Battery assembly and battery pack including the same

Abstract

A battery assembly according to an embodiment of the present invention includes a plurality of battery cells, a frame accommodating the plurality of battery cells, an inlet port and an outlet port for circulating a coolant inside the frame, and a venting unit provided on one side of the frame for discharging gas inside the frame when the pressure inside the frame exceeds a certain pressure. The coolant introduced through the inlet port directly cools the battery cells and is discharged through the outlet port.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0153058, filed November 7, 2023, and Korean Patent Application No. 10-2024-0154100, filed November 4, 2024, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery assembly and a battery pack including the same, and more particularly to an immersion cooling type battery assembly and a battery pack including the same. [Background technology]

[0003] Secondary batteries, which are easy to apply to various products and have electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electrical sources. These secondary batteries not only have the primary advantage of dramatically reducing the use of fossil fuels, but are also widely used as an energy source for environmental considerations and to increase energy efficiency, as they do not produce any by-products from energy use.

[0004] Secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting multiple battery cells in series. Alternatively, a battery pack may be configured by connecting multiple battery cells in parallel depending on the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack may be variously set depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, when connecting a plurality of battery cells in series / parallel to form a battery pack, a common method is to first form a battery module by creating a battery cell assembly including a plurality of battery cells and housing it in a module case, and then assemble one or more such battery modules and add other components to form a battery pack, or to place a plurality of battery cells in a pack frame and add other components to form a battery pack.

[0006] Because such battery cells are composed of rechargeable secondary cells, such high-power, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat generated from the multiple battery cells may be combined in a small space, causing a rapid and intense rise in temperature. In other words, a battery pack including multiple battery cells can obtain high power output, but it is difficult to remove the heat generated in the battery cells during charging and discharging. If the heat dissipation of the battery cells is not performed properly, the battery cells will deteriorate quickly, their lifespan will be shortened, and the possibility of explosion or fire will increase.

[0007] Furthermore, vehicle battery packs are often exposed to direct sunlight and high temperature conditions such as in summer or desert regions. In addition, because multiple battery cells are closely packed together to increase the vehicle's driving range, flames or heat generated in one battery cell can easily spread to adjacent battery cells, ultimately leading to the battery pack itself catching fire or exploding.

[0008] Fig. 1 is a perspective view showing a conventional battery pack, and Fig. 2 is an exploded perspective view of the battery pack of Fig. 1.

[0009] Referring to Figures 1 and 2, a conventional battery pack 10 may include a lower pack frame 11 on which multiple battery assemblies 1 are mounted, an upper pack frame 12 located on top of the battery assemblies 1, and an internal beam 13 that defines the location within the battery pack 10 where the battery assemblies 1 are mounted.

[0010] When battery assemblies 1 are mounted in a battery pack 10, the energy density of the battery pack 10 is reduced by the internal beams 13 that separate the battery assemblies 1, which has resulted in a problem that a larger number of battery packs 10 must be provided to achieve the required efficiency in a device, etc. Also, the weight of the battery packs 10 limits the number of battery packs 10 that can be mounted in a device. Therefore, in order to reduce the weight of the battery pack 10 and increase the energy density of the battery pack 10 at the same time, it has been necessary to mount a larger number of battery assemblies 1 in the battery pack 10.

[0011] In the conventional battery assembly 1, a bottom cooling method or a side cooling method has been used in which a heat sink is attached to a module case of the battery assembly 1 for cooling.

[0012] However, in this type of battery module, heat generated in the battery cells is transferred to a heat sink on one side of the module case for cooling, and a heat transfer path is not easily provided on the other side of the module case. This leads to limitations such as a serious temperature difference between one end and the other end of the battery cell assembly, or insufficient overall cooling efficiency. If the temperature difference is not resolved, issues with the safety and durability of the battery module may arise. Insufficient cooling efficiency may accelerate deterioration of the battery cells, or if thermal runaway occurs in some battery cells, the thermal runaway may spread due to insufficient response. This may lead to disasters such as fires and explosions of the battery module or a battery pack including the battery module, which may cause not only property damage but also safety issues.

[0013] To solve these problems, it has been proposed to use a method of directly cooling the battery cells by filling the inside of the battery pack with cooling water or insulating fluid, rather than relying on bottom cooling or side cooling. That is, for effective cooling of high-capacity battery packs, an immersion cooling method is used in which a cooling material directly cools the battery cells inside the battery pack.

[0014] Meanwhile, thermal propagation control is an important issue in the battery field. As shown in FIGS. 1 and 2, a conventional battery pack 10 contains multiple battery assemblies 1. Therefore, when thermal runaway occurs in at least one battery cell included in the multiple battery assemblies 1, gas and particles are generated. The gas is in a very high temperature state, and the particles may be conductive. To discharge the gas and particles to the outside, a venting unit may be provided in the battery module or battery pack. By discharging the generated gas and particles, the venting unit can prevent the thermal runaway from propagating to other battery cells or other battery assemblies 1.

[0015] However, with the immersion cooling method, the coolant directly contacts the battery cells to cool them, which can affect the operation of the venting unit and prevent gases and particles from being properly discharged when a thermal runaway event occurs. Furthermore, while the coolant circulates to cool the battery cells, gases generated by a thermal event can propagate along the coolant's circulation path, potentially causing additional damage within the battery pack or vehicle system. Summary of the Invention [Problem to be solved by the invention]

[0016] The problem to be solved by the present invention is to provide a battery assembly having a circulating structure for a cooling material in an immersion cooling method and a venting unit that exhausts gas in the event of a thermal runaway phenomenon, and a battery pack including the same.

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

[0018] A battery assembly according to an embodiment of the present invention includes a plurality of battery cells, a frame accommodating the plurality of battery cells, an inlet port and an outlet port for circulating a coolant inside the frame, and a venting unit provided on one side of the frame for discharging gas inside the frame when the pressure inside the frame exceeds a certain pressure. The coolant introduced through the inlet port directly cools the battery cells and is discharged through the outlet port.

[0019] The constant pressure may be greater than or equal to 1.0 bar and less than or equal to 2.5 bar.

[0020] The venting unit may be provided on the one surface of the frame other than the at least one surface of the frame on which the inlet port or the outlet port is provided.

[0021] The venting unit may be provided on an upper surface of the frame.

[0022] The venting unit may be a rupture disc type that ruptures when the internal pressure of the frame exceeds a certain pressure, a reversible type that opens and closes based on the internal pressure of the frame, or a valve type that opens when the internal pressure of the frame exceeds a certain pressure.

[0023] The venting unit may be attached to the upper surface of the frame by sealant, adhesive, bolting, or welding.

[0024] The battery cells may be stacked to form a battery cell stack, and the battery cell stack may be accommodated in the frame.

[0025] The frame may include a main frame that covers at least a portion of the battery cell stack including an upper surface thereof and has opposite open sides, and end plates that cover the open sides of the main frame, respectively.

[0026] The venting unit may be located on an upper surface of the main frame.

[0027] The inlet and outlet ports may be located in one of the end plates or in each of the end plates.

[0028] The battery cell may have a sealing portion, and at least a portion of the sealing portion may be provided on a portion of the battery cell facing the vent unit.

[0029] A separating member may be located between the battery cell and the venting unit.

[0030] One side space of the separating member may be a space facing the venting unit, and the other side space of the separating member may be a space through which the cooling material flows.

[0031] At least a portion of the separating member can burst when a pressure equal to or greater than a certain level is applied.

[0032] In order to form a portion that ruptures when a pressure exceeding a certain level is applied, the separating member may be formed with a notch, a boundary portion having a thickness difference, or a plurality of holes.

[0033] The separating member may include a mesh part.

[0034] The separating member may include an opening.

[0035] A separation member into which the battery cell is fitted may be located inside the frame.

[0036] One side space of the separating member may be a space facing the venting unit, and the other side space of the separating member may be a space through which the cooling material flows.

[0037] Cooling lines may be connected to the inlet port and the outlet port, respectively, and a venting valve may be disposed in at least one of the cooling lines.

[0038] The venting valve may discharge gas from the cooling line when the pressure in the cooling line reaches a predetermined pressure.

[0039] A battery pack according to an embodiment of the present invention includes at least one battery assembly, a pack frame that houses the battery assembly and has an open top, and a pack cover that covers the open top of the pack frame, wherein the pack cover is spaced apart from the venting unit to define a predetermined venting space between the venting unit and the pack cover.

[0040] In the venting space, the gap between the venting unit and the pack cover is 5 mm or more and 25 mm or less. [Effects of the Invention]

[0041] According to an embodiment of the present invention, the cooling efficiency of a battery assembly and a battery pack including the battery assembly can be improved by using a cooling material that directly cools the battery cells using an immersion cooling method.

[0042] In addition, gases and particles generated due to thermal runaway in at least one battery cell can be properly discharged through the venting unit, preventing them from spreading to other battery cells, thereby improving the stability of the battery assembly and the battery pack including the same even when a specific situation such as thermal runaway occurs.

[0043] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0044] [Figure 1] FIG. 1 is a perspective view showing a conventional battery pack. [Figure 2] FIG. 2 is an exploded perspective view of the battery pack of FIG. 1. [Figure 3] 1 is a perspective view showing a battery assembly according to an embodiment of the present invention; [Figure 4] FIG. 4 is an exploded perspective view of the battery assembly of FIG. 3. [Figure 5] 5 is a perspective view showing one of the battery cells included in the battery assembly of FIG. 4. FIG. [Figure 6] FIG. 10 is a perspective view showing a battery assembly according to another embodiment of the present invention. [Figure 7] 7 is an exploded perspective view of components other than the battery cells in the battery assembly of FIG. 6. FIG. [Figure 8] FIG. 7 is a cross-sectional view taken along the line AA' in FIG. 6. [Figure 9] 1 is an exploded perspective view of a venting unit according to an embodiment of the present invention; [Figure 10] FIG. 1 is a plan view showing a battery assembly according to an embodiment of the present invention. [Figure 11] 11 is a cross-sectional view showing a cross section taken along the line BB' in FIG. [Figure 12]1(a) and 1(b) are diagrams showing a venting valve according to one embodiment of the present invention. [Figure 13] 10(a) and 10(b) are diagrams showing a venting valve according to another embodiment of the present invention. [Figure 14] 1 shows a filter unit according to one embodiment of the present invention. [Figure 15] FIG. 10 shows a filter unit according to a modified embodiment of the present invention. [Figure 16] 1 is a perspective view showing a battery pack according to an embodiment of the present invention; [Figure 17] FIG. 17 is an exploded perspective view of the battery pack of FIG. 16. [Figure 18] 1 is a cross-sectional view of a battery pack according to an embodiment of the present invention; [Figure 19] FIG. 4 is a schematic diagram for explaining positions where a vent valve and a filter unit are arranged in the battery pack. [Figure 20] 1 is a perspective view showing a battery assembly according to an embodiment of the present invention; [Figure 21] 21 is a cross-sectional view showing a cross section taken along the line CC' in FIG. 20. FIG. [Figure 22] 1 is a perspective view illustrating a separation member and a battery cell according to an embodiment of the present invention. [Figure 23] 1A-1C illustrate separation members according to various embodiments of the present invention. [Figure 24] FIG. 10 is a perspective view showing a separation member including a mesh part and a battery cell according to another embodiment of the present invention. [Figure 25] FIG. 10 is a perspective view showing a separating member according to another embodiment of the present invention. [Figure 26] 26 is a cross-sectional view of a battery assembly to which the separating member of FIG. 25 is applied. DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 2 is a block diagram of a semiconductor device according to an embodiment of the present invention; FIG. 3 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0046] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0047] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to the drawings. In the drawings, thicknesses are exaggerated to clearly show various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0048] Furthermore, when a layer, film, region, plate, or other part is described as being "above" 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 between them. Conversely, when a part is described as being "directly above" another part, it means that there is no other part between them. Note that being "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" in the opposite direction of gravity.

[0049] Also, throughout the specification, when a part is described as "comprising" a certain element, this means that it can further include other elements, rather than excluding other elements, unless otherwise specified.

[0050] Furthermore, throughout the specification, "in a plane" means the part being viewed from above, and "in cross section" means the part being viewed from the side across a vertical cross section.

[0051] Fig. 3 is a perspective view showing a battery assembly according to one embodiment of the present invention. Fig. 4 is an exploded perspective view of the battery assembly of Fig. 3. Fig. 5 is a perspective view showing one of the battery cells included in the battery assembly of Fig. 4. Fig. 6 is a perspective view showing a battery assembly according to another embodiment of the present invention.

[0052] 3 to 6, a battery assembly 100 according to an embodiment of the present invention includes a plurality of battery cells 110, a frame 200 accommodating the plurality of battery cells 110, an inlet port 510 and an outlet port 516 for circulating a coolant inside the frame 200, and a venting unit 600 provided on one side of the frame 200 for discharging gas inside the frame 200 when the pressure inside the frame 200 exceeds a certain pressure. The coolant may be in direct contact with the battery cells 110 and circulate inside the frame 200. That is, the battery assembly 100 according to this embodiment employs an immersion cooling method in which the coolant directly cools the battery cells. In the present invention, at least a portion of the battery cells 110 may be cooled by contact with the coolant. That is, in one embodiment, a portion of the outer surface of the battery cells 110 may be in contact with the coolant, and in another embodiment, the entire outer surface of the battery cells 110 may be in contact with the coolant.

[0053] Hereinafter, the battery cell 110 according to this embodiment will be described in detail. The battery cell 110 according to this embodiment can be applied to any type of secondary battery, such as a prismatic, cylindrical, or pouch-type battery cell. However, the following description will be made of the battery cell 110, which is a pouch-type battery cell, as an example.

[0054] First, the battery cell 110 may be a pouch-type battery in which an electrode assembly having electrode leads 111 protruding in one or both directions is housed in a pouch case 114. However, this is merely an example, and battery cells according to other embodiments of the present invention may be prismatic batteries. For convenience of explanation, the following description will be based on the battery cell 110, which is a pouch-type battery.

[0055] The battery cell 110 may have a rectangular sheet shape. The battery cell 110 may be formed by accommodating an electrode assembly in a pouch case 114 made of a laminate sheet including a resin layer and a metal layer, and then bonding the outer periphery of the pouch case 114. As an example, the battery cell 110 may have a structure in which two electrode leads 111 protrude from one end and the other end of the cell body 113 on opposite sides. As another embodiment, all of the electrode leads 111 of the battery cell 110 may protrude in one direction. One of the electrode leads 111 is a positive electrode lead, and the other is a negative electrode lead.

[0056] The battery cell 110 may have a sealing portion 114s, which is a portion where the outer periphery of the pouch case 114 is bonded. Specifically, the battery cell 110 may be manufactured by bonding both end portions 114c, 114d of the pouch case 114 and an upper end portion 114b connecting them, with an electrode assembly (not shown) housed in the pouch case 114. In other words, the battery cell 110 according to this embodiment may have a total of three sealing portions 114s, which may be sealed by a method such as fusion welding, and the remaining lower end portion 114a may be a folding portion. In other words, the battery cell 110 according to this embodiment may be a pouch-type secondary battery in which the electrode assembly is housed inside the pouch case 114 and the outer periphery of the pouch case 114 is sealed to form the sealing portion 114s. 5 only shows that sealing portions 114s have been formed at both ends 114c and 114d of the pouch case 114, and the upper end 114b shows the state in which the sealing portion has been folded to one side after sealing has been completed, which will be explained again in FIG.

[0057] The laminate sheet pouch case 114 may include an inner resin layer for sealing, a metal layer for preventing the intrusion of substances, and an outer resin layer as the outermost layer. Based on the electrode assembly inside the pouch case 114, the inner resin layer may be located innermost, the outer resin layer may be located outermost, and the metal layer may be located between the inner and outer resin layers.

[0058] The outer resin layer has excellent tensile strength and weather resistance relative to its thickness and exhibits electrical insulation to protect the electrode assembly from the outside. This outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer may prevent air, moisture, etc. from entering the pouch-type secondary battery. This metal layer may include aluminum (Al). The inner resin layers may be heat-sealed to each other by applying heat and / or pressure with the electrode assembly inside. This inner resin layer may include cast polypropylene (CPP) or polypropylene (PP).

[0059] The pouch case 114 may be divided into two sections, and a recessed receiving section in which an electrode assembly can be placed may be formed in at least one of the two sections. A sealing section 114s may be formed along the outer periphery of the receiving section by joining the inner resin layers of the two sections of the pouch case 114 together. By sealing the pouch case 114 in this manner, a battery cell 110, which is a pouch-type battery, can be manufactured.

[0060] 5, the sealing portions 114s at both ends 114c and 114d of the battery cell 110 where the electrode leads 111 protrude from the battery cell 110 correspond to the so-called terrace parts of the battery cell 110. Such terrace parts are thinner than the cell body 113 of the battery cell 110.

[0061] A plurality of battery cells 110 may be formed, and the plurality of battery cells 110 may be stacked to form a battery cell stack 120. In the battery cell stack 120, the battery cells 110 may be electrically connected to each other. In particular, as shown in FIG. 4, a plurality of battery cells 110 may be stacked in one direction parallel to the y-axis while standing upright so that one surface of each cell body (113, see FIG. 5) faces each other. This allows the electrode leads 111 to protrude in a direction perpendicular to the direction in which the battery cells 110 are stacked. That is, in a battery cell 110, one electrode lead 111 may protrude in the x-axis direction, and the other electrode lead 111 may protrude in the negative x-axis direction. In the case of a battery cell in which the electrode leads 111 protrude in only one direction, the electrode leads 111 protrude in the x-axis direction or the negative x-axis direction.

[0062] As described above, the battery cells 110 are housed in the frame 200. The battery cell stack 120 can be housed in the frame 200. The frame 200 can be used to protect the battery cell stack 120 and electrical components connected thereto from external physical impacts. The battery cell stack 120 and electrical components connected thereto can be housed in the internal space of the frame 200.

[0063] The frame 200 may have a variety of structures. According to an embodiment of the present invention, the frame 200 may include a main frame 210 that covers at least a portion of the battery cell stack 120, including the top surface thereof, and has opposing open sides. Here, the main frame 210 may be in the form of a metal plate having an integrated top and bottom surface (z-axis direction and -z-axis direction) and both side surfaces (y-axis direction and -y-axis direction). The main frame 210 may be manufactured by extrusion molding.

[0064] However, the structure of the main frame 210 is not limited thereto, and in another embodiment, the main frame 210 may have a structure in which a U-shaped frame and an upper plate are combined. In this case, the U-shaped frame may have a lower surface and two side surfaces extending upward from both corners of the lower surface, and the upper plate may be in a plate-like shape. In this case, each frame or plate constituting the U-shaped frame may be manufactured by press molding. Furthermore, the main frame 210 may have a mono-frame or U-shaped frame structure, an L-shaped frame structure, or various other structures not described in the above examples.

[0065] The main frame 210 may have open sides. The open sides of the main frame 210 may be in the +x-axis direction and the −x-axis direction. More specifically, the main frame 210 may be provided in a form that is open along the longitudinal direction of the battery cells 110. In this case, the front and rear surfaces of the battery cell stack 120 are not blocked by the main frame 210. The front and rear surfaces of the battery cell stack 120 are blocked by the bus bar assembly 300, the end plate 400, etc., so that the front and rear surfaces of the battery cell stack 120 can be protected from external physical impacts, etc.

[0066] The battery assembly 100 may include busbar assemblies 300 located on one side and the other side of the battery cell stack 120. Specifically, a busbar assembly 300 may be located on each of both sides of the protruding electrode leads 111 of the battery cells 110 included in the battery cell stack 120. The busbar assemblies 300 may electrically connect the battery cells 110 constituting the battery cell stack 120 in series or parallel. Each busbar assembly 300 may include a busbar frame 310, a busbar 320, and a terminal busbar.

[0067] The bus bar frame 310 may be located on one surface of the battery cell stack 120 to cover one surface of the battery cell stack 120 and to guide the connection between the battery cell stack 120 and an external device. The bus bar frame 310 may be located on the front surface (x-axis direction) and the rear surface (-x-axis direction) of the battery cell stack 120.

[0068] The bus bar 320 can be attached to the bus bar frame 310. Specifically, the bus bar 320 can be attached to the surface of the bus bar frame 310 opposite to the surface facing the battery cell stack 120.

[0069] The bus bar frame 310 may include an electrically insulating material, and may limit contact of the bus bar 320 with other parts of the battery cell 110 other than the part connected to the electrode lead (111, see FIG. 5), thereby preventing an electrical short circuit from occurring.

[0070] The bus bar 320 may be mounted on one surface of the bus bar frame 310 and may electrically connect the battery cell stack 120 or the battery cells 110 to an external device circuit. The bus bar 320 is positioned on the bus bar frame 310, and the bus bar assembly 300 is covered by the end plate 400 of Fig. 4, so that it can be protected from external impacts and the like, and a decrease in durability of the battery due to external moisture and the like can be minimized.

[0071] The bus bar 320 may be electrically connected to the battery cell stack 120 via the electrode leads of the battery cells 110. Specifically, the electrode leads 111 of the battery cells 110 may pass through slits formed in the bus bar frame 310, bend, and be connected to the bus bar 320. The bus bar 320 may connect the battery cells 110 constituting the battery cell stack 120 in series or parallel. There is no particular limitation on the connection method between the electrode leads 111 and the bus bar 320, and welding may be used, for example.

[0072] 3 and 4, the battery assembly 100 may include terminal bus bars. The terminal bus bars may include a first terminal bus bar and a second terminal bus bar, and the first terminal bus bar and the second terminal bus bar may have polarities opposite to each other.

[0073] The terminal bus bars may be electrically connected to the bus bars 320 or electrode leads to electrically connect one battery assembly 100 to another battery assembly 100. The first and second terminal bus bars may be at least partially exposed to the outside of the end plate 400 to connect one battery assembly 100 to another external battery assembly 100, and the end plate 400 may be provided with terminal bus bar openings (not shown) for this purpose. The terminal bus bars may be connected to another battery assembly 100 or a BDU (Battery Disconnect Unit) through the exposed portions of the terminal bus bars through the terminal bus bar openings, and may form a high voltage (HV) connection with them.

[0074] The frame 200 according to an embodiment of the present invention may include end plates 400 that cover both open sides of the main frame 210. The end plates 400 may be positioned on both open sides (x-axis direction and -x-axis direction) of the main frame 210 and formed to cover the battery cell stack 120. The end plates 400 may physically protect the battery cell stack 120 and other electrical components from external impact.

[0075] The end plate 400 may have a coolant opening 410 formed therein for the inflow or outflow of a coolant. The coolant opening 410 is an opening provided in the end plate 400 and is a hole that penetrates the end plate 400. Thus, even when the end plate 400 is attached to the main frame 210, the coolant can flow into the main frame 210 or flow out from the main frame 210 to the outside through the coolant opening 410. The coolant opening 410 is covered by an inlet port 510 or an outlet port 516, which will be described later, and can be connected to a first cooling line 501 or a second cooling line 502, respectively.

[0076] The coolant opening 410 may be a hole formed to extend in the vertical direction (z-axis direction and -z-axis direction). The upper end of the coolant opening 410 may be located above the center of the battery cell stack 120 based on the height of the battery cell stack 120. The lower end of the coolant opening 410 may be located below the center of the battery cell stack 120 based on the height of the battery cell stack 120. Specifically, the length from the center of the coolant opening 410 to the upper end of the coolant opening 410 may be greater than or equal to the length from an upper corner of the end plate 400 to the upper end of the coolant opening 410. Furthermore, the length from the center of the coolant opening 410 to the lower end of the coolant opening 410 may be greater than or equal to the length from a lower corner of the end plate 400 to the lower end of the coolant opening 410. The length from the upper end to the lower end of the coolant opening 410 may be 0.5 to 0.9 times the length from the upper corner to the lower corner of the end plate 400.

[0077] The cooling material may be in direct contact with the battery cells 110, the bus bar assembly 300, and other electrical components housed inside the frame 200, and may receive heat generated therefrom. The cooling material may be a fluid. The cooling material may be electrically insulating because it is in direct contact with the battery cell stack 120, the bus bar assembly 300, and other electrical components in the battery assembly 100. The cooling material may be an insulating cooling material. As an example, the cooling material may be an insulating fluid. An insulating fluid is a fluid having insulating properties, and may include insulating oil, silicone-based fluid, etc.

[0078] However, the type of the cooling material is not limited to the above, and may be a non-flammable cooling material, since the cooling material must not ignite even when exposed to a high-temperature environment inside the battery assembly 100.

[0079] That is, in the present embodiment, the cooling material can directly contact and receive heat from the battery cells 110, bus bar assemblies 300, and other electrical components that generate heat within the battery assembly 100, thereby directly cooling them. Therefore, while conventional battery assemblies indirectly cool the battery assembly using a heat sink or the like, the battery assembly 100 according to the present embodiment can improve cooling efficiency through direct cooling, thereby extending the battery life.

[0080] Meanwhile, the inlet port 510 and the outlet port 516 may be provided on at least one other surface of the frame 200 than the surface of the frame 200 on which the venting unit 600 is provided. The relationship between the positions of the inlet port 510 and the outlet port 516 and the position of the venting unit 600 will be described later.

[0081] The inlet port 510 and the outlet port 516 can be located in one of the end plates 400 or in each of the end plates 400. In other words, in one embodiment, the inlet port 510 and the outlet port 516 can be both formed in one end plate 400, while in another embodiment, each of the inlet port 510 and the outlet port 516 can be formed in each of the end plates 400.

[0082] For example, the inlet port 510 may be formed in one of the end plates 400 covering one of the open sides of the main frame 210, and the outlet port 516 may be formed in the other end plate 400 covering the remaining open side of the main frame 210. The coolant flowing in through the inlet port 510 flows in one direction inside the frame 200 and can be discharged through the outlet port 516. That is, in one embodiment of the present invention, the coolant can flow in one direction from the end plate 400 having the inlet port 510 to the end plate 400 having the outlet port 516. However, in the present invention, the direction of movement of the coolant is not limited to this one direction and can be variously modified. The inlet port 510 or the outlet port 516 can be attached to the end plate 400 to cover the coolant opening 410 of the end plate 400.

[0083] 4, the battery assembly 100 may further include sealing assemblies. The sealing assemblies may be positioned on both open sides of the frame 200 and formed to cover the battery cell stack 120. That is, the sealing assemblies may be disposed between the end plates 400 and the battery cell stack 120 to isolate the open sides of the frame 200 from the external environment. Specifically, the sealing assemblies may serve to seal the coolant injected into the frame 200 to prevent the coolant from leaking to the outside.

[0084] Meanwhile, according to this embodiment, a cooling line 500 may be connected to the inlet port 510 and the outlet port 516. The cooling line 500 may correspond to a part of a coolant circulation structure that supplies a coolant to the battery assembly 100 and discharges the coolant that flows along the inside of the battery assembly 100 from the battery assembly 100. The cooling line 500 may include a first cooling line 501 connected to the inlet port 510 and a second cooling line 502 connected to the outlet port 516. In the coolant circulation structure, the coolant that moves along the first cooling line 501 flows into the inside of the frame 200 of the battery assembly 100 through the inlet port 510. The coolant flowing inside the frame 200 is discharged through the outlet port 516 and moves to the second cooling line 502. The coolant that moves along the second cooling line 502 may be cooled again and then supplied again to the first cooling line 501. The coolant circulation structure refers to this series of processes.

[0085] Fig. 7 is an exploded perspective view of components other than the battery cells in the battery assembly of Fig. 6. For ease of explanation, the battery cells are not shown.

[0086] 6 and 7, the venting unit 600 according to this embodiment is provided on one side of the frame 200 and discharges gas from inside the frame 200 when the pressure inside the frame 200 exceeds a certain pressure. When a thermal runaway phenomenon occurs in at least one battery cell 110 included in a plurality of battery assemblies 100, high-temperature gas and particles are generated. The generated gas increases the pressure inside the frame 200, and when the pressure inside the frame 200 exceeds a certain pressure, the venting unit 600 is activated to discharge the generated gas and particles to the outside of the frame 200. This prevents the thermal runaway phenomenon from causing thermal propagation to other battery cells or other battery assemblies 100.

[0087] As described above, the battery assembly 100 according to this embodiment employs an immersion cooling method in which a coolant flowing into the frame 200 through the inlet port 510 directly cools the battery cells 110. However, when gases or particles generated in the battery cells 110 come into contact with the coolant, problems may arise in which a thermal event or thermal runaway is accelerated, or the coolant may hinder the discharge of the gases or particles. To prevent these problems, it is preferable that a directional venting path for discharging gases generated in the battery cells 110 through the venting unit 600 be provided in a location that does not affect the immersion cooling method as much as possible. Therefore, the venting unit 600 according to this embodiment may be provided on at least one side of the frame 200, other than the side on which the inlet port 510 and the outlet port 516 are provided. In other words, the side of the frame 200 on which the venting unit 600 is provided and at least one side of the frame 200 on which the inlet port and the outlet port are respectively provided may be different sides. The side of the frame 200 on which the venting unit 600 is provided and at least one side of the frame 200 on which the inlet port and the outlet port are respectively provided may be perpendicular to each other.

[0088] For example, the venting unit 600 may be located on the top surface of the frame 200, and the inlet port 510 and the outlet port 516 may be located on the front and rear surfaces of the frame 200. Alternatively, the venting unit 600 may be located on one surface of the main frame 210, and the inlet port 510 and the outlet port 516 may be located on one of the end plates 400 or on each of the end plates 400.

[0089] In summary, the venting unit 600 can be located in a portion of the frame 200 that is far away from the portion where the inlet port 510 and the outlet port 516 are provided. This allows the venting unit 600 to be located as far away as possible from the inlet port 510 and the outlet port 516, respectively, thereby minimizing the effect of the directional venting path on the flow of the coolant flowing from the inlet port 510 to the outlet port 516 and the effect of the flow of the coolant on the directional venting path.

[0090] Meanwhile, a stable sealing structure is essential for implementing the immersion cooling method. When a coolant circulates inside the frame 200, it is necessary for the coolant to not leak out of the frame 200. However, since the battery assembly 100 according to this embodiment employs both immersion cooling and directional venting, the coolant circulating inside the frame 200 may leak through the venting unit 600, reducing the cooling efficiency of the immersion cooling. Furthermore, the coolant may affect the operation of the venting unit 600, resulting in a problem where the venting unit 600 is unable to properly discharge gases or particles during thermal runaway. To prevent this problem, the venting unit 600 is preferably located in an area that is not affected by the coolant. That is, the venting unit 600 according to this embodiment may be located on the top surface of the frame 200, where it is not affected by the coolant. When the venting unit 600 is located on the top surface of the frame 200, the possibility of the cooling material leaking through the venting unit 600 can be reduced, and the influence of the cooling material on the operation of the venting unit 600 can be minimized.

[0091] Meanwhile, the venting unit 600 according to this embodiment may have a higher operating pressure than a venting unit of a model that does not employ an immersion cooling method. Here, the operating pressure of the venting unit 600 corresponds to the pressure inside the frame 200 that is a reference point at which the venting unit 600 starts to exhaust gas inside the frame 200. In other words, in the venting unit 600 that exhausts gas inside the frame 200 when the pressure inside the frame 200 is equal to or higher than a certain pressure, the certain pressure may correspond to the operating pressure of the venting unit 600.

[0092] The operating pressure of the venting unit 600 according to this embodiment may be 1.0 bar or more and 2.5 bar or less. The venting unit 600 may be designed to operate and exhaust internal gas when the pressure inside the frame 200 is 1.0 bar or more and 2.5 bar or less. The operating pressure of the venting unit in a model that does not use immersion cooling is in the range of 0.1 bar to 0.99 bar (several tens of kPa). Therefore, it can be confirmed that the operating pressure of the venting unit 600 according to this embodiment, in which immersion cooling is used, is higher than the operating pressure of the venting unit in a model that does not use immersion cooling.

[0093] As described above, the cooling line 500 connected to the battery assembly 100 may correspond to a part of a coolant circulation structure that supplies a coolant to the battery assembly 100 and then discharges the coolant that has flowed inside the battery assembly 100 from the battery assembly 100. When the coolant is injected into the battery assembly 100 through the first cooling line 501 and the inlet port 510 due to the coolant circulation structure, if air is present inside the cooling line 500, the inlet port 510, the outlet port 516, the frame 200, etc., the volume of the air decreases due to the injection of the coolant, ultimately increasing the internal pressure. In order to inject the coolant while overcoming this increased internal pressure, the coolant must be injected at a higher pressure. Ultimately, the internal pressure may rise to a level that the frame 200 cannot withstand, which may result in damage to the frame 200. Therefore, it is preferable to inject the coolant after creating a maximum vacuum inside the cooling line 500, the inlet port 510, the outlet port 516, the frame 200, etc. If the cooling material is injected after evacuating the interior of the cooling line 500, the inlet port 510, the outlet port 516, the frame 200, etc., the injection of the cooling material is much easier and damage to structures such as the frame 200 can be prevented.

[0094] Furthermore, air generally has a lower heat transfer coefficient than a coolant. If air pockets exist inside the coolant circulation structure, the cooling performance of the immersion cooling of the battery assembly 100 may be reduced. Therefore, from the viewpoint of cooling performance, it is preferable to inject the coolant after removing air from the cooling line 500, the inlet port 510, the outlet port 516, the frame 200, etc. to create a vacuum.

[0095] However, in reality, it is not possible to create a complete vacuum inside the cooling material circulation structure, i.e., inside the cooling line 500, the inlet port 510, the outlet port 516, and the frame 200, etc., so the cooling material can be injected after removing the air by creating a vacuum as close to the maximum possible level.

[0096] During normal operation of the battery assembly 100, the internal pressure of the battery assembly 100, i.e., the internal pressure of the frame 200, becomes highest when a coolant is injected into the coolant circulation structure in a vacuum or near-vacuum state. The situation in which a coolant is injected into the coolant circulation structure becomes the situation in which the internal pressure of the frame 200 becomes highest during normal operation, and the venting unit 600 should not operate in this situation. This is because the venting unit 600 does not operate while the battery assembly 100 is operating normally, but must operate when a thermal runaway phenomenon occurs inside the battery assembly 100. Therefore, the operating pressure of the venting unit 600 may be higher than the operating pressure of a venting unit in a model that does not use the immersion cooling method.

[0097] In other words, the venting unit 600 according to this embodiment should not operate while a coolant is being injected into the coolant circulation structure during normal operation of the battery assembly 100, but should operate when a thermal runaway phenomenon occurs inside the battery assembly 100 and the internal pressure of the frame 200 increases above a certain pressure. Therefore, the operating pressure of the venting unit 600 is preferably higher than that of a venting unit in a model to which the immersion cooling method is not applied, and as an example, the operating pressure of the venting unit 600 may be 1.0 bar or more and 2.5 bar or less.

[0098] If the operating pressure of the venting unit 600 is less than 1.0 bar, the venting unit 600 may operate while injecting coolant into the coolant circulation structure during normal operation of the battery assembly 100, resulting in a problem of discharging gas from inside the frame 200. On the other hand, if the operating pressure of the venting unit 600 exceeds 2.5 bar, the operating pressure of the venting unit 600 may be excessively high, and even if a thermal runaway phenomenon occurs inside the battery assembly 100, the venting unit 600 may not operate, resulting in a problem of not being able to discharge gas from inside the frame 200.

[0099] Meanwhile, the venting unit 600 according to this embodiment may be a rupture disc type that ruptures when the internal pressure of the frame 200 exceeds a certain pressure, a reversible type that opens and closes based on a certain pressure inside the frame 200, or a valve type that opens when the internal pressure of the frame exceeds a certain pressure.

[0100] However, there are no particular limitations on the type or shape of the venting unit 600 as long as it can exhaust gas and particles from inside the frame 200 when a thermal runaway phenomenon occurs inside the battery assembly 100. Hereinafter, a detailed configuration of the venting unit 600 will be described as an example structure.

[0101] Fig. 8 is a cross-sectional view taken along line AA' in Fig. 6. Fig. 9 is an exploded perspective view of a venting unit according to an embodiment of the present invention.

[0102] 6 to 9, a frame hole 200H may be formed in the frame 200, and the venting unit 600 may be attached to the outer surface of the frame 200 so as to cover the frame hole 200H. The frame hole 200H may be formed in the upper surface of the frame 200. More specifically, the frame hole 200H may be formed in the upper surface of the main frame 210.

[0103] The venting unit 600 according to one embodiment of the present invention may include an upper flange 610 , a lower flange 620 , a disk 630 , a sealing member 640 , and a bolt 650 .

[0104] The upper flange 610 and the lower flange 620 may be members having a central through-hole. The upper flange 610 and the lower flange 620 are for fixing the disk 630. The upper flange 610 and the lower flange 620 may be coupled to each other, and the disk 630 may be positioned between the upper flange 610 and the lower flange 620. The coupling method between the upper flange 610 and the lower flange 620 is not limited, and a bolting coupling may be used, for example. At least one bolt 650 may couple the upper flange 610 and the lower flange 620. For example, the at least one bolt 650 may pass through a through-hole in the upper flange 610 and then be fastened to a threaded hole formed in the lower flange 620. The central through-hole of the upper flange 610 and the lower flange 620 may be positioned to correspond to the frame hole 200H of the frame 200.

[0105] The disc 630 may be a rupture disc that ruptures when a certain pressure is applied. The disc 630 may cover the centrally perforated portion of the upper flange 610 and the lower flange 620. A portion of the disc 630 may be positioned to correspond to the frame hole 200H of the frame 200. If a thermal runaway phenomenon occurs in a battery cell inside the frame 200, gas generated inside the frame 200 may pass through the frame hole 200H and pressurize the disc 630. If a certain pressure is applied to the disc 630 by the gas, the disc 630 may rupture. When the disc 630 ruptures, the venting unit 600 is activated, and the gas inside the frame 200 can be discharged through the ruptured portion of the disc 630.

[0106] The sealing member 640 may be an O-ring-like member. The sealing member 640 ensures the airtightness of the venting unit 600 and can prevent gas inside the frame 200 from leaking into the gap between the upper flange 610 and the lower flange 620 before the disk 630 bursts. For example, the sealing member 640 can be positioned between the lower flange 620 and the peripheral edge of the disk 630. Also, a groove 620G can be formed in the lower flange 620, and the sealing member 640 can be fitted into this groove 620G. The sealing member 640 can prevent gas from leaking into the gap between the lower flange 620 and the peripheral edge of the disk 630.

[0107] Meanwhile, the venting unit 600 may be attached to the upper surface of the frame 200 by using a sealant, adhesive, bolting, or welding. Specifically, the venting unit 600 may be placed on the upper surface of the frame 200 and fixed to the upper surface of the frame 200 by using a sealant, adhesive, bolting, or welding. In addition, the sealant, adhesive, bolting, or welding may ensure the hermeticity of the venting unit 600.

[0108] As an example, as shown in FIGS. 7 and 8, the venting unit 600 may be attached and fixed to the upper surface of the frame 200 by an adhesive 700. The adhesive 700 may be located between the venting unit 600 and the upper surface of the frame 200. The adhesive 700 may be provided on an outer portion of the upper surface of the frame 200. In particular, the adhesive 700 may be connected along the outer periphery of the frame hole 200H of the frame 200. The venting unit 600 may be attached and fixed to the outer portion of the upper surface of the frame 200 by such adhesive 700. In addition, the adhesive 700 may prevent gas inside the frame 200 from leaking into a gap between the venting unit 600 and the upper surface of the frame 200.

[0109] Fig. 10 is a plan view showing a battery assembly according to an embodiment of the present invention, and Fig. 11 is a cross-sectional view showing a cross section along line BB' in Fig. 10.

[0110] 3, 4, 10, and 11, the battery assembly 100 includes an inlet port 510 and an outlet port 516 for circulating a coolant inside the frame 200. A cooling line 500 can be connected to each of the inlet port 510 and the outlet port 516. The coolant travels from a coolant storage container 2100 (described below) through a heat exchanger 2200 and the cooling line 500, then flows into the frame 200 through the inlet port 510, flows out of the frame 200 through the outlet port 516, and can be collected in the coolant storage container through the cooling line 500. Meanwhile, the outlet port 516 has the same shape and structure as the inlet port 510, and therefore the outlet port 516 is not shown in FIGS. 10 and 11, and hereinafter, description of the same or corresponding content as the inlet port 510 will be omitted.

[0111] As mentioned above, the cooling line 500 may include a first cooling line 501 connected to an inlet port 510 and a second cooling line 502 connected to an outlet port 516. The cooling line 500 may be a rigid pipe-shaped member that allows the cooling material to flow through it.

[0112] The inlet port 510 may have a shape corresponding to the coolant opening 410 in order to cover the coolant opening 410. As described above, the coolant opening 410 is a hole extending in the vertical direction, so the inlet port 510 may also have a shape extending in the vertical direction. Furthermore, the inlet port 510 may include a cover member 511 for covering the coolant opening 410 of the end plate 400. The cover member 511 may be formed to be inclined downward on a surface facing the coolant opening 410. As a result, the cross-sectional area of ​​the inlet port 510 may decrease from the top to the bottom (in the -z-axis direction).

[0113] Considering the above-described shape and position of the coolant opening 410 extending vertically, the lower end of the coolant opening 410 connected to the inlet port 510 may be located below the center based on the height of the battery cell stack 120. That is, the lower end of the coolant opening 410 connected to the inlet port 510 may be located near a lower corner of the end plate 400. Also, the upper end of the coolant opening 410 connected to the outlet port 516 may be located above the center based on the height of the battery cell stack 120. That is, the upper end of the coolant opening 410 connected to the outlet port 516 may be located near an upper corner of the end plate 400.

[0114] If the lower end of the coolant opening 410 connected to the inlet port 510 is located above the center of the battery cell stack 120, the coolant flows into the frame 200 from a high position, causing bubbles to form in the coolant, which can impede the cooling effect.

[0115] In addition, if the upper end of the coolant opening 410 connected to the outlet port 516 is located below the center based on the height of the battery cell stack 120, the coolant that flows into the inside of the battery assembly 100 will only fill up to the height of the outlet port 516 and then escape to the outside, which may result in the inside of the battery assembly 100 not being filled with a sufficient amount of coolant, resulting in reduced cooling performance.

[0116] It is preferable that the lower end of the cooling material opening 410 connected to the inlet port 510 is located below the center based on the height of the battery cell stack 120, and the upper end of the cooling material opening 410 connected to the outlet port 516 is located above the center based on the height of the battery cell stack 120.

[0117] In addition, since the coolant opening 410 connected to the inlet port 510 extends in the vertical direction, the coolant flowing into the frame 200 through the inlet port 510 can come into contact with the entire battery cell stack 120. Similarly, the coolant in contact with the entire battery cell stack 120 can flow out of the frame 200 through the outlet port 516. Therefore, the coolant can flow without stagnating in any part within the frame 200, thereby improving the overall cooling performance and cooling efficiency of the battery assembly 100.

[0118] In addition, the coolant flowing in from the first cooling line 501 can flow along the inclined cover member 511 between the first cooling line 501 and the coolant opening 410. Therefore, the coolant can flow into the battery assembly 100 without abrupt changes in flow direction, thereby reducing the possibility of bubbles being generated inside the coolant.

[0119] In addition, since the cross-sectional area of ​​the inlet port 510 increases from the first cooling line 501 toward the coolant opening 410, the flow rate of the coolant flowing in from the first cooling line 501 decreases inside the inlet port 510. Therefore, the flow rate of the coolant decreases before it flows into the frame 200 and comes into contact with the battery cells 110, thereby reducing abrupt changes in flow rate inside the frame 200. This reduces the possibility of bubbles being generated inside the coolant due to abrupt changes in flow rate, and increases the time the coolant is in contact with the battery cells 110, thereby improving cooling performance.

[0120] 12(a) and 12(b) are diagrams illustrating a venting valve according to one embodiment of the present invention, where FIG. 12(a) illustrates the state of the venting valve 520a before gas is vented, and FIG. 12(b) illustrates the state of the venting valve 520a while gas is vented.

[0121] 3, 4, 10, and 12, as described above, cooling lines 500 may be connected to the inlet port 510 and the outlet port 516, respectively. A venting valve 520, 520a may be disposed in at least one of the cooling lines 500. The cooling line 500 may include a first cooling line 501 connected to the inlet port 510 and a second cooling line 502 connected to the outlet port 516. A venting valve 520, 520a may be disposed in at least one of the first cooling line 501 and the second cooling line 502.

[0122] When gas is generated inside the battery assembly 100 due to thermal runaway, the gas is discharged through the venting unit 600 as described above. However, some of the gas may be discharged to the outside of the frame 200 through the coolant openings 410 formed for the inflow and outflow of the coolant, rather than through the venting unit 600. As a result, the gas generated inside the battery assembly 100 may diffuse through the cooling line 500 toward the surrounding area or other adjacent battery assemblies 100.

[0123] According to one embodiment of the present invention, to solve the above problem, a venting valve 520 can be connected to the cooling line 500. Gas generated inside the battery assembly 100 and flowing into the cooling line 500 can be vented through the venting valve 520. Therefore, gas that diffuses along the cooling line 500 to the surrounding area or other adjacent battery assemblies 100 can be discharged from the cooling line 500, thereby reducing the pressure in the cooling line 500 and preventing the gas from diffusing through the cooling line 500.

[0124] The venting valve 520 can be connected to the cooling line 500. For example, the venting valve 520 can be connected to each of the first cooling line 501 and the second cooling line 502. When the pressure of the cooling line 500 reaches a predetermined pressure due to gas generated inside the battery assembly 100, the venting valve 520 can discharge the gas from the cooling line 500. That is, when the pressure of at least one of the first cooling line 501 and the second cooling line 502 reaches a predetermined pressure, the venting valve 520 can discharge the gas from the cooling line 500, which has reached the predetermined pressure, of the first cooling line 501 and the second cooling line 502.

[0125] Referring to (a) of FIG. 12, the venting valve 520a includes a valve inlet 521 through which gas from the cooling line 500 flows, a main body 522 that forms an internal space 523 through which the gas flowing into the valve inlet 521 flows, a blocking member 525 that is movable to close the valve inlet 521, a valve spring 527 that pressurizes the blocking member 525, a cap portion 524a that guides the discharge direction of the gas, and a valve outlet 529 through which the gas is discharged.

[0126] The blocking member 525 is accommodated in the internal space 523 and is movable to close the valve inlet 521, or to separate from the internal space 523 to form a first flow path through which gas flows. That is, the blocking member 525 is movable in the extension direction of the valve shaft 526 extending from the cap portion 524a toward the valve inlet 521. As one example, the valve shaft 526 is extendable and retractable in a telescopic manner, and the blocking member 525 is fixed to the end of the valve shaft 526 and is movable in the extension direction of the valve shaft 526. As another example, the valve shaft 526 extends through the blocking member 525, and the blocking member 525 is inserted into the valve shaft 526 and is movable in the extension direction of the valve shaft 526. Meanwhile, the structure or manner in which the blocking member 525 moves in the extension direction of the valve shaft 526 is not limited to the above and can be variously modified or changed.

[0127] The valve spring 527 may be disposed on the valve shaft 526 to pressurize the blocking member 525 in a direction that closes the valve inlet 521. As a result, the blocking member 525 can prevent the coolant in the cooling line 500 from leaking out through the venting valve 520 under normal circumstances. If gas diffuses through the cooling line 500, the pressure in the cooling line 500 reaches a predetermined pressure that is higher than the pressure at which the coolant normally circulates. Due to this high-pressure environment generated in the cooling line 500, the blocking member 525 overcomes the pressure of the valve spring 527 and moves in a direction away from the internal space 523, thereby forming the first flow path. Therefore, the elastic coefficient of the valve spring 527 can be determined in consideration of the pressure in the cooling line 500 when a thermal runaway phenomenon occurs in the battery assembly 100. However, the elastic coefficient of the valve spring 527 can be varied in various ways depending on the specifications of the battery assembly 100 and the battery pack including the same.

[0128] Gas flowing into the valve inlet 521 moves from the inside of the body 522 to the cap 524a along the first flow path, which is inclined outward. High-temperature and / or high-pressure gas passes through the inclined first flow path to reduce its temperature and / or pressure. While the first flow path is inclined in the embodiment shown in FIG. 12, this is not intended to limit the scope of the present invention. For example, the shape of the first flow path may be varied or modified in various ways depending on the cross-sectional shape of the internal space 523 in which the body 522 is formed.

[0129] 12(a) may include a second flow path 528 formed to bend the path of gas flowing in from the first flow path of the body 522. This may determine the direction of gas discharged from the venting valve 520a. For example, the gas discharged from the venting valve 520a may be bent by the second flow path 528 to flow in the extension direction (x-axis or -x-axis direction) of the frame 200 of the battery assembly 100. This may minimize the impact of the gas discharged from the venting valve 520a on other adjacent battery assemblies 100.

[0130] Figures 13(a) and 13(b) are diagrams illustrating venting valves according to other embodiments of the present invention, where Figure 13(a) illustrates the state of venting valve 520b while gas is being vented, and Figure 13(b) illustrates the state of venting valve 520c while gas is being vented.

[0131] 13(a), the cap portion 524b of the venting valve 520b may include a plate-shaped portion 5241 spaced apart from the body portion 522 and facing the internal space 523. Meanwhile, hereinafter, descriptions of the same or corresponding contents as those of the venting valve 520a described with reference to FIG. 12(a) will be omitted.

[0132] The separated space 5242 between the main body 522 and the plate-shaped part 5241 can be opened to communicate with the outside. The gas that has passed through the first flow path formed between the main body 522 and the blocking member 525 expands in the separated space 5242 of the cap part 524b, reducing the temperature and / or pressure of the gas, and can be discharged to the outside of the cooling line (500, see FIGS. 3 and 4).

[0133] 13(b), cap portion 524c of venting valve 520c may further include a skirt portion 5243 extending from the periphery of plate-shaped portion 5241 toward main body portion 522. Meanwhile, hereinafter, descriptions of the same or corresponding contents as those of venting valves 520a and 520b described with reference to FIGS. 12(a) and 12(b) will be omitted.

[0134] Gas discharged to the outside through separation space 5242 between main body 522 and plate-like portion 5241 by skirt portion 5243 of cap portion 524c is bent downward toward venting valve 520c and discharged. This prevents gas discharged from venting valve 520c from directly contacting pack cover 1200 of the battery pack (described later), thereby preventing damage to pack cover 1200 due to high-temperature and / or high-pressure gas.

[0135] FIG. 14 shows a filter unit according to one embodiment of the present invention.

[0136] 3, 4, 10, and 14, a filter unit 530 may be provided in the cooling line 500. Specifically, the filter unit 530 may be disposed in the cooling line 500 between the inlet port 510 and the venting valve 520 and between the outlet port 516 and the venting valve 520. More specifically, one filter unit 530 may be disposed in the first cooling line 501 between the inlet port 510 and the venting valve 520, and another filter unit 530 may be disposed in the second cooling line 502 between the outlet port 516 and the venting valve 520.

[0137] The filter unit 530 may include a filter inlet 531 through which the cooling material flows, a filter body 533, a filter member 534 disposed in the filter body 533 and filtering the cooling material flowing in from the filter inlet 531, and a filter outlet 536 through which the cooling material filtered by the filter member 534 flows out. In this case, the filter member 534 may be a porous metal filter.

[0138] The cooling substance flowing through the cooling line 500 can pass through the filter member 534, but other foreign matter can be filtered out by the filter member 534. In particular, high-temperature particles and / or flames traveling through the cooling line 500 can be filtered out by the filter member 534.

[0139] The gas generated by the thermal runaway phenomenon in the battery assembly 100 may contain high-temperature particles such as active material particles and electrolyte in the form of sparks. Furthermore, when such gas is discharged, flames may also be discharged. Such gas may spread to the surrounding or adjacent battery assemblies 100 through the cooling line 500. The filter unit 530 is connected to the cooling line 500 to filter out the above-mentioned high-temperature particles and / or flames.

[0140] As described above, the filter unit 530 may be disposed in the first cooling line 501 between the inlet port 510 and the venting valve 520. Another filter unit 530 may be disposed in the second cooling line 502 between the outlet port 516 and the venting valve 520. That is, gas generated within the battery assembly 100 can be filtered through the filter unit 530 before flowing into the venting valve 520. Therefore, flames traveling along with the gas in the cooling line 500 can be filtered, thereby improving the operational reliability of the venting valve 520. Furthermore, since the gas discharged through the venting valve 520 has passed through the filter unit 530, it can be discharged with internal foreign matter removed and / or with a reduced temperature. Therefore, even if the gas that has passed through the filter unit 530 is discharged through the venting valve 520, its impact on the surroundings can be reduced.

[0141] The filter inlet 531 may include a diffusion section 532 whose cross-sectional area increases toward the filter member 534. The gas flowing into the filter inlet 531 can be reduced in temperature and pressure by passing through the diffusion section 532 whose cross-sectional area increases. Therefore, the gas flowing into the filter unit 530 is first reduced in temperature and pressure by the diffusion section 532, and then high-temperature particles and / or flames can be filtered by the filter member 534.

[0142] The connecting member 506 is a member that connects the cooling line 500 and the filter unit 530. That is, the connecting member 506 can connect the filter inlets 531 of the filter units 530 arranged in the first cooling line 501 and the second cooling line, respectively, to the first cooling line 501 and the second cooling line. The connecting member 506 can be connected to the cooling line 500 and the filter unit 530 by screw connection, thereby connecting the cooling line 500 and the filter unit 530 to each other. The connection between the filter unit 530 and the cooling line 500 can be more easily achieved through the connecting member 506. Meanwhile, the manner in which the connecting member 506 fixes the cooling line 500 and the filter unit 530 is not limited to the above and can be variously modified and changed.

[0143] FIG. 15 is a diagram showing a filter unit according to a modified embodiment of the present invention.

[0144] 15, the filter unit 530 may further include an elastic member 535 connected to the filter member 534. In this case, the filter member 534 is movable between a first position where the cooling material is filtered and a second position where the cooling material is bypassed. In the example shown in FIG. 15, the filter member 534 is shown in the first position.

[0145] The filter member 534 is maintained in the first position by the elastic member 535. When the cooling material flows into the filter unit 530 and passes through the filter member 534, the filter member 534 receives pressure in the direction of the cooling material flow. As a result, the filter member 534 receives a force that tries to move to the second position where the cooling material is bypassed. If pressure exceeding a certain level is applied to the filter member 534, the filter member 534 may be damaged. To prevent this, when the pressure applied to the filter member 534 reaches a predetermined filter pressure, the filter member 534 can move from the first position to the second position. In this case, the predetermined filter pressure may be a pressure at which the force applied to the filter member 534 exceeds the restoring force of the elastic member 535.

[0146] The pressure applied to the filter member 534 may reach the predetermined filter pressure when the pressure inside the filter unit 530 increases due to gas released due to thermal runaway occurring inside the battery assembly 100. However, the above-described case is merely an example, and there may be various cases when the pressure applied to the filter member 534 reaches the predetermined filter pressure. For example, foreign matter in the cooling material flowing through the cooling line 500 accumulates on the filter member 534, increasing the pressure applied to the filter member 534. When a certain level of foreign matter accumulates on the filter member 534, the pressure applied to the filter member 534 may reach the predetermined filter pressure.

[0147] When the pressure applied to the filter element 534 reaches a predetermined filter pressure, such as in the case described above, the filter element 534 moves from the first position to the second position, and the cooling substance that has flowed into the filter unit 530 can bypass the filter element 534 and flow out of the filter unit 530 through the filter outlet 536 without being filtered by the filter element 534.

[0148] Meanwhile, although not shown in FIG. 15 , the battery assembly 100 may further include a position sensor that detects movement of the filter member 534. The position sensor can detect movement of the filter member 534 from the first position to the second position. For example, the position sensor can include a Hall sensor (hall IC) that uses the Hall effect to generate a signal by detecting a change in a magnetic field. The position sensor can generate an electric signal when it detects movement of the filter member 534 from the first position to the second position. Whether a pressure greater than a predetermined filter pressure is applied to the filter member 534 can be monitored based on the electric signal generated by the position sensor.

[0149] Fig. 16 is a perspective view showing a battery pack according to one embodiment of the present invention, and Fig. 17 is an exploded perspective view of the battery pack of Fig. 16.

[0150] 16 and 17, a battery pack 1000 according to an embodiment of the present invention includes at least one battery assembly 100, a pack frame 1100 that houses the battery assembly 100 and has an open top, and a pack cover 1200 that covers the open top of the pack frame 1100. The pack frame 1100 and the pack cover 1200 are joined to each other by welding or other methods to seal the interior of the battery pack 1000. In addition, various control and protection systems, such as a BMS (Battery Management System) and a BDU (Battery Disconnect Unit), may be installed inside the battery pack 1000 together with the battery assembly 100. Although a venting unit is not shown on the battery assembly 100 in FIG. 17, this is for convenience, and the battery assembly 100 of the present invention is provided with a venting unit.

[0151] The pack frame 1100 may include side pack frames 1150 and at least two internal beams 1110 formed on the bottom surface of the pack frame 1100. Here, the bottom surface of the pack frame 1100 and the at least two internal beams 1110, and the bottom surface of the pack frame 1100 and the side pack frames 1150 may be joined to each other by a method such as welding.

[0152] The multiple battery assemblies 100 can be mounted in an area defined by the side pack frame 1150 and at least two internal beams 1110. In other words, the multiple battery assemblies 100 can be arranged in the area between the side pack frame 1150 and the internal beams 1110, and in the area located between adjacent internal beams 1110. More specifically, in the battery pack 1000, the battery assemblies 100 can be arranged between a pair of adjacent internal beams 1110 among the multiple internal beams 1110 and the side pack frame 1150.

[0153] As a result, the plurality of battery assemblies 100 are surrounded by at least two internal beams 1110 and the side pack frame 1150, and each battery assembly 100 can be protected from external impacts.

[0154] The side pack frames 1150 may be disposed on the periphery of the bottom surface of the pack frame 1100, and may extend upward (in the z-axis direction) from the bottom surface of the pack frame 1100. More specifically, they may extend upward from each periphery of the bottom surface of the pack frame 1100. Here, the upper end of the side pack frame 1150 may contact the pack cover 1200. At this time, the upper end of the side pack frame 1150 and the pack cover 1200 may be joined to each other by a method such as welding, thereby sealing the interior of the battery pack 1000.

[0155] The multiple internal beams 1110 may be spaced apart from one another. Here, the distance between adjacent internal beams 1110 may be the same as or greater than the size of the battery assembly 100. Furthermore, the ends of the internal beams 1110 may contact the inner surface 1151 of the side pack frame 1150. More specifically, both ends of the internal beams 1110 may contact the inner surface 1151 of the side pack frame 1150, respectively.

[0156] When the plurality of battery assemblies 100 are mounted on the pack frame 1100, each of the plurality of battery assemblies 100 can be connected to a cooling line 500. Specifically, a first cooling line 501 can be connected to an inlet port 510 of each of the plurality of battery assemblies 100, and a second cooling line 502 can be connected to an outlet port 516 of each of the plurality of battery assemblies 100.

[0157] In this case, the cooling lines 500 connecting the plurality of battery assemblies 100 may extend through the upper part of the internal beam 1110. As another example, the cooling lines 500 connecting the plurality of battery assemblies 100 may extend through the internal beam 1110. However, the connection structure of the cooling lines 500 connecting the plurality of battery assemblies 100 is not limited to the above, and may be variously changed or modified depending on the arrangement of the plurality of battery assemblies 100 and various components such as a BMS (Battery Management System) and a BDU (Battery Disconnect Unit) arranged inside the battery pack 1000.

[0158] FIG. 18 is a cross-sectional view of a battery pack according to an embodiment of the present invention.

[0159] 3, 16, and 18, the pack cover 1200 is spaced apart from the venting unit 600 of the battery assembly 100 so that a predetermined venting space is formed between the venting unit 600 and the pack cover 1200. When a thermal runaway phenomenon occurs inside the battery assembly 100, gas generated inside the battery assembly 100 is discharged to the outside of the battery assembly 100 through the venting unit 600. Because the venting unit 600 is installed on the upper surface of the frame 200, the gas can be discharged toward the upper side of the battery assembly 100. Since a sufficient venting space must be secured to allow the gas discharged through the venting unit 600 to move, the pack cover 1200 is preferably positioned apart from the venting unit 600. In other words, the venting space formed by the pack cover 1200 being spaced apart from the venting unit 600 serves as a flow path for the gas discharged through the venting unit 600 to move. If such a venting space is not provided inside the battery pack 1000, the gas discharged through the venting unit 600 may not reach the venting device (not shown) provided in the battery pack 1000, which may cause the battery pack 1000 to explode as the battery pack 1000 becomes unsealed.

[0160] Meanwhile, in the venting space, the distance D between the venting unit 600 and the pack cover 1200 may be 5 mm or more and 25 mm or less. If the distance D between the venting unit 600 and the pack cover 1200 is less than 5 mm, the venting space is too narrow, and gas discharged through the venting unit 600 cannot flow smoothly inside the battery pack 1000. As a result, the gas cannot reach a venting device (not shown) installed in the battery pack 1000, which may cause an explosion of the battery pack 1000. Furthermore, if the distance D between the venting unit 600 and the pack cover 1200 exceeds 25 mm, the venting space becomes too wide, and the height of the battery pack 1000 may increase more than necessary. This may hinder the space utilization and energy density of the battery pack 1000.

[0161] FIG. 19 is a conceptual diagram for explaining the positions where the vent valve and the filter unit are arranged in the battery pack.

[0162] 3, 4, and 19, the battery pack 1000 can be connected to an external device 2000 including a coolant storage container 2100 and a heat exchanger 2200. For ease of explanation, only components for circulating the coolant are shown in FIG. 19, but various components may be included depending on the device to which the battery pack 1000 is attached.

[0163] The coolant stored in the coolant storage container 2100 passes through the heat exchanger 2200 and then circulates along the cooling line 500 of the battery pack 1000. Specifically, the coolant that has passed through the heat exchanger 2200 may flow into the inlet port 510 of each of the plurality of battery assemblies 100 through the first cooling line 501. The coolant that has flowed into the plurality of battery assemblies 100 may cool the battery assemblies 100 and then flow out into the second cooling line 502 through the outlet port 516 of each of the plurality of battery assemblies 100. The coolant that has flowed out into the second cooling line 502 may flow back into the coolant storage container 2100.

[0164] 19, a venting valve 520 may be disposed between the inlet port 510 of each of the plurality of battery assemblies 100 and between the outlet port 516 of each of the plurality of battery assemblies 100. Therefore, even if a thermal runaway phenomenon occurs in one of the plurality of battery assemblies 100, the venting valve 520 disposed between the plurality of battery assemblies 100 can prevent gas from propagating to an adjacent battery assembly 100.

[0165] A venting valve 520 may be additionally disposed between the most upstream of the first cooling line 501 and the inlet port 510 of the battery assembly 100 disposed most adjacent to the most upstream of the first cooling line 501. In addition, a venting valve 520 may be additionally disposed between the most downstream of the second cooling line 502 and the outlet port 516 of the battery assembly 100 disposed most adjacent to the most downstream of the second cooling line 502. Therefore, even if a thermal runaway phenomenon occurs in the battery assembly 100 closest to the external device 2000 among the plurality of battery assemblies 100, the transmission of gas to the external device 2000 can be prevented by the venting valves 520 disposed between the most upstream of the first cooling line 501 and the battery assembly 100 disposed most adjacent to the most upstream of the first cooling line 501, and between the most downstream of the second cooling line 502 and the battery assembly 100 disposed most adjacent to the most downstream of the second cooling line 502.

[0166] A filter unit 530 may be disposed between the inlet port 510 of each of the plurality of battery assemblies 100 and the venting valve 520 located on the flow direction side of the first cooling line 501 from the inlet port 510. Furthermore, a filter unit 530 may be additionally disposed between the most upstream side of the first cooling line 501 and the venting valve 520 located closest to the most upstream side of the first cooling line 501. Furthermore, a filter unit 530 may be disposed between the outlet port 516 of each of the plurality of battery assemblies 100 and the venting valve 520 located on the flow direction side of the second cooling line 502 from the outlet port 516. Therefore, the coolant circulating inside the battery pack 1000 can be filtered by the filter unit 530 before flowing into the venting valve 520.

[0167] The battery pack 1000 may include a pressure sensor 540 that measures the pressure of at least one of the first cooling line 501 and the second cooling line 502. More specifically, the pressure sensor 540 may be disposed at least one of between the most upstream of the first cooling line 501 and the filter unit 530 disposed most adjacent to the most upstream of the first cooling line 501, and between the most downstream of the second cooling line 502 and the filter unit 530 disposed most adjacent to the most downstream of the second cooling line 502.

[0168] The pressure sensor 540 measures the pressure in the cooling line 500 to monitor whether the cooling material is circulating smoothly along the cooling line 500. For example, if the filter member (534, see FIG. 14) of the filter unit 530 is clogged with foreign matter, the pressure in the cooling line 500 measured by the pressure sensor 540 increases. Therefore, the pressure sensor 540 can monitor whether there is an abnormality in the circulation in the cooling line 500 of the battery pack 1000.

[0169] 15 , a position sensor that detects the position of filter member 534 can identify filter unit 530 in which a pressure equal to or greater than a predetermined filter pressure is applied to filter member 534, which can easily identify filter unit 530 in which an abnormality has occurred among the multiple filter units 530 included in battery pack 1000. This can facilitate maintenance related to the circulation of the cooling material in battery pack 1000.

[0170] Fig. 20 is a perspective view showing a battery assembly according to one embodiment of the present invention, and Fig. 21 is a cross-sectional view showing a cross section along the line CC' in Fig. 20.

[0171] 5, 20, and 21, as described above, the battery cell 110 may have a sealing portion 114s that is a portion where the outer periphery of the pouch case 114 is adhered. Fig. 21 shows the sealing portion 114s, which corresponds to the upper end 114b of the battery cell 110, folded to make use of space after sealing is completed.

[0172] At least a portion of the sealing portion 114s may be provided on a portion of the battery cell 110 that faces the venting unit 600. That is, at least a portion of the sealing portion 114s may be positioned in the battery cell 110 so as to face the venting unit 600.

[0173] As an example, the upper end 114b of the battery cell 110 may be a sealing portion (114s, see FIGS. 5 and 21) where the pouch case 114 is sealed, and the lower end 114a of the battery cell 110 may be a folding portion where the pouch case 114 is folded, rather than a sealing portion. The venting unit 600 may be provided on the upper surface of the frame 200. The sealing portion 114s at the upper end 114b of the battery cell 110 may be positioned to face the venting unit 600 provided on the upper surface of the frame 200.

[0174] When a thermal event or thermal runaway occurs in the battery cell 110, gas is generated in the battery cell 110, increasing the internal pressure of the battery cell 110. This gas can be discharged mainly through the sealing portion 114s of the battery cell 110. That is, the increased internal pressure causes the sealing of a portion of the sealing portion 114s to be released, and venting gas can be ejected and discharged through the released portion of the sealing portion 114s.

[0175] By arranging at least a portion of the sealing portion 114s of the battery cell 110 to face the venting unit 600, a "directional venting" structure can be more clearly realized, which allows gases and particles generated in the battery cell 110 to be discharged through the venting unit 600.

[0176] The configuration of the separator according to various embodiments of the present invention will be described in detail below. Figure 22 is a perspective view showing a separator and a battery cell according to an embodiment of the present invention.

[0177] 20 to 22, in the battery assembly 100 according to an embodiment of the present invention, a separation member 900 may be positioned between the battery cell 110 and the venting unit 600. For example, the separation member 900 may be positioned in the space between the battery cell 110 and the venting unit 600 inside the frame 200.

[0178] One side space of the separation member 900 may be a space S1 facing the venting unit 600, and the other side space of the separation member 900 may be a space S2 through which a coolant flows. The space S2 through which a coolant flows refers to a space through which the coolant flowing into the frame 200 through the inlet port 510 comes into contact with the battery cells 110 and flows.

[0179] As described above, when gases or particles generated in the battery cells 110 come into contact with the cooling material, problems may occur such as accelerating a thermal event or thermal runaway, or the cooling material may prevent the gases or particles from being discharged. To prevent these problems, it is preferable that the directional venting path that discharges gases or the like generated in the battery cells 110 through the venting unit 600 and the immersion cooling method are configured so as not to affect each other.

[0180] The separating member 900 according to this embodiment can distinguish and separate a space where gases and particles generated in the battery cells 110 are discharged through the venting unit 600 from a space where a coolant flows in contact with the battery cells 110 to cool the battery cells 110. Therefore, it is possible to minimize mutual influence and interference between the directional venting path where gases generated in the battery cells 110 are discharged and the coolant that flows in contact with the battery cells 110. This can prevent problems where gases or particles come into contact with the coolant, accelerating a thermal event or thermal runaway, or where the coolant prevents the discharge of the gases or particles.

[0181] The separator 900 is not particularly limited in shape or material as long as it can separate the space S1 facing the venting unit 600 from the space S2 through which the cooling material flows. As an example, the separator 900 may be a plate-shaped member having a predetermined thickness. FIG. 22 shows an example of the separator 900, which is a plate-shaped member that covers the upper part of the battery cell 110. The separator 900 according to this embodiment may be a member separate from the frame 200 and coupled or fixed to the frame 200. The separator according to other embodiments may be a member integrated with the frame 200.

[0182] Meanwhile, since the gas generated in the battery cell 110 is guided to the venting unit 600, the separating member 900 may include a material that is easily ruptured by the gas emitted from the battery cell 110. At least a portion of the separating member 900 is ruptured by the gas or particles emitted from the battery cell 110, and the gas or particles move through the ruptured portion to the space S1 facing the venting unit 600 and can be discharged through the venting unit 600.

[0183] Meanwhile, as described above, a plurality of battery cells 110 may be stacked to form the battery cell stack 120. A plurality of battery cell stacks 120 may also be provided within the frame 200. For example, the battery cell stack 120 may include a first battery cell stack 120a and a second battery cell stack 120b. Within one battery cell stack 120, the first battery cell stack 120a and the second battery cell stack 120b may be arranged along a direction perpendicular to the direction in which the battery cells 110 are stacked. For example, within one battery cell stack 120, the battery cells 110 may be stacked along a direction parallel to the y-axis, and the first battery cell stack 120a and the second battery cell stack 120b may be arranged along a direction parallel to the x-axis. The separator 900 according to this embodiment may be disposed to cover the entire upper portions of the first battery cell stack 120a and the second battery cell stack 120b.

[0184] By providing multiple battery cell stacks 120 within one frame, it is possible to increase the battery capacity and energy density of the battery assembly 100. The loss in battery capacity and energy density that occurs due to the provision of immersion cooling-related structures such as the inlet port 510 and the outlet port 516 can be compensated for by the multiple battery cell stacks 120.

[0185] FIG. 23 illustrates a separation member according to various embodiments of the present invention.

[0186] 21 and 23(a) to 23(d), at least a portion of the separating members 900a, 900b, 900c, and 900d according to the embodiment of the present invention can be ruptured when a pressure equal to or greater than a certain level is applied. At least a portion of the separating member 900 is ruptured by gas or particles emitted from the battery cell 110, and the gas or particles move through the ruptured portion into the space S1 facing the venting unit 600 and can be discharged through the venting unit 600.

[0187] 23(a), a separating member 900a according to an embodiment of the present invention may be a plate-shaped member. The separating member 900a may include a material that is easily ruptured by gas emitted from a battery cell, or may have a sufficiently thin thickness so that the separating member 900a is easily ruptured by gas emitted from a battery cell.

[0188] 23(b), a separation member 900b according to another embodiment of the present invention may have notches N1 and N2 formed therein to form a portion that ruptures when a pressure above a certain level is applied. The notches N1 and N2 refer to portions of the separation member 900b that are recessed by a predetermined thickness. The separation member 900b may include a first portion 910 and a second portion 920, which may be separated by the notches N1 and N2. The first portion 910 is a portion where rupture is induced, and the notches N1 and N2 and the first portion 910 rupture due to gas emitted from the battery cell, allowing the gas to move to a space facing the venting unit.

[0189] 23(c), a separation member 900c according to another embodiment of the present invention may have a boundary portion with a difference in thickness to form a portion that ruptures when a pressure above a certain level is applied. The separation member 900c may include a first portion 910 and a second portion 920. The first portion 910 may be thinner than the second portion 920 and may be the portion where rupture is induced. The boundary between the first portion 910 and the second portion 920 may correspond to the boundary portion with a difference in thickness. The first portion 910, which has a weak strength due to its thin thickness, may rupture due to gas emitted from the battery cell, and the gas may move through the ruptured first portion 910 to a space facing the venting unit.

[0190] 23(d), a separation member 900d according to another embodiment of the present invention may have a plurality of holes H1, H2, H3, and H4 formed therein to form a portion that ruptures when a pressure above a certain level is applied. The plurality of holes H1, H2, H3, and H4 refer to holes that penetrate the separation member 900d. The separation member 900d may include a first portion 910 and a second portion 920, and the first portion 910 and the second portion 920 may be separated by a plurality of holes H1, H2, H3, and H4 arranged at predetermined intervals. The plurality of holes H1, H2, H3, and H4 arranged at predetermined intervals may form a boundary between the first portion 910 and the second portion 920. Gas emitted from the battery cell ruptures the portion between the plurality of holes H1, H2, H3, and H4 or the first portion 910, allowing the gas to move to a space facing the venting unit.

[0191] FIG. 24 is a perspective view showing a separation member including a mesh part and a battery cell according to another embodiment of the present invention.

[0192] 24, a separation member 900e according to another embodiment of the present invention may include a mesh part MP. For example, the mesh part MP may be provided in at least one region of the separation member 900e. The mesh part MP refers to a porous structure and may include, for example, a metal material. The mesh part MP may be formed by weaving metal wires.

[0193] Gas and particles emitted from the battery cells pass through the mesh part MP of the separating member 900e and move to the space (S1, see FIG. 21) facing the venting unit (600, see FIG. 21), and then can be discharged through the venting unit 600. In other words, the mesh part MP of the separating member 900e can guide the movement of gas and particles emitted from the battery cells.

[0194] Furthermore, particles emitted from the battery cell may include high-temperature metal particles, which may cause explosions or fires when they come into contact with external oxygen. However, when the high-temperature metal particles pass through the mesh part MP, they collide with the mesh part MP, lowering the temperature of the metal particles and preventing explosions or fires. Furthermore, because the mesh part MP has a porous structure, it can restrict the coolant from flowing into the space (S1, see FIG. 21) facing the venting unit (600, see FIG. 21). The mesh part MP according to this embodiment can prevent gas generated in the battery cell 110 from causing explosions or fires while simultaneously restricting the overflow of the coolant.

[0195] FIG. 25 is a perspective view showing a separating member according to another embodiment of the present invention.

[0196] 25, a separator 900f according to another embodiment of the present invention may include an opening P. Such a separator 900f may be positioned between a battery cell 110 (see FIG. 21) and a venting unit 600 (see FIG. 21). Because the opening P is formed in the separator 900f, gas and particles generated in the battery cell 110 can be directly ejected into the space S1 facing the venting unit 600 through the opening P, and can be directly discharged to the outside through the venting unit 600.

[0197] FIG. 26 is a cross-sectional view of a battery assembly to which the separating member of FIG. 25 is applied.

[0198] 25 and 26 together, in a battery assembly according to another embodiment of the present invention, a separation member 900f into which the battery cell 110 is fitted may be located inside the frame 200. In particular, Fig. 26 shows in cross section that the battery cell 110 is located inside the frame 200 in a state where it is fitted into the separation member 900f.

[0199] One side space of the separation member 900f may be a space S1 facing the venting unit 600, and the other side space of the separation member 900f may be a space S2 through which a coolant flows. The space S2 through which a coolant flows refers to a space through which the coolant that has flowed into the frame 200 through the inlet port 510 comes into contact with the battery cells 110 and flows.

[0200] An opening P may be formed in the separator 900f, and the battery cell 110 can be fitted into the opening P. For example, a partial area of ​​the upper portion of the battery cell 110 can be fitted into the opening P of the separator 900f. Unlike the embodiment described above in which the separator 900f having the opening P formed therein is positioned between the battery cell (110, see FIG. 21) and the venting unit (600, see FIG. 21), in the embodiment of FIG. 26, the separator 900f can be positioned inside the frame 200 with the battery cell 110 fitted into the opening P of the separator 900f.

[0201] Because the battery cell 110 is fitted into the separating member 900f, one end of the battery cell 110 can be exposed to the space S1 facing the venting unit 600. For example, the upper end 114b of the battery cell 110 can be exposed to the space S1 facing the venting unit 600. Gas and particles generated in the battery cell 110 can be directly ejected into the space S1 facing the venting unit 600 and directly discharged to the outside through the venting unit 600. At the same time, the separating member 900f can separate the space S1 facing the venting unit 600 from the space S2 through which the coolant flows.

[0202] Therefore, the directional venting function is not hindered at all, and the space where the gas is discharged through the venting unit 600 and the space where the coolant flows in contact with the battery cell 110 can be effectively separated and separated. This minimizes mutual influence and interference between the directional venting path where the gas generated in the battery cell 110 is discharged and the coolant that flows in contact with the battery cell 110.

[0203] A battery assembly 100 and a battery pack 1000 including the battery assembly 100 according to an embodiment of the present invention can be applied to a variety of external devices 2000. In the embodiment shown in Fig. 19, an electric vehicle and a hybrid vehicle are shown as examples of such devices, but the present invention is not limited thereto. In other words, the present invention can be applied to a variety of devices that can use a battery assembly and a battery pack including the battery assembly, and can be applied to, for example, transportation means such as an electric bicycle and / or an energy storage system (ESS), which also fall within the scope of the present invention.

[0204] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are used merely for convenience of explanation and may vary depending on the position of the object of interest, the position of the observer, etc.

[0205] One or more battery assemblies according to the above-described embodiments may be installed 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.

[0206] The battery assembly or battery pack can be applied to various devices, specifically, but not limited to, transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, and ESS (Energy Storage Systems).

[0207] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0208] 100: Battery assembly 110: Battery cell 120: Battery cell stack 200: Frame 210: Mainframe 400: End plate 510: Inlet port 516: Outflow port 600: Venting unit

Claims

1. a plurality of battery cells; a frame that houses the plurality of battery cells; an inlet port and an outlet port for circulating a cooling material inside the frame; a venting unit provided on one side of the frame and configured to exhaust gas from the inside of the frame when the pressure inside the frame is equal to or greater than a specific pressure; The cooling material flowing in through the inlet port directly cools the battery cells and is discharged through the outlet port.

2. 2. The battery assembly of claim 1, wherein the specific pressure is equal to or greater than 1.0 bar and equal to or less than 2.5 bar.

3. The battery assembly according to claim 1 , wherein the one side of the frame on which the venting unit is provided is different from at least one side of the frame on which the inlet port or the outlet port is provided.

4. The battery assembly according to claim 1 , wherein the venting unit is provided on an upper surface of the frame.

5. 2. The battery assembly of claim 1, wherein the venting unit is a rupture disc type that ruptures when the internal pressure of the frame reaches or exceeds the specific pressure, a reversible type that opens and closes based on the specific pressure inside the frame, or a valve type that opens when the internal pressure of the frame reaches or exceeds the specific pressure.

6. The battery assembly of claim 1 , wherein the venting unit is attached to the upper surface of the frame by a sealant, an adhesive, bolting, or welding.

7. The battery cells are stacked to form a battery cell stack; The battery assembly of claim 1 , wherein the battery cell stack is housed in the frame.

8. 8. The battery assembly according to claim 7, wherein the frame includes: a main frame that covers at least a portion of the battery cell stack including an upper surface thereof and has opposite open sides; and end plates that cover the open sides of the main frame, respectively.

9. The battery assembly according to claim 8 , wherein the venting unit is located on one surface of the main frame.

10. The battery assembly of claim 8 , wherein the inlet port and the outlet port are located in one of the end plates or in each of the end plates.

11. the battery cell has a sealing portion; The battery assembly according to claim 1 , wherein at least a portion of the sealing portion is provided on a portion of the battery cell that faces the vent unit.

12. The battery assembly according to claim 1 , wherein a separating member is located between the battery cell and the venting unit.

13. The battery assembly according to claim 12 , wherein one side space of the separating member faces the vent unit, and the other side space of the separating member is a space through which the cooling material flows.

14. The battery assembly according to claim 12 , wherein at least a portion of the separating member ruptures when a pressure equal to or greater than a certain level is applied.

15. The battery assembly according to claim 12 , wherein the separating member has a notch, a boundary portion having a thickness difference, or a plurality of holes formed therein to form a portion that ruptures when a pressure greater than a certain level is applied.

16. The battery assembly of claim 12 , wherein the separating member includes a mesh part.

17. The battery assembly of claim 12 , wherein the separating member includes an opening.

18. The battery assembly according to claim 1 , wherein a separation member into which the battery cells are fitted is located inside the frame.

19. The battery assembly according to claim 18 , wherein one side space of the separating member faces the vent unit, and the other side space of the separating member is a space through which the cooling material flows.

20. cooling lines are connected to the inlet port and the outlet port, respectively; The battery assembly of claim 1 , wherein a venting valve is disposed in at least one of the cooling lines.

21. 21. The battery assembly of claim 20, wherein the venting valve discharges gas from the cooling line when the pressure in the cooling line reaches a predetermined pressure.

22. At least one battery assembly according to any one of claims 1 to 21; a pack frame that houses the battery assembly and has an open top; a pack cover that covers the open top of the pack frame, The pack cover is spaced apart from the venting unit so that a predetermined venting space is formed between the venting unit and the pack cover.

23. 23. The battery pack according to claim 22, wherein a distance between the venting unit and the pack cover in the venting space is 5 mm or more and 25 mm or less.

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