Battery module, battery pack and vehicle including same

Abstract

The present invention relates to a battery module accommodated in a pack case, the battery module comprising: a plurality of battery cells; a module case configured to accommodate the plurality of battery cells; and an expansion member provided outside the module case and configured to expand at least partially in the outward direction of the module case by heat.

Description

Battery modules, battery packs containing the same, and vehicles

[0001] The present invention relates to a battery module, a battery pack including the same, and a vehicle.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0101823, filed on July 31, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0003] Secondary batteries, which boast high electrical properties such as high energy density and easy applicability across a wide range of product categories, 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 attracting attention as a new 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.

[0004] Commonly used secondary batteries today include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. When high output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Furthermore, to increase charge / discharge capacity, multiple battery cells are connected in parallel to form a battery module or pack. Therefore, the number of battery cells included in a battery module or pack can vary depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, since battery cells undergo chemical reactions during charging and discharging, their performance can deteriorate if used in environments above optimal temperatures. Furthermore, if thermal control fails to maintain optimal temperatures, there's a constant risk of unexpected fire or explosion. Furthermore, battery modules are structured to house these 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, posing a significant risk.

[0006] Therefore, there is a need to develop a structure that can suppress and delay heat propagation so that even if a thermal event occurs in some battery cells within a battery module, gas or flames are prevented from being transferred to other battery cells within the battery module and causing thermal runaway by more reliably separating battery cells.

[0007] Accordingly, the problem to be solved by the present invention is to provide a battery module in which the battery cells are clearly separated into compartments so that the propagation of thermal runaway between battery cells can be effectively prevented or delayed.

[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 addition, another problem that the present invention seeks to solve is to provide a battery pack and a vehicle including such a battery module.

[0010] However, the problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0011] In order to solve the above problem, the present invention provides a battery module, characterized in that it comprises a plurality of battery cells, a module case configured to accommodate the plurality of battery cells, and an expansion member provided on the outside of the module case and configured to expand at least partially in the outward direction of the module case due to heat.

[0012] The above-mentioned expansion member may be composed of a foamed fireproof paint.

[0013] The above-mentioned expansion member may be configured to expand to define a space between the module case and the pack case.

[0014] The above-mentioned expansion member may be configured to be expanded and contactable with the pack case.

[0015] At least one side of the module case may be formed with a plurality of venting holes configured to discharge venting gas generated from the battery cell to the outside, and the expansion member may be provided between adjacent venting holes.

[0016] The above expansion member may be configured to prevent the venting gas discharged from the venting hole from flowing toward another venting hole.

[0017] The above expansion member may be configured to expand along the direction of movement of the venting gas discharged from the venting hole.

[0018] The above expansion member may be configured to have a differential expansion rate at least partially depending on the location.

[0019] In addition, the present invention provides a battery pack characterized by including a battery module according to the present invention.

[0020] And, the present invention provides an automobile characterized by including a battery pack according to the present invention.

[0021] In addition, the present invention provides a battery pack characterized by including: a plurality of battery cells; a pack case configured to accommodate the plurality of battery cells; and an expansion member provided between the plurality of battery cells and the pack case and configured to expand at least partially outwardly due to heat.

[0022] According to one aspect of the present invention, when a thermal event occurs in a battery cell, the venting path can be reliably separated from the outside of the module case by the expansion of the expandable member. In particular, according to this aspect of the present invention, high-temperature gases or flames discharged into the outer space of the module case can be suppressed from moving along the stacking direction of the battery cells.

[0023] That is, according to the above aspect of the present invention, even if a thermal event occurs in some battery cells within a battery module, the transfer of gas or flames to other battery cells within the battery module and causing thermal runaway can be effectively prevented or delayed. This ensures the safety and reliability of the battery module.

[0024] In addition, according to another aspect of the present invention, an event due to thermal runaway phenomenon, such as a fire or explosion, of a battery pack including a plurality of battery modules or a device equipped with the same can be prevented or delayed.

[0025] In addition, the present invention may have various other effects, which will be described in each embodiment configuration, or an explanation of effects that can be easily inferred by a person skilled in the art will be omitted.

[0026] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0027] FIG. 1 is a perspective view of a battery module according to one embodiment of the present invention.

[0028] Figure 2 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0029] FIG. 3 is a drawing showing an expanded member in a battery module according to one embodiment of the present invention.

[0030] Fig. 4 is a cross-sectional view of a battery module according to one embodiment of the present invention. For example, Fig. 4 may be a drawing showing the cross-sectional view taken along line I-I' of Fig. 1.

[0031] FIG. 5 is a cross-sectional view of an expanded member in a battery module according to one embodiment of the present invention.

[0032] FIG. 6 is a perspective view of an expandable member included in a battery module according to one embodiment of the present invention in an at least partially expanded state.

[0033] Figure 7 is a cross-sectional view of a battery module according to another embodiment of the present invention.

[0034] FIG. 8 is a schematic exploded perspective view of a battery pack including a battery module according to one embodiment of the present invention.

[0035] Figure 9 is a cross-sectional view of a battery pack according to one embodiment of the present invention.

[0036] FIG. 10 is a drawing showing an expansion member at least partially expanded in a battery pack according to one embodiment of the present invention.

[0037] FIG. 11 is a schematic perspective view of a vehicle including a battery pack according to one embodiment of the present invention.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043]

[0044] FIG. 1 is a perspective view of a battery module according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of a battery module according to one embodiment of the present invention. In addition, FIG. 3 is a drawing showing an expanded member in a battery module according to one embodiment of the present invention.

[0045] Referring to FIGS. 1 to 3, a battery module (10) according to one embodiment of the present invention may include a battery cell (100), a module case (200), and an expansion member (300).

[0046] First, referring primarily to FIG. 2, a plurality of battery cells (100) may be included. In addition, although not shown in the drawing, the plurality of battery cells (100) may include an electrode assembly, a cell case accommodating the electrode assembly, and electrode leads connected to the electrode assembly and extending outward from the cell case to function as electrode terminals. In this case, the plurality of battery cells (100) may be electrically connected to each other.

[0047] The battery cell (100) may be a pouch-type secondary battery. The cell case of such a pouch-type secondary battery may be configured in a pouch shape in which a metal layer made of aluminum is interposed between polymer layers.

[0048] A plurality of battery cells (100) can be arranged in a vertical direction (Z-axis direction) and in a parallel manner in the front-back direction (Y-axis direction), as shown in FIG. 2.

[0049] Meanwhile, the present invention is not limited by the specific type or shape of the battery cell (100), and various battery cells (100) known at the time of filing of the present invention may be employed to construct the battery pack (1) of the present invention. In this embodiment, a pouch-type secondary battery having a high energy density and easy stacking is targeted as shown in the drawing, but it goes without saying that a cylindrical or square secondary battery may be applied as the battery cell (100).

[0050] Meanwhile, referring to FIG. 2, the battery module (10) of the present invention may further include a busbar frame assembly (400). The busbar frame assembly (400) may be configured to cover at least one side of a plurality of battery cells (100). In the present embodiment, as illustrated in FIG. 2, the busbar frame assembly (400) may be coupled to the front and rear of the plurality of battery cells (100).

[0051] The busbar frame assembly (400) may include a busbar frame (410) and a plurality of busbars (420). The busbar frame (410) may be arranged to be connected to the front and rear of a plurality of battery cells (100). The busbar frame (410) may have slits through which electrode leads (110) of the battery cells (100) may be drawn out in the +Y-axis or -Y-axis direction. In addition, the busbar frame (410) may be formed of a material having electrical insulation, such as a plastic material, and may be configured to allow a busbar (420) to be attached to an outer surface thereof.

[0052] A plurality of bus bars (420) are provided in the form of bars and are made of a metal material such as copper, aluminum, nickel, etc. as a means for connecting battery cells (100) in series and / or in parallel. The electrode leads (110) of the battery cells (100) pass through slits in the bus bar frame (410) and are drawn outward from the bus bar frame (410), and the portion drawn out in this manner can be attached to the surface of the bus bar (420) by welding or the like.

[0053] The above module case (200) may be configured to accommodate a plurality of battery cells (100). Specifically, the module case (200) may have an internal space formed therein and may be configured to accommodate a plurality of battery cells (100) and a busbar frame assembly (400) in the internal space.

[0054] The above-mentioned expansion member (300) may be provided on the outside of the module case (200). The expansion member (300) may be configured to cover the outer surface of the module case (200). The expansion member (300) may be configured to cover at least one side of the module case (200). For example, as in the embodiment illustrated in FIG. 1, the expansion member (300) may be provided on the outside of the upper surface of the module case (200).

[0055] The expansion member (300) can be applied to the outer surface of the module case (200) with a very thin thickness. The expansion member (300) can be configured flat on the outer surface of the module case (200).

[0056] Referring to FIG. 3, the expandable member (300) may be configured to expand at least partially by heat. The expandable member (300) may be configured to expand at a specific temperature. For example, the expandable member (300) may be configured to expand at 200 to 300°C.

[0057] In addition, the expansion member (300) can expand in the outward direction of the module case (200). That is, the expansion member (300) can expand in the outward direction of the module case (200) due to heat such as venting gas or flame generated when a thermal event occurs in the battery cell (100).

[0058] According to the above-described embodiment of the present invention, when a thermal event of the battery cell (100) occurs, the venting path can be reliably separated from the outside of the module case (200) as the expansion member (300) expands due to heat toward the outside of the module case (200). In particular, according to the above-described embodiment of the present invention, high-temperature gas or flames discharged to the outside space of the module case (200) can be suppressed from moving along the stacking direction of the battery cell (100).

[0059] That is, according to the above-described embodiment of the present invention, even if a thermal event occurs in some battery cells (100) within the battery module (10), it is possible to effectively prevent or delay the transfer of gas or flames to other battery cells (100) and cause thermal runaway. As a result, the safety and reliability of the battery module (10) can be guaranteed.

[0060]

[0061] Meanwhile, the expansion member (300) may be made of a material having flame retardant and / or fire-resistant properties. The expansion member (300) may be formed by directly foaming the outer surface of the module case (200). Such a material can be easily formed as a coating layer on the outer surface of the assembled module case (200) by a foam coating method.

[0062] For example, the expansion member (300) may be composed of an intumescent fire protection material. An intumescent fire protection material is a paint that foams when exposed to heat, forming a carbon layer (char). The intumescent fire protection material causes the film to rapidly expand and thicken by 50 to 100 times. The carbon layer (char) can prevent heat and air from penetrating into the film, thereby exhibiting a heat-insulating effect and a combustion delay effect. This can prevent a decrease in the strength of the module case (200) made of a metal material.

[0063] According to the above-described embodiment of the present invention, compared to attaching a sheet-shaped refractory member separately provided to the module case (200), the process of separately manufacturing the refractory member according to the size of the outer surface of the module case (200) is omitted, so that cost and time can be reduced when manufacturing a battery module.

[0064] The expansion member (300) may be a conformal coating layer formed along the outer surface of the module case (200). In particular, the expansion member (300) may be a conformal coating foam coating layer. Here, conformal coating refers to applying a coating agent thinly for purposes such as corrosion prevention. As a conformal coating material, a foamed refractory paint, etc., may be used as described above.

[0065] Using the conformal coating method, the expansion member (300) can be coated with a uniform thickness along the curve of the outer surface of the module case (200).

[0066] In addition, according to the above-described embodiment of the present invention, the drying time can be shortened, thereby reducing the manufacturing time, and since it is easy to inspect whether or not the coating has been applied, productivity can be improved. In addition, since the coating can be applied along the curves of the outer surface of the module case (200) with a uniform thickness, the metal material of the module case (200) can be prevented from being directly exposed to the outside in any part, and the maintenance of the heat conduction and heat radiation prevention effects for the entire area of ​​the module case (200) can be ensured.

[0067]

[0068] Fig. 4 is a cross-sectional view of a battery module according to one embodiment of the present invention. For example, Fig. 4 may be a drawing illustrating the cross-sectional view taken along line I-I' of Fig. 1. In addition, Fig. 5 is a cross-sectional view of a battery module according to one embodiment of the present invention in an expanded state of an expandable member.

[0069] Specifically, referring to FIGS. 4 and 5, the expansion member (300) can be configured to expand to define a space between the module case (200) and the pack case (2).

[0070] When a thermal event occurs in one battery cell (100), venting gas or flame, etc. may move toward the space between the module case (200) and the pack case (2), and there is a concern that such venting gas or flame, etc. may move along the stacking direction (left-right direction) of the battery cells (100) in the space between the module case (200) and the pack case (2) and be transferred to another adjacent battery cell (100). However, according to the above-described embodiment of the present invention, when a thermal event occurs in one battery cell (100), it is possible to suppress high-temperature venting gas or flame, etc. from being transferred to the adjacent battery cell (100) along the stacking direction (left-right direction) of the battery cells (100) in the space between the module case (200) and the pack case (2).

[0071] Moreover, the expandable member (300) may be configured to be expanded and contact the pack case (2). That is, the expandable member (300) may be configured to fill the space between the module case (200) and the pack case (2).

[0072] According to the above-described embodiment of the present invention, the gap between the expansion member (300) and the pack case (2) is minimized, so that the space between the module case (200) and the pack case (2) can be more reliably partitioned. As a result, thermal runaway propagation to adjacent other battery cells (100) can be effectively prevented.

[0073]

[0074] Meanwhile, referring to FIG. 2 and the like, the module case (200) may include a case body (210) and a top plate (220). The case body (210) may be configured to accommodate a battery cell (100). The case body (210) may be formed of a metal material having rigidity and heat resistance to physically or chemically protect the accommodated battery cell (100).

[0075] At this time, the upper surface and the front and rear surfaces of the case body (210) may be opened. For example, the case body (210) may be provided as a U-frame. When the case body (210) is provided as a U-frame, it may be provided to cover both sides and the lower surface of the plurality of battery cells (100). The case body (210) may include a left plate and a right plate that cover both sides of the plurality of battery cells (100), and a lower plate that covers the lower surfaces of the plurality of battery cells (100). In addition, the left plate, the right plate, and the lower plate may be configured in an integrated form.

[0076] The top plate (220) may be provided to form the upper surface of the module case (200). When the case body (210) is provided as a U-frame, the top plate (220) may be coupled to the open upper surface of the case body (210). The top plate (220) may be welded to the case body (210) to be coupled to each other. At this time, the shape in which the top plate (220) and the case body (210) are coupled may be a square tubular shape with the front and back sides open.

[0077] In addition, the module case (200) may include an end plate (230) provided on the open front and rear sides of the case body (210). The end plate (230) may be welded and joined to the case body (210). Meanwhile, although not shown for convenience, the end plate (230) may have, for example, an inner side made of an insulating material and an outer side made of a metal material. In addition, the end plate (230) may be partially provided with holes or slits to expose components that need to be exposed to the outside, such as a positive terminal and a negative terminal of the battery module (10) or a connector.

[0078] In addition, the module case (200) may be formed in various other shapes. For example, the module case (200) may be provided with a box-shaped lower case having an upper open end and an upper cover that closes the upper open end of the lower case. Alternatively, the module case (200) may be provided as a monoframe. For example, the case body (210) may be configured in the shape of a square tube having an upper surface, a lower surface, a left surface, and a right surface, and having an open front and back surface.

[0079] Meanwhile, as illustrated in FIGS. 1 to 5, a venting hole (H) may be formed in the module case (200). The venting hole (H) may be configured to allow venting gas generated in the battery cell (100) to be discharged to the outside of the module case (200). The venting hole (H) may be formed on one side of the module case (200), and directional venting in one direction may be possible. For example, the venting hole (H) may be formed on the upper surface of the module case (200).

[0080] For example, a venting hole (H) may be formed in the top plate (220), and directional venting of the battery module (10) toward the top may be possible through the venting hole (H). A plurality of venting holes (H) may be provided, and may be provided at regular intervals in the horizontal direction (X-axis, Y-axis direction). The venting holes (H) may be configured in a long form extending along the longitudinal direction of the battery cell (100).

[0081] In this way, the venting hole (H) provided on the upper surface of the module case (200) can be provided so that, when thermal runaway of the battery module (10) occurs, gas or flame generated inside the battery module (10) can be discharged to the outside of the battery module (10). The remaining portion of the module case (200) excluding the venting hole (H) is sealed, and the gas or flame can be discharged in a straight line toward the venting hole (H).

[0082] According to the above-described embodiment of the present invention, even if a thermal event occurs at any location of the battery cell (100), the gas or flame generated in the battery cell (100) is discharged to the outside of the battery module (10) through specific venting holes (H) provided at the upper portion of the battery cell (100), thereby facilitating venting.

[0083] Referring to FIGS. 4 and 5, the expansion member (300) may be provided between adjacent venting holes (H). For example, a plurality of venting holes (H) may be arranged in a row along the longitudinal direction of the battery cell (100) to form a venting hole array, and a plurality of such venting hole arrays may be provided and arranged along the stacking direction of the battery cell (100). The expansion member (300) may be provided between adjacent venting hole arrays. The venting hole array may be arranged for each cell group (G).

[0084] Specifically, when venting gas or flames generated from a battery cell (100) included in a cell group (G) are discharged through a venting hole (H), an expandable member (300) provided on both sides of the venting hole (H) may expand. Accordingly, the expandable member (300) may be configured to suppress the venting gas discharged from the venting hole (H) from heading toward another venting hole (H).

[0085] According to the above-described embodiment of the present invention, even if a thermal event occurs in a battery cell (100) included in a certain cell group (G) and venting gas or flames are discharged through a venting hole (H) corresponding to the cell group (G), the venting gas or flames flowing between the module case (200) and the pack case (2) are blocked by the expanded expandable member (300) and can be prevented from moving to another venting hole (H). That is, according to the above-described embodiment of the present invention, since the venting paths between the cell groups (G) can be separated, thermal runaway between the battery cells (100) can be prevented or delayed.

[0086]

[0087] Meanwhile, referring to FIGS. 4 and 5, the battery module (10) according to one embodiment of the present invention may further include a barrier member (500). The barrier member (500) may be provided in the internal space of the module case (200). The barrier member (500) may be provided between the battery cells (100). At least one barrier member (500) may be included in one battery module (10). A plurality of barrier members (500) may be provided along one direction in which the battery cells (100) are arranged. The barrier member (500) may be provided in a form in which it is arranged for at least one battery cell (100).

[0088] In particular, the barrier member (500) may be configured to partition between a plurality of battery cells (100). The barrier member (500) may be configured to group a plurality of battery cells (100). For example, as illustrated in FIG. 4, a barrier member (500) may be arranged for each of four battery cells (100), thereby grouping the battery cells (100) into groups of four. Accordingly, a cell group (G) including four battery cells (100) may be partitioned by the barrier member (500).

[0089] This barrier member (500) may be configured to block heat generated when a thermal event occurs inside the battery module (10). That is, the barrier member (500) may be configured to block the flow of heat or fluid between battery cells (100). Here, the fluid may include venting gas, flame, particles, etc.

[0090] To this end, the barrier member (500) may be formed of a material with excellent heat and / or fire resistance. Accordingly, the barrier member (500) may be configured to maintain a sealed structure without deformation even under high temperatures and pressures. For example, the barrier member (500) may be formed of an insulating pad that is thinner than the battery cell (100). Furthermore, the barrier member (500) may be formed in the form of a compressive pad, for example, formed of a material such as silicone or aerogel.

[0091] According to the above-described embodiment of the present invention, even if a thermal event occurs in any of the battery cells (100) grouped by the barrier member (500), the movement of venting gas, flames, and / or particles to other groups of battery cells (100) can be suppressed. The propagation of thermal runaway between battery cells (100) can be effectively prevented or delayed. Accordingly, the safety and reliability of the battery module (10) can be guaranteed.

[0092] In addition, according to the above-described embodiment of the present invention, the barrier member (500) can contribute to the structural rigidity of the battery cells (100) by compressing the battery cells (100) when the battery cells (100) are swollen.

[0093] A barrier member (500) may be provided between the venting holes (H). In addition, an expansion member (300) may be provided at a position corresponding to the barrier member (500).

[0094] According to the above-described embodiment of the present invention, since the cell groups (G) are partitioned by the barrier members (500), the venting paths provided between the adjacent barrier members (500) for each cell group (G) can be further separated. As a result, thermal runaway between the battery cells (100) can be further suppressed.

[0095]

[0096] FIG. 6 is a perspective view of an expandable member included in a battery module according to one embodiment of the present invention in an at least partially expanded state.

[0097] The expandable member (300) may be configured to gradually expand along the direction of movement of the venting gas or flame, etc. Specifically, the expandable member (300) may be configured to expand along the direction of movement of the venting gas discharged from the venting hole (H). Accordingly, the expandable member (300) may be fully expanded or only partially expanded.

[0098] For example, as in the embodiment illustrated in FIG. 6, when a thermal event occurs in a battery cell (100) of a cell group (G), if venting gas or flame, etc., is discharged to the outside of the module case (200) through the corresponding venting hole (H), only the expansion member (300) provided around the venting hole (H) can expand in the outside direction of the module case (200) (see part A of FIG. 6).

[0099] According to the above-described embodiment of the present invention, a path can be formed by the expandable member (300) to guide the venting direction around the venting hole (H) (see the bold arrow in FIG. 6). Accordingly, venting gas or flame, etc. can be quickly guided in a specific direction so that other battery cells (100) are not affected. In addition, according to the above-described embodiment of the present invention, venting gas or flame, etc. can be prevented from moving toward other venting holes (H) due to being blocked by the expandable member (300).

[0100]

[0101] Figure 7 is a cross-sectional view of a battery module according to another embodiment of the present invention.

[0102] The expandable member (300) may be configured to have a differential expansion rate at least partially depending on the location. Here, the expansion rate may be a value expressed as a percentage (%), which is the value obtained by dividing the volume of the expandable member (300) after the expandable member (300) has expanded at a specific temperature by the volume of the expandable member (300) before the expandable member (300) has expanded. The expansion rate of the expandable member (300) may be provided differently by varying the composition ratio or material of the expandable member (300) depending on the location of the expandable member (300).

[0103] For example, the expansion member (300) may be configured to have a different expansion rate from the center to the periphery of the module case (200). Accordingly, when a thermal event occurs within the battery module (10), the expanded volume or height may be provided differently at each location of the expansion member (300).

[0104] According to the above-described embodiment of the present invention, the expansion ratio of the expansion member (300) is configured differently for each location depending on the location where the module case (200) is easily heated, so that the expansion member (300) can expand depending on the height of the space between the module case (200) and the pack case (2). The expansion ratio of the expansion member (300) can be designed through experiments.

[0105] As an example, as in the embodiment illustrated in FIG. 7, the expansion member (300) may be configured such that the expansion rate increases at least partially from the center to the periphery of the module case (200). In particular, the expansion member (300) provided on the outer surface of the top plate (220) may be configured such that the expansion rate is at least partially different along the stacking direction of the battery cells (100).

[0106] When thermal runaway of the battery cell (100) occurs inside the module case (200), the central portion of the top plate (220) may swell upward. In this case, the edge portion of the top plate (220) may be lifted, and the top plate (220) may be separated from the case body (210). However, according to the above-described embodiment of the present invention, the expansion rate of the expansion member (300) increases from the central portion of the top plate (220) to the outer portion, so that the expansion member (300) can expand to fill the space between the module case (200) and the pack case (2) without any gap.

[0107] In addition, according to the above-described embodiment of the present invention, the expansion member (300) provided on the outer portion of the top plate (220) can press the edge of the top plate (220). Accordingly, when the expansion member (300) expands, the top plate (220) and the case body (210) can be prevented from being separated, so that the bonding force between the top plate (220) and the case body (210) can be maintained. Therefore, according to the above-described embodiment of the present invention, the structural stability of the battery module (10) can be secured.

[0108]

[0109] FIG. 8 is a schematic exploded perspective view of a battery pack including a battery module according to one embodiment of the present invention, and FIG. 9 is a cross-sectional view of a battery pack according to one embodiment of the present invention. In addition, FIG. 10 is a drawing showing an expandable member at least partially expanded in a battery pack according to one embodiment of the present invention.

[0110] Referring to FIG. 8, a battery pack (1) according to one embodiment of the present invention may include one or more battery cells (100) or battery modules (10) according to one embodiment of the present invention as described above. The battery pack (1) according to the present invention may further include a pack case (2) for accommodating a BMS (Battery Management System), a current sensor, a fuse, and the like for integrated control of charging and discharging of one or more battery modules (10), and the above-described components.

[0111] The pack case (2) may include a plurality of plates. For example, the pack case (2) may be configured in a box shape and may be configured to cover the upper surface, lower surface, and side surfaces of a plurality of battery cells (100) or a plurality of battery modules (10). In addition, the pack case (2) may further include a cross beam configured to partition a plurality of battery cells (100) or a plurality of battery modules (10).

[0112] In addition, the battery pack (1) according to one embodiment of the present invention may include a venting device (3). The venting device (3) may be provided in the pack case (2). The venting device (3) may be configured to discharge gas generated from battery cells (100) stored therein to the outside of the pack case (2). When venting gas is generated inside the pack case (2) and the internal pressure increases, the venting device (3) may be configured to open due to the pressure of the venting gas to discharge the venting gas to the outside of the pack case (2).

[0113] For example, the venting device (3) may be configured to open and close depending on the internal pressure within the pack case (2). Alternatively, the venting device (3) may be configured in the form of a hole. Meanwhile, the present invention is not limited by the specific type or shape of the venting device (3), and various venting devices (3) known at the time of filing of the present invention may be employed to configure the battery pack (1) of the present invention.

[0114] Meanwhile, the number or location of the venting device (3) described based on the embodiment of Fig. 8 is merely an example, and it is obvious that the number or location may be changed to various other numbers or locations.

[0115] Also, referring to FIGS. 8 and 9, the battery pack (1) according to one embodiment of the present invention may be provided with the above-described expansion member (300). The expansion member (300) may be provided for each of a plurality of battery modules (10). The expansion member (300) may be configured to at least partially expand due to heat to partition the space between the module case (200) and the pack case (2).

[0116] In addition, according to the above-described embodiment of the present invention, when a thermal event occurs in a battery module (10), the venting path can be reliably separated from the outside of the module case (200) as the expansion member (300) expands in the outward direction of the module case (200) due to heat. In particular, according to the above-described embodiment of the present invention, high-temperature gas or flames discharged to the outer space of the module case (200) can be suppressed from moving along the stacking direction of the battery cell (100) or the battery module (10) (see the bold arrow in FIG. 9).

[0117] That is, according to the above-described embodiment of the present invention, even if a thermal event occurs within a battery module (10), it is possible to effectively prevent or delay the transfer of gas or flames to other battery modules (10) and cause thermal runaway. As a result, the safety and reliability of the battery pack (1) can be guaranteed.

[0118] In particular, in a battery pack (1) according to one embodiment of the present invention, as in the embodiment illustrated in FIG. 10, when a thermal event occurs in any battery module (10), the expansion member (300) may be configured to expand along the direction of movement of venting gas or flame, etc. (see part B of FIG. 10).

[0119] According to the above-described embodiment of the present invention, a path that can induce a venting direction can be formed by the expansion member (300). Accordingly, venting gas or flames can be quickly directed in a specific direction so that other battery cells (100) are not affected.

[0120] In particular, according to the above-described embodiment of the present invention, venting can be induced toward the venting device (3) by the expansion member (300) (see the bold arrow in FIG. 10). As a result, venting gas or flames, etc. can be moved to the venting device (3) and quickly discharged to the outside of the pack case (2) while minimizing the impact on other battery modules (10). Accordingly, the internal pressure of the pack case (2) can be reduced, thereby suppressing or delaying thermal runaway between battery modules (10).

[0121]

[0122] FIG. 11 is a schematic perspective view of a vehicle including a battery pack according to one embodiment of the present invention.

[0123] Referring to FIG. 11, a vehicle (V) according to an embodiment of the present invention may include one or more battery packs (1) according to an embodiment of the present invention or battery modules (10) according to an 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-wheel vehicle and a two-wheel vehicle. The vehicle (V) operates by receiving power from a battery pack (1) or a battery module (10) according to an embodiment of the present invention.

[0124] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. In the battery module accommodated in the pack case, Multiple battery cells; a module case configured to accommodate the plurality of battery cells; and A battery module characterized by including an expansion member provided on the outside of the module case and configured to expand at least partially in the outward direction of the module case due to heat.

2. In paragraph 1, A battery module characterized in that the above-mentioned expansion member is composed of a foamed fire-resistant paint.

3. In paragraph 1, A battery module characterized in that the expansion member is configured to expand to define a space between the module case and the pack case.

4. In paragraph 1, A battery module characterized in that the expansion member is configured to expand and contact the pack case.

5. In paragraph 1, At least one side of the module case is formed with a plurality of venting holes configured to discharge venting gas generated from the battery cell to the outside, A battery module characterized in that the above expansion member is provided between adjacent venting holes.

6. In paragraph 5, A battery module characterized in that the expansion member is configured to suppress the venting gas discharged from the venting hole from moving toward another venting hole.

7. In paragraph 5, A battery module characterized in that the expansion member is configured to expand along the direction of movement of the venting gas discharged from the venting hole.

8. In paragraph 1, A battery pack characterized in that the expansion member has an expansion rate that is differentially configured at least partially depending on the location.

9. A battery pack comprising a battery module according to any one of claims 1 to 8.

10. A vehicle including a battery pack according to Article 9.

11. Multiple battery cells; A pack case configured to accommodate the plurality of battery cells; and A battery pack characterized by including an expansion member provided between the plurality of battery cells and the pack case and configured to expand at least partially outwardly due to heat.

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