Battery pack with enhanced fire safety

Abstract

A battery pack according to the present invention may include a pack case having a plurality of module mounting areas separated by partitions, battery modules each having a sensor member that transmits a danger signal when a thermal event occurs and disposed in the module mounting areas, and a fire extinguishing unit configured to receive the danger signal and supply extinguishing water to the module mounting area in which a target battery module that transmitted the danger signal is located among the battery modules.

Description

Technical Field

[0001] The present invention relates to a battery pack, and more specifically, to a battery pack that can prevent damage to other surrounding battery modules and prevent ignition of a specific battery module when a thermal event occurs in the specific battery module included in the battery pack.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0106396 filed on August 24, 2022, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] Secondary batteries not only have the temporary advantage of significantly reducing the use of fossil fuels but also have the advantage of producing no by-products associated with energy use. Therefore, they are attracting attention as a new energy source for environmental friendliness and improving energy efficiency.

[0004] For this reason, the application of secondary batteries to a wide variety of devices is increasing. For example, they are widely used as an energy source for wireless mobile devices or wearable devices, which are multifunctional small products. They are also used as an energy source or a power storage device (ESS) for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline vehicles and diesel vehicles.

[0005] Generally, the operating voltage per secondary battery is around about 2.5V to 4.5V. Therefore, in the case of electric vehicles and power storage devices that require high capacity and high output, a battery module in which a plurality of secondary batteries are connected in series and / or in parallel, and a battery pack in which the battery modules are connected in series and / or in parallel are configured and used as an energy source.

[0006] Thus, as secondary batteries are used as high-capacity and high-output energy sources, ensuring the safety of the battery modules / packs has become an important issue.

[0007] Recent battery modules are designed to house as many rechargeable batteries as possible in an intensive manner to improve energy density. As a result, if even one rechargeable battery malfunctions and ignites, a thermal runaway phenomenon is likely to occur, causing a chain reaction of fires to spread to other rechargeable batteries. Therefore, there has been a surge in research on battery packs that include fire suppression systems to extinguish fires before they spread to other rechargeable batteries or battery modules to an uncontrollable extent.

[0008] However, conventional battery pack fire suppression systems often miss the initial golden time to suppress the spread of fire because water is not properly injected after a flame has erupted in a battery module. As a result, gas and flames spread from the affected battery module to other surrounding battery modules, increasing the risk of the battery pack burning down or exploding very quickly and causing fatal damage to the user. [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention was created to solve the above-mentioned problems, and its objective is to provide a battery pack that can quickly and intensively inject fire-extinguishing water into a battery module where a thermal event has occurred, thereby suppressing the ignition of the battery module.

[0010] Another object of the present invention is to provide a battery pack that can effectively suppress a chain reaction of thermal runaway from one battery module to another when a thermal event occurs.

[0011] The technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0012] According to the present invention, a battery pack may be provided that includes a pack case having a plurality of module mounting areas separated by partitions, battery modules each arranged in the module mounting area and equipped with a sensor member that transmits a danger signal when a thermal event occurs, and a fire extinguishing unit configured to receive the danger signal and supply fire extinguishing water to the module mounting area where the target battery module that transmitted the danger signal is located.

[0013] The sensor member may include at least one of a temperature sensor for sensing changes in the temperature of the battery module and a gas sensor for sensing gases generated in the battery module.

[0014] The sensor member may be configured to transmit the danger signal to the fire extinguishing unit when the rate of change (dT / dt) of the temperature of the battery module remains > 1°C for 3 seconds or more, based on a preset threshold temperature.

[0015] The fire extinguishing unit may include a fire water storage tank located inside or outside the pack case, a plurality of fire water supply pipes connecting the fire water storage tank to each of the module mounting areas, and a control unit that controls, based on the danger signal, to selectively open only the fire water supply pipe connected to the module mounting area where the target battery module is located.

[0016] The pack case may include a pack tray having a base portion that supports the lower part of the battery module and a wall portion that forms a wall along the outer edge of the base portion, and a pack cover that covers the upper part of the battery module and is provided so as to be connectable to the pack tray.

[0017] Each module mounting area may be configured in the pack tray such that it surrounds each battery module with a partition wall that is higher than the battery module.

[0018] A passage may be provided between the opposing wall sections and the partition wall, and the fire extinguishing water supply pipe may be placed in the passage.

[0019] The fire extinguishing water supply pipe may be provided with a water injection port at one end, wherein the front portion of the water injection port is fitted into a through hole formed in the bulkhead, and the rear portion is fixedly connected to the bulkhead while sealing the through hole.

[0020] The battery module comprises a battery cell and a module case that houses the battery cell, and the module case may have a softer portion facing the front portion of the water injection port, which has relatively lower mechanical rigidity than other portions.

[0021] The soft portion is thinner than the surrounding area and can be made from a non-metallic material.

[0022] The module case may be provided with a metal mesh at at least one of the front and rear of the soft portion.

[0023] The battery module comprises a battery cell and a module case that houses the battery cell inside, the module case having a water injection hole in its upper part that covers the top of the battery cell, and the water injection hole and the water injection port can be connected by an extension hose within the module mounting area.

[0024] The base part includes a cooling unit in which cooling water can flow, and the cooling unit may include a plurality of area-unit cooling pipes arranged at positions corresponding to the lower regions of each of the module mounting areas, and a coolant control valve for controlling the flow rate of each of the area-unit cooling pipes.

[0025] Based on the danger signal transmitted from the sensor member, the coolant control valve of the battery pack may be selectively opened and closed so that the flow rate of the cooling water to the area-unit cooling pipe corresponding to the module mounting area where the other battery modules adjacent to the target battery module are located increases.

[0026] The battery pack may include a pack case having a plurality of module mounting areas partitioned by partition walls, a sensor member for transmitting a danger signal when a thermal event occurs, battery modules respectively arranged in the module mounting areas, and a cooling unit for selectively cooling only the module mounting areas where the other battery modules adjacent to the target battery module that transmitted the danger signal are located.

[0027] The pack case includes a pack tray including a base part for supporting the lower part of the battery module and a wall part for forming a wall along the outer peripheral edge of the base part, and the cooling unit may be disposed inside the base part and may include a plurality of area-unit cooling pipes arranged at positions corresponding to the lower regions of each of the module mounting areas, and a coolant control valve for controlling the flow rate of each of the area-unit cooling pipes.

[0028] Based on the danger signal transmitted from the sensor member, the coolant control valve of the battery pack may be selectively opened and closed so that the flow rate of the cooling water to the area-unit cooling pipe corresponding to the module mounting area where the other battery modules adjacent to the target battery module are located increases.

[0029] The battery pack may further include a cooling chiller that supplies cooling water to the area unit cooling pipe, and the cooling chiller may include a control unit that receives a danger signal from the sensor member and selectively opens and closes the coolant control valve.

[0030] The battery pack may include a pack case having a plurality of module mounting areas partitioned by partition walls, a sensor member that transmits a danger signal when a thermal event occurs, battery modules respectively disposed in the module mounting areas, and a cooling unit that cools the entire module mounting area based on the danger signal transmitted from at least one of the battery modules.

[0031] According to another aspect of the present invention, an automobile including the above-described battery pack may be provided.

Advantages of the Invention

[0032] According to an embodiment of the present invention, it is possible to provide a battery pack that can quickly and intensively inject fire extinguishing water targeting a battery module in which a thermal event has occurred to prevent the propagation of gas and flame to other surrounding battery modules.

[0033] In particular, according to the present invention, by injecting fire extinguishing water into the module mounting area in which the target battery module is housed before the ignition of the target battery module in which a thermal event has occurred intensifies, and flooding the target battery module, it is possible to more firmly suppress ignition and prevent the propagation of thermal runaway to other battery modules.

[0034] Furthermore, according to one embodiment of the present invention, since firefighting water is not injected into the module mounting area containing battery modules that do not show danger signals, other battery modules other than the target battery module are not damaged by flooding. Therefore, the other battery modules other than the target battery module are reusable.

[0035] Furthermore, according to one embodiment of the present invention, it is possible to concentrate cooling of battery modules around a battery module where a thermal event has occurred, thereby effectively suppressing a chain reaction of thermal runaway.

[0036] Furthermore, according to one embodiment of the present invention, when a thermal event occurs inside the battery pack, all battery modules can be cooled based on a danger signal from a sensor component, thereby effectively suppressing a chain reaction of thermal runaway.

[0037] The effects of the present invention are not limited in any way to those described above, and any other effects not mentioned will be clearly understood by a person with ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawing]

[0038] [Figure 1] This is a schematic perspective view of a battery pack according to one embodiment of the present invention. [Figure 2] This is a schematic perspective view showing the configuration of a battery pack according to one embodiment of the present invention. [Figure 3] Figure 2 shows an alternative example of the battery pack, schematically illustrating a battery pack in which the fire extinguishing units are all located inside the pack case. [Figure 4] This is a plan view of a portion of a battery pack according to one embodiment of the present invention. [Figure 5] This is a cross-sectional view of a portion of a battery pack according to one embodiment of the present invention. [Figure 6]Figure 5 shows a metal mesh screen. [Figure 7] This figure corresponds to Figure 5 and schematically shows a structure for injecting fire extinguishing water into a battery pack according to another embodiment of the present invention. [Figure 8] This is a reference diagram illustrating a battery pack fire suppression system according to one embodiment of the present invention. [Figure 9] This is a reference diagram illustrating a battery pack fire suppression system according to one embodiment of the present invention. [Figure 10] This figure schematically shows the configuration of a cooling unit disposed inside the base portion of a pack tray in a battery pack according to yet another embodiment of the present invention. [Figure 11] Figure 10 is a reference diagram illustrating the cooling system using the battery pack. [Figure 12] This is a reference diagram illustrating a cooling system for a battery pack according to yet another embodiment of the present invention. [Figure 13] This diagram schematically shows an automobile including a battery pack according to one embodiment of the present invention. [Modes for carrying out the invention]

[0039] The present invention will be described in detail below with reference to the attached drawings. The terms and words used in this specification and the claims are not to be interpreted in their ordinary or dictionary sense, but rather in accordance with the principle that the inventor may appropriately define the concepts of terms in order to best describe the invention, and are to be interpreted in the sense and concepts corresponding to the technical idea of ​​the present invention.

[0040] Therefore, the embodiments described herein and the configurations shown in the drawings represent only preferred embodiments of the present invention and do not represent the entire technical concept of the invention. It should be understood that there are various equivalents and modifications that can be substituted for these embodiments at the time of filing this application.

[0041] Figure 1 is a schematic perspective view of a battery pack according to one embodiment of the present invention, and Figure 2 is a schematic perspective view showing the configuration of the battery pack according to one embodiment of the present invention.

[0042] A battery pack 10 according to one embodiment of the present invention includes a pack case 100 having a plurality of module mounting areas 120, battery modules 200 arranged in each of the module mounting areas 120, and a fire extinguishing unit 300 for supplying fire extinguishing water in the event of a fire in the battery modules 200.

[0043] The pack case 100 has an internal space that can accommodate multiple battery modules 200. For example, the pack case 100 may include a pack tray 110 and a pack cover 130, as shown in Figures 1 and 2. The pack tray 110 is formed in the shape of a box with an open top and can accommodate battery modules 200 in its internal space. More specifically, the pack tray 110 may include a base portion 111 that supports the lower part of the battery modules 200 and a wall portion 112 that forms a wall along the outer periphery of the base portion 111. The pack cover 130 is bolted to a fastening groove T1 located at the upper end of the wall portion 112 of the pack tray 110 and is coupled to the pack tray 110, and may be formed in the shape of a lid that covers the top of all battery modules 200.

[0044] Furthermore, the pack case 100 may have module mounting areas 120 inside. For example, as shown in the embodiment of Figure 2, six module mounting areas 120 separated by partition walls 121 may be provided inside the pack tray 110, and at least one battery module 200 may be placed in each module mounting area 120. Each module mounting area 120 may be configured to surround each battery module 200 with partition walls 121 that are higher than the battery module 200.

[0045] For reference, although not shown in the diagram for ease of drawing, the battery modules 200 may be electrically connected to each other by components such as flexible busbars (not shown), and these flexible busbars may be installed penetrating the partition wall 121. Depending on the required electrical capacity or output of the battery pack 10, the battery pack 10 may contain fewer than 5 or 7 or more battery modules 200, thereby determining the size of the pack case 100 and the number of module mounting areas 120.

[0046] The pack cover 130 and the partition wall 121 may be configured such that the upper end of the partition wall 121 contacts the inner surface of the pack cover 130. In this case, a fastening groove into which bolts can be tightened may be formed at the upper end of the partition wall 121, as shown as "T1" in Figure 2, similar to the upper end of the pack tray 110. In this case, when the pack tray 110 and the pack cover 130 are combined, bolts can be tightened not only around the outer edge of the pack cover 130 but also in the middle region of the pack cover 130, thereby strengthening the fixation between the pack cover 130 and the pack tray 110. Furthermore, the upper part of each module mounting area 120 can be more tightly shielded by the pack cover 130, improving the airtightness of the module mounting area 120.

[0047] According to the above configuration of the present invention, each battery module 200 is arranged in a module mounting area 120 separated by a partition wall 121, so that even if an accident such as a fire occurs in a particular battery module 200, other battery modules 200 can be protected from the gas and flames generated in that particular battery module 200.

[0048] The battery module 200 can be described as an energy storage device in which a plurality of battery cells 210 are electrically connected to have a predetermined capacity and output. Such a battery module 200 may include components such as busbars for electrically connecting the battery cells 210, components for sensing the voltage of the battery cells 210, and a module case 220 capable of housing the battery cells 210 and the aforementioned components as a single unit.

[0049] The battery cell 210 can be any type of battery cell 210 known at the time of filing the application of the present invention. For example, whether it is a generally cylindrical or rectangular battery cell 210 in which an electrode assembly and electrolyte are sealed and housed in a metal can-type outer material, or a generally plate-shaped pouch-type battery cell 210 in which an electrode assembly and electrolyte are sealed and housed in a pouch-type outer material, any type of battery cell 210 can be applied to the battery module 200.

[0050] The module case 220 is a structure that supports the battery cell 210 to prevent it from moving and protects it from external impacts, and may be made of a material with high mechanical rigidity. In this embodiment, the module case 220 may be provided in the shape of a roughly rectangular box, including four side portions 221 that cover the front, rear, left, and right sides of the battery cell 210, and an upper portion 222 and a lower portion that cover the top and bottom of the battery cell 210.

[0051] In particular, a battery module 200 according to one embodiment of the present invention includes a sensor member 230. The sensor member 230 may include at least one of a temperature sensor for sensing changes in the temperature of the battery module 200 and a gas sensor for sensing gases generated in the battery module 200.

[0052] The sensor member 230 may be mounted on the outside or inside of the module case 220. The sensor member 230 may also be configured to wirelessly transmit a danger signal to an external device when a thermal event occurs in the battery module 200. Here, the external device refers to the control unit 330 of the fire extinguishing unit 300. The external device may include, for example, an electronic control unit (ECU) of an electric vehicle equipped with the battery pack 10 of the present invention. In this case, based on the danger signal, the ECU may output a warning sound and a warning message from a display in the vehicle or the like so that the driver can take prompt action.

[0053] On the other hand, the fire extinguishing unit 300 is configured to supply fire extinguishing water to the module mounting area 120 where the target battery module 200, which has received a danger signal from the sensor member 230 and experienced a thermal event, is located.

[0054] Such a fire extinguishing unit 300 may include a fire extinguishing water storage tank 310, a plurality of fire extinguishing water supply pipes 320, and a control unit 330, as shown in Figure 2.

[0055] The fire extinguishing water storage tank 310 contains fire extinguishing water and can be located inside or outside the pack case 100. For example, as shown in Figure 2, the fire extinguishing water storage tank 310 may be located outside the pack case 100, in which case the fire extinguishing water supply pipe 320 may extend from the fire extinguishing water storage tank 310 through the pack case 100 to each module mounting area 120 inside the pack case 100.

[0056] On the other hand, the fire extinguishing unit 300A according to the implementation configuration in Figure 3 is an alternative example of the fire extinguishing unit 300 according to the implementation configuration in Figure 2, and the fire extinguishing water storage tank 310 and the control unit 330 may be installed inside the pack case 100. In other words, the fire extinguishing unit 300A may be integrally housed inside the pack case 100.

[0057] The fire-fighting water storage tank 310 may be equipped with a water supply pump (not shown) and a control valve (not shown) and configured to selectively supply fire-fighting water to the plurality of fire-fighting water supply pipes 320. For example, if a danger signal is received from a module mounting area 120, the control valve may be activated to open a specific fire-fighting water supply pipe 320 connected to that module mounting area 120, and the water supply pump may be activated to supply fire-fighting water to the specific fire-fighting water supply pipe 320. As an alternative to the water supply pump, a nitrogen tank (not shown) may be connected to the fire-fighting water storage tank 310. For example, when a danger signal is received, the valve of the nitrogen tank may be opened and nitrogen may be blown into the fire-fighting water storage tank 310, and at this time, the pressure of the nitrogen gas may cause fire-fighting water to be supplied from the fire-fighting water storage tank 310 to the fire-fighting water supply pipes 320.

[0058] The control unit 330 may be configured to control, for example, the opening and closing of a water supply pump, a valve in a nitrogen tank, or the control valve. Alternatively, the control unit 330 may be configured to selectively open only the fire extinguishing water supply pipe 320 connected to the module mounting area 120 where the target battery module 200 is located, based on a danger signal received from the sensor member 230, thereby controlling the supply of fire extinguishing water from the fire extinguishing water storage tank 310. Such a control unit 330 may selectively include processors, application-specific integrated circuits (ASICs), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., as known in the industry.

[0059] Referring to Figures 2 to 4, the fire water supply pipe 320 may be configured such that one end is connected to the fire water storage tank 310 and the other end is connected to the corresponding module mounting area 120. In particular, the battery pack 10 according to this embodiment may be configured such that a passage P is provided between the opposing wall portions 112 and the partition wall 121 inside the pack case 100, and the fire water supply pipe 320 can be positioned along this passage P. On the other hand, in the drawings of this embodiment, the width of the fire water supply pipe 320 and the passage P are shown to be relatively large compared to the surrounding components in order to highlight the main components, but the passage may be designed to be, for example, 10 cm or less, and the fire water supply pipe 320 may also be configured to overlap within the passage P in the vertical direction (±Z direction) rather than in the left-right direction (±X direction). This makes it possible to make the battery pack 10 lighter and thinner.

[0060] More specifically, as shown in Figure 2, the battery pack 10 may house six battery modules 200 in two rows of three, separated from each other, in six module mounting areas 120, and the fire extinguishing water storage tank 310 may be positioned in front of the six module mounting areas 120 (in the -Y direction). Six fire extinguishing water supply pipes 320 may be used to connect the fire extinguishing water storage tank 310 and the six module mounting areas 120. For example, one battery module 200 may be housed in each of the three module mounting areas 120 located to the left of the fire extinguishing water storage tank 310, and one fire extinguishing water supply pipe 320 may be connected to each. Similarly, one battery module 200 may be housed in each of the three module mounting areas 120 located to the right of the fire extinguishing water storage tank 310, and one fire extinguishing water supply pipe 320 may be connected to each.

[0061] More specifically, as shown in Figure 4, one battery module 200A, 200B, and 200C are housed in the first module mounting area 120A, the second module mounting area 120B, and the third module mounting area 120C on the right, which are closest to the fire extinguishing water storage tank 310. The first fire extinguishing water supply pipe 320 on the right, indicated by "R1", is connected to the first module mounting area 120A on the right, the second fire extinguishing water supply pipe 320 on the right, indicated by "R2", is connected to the second module mounting area 120B on the right, and the third fire extinguishing water supply pipe 320 on the right, indicated by "R3", is connected to the third module mounting area 120C on the right. In this manner, the three module mounting areas 120 located on the left side can also be connected to the fire extinguishing water supply pipes 320.

[0062] Referring to Figure 5, the fire extinguishing water supply pipe 320 may include a piping hose 321 and a water inlet port 323 that is connected to the piping hose 321 by crimp fitting.

[0063] The piping hose 321 is not particularly limited in shape or material, but it is preferably made from a material that is fire-resistant, such as silicone, while also being flexible.

[0064] The water injection port 323 may be made of metal or, even if non-metallic, from a material with high mechanical rigidity, and may be partially fitted into the module mounting area 120 and firmly fixed to the partition wall 121. That is, as shown in Figure 5, the water injection port 323 may be configured such that the front portion 323a is fitted into a through hole formed in the partition wall 121, and the rear portion 323b is fixedly fixed to the partition wall 121 while sealing the through hole.

[0065] A flange portion 323c is provided at the rear portion 323b of the water injection port 323, which restricts its insertion into the through hole. The flange portion may be configured to be fixed to the bulkhead 121 by bolting it with bolt B2. As shown in an enlarged view in Figure 5, the flange portion 323c includes a groove formed in the direction of the bolt B2 head, and a rubber O-ring O may be interposed in the groove. With this configuration, the water injection port 323 can be airtightly and firmly attached to the bulkhead 121, and despite strong water pressure, the water injection port 323 will not detach from the bulkhead 121, making it possible to stably supply fire extinguishing water into the module mounting area 120. As a result, the module mounting area 120 can be filled with fire extinguishing water, the battery module 200 can be submerged, and ignition can be suppressed.

[0066] Returning to Figure 5, the module case 220 of the battery module 200 according to one embodiment of the present invention is provided with a soft portion 224 at a location facing the front portion 323a of the water injection port 323. The soft portion 224 is a part of the module case that has the lowest relative mechanical rigidity. The soft portion 224 is thinner than its surroundings and may be made of a non-metallic material. For example, the soft portion 224 may be made of a plastic material that will break or melt when subjected to a certain strength of water pressure or heat and gas pressure.

[0067] Thus, if the portion of the module case 220 facing the front portion 323a of the water injection port 323 is the weak portion 224 described above, the weak portion 224 can crack due to water pressure. This creates a hole in the side portion 221 of the module case 220, allowing fire-extinguishing water to be directly injected into the battery module 200 through the hole. As a result, the internal space of the module case 220 can be filled with fire-extinguishing water more quickly, and the ignition of the battery module 200 can be suppressed more effectively.

[0068] Furthermore, referring to the enlarged view of Figure 5 and Figure 6, the module case 220 of the battery module 200 is provided with metal mesh nets 225 and 226 at at least one of the front and rear of the soft part 224. The metal mesh nets 225 and 226 prevent flames and sparks from easily being discharged to the outside of the module case 220 even if the soft part 224 is burned out when gas, flames, and sparks are ejected from the battery cell 210, thereby preventing flames and sparks from scattering from the module mounting area 120, and together they serve to protect the water injection port 323 from thermal damage. Here, the sparks refer to high-temperature electrode plate fragments and electrode active material detached from the electrode assembly inside the battery cell 210.

[0069] On the other hand, Figure 7 is a diagram corresponding to Figure 5, and schematically shows a structure for injecting fire extinguishing water applied to a battery pack 10 according to another embodiment of the present invention.

[0070] The same component numbers as in the previously described embodiments refer to the same components, and redundant explanations of the same components will be omitted. The explanation will focus on the differences from the previously described embodiments.

[0071] In another embodiment of the present invention, the module case 220 of the battery module 200 is provided with a water injection hole 222a in the upper part 222 that covers the top of the battery cell 210, as shown in Figure 7. Furthermore, an extension hose EP connecting the water injection hole 222a and the water injection port 323 is provided inside the module mounting area 120.

[0072] According to the configuration shown in Figure 7, fire extinguishing water can be directly injected into the module case 220 through the water injection hole 222a located in the upper part 222 of the module case 220. The previously described embodiment has the advantage that fire extinguishing water can be injected into the module case 220 through a hole created after the soft part 224 is burned, but it has the problem that if a hole is created in the side part 221 of the module case 220 and the water level rises inside the module case 220, the fire extinguishing water will be discharged to the outside of the module case 220 again through the hole. However, according to the configuration of this embodiment, since fire extinguishing water is injected into the module case 220 through the water injection hole 222a located in the upper part 222 of the module case 220, the problem described in the previously described embodiment can be solved.

[0073] Figures 8 and 9 are reference diagrams illustrating a fire extinguishing system for a battery pack 10 according to one embodiment of the present invention.

[0074] Next, with reference to Figures 8 and 9, the fire extinguishing system of the battery pack 10 according to the present invention will be briefly described.

[0075] For example, as shown in Figure 8, if a thermal event occurs in the second battery module 200 on the right, the sensor member 230 of that battery module 200 transmits a danger signal to the control unit 330 of the fire extinguishing unit 300. In other words, in Figure 8, a danger signal is emitted from the second sensor member 230 and transmitted to the control unit 330 of the fire extinguishing unit 300.

[0076] In this case, the sensor member 230 may be configured to transmit the danger signal to the fire extinguishing unit 300 when the temperature change rate (dT / dt) of the battery module 200 remains > 1°C for 3 seconds or more, based on a preset threshold temperature. Here, the preset threshold temperature may mean the highest value within the temperature range of the battery module 200 that is considered normal during charging and discharging of the battery cell 210.

[0077] Based on the aforementioned preset threshold temperature, if the rate of change (dT / dt) of the battery module 200 remains > 1°C for 3 seconds or more, the likelihood of the battery module 200 catching fire increases further over time. Therefore, the sensor member 230 may be configured to transmit a danger signal to the fire extinguishing unit 300 if the above conditions are met, so that fire extinguishing water can be injected preemptively just before the battery module 200 catches fire.

[0078] Based on the danger signal from the second sensor member 230, the control unit 330 of the fire extinguishing unit 300 is activated and selectively opens only the second fire extinguishing water supply pipe 320 from the six fire extinguishing water supply pipes 320, which corresponds to "R2" in Figure 6, and fire extinguishing water from the fire extinguishing water storage tank 310 is injected into the module mounting area 120 where the target battery module 200, i.e., the second battery module 200B from the right, is located.

[0079] As a result, the target battery module 200 in the module mounting area 120 is submerged in water, which suppresses ignition and prevents the spread of gas and flames to other adjacent battery modules 200. Furthermore, since no firefighting water is injected into the module mounting area 120 where other battery modules 200 are housed, the other battery modules 200 other than the target battery module 200B are not affected by the water ingress.

[0080] For example, as shown in Figure 9, if danger signals are simultaneously emitted from the second sensor member 230 of the second battery module 200B on the right and the third sensor member 230 of the third battery module 200C on the right, the danger signals from the second sensor member 230 and the third sensor member 230 can be transmitted to the control unit 330 of the fire extinguishing unit 300, respectively. In this case, based on the two danger signals, the control unit 33 of the fire extinguishing unit 300 selectively opens only the second fire extinguishing water supply pipe 320 and the third fire extinguishing water supply pipe 320 on the right, which correspond to "R2" and "R3" in Figure 6, out of the six fire extinguishing water supply pipes 320, so that fire extinguishing water is supplied to the module mounting area 120 where the second battery module 200B and the third battery module 200C on the right are located, respectively. This allows the module mounting area 120 to be filled with fire-extinguishing water, thereby suppressing the ignition of the target battery modules 200B and 200C.

[0081] Figure 10 is a schematic diagram showing the configuration of a cooling unit 111a disposed inside the base portion 111 of a pack tray 110 in a battery pack 10 according to yet another embodiment of the present invention, and Figure 11 is a reference diagram for illustrating the cooling system of the battery pack 10 in Figure 10.

[0082] A pack tray 110 of a battery pack 10 according to yet another embodiment of the present invention includes a cooling unit 111a through which cooling water can flow. The cooling unit 111a may be built into the base portion 111 of the pack tray 110.

[0083] For example, the cooling unit 111a may include, as shown in Figure 10, a plurality of area-unit cooling pipes 111b (A to F) positioned in locations corresponding to the lower region of each module mounting area 120, and a coolant control valve 111c that controls the flow rate of each area-unit cooling pipe 111b.

[0084] Furthermore, the cooling unit 111a may be configured to selectively cool only the module mounting area 120 of the battery module 200 where the target battery module that transmitted the danger signal is located and other surrounding battery modules are located.

[0085] To give an analogy, the cooling unit 111a in this embodiment includes six area-specific cooling tubes 111b (A to F), and each of these six area-specific cooling tubes 111b (A to F) is built into a base portion 111 located at the bottom of six module mounting areas 120. Cooling water is supplied to these area-specific cooling tubes 111b (A to F) to cool the module mounting areas 120 and absorb the heat from the battery module 200.

[0086] The cooling unit 111a may be connected to a cooling chiller (not shown) located outside the pack case 100. The cooling water may be circulated in a manner in which it is heated in the pack tray 110 by absorbing heat from the battery module 200, cooled in the cooling chiller, and then returned to the pack tray 110. Here, the cooling chiller refers to a device that removes heat from the cooling water.

[0087] On the other hand, a cooling unit 111a according to yet another embodiment of the present invention may be configured to allow cooling water to flow through all area-specific cooling pipes 111b under normal conditions, i.e., when there is no danger signal from the sensor member 230. However, if a danger signal is emitted from the sensor member 230, the cooling unit 111a may be configured to transmit the danger signal to a control unit (not shown) located in the cooling chiller, which then selectively opens and closes the coolant control valve 111c based on the danger signal to increase the flow rate of cooling water to the area-specific cooling pipes 111b located beneath the module mounting area 120 of the target battery module 200 and other adjacent module mounting areas 120. This allows the flow rate of cooling water to be concentrated in specific area-specific cooling pipes 111b when a thermal event occurs.

[0088] For example, as shown in Figure 11, if a thermal event occurs in the second battery module 200 on the left and a danger signal is emitted from sensor member 230 no. 5, the control unit 330 selectively opens and closes the coolant control valve 111c based on the danger signal, increasing the flow rate of cooling water to the area-unit cooling pipes 111b(B, D, F) that cool the second battery module 200 on the left and the other adjacent battery modules 200. That is, the coolant control valves 111c of the area-unit cooling pipes 111b shown as 111b(B), 111b(D), and 111b(F) in Figure 11 are opened, and the coolant control valves 111c of the remaining area-unit cooling pipes 111b are closed. As a result, cooling water circulates only through the area-specific cooling pipes 111b, indicated as 111b(B), 111b(D), and 111b(F) in Figure 11, enabling concentrated cooling of the module mounting area 120 and the battery module 200 located above the area-specific cooling pipes 111b.

[0089] For reference, if the pack tray 110 is continuously exposed to high-temperature gas and flames when the battery module 200 ignites, the surrounding battery modules 200 near the affected battery module 200 will be thermally affected by the accumulated heat, and if this intensifies, there is a high possibility of a chain reaction occurring in which the surrounding battery modules 200 also ignite. However, with the cooling system according to the present invention as described above, it is possible to concentrate the cooling around the affected battery module 200, thereby blocking the spread of heat from the affected battery module 200 to the surrounding area, and effectively preventing structural collapse of the pack case 100 due to heat.

[0090] On the other hand, the cooling unit 111a described above can be integrated into a battery pack that includes the fire extinguishing unit 300 described above. That is, the battery pack 10 according to the present invention may be configured to include both the fire extinguishing unit 300 and the cooling unit 111a. In this case, when a thermal event occurs in some of the battery modules 200 included in the battery pack 10, the fire in those battery modules 200 can be quickly suppressed, and the propagation of thermal runaway to other surrounding battery modules can be prevented even more effectively.

[0091] Figure 12 is a reference diagram illustrating a cooling system for a battery pack according to yet another embodiment of the present invention.

[0092] A battery pack according to yet another embodiment of the present invention has a similar main configuration to the battery pack in the embodiment shown in Figure 10, but differs in that a cooling unit 111a is configured to allow all battery modules to be cooled when a risk of internal ignition in the battery pack is detected.

[0093] For example, as shown in Figure 12, a battery pack according to yet another embodiment of the present invention may be configured such that if a danger signal is emitted from a sensor member 230 of at least one of the battery modules 200, cooling water flows to the area-unit cooling pipes 111b(A~F) corresponding to all module mounting areas 120 based on the danger signal.

[0094] In this case, not only is a chain reaction of thermal runaway from the battery module experiencing a thermal event to other battery modules suppressed, but the rate of ignition of the affected battery module is also significantly slowed. Therefore, the driver of an electric vehicle containing such a battery pack will have sufficient time to detect an accident such as a fire in the battery pack and evacuate to a safe place or take the necessary measures.

[0095] Next, with reference to Figure 13, the automobile according to the present invention will be briefly described.

[0096] Figure 13 is a schematic diagram showing an automobile including a battery pack 10 according to one embodiment of the present invention.

[0097] Referring to Figure 13, the automobile 1 according to the present invention may be configured to include the battery pack 10 described above according to one embodiment of the present invention, an electronic control unit (ECU) 20, an inverter 30, and a motor 40. Preferably, the automobile 1 may be an electric vehicle.

[0098] The battery pack 10 can be used as an electrical energy source to drive the automobile 1 by providing driving force to the motor 40. The battery pack 10 can be charged and discharged by the inverter 30 in response to the driving of the motor 40 and / or an internal combustion engine (not shown). The battery pack 10 can be charged by a regenerative charging device coupled with the brake. The battery pack 10 can be electrically connected to the automobile's motor 40 via the inverter 30.

[0099] The ECU 20 is an electromagnetic control device that controls the state of the vehicle 1. For example, it determines torque information based on information such as the accelerator, brakes, and speed, and controls the output of the motor 40 to match the torque information. The ECU 20 also sends a control signal to the inverter 30 so that the battery pack 10 can be charged or discharged based on state information such as the charge state (SOC) and state of health (SOH) of the battery pack 10, which is passed on by the battery management system (BMS). The inverter 30 causes the battery pack 10 to be charged or discharged based on the control signal from the ECU 20. The motor 40 drives the vehicle 1 using the electrical energy of the battery pack 10 based on the control information (e.g., torque information) passed on from the ECU 20.

[0100] As described above, the battery pack 10 maintains an appropriate temperature for the battery module 200 under normal conditions, and if a thermal issue occurs in the battery module 200, it can quickly submerge the affected battery module 200 in water to suppress fire. Therefore, safety is maintained even if a problem or malfunction occurs in the battery pack 10 while the vehicle 1 is in operation.

[0101] Although the present invention has been described above with limited embodiments and drawings, the technical idea of ​​the present invention is not limited in any way to these, and it goes without saying that it is possible for a person with ordinary skill in the art to which the present invention belongs to to implement the invention with various modifications and variations within the equivalent scope of the technical idea and claims of the present invention.

[0102] On the other hand, while directional terms such as up, down, left, and right have been used in this specification, these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art that they may vary depending on the position of the object in question, the observer's position, etc. [Explanation of Symbols]

[0103] 1. Automobile 10 Battery Packs 30 Inverter 33 Control Unit 40 motors 100 pack case 110 Pack Tray 111 Base section 111a Cooling Unit 111b Area-specific cooling pipe 111c Coolant control valve 112 Wall section 120 module installation area 120A module installation area 120B module installation area 120C module installation area 121 Bulkhead 130 Pack Cover 200 Target Battery Modules 200A Battery Module 200B Target Battery Module 200C Target Battery Module 210 battery cells 220 Module Case 221 Side part 222 Upper part 222a Water injection hole 224 Soft area 225 Metal Mesh Net 226 Metal mesh 230 Sensor component 300 fire extinguishing units 300A Fire Extinguishing Unit 310 Firefighting water storage tank 320 Fire extinguishing water supply pipe 321 Piping hose 323 Water Inlet Port 323a Anterior part 323b Posterior part 323c Flange section 330 Control Unit

Claims

1. A pack case having multiple module mounting areas separated by partitions, A sensor component is provided to transmit a danger signal when a thermal event occurs, and battery modules are arranged in the module mounting area, A fire extinguishing unit configured to receive the aforementioned danger signal and supply fire extinguishing water to the module mounting area where the target battery module that transmitted the danger signal is located, Includes, The aforementioned fire extinguishing unit is A fire extinguishing water storage tank located inside or outside the aforementioned pack case, Multiple fire water supply pipes connecting the fire water storage tank and each of the module installation areas, A control unit that, based on the aforementioned danger signal, controls the selective opening of only the fire extinguishing water supply pipe connected to the module mounting area where the target battery module is located, Includes, The fire extinguishing water supply pipe is equipped with a water inlet port at one end. A battery pack in which the water injection port is configured such that its front portion is fitted into a through hole formed in the bulkhead, and its rear portion is fixedly connected to the bulkhead while sealing the through hole.

2. The battery pack according to claim 1, wherein the sensor member includes at least one of a temperature sensor for sensing changes in the temperature of the battery module and a gas sensor for sensing gas generated in the battery module.

3. The battery pack according to claim 1, wherein the sensor member is configured to transmit the danger signal to the fire extinguishing unit when the rate of change of the temperature of the battery module (dT / dt) > 1°C continues for 3 seconds or more, based on a preset threshold temperature.

4. The aforementioned pack case is A pack tray comprising a base portion that supports the lower part of the battery module, and a wall portion that forms a wall along the outer edge of the base portion, A pack cover is provided to cover the top of the battery module and to be connectable to the pack tray, The battery pack according to claim 1, including the following:

5. The battery pack according to claim 4, wherein each module mounting area is configured in the pack tray so as to surround each battery module with a partition wall that is higher than the battery module.

6. A pack case comprising multiple module mounting areas separated by partitions, A sensor component is provided to transmit a danger signal when a thermal event occurs, and battery modules are arranged in the module mounting area, A fire extinguishing unit configured to receive the aforementioned danger signal and supply fire extinguishing water to the module mounting area where the target battery module that transmitted the danger signal is located, Includes, The aforementioned fire extinguishing unit is A fire extinguishing water storage tank located inside or outside the aforementioned pack case, Multiple fire water supply pipes connecting the fire water storage tank and each of the module installation areas, A control unit that, based on the aforementioned danger signal, controls the selective opening of only the fire extinguishing water supply pipe connected to the module mounting area where the target battery module is located, Includes, The aforementioned pack case is A pack tray comprising a base portion that supports the lower part of the battery module, and a wall portion that forms a wall along the outer edge of the base portion, A pack cover is provided to cover the top of the battery module and to be connectable to the pack tray, Includes, A battery pack in which a passage is provided between opposing wall sections and a partition wall, and the fire extinguishing water supply pipe is arranged in the passage.

7. The battery module comprises a battery cell and a module case that houses the battery cell inside. The battery pack according to claim 1, wherein the module case has a weaker portion in the portion facing the front portion of the water injection port, which has relatively lower mechanical rigidity than other portions.

8. The battery pack according to claim 7, wherein the soft portion is thinner than the surrounding area and is made of a non-metallic material.

9. The battery pack according to claim 7, wherein the module case is provided with a metal mesh at at least one of the front and rear of the soft portion.

10. The battery module comprises a battery cell and a module case that houses the battery cell inside. The module case has a water injection hole in the upper part that covers the top of the battery cell. The battery pack according to claim 1, wherein the water injection hole and the water injection port are connected by an extension hose within the module mounting area.

11. A pack case comprising multiple module mounting areas separated by partitions, A sensor component is provided to transmit a danger signal when a thermal event occurs, and battery modules are arranged in the module mounting area, A fire extinguishing unit configured to receive the aforementioned danger signal and supply fire extinguishing water to the module mounting area where the target battery module that transmitted the danger signal is located, Includes, The aforementioned fire extinguishing unit is A fire extinguishing water storage tank located inside or outside the aforementioned pack case, Multiple fire water supply pipes connecting the fire water storage tank and each of the module installation areas, A control unit that, based on the aforementioned danger signal, controls the selective opening of only the fire extinguishing water supply pipe connected to the module mounting area where the target battery module is located, Includes, The aforementioned pack case is A pack tray comprising a base portion that supports the lower part of the battery module, and a wall portion that forms a wall along the outer edge of the base portion, A pack cover is provided to cover the top of the battery module and to be connectable to the pack tray, Includes, The base portion is equipped with a cooling unit through which cooling water can flow, The cooling unit is A battery pack comprising a plurality of area-specific cooling pipes positioned at locations corresponding to the lower region of each module mounting area, and a coolant control valve for controlling the flow rate of each area-specific cooling pipe.

12. The battery pack according to claim 11, wherein the coolant control valve is selectively opened and closed based on a danger signal transmitted from the sensor member, thereby increasing the flow rate of cooling water to the area unit cooling pipes corresponding to the module mounting area where other battery modules adjacent to the target battery module are located.

13. A pack case having multiple module mounting areas separated by partitions, A sensor component is provided to transmit a danger signal when a thermal event occurs, and battery modules are arranged in the module mounting area, A cooling unit that selectively cools only the module mounting area of ​​the battery module where the target battery module that transmitted the danger signal and other battery modules adjacent to it are located, A battery pack, including the battery pack.

14. The pack case includes a base portion that supports the lower part of the battery module, and a pack tray having a wall portion that forms a wall along the outer edge of the base portion. The cooling unit is installed inside the base portion, A plurality of area-unit cooling pipes are arranged at positions corresponding to the lower region of each module mounting area, and through which cooling water can flow, A coolant control valve that controls the flow rate of each of the aforementioned area-unit cooling pipes, The battery pack according to claim 13, including the following:

15. The battery pack according to claim 14, wherein the coolant control valve is selectively opened and closed based on a danger signal transmitted from the sensor member, thereby increasing the flow rate of cooling water to the area unit cooling pipes corresponding to the module mounting area where other battery modules adjacent to the target battery module are located.

16. The system further includes a cooling chiller that supplies cooling water to the aforementioned area-unit cooling pipes, The battery pack according to claim 15, wherein the cooling chiller includes a control unit that receives a danger signal from the sensor member and selectively opens and closes the coolant control valve.

17. An automobile comprising a battery pack according to any one of claims 1 to 16.

Images