Battery pack and motor vehicle including the same

Abstract

The present invention relates to a battery pack including a plurality of battery cells, a pack tray having an open upper portion for accommodating the plurality of battery cells, a pack lid configured to cover the open upper portion of the pack tray, and a reinforcing member coupled to the pack lid and configured to suppress deformation of the pack lid.

Description

Technical Field

[0001] The present invention relates to a battery pack and an automobile including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0056234 filed on April 28, 2023, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

[0003] This application claims priority based on Korean Patent Application No. 10-2023-0137151 filed on October 13, 2023, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0004] Secondary batteries, which are highly applicable to a group of products and have electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source. Such secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency improvement because they have not only the primary merit of significantly reducing the use of fossil fuels but also the merit of generating no by-products associated with energy use.

[0005] The types of secondary batteries currently widely used include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of such a unit secondary battery cell, that is, a unit battery cell, is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack may be configured by connecting a plurality of battery cells in series. Also, depending on the charge and discharge capacity required for the battery pack, a battery pack may be configured by connecting a plurality of battery cells in parallel. Therefore, the number of battery cells included in the battery pack can be variously set according to the required output voltage or charge and discharge capacity.

[0006] On the other hand, when configuring a battery pack by connecting a plurality of battery cells in series / parallel, generally, a battery module including at least one battery cell is first configured, and other components are added using this at least one battery module to configure a battery pack or a battery rack. Alternatively, recently, a cell-to-pack type battery pack that directly accommodates a plurality of battery cells in a pack housing or the like without modularizing them has also been manufactured.

[0007] When a thermal event such as thermal runaway occurs inside a battery pack, gas may be ejected from the battery cells contained therein, and such gas may contain a flame or the like. Also, in a battery pack including a plurality of battery modules, there is a possibility that thermal runaway or the like occurring in a specific battery module may spread to other battery modules. If such thermal propagation between battery modules is not appropriately controlled, it may lead to a fire or explosion of the entire battery pack, which is very dangerous.

[0008] Furthermore, in a conventional battery pack, when a thermal runaway occurs inside the battery pack, vent gas or the like moves from the space between the pack lead provided at the upper part of the battery module and the battery module, and is discharged to the outside. However, if a specific part of the pack lead is deformed outward by high-temperature vent gas or a spark, other surrounding parts are deformed inward, resulting in a problem that the vent flow path cannot be secured. As a result, there has been a problem that vent gas, heat, sparks, etc. do not spread uniformly and are accelerated to randomly transfer to adjacent battery cells or battery modules.

[0009] Therefore, when a thermal event occurs in a battery module or a battery cell, a structure is required to minimize heat propagation in the battery pack by preventing the pack lead from being thermally deformed by high-temperature vent gas or a spark.

[0010] In addition, for this reason, a technique for securing a vent path for smoothly discharging vent gas or the like to the outside of the battery pack when a thermal event occurs in the battery module or the battery cell is also required. Summary of the Invention Problems to be Solved by the Invention

[0011] Therefore, the present invention has been made to solve the above-described problems and the like, and an object thereof is to provide a battery pack capable of ensuring safety and reliability when a thermal event occurs in a battery cell or a battery module, and an automobile including the same.

[0012] However, the problems to be solved by the present invention are not limited to the above-described problems, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention described below. Means for Solving the Problems

[0013] To solve the above problems, a battery pack according to an embodiment of the present invention may include: a plurality of battery cells; a pack tray having an open top for accommodating the plurality of battery cells; a pack lead configured to cover the open top of the pack tray; and a reinforcing member coupled to the pack lead and configured to suppress deformation of the pack lead.

[0014] A vent passage configured to allow vent gas generated in the battery cells to flow is formed between the pack lead and the battery cells, and the reinforcing member may be configured to maintain the height of the vent passage.

[0015] The reinforcing member may be made of a material having a lower coefficient of thermal expansion than the pack lead.

[0016] The reinforcing member may be formed in a shape extending in a long shape along the stacking direction of the plurality of battery cells.

[0017] A plurality of the reinforcing members may be provided at a predetermined distance apart in the horizontal direction.

[0018] The battery pack may further include a module case that houses the plurality of battery cells in an internal space and has at least one vent hole formed to communicate with the internal space on the upper side, and the vent hole may be disposed between adjacent reinforcing members.

[0019] At least a part of the reinforcing member may be configured to protrude from the pack lead toward the battery cell side.

[0020] The reinforcing member may include a protruding portion configured to protrude from the pack lead and a support portion extending from both sides of the protruding portion and supported by the pack lead.

[0021] The battery pack may further include an insulating coating layer formed on an outer surface of the reinforcing member.

[0022] The packet tray includes a vent portion configured to discharge the vent gas to the outside of the packet tray, and the reinforcing member may be formed to extend in a long shape toward the vent portion.

[0023] The interval between adjacent reinforcing members may be configured to become narrower as it approaches the vent portion.

[0024] Of the plurality of reinforcing members, at least a part of the width of the reinforcing member coupled to the central portion of the pack lead may be configured to be wider than the width of the reinforcing member coupled to the edge portion of the pack lead.

[0025] Furthermore, the automobile according to the present invention may include the battery pack according to the present invention.

Advantages of the Invention

[0026] According to one aspect of the present invention, it is possible to ensure safety and reliability by preventing the pack lead from being thermally deformed by high-temperature vent gas or sparks generated when a thermal event occurs in a battery cell or a battery module.

[0027] Also, according to one aspect of the present invention, when a thermal event occurs in a battery cell or a battery module, in the process of discharging high-temperature gas generated in the battery module to the outside of the pack case, other battery modules are prevented from receiving thermal damage as much as possible, and further chain ignition can be prevented.

[0028] Furthermore, according to one aspect of the present invention, since a stable vent flow path between the battery module and the pack lead is ensured, vent gas generated when an abnormal situation occurs in the battery module can be smoothly discharged to the outside of the pack case.

[0029] Furthermore, according to one aspect of the present invention, it is possible to effectively ensure the thermal propagation prevention performance of the pack unit.

[0030] Thereby, it is possible to prevent or delay events associated with the thermal runaway phenomenon of a battery pack including a plurality of battery modules or an apparatus equipped with them, such as a fire or an explosion.

[0031] In particular, in the case of an electric vehicle, by suppressing or delaying the thermal runaway propagation between battery cells or between battery modules, it is possible to secure sufficient time for passengers to escape or operate.

[0032] In addition to this, the present invention can have various other effects, which will be described in the section of the mode for carrying out the invention, or the description of effects that can be easily inferred by those skilled in the art will be omitted.

[0033] The following drawings attached to this specification illustrate preferred embodiments of the present invention and are for the purpose of further understanding the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention is not construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0034]

Figure 1

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Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and the claims are not to be construed as being limited to ordinary or dictionary meanings, but are to be interpreted in accordance with the meaning and concept corresponding to the technical idea of the present invention in accordance with the principle that the inventor himself can appropriately define the concept of the terms in order to explain the invention in the best way.

[0036] Therefore, the embodiments described in this specification and the configurations shown 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. It should be understood that there may be various equivalents and alternative embodiments that can replace them at the time of this application.

[0037] In addition, the present invention includes various embodiments. For each embodiment, duplicate descriptions for substantially the same or similar configurations will be omitted, and the description will focus on the differences.

[0038] On the other hand, in the present invention, terms representing directions such as up, down, left, right, front, and back may be used. However, these terms are for convenience of explanation and it is self-evident to those skilled in the art of the present invention that they may vary depending on the position of the object in question and the position of the observer.

[0039] For example, in an embodiment of the present invention, the X-axis direction shown in the drawings may mean the left-right direction, the Y-axis direction may mean the front-back direction perpendicular to the X-axis direction on the horizontal plane (X-Y plane), and the Z-axis direction may mean the up-down direction (vertical direction) perpendicular to both the X-axis direction and the Y-axis direction.

[0040] FIG. 1 is an overall perspective view of a battery pack according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the battery pack according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of a battery module included in the battery pack according to an embodiment of the present invention. Also, FIG. 4 is a diagram showing the direction in which vent gas is discharged when the battery pack according to an embodiment of the present invention includes a reinforcing member. For example, FIG. 4 may be a cross-sectional view taken along line I-I' of FIG. 1. And FIG. 5 is a comparative example and is a diagram showing the direction in which vent gas is discharged when the battery pack according to an embodiment of the present invention does not include a reinforcing member. For example, FIG. 5 may be a cross-sectional view taken along line I-I' of FIG. 1.

[0041] Referring to FIGS. 1 to 4, a battery pack 1 according to an embodiment of the present invention includes battery cells 100, a pack tray 200, pack leads 300, and a reinforcing member 400.

[0042] First, mainly referring to FIG. 3, there can be a plurality of battery cells 100. Although not shown in the figure, such a plurality of battery cells 100 may include an electrode assembly, a cell case that houses the electrode assembly, and an electrode lead that is connected to the electrode assembly and drawn out to the outside of the cell case to function as an electrode terminal. At this time, the plurality of battery cells 100 can be electrically connected to each other.

[0043] The battery cell 100 can be a pouch-type secondary battery. The cell case of such a pouch-type secondary battery can be configured as a pouch in which a metal layer made of aluminum is interposed between polymer layers.

[0044] As shown in FIG. 2, the plurality of battery cells 100 can be arranged side by side in the front-rear direction (Y-axis direction) in a state of being erected in the vertical direction (Z-axis direction). At this time, each battery cell 100 may have a seal portion facing the left-right direction (X-axis direction) and the up-down direction (Z-axis direction), and an accommodation portion facing the front-rear direction (Y-axis direction).

[0045] On the other hand, the present invention is not limited by the specific type and form of such a battery cell 100, and various battery cells 100 that are known at the time of filing the present invention can be adopted to constitute the battery pack 1 of the present invention.

[0046] In this embodiment, as shown in the figure, a pouch-type secondary battery with high energy density and easy stacking is targeted, but it goes without saying that a cylindrical secondary battery or a rectangular secondary battery may also be applied as the battery cell 100.

[0047] Referring to FIG. 2 and the like, the pack tray 200 can be configured to accommodate a plurality of battery cells 100. That is, the pack tray 200 can provide an accommodation space for accommodating a plurality of battery cells 100. Further, the pack tray 200 can be configured such that its upper part is open.

[0048] The pack tray 200 is made of, or may include, a material capable of ensuring mechanical rigidity, such as a metal like steel or stainless steel (SUS: Steel Use Stainless) or plastic, in order to safely protect the battery cells 100 and the like housed therein.

[0049] Referring mainly to FIGS. 1, 2, etc., the pack lead 300 may be configured to cover the upper portions of the plurality of battery cells 100. The pack lead 300 may be configured to cover the open upper portion of the pack tray 200. The pack lead 300 may be configured to be coupled to the upper portion of the pack tray 200 to form the upper surface of the pack tray 200. The pack lead 300 protects the components housed therein, such as the battery cells 100, and can prevent the vent gas and / or sparks discharged from such battery cells 100 from being discharged outside the pack tray 200, particularly the upper portion.

[0050] Also, referring to FIGS. 2 and 4, the battery pack 1 according to an embodiment of the present invention may further include a reinforcing member 400. The reinforcing member 400 may be located above the battery cells 100. The reinforcing member 400 may be coupled to the pack lead 300. In particular, the reinforcing member 400 may be coupled to the lower portion of the pack lead 300.

[0051] The reinforcing member 400 may be configured to suppress deformation of the pack lead 300. In particular, the reinforcing member 400 may be configured to suppress deformation of the pack lead 300 due to heat and pressure, such as high-temperature vent gas and sparks generated in the battery cells 100 when a thermal event occurs. That is, the reinforcing member 400 may be configured to prevent thermal deformation of the pack lead 300. Further, the reinforcing member 400 may be configured to suppress partial deformation of the pack lead 300.

[0052] As in the comparative example shown in FIG. 5, when a thermal event occurs in the battery cell 100 without the reinforcement member 400 being provided, the shape of the pack lead 300 may be deformed by the pressure and / or high heat of vent gas, spark, etc. discharged from the battery cell 100. For example, a part of the pack lead 300 located at the part where vent gas, spark, etc. are discharged may bulge upward (FIG. 5, part A), and the adjacent part may conversely be concave downward (FIG. 5, part B). As a result, in the part where the pack lead 300 is concave downward, the distance between the pack lead 300 and the battery cell 100 becomes small, and the vent flow path is not secured. Therefore, the discharge of vent gas to the outside of the pack tray 200 may be inhibited.

[0053] However, according to an embodiment of the present invention, since the reinforcement member 400 is provided on the pack lead 300, when high-temperature vent gas or the like is applied to the pack lead 300, it is possible to suppress a specific part of the pack lead 300 from bending upward or downward. That is, according to the above embodiment of the present invention, the reinforcement member 400 can prevent or suppress the formation of bending in a specific part of the pack lead 300.

[0054] Thereby, when an abnormal situation occurs in the battery cell 100, a path for discharging the high-temperature vent gas generated in the battery cell 100 to the outside of the battery pack 1 can be secured. Thus, according to the above aspect of the present invention, the propagation of thermal runaway in the battery pack 1 can be effectively prevented or delayed, so that the safety and reliability of the battery pack 1 can be ensured.

[0055] Specifically, referring to FIG. 4, since the pack lead 300 and the battery cell 100 or the battery module 10 are spaced apart by a predetermined distance, vent gas, sparks, etc. can move through the spaced space. That is, a vent flow path S configured such that vent gas flows can be formed between the pack lead 300 and the battery cell 100. Here, the reinforcing member 400 can be configured to maintain the height h of the vent flow path S. The height h of the vent flow path S refers to the length in the vertical direction (Z-axis direction) and can mean the vertical distance from the upper surface of the battery cell 100 or the battery module 10 to the lower surface of the pack lead 300.

[0056] Therefore, according to the above embodiment of the present invention, since the distance h between the pack lead 300 and the battery cell 100 is kept constant by the reinforcing member 400, the volume of the vent flow path S can be ensured. Therefore, vent gas, heat, etc. can be smoothly discharged to the outside of the battery pack 1 through the vent flow path S, and thermal runaway between the battery cells 100 can be effectively suppressed or delayed. Also, vent gas, sparks, etc. discharged upward from the battery cell 100 can be reflected by the pack lead 300 to prevent re-inflow to adjacent battery cells 100 or battery modules 10. Thereby, the safety and reliability of the battery pack 1 can be ensured.

[0057] On the other hand, the reinforcing member 400 can be made of a material having a lower coefficient of thermal expansion than the pack lead 300. The reinforcing member 400 can be composed only of a material having a lower coefficient of thermal expansion than the pack lead 300. However, the difference in the coefficient of thermal expansion between the reinforcing member 400 and the pack lead 300 can be configured such that the reinforcing member 400 does not separate from the pack lead 300 when a thermal event occurs. According to the above embodiment of the present invention, it is possible to prevent the pack lead 300 from being thermally deformed by high-temperature vent gas, sparks, etc. during an abnormal situation of the battery module 10 or the battery cell 100, and minimize heat propagation in the battery pack 1.

[0058] The reinforcing member 400 can be made of a material having fire resistance. Thereby, even if a thermal event occurs inside, it is possible to prevent the reinforcing member 400 from melting or disappearing due to high heat such as a flame. Therefore, even if a flame occurs, the function of preventing the deformation of the pack lead 300 by the reinforcing member 400 and maintaining the interval between the pack lead 300 and the battery cell 100 is ensured.

[0059] The reinforcing member 400 can be a rigid body. The reinforcing member 400 can be composed of a material having higher strength than the pack lead 300. Here, in contrast to an elastic body, a rigid body means that, for example, the reinforcing member 400 can be made of a metal such as stainless steel (SUS: Steel Use Stainless) or a material such as reinforced fiber plastic.

[0060] Thereby, not only the thermal deformation of the pack lead 300 due to high-temperature vent gas or the like from the inside is prevented, but also since the mechanical rigidity of the reinforcing member 400 increases, it is possible to prevent the pack lead 300 from elastically deforming even when an external impact is applied.

[0061] FIG. 6 is a top view of the inside of a battery pack according to an embodiment of the present invention, and is a diagram for explaining the direction in which vent gas moves when a thermal event occurs in a battery module. Further, FIG. 7 is an enlarged cross-sectional view of a part of a battery pack according to an embodiment of the present invention.

[0062] As described above, the plurality of battery cells 100 can be arranged and stacked along the front-rear direction (Y-axis direction). At this time, as in the embodiment shown in FIG. 6, the reinforcing member 400 can be formed in a shape extending in a long shape along the stacking direction of the plurality of battery cells 100. That is, the reinforcing member 400 can be formed to extend in a long shape along the front-rear direction of the battery pack 1. The length of the reinforcing member 400 can be configured to be substantially the same as the length of the pack lead 300 in the front-rear direction.

[0063] According to the above-described embodiment of the present invention, since the reinforcing member 400 holds both ends of the pack lead 300 long in the longitudinal direction, it is possible to more effectively prevent the pack lead 300 from deforming in the height direction due to heat.

[0064] On the other hand, a plurality of reinforcing members 400 may be provided. The plurality of reinforcing members 400 may be arranged so as to be spaced apart from each other by a predetermined distance in the horizontal direction. At this time, the vent flow path S may be formed between adjacent reinforcing members 400. That is, the vent flow path S may be formed between the pack lead 300, the reinforcing member 400, and the battery cell 100 so that vent gas or the like can flow when a thermal event occurs in any of the battery cells 100. The vent flow path S may also be formed in a long shape extending along the front-rear direction, similar to the direction in which the reinforcing member 400 extends.

[0065] Thereby, the reinforcing member 400 can guide the vent gas or the like flowing through the vent flow path S in the front-rear direction of the pack tray 200 and smoothly discharge it to the outside.

[0066] On the other hand, referring to FIGS. 2 and 3, the plurality of battery cells 100 may be modularized into one or more battery modules 10. That is, the battery pack 1 according to the present invention may include one or more battery modules 10. And the plurality of battery cells 100 may be included as components of one or more battery modules 10. At this time, the plurality of battery cells 100 included in the battery module 10 may be electrically connected to each other.

[0067] Furthermore, a plurality of battery modules 10 may be provided inside the pack tray 200. That is, the battery pack 1 according to the present invention includes a plurality of battery modules 10, and the plurality of battery cells 100 included in the battery pack 1 may be divided and accommodated in the plurality of battery modules 10.

[0068] In particular, the battery pack 1 according to the present invention may include a module case 11. The module case 11 may be configured such that an empty space is formed inside and at least a part of a plurality of battery cells 100 is accommodated in the internal space. In particular, the module case 11 may be included in each battery module 10 and may serve as a boundary that groups a plurality of battery cells 100 into a plurality of battery modules 10 and physically limits the internal space of each battery module 10.

[0069] Also, although not shown in the drawings, the battery module 10 may include a bus bar assembly and / or module terminals that are electrically connected to a plurality of battery cells 100 accommodated therein.

[0070] The battery module 10 may include a vent hole H. The vent hole H may be configured such that gas generated in the battery cells 100 accommodated inside the module case 11 is discharged to the outside of the module case 11.

[0071] Specifically, the vent hole H is provided in the module case 11 and can enable directional venting in a specific direction. For example, as shown in FIG. 7, the vent hole H may be provided at the upper part of the module case 11. According to such an embodiment, vent gas and / or sparks can be induced to be discharged above the battery module 10.

[0072] A plurality of vent holes H may be provided. The vent holes H may be arranged in a row in the front-rear direction or the left-right direction. For example, as shown in FIG. 7, the vent holes H may be arranged in a row along the longitudinal direction (left-right direction) of the battery cells 100 to form one row. These rows may be arranged in a plurality along the stacking direction (front-rear direction) of the battery cells 100.

[0073] Further, the plurality of vent holes H can be arranged between adjacent reinforcing members 400 among the plurality of reinforcing members 400. All of the plurality of vent holes H may be arranged between adjacent reinforcing members 400, or as shown in FIG. 7, a part of the plurality of vent holes H may be arranged between adjacent reinforcing members 400. That is, when the battery pack 1 is viewed from above, it can be arranged so that the overlapping portion of the reinforcing member 400 and the vent hole H is minimized.

[0074] According to the above embodiment of the present invention, it is possible to prevent the flow of vent gas or the like discharged upward from being obstructed by the reinforcing member 400. Thereby, the vent gas or the like can smoothly flow into the vent passage S and be discharged to the outside of the battery pack 1.

[0075] Further, the reinforcing member 400 can be provided so as to be spaced apart from the upper surface of the battery cell 100 or the battery module 10 in a vertical direction by a predetermined distance. Thereby, even if the reinforcing member 400 overlaps the vent hole H, the vent gas or the like can smoothly be discharged upward through the vent hole H and flow into the vent passage S.

[0076] The position, shape, etc. of the reinforcing member 400 can be configured to be different depending on the position where the vent hole H is formed, and the area, number, etc. of the reinforcing member 400 can be freely adjusted depending on the area, number, etc. of the vent hole H.

[0077] FIG. 8 is a cross-sectional view of a battery pack according to an embodiment of the present invention. For example, FIG. 8 may be a cross-sectional view taken along the line II-II' of FIG. 1.

[0078] Referring to FIG. 8, at least a part of the reinforcing member 400 can be configured to protrude from the pack lead 300 toward the battery cell 100 side. That is, at least a part of the reinforcing member 400 can be configured to protrude downward from the pack lead 300.

[0079] Specifically, the reinforcing member 400 may include a protruding portion 410 and a supporting portion 420. The protruding portion 410 may be configured to protrude from the pack lead 300. The protruding portion 410 may be provided at the central portion of the reinforcing member 400. At this time, the lower surface of the protruding portion 410 may be configured as a flat surface.

[0080] According to the above embodiment of the present invention, when a thermal event occurs and the pack lead 300 tends to be deformed by heat, the lower surface of the protruding portion 410 presses the upper surface of the battery cell 100 or the module case 11, thereby preventing a part of the pack lead 300 from moving downward. Further, even when an external impact is applied, the lower surface of the protruding portion 410 can be supported by the upper surface of the battery cell 100 or the module case 11. Thus, according to the above embodiment of the present invention, the deformation of the pack lead 300 can be surely prevented and the vent flow path S can be appropriately secured.

[0081] The supporting portion 420 may be configured to extend from the protruding portion 410 to both sides. The supporting portion 420 may be formed by bending both side ends of the reinforcing member 400. Such a supporting portion 420 may be provided to contact and support the pack lead 300. The supporting portion 420 may be in surface contact with the lower surface of the pack lead 300. Therefore, the supporting portion 420 may have an outer surface parallel to the lower surface of the pack lead 300. At this time, it is preferable to secure the contact area between the pack lead 300 and the supporting portion 420. According to the above embodiment of the present invention, the supporting portion 420 can stably fix the pack lead 300 and the reinforcing member 400. Therefore, the shape, position, etc. of the pack lead 300 can be stably maintained without being deformed by external vibration, impact, heat, etc.

[0082] FIG. 9 is a cross-sectional view of a battery pack according to another embodiment of the present invention. For example, FIG. 9 may be a cross-sectional view taken along the line II-II' of FIG. 1.

[0083] On the one hand, referring to FIG. 9, the battery pack 1 according to another embodiment of the present invention may include a reinforcing member 400 formed with an insulating coating layer 500. The insulating coating layer 500 may be formed on the outer surface of the reinforcing member 400. The insulating coating layer 500 may be formed on the portion of the reinforcing member 400 that is exposed from the pack lead 300. That is, the insulating coating layer 500 may be formed on the remaining surfaces of the reinforcing member 400 except for the surface that contacts the pack lead 300. For example, the insulating coating layer 500 may be provided so as to surround the lower surfaces of the protruding portion 410 and the support portion 420.

[0084] The insulating coating layer 500 may be configured to electrically insulate the reinforcing member 400 and prevent heat conduction and the like. For this reason, the insulating coating layer 500 may be made of a material such as polyurethane or silicon. According to the above embodiment of the present invention, by providing the insulating coating layer 500, the insulating and / or heat conduction prevention effect can be surely maintained even for the portion of the reinforcing member 400 that is exposed to vent gas, spark, etc.

[0085] The insulating coating layer 500 may be a coating layer formed by directly foaming on the outer surface of the reinforcing member 400 after assembling the reinforcing member 400 to the pack lead 300. According to the above embodiment of the present invention, the outer surface of the reinforcing member 400 can be easily covered as compared with attaching a separately prepared sheet-like insulating member. In addition, the process of separately manufacturing an insulating member according to the size and shape of the outer surface of the reinforcing member 400 can be omitted, and the cost and time required for manufacturing the battery pack 1 can be reduced.

[0086] FIG. 10 is a top perspective view of a battery pack according to an embodiment of the present invention.

[0087] On the one hand, referring to FIG. 10, the pack tray 200 according to an embodiment of the present invention may include a base frame 210 and a side frame 220.

[0088] The base frame 210 can form the lower surface of the packet tray 200 and can be configured in a rectangular plate shape. And the base frame 210 can be configured such that a plurality of battery cells 100 are placed on the upper surface. Further, the base frame 210 has a flat upper surface and can be configured such that a plurality of battery cells 100 or module cases 11 are stably placed thereon.

[0089] The side frame 220 may extend upward from each corner of the base frame 210. The side frame 220 has a plurality of unit wall bodies and can be provided so as to surround a plurality of battery cells 100 or battery modules 10. More specifically, the side frame 220 can form the side surface of the packet tray 200 including a rear wall body located at the +Y direction side end of the base frame 210, a right side wall body located at the +X direction side end, a front wall body located at the -Y direction side end, and a left side wall body located at the -X direction side end.

[0090] Also, the packet tray 200 may include a vent portion 230. The vent portion 230 can be configured to discharge the gas generated in the battery cell 100 housed therein to the outside of the packet tray 200. The vent portion 230 can take the form of a hole penetrating between the inside and the outside of the packet tray 200. Alternatively, the vent portion 230 can be configured to be attachable to the hole of the packet tray 200 and can take the form of a vent device configured to operate when vent gas is generated inside the packet tray 200.

[0091] The vent part 230 can be provided on the side surface of the pack tray 200, that is, on the side frame 220. A plurality of vent parts 230 can be provided. The vent part 230 can be located on at least a part of the unit wall bodies among the plurality of unit walls of the side frame 220. Also, the vent part 230 may be separately formed on two or more unit wall bodies respectively, or two or more vent parts 230 may be formed on one unit wall body. For example, as shown in FIG. 10, a plurality of vent parts 230 can be provided on the front wall body and the rear wall body respectively. Also, the plurality of vent parts 230 can be provided so as to be symmetric with respect to the central axis of the side frame 220.

[0092] According to the above embodiment of the present invention, in the event of an abnormal situation of the battery cell 100, high-temperature gas or the like can be discharged in both directions of the pack tray 200, so it is easy to discharge the gas to the outside of the pack tray 200 more quickly.

[0093] On the other hand, the number and position of the vent parts 230 described based on the embodiment of FIG. 10 are merely examples, and it goes without saying that they can be changed to a plurality of other numbers and positions.

[0094] On the other hand, the pack tray 200 may further include a center beam 240 and a cross beam 250. The center beam 240 and the cross beam 250 can be configured to partition between a plurality of battery cells 100 or battery modules 10. The center beam 240 and the cross beam 250 can be provided between a plurality of battery cells 100 and the side frame 220 where the vent part 230 is provided. For example, the center beam 240 is formed in a partition wall shape that extends longitudinally in the front-rear direction and can be interposed between adjacent battery modules 10 in the left-right direction. Also, the cross beam 250 is formed in a partition wall shape that extends longitudinally in the left-right direction and can be interposed between adjacent battery modules 10 in the front-rear direction.

[0095] According to such an embodiment, it is possible to prevent heat or flame from directly facing between the cell assembly or battery module 10 in which the accommodation space is separated by the center beam 240 and the cross beam 250.

[0096] Further, the center beam 240 and the cross beam 250 may be provided at a predetermined interval from the pack lead 300. That is, the center beam 240 and the cross beam 250 may be provided so as to be separated by a predetermined distance without at least a part of the upper end contacting the lower surface of the pack lead 300.

[0097] On the other hand, the plurality of reinforcing members 400 may be provided symmetrically about the center beam 240. A plurality of reinforcing members 400 may be provided between the center beam 240 and the side frame 220. For example, as in the embodiment shown in FIG. 10, two reinforcing members 400 may be provided between the center beam 240 and the side frames 220 on both sides. Such two reinforcing members 400 may be arranged at a distance D from each other, and a vent flow path S may be formed between the two reinforcing members 400.

[0098] The reinforcing member 400 may be formed to extend in a long shape toward the vent portion 230. Thereby, vent gas or the like moving in the vent flow path S between the two reinforcing members 400 can be directed toward the vent portion 230. At this time, according to an embodiment of the present invention, the two reinforcing members 400 may be provided parallel to each other so that the interval D between the reinforcing members 400 is maintained constant.

[0099] According to the above embodiment of the present invention, when a thermal event of the battery cell 100 occurs, the reinforcing member 400 guides the vent gas toward the vent portion 230, so that the vent gas can be quickly discharged to the outside of the pack tray 200. Thereby, an increase in the internal pressure in the pack tray 200 can be prevented, and further chain ignition of other battery cells 100 can be prevented.

[0100] The reinforcing members 400 can be provided in plural at the central portion and the edge portion of the pack lead 300 respectively. As in the embodiment shown in FIG. 10, two reinforcing members 400 can be provided on both sides with reference to the center beam 240 of the pack lead 300. At the same time, two reinforcing members 400 can be provided at both edge portions of the pack lead 300 respectively.

[0101] At this time, the distance d between the two reinforcing members 400 coupled to the central portion of the pack lead 300 can be made smaller than the distance D between one of the reinforcing members 400 and the reinforcing member 400 coupled to the edge portion of the pack lead 300. That is, the density of the reinforcing members 400 provided at the central portion of the pack lead 300 can be configured to be higher than that at the edge portion of the pack lead 300.

[0102] The central portion of the pack lead 300 is more likely to undergo thermal deformation than the edge portion of the pack lead 300. However, in the above embodiment of the present invention, the reinforcing members 400 arranged with a narrow interval at the central portion can fix the pack lead 300 more stably. Thereby, it is possible to prevent the central portion of the pack lead 300 from lifting from the pack tray 200.

[0103] On the other hand, referring to FIGS. 2, 4, and 10, the reinforcing member 400 can be coupled to the pack lead 300. In particular, the reinforcing member 400 can be provided in a form coupled to the lower surface of the pack lead 300. The reinforcing member 400 can be coupled and fixed to the pack lead 300 by a coupling member 600 such as a bolt. At this time, as shown in FIG. 10, the reinforcing member 400 can be configured to be placed on a cross beam 250 extending in a long shape in the left - right direction. Specifically, the reinforcing member 400 is placed on the cross beam 250, and when the pack lead 300 is placed on the reinforcing member 400, the pack lead 300, the reinforcing member 400, and the cross beam 250 can be coupled to each other by a coupling member 600 such as a bolt at the upper portion of the pack lead 300.

[0104] According to the above embodiment of the present invention, a coupling and fixing structure between the reinforcing member 400 and the pack lead 300 can be realized with a simple structure. Further, according to the above embodiment of the present invention, since the reinforcing member 400 is manufactured to be pre-mounted on the cross beam 250, when the pack lead 300 is coupled to the upper part of the pack tray 200, the reinforcing member 400 can be automatically attached to the cross beam 250. Therefore, the time and cost in the manufacture of the battery pack 1 are reduced, and as a result, productivity is improved. Also, since the reinforcing member 400 can be stably fixed to the cross beam 250, the rigidity of the reinforcing member 400 can be further ensured.

[0105] FIG. 11 is a top perspective view of a battery pack according to still another embodiment of the present invention.

[0106] According to still another embodiment of the present invention, the reinforcing member 400' located at the central part of the pack lead 300 can be configured such that the central part is bent. It can be said that the reinforcing member 400' is formed in a slanted line. Specifically, the distance D' between two adjacent reinforcing members 400, 400' can be configured to become narrower as it approaches the vent part 230. Here, the reinforcing members 400, 400' can mean the reinforcing members 400, 400' provided between the center beam 240 and the side frame 220. That is, in the above embodiment, the width D' of the vent flow path S can become narrower as it approaches the vent part 230.

[0107] According to the above embodiment of the present invention, the reinforcing members 400, 400' can guide the vent gas etc. in the vent flow path S toward the vent part 230. Thereby, vent gas, sparks, etc. can be smoothly discharged to the outside of the battery pack 1, and thermal runaway between the battery modules 10 can be suppressed or prevented.

[0108] FIG. 12 is a cross-sectional view of a battery pack according to still another embodiment of the present invention. For example, FIG. 12 can be a cross-sectional view taken along line II-II' of FIG. 1.

[0109] According to still another embodiment of the present invention, among the plurality of reinforcing members 400, at least a part of the width W of the reinforcing member 400 coupled to the central portion of the pack lead 300 may be configured to be wider than the width w of the reinforcing member 400 coupled to the edge portion of the pack lead 300. In particular, the width of the central portion of the reinforcing member 400 coupled to the central portion of the pack lead 300 may be configured to be wider than other portions. At this time, as the width of the support portion 420 of the reinforcing member 400 becomes wider, it becomes possible to prevent the pack lead 300 from moving upward and deforming.

[0110] Alternatively, different from this embodiment, at least a part of the height of the reinforcing member 400 coupled to the central portion of the pack lead 300 may be configured to be larger than the height of the reinforcing member 400 coupled to the edge portion of the pack lead 300.

[0111] According to the above embodiment of the present invention, by providing the reinforcing member 400 having a wide width at the central portion of the pack lead 300, the central portion of the pack lead 300 can be fixed more stably. Thereby, it is possible to more effectively prevent the central portion of the pack lead 300 from lifting from the pack tray 200.

[0112] FIG. 13 is a schematic perspective view of an automobile including a battery pack according to an embodiment of the present invention.

[0113] Referring to FIG. 13, an automobile 3 according to an embodiment of the present invention may include one or more battery packs 1 according to the above-described embodiment. The automobile 3 according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile 3 includes four-wheel automobiles and two-wheel automobiles. The automobile 3 may be driven by being supplied with power from the battery pack 1 or the battery module 10 according to an embodiment of the present invention.

[0114] The preferred embodiments of the present invention have been illustrated and described above. However, the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made by those with ordinary knowledge in the technical field to which the invention pertains without departing from the gist of the invention claimed in the claims. Such modifications should not be individually understood apart from the technical idea and prospect of the present invention.

Explanation of Reference Numerals

[0115] 1 Battery pack 3 Automobile 10 Battery module 11 Module case 100 Battery cell 200 Pack tray 210 Base frame 220 Side frame 230 Vent part 240 Center beam 250 Cross beam 300 Pack lead 400, 400’ Reinforcing member 400 Reinforcing member 400’ Reinforcing member 410 Protrusion 420 Support part 500 Insulating coating layer 600 Coupling member

Claims

1. A plurality of battery cells, a pack tray with an open top for accommodating the plurality of battery cells, a pack lid configured to cover the open top of the pack tray, and a reinforcing member coupled to the pack lid and configured to suppress deformation of the pack lid. A battery pack comprising the above.

2. A vent flow path is formed between the pack lid and the battery cells and is configured such that vent gas generated in the battery cells can flow therethrough. The battery pack according to claim 1, wherein the reinforcing member is configured to maintain the height of the vent flow path.

3. The battery pack according to claim 1, wherein the reinforcing member is made of a material having a lower coefficient of thermal expansion than the pack lid.

4. The battery pack according to claim 1, wherein the reinforcing member is formed in a shape that extends longitudinally along the stacking direction of the plurality of battery cells.

5. The battery pack according to claim 1, wherein a plurality of the reinforcing members are provided at a predetermined distance apart in the horizontal direction.

6. Further comprising a module case that houses the plurality of battery cells in an internal space and has at least one vent hole formed on the upper side to communicate with the internal space, The battery pack according to claim 5, wherein the vent hole is disposed between adjacent ones of the reinforcing members.

7. The battery pack according to claim 1, wherein at least a part of the reinforcing member is configured to protrude from the pack lid toward the battery cell side.

8. The reinforcing member comprises a protruding portion configured to protrude from the pack lid, and support portions that extend from both sides of the protruding portion and are supported by the pack lid. The battery pack according to claim 7.

9. The battery pack according to claim 1, further comprising an insulating coating layer formed on an outer surface of the reinforcing member.

10. The pack tray comprises a vent portion configured to discharge vent gas to the outside of the pack tray, and the battery pack according to claim 5, wherein the reinforcing member is formed to extend longitudinally toward the vent portion.

11. The battery pack according to claim 10, wherein the distance between adjacent ones of the reinforcing members is configured to become narrower as it approaches the vent portion.

12. Among the plurality of the reinforcing members, at least a part of the width of the reinforcing member coupled to the central portion of the pack lead is configured to be wider than the width of the reinforcing member coupled to the edge portion of the pack lead. The battery pack according to claim 5.

13. An automobile including the battery pack according to any one of claims 1 to 12.

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