Battery pack and vehicle including the same

Abstract

A battery pack and an automobile including the same are disclosed. A battery pack according to one embodiment of the present invention comprises 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 housed; and a cover member coupled to the pack case, wherein the cover member is configured as a double structure in which at least one is deformably formed.

Description

Technology Field

[0001] The present invention relates to a battery pack and an automobile including the same, and more specifically, to a battery pack and an automobile including the same in which heat can be evenly diffused and gas can be smoothly discharged when a thermal event occurs. Background Technology

[0002] Generally, a secondary battery refers to a battery capable of repeated charging and discharging, such as lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. A battery cell corresponding to the most basic secondary battery can provide an output voltage of approximately 2.5V to 4.2V.

[0003] Recently, as these battery cells are applied to devices requiring high output voltage and large charging capacity, such as electric vehicles or Energy Storage Systems (ESS), battery modules configured by connecting multiple battery cells in series, parallel, or a combination of series and parallel, and battery packs configured by connecting these battery modules again in series, parallel, or a combination of series and parallel are widely used.

[0004] Lithium secondary batteries are currently in the spotlight due to their advantages, such as high operating voltage and significantly higher energy density, but because they use organic electrolytes, if the lithium secondary battery is overcharged, it causes overcurrent and overheating, which in severe cases can lead to explosions or fires caused by ignition.

[0005] Various types of secondary batteries include a battery module in which a plurality of battery cells are stacked and inserted into the module case, equipped with a module case capable of protecting the battery cells, and a battery pack containing a plurality of battery modules.

[0006] Figure 1 is a cross-sectional view of a conventional battery pack.

[0007] 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 by a fastening member (5), such as a bolt, while in contact with or close 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), there is no buffer space or buffer space formed for heat or gas caused by the flame to move even if a flame occurs.

[0008] In this state, if a flame occurs in the battery cell (6), the heat from the flame is blocked by the cover member (3) and cannot spread, and is concentrated within the battery module (4) where the flame occurred. Additionally, as the gas generated inside 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.

[0009] At this time, if an explosion occurs in the battery module (4) where the flame has been generated, the flame may spread to other battery modules (4), causing a thermal runaway phenomenon. If the flame leaks out due to such a thermal runaway phenomenon, there is a problem that the driver of the electric vehicle may suffer burns or be put in a dangerous situation.

[0010] Alternatively, there is a problem in that the battery module (4) to battery pack (1) is damaged or completely burned due to a chain reaction of flames caused by flame propagation, and the stability of the battery module (4) to battery pack (1) cannot be secured. The problem to be solved

[0011] Accordingly, the technical problem to be solved by the present invention is to provide a battery pack and an automobile including the same, which, when a flame occurs from any one battery cell, allows the heat caused by the flame to spread evenly within the battery pack to prevent heat concentration and thereby have a uniform thermal distribution.

[0012] In addition, the invention provides a battery pack that allows for smooth venting so that gas can be easily discharged, and a vehicle including the same.

[0013] In addition, the invention provides a battery module capable of preventing thermal runaway by preventing a chain reaction of flames caused by flame propagation, a battery pack including the same, and an automobile.

[0014] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0015] 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 housed; and a cover member coupled to the pack case, wherein the cover member is configured with a double structure in which at least one is deformably formed.

[0016] 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.

[0017] In one embodiment, the first cover may be located on the inside and the second cover may be located on the outside.

[0018] In one embodiment, the pack case comprises: a lower frame on which the plurality of battery modules are seated; a side frame extending upward from the edge of the lower frame; an inner frame extending upward within 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 coupling portion to which the second cover is fastened may be formed on at least one of the inner frame and the partition frame.

[0019] In one embodiment, the fastening coupling portion 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.

[0020] In one embodiment, a through hole may be formed in the first cover at a position corresponding to the protrusion.

[0021] In one embodiment, the through hole of the first cover passes through the protrusion, and the first cover may come into contact with at least one of the inner frame and the bulkhead frame.

[0022] In one embodiment, the second cover may be located on the upper side of the first cover and fastened to the fastening coupling portion.

[0023] In one embodiment, the first cover is fastened at the edge, and deformation occurs in the portion excluding the edge due to venting gas generated from the battery cell, thereby forming a passage.

[0024] In one embodiment, the first cover may be deformed within the gap formed between it and the second cover.

[0025] In one embodiment, a venting portion may be formed in the pack case.

[0026] 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.

[0027] In one embodiment, when the first cover is deformed, a passage is formed, and the venting gas can move to the venting section through the passage.

[0028] Meanwhile, according to another aspect of the present invention, a vehicle comprising at least one of the aforementioned battery packs may be provided. Effects of the invention

[0029] The embodiments of the present invention have the effect of preventing heat concentration and thereby enabling a uniform thermal distribution by ensuring that heat from the flame spreads evenly within the battery pack when a flame occurs from any one battery cell.

[0030] In addition, it facilitates ventilation, allowing gas to be easily discharged.

[0031] In addition, it has the effect of preventing thermal runaway phenomena by preventing a chain reaction of flames caused by flame propagation.

[0032] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below. Brief explanation of the drawing

[0033] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. Figure 1 is a cross-sectional view of a conventional battery pack. FIG. 2 is an overall perspective view of a battery pack according to one embodiment of the present invention. FIG. 3 is an exploded perspective view of a battery pack according to one embodiment of the present invention. Figure 4 is a drawing showing the first cover in Figure 3 combined with the pack case. Figure 5 is an enlarged view of part B of Figure 4. FIG. 6 is a plan view of a battery pack with a cover member removed according to one embodiment of the present invention. FIG. 7 is a drawing illustrating a venting portion in a battery pack according to one embodiment of the present invention. Figure 8 is a drawing illustrating the venting hole of the venting section in Figure 7. Figure 9 is a cross-sectional view taken along A-A' of Figure 2. Figure 10 is a drawing showing the first cover in Figure 9 in a deformed state. FIG. 11 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention. Specific details for implementing the invention

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely one preferred embodiment of the present invention and do not represent all aspects of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0035] In the drawings, the size of each component or specific part constituting the component is exaggerated, omitted, or schematically depicted for convenience and clarity of explanation. Accordingly, the size of each component does not entirely reflect its actual size. If it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such description shall be omitted.

[0036] As used in this specification, the terms "combination" or "connection" include not only cases where one member and another member are directly joined or directly connected, but also cases where one member is indirectly joined or indirectly connected to another member through a connecting member.

[0037] FIG. 2 is an overall 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 drawing showing the first cover coupled to the pack case in FIG. 3, FIG. 5 is an enlarged view of part B in FIG. 4, FIG. 6 is a plan view showing the battery pack according to an embodiment of the present invention with the cover member removed, FIG. 7 is a drawing showing the venting portion of the battery pack according to an embodiment of the present invention, FIG. 8 is a drawing showing the venting hole of the venting portion in FIG. 7, FIG. 9 is a cross-sectional view taken along A-A' in FIG. 2, and FIG. 10 is a drawing showing the first cover deformed in FIG. 9.

[0038] Referring to FIGS. 2 and FIGS. 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).

[0039] A plurality of battery cells (110, see FIG. 9) are stacked in each battery module (100), 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 horizontal and vertical directions, but are not limited thereto.

[0040] Referring to FIG. 9, the battery module (100) may have a plurality of battery cells (110) and a module case (120).

[0041] Multiple battery cells (110) can be stacked together. The battery cells (110) can have various structures, and additionally, the multiple battery cells (110) can be stacked in various ways.

[0042] 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.

[0043] The battery cell (110) may be provided with electrode leads. The electrode leads may be made of a conductive material and serve as a type of terminal that is exposed to the outside and connected to an external device. The electrode leads may include a positive electrode lead and a negative electrode lead.

[0044] 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).

[0045] A battery cell (110) may be provided with a plurality of cartridges (not shown) for housing the battery cell (110). Each cartridge (not shown) may be manufactured by injection molding of plastic, and a plurality of cartridges (not shown) may be stacked, each having a housing portion formed to accommodate the battery cell (110). A cartridge assembly formed by stacking a plurality of cartridges (not shown) may be provided with a connector element or a terminal element.

[0046] The connector element may include various types of electrical connection components or connection members for connecting to a BMS (Battery Management System, not shown), for example, which can provide data on the voltage or temperature of the battery cell (110).

[0047] Additionally, the terminal element includes a positive terminal and a negative terminal as a main terminal connected to the battery cell (110). The terminal element is equipped with a terminal bolt so that it can be electrically connected to the outside. Meanwhile, the battery cell (110) may have various shapes.

[0048] 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) and thereby protects the battery cells (110) from external vibrations or shocks.

[0049] The module case (120) may be formed in a shape corresponding to the shape of a stack of multiple battery cells (110). For example, if the stack of multiple battery cells (110) is formed in a cuboid shape, the module case (120) may also be formed in a cuboid shape to correspond thereto. However, it 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).

[0050] Additionally, the module case (120) can be manufactured, for example, by bending a metal plate, thereby allowing the module case (120) to be manufactured as a single unit. When the module case (120) is manufactured as a single unit, the joining process becomes simpler and more streamlined. Alternatively, the module case (120) may be provided as a separate unit and joined by welding or the like. However, the material of the module case (120) is not limited to metal.

[0051] Referring to FIGS. 3 and FIGS. 6, a plurality of battery modules (100) are housed 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 partition frame (240).

[0052] The lower frame (210) is configured to accommodate a plurality of battery modules (100). The lower frame (210) may be formed in the shape of a square plate, but is not limited thereto. The lower frame (210) forms the bottom portion of the pack case (200).

[0053] 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 pre-set space between it and the lower frame (210). A plurality of battery modules (100) are seated in the space between the side frame (220) and the lower frame (210). The side frame (220) may include a long side frame that is relatively long and a short side frame that is relatively short. Alternatively, the lengths of the side frames (220) may all be the same.

[0054] The inner frame (230) extends upward within the lower frame (210) and is coupled to the side frame (220). One or more inner frames (230) may be provided, and a plurality of battery modules (100) may be arranged facing each other with respect to the inner frame (230). The inner frame (230) may be arranged to intersect with the partition frame (240).

[0055] The partition frame (240) is coupled to the inner frame (230). The partition frame (240) is interposed between a plurality of battery modules (100). In FIG. 3, one partition frame (240) is positioned between two adjacent battery modules (100), but it is not limited thereto.

[0056] Here, a fastening coupling part (250) to which a second cover (320) is fastened may be formed on at least one of the inner frame (230) and the bulkhead frame (240), and this will be described later.

[0057] The cover member (300) is coupled to the pack case (200). The cover member (300) is configured with a double structure in which at least one is deformably formed.

[0058] 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 is deformable. The first cover (310) may be formed so that deformation occurs at various locations, for example, so that deformation occurs at the center of the first cover (310).

[0059] To this end, referring to FIG. 4, the first cover (310) is secured by being fastened with a bolt or the like after contacting the joint (350) at the edge, and the center may be unfastened. Here, referring to FIG. 3, the first cover (310) may be located on the inner side of the second cover (320).

[0060] 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 located on the outside of the first cover (310).

[0061] Referring to FIG. 3, as described above, the fastening coupling part (250) may be formed in at least one of the inner frame (230) and the partition frame (240), and the second cover (320) may be fastened to the fastening coupling part (250) by a fastening member such as a bolt.

[0062] Referring to FIGS. 4 and 5, the fastening coupling portion (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 partition frame (240) (see FIG. 3). The fastening hole (252) is formed in the protrusion (251). Here, the second cover (320) may be positioned above the first cover (310) and fastened to the fastening coupling portion (250).

[0063] To explain this, as shown in FIG. 3, a through hole (311) may be formed in the first cover (310) at a position corresponding to the protrusion (251). Then, 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 partition frame (240).

[0064] That is, the first cover (310) is placed on the inner frame (230) and the partition frame (240) without passing through the fastening coupling part (250) and being fixed to the inner frame (230) and the partition frame (240), and the edge of the first cover (310) is fixed to the pack case (200), so when flames and gas are generated and the pressure inside the battery module (100) increases, the shape of the center of the first cover (310) can be deformed (for example, the center is changed to bend upward).

[0065] Here, the first cover (310) can be deformed within the gap (330) formed between it and the second cover (320).

[0066] For example, referring to FIG. 9, the first cover (310) is normally placed on the inner frame (230) and the bulkhead frame (240) and maintained in contact. However, when flames and gas are generated and the pressure inside the battery module (100) increases, the first cover (310) is deformed so that the center of the first cover (310) moves upward, as in FIG. 10. When the first cover (310) is deformed in this way, a passage (340) is formed between the first cover (310) with the deformed center and the battery cell (110).

[0067] That is, deformation occurs in the center of the first cover (310), excluding the edges, due to the flame and venting gas generated in the battery cell (110), and as shown by the arrow in FIG. 10, heat from the flame spreads to other battery modules (100) through the passage (340), resulting in a uniform thermal distribution overall and preventing heat from concentrating in any one battery module (100).

[0068] And, as indicated by the arrow in FIG. 10, the venting gas can be moved through the passage (340) to the venting section (260) and discharged. Referring to FIG. 7 and FIG. 8, the venting section (260) can be formed in the pack case (200).

[0069] The venting section (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.

[0070] Also, 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 to open when the internal pressure of the pack case (200) exceeds a preset value.

[0071] That is, the venting valve (262) normally blocks the venting hole (261), but when venting gas leaks out 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).

[0072] As described above, when the first cover (310) is deformed by the flame and venting gas generated in the battery cell (110) and a passage (340) is formed between the first cover (310) and the battery cell (110) as in FIG. 10, the venting gas moves along the passage (340) to the venting section (260) (see arrow in FIG. 10), and the venting valve (262) is opened by the venting gas that has moved in this way, so that the venting gas can be discharged to the outside of the pack case (200).

[0073] That is, the ventilation is facilitated by the passage (340) formed by the deformation of the first cover (310), so that gas can be easily discharged.

[0074] And, as described above, as heat spreads to other battery modules (100) through the passage (340), heat concentration in any one battery module (100) is prevented, and thereby, a uniform thermal distribution can be achieved.

[0075] In addition, since the venting gas is discharged smoothly through the passage (340), it is possible to prevent a chain reaction of flames caused by flame propagation and thus prevent thermal runaway.

[0076] FIG. 11 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0077] 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 above embodiments. Here, the vehicle (20) includes various vehicles configured to use electricity, such as, for example, electric vehicles or hybrid vehicles.

[0078] In this specification, where terms indicating directions such as up, down, left, and right are used, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0079] Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims set forth below by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed above should be considered in an illustrative rather than a restrictive sense. That is, the scope of the true technical spirit of the present invention is indicated in the claims, and all variations within the equivalent scope thereof should be interpreted as being included in the present invention. Explanation of the symbols

[0080] 10 : Battery pack 100 : Battery module 110: Battery cell 120: Module case 200 : Pack case 210 : Bottom frame 220: Side frame 230: Inner frame 240 : Bulkhead frame 250 : Fastening joint 251 : Protrusion 252 : Fastening hole 260: Venting section 261: Venting hole 262 : Venting valve 300 : Cover member 310: First cover 311: Through hole 320 : Second cover 330 : Spacing 340 : Movement path 20 : Cars

Claims

Claim 1 A battery pack 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 housed; and a cover member coupled to the pack case, wherein the cover member is configured with a double structure in which at least one side is deformably formed, and the cover member comprises: a first cover in which at least one side is deformably formed; and a second cover spaced apart from the first cover by a predetermined interval, wherein the pack case comprises a partition frame interposed between the plurality of battery modules and an inner frame arranged to intersect the partition frame, wherein a fastening coupling portion for fastening the second cover is formed on at least one of the inner frame and the partition frame, and the fastening coupling portion comprises a protrusion protruding from at least one of the inner frame and the partition frame; and a fastening hole formed in the protrusion, and a through hole formed in the first cover at a position corresponding to the protrusion. Claim 2 delete Claim 3 A battery pack according to claim 1, characterized in that the first cover is located on the inside and the second cover is located on the outside. Claim 4 A battery pack according to paragraph 3, wherein the pack case comprises: a lower frame on which the plurality of battery modules are seated; and a side frame extending upward from the edge of the lower frame, wherein the inner frame extends upward within the lower frame and is coupled to the side frame, and the bulkhead frame is coupled to the inner frame. Claim 5 delete Claim 6 delete Claim 7 A battery pack according to claim 1, characterized in that the through hole of the first cover passes through the protrusion, and the first cover contacts at least one of the inner frame and the bulkhead frame. Claim 8 A battery pack according to claim 4, wherein the second cover is located on the upper side of the first cover and is fastened to the fastening coupling portion. Claim 9 A battery pack 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 housed; and a cover member coupled to the pack case, wherein the cover member is composed of a double structure in which at least one side is formed to be deformable, and the cover member comprises: a first cover in which at least one side is formed to be deformable; and a second cover spaced apart from the first cover by a preset distance, wherein the first cover is fastened at the edge, and deformation occurs in the portion excluding the edge due to venting gas generated from the battery cells to form a passage for movement. Claim 10 A battery pack according to claim 1, wherein the first cover is deformed within the gap formed between it and the second cover. Claim 11 A battery pack 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 housed; and a cover member coupled to the pack case, wherein the cover member is configured with a double structure in which at least one side is deformable, and the cover member comprises: a first cover in which at least one side is deformable; and a second cover spaced apart from the first cover by a preset distance, wherein a venting portion is formed in the pack case, and the venting portion comprises: a venting hole through which venting gas generated from the battery cells 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, wherein a passage is formed when the first cover is deformed, and the venting gas moves to the venting portion through the passage. Claim 12 delete Claim 13 delete Claim 14 An automobile comprising at least one battery pack according to any one of paragraphs 1, 3, 4, 7 through 11.

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