Battery pack

Abstract

The present invention discloses a battery pack including a case having an open top and providing an interior space, a plurality of battery cells accommodated inside the case, and a pack cover covering the top of the case and including a flat portion and a protrusion protruding above the flat portion.

Description

[Technical Field]

[0001] The present invention relates to a battery pack.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0181135, filed on December 13, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] As demand for portable electronic products such as laptops, video cameras, and mobile phones has grown rapidly, and as the commercialization of robots and electric vehicles has progressed in earnest, research into high-performance batteries that can be repeatedly charged and discharged has been actively conducted.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention due to their advantages of being able to be freely charged and discharged since they have almost no memory effect compared to nickel-based secondary batteries, an extremely low self-discharge rate, and a high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively, and include an electrode assembly in which a positive electrode plate coated with the positive electrode active material and a negative electrode plate coated with the negative electrode active material are disposed with a separator interposed therebetween, and an exterior material, such as a battery case, that hermetically houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries can be classified into can-type secondary batteries in which an electrode assembly is housed in a metal can and pouch-type secondary batteries in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] In recent years, secondary batteries have been widely used for driving and storing energy not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS). A plurality of such secondary batteries are electrically connected and housed together inside a module case to form a battery module. A plurality of such battery modules are connected to form a battery pack.

[0008] However, when multiple secondary batteries (battery cells) or multiple battery modules are densely packed in a small space, they may be vulnerable to thermal events. In particular, if an event such as thermal runaway occurs in one battery cell, high-temperature gas, flames, and heat may be generated. If such gas, flame, or heat is transmitted to other battery cells included in the same battery module, an explosive chain reaction such as thermal propagation may occur. This chain reaction may not only cause accidents such as fires or explosions in the battery module, but also fires or explosions in other battery modules.

[0009] Furthermore, in the case of medium- to large-sized battery packs, such as those used in electric vehicles, the risk of thermal chain reactions may be even higher because they include a large number of battery cells and battery modules in order to increase output and / or capacity. Furthermore, in the case of battery packs installed in electric vehicles, users such as drivers may be present nearby. Therefore, if a thermal event occurring in a specific battery cell or module is not properly controlled and a chain reaction occurs, it may result in significant property damage as well as loss of life. Therefore, it is necessary to improve the thermal safety of battery packs by properly controlling thermal events occurring in battery cells and modules. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention is directed to overcoming the above-mentioned problems and other problems.

[0011] Another object of the present invention is to provide a battery pack with improved electrical safety when a thermal event occurs.

[0012] It is yet another object of the present invention to provide a battery pack capable of suppressing heat propagation caused by the diffusion of vent gas.

[0013] It is yet another object of the present invention to provide a battery pack that can quickly vent vent gas to the outside of the case when a thermal event occurs.

[0014] It is yet another object of the present invention to provide a battery pack that allows for easy control of venting when a thermal event occurs. [Means for solving the problem]

[0015] To achieve the above object, a battery pack according to one aspect of the present invention includes a case having an open top and providing an interior space, a plurality of battery cells housed inside the case, and a pack cover covering the top of the case and having a flat portion and a protrusion protruding above the flat portion.

[0016] The flat plate portion may also surround the protrusion.

[0017] The protrusion may also form a space therein.

[0018] The case may further include a base plate and a peripheral wall provided along a periphery of the base plate, and the flat plate portion may be coupled to the peripheral wall.

[0019] Furthermore, a plurality of the protruding portions may be provided, and each of the plurality of protruding portions may be surrounded by the flat plate portion.

[0020] The peripheral wall may also comprise a front wall.

[0021] The battery pack may further include a vent device provided on the front wall, and the protrusion may extend along the front-rear direction.

[0022] Furthermore, a plurality of the protrusions may be provided, and the flat plate portion may include a partition located between two adjacent protrusions, the partition extending toward the front wall.

[0023] The battery pack may further include a partition wall that divides the internal space and extends in a front-rear direction, and the partition may face the partition wall.

[0024] The compartment may also be coupled to the partition wall.

[0025] The battery pack may further include a module case located inside the case and accommodating the plurality of battery packs, and the protrusion may face an upper surface of the module case.

[0026] The module case may also have a vent hole formed on the top surface.

[0027] A motor vehicle according to another aspect of the present invention includes a battery pack according to an aspect of the present invention. [Effects of the Invention]

[0028] According to one aspect of the present invention, the thermal safety of a battery pack can be improved.

[0029] According to one aspect of the present invention, it is possible to suppress the occurrence of heat propagation due to the diffusion of vent gas.

[0030] According to one aspect of the present invention, when a thermal event occurs, vent gas can be quickly vented to the exterior of the case.

[0031] According to one aspect of the present invention, venting of a battery pack can be easily controlled.

[0032] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, are intended to facilitate a further understanding of the technical concepts of the present invention; therefore, the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a diagram illustrating a battery pack according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a partial configuration of the battery pack of FIG. 1 in an separated state. [Figure 3] FIG. 2 is a diagram showing a pack cover of the battery pack of FIG. 1. [Figure 4] 4 is a view of the pack cover of FIG. 3 viewed from another direction. FIG. [Figure 5] FIG. 5 is a diagram schematically illustrating a cross-sectional configuration taken along the line BB' in FIG. [Figure 6] FIG. 3 is a diagram showing the battery module of FIG. 2. [Figure 7] FIG. 2 is a diagram schematically illustrating a cross-sectional configuration taken along the line AA' in FIG. [Figure 8] FIG. 8 is an enlarged view of part C in FIG. 7. [Figure 9] This is an enlarged view of part C in Figure 7 when a thermal event occurs. [Figure 10] FIG. 1 illustrates the flow of vent gas when a thermal event occurs. [Figure 11] FIG. 9 shows a variation of FIG. 8. [Figure 12] FIG. 9 is a diagram showing another variation of FIG. 8. [Figure 13]10A and 10B are diagrams illustrating a battery pack according to another embodiment of the present invention. [Figure 14] FIG. 14 is a view showing the pack cover of FIG. 13. [Figure 15] 15 is a view of the pack cover of FIG. 14 viewed from another direction. [Figure 16] 15 is a diagram schematically showing a cross-sectional configuration taken along the cutting line EE' in FIG. 14. FIG. [Figure 17] FIG. 14 is a diagram schematically showing a cross-sectional configuration taken along the line DD' in FIG. [Figure 18] 14 is a diagram illustrating a schematic cross-sectional configuration along the section line DD' in FIG. 13 when a thermal event occurs. [Figure 19] FIG. 1 illustrates the flow of vent gas when a thermal event occurs. DETAILED DESCRIPTION OF THE INVENTION

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

[0035] Therefore, it should be understood that the 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 the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can replace them at the time of this application.

[0036] The +X axis direction can also be referred to as the front, the −X axis direction as the rear, the +Y axis direction as the up, the −Y axis direction as the down, the +Y axis direction as the right, and the −Y axis direction as the left.

[0037] Fig. 1 is a diagram showing a battery pack according to an embodiment of the present invention, and Fig. 2 is a diagram showing a partial configuration of the battery pack in Fig. 1. Referring to Fig. 1 and Fig. 2, the battery pack according to an embodiment of the present invention includes a case 100, a plurality of battery cells 220, and a pack cover 500.

[0038] The case 100 may provide a space inside. The case 100 may have an open top. The case 100 may have a cubic shape. The case 100 may form the exterior of a battery pack.

[0039] A plurality of battery cells 220 may be provided. In this case, the battery cell 220 may refer to a secondary battery. The battery cell 220 may be pouch-shaped. The battery cell 220 may extend along the Y-axis direction. The plurality of battery cells 220 may be stacked along the X-axis direction. The plurality of battery cells 220 may be housed inside the case 100.

[0040] The pack cover 500 may be plate-shaped. The pack cover 500 may be square-shaped. The pack cover 500 may cover the interior space of the case 100. The pack cover 500 may also cover the top surface of the case 100. The pack cover 500 may include a flat plate portion 510 and a protruding portion 520. The flat plate portion 510 may be a flat plate. The protruding portion 520 may protrude upward from the flat plate portion 510. The flat plate portion 510 and the protruding portion 520 may be integrally formed.

[0041] This configuration of the present invention can improve the thermal safety of the battery pack. When a thermal event occurs, vent gas can be discharged in the +Z-axis direction. At this time, the protrusion 520 can contain the vent gas and guide its flow. This prevents the vent gas from dispersing and suppresses the propagation of the thermal event. In addition, the protrusion 520 allows the pack cover 500 to easily deform. The protrusion 520 can expand and deform upward or outward due to the vent gas. This makes it easy to contain or collect the vent gas.

[0042] 3 is a diagram showing the pack cover 500 of the battery pack of FIG. 1, FIG. 4 is a diagram showing the pack cover 500 of FIG. 3 viewed from another direction, and FIG. 5 is a diagram showing a schematic cross-sectional configuration along the cutting line B-B' of FIG. 4.

[0043] 3 to 5, the flat portion 510 may surround the protrusion 520. The flat portion 510 may be provided along the periphery of the pack cover 500. The protrusion 520 may be located inside the flat portion 510. The flat portion 510 may be coupled to the case 100. The protrusion 520 may be provided in an area where the battery cell 220 is located.

[0044] This configuration of the present invention can improve the assembly of the battery pack. By joining the flat plate portion 510 of the pack cover 500 to the case 100, the pack cover 500 and the case 100 can be easily joined.

[0045] 3 to 5, the protrusion 520 may form a space S1 therein. The protrusion 520 may be formed by bending a portion of a flat plate. The thickness of the protrusion 520 may be substantially the same as the thickness of the flat plate portion 510. The protrusion 520 may form a space S1 therein.

[0046] This configuration of the present invention can improve the thermal safety of the battery pack. When a thermal event occurs, vent gas can be discharged in the +Z-axis direction. At this time, the vent gas is contained or collected in the space S1 formed by the protrusion 520. This prevents the vent gas from dispersing, thereby suppressing the propagation of the thermal event.

[0047] 3 to 5 , a plurality of protrusions 520 may be provided. The plurality of protrusions 520 may be surrounded by the flat plate portion 510. The plurality of protrusions 520 may also be partitioned by the flat plate portion 510. The plurality of protrusions 520 may be positioned to correspond to a portion of the plurality of battery cells 220, respectively.

[0048] This configuration of the present invention can improve the thermal safety of the battery pack. By providing multiple protrusions 520, the containment or collection of vent gas can be managed in smaller units, which can further suppress the propagation of thermal events.

[0049] 1 to 5, the case 100 may include a base plate 110 and a peripheral wall 120. The base plate 110 may be flat or rectangular.

[0050] The peripheral wall 120 may be provided along the periphery of the base plate 110. The peripheral wall 120 may be coupled, fastened, fixed, or attached to the top surface of the base plate 110. The peripheral wall 120 may also be made up of multiple parts. The peripheral wall 120 may include a front wall 121, a rear wall, and side walls.

[0051] The plate portion 510 may be fastened, bonded, attached or fixed to the peripheral wall 120. The plate portion 510 may also be fastened to the upper side or top surface of the peripheral wall 120.

[0052] This configuration of the present invention can improve the assembly of the battery pack. By joining the flat plate portion 510 of the pack cover 500 to the case 100, the pack cover 500 and the case 100 can be easily joined.

[0053] 1 to 5, a battery pack according to an embodiment of the present invention may include a vent device 400. The vent device 400 may establish or block communication between the inside and outside of the case 100. The vent device 400 may discharge vent gas to the outside when the internal pressure of the case 100 becomes high. For example, the vent device 400 may be a gas valve.

[0054] A plurality of vent devices 400 may be provided. The plurality of vent devices 400 may be provided on the front wall 121. The plurality of vent devices 400 may be arranged along the left-right direction or the Y-axis direction.

[0055] The protrusion 520 may extend along the front-rear direction or the X-axis direction. Alternatively, the protrusion 520 may extend toward the front wall 121.

[0056] According to this configuration of the present invention, the protrusion 520 can guide the vent gas toward the vent device 400. This allows the vent gas to be quickly discharged to the outside of the case 100. This can further suppress the propagation of a thermal event.

[0057] 1 to 5, the flat plate portion 510 may include a partition portion 511 and a connecting portion 512. The partition portion 511 may be located between adjacent protrusions 520. Alternatively, the partition portion 511 may separate adjacent protrusions 520. The connecting portion 512 may be located along the periphery of the pack cover 500. The connecting portion 512 may be connected to the peripheral wall 120.

[0058] The partition 511 may extend along the front-rear direction or the X-axis direction. Alternatively, the partition 511 may extend toward the front wall 121.

[0059] In accordance with this configuration of the present invention, the provision of multiple protrusions 520 allows for the containment or collection of vent gas to be managed in smaller increments. Also, the discharge of vent gas can be managed in smaller increments. This allows for the vent gas to be discharged more quickly, further reducing the propagation of a thermal event.

[0060] 6 is a diagram showing the battery module 200 of FIG. 2, FIG. 7 is a diagram showing a schematic cross-sectional configuration along the section line A-A' of FIG. 1, FIG. 8 is an enlarged view of part C of FIG. 7, and FIG. 9 is an enlarged view of part C of FIG. 7 when a thermal event occurs.

[0061] 6 to 9, the battery pack may include a plurality of battery modules 200. The battery module 200 may include a plurality of battery cells 220 and a module case 210 (100). The module case 210 (100) may form the exterior of the battery module 200. The module case 210 (100) may be cubic. The module case 210 (100) may extend in the left-right direction or the Y-axis direction. The battery module 200 may be housed in the internal space of the case 100. The plurality of battery cells 220 may be housed in the module case 210 (100).

[0062] Also, the protrusion 520 may face the upper surface of the module case 210 (100). Alternatively, the protrusion 520 may cover the upper surface of the module case 210 (100).

[0063] This configuration of the present invention can improve the thermal safety of the battery pack. When a thermal event occurs, vent gas can be discharged from the module case 210 (100) in the +Z-axis direction. At this time, the protrusion 520 can contain the vent gas and guide its flow. This prevents the vent gas from dispersing and suppresses the propagation of the thermal event to adjacent battery modules 200.

[0064] 6 to 9, the module case 210 (100) may include a vent hole 211. A plurality of vent holes 211 may be provided. The plurality of vent holes 211 may be formed on the top surface of the case 100. The plurality of vent holes 211 may provide communication between the outside and the inside of the module case 210 (100).

[0065] According to this configuration of the present invention, the vent gas can be easily collected and the dispersion of the vent gas can be further suppressed. The vent gas passes through the vent hole 211 and is discharged toward the protruding portion 520.

[0066] 6 to 9 , a battery pack according to an embodiment of the present invention may further include a partition wall 300. The partition wall 300 may divide the interior space of the case 100. The partition wall 300 may include a center wall 310 and a cross wall 320. The center wall 310 may extend in the front-rear direction or the X-axis direction. The center wall 310 may be located in the center of the interior space of the case 100. Furthermore, the partition portion 511 may face the center wall 310. Furthermore, the partition portion 511 may extend along the center wall 310. The cross wall 320 may extend in the left-right direction or the Y-axis direction. A plurality of cross walls 320 may be provided. The plurality of cross walls 320 may be arranged along the front-rear direction or the X-axis direction.

[0067] This configuration of the present invention can improve the thermal safety of the battery pack. The partition 511 is disposed opposite the center wall 310, which can improve the alignment between the protrusion 520 and the battery module 200. This can improve the accuracy of containing or collecting vent gas.

[0068] 10 is a diagram showing the flow of vent gas when a thermal event occurs. Referring to FIG. 10, when a thermal event occurs in the battery module 200, the vent gas may flow forward or in the +X-axis direction along the protrusion 520. In addition, movement of the vent gas toward the +Y-axis or -Y-axis may be suppressed. This allows the vent gas to be quickly discharged to the outside of the case 100 through the vent device 400 without propagating the thermal event to an adjacent battery module 200.

[0069] Fig. 11 is a diagram showing a variation of Fig. 8. Referring to Fig. 11, the center wall 310 may support the partition 511. Alternatively, the center wall 310 may contact the partition 511. This can prevent a gap from forming between the center wall 310 and the partition 511 even if a thermal event occurs.

[0070] According to this configuration of the present invention, the diffusion of vent gas can be more reliably suppressed.

[0071] Fig. 12 is a diagram showing another variation of Fig. 8. Referring to Fig. 12, the compartment 511 may be coupled to the partition wall 300. The compartment 511 may be fastened, coupled, fixed, or attached to the upper portion or upper end of the center wall 310. Alternatively, the compartment 511 and the center wall 310 may be coupled by welding. Alternatively, the battery pack may further include a fastening member S that fastens the compartment 511 and the center wall 310 together.

[0072] According to this configuration of the present invention, the diffusion of vent gas can be more reliably suppressed.

[0073] FIG. 13 is a view showing a battery pack according to another embodiment of the present invention, FIG. 14 is a view showing pack cover 500 of FIG. 13, FIG. 15 is a view of pack cover 500 of FIG. 14 viewed from another direction, and FIG. 16 is a view schematically showing a cross-sectional configuration along section line E-E' of FIG. 14.

[0074] 13 to 16, a pack cover 500 of a battery pack according to another embodiment of the present invention may include multiple compartments 511. The pack cover 500 may include four protrusions 520 and three compartments 511 that separate the four protrusions 520. The multiple compartments 511 may separate the protrusions 520 into smaller units.

[0075] The plurality of partitions 511 or the plurality of protrusions 520 may extend along the front-rear direction or the X-axis direction, and the plurality of partitions 511 or the plurality of protrusions 520 may be arranged along the left-right direction or the Y-axis direction.

[0076] By providing multiple protrusions 520, the space S2 formed by the protrusions 520 can be managed in smaller units, which allows the storage or collection of vent gas to be managed in smaller units, thereby further suppressing the propagation of a thermal event.

[0077] FIG. 17 is a diagram showing a schematic cross-sectional configuration along the section line D-D' in FIG. 13, FIG. 18 is a diagram showing a schematic cross-sectional configuration along the section line D-D' in FIG. 13 when a thermal event occurs, and FIG. 19 is a diagram showing the flow of vent gas when a thermal event occurs.

[0078] 17 to 19, when a thermal event occurs in the battery module 200, the vent gas may flow forward or in the +X-axis direction along the protrusion 520. In addition, the vent gas may be restricted from moving in the +Y-axis or -Y-axis direction. Even when a thermal event occurs in a certain battery module 200, the protrusion 520 that receives or collects the vent gas may differ depending on which part of the battery module 200 the vent gas is discharged from.

[0079] For example, if vent gas is generated in the central portion, the protrusion 520a facing that portion can expand to contain or capture the vent gas. This can also prevent the vent gas from diffusing into the space S2 formed by the adjacent protrusion 520b. This can also prevent the vent gas from diffusing beyond the center wall 310 in the −Y axis direction.

[0080] This allows the vent gas to be quickly discharged outside the case 100 through the vent device 400 without propagating the thermal event to adjacent battery modules 200 or to other parts of the battery module 200 where the thermal event occurred.

[0081] In addition, the battery pack according to an embodiment of the present invention may further include various components, for example, battery pack components known at the time of filing of the present invention, such as a battery management system (BMS), bus bars, relays, and current sensors.

[0082] A vehicle according to an embodiment of the present invention includes the battery pack according to the embodiment of the present invention described above. The battery pack according to an embodiment of the present invention may be applied to vehicles such as electric vehicles and hybrid vehicles. In addition to the battery pack, the vehicle according to an embodiment of the present invention may further include various other components included in the vehicle, such as a body, a motor, and a control device such as an electronic control unit (ECU).

[0083] Meanwhile, although terms indicating directions such as up, down, left, right, front, and rear are used in this specification, it will be obvious to those skilled in the art that these terms are used for the convenience of explanation and may vary depending on the position of the object or the position of the observer, etc.

[0084] As described above, the present invention has been described using limited embodiments and drawings, but the present invention is not limited thereto, and it goes without saying that various changes and modifications can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the claims.

Claims

1. A case with an open top that provides internal space, a plurality of battery cells housed inside the case; a pack cover that covers the top surface of the case and has a flat portion and a protrusion that protrudes above the flat portion.

2. The battery pack according to claim 1 , wherein the flat portion surrounds the protrusion.

3. The battery pack according to claim 1 , wherein the protrusion defines a space therein.

4. The case is A base plate and a peripheral wall provided along the periphery of the base plate, The battery pack according to claim 1 , wherein the flat portion is coupled to the peripheral wall.

5. The protrusion is provided in plurality, The battery pack according to claim 1 , wherein each of the plurality of protrusions is surrounded by the flat plate portion.

6. the peripheral wall comprises a front wall; the battery pack further includes a vent device disposed on the front wall; The battery pack according to claim 4 , wherein the protrusion extends along the front-rear direction.

7. The protrusion is provided in plurality, the flat plate portion includes a partition portion located between two adjacent protrusions, The battery pack of claim 6 , wherein the compartment extends toward the front wall.

8. The interior space is divided into two parts, and the interior space is divided into two parts. The ... The battery pack according to claim 7 , wherein the compartment faces the partition wall.

9. The battery pack of claim 8 , wherein the compartment is coupled to the partition wall.

10. a module case located inside the case and accommodating a plurality of the battery packs; The battery pack according to claim 1 , wherein the protrusion faces the opposite surface of the module case.

11. The battery pack according to claim 10 , wherein the module case has a vent hole formed on an upper surface thereof.

12. A motor vehicle comprising a battery pack according to any one of claims 1 to 11.

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