Battery pack and automobile including same

Abstract

The battery pack according to the present invention includes a pack case including a plurality of cell units stacked in one direction, each of which includes one or more stacked battery cells, and a cell cover capable of accommodating the cell stack, a pack tray on which the plurality of cell units are placed, and a pack cover covering the plurality of cell units and coupled to the pack tray, wherein the cell cover has an upper end opening so as not to cover an upper side of the cell stack, and the pack cover has an extinguishant supplying portion capable of supplying an extinguishing material to the cell cover through the upper end opening of the cell cover, and the extinguishant supplying portion may be configured such that at least a portion of the extinguishant supplying portion is thermally melted to supply the extinguishing material inside the cell cover.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0070537, filed on June 10, 2022, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] The present invention relates to a battery pack and a vehicle including the same, and more particularly to a battery pack and a vehicle including the same that have a cooling function for managing heat in battery cells and a fire extinguishing function for preventing the ignition or spread of fire when a thermal event occurs in a specific battery cell. [Background technology]

[0003] Generally, the operating voltage of each secondary battery is approximately 2.5 V to 4.5 V. Therefore, in the case of electric vehicles and power storage devices that require large capacity and high output, a battery module in which a plurality of secondary batteries are connected in series and / or parallel, and a battery pack in which the battery modules are connected in series and / or parallel, are configured and used as an energy source.

[0004] Depending on the output and capacity of the battery pack required for an electric vehicle, the number of lithium secondary batteries in one battery module may increase, or the number of battery modules in one battery pack may increase.

[0005] Meanwhile, as an example, a battery module of a battery pack for an electric vehicle includes battery cells, bus bar frames for electrically connecting the battery cells, and a module housing capable of accommodating the battery cells and the bus bar frames together, and is mounted on a pack tray.

[0006] Meanwhile, in the case of conventional battery packs that house battery modules as described above, the gaps that occur between the battery modules and between the battery modules and the beam frame, as well as the volume occupied by the module housing of the battery modules, act as factors that reduce the energy density per unit volume of the battery pack.For this reason, in recent years, as part of efforts to increase the energy capacity of battery packs, active research and development efforts have been made on cell-to-pack (a method in which the battery cell is directly incorporated into the battery pack case, omitting the battery module unit) type battery packs.

[0007] However, when designing a cell-to-pack type battery pack, issues have arisen as to how to apply a cooling system to manage the heat of the battery cells and a fire extinguishing system to prevent ignition or the spread of fire when a thermal event occurs in the battery cells, as well as how to efficiently apply the cooling system and fire extinguishing system within the limited internal space of the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been devised to solve the above-mentioned technical problems, and its purpose is to provide a cell-to-pack type battery pack equipped with a fire extinguishing system that can quickly extinguish a fire in a specific battery cell housed in a pack case when a thermal event occurs in the specific battery cell.

[0009] Another object of the present invention is to provide a cell-to-pack type battery pack that can effectively dissipate heat generated from battery cells housed in the battery pack.

[0010] The technical problems that the present invention aims to solve are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0011] According to one aspect of the present invention, a battery pack includes a pack case having a plurality of cell units stacked in one direction, each of which includes one or more stacked battery cells, and a cell cover capable of accommodating the cell stack, a pack tray on which the plurality of cell units are placed, and a pack cover that covers the plurality of cell units and is coupled to the pack tray, wherein the cell cover has an upper end opening so as not to cover an upper side of the cell stack, and the pack cover has a fire extinguishant supply port that can supply a fire extinguishing substance to the cell cover through the upper end opening of the cell cover, and the fire extinguishant supply port may be configured so that at least a portion of the fire extinguishant supply port is thermally melted to supply the fire extinguishing substance into the cell cover.

[0012] The battery pack further includes a first thermal resin that is applied to the upper surface of the cell stack but is not provided at at least one of one end and the other end of the upper open end of the cell cover along the longitudinal direction of the cell cover, the pack cover contacts the first thermal resin, and the extinguishing agent injection port can be provided at a position that faces up and down at least one of one end and the other end of the upper open end of the cell cover.

[0013] The extinguishing agent injection section may be provided vertically above each of the cell units.

[0014] The extinguishing substance may be cooling water, and the pack cover may have a flow path therein through which the cooling water can flow.

[0015] The extinguishing agent injection portion may include a hole communicating with the flow path, and a melt cap connected to the hole and made of a heat-meltable resin material.

[0016] The extinguishing agent feeding section may include a fire extinguishing unit including a gas storage container that stores compressed gas and has a gas discharge outlet on one side, and a container lid body formed from a heat-melting material and capable of closing the gas discharge outlet, and a unit mounting port formed through the pack cover so that the fire extinguishing unit can be fitted into the container lid body so that the container lid body faces the upper end open portion of the cell cover.

[0017] The compressed gas may be carbon dioxide.

[0018] The container lid may have a screw thread on its outer periphery, and the unit mounting opening may include a lid fastening opening that is threadably engageable with the container lid.

[0019] The cell unit may include a cell stack consisting of one or two or more stacked battery cells, and a cell cover provided to cover both side portions of the cell stack along the width direction of the cell stack and the bottom of the cell stack.

[0020] The cell cover may include a first side cover portion covering one side portion of the cell stack along the width direction of the cell stack, a second side cover portion covering the other side portion of the cell stack, and a lower cover portion formed integrally with the first side cover portion and the second side cover portion and covering the lower part of the cell stack.

[0021] The battery pack may include busbar frame assemblies including busbars electrically connected to electrode leads of the battery cells, the busbar frame assemblies being disposed at front and rear ends of the cell stack along a longitudinal direction of the cell stack, and being coupled to the cell covers.

[0022] The battery pack may further include a heat insulating pad disposed between the cell units in the plurality of cell units.

[0023] The battery pack may include a second thermal resin interposed between a lower cover portion of the cell cover and a surface of the pack tray.

[0024] The battery cell may be a pouch-type battery cell.

[0025] According to another aspect of the present invention, there may be provided a vehicle including the battery pack described above. [Effects of the Invention]

[0026] According to one aspect of the present invention, it is possible to provide a cell-to-pack type battery pack that is equipped with a fire extinguishing system that can quickly extinguish a fire in a specific battery cell housed in a pack case when a thermal event occurs in the specific battery cell.

[0027] According to the battery pack of the present invention, when a specific battery cell ignites, a fire-extinguishing material falls from the pack cover located on top of the specific battery cell to suppress the ignition of the specific battery cell, thereby preventing the transfer of thermal energy to other surrounding battery cells.

[0028] According to another aspect of the present invention, a pack cover having a built-in flow path through which coolant flows can exchange heat with the battery cells, and when the battery cells ignite or generate heat, the pack cover is partially melted by heat, allowing the coolant to drip off. Therefore, the pack cover can normally absorb heat from the battery cells, and when the battery cells ignite, the coolant can be used as a fire extinguishing agent.

[0029] In addition to these, the present invention can have various other effects, which will be explained in the sections for each embodiment, and explanations of effects that can be easily inferred by those skilled in the art will be omitted. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a diagram showing a schematic configuration of a battery pack according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view schematically illustrating a cell unit group according to an embodiment of the present invention. [Figure 3] FIG. 2 is a perspective view of a cell unit according to one embodiment of the present invention. [Figure 4] FIG. 4 is an exploded perspective view of the cell unit of FIG. 3. [Figure 5] FIG. 4 is an enlarged view of one end of the cell unit of FIG. 3. [Figure 6] FIG. 2 is a diagram illustrating a fire extinguishing configuration of a battery pack according to an embodiment of the present invention. [Figure 7] FIG. 2 is a diagram illustrating a fire extinguishing configuration of a battery pack according to an embodiment of the present invention. [Figure 8] FIG. 2 is a diagram illustrating a cooling configuration of a battery pack according to an embodiment of the present invention. [Figure 9] FIG. 10 is a diagram illustrating a schematic configuration of a battery pack according to another embodiment of the present invention. [Figure 10] FIG. 10 shows a schematic diagram of a fire suppression arrangement according to another embodiment of the present invention. [Figure 11] FIG. 10 shows a schematic diagram of a fire suppression arrangement according to another embodiment of the present invention. [Figure 12] FIG. 10 shows a schematic diagram of a fire suppression arrangement according to another embodiment of the present invention. [Figure 13] 1 is a diagram illustrating a schematic diagram of a vehicle including a battery pack according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best explain the invention.

[0032] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0033] FIG. 1 is a diagram showing a schematic configuration of a battery pack according to one embodiment of the present invention, FIG. 2 is a perspective view showing a schematic configuration of a cell unit group according to one embodiment of the present invention, FIG. 3 is a perspective view of a cell unit according to one embodiment of the present invention, and FIG. 4 is an exploded perspective view of the cell unit of FIG. 3.

[0034] 1 to 4, a battery pack according to one embodiment of the present invention includes a plurality of cell units 100 and a pack case 200 capable of accommodating the plurality of cell units 100.

[0035] The cell unit 100 includes one or more stacked battery cells 110 and a cell cover 120 .

[0036] The battery cell 110 may be a pouch-type battery cell 110. The pouch-type battery cell 110 may include an electrode assembly, a pouch case that houses the electrode assembly, and an electrode lead 111 that is connected to the electrode assembly and exposed to the outside of the pouch case. The electrode lead 111 includes a pair of a positive electrode lead and a negative electrode lead. Here, the positive electrode lead and the negative electrode lead may be provided at both ends of the battery cell 110 along the longitudinal direction of the battery cell 110.

[0037] Such pouch-type battery cells 110 may be arranged with their wide surfaces perpendicular to the ground and stacked in one direction (X direction) until a predetermined number of them are stacked. Hereinafter, a cell stack refers to the pouch-type battery cells 110 stacked as described above. For example, as shown in FIG. 4, two pouch-type battery cells 110 may be stacked in one direction. In this case, the positive electrode lead of each pouch-type battery cell 110 may face forward (-Y direction), and the negative electrode lead of each pouch-type battery cell 110 may face backward (+Y direction). In this case, the two pouch-type battery cells 110 may be connected in parallel by welding the electrode leads 111 of the same polarity to terminal bus bars 131 located on the corresponding sides, thereby forming a single power bank.

[0038] That is, two pouch-type battery cells 110 are housed in a cell cover 120 to maintain a stacked state, and can be connected in parallel via a terminal bus bar 131 of a bus bar frame assembly 130. The terminal bus bar 131 is configured to have a portion exposed and can function as a positive terminal or a negative terminal of the cell unit 100. In this embodiment, the cell unit 100 is configured using two pouch-type battery cells 110, but the cell unit 100 may also be configured using one, three, four or more pouch-type battery cells 110.

[0039] Meanwhile, the pouch-type battery cell 110 may include a housing portion R corresponding to a portion that houses an electrode assembly inside a pouch case, and four edge portions E1 to E4 that surround the housing portion R. The four edge portions E1 to E4 refer to, for example, an upper edge portion E1, a lower edge portion E2, a front edge portion E3, and a rear edge portion E4 based on the housing portion R in a pouch-type battery cell 110 that is arranged upright, as shown in FIG.

[0040] Here, the edge portions E1 to E4 may all be sealing portions, or the remaining three edge portions E2, E3, and E4 or E1, E3, and E4 excluding the upper edge portion E1 or the lower edge portion E2 may be sealing portions. In other words, a pouch-type battery cell 110 that uses a method of folding one laminate film to accommodate an electrode assembly has three sealing portions, and a pouch-type battery cell 110 that uses a method of joining the edges of two laminate films has four sealing portions. Thus, in the pouch-type battery cell 110, three edge portions E2, E3, and E4 or E1, E3, and E4 may be sealing portions, or all four edge portions E1 to E4 may be sealing portions.

[0041] The cell cover 120 is a component that accommodates or supports the cell stack so that the cell stack can be stably maintained in an upright state in the pack case 200. For example, the cell cover 120 may be fabricated in a shape that encloses the lower edge portion E2 and both sides of the receiving portion R of one pouch-type battery cell 110. Alternatively, as in this embodiment, the cell cover 120 may be fabricated in a shape that covers the lower edge portions of two pouch-type battery cells 110 that form the cell stack, one side of the receiving portion of the first pouch-type battery cell 110 in the stacking order, and one side of the receiving portion of the second pouch-type battery cell 110. In other words, the cell cover 120 may be provided to cover both side portions of the cell stack along the width direction of the cell stack and the bottom of the cell stack. Such a cell cover 120 has a generally "U"-shaped cross section, and has an upper open portion that exposes the upper side of the cell stack (corresponding to the upper edge portion of the pouch-type battery cell 110) when the cell stack is housed therein.

[0042] The cell cover 120 may be formed from a variety of materials. In particular, the cell cover 120 may be formed from metal to ensure rigidity. Metal can more stably maintain the stacked state of the pouch-type battery cells 110 and more safely protect the pouch-type battery cells 110 from external impacts. For example, the cell cover 120 may be entirely formed from stainless steel (SUS) or may be formed from an alloy containing stainless steel.

[0043] In other words, the pouch-type battery cells 110 are difficult to securely accommodate in the pack case 200 due to the soft pouch case, which has low hardness, and may also be vulnerable to external shocks and vibrations. The cell cover 120 is a component that compensates for the above-mentioned problems of the pouch-type battery cells 110, and enables the stacked state of the pouch-type battery cells 110 to be stably maintained when the pouch-type battery cells 110 are accommodated in the pack case 200. The cell cover 120 may be formed from a thin plate having a thickness of approximately 2 mm or less so as to minimize its volume inside the pack case 200.

[0044] Specifically, the configuration of the cell cover 120 according to this embodiment will be described. As shown in FIGS. 3 and 4, the cell cover 120 includes a lower cover portion 121, a first side cover portion 122, and a second side cover portion 123.

[0045] The lower cover part 121 may be configured to enclose the lower edge part E2 of the pouch-type battery cell 110 housed therein. The lower cover part 121 may be configured to be spaced apart from the lower edge part E2 of the pouch-type battery cell 110. When the cell unit 100 is placed on the pack tray 210, the cell cover 120 may be placed such that the lower cover part 121 faces the bottom plate 211 of the pack tray 210.

[0046] The first side cover part 122 may be configured in a shape extending upward from one edge line along the width direction of the lower cover part 121. For example, the first side cover part 122 may be configured in a shape extending upward from the left end part of the lower cover part 121 to a length longer than the housing part R of the pouch-type battery cell 110.

[0047] The first side cover portion 122 may be configured to cover one side of the at least one pouch-type battery cell 110. For example, the first side cover portion 122 may be configured to cover one side of the cell stack along the width direction of the cell stack in FIG.

[0048] The second side cover part 123 may be configured in a shape extending upward from the other edge line along the width direction of the lower cover part 121. For example, the second side cover part 123 may be configured in a shape extending upward from the right end part of the lower cover part 121 longer than the housing part R of the pouch-type battery cell 110.

[0049] The second side cover portion 123 may be configured to cover one side of the at least one pouch-type battery cell 110. For example, the second side cover portion 123 may be configured to cover the other side of the cell stack along the width direction of the cell stack in FIG.

[0050] The first side cover part 122 and the second side cover part 123 may be integrally formed with the lower cover part 121. The distance between the first side cover part 122 and the second side cover part 123 may be determined within a range in which the pouch-type battery cell 110 accommodated inside the cell cover 120 can be compressed.

[0051] According to this configuration of the cell cover 120, the pouch-type battery cell 110 is pressed by the cell cover 120, and its upper edge portion E1 is exposed above the cell cover 120 and can directly face the pack cover 220 described below. The lower cover portion 121 of the cell cover 120 can directly face the bottom plate 211 of the pack case 200. In this case, heat exchange between the lower edge portion of the pouch-type battery cell 110 and the bottom plate 211 of the pack case 200 can be more smoothly performed. In addition, the second thermal resin G2 can be applied to the bottom plate 211 of the pack case 200 to increase the heat transfer rate between the pouch-type battery cell 110, the lower cover portion 121 of the cell cover 120, and the bottom plate 211 of the pack case 200.

[0052] Therefore, by mounting the pouch-type battery cells 110 in the pack case 200 using a cell cover 120 configured in this manner, the pouch-type battery cells 110 can be arranged in the pack case 200 in a space-efficient manner, the stacked state of the pouch-type battery cells 110 can be stably maintained, and the cooling structure for the pouch-type battery cells 110 is simple yet efficient.

[0053] 3 and 4, the cell unit 100 according to one embodiment of the present invention may include a bus bar frame assembly 130.

[0054] The bus bar frame assembly 130 includes terminal bus bars 131 electrically connected to the electrode leads 111 of the pouch-type battery cells 110, and may be disposed at the front and rear of the cell stack along the longitudinal direction of the cell stack.

[0055] The bus bar frame assembly 130 may include a first bus bar frame assembly and a second bus bar frame assembly, and the first bus bar frame assembly and the second bus bar frame assembly may have substantially the same configuration.

[0056] In this embodiment, the positive electrode leads of the two stacked pouch-type battery cells 110 may be integrally welded to the terminal bus bar 131 of the first bus bar frame assembly, and the negative electrode leads may be integrally welded to the terminal bus bar 131 of the second bus bar assembly. In this case, the two pouch-type battery cells 110 have a 2P1S electrical connection structure.

[0057] Looking at the main components of the bus bar frame assembly 130, as shown in FIG. 4, the bus bar frame assembly 130 may include a terminal bus bar 131, a bus bar housing 132, and a bus bar cover 133.

[0058] The terminal bus bars 131 may be made from a metal such as copper, nickel, or aluminum, and the bus bar housings 132 may be made from an electrically insulating material such as plastic.

[0059] The bus bar housing 132 supports the terminal bus bar 131 and may be coupled to the cell cover 120. That is, the bus bar housing 132 may be configured to be coupled to each of the front open end and the rear open end of the cell cover 120, as shown in Fig. 3. In this case, the bus bar housing 132 may be coupled to be fixed to the cell cover 120 using a variety of fastening methods, such as adhesive bonding, welding, fitting, hook-and-loop fastening, bolting, or riveting. Therefore, in this embodiment, each of the front open end and the rear open end of the cell cover 120 may be covered by the bus bar housing 132.

[0060] The bus bar housing 132 may be formed in a box shape having a roughly rectangular parallelepiped structure. The bus bar housing 132 may have slits into which the electrode leads 111 of the battery cells 110 can be inserted so that the electrode leads 111 can pass through the body. The electrode leads 111 of the battery cells 110 may be drawn out through the bus bar housing 132 through the slits, and the drawn portions may be attached to the terminal bus bar 131. Laser welding may be performed when the electrode leads 111 are attached to the terminal bus bar 131. The portion where the electrode leads 111 and the terminal bus bar 131 are connected is shielded by a bus bar cover 133 made of an insulating material, and an upper end portion of the terminal bus bar 131, which has a greater thickness than other portions, may be exposed to the outside through a window 133 a of the bus bar cover 133.

[0061] A plurality of cell units 100 according to an embodiment of the present invention may be stacked in one direction, as shown in Fig. 2. Although not shown in Fig. 2, a first thermal resin may be applied to the upper surface of the cell stack (corresponding to the upper edge E1 of the pouch-type battery cell 110) exposed through the upper end opening of each cell cover 120 in the stacked cell units 100. In this case, the first thermal resin may be applied only to the remaining portion of the upper surface of the cell stack along the longitudinal direction of the cell stack, excluding both end portions. This will be described in detail later.

[0062] 2, a heat insulating pad P may be disposed between the cell units 100. For example, the heat insulating pad P may be attached to one or both sides of the cell unit 100. The heat insulating pad P serves to prevent heat exchange between the cell units 100. Silicon or mica sheets may be used as the heat insulating pad P. The cell units 100 stacked in this manner are referred to as a cell unit group 10.

[0063] Meanwhile, the pack case 200 according to one embodiment of the present invention may include a pack tray 210 and a pack cover 220 .

[0064] 1, the pack tray 210 may include a bottom plate 211 and a plurality of beam frames that are arranged perpendicular to the bottom plate 211 and form walls. The plurality of beam frames may include an outer beam frame 212a that forms a wall along the periphery of the bottom plate 211, and an inner beam frame 212b that crosses the bottom plate 211 on the inside of the bottom plate 211 to define the internal space of the pack tray 210.

[0065] Each cell unit group 10 may be placed in an internal space of the pack tray 210, which is defined by being surrounded by the plurality of beam frames. For example, as shown in FIG. 1, each cell unit group 10 may be placed in an internal space of the pack tray 210, which is surrounded by the outer beam frame 212a and the inner beam frame 212b of the pack tray 210. While the pack tray 210 is configured to accommodate four cell unit groups 10 according to this embodiment, the pack tray 210 may be configured to accommodate fewer than four or more than four cell unit groups 10 by changing the area of ​​the bottom plate 211 of the pack tray 210 or the number and positions of the outer beam frame 212a and the inner beam frame 212b.

[0066] When each cell unit group 10 is loaded onto the pack tray 210, the cell units 100 located on the outermost periphery of each cell unit group 10 may be arranged to face the outer beam frame 212a or the inner beam frame 212b. In this case, the beam frames support the outermost cell units 100 on both sides of each cell unit group 10, thereby preventing the battery cells 110 from swelling during charging and discharging. In addition, when a thermal event occurs in a cell unit group 10, the beam frames may function as a firewall that prevents the diffusion of thermal energy between the cell unit groups 10. To enhance the firewall function, a heat insulating material such as a mica sheet may be attached to the surface of the beam frame.

[0067] A second thermal resin G2 may be applied to the bottom plate 211 of the pack tray 210. As described above, the second thermal resin G2 may promote heat exchange between the lower cover portion 121 of the cell cover 120 and the bottom plate 211 of the pack tray 210, thereby increasing the fixation of the cell unit 100.

[0068] As shown in FIG. 1, the pack cover 220 covers a plurality of cell units 100 and can be provided so as to be connectable to the pack tray 210 .

[0069] In particular, the pack cover 220 according to the present invention may be configured to include a fire extinguishing agent supplying portion 221 through which a fire extinguishing agent can be supplied to the cell cover 120 through an upper end opening of the cell cover 120 .

[0070] Hereinafter, the configuration of a fire extinguishing system for a battery pack according to an embodiment of the present invention will be mainly described with reference to FIGS. 1, 3, and 5 to 7.

[0071] The pack cover 220 according to one embodiment of the present invention may include a flow path 222 through which cooling water can flow, and an extinguishing agent supply port 221 provided at each pre-designated position on the pack cover 220. Here, the pre-designated position may mean the vertically upper portion of each cell unit 100. That is, the extinguishing agent supply port 221 may be provided at each vertically upper portion of each cell unit 100.

[0072] As shown in FIG. 1 , the flow paths 222 may be provided inside the pack cover 220 in a staggered or meandering shape. For example, the pack cover 220 may include an inlet port and an outlet port, with the inlet port connected to the inlet of the flow path 222 and the outlet port connected to the outlet of the flow path 222. Cooling water may flow along the flow path 222 via the inlet port and be discharged to the outside of the pack cover 220 via the outlet port. Although not shown, the inlet port and the outlet port may be connected to a cooling chiller. In this case, heat inside the pack case 200 is absorbed by the cooling water flowing along the flow path 222, and the heat-absorbing cooling water may be removed in the cooling chiller. The cooling water from which the heat has been removed may then re-enter the flow path 222 via the inlet port. That is, the cooling water may circulate in the order of the inlet port, flow path 222, outlet port, cooling chiller, and inlet port.

[0073] Meanwhile, as an alternative example of the pack cover 220 having the flow passage 222, a fire tank type pack cover 220 that stores a certain amount of fire extinguishing water or fire extinguishing material inside may be applied.

[0074] The extinguishing agent supplying portion 221 may be configured such that at least a portion thereof is thermally melted to allow the extinguishing agent to fall and fill the inside of the cell cover 120 of each cell unit 100 .

[0075] 6 and 7, the fire-extinguishing agent inlet 221 according to this embodiment includes a hole 221b communicating with the flow path 222 and a melt cap 221a made of a heat-meltable resin material and coupled to the hole 221b. The hole 221b may be formed by drilling a specific portion of the underside of the pack cover 220 to allow communication with the flow path 222. The melt cap 221a may be configured to close the hole 221b. Therefore, the coolant inside the pack cover 220 can normally flow along the flow path 222 without leaking out of the pack cover 220. When a thermal event occurs inside the battery pack, the melt cap 221a melts due to heat, allowing the coolant to pour down from the pack cover 220 into the inside of the battery pack. That is, in this embodiment, the coolant can be used as a fire-extinguishing material to suppress a thermal event.

[0076] In particular, a battery pack according to one embodiment of the present invention includes a plurality of stacked cell units 100 as described above, and can be configured to prevent or delay the transmission of heat to adjacent cell units 100 by pouring cooling water onto the specific cell unit 100 when a fire occurs in a specific cell unit 100 among the plurality of cell units 100, thereby lowering the temperature of the battery cells 110 included in the specific cell unit 100.

[0077] For this purpose, according to an embodiment of the present invention, a fire extinguishing agent inlet 221 may be provided at the vertical upper portion of each cell unit 100. As described above, the cell cover 120 constituting the cell unit 100 has a generally U-shaped vertical cross section and an open top end. Therefore, when a thermal event occurs in a battery cell 110, high-temperature gas, flames, sparks, etc. generated in the battery cell 110 are directed toward the pack cover 220 through the open top end of the cell cover 120. At this time, if heat is concentrated on the melt cap 221a located in the vertical upper region of the battery cell 110 where the thermal event occurred, causing it to melt, the closed hole 221b opens, allowing coolant to fall and seep into the cell cover 120 through the open top end.

[0078] A battery pack according to an embodiment of the present invention may further include a first thermal resin G1 between the cell unit 100 and the cell cover 120 to promote heat exchange between the cell unit 100 and the cell cover 120.

[0079] The first thermal resin G1 is applied to the upper surface of the cell stack (upper edge portion of the pouch-type battery cell 110), but may not be provided at at least one of one end S1 and the other end S2 of the upper open end of the cell cover 120 along the longitudinal direction of the cell cover 120. The pack cover 220 is in contact with the first thermal resin G1, and the extinguishing agent injection port 221 of the pack cover 220 may be provided at a position that faces up and down at least one of one end S1 and both end portions of the upper open end of the cell cover 120.

[0080] 3, the first thermal resin G1 is applied to the upper edge E1 of the pouch-type battery cell 110 housed inside the cell cover 120, thereby allowing the upper open end of the cell cover 120 to be partially covered by the first thermal resin G1. However, the first thermal resin G1 is not applied to or filled into one end S1 and the other end S2 of the upper open end of the cell cover 120. In this way, the one end S1 and the other end S2 of the upper open end of the cell cover 120 that are not covered by the first thermal resin G1 can function as an injection port through which a fire-extinguishing substance can be injected into the inside of the cell cover 120.

[0081] 5 and 6, the front edge E3 and rear edge E4 of the pouch-type battery cell 110 may be located below one end S1 and the other end S2 of the upper open portion of the cell cover 120, respectively. The front edge E3 and rear edge E4 of the pouch-type battery cell 110 are seals formed by heat-sealing the pouch case. Therefore, there is more free space in the area where the front edge E3 and rear edge E4 of the pouch-type battery cell 110 are located than in other areas of the cell cover 120. In addition, since the temperatures of the front edge E3 and rear edge E4, from which the electrode leads 111 are drawn, are relatively high in the pouch-type battery cell 110, there is a high possibility that the front edge E3 or the rear edge E4 may tear open and release high-temperature gas or sparks when the internal pressure increases.

[0082] Therefore, it can be said that it is more effective to place the extinguishing agent injection section 221 vertically above the cell cover 120, corresponding to one end S1 and the other end S2 of the upper open end, in order to accurately and quickly inject extinguishing material targeting the specific cell unit 100 where a thermal event has occurred.

[0083] According to the configuration of the extinguishing agent injection port 221 and the cell unit 100 of this embodiment, for example, when high-temperature gas is ejected from a battery cell 110 included in a specific cell unit 100 among the plurality of cell units 100, the melt cap 221a melts due to the high-temperature gas, and at this time, the hole 221b is opened as shown in Fig. 7. Then, the cooling water inside the pack cover 220 is poured down and can fill the inside of the cell cover 120 through one end portion S1 of the upper end opening of the cell cover 120.

[0084] Furthermore, according to the configuration of the present invention, the melt cap 221a located on the top of the cell cover 120 housing the battery cell 110 in which an event has occurred melts due to heat, but the melt caps 221a located on the top of the other cell covers 120 housing the battery cells 110 in which an event has not occurred do not melt because they receive little or no thermal damage. Therefore, as shown by F in Fig. 7, the coolant fills only inside the cell cover 120 housing the battery cell 110 in which an event has occurred.

[0085] Therefore, the fire extinguishing system for a battery pack according to the present invention is configured to inject a fire extinguishing material only into a specific cell unit 100 where a thermal event has occurred, thereby enabling intensive cooling of only that specific cell unit, thereby preventing heat transfer to other adjacent cell units 100 and preventing battery cells constituting other cell units from being submerged in coolant. Therefore, battery cells 110 that are not submerged in coolant can be reused.

[0086] Meanwhile, the battery pack according to an embodiment of the present invention is configured such that heat from the battery cells 110 is dissipated through the pack tray 210 and the pack cover 220, and heat exchange between the cell units 100 is prevented.

[0087] Specifically, as shown in FIG. 8 , a second thermal resin G2 may be provided on the bottom plate 211 of a pack tray 210 on which a cell unit 100 is placed. That is, the second thermal resin G2 may be provided between the lower cover portion 121 of each cell cover 120 and the surface of the pack tray 210. Also, in each cell unit 100, a third thermal resin G3 may be interposed between the lower edge portion E2 of the pouch-type battery cell 110 inside the cell cover 120 and the lower cover portion 121 of the cell cover 120. The third thermal resin G3 fills the gap between the lower edge portion of the pouch-type battery cell 110 and the lower cover portion 121 of the cell cover 120 so that no empty space is left, thereby promoting heat exchange between the pouch-type battery cell 110 and the cell cover 120. In addition, the fixation of the pouch-type battery cell 110 inside the cell cover 120 may be strengthened.

[0088] According to the above configuration, heat of all battery cells 110 mounted in the battery pack can be conducted from the lower edge portion → the third thermal resin G3 → the lower cover portion 121 of the cell cover 120 → the second thermal resin G2 → the bottom plate 211 of the pack tray 210. Although not shown, the cooling effect can be increased by disposing a heat sink (not shown) below the pack tray 210 or by allowing cooling water to flow inside the pack tray 210. In addition, heat of all battery cells 110 can be conducted from the upper edge portion → the first thermal resin G1 → the cooling water inside the pack cover 220.

[0089] Furthermore, the heat exchange between the cell units 100 can be prevented by the insulating pads P arranged between the cell units 100. In this case, the temperature gradient in the direction of the pack cover 220 or pack tray 210 in each cell unit 100 becomes larger, and heat can be conducted more quickly in the direction of the pack cover 220 or pack tray 210.

[0090] As described above, according to the cooling configuration of the battery pack of the present invention, heat transfer between the battery cells 110 included in different cell units 100 is minimized, and heat from all the battery cells 110 can be transferred in the vertical direction and dissipated through the pack case 200. Therefore, it is possible to provide a battery pack with improved cooling performance for all the battery cells 110.

[0091] FIG. 9 is a diagram schematically illustrating a configuration of a battery pack according to another embodiment of the present invention, and FIGS. 10 to 12 are diagrams schematically illustrating a fire extinguishing configuration according to another embodiment of the present invention.

[0092] Next, a battery pack according to another embodiment of the present invention will be described with reference to FIGS.

[0093] The same component numbers as those in the previously described embodiment indicate the same components, and redundant explanations of the same components will be omitted, with the focus being on the differences from the previously described embodiment.

[0094] The battery pack according to this embodiment of the present invention differs from the battery pack according to the above-described embodiment in the components of the pack cover 220A and the extinguishant injection port 221A.

[0095] 9, the extinguishing agent inlet 221A according to this embodiment is provided at the vertical upper portion of each cell unit 100, similar to the previously described embodiment, and is located at one end S1 and the other end S2 of the upper open end of the cell cover 120. If necessary, the extinguishing agent inlet 221 may be provided at only one of the end S1 and the other end S2 of the upper open end of the cell cover 120. However, a pack cover 220A according to another embodiment of the present invention does not include a cooling water flow path 222. Instead, the pack cover 220A may be configured so that at least a portion thereof is thermally melted to inject compressed cooling gas as a fire extinguishing material into the cell cover 120.

[0096] Specifically, referring to FIGS. 10 and 11, the extinguishing agent supplying section 221A according to one embodiment of the present invention includes a fire extinguishing unit 223 and a unit mounting opening 224 configured to allow the fire extinguishing unit 223 to be fitted thereto.

[0097] The fire extinguishing unit 223 contains compressed cooling gas and may be configured to be connectable and disconnectable to the unit mounting port 224. Therefore, when the compressed cooling gas of the fire extinguishing unit 223 is used up or a defect is found, the fire extinguishing unit 223 can be removed from the unit mounting port 224 and replaced with a new one.

[0098] For example, the fire extinguishing unit 223 may include a gas storage container 223a that contains the compressed gas and has a gas outlet on one side, and a container lid 223b that is formed from a heat-melting material and is capable of closing the gas outlet.

[0099] The unit mounting opening 224 is a portion where the fire extinguishing unit 223 can be fixed to the pack cover 220. The unit mounting opening 224 may be configured to have a shape formed to penetrate the pack cover 220 in a thickness direction so that the fire extinguishing unit 223 can be fitted in such a way that the container lid body 223b faces the upper end opening of the cell cover 120.

[0100] The container lid 223b may have a screw thread on its outer periphery, and the unit mounting opening 224 may include a lid fastening opening 224a that is provided so as to be able to be screwed onto the container lid 223b.

[0101] According to the above-described configuration, as shown in FIG. 11, the fire extinguishing unit 223 can be inserted into the unit mounting opening 224, and at this time, the container lid 223b and the lid fastening opening 224a can be screwed together to fix the fire extinguishing unit 223 to the unit mounting opening 224.

[0102] In addition, the container lid 223b coupled to the lid fastening hole 224a may be disposed to face one end S1 or the other end S2 of the upper open end of the cell cover 120 described above.

[0103] Therefore, in the above-described embodiment, when a thermal event occurs, the melt cap 221a melts due to the heat, causing the cooling water in the pack cover 220 to pour out. In other embodiments of the present invention, when a thermal event occurs, the container lid body 223b melts due to the heat, causing the compressed gas to be injected into the inside of the cell cover 120.

[0104] Carbon dioxide (CO2) can be used as the compressed gas. That is, the gas storage container 223a contains compressed carbon dioxide. When the container cover 223b melts due to heat and the gas outlet of the gas storage container 223a is opened even slightly, the carbon dioxide is released very quickly from the gas storage container 223a as shown in FIG. 12 and can cool the battery cell 110 and the air inside the cell cover 120 by adiabatic expansion.

[0105] According to this fire extinguishing configuration of the battery pack according to another embodiment of the present invention, gaseous carbon dioxide is injected into the target cell cover 120 to cool the air inside the target cell cover 120 and the battery cell 110 in which a thermal event has occurred. Therefore, according to another embodiment of the present invention, compared to when coolant is used as a fire extinguishing material, electrical safety issues such as short circuits that may occur due to the infiltration of the battery cell 110 are eliminated.

[0106] Meanwhile, the battery pack may further include a control module 20. The control module 20 may include a battery management system (BMS) that manages the charge / discharge operation, state of charge (SOC), state of health (SOH), etc. of the battery cells 110, and may be installed in the internal space of the pack case 200. The battery pack may further include a switching unit. The switching unit may be configured to control an electrical connection between the battery pack and an external circuit. To this end, the switching unit may selectively include a current sensor, a power relay, a fuse, etc.

[0107] Such a battery pack according to the present invention can be used as a power energy source for an automobile. That is, an automobile V according to the present invention can include the battery pack according to the present invention described above, as shown in FIG. 13 . Here, the automobile according to the present invention can include, for example, a specific automobile that uses electricity as a power source, such as an electric automobile or a hybrid automobile. Furthermore, the automobile according to the present invention can further include, in addition to the battery pack according to the present invention, various other components included in the automobile, such as a body and a motor.

[0108] Meanwhile, although directional terms such as up, down, left, right, front, and rear are used in this specification, it will be obvious to those skilled in the art of the present invention that these terms are used merely for ease of explanation and may differ depending on the position of the object in question, the position of the observer, etc.

[0109] Although the present invention has been described above using limited embodiments and drawings, it is not limited to these in any way, and it goes without saying that a person having ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations within the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0110] 10 Cell Unit Group 20 Control Module 100 outermost cell unit 110 battery cells 111 Electrode lead 120 Cell Cover 120 target cell cover 121 Lower cover part 122 first side cover part 123 Second side cover part 130 Bus bar frame assembly 131 Terminal bus bar 132 Busbar housing 133 Busbar cover 133a Window 200 pack case 210 Pack Tray 211 Bottom plate 212a Outer beam frame 212b Beam Frame 220,220A pack cover 221, 221A Fire extinguishing agent injection section 221a Melt Cap 221b hole 222 Channel 223 Fire Extinguishing Unit 223a Gas storage container 223b Container lid 224 Unit mounting port 224a Lid fastening port G1 First Thermal Resin G2 Secondary Thermal Resin G3 Third Thermal Resin S1,S2 terminal part

Claims

1. A plurality of cell units each including a cell stack consisting of one or more stacked battery cells and a cell cover capable of accommodating the cell stack, stacked in one direction; a pack case including a pack tray on which the plurality of cell units are placed, and a pack cover that covers the plurality of cell units and is coupled to the pack tray; Including, the cell cover has an upper end opening portion so as not to cover an upper side surface of the cell stack, and the pack cover has a fire extinguishing agent supply portion that can supply a fire extinguishing substance to the cell cover through the upper end opening portion of the cell cover, The fire-extinguishing agent dispensing portion is configured so that at least a portion thereof is thermally melted to dispense the fire-extinguishing agent into the cell cover, Each of the plurality of cell units includes a first thermal resin applied to the upper surface of the cell stack; The battery pack, wherein the pack cover is in contact with the first thermal resin.

2. The first thermal resin is applied to the upper surface of the cell stack, but is not provided at at least one of the one end and the other end in the upper end opening of the cell cover along the longitudinal direction of the cell cover; 2. The battery pack according to claim 1, wherein the extinguishing agent dispensing portion is provided at a position that faces vertically at least one of the one end portion and the other end portion of the upper end opening of the cell cover.

3. The battery pack according to claim 1 , wherein the extinguishing agent injection section is provided vertically above each of the cell units.

4. the extinguishing substance is cooling water; The battery pack according to claim 1 , wherein the pack cover has a flow path therein through which the cooling water can flow.

5. The extinguishing agent injection section includes: a hole communicating with the flow path; a melt cap connected to the hole and made of a heat-meltable resin material; 5. The battery pack of claim 4, comprising:

6. The extinguishing agent injection section includes: a fire extinguishing unit including a gas storage container that stores compressed gas and has a gas discharge port on one side, and a container lid that is made of a heat-melting material and is provided so as to be able to close the gas discharge port; a unit mounting opening formed through the pack cover so that the container lid body faces the upper end opening of the cell cover and the fire extinguishing unit can be fitted into the unit mounting opening; 10. The battery pack of claim 1, comprising:

7. 7. The battery pack of claim 6, wherein the compressed gas is carbon dioxide.

8. The battery pack according to claim 6 , wherein the container lid has a screw thread on an outer periphery thereof, and the unit mounting opening includes a lid fastening opening that is threadably engageable with the container lid.

9. The cell unit comprises: The cell stack is composed of one or more stacked battery cells; the cell cover provided to cover both side surfaces of the cell stack along the width direction of the cell stack and a lower portion of the cell stack; 10. The battery pack of claim 1, comprising:

10. The cell cover is 2. The battery pack according to claim 1, comprising: a first side cover portion that covers one side portion of the cell stack along the width direction of the cell stack; a second side cover portion that covers the other side portion of the cell stack; and a lower cover portion that is formed integrally with the first side cover portion and the second side cover portion and that covers a lower portion of the cell stack.

11. 11. The battery pack according to claim 10, comprising: a bus bar frame assembly including bus bars electrically connected to electrode leads of the battery cells, the bus bar frame assembly being disposed at a front portion and a rear portion of the cell stack along a longitudinal direction of the cell stack, and coupled to the cell covers.

12. The battery pack according to claim 1 , further comprising a heat insulating pad disposed between the cell units in the plurality of cell units.

13. A cell stack, each consisting of one or more stacked battery cells, and a cell cover capable of accommodating the cell stack, comprising a plurality of cell units stacked in one direction; a pack case including a pack tray on which the plurality of cell units are placed, and a pack cover that covers the plurality of cell units and is coupled to the pack tray; a second thermal resin interposed between the lower cover portion of the cell cover and the surface of the pack tray; Including, the cell cover has an upper end opening portion so as not to cover an upper side surface of the cell stack, and the pack cover has a fire extinguishing agent supply portion that can supply a fire extinguishing substance to the cell cover through the upper end opening portion of the cell cover, The fire-extinguishing agent injection portion is configured so that at least a portion thereof is thermally melted to inject the fire-extinguishing material into the interior of the cell cover.

14. The battery pack according to claim 1 , wherein the battery cells are pouch-type battery cells.

15. A motor vehicle comprising a battery pack according to any one of claims 1 to 14.

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