072] The expandable member (220) may include materials corresponding to foamed polymers that increase in volume at a predetermined temperature. For example, the expandable member (220) may include at least one of silica gel, foamed silicone, polystyrene, polyurethane, polyethylene, and polypropylene. Meanwhile, the expansion temperature and material of the expandable member (220) are not limited by the above-described, and may include various foamed materials having high-temperature durability, electrical insulation, etc., and may have an expansion temperature depending on the material.

[0073] The expandable member (220) may expand toward the terminal busbar (22) to shield at least a portion of an open area of ​​the battery module (1200) connected to the busbar (210) when the volume increases. At this time, the open area may be an area formed by the terminal busbar (22) on the battery module (1200). For example, the open area may be an area formed as the terminal busbar (22) of the battery module (1200) is exposed to the outside of the battery module (1200). More specifically, the battery module (1200) includes an opening that exposes the terminal busbar (22) to the outside, and the open area may be an area other than an area occupied by the terminal busbar (22) on the opening. That is, the open area may be a gap formed between the module frame (30) of the battery module (1200) and the terminal busbar (22).

[0074] The inflatable member (220) may be placed on a pair of cap members (230) placed at both ends (212) of the bus bar (210). For example, the inflatable member (220) may be placed in the pocket portion (232) by heterogeneous injection or spray application.

[0075] Heterogeneous injection molding is an injection molding method for manufacturing a single part using two or more different materials. The cap member (230) and / or connecting member (240) and the expandable member (220) described below can be formed on the busbar (210) by heterogeneous injection molding. At this time, in the heterogeneous injection molding process, a hot melt material is injected into the mold using low injection pressure and quickly hardened, thereby forming a busbar assembly (200).

[0076] Spray application may be arranged in such a way that the expandable member (220) is applied within the pocket portion (232) of the cap member (230) formed by the injection molding method. However, the method by which the expandable member (220) is formed or arranged in the pocket portion (232) is not limited to the above-described method, and may be variously modified or changed depending on the environment in which the present invention is implemented.

[0077] The cap member (230) may include a pillar portion (231) extending upward from each end (212) of the bus bar (210), a pocket portion (232) in which the expandable member (220) is placed, and a plate portion (233) formed on the upper side of the pillar portion (231).

[0078] The pocket portion (232) may be formed on the pillar portion (231). More specifically, the pocket portion (232) may be formed between the end portion (212) of the bus bar (210) and the plate portion (233). The pocket portion (232) may be an empty space having a certain volume in which the expandable member (220) is placed. For example, the pocket portion (232) may be formed by recessing inward from the surface of the pillar portion (231) of the cap member (230), and the expandable member (220) may be placed on the space formed by the pocket portion (232).

[0079] The pocket portion (232) may be formed to surround at least a portion of the circumference of the pillar portion (231). As in the example illustrated in FIG. 6, the pocket portion (232) may be formed by recessing one side in the longitudinal direction along which the bus bar (210) extends on the pillar portion (231) and both side sides in the width direction of the bus bar (210) perpendicular to the longitudinal direction. Accordingly, as in the example illustrated in FIG. 4, the bus bar assembly (200) may be coupled to the battery module (1200) in various directions.

[0080] The cap member (230) may further include a through hole (234) penetrating the pillar portion (231). A fixing member (not shown) for connecting the electrode and the bus bar (210) may be inserted through the through hole (234). For example, the fixing member may be connected to the terminal bus bar (22) of the battery module (1200) by penetrating the through hole (234) of the cap member (230) and the bus bar fastening holes (213) formed at both ends (212) of the bus bar (210). In the above-described manner, the bus bar assembly (200) and the terminal bus bar (22) of the battery module (1200) may be physically and electrically connected.

[0081] The busbar assembly (200) may further include a connecting member (240) that is integrally formed with a pair of cap members (230). Specifically, one end of the connecting member (240) may be integrally formed with the cap member (230) that surrounds at least a portion of one end of the busbar (210), and the other end of the connecting member (240) may be integrally formed with the cap member (230) that surrounds at least a portion of the other end of the busbar (210). For example, the connecting member (240) and the pair of cap members (230) may be integrally formed by injection molding.

[0082] The connecting member (240) may be formed to extend along the longitudinal direction of the bus bar (110) between a pair of cap members (230). For example, the connecting member (240) may be positioned on the upper and lower surfaces of the main body (211) of the bus bar (210), as in the example illustrated in FIG. 5, and may extend along the longitudinal direction of the bus bar (210). However, the position of the connecting member (240) is not limited to the above-described position, and may be variously modified or changed to an appropriate position as needed.

[0083] A pair of cap members (230) and a connecting member (240) may be formed of an insulating material. As described above, the pair of cap members (230) may surround at least a portion of both ends (212) of the bus bar (210) (e.g., the remaining portion excluding the lower surface of both ends (212)), and the connecting member (240) may surround the main body (211) between the both ends (212) of the bus bar (210). Accordingly, in a busbar assembly (200) according to one embodiment of the present invention, a pair of cap members (230) and a connecting member (240) surround at least a portion of both ends (212) of the busbar (210) and the outer surface of the main body (211), thereby forming an insulating structure for the busbar (210) from the external environment, and preventing an electrical short between the busbar (210) and other metal structures and / or electrical components.

[0084] Here, the insulating member may include a refractory silicone material. The refractory silicone material may be ceramicized in a high-temperature environment. For example, the refractory silicone material may be ceramicized at a temperature of about 200°C or higher.

[0085] The above-mentioned refractory silicone material is a material that becomes ceramicized when exposed to flame or high temperature, unlike general silicone materials that burn when exposed to flame or high temperature. The above-mentioned refractory silicone material may include a silicone polymer and silica. The applicable silicone polymer may be a polysiloxane series compound having a vinyl group as a functional group, and corresponds to the base material of the refractory silicone material. The silica may be fumed silica as a reinforcing filler included in the silicone polymer. A high-purity silicon chloride (SiCl4) compound can be manufactured using metallic silicon as a main raw material through a reaction with hydrochloric acid and a purification process. Fumed silica can be obtained by reacting this with hydrogen and oxygen in a high-temperature flame. In addition, the refractory silicone material may include platinum (Pt) as a catalyst.

[0086] When the above-mentioned refractory silicone material is exposed to flame or high temperature, the silicone polymer decomposes and silica (SiO2) is cross-linked to form a ceramic material. The refractory silicone member (300) according to the present embodiment maintains electrical insulation properties by being ceramicized rather than burning or melting even when exposed to an internal flame or placed in a high-temperature environment.

[0087] FIG. 10 is a perspective view of a busbar assembly according to another embodiment of the present invention.

[0088] Referring to FIG. 10, the pocket portion (232) may be formed to surround the entire circumference of the pillar portion (231). Compared to the embodiment illustrated in FIG. 6, since the pocket portion (232) is formed to surround the entire circumference of the pillar portion (231), the expandable member (220) accommodated in the pocket portion (232) may also be arranged to surround the entire pillar portion (231). Accordingly, the busbar assembly (200) illustrated in FIG. 10 can more effectively shield an open area of ​​the battery module (1200) where a cell event, such as a thermal runaway phenomenon, has occurred, regardless of the direction in which the busbar assembly (200) is coupled to the battery module (1200). In addition, since the weight and / or volume in which the expandable member (220) is arranged may increase, the busbar assembly (200) illustrated in FIG. 10 can effectively shield a wider area.

[0089] FIG. 11 is a drawing exemplarily illustrating a state in which a plurality of battery modules are electrically connected by a busbar assembly according to an embodiment of the present invention. FIG. 12 is a drawing exemplarily illustrating a state in which a cell event occurs in any one of a plurality of battery modules electrically connected by a busbar assembly according to an embodiment of the present invention. FIG. 13 is a drawing exemplarily illustrating a state in which an expandable member in the busbar assembly illustrated in FIG. 12 has expanded.

[0090] Referring to FIGS. 11 to 13, the busbar assembly (200) electrically connects between battery modules (1200). For example, as illustrated in FIG. 4, the busbar assembly (200) can electrically connect between terminal busbars (22) of the battery modules (1200). That is, each of the two ends (212) of the busbar assembly (200) can be connected to a terminal busbar (22) of the battery module (1200). However, the objects to which the busbar assembly (200) electrically connects are not limited by the above-described. For example, one or more battery modules (1200) according to the present 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 (1000). At this time, the busbar assembly (200) can electrically connect at least one of the battery modules (1200), the battery module (1200) and the BDU module (1300), the battery module (1200) and the BMS module (1400), or the BDU module (1300) and the BMS module (1400). For convenience of explanation, the following description is based on the busbar assembly (200) that electrically connects the battery modules (1200), but the same may also be applied to the busbar assembly (200) that electrically connects other components.

[0091] As described above, the environment in which the expandable member (220) expands may be a high-temperature environment in which the temperature inside the battery pack (1000) is elevated due to phenomena such as overcurrent, overheating, and thermal runaway of a plurality of battery modules (1200) mounted inside the battery pack (1000). For example, the high-temperature environment may be an environment heated to a temperature at which a fire occurs in a battery cell (11) located inside the battery pack (1000) due to a cell event (CE) such as thermal runaway, and some of the internal components of the battery pack (1000) may be destroyed.

[0092] As illustrated in FIG. 12, when a cell event (CE) occurs inside a specific battery module (1200) among a plurality of battery modules (1200), venting gas, particles, flames, etc. may be generated from inside the battery module (1200) and may spread to the surroundings. Specifically, the venting gas, particles, flames, etc. generated from the battery module (1200) where the cell event (CE) occurred may be discharged to the outside through an open area of ​​the specific battery module (1200), for example, an open area formed near the terminal bus bar (22). At this time, when the high-temperature venting gas, particles, or flames, etc. reach the bus bar assembly (200), they come into contact with the expandable member (220) arranged in the pocket portion (232) of the bus bar assembly (200), and the expandable member (220) accommodated in the pocket portion (232) may be heated.

[0093] The expanded portion (220e) of the expandable member (220) mainly shields an open area formed near the terminal bus bar (22) of the battery module (1200) where a cell event (CE) has occurred, thereby blocking venting gas, particles, flames, etc. generated from inside the battery module (1200) from being discharged to the outside and blocking air from being introduced into the battery module (1200). Accordingly, the expanded portion (220e) of the expandable member (220) can have a heat-insulating effect and a combustion delay effect, thereby preventing venting gas, particles, flames, etc. generated from the battery module (1200) where a cell event (CE) has occurred from being transmitted to another adjacent battery module (1200).

[0094] Meanwhile, as described above, the busbar assembly (200) can electrically connect not only the battery modules (1200) but also other components (e.g., BDU module (1300) and BMS module (1400), etc.), so that when a predetermined temperature is reached, the busbar assembly (200) can expand in volume to shield the open areas of the BDU module (1300) and BMS module (1400) coupled with the busbar assembly (200).

[0095] Meanwhile, the battery modules and battery packs including the same according to embodiments of the present invention can be applied to various devices. Such devices can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, and / or energy storage systems (ESS). However, the present invention is not limited thereto, and can be applied to various devices that can use the battery modules and battery packs including the same, which also fall within the scope of the present invention.

[0096] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0097] [Explanation of symbols]

[0098] 200: Busbar assembly

[0099] 210: Busbar

[0100] 211: Main Body

[0101] 212: End

[0102] 213: Busbar fastener

[0103] 220: Inflatable member

[0104] 230: Cap absence

[0105] 231: Pillar

[0106] 232: Pocket

[0107] 233: Plate top

[0108] 234: Penetration hole

[0109] 240: Absence of connection

[0110] 1000: Battery pack

[0111] 1100: Pack Frame

[0112] 1200: Battery module

[0113] 1300: BDU module

[0114] 1400: BMS module

Claims

1. A bus bar connected to the terminal bus bars of a plurality of battery modules and guiding electrical connection between two battery modules among the plurality of battery modules; and Including an expandable member disposed on each end of the above bus bar, A busbar assembly wherein the inflatable member increases in volume toward the terminal busbar when a predetermined temperature is reached so as to shield at least a portion of the open area formed as the terminal busbar is exposed to the outside on the battery module.

2. In paragraph 1, Further comprising a pair of cap members surrounding at least a portion of both ends of the above bus bar, A busbar assembly, wherein the cap member includes a pocket portion in which the expandable member is placed.

3. In paragraph 2, The above cap member includes a pillar portion extending upward from the end of the bus bar, A busbar assembly in which the pocket portion is formed on the pillar portion.

4. In paragraph 3, The above cap member further includes a plate-shaped portion formed on the upper side of the pillar portion, A busbar assembly, wherein the pocket portion is formed between the end portion of the busbar and the plate portion.

5. In paragraph 3, A busbar assembly in which the pocket portion is formed by recessing inward from the surface of the pillar portion.

6. In paragraph 3, A busbar assembly, wherein the pocket portion is formed to surround at least a portion of the circumference of the pillar portion.

7. In paragraph 3, A busbar assembly in which the pocket portion is formed to surround the entire circumference of the pillar portion.

8. In paragraph 3, The cap member further includes a through hole penetrating the pillar portion, A busbar assembly in which a fixing member for connecting the electrode and the busbar is inserted through the above through-hole.

9. In paragraph 2, A busbar assembly wherein the above inflatable member is placed in the pocket portion by heterogeneous injection or spray application.

10. In paragraph 1, Further comprising a connecting member integrated with the pair of cap members, A busbar assembly, wherein the pair of cap members and the connecting member are formed of an insulating member.

11. In paragraph 10, A busbar assembly wherein the insulating member comprises a refractory silicone material.

12. In paragraph 1, A busbar assembly wherein the inflatable member comprises at least one of silica gel, foamed silicone, polyurethane and polypropylene.

13. In paragraph 1, The above battery module includes an opening exposing the terminal bus bar to the outside, A busbar assembly, wherein the above open area is an area other than the area occupied by the terminal busbar on the above opening.

14. At least one busbar assembly according to paragraph 1; and Contains multiple battery modules, A battery pack, wherein at least one busbar assembly electrically connects between the plurality of battery modules.

15. In paragraph 14, A BDU (Battery Disconnect Unit) module for controlling the electrical connection of the above battery module; and Further comprising a BMS (Battery Management System) module that monitors and controls the operation of the above battery module, A battery pack, wherein said at least one busbar assembly electrically connects at least one of the plurality of 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.

16. In paragraph 15, A battery pack, wherein the inflatable member increases in volume when the predetermined temperature is reached to shield an open area of ​​at least one of the battery module, the BDU module, and the BMS module.

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