Battery pack and vehicle including the same

Abstract

A battery pack according to the present invention comprises: a plurality of battery modules; the battery pack includes a plurality of battery modules, and a pack case having an accommodation space accommodating the plurality of battery modules, in which the pack case may be configured such that at least one surface of the pack case is deformed when an internal pressure is increased due to exhaust gas and flame generated by a thermal event in the battery modules.

Description

Technical Field

[0001] The present disclosure relates to a battery pack, and more particularly to a battery pack in which, when a thermal event occurs in a battery module, the internal space of the battery pack housing increases in response to an increase in internal pressure, thereby reducing the internal pressure of the battery pack, reducing the rate of increase in internal pressure, and delaying heat propagation. This application claims priority to Korean Patent Application No. 10-2023-0087250 filed in Korea on July 5, 2023, the disclosure of which is incorporated herein by reference. Background Art

[0002] Semi-permanent batteries that convert electrical energy into chemical energy and can be repeatedly charged and discharged are called secondary batteries, as distinguished from primary batteries that cannot be reused after use.

[0003] In particular, lithium-ion secondary batteries have advantages such as high energy storage density, lightweight structure, miniaturization, good safety, low discharge rate, and long service life, and are therefore currently widely used in electric vehicle batteries. For reference, lithium-ion secondary batteries are classified into cylindrical, prismatic, and pouch types according to their manufacturing form, and their use ranges from electric vehicle batteries to ESS (Energy Storage System) batteries and other electrical devices.

[0004] Currently, the operating voltage of a lithium-ion secondary battery cell is approximately 2.5 V to 4.5 V. Therefore, to use secondary batteries as energy sources for electric vehicles, multiple lithium-ion battery cells are connected in series and / or parallel to produce a battery module, and the battery modules are then connected in series and / or parallel to produce a battery pack.

[0005] Furthermore, because secondary batteries involve chemical reactions during charging and discharging, their performance may deteriorate when used at temperatures above the appropriate temperature, and failure to maintain thermal control at the appropriate temperature may lead to unexpected fires or explosions. Furthermore, because battery packs, which are components of secondary batteries, have a structure in which secondary batteries are collectively stored within a battery pack housing, they may be susceptible to thermal events.

[0006] Therefore, if a specific battery module overheats or if a thermal event such as thermal runaway occurs, the internal pressure within the battery pack may increase due to the exhaust gas and flames generated in the battery module where the event occurred, thereby accelerating the accumulation of thermal energy, which may easily cause heat propagation to adjacent battery modules. This may lead to a cascade of thermal runaway of the battery modules and explosion of the entire battery pack.

[0007] Therefore, it is necessary to improve the structure of the battery pack that can reduce the internal pressure within the battery pack (which increases due to exhaust gas and flames generated in the event of a thermal event in the battery module with initial fire) and effectively distribute thermal energy, thereby delaying the chain heat propagation to adjacent battery modules. Summary of the Invention

[0008] Technical issues

[0009] The present disclosure is designed to solve the problems of the related art. Therefore, the present disclosure aims to provide a battery pack that can reduce the internal pressure within the battery pack that increases due to exhaust gas and flames generated when a thermal event occurs in a battery module that initially catches fire, or reduce the rate of increase of the internal pressure, and effectively distribute thermal energy, thereby delaying the chain heat propagation to adjacent battery modules.

[0010] The technical problems to be solved by the present disclosure are not limited to the above problems, and those skilled in the art can clearly understand other problems not mentioned above from the following description of the present invention.

[0011] Technical Solution

[0012] According to one aspect of the present disclosure, a battery pack is provided, comprising: a plurality of battery modules; and a battery pack housing having an accommodation space formed to accommodate the plurality of battery modules, wherein the battery pack housing can be configured such that when internal pressure increases due to exhaust gas and flames generated by a thermal event in the battery modules, at least one surface of the battery pack housing deforms.

[0013] The pack case may have an expansion space formed to be separated from the accommodation space in response to an increase in the internal pressure.

[0014] The expansion space may be formed by deformation of a bottom surface of the pack case.

[0015] The battery pack housing may include: a battery pack frame configured to have an upper opening and a lower opening and to accommodate the battery modules therein; and a lower frame portion disposed at a bottom of the battery pack frame to support the plurality of battery modules placed on the lower frame portion.

[0016] The lower frame portion may include a base plate coupled to the pack frame and configured to support the battery module; and a bottom cover disposed on the bottom surface of the pack case to cover the base plate.

[0017] The bottom cover may be configured to plastically deform and expand downward from the pack case when the internal pressure increases.

[0018] The bottom cover may be made of steel or SUS.

[0019] The bottom cover may be configured to have a thickness of 1.6 mm to 2.5 mm.

[0020] The substrate may have a plurality of lower exhaust holes through which the exhaust gas and solid exhaust including electrode exhaust move to the expansion space.

[0021] The battery modules may be arranged in the accommodation space of the pack case in a width direction and a length direction, and the plurality of lower exhaust holes may be provided parallel to the width direction.

[0022] One or more lower exhaust holes may be provided for each of the plurality of battery modules.

[0023] The lower frame portion may further include a bottom reinforcement bar disposed between a bottom of the base plate and the bottom cover, and the plurality of lower exhaust holes may be formed so as not to interfere with the bottom reinforcement bar.

[0024] A heat / fire resistant liner may be interposed between the base plate and the bottom cover.

[0025] The heat / fire resistant lining may be provided along the periphery of the base plate and the bottom cover.

[0026] The pack frame may have a plurality of exhaust valves provided along a width direction of the battery module.

[0027] The exhaust valve may be configured to operate when the internal pressure reaches a preset pressure or more after the bottom cover is deformed to form the expansion space.

[0028] The solid exhaust may be collected in the expansion space together with the exhaust gas through the lower exhaust hole, and the exhaust valve is configured to exhaust only the exhaust gas.

[0029] In another embodiment, the expansion space can be formed by deformation of the top surface and the bottom surface of the battery pack housing, and the expansion space formed by the deformation of the top surface of the battery pack housing and the expansion space formed by the deformation of the bottom surface of the battery pack housing can be connected to each other through the lower exhaust hole.

[0030] The battery pack housing may further include a top cover, which is disposed on the top of the battery pack frame to seal the accommodation space for accommodating the battery module, and the bottom cover may be configured to plastically deform and expand downward from the battery pack housing when the internal pressure increases, and the top cover may be configured to plastically deform and expand upward from the battery pack housing when the internal pressure increases.

[0031] In addition, according to the present disclosure, a vehicle is provided, which includes one or more battery packs as described above.

[0032] Beneficial effects

[0033] According to one aspect of the present disclosure, when exhaust gas and flames are generated due to a thermal event in a battery module that initially caught fire, additional expansion space can be created in response to the increased internal pressure caused by the exhaust gas and flames, thereby reducing the internal pressure of the battery pack or slowing the rate of increase in internal pressure. As a result, thermal energy can be effectively dispersed within the battery pack, delaying cascading heat propagation to adjacent battery modules and preventing explosion of the entire battery pack.

[0034] Furthermore, according to one aspect of the present disclosure, solid exhaust including electrode exhaust can be collected and separated in an additional expansion space formed at the bottom of the battery pack, and only exhaust gas can be discharged to the outside of the battery pack case, thereby minimizing clogging of the exhaust valve.

[0035] Furthermore, according to another aspect of the present disclosure, the top cover may also plastically deform in response to an increase in the internal pressure of the battery pack, thereby forming additional expansion space, so that the internal pressure of the battery pack may be further reduced or the rate of increase of the internal pressure may be further reduced.

[0036] Effects obtainable from the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned above will be clearly understood by those skilled in the art to which the present disclosure pertains from the description of the present invention described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings illustrate preferred embodiments of the present disclosure and are used to provide further understanding of the technical concept of the present disclosure together with the detailed description of the present disclosure. Therefore, the present disclosure is not to be construed as being limited to the accompanying drawings.

[0038] Figure 1 is a perspective view of an entire battery pack according to an embodiment of the present disclosure.

[0039] Figure 2 yes Figure 1 Exploded perspective view of the main components of the battery pack.

[0040] Figure 3is a schematic cross-sectional view of a battery pack according to an embodiment of the present disclosure.

[0041] Figure 4 yes Figure 2 Exploded perspective view of the lower frame portion of the battery pack.

[0042] Figure 5 is a top view of a battery pack with a top cover removed according to an embodiment of the present disclosure.

[0043] Figure 6 is a bottom view of a battery pack with a bottom cover removed according to an embodiment of the present disclosure.

[0044] Figure 7 is an enlarged cross-sectional view of a battery pack according to an embodiment of the present disclosure.

[0045] Figure 8 is a schematic diagram illustrating a state in which a bottom cover is deformed in a battery pack according to an embodiment of the present disclosure.

[0046] Figure 9 is a schematic diagram illustrating a state in which exhaust gas is discharged through a gas exhaust valve in a battery pack according to an embodiment of the present disclosure.

[0047] Figure 10 is a schematic cross-sectional view of a battery pack according to another embodiment of the present disclosure.

[0048] Figure 11 is a diagram illustrating a vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meanings and dictionary meanings, but should be interpreted according to the meanings and concepts corresponding to the technical aspects of the present disclosure based on the principle that the inventor is allowed to appropriately define the terms for the best interpretation.

[0050] Therefore, the configurations proposed in the embodiments and drawings of this specification merely indicate the most preferred embodiments of the present disclosure, and do not represent all technical ideas of the present disclosure. Therefore, it should be understood that various equivalents and modifications may be made to the most preferred embodiments when submitting this application.

[0051] Figure 1 is a perspective view of the entire battery pack according to an embodiment of the present disclosure, Figure 2 yes Figure 1 An exploded perspective view of the main components of the battery pack, and Figure 3 is a schematic cross-sectional view of a battery pack taken along line AA′ according to an embodiment of the present disclosure.

[0052] Reference Figures 1 to 3 The battery pack 10 according to the present embodiment may include a plurality of battery modules 100 and a pack case 200 having an accommodation space S formed to accommodate the plurality of battery modules 100 .

[0053] refer to Figure 2 The battery module 100 may include a plurality of battery cells (not shown). A battery cell includes a secondary battery including an electrode assembly, a pouch case containing an electrolyte and the electrode assembly, and the like. Although this embodiment will be described based on a pouch-type battery cell having high energy density and being easy to stack, this embodiment may also be applied to a cylindrical or prismatic secondary battery as a battery cell.

[0054] The pouch-type battery cell may include a pair of electrode leads (not shown) that are connected to the electrode assembly and extend to the outside of the pouch shell, thereby serving as electrode terminals. A pair of electrode leads may extend forward and backward in the length direction. Alternatively, a pair of electrode leads may extend toward both ends of the battery cell, that is, in the length direction (±Y-axis direction). If desired, the electrode lead may be positioned only at one end in the Y-axis direction, for example, at one end in the -Y-axis direction. Although not shown, electrical components (such as bus bars, bus bar frames, and module connectors) may be installed adjacent to a pair of electrode leads of the battery cell.

[0055] The battery module 100 may include a module housing 120 for accommodating battery cells. The module housing 120 is a component for accommodating one or more battery cells and may be made of a metal material or a plastic material (such as ABS resin) having high rigidity and durability to physically or chemically protect the accommodated battery cells. The terminal 140 of the battery module 100 may be provided on the front side or the rear side (both sides in the Y-axis direction) of the module housing 120. The terminal 140 may be a positive electrode or a negative electrode and may be provided on both sides of the battery module 100, or in some cases may be provided on only one side.

[0056] like Figure 2 As shown, the battery pack housing 200 can accommodate a plurality of battery modules 100. To this end, the battery pack housing 200 may have an accommodation space S formed therein to accommodate the plurality of battery modules 100. The battery modules 100 may be arranged in the accommodation space S of the battery pack housing 200 in the width direction (X-axis direction) and the length direction (Y-axis direction). In addition, the battery pack housing 200 is a component that protects the battery modules 100 from external impacts, etc., and can be made of a material with excellent mechanical strength (excluding the bottom surface of the battery pack housing 200).

[0057] refer to Figure 2, the battery pack case 200 is shown as being divided into a battery pack frame 210 and a lower frame portion 220. As shown in the figure, the battery pack case 200 can be provided by coupling the battery pack frame 210 and the lower frame portion 220 to each other, and therefore, the bottom surface of the battery pack case 200 can be the upper surface of the lower frame portion 220.

[0058] like Figure 2 and Figure 3 As shown, a plurality of lower exhaust holes H may be formed in the lower frame portion 220. The plurality of lower exhaust holes H may be provided at both ends of the battery module 100 in the length direction (Y-axis direction) and may be arranged parallel to the width direction (X-axis direction). One or more lower exhaust holes H may be provided for each of the plurality of battery modules 100.

[0059] Reference Figure 3 , the accommodation space S of the pack case 200 and the inside of the lower frame portion 220 may communicate with each other through the lower exhaust hole H. Gaseous exhaust including exhaust gas and solid exhaust including electrode exhaust may move through the lower exhaust hole H.

[0060] The battery pack case 200 may be configured such that when the internal pressure increases due to exhaust gas and flames generated by a thermal event in the battery module 100, at least one side of the battery pack case 200 is deformed. The battery pack case 200 may form an expansion space ES1 separated from the accommodation space S in response to the increase in internal pressure. For example, the expansion space ES1 may be formed by Figure 3 The bottom surface of the battery pack case 200 (in this embodiment, the bottom cover 223 described later) is deformed.

[0061] More specifically, the lower frame portion 220 may include a base plate 221, a bottom reinforcement bar 222, and a bottom cover 223, as will be described later. When internal pressure increases, the bottom cover 223 can deform within the battery pack housing 200. That is, exhaust gases and solid waste generated in the accommodation space S can be discharged into the lower frame portion 220 through the lower exhaust holes H. Here, the expansion space ES1 may be the interior of the lower frame portion 220, which expands due to the deformation of the bottom cover 223. Therefore, if exhaust gases, flames, or the like are generated due to a thermal event, causing the internal pressure of the battery pack 10 to increase due to these emissions, a separate expansion space ES1 may be formed in addition to the accommodation space S of the battery pack 10. Consequently, the generated exhaust gases and solid waste can be discharged into the expansion space ES1 formed by the deformation of the bottom cover 223 of the lower frame portion 220, as well as into the accommodation space S, thereby reducing the internal pressure of the battery pack 10 or slowing down the rate of increase in internal pressure. According to the present disclosure, since the heat propagation rate decreases when the internal pressure increase is slowed, heat propagation delay performance can be improved.

[0062] Hereinafter, the battery pack case 200 will be described in more detail.

[0063] For further reference Figure 2 The pack case 200 may include a pack frame 210 accommodating the battery module 100 , a top cover 240 disposed on the top of the pack frame 210 , and a lower frame portion 220 disposed on the bottom of the pack frame 210 .

[0064] The battery pack frame 210 may be configured as a rectangular frame. Furthermore, the battery pack frame 210 may be configured to have an upper opening and a lower opening. A top cover 240 may be provided on the top of the battery pack frame 210, and a lower frame portion 220 may be provided on the bottom. Thus, the battery pack frame 210 may form an accommodation space S for accommodating the battery module 100 therein.

[0065] Figure 4 yes Figure 2 An exploded perspective view of the lower frame portion of the battery pack, Figure 5 is a top view of a battery pack with a top cover removed according to an embodiment of the present disclosure, Figure 6 is a bottom view of a battery pack with a bottom cover removed according to an embodiment of the present disclosure, and Figure 7 is an enlarged cross-sectional view of a battery pack according to an embodiment of the present disclosure.

[0066] refer to Figures 4 to 7 as well as Figure 2 and Figure 3 , the battery pack frame 210 has horizontal partitions 211 (in the Y-axis direction) and vertical partitions 212 (in the X-axis direction) that separate the interior of the battery pack frame 210. The horizontal partitions 211 can be arranged in the length direction (Y-axis direction) and spaced apart by the width of the battery module 100. The vertical partitions 212 can be arranged to extend from the center of the battery pack frame 210 in the width direction (X-axis direction) so as to separate the battery modules 100 adjacent in the length direction from each other. In the present embodiment, five horizontal partitions 211 and one vertical partition 212 are provided in the battery pack frame 210, so that 10 battery modules 100 are accommodated in the accommodation space S. In addition, the scope of the present disclosure is not limited to the number of horizontal partitions 211 and vertical partitions 212 or the number of battery modules 100 accommodated in the present embodiment.

[0067] A plurality of exhaust valves 213 may be provided on one side of the battery pack frame 210 in the width direction of the battery module 100. The exhaust valve 213 may be provided on both sides in the width direction (X-axis direction). The exhaust valve 213 may be provided so that the exhaust gas is discharged in the width direction (X-axis direction) of the battery module 100 (in the length direction in the case of a vehicle). The exhaust valve 213 may be operated so that the accommodating space S inside the battery pack housing 200 may be connected to the outside or may be isolated from the outside. The exhaust valve 213 may be operated when the internal pressure reaches a preset pressure or greater, which will be described in detail in the operation description later.

[0068] Return Reference Figure 1 and Figure 2 The top cover 240 may be disposed on the top of the pack frame 210 , and the top cover 240 may be configured to seal the accommodation space S accommodating the battery module 100 . The top cover 240 in this embodiment may be configured to completely cover ten battery modules 100 .

[0069] refer to Figures 4 to 7 The lower frame portion 220 is provided on the bottom of the battery pack frame 210 to support the plurality of battery modules 100 mounted on the lower frame portion 220. The lower frame portion 220 may include: a base plate 221 coupled to the battery pack frame 210 to support the battery modules 100; a bottom reinforcement bar 222 provided between the bottom of the base plate 221 and a bottom cover 223; and a bottom cover 223 provided on the bottom surface of the battery pack case 200 to cover the base plate 221.

[0070] The base plate 221 may be coupled to the bottom of the pack frame 210. Figure 7 , the base plate 221 may be coupled to a stepped portion provided on a lower portion of the battery pack frame 210. The base plate 221 may form a bottom surface of the battery pack case 200 and may be provided to contact the bottoms of the plurality of battery modules 100 accommodated in the accommodation space S. Thus, the plurality of battery modules 100 may be stably positioned and supported.

[0071] In addition, although not shown in the figure, a plurality of coolant flow paths may be provided on the bottom of the base plate 221, and the base plate 221 and the cooling system may be configured integrally. For example, the base plate 221 may be integrated with a heat sink.

[0072] A plurality of lower exhaust holes H may be formed at the edge of the substrate 221. The plurality of lower exhaust holes H may be arranged parallel to the width direction of the battery module 100. The plurality of lower exhaust holes H may be arranged in a pair of rows on both sides of the battery module 100 in the length direction (Y-axis direction). One or more lower exhaust holes H may be provided for each battery module 100. In this embodiment, two lower exhaust holes H may be formed for each battery module 100, such as Figure 5 and Figure 6 As shown. Exhaust gas and solid exhaust including electrode exhaust generated in the accommodation space S can move to the expansion space ES1 of the lower frame portion 220 through the lower exhaust holes H. In addition, the arrangement of the plurality of lower exhaust holes H of each battery module 100 or the number of the lower exhaust holes H is not limited to this embodiment and can be changed variously.

[0073] refer to Figure 4 The bottom reinforcement bar 222 may be provided between the bottom of the base plate 221 and the bottom cover 223. The bottom reinforcement bar 222 may be provided to be in direct contact with the bottom of the base plate 221. The bottom reinforcement bar 222 may support the bottom of the base plate 221 to structurally reinforce the base plate 221, thereby preventing the base plate 221 from sagging or bending. Figure 4 and Figure 6 , a plurality of bottom reinforcement bars 222 may be provided. In addition, the bottom reinforcement bars 222 may be formed so as not to interfere with the plurality of lower exhaust holes H. Therefore, the bottom reinforcement bars 222 do not hinder the flow of exhaust gas and solid exhaust discharged through the lower exhaust holes H.

[0074] like Figure 4 As shown, the heat-resistant / refractory liner 224 may be interposed between the base plate 221 and the bottom cover 223. The heat-resistant / refractory liner 224 may be disposed along the periphery of the base plate 221 and the bottom cover 223. Specifically, the heat-resistant / refractory liner 224 may be disposed along the edge region of the base plate 221, as shown in FIG. Figure 6 As shown, it can also be set at both ends of the bottom reinforcement strip 222. Figure 7 As shown, the heat-resistant / fire-resistant gasket 224 can seal the base plate 221, bottom reinforcement bar 222, and bottom cover 223 arranged sequentially from above in the peripheral area where the bottom reinforcement bar 222 is provided, and can also seal the space between the base plate 221 and bottom cover 223 in the peripheral area where the bottom reinforcement bar 222 is not provided. The heat-resistant / fire-resistant gasket 224 can be made of a material with heat resistance and fire resistance. By providing the heat-resistant / fire-resistant gasket 224, it is possible to prevent exhaust gas or solid exhaust materials in the expansion space ES1, which are at a higher temperature or higher pressure than the outside, from randomly leaking out of the battery pack case 200.

[0075] The bottom cover 223 may be provided on the bottom surface of the battery pack case 200 to cover the substrate 221. The bottom cover 223 may be provided to contact the lower end of the battery pack frame 210, as shown in FIG. Figure 7 As shown, the bottom cover 223 may be spaced a predetermined distance apart from the base plate 221 and the bottom reinforcement bar 222. Although not shown in the drawings, the bottom cover 223 may be bolted to the battery pack frame 210. Even when the bottom cover 223 is deformed due to increased internal pressure from exhaust gas and flames, the bottom cover 223 may be securely fixed to the battery pack frame 210.

[0076] The bottom cover 223 can be configured to plastically deform and expand downward from the battery pack frame 210 when the internal pressure within the accommodation space S increases. That is, the bottom cover 223 can be spaced apart from the base plate 221 or the bottom reinforcement bar 222 by a predetermined distance or more. In addition, the space formed by the separation distance can form an expansion space ES1. In this case, the base plate 221 and the bottom reinforcement bar 222 do not experience any deformation.

[0077] The bottom cover 223 can be made of steel or SUS. In addition, the thickness t of the bottom cover 223 can be less than the thickness of the battery pack frame 210. The bottom cover 223 in this embodiment can be configured to have a thickness of 1.6 mm to 2.5 mm. Therefore, the bottom cover 223 can be easily deformed, and in particular, its plastic deformation can occur, so that the expansion space ES1 can be formed inside the battery pack housing 200 through deformation. The bottom cover 223 can be deformed to form the expansion space ES1, while the base plate 221 and the bottom reinforcement bar 222 remain almost unchanged.

[0078] According to this implementation, in addition to the existing accommodation space S, a separate expansion space ES1 can be provided, thereby increasing the volume within the battery pack housing 200 capable of accommodating exhaust gases and the like. Exhaust gases and solid waste can therefore be distributed within the expansion space ES1, thereby reducing internal pressure or slowing the rate of increase in internal pressure. Consequently, thermal energy can be effectively dispersed, delaying cascading heat propagation to adjacent battery modules 100 and preventing explosion of the entire battery pack 10.

[0079] Furthermore, according to the configuration implemented above, solid exhaust including electrode exhaust can be collected and separated in the additional expansion space ES1 formed on the bottom of the battery pack 10, and only exhaust gas can be discharged to the outside, thereby minimizing clogging of the exhaust valve 213. That is, after the expansion space ES1 is formed by deformation of the bottom cover 223, the exhaust valve 213 can be operated when the internal pressure reaches a preset pressure or higher, and the exhaust valve 213 can be configured to discharge only the exhaust gas.

[0080] Furthermore, the implemented configuration effectively prevents exhaust gas or flames from reaching the upper side of the battery pack 10 in situations such as thermal runaway. In particular, in situations where passengers are positioned above the battery pack 10, such as in electric vehicles, the implemented configuration can suppress or delay the movement of gas or flames toward the passengers. Furthermore, while ensuring the safety of the upper side of the battery pack 10, there is no need for a structure that would impose layout or other restrictions that might be required when installing the battery pack 10 in a vehicle.

[0081] Figure 8is a schematic diagram showing a state in which a bottom cover is deformed in a battery pack according to an embodiment of the present disclosure, and Figure 9 is a schematic diagram illustrating a state in which exhaust gas is discharged from a battery pack through a gas exhaust valve according to an embodiment of the present disclosure.

[0082] In the following, reference will be made to Figures 1 to 9 A process of easily discharging exhaust gas to the outside according to the present embodiment is described in detail.

[0083] First, if Figure 8 If a thermal event occurs in a specific battery module 100 in the battery module 100 , the internal pressure increases in the accommodation space S, and a large amount of exhaust gas and solid exhaust are generated in the accommodation space S.

[0084] Next, the exhaust gas and solid exhaust can be discharged into the lower frame portion 220 through the lower exhaust hole H. The exhaust gas and the like can enter the expansion space ES1 of the lower frame portion 220, and at this time, the heat-resistant / refractory liner 224 can completely seal the base plate 221 and the bottom cover 223 (see the arrow indicating the movement direction of the exhaust gas and the like in the figure).

[0085] Next, as the internal pressure in the accommodation space S increases, the bottom cover 223 plastically deforms in response to the internal pressure. In this process, the gap between the bottom cover 223 and the base plate 221 increases and expands, thereby forming a separate expansion space ES1 in the lower frame portion 220 .

[0086] Therefore, the generated exhaust gas and solid exhaust can be discharged into the expansion space ES1 and the accommodation space S. In particular, the solid exhaust that moves to the expansion space ES1 can be collected in the expansion space ES1. The solid exhaust including the electrode exhaust is solid particles and is heavier than the gas exhaust, so it can be collected in the expansion space ES1.

[0087] Finally, after the expansion space ES1 is formed, if the internal pressure reaches a preset pressure or more, the exhaust valve 213 is opened as shown in FIG. Figure 9 The operation is shown. Only the exhaust gas in the accommodation space S and the expansion space ES1 is discharged to the outside of the battery pack housing 200 through the exhaust valve 213. The exhaust gas can be discharged in the width direction of the battery module 100. In addition, solid exhaust including electrode exhaust remains collected in the expansion space ES1 due to its own weight.

[0088] According to the above operation, the internal pressure of the battery pack 10 can be reduced or the rate of increase of the internal pressure can be reduced. Therefore, the heat energy can be effectively dispersed, so that the chain heat propagation to the adjacent battery module 100 can be prolonged.

[0089] In addition, since solid exhaust including electrode exhaust is collected and separated by the additional expansion space ES1 formed on the bottom of the battery stack 10 , and since only exhaust gas is discharged to the outside, clogging of the exhaust valve 213 may be minimized.

[0090] Then, reference will be made to Figure 10 Other embodiments of the battery pack 10 of the present disclosure are briefly described.

[0091] Figure 10 is a schematic cross-sectional view of a battery pack according to another embodiment of the present disclosure.

[0092] The same reference numerals as in the previous drawings denote the same components, and repeated description of the same components will be omitted, and the description will be based on the differences from the above-described embodiment.

[0093] A top cover 240 is provided on the top of the battery pack housing 200. Although not shown in the figure, the top cover 240 is bolted to the top of the battery pack frame 210. In this case, a coupling member may be provided along the periphery of the top cover 240 to facilitate coupling to the battery pack frame 210. Furthermore, the center area of ​​the top cover 240 and the vertical partitions 212 of the battery pack frame 210 are not coupled.

[0094] The battery pack housing 200 may have an expansion space separated from the accommodating space S in response to an increase in internal pressure, and in addition to the expansion space ES1 formed by the deformation of the bottom surface of the battery pack housing 200 in the previous embodiment, an expansion space ES2 may also be provided by deformation of the top surface of the battery pack housing 200.

[0095] Specifically, the top cover 240 may be configured to plastically deform when internal pressure increases, and may expand upward from the battery pack case 200. Therefore, the expansion space ES2 may be formed by deformation of the top cover 240 of the battery pack case 200. As described above, the expansion space ES2 formed on the top of the battery pack case 200 may communicate with the accommodation space S of the battery pack case 200, and may communicate with the expansion space ES1 formed by deformation of the bottom surface of the battery pack case 200 through the lower vent hole H.

[0096] In this embodiment, the top cover 240 may be made of aluminum or SUS to facilitate plastic deformation. Similar to the bottom cover 223, the top cover 240 may be configured to have a thickness of 1.6 mm to 2.5 mm.

[0097] According to this configuration, when a thermal event occurs, exhaust gases and solid emissions can be discharged and can move upward from the accommodating space S (see the thick arrow in the Z-axis direction in the figure) to first expand the top cover 240 to form an expansion space ES2. In addition, the exhaust gases and solid emissions can move to both sides in the figure (see the thick arrows in the ±Y-axis direction and the thick arrow in the -Z-axis direction in the figure) to form an expansion space ES1 by expanding the bottom cover 223 through the lower exhaust hole H. Since the expansion space ES2 is formed on the top of the battery pack housing 200 due to the deformation of the top cover 240, it is advantageous to promote the movement of the generated exhaust gases, etc. In addition, compared with the above-mentioned embodiment, since the expansion space ES2 is further provided, there is also the advantage of an increase in additional space that can accommodate exhaust gases, etc.

[0098] In addition, the order of forming expansion spaces ES1 and ES2 is not limited to the order described herein, and the bottom cover 223 can be deformed to preferentially form expansion space ES1 on the bottom of the battery pack housing 200, and then the top cover 240 can be deformed to form expansion space ES2 at the top of the battery pack housing 200, or the expansion spaces ES1 and ES2 can be formed simultaneously on the top and bottom of the battery pack housing 200.

[0099] According to this implementation configuration, expansion spaces ES1 and ES2 are formed on the top and bottom surfaces of the battery pack case 200, respectively, making it possible to further reduce the internal pressure increased by a thermal event or further reduce the rate of increase of the internal pressure, and to effectively disperse thermal energy, thereby delaying cascading heat propagation to adjacent battery modules 100. In particular, in response to an increase in the internal pressure of the battery pack 10, in addition to the accommodation space S and expansion space ES1 formed by the deformation of the bottom cover 223, the top cover 240 may also plastically deform to form an additional expansion space ES2, thereby further reducing the internal pressure of the battery pack 10 or further reducing the rate of increase of the internal pressure.

[0100] In addition, solid exhaust including electrode exhaust may be collected and separated by the additional expansion space ES1 formed on the bottom of the battery stack 10, and only exhaust gas may be discharged to the outside, so that the exhaust valve 213 (see FIG. Figure 9 ) blockage can be minimized.

[0101] In addition, although not shown, the battery pack 10 according to the present disclosure may further include various devices for controlling charging and discharging of the battery module 100 , such as a BMS (Battery Management System), a current sensor, a fuse, and the like.

[0102] Figure 11 is a diagram illustrating a vehicle according to an embodiment of the present disclosure.

[0103] Reference Figure 11 The battery pack 10 according to the present disclosure can be applied to a vehicle V such as an electric vehicle or a hybrid vehicle. That is, the vehicle V according to the present disclosure can include the battery pack 10 according to the present disclosure. The battery pack 10 can be installed in the vehicle body frame or in the trunk space under the vehicle seat, and the battery pack 10 can be installed in the reverse order as needed when installed in the vehicle.

[0104] In addition, although terms indicating directions such as up, down, left, right, forward, and backward are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the position of the target object or the position of the observer.

[0105] As described above, although the present disclosure has been described with reference to limited embodiments and drawings, the present disclosure is not limited thereto, and various modifications and changes may be made by those skilled in the art within the technical concept of the present disclosure and the equivalent scope of the claims to be described below.

[0106] [Description of Reference Signs]

[0107] V: Vehicle 10: Battery Pack

[0108] 100: Battery module 120: Module housing

[0109] 140: Terminal 200: Battery pack housing

[0110] S: Accommodation space 210: Battery pack frame

[0111] 211: Horizontal divider 212: Vertical divider

[0112] 213: Exhaust valve 220: Lower frame part

[0113] ES1, ES2: expansion space 221: substrate

[0114] H: Lower exhaust hole 222: Bottom reinforcement strip

[0115] 223: Bottom cover 224: Heat / fire resistant lining

[0116] 240: Top cover

Claims

1. A battery pack, comprising: multiple battery modules; as well as a battery pack housing having an accommodation space formed to accommodate the plurality of battery modules, The battery pack case is configured such that when internal pressure increases due to exhaust gas and flames generated by a thermal event in the battery module, at least one surface of the battery pack case deforms.

2. The battery pack according to claim 1, in, The pack case has an expansion space formed to be separated from the accommodation space in response to an increase in the internal pressure.

3. The battery pack according to claim 2, in, The expansion space is formed by deformation of a bottom surface of the pack case.

4. The battery pack according to claim 2, in, The battery pack housing comprises: a battery pack frame configured to have an upper opening and a lower opening and to accommodate the battery module therein; and A lower frame portion is provided at a bottom of the battery pack frame to support the plurality of battery modules mounted thereon.

5. The battery pack according to claim 4, in, The lower frame portion comprises: a base plate coupled to the pack frame and configured to support the battery module; and A bottom cover is provided on a bottom surface of the battery pack case so as to cover the substrate.

6. The battery pack according to claim 5, in, The bottom cover is configured to plastically deform and expand downward from the pack case when the internal pressure increases.

7. The battery pack according to claim 5, in, The bottom cover is made of steel or SUS.

8. The battery pack according to claim 5, in, The bottom cover is configured to have a thickness of 1.6 mm to 2.5 mm.

9. The battery pack according to claim 5, in, The substrate has a plurality of lower exhaust holes through which the exhaust gas and solid exhaust including electrode exhaust move to the expansion space.

10. The battery pack according to claim 9, in, The battery modules are arranged in the accommodation space of the battery pack case in the width direction and the length direction, and Wherein, the multiple lower exhaust holes are arranged parallel to the width direction.

11. The battery pack according to claim 10, in, One or more lower exhaust holes are provided for each of the plurality of battery modules.

12. The battery pack according to claim 10, in, The lower frame portion further includes a bottom reinforcement bar disposed between the bottom of the base plate and the bottom cover. Wherein, the plurality of lower exhaust holes are formed so as not to interfere with the bottom reinforcement strip.

13. The battery pack according to claim 5, in, A heat / fire resistant liner is interposed between the base plate and the bottom cover.

14. The battery pack according to claim 13, in, The heat / fire resistant lining is disposed along the periphery of the base plate and the bottom cover.

15. The battery pack according to claim 9, in, The battery pack frame has a plurality of exhaust valves provided along a width direction of the battery module.

16. The battery pack according to claim 15, in, The exhaust valve is configured to operate when the internal pressure reaches a preset pressure or more after the bottom cover is deformed to form the expansion space.

17. The battery pack according to claim 16, in, The solid exhaust is collected in the expansion space together with the exhaust gas through the lower exhaust hole, and Wherein, the exhaust valve is configured to discharge only the exhaust gas.

18. The battery pack according to claim 9, in, The expansion space is formed by deformation of the top and bottom surfaces of the battery pack case, and The expansion space formed by deformation of the top surface of the battery pack case and the expansion space formed by deformation of the bottom surface of the battery pack case are communicated with each other through the lower vent hole.

19. The battery pack according to claim 18, in, The battery pack housing further includes a top cover disposed on top of the battery pack frame to seal the accommodation space for accommodating the battery module. wherein the bottom cover is configured to plastically deform and expand downward from the battery pack housing when the internal pressure increases, and The top cover is configured to plastically deform and expand upward from the battery pack housing when the internal pressure increases.

20. A vehicle comprising the battery pack according to any one of claims 1 to 19.

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