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 a plurality of battery modules are housed; and a fastening member for fastening the pack case, wherein at least a portion of the fastening member is inserted into and fixed to the pack case and is configured such that at least a portion melts or burns when the temperature rises.

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. The battery cells corresponding to the most basic secondary batteries 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), the upper frame (2) is fixed to the bulkhead frame (4) by a bolt (3). That is, in the conventional battery pack (1), since the upper frame (2) is firmly fixed by the bolt (3), there is no buffer space or buffer space formed for heat or gas from the flame to move when a flame occurs.

[0008] In this state, if a flame occurs in the battery cell (5), the heat from the flame is blocked by the upper frame (2) and cannot spread, and is concentrated within the battery module (6) where the flame occurred. Additionally, as the gas generated inside the battery module (6) cannot be discharged, the internal pressure increases, and the possibility of explosion of the battery module (6) or battery pack (1) increases.

[0009] At this time, if an explosion occurs in the battery module (6) where the flame has been generated, the flame may spread to other battery modules (6), 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 (6) to battery pack (1) is damaged or completely burned due to a chain reaction of flames caused by flame propagation, and thus the stability of the battery module (6) 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 fastening member for fastening the pack case, wherein at least a portion of the fastening member is inserted into and fixed to the pack case, and at least a portion of the fastening member melts or burns when the temperature rises.

[0016] In one embodiment, a fastening coupling hole is formed in the pack case, and the fastening member includes a bolt and a first nut, and the first nut is made of a melting or burning material and can be inserted into the fastening coupling hole of the pack case to be fixed.

[0017] In one embodiment, the first nut may be coupled to the fastening coupling hole of the pack case by a snap-fit ​​connection.

[0018] In one embodiment, the first nut may be made of plastic.

[0019] In one embodiment, a bushing member may be coupled to the pack case on the upper side of the first nut to prevent breakage of the first nut and increase fixing force.

[0020] In one embodiment, the bolt may pass through the bushing member and be coupled to the first nut.

[0021] In one embodiment, the bushing member may be joined to the pack case by welding.

[0022] In one embodiment, the outer diameter of the bushing member may be larger than the outer diameter of the first nut.

[0023] In one embodiment, the pack case comprises an upper frame; and a partition frame that is fastened to the upper frame by the fastening member, wherein the fastening coupling hole is formed in the partition frame, and the first nut can be inserted into the fastening coupling hole of the partition frame and fixed.

[0024] In one embodiment, the fastening member includes a second nut coupled to the upper frame, and the bolt can be fastened to the first nut and the second nut, respectively.

[0025] In one embodiment, the second nut may be joined to the upper frame by welding.

[0026] In one embodiment, the second nut may be separated from the bulkhead frame.

[0027] In one embodiment, when a flame occurs in the battery cell and the first nut melts, the bolt separates from the bulkhead frame, causing the upper frame to deform upward, and a buffer space may be formed between the upper frame and the battery module.

[0028] In one embodiment, a venting portion is formed in the pack case, and when the upper frame is deformed, gas generated from the battery cell can move to the venting portion.

[0029] 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

[0030] 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 is generated from any one battery cell.

[0031] In addition, it facilitates ventilation, allowing gas to be easily discharged.

[0032] In addition, it has the effect of preventing thermal runaway phenomena by preventing a chain reaction of flames caused by flame propagation.

[0033] 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

[0034] 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 exploded perspective view of a battery pack according to one embodiment of the present invention. FIG. 3 is a cross-sectional view of a battery pack according to one embodiment of the present invention, in which a bolt is separated from a first nut fixed to the inside of a bulkhead frame. Figure 4 is a drawing showing the bolt in Figure 3 connected to the first nut fixed to the inside of the bulkhead frame. Figure 5 is a drawing illustrating the first nut melting in Figure 4 and the upper frame and bolt separating from the bulkhead frame. FIG. 6 is a cross-sectional view of a battery pack according to one embodiment of the present invention, in which a first nut melts and the upper frame deforms, forming a buffer space. FIG. 7 is a perspective view of a battery pack according to a modified embodiment of the present invention, and only a part is shown. FIG. 8 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

[0035] 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.

[0036] 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.

[0037] 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.

[0038] FIG. 2 is an exploded perspective view of a battery pack according to an embodiment of the present invention, FIG. 3 is a cross-sectional view of a battery pack according to an embodiment of the present invention showing a bolt separated from a first nut fixed to the inside of a bulkhead frame, FIG. 4 is a drawing showing the bolt coupled to the first nut fixed to the inside of a bulkhead frame in FIG. 3, FIG. 5 is a drawing showing the first nut melting and the upper frame and the bolt separating from the bulkhead frame in FIG. 4, FIG. 6 is a cross-sectional view of a battery pack according to an embodiment of the present invention showing a buffer space formed as the upper frame deforms while the first nut melts.

[0039] Referring to FIG. 2, 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 fastening member (300).

[0040] A battery module (100) is housed in a pack case (200). In addition, a plurality of battery cells (110, see FIG. 6) are stacked in each battery module (100), and a plurality of battery modules (100) can be provided and arranged in various ways. For example, the battery modules (100) can be arranged in horizontal and vertical directions, but are not limited thereto.

[0041] The battery module (100) may be equipped with a plurality of battery cells (110) and a module case (120, see FIG. 6).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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).

[0046] 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.

[0047] 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).

[0048] 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.

[0049] 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.

[0050] 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).

[0051] 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.

[0052] A plurality of battery modules (100) are housed in the pack case (200). The pack case (200) may be configured to include, for example, an upper frame (210), a lower frame (220), a side frame (230), and a partition frame (240).

[0053] Referring to FIGS. 2 and FIGS. 6, the upper frame (210) is connected to the side frame (230) and the bulkhead frame (240). Here, the bulkhead frame (240) is connected by a fastening member (300) configured such that at least a portion of it melts or burns when the temperature rises. For example, the fastening member (300) may be a bolt (310) and a first nut (320), wherein the first nut (320) is configured to melt or burn by a flame, and the bolt (310) may be a standard bolt or a bolt configured to melt or burn by a flame.

[0054] And, the upper frame (210) is fixed to the side frame (230) by a standard bolt (310a, see FIG. 2) that is commonly used.

[0055] That is, when a thermal event occurs in the battery cell (110), etc., the upper frame (210) is fixed to the side frame (230) by a normal bolt (310a), but the first nut (320) of the fastening member (300) that fastens the bulkhead frame (240) melts or burns, so the upper frame (210) is separated from the bulkhead frame (240) in the event of a thermal event (see FIG. 6), and thereby a buffer space (500) can be formed between the upper frame (210) and the bulkhead frame (240). A detailed explanation of this will be provided later.

[0056] The lower frame (220) is configured to accommodate a plurality of battery modules (100). The lower frame (220) may be formed in the shape of a square plate, but is not limited thereto. The lower frame (220) forms the bottom portion of the pack case (200).

[0057] The side frame (230) may be configured to extend upward from the edge of the lower frame (220). The side frame (230) defines the height of the pack case (200) and forms a pre-set space between it and the lower frame (220).

[0058] Then, a plurality of battery modules (100) are seated in the space between the side frame (230) and the lower frame (220). The side frame (230) may include a long side frame (230) that is relatively long and a short side frame (230) that is relatively short. Alternatively, the lengths of the side frames (230) may all be the same.

[0059] The bulkhead frame (240) extends upward within the lower frame (220) and is coupled to the side frame (230). One or more bulkhead frames (240) may be provided, and a battery module (100) may be placed between the plurality of bulkhead frames (240) or between the bulkhead frame (240) and the side frame (230). Here, the bulkhead frames (240) may be arranged in a horizontal or vertical direction within the side frame (230).

[0060] And, referring to FIG. 3, a fastening coupling hole (241) may be formed in the bulkhead frame (240) so that the upper frame (210) is fastened by a fastening member (300).

[0061] The fastening member (300) is configured to fasten the upper frame (210) of the pack case (200). Here, at least a portion of the fastening member (300) is inserted into and fixed to the pack case (200). Referring to FIG. 3, for example, the fastening member (300) may include a bolt (310) and a first nut (320), the first nut (320) may be inserted into and fixed to the fastening coupling hole (241) of the bulkhead frame (240) of the pack case (200). For example, the first nut (320) may be firmly connected and fixed to the fastening coupling hole (241) of the bulkhead frame (240) by a snap-fit ​​method (e.g., a press-fit method).

[0062] In addition, the fastening member (300) is configured such that at least a portion of it melts or burns when the temperature rises. For example, the first nut (320) of the fastening member (300) may be configured to melt or burn. That is, in the battery pack (10) according to one embodiment of the present invention, the first nut (320) is configured to melt or burn when the temperature rises due to the generation of flames, etc.

[0063] And, as described above, the first nut (320), configured to melt or burn upon a rise in temperature, and the bolt (310) fastened to the first nut (320) fasten the upper frame (210) and the bulkhead frame (240). Here, the bolt (310) may be a standard bolt or a bolt configured to melt or burn upon a flame.

[0064] The fastening member (300) may vary. However, for the sake of convenience of explanation, the following description focuses on the case where the fastening member (300) includes a standard bolt (310) and a first nut (320) configured to melt or burn when the temperature rises.

[0065] Referring to FIGS. 3 and 4, as described above, the first nut (320) is inserted into and fixed in the fastening coupling hole (241) of the bulkhead frame (240). The first nut (320) is made of various types of melting or burning materials.

[0066] That is, the first nut (320) can be formed of various materials so that at least a portion of it melts or burns when the temperature rises, for example, it can be made of various plastic materials that can melt at a preset temperature, but is not limited thereto.

[0067] Here, the bushing member (400) can be coupled to the bulkhead frame (240) of the pack case (200). That is, in order to prevent damage to the first nut (320) and increase the fixing force, for example, the bushing member (400) can be coupled to the fastening coupling hole (241) of the bulkhead frame (240) so that it is positioned above the first nut (320).

[0068] And, in this structure, the bolt (310) can pass through the bushing member (400) and be coupled to the first nut (320).

[0069] The bushing member (400) can be joined to the bulkhead frame (240) of the pack case (200) in various ways, for example, by welding, but is not limited thereto. For example, the bushing member (440) can also be joined to the fastening connection hole (241) of the bulkhead frame (240) by an interference fit, similar to the first nut (320).

[0070] And, as shown in FIG. 5, the outer diameter of the bushing member (400) may be configured to be larger than the outer diameter of the first nut (320) in order to support the first nut (320) on the upper side of the first nut (320).

[0071] Additionally, the fastening member (300) may include a second nut (330) that is coupled to the upper frame (210), in which case the bolt (310) is fastened to the first nut (320) and the second nut (330), respectively.

[0072] As described above, the second nut (330) is joined to the upper frame (210). Here, the method of joining the second nut (330) to the upper frame (210) varies, and for example, it may be joined by welding, but is not limited thereto.

[0073] In FIG. 4, the second nut (330) is not connected in a state where it only contacts the bulkhead frame (240), but is separated from the bulkhead frame (240). In FIG. 4, the second nut (330) and the bulkhead frame (240) are in a state of contact, but it is acceptable for the second nut (330) and the bulkhead frame (240) to be spaced apart at a predetermined distance.

[0074] Referring to FIG. 4, the bolt (310) is coupled to the second nut (330) coupled to the upper frame (210) to first fasten the upper frame (210) and the bulkhead frame (240), and the bolt (310) is coupled to the first nut (320) to second fasten the upper frame (210) and the bulkhead frame (240).

[0075] Here, when a thermal event occurs in the battery cell (110), etc., the first nut (320) melts or burns. And, as shown in FIG. 5, when the first nut (320) fastened to the bolt (310) melts, the fastening force of the bolt (310) weakens, and the upper frame (210) is separated from the bulkhead frame (240) together with the bolt (310).

[0076] Referring to FIG. 6, when a flame is generated in the battery cell (110) and the first nut (320) melts, the bolt (310) is separated from the bulkhead frame (240) and the upper frame (210) is deformed upward, and accordingly, a buffer space (500) is formed between the upper frame (210) and the battery module (100).

[0077] That is, the upper frame (210) is deformed upward by the flame and gas generated from the battery cell (110) to form a buffer space (500), and as heat from the flame spreads to other battery modules (100) through the buffer space (500), a uniform thermal distribution is achieved overall, and heat can be prevented from concentrating in any one battery module (100).

[0078] FIG. 7 is a perspective view of a battery pack according to a modified embodiment of the present invention, and only a part is shown.

[0079] Referring to FIG. 7, there is a difference from the previously described embodiment in that a venting portion (250) is formed in the pack case (200). However, any parts of the modified embodiment that are common to the parts described in the previously described embodiment are replaced with the description of the previously described embodiment. Additionally, any parts of the modified embodiment that are applicable to the previously described embodiment may be applied to the previously described embodiment.

[0080] Referring to FIG. 7, a venting section (250) is formed in the pack case (200). As described above, when the temperature rises and the first nut (320) melts and the upper frame (210) deforms, the gas generated from the battery cell (110) can move to the venting section (250) and be discharged.

[0081] The venting section (250) may include a venting hole (251) and a venting valve (252). The venting hole (251) is a hole through which gas generated from the battery cell (110) is discharged, and may be formed in the pack case (200), for example, the side frame (230), but is not limited thereto.

[0082] Additionally, a venting valve (252) may be installed in the venting hole (251). The venting valve (252) may be configured in various ways. For example, the venting valve (252) may be configured to close the venting hole (251) and to open when the internal pressure of the pack case (200) exceeds a preset value.

[0083] That is, the venting valve (252) normally blocks the venting hole (251), but when 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 (252) opens and the gas is discharged from the pack case (200) through the venting hole (251).

[0084] As described above, when the upper frame (210) is deformed upward by the flame and gas generated in the battery cell (110) to form a buffer space (500), the gas moves along the buffer space (500) to the venting section (250), and the gas can be discharged to the outside of the pack case (200) as the venting valve (252) opens due to the pressure of the gas.

[0085] That is, the buffer space (500) formed by the deformation of the upper frame (210) facilitates ventilation, thereby allowing gas to be easily discharged.

[0086] And, as described above, as heat spreads to other battery modules (100) through the buffer space (500), heat concentration in any one battery module (100) is prevented, and thereby, a uniform thermal distribution can be achieved.

[0087] In addition, since the gas discharge is facilitated by the buffer space (500) formed between the upper frame (210) and the battery module (100), the chain reaction of flames caused by flame propagation is prevented, thereby preventing thermal runaway.

[0088] FIG. 8 is a drawing for explaining a vehicle including a battery pack (10) according to each embodiment of the present invention.

[0089] Referring to FIG. 8, 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.

[0090] 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.

[0091] 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

[0092] 10: Battery pack 100: Battery module 110: Battery cell 120 : Module Case 200 : Pack Case 210 : Upper frame 220 : Lower frame 230: Side frame 240: Bulkhead frame 241 : Fastening connection hole 250 : Venting part 251 : Venting hole 252 : Venting valve 300 : Fastening member 310 : Bolt 320: 1st nut 330: 2nd nut 400 : Bushing member 500 : Cushioning space 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 fastening member for fastening the pack case, wherein at least a portion of the fastening member is inserted and fixed into the pack case and configured to melt or burn when the temperature rises, wherein a fastening coupling hole is formed in the pack case, and the fastening member includes a bolt and a first nut, wherein the first nut is made of a material that melts or burns and is inserted and fixed into the fastening coupling hole of the pack case, and wherein the pack case includes an upper frame; and a partition frame that is fastened to the upper frame by the fastening member, wherein the fastening coupling hole is formed in the partition frame, and the first nut is inserted and fixed into the fastening coupling hole of the partition frame, and wherein the fastening member includes a second nut that is coupled to the upper frame, and wherein the bolt is fastened to the first nut and the second nut, respectively. Claim 2 delete Claim 3 A battery pack according to claim 1, characterized in that the first nut is coupled to the fastening coupling hole of the pack case by a snap-fit ​​connection. Claim 4 A battery pack according to claim 1, characterized in that the first nut is made of plastic. Claim 5 A battery pack according to claim 4, characterized in that a bushing member is coupled to the pack case on the upper side of the first nut to prevent breakage of the first nut and increase fixing force. Claim 6 A battery pack according to claim 5, characterized in that the bolt passes through the bushing member and is coupled to the first nut. Claim 7 A battery pack according to claim 5, characterized in that the bushing member is joined to the pack case by welding. Claim 8 A battery pack according to claim 5, characterized in that the outer diameter of the bushing member is larger than the outer diameter of the first nut. Claim 9 delete Claim 10 delete Claim 11 A battery pack according to claim 1, characterized in that the second nut is joined to the upper frame by welding. Claim 12 A battery pack according to claim 1, characterized in that the second nut is separated from the bulkhead frame. Claim 13 A battery pack according to claim 12, characterized in that when a flame occurs in the battery cell and the first nut melts, the bolt separates from the bulkhead frame, the upper frame is deformed upward, and a buffer space is formed between the upper frame and the battery module. Claim 14 A battery pack according to claim 1, wherein a venting portion is formed in the pack case, and gas generated from the battery cell moves to the venting portion when the upper frame is deformed. Claim 15 An automobile comprising at least one battery pack according to any one of paragraphs 1, 3 through 8, and 11 through 14.

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