Thermal runaway detection system and battery system

Abstract

The present disclosure relates to a thermal runaway detection system comprising an exhaust device (55) having a sealing body (551, 552, 553) disposed in an exhaust passage (555). Herein, the sealing body (551, 552, 553) is configured to close the exhaust passage (555) at a first position and to open the exhaust passage (555) at a second position. The thermal runaway detection system further comprises a thermal runaway detection circuit (60) configured to monitor the position of the sealing body (551, 552, 553) and output a signal corresponding to that position. The thermal runaway detection circuit (60) includes a first detection node (63) connected to an exhaust device (55) and a second detection node (64) connected to an exhaust device (55), wherein the first detection node (63) and the second detection node (64) are set to a conductive state through a sealing body (551, 552, 553) at either a first position and a second position, and the controller (65) is configured to detect the conductivity of the conductive path and also output a signal corresponding to the conductivity of the conductive path.

Description

Technology Field

[0001] The present disclosure relates to a thermal runaway detection system, and in particular to a combination of a thermal runaway detection circuit and an exhaust device configured to detect abnormal overpressure in a battery system connected to an exhaust device. Additionally, the present disclosure relates to a battery submodule, a battery module or a battery system comprising such a thermal runaway detection system, and a thermal runaway detection method. Background Technology

[0002] Rechargeable or secondary batteries differ from primary batteries, which perform only irreversible conversion from chemical energy to electrical energy, in that they can be repeatedly charged and discharged. Low-capacity secondary batteries are used as power sources for small electronic devices such as cellular phones, laptop computers, and camcorders, whereas high-capacity secondary batteries are used as power sources for hybrid vehicles.

[0003] Generally, secondary batteries include an electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes, a case housing the electrode assembly, and electrode terminals electrically connected to the electrode assembly. An electrolyte solution is injected into the case of the secondary battery to enable charging and discharging of the secondary battery through a chemical reaction between the positive electrode, the negative electrode, and the electrolyte solution. The shape of the case varies depending on the application of the battery, such as being cylindrical or rectangular.

[0004] Secondary batteries can be used as battery modules formed from multiple unit battery cells combined in series and / or parallel to provide high energy density, for example, for driving a hybrid vehicle motor. That is, the battery module is formed by connecting the electrode terminals of multiple unit battery cells according to the required amount of power to implement a high-power secondary battery, for example, for an electric vehicle.

[0005] Battery modules can be configured using a block design or a modular design. In the block design, each battery is combined into a common current collector structure, and the battery management system and its units are housed within a housing. In the modular design, multiple battery cells are connected to form submodules, and several submodules are connected to form battery modules. Battery management functions may be implemented in whole or in part at the battery module or submodule level, thereby improving compatibility. One or more battery modules are mechanically and electrically integrated, equipped with a thermal management system, and configured to communicate with one or more electrical consumers to form a battery system.

[0006] At the battery submodule level, battery module level, or battery system level, a case may be used to enclose all components constituting each device. To provide thermal control for the enclosed components, a thermal management system may be used to efficiently emit, discharge, and / or dissipate the heat generated within the case. If such a thermal management system is omitted, or if heat dissipation from the case is not sufficiently performed, an abnormal reaction may occur within it due to a rise in internal temperature. An example of such an abnormal operating condition is thermal runaway of a battery cell, which can be caused by an overheated or overcharged lithium-ion cell. Thermal runaway is a self-accelerating chemical reaction within the cell that generates large amounts of heat and gas until all available material is depleted. Due to the large amounts of hydrogen and carbon monoxide in the generated gas, the resulting gas can be toxic and flammable.

[0007] Thermal runaway causes heat to propagate along the battery cells of a battery module, which can eventually lead to a fire in the battery module. Therefore, early detection of thermal runaway in a battery module is essential for taking timely action or, for example, to output a timely warning signal to passengers of an electric vehicle. However, until now, thermal runaway detection has generally been based on internal cell measurements, such as cell voltage, cell current, and / or cell temperature. In other words, until now, secondary effects associated with thermal runaway within the battery module have been detected, rather than the thermal runaway itself. Furthermore, to avoid false alarms, trigger thresholds are typically set to be associated with heat propagation across at least two cells—that is, by detecting abnormal cell voltage, current, and / or temperature in at least two cells. However, these trigger thresholds are often based on specific battery system models and may therefore not be suitable for all battery modules regardless of their geometry. The problem to be solved

[0008] The problem to be solved through the embodiments of the present invention is to provide a thermal runaway detection system capable of reliably detecting the thermal runaway itself rather than detecting secondary effects, a battery system including the same, and a thermal runaway detection method. means of solving the problem

[0009] According to one aspect of the present invention for solving the above problem, a thermal runaway detection system comprising a venting device and a thermal runaway detection circuit is provided. Herein, the venting device has a sealing body located within a venting passage, that is, a passage or opening configured to allow gas discharged from a thermal runaway of a battery cell to pass through. The sealing body is configured to close the venting passage at a first position of the sealing body and to open the venting passage at a second position different from the first position of the sealing body. The position of the sealing body may refer to a spatial position of the sealing body where there is no change in the state of the sealing body. Accordingly, the sealing body may remain in an unchanged state even if it moves from the first position to the second position or from the second position to the first position.

[0010] The thermal runaway detection system further includes a thermal runaway detection circuit configured to monitor the position of the sealing body and output a signal corresponding to that position. Here, monitoring the position of the sealing body is performed by selectively closing and opening a conductive path based on the position of the sealing body. However, the position of the sealing body may also be measured using optical and / or mechanical means. For example, a laser beam may be selectively blocked depending on the position of the sealing body, and if not blocked, it may be detected by a photodiode. Accordingly, a signal output from the photodiode may be used to monitor the position of the sealing body. Additionally, capacitive measurements may be performed to determine the position of the sealing body. In this case, the sealing body may be configured as a movable plate of a capacitor. As mechanical means, for example, a gear rack may be used to determine the position of the sealing body. Depending on the method used to determine the position of the sealing body, a circuit suitable for outputting a signal may be used.

[0011] The battery cell includes a vent opening that allows gases generated in an abnormal operation condition to be released from the cell when a specific overpressure and / or a specific temperature is exceeded inside the cell. This vent opening is covered with a membrane or notch that ruptures and opens when the pressure inside the battery cell exceeds a preset pressure threshold.

[0012] The case (or housing) of a battery submodule, battery module, or battery system may be designed to enclose internal components in a hermetic manner. Accordingly, to prevent damage to the case (housing), an opening may be implemented in the case (or housing) of the battery submodule, battery module, or battery system. The opening must be able to safely vent exhaust gases to protect people from dangerous smoke and gases that may occur during thermal runaway (exhaust) or other functional failure of the battery cells within the case. To rapidly vent exhaust gases, the opening may be configured to open at a specific pressure inside the case.

[0013] The opening of the above case may be used as the exhaust passage, and the sealing body configured to affect the open or closed state of the exhaust passage may be used to detect thermal runaway of at least one battery cell within the case (or housing). Thus, when pressure rises rapidly due to the exhaust of the battery cell within the case (or housing), thermal runaway of a battery submodule, battery module, or battery system placed within the case (or housing) can be determined with a very fast response time by detecting the open state of the exhaust device. Furthermore, the detection of thermal runaway through the detection of the open state of the exhaust device can be performed independently of internal battery measurements that may be damaged by thermal propagation, such as voltage or temperature measurements of the battery cell. Additionally, since the exhaust device is configured to open due to sufficient overpressure from the inside, using the open state of the exhaust device for thermal runaway detection may have a very low risk of false alarms regarding thermal runaway.

[0014] In one embodiment, the thermal runaway detection circuit of the thermal runaway detection system may include a first detection node connected to the exhaust device and a second detection node connected to the exhaust device. That is, a conductive path is formed between the first and second detection nodes of the thermal runaway detection circuit and the exhaust device, respectively. The exhaust device may include first and second contact nodes, for example, contact pads, that enable electrical contact with the first and second detection nodes.

[0015] The conductive path between the first detection node and the second detection node may be set to a conductive state through the sealing body at either the first position or the second position. The conductive path between the first and second detection nodes may be set to a non-conductive state at the other of the first and second positions of the sealing body. That is, the conductivity of the conductive path depends on whether the sealing body opens or closes, i.e., seals, the exhaust passage. Therefore, the conductivity of the conductive path can indicate whether the exhaust passage is open or closed.

[0016] The thermal runaway detection circuit may further include a controller configured to detect the conductivity of the conductive path and output a signal corresponding to the conductivity of the conductive path. The controller may be configured to measure voltage and / or current on the conductive path, or to control means for measuring voltage and / or current on the conductive path. The controller may also be configured to determine the conductivity of the conductive path based on measurement signals obtained for voltage and / or current on the conductive path. The signal corresponding to the conductivity of the conductive path generated by the controller may take different values ​​for different conductivity states of the conductive path. Here, the value of the signal may indicate conductivity as a number that can serve as a measure of conductivity. The signal may take a first value for conductivity below a predefined threshold and a second value for conductivity exceeding a predefined threshold. Additionally, preferably, one of the first and second values ​​may be 0.

[0017] In another embodiment, the sealing body can move from the first position to the second position in a reversible manner. Subsequently, when the pressure inside the case drops below the pressure threshold again, the sealing body can move back to the first position to close the exhaust passage. Thus, under normal operating conditions, the exhaust device can protect the components inside the case from the influence of the external environment by closing the exhaust passage. Therefore, even if the sealing body moves to the second position to allow exhaust gas to be released through the exhaust passage, the thermal runaway detection system can be reused later.

[0018] In another embodiment, the exhaust device may be placed in a housing, such as, for example, a battery submodule, a battery module, or a case of a battery system. According to this embodiment, the sealing body of the exhaust device may be configured to switch, i.e., move from the first position to the second position when the pressure within the housing exceeds a predefined pressure threshold. Since the sealing body of the exhaust device is reversibly movable between the first position and the second position, the housing may be used even after an exhaust event of at least one battery cell within the housing. Additionally, while the sealing body is in a first state that closes the exhaust passage, it can advantageously protect the interior of the housing from environmental influences.

[0019] In another embodiment, the conductive path between the first detection node and the second detection node may be set to a conductive state through the sealing body at the first location. In other words, the sealing body may provide an electrical short circuit to the conductive path while simultaneously closing the exhaust passage. In this case, the conductive path may be set to a non-conductive state at the second location of the sealing body.

[0020] According to another embodiment, the contact area in which the sealing body contacts the sealing surface to seal the exhaust passage may be formed as an electrical contact portion. According to another embodiment, the sealing body may be configured to be conductive or may include an electrically conductive path. Thus, the conductive path between the first and second detection nodes may be electrically short-circuited simultaneously with the sealing body sealing the exhaust passage and contacting the contact area. The sealing body is a valve plate, and the exhaust device may further include a spring for pushing the valve plate to the first position (closed position). In this case, the sealing body may be a portion that electrically conducts the conductive path at least while the sealing body is in the first position to close the exhaust passage. That is, the sealing body may electrically short-circuit the conductive path while in the first position.

[0021] According to another embodiment, the thermal runaway detection circuit may have a first power input connected to a first cell terminal of the at least one battery cell and a second power input connected to a second cell terminal of the at least one battery cell. In this embodiment, the venting of the at least one battery cell may affect the transition from the first position to the second position of the sealing body. According to this embodiment, the thermal runaway detection circuit, in particular the controller of the thermal runaway detection circuit, may be powered by the at least one battery cell monitored by the thermal runaway detection system. That is, the controller may be connected to the first power input and the second power input, and may be powered through the at least one battery cell.

[0022] According to another embodiment, the first detection node of the thermal runaway detection circuit may be connected to the first power input, and the second detection node of the thermal runaway detection circuit may be connected to the second power input. The first detection node of the thermal runaway detection circuit may be connected to the first power input through the controller or independently of the controller. Additionally, the second detection node of the thermal runaway detection circuit may be connected to the second power input through the controller or independently of the controller. Furthermore, the first detection node may be different from the first power input, and the second detection node may be different from the second power input. The power supply of the controller through the first power input and the second power input may be independent of the conductivity state of the conductive path. That is, the controller and the conductive path (i.e., the exhaust device having the sealing body) may be connected in parallel to each other for the at least one battery cell operating as a power source.

[0023] According to another embodiment, the controller of the thermal runaway detection system, particularly the thermal runaway detection circuit, may be configured to output a signal while the conductive path is set to a conductive state. According to this embodiment, while the controller detects a characteristic indicating that the conductive path is in a conductive state, namely a voltage or current on the conductive path, the signal output by the controller in response to this characteristic may be a high-level signal. This high-level signal from the controller may be output to the outside of the controller, or at least used to output a signal indicating the conductivity of the conductive path within the controller. That is, the controller of this embodiment may detect a signal corresponding to the conductivity of the conductive path when determining such conductivity, and simultaneously output this signal corresponding to the conductivity of the conductive path.

[0024] In another embodiment, the controller may be configured to output the signal when the current flowing through the conductive path falls below a preset current threshold. According to this embodiment, the controller may be configured to detect the current flowing through the conductive path and may be further configured to compare this measured current with a preset current. This comparison may be performed using a comparator, etc. According to this embodiment, the thermal runaway detection system may further include a shunt resistor interconnected between the first power input and the first detection node, or between the second power input and the second detection node. The shunt resistor may be integrated into the thermal runaway detection circuit, or an extension of the conductive path on a substrate carrier housing the thermal runaway detection circuit. According to this embodiment, the controller may be configured to detect a voltage drop through the shunt resistor and determine the current flowing along the conductive path based on the voltage drop detected through the shunt resistor. In this embodiment, the controller may be connected to a node upstream of the shunt resistor to take the upstream voltage of the shunt resistor, and may be connected to another node downstream of the shunt resistor to take the downstream voltage of the shunt resistor.

[0025] Another aspect of the present invention relates to a battery submodule comprising a plurality of aligned battery cells. The battery submodule may further comprise a battery submodule housing that surrounds the plurality of aligned battery cells. The battery submodule may further comprise a thermal runaway detection system, and the exhaust device may be disposed in an exhaust passage of the submodule housing. In one embodiment of the battery submodule, the exhaust passage of the thermal runaway detection system may connect the interior of the battery submodule housing to the exterior of the battery submodule housing, depending on whether the position of the sealing body is one of the first and second positions. Embodiments of the battery submodule may include the embodiments of the thermal runaway detection system described above.

[0026] Another aspect of the present invention relates to a battery module comprising a plurality of battery submodules, wherein each battery submodule included in the battery module comprises a plurality of aligned battery cells. The battery module may include a plurality of the aforementioned battery submodules. The battery module may further include a battery module housing surrounding the aforementioned battery submodules and the thermal runaway detection system. Here, the exhaust device may be disposed in the exhaust passage of the battery module housing. That is, the exhaust passage of the thermal runaway detection system may connect the interior of the battery module housing to the exterior of the battery module housing depending on whether the position of the sealing body is one of the first and second positions. Embodiments of the battery module may include the embodiments of the thermal runaway detection system described above.

[0027] Another aspect of the present invention relates to a battery system comprising at least one battery module and a system controller configured to operate at least one battery module. The system controller is a battery management system configured to detect the state of the battery cells of the battery module, perform balancing of the cells, establish a communication connection with an external load, etc. The battery module comprises at least one battery submodule, and each battery submodule may comprise a plurality of aligned battery cells stacked together. The battery system may further comprise a battery system housing and the thermal runaway detection system described above. Here, the exhaust device may be disposed in the exhaust passage of the battery system housing. That is, the exhaust passage of the thermal runaway detection system may connect the interior of the battery system housing to the exterior of the battery system housing, for example, at the first position of the sealing body, depending on whether the position of the sealing body is one of the first and second positions. Embodiments of the battery system may include embodiments of the thermal runaway detection system described above.

[0028] Another aspect of the present invention relates to a vehicle comprising the aforementioned battery submodule, the aforementioned battery module, and / or the aforementioned battery system, and further comprising at least one vehicle control unit configured to accommodate the same, wherein the vehicle control unit may be configured to receive a signal output from the controller and indicating the conductivity of the conductive path. The vehicle may comprise at least one output means, and the vehicle control unit may be further configured to control the output means to output a warning to a passenger based on the signal received from the controller. The output means of the vehicle may include a display for outputting a visual warning to a passenger. The output means of the vehicle may include a speaker for outputting an auditory warning to a passenger to warn the passenger. The output means may also include means for providing a haptic warning to a passenger, such as vibration, for example. Embodiments of the vehicle may include embodiments of the aforementioned thermal runaway detection system.

[0029] Another aspect of the present invention relates to a method for detecting thermal runaway of at least one battery cell among a plurality of battery cells disposed within a housing, wherein an exhaust device having a sealing body may be disposed in an exhaust passage of the housing. Here, the sealing body may be configured to close the exhaust passage at a first position and open the exhaust passage at a second position different from the first position in response to a predefined pressure within the housing. Additionally, the sealing body is configured to set a conductive path to a conductive state in one of a first state and a second state, and to set the conductive path to a non-conductive state in the other state. The method for detecting thermal runaway may include the step of detecting the conductive state of the conductive path through a controller configured to detect the conductivity of the conductive path, and the step of outputting a first signal. The method for detecting thermal runaway may further include the step of detecting the non-conductive state of the conductive path through the controller, and the step of outputting a second signal. Here, one of the first and second signals may indicate thermal runaway of the battery cell.

[0030] In one embodiment, the method for detecting thermal runaway further comprises the step of outputting a warning in response to a signal indicating thermal runaway of a battery cell, or the step of performing at least one countermeasure in response to a signal indicating thermal runaway of a battery cell. As mentioned above in the description relating to the vehicle according to one aspect of the present invention, the warning may be output, for example, through at least one output means of the vehicle. The countermeasure may include blocking at least one or all of the plurality of battery cells, or releasing a extinguishing (and / or cooling) substance to one or all of the plurality of battery cells. The step of performing the countermeasure may include the step of increasing the cooling performance of the cooling system of at least one battery cell, or the step of activating an activation means to increase the thermal conductivity between the plurality of battery cells by, for example, activating an additional exhaust means such as a ventilation fan. The method for detecting thermal runaway may further comprise the step of stopping the output of the warning or stopping the performance of the countermeasure in response to another signal indicating that there is no thermal runaway, i.e., a signal indicating that the battery cells are in a normal state.

[0031] Another aspect of the present disclosure relates to a computer program comprising instructions that, when the program is executed by a controller of the aforementioned thermal runaway detection system, cause the controller to perform the steps of the aforementioned thermal runaway detection method. Herein, the controller may control other components of the thermal runaway detection system to perform the steps of the thermal runaway detection method. Effects of the invention

[0032] According to embodiments of the present invention, thermal runaway of a battery submodule, battery module, or battery system disposed within a case / housing can be detected with a very fast response time. Furthermore, the detection of thermal runaway can be performed independently of internal battery measurements that may be damaged by thermal propagation, such as voltage or temperature measurements of battery cells. Additionally, the risk of false warnings regarding thermal runaway is very low, and the system can be reused in a normal state after the thermal runaway is detected. Brief explanation of the drawing

[0033] FIG. 1 schematically illustrates a battery module according to one embodiment. FIG. 2 schematically illustrates a thermal runaway detection circuit according to one embodiment. FIG. 3 schematically illustrates an example of an exhaust device constituting a thermal runaway detection circuit according to one embodiment. FIG. 4 schematically illustrates another example of an exhaust device constituting a thermal runaway detection circuit according to one embodiment. Specific details for implementing the invention

[0034] The effects and features of the embodiments and the methods of implementation thereof will be described in detail below with reference to the attached drawings. In the drawings, the same reference numerals indicate the same components, and redundant descriptions thereof are omitted. The features of the present invention and the methods for achieving them can be more easily understood by referring to the detailed description of the embodiments below and the attached drawings. However, the present invention may be implemented in various forms and is not limited to the exemplified embodiments.

[0035] In this document, the term "and / or" includes any and all combinations of one or more of the items listed in relation. Additionally, when describing embodiments of the present invention, the use of "may" or "may" indicates one or more embodiments of the present invention. In this document, terms including ordinal numbers such as "first," "second," etc., may be used to describe various components, but said components are not limited by these terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be named the first component, and similarly, the first component may be named the second component.

[0036] In this document, terms indicating spatial relationships, such as "below," "under," "above," and "upper / upper," may be used for convenience of explanation when describing the relationship between a component or feature. It should be understood that these terms indicating spatial relationships are intended to include not only the directions depicted in the drawings but also the directions that change during the use or operation of the device.

[0037] Where in this document one component or layer is described as being "on," "connected," or "combined" with respect to another component or layer, "on," "connected," and "combined" include both being formed directly or through one or more other components or layers. Additionally, where one component or layer is described as being "between" two components or layers, it should be understood that it is the only component or layer between the two components or layers, or that one or more interposed elements or layers exist.

[0038] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0039] FIG. 1 is a perspective view illustrating a battery module (50) according to one embodiment. The battery module (50) illustrated in FIG. 1 may be a battery module (50) used in an electric vehicle. The battery module (50) may include a housing (53) having four lateral exterior walls and a single straight partition wall (54) extending from the center of the housing (53). The housing (53) may be closed by an upper cover (not shown) to maintain an airtight state.

[0040] The partition wall (54) can divide the housing (53) into two submodule compartments. Battery submodules (20) are placed in each of the two submodule compartments. Each battery submodule (20) includes 10 aligned battery cells (10), and these battery cells (10) can be stacked in a stacking direction such that their wide sides face each other. The stacking direction of the battery submodule (20) also corresponds to the longitudinal direction of the battery submodule (20), and the battery submodule (20) can be configured to have the largest extension along the longitudinal direction of the battery submodule (20). The battery submodule (20) can be positioned in the cell compartment such that its longitudinal direction is parallel to the partition wall (54). The first battery submodule (20a) is described below, and its configuration may also be the same as the second battery submodule (20b) which forms part of the battery module (50).

[0041] The first battery submodule (20a) comprises 10 battery cells (10), and each battery cell (10) of the first battery submodule (20a) may comprise an electrode assembly that is housed in a case (16) together with an electrolyte. In particular, the case (16) of each battery cell (10) may have a cuboidal or prismatic shape and may be formed of a metal such as aluminum. Each battery cell (10) may comprise a cap assembly (14) for sealing an opening of the case (16). Each cap assembly (14) may comprise a cap plate for covering an opening of the case (16), a first cell terminal (11) (positive terminal), and a second cell terminal (12) (negative terminal). The cell terminals (11, 12) may be formed to protrude from the cap assembly (14). The cap assembly (14) may include a vent (13) having a vent opening covered by a membrane or a notch. The membrane or notch may be configured to open in response to a specific overpressure within the battery cell (10).

[0042] The battery cells (10) of the first battery submodule (20a) can be connected to each other via busbars (15) in a 2p5s configuration. The battery cells (10) of the second battery submodule (20b) can be connected to each other via busbars (15) in the same configuration. In this configuration, each busbar (15) connects two first cell terminals (11) of two first battery cells (10a) to two second cell terminals (12) of two second battery cells (10b), that is, each busbar (15) can connect a total of four cell terminals (11, 12). That is, two battery cells (10) can be connected in parallel to form one battery bank, and five battery banks configured in this way can be connected in series to form a battery submodule (20) in a 2p5s configuration.

[0043] Additionally, the first battery submodule (20a) is connected to the second battery submodule (20b) through an interconnect (busbar) (17), and the interconnect (17) can interconnect two first terminals (11) of the second battery submodule (20b) to two second terminals (12) of the first battery submodule (20a). Additionally, two first cell terminals of the first battery submodule (20a) are connected to a first module terminal (51) (positive terminal) through a first terminal connector (18), and two second cell terminals (12) of the second battery submodule (20b) can be connected to a second module terminal (52) (negative terminal) through a second terminal connector (19). A high-current path can be formed between the module terminals (51, 52) by the busbar (15), interconnect (17), and terminal connector (18, 19). That is, this high-current path can extend from the first module terminal (51) to the second module terminal (52) along the battery cells (10) of the battery submodules (20a, 20b).

[0044] The battery module (50) may further include a thermal runaway detection system according to the embodiment. The thermal runaway detection system of the battery module (50) may include a venting device (55) disposed on the side outer wall of the housing (53) of the battery module (50). Additionally, the thermal runaway detection system of the battery module (50) may further include a thermal runaway detection circuit (60). The thermal runaway detection circuit (60) may include a first power input (61) connected to the first terminal of the cells of the second battery submodule (20b) and may further include a second power input (62) connected to the second terminal of the cells of the first battery submodule (20a). Accordingly, the thermal runaway detection circuit (60) may be powered by at least a part of the battery module (50). The thermal runaway detection circuit (60) may further include a first detection node (63) connected to the exhaust device (55) and a second detection node (64) connected to the exhaust device (55). The exhaust device (55) may include a sealing body (not shown) configured to seal an exhaust passage on the outer side wall of the battery module (50) according to its location. Additionally, the thermal runaway detection circuit (60) may be configured to monitor the location of the sealing body through the first detection node (63) and the second detection node (64). The thermal runaway detection circuit (60) may output a signal (not shown) indicating the location of the sealing body based on the monitored location of the sealing body. This location of the sealing body may correspond to whether or not there is exhaust due to thermal runaway. Thus, thermal runaway can be reliably detected based on the signal output by the thermal runaway detection circuit (60) corresponding to the location of the sealing body.

[0045] One embodiment of a thermal runaway detection circuit (60) is schematically illustrated in FIG. 2, and embodiments of an exhaust device (55) constituting the same are schematically illustrated in FIG. 3 and FIG. 4, respectively. Hereinafter, these embodiments may be described in connection with the battery module (50) of FIG. 1. However, according to other embodiments of the thermal runaway detection circuit (60) and the exhaust device (55), the thermal runaway detection circuit (60) and the exhaust device (55) may be used independently of the battery module (50) of FIG. 1 in a battery system.

[0046] As schematically illustrated in FIG. 2, the thermal runaway detection circuit (60) may include a conductive path (shown as a dotted line) connecting a first power input (61) and a first detection node (63). The thermal runaway detection circuit (60) may further include another conductive path (also shown as a dotted line) connecting a second power input (62) and a second detection node (64). Additionally, a controller (65) is interconnected between these conductive paths and can be connected to the first and second power inputs (61, 62) accordingly. Thus, the controller (65) can be powered by the second battery submodule (20b) of FIG. 1. Additionally, a shunt resistor (67) may be placed in the conductive path between the first power input (61) and the first detection node (63). The controller (65) can be connected to a first voltage measurement node downstream of the shunt resistor (67) and a second voltage measurement node upstream of the shunt resistor (67). Thus, the controller (65) can obtain a first voltage downstream of the shunt resistor (67) and a second voltage upstream of the shunt resistor (67), and thereby determine a voltage drop across the shunt resistor (67). Based on a known resistance value of the shunt resistor (67), the controller (65) can determine the current passing through the shunt resistor (67) and, accordingly, the current passing through the first detection node (63). As the first detection node (63) and the second detection node (64) are connected via an exhaust device (55) as shown in FIG. 1, the current passing through the first detection node (63) also represents the current passing through the exhaust device (55), and thus can be used to monitor the position of the sealing body. This will be explained in more detail in connection with the exemplary embodiments of FIGS. 3 and FIGS. 4.

[0047] As schematically illustrated in FIG. 3, the exhaust device (55) may include an exhaust passage (555) connecting the inside and outside of the housing (53). The exhaust passage (555) may be selectively opened or closed based on the positions of the first sealing body (551) and the second sealing body (552). Each sealing body (551, 552) may be connected to the side wall of the exhaust passage through a torsion spring (not shown).

[0048] A torsion spring can pre-stress the first and second sealing bodies (551, 552) so that they come into contact with each other to close the exhaust passage (555) at a first position, as illustrated in the left part of FIG. 3. Additionally, each of the first and second sealing bodies (551, 552) may be made of a conductive material, preferably aluminum. Additionally, the first sealing body (551) may be connected to a first detection node (63), and the second sealing body (552) may be connected to a second detection node (64). Thus, when the first and second sealing bodies (551, 552) come into contact with each other, the conductive path between the first detection node (63) and the second detection node (64) may be short-circuited through the first and second sealing bodies (551, 552).

[0049] When the pressure inside the housing (53) exceeds a predefined threshold, the first and second sealing bodies (551, 552) can be moved to a second position against a spring force applied by each torsion spring as shown in the right part of FIG. 3. In this second position, the first and second sealing bodies (551, 552) no longer come into contact with each other and open the exhaust passage (555) so that exhaust gas (556) released by at least one of the battery cells (10) of the housing (53) can exit the housing (53) through the exhaust passage (555). At the same time, the conductive path between the first and second detection nodes (63, 64) is set to open, i.e., non-conductive, so that the thermal runaway detection circuit (60) (e.g., see FIG. 2) can detect the second position of the first and second sealing bodies (551, 552), and in response to this, the controller (65) of the thermal runaway detection circuit (60) can output a signal (66) indicating that the first and second sealing bodies (551, 552) are in the second position and that an exhaust event related to thermal runaway has occurred.

[0050] Another embodiment of the exhaust device (55) is schematically illustrated in FIG. 4. Here, the exhaust device (55) may include a single sealing body (553) that is pressurized by a linear spring (554) to contact an area of ​​the exhaust device (55) to close the exhaust passage (555). The exhaust passage (555) is closed at a first position of the sealing body (553) as shown in the left part of FIG. 4, and at this first position, exhaust gas (556) cannot be discharged from the housing (53). At the same time, at the first position of the sealing body (553), the conductive path between the first detection node (63) and the second detection node (64) can be short-circuited by the conductive sealing body (553).

[0051] However, if the pressure inside the housing (53) exceeds a predetermined value and the force applied to the sealing body (553) by this pressure exceeds the force applied by the spring (554), the sealing body (553) may move from a first position to a second position as shown in the right part of FIG. 4. In this second position, the exhaust passage (555) is opened and thus exhaust gas (556) released by at least one of the battery cells (10) inside the housing (53) may be released from the housing (53) through the gas passage (555). At the same time, the conductive path between the first and second detection nodes (63 and 64) is set to open, i.e., non-conductive, so that the thermal runaway detection circuit (60) (e.g., see FIG. 2) can detect a second location, and in response, the thermal runaway detection circuit (60) can output a signal (66) indicating that a second location of the sealing body (553) and an exhaust event due to thermal runaway has occurred.

[0052] Electronic or electrical devices and / or any other related devices or components according to embodiments of the present invention may be implemented by any suitable hardware, firmware (e.g., ASIC), software, or a combination of software, firmware, and hardware. For example, various components of these devices may be formed on a single integrated circuit (IC) chip or on a discrete IC chip. Additionally, various components of these devices may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or a substrate. Furthermore, various components of these devices may be processes or threads that run on one or more processors included in one or more computing devices, execute computer program instructions, and interact with other system components to perform the various functions described herein.

[0053] Computer program instructions are stored in memory that can be implemented in a computing device using a standard memory device, such as random access memory (RAM), for example. Computer program instructions may also be stored in other non-volatile computer-readable media, such as CD-ROMs, flash drives, for example. Furthermore, those skilled in the art will understand, without departing from the scope of the exemplary embodiments of the present invention, that the functions of various computer equipment may be combined or integrated into a single computing device, and that the functions of a specific computing device may be distributed among one or more other computing devices. Explanation of the symbols

[0054] 10: Battery cell 11: First cell terminal (positive cell terminal) 12: Second cell terminal (negative cell terminal) 13: Exhaust pipe 14: Cap assembly 15: Busbar 16: Cell Housing 17: Submodule interconnect 18: First terminal connector 19: Second terminal connector 20: Battery submodule 50: Battery module 51: 1st module terminal (positive terminal) 52: Second module terminal (negative terminal) 53: Battery module housing 54: Bulkhead 55: Exhaust system 551: First rotary sealing body 552: Second rotary sealing body 553: Movable sealing body 554: Spring 555: Exhaust passage 556: Exhaust gas flow 60: Thermal runaway detection circuit 61: First power input 62: Second power input 63: 1st detection node 64: 2nd detection node 65: Controller 66: Signal output 67: Shunt resistor

Claims

Claim 1 A thermal runaway detection system comprising: an exhaust device including a sealing body disposed in an exhaust passage; and a thermal runaway detection circuit configured to monitor the position of the sealing body and output a signal corresponding to the position of the sealing body, wherein the sealing body is configured to close the exhaust passage at a first position and open the exhaust passage at a second position different from the first position, and wherein the thermal runaway detection circuit comprises: a first detection node connected between a first cell terminal of at least one battery cell and the exhaust device; a second detection node connected between a second cell terminal of at least one battery cell and the exhaust device; a conductive path between the first detection node and the second detection node; and a controller configured to detect the conductivity of the conductive path and output a signal corresponding to the conductivity of the conductive path, wherein the conductive path is set to a conductive state through the sealing body at either the first position or the second position, and when the conductive path becomes a conductive state, current flows through the conductive path by the at least one battery cell. Claim 2 A thermal runaway detection system according to claim 1, wherein the thermal runaway detection circuit comprises a first detection node connected to the exhaust device, a second detection node connected to the exhaust device, a conductive path between the first detection node and the second detection node, and a controller configured to detect the conductivity of the conductive path and output a signal corresponding to the conductivity of the conductive path, wherein the conductive path is set to a conductive state through the sealing body at either the first position and the second position. Claim 3 A thermal runaway detection system according to claim 1, wherein the exhaust device is disposed in a housing and configured to switch from the first position to the second position when the pressure within the housing exceeds a predefined pressure threshold, and the sealing body moves from the first position to the second position in a reversible manner. Claim 4 A thermal runaway detection system according to paragraph 2, wherein the conductive path is set to a conductive state through the sealing body at the first position, and the conductive path is set to a non-conductive state at the second position. Claim 5 In paragraph 2, the thermal runaway detection circuit comprises a first power input connected to the first cell terminal and a second power input connected to the second cell terminal, wherein the first detection node is connected to the first power input and the second detection node is connected to the second power input, a thermal runaway detection system. Claim 6 In paragraph 5, the above controller is connected to the first power input and the second power input and receives power through the at least one battery cell, a thermal runaway detection system. Claim 7 A thermal runaway detection system according to claim 5, wherein the controller outputs a signal to indicate the first position while the conductive path is set to a conductive state, and the controller outputs a signal to indicate the second position when the current flowing through the conductive path falls below a predefined current threshold. Claim 8 A thermal runaway detection system according to claim 5, further comprising a shunt resistor interconnected between the first power input and the first detection node, or between the second power input and the second detection node, wherein the controller is further configured to detect a voltage drop across the shunt resistor. Claim 9 A battery submodule comprising a plurality of aligned battery cells, a battery submodule housing surrounding the plurality of aligned battery cells, and a thermal runaway detection system according to any one of claims 1 to 8, wherein the exhaust device is disposed in the exhaust passage of the battery submodule housing. Claim 10 A battery module comprising a plurality of battery submodules, a battery module housing, and a thermal runaway detection system according to any one of claims 1 to 8, wherein the exhaust device is disposed in the exhaust passage of the battery module housing. Claim 11 A battery system comprising a plurality of battery modules, a battery system housing, and a thermal runaway detection system according to any one of claims 1 to 8, wherein the exhaust device is disposed in the exhaust passage of the battery system housing. Claim 12 A vehicle comprising a battery system according to claim 11, at least one vehicle control unit configured to receive said signal, and at least one output means further comprising said vehicle control unit configured to control said output means to output a warning to a customer based on said signal. Claim 13 A method for detecting thermal runaway of at least one battery cell among a plurality of battery cells disposed within a housing, comprising: a step in which a controller detects that a conductive path between a first detection node and a second detection node connected to an exhaust device is in a first state as the exhaust device having a sealing body is disposed in an exhaust passage of the housing, and the sealing body closes the exhaust passage at a first position; a step in which the controller outputs a first signal as the conductive path is detected in the first state; a step in which the controller detects that the conductive path is in a second state different from the first state as the sealing body opens the exhaust passage at a second position different from the first position in response to a predefined pressure inside the housing; and a step in which the controller outputs a second signal as the conductive path is detected in the second state, wherein either the first state or the second state is a conductive state and the other is a non-conductive state, and one of the first signal and the second signal indicates thermal runaway of the at least one battery cell, and the first detection node is of the at least one battery cell A thermal runaway detection method in which a first cell terminal is connected between the exhaust device and the first cell terminal, the second detection node is connected between the second cell terminal of the at least one battery cell and the exhaust device, and when the conductive path becomes conductive, current flows through the conductive path by the at least one battery cell. Claim 14 A method for detecting thermal runaway according to claim 13, comprising the steps of: a vehicle control unit receiving a signal indicating thermal runaway among the first signal and the second signal, outputting a warning through the vehicle's output means or performing at least one countermeasure; and a vehicle control unit receiving a signal not indicating thermal runaway among the first signal and the second signal, stopping the output of the warning or stopping the performance of the countermeasure.

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