Battery module, battery pack and vehicle including same

Abstract

Provided is a battery module that can delay thermal propagation to an adjacent battery cell by controlling the direction of gas and flame ejected from a battery cell. The battery module of the present invention comprises: a cell stack including a plurality of battery cells; and one or more mechanisms, wherein an intumescent fire protection member is provided on the surface facing the cell stack in the mechanism closest to the cell stack from among the mechanisms, is a coating layer integrally formed on the mechanism by applying an intumescent fire protection material, and expands into the space between a battery cell and a neighboring battery cell so as to isolate the neighboring battery cell when the battery cell generates heat.

Description

Battery modules, battery packs and vehicles including the same

[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, each configured to delay thermal runaway. This application claims priority to Korean Patent Application No. 10-2023-0160357, filed November 20, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] Secondary batteries, which offer high applicability across a wide range of product categories and possess 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) powered by electrical power sources. These batteries are widely used as an energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0003] Due to the need for high output and large capacity in medium- to large-sized devices such as automobiles, battery modules comprising multiple battery cells electrically connected and medium- to large-sized battery packs comprising such modules are used. It is desirable for these battery modules and packs to be manufactured with the smallest possible size and weight, so square and pouch-type batteries, which can be stacked with high density and have a low weight-to-capacity ratio, are primarily used as unit cells in battery modules. In particular, pouch-type battery cells using aluminum laminate sheets as external components are attracting attention due to their advantages such as light weight, low manufacturing cost, and ease of shape modification.

[0004] However, since battery cells undergo chemical reactions during charging and discharging, their performance may deteriorate if used in environments above their optimal temperature. Furthermore, if thermal control fails to maintain optimal temperatures, there is a constant risk of unexpected fire or explosion. Furthermore, battery modules are structured to house these battery cells tightly within the module case. Therefore, if a thermal event occurs in a single battery cell, the resulting high-temperature gases and flames can spread to adjacent cells, potentially triggering a chain reaction of battery cell explosions, making them extremely dangerous.

[0005] In particular, with the recent demand for heat transfer delay technology in automotive battery modules, there is a need to suppress and delay gas and flames emitted from the battery module. Venting gas emitted before a battery module ignites can lead to a chain reaction of fires, necessitating a solution.

[0006] However, pouch-type battery cells have the problem of flames easily spreading to adjacent battery cells through electrode leads during thermal runaway. However, there is currently no structure in place to control the direction of gas and flame within the battery module.

[0007] The problem to be solved by the present invention is to provide a battery module capable of delaying heat transfer to adjacent battery cells by controlling the direction of gas and flame 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.

[0009] In order to solve the above problem, the battery module of the present invention comprises a cell stack including a plurality of battery cells; and one or more structures, wherein a foamed fireproof member is provided on a surface of the structure closest to the cell stack among the structures facing the cell stack, and the foamed fireproof member is a coating layer formed integrally with the structure by applying an intumescent fire protection material, and the foamed fireproof member expands into a space between neighboring battery cells when heat is generated in the battery cells to isolate the neighboring battery cells.

[0010] Another battery module of the present invention comprises: a cell stack including a plurality of battery cells; a busbar frame assembly disposed on at least one side of the cell stack and including a busbar and a busbar frame; and a foamed fireproof member provided in the busbar frame assembly, wherein the busbar frame includes a rib that can be interposed in a gap between adjacent battery cells, and the foamed fireproof member is positioned in the rib.

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

[0012] The above rib may be a plate-shaped protrusion of a certain thickness.

[0013] The above rib may be integrally injection-molded with the busbar frame and may be provided at a position that does not overlap with a lead slot provided in the busbar frame so that the electrode lead passes through.

[0014] The above-mentioned foamed fireproof member can expand into the space between neighboring battery cells when heat is generated in the battery cell, thereby isolating the neighboring battery cells.

[0015] The above-mentioned foamed refractory material can expand to the storage compartment when heat is generated in the battery cell.

[0016] A gap is maintained between the rear surface of the busbar frame and the battery cell, and the rib is provided on the rear surface of the busbar frame to protrude in the direction of the gap, and the foamed fireproof member expands when heat is generated in the battery cell and reaches the battery cell to eliminate the gap.

[0017] The expanded foam refractory material can be shaped to fit the shape of the gap while filling the gap between the battery cells.

[0018] The above-mentioned foamable refractory member may be a coating layer formed integrally with the rib by applying foamable refractory paint.

[0019] The above-mentioned foamed fireproof member may not wrap one or the other end of the rib in the longitudinal direction, but may wrap only a portion of the rib in the longitudinal direction.

[0020] The above fire-resistant paint is a liquid paint mixed with a foaming material and a polymer, and the foaming fire-resistant member may be insulating.

[0021] The above-mentioned foamed fire-resistant member can prevent flames and gases generated from ignited battery cells from moving in the stacking direction of the battery cells or in the longitudinal direction of the battery cells when an internal ignition occurs in the battery module.

[0022] The battery module further includes a module case configured to accommodate the cell stack, the busbar frame assembly, and the foamed refractory member, and may include a plurality of venting holes in a lower surface of the module case.

[0023] The above cell laminate is in the form of a compressible pad and may further include a blocking member made of silicone, aerogel or polyurethane.

[0024] The above rib has a hole through both sides, and the foamed refractory material formed on the surface of the rib may fill the hole.

[0025] The above rib may be a part in which a refractory material is packaged on the surface of the rib by heterogeneous injection, and the above rib may be assembled to the busbar frame.

[0026] One side of the contact surface of the foamed refractory member of the above rib may have a repetitive notch configuration or a sawtooth-shaped uneven portion.

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

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

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

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

[0031] According to the present invention, an explosion due to a short circuit of a battery module or battery pack in a thermal runaway situation can be prevented.

[0032] By including such battery modules or battery packs, a vehicle with improved safety can be provided.

[0033] Figure 1 is a conceptual diagram of a battery module proposed in the present invention.

[0034] Figure 2 is a perspective view of the entire battery module according to one embodiment of the present invention.

[0035] Figure 3 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0036] FIG. 4 is a drawing of a battery module according to one embodiment of the present invention, viewed from the upper side, showing a busbar frame before being bonded to a cell stack.

[0037] FIG. 5 is a cross-sectional view of a portion of a battery module viewed from the upper side after a busbar frame is coupled to a cell stack according to one embodiment of the present invention.

[0038] Figure 6 is an enlarged view of part A of Figure 3.

[0039] FIG. 7 is an enlarged view of a portion of a busbar frame in a battery module according to another embodiment of the present invention.

[0040] FIG. 8 is an enlarged view of a portion of a busbar frame in a battery module according to another embodiment of the present invention.

[0041] FIG. 9 is a schematic drawing illustrating a battery pack according to one embodiment of the present invention.

[0042] Figure 10 is a schematic drawing of a vehicle according to one embodiment of the present invention.

[0043] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0044] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0045] Furthermore, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar components will be omitted, and the differences will be described.

[0046] Meanwhile, in the present invention, terms indicating directions such as up, down, left, right, front, and back may be used, but it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0047] For example, in an embodiment of the present invention, the X-axis direction shown in the drawing may mean a left-right direction, the Y-axis direction may mean a front-back direction perpendicular to the X-axis direction on a horizontal plane (XY plane), and the Z-axis direction may mean an up-down direction (vertical direction) perpendicular to both the X-axis direction and the Y-axis direction.

[0048] The present invention provides a flame direction-inducing battery module for thermal runaway delay. A battery pack and a vehicle including such a battery module are also provided.

[0049] Figure 1 is a conceptual diagram of a battery module proposed in the present invention.

[0050] Referring to Fig. 1, a battery module (1) is configured to further include components such as a cell stack (2) and a module case (3). The battery module (1) has a basic configuration of a cell stack (2) in which battery cells are stacked. The cell stack (2) is accommodated within a module case (3). The module case (3) further includes electrical components for electrical connection of the battery cells and one or more mechanisms (4) to maintain the structure.

[0051] The battery module (1) particularly includes a foamed fireproof member (5) provided on at least a portion of the above-described device (4). In particular, the foamed fireproof member (5) is preferably provided on the device (4) that is positioned closest to the cell stack (2) among the devices (4). In addition, it is also preferable that the foamed fireproof member (5) is provided on the surface of the device (4) facing the cell stack (2), in other words, on the cell adjacent surface (4a).

[0052] Furthermore, the intumescent fire protection member (5) may be a coating layer formed integrally with the device (4) by applying an intumescent fire protection material. The intumescent fire protection material includes a foam material that foams when exposed to heat. When heat is generated in the battery cell, the foam material may foam, causing the intumescent fire protection member (5) to expand.

[0053] The foamed fireproof member (5) can be positioned opposite to the part of the battery cell where heat is mainly generated. For example, if the basic unit of the cell stack (2) is a pouch-shaped battery cell, the foamed fireproof member can be provided on an adjacent device so as to be positioned around the electrode leads of the pouch-shaped battery cell. When heat is generated in the pouch-shaped battery cell, the foamed fireproof member (5) around it expands. If the foamed fireproof member (5) is positioned around the electrode leads, the expanded foamed fireproof member (5) can wrap around the electrode leads or block the gap between neighboring electrode leads, thereby delaying thermal runaway from one battery cell to another adjacent battery cell.

[0054] Such a foamed refractory member (5) can expand into the space between adjacent battery cells when heat is generated in the battery cell, thereby insulating the adjacent battery cells. Preferably, the structure (4) positioned closest to the cell stack (2) may be a busbar frame assembly (BFA), and the structure of the battery module will be described in more detail in the following embodiments.

[0055] Fig. 2 is a perspective view of a battery module according to an embodiment of the present invention. Fig. 3 is an exploded perspective view of a battery module according to an embodiment of the present invention. Fig. 4 is a view of a battery module according to an embodiment of the present invention, viewed from above, before a busbar frame is coupled to a cell stack. Fig. 5 is a view of a cross-section of a portion of a battery module according to an embodiment of the present invention, viewed from above, after a busbar frame is coupled to a cell stack. For example, Fig. 5 may be a view showing a cross-section taken along line II' of Fig. 2. Fig. 6 is an enlarged view of portion A of Fig. 3.

[0056] First, referring to FIGS. 2 to 4, a battery module (10) according to one embodiment of the present invention includes a cell stack (100), a busbar frame assembly (200), a foamed fireproof member (300), and a module case (400).

[0057] The cell stack (100) may include a plurality of battery cells (110). The battery cells (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 in series and / or in parallel to each other through a bus bar (600) of a bus bar frame assembly (200).

[0058] Meanwhile, the present invention is not limited by the 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 employed to configure the battery module (10) of the present invention. In this embodiment, a pouch-type battery cell having a high energy density and easy stacking is mainly described as the subject, as shown in the drawing, but it goes without saying that a square battery cell or a cylindrical battery cell may also be applied to the battery cell (110).

[0059] As detailed in FIG. 4, the battery cell (110) may include a receiving portion (112) and a sealing portion (111). The receiving portion (112) may be configured to receive an electrode assembly, and the sealing portion (111) may be configured such that an outer edge of the receiving portion (112) is heat-sealed to seal it. 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 extend outward from the battery case. The electrode leads (113) may be provided as a pair, and the pair of electrode leads (113) may extend from both ends of the battery cell (110), i.e., in the longitudinal direction (Y-axis direction). That is, the electrode leads (113) may extend in both directions. At this time, the pair of electrode leads (113) may be a positive electrode lead and a negative electrode lead. Depending on the need, the battery cell (110) may have a form in which two electrode leads (113) are positioned only at one end in the Y-axis direction. That is, the electrode leads (113) may be pulled out in one direction.

[0060] The cell stack (100) may be prepared by stacking a plurality of battery cells (110) in one direction. For example, as illustrated in FIG. 3, a plurality of battery cells (110) may be stacked in a vertical direction (Z-axis direction) and arranged side by side in the left-right direction (X-axis direction). At this time, each battery cell (110) may have a sealing portion (111) facing the front-back direction (Y-axis direction) and the up-down direction (Z-axis direction), and a storage portion (112) facing the left-right direction (X-axis direction).

[0061] A component included in a battery module (10) for electrical connection between battery cells (110) included in a cell stack (100) is a busbar frame assembly (200). The busbar frame assembly (200) is provided on a side from which the electrode leads (113) of the battery cells (110) protrude. Since the busbar frame assembly (200) is formed on the side from which the electrode leads (113) protrude, it can be formed on at least one side of the front and rear of the battery cells (110). Accordingly, the busbar frame assembly (200) can be arranged on at least one side of the cell stack (100). As in the illustrated example, the busbar frame assembly (200) can be provided on both sides in the front-rear direction of the battery cells (110). Accordingly, the busbar frame assembly (200) can be provided on a longitudinal end of the battery cells (110).

[0062] The busbar frame assembly (200) may include a busbar (600) electrically connected to a battery cell (110) and a busbar frame (500) supporting the busbar. The busbar frame assembly (200) may further include a terminal busbar and a circuit in the form of a PCB or FPCB.

[0063] The busbar (600) is electrically connected to the battery cells (110) and serves to connect the battery cells (110) together. It is made of a metal with excellent conductivity, such as copper or aluminum. The terminal busbar is also electrically connected to the battery cells (110) and relates to charging and discharging. The circuit can be configured to measure the voltage of battery cells (110) connected in series and the temperature of any battery cell (110).

[0064] The busbar frame (500) is a mechanism that performs the function of supporting the busbar (600), etc., and can also be used for the purpose of bending the electrode leads (113) and shaping them so that they can be welded to the busbar (600). In the battery module (10), the mechanism closest to the battery cell (110) is the busbar frame assembly (200), and among them, the busbar frame (500) is the busbar frame assembly (200).

[0065] The busbar frame (500) is preferably made of a plastic material to ensure insulation. For example, the busbar 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 terphthalate (PBT). The busbar frame (500) made of a plastic material may be injection molded.

[0066] The module case (400) may be configured to have an internal space formed therein to accommodate a cell laminate (100), a busbar frame assembly (200), and a foamed refractory member (300). The module case (400) may include a number of venting holes (not shown) on its lower surface.

[0067] The module case (400) of the present embodiment may include a case body (410) and end plates (420) arranged on the front and rear sides of the case body (410). The type and shape of the module case (400) may vary, and the present invention is not limited thereto.

[0068] Here, the case body (410) is provided with an upper plate, a lower plate, a left plate, and a right plate to form a storage space, and a cell stack (100) can be stored in this storage space. This case body (410) can be made of a metal material having rigidity and heat resistance to physically or chemically protect the stored cell stack (100).

[0069] In addition, the end plate (420) may be configured to be combined with the case body (410) to cover an open portion of the case body (410). More specifically, the case body (410) may be configured to have an open front and rear, and the end plate (420) may be configured to be combined with the open portions of the front and rear of the case body (410).

[0070] Meanwhile, the case body (410) may be provided with the above-described venting holes, and directional venting in one direction may be possible. A plurality of venting holes may be formed on the lower surface of the case body (410), and directional venting toward the bottom of the battery module (10) may be possible through the venting holes. According to this embodiment, when gas is discharged from the battery module (10), the discharged gas can effectively prevent the flame from moving upward. In particular, in a case where a passenger is positioned on the upper side of the battery module (10) or a battery pack including the same, such as in an electric vehicle, the above-described embodiment can suppress or delay the gas from moving toward the passenger.

[0071] In the present embodiment, in particular, as shown in detail in FIGS. 4 to 6, the busbar frame (500) may include a rib (511) that may be interposed in a gap between battery cells (110). Specifically, the rib (511) of the busbar frame assembly (200) may be interposed in a gap between sealing portions (111) of at least partially adjacent battery cells (110) and / or between receiving portions (112). A portion that protrudes convexly from the receiving portion (112) is also called a cup surface. The rib (511) may protrude from the busbar frame (500) toward the cup surface.

[0072] 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 irregular or varying thickness or a volume rather than a plate shape.

[0073] When the busbar frame (500) is injection molded, the rib (511) may be integrally provided with the busbar frame (500). The busbar (600) may be provided on the front surface, or in other words, the outer surface, of the busbar frame (500). Here, the outer surface refers to the surface facing the outside of the battery module (10).

[0074] A lead slot (512) is formed in the busbar frame (500). The lead slot (512) may be located on a side where electrode leads (113) of a plurality of battery cells (110) are provided. The lead slot (512) may be provided so that at least a portion of the electrode leads (113) of the plurality of battery cells (110) pass through it. At this time, the plurality of electrode leads (113) passing through the lead slot (512) may be provided so as to be folded and stacked on each other. By this stacking structure, the plurality of battery cells (110) whose electrode leads (113) are in contact with each other may be electrically connected to each other.

[0075] A plurality of lead slots (512) may be provided so as to be spaced apart from each other along the stacking direction (X-axis direction) of the battery cells (110). In particular, the lead slots (512) may be provided at a position that does not overlap with the rib (511). Accordingly, the electrode lead (113) and the rib (511) can be placed at a position where they do not normally contact each other, and the electrode lead (113) is not pressed or damaged by the rib (511).

[0076] A busbar (600) may be provided between the busbar frame (500) and the stacked electrode leads (113). This busbar (600) may be electrically connected to the electrode leads (113). In addition, through this electrical connection, the busbar (600) may be configured to transmit status information about the battery cell (110) to an external component. For example, the busbar (600) may be configured to transmit voltage information of the battery cell (110) to an external control device such as a BMS (Battery Management System).

[0077] The foamed refractory member (300) may be integrally provided with the busbar frame assembly (200). For example, the foamed refractory 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 coating may be performed by spraying or comma coating. Of course, the coating may also be performed by various printing methods such as brushing, engraving, roller, silk screen, stamping, inkjet, etc., or by other methods such as quantitative dispensing, spindle coating, and impregnation. In addition to the direct coating method using the above method, the development of foamed refractory member (300) products in the form of sheets and tapes is also possible depending on the application location and application method of the product.

[0078] The foamed fireproof member (300) may be positioned on the cell-adjacent surface of the busbar frame assembly (200). The cell-adjacent surface is the back surface, or in other words, the inner surface, of the busbar frame (500). The battery cell (110) tends to swell during use. Considering that swelling may occur, a gap is provided between the back surface of the busbar frame (500) and the battery cell (110) (for example, the gap indicated by G in FIG. 5). If venting gas moves through this gap, it may affect the adjacent battery cell (110). In the present embodiment, a rib (511) is configured to protrude in the direction of this gap, and the foamed fireproof member (300) is positioned therein. When the foamed fireproof member (300) expands and reaches the battery cell (110), this gap disappears. As shown in the inset of Fig. 5, the expanded foamed refractory member (300') reaches the battery cells (110) and fills the space between the battery cells (110). According to this configuration, even if a thermal event occurs in one battery cell (110) and venting gas is emitted, it is possible to prevent the adjacent battery cells (110) from being affected.

[0079] In this embodiment, the foamed fireproof member (300) may be positioned only on the surface of the rib (511). As illustrated, the rib (511) is a plate-shaped protrusion with a constant thickness, and the foamed fireproof member (300) may be provided in a form that surrounds the protruding portion. For example, it may surround relatively wide sides of the rib (511) and a narrow side therebetween. In this case, the foamed fireproof member (300) may not surround one end or the other end of the rib (511) in the longitudinal direction (Z-axis direction), but may only surround a portion in the longitudinal direction. The foamed fireproof member (300) may not expand in the portion of the rib (511) that is not wrapped. Even when the foamed refractory member (300) expands, a space can be created in the rib (511) portion where the foamed refractory member (300) is not wrapped, through which gas or flame emitted from the battery cell (110) can move. Accordingly, the direction of the gas or flame can be induced in a specific direction.

[0080] The battery cell (110) tends to swell during use. Considering that swelling may occur, a gap is secured between the rear surface of the busbar frame (500) and the battery cell (110). The rib (511) is provided in the already secured gap. There is no need to change the size of the busbar frame (500) to provide the rib (511). Therefore, a compact battery module (10) structure can be maintained. There is no need to provide a separate space to include the foamed fireproof member (300) in the battery module (10). The foamed fireproof member (300) can be positioned in the rib (511). Therefore, a compact battery module (10) structure can be maintained.

[0081] The foamed refractory member (300) may be a foamed refractory paint coating layer. The foamed refractory member (300) may be formed by applying foamed refractory paint to the rear surface of the busbar frame assembly (200), particularly to the rib (511) portion. The refractory paint is a liquid containing a foamed material and may be configured to harden when heat is applied or over time after application.

[0082] For example, a fire-resistant paint may be a liquid paint mixed with a foaming material and a polymer. It may further include a fire-resistant material to further enhance fire resistance. Furthermore, the fire-resistant paint may further include other ingredients to achieve both excellent chemical resistance and excellent adhesion to the adherend. For example, a raw material containing a foaming material and a polymer is prepared, and a curing agent, a leveling agent, a pigment, a solvent, a release agent, a filler, etc. are added and stirred to produce a fire-resistant paint, taking into account the coating properties (surface strength, acid resistance, weather resistance, etc.) and adhesion. This fire-resistant paint is applied to the rib (511) and cured to form a coating layer.

[0083] 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, imparting adhesiveness and flexibility. The polymer can be modified and altered to suit the characteristics of the intended product, without limitation. It may also include epoxy, polysulfide, polysiloxane, polysilarylene, or a combination thereof.

[0084] Any foaming material can be used as long as it can foam when heated. The degree of expansion resulting from foaming will vary depending on the type, composition, and purity of the foaming material.

[0085] As an example of a foaming material, the foaming material may include an acid source, a blowing agent, and a carbon source. For example, the foaming material may include a polyphosphate acid source, a blowing agent, and a pentaerythritol carbon source. Without being bound by theory, since the foaming material utilizes two energy absorption mechanisms involving char formation and subsequent char expansion, any foaming material capable of implementing these mechanisms is sufficient.

[0086] The acid source may include, for example, an organic or inorganic phosphorus compound, an organic or inorganic sulfate (e.g., ammonium sulfate), or a combination thereof. The organic or inorganic phosphorus compound may be an organophosphate or organophosphonate (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-bromoisopropyl phosphonate, polyaminotriazine phosphate, melamine phosphate, triphenyl phosphate, or guanylurea phosphate); an organophosphite ester (e.g., trimethyl phosphite or triphenyl phosphite); phosphazenes (e.g., hexaphenoxycyclotriphosphazene); phosphorus-containing inorganic compounds (e.g., phosphoric acid, phosphorous acid, phosphites, urea phosphates, ammonium phosphates (e.g., ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate, etc.)); or combinations thereof.

[0087] The blowing agent may include dicyandiamide, azodicarbonamide, melamine, guanidine, glycine, urea (e.g., urea-formaldehyde resin or methyloleated guanylurea phosphate), halogenated organic material (e.g., chlorinated paraffin), or combinations thereof.

[0088] The carbon source may include dextrin, phenol-formaldehyde resin, pentaerythritol (e.g., its dimer or trimer), clay, polymer (e.g., polyamide 6, amino-poly(imidazoline-amide) or polyurethane) or combinations thereof. The amino-poly(imidazoline-amide) may contain repeating amide linkages and imidazoline groups.

[0089] There are no restrictions on refractory materials as long as they are refractory and suitable for manufacturing into paint.

[0090] The thickness of the coating layer can be controlled by changing the state of foam materials, refractory materials, and polymers using various solvents or water. If the solvent content is too low, the viscosity may increase, reducing coating workability. If the content is too high, the curing (drying) time may be long, which may be undesirable. Solvents can be organic solvents such as toluene or xylene, or polar hydrocarbons. Physical properties can vary depending on the solvent ratio and component ratio. By adjusting the solvent ratio according to the user's process characteristics, the thickness and degree of expansion can be controlled.

[0091] In addition, various additives can be used to adjust the post-curing material properties and the degree of foaming and expansion required by the coating to maintain the physical strength required by the industry. Other components, other than the foaming material, can be modified and adjusted depending on the characteristics of the intended product, without being limited to the above.

[0092] When the foam material is heated and foams, the foamable fireproof member (300) can expand. The foamable fireproof member (300) can be configured to foam up to the cup surface of the battery cell (110). In particular, when the rib (511) is provided between adjacent battery cells (110) and the foamable fireproof member (300) is positioned there, foam is only generated at that portion, so the effect of foaming up to the cup surface of the battery cell (110) and being positioned becomes evident. In addition, the expanded foamable fireproof member (300') can be shaped to fit the shape of the gap between the battery cells (110) while filling the gap. Please refer to the inset drawing of Fig. 5. The thickness of the foamable fireproof member (300) can be determined in consideration of the size of the rib (511) or the size of the free space. In addition, if the thickness of the foamable refractory member (300) is too small, the degree of expansion due to foaming may not be sufficient. If the thickness of the foamable refractory member (300) is too large, the curing time may be long when coating with refractory paint, and it may be difficult to achieve a low price.

[0093] The front of the busbar frame assembly (200) and the front of the busbar frame (500) are portions facing the outside of the battery module (10). The back of the busbar frame assembly (200) and the back of the busbar frame (500) are portions facing the cell stack (100). The foamed fireproof member (300) can be formed by applying foamed fireproof paint to the back of the busbar frame assembly (200). In the present embodiment, a rib (511) is formed on the back of the busbar frame (500). The foamed fireproof member (300) can be positioned facing the cell stack (100) by being formed on the surface of the rib (511). It is preferable that the foamed fireproof member (300) be insulating so as not to generate unnecessary conduction, and it is preferable that it not be formed in a portion where electrical connection is required.

[0094] The foamed refractory member (300) has a heat transfer delay effect. For example, when thermal runaway occurs in a battery cell (110), the heat is discharged to the electrode lead (113) of the battery cell (110). As described several times above, the foamed refractory member (300) is included on the back of the busbar frame assembly (200), and the foamed refractory member (300) is positioned adjacent to the cell. The heat discharged toward the electrode lead (113) causes the foamed material in the refractory paint to expand. The foamed refractory member (300) can expand well in all directions. In particular, when the foamed refractory member (300) is a coating layer, it can expand in the thickness direction of the coating layer. Therefore, the foamed refractory member (300) can expand well from the back of the busbar frame assembly (200) toward the cell stack (100). The expanded foam refractory member (300') can compress the vicinity of the electrode lead (113) of the battery cell (110) to delay heat transfer to the adjacent battery cell (110). In particular, the foam refractory member (300) can expand and reach the cup surface of the battery cell (110). This further enhances the isolation between adjacent battery cells (110).

[0095] The expanded foamed fireproof member (300') can block air from entering, thereby preventing the spread of fire. Furthermore, it exhibits heat-insulating and combustion-retarding effects. In particular, the expanded foamed fireproof member (300') can extend to the cup surface between adjacent battery cells (110) to fill the space between the electrode leads (113) of the adjacent battery cells (110), thereby isolating them from each other, thereby exhibiting an excellent heat transfer delay effect.

[0096] The action of the foaming fireproof paint that can form the foaming fireproof member (300) is further explained as follows.

[0097] The foaming material within the refractory coating layer can generate char as it foams. As the foaming material foams, it is divided into a condensed phase and a gas phase. In the condensed phase, the coating layer expands to form char, and in the gas phase, it can capture radicals. In the condensed phase, the char acts as a barrier to heat and air penetration into the coating layer, thereby exhibiting a heat insulating effect and a combustion delay effect. For example, the heat insulating effect of the coating layer can be selected to maintain the temperature inside the steel frame below 500℃ even at a fire temperature of 1000℃, thereby preventing a decrease in the strength of the steel frame.

[0098] The expanded foamed fireproof member (300') can perform a function of blocking heat such as flames generated from the ignited battery cells (110) from moving in the stacking direction of the battery cells (110) or the longitudinal direction of the battery cells (110) when an internal fire occurs in the battery module (10). The flames or gases can move in the vertical direction and thus can be discharged to the outside of the battery module (10) without affecting other battery cells (110). When the venting hole of the battery module (10) is formed on the lower surface of the case body (410), the direction of movement of the flames or gases can be guided downward from within the battery module (10) to ensure safe discharge.

[0099] In this way, according to the present invention, heat transfer to neighboring battery cells (110) can be minimized. Gas and flame in one battery cell (110) where thermal runaway has occurred are prevented from proceeding toward the positive / negative leads of other battery cells (110), and may be ejected into the upper or lower space not filled by the expanded foamed fire-resistant member (300'). In this way, according to the present invention, by controlling the direction of gas and flame discharge, the safety of the battery module (10) or the battery pack including the same is improved.

[0100] If the direction of flame emission is not controlled in this way, heat can easily spread to adjacent battery cells due to flames and discharged substances emitted from a battery cell where thermal runaway has occurred. In particular, pouch-type battery cells have a problem in that flames are easily emitted in the positive / negative direction, easily causing heat to spread to adjacent battery cells. However, according to the present invention, heat spread can be reliably blocked because flames or gases cannot move to neighboring battery cells through the electrode lead side.

[0101] The expanded foamed refractory member (300') may extend to the cup surface between adjacent battery cells (110) and fill the space between the electrode leads (113) of the neighboring battery cells (110). As a result, conductive materials contained in the gas discharged from any one battery cell (110) in which thermal runaway has occurred cannot be deposited in the space between the electrode leads (113). Accordingly, unintended current conduction caused by the deposited conductive materials does not occur, resulting in a short circuit of the battery module (10) or the battery pack including the same. In this way, according to the present invention, an explosion due to a short circuit of the battery module or the battery pack in a thermal runaway situation can be prevented.

[0102] Thus, according to the present invention, heat transfer between adjacent battery cells can be delayed simply by providing a foamed refractory member (300). Since many members are not used to delay heat transfer, a compact battery module (10) can be manufactured.

[0103] The foamed fireproof member (300) may be provided in multiple numbers. The foamed fireproof member (300) may be formed at each rib (511). Additionally, the ribs (511) may be provided between each sealing portion (111) of adjacent battery cells (110). According to the above-described embodiment of the present invention, the foamed fireproof member (300) may be provided at each space between adjacent battery cells (110), thereby achieving an excellent heat transfer delay effect.

[0104] Meanwhile, the cell stack (100) included in the battery module (10) of the present invention may further include blocking members (120, 130). The blocking members (120, 130) may be included in multiple numbers. In this case, the multiple blocking members (120, 130) may be arranged at a predetermined distance apart from each other in one direction, that is, along the stacking direction of the battery cells (110). In addition, the multiple blocking members (120, 130) may be provided at regular intervals for each of at least one battery cell (110) (for example, for each of one or multiple battery cells (110)). The blocking members (120, 130) may be in direct contact with both surfaces of at least some of the battery cells (110) among the plurality of battery cells (110). In particular, the blocking members (120, 130) may be in direct contact with the receiving portion (112) of the battery cell (110). In this embodiment, a plurality of blocking members (120, 130) may be provided in a form in which at least two or more battery cells (110) are arranged.

[0105] These blocking members (120, 130) are in the form of compressible pads and may be made of materials with excellent heat and / or fire resistance, such as silicone, aerogel, or polyurethane. Since the blocking members (120, 130) are compressible, they can effectively counteract the expansion of the battery cells (110) when the battery cells (110) experience swelling.

[0106] In addition, in the event of an internal ignition of the battery module (10), the heat-resistant and / or fire-resistant blocking member (120, 130) can perform a thermal barrier function to block heat, such as a flame, generated from the ignited battery cell (110) from spreading in the stacking direction of the battery cells (110). Accordingly, the blocking member (120, 130) together with the foamed fire-resistant member (300) can further minimize heat transfer to neighboring battery cells (110). The blocking member (120, 130) can block not only heat but also high-temperature gases, flames, discharged substances, etc. generated from the battery cells (110). Accordingly, the blocking member (120, 130) can partition or separate the battery cells (110) to prevent flames, etc. from spreading between the battery cells (110).

[0107] The blocking member (120) may be located at the outermost part of the cell stack (100), and the blocking member (130) may be located between the battery cells (110).

[0108] Fig. 7 is an enlarged view of a portion of a busbar 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 of Fig. 3, similar to Fig. 6.

[0109] Referring to Fig. 7, a rib (511) has a hole (H) that penetrates both sides of the rib (511). For example, the rib (511) may have a mesh structure having a plurality of holes (H). In the mesh structure, the shape of the hole (H) can be manufactured in various shapes such as circle, square, hexagon, etc.

[0110] A foamed fireproof member (300) is formed on the surface of the rib (511). The foamed fireproof member (300) can be formed by applying a fireproof paint as described above. As shown in the inset of Fig. 7, the foamed fireproof member (300) is connected on both sides of the rib (511) through a hole (H), that is, the fireproof paint can meet and solidify on the inside and outside of the rib (511), and the hole (H) is filled with the foamed fireproof member (300). In order to maximize the effect of the fireproof paint, it is applied sufficiently so that the inside and outside of the rib (511) are connected. According to the present embodiment, structural rigidity can be imparted while maximizing the amount of fireproof paint.

[0111] As another example, it is also possible to prepare a rib (511) having a foamed refractory member (300) in the form of a component in which a refractory material is packaged on the surface of a mesh-structured rib (511) and assemble it to a busbar frame (500). The packaging component can be formed by heterogeneous injection molding. Homogeneous injection molding is also known as low-pressure injection molding. A very low pressure, for example, an injection pressure of 0.15-4 MPa, can be used to inject a hot melt material into a mold and quickly harden it. Therefore, in this case, the refractory material is prepared by including a foamed material in a thermoplastic resin, and the rib (511) is first placed in an injection mold, and the refractory material is injected into the cavity of the injection mold so that the refractory material surrounds the rib (511) and then hardens to obtain a final injection molded product. The extracted injection molded product can be assembled to an appropriate location on the busbar frame (500) and used.

[0112] Fig. 8 is an enlarged view of a portion of a busbar frame in a battery module according to another embodiment of the present invention. For example, Fig. 8 may be an enlarged view of portion A of Fig. 3, similar to Fig. 6.

[0113] Referring to Fig. 8, one side of the contact surface of the foamed refractory member (300) of the rib (511) may be provided with a repetitive notch configuration or a sawtooth-shaped uneven portion (P) to increase the contact area with the foamed refractory member (300).

[0114] FIG. 9 is a schematic diagram illustrating a battery pack according to an embodiment of the present invention. The 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, a current sensor, a fuse, etc. for integrated control of charging and discharging of one or more battery modules (10). The BMS estimates the status of battery cells in the battery pack and manages the battery pack using the estimated status information. For example, it estimates and manages battery pack status information such as the SOC (State Of Charge), SOH (State Of Health), maximum input / output power allowance, and output voltage of the battery pack. In addition, the charging or discharging of the battery pack can be controlled using this status information, and further, the replacement time of the battery pack can be estimated.

[0115] The battery modules (10) can be arranged neatly in a pack case (810) in a nearly rectangular shape, and each battery module (10) is connected so as to secure the power required for driving the vehicle.

[0116] The pack case (810) is a container for fixing and storing battery modules (10) and is a rectangular box. In addition, this pack case (810) can be disposed at a predetermined location within the vehicle.

[0117] Additionally, the battery pack according to the present invention can have the module case (400) described above directly function as a pack case. In this case, battery pack components such as a BMS, busbar, and relay may be included within the module case (400). In this case, it is also called a cell-to-pack because the battery cells (110) are directly housed within the pack case.

[0118] The battery pack (800) according to an embodiment of the present invention can be applied to various devices. Representative examples of such devices include 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 Energy Storage System (ESS). An ESS refers to a standalone system that stores power of several hundred kWH or more. An ESS is a core component of the renewable energy industry. Since renewable energy sources such as solar and wind power cannot produce power at a desired time, it is important to store the power and make it available for use 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.

[0119] Figure 10 is a schematic drawing of a vehicle according to one embodiment of the present invention.

[0120] A vehicle (V) according to one embodiment of the present invention may include one or more battery packs (800) according to one embodiment of the present invention or battery modules (10) according to one embodiment of the present invention. The vehicle (V) according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle (V) includes a four-wheeled vehicle and a two-wheeled vehicle. The vehicle (V) operates by receiving power from the battery pack (800) or the battery module (10) according to one embodiment of the present invention.

[0121] In addition to the battery pack (800) or battery module (10) according to the embodiment of the present invention, the vehicle (V) may further include various other components included in the vehicle, such as a body or a motor.

[0122] The battery pack (800) or battery module (10) can be installed at a predetermined location within the vehicle (V). The battery pack (800) or battery module (10) can be electrically connected to the motor of the vehicle (V) via an inverter. The battery pack (800) or battery module (10) can be used as an electric energy source to provide driving force to the motor of the vehicle (V) to drive the vehicle (V). In this case, the battery pack (800) or battery module (10) is configured to have a high nominal voltage of 100 V or more. The battery pack (800) or battery module (10) can be charged or discharged by the inverter according to the driving of the motor and / or the internal combustion engine. The battery pack (800) or battery module (10) can be charged by a regenerative charging device combined with a brake.

[0123] In this way, the battery pack (800) or battery module (10) equipped in the vehicle (V) can provide the electric energy required for various operations of the vehicle (V). In addition, since the battery pack (800) or battery module (10) has the various effects mentioned above, the vehicle (V) including it can also have all of those effects.

[0124] For example, the battery pack (800) or battery module (10) can have high safety. Since automobiles are directly related to human life, safety is something that can never be compromised. Battery cells (110), which may be lithium ion batteries, always have a risk of fire due to the physical properties of lithium. However, even if a thermal event occurs in the battery cell (110) of the battery pack (800) or battery module (10) according to the present invention, it can prevent the event from spreading to other parts. In addition, the thermal stability of the battery pack (800) or battery module (10) according to the present invention is further enhanced. Therefore, the safety of the automobile (V) including the battery pack (800) or battery module (10) is improved.

[0125] The present invention has been described with reference to specific embodiments. However, those skilled in the art will clearly understand that various modifications can be implemented within the technical scope of the present invention. Therefore, the embodiments disclosed above should be considered illustrative rather than limiting. In other words, the true scope of the present invention is set forth in the claims, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

[0126] [Explanation of symbols]

[0127] 1, 10: Battery module 2, 100: Cell stack

[0128] 3,400: Module case 110: Battery cell

[0129] 111: Sealing section 112: Storage section

[0130] 113: Electrode lead 120, 130: Blocking member

[0131] 200: Busbar frame assembly 300: Foamed fireproof member

[0132] 500: Busbar frame 511: Rib

[0133] 512: Lead slot 600: Busbar

[0134] 800: Battery Pack H: Hole

[0135] P: bumps V: car

Claims

1. A cell stack comprising a plurality of battery cells; and A battery module comprising one or more devices, Among the above devices, a foamed fireproof member is provided on the surface of the device closest to the cell stack facing the cell stack. The above-mentioned foamable fire protection member is a coating layer formed integrally with the above-mentioned structure by applying an intumescent fire protection material, and the above-mentioned foamable fire protection member is a battery module characterized in that when heat is generated in the battery cell, the above-mentioned foamable fire protection member expands into the space between neighboring battery cells to isolate the neighboring battery cells.

2. A cell stack comprising a plurality of battery cells; A busbar frame assembly disposed on at least one side of the cell laminate and including a busbar and a busbar frame; and Including a foamed fireproof member provided in the above busbar frame assembly, The above busbar frame includes ribs that can be interposed in the gap between adjacent battery cells, A battery module, characterized in that the above-mentioned foamable refractory member is positioned in the above-mentioned rib.

3. In the second paragraph, each of the battery cells is a pouch-type battery cell including an electrode lead, a storage portion, and a sealing portion. A battery module characterized in that the rib of the busbar frame is at least partially interposed in a gap between sealing portions or between receiving portions of adjacent battery cells and protrudes toward the receiving portion.

4. A battery module according to claim 2, characterized in that the rib is a plate-shaped protrusion having a constant thickness.

5. A battery module according to claim 3, characterized in that the rib is integrally injection-molded with the busbar frame and is provided at a position that does not overlap with a lead slot provided in the busbar frame so that the electrode lead passes through.

6. A battery module according to claim 3, characterized in that the foamable fire-resistant member expands into the space between neighboring battery cells when heat is generated in the battery cell, thereby insulating the neighboring battery cells.

7. A battery module according to claim 3, characterized in that the foamable fireproof member expands to the storage compartment when heat is generated in the battery cell.

8. In the third paragraph, a gap is maintained between the rear surface of the busbar frame and the battery cell, and the rib is provided on the rear surface of the busbar frame to protrude in the direction of the gap. A battery module characterized in that the above-mentioned foamable refractory material expands when heat is generated in the battery cell and reaches the battery cell to eliminate the gap.

9. In paragraph 8, A battery module characterized in that the expanded foamed refractory member fills the gap between the battery cells and is deformed to fit the shape of the gap.

10. A battery module according to claim 2, characterized in that the foamable refractory member is a coating layer formed integrally with the rib by applying a foamable refractory paint.

11. A battery module according to claim 10, characterized in that the foamable fire-resistant member does not wrap one or the other end of the rib in the longitudinal direction, but wraps only a portion of the rib in the longitudinal direction.

12. A battery module according to claim 10, wherein the fire-resistant paint is a liquid paint mixed with a foaming material and a polymer, and the foamed fire-resistant member is insulating.

13. A battery module according to claim 2, characterized in that the foamable fire-resistant member blocks flames and gases generated from ignited battery cells from moving in the stacking direction of the battery cells or the longitudinal direction of the battery cells when an internal ignition occurs in the battery module.

14. In the second paragraph, the battery module further includes a module case configured to accommodate the cell stack, the busbar frame assembly, and the foamed fireproof member. A battery module characterized by including a plurality of venting holes on the lower surface of the module case.

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

16. In the second paragraph, the rib has a hole penetrating both sides, A battery module characterized in that the foamable refractory material formed on the rib surface fills the hole.

17. A battery module according to claim 2, characterized in that the rib is a component in which a refractory material is packaged on the rib surface by heterogeneous injection molding, and the rib is assembled to the busbar frame.

18. A battery module according to claim 2, characterized in that one side of the contact surface of the foamable refractory member of the rib has a repetitive notch configuration or a sawtooth-shaped uneven portion.

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

20. A vehicle characterized by including at least one battery module according to any one of claims 1 to 18.

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