Battery pack and device containing same

Abstract

A battery pack according to one embodiment of the present invention includes a plurality of battery cells stacked in one direction, a pack case that houses the battery cells in an internal space, a cell cover that at least partially surrounds at least some of the plurality of battery cells in the internal space of the pack case, and a burst sheet formed between an upper portion of the cell cover and the battery cells.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0089845, filed July 20, 2022, Korean Patent Application No. 10-2022-0089846, filed July 20, 2022, and Korean Patent Application No. 10-2023-0091053, filed July 13, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery pack and a device including the same, and more particularly to a battery pack with enhanced safety and a device including the same. [Background technology]

[0003] In modern society, as the use of portable devices such as mobile phones, laptops, video cameras, and digital cameras has become commonplace, technological development in fields related to these mobile devices is accelerating. Furthermore, rechargeable secondary batteries are being used as the power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and other vehicles as a way to address air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and there is a growing need for the development of secondary batteries.

[0004] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages of being able to be charged and discharged freely, having a low self-discharge rate, and having a high energy density.

[0005] Such a lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with a positive electrode active material and a negative electrode active material, are arranged with a separator sandwiched therebetween, and an exterior material, i.e., a battery case, that hermetically houses the electrode assembly together with an electrolyte.

[0006] Generally, secondary batteries are classified into can-type batteries, in which the electrode assembly is housed in a metal can, and pouch-type batteries, in which the electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] Recently, battery packs have been widely used for driving and storing energy in medium- to large-sized devices such as electric vehicles and energy storage systems. A conventional battery pack includes one or more battery modules and a control unit, such as a Battery Management System (BMS), that controls the charging and discharging of the battery pack inside a pack case. Here, a battery module is configured to include multiple battery cells inside a module case.

[0008] That is, in the case of a conventional battery pack, a plurality of battery cells (secondary batteries) are housed inside a module case to form each battery module, and one or more such battery modules are housed inside a pack case to form a battery pack.

[0009] In particular, pouch-type batteries have various advantages, such as light weight and little dead space when stacked, but are vulnerable to external impacts and have somewhat poor assembly properties. Therefore, battery packs are generally manufactured by first modularizing a plurality of cells and then housing them inside a pack case. As a typical example, a conventional battery pack is configured by first housing a plurality of battery cells inside a module case to form a battery module, and then housing one or more such battery modules inside a pack case. Furthermore, as disclosed in the following prior art document (Korea Patent Publication No. 10-2015-0044599), a conventional battery module is often constructed by stacking a plurality of battery cells using various components, such as a plastic stacking frame (also called a cartridge), plates at both ends in the cell stacking direction, and fastening members such as bolts. The stack thus formed is then often housed inside a module case to form a module.

[0010] However, such conventional battery packs may be disadvantageous in terms of energy density. Typically, in the process of modularizing a plurality of battery cells by housing them inside a module case, various components such as the module case or a stacking frame may unnecessarily increase the volume of the battery pack or reduce the space occupied by the battery cells. Furthermore, the space occupied by the components themselves, such as the module case or the stacking frame, may be reduced, as well as the space occupied by the battery cells may be reduced to ensure assembly tolerances for these components. Therefore, conventional battery packs may have limitations in increasing their energy density.

[0011] In addition, conventional battery packs can be difficult to assemble. In particular, manufacturing a battery pack requires first modularizing a plurality of battery cells to form a battery module, and then housing the battery module in a pack case, which complicates the manufacturing process. Furthermore, as disclosed in the prior art, the process and structure of forming a cell stack using a stacking frame, bolts, plates, etc. can be very complicated.

[0012] Furthermore, in the case of a conventional battery pack, a module case is housed inside a pack case, and battery cells are housed inside the module case, which makes it difficult to ensure excellent cooling performance. In particular, when heat from the battery cells housed inside the module case is dissipated to the outside of the pack case through the module case, the cooling efficiency is reduced and the cooling structure becomes complicated.

[0013] In addition, gas venting may occur inside the battery cell due to heat generated from the battery cell, etc. In this case, if a structure for gas venting is not provided, gas may be vented from the battery cell without a specific direction, increasing the possibility of damage to adjacent battery cells. In addition, there is a problem that the safety of the battery pack cannot be ensured due to the gas venting being released to the outside of the modularized battery cell and battery pack. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Republic of Korea Patent Publication No. 10-2015-0044599 (Publication Date: April 27, 2015) Summary of the Invention [Problem to be solved by the invention]

[0015] The problem to be solved by the present invention is to provide a battery pack and a device including the same that have improved durability and safety by providing a vent structure for gas inside the battery cell.

[0016] However, the problems that the embodiments of the present invention attempt to solve are not limited to the problems described above, and other problems not described can be expanded to the extent that they can be clearly understood by a person skilled in the art from the description of the present invention. [Means for solving the problem]

[0017] A battery pack according to one embodiment of the present invention includes a plurality of battery cells stacked in one direction, a pack case that houses the battery cells in an internal space, cell covers that at least partially surround at least some of the plurality of battery cells in the internal space of the pack case, and a rupture sheet formed between an upper portion of the cell cover and the battery cells.

[0018] The rupture sheet may include a plurality of rupture layers and a rupture inducing member formed between the plurality of rupture layers.

[0019] The cell cover may include a plurality of holes formed through an upper portion of the cell cover, and the burst sheet may include a plurality of vent portions formed in an area of ​​the burst sheet corresponding to the holes.

[0020] The vent portion is formed by a plurality of vent holes formed in an area of ​​the burst sheet corresponding to the holes in the cell cover.

[0021] The shape of the vent hole may be the same as or smaller than the shape of the cell cover.

[0022] In a battery pack according to another embodiment of the present invention, the vent portion may include a rupture portion including at least three corner portions, and a connection portion which is one corner portion connected to the rupture sheet.

[0023] The rupture portion is formed along the length of the rupture sheet, and the connection portion is formed to extend along the width of the rupture sheet.

[0024] The cell cover may further include a first end plate and a second end plate covering a front side and a rear side of the cell cover, respectively, and the rupture portion may be positioned closer to the first end plate than the connecting portion, and the connecting portion may be positioned closer to the second end plate than the rupture portion.

[0025] A plurality of cell units including the plurality of battery cells and the cell covers are mounted in the pack case facing each other, and the rupture portions provided on the facing cell units are arranged to face in opposite directions.

[0026] According to an embodiment of the present invention, the vent is formed by rupture of the plurality of rupture layers caused by the expansion of the rupture inducing member.

[0027] The plurality of burst layers may include a first burst layer and a second burst layer, the first burst layer being positioned opposite one side of the second burst layer, and the other side of the second burst layer being positioned opposite the battery cell.

[0028] The first rupture layer and the second rupture layer may have a laminate structure.

[0029] The rupture inducing member can expand at a temperature above a certain level to rupture and cut the rupture layers.

[0030] The rupture inducing member may include a shape memory alloy.

[0031] A device according to yet another embodiment of the present invention includes the battery pack described above. [Effects of the Invention]

[0032] According to the embodiment, a plurality of battery cells can be stably housed inside a pack case without the need for a stacking frame such as a plastic cartridge or a separate module case. Furthermore, according to one aspect of the present invention, a configuration in which battery cells having cases made of a flexible material are directly stacked inside a pack case can be more easily realized by forming the battery cells into a simple and strong form.

[0033] In particular, according to one embodiment of the present invention, a configuration in which a plurality of battery cells are stacked in a horizontal direction while being vertically upright can be easily realized.

[0034] According to one aspect of the present invention, the energy density of a battery pack can be improved.

[0035] Furthermore, according to one embodiment of the present invention, the battery cells are directly housed in the pack case without being modularized, eliminating the need for a module case. This reduces the space occupied by such a module case, allowing more battery cells to be placed inside the pack case, thereby further improving the energy density of the battery pack.

[0036] Furthermore, according to one aspect of the present invention, the assembly of a battery pack can be improved. In particular, according to one embodiment of the present invention, the steps of accommodating battery cells in a module case to form a battery module and accommodating one or more battery modules thus assembled in a pack case are not performed. Therefore, the manufacturing process is simplified and the manufacturing time is reduced.

[0037] According to one aspect of the present invention, a configuration for easily changing the number of battery cells enclosed by a cell cover can be easily realized. In particular, according to one embodiment of the present invention, the number of unit cells accommodated by the cell cover can be easily changed by changing the width of the cell cover. Therefore, in this case, changes to the capacity or output of a single cell cover can be easily made.

[0038] Furthermore, according to one embodiment of the present invention, it is possible to easily realize a configuration in which the bus bars and terminals of each unit are positioned on the side, top or bottom of each cell cover for each cell unit.

[0039] According to an embodiment of the present invention, when a flexible battery cell is inserted into a pack case, the cell cover can be gripped without directly gripping the battery cell. Therefore, the battery cell handling process can be performed more easily and safely. Furthermore, in this case, the battery cell can be prevented from being damaged or broken during the cell handling process, such as inserting the battery cell into the pack case.

[0040] Furthermore, according to one aspect of the present invention, the safety of the battery pack can be improved.

[0041] In particular, according to an embodiment of the present invention, gases and the like discharged from each battery cell can be smoothly discharged to the outside. Furthermore, according to an embodiment of the present invention, the discharge direction of gases and flames discharged from the battery cells can be controlled. Therefore, the propagation of thermal runaway between adjacent battery cells can be effectively prevented.

[0042] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Brief explanation of the drawings]

[0043] [Figure 1] 1 is a schematic perspective view showing a partial configuration of a battery pack according to an embodiment of the present invention in an separated state. [Figure 2] 1 is an exploded perspective view schematically illustrating a cell unit including a battery cell and a cell cover that are housed inside a battery pack according to an embodiment of the present invention; [Figure 3] FIG. 3 is a perspective view showing the components of FIG. 2 joined together. [Figure 4] 10A and 10B are diagrams showing a rupture sheet included in the battery pack of the present invention. [Figure 5] FIG. 5 is an enlarged cross-sectional view of part A in FIG. 4, showing the state of the burstable sheet before it bursts. [Figure 6] 6 is a cross-sectional view showing the state in which the burst sheet of FIG. 5 has burst due to venting of gas inside the battery cell. [Figure 7] 10 is an exploded perspective view schematically illustrating a cell unit including a configuration of a battery cell and a cell cover housed inside a battery pack according to another embodiment of the present invention. FIG. [Figure 8] FIG. 8 is a perspective view showing the components of FIG. 7 joined together. [Figure 9] 10A and 10B are diagrams illustrating a burst sheet included in a battery pack according to another embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view taken along the line BB' in FIG. 9, showing the state of the burstable sheet before it bursts. [Figure 11] 11 is a cross-sectional view showing the state in which the burst sheet of FIG. 10 has burst due to venting of gas inside the battery cell. FIG. [Figure 12] FIG. 2 is a diagram showing area C of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0044]

[0033] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the embodiments. The present invention can be realized in various different forms other than those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0045] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0046] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily enlarged or reduced for the sake of convenience, and it is obvious that the content of the present invention is not limited to the drawings. In the following drawings, the thickness of each layer is enlarged to clearly show various layers and regions. In the following drawings, the thickness of some layers and regions is exaggerated for the sake of convenience.

[0047] Furthermore, when a layer, film, region, plate, or other portion is described as being "above" another portion, this should be interpreted as including not only the case where the layer, film, region, plate, or other portion is "directly above" the other portion, but also the case where there is another portion between them. Conversely, when a layer, film, region, plate, or other portion is described as being "directly above" another portion, it can mean that there is no other portion between them. Note that being "above" a reference portion means being located above or below the reference portion, and does not necessarily mean being "above" in the opposite direction of gravity. Meanwhile, similar to the description of being "above" another portion, the description of being "below" another portion can be understood with reference to the above content.

[0048] Furthermore, throughout the specification, when a part is described as "comprising" a certain element, this means that it can further include other elements, rather than excluding other elements, unless otherwise specified.

[0049] Furthermore, throughout the specification, "in a plane" means the part is viewed from above, and "in cross section" means the part is viewed from the side through a vertical cross section.

[0050] Fig. 1 is a schematic perspective view showing a partial separation of the configuration of a battery pack according to an embodiment of the present invention, Fig. 2 is an exploded perspective view showing a cell unit including a configuration of a battery cell and a cell cover housed inside the battery pack according to an embodiment of the present invention, and Fig. 3 is a perspective view showing the components of Fig. 2 assembled together.

[0051] 1 to 3, a battery pack 1000 according to an embodiment of the present invention includes a battery cell 100, a cell cover 200, and a pack case 600.

[0052] A plurality of the battery cells 100 are included in a battery pack 1000. The plurality of battery cells 100 are stacked in at least one direction. For example, referring to FIG. 1, the plurality of battery cells 100 are stacked in a horizontal direction, for example, in the left-right direction (x-axis direction in the drawing). Alternatively, the plurality of battery cells 100 may be stacked in the front-back direction (y-axis direction in the drawing) as shown in FIG. 1.

[0053] Furthermore, the plurality of battery cells 100 are arranged horizontally and in a form of a plurality of rows in the left-right and horizontal directions. For example, referring to FIG. 1, the plurality of battery cells 100 are stacked in a form of two rows of cells arranged in the left-right direction in the front-rear direction.

[0054] The battery pack 1000 according to the present invention may employ various types of battery cells 100 known at the time of filing of the present invention. As an example, the battery cell may be a pouch-type battery cell. Such a pouch-type battery cell is formed by accommodating an electrode assembly in a pouch case made of a laminate sheet including a resin layer and a metal layer, and then fusing the outer periphery of the pouch case. Such a battery cell is formed in a rectangular sheet structure. However, the structure of the battery cell is not limited thereto, and various types of battery cells may be applied. Therefore, detailed description of the configuration of such a battery cell will be omitted.

[0055] The pack case 600 has an empty space formed therein and can accommodate a plurality of battery cells 100. For example, as shown in FIG. 1, the pack case 600 may include an upper case 610 and a lower case 620. As a more specific example, the lower case 620 may be configured in a box shape with an open top end and can accommodate a plurality of battery cells 100 in the internal space. The upper case 610 is configured in a lid shape that covers the open top end of the lower case 620. In this case, the upper case 610 may be configured in a box shape with an open bottom end. The internal space of the pack case 600 accommodates the plurality of battery cells 100 as well as the cell cover 200. The pack case 600 may be made of a plastic or metal material. Alternatively, the pack case 600 may employ various exterior materials for battery packs known at the time of filing of the present application.

[0056] The cell cover 200 is configured to surround the battery cells 100 in the internal space of the pack case 600. In other words, the cell cover 200 is configured to surround at least some of the battery cells 100 among the multiple battery cells 100 included in the battery pack 1000. Furthermore, the cell cover 200 is provided to at least partially surround the battery cells 100.

[0057] The cell cover 200 is configured to surround the battery cells 100 in this manner, thereby supporting the stacked state of the plurality of battery cells 100 inside the pack case 600. For example, the plurality of battery cells 100 are stacked in the horizontal direction (x-axis direction in the drawing) as shown in Fig. 1. At this time, the cell cover 200 is configured to stably maintain the stacked state of the plurality of battery cells 100 stacked in this horizontal direction.

[0058] According to this aspect of the present invention, a plurality of battery cells 100 are directly placed and housed inside the pack case 600 without a module case. In particular, the exterior material of the battery cells 100 is made of a soft material, which makes them vulnerable to external impacts and has low hardness. Therefore, it is not easy to house the battery cells 100 by themselves inside the pack case 600 without housing them in a module case. However, in the present invention, the plurality of battery cells 100 are directly housed inside the pack case 600 while being at least partially surrounded by the cell cover 200 and coupled with the cell cover 200, and the stacked state can be stably maintained.

[0059] Therefore, according to this aspect of the present invention, there is no need to additionally provide a module case, a stacking frame, or fastening members such as bolts for maintaining the stacked state of the cells in the battery pack 1000. Therefore, the space occupied by other components such as the module case and the stacking frame and the space required to ensure tolerances can be eliminated. As a result, the battery cells can occupy the additional space eliminated, thereby further improving the energy density of the battery pack.

[0060] Furthermore, according to this aspect of the present invention, since a module case, stacking frame, bolts, etc. are not provided, the volume and weight of the battery pack can be reduced and the manufacturing process can be simplified.

[0061] Furthermore, according to this aspect of the present invention, handling of the battery cells 100 becomes easier. For example, when a plurality of battery cells 100 are stored inside a pack case, the battery cells 100 can be held by a jig or the like. In contrast, in the case of the present invention, the jig does not hold the battery cells 100 directly, but can hold the cell covers 200 surrounding the battery cells 100. Therefore, damage or breakage of the battery cells 100 by the jig can be prevented.

[0062] Furthermore, according to this aspect of the present invention, the cell cover 200 is coupled to the battery cell 100, so that the battery cell 100 can be effectively protected without a module case.

[0063] The cell cover 200 may be made of various materials to ensure rigidity. In particular, the cell cover 200 is made of a metal material. Such a metal material can more stably maintain the stacked state of the battery cells 100 and more safely protect the battery cells 100 from external impacts. In particular, the cell cover 200 may be made of a steel material or a stainless steel (SUS) material. For example, the entire cell cover 200 is made of SUS material.

[0064] In this way, when the cell cover 200 is made of a steel material, it has excellent mechanical strength or rigidity, and can therefore more stably support the stacked state of the battery cells 100. In addition, in this case, it is possible to more effectively prevent damage or breakage of the battery cells 100 from external impacts, such as needle-shaped objects. In addition, in this case, the battery cells 100 can be handled more easily.

[0065] Furthermore, when the cell cover 200 is made of steel as in the above embodiment, its high melting point allows the overall structure to be stably maintained even when a flame breaks out from the battery cell 100. In particular, since steel has a higher melting point than aluminum, it does not melt even when a flame breaks out from the battery cell 100 and can stably maintain its shape. Therefore, it can have excellent effects such as preventing or delaying the spread of flame between the battery cells 100 and controlling vents.

[0066] The cell cover 200 is configured to surround one or more battery cells 100. For example, as shown in Figures 2 and 3, one cell cover 200 is configured to surround one battery cell 100 or multiple battery cells 100. In this case, a cell cover 200 is individually coupled to each battery cell 100 of the multiple battery cells 100, or the cell cover 200 is configured to surround two or more battery cells 100 together.

[0067] The cell cover 200 can be at least partially adhered to the outer surface of the battery cell 100. For example, the cell cover 200 can be adhered to the inner surface of the battery cell 100 housing.

[0068] The battery pack 1000 may include one or more cell covers 200. In particular, the cell covers 200 are configured to group and unitize the plurality of battery cells 100 included in the battery pack 1000. In this case, one cell cover 200 can be said to constitute one cell unit 10. One cell unit 10 can include one or more battery cells 100. The battery pack 1000 may include multiple cell units 10, in which case, it can be said that multiple cell covers 200 are included in the battery pack 1000. As an example, if the cell cover 200 is configured to surround one battery cell 100, the battery pack 1000 may include the same number of cell covers 200 as the number of battery cells 100. As another example, if the cell cover 200 is configured to surround two or more battery cells 100, the battery pack 1000 may include a number of cell covers 200 that is smaller than the number of battery cells 100.

[0069] The cell cover 200 is configured to support multiple battery cells 100 in an upright position. As shown in FIG. 2 , each battery cell 100 has two wide surfaces, and the corners of the wide surfaces may have sealed or folded portions of the pouch exterior material. Therefore, it is generally difficult to stack the battery cells 100 in an upright position. However, in the battery pack 1000 according to the present invention, the cell cover 200 is configured to surround one or more battery cells 100 and support the enclosed battery cells 100 in an upright position, i.e., an upright position.

[0070] In particular, the cell cover 200 is configured so that a plurality of battery cells 100 can be stacked horizontally in a vertically standing state. For example, as in the embodiment shown in FIGS. 1 to 3, a plurality of cell covers 200 are stacked horizontally, and each cell cover 200 is configured to surround one or more battery cells 100. In this case, the cell cover 200 can stably maintain a configuration in which a plurality of battery cells 100 are stacked horizontally in a vertically standing state.

[0071] In particular, the cell cover 200 is configured to be able to stand on its own in the internal space of the pack case 600. In other words, the cell cover 200 is configured to maintain an upright state by itself without the assistance of other components provided in the battery pack 1000, such as the pack case 600 or the battery cells 100.

[0072] For example, in the embodiment of FIG. 1, the cell cover 200 is placed directly on the bottom surface of the lower case 620. At this time, a portion of the cell cover 200, particularly the lower end portion of the cell cover 200, is placed in direct contact with the bottom surface of the lower case 620. The cell cover 200 is configured to stably maintain the placed state when the lower end portion is placed in this manner. At this time, if the cell cover 200 is made of a metal material with excellent rigidity such as steel, particularly a stainless steel material, the freestanding state can be more stably maintained. Therefore, in this case, the upright state of the battery cell 100 can be more reliably supported.

[0073] The cell cover 200 is configured to partially surround the battery cell 100 so that at least one side of the surrounded battery cell 100 is exposed to the outside. That is, the cell cover 200 is configured to surround only a portion of the battery cell 100 rather than completely surround the entire battery cell 100. In particular, the cell cover 200 is configured so that at least one side of the battery cell 100 is exposed toward the pack case 600.

[0074] 2 and 3, the cell cover 200 is configured to surround one battery cell 100, and the lower portion of the surrounded battery cell 100, i.e., the battery cell 100 accommodated in the internal space, is not surrounded by the cell cover 200. Therefore, the lower portion of the battery cell 100 is exposed toward the pack case 600 and can directly face the pack case 600. In particular, with reference to the embodiment of FIG. 1, the lower portion of the battery cell 100 can be exposed toward the bottom surface of the lower case 620.

[0075] According to this embodiment of the present invention, the cooling performance of the battery pack 1000 can be more effectively ensured. In particular, according to this embodiment, the battery cells 100 and the pack case 600 can be in direct face-to-face contact with each other. Therefore, heat released from each battery cell 100 is directly transferred to the pack case 600, improving the cooling performance. In addition, in this case, a separate cooling structure does not need to be provided between the battery cells 100 and the pack case 600, thereby achieving efficient cooling performance. In addition, in this case, no space is provided between the battery cells 100 for a refrigerant such as air to flow in.

[0076] Meanwhile, in the battery pack 1000 according to the present invention, a thermal interface material (TIM) may be interposed to improve heat transfer performance between different components. For example, the TIM may be filled between the battery cell 100 and the cell cover 200, between the cell cover 200 and the pack case 600, and / or between the battery cell 100 and the pack case 600. In this case, the cooling performance of the battery pack 1000, for example, dual cooling performance, may be further improved.

[0077] In particular, the cell cover 200 is configured to surround edge portions E1 to E4 of the battery cell 100 accommodated therein that do not have electrode leads. For example, referring to the embodiment shown in FIG. 2, the battery cell 100 may have two electrode leads 110, i.e., a positive electrode lead and a negative electrode lead. In this case, the two electrode leads 110 may be located at the front edge portion E3 and the rear edge portion E4, respectively. In this case, the cell cover 200 is configured to surround one of the remaining two edge portions E1 and E2, excluding the front edge portion E3 and the rear edge portion E4.

[0078] 2 and 3, the battery cell 100 can be said to be formed in a substantially hexahedral shape. Electrode leads 110, i.e., a negative electrode lead and a positive electrode lead, are formed on two of the six faces. The cell cover 200 is provided to surround at least a portion of three of the remaining four faces of the six-sided battery cell 100, excluding the two faces on which the electrode leads 110 are formed.

[0079] According to this embodiment of the present invention, it is easy to realize a configuration in which one cell cover 200 supports and protects one or more battery cells. In particular, according to this embodiment, the lower edge portion E2 is not surrounded by the cell cover 200 and can be in direct face-to-face contact with the pack case 600. Therefore, heat from the battery cells 100 surrounded by the cell cover 200 can be quickly and smoothly dissipated to the lower pack case 600 side. Therefore, the cooling performance of the battery pack 1000 can be more effectively ensured.

[0080] In particular, this configuration can be more effectively implemented when cooling is primarily performed at the bottom of the pack case 600. For example, in the case of a battery pack mounted on an electric vehicle, since it is mounted at the bottom of the vehicle body, cooling is primarily performed at the bottom of the pack case 600. In this case, when the lower edge portion E2 of each battery cell 100 is in face-to-face contact with the pack case 600 as in the above embodiment, heat is rapidly transferred from each battery cell 100 to the pack case 600, thereby further improving cooling performance.

[0081] 2 and 3, the cell cover 200 can be said to be formed in a shape similar to the letter "n." The cell cover 200 can be said to be configured to cover the battery cell 100 housed therein except for the front side (y-axis direction) and rear side (-y-axis direction) from which the electrode leads 110 protrude, and the bottom side (-z-axis direction). In other words, the cell cover 200 is provided to cover the outer side and top side of the housing portion of the battery cell 100 housed therein.

[0082] More specifically, the cell cover 200 may include an upper cover portion 210, a first side cover portion 220, and a second side cover portion 230, as shown in FIG.

[0083] Here, the upper cover part 210 is configured to surround the upper part (z-axis direction) of the battery cell 100 accommodated therein. In particular, the upper cover part 210 is configured to be in contact with or spaced apart from the upper edge part E1 of the battery cell 100. Also, the upper cover part 210 is configured to have a planar shape. In this case, the cross section of the upper cover part 210 is formed in a horizontal linear shape, so that the upper edge part E1 of the battery cell 100 can be linearly surrounded from the outside.

[0084] The first side cover part 220 extends downward (in the negative z-axis direction) from one end of the upper cover part 210. For example, the first side cover part 220 extends downward (in the negative z-axis direction) from the left end (in the x-axis direction) of the upper cover part 210. Furthermore, the first side cover part 220 is formed in a flat shape. In this case, the first side cover part 220 is bent from the upper cover part 210.

[0085] The first side cover part 220 is configured to surround the outside of one side of the storage part of the battery cell 100 housed therein. For example, when one battery cell 100 is housed in the cell cover 200, the first side cover part 220 is configured to surround the left side surface of the storage part of the housed battery cell 100 from the left side. Here, the first side cover part 220 can directly contact the outer surface of the storage part.

[0086] The second side cover part 230 may be positioned spaced apart from the first side cover part 220 in the horizontal direction. The second side cover part 230 is configured to extend downward from the other end of the upper cover part 210. For example, the second side cover part 230 is configured to extend downward (in the z-axis direction) from the right end part (negative x-axis direction) of the upper cover part 210. The second side cover part 230 is also configured to have a planar shape like the first side cover part 220. In this case, the second side cover part 230 and the first side cover part 220 can be said to be arranged parallel to each other while being spaced apart in the horizontal direction.

[0087] The second side cover part 230 is configured to surround the outside of the other side storage part of the battery cell 100 housed therein. For example, when one battery cell 100 is housed in the cell cover 200, the second side cover part 230 is configured to surround the right surface of the storage part of the housed battery cell 100 from the right side. Here, the second side cover part 230 can directly contact the outer surface of the storage part.

[0088] In the above embodiment, the internal space of the cell cover 200 is defined by the upper cover part 210, the first side cover part 220, and the second side cover part 230. The cell cover 200 can accommodate one or more battery cells 100 in the internal space defined in this manner.

[0089] In addition, in the above embodiment, the lower ends (-z-axis direction) of the first and second side cover parts 220 and 230 may contact the bottom surface of the pack case 600. In particular, the contact structure between the lower ends of the first and second side cover parts 220 and 230 and the pack case 600 is formed to extend elongated in the front-rear direction (y-axis direction in the drawing). According to this embodiment, a self-standing structure of the cell cover 200 that can maintain the battery cells 100 housed therein in an upright state can be more stably achieved.

[0090] Furthermore, the first side cover part 220 and the second side cover part 230 may have the same height. That is, the first side cover part 220 and the second side cover part 230 may have the same length extending downward from the upper cover part 210. In this case, the self-standing structure of the cell cover 200 can be more easily achieved.

[0091] Meanwhile, to explain the cell cover 200 and battery cell 100 according to one embodiment of the present invention again, the upper cover part 210 can face the upper edge part E1 of the battery cell 100 and can surround the upper edge part E1 together with the first side cover part 220 and the second side cover part 230.

[0092] In addition, the cross-sectional areas of the first side cover part 220 and the second side cover part 230 are larger than the cross-sectional area of ​​the battery cell 100 that the first side cover part 220 and the second side cover part 230 face, thereby preventing the storage part from being exposed to the outside and ensuring maximum safety.

[0093] Meanwhile, in the above embodiment, the cell cover 200 is mainly illustrated or described as being formed in an n-shape, but the cell cover 200 may be formed in various other shapes. For example, the cell cover 200 may be formed in various other shapes such as an I-shape, a U-shape, an L-shape, etc.

[0094] 2, the battery pack 1000 according to the present invention may further include a busbar assembly 300. Here, the busbar assembly 300 is configured to electrically connect the plurality of battery cells 100 to one another. For example, as shown in FIG. 2, the busbar assembly 300 is coupled to the electrode leads 110 of the plurality of battery cells 100 to electrically connect the plurality of battery cells 100 in series and / or parallel. The busbar assembly 300 may include busbar terminals made of an electrically conductive material such as copper or aluminum and in direct contact with the electrode leads 110, and a busbar housing made of an electrically insulating material such as plastic and supporting the busbar terminals.

[0095] Furthermore, when the electrode leads 110 are provided on both sides of the battery cell 100, the bus bar assemblies 300 are also included on both sides where the electrode leads 110 are provided. For example, as shown in FIG. 2, when the electrode leads 110 protrude on both the front side (y-axis direction) and the rear side (-y-axis direction), the bus bar assemblies 300 can also be located on both the front side and the rear side.

[0096] The busbar assembly 300 is coupled to one or more cell covers 200. At this time, the busbar assembly 300 is coupled to an end of one cell cover 200. At this time, one or more battery cells 100 are housed in one cell cover 200.

[0097] The bus bar assembly 300 can be coupled to the cell cover 200 in various ways. For example, the bus bar assembly 300 can be coupled and fixed to the cell cover 200 by various fastening methods such as adhesion, welding, fitting, hook coupling, bolting coupling, and rivet coupling.

[0098] 2 and 3, the battery pack 1000 according to the present invention may further include an insulating cover unit 350. In this case, the insulating cover unit 350 is made of an electrically insulating material and prevents the bus bar assembly 300 from being exposed to the outside by the end plate, thereby ensuring and maintaining electrical insulation.

[0099] Meanwhile, the battery pack 1000 according to the present invention may further include an end plate 400. In this case, the end plate 400 may include a first end plate 410 and a second end plate 420 that respectively cover the front side (y-axis direction) and rear side (-y-axis direction) of the cell cover 200. That is, the first end plate 410 is formed at the outermost portion of the bus bar assembly 300 and the insulating cover part 350 that covers the front edge part E3 of the battery cell 100. In addition, the second end plate 420 is formed at the outermost portion of the bus bar assembly 300 and the insulating cover part 350 that covers the rear edge part E4 of the battery cell 100.

[0100] The end plate 400 can secure the bus bar assembly 300 and the insulating cover part 350 to ensure the structural stability of the cell unit 10. In this case, holes that expose the insulating cover part 350 may be formed in the end plate 400, and directional venting may be induced through the holes, as the case may be.

[0101] The battery pack 1000 according to this embodiment includes a rupture sheet 500. The rupture sheet 500 is formed between an upper portion of the cell cover 200 and the battery cell 100. More specifically, the rupture sheet 500 is formed between the upper cover portion 210 of the cell cover 200 and the upper edge portion E1 of the battery cell 100. In addition, the rupture sheet 500 included in the battery pack 1000 according to this embodiment includes a shape memory alloy (SMA).

[0102] Holes 215 are formed in the cell cover 200, and a plurality of holes 215 are formed on the cell cover 200. In this case, the holes 215 may be formed on the upper part of the cell cover 200, i.e., on the upper cover part 210. That is, a plurality of holes 215 are formed in the cell cover 200, and the holes 215 are formed to penetrate the upper part of the cell cover 200. Therefore, gas inside the battery cells 100 and the cell units 10 can be smoothly discharged to the outside through the holes 215 formed in the cell cover 200.

[0103] The burstable sheet 500 included in the battery pack 1000 according to this embodiment will be described in more detail below.

[0104] Fig. 4 is a diagram showing a burst sheet included in a battery pack of the present invention. Fig. 5 is an enlarged cross-sectional view of part A in Fig. 4, showing the state of the burst sheet before it bursts. Fig. 6 is a cross-sectional view showing the state of the burst sheet in Fig. 5 after it has burst due to venting of gas inside the battery cell.

[0105] 2 to 6, the burst sheet 500 of the present invention may include a vent portion 501 formed in an area of ​​the burst sheet 500 corresponding to the position of the hole 215 formed in the cell cover 200.

[0106] In this case, the vent portion 501 may be formed by forming a plurality of vent holes 550 in an area of ​​the rupturable sheet 500 corresponding to the holes 215 in the cell cover 200, as will be described below. Thus, the vent portion 501 is formed in a portion of the rupturable sheet 500 corresponding to the position of the edge of the holes 215. Therefore, the vent portion 501 is formed by a group of a plurality of vent holes 550 on the rupturable sheet 500, and a plurality of vent portions 501 are also formed on the rupturable sheet 500, thereby forming a plurality of vent paths. In addition, gas generated within the battery cell 100 and the cell unit 10 can be quickly discharged through the vent paths during venting.

[0107] 5, the vent holes 550 are formed by the rupture of the burstable layers 510, 520, and are not formed in the normal state of the battery pack before the burstable layers 510, 520 rupture. Therefore, in the normal state of the battery pack, the burstable sheet 500 can be maintained in a state in which the vent holes 550 are not formed, as shown in FIG.

[0108] In this case, the vent portion 501 of the burstable sheet 500 may contain a shape memory alloy. That is, among the portions of the burstable sheet 500, the portion of the burstable sheet 500 corresponding to the position of the hole 215, i.e., the vent portion 501, may contain a shape memory alloy.

[0109] 5, the burst sheet 500 may include a plurality of burst layers 510, 520, including a first burst layer 510 and a second burst layer 520, and a burst induction member 530 formed between the plurality of burst layers 510, 520. The plurality of burst layers 510, 520 may include a greater number of burst layers, but as an example, the burst sheet 500 will be described with reference to FIG. 5 including two burst layers, the first burst layer 510 and the second burst layer 520. Here, the first burst layer 510 faces one side of the second burst layer 520, and the other side of the second burst layer 520 faces the battery cell 100. That is, the second burst layer 520 may be located between the battery cell 100 and the first burst layer 510. In other words, the plurality of burst layers 510 and 520 may have a structure in which the second burst layer 520 and the first burst layer 510 are sequentially stacked on the battery cell 100 .

[0110] 5 illustrates a cross section of a vent portion 501, which is a portion of the rupture sheet 500 corresponding to the hole 215 in the cell cover 200, within the region of the rupture sheet 500. Specifically, the vent portion 501 may include a plurality of rupture layers 510, 520 and a rupture induction member 530. Therefore, the rupture induction member 530 is formed in a portion of the rupture sheet 500 corresponding to the position of the hole 215 in the cell cover 200.

[0111] Specifically, rupture inducing member 530 formed between first rupture layer 510 and second rupture layer 520 is formed to contact first rupture layer 510 and second rupture layer 520, respectively.

[0112] The first rupture layer 510 and the second rupture layer 520 are formed into a plate-shaped sheet, but are not limited thereto.

[0113] The rupture inducing member 530 may include a shape memory alloy. More specifically, the rupture inducing member 530 may include a shape memory alloy or be formed of a shape memory alloy, and expand due to the expansion of the shape memory alloy. That is, when heat above a certain temperature is applied to the rupture sheet 500, the rupture inducing member 530 expands, thereby inducing the rupture and cutting of the rupture sheet 500. This is due to the characteristic that a shape memory alloy exists in a different shape at low temperatures, but memorizes a shape at high temperatures, and returns to the high-temperature shape when heat is applied.

[0114] Specifically, when gas inside the battery cell 100 and the cell unit 10 is vented, heat exceeding a predetermined temperature may be generated inside the battery. More specifically, when the gas is vented, heat having a temperature of at least 100° C. may also be generated. Therefore, when the gas is vented, the heat is transferred to the rupture inducing member 530.

[0115] In this case, the rupture inducing member 530 may include a material that expands when a temperature of at least 100° C. or higher is applied. That is, the rupture inducing member 530 may include a shape memory alloy that expands when a temperature of at least 100° C. or higher is applied. Therefore, the rupture inducing member 530 can expand when gas is vented from the battery cell 100 and the cell unit 10. In other words, the shape change of the rupture inducing member 530 at high temperatures also enables the first rupture layer 510 and the second rupture layer 520 to deform, rupture, and / or cut.

[0116] 6, rupture induction member 530 may include first rupture induction member 530a and second rupture induction member 530b. First rupture induction member 530a may be rupture induction member 530 expanded by heat transferred during gas venting, and second rupture induction member 530b may be rupture induction member 530 that has not yet expanded.

[0117] Specifically, first rupture inducing member 530a expands due to the heat, and in this case, can cut a portion of first rupture layer 510 and second rupture layer 520. That is, the expansion of rupture inducing member 530 can deform and cut rupture layers 510 and 520. In this case, vent holes 550 are formed on rupture sheet 500 by first rupture layer 510 and second rupture layer 520 that have been deformed and cut, thereby allowing gas inside battery cell 100 and cell unit 10 to be released to the outside.

[0118] 4 to 6, the shape of the vent hole 550 may be formed by cutting and lifting the first rupture layer 510 and the second rupture layer 520. Therefore, as shown in FIG. 4, the vent hole 550 is formed along a black solid line or curved shape. That is, the shape of the vent hole 550 may correspond to the shape of the hole 215 of the cell cover 200. Specifically, the shape of the vent hole 550 may be the same as or smaller than the shape of the hole 215 of the cell cover 200. However, the shape of the vent hole 550 is not limited thereto.

[0119] For example, when the heat is transferred to second rupture inducing member 530b, second rupture inducing member 530b can also cut first rupture layer 510 and second rupture layer 520. In this case, vent hole 550 is formed to have a larger area than the size of vent hole 550 when only first rupture inducing member 530a ruptures.

[0120] In addition, the rupture sheet 500, particularly the vent portion 501 on the rupture sheet 500, may include a plurality of rupture inducing members 530, and thus a plurality of vent holes 550 are formed on the rupture sheet 500 and the vent portion 501.

[0121] Furthermore, the rupture induction members 530 are formed along the shape of the holes 215 of the cell cover 200. That is, the plurality of vent holes 550 are formed along the shape along which the plurality of rupture induction members 530 are formed, and the shape of the vent portion 501 is formed along the shape along which the plurality of vent holes 550 are formed. In other words, the plurality of vent holes 550 are formed in the portions of the rupture sheet 500 corresponding to the positions of the holes 215, and the plurality of vent holes 550 formed in the portions of the rupture sheet 500 corresponding to the positions of the holes 215 may form the vent portion 501.

[0122] Therefore, in the normal operating state of the battery cell 100 and the cell unit 10, the vent hole 550 is not formed in the rupture sheet 500, but when the gas inside the battery cell 100 is vented, the rupture induction member 530 forms the vent hole 550 on the rupture sheet 500, thereby allowing the gas inside the battery cell 100 to be effectively discharged to the outside.

[0123] Therefore, the burstable sheet 500 included in the battery pack 1000 according to this embodiment forms the vent hole 550 and the vent portion 501 only when the gas in the battery cell 100 and the cell unit 10 is vented, thereby improving the stability of the battery pack 1000 and ensuring the performance of the battery pack 1000.

[0124] Additionally, although not shown in the drawings, the vent portion 501 provided in the rupture sheet 500 including the shape memory alloy may also be provided in the cell cover 200. In this case, the vent portion provided in the cell cover 200 is provided in the form of a hole 215. However, the vent portion provided in the cell cover 200 is formed by the same mechanism as that described above in which the vent portion 501 is formed in the rupture sheet 500. In this case, the rupture sheet 500 is not positioned between the cell cover 200 and the battery cell.

[0125] In other words, the cell cover 200 may be provided with a structure similar to that of the burst sheet 500, and when heat above a certain temperature is applied to the cell cover 200, a vent is formed in the cell cover 200, and a region of the cell cover 200 bursts and cuts, venting gas to the outside. A battery pack according to this modification does not include the burst sheet 500, and a structure similar to the vent 501 of the burst sheet 500 may be included in the cell cover 200 itself. This reduces the manufacturing cost of the battery and improves process efficiency.

[0126] A modified example of the battery pack according to the embodiment of the present invention will be described below, and a description of the same configuration as that described above will be omitted.

[0127] Fig. 7 is an exploded perspective view schematically illustrating a cell unit including a battery cell and a cell cover configured to be housed inside a battery pack according to another embodiment of the present invention. Fig. 8 is a perspective view illustrating a state in which the components of Fig. 7 are combined. Fig. 9 is a view illustrating a burst sheet included in a battery pack according to another embodiment of the present invention.

[0128] 7 to 9, a battery pack according to another embodiment of the present invention includes a battery cell 100, a cell cover 200 that covers the battery cell 100, and a burst sheet 500′ positioned between the battery cell 100 and the cell cover 200.

[0129] The burst sheet 500' is formed between the battery cell 100 and the upper part of the cell cover 200. The burst sheet 500' may include vent portions 501' formed in an area of ​​the burst sheet 500 corresponding to the positions of the holes 215 formed in the cell cover 200. A plurality of vent portions 501' are formed in an area of ​​the burst sheet 500' corresponding to the positions of the holes 215 in the cell cover 200. That is, the number of vent portions 501' may correspond to the number of holes 215. Specifically, the number of vent portions 501' may be the same as or less than the number of holes 215.

[0130] At least one corner of the vent portion 501' is connected to the burst sheet 500', and the remaining corners can form a burst portion 560 when the burst sheet 500' bursts in a high temperature state.

[0131] Specifically, with reference to FIG. 9, the vent portion 501 ′ can include a plurality of rupture portions 560 .

[0132] The rupture portion 560 may be a region of the burstable sheet 500' formed by the bursting of the burstable sheet 500'. Specifically, the rupture portion 560 is not formed in a battery pack in a normal state, but may be a region of the burstable sheet 500' formed by the bursting of the burstable sheet 500' when high-temperature gas or flame is generated in the battery cell 100.

[0133] Rupture portion 560 may include at least three corners. Specifically, at least one corner may be connected to burst sheet 500', and the remaining corners may constitute burst portion 560. Here, one corner connected to burst sheet 500' is defined as connecting portion 561.

[0134] The remaining corners constituting the rupture portion 560 other than the connecting portion 561 may be positioned closer to the first end plate 410 of the first end plate 410 and the second end plate 420. Here, being positioned closer to the first end plate 410 can also be explained as being positioned farther away from the second end plate 420. That is, in the vent portion 501′, the rupture portion 560 may be positioned closer to the first end plate 410, and the connecting portion 561 may be positioned closer to the second end plate 420.

[0135] Furthermore, the connecting portion 561 connected to the rupturable sheet 500' at the rupturable portion 560 may extend along the width direction of the rupturable sheet 500' (the x-axis direction in FIG. 7). In other words, the remaining corners forming the rupturable portion 560 are formed so as to be close to the second end plate 420 along the longitudinal direction of the rupturable sheet 500' (the y-axis direction in FIG. 7).

[0136] As a result, the remaining corners of the rupturable sheet 500' according to this embodiment that form the rupturable portion 560 are formed in a direction approaching the second end plate 420 (the -y-axis direction in FIG. 7), thereby guiding the exhaust path of the gas and flames exhausted by the rupturable portion 560.

[0137] More specifically, the corners of the rupture portion 560 may be connected to each other. As an example, the rupture portion 560 may have a rectangular shape, and one corner, which is the connecting portion 561, may be connected to the rupture sheet 500', and the remaining corners may form the rupture portion 560 by rupturing the rupture sheet 500' at a high temperature. However, the shape of the rupture portion 560 is not limited to this, and any shape that can guide the discharge direction of the gas and flame in the cell unit 10' in a predetermined direction may be used.

[0138] Therefore, the cell unit 10' according to this embodiment has the advantage that the rupturable portion 560 can be formed by cutting a portion of the rupturable sheet 500', which simplifies the manufacturing process and reduces manufacturing costs.

[0139] In other words, a plurality of rupture portions 560 are gathered together on the rupture sheet 500' to form a vent portion 501', and a plurality of vent portions 501' are also formed on the rupture sheet 500'. Therefore, a plurality of vent paths are formed on the rupture sheet 500'. In addition, if high-temperature gas or flames are generated inside the battery cell 100 and the cell unit 10', they can be quickly discharged to the outside through the vent paths.

[0140] The vent portion 501' and the rupture portion 560 will be described in detail below.

[0141] Fig. 10 is a cross-sectional view taken along line BB' in Fig. 9, showing the state of the burst sheet before it bursts. Fig. 11 is a cross-sectional view showing the state of the burst sheet in Fig. 10 after it has burst due to venting of gas inside the battery cell.

[0142] 10 and 11, a burst sheet 500' according to another embodiment of the present invention may include a plurality of burst layers 510, 520 and a burst induction member 530'. Specifically, the burst sheet 500' may include a first burst layer 510 and a second burst layer 520 having a laminated structure, and a burst induction member 530' located between the first burst layer 510 and the second burst layer 520. Here, the burst induction member 530' may be located in a portion of the burst sheet 500' where the burst portion 560 is formed.

[0143] Specifically, the rupture inducing member 530' formed between the first rupture layer 510 and the second rupture layer 520 is formed to contact the first rupture layer 510 and the second rupture layer 520, respectively.

[0144] Therefore, the shape change of the rupture inducing member 530' at high temperature also allows the first rupture layer 510 and the second rupture layer 520 to change shape, rupture, and / or break.

[0145] In other words, the rupture inducing member 530' expands due to high-temperature heat, gas, or flame generated from the battery cell 100, thereby cutting a portion of the first rupture layer 510 and the second rupture layer 520. That is, the rupture inducing member 530' expands, deforming and cutting the rupture layers 510 and 520. Therefore, the deformed and cut first rupture layer 510 and second rupture layer 520 form a rupture portion 560 on the rupture sheet 500', and at this time, the first rupture layer 510 and the second rupture layer 520 where the connecting portion 561 is located are not cut. In other words, the formation of the rupture portion 560 allows gas inside the battery cell 100 and the cell unit 10 to be discharged to the outside.

[0146] More specifically, the rupture portion 560 may be formed by cutting the first rupture layer 510 and the second rupture layer 520 and lifting them upward (in the z-axis direction). Therefore, as shown in Figures 7 and 8, the rupture portion 560 is formed along the solid black line, but the shape of the rupture portion 560 is not limited thereto.

[0147] In addition, the rupture sheet 500', particularly the vent portion 501' on the rupture sheet 500', may include a plurality of rupture inducing members 530', so that a plurality of rupture portions 560 are formed on the rupture sheet 500' and the vent portion 501'.

[0148] 7 to 11, the rupture induction members 530' may be positioned inside the holes 215 of the cell cover 200. That is, a plurality of rupture portions 560 are formed along the positions where the plurality of rupture induction members 530' are formed, and the shape of the vent portion 501' is formed along the shape where the plurality of rupture portions 560 are formed. In other words, a plurality of rupture portions 560 may be formed in portions of the rupture sheet 500' corresponding to the positions of the holes 215, and the plurality of rupture portions 560 formed in portions of the rupture sheet 500' corresponding to the positions of the holes 215 may form the vent portion 501'.

[0149] As a result, gaps are formed between at least two vent portions 501′ and the upper portion of the cell cover 200, and these gaps can ensure more diverse exhaust paths for the gas and flame inside the cell cover 200. In other words, the gas and flame inside the cell cover 200 can be exhausted through different paths, and the speed at which the gas and flame are exhausted can be adjusted.

[0150] The burstable sheet 500' may include at least two burstable portions 560, and the at least two burstable portions 560 may be spaced apart from each other along the longitudinal direction of the burstable sheet 500'. More specifically, the at least two burstable portions 560 may be arranged in the same direction. The number of burstable portions 560 may be four as shown in the drawing, but is not limited thereto and various numbers may be used.

[0151] Therefore, in the normal operating state of the battery cell 100 and the cell unit 10', the rupture portion 560 is not formed in the rupture sheet 500', but when the gas inside the battery cell 100 is vented, the rupture portion 560 is formed on the rupture sheet 500' by the rupture induction member 530', thereby allowing the gas inside the battery cell 100 to be effectively discharged to the outside.

[0152] In short, the burstable sheet 500' included in the battery pack according to this embodiment forms the burstable portion 560 and the vent portion 501' only when the gas in the battery cell 100 and the cell unit 10' is vented, thereby improving the stability of the battery pack 1000 and ensuring the performance of the battery pack 1000.

[0153] Additionally, although not shown in the drawings, the vent portion 501' provided in the burst sheet 500' including the shape memory alloy may also be provided in the cell cover 200. In this case, the cell cover 200 does not include the hole 215 and has the same shape as the vent portion 501' provided in the burst sheet 500'.

[0154] The vent portion provided in the cell cover 200 is formed by the mechanism described above in which the vent portion 501' is formed in the burst sheet 500'. At this time, the burst sheet 500' is not positioned between the cell cover 200 and the battery cell.

[0155] In other words, the cell cover 200 may be provided with a structure similar to that of the burst sheet 500', and thus, when heat above a certain temperature is applied to the cell cover 200, a vent is formed in the cell cover 200, and a region of the cell cover 200 bursts and cuts, venting gas to the outside. A battery pack according to this modification does not include the burst sheet 500', but may have a structure similar to the vent 501' of the burst sheet 500' included in the cell cover 200 itself. This reduces battery manufacturing costs and improves process efficiency.

[0156] FIG. 12 is a diagram showing area C in FIG.

[0157] 1 and 12, in a battery pack 1000' according to another embodiment of the present invention, the second end plates 420 of the cell units 10' facing each other are positioned close to each other. Accordingly, the vent portion 501' is formed so that it can be lifted toward the first end plate 410 in a high-temperature state to vent gas. More specifically, the vent portion 501' can guide the exhaust path of gas and flames within the cell cover 200' so that they are exhausted toward the first end plate 410.

[0158] In other words, the multiple cell units 10' are mounted facing each other in the pack case, and the vents 501' provided on the multiple cell units 10' facing each other are arranged to face in opposite directions. That is, the rupture portions 560 provided on the multiple cell units 10' facing each other are arranged to face in opposite directions. For example, in this drawing, if the vent 501' provided on one cell unit 10' is mounted so that it faces in the -y-axis direction, the vent 501' provided on the other opposite cell unit 10' is mounted so that it faces in the y-axis direction.

[0159] In this case, the first end plate 410 of the cell unit 10' housed in the battery pack 1000' is formed toward the outside of the battery pack 1000', not toward the internal space of the pack case 600, thereby minimizing damage to the normally operating cell unit 10 caused by flames and gases discharged by the vent portion 501'.

[0160] Furthermore, Figure 12 shows a state in which flames and gases are generated in all of the cell units 10' installed in the battery pack 1000'. However, even if flames and gases are generated in some of the cell units 10' installed in the battery pack 1000', the impact on adjacent cell units 10' or cell units 10' facing each other can be minimized, thereby improving the safety of the battery pack 1000'.

[0161] Meanwhile, although not specifically mentioned above, a battery pack according to an embodiment of the present invention may additionally include a battery management system (BMS) for managing the temperature, voltage, etc. of the battery and / or a cooling device.

[0162] A battery pack according to an embodiment of the present invention may be applied to various devices. For example, the device to which the battery pack is applied may be a means of transportation such as an electric bicycle, an electric vehicle, a hybrid vehicle, etc. However, the above-mentioned devices are not limited thereto, and the battery pack according to this embodiment may be used in various devices other than the above-mentioned examples, and this also falls within the scope of the present invention.

[0163] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0164] 10, 10': cell unit 100: Battery cell 110: Electrode lead 200, 200': Cell cover 210: Upper cover part 215: Hall 220: First side cover part 230: Second side cover part 300: Busbar assembly 350: Insulation cover part 400: End plate 500, 500': Bursting sheet 501, 501': Vent section 510: 1st rupture layer 520:Second rupture layer 530: Explosion induction element 550: Vent hole 560:Rupture part 561:Connection part 600: Pack case 610: Upper case 620: Lower case 1000, 1000': Battery pack

Claims

1. A plurality of battery cells stacked in one direction; a pack case that houses the battery cell in its internal space; a cell cover that at least partially surrounds at least some of the plurality of battery cells in an internal space of the pack case; a burst sheet formed between an upper portion of the cell cover and the battery cell, The burstable sheet is A plurality of rupture layers; a rupture induction member formed between the plurality of rupture layers, the cell cover includes a plurality of holes formed through an upper portion of the cell cover; the burst sheet includes a plurality of vents formed in an area of ​​the burst sheet corresponding to the holes, The vent portion is formed by rupture of the plurality of rupture layers caused by deformation of the rupture induction member due to heating.

2. The battery pack according to claim 1 , wherein the vent portion is formed by a plurality of vent holes formed in an area of ​​the burst sheet corresponding to the holes in the cell cover.

3. The battery pack of claim 2 , wherein the shape of the vent hole is the same as or smaller than the shape of the hole of the cell cover.

4. The vent portion is a rupture portion formed by one straight line extending in the width direction of the rupture sheet and two straight lines extending along the longitudinal direction of the rupture sheet; 2. The battery pack according to claim 1, further comprising: a connecting portion that connects a portion of the rupture portion surrounded by the three straight lines to the rupture sheet.

5. The rupture portion is formed along the longitudinal direction of the rupture sheet, The battery pack according to claim 4 , wherein the connecting portion is formed to extend along a width direction of the burst sheet.

6. The cell cover further includes a first end plate and a second end plate that cover a front side and a rear side of the cell cover, respectively; the rupture portion is located closer to the first end plate than the connection portion, The battery pack according to claim 4 , wherein the connecting portion is located closer to the second end plate than the rupture portion.

7. a plurality of cell units, each including the plurality of battery cells and the cell cover, are mounted in the pack case facing each other; The battery pack according to claim 4 , wherein the rupture portions provided on the plurality of cell units facing each other are arranged to face in opposite directions.

8. the plurality of rupture layers include a first rupture layer and a second rupture layer; the first rupture layer is positioned opposite one surface of the second rupture layer; The battery pack according to claim 1 , wherein the other surface of the second rupture layer faces the battery cell.

9. The battery pack of claim 8 , wherein the first burst layer and the second burst layer have a laminated structure.

10. The battery pack according to claim 1 , wherein the rupture inducing member expands at a temperature equal to or higher than a certain temperature to rupture and cut the plurality of rupture layers.

11. The battery pack according to claim 1 , wherein the rupture inducing member includes a shape memory alloy.

12. A device including the battery pack of claim 1.

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