Battery pack

Abstract

A battery pack is disclosed. The battery pack according to an embodiment of the present invention comprises: a case having an open top, and providing an inner space; a plurality of battery cells accommodated in the case; and a pack cover covering the top of the case, and provided with flat parts and protruding parts protruding upward past the flat parts.

Description

battery pack

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

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

[0003] As demand for portable electronic products such as laptops, video cameras, and mobile phones rapidly increases and the commercialization of robots and electric vehicles becomes more widespread, research into high-performance secondary batteries capable of repeated charging and discharging is actively underway.

[0004] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based secondary batteries.

[0005] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative electrode active materials, respectively. Lithium secondary batteries comprise an electrode assembly comprising positive and negative plates coated with the positive and negative electrode active materials, respectively, with a separator interposed between them, and an outer case, i.e., a battery case, that seals and encloses the electrode assembly together with an electrolyte.

[0006] In general, lithium secondary batteries can be classified into can-type secondary batteries in which the electrode assembly is built into a metal can and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

[0007] Recently, secondary batteries have been widely used for power and energy storage, not only in small devices like portable electronic devices but also in medium- to large-sized devices like electric vehicles and energy storage systems (ESS). Multiple secondary batteries can be electrically connected and housed within a module case to form a single battery module. Furthermore, multiple such battery modules can be connected to form a single battery pack.

[0008] However, when multiple secondary batteries (battery cells) or battery modules are densely packed in a confined space, they can be vulnerable to thermal events. Specifically, if a thermal runaway event occurs in a single battery cell, high-temperature gases, flames, and heat can be generated. If these gases, flames, or heat are transferred to other battery cells within the same battery module, an explosive chain reaction, such as thermal propagation, can occur. This chain reaction can not only cause a fire or explosion in the battery module in question, but can also trigger fires or explosions in other battery modules.

[0009] Moreover, for medium- to large-sized battery packs, such as those used in electric vehicles, the risk of thermal chain reactions can be even greater due to the inclusion of a large number of battery cells and battery modules to increase output and / or capacity. Furthermore, battery packs installed in electric vehicles may be surrounded by users, such as drivers. Therefore, if a thermal event occurring in a specific battery cell or module is not properly controlled and a chain reaction occurs, it can result in significant property damage and even human casualties. Therefore, it is necessary to appropriately control thermal events occurring in battery cells or modules to improve the thermal safety of battery packs.

[0010] The present invention aims to solve the above-mentioned problems and other problems.

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

[0012] Another object of the present invention may be to provide a battery pack capable of suppressing heat propagation due to diffusion of venting gas.

[0013] Another object of the present invention may be to provide a battery pack capable of quickly discharging venting gas to the outside of the case when a thermal event occurs.

[0014] Another object of the present invention may be to provide a battery pack that is easy to control venting when a thermal event occurs.

[0015] In order to achieve the above purpose, a battery pack according to one embodiment of the present invention may include a case having an open upper surface and providing an internal space; a plurality of battery cells accommodated inside the case; and a pack cover covering the upper surface of the case and having a flat portion and a protrusion protruding upward from the flat portion.

[0016] Additionally, the flat portion can surround the protrusion.

[0017] Additionally, the protrusion can form a space inside.

[0018] In addition, the case further includes: a base plate; and a peripheral wall provided along the perimeter of the base plate, wherein the flat portion can be coupled to the peripheral wall.

[0019] In addition, the protrusions are provided in plurality, and each of the plurality of protrusions can be surrounded by the flat plate.

[0020] Additionally, the perimeter wall may include a front wall.

[0021] In addition, the battery pack further includes a venting device installed on the front wall, and the protrusion can extend in the front-rear direction.

[0022] In addition, the protrusions are provided in multiple numbers, the flat portion has a partition located between two adjacent protrusions, and the partition can extend toward the front wall.

[0023] In addition, the battery pack further includes a partition wall that divides the internal space and extends in the front-rear direction, and the partition wall can face the partition wall.

[0024] Additionally, the partition portion can be coupled to the partition wall.

[0025] In addition, the case further includes a module case positioned inside the case and accommodating the plurality of battery packs, and the protrusion may face the upper surface of the module case.

[0026] Additionally, the module case may have a venting hole formed on the upper surface.

[0027] A vehicle according to one aspect of the present invention comprises a battery pack of the present invention.

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

[0029] According to at least one of the embodiments of the present invention, heat transmission due to diffusion of venting gas can be suppressed.

[0030] According to at least one of the embodiments of the present invention, when a thermal event occurs, venting gas can be quickly discharged to the outside of the case.

[0031] According to at least one of the embodiments of the present invention, venting control of a battery pack can be facilitated.

[0032] 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.

[0033] FIG. 1 is a drawing showing a battery pack according to one embodiment of the present invention.

[0034] Fig. 2 is a diagram showing a partial configuration of the battery pack of Fig. 1 in isolation.

[0035] FIG. 3 is a drawing showing a pack cover of the battery pack of FIG. 1.

[0036] Figure 4 is a drawing of the pack cover of Figure 3 viewed from another direction.

[0037] Fig. 5 is a drawing schematically showing a cross-sectional configuration along the cutting line B-B' of Fig. 4.

[0038] Fig. 6 is a drawing showing the battery module of Fig. 2.

[0039] Fig. 7 is a drawing schematically showing a cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0040] Figure 8 is an enlarged view of part C of Figure 7.

[0041] Figure 9 is an enlarged view of part C of Figure 7 when a thermal event occurs.

[0042] Figure 10 is a diagram showing the flow of venting gas when a thermal event occurs.

[0043] Fig. 11 is a drawing showing a modified embodiment of Fig. 8.

[0044] Fig. 12 is a drawing showing another modified embodiment of Fig. 8.

[0045] FIG. 13 is a drawing showing a battery pack according to another embodiment of the present invention.

[0046] Figure 14 is a drawing showing the pack cover of Figure 13.

[0047] Figure 15 is a drawing of the pack cover of Figure 14 viewed from a different direction.

[0048] Fig. 16 is a drawing schematically showing a cross-sectional configuration along the cutting line E-E' of Fig. 14.

[0049] Fig. 17 is a drawing schematically showing a cross-sectional configuration along the cutting line D-D' of Fig. 13.

[0050] Fig. 18 is a schematic diagram showing a cross-sectional configuration along the cutting line D-D' of Fig. 13 when a thermal event occurs.

[0051] Figure 19 is a diagram showing the flow of venting gas when a thermal event occurs.

[0052] 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.

[0053] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0054] The +X-axis direction can be called forward, and the -X-axis direction can be called backward. The +Y-axis direction can be called upward, and the -Y-axis direction can be called downward. The +Y-axis direction can be called right, and the -Y-axis direction can be called left.

[0055] FIG. 1 is a drawing illustrating a battery pack according to an embodiment of the present invention. FIG. 2 is a drawing illustrating a partial configuration of the battery pack of FIG. 1 in isolation. Referring to FIGS. 1 and 2, a battery pack according to an embodiment of the present invention may include a case (100), a plurality of battery cells (220), and a pack cover (500).

[0056] The case (100) can provide space inside. The case (100) can have an open top. The case (100) can have a rectangular parallelepiped shape. The case (100) can form the exterior of the battery pack.

[0057] A plurality of battery cells (220) may be provided. In this case, the battery cells (220) may refer to secondary batteries. The battery cells (220) may have a pouch shape. In addition, the battery cells (220) may extend along the Y-axis direction. A plurality of battery cells (220) may be stacked along the X-axis direction. A plurality of battery cells (220) may be accommodated inside the case (100).

[0058] The pack cover (500) may have a plate shape. The pack cover (500) may have a square shape. The pack cover (500) may cover the internal space of the case (100). In addition, the pack cover (500) may cover the upper surface of the case (100). The pack cover (500) may have a flat portion (510) and a protrusion (520). The flat portion (510) may have a flat plate shape. The protrusion (520) may protrude upward from the flat portion (510). The flat portion (510) and the protrusion (520) may be formed integrally.

[0059] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. When a thermal event occurs, venting gas can be discharged in the +Z-axis direction. At this time, the protrusion (520) can accommodate the venting gas and guide the flow of the venting gas. This can prevent the venting gas from dispersing and suppress the propagation of the thermal event. In addition, the protrusion (520) can facilitate deformation of the pack cover (500). The protrusion (520) can expand and deform upward or outward due to the venting gas. This can facilitate the accommodation or capture of the venting gas.

[0060] Fig. 3 is a drawing showing the pack cover (500) of the battery pack of Fig. 1. Fig. 4 is a drawing showing the pack cover (500) of Fig. 3 from another direction. Fig. 5 is a drawing schematically showing the cross-sectional configuration along the cutting line B-B' of Fig. 4.

[0061] Referring to FIGS. 3 to 5, the flat portion (510) may surround the protrusion (520). The flat portion (510) may be provided along the perimeter of the pack cover (500). The protrusion (520) may be located on the inside of 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.

[0062] According to this configuration of the present invention, the assembly of the battery pack can be improved. Since the flat portion (510) of the pack cover (500) and the case (100) are combined, the combination of the pack cover (500) and the case (100) can be easily achieved.

[0063] Referring to FIGS. 3 to 5, the protrusion (520) can form a space (S1) therein. The protrusion (520) can be formed by bending a portion of a flat plate. The thicknesses of the protrusion (520) and the flat plate (510) can be substantially the same. In addition, the protrusion (520) can form a space (S1) therein.

[0064] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. When a thermal event occurs, venting gas can be discharged in the +Z-axis direction. At this time, the venting gas can be accommodated or captured in the space (S1) formed by the protrusion (520). This can prevent the venting gas from dispersing and suppress the propagation of the thermal event.

[0065] Referring to FIGS. 3 to 5, a plurality of protrusions (520) may be provided. The plurality of protrusions (520) may be surrounded by the flat portion (510). In addition, the plurality of protrusions (520) may be partitioned by the flat portion (510). The plurality of protrusions (520) may be positioned to correspond to a portion of each of the plurality of battery cells (220).

[0066] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. By providing multiple protrusions (520), the acceptance or capture of venting gas can be managed in smaller units. This can further suppress the propagation of thermal events.

[0067] Referring to FIGS. 1 to 5, the case (100) may include a base plate (110) and a peripheral wall (120). The base plate (110) may have a flat shape. The base plate (110) may have a square shape.

[0068] A perimeter wall (120) may be provided along the perimeter of the base plate (110). The perimeter wall (120) may be joined, fastened, fixed, or attached to the upper surface of the base plate (110). In addition, the perimeter wall (120) may be composed of a plurality of parts. The perimeter wall (120) may include a front wall (121), a rear wall, and a side wall.

[0069] The flat portion (510) can be fastened, joined, attached or fixed to the peripheral wall (120). In addition, the flat portion (510) can be fastened to the upper side or upper surface of the peripheral wall (120).

[0070] According to this configuration of the present invention, the assembly of the battery pack can be improved. Since the flat portion (510) of the pack cover (500) and the case (100) are combined, the combination of the pack cover (500) and the case (100) can be easily achieved.

[0071] Referring to FIGS. 1 to 5, a battery pack according to an embodiment of the present invention may include a venting device (400). The venting device (400) may connect or block the interior and exterior of the case (100). When the pressure inside the case (100) increases, the venting device (400) may discharge venting gas to the exterior. For example, the venting device (400) may be a gas valve.

[0072] A plurality of venting devices (400) may be provided. A plurality of venting devices (400) may be installed on the front wall (121). A plurality of venting devices (400) may be arranged in the left-right direction or along the Y-axis direction.

[0073] The protrusion (520) may extend in the forward / backward direction or along the X-axis direction. Alternatively, the protrusion (520) may extend toward the front wall (121).

[0074] According to this configuration of the present invention, the protrusion (520) can guide the venting gas toward the venting device (400). This allows the venting gas to be quickly discharged to the outside of the case (100). This can further suppress the propagation of thermal events.

[0075] Referring to FIGS. 1 to 5, the flat portion (510) may include a partition portion (511) and a connecting portion (512). The partition portion (511) may be positioned between adjacent protrusions (520). Alternatively, the partition portion (511) may separate adjacent protrusions (520). The connecting portion (512) may be positioned along the perimeter of the pack cover (500). The connecting portion (512) may be connected to the peripheral wall (120).

[0076] The partition (511) may extend in the forward / backward direction or along the X-axis direction. Alternatively, the partition (511) may extend toward the front wall (121).

[0077] According to this configuration of the present invention, by providing a plurality of protrusions (520), the acceptance or capture of venting gas can be managed in smaller units. Furthermore, the discharge of venting gas can be managed in smaller units. This allows for rapid discharge of venting gas and further suppression of thermal event propagation.

[0078] Fig. 6 is a drawing showing the battery module (200) of Fig. 2. Fig. 7 is a drawing schematically showing a cross-sectional configuration taken along the cutting line A-A' of Fig. 1. Fig. 8 is an enlarged drawing of part C of Fig. 7. Fig. 9 is an enlarged drawing of part C of Fig. 7 when a thermal event occurs.

[0079] Referring to FIGS. 6 to 9, a 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 have a rectangular parallelepiped shape. The module case (210) (100) may extend in the left-right direction or the Y-axis direction. The battery module (200) may be accommodated in the internal space of the case (100). A plurality of battery cells (220) may be accommodated in the module case (210) (100).

[0080] And 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).

[0081] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. When a thermal event occurs, venting gas can be discharged from the module case (210) (100) in the +Z-axis direction. At this time, the protrusion (520) can accommodate the venting gas and guide the flow of the venting gas. This can prevent the venting gas from dispersing and suppress the thermal event from spreading to adjacent battery modules (200).

[0082] Referring to FIGS. 6 to 9, the module case (210) (100) may include a venting hole (211). The venting hole (211) may be provided in multiple numbers. The multiple venting holes (211) may be formed on the upper surface of the case (100). The multiple venting holes (211) may connect the exterior and interior of the module case (210) (100).

[0083] According to this configuration of the present invention, the collection of venting gas can be facilitated, and the dispersion of the venting gas can be further suppressed. The venting gas can be discharged toward the protrusion (520) through the venting hole (211).

[0084] Referring to FIGS. 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 partition the internal 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-back direction or the X-axis direction. The center wall (310) may be located at a central portion of the internal space of the case (100). And the partition portion (511) may face the center wall (310). In addition, 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. The cross walls (320) may be provided in multiple numbers. The multiple cross walls (320) may be arranged along the front-back direction or the X-axis direction.

[0085] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. Since the compartment (511) is positioned facing the center wall (310), the alignment between the protrusion (520) and the battery module (200) can be improved. This can improve the accuracy of accepting or capturing venting gas.

[0086] Fig. 10 is a diagram illustrating the flow of venting gas when a thermal event occurs. Referring to Fig. 10, when a thermal event occurs in a battery module (200), the venting gas may flow forward or in the +X-axis direction along the protrusion (520). In addition, the venting gas may be prevented from moving in the +Y-axis or -Y-axis. Accordingly, the venting gas may be quickly discharged to the outside of the case (100) through the venting device (400) without propagating the thermal event of the adjacent battery module (200).

[0087] Fig. 11 is a drawing showing a modified embodiment of Fig. 8. Referring to Fig. 11, the center wall (310) can support the partition (511). Alternatively, the center wall (310) can be in contact with the partition (511). As a result, even if a thermal event occurs, the formation of a gap between the center wall (310) and the partition (511) can be suppressed.

[0088] According to this configuration of the present invention, the diffusion of venting gas can be more strongly suppressed.

[0089] Fig. 12 is a drawing showing another modified embodiment of Fig. 8. Referring to Fig. 12, the partition part (511) can be coupled to the partition wall (300). The partition part (511) can be fastened, coupled, fixed, or attached to the upper or upper part of the center wall (310). Alternatively, the partition part (511) and the center wall (310) can be coupled by welding. Alternatively, the battery pack may further include a fastening member (S) that fastens the partition part (511) and the center wall (310).

[0090] According to this configuration of the present invention, the diffusion of venting gas can be more strongly suppressed.

[0091] Fig. 13 is a drawing showing a battery pack according to another embodiment of the present invention. Fig. 14 is a drawing showing the pack cover (500) of Fig. 13. Fig. 15 is a drawing showing the pack cover (500) of Fig. 14 from another direction. Fig. 16 is a drawing schematically showing a cross-sectional configuration along the cutting line E-E' of Fig. 14.

[0092] Referring to FIGS. 13 to 16, a pack cover (500) of a battery pack according to another embodiment of the present invention may include a plurality of compartments (511). The pack cover (500) may include four protrusions (520) and three compartments (511) that partition the four protrusions (520). The plurality of compartments (511) may partition the protrusions (520) into smaller units.

[0093] The plurality of partitions (511) or the plurality of protrusions (520) may extend in the front-back direction or along the X-axis direction. And the plurality of partitions (511) or the plurality of protrusions (520) may be arranged in the left-right direction or along the Y-axis direction.

[0094] By providing multiple protrusions (520), the space (S2) formed by the protrusions (520) can be managed in smaller units. This allows the acceptance or capture of venting gas to be managed in smaller units. This allows the propagation of thermal events to be further suppressed.

[0095] Fig. 17 is a schematic diagram illustrating a cross-sectional configuration taken along the line D-D' of Fig. 13. Fig. 18 is a schematic diagram illustrating a cross-sectional configuration taken along the line D-D' of Fig. 13 when a thermal event occurs. Fig. 19 is a diagram illustrating the flow of venting gas when a thermal event occurs.

[0096] Referring to FIGS. 17 to 19, when a thermal event occurs in a battery module (200), the venting gas may flow forward or in the +X-axis direction along the protrusion (520). In addition, the venting gas may be prevented from moving in the +Y-axis or -Y-axis. Even if a thermal event occurs in a battery module (200), the protrusion (520) that receives or captures the venting gas may vary depending on which part of the battery module (200) the venting gas is emitted from.

[0097] For example, if venting gas is generated in the central portion, the protrusion (520a) facing that portion can expand to accommodate or capture the venting gas. Furthermore, the venting gas can be prevented from spreading into the space (S2) formed by the adjacent protrusion (520b). Furthermore, the venting gas can be prevented from spreading in the -Y-axis direction beyond the center wall (310).

[0098] Due to this, the venting gas can be quickly discharged to the outside of the case (100) through the venting device (400) without propagating the thermal event to other parts of the battery module (200) where the thermal event occurred, as well as to adjacent battery modules (200).

[0099] In addition, the battery pack according to the present invention may further include various components, for example, components of a battery pack known at the time of filing of the present invention, such as a BMS, a bus bar, a relay, a current sensor, etc.

[0100] A vehicle according to the present invention may include the battery pack according to the present invention described above. The battery pack according to the present invention may be applied to vehicles such as electric vehicles or hybrid vehicles. Furthermore, in addition to the battery pack, the vehicle according to the present invention may further include various other components included in the vehicle, such as a body, a motor, and control devices such as an electronic control unit (ECU).

[0101] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, 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.

[0102] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by a person having ordinary skill in the art to which the present invention pertains within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below.

Claims

1. A case with an open top and internal space; A plurality of battery cells accommodated inside the case; and, A battery pack comprising a pack cover covering the upper surface of the case and having a flat portion and a protrusion protruding upward from the flat portion.

2. In paragraph 1, The above reputation section, A battery pack surrounding the above protrusion.

3. In paragraph 1, The above protrusion is a battery pack that forms a space inside.

4. In paragraph 1, The above case is: Base plate; and, Further comprising a peripheral wall provided along the perimeter of the above base plate, The above reputation section, A battery pack coupled to the above perimeter wall.

5. In paragraph 1, The above protrusions are provided in multiples, Each of the above multiple protrusions, A battery pack surrounded by the above flat panel.

6. In paragraph 1, The above perimeter wall is, Equipped with a front wall, The above battery pack, Further comprising a venting device installed on the front wall; The above protrusion is, A battery pack extending in the forward and backward directions.

7. In paragraph 6, The above protrusions are provided in multiples, The above reputation section, Having a partition located between two adjacent protrusions, The above section is, A battery pack extending toward the front wall.

8. In paragraph 7, It further includes a partition wall that divides the above internal space and extends in the front-back direction, The above section is, Battery pack facing the above partition wall.

9. In paragraph 8, The above section is, A battery pack coupled to the above partition wall.

10. In paragraph 1, Further comprising a module case positioned inside the case and accommodating the plurality of battery packs, The above protrusion is, A battery pack facing the upper surface of the above module case.

11. In Article 10, The above module case is, A battery pack having a venting hole formed on an upper surface.

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

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