Battery packs and devices containing them

Abstract

A battery pack according to one embodiment of the present invention includes at least one battery assembly containing a plurality of battery cells, and a pack housing that houses at least one of the battery assemblies. A plurality of venting channels extending in one direction are formed inside the bottom frame of the pack housing. Venting holes communicating with the venting channels are formed on the lower surface of the battery assembly, and each of the venting channels has an independent venting channel that is not shared with one another.

Description

Technical Field

[0001] Cross-reference of related applications This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0153573 filed on November 8, 2023, and Korean Patent Application No. 10-2024-0147344 filed on October 25, 2024, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a battery pack and a device including the same, and more specifically, to a battery pack and a device including the same that can minimize internal thermal runaway transfer and prevent structural collapse.

Background Art

[0003] In modern society, as the use of portable devices such as mobile phones, notebook computers, video cameras, and digital cameras has become common, technological development in fields related to such mobile devices has become active. In addition, rechargeable secondary batteries are a solution for solving problems such as air pollution in existing gasoline vehicles that use fossil fuels, and are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc., so the need for development of secondary batteries is increasing.

[0004] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among these, lithium secondary batteries are attracting attention because they have almost no memory effect, can be charged and discharged freely, have a very low self-discharge rate, and have a high energy density compared to nickel-based secondary batteries.

[0005] Such lithium secondary batteries primarily use lithium oxides and carbon materials as the positive electrode active material and negative electrode active material, respectively. A lithium secondary battery comprises an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with the positive electrode active material and negative electrode active material respectively, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium-ion secondary batteries can be classified into two types based on the shape of their casing: can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in an aluminum laminate sheet pouch.

[0007] In the case of secondary batteries used in small devices, two to three battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module is used in which multiple battery cells are electrically connected. Such battery modules have improved capacity and output by connecting multiple battery cells in series or parallel to each other to form a stack of battery cells. One or more battery modules can be installed together with various control and protection systems such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system to form a battery pack.

[0008] A battery pack includes battery modules as a sub-concept, and a battery module includes battery cells as a sub-concept. The number of battery cells in a battery module or the number of battery modules in a battery pack can be determined in various ways depending on the output and capacity of the battery pack required for the electric vehicle.

[0009] However, one of the most important issues with such battery packs is safety. In particular, if a thermal event occurs in any one of the multiple battery cells contained in the battery pack, it is necessary to prevent the propagation of such a thermal event to the other battery cells.

[0010] If thermal propagation between battery cells is not properly suppressed, this can lead to thermal events in other battery cells within the battery pack, potentially causing larger problems such as fire or explosion of the battery pack. Furthermore, fires or explosions in battery packs can cause significant damage to surrounding lives and property. Therefore, such battery packs require a configuration that can appropriately control the aforementioned thermal events and their propagation. [Overview of the project] [Problems that the invention aims to solve]

[0011] The problem that the present invention aims to solve is to provide a battery pack and a device including the same that, when a thermal event occurs in a particular battery cell, can cause venting gas, particles, or flames to move along a predetermined path and be discharged to the outside of the battery pack, thereby preventing the thermal event from propagating to other adjacent battery cells.

[0012] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly expanded from the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0013] A battery pack according to one embodiment of the present invention includes at least one battery assembly containing a plurality of battery cells, and a pack housing that houses at least one of the battery assemblies. A plurality of venting channels extending in one direction are formed inside the bottom frame of the pack housing. Venting holes communicating with the venting channels are formed on the lower surface of the battery assembly, and each of the venting channels has an independent venting channel that is not shared with one another.

[0014] At least one of the ends of the venting channel may be provided with a rupture section that is designed to burst when a certain pressure is exceeded.

[0015] A flange portion may be provided on the outer circumference of the venting hole, protruding in the direction in which the venting channel is located. The flange portion is insertable into the venting flow path of the venting channel.

[0016] The venting channel can extend along the longitudinal direction of the battery cell, which is perpendicular to the direction in which the battery cells are stacked.

[0017] The number of battery cells may be greater than the number of venting channels.

[0018] The venting channels may be provided such that there is one corresponding venting channel per unit of the battery cell with a capacity of 50Ah or more and 300Ah or less.

[0019] The battery assembly may include a plurality of battery cell units. Each battery cell unit may include at least one of the battery cells and a cell cover that partially encloses at least one of the battery cells. The cell cover may include a side portion that covers one side of the battery cell.

[0020] Each of the bending channels can be positioned to correspond to each of the battery cell units.

[0021] Each of the bending channels can communicate with each of the battery cell units on a one-to-one basis.

[0022] The cell cover can include a side surface portion that connects the side surfaces and a bottom surface portion that covers the lower portion of at least one of the battery cells. A cell cover bending hole communicating with the bending hole may be formed in the bottom surface portion.

[0023] A cell cover flange portion protruding in the direction in which the bending channel is located may be provided on the outer periphery of the cell cover bending hole. The cell cover flange portion can be inserted into the bending flow path of the bending channel.

[0024] The cell cover can include a side surface portion that connects the side surfaces and a top surface portion that covers the upper portion of at least one of the battery cells. A portion opened on the lower side of the cell cover can communicate with the bending hole.

[0025] The bottom frame can include a bending plate on which the battery assembly is placed and a lower plate located below the bending plate. A bending channel may be formed between the bending plate and the lower plate.

[0026] The bending plate can include an opening formed in a portion corresponding to the bending hole. The bending hole can communicate with the bending channel through the opening.

[0027] A flange portion protruding in the direction in which the bending channel is located may be provided on the outer periphery of the bending hole. The flange portion can be inserted into the bending flow path of the bending channel while passing through the opening.

[0028] A bending unit can be located between the bending plate and the lower plate. The bending channel may be formed in the bending unit. The bending unit may be in a form in which a plate material extends in a zigzag manner such that upper open regions and lower open regions are alternately positioned along the direction in which the battery cells are stacked.

[0029] While the upper open region is covered by the bending plate, any one of the bending channels may be formed. While the lower open region is covered by the lower plate, another one of the bending channels may be formed.

[0030] A bending space may be provided between the bending plate and the lower plate, and the pack housing may include a discharge portion communicating with the bending space.

[0031] The bending space may be a space between the bending plate and the lower plate excluding the bending channel.

[0032] The gas generated in the battery cell can be discharged to the outside through the discharge portion after sequentially passing through the bending channel and the bending space. The gas can flow while bending at least once in the bending space.

[0033] The pack housing may include a side portion extending along the periphery of the bottom frame. An internal hollow may be provided in any one of the side portions to communicate the discharge portion and the bending space with each other.

[0034] A bending extension portion communicating with the discharge portion can be located in the bending space.

[0035] The venting extension may be a tubular member having an inlet and an outlet.

[0036] Multiple flow channels that bend and extend in a series of ways may be formed within the internal space of the venting extension.

[0037] A device according to one embodiment of the present invention includes the battery pack. [Effects of the Invention]

[0038] According to an embodiment of the present invention, when a thermal event occurs in a battery cell, the high-temperature venting gas, particles, or flame ejected from the battery cell moves along a predetermined path and is discharged to the outside of the battery pack. At this time, since the venting channels through which the venting gas, particles, or flame flows are independent venting channels that are not shared with each other, the propagation of a thermal event occurring in a particular battery cell to other battery cells can be minimized.

[0039] The effects of the present invention are not limited to those described above, and other effects not mentioned will be clearly understood by those skilled in the art from the claims. [Brief explanation of the drawing]

[0040] [Figure 1] This is an exploded perspective view showing a battery pack according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view showing a section along the cutting line A-A' in Figure 1. [Figure 3] This is a partial cross-sectional view showing an enlarged view of section "B" in Figure 2. [Figure 4] Figure 1 is a perspective view showing the battery assembly included in the battery pack. [Figure 5] Figure 4 is an exploded perspective view of the battery assembly. [Figure 6] Figure 4 is a perspective view showing the battery cell stack included in the battery assembly. [Figure 7]This is a plan view showing one of the battery cells included in the battery cell stack shown in Figure 6. [Figure 8] Figure 6 is a perspective view showing the cell cover and pad included in the battery cell stack. [Figure 9] Figure 6 is an exploded perspective view of a battery cell unit included in a battery cell stack. [Figure 10] Figure 10(a) is a perspective view of the cell cover in Figure 9 from a different angle, and Figure 10(b) is a cross-sectional view showing a section along the cutting line C-C' in Figure 9. [Figure 11] This is a partial perspective view showing an enlarged view of the lower surface of the lower frame of a battery assembly according to one embodiment of the present invention. [Figure 12] This is a plan view showing the lower surface of the lower frame of a battery assembly according to one embodiment of the present invention. [Figure 13] This is a cross-sectional view showing a section along the cutting line D-D' in Figure 12. [Figure 14] This is a perspective view showing a busbar frame and busbar according to an embodiment of the present invention. [Figure 15] This is a perspective view showing a pack housing included in a battery pack according to one embodiment of the present invention. [Figure 16] This is a perspective view showing only the first side frame and bottom frame of a pack housing according to one embodiment of the present invention. [Figure 17] Figure 16 is a perspective view showing the first side frame with the inner frame removed. [Figure 18] Figure 17 is an exploded perspective view of the first side frame and bottom frame. [Figure 19] This is a partial perspective view showing an enlarged view of section "E" in Figure 17. [Figure 20] Figure 17 is a perspective view showing the venting plate removed. [Figure 21] This is a cross-sectional view showing a section along the cutting line F-F' in Figure 17. [Figure 22]This is a perspective view showing a venting unit, a venting channel plate, and a venting flap according to one embodiment of the present invention. [Figure 23] Figure 22 is an exploded perspective view of the venting unit, venting channel plate, and venting flap. [Figure 24] This is a cross-sectional view showing the section along the cutting line G-G' in Figure 23. [Figure 25] Figures 25(a) and (b) are partial views showing the venting channel plate and venting flap in Figure 23 connected and separated from each other, respectively. [Figure 26] This is a partial diagram showing a rupture according to another embodiment of the present invention. [Figure 27] This is a perspective view showing the outer frame of the first side section, the venting extension, and the lower plate of the bottom frame according to one embodiment of the present invention. [Figure 28] This is a perspective view showing the path through which gas and flames discharged from a venting unit according to one embodiment of the present invention travel. [Figure 29] This is a perspective view showing the path through which gas and flames discharged from a venting unit according to one embodiment of the present invention travel. [Figure 30] Figure 16 is a cross-sectional perspective view of the section along the cutting line I-I'. [Figure 31] This is a perspective view showing a venting extension according to one embodiment of the present invention. [Figure 32] Figure 31 is an exploded perspective view of the venting extension. [Figure 33] Figure 31 is a perspective view showing the labyrinth bracket included in the venting extension. [Figure 34] This is a cross-sectional view showing a section along the cutting line J-J' in Figure 31. [Figure 35] This is an exploded perspective view showing a battery cell unit according to another embodiment of the present invention. [Figure 36] This is a cross-sectional view of a cell cover according to another embodiment of the present invention. [Figure 37]Figure 36 is a cross-sectional view of a battery pack to which a cell cover has been applied. [Modes for carrying out the invention]

[0041] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be realized in a variety of different forms and is not limited to the embodiments described herein.

[0042] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0043] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for the sake of explanation, and the present invention is not limited to those shown. In the drawings, the thicknesses are shown enlarged to clearly represent various layers and regions. Also, in the drawings, the thicknesses of some layers and regions are shown exaggerated for the sake of explanation.

[0044] Furthermore, when we say that a layer, membrane, region, plate, or other part is "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when we say that one part is "directly above" another part, it means that there is no other part in between. Note that being "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "up" in the opposite direction of gravity.

[0045] Furthermore, when a specification as a whole states that a certain part "includes" a certain component, this means that, unless otherwise stated, it does not exclude other components, but rather further includes other components.

[0046] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0047] Figure 1 is an exploded perspective view showing a battery pack according to one embodiment of the present invention. Figure 2 is a cross-sectional view showing a cross-section along the cutting line A-A' in Figure 1. Figure 3 is a partial cross-sectional view showing an enlarged view of portion "B" in Figure 2.

[0048] Referring to Figures 1 to 3, a battery pack 1000 according to one embodiment of the present invention includes at least one battery assembly 100 containing a plurality of battery cells 110, and a pack housing 1100 that houses at least one battery assembly 100. Inside the pack housing 1100, a plurality of venting channels VC extending in one direction are formed, and venting holes 300VH communicating with the venting channels VC are formed on the lower surface of the battery assembly 100. Each venting channel VC has an independent venting channel that is not shared with one another.

[0049] When a thermal event occurs in a specific battery cell 110, causing high-temperature gas, particles, or flames to be ejected from that battery cell 110, the gas, particles, or flames flow from the battery cell 110 into the venting channel VC. Here, the particles may be metallic particles. The venting channels VC can have independent venting paths without sharing space with each other. Therefore, high-temperature gas, particles, or flames passing through one venting channel VC do not propagate to other adjacent venting channels VC. This minimizes the propagation of a thermal event occurring in a specific battery cell 110 to other battery cells 110.

[0050] The structure of the battery pack according to this embodiment will be described in more detail below.

[0051] Figure 4 is a perspective view showing the battery assembly included in the battery pack of Figure 1. Figure 5 is an exploded perspective view of the battery assembly of Figure 4. Figure 6 is a perspective view showing the battery cell stack included in the battery assembly of Figure 4. Figure 7 is a plan view showing one of the battery cells included in the battery cell stack of Figure 6.

[0052] Referring to Figures 1, 2, and 4-7, the battery cells 110 according to this embodiment can be stacked along one direction to form a battery cell stack 110A. The battery cells 110 will now be described.

[0053] The battery cell 110 in this embodiment may be of various forms, such as a pouch-type battery cell, a prismatic battery cell, or a cylindrical battery cell. As an example, as shown in Figure 7, the battery cell 110 in this embodiment may be a pouch-type battery cell. The following description will focus on pouch-type battery cells, but the battery cell 110 in this embodiment is not limited to this, and various types of battery cells can be applied.

[0054] The battery cell 110 according to this embodiment may be in a form in which an electrode assembly having electrode leads 111 protruding in one direction or both directions is housed in a pouch case 114. Such a battery cell 110 may be in the shape of a rectangular sheet. The battery cell 110 can be formed by housing the electrode assembly in a laminate sheet pouch case 114 containing a resin layer and a metal layer, and then bonding the outer periphery of the pouch case 114. As an example, the battery cell 110 may have a structure in which two electrode leads 111 face each other and protrude from one end 114a and the other end 114b of the cell body 113, respectively. In another embodiment, the battery cell 110 may have a structure in which all electrode leads 111 protrude in one direction. One of the electrode leads 111 is the positive electrode lead and the other is the negative electrode lead.

[0055] The battery cell 110 can be manufactured by housing an electrode assembly (not shown) in a pouch case 114 and then bonding both ends 114a, 114b of the pouch case 114 to a connecting side portion 114c. In other words, the battery cell 110 according to one embodiment of the present invention has a total of three sealing portions 114s, the sealing portions 114s are sealed by methods such as fusion bonding, and the remaining side portion may consist of a folding portion 115. That is, the battery cell 110 according to this embodiment can be a pouch-type secondary battery in which the electrode assembly is housed inside the pouch case 114, and the outer periphery of the pouch case 114 is sealed to form the sealing portions 114s. Figure 7 only shows that sealing portions 114s are formed at both ends 114a and 114b of the pouch case 114, and does not show a sealing portion on the side opposite the folding portion 115. However, the sealing portion on the side opposite the folding portion 115 is folded to one side after sealing is completed for space utilization.

[0056] The laminated sheet pouch case 114 may include an inner resin layer for sealing, a metal layer to prevent penetration of materials, and an outermost outer resin layer. With respect to the electrode assembly inside the pouch case 114, the inner resin layer may be located on the innermost side, the outer resin layer on the outermost side, and the metal layer may be located between the inner and outer resin layers.

[0057] The outer resin layer may have excellent tensile strength relative to its thickness, weather resistance, and electrical insulation properties to protect the electrode assembly from the outside. Such an outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. A metal layer may prevent air, moisture, etc., from entering the inside of the pouch-type secondary battery. Such a metal layer may include aluminum (Al). The inner resin layers may be heat-sealed to each other by applied heat and / or pressure with the electrode assembly inside. Such inner resin layers may include casted polypropylene (CPP) or polypropylene (PP).

[0058] The pouch case 114 is divided into two parts, and a recessed storage section can be formed in at least one of the two parts on which an electrode assembly can be placed. Along the outer circumference of such a storage section, a sealing section 114s may be provided by joining the inner resin layers of the two parts of the pouch case 114 together. In this manner, the pouch case is sealed, and a battery cell 110, which is a pouch-type secondary battery, can be manufactured.

[0059] The battery cell stack 110A may consist of multiple battery cells 110. Multiple battery cells 110 can be stacked in a manner that allows them to be electrically connected to one another. For example, multiple battery cells 110 can be stacked in an upright position along a direction parallel to the x-axis. This allows the electrode leads 111 to protrude in a direction perpendicular to the direction in which the battery cells 110 are stacked. In a battery cell 110, one electrode lead 111 can protrude in the y-axis direction, and the other electrode lead 111 can protrude in the -y-axis direction. If a battery cell has electrode leads 111 protruding in only one direction, the electrode leads 111 can protrude in either the y-axis direction or the -y-axis direction.

[0060] Figure 8 is a perspective view showing the cell cover and pads included in the battery cell stack of Figure 6. Figure 9 is an exploded perspective view of the battery cell unit included in the battery cell stack of Figure 6.

[0061] Referring together to Figures 5 to 9, in the battery cell stack 110A according to this embodiment, the battery cells 110 can be stacked to form a battery cell unit 110U. Specifically, the battery assembly 100 according to this embodiment may include a plurality of battery cell units 110U, and each battery cell unit 110U may include at least one battery cell 110 and a cell cover 200 that partially surrounds at least one battery cell 110.

[0062] In other words, according to this embodiment, one or more battery cells 110 are arranged inside the cell cover 200 to form a battery cell unit 110U, and such battery cell units 110U can be stacked along one direction to form a battery cell stack 110A.

[0063] Within the battery cell unit 110U, the battery cells 110 may consist of one or more. Figure 9 shows, as an example, that the battery cell unit 110U includes three battery cells 110. Multiple battery cells 110 can be stacked in a manner that allows them to be electrically connected to one another. In particular, multiple battery cells 110 can be stacked within the battery cell unit 110U along a direction parallel to the x-axis while remaining upright with one face of each cell body 113 facing each other.

[0064] Figure 10(a) is a perspective view of the cell cover in Figure 9 from a different angle, and Figure 10(b) is a cross-sectional view showing a section along the cutting line C-C' in Figure 9.

[0065] Referring to Figures 2, 6, 8, 9, and 10(a) and (b), the cell cover 200 according to this embodiment may include a side portion 210 that covers one side of the battery cell 110. The cell cover 200 may also include a bottom portion 220 that connects the side portions 210 and covers the lower part of at least one battery cell 110.

[0066] The cell cover 200 may include two side portions 210 and one bottom portion 220. One side portion 210 and one bottom portion 220 may be perpendicular, and each side portion 210 may extend upward from opposite sides of the bottom portion 220. The cell cover 200 according to this embodiment may be open on the top. That is, if the cell cover 200 is cut along the xz plane in Figure 9, the cell cover 200 may have a "U" shape. The cell cover 200 may be provided so as to surround at least a portion of three of the remaining four sides of the six-sided battery cell 110, excluding the two sides on which the electrode leads 111 are formed.

[0067] By positioning the battery cells 110 between the side portions 210 of the cell cover 200, the battery cells 110 within the battery cell stack 110A can be divided into battery cell units 110U. By dividing the battery cells 110 within the battery cell stack 110A into battery cell units 110U using the cell cover 200, the propagation of thermal events and thermal runaways can be delayed. Even if a thermal event or thermal runaway occurs in any one of the battery cells 110, the side portions 210 of the cell cover 200 are positioned in the direction in which the battery cells 110 are stacked, thus preventing the thermal event or thermal runaway from propagating to the battery cells 110 of adjacent battery cell units 110U.

[0068] The cell cover 200 can not only delay thermal runaway but also complement the rigidity of the battery cell 110, thereby allowing the battery cell 110 to maintain an upright position. The cell cover 200 can support the battery cell 110 by covering at least a portion of it, and can stably maintain the stacked state of the battery cells 110 arranged upright in one direction. More specifically, the side portion 210 of the cell cover 200 supports the side of the battery cell 110, thereby maintaining the upright position of the battery cell 110.

[0069] The cell cover 200 can be manufactured from a material that has a high melting point to prevent melting even in the event of thermal runaway, and that can block thermal events and the propagation of thermal runaway. Furthermore, the cell cover 200 can be manufactured from a material with mechanical strength above a certain range to stably support the battery cell 110, thereby protecting the battery cell 110 from external impacts. There are no specific restrictions on the material used for the cell cover 200, but examples include at least one of mica, steel, aluminum, or plastic.

[0070] Furthermore, in order to maintain the upright position of the battery cell 110 within the cell cover 200, an adhesive foil 700 may be additionally placed between the battery cell 110 and the side portion 210 of the cell cover 200. The adhesive foil 700 is not subject to any special restrictions on its material or form, as long as it can perform its adhesive function. For example, the adhesive foil 700 may be double-sided tape, and such double-sided tape may be made of polyethylene terephthalate (PET) with an acrylic material applied to it, or may contain an acrylic material. In addition, the adhesive foil 700 in other embodiments may be a spray-type adhesive, and such a spray-type adhesive may contain synthetic rubber.

[0071] Pads 400 can be interposed between the battery cell units 110U, that is, between the cell covers 200. Pads 400 can also be interposed on the outer surface of the cell cover 200 of the outermost battery cell unit 110U. Such pads 400 can function as a thermal barrier, blocking the propagation of thermal events and thermal runaway. In other words, there are no special restrictions on the material of the pads 400 in this embodiment, as long as they can achieve a predetermined level of thermal insulation. For example, the pads 400 can include silicon (Si) material or aerogel material.

[0072] On the other hand, a cell cover venting hole 220H may be formed in the lower surface portion 220 of the cell cover 200 according to this embodiment. If a thermal event generates high-temperature gas, particles, or flames in any one of the battery cells 110, as described above, the side portion 210 of the cell cover 200 can prevent the high-temperature gas, particles, or flames from propagating to adjacent battery cells 110. The high-temperature gas, particles, or flames can be discharged through the cell cover venting hole 220H formed in the lower surface portion 220. Such a cell cover venting hole 220H can communicate with a venting hole 300VH provided on the lower surface of the battery assembly 100. A more detailed explanation of this will be given later.

[0073] The following describes in detail the configuration by which downward venting is induced in the battery pack according to this embodiment.

[0074] Figure 11 is a partial perspective view showing an enlarged view of the lower surface of the lower frame of a battery assembly according to one embodiment of the present invention. Figure 12 is a plan view showing the lower surface of the lower frame of a battery assembly according to one embodiment of the present invention. Figure 13 is a cross-sectional view showing a section along the cutting line D-D' in Figure 12.

[0075] Referring together to Figures 5 and 11-13, the battery assembly 100 according to this embodiment may further include a module frame 300 in which the battery cell stack 110A is housed. The module frame 300 may include an upper frame 310 and a lower frame 320, and the battery cell stack 110A can be housed in the internal space formed by the upper frame 310 and the lower frame 320.

[0076] As described above, a venting hole 300VH is formed on the lower surface of the battery assembly 100, communicating with a venting channel VC inside the pack housing 1100. Specifically, the venting hole 300VH may be formed on the lower surface of the lower frame 320. The module frame 300 may also include a mounting portion 300M for fixing the battery assembly 100 to the bottom frame 1150 of the pack housing 1100. For example, a mounting hole may be formed in the mounting portion 300M, and mounting bolts may pass through these mounting holes and be fastened to the bottom frame 1150 to fix the battery assembly 100 in place.

[0077] Referring to Figures 1, 2, 3, 5, 7, and 11-13, as described above, multiple venting channels VC are formed inside the pack housing 1100, extending in one direction, and each venting channel VC has an independent venting flow path that is not shared with one another. The fact that multiple venting channels VC extend in one direction means that the independent venting flow path of each venting channel VC extends in that one direction.

[0078] The venting channel VC can extend along the longitudinal direction of the battery cell 110, which is perpendicular to the direction in which the battery cells 110 are stacked. Here, the direction in which the battery cells 110 are stacked may be parallel to the x-axis, and the longitudinal direction of the battery cell 110 perpendicular to this may be parallel to the y-axis, which is the direction in which the electrode leads 111 protrude from the battery cell 110. The extension direction of the venting channel VC will be explained again with reference to Figure 22, etc.

[0079] The pack housing 1100 includes a bottom frame 1150 on which the battery assembly 100 is placed, and multiple venting channels VC may be formed inside such bottom frame 1150. An opening 1151P is also formed in the bottom frame 1150 to guide high-temperature gases, particles, or flames generated during thermal events of the battery cell 110 into the venting channels VC. Specifically, a venting hole 300VH formed in the lower frame 320 of the module frame 300 can communicate with the venting channels VC via the opening 1151P in the bottom frame 1150. Furthermore, in the battery cell unit 110U according to this embodiment, a cell cover venting hole 220H formed in the cell cover 200 can communicate with the venting hole 300VH. That is, the venting hole 300VH can be positioned corresponding to the opening 1151P, and the cell cover venting hole 220H can be positioned corresponding to the venting hole 300VH.

[0080] As a result, when a thermal event occurs in a specific battery cell 110 and high-temperature gas, particles, or flames are ejected from that battery cell 110, the gas, particles, or flames can flow into the venting channel VC inside the bottom frame 1150 of the pack housing 1100 via the cell cover venting hole 220H, venting hole 300VH, and opening 1151P. The gas, particles, or flames that flow into the venting channel VC are discharged to the outside of the battery pack 1000. The battery pack 1000 according to this embodiment has a "bottom venting" structure that discharges high-temperature gas, particles, or flames generated inside the battery assembly 100 to the outside using the bottom frame 1150 of the pack housing 1100. As will be described later, there are high-voltage current paths in the upper region of the battery assembly 100, such as the HV (High voltage) connection of the terminal busbar. Here, HV connection refers to the connection of power sources that supply power requiring high voltage, and means the connection between battery cells or between battery assemblies. In this case, if high-temperature gases or particles from thermal events in the battery cells come into contact with a high-voltage path such as an HV connection, short circuits or arc discharges may occur, which could lead to additional explosions and flames. In contrast, in the case of the battery pack according to this embodiment, as mentioned earlier, it has a "lower venting" structure, so that high-temperature gases and particles from thermal events are discharged downwards, that is, to the bottom frame 1150 of the pack housing 1100. Therefore, there is no risk of high-temperature gases or particles coming into contact with a high-voltage path such as an HV connection, and ultimately, safety against thermal runaway phenomena can be enhanced.

[0081] On the other hand, in a battery assembly 100 according to one embodiment of the present invention, the battery cells 110 can be arranged such that the folding portion 115 of the battery cell 110 faces upward and one side portion 114c of the battery cell 110 faces downward. In other words, the battery cells 110 can be arranged such that the folding portion 115 of the battery cell 110 faces upward and the sealing portion 114s of one side portion 114c of the battery cell 110 faces downward.

[0082] The lower end of the battery cell 110 may be a sealing portion 114s where the pouch case 114 is sealed, and the upper end of the battery cell 110 may be a folding portion 115 where the pouch case 114 is folded, rather than a sealing portion. This allows the battery cell 110 to be positioned so that its sealing portion 114s faces the venting channel VC inside the pack housing 1100. The sealing portion 114s of the battery cell 110 can also be positioned so as to face the cell cover venting hole 220H of the cell cover 200. Referring to Figure 7, the battery cell 110 can be positioned inside the battery assembly 100 in an inverted state, with a sealing portion 114s on one side 114c of the battery cell 110, the sealing portion 114s on one side 114c facing downwards, and the folding portion 115 of the battery cell 110 facing upwards.

[0083] When a thermal event or thermal runaway occurs in the battery cell 110, venting gas is generated in the battery cell 110, increasing the internal pressure of the battery cell 110. This venting gas can be mainly discharged through the sealing portion 114s of the battery cell 110. In other words, the increased internal pressure causes a partial release of the sealing portion 114s, allowing the venting gas and other substances to be discharged through the released portion of the sealing portion 114s.

[0084] In the battery assembly 100 according to this embodiment, the battery cells 110 can be arranged such that the lower end of each battery cell becomes a sealing portion 114s and the upper end of each battery cell becomes a folding portion 115. With this arrangement, a "lower venting" structure that discharges venting gas and particles generated in the battery cells 110 downwards can be more clearly realized.

[0085] Each venting channel VC has an independent venting flow path that is not shared with one another. Therefore, gas, particles, or flames will flow into any one venting channel VC that communicates with the battery cell 110 where a thermal event has occurred, but such gas, particles, or flames will not propagate to other adjacent venting channels VC. Consequently, gas, particles, or flames will not flow into other battery cells 110 that communicate with other venting channels VC, and as a result, the thermal event will not propagate to or trigger other battery cells 110.

[0086] Each venting channel VC can be positioned to correspond to each battery cell unit 110U. Each venting channel VC can communicate with each battery cell unit 110U on a one-to-one basis. In other words, the number of venting channels VC can match the number of battery cell units 110U in the battery cell stack 110A, and any one battery cell unit 110U may communicate only with the venting channel VC located below it, and not with the other venting channels VC.

[0087] High-temperature gas and flames generated in any one battery cell unit 110U are discharged only into the venting channel VC that is in communication with it, and their movement to other venting channels VC is restricted. As described above, in the battery cell stack 110A according to this embodiment, the battery cells 110 can be housed in the cell cover 200 to form a battery cell unit 110U. High-temperature gas and flames caused by thermal runaway in any one battery cell unit 110U are blocked by the side portion 210 of the cell cover 200 and cannot propagate to other adjacent battery cell units 110U.

[0088] When high-temperature gas or flames are discharged to the corresponding venting channels VC at the top of the battery cell unit 110U, each venting channel VC has an independent venting path that is not shared with others, so that the high-temperature gas or flames do not flow into other adjacent venting channels VC. Therefore, there is no risk of high-temperature gas or flames flowing back into other adjacent venting channels VC and other battery cell units 110U located above them. If the venting paths of the venting channels VC were shared with each other, the battery cell unit 110U that did not experience thermal runaway would have a relatively lower internal pressure compared to the battery cell unit 110U that did experience thermal runaway, thus posing a risk of the generated high-temperature gas or flames flowing into its interior. In this embodiment, by realizing a unique venting path for each battery cell unit 110U, thermal runaway transitions between battery cells 110 are minimized, and structural collapse of the battery pack is prevented.

[0089] In the battery pack 1000 according to this embodiment, the number of battery cells 110 may be greater than the number of venting channels VC. The battery cell unit 110U may include multiple battery cells 110 and a cell cover that partially surrounds the battery cells 110. Multiple battery cells 110 in the battery cell unit 110U can be covered by the cell cover 200. Each venting channel VC can be positioned to correspond to each such battery cell unit 110U. One of the venting channels VC can correspond to various battery cells 110 within the battery cell unit 110U. Therefore, the number of battery cells 110 may be greater than the number of venting channels VC.

[0090] If the number of battery cells 110 and the number of venting channels VC were set to be the same, with one venting channel VC corresponding to each individual battery cell 110, a large number of independent venting channels VC would be required, resulting in a structurally complex and inefficient design. Therefore, in this embodiment, various battery cells 110 are bundled together to form a battery cell unit 110U, and each venting channel VC is provided to correspond to each of these battery cell units 110U, thereby efficiently realizing independent venting channels VC.

[0091] As one example, in the battery pack 1000 according to this embodiment, mutually independent venting channels VC may be provided such that one venting channel VC corresponds to each unit of battery cells 110 with capacities of 50Ah or more and 300Ah or less. Forming the venting channels VC based on the capacity unit of the battery cells 110 in this way may be more effective in realizing independent venting channels VC than setting each individual battery cell 110 to correspond to one venting channel VC.

[0092] As another example, in the battery pack 1000 according to this embodiment, mutually independent venting channels VC may be provided such that one venting channel VC corresponds to each unit of battery cells 110 with a thickness of 8 mm or more and 30 mm or less. Forming the venting channels VC based on the thickness unit of the battery cells 110 in this way may be more effective in realizing independent venting channels VC than setting one venting channel VC to correspond to each individual battery cell 110. The thickness range of 8 mm or more and 30 mm or less may correspond to the total widthwise thickness of the battery cells 110 provided in one battery cell unit 110U.

[0093] On the other hand, according to this embodiment, a flange portion 300F may be provided on the outer circumference of the venting hole 300VH, protruding in the direction in which the venting channel VC is located. Such a flange portion 300F can be inserted into the venting passage of the venting channel VC. More specifically, the flange portion 300F can be inserted into the venting passage of the venting channel VC while passing through the opening 1151P of the bottom frame 1150.

[0094] Figures 11 to 13 show the shape of the flange portion 300F formed on the lower frame 320 of the module frame 300. The flange portion 300F extends along the outer circumference of the venting hole 300VH and can project downward perpendicular to one surface of the lower frame 320. Figures 2 and 3 show how, when the battery assembly 100 is placed on the bottom frame 1150 of the pack housing 1100, the flange portion 300F formed on the lower surface of the battery assembly 100 is inserted into the venting channel VC while passing through the opening 1151P.

[0095] Although the venting hole 300VH is in communication with the venting channel VC, hot gas, particles, or flames discharged through the venting hole 300VH may flow back in the direction from which the battery cell 110 was located, and leak into the gap between the venting hole 300VH and the opening 1151P. This may cause other thermal events in adjacent battery cells 110, and ultimately, the flames may spread throughout the battery assembly 100 and the battery pack 1000. In addition, the impact generated when the battery cell 110 ignites may cause deformation at the contact surface between the battery assembly 100 and the bottom frame 1150. In this case, the possibility of hot gas, particles, or flames leaking into the gap between the venting hole 300VH and the opening 1151P increases further, and gas or flames may flow back into other adjacent battery cell units 110U. In this case as well, the flames may spread throughout the battery assembly 100 and the battery pack 1000.

[0096] To prevent such backflow or outflow of venting gas, a flange portion 300F according to this embodiment may be provided. Since the flange portion 300F is inserted into the venting flow path of the venting channel VC while passing through the opening 1151P, high-temperature gas or flames that have flowed into any one of the venting channels VC will not flow out into the gap between the venting hole 300VH and the opening 1151P. Therefore, even if a thermal event occurs in any one of the battery cells 110, the propagation of such a thermal event to other battery cells 110 can be minimized. Ultimately, it is possible to prevent flames from spreading throughout the battery assembly 100 and the entire battery pack 1000.

[0097] On the other hand, in the battery assembly 100, the battery cell 110 can be separated from the venting hole 300VH or the lower surface of the lower frame 320 by a predetermined distance. For example, the battery cell 110 can be separated from the venting hole 300VH or the lower surface of the lower frame 320 by a distance of 0.5 mm or more. If the battery cell 110 is in contact with the venting hole 300VH or the lower frame 320, or separated by a distance of less than 0.5 mm, the battery cell 110 may be damaged by vibration or shock.

[0098] Figure 14 is a perspective view showing a busbar frame and busbar according to an embodiment of the present invention. In particular, Figure 14 shows two busbar frames 500, and the busbar frame 500 located on the right shows the busbar 510 and terminal busbar 520 separated from the busbar frame 500.

[0099] Referring to Figures 4, 5, and 14, the busbar frame 500 may be arranged on one or both sides of the battery cell stack 110A in the direction in which the electrode leads 111 protrude. For example, in the battery cell 110 according to this embodiment, the electrode leads (111, see Figure 7) can protrude in both directions, that is, in the y-axis direction and the -y-axis direction. This makes it possible to arrange the busbar frame 500 on both the y-axis direction and the -y-axis direction of the battery cell stack 110A.

[0100] A busbar 510 and a terminal busbar 520 can be mounted on the opposite side of the busbar frame 500 from the side facing the battery cell stack 110A. The electrode leads 111 pass through a slit 500S formed in the busbar frame 500, then bend and can be connected to the busbar 510 or the terminal busbar 520. There are no special restrictions on how the electrode leads 111 are connected to the busbar 510 or the terminal busbar 520, as long as electrical connection is possible; for example, welding may be used. The battery cells 110 within the battery cell stack 110A can be electrically connected to each other using the busbar 510. On the other hand, as shown in Figure 4, a portion of the terminal busbar 520 is exposed to the outside of the module frame 300. The battery assembly 100 forms an HV connection with other battery assemblies and electrical components via such a terminal busbar 520. As described above, the battery pack 1000 according to this embodiment has a "lower venting" structure, which minimizes the impact of high-temperature gases, particles, or flames on high-voltage paths such as the HV connection of the terminal busbar 520.

[0101] The following provides a detailed explanation of the specific forms of the pack housing and venting channels.

[0102] Figure 15 is a perspective view showing a pack housing included in a battery pack according to one embodiment of the present invention. Figure 16 is a perspective view showing only the first side frame and bottom frame in the pack housing according to one embodiment of the present invention. Figure 17 is a perspective view showing the first side frame with the inner frame removed as in Figure 16. Figure 18 is an exploded perspective view of the first side frame and bottom frame of Figure 17.

[0103] Referring to Figures 1, 2 and 15-18, a pack housing 1100 according to one embodiment of the present invention may be a housing with an open top. The pack housing 1100 may include a bottom frame 1150 on which a battery assembly 100 is placed, and side portions 1110, 1120, 1130, and 1140 extending along the periphery of such bottom frame 1150. For example, the pack housing 1100 may include a first side portion 1110, a second side portion 1120, a third side portion 1130, a fourth side portion 1140, and a bottom frame 1150. The first to fourth side portions 1110, 1120, 1130, and 1140 may be arranged along the four sides of the periphery of a rectangular bottom frame 1150. The battery assembly 100 can be placed in the internal space formed by the bottom frame 1150 and the first to fourth side portions 1110, 1120, 1130, and 1140.

[0104] Furthermore, the pack cover 1200 can cover the open top of the pack housing 1100. Although not specifically shown, a gasket can be interposed between the first to fourth side portions 1110, 1120, 1130, and 1140 of the pack housing 1100 and the pack cover 1200 to improve airtightness.

[0105] Furthermore, the bottom frame 1150 can be used to define an area where the battery assembly 100 is placed, and to position a cross beam 1160 and a fixing beam 1170 for securing the battery assembly 100. The cross beam 1160 may be positioned alongside the first and second side sections 1110 and 1120, and the fixing beam 1170 may be positioned alongside the third and fourth side sections 1130 and 1140.

[0106] The bottom frame 1150 in this embodiment may include a venting plate 1151 on which the battery assembly 100 is placed, and a lower plate 1152 located below the venting plate 1151. A venting unit 1300 may be located between the venting plate 1151 and the lower plate 1152, and the aforementioned venting channel VC can be formed in such a venting unit 1300.

[0107] In a battery pack structure with "lower venting," the space between the venting plate 1151 and the lower plate 1152 is utilized as a space through which gas or flame flows, that is, a space in which a venting channel VC is formed. Furthermore, the venting unit 1300 can be realized as an independent venting channel VC without sharing such space with each other. In addition, the aforementioned opening 1151P may be formed in the venting plate 1151 of the bottom frame 1150. That is, the venting plate 1151 may include an opening 1151P formed in the portion corresponding to the venting hole 300VH of the battery assembly 100, and the venting hole 300VH can communicate with the venting channel VC via the opening 1151P. The opening 1151P may be provided by opening at least a portion of the area of ​​the venting plate 1151 that corresponds to the venting channel VC. There are no special restrictions on the number or area of ​​the openings 1151P. The flange portion 300F provided on the outer circumference of the venting hole 300VH can be inserted into the venting flow path of the venting channel VC while passing through the opening 1151P of the bottom frame 1150.

[0108] Figure 19 is a partial perspective view showing an enlarged view of section "E" in Figure 17. Figure 20 is a perspective view showing Figure 17 with the venting plate removed. Figure 21 is a cross-sectional view showing a section along the cutting line F-F' in Figure 17.

[0109] Referring to Figures 16 to 21, a venting space 1150S may be provided between the venting plate 1151 and the lower plate 1152 in the bottom frame 1150, and such a pack housing 1100 may include a discharge section 1111DH that communicates with such a venting space 1150S. The discharge section 1111DH may be an open hole formed in the pack housing 1100, or a structure in which a venting device is coupled to the hole. Here, a venting device refers to a structure that opens when the internal pressure exceeds a certain level to discharge internal gases, etc.

[0110] Specifically, the venting space 1150S may be the space between the venting plate 1151 and the lower plate 1152 excluding the venting channel VC. The venting space 1150S can correspond to the space between the venting plate 1151 and the lower plate 1152 excluding the venting unit 1300. Alternatively, the venting space 1150S may be the space through which gas and particles discharged from the venting channel VC of the venting unit 1300 flow between the venting plate 1151 and the lower plate 1152. Referring to the arrows in Figure 20, gas and particles discharged from the venting channel VC of the venting unit 1300 can flow along the venting space 1150S between the venting plate 1151 and the lower plate 1152 and flow into the venting extension 1400, which will be described later. The gas that flows into the venting extension 1400 is discharged to the outside of the battery pack through the discharge section 1111DH, which is formed in the pack housing 1100 and communicates with the venting space 1150S.

[0111] The discharge section 1111DH formed in the pack housing 1100 has no particular restrictions on its position, as long as it can communicate with the venting space 1150S.

[0112] As an example, an internal hollow 1110S may be provided in any one of the side sections 1110, 1120, 1130, or 1140, which connects the discharge section 1111DH and the venting space 1150S to each other. Hereinafter, the discharge section 1111DH and the internal hollow 1110S formed in the first side section 1110 will be described as an example.

[0113] The first side portion 1110 in this embodiment may include an outer frame 1111 and an inner frame 1112. Figure 16 shows both the outer frame 1111 and the inner frame 1112, while Figure 17 shows only the outer frame 1111.

[0114] The first side portion 1110 may include an internal hollow 1110S provided inside it. The internal hollow 1110S may be formed between the outer frame 1111 and the inner frame 1112. The outer frame 1111 may have an outer frame hole (1111H, see Figures 18 and 19) that communicates with the internal hollow 1110S, and the venting plate 1151 may have a through hole (1151H, see Figure 18) that communicates with such an outer frame hole 1111H. In other words, the venting space 1150S between the venting plate 1151 and the lower plate 1152 can communicate with the internal hollow 1110S of the first side portion 1110 via the through hole 1151H and the outer frame hole 1111H.

[0115] In other words, high-temperature gases and particles flowing along the venting space 1150S can flow into the internal hollow 1110S through the through-hole 1151H and the outer frame hole 1111H. The discharge section 1111DH may be formed in the outer frame 1111 of the first side section 1110. The high-temperature gases and particles that have flowed into the internal hollow 1110S can finally be discharged to the outside of the battery pack 1000 through the discharge section 1111DH.

[0116] In summary, gases and particles generated by thermal events in any one of the battery cells 110 can be discharged to the outside through the discharge section 1111DH after sequentially passing through the venting channel VC and venting space 1150S of the venting unit 1300. More specifically, the gases and particles flow along the venting channel VC and venting space 1150S of the venting unit 1300, pass through the internal hollow 1110S of the first side section 1110, and are discharged through the discharge section 1111DH. However, as mentioned above, the formation of the discharge section 1111DH in the first side section 1110 is merely one example of the present invention, and it can of course be formed in other configurations of the pack housing 1100.

[0117] At this time, the gas and particles can flow through the venting space 1150S, bending at least once, as shown by the arrow in Figure 20. Some of the gas and particles can bend several times in the venting space 1150S and flow along a longer path. In the case of the battery pack 1000 according to this embodiment, the high-temperature gas and particles that have passed through the venting channel VC of the venting unit 1300 are not immediately discharged through the discharge section 1111DH, but rather can flow to some extent along the separately provided venting space 1150S before being discharged. In particular, some of the gas and particles can flow along the edge portion of the venting unit 1300 within the venting space 1150S for a long time before being discharged through the discharge section 1111DH. In other words, in this embodiment, by providing a separate venting space 1150S in addition to the venting channel VC, a longer venting path can be secured for the movement of high-temperature gas and particles inside the battery pack 1000. While the high-temperature gas and particles move along the extended venting path, their temperature may decrease. Therefore, it is possible to prevent the gas or particles from triggering an explosion. Also, as the venting path becomes longer, it is possible to block oxygen flowing in from outside the battery pack 1000 from encountering the gas, ultimately preventing an explosion from occurring. Furthermore, the gas or particles can bend several times as they flow through the longer venting path. This allows larger particles to be filtered out in the venting path.

[0118] The following describes in detail the structure of the venting unit and rupture section according to this embodiment.

[0119] Figure 22 is a perspective view showing a venting unit, venting channel plate, and venting flap according to one embodiment of the present invention. Figure 23 is an exploded perspective view of the venting unit, venting channel plate, and venting flap of Figure 22. Figure 24 is a cross-sectional view showing a section along the cutting line G-G' of Figure 23. Figures 25(a) and (b) are partial views showing the venting channel plate and venting flap of Figure 23 joined together and separated from each other, respectively.

[0120] Referring to Figures 2, 17, and 21-25, as described above, the aforementioned venting channel VC may be formed in the venting unit 1300. The venting channel VC can also extend along the longitudinal direction of the battery cell 110, which is perpendicular to the direction in which the battery cells 110 are stacked. Here, the direction in which the battery cells 110 are stacked may be parallel to the x-axis, and the longitudinal direction of the battery cell 110 perpendicular to this may be parallel to the y-axis, which is the direction in which the electrode leads (111, see Figure 7) protrude from the battery cell 110. In this way, only when the extension direction of the venting channel VC is the same as the longitudinal direction of the battery cell 110 can gases, particles, etc. generated in any one of the battery cells 110 flow only through any one of the venting channels VC located at the bottom of that battery cell 110. This prevents thermal events or thermal runaway that occur in any one of the battery cells 110 from propagating to the other battery cells 110. If the extension direction of the venting channel VC is perpendicular to the longitudinal direction of the battery cell 110, then any one of the venting channels VC will share space with all the battery cells 110 in the battery cell stack 110A, and a thermal event or thermal runaway occurring in any one of the battery cells 110 will easily propagate to the other battery cells 110 through that venting channel VC.

[0121] On the other hand, as long as each venting channel VC has an independent venting flow path that is not shared with each other, there are no special restrictions on the form of the venting unit 1300. For example, the venting unit 1300 may have a form in which the plate material extends in a zigzag pattern such that the upper open region VC1 and the lower open region VC2 are alternately located along the direction in which the battery cells 110 are stacked.

[0122] Specifically, by placing a venting unit 1300, which has a zigzag shape extending from a plate, between a venting plate 1151 and a lower plate 1152, mutually independent venting channels VC can be formed between them. The space between the venting plate 1151 and the lower plate 1152 can be utilized as a space through which gas or flame flows, that is, a space in which venting channels VC are formed. In other words, a venting unit 1300 with a zigzag shape extending from a plate can create such a space between the venting plate 1151 and the lower plate 1152 as venting channels VC, which are independent venting flow paths that are not shared between them.

[0123] More specifically, one venting channel VC may be formed while the upper open region VC1 is covered by the venting plate 1151, and another venting channel VC may be formed while the lower open region VC2 is covered by the lower plate 1152.

[0124] In other words, in the venting unit 1300 according to this embodiment, the venting channel VC formed by covering the upper open region VC1 with the venting plate 1151 and the venting channel VC realized by covering the lower open region VC2 with the lower plate 1152 can be positioned alternately. On the other hand, the upper open region VC1 can communicate directly with the opening 1151P of the venting plate 1151, but the lower open region VC2 is blocked by the venting unit 1300. Therefore, a separate inflow hole 1300H can be formed in the part of the venting unit 1300 corresponding to the lower open region VC2. In other words, the lower open region VC2 can communicate with the opening 1151P of the venting plate 1151 via the inflow hole 1300H formed in the venting unit 1300.

[0125] As described above, in the present invention, there are no special restrictions on the form of the venting unit 1300, as long as each venting channel VC has an independent venting channel that is not shared with one another. However, when using a venting unit 1300 in which a plate material extends in a zigzag shape, as in this embodiment, there is the advantage that a venting channel VC having an independent venting channel can be easily realized with just a single plate material. In other words, a partition structure can be easily created between the venting channels VC simply by bending the plate material into a zigzag shape. Furthermore, multiple venting channels VC can be easily realized simply by arranging a venting plate 1151 and a lower plate 1152 above and below such a plate material.

[0126] On the other hand, in this embodiment, at least one of the ends of the venting channel VC may be provided with a rupture section 1320R that ruptures above a certain pressure. Specifically, a venting channel plate 1310 and a venting flap (1320) can be placed at both ends of the venting unit 1300, in particular at both ends along the direction in which the venting channel VC extends. In a typical state where no thermal events occur, both ends of the venting channel VC are closed by such a venting channel plate 1310 and venting flap 1320. The rupture section 1320R that ruptures above a certain pressure can be formed on the venting flap 1320.

[0127] Specifically, venting channel plates 1310 can be positioned at both ends of the venting unit 1300, and venting flaps 1320 can be positioned on the outer surfaces of the venting channel plates 1310. A venting channel opening 1310P may be formed in the portion of the venting channel plate 1310 corresponding to the venting channel VC. The venting channel VC can face the rupture section 1320R through the venting channel opening 1310P.

[0128] Furthermore, a groove (1320G) may be formed around the rupture portion 1320R, excluding the connecting portion 1320C. In other words, the rupture portion 1320R can be provided on the venting flap 1320 by forming an open groove 1320G in the venting flap 1320, excluding only the connecting portion 1320C. Also, as shown in Figures 25(a) and (b), when viewed from the venting channel VC, the groove 1320G of the venting flap 1320 is blocked by the venting channel plate 1310. In other words, since the venting channel opening 1310P is formed in the region inside the groove (1320G) of the venting flap 1320, when viewed from the venting channel VC, only the rupture portion 1320R is exposed through the venting channel opening 1310P, and the groove 1320G is not exposed.

[0129] As a result, under typical conditions where no thermal events occur, both ends of the venting channel VC may not communicate with the open groove 1320G, but may be blocked by the rupture portion 1320R of the venting flap 1320. Therefore, under typical conditions where no thermal events occur, the venting channel VC can be isolated from the venting space (1150S, see Figure 20) by the rupture portion 1320R. In other words, under typical conditions where no thermal events occur, the venting channel VC can have an independent venting channel that is not shared with the venting space 1150S and is not shared between them.

[0130] When gas or other substances flow into a venting channel VC and the internal pressure increases, the rupture section 1320R can rupture. Specifically, if the increased internal pressure of the venting channel VC exceeds the limit strength of the connecting section 1320C, the connecting section 1320C breaks, and the rupture section 1320R can be separated from the venting flap 1320. This opens the venting channel VC, and the gas inside the venting channel VC can be discharged into the venting space 1150S. The other venting channels VC are still sealed off from the venting space 1150S by the rupture section 1320R, so gas and particles do not flow into them. In other words, the structure of the rupture section 1320R allows each venting channel VC to have an independent venting flow path without being shared with each other, minimizing the propagation of thermal events or thermal runaway that occur in a particular battery cell to other battery cells.

[0131] Figure 26 is a partial view showing a rupture section according to another embodiment of the present invention. Referring to Figure 26, a venting flap 1320' according to another embodiment of the present invention can be placed at least one of the ends of the venting channel VC. In this case, a rupture section 1320R', which has a structure that ruptures above a certain pressure, may be formed on the venting flap 1320'. Such a rupture section 1320R' can be located in a place corresponding to the venting channel. The rupture section 1320R' according to this embodiment may have a different form from the rupture section described above and may be a part that is thinner in thickness than other parts of the venting flap 1320'. When the internal pressure of the venting channel VC exceeds the limit strength of the relatively thin rupture section 1320R', the rupture section 1320R' ruptures or opens up, allowing the gas in the venting channel VC to be discharged into the venting space 1150S.

[0132] The aforementioned rupture sections 1320R and 1320R' normally block the venting channel VC, but they function to rupture when the internal pressure of the venting channel VC exceeds a certain level. These are exemplary structures, and the present invention is not necessarily limited to such structures of rupture sections 1320R and 1320R'.

[0133] Figure 27 is a perspective view showing the outer frame of the first side section, the venting extension, and the lower plate of the bottom frame according to one embodiment of the present invention. Figures 28 and 29 are perspective views showing the paths through which gas and flames discharged from the venting unit according to one embodiment of the present invention travel. Figure 30 is a cross-sectional perspective view of the section along the cutting line I-I' in Figure 16.

[0134] Referring to Figures 16, 18, and 27-30, as described above, gas and particles flowing into the venting space 1150S can be discharged to the outside of the battery pack through the discharge section 1111DH which communicates with the venting space 1150S. As previously stated, in one embodiment of the present invention, the discharge section 1111DH and the internal hollow 1110S may be formed in the first side portion 1110. The internal hollow 1110S may be formed inside the first side portion 1110. The outer frame 1111 of the first side portion 1110 may have an outer frame hole (1111H, see Figures 18 and 19) which communicates with the internal hollow 1110S, and the venting plate 1151 may have a through hole (1151H, see Figure 18) which communicates with such an outer frame hole 1111H. The venting space 1150S between the venting plate 1151 and the lower plate 1152 can communicate with the internal hollow 1110S of the first side portion 1110 through the through hole 1151H and the outer frame hole 1111H.

[0135] According to this embodiment, the venting extension 1400 communicating with the discharge section 1111DH can be located in the venting space 1150S. The venting extension 1400 communicating with the discharge section 1111DH can be located between the venting plate 1151 and the lower plate 1152. The venting extension 1400 may be a tubular member having an inlet 1440 and an outlet 1450. The venting extension 1400 may be a tubular member extending from the inlet 1440 to the outlet 1450. As an example, a rectangular tubular venting extension 1400 is shown in Figures 18 and 27 to 30.

[0136] The inlet 1440 of the venting extension 1400 can be located in the venting space 1150S. The inlet 1440 of the venting extension 1400 can be located in the venting space 1150S between the venting plate 1151 and the lower plate 1152. The outlet 1450 of the venting extension 1400 can communicate with the outlet 1111DH. The outlet 1450 of the venting extension 1400 can communicate with the through hole 1151H of the venting plate 1151 and the outer frame hole 1111H of the first side portion 1110.

[0137] As shown in Figure 28, high-temperature gases discharged from the venting unit 1300 flow through the venting space 1150S and can flow into the interior of the venting extension 1400 through the inlet 1440 of the venting extension 1400. As shown in Figures 29 and 30, the high-temperature gases that have moved along the interior of the venting extension 1400 can sequentially pass through the outlet 1450, the through-hole 1151H of the venting plate 1151, and the outer frame hole 1111H, and flow into the internal hollow 1110S of the first side portion 1110. Thereafter, the gases can be discharged to the outside of the battery pack through the discharge section 1111DH. In other words, the venting extension 1400 according to this embodiment can function as a venting passage connecting the venting space 1150S and the discharge section 1111DH.

[0138] The venting extension 1400 can be located adjacent to the area of ​​the pack housing 1100 where the discharge section 1111DH is formed. The venting extension 1400 can be located adjacent to the first side section 1110 where the discharge section 1111DH is formed. The venting extension 1400 can be located adjacent to the first side section 1110 where the discharge section 1111DH is formed, among the first side section 1110, second side section 1120, third side section 1130 and fourth side section 1140 of the pack housing 1100. As described above, the discharge port 1450 of the venting extension 1400 can communicate with the discharge section 1111DH by communicating with the outer frame hole 1111H of the first side section 1110.

[0139] Gases and particles generated by thermal events in the battery assembly 100 within the battery pack 1000 can flow into the venting space 1150S via the venting channel VC.

[0140] At this time, if a thermal event occurs in the battery assembly 100, which is far from the discharge section 1111DH, a long venting path can be secured for the gas and particles that have flowed into the venting space 1150S to travel to the discharge section 1111DH. As the high-temperature gas and particles move along the long venting path, their temperature may decrease.

[0141] In contrast, if a thermal event occurs in the battery assembly 100, which is located close to the discharge section 1111DH, without the venting extension 1400, gas and particles flowing into the venting space 1150S will immediately move to the discharge section 1111DH. In other words, a long venting path cannot be secured for the gas and particles flowing into the venting space 1150S to move to the discharge section 1111DH. As a result, the gas and particles are discharged to the outside through the discharge section 1111DH at a high temperature, where they come into contact with external oxygen and gases, potentially causing an explosion.

[0142] Therefore, in this embodiment, a venting extension 1400 communicating with the discharge section 1111DH is provided in the venting space 1150S to ensure a longer venting path for gas and particles to move to the discharge section 1111DH in the event of a thermal event occurring in the battery assembly 100 located close to the discharge section 1111DH. In other words, gas and particles flowing into the venting space 1150S do not immediately move to the discharge section 1111DH, but rather move along the venting space 1150S to the inlet 1440 of the venting extension 1400, and then flow along the inside of the venting extension 1400 before finally reaching the discharge section 1111DH. While the gas and particles move along this extended venting path, their temperature may decrease. Therefore, it is possible to prevent the gas and particles from triggering an explosion. Furthermore, as the venting path lengthens, it becomes possible to prevent oxygen flowing in from outside the battery pack 1000 from encountering gases, ultimately preventing explosions. In addition, the longer venting path allows gases and particles to flow through several bends. This allows larger particles to be filtered out in the venting path.

[0143] Figure 31 is a perspective view showing a venting extension according to one embodiment of the present invention. Figure 32 is an exploded perspective view of the venting extension of Figure 31. Figure 33 is a perspective view showing a labyrinth bracket included in the venting extension of Figure 31. Figure 34 is a cross-sectional view showing a section along the cutting line J-J' of Figure 31.

[0144] Referring to Figures 30 to 34, as described above, the venting extension 1400 according to one embodiment of the present invention may be a tubular member. A flow path that bends and extends multiple times may be formed in the internal space of the venting extension 1400. The venting extension 1400 may be an ash tray assembly. A labyrinth bracket (1430) may be placed in the internal space of the venting extension 1400. Such a labyrinth bracket 1430 can make the internal space of the venting extension 1400 a passage with a complex path rather than a simple straight passage.

[0145] The venting extension 1400 may include an upper tray 1410 and a lower tray 1420. The upper tray 1410 may have two sides and a top surface, and an open bottom. The lower tray 1420 may have two sides and a bottom surface, and an open top. The upper tray 1410 and the lower tray 1420 may be joined together by their sides to form a venting extension 1400 with an internal space. The labyrinth bracket 1430 may be a plate-shaped material with an inclined slope. By placing such a labyrinth bracket 1430 in the internal space of the venting extension 1400, a flow path that bends multiple times can be formed in the internal space of the venting extension 1400. As long as a flow path that bends multiple times can be formed, there are no special restrictions on the shape, size, and number of labyrinth brackets 1430.

[0146] In this embodiment, a venting extension 1400 is provided in the path through which high-temperature gas moves from the venting space 1150S to the discharge section 1111DH. The labyrinth bracket 1430 inside the venting extension 1400 can function as a kind of maze or trap that filters out sparks and particles. In other words, when high-temperature gas passes through the complex internal path of the venting extension 1400, it becomes blocked by large particles such as sparks and particles that move with the gas, and is ultimately not discharged through the discharge section 1111DH. In other words, by preventing the outflow of sparks and particles, it is possible to prevent an explosion caused by the battery pack 1000. Also, in the case of a flame with strong directional properties, the intensity of the flame may decrease as it passes through the flow path of the venting extension 1400, which bends and extends multiple times.

[0147] Figure 35 is an exploded perspective view showing a battery cell unit according to another embodiment of the present invention.

[0148] Referring to Figure 35, a battery cell unit 110U according to another embodiment of the present invention may include at least one battery cell 110 and a cell cover 200 that partially surrounds the at least one battery cell 110. The cell cover 200 according to this embodiment may include a side portion 210 that covers one side of the battery cell 110. The cell cover 200 may also include a top portion 230 that connects the side portions 210 and covers the top of the at least one battery cell 110.

[0149] The cell cover 200 according to this embodiment may include two side portions 210 and one top portion 230. One side portion 210 and one top portion 230 may be perpendicular to each other, and each side portion 210 may extend downward from opposite sides of the top portion 230. The cell cover 200 according to this embodiment may be open on the bottom. That is, if the cell cover 200 is cut along the xz plane in Figure 35, the cell cover 200 may have an "n" shape. The cell cover 200 may be provided so as to surround at least a portion of three of the remaining four sides of the six-sided battery cell 110, excluding the two sides on which the electrode leads 111 are formed.

[0150] Unlike the cell covers described in Figures 9 and 10, the cell cover 200 in this embodiment has an open bottom, eliminating the need for a cell cover venting hole 220H. The open bottom portion of the cell cover 200 can communicate with the venting hole 300VH formed on the bottom surface of the battery assembly 100. Gases and particles generated in the battery cell 110 can move to the open bottom portion of the cell cover 200 and then flow into the venting channel VC through the venting hole 300VH.

[0151] Figure 36 is a cross-sectional view of a cell cover according to another embodiment of the present invention. Figure 37 is a cross-sectional view of a battery pack to which the cell cover of Figure 36 is applied.

[0152] Referring to Figures 36 and 37, a cell cover 200 according to another embodiment of the present invention can cover a side portion 210 that covers one side of a battery cell, and a bottom portion 220 that connects the side portion 210 and covers the lower part of at least one battery cell 110. Furthermore, cell cover venting holes 220H may be formed in the bottom portion 220 of the cell cover 200. The fact that the cell cover 200 according to this embodiment includes a side portion 210 and a bottom portion 220, and that cell cover venting holes 220H are formed in the bottom portion 220, is similar to the cell cover described in Figures 9 and 10.

[0153] However, according to this embodiment, a cell cover flange portion 200F may be provided on the outer circumference of the cell cover venting hole 220H, protruding in the direction in which the venting channel VC is located, and the cell cover flange portion 200F can be inserted into the venting flow path of the venting channel VC. As shown in Figure 37, the cell cover flange portion 200F of the cell cover 200 according to this embodiment can be inserted into the venting flow path of the venting channel VC by passing through the venting hole 300VH of the lower frame 320 and the opening portion 1151P of the venting plate 1151. Furthermore, when the cell cover flange portion 200F is inserted into the lower open region VC2, it can additionally pass through the inflow hole 1300H of the venting unit 1300.

[0154] The cell cover flange portion 200F in this embodiment can perform the function of the flange portion 300F described in Figures 11 to 13. In other words, in the case of a battery assembly to which the cell cover flange portion 200F is applied, no flange portion is formed in the venting hole 300VH.

[0155] The cell cover flange portion 200F extends along the outer circumference of the cell cover venting hole 220H and can protrude downward. Since the cell cover flange portion 200F is inserted into the venting flow path of the venting channel VC while passing through the opening 1151P, high-temperature gas or flames that have entered either one of the venting channels VC will not flow out into the gap between the venting hole 300VH and the opening 1151P. Therefore, even if a thermal event occurs in one of the battery cells 110, the propagation of such a thermal event to other battery cells 110 can be minimized. Ultimately, it is possible to prevent flames from spreading throughout the battery assembly 100 and the entire battery pack 1000.

[0156] On the other hand, the battery pack 1000 according to this embodiment may include a cooling member (not shown) for cooling the battery assembly 100. Such a cooling member can be located on top of the battery assembly 100. By realizing a "bottom venting" structure that discharges high-temperature gas, particles, or flames generated inside the battery assembly 100 to the outside using the bottom frame 1150 of the pack housing 1100, the cooling member can be located on top of the battery assembly 100 rather than on the bottom.

[0157] The cooling element is not limited in form or method, as long as it can cool the heat generated in the battery assembly 100. For example, the cooling element may be a heat sink through which a circulating coolant flows. Also, if necessary, a thermal resin for heat transfer can be placed between the cooling element and the battery assembly 100.

[0158] In this embodiment, terms indicating directions such as front, back, left, right, up, and down were used, but these terms are merely for convenience of explanation and will vary depending on the position of the object being examined, the observer's position, etc.

[0159] One or more battery assemblies according to the above-described embodiment can be mounted together with various control and protection systems, such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system, to form a battery pack.

[0160] The aforementioned battery assemblies and battery packs are applicable to a wide range of devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, as well as to energy storage systems (ESS), but are not limited to these, and are applicable to a variety of devices that can use secondary batteries.

[0161] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, utilizing the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of symbols]

[0162] 100: Battery Assembly 110: Battery cell 110U: Battery cell unit 110A: Battery cell stack 200: Cell cover 300: Module Frame 300F: Flange section 1000: Battery pack 1100: Pack Housing 1150: Bottom frame 1200: Pack Cover 1300: Venting Unit 1400: Venting extension

Claims

1. A battery assembly comprising at least one battery cell and A pack housing for housing at least one of the battery assemblies, Multiple venting channels extending in one direction are formed inside the bottom frame of the pack housing. A venting hole communicating with the venting channel is formed on the lower surface of the battery assembly. Each of the aforementioned venting channels is a battery pack having independent venting channels that are not shared with one another.

2. The battery pack according to claim 1, wherein at least one of the ends of the venting channel is provided with a rupture section that is designed to burst when subjected to a certain pressure or higher.

3. A flange portion is provided on the outer circumference of the venting hole, projecting in the direction in which the venting channel is located. The battery pack according to claim 1, wherein the flange portion is inserted into the venting flow path of the venting channel.

4. The battery pack according to claim 1, wherein the venting channel extends along the longitudinal direction of the battery cell, which is perpendicular to the direction in which the battery cells are stacked.

5. The battery pack according to claim 1, wherein the number of battery cells is greater than the number of venting channels.

6. The battery pack according to claim 1, wherein the venting channels are provided such that one venting channel corresponds to each unit of the battery cell with a capacity of 50 Ah or more and 300 Ah or less.

7. The battery assembly includes a plurality of battery cell units, The battery cell unit includes at least one of the battery cells and a cell cover that partially surrounds at least one of the battery cells. The battery pack according to claim 1, wherein the cell cover includes a side portion that covers one side of the battery cell.

8. The battery pack according to claim 7, wherein each of the venting channels is positioned to correspond to each of the battery cell units.

9. The battery pack according to claim 7, wherein each of the venting channels is in one-to-one communication with each of the battery cell units.

10. The cell cover includes a lower portion that connects the side portions and covers the lower part of at least one of the battery cells, The battery pack according to claim 7, wherein a cell cover venting hole communicating with the venting hole is formed in the lower portion.

11. A cell cover flange portion is provided on the outer circumference of the cell cover venting hole, protruding in the direction in which the venting channel is located. The battery pack according to claim 10, wherein the cell cover flange portion is inserted into the venting flow path of the venting channel.

12. The cell cover includes a top portion that connects the side portions and covers the top of at least one of the battery cells. The battery pack according to claim 7, wherein the portion open on the lower side of the cell cover communicates with the venting hole.

13. The bottom frame includes a venting plate on which the battery assembly is placed, and a lower plate located below the venting plate. The battery pack according to claim 1, wherein the venting channel is formed between the venting plate and the lower plate.

14. The venting plate includes an opening formed in the portion corresponding to the venting hole, The battery pack according to claim 13, wherein the venting hole communicates with the venting channel through the opening.

15. A flange portion is provided on the outer circumference of the venting hole, projecting in the direction in which the venting channel is located. The battery pack according to claim 14, wherein the flange portion is inserted into the venting flow path of the venting channel while passing through the opening.

16. The venting unit is positioned between the venting plate and the lower plate. The venting channel is connected to the aforementioned venting unit. The battery pack according to claim 13, wherein the venting unit has a form in which the plate material extends in a zigzag pattern such that upper open regions and lower open regions are alternately located along the direction in which the battery cells are stacked.

17. The upper open region is covered by the venting plate, and one of the venting channels is formed therein. The battery pack according to claim 16, wherein the lower open region is covered by the lower plate, and another venting channel is formed.

18. A venting space is provided between the venting plate and the lower plate. The battery pack according to claim 13, wherein the pack housing includes a discharge section that communicates with the venting space.

19. The battery pack according to claim 18, wherein the venting space is the space between the venting plate and the lower plate, excluding the venting channel.

20. The gas generated in the battery cell is discharged to the outside through the exhaust section, sequentially passing through the venting channel and the venting space. The battery pack according to claim 18, wherein the gas flows through the venting space, making at least one bend.

21. The pack housing includes side portions that extend along the periphery of the bottom frame, The battery pack according to claim 18, wherein one of the side portions is provided with an internal hollow that connects the discharge portion and the venting space to each other.

22. The battery pack according to claim 18, wherein the venting extension communicating with the discharge section is located in the venting space.

23. The battery pack according to claim 22, wherein the venting extension is a tubular member having an inlet and an outlet.

24. The battery pack according to claim 22, wherein a flow path that bends and extends multiple times is formed in the internal space of the venting extension.

25. A device comprising the battery pack described in claim 1.

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