Battery pack and vehicle including same

Abstract

Disclosed are a battery pack and a vehicle including same. The battery pack according to an embodiment of the present invention includes: a plurality of battery modules, each having a plurality of stacked battery cells; a pack case in which the plurality of battery modules are accommodated; and a cover member coupled to the pack case, wherein the cover member has a dual structure in which at least one element thereof can change in form.

Description

Battery pack and vehicle including same

[0001] This application claims priority to Korean Patent Application No. 10-2024-0028132, filed on February 27, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0002] The present invention relates to a battery pack and a vehicle including the same, and more particularly, to a battery pack and a vehicle including the same, which can evenly spread heat and smoothly discharge gas when a thermal event occurs.

[0003] Generally, secondary batteries refer to batteries that can be repeatedly charged and discharged, such as lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. A battery cell, the most basic type of secondary battery, can provide an output voltage of approximately 2.5 V to 4.2 V.

[0004] Recently, as these battery cells are applied to devices that require high output voltage and large charging capacity, such as electric vehicles and Energy Storage Systems (ESS), battery modules composed of multiple battery cells connected in series, parallel, or a combination of series and parallel, and battery packs composed of these battery modules connected again in series, parallel, or a combination of series and parallel, are widely used.

[0005] Lithium secondary batteries are currently in the spotlight due to their advantages such as high operating voltage and significantly higher energy density. However, because they use organic electrolytes, there is a problem that lithium secondary batteries can cause overcurrent and overheating when overcharged, which in severe cases can cause fire due to explosion or ignition.

[0006] Various types of secondary batteries include battery modules in which a plurality of battery cells are stacked and inserted into a module case that is equipped with a module case that can protect the battery cells, and battery packs including a plurality of battery modules.

[0007] Figure 1 is a cross-sectional view of a conventional battery pack.

[0008] Referring to Fig. 1, in the case of a conventional battery pack (1), a cover member (3) coupled to a pack case (2) is fixed with a fastening member (5) such as a bolt while in contact with or in close proximity to a battery module (4). That is, in the conventional battery pack (1), since one cover member (3) is firmly fixed to the pack case (2), even if a flame occurs, no free space or buffer space is formed through which heat or gas caused by the flame can move.

[0009] In this state, if a flame occurs in the battery cell (6), the heat caused by the flame is blocked by the cover member (3) and cannot spread, but is concentrated within the battery module (4) where the flame occurred. In addition, since the gas generated within the battery module (4) cannot be discharged, the internal pressure increases and the possibility of explosion of the battery module (4) or battery pack (1) increases.

[0010] At this time, if an explosion occurs in the battery module (4) where the flame occurred, the flame may spread to other battery modules (4) and a thermal runaway phenomenon may occur. If the flame leaks out due to this thermal runaway phenomenon, there is a problem that the driver of the electric vehicle may be burned or put in a dangerous situation.

[0011] Alternatively, there is a problem in that the battery module (4) or battery pack (1) is damaged or burned down by a chain reaction of flames due to flame propagation, making it impossible to secure the stability of the battery module (4) or battery pack (1).

[0012] Accordingly, the technical problem to be achieved by the present invention is to provide a battery pack and an automobile including the same, which can prevent heat concentration by evenly dispersing heat caused by a flame within the battery pack when a flame occurs from a single battery cell, thereby achieving uniform thermal distribution.

[0013] In addition, the present invention provides a battery pack and a vehicle including the same, which enable easy venting and easy discharge of gases.

[0014] In addition, the present invention provides a battery module capable of preventing a thermal runaway phenomenon by preventing a chain reaction of flames due to flame propagation, a battery pack including the same, and a vehicle.

[0015] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0016] According to one aspect of the present invention, a battery pack may be provided, comprising: a plurality of battery modules in which a plurality of battery cells are stacked; a pack case in which the plurality of battery modules are accommodated; and a cover member coupled to the pack case, wherein the cover member is characterized by having a double structure in which at least one of the cover members is formed to be deformable.

[0017] In one embodiment, the cover member may include a first cover having at least one side formed to be deformable; and a second cover spaced apart from the first cover by a preset distance.

[0018] In one embodiment, the first cover may be located on the inside and the second cover may be located on the outside.

[0019] In one embodiment, the pack case includes a lower frame on which the plurality of battery modules are mounted; a side frame extending upward from an edge of the lower frame; an inner frame extending upward inside the lower frame and coupled to the side frame; and a partition frame coupled to the inner frame and interposed between the plurality of battery modules, wherein a fastening joint to which the second cover is fastened may be formed on at least one of the inner frame and the partition frame.

[0020] In one embodiment, the fastening joint may include a protrusion protruding from at least one of the inner frame and the bulkhead frame; and a fastening hole formed in the protrusion.

[0021] In one embodiment, the first cover may have a through hole formed at a corresponding position of the protrusion.

[0022] In one embodiment, the through hole of the first cover passes through the protrusion, and the first cover can contact at least one of the inner frame and the bulkhead frame.

[0023] In one embodiment, the second cover may be positioned on the upper side of the first cover and may be fastened to the fastening joint.

[0024] In one embodiment, the first cover is fastened at an edge, and deformation may occur in a portion excluding the edge due to venting gas generated from the battery cell, thereby forming a passage.

[0025] In one embodiment, the first cover can be deformed within the gap formed between the first cover and the second cover.

[0026] In one embodiment, the pack case may have a venting portion formed therein.

[0027] In one embodiment, the venting portion may include a venting hole through which venting gas generated from the battery cell is discharged; and a venting valve that closes the venting hole and opens when the internal pressure of the pack case exceeds a preset value.

[0028] In one embodiment, when the first cover is deformed, a passage is formed, and the venting gas can move to the venting portion through the passage.

[0029] Meanwhile, according to another aspect of the present invention, a vehicle including at least one battery pack as described above can be provided.

[0030] Embodiments of the present invention have the effect of preventing heat concentration by evenly dispersing heat caused by a flame within a battery pack when a flame occurs from one battery cell, thereby achieving uniform thermal distribution.

[0031] Additionally, it has the effect of facilitating venting, allowing gas to be discharged easily.

[0032] Additionally, it has the effect of preventing thermal runaway by preventing a chain reaction of flames due to flame propagation.

[0033] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0034] 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.

[0035] Figure 1 is a cross-sectional view of a conventional battery pack.

[0036] Figure 2 is a perspective view of the entire battery pack according to one embodiment of the present invention.

[0037] Figure 3 is an exploded perspective view of a battery pack according to one embodiment of the present invention.

[0038] Figure 4 is a drawing showing the first cover in Figure 3 combined with the pack case.

[0039] Figure 5 is an enlarged view of part B of Figure 4.

[0040] FIG. 6 is a plan view of a battery pack according to one embodiment of the present invention with the cover member removed.

[0041] FIG. 7 is a drawing illustrating a venting portion in a battery pack according to one embodiment of the present invention.

[0042] Fig. 8 is a drawing showing a venting hole of the venting part in Fig. 7.

[0043] Figure 9 is a cross-sectional view taken along line A-A' of Figure 2.

[0044] Fig. 10 is a drawing showing the first cover in Fig. 9 in a deformed state.

[0045] FIG. 11 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms or words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention. Therefore, it should be understood that 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 idea of ​​the present invention, and various equivalents and modifications may exist as of the time of this application.

[0047] In the drawings, the sizes of each component or specific parts of that component are exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect its actual size. If a detailed description of a related known function or configuration is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0048] The term 'joint' or 'connection' as used herein includes not only cases where one member is directly joined or directly connected to another member, but also cases where one member is indirectly joined or indirectly connected to another member through a connecting member.

[0049] FIG. 2 is a perspective view of a battery pack according to an embodiment of the present invention, FIG. 3 is an exploded perspective view of a battery pack according to an embodiment of the present invention, FIG. 4 is a view showing a state in which a first cover is coupled to a pack case in FIG. 3, FIG. 5 is an enlarged view of part B in FIG. 4, FIG. 6 is a plan view showing a state in which a cover member is removed from a battery pack according to an embodiment of the present invention, FIG. 7 is a view showing a venting part in a battery pack according to an embodiment of the present invention, FIG. 8 is a view showing a venting hole of the venting part in FIG. 7, FIG. 9 is a cross-sectional view taken along line A-A' of FIG. 2, and FIG. 10 is a view showing a state in which the first cover is deformed in FIG. 9.

[0050] Referring to FIGS. 2 and 3, a battery pack (10) according to one embodiment of the present invention may be configured to include a plurality of battery modules (100), a pack case (200), and a cover member (300).

[0051] Each battery module (100) has a plurality of battery cells (110, see FIG. 9) stacked on it, and a plurality of battery modules (100) are provided and arranged in various ways. For example, as shown in FIG. 3, the battery modules (100) may be arranged in a horizontal or vertical direction, but are not limited thereto.

[0052] Referring to FIG. 9, a battery module (100) may have a plurality of battery cells (110) and a module case (120).

[0053] A plurality of battery cells (110) can be stacked on top of each other. The battery cells (110) can have various structures, and furthermore, the plurality of battery cells (110) can be stacked in various ways.

[0054] The battery cell (110) may have a structure in which a plurality of unit cells arranged in the order of positive plate-separator-negative plate or bi-cells arranged in the order of positive plate-separator-negative plate-separator-positive plate-separator-negative plate are stacked according to the battery capacity.

[0055] The battery cell (110) may be equipped with an electrode lead. The electrode lead is a type of terminal that is exposed to the outside and connected to an external device, and may be made of a conductive material. The electrode lead may include a positive electrode lead and a negative electrode lead.

[0056] The positive electrode lead and the negative electrode lead may be positioned in opposite directions with respect to the longitudinal direction of the battery cell (110), or the positive electrode lead and the negative electrode lead may be positioned in the same direction with respect to the longitudinal direction of the battery cell (110).

[0057] A battery cell (110) may be provided with a plurality of cartridges (not shown) for storing the battery cell (110). Each cartridge (not shown) may be manufactured by injection molding plastic, and a plurality of cartridges (not shown) having a storage portion capable of storing the battery cell (110) may be stacked. A cartridge assembly in which a plurality of cartridges (not shown) are stacked may be provided with a connector element or a terminal element.

[0058] The connector element may include various types of electrical connection components or connecting members for connection to, for example, a BMS (Battery Management System, not shown) that can provide data on the voltage or temperature of the battery cell (110).

[0059] In addition, the terminal element is a main terminal connected to the battery cell (110) and includes a positive terminal and a negative terminal. The terminal element is provided with a terminal bolt so that it can be electrically connected to the outside. Meanwhile, the battery cell (110) may have various shapes.

[0060] Referring to Fig. 9, a plurality of battery cells (110) are stacked and stored in a module case (120). The module case (120) surrounds the plurality of battery cells (110), thereby protecting the battery cells (110) from external vibrations or shocks.

[0061] The module case (120) may be formed in a shape corresponding to the shape of a stacked body in which a plurality of battery cells (110) are stacked. For example, if the stacked body in which a plurality of battery cells (110) are stacked is formed in a hexahedral shape, the module case (120) may also be formed in a hexahedral shape corresponding thereto. However, the present invention is not limited thereto. Here, the module case (120) may include an upper module case (120), a lower module case (120), and a side module case (120).

[0062] In addition, the module case (120) can be manufactured by, for example, bending a metal plate, whereby the module case (120) can be manufactured as an integral part. When the module case (120) is manufactured as an integral part, the joining process is simplified and simplified. Alternatively, the module case (120) can be provided in a detachable form and joined by welding or the like. However, the material of the module case (120) is not limited to a metal material.

[0063] Referring to FIGS. 3 and 6, a plurality of battery modules (100) are stored in a pack case (200). The pack case (200) may be configured to include, for example, a lower frame (210), a side frame (220), an inner frame (230), and a bulkhead frame (240).

[0064] The lower frame (210) is configured to accommodate a plurality of battery modules (100). The lower frame (210) may be formed in a square plate shape, but is not limited thereto. The lower frame (210) forms the bottom of the pack case (200).

[0065] The side frame (220) may be configured to extend upward from the edge of the lower frame (210). The side frame (220) defines the height of the pack case (200) and forms a preset space between it and the lower frame (210). In addition, a plurality of battery modules (100) are mounted in the space between the side frame (220) and the lower frame (210). The side frame (220) may include a long side frame having a relatively long length and a short side frame having a relatively short length. Alternatively, the lengths of the side frames (220) may all be the same.

[0066] The inner frame (230) extends upward from within the lower frame (210) and is connected to the side frame (220). One or more inner frames (230) may be provided, and a plurality of battery modules (100) may be arranged to face each other based on the inner frame (230).

[0067] The bulkhead frame (240) is coupled to the inner frame (230). In addition, the bulkhead frame (240) is interposed between a plurality of battery modules (100). In FIG. 3, one bulkhead frame (240) is positioned between two adjacent battery modules (100), but the present invention is not limited thereto.

[0068] Here, a fastening joint (250) to which a second cover (320) is fastened can be formed on at least one of the inner frame (230) and the bulkhead frame (240), which will be described later.

[0069] The cover member (300) is coupled to the pack case (200). In addition, the cover member (300) is configured as a double structure in which at least one of the cover members is formed to be deformable.

[0070] Referring to FIG. 3, the cover member (300) may include, for example, a first cover (310) and a second cover (320). The first cover (310) may be formed so that at least one side thereof is deformable. The first cover (310) may be formed so that deformation occurs at various locations, and for example, the first cover (310) may be formed so that deformation occurs at the center thereof.

[0071] To this end, referring to FIG. 4, the first cover (310) is fixed by being fastened by a bolt or the like after contacting the joint (350) at the edge, and the center may be in an unfastened state. Here, referring to FIG. 3, the first cover (310) may be located on the inside of the second cover (320).

[0072] Referring to FIG. 9, the second cover (320) is spaced apart from the first cover (310) by a preset distance (330). That is, a space may be formed between the first cover (310) and the second cover (320). Here, referring to FIG. 3, the second cover (320) may be positioned on the outside of the first cover (310).

[0073] Referring to FIG. 3, as described above, the fastening joint (250) can be formed on at least one of the inner frame (230) and the bulkhead frame (240), and the second cover (320) can be fastened to the fastening joint (250) by a fastening member such as a bolt.

[0074] Referring to FIGS. 4 and 5, the fastening joint (250) may include a protrusion (251) and a fastening hole (252). The protrusion (251) may be formed to protrude from at least one of the inner frame (230) and the bulkhead frame (240) (see FIG. 3). In addition, the fastening hole (252) is formed in the protrusion (251). Here, the second cover (320) may be positioned on the upper side of the first cover (310) and fastened to the fastening joint (250).

[0075] In this regard, as shown in FIG. 3, a through hole (311) may be formed in the first cover (310) at a corresponding position to the protrusion (251). And, as shown in FIG. 4, when the first cover (310) is seated on the pack case (200) to be coupled to the pack case (200), the through hole (311) of the first cover (310) passes through the protrusion (251), and the first cover (310) may come into contact with at least one of the inner frame (230) and the bulkhead frame (240).

[0076] That is, the first cover (310) is placed on the inner frame (230) and the bulkhead frame (240) without being fixed to the inner frame (230) and the bulkhead frame (240) by passing through the fastening joint (250), and the edge of the first cover (310) is fixed to the pack case (200). Therefore, when a flame and gas are generated and the pressure inside the battery module (100) increases, the shape of the center of the first cover (310) may be deformed (for example, the center may be changed to bend upward).

[0077] Here, the first cover (310) can be deformed within the gap (330) formed between it and the second cover (320).

[0078] For example, referring to FIG. 9, the first cover (310) is normally placed on the inner frame (230) and the bulkhead frame (240) and is maintained in contact. However, when flames and gas are generated and the pressure inside the battery module (100) increases, as shown in FIG. 10, the first cover (310) is deformed so that the center of the first cover (310) moves upward, and when the first cover (310) is deformed in this manner, a passage (340) is formed between the first cover (310) with the deformed center and the battery cell (110).

[0079] That is, deformation occurs in the center of the first cover (310) except for the edge due to the flame and venting gas generated from the battery cell (110), and as shown in the arrow of FIG. 10, the heat from the flame spreads to another battery module (100) through the passage (340), thereby achieving an overall uniform thermal distribution, and preventing heat from being concentrated in any one battery module (100).

[0080] And, as shown in the arrow of Fig. 10, the venting gas can be discharged by moving to the venting part (260) through the passage (340). Referring to Figs. 7 and 8, a venting part (260) can be formed in the pack case (200).

[0081] The venting portion (260) may include a venting hole (261) and a venting valve (262). Referring to FIG. 8, the venting hole (261) is a hole through which venting gas generated from the battery cell (110) is discharged, and may be formed in the pack case (200), for example, the side frame (220), but is not limited thereto.

[0082] And, referring to FIG. 7, a venting valve (262) may be installed in the venting hole (261). The venting valve (262) may be configured in various ways. For example, the venting valve (262) may be configured to close the venting hole (261) and open when the internal pressure of the pack case (200) exceeds a preset value.

[0083] That is, the venting valve (262) normally blocks the venting hole (261), but when the venting gas leaks from the battery cell (110) and the internal pressure of the pack case (200) exceeds a preset value or range, the venting valve (262) opens and the venting gas is discharged from the pack case (200) through the venting hole (261).

[0084] As described above, when the first cover (310) is deformed by the flame and venting gas generated from the battery cell (110), and a passage (340) is formed between the first cover (310) and the battery cell (110) as shown in FIG. 10, the venting gas moves along the passage (340) to the venting portion (260) (see the arrow in FIG. 10), and when the venting valve (262) is opened by the venting gas moved in this way, the venting gas can be discharged to the outside of the pack case (200).

[0085] That is, the venting is facilitated by the movement passage (340) formed by the deformation of the first cover (310), so that gas can be easily discharged.

[0086] And, as described above, as the heat spreads to other battery modules (100) through the passage (340), the concentration of heat in any one battery module (100) is prevented, thereby enabling a uniform thermal distribution.

[0087] In addition, since the venting gas is discharged smoothly by the passage (340), ultimately, a chain reaction of flames due to flame propagation is prevented, thereby preventing thermal runaway.

[0088] FIG. 11 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0089] Referring to FIG. 11, a vehicle (20) according to one embodiment of the present invention may include one or more battery packs (10) according to each of the embodiments described above. Here, the vehicle (20) includes various types of vehicles that are designed to use electricity, such as electric vehicles or hybrid vehicles.

[0090] In this specification, when terms indicating directions such as up, down, left, and right are used, these terms are only for convenience of explanation, and it is obvious to those skilled in the art that these terms may vary depending on the location of the target object or the location of the observer.

[0091] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and those skilled in the art to which the present invention pertains may make various modifications and variations within the scope of the technical spirit of the present invention and the equivalent scope of the claims to be described below. Therefore, the embodiments disclosed above should be considered in an illustrative rather than a restrictive sense. In other words, the true scope of the technical spirit of the present invention is set forth in the claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

[0092] The present invention relates to a battery pack and an automobile including the same, and is particularly applicable to industries related to secondary batteries.

Claims

1. Multiple battery modules in which multiple battery cells are stacked; A pack case in which the plurality of battery modules are stored; and Includes a cover member that is coupled to the above pack case, A battery pack characterized in that the above cover member is formed of a double structure in which at least one of the cover members is deformable.

2. In paragraph 1, The above cover member, A first cover formed such that at least one side thereof is deformable; and A battery pack comprising a second cover spaced apart from the first cover by a preset distance.

3. In paragraph 2, A battery pack, characterized in that the first cover is located on the inside and the second cover is located on the outside.

4. In paragraph 3, The above pack case is, A lower frame on which the plurality of battery modules are mounted; A side frame extending upward from the edge of the lower frame; an inner frame extending upwardly within the lower frame and coupled to the side frame; and A bulkhead frame is coupled to the inner frame and interposed between the plurality of battery modules, A battery pack characterized in that at least one of the inner frame and the bulkhead frame has a fastening joint formed thereon to which the second cover is fastened.

5. In paragraph 4, The above fastening joint is, a protrusion protruding from at least one of the inner frame and the bulkhead frame; and A battery pack characterized by including a fastening hole formed in the above protrusion.

6. In paragraph 5, A battery pack characterized in that a through hole is formed in the first cover at a position corresponding to the protrusion.

7. In paragraph 6, A battery pack characterized in that the through hole of the first cover passes through the protrusion, and the first cover comes into contact with at least one of the inner frame and the bulkhead frame.

8. In paragraph 4, A battery pack characterized in that the second cover is positioned on the upper side of the first cover and is fastened to the fastening joint.

9. In paragraph 2, A battery pack characterized in that the first cover is fastened at an edge, and deformation occurs in a portion excluding the edge due to venting gas generated from the battery cell, thereby forming a movement passage.

10. In paragraph 2, A battery pack characterized in that the first cover is deformed within the gap formed between the first cover and the second cover.

11. In paragraph 2, A battery pack characterized in that a venting portion is formed in the above pack case.

12. In paragraph 11, The above venting part, A venting hole through which venting gas generated from the battery cell is discharged; and A battery pack characterized by including a venting valve that closes the venting hole and opens when the internal pressure of the pack case exceeds a preset value.

13. In paragraph 12, A battery pack characterized in that when the first cover is deformed, a passage is formed, and the venting gas moves to the venting section through the passage.

14. A vehicle comprising at least one battery pack according to any one of claims 1 to 13.

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