Battery module, battery pack, and automobile including the same

Abstract

The present invention provides a battery module capable of delaying heat propagation to adjacent battery cells by controlling the direction of gas and flame emitted from a battery cell. The battery module of the present invention includes a cell stack including a plurality of battery cells and one or more tangible members, wherein the tangible member closest to the cell stack among the tangible members has an intumescent fire-resistant member on a surface facing the cell stack, the intumescent fire-resistant member being a coating layer integrally formed on the tangible member by applying an intumescent fire protection material, and the intumescent fire-resistant member expands into the space between adjacent battery cells when the battery cells generate heat, thereby isolating the adjacent battery cells.

Description

[Technical Field]

[0001] The present invention relates to a battery module, a battery pack, and a vehicle including the same, and more particularly to a battery module, a battery pack, and a vehicle including the same, to which a configuration for delaying thermal runaway is applied.This application claims priority to Korean Patent Application No. 10-2023-0160357, filed on November 20, 2023, the entire contents of which are incorporated herein by reference in their entirety. [Background technology]

[0002] Secondary batteries, which are easily applicable to various products and have electrical properties such as high energy density, are commonly used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are powered by electrical sources. These secondary batteries are widely used as an energy source to improve energy efficiency and are environmentally friendly, as they not only have the major advantage of dramatically reducing the use of fossil fuels but also produce no by-products from energy use.

[0003] Due to the need for high output and large capacity, medium- to large-sized devices such as automobiles use battery modules in which a plurality of battery cells are electrically connected, and medium- to large-sized battery packs that include such battery modules as unit modules. Because it is desirable to manufacture such battery modules and battery packs as small and lightweight as possible, prismatic and pouch-type batteries, which can be stacked at high density and have a low weight relative to their capacity, are commonly used as unit cells for battery modules. In particular, pouch-type battery cells, which use an aluminum laminate sheet or the like as an exterior member, have attracted attention due to their advantages of low weight, low manufacturing costs, and easy shape modification.

[0004] However, because battery cells undergo chemical reactions during charging and discharging, their performance may be reduced if they are used in environments that are higher than the appropriate temperature, and if thermal control is not performed at the appropriate temperature, there is a risk of unexpected fire or explosion. Furthermore, battery modules are constructed by integrating these battery cells into a module case. Therefore, if a thermal event occurs in one battery cell, the emitted high-temperature gas and flames can spread to adjacent battery cells, potentially causing a chain reaction of battery cell explosions, which is extremely dangerous.

[0005] In particular, in recent years, there has been a demand for heat propagation delay technology for automotive battery modules, making it necessary to suppress and delay gas and flames emitted outside the battery module. Vent gas emitted before the battery module ignites may lead to chain fires, and a solution is needed.

[0006] However, pouch-type battery cells have a problem in that flames can easily spread to adjacent battery cells through electrode leads during thermal runaway. However, currently, there is no structure that can control the direction of gas and flames within the battery module. Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a battery module that can delay heat propagation to adjacent battery cells by controlling the direction of gas and flames emitted from a battery cell.

[0008] Another problem to be solved by the present invention is to provide a battery pack and a vehicle including such a battery module. [Means for solving the problem]

[0009] In order to solve the above problems, the battery module of the present invention is a battery module including a cell stack including a plurality of battery cells and one or more tangible members, wherein the tangible member closest to the cell stack among the tangible members has an intumescent fire-resistant member on the surface facing the cell stack, the intumescent fire-resistant member being a coating layer formed integrally with the tangible member by applying an intumescent fire protection material, and the intumescent fire-resistant member expands into the space between adjacent battery cells when the battery cells generate heat, thereby isolating the adjacent battery cells.

[0010] Another battery module of the present invention includes: a cell stack including a plurality of battery cells; a bus bar frame assembly disposed on at least one side of the cell stack and including a bus bar and a bus bar frame; and an intumescent fire-resistant member provided on the bus bar frame assembly, wherein the bus bar frame includes a rib that can be interposed in a gap between adjacent battery cells, and the intumescent fire-resistant member is located on the rib.

[0011] The battery cells may be pouch-type battery cells each including an electrode lead, a storage portion, and a sealing portion, and the rib of the bus bar frame may be at least partially interposed in a gap between the sealing portions or the storage portions of adjacent battery cells and protrude toward the storage portion.

[0012] The rib may be a plate-like protrusion with a constant thickness.

[0013] The rib may be integrally injection molded with the bus bar frame and provided at a position not overlapping with a lead slot provided in the bus bar frame so that the electrode lead passes through.

[0014] When the battery cells generate heat, the foam fire-resistant member expands into the space between the adjacent battery cells, thereby isolating the adjacent battery cells.

[0015] The foam fireproof member may expand to the receiving portion when the battery cell generates heat.

[0016] A gap is maintained between a rear surface of the bus bar frame and the battery cell, the rib is protruded from the rear surface of the bus bar frame in the gap direction, and the foamable fire-resistant member expands when the battery cell generates heat and reaches the battery cell, thereby eliminating the gap.

[0017] The expanded foamable fire-resistant member may be deformed to fit the shape of the gap while filling the gap between the battery cells.

[0018] The intumescent fireproof member may be a coating layer formed integrally with the rib by applying an intumescent fireproof paint.

[0019] The intumescent fire-resistant member may surround only a portion of the rib in the longitudinal direction, without surrounding either end of the rib in the longitudinal direction.

[0020] The fire-resistant paint may be a liquid paint made by mixing a foam material with a polymer, and the foam fire-resistant member may be insulating.

[0021] When an internal fire breaks out in the battery module, the foam fire-resistant member may block flames and gases generated in the ignited battery cell from traveling in the stacking direction of the battery cells or in the length direction of the battery cells.

[0022] The battery module may further include a module case configured to accommodate the cell stack, the bus bar frame assembly, and the foam fireproof member, and may include a plurality of vent holes on a lower surface of the module case.

[0023] The cell stack may further include a compressible pad-shaped insulating member made of silicone, aerogel, or polyurethane.

[0024] The rib may have holes penetrating both sides, and the foam fireproof member formed on the surface of the rib may fill the holes.

[0025] The rib may be a component in which a fire-resistant material is packaged on a surface of the rib by heterogeneous injection molding, and the rib may be assembled to the bus bar frame.

[0026] The rib may have a repeated notch structure or sawtooth-like concave and convex portions on one side of the contact surface with the intumescent fire-resistant member.

[0027] The battery pack of the present invention can include at least one battery module of the present invention.

[0028] The vehicle of the present invention may include at least one battery module of the present invention or may include a battery pack of the present invention. [Effects of the Invention]

[0029] According to one aspect of the present invention, it is possible to provide a battery module that has a compact structure without using many components and that can delay heat propagation to adjacent battery cells.

[0030] According to the present invention, the safety of the battery module or battery pack can be improved by controlling the direction of gas and flame discharge.

[0031] According to the present invention, it is possible to prevent an explosion due to a short circuit in a battery module or a battery pack in a thermal runaway situation.

[0032] By including such a battery module or battery pack, a vehicle can be provided with improved safety. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a conceptual diagram of a battery module proposed in the present invention. [Figure 2] 1 is an overall perspective view of a battery module according to an embodiment of the present invention; [Figure 3] 1 is an exploded perspective view of a battery module according to an embodiment of the present invention; [Figure 4] 1 is a view showing a state before a bus bar frame is coupled to a cell stack in a battery module according to an embodiment of the present invention, as viewed from above. FIG. [Figure 5] 4 is a cross-sectional view of a portion of a battery module according to an embodiment of the present invention after a bus bar frame is coupled to a cell stack, viewed from the upper side. FIG. [Figure 6] FIG. 4 is an enlarged view of part A in FIG. 3. [Figure 7] FIG. 10 is an enlarged view showing a portion of a bus bar frame in a battery module according to another embodiment of the present invention. [Figure 8] 10 is an enlarged view of a portion of a bus bar frame in a battery module according to still another embodiment of the present invention. FIG. [Figure 9] 1 is a schematic diagram illustrating a battery pack according to an embodiment of the present invention. [Figure 10] 1 is a schematic diagram of a vehicle according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and phrases used in the specification and claims should not be construed as being limited to their ordinary and dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0035] Therefore, it should be understood that the configurations shown in the embodiments described in this specification are merely the most desirable embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0036] The present invention includes many different embodiments, and the following description will focus on the differences and omit redundant descriptions of configurations that are substantially the same or similar to each other.

[0037] Meanwhile, in the present invention, terms indicating directions such as up, down, left, right, front, and back may be used, but it will be apparent to those skilled in the art that such terms are used for the convenience of explanation and may vary depending on the position of the target object, the position of the observer, etc.

[0038] For example, in an embodiment of the present invention, the X-axis direction shown in the drawings may refer to the left-right direction, the Y-axis direction may refer to the front-back direction perpendicular to the X-axis direction on a horizontal plane (XY plane), and the Z-axis direction may refer to the up-down direction (vertical direction) perpendicular to both the X-axis direction and the Y-axis direction.

[0039] The present invention provides a flame-directing battery module for delaying thermal runaway, as well as a battery pack and a vehicle including such a battery module.

[0040] FIG. 1 is a conceptual diagram of a battery module proposed in the present invention.

[0041] Referring to Fig. 1, a battery module 1 further includes components such as a cell stack 2 and a module case 3. Such a battery module 1 basically includes the cell stack 2 in which battery cells are stacked. The cell stack 2 is housed in the module case 3. The module case 3 further includes electrical components for electrically connecting the battery cells and one or more physical members 4 for maintaining the structure.

[0042] The battery module 1 particularly includes an intumescent fire-resistant member 5 provided on at least a part of the tangible member 4. In particular, it is desirable that the intumescent fire-resistant member 5 be provided on the tangible member 4 that is located closest to the cell stack 2, among the tangible members 4. It is also desirable that the intumescent fire-resistant member 5 be provided on the surface of the tangible member 4 that faces the cell stack 2, in other words, on the cell-adjacent surface 4a.

[0043] Furthermore, the intumescent fire-resistant element 5 may be a coating layer formed integrally with the material element 4 by applying an intumescent fire protection material. The intumescent fire-resistant element 5 contains a foam material that expands when heated. When heat is generated in the battery cell, the foam material expands, causing the intumescent fire-resistant element 5 to expand.

[0044] The foam fire-resistant member 5 may be positioned to face the portion of the battery cell where heat is primarily generated. For example, if the basic unit of the cell stack 2 is a pouch-type battery cell, the foam fire-resistant member may be provided on an adjacent material member so as to be positioned around the electrode leads of the pouch-type battery cell. When the pouch-type battery cell generates heat, the foam fire-resistant member 5 around the electrode leads expands. By disposing the foam fire-resistant member 5 around the electrode leads, the expanded foam fire-resistant member 5 can surround the electrode leads or isolate adjacent electrode leads, thereby delaying thermal runaway from one battery cell to another adjacent battery cell.

[0045] When the battery cells generate heat, the foamable fire-resistant member 5 expands into the space between adjacent battery cells, thereby isolating the adjacent battery cells. Preferably, the tangible member 4 located closest to the cell stack 2 is a bus bar frame assembly (BFA), and a more specific battery module structure will be described in the following embodiments.

[0046] FIG. 2 is an overall perspective view of a battery module according to one embodiment of the present invention. FIG. 3 is an exploded perspective view of a battery module according to one embodiment of the present invention. FIG. 4 is a view from above of a battery module according to one embodiment of the present invention before a bus bar frame is coupled to a cell stack. FIG. 5 is a view from above of a cross section of a portion of a battery module according to one embodiment of the present invention after a bus bar frame is coupled to a cell stack. For example, FIG. 5 is a view showing a cross section taken along line I-I' in FIG. 2. FIG. 6 is an enlarged view of portion A in FIG. 3.

[0047] 2 to 4, a battery module 10 according to an embodiment of the present invention includes a cell stack 100, a bus bar frame assembly 200, a foam fire-resistant member 300, and a module case 400.

[0048] The cell stack 100 may include a plurality of battery cells 110. The battery cell 110 may include an electrode assembly (including a positive electrode plate, a negative electrode plate, and a separator), an electrolyte, and a battery case. The plurality of battery cells 110 may be electrically connected to each other. For example, the plurality of battery cells 110 may be electrically connected to each other in series and / or parallel via the bus bars 600 of the bus bar frame assembly 200.

[0049] Meanwhile, the present invention is not limited to a specific type or shape of the battery cell 110, and various battery cells 110 known at the time of filing of the present invention may be adopted to configure the battery module 10 of the present invention. In this embodiment, as shown in the drawings, a pouch-type battery cell having high energy density and easy stacking will be mainly described, but it goes without saying that a prismatic battery cell or a cylindrical battery cell may also be applied to the battery cell 110.

[0050] As shown in detail in FIG. 4 , the battery cell 110 may include a receiving portion 112 and a sealing portion 111. The receiving portion 112 is configured to receive an electrode assembly, and the sealing portion 111 may be configured to seal the outer edge of the receiving portion 112 by heat sealing. Each of the plurality of battery cells 110 may include an electrode lead 113. The electrode lead 113 may be connected to the electrode assembly and configured to be extended to the outside of the battery case. The electrode leads 113 are provided in pairs, and the pair of electrode leads 113 may be extended from both ends of the battery cell 110, i.e., in the length direction (Y-axis direction). That is, the electrode leads 113 may be extended in both directions. In this case, the pair of electrode leads 113 may be a positive electrode lead and a negative electrode lead. If necessary, the battery cell 110 may have two electrode leads 113 located at only one end in the Y-axis direction. That is, the electrode leads 113 may be extended in one direction.

[0051] The cell stack 100 may be provided by stacking a plurality of battery cells 110 in one direction. For example, as shown in Fig. 3, the plurality of battery cells 110 may be stacked while standing vertically (Z-axis direction) and arranged parallel to each other in the left-right direction (X-axis direction). In this case, each battery cell 110 may have its sealing portion 111 facing the front-rear direction (Y-axis direction) and the up-down direction (Z-axis direction), and its storage portion 112 facing the left-right direction (X-axis direction).

[0052] The bus bar frame assembly 200 is a component included in the battery module 10 for electrical connection between the battery cells 110 included in the cell stack 100. The bus bar frame assembly 200 is provided on the side of the battery cell 110 from which the electrode leads 113 protrude. Since the bus bar frame assembly 200 is formed on the side from which the electrode leads 113 protrude, it may be formed on at least one of the front and rear sides of the battery cell 110. Therefore, the bus bar frame assembly 200 may be disposed on at least one side of the cell stack 100. As shown in the illustrated example, the bus bar frame assembly 200 may be provided on both sides of the battery cell 110 in the front-rear direction. Thus, the bus bar frame assembly 200 may be provided at the longitudinal end portions of the battery cell 110.

[0053] The bus bar frame assembly 200 may include a bus bar 600 electrically connected to the battery cell 110 and a bus bar frame 500 supporting the bus bar 600. The bus bar frame assembly 200 may further include a terminal bus bar and a circuit in the form of a PCB or FPCB.

[0054] The bus bar 600 is electrically connected to the battery cells 110 and connects the battery cells 110 to each other, and is made of a metal with excellent conductivity, such as copper or aluminum. The terminal bus bar is also electrically connected to the battery cells 110 and is involved in charging and discharging. The circuit can be configured to measure the voltage of the battery cells 110 connected in series and measure the temperature of any of the battery cells 110.

[0055] The bus bar frame 500 is a tangible member that functions to support the bus bar 600 and the like, and can also be used to bend the electrode leads 113 and shape them so that they can be welded to the bus bar 600. In the battery module 10, the tangible member that is closest to the battery cells 110 is the bus bar frame assembly 200, and the bus bar frame 500 in particular.

[0056] The bus bar frame 500 is preferably made of a plastic material to ensure insulation. For example, the bus bar frame 500 may be made of one or more materials selected from the group consisting of modified polypropylene oxide (MPPO), polycarbonate (PC), polyethylene (PE), and polybutylene terephthalate (PBT). The bus bar frame 500 made of a plastic material may be injection molded.

[0057] The module case 400 may have an internal space formed therein and may be configured to accommodate the cell stack 100, the bus bar frame assembly 200, and the foam fire-resistant member 300. The module case 400 may include a plurality of vent holes (not shown) on a lower surface thereof.

[0058] The module case 400 of this embodiment may include a case body 410 and end plates 420 disposed on the front and rear sides of the case body 410. There are various types and shapes of the module case 400, and the present invention is not limited thereto.

[0059] Here, the case body 410 has an upper plate, a lower plate, a left plate, and a right plate to form a storage space, and the cell stack 100 can be stored in the storage space. The case body 410 may be made of a metal material having rigidity and heat resistance to physically and chemically protect the stored cell stack 100.

[0060] Furthermore, the end plates 420 may be coupled to the case body 410 and configured to cover open portions of the case body 410. More specifically, the case body 410 may be configured to have open front and rear ends, and the end plates 420 may be configured to be coupled to the open portions of the case body 410 at the front and rear.

[0061] Meanwhile, the vent holes are formed in the case body 410, allowing directional venting in one direction. A plurality of vent holes are formed on the lower surface of the case body 410, allowing directional venting downward of the battery module 10 through the vent holes. According to this embodiment, when gas is discharged from the battery module 10, the discharged gas can be effectively prevented from moving upward. In particular, when a passenger is positioned above the battery module 10 or a battery pack including the battery module 10, such as in an electric vehicle, the above embodiment can prevent or delay gas from moving toward the passenger.

[0062] 4 to 6 , the bus bar frame 500 may include ribs 511 that may be interposed in gaps between the battery cells 110. Specifically, the ribs 511 of the bus bar frame assembly 200 may be interposed at least partially in gaps between the seal portions 111 of adjacent battery cells 110 and / or between the storage portions 112. The convexly protruding portion of the storage portion 112 is also referred to as a cup surface. The ribs 511 may protrude from the bus bar frame 500 toward the cup surface.

[0063] The rib 511 may be in the form of a plate-like protrusion of a constant thickness as shown in FIG. 6, or may be a three-dimensional structure with an uneven or variable thickness, or with more volume than a plate.

[0064] When the bus bar frame 500 is injection molded, the ribs 511 may be integrally formed on the bus bar frame 500. The bus bars 600 may be provided on the front surface, in other words, the outer surface, of the bus bar frame 500. Here, the outer surface refers to the surface facing outward from the battery module 10.

[0065] The bus bar frame 500 has lead slots 512 formed therein. The lead slots 512 may be located on the side where the electrode leads 113 of the plurality of battery cells 110 are provided. The lead slots 512 may be provided so that at least some of the electrode leads 113 of the plurality of battery cells 110 pass through them. In this case, the plurality of electrode leads 113 that pass through the lead slots 512 may be provided so as to be bent and stacked on top of each other. With this stacked structure, the plurality of battery cells 110 whose electrode leads 113 are in contact with each other may be electrically connected to each other.

[0066] A plurality of lead slots 512 may be provided so as to be spaced apart from one another along the stacking direction (X-axis direction) of the battery cells 110. In particular, the lead slots 512 may be provided at positions that do not overlap with the ribs 511. This positions the electrode leads 113 and the ribs 511 so that they do not come into contact with each other under normal circumstances, and prevents the electrode leads 113 from being compressed or damaged by the ribs 511.

[0067] The bus bar 600 may be provided between the bus bar frame 500 and the stacked electrode leads 113. The bus bar 600 may be electrically connected to the electrode leads 113. Furthermore, through such electrical connection, the bus bar 600 may be configured to transmit status information of the battery cells 110 to an external component. For example, the bus bar 600 may be configured to transmit voltage information of the battery cells 110 to an external control device such as a BMS (Battery Management System).

[0068] The intumescent fire-resistant member 300 may be integrally provided with the bus bar frame assembly 200. For example, the intumescent fire-resistant member 300 may be formed as a foam coating layer formed by applying a heat-absorbing foaming material as a paint-like coating material. The application may be performed by a spray method or a comma coating method. Of course, application may also be performed by various printing methods such as brush printing, intaglio printing, roller printing, silk screen printing, stamping, and inkjet printing, or by other methods such as metered discharge, spindle coating, and impregnation. In addition to the direct coating method described above, it is also possible to develop intumescent fire-resistant member 300 products in sheet and tape form depending on the application location and method of the product.

[0069] The foam fire-resistant member 300 may be located on the cell-adjacent surface of the bus bar frame assembly 200. The cell-adjacent surface is the back surface of the bus bar frame 500, i.e., the inner surface. The battery cells 110 tend to swell during use. To prevent swelling, a gap is provided between the back surface of the bus bar frame 500 and the battery cells 110 (for example, the gap indicated by G in FIG. 5). If vent gas moves through this gap, it may affect the adjacent battery cells 110. In this embodiment, a rib 511 is configured to protrude in the direction of the gap, and the foam fire-resistant member 300 is disposed on this rib. When the foam fire-resistant member 300 expands and reaches the battery cells 110, this gap disappears. The inset in FIG. 5 shows the expanded foam fire-resistant member 300′ reaching the battery cells 110 and filling the space between the battery cells 110. According to this configuration, even if a thermal event occurs in any one battery cell 110 and vent gas is discharged, it is possible to prevent the adjacent battery cells 110 from being affected.

[0070] In this embodiment, the intumescent fire-resistant member 300 may be disposed only on the surface of the rib 511. As shown in the figure, the rib 511 is a plate-like protrusion with a certain thickness, and the intumescent fire-resistant member 300 may be disposed in a form surrounding the protruding portion. For example, the rib 511 may surround both relatively wide sides and the narrow side between them. In this case, the intumescent fire-resistant member 300 may surround only a portion of the rib 511 in the longitudinal direction (Z-axis direction), without surrounding one end or the other end of the rib 511. The intumescent fire-resistant member 300 does not expand in the unsurrounded portion of the rib 511. Even if the intumescent fire-resistant member 300 expands, a space through which gas or flame emitted from the battery cell 110 can move may be provided in the portion of the rib 511 not surrounded by the intumescent fire-resistant member 300. Therefore, the direction of the gas or flame can be guided in a specific direction.

[0071] The battery cells 110 tend to swell during use. To account for the occurrence of swelling, a gap is secured between the rear surface of the bus bar frame 500 and the battery cells 110. The ribs 511 are provided at the already secured gap. There is no need to change the size of the bus bar frame 500 to provide the ribs 511. Therefore, the compact structure of the battery module 10 can be maintained. There is no need to provide a separate space for including the foam fire-resistant member 300 in the battery module 10. The foam fire-resistant member 300 is disposed on the ribs 511. Therefore, the compact structure of the battery module 10 can be maintained.

[0072] The intumescent fire-resistant member 300 may be an intumescent fire-resistant paint coating layer. The intumescent fire-resistant member 300 may be formed by applying an intumescent fire-resistant paint to the rear surface of the bus bar frame assembly 200, particularly to the rib 511. The fire-resistant paint is a liquid containing a foaming material, and may be configured to harden when heat is applied or over time after application.

[0073] For example, the fire-resistant paint may be a liquid paint made by mixing a foam material and a polymer. This may further include a fire-resistant material to further enhance fire resistance. Other components may be added to the fire-resistant paint to provide excellent chemical resistance and adhesion to the substrate. For example, a raw material containing a foam material and a polymer is prepared, and then a hardener, leveling agent, pigment, solvent, release agent, filler, etc. are added and stirred, taking into consideration coating properties (surface strength, acid resistance, weather resistance, etc.) and adhesion, to produce the fire-resistant paint. Such a fire-resistant paint is applied to the rib 511 and cured to form a coating layer.

[0074] Here, the polymer may be a resin such as enamel or urethane, or a rubber such as SBR or EPDM. The polymer acts as a binder that provides adhesion and flexibility. The polymer is not limited thereto and can be varied and modified depending on the properties of the product to be applied. The polymer may further include epoxy, polysulfide, polysiloxane, polysilarylene, or a combination thereof.

[0075] The foaming material may be any material that can foam when heated. The degree of expansion due to foaming varies depending on the type, component ratio, purity, etc. of the foaming material.

[0076] An example foam material may include an acid source, a blowing agent, and a carbon source. For example, the foam material may include a polyphosphate source, a blowing agent, and a pentaerythritol carbon source. Without being bound by theory, the foam material utilizes two energy absorption mechanisms: char formation and subsequent char expansion; therefore, any foam material capable of achieving these mechanisms is sufficient.

[0077] The acid source can include, for example, organic or inorganic phosphorus compounds, organic or inorganic sulfates (eg, ammonium sulfate), or combinations thereof. The organic or inorganic phosphorus compound can include an organic phosphate or organic phosphonate (e.g., tris(2,3-dibromopropyl)phosphate, tris(2-chloroethyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(1-chloro-3-bromoisopropyl)phosphate, bis(1-chloro-3-bromoisopropyl)-1-chloro-3-bromoisopropylphosphonate, polyaminotriazine phosphate, melamine phosphate, triphenyl phosphate, or guanylurea phosphate); an organophosphite ester (e.g., trimethyl phosphite or triphenyl phosphite); a phosphazene (e.g., hexaphenoxycyclotriphosphazene); a phosphorus-containing inorganic compound (e.g., phosphoric acid, phosphorous acid, phosphite, urea phosphate, ammonium phosphate (e.g., ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate, etc.)); or a combination thereof.

[0078] The blowing agent may include dicyandiamide, azodicarbonamide, melamine, guanidine, glycine, urea (e.g., urea-formaldehyde resin or methylolated guanylurea phosphate), halogenated organic materials (e.g., chlorinated paraffins), or combinations thereof.

[0079] The carbon source can include dextrin, phenol-formaldehyde resin, pentaerythritol (e.g., its dimer or trimer), clay, a polymer (e.g., polyamide 6, amino-poly(imidazoline-amide) or polyurethane), or a combination thereof. The amino-poly(imidazoline-amide) can include repeating amide bonds and imidazoline groups.

[0080] There is no limitation on the fire-resistant material as long as it has fire resistance and can be manufactured as a paint.

[0081] The thickness of the coating layer can be adjusted by changing the state of foam materials, fire-resistant materials, and polymers with various solvents or water. If the solvent content is too low, the viscosity may be high and the coating workability may be reduced, while if the solvent content is too high, the curing (drying) time may be long, which may be undesirable. Solvents can be organic solvents such as toluene and xylene, or polar hydrocarbons. The physical properties vary depending on the solvent ratio and the component ratio. The thickness and degree of expansion can be adjusted by adjusting the solvent ratio to suit the user's process characteristics.

[0082] In addition, various additives can be used to adjust the material properties after curing and the degree of foaming and expansion so that the material can maintain the physical strength required in the industry when coated on an adherend. Components other than the foam material are not limited to those mentioned above and can be modified and adjusted according to the properties of the product to be applied.

[0083] When the foam material is heated and foamed, the foamable fire-resistant member 300 may expand. The foamable fire-resistant member 300 may be configured to foam up to the cup surface of the battery cell 110. In particular, when the ribs 511 are provided between adjacent battery cells 110 and the foamable fire-resistant member 300 is placed thereon, the foaming occurs only in the ribs 511, reaching the cup surface of the battery cell 110, resulting in a significant positioning effect. The expanded foamable fire-resistant member 300' can fill the gaps between the battery cells 110 and deform to fit the shape of the gaps. See the inset in FIG. 5. The thickness of the foamable fire-resistant member 300 can be determined taking into account the size of the ribs 511 and the size of the clearance. If the foamable fire-resistant member 300 is too thin, the degree of expansion due to foaming may be insufficient. If the foamable fire-resistant member 300 is too thick, the curing time required for the fire-resistant coating may be extended, making it difficult to reduce the cost.

[0084] The front surface of the bus bar frame assembly 200 and the front surface of the bus bar frame 500 are portions that face the outside of the battery module 10. The back surface of the bus bar frame assembly 200 and the back surface of the bus bar frame 500 are portions that face the cell stack 100. The intumescent fire-resistant member 300 can be formed by applying an intumescent fire-resistant paint to the back surface of the bus bar frame assembly 200. In this embodiment, ribs 511 are formed on the back surface of the bus bar frame 500. The intumescent fire-resistant member 300 can be formed on the surface of such ribs 511, and thereby positioned to face the cell stack 100. The intumescent fire-resistant member 300 is preferably insulating to prevent unnecessary conduction, and is preferably not formed in portions that require electrical connection.

[0085] The intumescent fire-resistant member 300 has a heat propagation delay effect. For example, if thermal runaway occurs in one of the battery cells 110, heat is dissipated to the electrode lead 113 of that battery cell 110. As described several times above, the intumescent fire-resistant member 300 is included on the back surface of the bus bar frame assembly 200 and is positioned on the cell adjacent surface. The heat dissipated toward the electrode lead 113 causes the foam material in the fire-resistant coating to expand. The intumescent fire-resistant member 300 can expand effectively in all directions. In particular, if the intumescent fire-resistant member 300 is a coating layer, it can expand in the thickness direction of the coating layer. Therefore, the intumescent fire-resistant member 300 can expand effectively from the back surface of the bus bar frame assembly 200 toward the cell stack 100. The expanded intumescent fire-resistant member 300' compresses the vicinity of the electrode lead 113 of the battery cell 110, thereby delaying heat propagation to the adjacent battery cell 110. In particular, the foam fire-resistant member 300 can expand and reach the cup surface of the battery cell 110. This ensures isolation between adjacent battery cells 110.

[0086] The expanded foamable fire-resistant member 300' can block the inflow of air, thereby preventing the spread of fire. It also exhibits heat-shielding and combustion-retarding effects. In particular, the expanded foamable fire-resistant member 300' can expand up to the cup surface between adjacent battery cells 110 and fill the space between the electrode leads 113 of the adjacent battery cells 110 to isolate them from each other, thereby providing an excellent heat propagation retardation effect.

[0087] The operation of the intumescent fire-resistant coating that can form the intumescent fire-resistant member 300 is further described below.

[0088] The foam material in the fire-resistant paint coating layer can generate char as it foams. As the foam material foams, it separates into a condensed and gaseous phase. In the condensed phase, the coating layer expands to form char, while in the gaseous phase, it can capture radicals. In the condensed phase, it acts as char, preventing heat and air from penetrating the coating layer, providing a heat-shielding effect and a combustion-retarding effect. The heat-shielding effect of the coating layer can be achieved by selecting materials that can maintain the temperature inside the steel frame below 500°C even in a fire with a temperature of 1000°C, preventing a decrease in the steel frame's strength.

[0089] When an internal fire breaks out in the battery module 10, the expanded foam fire-resistant member 300′ can block the movement of hot air, such as flames generated in the ignited battery cell 110, in the stacking direction of the battery cells 110 or in the length direction of the battery cells 110. The flames and gases can move in the vertical direction and can be discharged to the outside of the battery module 10 without affecting other battery cells 110. When the vent hole of the battery module 10 is formed on the lower surface of the case body 410, the movement of the flames and gases can be guided downward from inside the battery module 10, allowing them to be safely discharged.

[0090] As described above, the present invention can minimize heat transfer to adjacent battery cells 110. Gas and flames in any one battery cell 110 in which thermal runaway occurs are prevented from moving toward the positive / negative electrode leads of other battery cells 110, and can be ejected into spaces toward the upper or lower end that are not filled by the expanded foamable fire-resistant member 300'. As described above, the present invention can improve the safety of the battery module 10 or a battery pack including the same by controlling the direction in which gas and flames are emitted.

[0091] If such control of the flame discharge direction is not performed, flames and ejected material emitted from a battery cell experiencing thermal runaway can easily cause heat to spread to adjacent battery cells. Pouch-type battery cells, in particular, have a problem in that flames are easily emitted toward the positive and negative electrodes, making heat spread to adjacent battery cells. However, according to the present invention, flames and gases cannot travel to adjacent battery cells via the electrode lead side, so heat spread can be reliably blocked.

[0092] The expanded foamable fire-resistant member 300' may extend up to the cup surface between adjacent battery cells 110 and fill the space between the electrode leads 113 of the adjacent battery cells 110. This prevents conductive materials contained in gas discharged from any one of the battery cells 110 experiencing thermal runaway from accumulating in the space between the electrode leads 113. This prevents unintended current flow caused by the accumulated conductive materials from causing a short circuit in the battery module 10 or a battery pack including the same. In this way, according to the present invention, it is possible to prevent explosions due to short circuits in the battery module or battery pack in the event of thermal runaway.

[0093] As described above, according to the present invention, heat propagation to adjacent battery cells can be delayed simply by providing the foam fire-resistant member 300. Because many members are not used to delay heat propagation, a compact battery module 10 can be manufactured.

[0094] A plurality of foam fire-resistant members 300 may be provided. The foam fire-resistant members 300 may be formed for each rib 511. Furthermore, the ribs 511 may be provided between the seal portions 111 of adjacent battery cells 110. According to the above embodiment of the present invention, the foam fire-resistant members 300 are provided in each space between adjacent battery cells 110, and therefore have an excellent heat propagation delay effect.

[0095] Meanwhile, the cell stack 100 included in the battery module 10 of the present invention may further include blocking members 120, 130. A plurality of blocking members 120, 130 may be included. In this case, the plurality of blocking members 120, 130 may be arranged at predetermined distances in one direction, i.e., the stacking direction of the battery cells 110. The plurality of blocking members 120, 130 may be provided at regular intervals for at least one battery cell 110 (e.g., for one or more battery cells 110). The blocking members 120, 130 may be in opposing contact with both surfaces of at least some of the plurality of battery cells 110. In particular, the blocking members 120, 130 may be in opposing contact with the receiving portions 112 of the battery cells 110. In this embodiment, a plurality of blocking members 120, 130 may be provided in a form in which the blocking members 120, 130 are arranged for at least two or more battery cells 110.

[0096] The blocking members 120 and 130 are in the form of compressible pads and may be made of a material with excellent heat resistance and / or fire resistance, such as silicone, aerogel, or polyurethane. Because the blocking members 120 and 130 are compressible, they can effectively accommodate expansion of the battery cell 110 when the battery cell 110 swells.

[0097] In addition, when an internal fire breaks out in the battery module 10, the blocking members 120, 130, which have heat resistance and / or fire resistance, can function as a thermal barrier that blocks hot air, such as a flame generated in the ignited battery cell 110, from progressing in the stacking direction of the battery cells 110. As a result, the blocking members 120, 130, together with the foam fire-resistant member 300, can further minimize heat propagation to adjacent battery cells 110. The blocking members 120, 130 can block not only heat but also high-temperature gas, flame, and vomit generated in the battery cells 110. As a result, the blocking members 120, 130 can prevent the propagation of fire, etc. between the battery cells 110 by partitioning or separating the battery cells 110.

[0098] The blocking member 120 may be located on the outermost side of the cell stack 100 , and the blocking member 130 may be located between the battery cells 110 .

[0099] 7 is an enlarged view of a portion of a bus bar frame in a battery module according to another embodiment of the present invention. For example, Fig. 7 may be an enlarged view of portion A in Fig. 3, similar to Fig. 6.

[0100] 7, the rib 511 has holes H penetrating through both sides of the rib 511. For example, the rib 511 may have a mesh structure having a plurality of holes H. The holes H of the mesh structure may be manufactured in various shapes, such as a circle, a square, or a hexagon.

[0101] The intumescent fire-resistant member 300 is formed on the surface of the rib 511. The intumescent fire-resistant member 300 may be formed by applying a fire-resistant coating as described above. As shown in the inset of FIG. 7 , the intumescent fire-resistant member 300 connects both sides of the rib 511 through the holes H. In other words, the fire-resistant coating can come into contact with and solidify on the inside and outside of the rib 511, and the holes H are filled with the intumescent fire-resistant member 300. To maximize the effect of the fire-resistant coating, the coating is applied in an amount sufficient to connect the inside and outside of the rib 511. According to this embodiment, structural rigidity can be imparted while maximizing the amount of fire-resistant coating.

[0102] As another example, a mesh-structured rib 511 may be provided with a foamed fire-resistant member 300 on its surface in the form of a packaged part containing a fire-resistant material, and then assembled to the bus bar frame 500. The packaged part may be formed by heterogeneous injection. Heterogeneous injection is also known as low-pressure injection. A hot melt material can be injected into a mold using very low pressure, for example, an injection pressure of 0.15 MPa to 4 MPa, and then rapidly hardened. Therefore, in this case, the fire-resistant material is provided as a thermoplastic resin containing a foamed material. The rib 511 is first placed in an injection mold, and the fire-resistant material is injected into the cavity of the injection mold so that it surrounds the rib 511 and then hardened, resulting in a final injection product. The removed injection product can be assembled in the appropriate position on the bus bar frame 500 for use.

[0103] 8 is an enlarged view of a portion of a bus bar frame in a battery module according to still another embodiment of the present invention. For example, Fig. 8 may be an enlarged view of portion A in Fig. 3, similar to Fig. 6.

[0104] Referring to Figure 8, by providing a repeated cutout structure or sawtooth-shaped unevenness P on one side of the contact surface of the rib 511 with the foamable fire-resistant material 300, it is possible to increase the contact area with the foamable fire-resistant material 300.

[0105] FIG. 9 is a schematic diagram showing a battery pack according to an embodiment of the present invention. A battery pack 800 according to an embodiment of the present invention may include one or more battery modules 10 according to an embodiment of the present invention as described above. The battery pack 800 according to the present invention may further include components of a battery pack known at the time of filing of the present invention, such as a BMS for integrated control of charging and discharging of one or more battery modules 10, a current sensor, and a fuse. The BMS estimates the state of the battery cells in the battery pack and manages the battery pack using the estimated state information. For example, the BMS estimates and manages state information of the battery pack, such as the SOC (State of Charge), SOH (State of Health), maximum input / output power allowance, and output voltage of the battery pack. Furthermore, the state information can be used to control charging or discharging of the battery pack and even to estimate when to replace the battery pack.

[0106] The battery modules 10 are roughly rectangular parallelepipeds and are arranged in an orderly fashion inside a pack case 810, and each battery module 10 is connected so as to ensure the power required to run the vehicle.

[0107] The pack case 810 is a rectangular box that is a container for fixedly storing the battery module 10. The pack case 810 can be placed in a predetermined position inside the automobile.

[0108] In addition, in the battery pack according to the present invention, the above-described module case 400 can function as a pack case as it is. In this case, components of the battery pack such as a BMS, bus bars, and relays can be included inside the module case 400. In this case, the battery cells 110 are directly housed in the pack case, which is also called a cell-to-pack.

[0109] The battery pack 800 according to an embodiment of the present invention can be applied to various devices. Representative examples of such devices include transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto. The battery pack 800 is suitable for use as a battery pack for electric vehicles. It can also be used as an energy source for an ESS. An ESS is a standalone system that stores hundreds of kWh or more of power. ESS is the core of the renewable energy industry. Because it is difficult to produce power at the desired time using renewable energy such as solar and wind power, it is important to store the power and use it when needed. The battery pack 800 according to an embodiment of the present invention can have an energy density and capacity suitable for use as an energy source for such an ESS.

[0110] FIG. 10 is a schematic diagram of a vehicle according to one embodiment of the present invention.

[0111] The automobile V according to an embodiment of the present invention may include one or more of the battery pack 800 according to an embodiment of the present invention or the battery module 10 according to an embodiment of the present invention. The automobile V according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile V includes a four-wheeled vehicle and a two-wheeled vehicle. The automobile V operates by receiving power from the battery pack 800 or the battery module 10 according to an embodiment of the present invention.

[0112] In addition to the battery pack 800 and the battery module 10 according to the embodiment of the present invention, the automobile V may further include various other components included in an automobile, such as a body and a motor.

[0113] The battery pack 800 or the battery module 10 may be disposed at a predetermined position within the vehicle V. The battery pack 800 or the battery module 10 may be electrically connected to a motor of the vehicle V via an inverter. The battery pack 800 or the battery module 10 may be used as an electric energy source that provides driving force to the motor of the vehicle V to drive the vehicle V. In this case, the battery pack 800 or the battery module 10 is configured to have a high nominal voltage of 100 V or more. The battery pack 800 or the battery module 10 may be charged and discharged by the inverter in response to the driving of the motor and / or the internal combustion engine. The battery pack 800 or the battery module 10 may be charged by a regenerative charging device coupled to a brake.

[0114] In this way, the battery pack 800 or the battery module 10 provided in the vehicle V can provide the electrical energy required for various operations of the vehicle V. Furthermore, since the battery pack 800 or the battery module 10 has various effects as described above, the vehicle V including the battery pack 800 or the battery module 10 can also have such effects.

[0115] As an example of the effect, the battery pack 800 or the battery module 10 can have high safety. Since automobiles are directly related to human life, safety cannot be compromised. Battery cells 110, such as lithium-ion batteries, always have a risk of fire due to the physical properties of lithium. However, the battery pack 800 or the battery module 10 according to the present invention can prevent a thermal event from spreading to other parts even if it occurs in the battery cell 110. Furthermore, the battery pack 800 or the battery module 10 according to the present invention has improved thermal stability. Therefore, the stability of an automobile V including such a battery pack 800 or the battery module 10 is improved.

[0116] The present invention has been described above with reference to specific embodiments. However, those skilled in the art will clearly understand that various modifications can be made within the technical scope of the present invention. Therefore, the above-disclosed embodiments should be considered from an illustrative rather than a restrictive perspective. That is, the true scope of the technical concept of the present invention is defined by the appended claims, and all differences within the scope of equivalents thereto should be construed as being included in the present invention. [Explanation of symbols]

[0117] 1, 10: Battery module 2, 100: Cell stack 3, 400: Module case 110: Battery cell 111: Seal part 112: Storage area 113: Electrode lead 120, 130: blocking member 200: Bus bar frame assembly 300: Foam fireproof material 500: Busbar frame 511: Rib 512: Lead slot 600: Busbar 800: Battery pack H: Hole P: Uneven part V: Automobile

Claims

1. a cell stack including a plurality of battery cells; one or more tangible members, a foam fire-resistant member is provided on a surface of the tangible member closest to the cell stack, the surface facing the cell stack, among the tangible members; The intumescent fire-resistant member is a coating layer formed integrally with the tangible member by applying an intumescent fire-resistant paint, and the intumescent fire-resistant member expands into the space between adjacent battery cells when the battery cells generate heat, thereby isolating the adjacent battery cells.

2. a cell stack including a plurality of battery cells; a bus bar frame assembly disposed on at least one side of the cell stack and including a bus bar and a bus bar frame; a foam fire-resistant member provided on the bus bar frame assembly, the bus bar frame includes a rib that can be interposed in a gap between adjacent battery cells; The foam fire-resistant member is located on the rib.

3. the battery cells are pouch-type battery cells each including an electrode lead, a storage portion, and a sealing portion; 3. The battery module according to claim 2, wherein the ribs of the bus bar frame are at least partially interposed in gaps between the sealing portions or the receiving portions of adjacent battery cells and protrude toward the receiving portions.

4. The battery module according to claim 2 , wherein the rib is a plate-shaped protrusion having a constant thickness.

5. 4. The battery module according to claim 3, wherein the ribs are injection molded integrally with the bus bar frame and are provided at positions that do not overlap with lead slots provided in the bus bar frame so that the electrode leads pass through.

6. The battery module according to claim 3 , wherein the foam fire-resistant member expands into spaces between adjacent battery cells when the battery cells generate heat, thereby isolating the adjacent battery cells.

7. The battery module according to claim 3 , wherein the foam fireproof member expands to the receiving portion when the battery cell generates heat.

8. a gap is maintained between a rear surface of the bus bar frame and the battery cell, and the rib is protruded from the rear surface of the bus bar frame in the gap direction; The battery module according to claim 3 , wherein the foam fire-resistant member expands when the battery cells generate heat, and reaches the battery cells, thereby eliminating the gap.

9. The battery module according to claim 8 , wherein the expanded foam fire-resistant member fills the gaps between the battery cells and deforms to fit the shapes of the gaps.

10. The battery module according to claim 2 , wherein the intumescent fireproof member is a coating layer formed integrally with the rib by applying an intumescent fireproof paint.

11. The battery module according to claim 10 , wherein the foam fire-resistant member does not surround one end or the other end of the rib in the length direction, but surrounds only a part of the rib in the length direction.

12. The battery module according to claim 10 , wherein the fire-resistant paint is a liquid paint made by mixing a foam material and a polymer, and the foam fire-resistant member has insulating properties.

13. 3. The battery module of claim 2, wherein the foam fire-resistant member blocks flames and gases generated in a ignited battery cell from traveling in a stacking direction of the battery cells or a length direction of the battery cells when an internal fire occurs in the battery module.

14. the battery module further includes a module case configured to house the cell stack, the bus bar frame assembly, and the foam fire-resistant member; The battery module according to claim 2 , wherein the lower surface of the module case comprises a plurality of vent holes.

15. The battery module according to claim 2 , wherein the cell stack is in the form of a compressible pad and further includes a blocking member made of silicone, aerogel, or polyurethane.

16. The rib has holes penetrating both sides, The battery module according to claim 2 , wherein the foam fireproof material formed on the surface of the rib fills the holes.

17. The battery module according to claim 2 , wherein the ribs are components in which a fire-resistant material is packaged on a surface of the ribs by heterogeneous injection molding, and the ribs are assembled to the bus bar frame.

18. The battery module according to claim 2 , wherein one side of the contact surface of the rib with the foam fire-resistant member has a repeated notch structure or a sawtooth-like concave and convex structure.

19. A battery pack comprising at least one battery module according to any one of claims 1 to 18.

20. A motor vehicle comprising at least one battery module according to any one of claims 1 to 18.

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