Battery system and electric vehicle including the same

Abstract

A battery system according to one embodiment of the present disclosure comprises: a battery housing including a cover element; a plurality of battery cells accommodated within the battery housing, each having an exhaust outlet that allows an exhaust gas stream to be discharged upon thermal runaway and having an exhaust surface facing the cover element; a fire extinguishing agent supply unit; a first supply pipe connected to the fire extinguishing agent supply unit and extending laterally along the exhaust outlet of the plurality of battery cells on a first side; and a first discharge pipe provided for each of the plurality of battery cells, extending toward the exhaust outlet of each battery cell and connected to the first supply pipe, and having a first free end positioned on the side of the exhaust outlet and facing the exhaust outlet, wherein the first discharge pipe is configured to discharge a fire extinguishing agent supplied by the fire extinguishing agent supply unit and the first supply pipe to the exhaust outlet through the free end when an exhaust gas stream is applied.

Description

Technology Field

[0001] The present disclosure relates to a battery system and an electric vehicle including the same. Background Technology

[0002] A battery module consists of multiple battery cells connected to each other in series or parallel. In other words, to realize a high-output secondary battery, a battery module is constructed by interconnecting the electrode terminals of multiple battery cells according to the required power amount.

[0003] The battery main module can be configured in a block structure or a modular structure. In a block structure, each unit battery cell arranged in a housing is connected to a common current collector structure and a common battery management system. In a modular structure, a sub-module is configured by connecting multiple battery cells, and a battery module is configured by connecting multiple sub-modules. In vehicle applications, the battery system includes multiple battery modules connected in series to provide a desired voltage.

[0004] A battery pack is a set of multiple battery modules, and the battery modules can generally be identical. They can be configured in series, parallel, or a combination of both to provide the desired voltage, capacity, or power density. The components of a battery pack include individual battery modules and interconnects that provide electrical conductivity between them.

[0005] The battery system may include a battery management system (BMS), which is a suitable electronic system configured to manage secondary batteries, battery modules, and battery packs, such as protecting the secondary batteries from operating outside a safe operating range, monitoring the condition of the secondary batteries, calculating secondary data, reporting such data, controlling their environment, and certifying and / or balancing. For example, the BMS may monitor the condition of the secondary batteries, indicated by voltage (e.g., total voltage of the battery pack or battery module and / or voltage of individual cells), temperature (e.g., average temperature of the battery pack or battery module, coolant intake temperature, coolant output temperature, temperature of individual cells), coolant flow (e.g., flow rate and / or coolant pressure), and current. In addition, the BMS can calculate values ​​based on the above parameters, such as minimum and maximum cell voltage, state of charge (SOC), or depth of discharge (DOD), to represent the battery's charge level, state of health (SOH; a measurement value defined as the remaining capacity of the battery as a percentage of the original capacity), state of power (SOP: the amount of power available during a defined time interval considering current power usage, temperature, and other conditions), state of safety (SOS), maximum charge current as charge current limit (CCL), maximum discharge current as discharge current limit (DCL), and the cell's internal impedance determining the open circuit voltage.

[0006] A BMS can be centralized, where a single controller is connected to the battery cells via multiple wires. In other cases, the BMS can be distributed, where a battery management system board is installed in each cell and only a single communication cable is connected between the battery and the controller. In another embodiment, the BMS may have a modular structure containing several controllers, each capable of handling a specific number (e.g., a group) of cells while communicating with one another. A centralized BMS is the most economical but has the disadvantages of the lowest scalability and the need for multiple wires. A distributed BMS is the most expensive but offers the simplest installation and the cleanest assembly. A modular BMS can provide a compromise between the features and disadvantages of the other two methods.

[0007] A BMS can protect the battery pack from operating outside its safe operating range. Operation outside the safe operating range may be indicated by overcurrent, overvoltage (e.g., during charging), overheating, low temperature, overpressure, ground fault, or leakage current detection. The BMS can prevent the battery from operating outside its safe operating range by including an internal switch (e.g., a relay or solid-state device) that opens when the battery operates outside its safe operating range, or by requesting the device to which the battery is connected to reduce or shut down battery usage and / or by actively controlling the environment, such as heaters, fans, air conditioners, and / or liquid cooling.

[0008] An active or passive thermal management system is included to control the heat of the battery pack, thereby efficiently releasing, discharging, and / or dissipating heat generated in the rechargeable battery, allowing at least one battery module to be safely used. If heat is not sufficiently released, discharged, or dissipated, temperature variations may occur between individual battery cells, and consequently, at least one battery module may no longer be able to generate the designed (or intended) output. Furthermore, a rise in internal temperature can lead to abnormal reactions, resulting in degraded charge / discharge performance and a shortened lifespan of the secondary battery. Therefore, cell cooling is required to effectively release, discharge, and dissipate the heat generated in the cells.

[0009] The thermal decomposition of cell components can lead to so-called thermal runaway. Generally, thermal runaway refers to a phenomenon accelerated by a rise in temperature, which causes energy to be released and further increase the temperature. Thermal runaway occurs when conditions are altered in such a way that a temperature rise causes the temperature to rise even more, which can often lead to destructive consequences. In secondary battery systems, thermal runaway is associated with a powerful exothermic reaction accelerated by a rise in temperature. In thermal runaway, the battery cell temperature rises relatively very rapidly, and stored energy is released relatively abruptly. In severe cases, thermal runaway can cause the battery cell to explode or ignite. Even in minor cases, it can cause irreparable damage to the battery cell.

[0010] If a battery cell is heated above a critical temperature of approximately 150°C or higher, it may transition into a thermal runaway state. Generally, if the lower or higher temperature exceeds the safe range, irreversible damage to the battery cell may occur, which can trigger thermal runaway. Thermal runaway can also occur due to internal or external short circuits or poor battery management. For example, overcharging or rapid charging can induce thermal runaway.

[0011] During thermal runaway, the temperature of the failed battery cell can exceed approximately 700°C. Additionally, a large amount of hot gas may be released from inside the failed battery cell into the battery pack through the exhaust port of the cell housing. The main components of the released gas may be H2, CO2, CO, electrolyte vapor, and other hydrocarbons. Therefore, the released gas is flammable and potentially toxic. Furthermore, the released gas can increase the gas pressure inside the battery pack. High temperatures can cause the thermal runaway process to spread to surrounding cells and lead to fires in the battery pack that are difficult to extinguish.

[0012] The battery exhaust concept allows exhaust gas streams emitted from one or more battery cells to diffuse into the battery housing and exit to the outside (e.g., the surrounding environment surrounding the battery housing) through a housing exhaust valve. In this way, the exhaust gas stream heats components inside the battery housing, such as other battery cells. For example, particles from the exhaust gas stream can settle on the battery cells, leading to heat propagation and potentially causing thermal runaway in adjacent battery cells.

[0013] Furthermore, thermal runaway can damage the electrical cell insulation (e.g., plastic foil) of affected battery cells. In other words, if one or more battery cells overheat, the cell insulation may melt. This results in reduced electrical resistance between components with large differential voltages (>20V), which can lead to internal short circuits and arcs. When thermal runaway occurs in a single cell, the surrounding environment heats up due to the cell's exothermic reaction. Since the released energy is limited by the cell's size and chemical properties, adequate insulation is required to prevent heat propagation.

[0014] To mitigate heat propagation, sprinkler pipes containing a fire extinguishing agent (e.g., liquid such as water) may be positioned over the exhaust outlet of a battery cell to spray the liquid into the battery cell affected by thermal runaway. However, in this arrangement, the pipe may partially block the exhaust outlet, preventing the affected battery cell from effectively venting gas. Additionally, when the liquid is discharged through the opening in the side wall of the pipe, the spray angle of the discharged liquid becomes relatively wide, which may make it difficult for the liquid to enter the interior of the battery cell. The problem to be solved

[0015] The embodiments of the present disclosure are intended to overcome or reduce at least some of the disadvantages of the prior art and to provide a battery system that more safely handles thermal runaway of one or more battery cells. means of solving the problem

[0016] The present disclosure may be defined by the appended claims. The following description is subject to such limitations. Any disclosures outside the scope of the claims are for illustrative and comparative purposes only.

[0017] A battery system according to an embodiment of the present disclosure comprises: a battery housing including a cover element; a plurality of battery cells accommodated within the battery housing, each having an exhaust outlet that allows an exhaust gas stream to be discharged upon thermal runaway and having an exhaust surface facing the cover element; a fire extinguishing agent supply unit; a first supply pipe connected to the fire extinguishing agent supply unit and extending laterally along the exhaust outlet of the plurality of battery cells on a first side; and a first discharge pipe corresponding to each of the plurality of battery cells, extending toward the exhaust outlet of each battery cell and connected to the first supply pipe, and having a first free end positioned on the side of the exhaust outlet and facing the exhaust outlet, wherein the first discharge pipe is configured to discharge a fire extinguishing agent supplied by the fire extinguishing agent supply unit and the first supply pipe to the exhaust outlet through the first free end when an exhaust gas stream is applied.

[0018] According to an embodiment of the present disclosure, the apparatus further comprises a second supply pipe connected to a fire extinguishing agent supply unit and extending laterally along the exhaust outlet of a plurality of battery cells on a second side opposite to the first side, and a second discharge pipe corresponding to each of the plurality of battery cells, extending toward the exhaust outlet of each battery cell and connected to the second supply pipe, and having a second free end facing the exhaust outlet located on the side of the exhaust outlet opposite to the first end and facing the exhaust outlet, wherein the second discharge pipe can discharge the fire extinguishing agent supplied by the fire extinguishing agent supply unit and the second supply pipe through the second free end when an exhaust gas stream is applied.

[0019] According to an embodiment of the present disclosure, the first supply pipe and / or the second supply pipe may be attached to the inner surface of the cover element.

[0020] According to an embodiment of the present disclosure, the cover element may be an upper cover.

[0021] According to an embodiment of the present disclosure, the first exhaust pipe may be extended toward the exhaust outlet of the battery cell at a certain angle with respect to the cover element, and / or the second exhaust pipe may be extended toward the exhaust outlet of the battery cell at a certain angle with respect to the cover element.

[0022] According to an embodiment of the present disclosure, the constant angle may be 35°.

[0023] According to an embodiment of the present disclosure, the first discharge pipe may include a first sealing element configured to seal the first free end and to unseal when exposed to an exhaust gas stream, and / or the second discharge pipe may include a second sealing element configured to seal the second free end and to unseal when exposed to an exhaust gas stream.

[0024] In another embodiment of the present disclosure, an electric vehicle includes a battery system as described above.

[0025] Further embodiments of the present disclosure may be understood from dependent claims or the following description. Effects of the invention

[0026] According to the present disclosure, a discharge pipe can accurately discharge a fire extinguishing agent toward the exhaust outlet of a battery cell without blocking it.

[0027] According to the present disclosure, sufficient cooling and prevention of heat propagation can be provided while using a cell spacer thinner than that of a known battery system.

[0028] According to the present disclosure, the cost of preventing heat propagation can be reduced. Brief explanation of the drawing

[0029] The features of the present disclosure will become apparent to those skilled in the art by describing embodiments in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of a battery system according to an embodiment. Figure 2 is a drawing showing the front view of the battery system of Figure 1 when it is in the first state. Figure 3 is a drawing showing the front view of the battery system of Figure 1 when it is in a second state. Specific details for implementing the invention

[0030] The following description is detailed with reference to the embodiments illustrated in the attached drawings. The effects and features of the exemplary embodiments and the methods of implementation will be described with reference to the attached drawings. In the drawings, the same reference numerals indicate the same components, and redundant descriptions are omitted. However, the present disclosure may be embodied in various other forms and should not be interpreted as being limited to the embodiments illustrated herein. Rather, these embodiments are provided as examples to ensure that the present disclosure is thorough and complete and fully conveys the aspects and features of the present disclosure to those skilled in the art.

[0031] Accordingly, processes, elements, and techniques that are not considered necessary for a person skilled in the art to fully understand the aspects of the present disclosure may not be described. In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity.

[0032] The term “and / or (and / or)” as used in this disclosure includes all combinations of one or more of the listed items. Additionally, the use of “may” when describing embodiments of this disclosure relates to “one or more embodiments of this disclosure.” In the following description of embodiments of this disclosure, terms in the singular form may include the plural form unless otherwise specified in the context.

[0033] The terms “first” and “second” are used to describe various elements, but these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. For example, the first element may be named the second element, and similarly, the second element may be named the first element, and this does not depart from the scope of the present disclosure.

[0034] The terms “include” and “include” may be understood as specifying attributes, domains, fixed numbers, steps, processes, elements, components, and combinations thereof, but not excluding other attributes, domains, fixed numbers, steps, processes, elements, components, and combinations thereof.

[0035] The term "essentially composed" means that additional components may be included, provided that they do not substantially alter the essential characteristics of the particular composition.

[0036] Additionally, where a film, region, or element is referred to as being "above" or "on" another film, region, or element, it may be located directly on the other film, region, or element, or an intermediate film, region, or element may exist.

[0037] The terms "upper" and "lower" herein are defined according to the Z-axis. For example, the upper cover is located at the upper end of the Z-axis, while the lower cover is located at the lower end. In the drawings, the size of elements may be exaggerated for clarity. For example, the size or thickness of each element in the drawings may be arbitrarily depicted for exemplary purposes and should not be interpreted as limiting the embodiments of the present disclosure.

[0038] Unless otherwise defined, all terms used in this disclosure, including technical and scientific terms, have the same meaning as generally understood by a person skilled in the art to which this disclosure pertains. Furthermore, it should be understood that terms such as those defined in commonly used dictionaries should be interpreted in a meaning consistent with the relevant technology and / or the context of this specification, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0039] According to one aspect of the present disclosure, a battery system is provided. The battery system comprises a plurality of battery cells. The battery cells are accommodated within a battery housing of the battery system. The battery cells may be arranged along a stacking direction or stacked to form one or more cell stacks. The battery cells may be interconnected through electrical connection means (e.g., busbars) in contact with each electrode terminal of the battery cells to form one or more battery modules / battery packs. The battery cells may be arranged to form one or more battery packs. In a battery pack, the battery cells may be electrically interconnected in series and / or parallel, for example as described above. A plurality of battery modules, each comprising a battery cell, may each form a battery pack. The battery cells may be, for example, prismatic or cylindrical cells.

[0040] Each battery cell may include an exhaust outlet on the exhaust surface of the battery cell, which may be the terminal surface of the battery cell where the electrode terminals of the battery cell are located. The exhaust outlet allows a stream of exhaust gases to escape from the battery cell during thermal runaway. An exhaust valve may be provided at the exhaust outlet. The exhaust surface of the battery cell faces the cover element of the battery housing. That is, the cover element is positioned opposite the exhaust surface of the battery cell to cover the battery cell. When assembling the battery system, the battery cell can be placed on the housing base of the battery housing, and then the cover element can be placed on the housing base so that the battery cell is completely surrounded by the battery housing.

[0041] The battery system includes a first supply pipe extending laterally along the exhaust outlet of the battery cell. The battery system may include at least one supply pipe (e.g., a first supply pipe and a second supply pipe) which extends laterally along the exhaust outlet on opposite sides of the battery cell as described below. For example, at least one supply pipe may extend parallel to the stacking direction of the battery cell. The first supply pipe is fluidly connected to a fire extinguishing agent supply unit of the battery system capable of supplying a fire extinguishing agent for extinguishing and / or cooling in the event of a thermal runaway of one of the battery cells. The fire extinguishing agent may be a gas or a liquid (e.g., water). The fire extinguishing agent may be stationary or moving and may be pumped, for example, through at least one pipe. The fire extinguishing agent inside the pipe may be under pressure. Being under pressure may mean that the fire extinguishing agent is under pressure higher than the pressure inside the battery housing, for example, higher than atmospheric pressure. The fire extinguishing agent may be any agent (e.g., water, an aqueous solution, or a liquid chemical) suitable for cooling the affected battery cell and the exhaust gas stream. The fire extinguishing agent can be pressurized by a pressure generating device of the battery system. For example, the first supply pipe can be made of plastic or a metal such as aluminum.

[0042] The battery system further comprises a first discharge pipe for each battery cell. That is, the battery system comprises a plurality of first discharge pipes, one provided for each battery cell. Each first discharge pipe is connected to a first supply pipe and connected to a fire extinguishing agent supply unit through the first supply pipe. The first discharge pipe extends toward the exhaust outlet of the relevant battery cell, i.e., the exhaust outlet of the battery cell where the first discharge pipe is placed, and a first free end, i.e., an exposed end, faces the exhaust outlet of the battery cell. The first free end is located to the side or adjacent to the exhaust outlet. That the first free end is located to the side of the outlet means that the first free end is located next to the outlet rather than directly above the outlet. That is, each first discharge pipe has a first end to which the first discharge pipe is connected to the first supply pipe and a free end, i.e., a second end, facing the respective exhaust outlet. The first discharge pipe may be made of, for example, plastic or a metal such as aluminum. The inner diameter of the first discharge pipe can be 2.6 mm to 3.7 mm, for example, 3.1 mm.

[0043] According to the present disclosure, a first discharge pipe is configured to discharge a fire extinguishing agent supplied by a fire extinguishing agent supply unit and a first supply pipe to each exhaust outlet through a first free end when an exhaust gas stream is applied. For example, if an exhaust gas stream is discharged through an outlet of one of the battery cells and comes into contact with a first free end positioned laterally at the outlet, the first free end may rupture or melt. Thus, the first discharge pipe may rupture near the exhaust outlet where the exhaust gas stream is discharged. The first free end may rupture as the first free end or a sealing element positioned at the first free end is damaged due to the heat flow of the exhaust gas stream. For example, high-temperature gases and particles of the exhaust gas stream may burn or melt the first free end or the sealing element. Consequently, the fire extinguishing agent is discharged from the first free end or sprayed into the affected base battery cell to cool the same battery cell and also cool the discharged exhaust gas stream.

[0044] When the exhaust gas stream is cooled, the temperature of the exhaust gas stream is significantly reduced, which can prevent potential melting of the battery components and prevent arc and heat propagation. When the first free end ruptures, if pressure is applied to the extinguishing agent, the extinguishing agent is rapidly discharged and rapidly dispersed or sprayed from the first free end, thereby enhancing the cooling effect. Additionally, since the first free end is located to the side of the exhaust outlet, the first discharge pipe does not block the exhaust outlet. Furthermore, since the extinguishing agent is discharged from the first discharge pipe through the first free end facing the exhaust outlet, the direction of discharge guidance of the extinguishing agent is improved. For example, the spray cone of the extinguishing agent discharged from the first free end can be narrowed. Consequently, the extinguishing agent can be aimed directly at the exhaust outlet, and the extinguishing agent can be introduced through the exhaust outlet (e.g., an open exhaust valve) even if the first free end is not positioned directly above or overlaps the exhaust outlet. Therefore, if one of the battery cells enters a thermal runaway, the extinguishing agent can be delivered into the battery cell and to the hottest point of the battery cell. This significantly lowers the temperature and keeps adjacent cells within a safe zone, thereby preventing heat propagation. The affected battery cells can be cooled by the evaporation of the extinguishing agent. Test results using water as the extinguishing agent showed that even when a thin cell spacer of 1.8 mm was placed between the affected battery cell and the adjacent battery cell, the maximum temperature of the adjacent battery cell was only 80°C. Therefore, according to the present disclosure, sufficient cooling and prevention of heat propagation can be provided while using a thinner cell spacer than in known battery systems. Thus, costs can be reduced.

[0045] According to an embodiment, the battery system further comprises a second supply pipe. As described above, a plurality of supply pipes may be provided, for example, a first supply pipe and a second supply pipe extend laterally along the exhaust outlet of a battery cell on opposite sides. According to the present embodiment, the second supply pipe is connected to a fire extinguishing agent supply unit and extends laterally along the exhaust outlet of a battery cell on a second side opposite to the first side to which the first supply pipe extends. Additionally, according to the present embodiment, a second discharge pipe is provided for each battery cell, the second discharge pipe is connected to the second supply pipe and extends toward the exhaust outlet of the associated battery cell, and the second free end is located on the side of the exhaust outlet of the associated battery cell and on the opposite side of the first free end. The second free end also faces the exhaust outlet. The second discharge pipe is configured to discharge the fire extinguishing agent supplied by the fire extinguishing agent supply unit and the second supply pipe through its second free end when an exhaust gas stream is applied. Accordingly, the second supply pipe and the second discharge pipe may be identical to the first supply pipe and the first discharge pipe, respectively, but may be positioned opposite to the exhaust outlet, for example, by mirror symmetry along the stacking axis of the battery cell. The description and embodiments disclosed with respect to the first supply pipe and the first discharge pipe may also be valid for the second supply pipe and the second discharge pipe. By providing two of these pipes instead of just one, the aforementioned effects, such as cooling and prevention of heat propagation, are enhanced. Additionally, the second supply pipe and the second discharge pipe provide redundancy in that even if one of the pipes is blocked by particles released during thermal runaway, for example, the other pipe can still discharge a fire extinguishing agent over or into the affected battery cell. The inner diameter of the second discharge pipe may be 2.6 mm to 3.7 mm (e.g., 3.1 mm).

[0046] According to the embodiment, the first supply pipe and / or the second supply pipe are attached to the inner surface of the cover element. Thus, for example, the first discharge pipe and / or the second discharge pipe can be attached to the inner surface of the cover element through the first supply pipe and / or the second supply pipe. Thus, at least one supply pipe / discharge pipe can be installed without additional work when installing the cover element, thereby facilitating the assembly process. That is, at least one supply pipe / discharge pipe can be installed by simply placing the cover element, for example, the upper cover, on the housing base of the battery housing after inserting the battery cell. According to the embodiment, the cover element is the upper cover. The fire extinguishing agent can easily reach the exhaust outlet located below the battery cell by being influenced by gravity. On the other hand, the cover element may also be the lower cover. The fire extinguishing agent can reach the exhaust outlet located when pressurized to a pressure high enough to overcome gravity, for example.

[0047] According to an embodiment, the first discharge pipe extends toward the exhaust outlet of the associated battery cell at a certain angle relative to the cover element. In one embodiment, the second discharge pipe extends toward the exhaust outlet of the associated battery cell at a certain angle relative to the cover element. According to one embodiment, the angle may be between 25° and 45°, or between 30° and 40°, or the angle may be 35°. By providing at least one discharge pipe at such an angle, the second free end can be directed toward the exhaust outlet to direct the fire extinguishing agent toward the exhaust outlet, while at the same time, at least one discharge pipe can be positioned to the side rather than directly above the exhaust outlet.

[0048] According to an embodiment, the first discharge pipe includes a first sealing element that seals a first free end, and the first sealing element is adjusted to melt, for example, when the first sealing element is exposed to an exhaust gas stream. The exhaust gas stream may be discharged from the exhaust outlet at high pressure and temperature. Therefore, when the first sealing element is exposed to the exhaust gas stream, it may melt by acting on the heat and pressure of the exhaust gas stream. According to an embodiment, the second discharge pipe includes a second sealing element that seals a second free end, and the second sealing element is adjusted to melt, for example, when the second sealing element is exposed to an exhaust gas stream. The sealing element may be configured to sufficiently seal each discharge pipe so that the fire extinguishing agent is safely kept within the pipe system while the battery system is operating normally. However, when the sealing element is exposed to the exhaust gas stream, it may be released so that the fire extinguishing agent can escape from each discharge pipe at the free end. For example, the sealing element may include or be configured with a meltable plug inserted into the free end of each discharge pipe, and the meltable plug is adjusted to melt when the meltable plug is exposed to the temperature of the exhaust gas stream.

[0049] FIG. 1 is a schematic perspective view of a battery system (100) according to an embodiment. FIG. 2 and FIG. 3 are front views of the battery system (100). The battery system (100) includes a battery housing (11) that accommodates a plurality of battery cells (12) and a cover element (20) that covers the battery cells (12) from the top. Thus, the cover element (20) may be an upper cover. The cover element (20) may constitute a part of the battery housing (11). The battery housing (11) and the cover element (20) are not shown in FIG. 1 so that internal elements of the battery system (100) can be seen.

[0050] Each battery cell (12) includes an exhaust surface (13) having an exhaust outlet (14), and an exhaust valve (not shown) may be placed inside the exhaust outlet (14). If one of the battery cells (12) is affected by thermal runaway, an exhaust gas stream (V) may exit from the affected battery cell (12) through the exhaust outlet (14), as shown in FIG. 2. As can be seen in FIG. 2, the exhaust surface (13) of the battery cell (12) faces the cover element (20). The battery cell (12) may further include an electrode terminal (16) for electrical connection at the exhaust surface (13).

[0051] As schematically illustrated, the first supply pipe (30) and the second supply pipe (30') of the battery system (100) are connected to a fire extinguishing agent supply unit (40). The fire extinguishing agent can be supplied from the fire extinguishing agent supply unit (40) to the first supply pipe (30) and the second supply pipe (30') through a pump (42).

[0052] As illustrated in FIG. 1, the first and second supply pipes (30, 30') extend laterally along the exhaust outlets (14) of the battery cells (12) facing each other. That is, the first supply pipe (30) extends along the first side of the exhaust outlet (14), and the second supply pipe (30') extends along the second side of the exhaust outlet (14), where the second side is opposite to the first side. In the illustrated embodiment, the first and second supply pipes (30, 30') are positioned outwardly and extend to both sides of the battery cell (12), but the first and second supply pipes (30, 30') may instead extend over the battery cell (12). The first and second supply pipes (30, 30') may each be attached to the inner surface of the cover element (20) as illustrated in FIG. 2 and FIG. 3.

[0053] The discharge pipes (32, 32') each extend from the first and second supply pipes (30, 30') toward the exhaust outlet (14). That is, the battery system (100) includes a plurality of first discharge pipes (32) provided one for each battery cell (12). The first discharge pipe (32) is connected to the first supply pipe (30) and extends toward the exhaust outlet (14) of the associated battery cell (12). The first discharge pipe (32) is located on the side or next to the exhaust outlet (14) on the first side and has a first free end (34) facing toward the exhaust outlet (14). Correspondingly, the battery system (100) includes a plurality of second discharge pipes (32') provided one for each battery cell (12). The second discharge pipe (32') is connected to the second supply pipe (30') and extends toward the exhaust outlet (14) of the associated battery cell (12). The second exhaust pipe (32') is located on the side or next to the exhaust outlet (14) on the second side opposite the first side and has a second free end (34') facing the same exhaust outlet (14).

[0054] As can be seen in FIGS. 2 and 3, the first exhaust pipe (32) and the second exhaust pipe (32') each extend toward the exhaust outlet (14) of the associated battery cell (12) at an angle α with respect to the cover element (20). The angle α may be approximately 35°.

[0055] Additionally, the first and second discharge pipes (32, 32') each include a first and second sealing element (36, 36'). The first and second sealing elements (36, 36') are positioned at the free end (34, 34') and may be configured in the form of a meltable plug that prevents a fire extinguishing agent supplied to the first and second discharge pipes (32, 32') through the first and second supply pipes (30, 30') during normal operation of the battery system (100) from escaping the first and second discharge pipes (32, 32').

[0056] The first and second discharge pipes (32, 32') are configured to discharge the fire extinguishing agent supplied by the fire extinguishing agent supply unit (40) and the first and second supply pipes (30, 30') over the exhaust outlet (14) through the free ends (34, 34') when the exhaust gas stream (V) is applied. That is, when a thermal runaway occurs in one of the battery cells (12), the exhaust gas stream (V) containing high-temperature gas and particles is discharged through the exhaust outlet (14) as indicated by the arrow in FIG. 2. The exhaust gas stream (V) comes into contact with the free ends (34, 34') of the first and second discharge pipes (32, 32'), and due to the high temperature of the exhaust gas stream (V) rising to 1000°C, the sealing element (36, 36') melts, and the free ends (34, 34') are opened.

[0057] As a result of the melting of the sealing elements (36, 36'), a fire extinguishing agent (e.g., water) is discharged from the free ends (34, 34') of the first and second discharge pipes (32, 32') and is discharged directly and accurately toward the exhaust outlet (14). Thus, the discharged fire extinguishing agent cools the discharged exhaust gas stream (V) and the affected battery cell (12). This is illustrated in FIG. 3, which shows the upper part of the battery cell (12) burning due to thermal runaway and the exhaust outlet (14) positioned therein.

[0058] Since the free ends (34, 34') of the first and second discharge pipes (32, 32') are located on the side of the exhaust outlet (14), the first and second discharge pipes (32, 32') do not block the exhaust outlet (14). Additionally, since the fire extinguishing agent is discharged toward the exhaust outlet (14) through the free ends (34, 34') of the first and second discharge pipes (32, 32'), the direction of discharge of the fire extinguishing agent is improved. For example, the spray cone of the fire extinguishing agent exiting through the free ends (34, 34') can be narrowed. As a result, the fire extinguishing agent can be aimed directly at the exhaust outlet (14), and can be introduced through the exhaust outlet (14) even if the free ends (34, 34') are not positioned directly above the exhaust outlet (14). Accordingly, the fire extinguishing agent can be supplied to the affected battery cell (12) and to the highest temperature part of the battery cell (12), as shown in FIG. 3, which illustrates a battery cell (12) that has been burned at the top where the exhaust outlet (14) is located.

[0059] As a result, the temperature is significantly reduced, and adjacent battery cells (12) are kept within a safe zone, preventing heat propagation. The affected battery cells (12) can be cooled by the evaporation of the fire extinguishing agent. When the exhaust gas stream is cooled, the temperature of the exhaust gas stream is significantly reduced, which can prevent potential melting of the battery components and prevent arcing and heat propagation. In a test using water as the fire extinguishing agent, the maximum temperature of adjacent battery cells was only 80°C, which was performed with a thin cell spacer of 1.8 mm placed between the affected battery cells (12) and the adjacent battery cells (12). Thus, according to the present disclosure, sufficient cooling and prevention of heat propagation can be provided while using a thinner cell spacer than in known battery systems. Thus, costs can be reduced. Explanation of the symbols

[0060] 11: Battery housing 12: Battery cell 13: Exhaust surface 14: Exhaust outlet 16: Electrode terminal 20: Cover Element 30: 1st supply pipe 30': Second supply pipe 32: First discharge pipe 32': Second discharge pipe 34: First free end 34': Second free end 36: Sealing element of the first discharge pipe 36': Sealing element of the second discharge pipe 40: Fire extinguishing agent supply unit 42: Pump 100: Battery System V: Exhaust gas stream

Claims

Claim 1 A battery system comprising: a battery housing including a cover element; a plurality of battery cells accommodated within the battery housing, each having an exhaust outlet that allows an exhaust gas stream to be discharged upon thermal runaway and an exhaust surface facing the cover element; a fire extinguishing agent supply unit; a first supply pipe connected to the fire extinguishing agent supply unit and extending laterally along the exhaust outlet of the plurality of battery cells on a first side; and a first discharge pipe provided for each of the plurality of battery cells, extending toward the exhaust outlet of each battery cell and connected to the first supply pipe, and having a first free end positioned on the side of the exhaust outlet and facing the exhaust outlet, wherein the first discharge pipe is configured to discharge a fire extinguishing agent supplied by the fire extinguishing agent supply unit and the first supply pipe to the exhaust outlet through the first free end when an exhaust gas stream is applied. Claim 2 A battery system according to claim 1, further comprising: a second supply pipe connected to a fire extinguishing agent supply unit and extending laterally along the exhaust outlet of the plurality of battery cells on a second side opposite to the first side; and a second discharge pipe corresponding to each of the plurality of battery cells, extending toward the exhaust outlet of each battery cell and connected to the second supply pipe, and having a second free end positioned on the side of the outlet opposite to the first free end and facing the exhaust outlet, wherein the second discharge pipe discharges the fire extinguishing agent supplied by the fire extinguishing agent supply unit and the second supply pipe through the second free end when an exhaust gas stream is applied. Claim 3 In claim 2, the first supply pipe and / or the second supply pipe are attached to the inner surface of the cover element in a battery system. Claim 4 In claim 3, the cover element is a battery system that is an upper cover. Claim 5 A battery system according to claim 2, wherein the first discharge pipe extends toward the exhaust outlet of the battery cell at a certain angle with respect to the cover element and / or the second discharge pipe extends toward the exhaust outlet of the battery cell at a certain angle with respect to the cover element. Claim 6 In claim 5, the battery system in which the constant angle is 35°. Claim 7 A battery system according to claim 2, wherein the first discharge pipe includes a first sealing element configured to seal the first free end and release the seal when exposed to an exhaust gas stream, and / or the second discharge pipe includes a second sealing element configured to seal the second free end and release the seal when exposed to an exhaust gas stream. Claim 8 An electric vehicle comprising a battery system according to any one of claims 1 to 7.

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