Battery pack enabling extinguishant penetration to individual pouch battery cells

Abstract

A battery pack according to one embodiment of the present invention comprises a storage portion in which an electrode assembly is housed, an edge portion having a narrower area than the storage portion and having an electrode lead protruding therefrom, an electrolyte, and a pouch outer material, a plurality of battery cells stacked in at least one direction, and a plurality of cell channels arranged in a U-shape between each of the plurality of battery cells to receive a fire extinguishing solution, wherein the cell channels include a pair of side walls facing the storage portion of the battery cells and forming a flow path open in the front-rear direction, and a bottom surface disposed between the side walls, thereby blocking heat propagation between adjacent battery cells through the space formed by the bottom surface and the side walls, and allowing the fire extinguishing solution to diffuse into the storage portion through the flow path in the event of a thermal runaway of the battery cells.

Description

Technology Field

[0001] The present invention relates to the field of secondary batteries, battery thermal management, and battery safety technology.

[0002] More specifically, the invention relates to a battery pack used in an electric vehicle or an energy storage system (ESS), wherein a U-shaped cell channel is arranged between a plurality of battery cells, and in normal circumstances, it functions as an insulating barrier that blocks heat propagation between cells through the internal space (flow path) of the cell channel, and in the event of thermal runaway of a battery cell, the flow path functions as a passage for penetration and diffusion of a fire extinguishing solution, thereby blocking the propagation of overheating of a specific cell to adjacent cells and suppressing a fire, and the battery pack and the cell channel included therein. Background Technology

[0003] With the recent rapid growth of the mobility and energy industries, including electric vehicles and energy storage systems, the importance of safety and reliability for secondary battery packs, which serve as core energy sources, is increasing significantly. Since battery packs operate under rapid charging and discharging conditions involving high voltage and current, and consist of hundreds or more individual battery cells, preventing thermal runaway from a single cell from propagating to adjacent cells can affect the safety of the entire battery pack.

[0004] However, conventional high-density battery pack structures mostly involved stacking pouch-type battery cells densely with minimal spacing to secure energy density. In such densely stacked structures, if thermal runaway occurred in a specific battery cell, heat could be conducted to adjacent cells, causing thermal runaway propagation.

[0005] Since the battery cells are densely packed without gaps, there is no physical passage for the extinguishing solution released during a thermal runaway to penetrate deep into the surface of the overheated cell. As a result, the extinguishing solution only reaches parts of the top or sides of the cell and does not reach the center of the fire, which leads to a failure in initial suppression and a limitation in preventing a chain reaction of thermal runaway. The problem to be solved

[0006] The present invention aims to provide a battery pack and a cell channel including the same, which block, delay, and suppress thermal runaway propagation and fire by arranging a cell channel between battery cells so that, under normal conditions, it functions as an insulating barrier that blocks thermal propagation through the flow path of the cell channel, and in the event of thermal runaway, the flow path functions as a dedicated passage that penetrates and diffuses a fire extinguishing solution into the core heat-generating part of the cell. means of solving the problem

[0007] A battery pack according to one embodiment of the present invention comprises a storage portion in which an electrode assembly is housed, an edge portion having a narrower area than the storage portion and having an electrode lead protruding therefrom, an electrolyte, and a pouch outer material, a plurality of battery cells stacked in at least one direction, and a plurality of cell channels arranged in a U-shape between each of the plurality of battery cells to receive a fire extinguishing solution, wherein the cell channels include a pair of side walls facing the storage portion of the battery cells and forming a flow path open in the front-rear direction, and a bottom surface disposed between the side walls, thereby blocking heat propagation between adjacent battery cells through the space formed by the bottom surface and the side walls, and allowing the fire extinguishing solution to diffuse into the storage portion through the flow path in the event of a thermal runaway of the battery cells.

[0008] A plurality of holes may be formed in the above side wall to allow the extinguishing solution introduced through the above flow path to diffuse to the surface of the above storage portion of the battery cell.

[0009] The above hole is sealed by a membrane to maintain thermal insulation performance through the air layer inside the above flow path, and in the event of thermal runaway of the battery cell, the membrane can rupture due to the supply pressure of the above extinguishing solution to diffuse the above extinguishing solution.

[0010] A plurality of guide grooves are formed on the inner side of the above side wall to induce the diffusion of the fire extinguishing solution.

[0011] The guide groove extends from the bottom surface in the vertical direction of the side wall and can diffuse the extinguishing solution to the upper part of the storage portion by capillary action.

[0012] The guide groove extends in the front-rear direction of the bottom surface and in the front-rear direction of the side wall, and can reduce flow resistance when the extinguishing solution diffuses through the flow path.

[0013] The width of the above bottom surface may be at least 2 times and no more than 3 times the thickness of the above side wall.

[0014] The above hole includes a first hole formed on the inner side of the side wall and a second hole formed on the outer side of the side wall, and has a countersink shape in which the cross-sectional area of ​​the first hole is smaller than the cross-sectional area of ​​the second hole, and can induce the extinguishing solution to spread radially along the inclined surface of the second hole.

[0015] The battery pack further comprises a fire extinguishing solution capsule disposed adjacent to the battery cell, wherein the fire extinguishing solution capsule stores the fire extinguishing solution in a sealed state and can rupture upon thermal runaway of the battery cell to release the fire extinguishing solution into the flow path. Effects of the invention

[0016] According to an embodiment of the present invention, by arranging U-shaped cell channels between battery cells, the side walls and bottom surface of the cell channels and the empty space inside them act as an air layer under normal conditions, thereby functioning as an insulating barrier that blocks heat propagation between adjacent battery cells.

[0017] In addition, according to an embodiment of the present invention, in the event of thermal runaway of a battery cell, a fire extinguishing solution released from a fire extinguishing solution capsule placed inside the pack case can be transported through an open flow path of the cell channel. This provides a dedicated passage that allows the fire extinguishing solution to easily diffuse to the widest surface of the battery cell, which is difficult to access from outside the pack, thereby suppressing the fire and preventing a chain reaction of thermal runaway.

[0018] In addition, according to an embodiment of the present invention, a plurality of holes are formed in the side wall of the cell channel so that the extinguishing solution transported along the flow path can directly escape through these holes to the surface of the battery cell's housing and easily diffuse.

[0019] In addition, according to an embodiment of the present invention, a guide groove can be formed on the inner side of the side wall to facilitate the diffusion of the fire extinguishing solution. The guide groove extends in the vertical direction to draw the fire extinguishing solution up to the top of the cell, thereby eliminating blind spots in fire suppression. Brief explanation of the drawing

[0020] FIG. 1 is a schematic perspective view showing a portion of a battery pack according to one embodiment of the present invention separated. FIG. 2 is an exploded perspective view schematically showing the configuration of a pouch-type battery cell and a cell channel housed inside a battery pack according to one embodiment of the present invention. FIGS. 3 to 6 are perspective views showing some configurations of a battery pack according to one embodiment of the present invention omitted. Specific details for implementing the invention

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0022] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0023] FIG. 1 is a schematic perspective view showing a portion of the configuration of a battery pack according to one embodiment of the present invention separated. FIG. 2 is an exploded perspective view schematically showing the configuration of a pouch-type battery cell and a cell channel housed inside a battery pack according to one embodiment of the present invention.

[0024] Referring to FIGS. 1 and 2, a battery pack (10) according to one embodiment of the present invention may include a pouch-type battery cell (100), a cell channel (200), and a pack case (300).

[0025] A pouch-type battery cell (100) is a pouch-type secondary battery and may include an electrode assembly, an electrolyte, and a pouch outer material. A plurality of such pouch-type battery cells (100) may be included in a battery pack (10). And, such a plurality of pouch-type battery cells (100) may be stacked in at least one direction. For example, referring to FIGS. 1 and 2, a plurality of pouch-type battery cells (100) may be stacked and arranged in a horizontal direction, such as a left-right direction (the Y-axis direction of the drawing).

[0026] Additionally, as shown in FIG. 1, a plurality of pouch-type battery cells (100) may be arranged in a front-rear direction (the X-axis direction of the drawing). Furthermore, the plurality of pouch-type battery cells (100) may be arranged in a horizontal direction, but may be arranged in a form that forms multiple rows in the left-right direction and the front-rear direction. For example, referring to FIG. 1, the plurality of pouch-type battery cells (100) may be stacked in a form in which two rows of cells arranged in the left-right direction are provided in the front-rear direction.

[0027] The cell channel (200) can be placed between pouch-type battery cells (100) in the internal space of the pack case (300).

[0028] The cell channel (200) may be configured to support the stacked state of a plurality of pouch-type battery cells (100) inside the pack case (300). For example, a plurality of pouch-type battery cells (100) may be stacked in a horizontal direction (the Y-axis direction of the drawing) as shown in FIGS. 1 and 2. At this time, the cell channel (200) may be configured to stably maintain the stacked state of the plurality of pouch-type battery cells (100) stacked in the horizontal direction.

[0029] According to this aspect of the present invention, a plurality of pouch-type battery cells (100) can be directly seated and stored inside a pack case (300) without a module case. In particular, in the case of pouch-type battery cells (100), the outer material is made of a flexible material, making it vulnerable to external impact and having low hardness. Therefore, it is not easy to store the pouch-type battery cells (100) themselves inside the pack case (300) without storing them in a module case.

[0030] However, in the case of the present invention, a cell channel (200) is arranged between a plurality of pouch-type battery cells (100) and is directly stored inside a pack case (300), and the stacked state can be stably maintained. A CTP (Cell To Pack) type battery pack using pouch-type battery cells (100) can be implemented. That is, in the case of the present invention, instead of storing pouch-type battery cells (100) inside a separate module case and storing such a module case inside a pack case (300), the battery pack (10) can be provided in a form in which pouch-type battery cells (100) are directly stored inside a pack case (300).

[0031] As a result, the battery pack (10) may not be equipped with fastening members such as a module case, a stacking frame, or bolts to maintain the stacked state of the cells. Therefore, the space occupied by other components, such as a module case or a stacking frame, or the space required to secure tolerances resulting therefrom, can be eliminated. Consequently, the battery cells (100) can occupy more space by the amount of space eliminated, thereby improving the energy density of the battery pack.

[0032] In addition, since a module case, a stacking frame, bolts, etc. are not provided, the volume and weight of the battery pack (10) can be reduced and the manufacturing process can be simplified. A cell channel (200) is arranged between pouch-type battery cells (100) so that the pouch-type battery cells (100) can be protected and insulated without a module case.

[0033] The cell channel (200) can be adhered to the outer surface of the battery cell (100). For example, the inner surface of the cell channel (200) can be adhered to the storage portion (115) of the pouch-type battery cell (100).

[0034] A cell channel (200) may be configured to support a plurality of pouch-type battery cells (100) in an upright state. Each pouch-type battery cell (100) has two wide surfaces, and the corner portions of the wide surfaces may have sealing portions or folded portions of the pouch outer material. In a battery pack according to the present invention, the cell channel (200) may be disposed between the pouch-type battery cells (100) to support the upright state, i.e., the standing state, of the pouch-type battery cells (100).

[0035] In particular, the cell channel (200) can be configured so that a plurality of pouch-type battery cells (100) can be stacked in a horizontal direction (Y-axis direction of the drawing) while standing upright. For example, as in the embodiment shown in FIGS. 1 and 2, a plurality of cell channels (200) can be stacked alternately with the pouch-type battery cells (100) in a horizontal direction. By the cell channel (200), a configuration in which a plurality of pouch-type battery cells (100) are stacked side by side in a horizontal direction while standing upright can be stably maintained.

[0036] The cell channel (200) can be configured to be upright within the internal space of the pack case (300). That is, the cell channel (200) can be configured to maintain an upright state on its own without the help of other components provided in the battery pack (10), such as the pack case (300) or the pouch-type battery cell (100).

[0037] For example, the cell channel (200) can be placed directly on the bottom surface of the lower case (320) in FIG. 1. At this time, the bottom surface (202) of the cell channel (200) can be placed in direct contact with the bottom surface of the lower case (320).

[0038] As the cell channel (200) is positioned between the pouch-type battery cells (100), at least one side of the pouch-type battery cells (100) (e.g., the bottom of the cell) can be configured to be exposed toward the pack case (300).

[0039] For example, the cell channel (200) is positioned between pouch-type battery cells (100), and the lower portion of the battery cells (100) accommodated in the internal space of the pack case (300) is exposed toward the pack case (300) so as to be directly facing the pack case (300). In particular, referring to FIG. 1, the lower portion of the battery cells (100) may be exposed toward the bottom surface of the lower case (320).

[0040] According to this embodiment of the present invention, the cooling performance of the battery pack (10) can be improved. The pouch-type battery cell (100) and the pack case (300) can be in direct contact. That is, one side of the pouch-type battery cell (100) can face or come into direct contact with the pack case (300). Accordingly, heat released from each pouch-type battery cell (100) is directly transferred to the pack case (300), thereby improving the cooling performance. In addition, in this case, since a separate cooling structure does not need to be provided between the pouch-type battery cell (100) and the pack case (300), efficient cooling performance can be achieved.

[0041] According to one aspect of the present invention, a configuration of a long cell with a long length in a specific direction can be formed more easily. For example, in the case of a conventional rectangular cell, if the length in a specific direction is formed to be long, the process of inserting the electrode assembly into the rectangular case may be difficult. In particular, problems such as damage to the electrode assembly may occur during the insertion process of such an electrode assembly.

[0042] However, according to one embodiment of the present invention, extending the length of the pouch-type battery cell (100) and the cell channel (200) in one direction can be easily implemented during the molding of the pouch outer material, the manufacturing of the electrode assembly, or the manufacturing stage of the cell channel (200). Therefore, even when manufacturing a battery pack (10) using a long cell, excellent assembly, processability, and productivity can be secured.

[0043] Each pouch-type battery cell (100) may include a storage portion (115) and edge portions (111, 112, 113, 114). Here, the storage portion (115) may be a portion in which an electrode assembly is stored, configured such that a positive plate and a negative plate are stacked together with a separator interposed therein. Additionally, an electrolyte may be stored in the storage portion (115). The storage portion (115) may have the widest surface area in the pouch-type battery cell (100). The edge portions (111, 112, 113, 114) may be arranged to surround the storage portion (115). The edge portions (111, 112, 113, 114) have a narrower area than the storage portion (115), and some of the edge portions (111, 112, 113, 114) may be parts where the electrode lead (110) protrudes.

[0044] In particular, the edge portions (111, 112, 113, 114) may be sealing portions in which the pouch outer material, which is the case of the pouch-type battery cell (100), is sealed. For example, in the embodiment of FIG. 2, four edge portions (111, 112, 113, 114) are provided and may be located at the upper side corner, lower side corner, front side corner, and rear side corner, respectively, with respect to the storage portion (115). At this time, all four edge portions (111, 112, 113, 114) may be sealing portions.

[0045] Alternatively, some of the four edge portions (111, 112, 113, 114) may be configured in a folded form rather than as sealing portions. For example, in the embodiment of FIG. 2, the upper edge portion (111), the front edge portion (113), and the rear edge portion (114) are all sealing portions, but the lower edge portion (112) may be a folded portion of the pouch outer material. The upper edge portion (111) may be a Double Side Folding (DSF) portion as a sealing portion of the pouch-type battery cell (100), and the lower edge portion (112) may be an unsealed portion of the pouch-type battery cell (100).

[0046] Here, a battery cell in which all four edge portions (111, 112, 113, 114) are sealed can be referred to as a four-sided sealed cell, and a battery cell in which three edge portions (111, 113, 114) are sealed can be referred to as a three-sided sealed cell.

[0047] A single cell channel (200) can be positioned on the surface of each storage unit (115) for two adjacent pouch-type battery cells (100). Accordingly, cooling performance between the storage unit (115) and the cell channel (200) can be further improved. In particular, in this case, surface cooling is implemented through the wide surface of the storage unit (115), thereby improving cooling efficiency.

[0048] The lower edge portion (112) faces the pack case (300) and can come into direct contact with the pack case (300). Therefore, heat from the pouch-type battery cell (100) can be quickly and smoothly discharged toward the lower pack case (300). Thus, the cooling performance of the battery pack can be improved.

[0049] In particular, such a configuration can be effectively implemented when cooling is mainly performed at the bottom of the pack case (300). For example, in the case of a battery pack (10) mounted on an electric vehicle, since it is mounted on the bottom of the vehicle body, cooling can mainly be performed at the bottom of the pack case (300). At this time, when the lower edge portion (112) of the pouch-type battery cell (100) comes into contact with the pack case (300), heat is rapidly transferred from each battery cell (100) to the pack case (300), thereby improving cooling performance.

[0050] The pack case (300) has an empty space formed inside and can accommodate a plurality of pouch-type battery cells (100). For example, the pack case (300) may be equipped with an upper case (310) and a lower case (320) as shown in FIG. 1. The lower case (320) is configured in the shape of a box with an open top so that a plurality of battery cells (100) can be accommodated in the internal space. The upper case (310) may be configured in the shape of a cover that covers the upper opening of the lower case (320). At this time, the upper case (310) may be configured in the shape of a box with an open bottom.

[0051] Additionally, a cell channel (200) can be stored along with a plurality of pouch-type battery cells (100) in the internal space of the pack case (300). The pack case (300) may be made of plastic or metal.

[0052] Additionally, the pack case (300) may be configured with an internal space that is sealed. In particular, the pack case (300) may be configured to be directly exposed to the outside. Therefore, the pack case (300) needs to ensure performance such as water resistance and dust resistance at a certain level or higher, and to this end, it may be configured in a sealed form.

[0053] The battery pack (10) according to the present invention may further include a battery management system (400). The battery management system (400, BMS, Battery Management System) is mounted in the internal space of the pack case (300) and may be configured to generally control the charging and discharging operation or data transmission and reception operation of the pouch-type battery cell (100). The battery management system (400) may be provided at the pack level rather than at the module level. The battery management system (400) may be provided to control the charging and discharging state, power state, and performance state of the pouch-type battery cell (100) through the pack voltage and pack current.

[0054] The battery pack (10) according to the present invention may further include a battery disconnect unit (500). The battery disconnect unit (500, BDU, Battery Disconnect Unit) may be configured to control the electrical connection of battery cells (100) to manage the power capacity and function of the battery pack (10). To this end, the battery disconnect unit (500) may include a power relay, a current sensor, a fuse, etc.

[0055] In the case of a battery pack (10) according to one embodiment of the present invention, it may further include a Manual Service Disconnector (MSD) that allows a worker to manually disconnect the service plug to cut off the power.

[0056] The battery pack (10) may further include a busbar assembly (700). Here, the busbar assembly (700) may be configured to electrically connect a plurality of pouch-type battery cells (100) to each other. For example, the busbar assembly (700) may be coupled to the electrode leads (110) of two pouch-type battery cells (100) to electrically connect the two pouch-type battery cells (100) in series and / or parallel. The busbar assembly (700) may have a busbar terminal made of an electrically conductive material such as copper or aluminum that is in direct contact with the electrode leads (110), and a busbar housing made of an electrically insulating material such as plastic that supports the busbar terminal.

[0057] In a pouch-type battery cell (100), if electrode leads (110) are provided on both sides, a busbar assembly (700) may also be included on both sides where electrode leads (110) are provided. For example, as shown in FIG. 2, if electrode leads (110) protrude both to the front side (in the direction of the -X axis of the drawing) and the rear side (in the direction of the +X axis of the drawing), a busbar assembly (700) may also be located on both the front side and the rear side.

[0058] The busbar assembly (700) can be coupled with the electrode lead (110). For example, referring to the illustration in FIG. 2, the cell channel (200) can be stacked horizontally by being placed between each different pouch-type battery cell (100). In this case, the busbar assembly (700) can be placed at the front and rear ends of the pouch-type battery cell (100) respectively and coupled with the electrode lead (110).

[0059] The busbar assembly (700) can be connected and fixed to the electrode lead (110) through various fastening methods such as bonding, welding, snap-fitting, hook-fitting, bolting, and rivet-fitting.

[0060] A plurality of pouch-type battery cells (100) may be unitized by a busbar assembly (700). For example, referring to the embodiment of FIG. 2, two pouch-type battery cells (100) are combined by the same busbar assembly (700). In this case, the two pouch-type battery cells (100) shown in FIG. 2 and the cell channel (200) placed between them can be said to be included in one cell unit.

[0061] A battery pack (10) according to one embodiment of the present invention may include a plurality of battery cells (100), a digestion solution capsule (600), and a plurality of cell channels (200).

[0062] The cell channel (200) can be arranged in a U-shape between each of the stacked multiple battery cells (100). That is, it can have an alternating stacked structure such as cell channel (200), battery cell (100), cell channel (200), and battery cell (100) in the horizontal direction (the Y-axis direction of the drawing). The cell channel (200) is arranged in a U-shape so that a extinguishing solution can enter the flow path (203) of the cell channel (200).

[0063] The cell channel (200) may include a side wall (201) and a bottom surface (202) to form a U-shaped cross-sectional structure.

[0064] A pair of side walls (201) may face the storage portion (115) of the battery cell (100). A bottom surface (202) may be positioned between the side walls (201). A pair of side walls (201) and a bottom surface (202) may form a flow path (203) that is open in the front-rear direction (X direction in the drawing). That is, the cell channel (200) has an internal space formed by the side walls (201) and the bottom surface (202), and this space may be a flow path (203) into which a fire extinguishing solution flows.

[0065] Heat propagation between adjacent battery cells (100) can be blocked through the flow path (203) formed by the bottom surface (202) and the side wall (201). For example, the side wall (201) and the bottom surface (202) of the cell channel (200) may be formed of a material with low thermal conductivity, and the empty space inside the flow path (203) may act as an air layer to block direct heat conduction between adjacent battery cells (100).

[0066] In a situation such as thermal runaway of the battery cell (100), the extinguishing solution can be diffused into the storage section (115) through the flow path (203). That is, when the extinguishing solution is supplied from the extinguishing solution capsule (600) provided inside the battery pack (10), the extinguishing solution can flow into the flow path (203) of the cell channel (200).

[0067] Since the Euro (203) extends along the storage portion (115), which is the widest surface of the battery cell (100), the extinguishing solution can quickly penetrate to the center and bottom of the wide surface of the battery cell (100).

[0068] The width (w) of the bottom surface (202) of the cell channel (200) may be at least 2 times and no more than 3 times the thickness (t) of the side wall (201).

[0069] These numerical limitations may be limitations that satisfy the normal heat propagation blocking function of the cell channel (200), the fire extinguishing solution diffusion function during thermal runaway, and the energy density securing function of the battery pack (10).

[0070] A lower limit where the width (w) of the bottom surface is more than twice the thickness (t) of the side wall may be related to fluid resistance inside the Euro (203). The side wall (201) may have a thickness (t) of a certain level or more to block heat propagation between battery cells (100).

[0071] However, if the width (w) of the bottom surface (202) becomes similar to or narrower than the thickness (t) of the side wall (201), the flow path (203) loses its function as a channel and may take the shape of a narrow gap. Such a narrow gap increases fluid resistance, which may limit the rapid diffusion of the extinguishing solution during thermal runaway. Therefore, ensuring the width (w) of the bottom surface (202) is at least twice the thickness (t) of the side wall (201) may be a threshold value to ensure a minimum effective flow rate of the extinguishing solution while maintaining thermal isolation between the battery cells (100).

[0072] The upper limit that the width (w) of the bottom surface (202) is less than or equal to three times the thickness (t) of the side wall (201) may be related to the energy density of the battery pack (10).

[0073] If the width (w) of the bottom surface is more than three times the thickness (t) of the side wall, it may be easy to secure the flow rate of the extinguishing solution, but the cell channel (200) may occupy the space where the battery cell (100) can be placed. That is, the width of the cell channel (200) within the battery cell (100) increases, and the volume occupied by the cell channel (200) within the battery pack (10) may increase. This may reduce the overall energy density of the battery pack (10). Therefore, limiting the width (w) of the bottom surface (202) to three times or less the thickness (t) of the side wall (201) may be a threshold value for securing the flow path space required for the diffusion of the extinguishing solution while minimizing the reduction in the energy density of the battery pack (10).

[0074] The extinguishing solution capsule (600) may be placed in the internal space of the pack case (300). For example, it may be placed in the internal space of the pack case (300) that is distinct from the stacking area of ​​the battery cell (100), such as the space adjacent to the battery management system (400) or the space adjacent to the battery cutoff unit (500).

[0075] The extinguishing solution capsule (600) may be a storage unit that stores a extinguishing solution in a sealed state in a liquid or gaseous state during normal operation.

[0076] The extinguishing solution capsule (600) may be configured to rupture under specific conditions that occur during thermal runaway of the battery cell (100). For example, the outer wall or part of the capsule (600) may be formed of a low-melting-point material that melts at a preset reference temperature, or may include a ruptured seal that is mechanically ruptured by a rapid increase in pressure inside the pack case (300) during thermal runaway.

[0077] When the digestive solution capsule (600) is ruptured by heat or pressure, the digestive solution contained therein can be released into the internal space of the pack case (300).

[0078] The extinguishing solution released inside the pack case (300) can be released into the flow path (203) through the flow path (203) which is open in the front-rear direction of the cell channel (200). The extinguishing solution supplied to the flow path (203) can move rapidly along the flow path (203) and spread over the entire surface of the storage section (115) to suppress thermal runaway and block heat propagation to adjacent battery cells (100).

[0079] FIGS. 3 to 6 are perspective views showing some configurations of a battery pack according to one embodiment of the present invention omitted.

[0080] Referring to FIG. 3, a plurality of holes (205) may be formed in the side wall (201) of the cell channel (200a).

[0081] The hole (205) can diffuse the extinguishing solution introduced through the flow path (203) to the surface of the storage section (115) of the battery cell (100). The hole (205) can function as a passage for the diffusion of the extinguishing solution in the cell channel (200a). In the event of a thermal runaway of the battery cell (100), the extinguishing solution introduced through the flow path (203) can diffuse through these plurality of holes (205) to the outside of the side wall (201), i.e., to the surface of the storage section (115).

[0082] The hole (205) can be sealed by a membrane (204). Normally, the membrane (204) seals the hole (205) to maintain insulation performance through the air layer inside the flow path (203). That is, each battery cell (100) can be insulated. If the hole (205) is open, the surface of the storage section (115) may be exposed through the hole (205). Heat may be conducted or convected into the flow path (203) through the storage section (115) of the battery cell (100). However, by blocking this with the membrane (204), the insulation function of each battery cell (100) can be improved.

[0083] When the battery cell (100) undergoes thermal runaway, a supply pressure of the extinguishing solution may be generated inside the flow path (203). At this time, the membrane (204) may rupture due to the supply pressure. When the membrane (204) ruptures, the sealed hole (205) is immediately opened, allowing the extinguishing solution to spread to the surface of the storage section (115).

[0084] Under normal circumstances, the cell channel (200a) forms an air layer sealed by the membrane (204) to block heat propagation between the battery cells (100). At the same time, only when an emergency situation called thermal runaway occurs, the membrane (204) is ruptured by pressure and the hole (205) is opened, so that the fire extinguishing solution can be supplied to the storage unit (115) when needed.

[0085] Referring to FIG. 4, the hole (206) of the cell channel (200b) may include a first hole (2061) and a second hole (2062).

[0086] The first hole (2061) may be formed on the inner side of the side wall (201) facing the Euro (203). The second hole (2062) may be formed on the outer side of the side wall (201) facing the storage portion (115).

[0087] The cross-sectional area of ​​the first hole (2061) may be smaller than the cross-sectional area of ​​the second hole (2062). That is, the hole (206) may have a countersink shape in which the cross-sectional area gradually widens from the inside to the outside of the flow path (203).

[0088] When the extinguishing solution introduced through the Euro (203) passes through the relatively narrow first hole (2061) and reaches the wider second hole (2062), the extinguishing solution can be induced to spread radially along the slope of the second hole (2062).

[0089] This can help the fire extinguishing solution spread naturally and widely along the storage portion (115), which is the surface of the battery cell (100) exiting the hole (206), even if the solution is not sprayed at high pressure. Therefore, the countersink shape facilitates the diffusion of the fire extinguishing solution to the surface of the storage portion (115) even under low supply pressure, thereby improving fire suppression efficiency during thermal runaway.

[0090] Accordingly, the countersink shaped hole (206) can induce natural radial diffusion using the surface tension and fluid flow of the extinguishing solution without a separate pressurizing device. This allows the extinguishing solution to spread through the inclined surface of the second hole (2062) rather than being concentrated only at a narrow point of the storage section (115), thereby increasing the extinguishing efficiency.

[0091] Referring to FIG. 5, a plurality of guide grooves (207) may be formed on the inner side of the side wall (201) of the cell channel (200c).

[0092] The guide groove (207) of the cell channel (200c) can be formed as an intaglio pattern on the surface of the inner wall, i.e., the side wall (201), of the Euro (203).

[0093] The guide groove (207) can induce diffusion of the extinguishing solution introduced into the flow path (203). The guide groove (207) may be a structure that helps the extinguishing solution introduced into the flow path (203) spread along the inner side of the side wall (201). The guide groove (207) can induce diffusion by utilizing the surface tension of the extinguishing solution or promote flow in a specific direction.

[0094] The guide groove (207) extends from the bottom surface (202) of the Euro (203) in the vertical direction (Z direction in the drawing) of the side wall (201) and can spread the extinguishing solution to the top of the storage portion (115) by capillary action.

[0095] These vertical guide grooves (207) can quickly draw up the fire extinguishing solution accumulated on the bottom surface (202) of the flow path (203) against gravity along the side wall (201) to the top of the storage section (115) of the battery cell (100). By allowing the fire extinguishing solution to reach the top of the battery cell (100), where heat generation may be severe, rather than remaining only on the bottom surface (202) of the flow path (203), the efficiency of suppressing thermal runaway can be improved.

[0096] Referring to FIG. 6, the guide groove (208) of the cell channel (200d) may extend parallel to the front-rear direction (X-axis direction in the drawing) of the bottom surface (202) and the front-rear direction of the side wall (201). Unlike the guide groove (207) shown in FIG. 5, this guide groove (208) may be formed along the front-rear direction of the flow path (203).

[0097] The guide groove (208) can reduce the flow resistance that occurs when the extinguishing solution introduced into the flow path (203) moves along the front and rear directions of the flow path (203).

[0098] For example, when a fire extinguishing solution flows into one end (e.g., forward) of the flow path (203) and into the other end (e.g., rear), this horizontal guide groove (208) can stabilize the flow of the fluid and reduce frictional resistance.

[0099] Therefore, this structure can improve the transport speed so that when the digestion solution diffuses through the channel (203), it can quickly reach the rear end far from the entrance of the channel (203).

[0100] The guide groove (208) can facilitate the diffusion of the fire extinguishing solution, particularly in battery packs where the battery cell (100) is long (e.g., long cell battery cell). By minimizing the time it takes for the fire extinguishing solution to reach from one end (e.g., front) of the flow path (203) to the other end (e.g., rear), the fire extinguishing solution can be supplied without delay throughout the entire pack in the event of a thermal runaway. Thus, the initial golden time for fire suppression can be secured.

[0101] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0102] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back have been used in this invention, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the position of the object or the position of the observer. Explanation of the symbols

[0103] 100: Battery Cells 300: Pack Case 200: Cell channel 201: Sidewall 202: Floor surface 203: Euro 205, 206: Holes 207, 208: Guide grooves 111, 112, 113, 114: Edge 110: Electrode Lead Fire Extinguishing Solution Capsule: 600

Claims

Claim 1 A plurality of battery cells stacked in at least one direction, each comprising a storage portion in which an electrode assembly is housed, an edge portion having a narrower area than the storage portion and having an electrode lead protruding therefrom, an electrolyte, and a pouch outer material; a plurality of cell channels arranged in a U-shape between each of the plurality of battery cells to receive a fire extinguishing solution; and a fire extinguishing solution capsule disposed adjacent to the battery cell, wherein the outer wall is formed of a low-melting-point material that melts at a preset reference temperature and includes a ruptureable seal that is mechanically ruptured by a rapid increase in pressure, and stores the fire extinguishing solution in a sealed state, wherein the cell channel faces the storage portion of the battery cell and forms a flow path open in the front-rear direction; A battery pack comprising a bottom surface disposed between the side walls, blocking heat propagation between adjacent battery cells through the space formed by the bottom surface and the side walls, diffusing the extinguishing solution into the storage portion through the flow path during thermal runaway of the battery cells, and wherein the extinguishing solution capsule releases the extinguishing solution into the flow path when the seal ruptures during thermal runaway of the battery cells. Claim 2 A battery pack according to claim 1, wherein a plurality of holes are formed in the side wall to allow the extinguishing solution introduced through the flow path to diffuse to the surface of the storage portion of the battery cell. Claim 3 A battery pack according to claim 2, wherein the hole is sealed by a membrane to maintain thermal insulation performance through an air layer inside the flow path, and the membrane ruptures due to the supply pressure of the extinguishing solution during thermal runaway of the battery cell to diffuse the extinguishing solution. Claim 4 A battery pack according to claim 1, wherein a plurality of guide grooves are formed on the inner side of the side wall to induce the diffusion of the extinguishing solution. Claim 5 In claim 4, the guide groove extends from the bottom surface in the vertical direction of the side wall and diffuses the extinguishing solution to the upper part of the storage portion by capillary action. Claim 6 In claim 4, the guide groove extends in the front-rear direction of the bottom surface and in the front-rear direction of the side wall, and reduces flow resistance when the extinguishing solution diffuses through the flow path.

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