Thermal runaway management system and method, and battery pack

Abstract

Provided are a thermal runaway management system and method, and a battery pack. The thermal runaway management system comprises a battery monitoring circuit, a fire suppression assembly, and a gas collection assembly, wherein the battery monitoring circuit and the fire suppression assembly are both arranged inside a battery pack; the battery monitoring circuit is electrically connected to a battery cell in the battery pack; the fire suppression assembly and the gas collection assembly are electrically connected to the battery monitoring circuit; the battery monitoring circuit can be configured to monitor the temperature of the battery cell, control the fire suppression assembly to perform fire extinguishing inside the battery pack, and simultaneously control the gas collection assembly to collect gas inside the battery pack.

Description

Thermal runaway management system, method and battery pack

[0001] This application claims priority to Chinese Patent Application No. 202411283352.2 and 202422247553.9, filed on September 12, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a thermal runaway management system, method and battery pack. BACKGROUND

[0003] Thermal runaway refers to a phenomenon in which the internal chemical reaction of a battery is out of control under certain conditions (such as high temperature, overcharging, internal short circuit, etc.), generating a large amount of heat and possibly causing a fire or explosion. SUMMARY

[0004] Short circuit inside the battery, causing electrolyte to burn or explode, or positive material decomposing to produce oxygen at high temperature, exacerbating heat accumulation, or negative material reacting violently with electrolyte, causing temperature to rise rapidly, or over-discharge of the battery causing internal pressure to decrease, all of which can cause thermal runaway.

[0005] In a first aspect, the present application provides a thermal runaway management system, comprising:

[0006] A battery monitoring circuit is arranged inside the battery pack and electrically connected to the battery cells in the battery pack.

[0007] A fire-fighting assembly is arranged inside the battery pack and electrically connected to the battery monitoring circuit.

[0008] A gas collection assembly is electrically connected to the battery monitoring circuit and communicates with the interior of the battery pack.

[0009] The battery monitoring circuit is configured to at least monitor the temperature of the battery cells and control the fire-fighting assembly to perform fire extinguishing inside the battery pack, and control the gas collection assembly to collect the gas inside the battery pack.

[0010] In a second aspect, the present application provides a thermal runaway management method applied to a battery pack, the battery pack comprising a thermal runaway management system, the thermal runaway management system comprising a battery cell monitoring module, a temperature monitoring circuit, a fire-fighting assembly and a gas collection assembly; the method comprising:

[0011] Obtaining first temperature information collected by the battery cell monitoring module at the battery cells in the battery pack, second temperature information collected by the temperature monitoring circuit at the battery cells, and first collection information collected by the fire-fighting assembly in the battery pack.

[0012] If at least one of the first temperature information, the second temperature information and the first collection information is abnormal, a thermal runaway region in the battery pack is determined;

[0013] The fire-fighting assembly is controlled to perform fire extinguishing in the thermal runaway region, and the gas collection assembly is controlled to collect gas inside the battery pack.

[0014] In a third aspect, the application further provides a battery pack comprising the thermal runaway management system provided in the first aspect. Advantages

[0015] The thermal runaway management system provided by the application comprises a battery monitoring circuit, a fire-fighting assembly and a gas collection assembly. The battery monitoring circuit and the fire-fighting assembly are both arranged inside the battery pack. The battery monitoring circuit is electrically connected to the battery cells in the battery pack, and the fire-fighting assembly is electrically connected to the battery monitoring circuit. The battery monitoring circuit can be configured to monitor the temperature of the battery cells, and can control the fire-fighting assembly to perform fire extinguishing inside the battery pack and control the gas collection assembly to collect gas inside the battery pack after detecting thermal runaway of the battery cells. The thermal runaway management system not only realizes monitoring of thermal runaway of the battery cells, but also can timely control the spread of thermal runaway in the battery pack and timely treat the exhaust gas generated by thermal runaway, thereby effectively improving the safety and reliability of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0016] FIG. 1 is a first schematic block diagram of the thermal runaway management system provided by the application;

[0017] FIG. 2 is a second schematic block diagram of the thermal runaway management system provided by the application;

[0018] FIG. 3 is a third schematic block diagram of the thermal runaway management system provided by the application;

[0019] FIG. 4 is a fourth schematic block diagram of the thermal runaway management system provided by the application;

[0020] FIG. 5 is a circuit diagram of the air flow assembly provided by the application;

[0021] FIG. 6 is a flowchart of the thermal runaway management method provided by the application.

[0022] REFERENCE SIGNS:

[0023] 10, thermal runaway management system; 100, battery monitoring circuit; 101, battery cell monitoring module; 102, temperature monitoring circuit; 200, fire-fighting assembly; 201, smoke detector; 202, fire extinguishing module; 203, fire-fighting control module; 300, gas collection assembly; 301, gas collection pipeline; 302, air flow assembly; 303, backup power supply; 304, first switch; 305, second switch; 306, third switch; 307, fourth switch; 20, battery cell; 30, air valve. Embodiments of the present application

[0024] Embodiments of the present application provide a thermal runaway management system, method and battery pack.

[0025] For ease of understanding, the present application first introduces a thermal runaway management system, and then introduces a thermal runaway management method in detail based on the thermal runaway management system.

[0026] Referring to FIG. 1, FIG. 1 is a first schematic block diagram of a thermal runaway management system provided by the present application. As shown in FIG. 1, a thermal runaway management system 10 includes:

[0027] A battery monitoring circuit 100 is arranged inside the battery pack and is electrically connected to the battery cells 20 in the battery pack.

[0028] A fire-fighting assembly 200 is arranged inside the battery pack and is electrically connected to the battery monitoring circuit 100.

[0029] A gas collection assembly 300 is electrically connected to the battery monitoring circuit 100 and is in communication with the inside of the battery pack.

[0030] The battery monitoring circuit 100 is configured to at least monitor the temperature of the battery cells 20 and control the fire-fighting assembly 200 to perform fire extinguishing inside the battery pack, and control the gas collection assembly 300 to collect the gas inside the battery pack.

[0031] In this embodiment, the battery monitoring circuit 100 can monitor the temperature, voltage and current of the battery cells 20 in the battery pack to ensure that the battery operates within a safe range. The fire-fighting assembly 200 can directly perform fire extinguishing inside the battery pack when the battery cells 20 are in thermal runaway, thereby being able to quickly extinguish the battery cells 20 in the thermal runaway state and effectively prevent the battery pack from reigniting, reducing the risk of secondary injury caused by the battery pack.

[0032] The thermal runaway management system 10 provided in the application comprises a battery monitoring circuit 100, a fire extinguishing assembly 200 and a gas collection assembly 300, the battery monitoring circuit 100 and the fire extinguishing assembly 200 are arranged in the battery pack, the battery monitoring circuit 100 is electrically connected with the battery cell 20 in the battery pack, the fire extinguishing assembly 200 is electrically connected with the battery monitoring circuit 100, the battery monitoring circuit 100 can be configured to monitor the temperature of the battery cell 20, and can control the fire extinguishing assembly 200 to perform fire extinguishing in the battery pack after monitoring that the battery cell 20 has thermal runaway, and control the gas collection assembly to collect the gas in the battery pack, so that the monitoring of the thermal runaway of the battery cell 20 is realized, the spread of the thermal runaway in the battery pack can be controlled in time, the waste gas generated by the thermal runaway can be treated in time, and the safety and reliability of the battery pack are effectively improved.

[0033] In some embodiments, as shown in FIG. 2, the battery monitoring circuit 100 comprises:

[0034] a battery cell monitoring module 101 electrically connected with the battery cell 20;

[0035] a temperature monitoring circuit 102 electrically connected with the battery cell monitoring module 101 and configured to monitor the temperature of the battery cell 20;

[0036] The battery cell monitoring module 101 is configured to monitor the state of the battery, and control the fire extinguishing assembly 200 to perform fire extinguishing in the battery pack, and control the gas collection assembly 300 to collect the gas in the battery pack.

[0037] Specifically, the battery cell monitoring module 101 can monitor the temperature, voltage and current of the battery cell 20 in the battery pack to ensure that the battery operates in a safe range, and the temperature monitoring circuit 102 can monitor the temperature of each battery cell 20 in the battery pack.

[0038] In addition, the battery cell monitoring module 101 can obtain the temperature monitored by the temperature monitoring circuit 102 on the battery cell 20, and can further determine whether the battery cell 20 has thermal runaway, so that the misjudgment of the thermal runaway of the battery cell 20 can be avoided, and the accuracy of the thermal runaway monitoring of the battery cell 20 is improved.

[0039] In the embodiment, by simultaneously arranging the battery cell monitoring module 101 and the temperature monitoring module in the battery pack, the misjudgment of the thermal runaway of the battery cell 20 can be avoided, and the accuracy of the thermal runaway monitoring of the battery cell 20 is improved.

[0040] Meanwhile, the battery cell monitoring module 101 can be a slave module of the battery management system, the slave module is an important component of the battery management system, undertakes multiple key tasks such as data acquisition, balance management, communication and thermal management, and is a key link to ensure the efficient and safe operation of the battery.

[0041] In some embodiments, the temperature monitoring circuit 102 comprises a thermal switch; one end of the thermal switch is electrically connected to one end of the battery cell 20, and the other end of the thermal switch is electrically connected to the battery cell monitoring module 101.

[0042] Specifically, the thermal switch is an electromechanical temperature control device that uses the different thermal expansion coefficients of the layers of the bimetallic strip. When the temperature changes, the deformation of the active layer is greater than that of the passive layer, so the overall bimetallic strip will bend towards the passive layer side. The curvature of this composite material changes to produce a deformation characteristic to achieve current on / off.

[0043] The thermal switch can produce on / off state changes according to changes in environmental temperature, and is divided into positive temperature coefficient and negative temperature coefficient. It is configured in the safety and control system, monitors the temperature and plays a control role on the related device. Thermal switches can be implemented using a variety of technologies, including bimetallic switches, thermal reed switches, mercury switches, rod and tube switches with different temperature coefficients, and pneumatic switches.

[0044] When the temperature monitoring circuit 102 is used to monitor the temperature of the battery cell 20 in the battery pack, a thermal switch can be used to achieve it. The cost of the thermal switch is low, and there is no risk of communication abnormalities, thereby reducing the misjudgment of thermal runaway of the battery cell 20 and improving the accuracy of thermal runaway monitoring of the battery cell 20. Each battery cell 20 in the battery pack is equipped with a thermal switch. When the battery cell 20 is operating normally, the thermal switch is in a closed state; when the battery cell 20 is in thermal runaway, the temperature rises, at which point the thermal switch is disconnected. At this time, the battery cell monitoring module 101 cannot receive the current signal or voltage information at the thermal switch, and thus the thermal runaway of the battery cell 20 can be determined.

[0045] In some embodiments, as shown in FIG. 3, the fire fighting assembly 200 comprises a smoke detector 201 and a fire extinguishing module 202; wherein the smoke detector 201 and the fire extinguishing module 202 are electrically connected to the battery monitoring circuit 100, the smoke detector 201 is configured to detect smoke inside the battery pack, and the fire extinguishing module 202 is configured to perform fire extinguishing inside the battery pack.

[0046] Specifically, the smoke detector 201 is a device specifically used to monitor the internal environment of the battery pack to prevent dangerous situations such as fire and overheating. The smoke detector 201 of the battery pack usually uses photoelectric or ionic sensors to detect smoke and exhaust particles.

[0047] In the embodiment, each battery cell 20 in the battery pack can correspond to one smoke detector 201. When a certain battery cell 20 in the battery pack is in thermal runaway, the corresponding smoke detector 201 can detect the smoke generated by the thermal runaway of the battery cell 20 to determine whether the battery cell 20 is in thermal runaway, thereby further reducing the misjudgment of the thermal runaway of the battery cell 20 and improving the accuracy of the thermal runaway monitoring of the battery cell 20. Meanwhile, after determining the thermal runaway of the battery cell 20, the fire extinguishing module 202 can be used for fire extinguishing to prevent the thermal runaway of the battery cell 20 from spreading and avoid other battery cells 20 in the battery pack that are not in thermal runaway from being affected, thereby effectively improving the safety and reliability of the battery pack.

[0048] In some embodiments, as shown in FIG. 3, the fire-fighting assembly 200 further includes a fire-fighting control module 203; wherein the fire-fighting control module 203 is electrically connected to the battery monitoring circuit 100, the smoke detector 201 and the fire extinguishing module 202 respectively, and the fire-fighting control module 203 is configured to control the fire extinguishing module 202 to perform fire extinguishing inside the battery pack.

[0049] Specifically, the battery monitoring circuit 100 can obtain the smoke information monitored by the smoke detector 201 at the corresponding battery cell 20 through the fire-fighting control module 203, and then determine whether the battery cell 20 is in thermal runaway. Meanwhile, after determining the thermal runaway of the battery cell 20, the battery monitoring circuit 100 can control the fire extinguishing module 202 to perform fire extinguishing through the fire-fighting control module 203 to prevent the thermal runaway of the battery cell 20 from spreading and avoid other battery cells 20 in the battery pack that are not in thermal runaway from being affected, thereby effectively improving the safety and reliability of the battery pack.

[0050] In some embodiments, as shown in FIG. 4, the gas collection assembly 300 includes a gas collection pipeline 301, and the battery pack is provided with a gas valve 30; wherein the gas collection pipeline 301 is arranged outside the battery pack; one end of the gas collection pipeline 301 is in communication with one end of the gas valve 30, and the other end of the gas valve 30 is in communication with the inside of the battery pack.

[0051] In the embodiment, the gas collection pipeline 301 is arranged outside the battery pack, one end of the gas collection pipeline 301 can be provided with a plurality of gas collection inlets, and each inlet is in communication with one gas valve 30. The gas valve 30 can be opened during the process of collecting the gas generated by the thermal runaway of the battery cell 20 in the gas collection pipeline 301, thereby enabling the gas generated by the thermal runaway of the battery cell 20 to be discharged from the battery pack in time and be discharged directionally to prevent the exhaust gas from being directly discharged into the air, thereby reducing the harm to the environment and the human body.

[0052] The breather valve 30 is a device for balancing the pressure inside and outside the sealed equipment and preventing moisture, dust and other contaminants from entering. Its main function is to maintain good air permeability while preventing the intrusion of water droplets, drizzle, fine impurities and chemicals.

[0053] In some embodiments, the battery pack is also provided with a balance valve, one end of the balance valve being in communication with the inside of the battery pack, and the other end of the balance valve being in communication with the outside of the battery pack.

[0054] In this embodiment, the balance valve is provided on the box where the battery pack is located and is in communication with the inside of the battery pack. The balance valve can be opened after the thermal runaway of the battery cell 20 in the battery pack is controlled and the exhaust gas in the battery pack is discharged, thereby adjusting the air pressure inside the battery pack and avoiding secondary damage to the deformation of the battery pack. The balance valve can be divided into three types: static balance valve, dynamic balance valve and pressure-independent balance valve.

[0055] In addition, the balance valve can also be opened during the thermal runaway of the battery cell 20 in the battery pack and the exhaust gas discharge process in the battery pack to avoid secondary damage to the deformation of the battery pack, greatly improving the safety and reliability of the battery pack. It should be noted that the opening of the balance valve can be selected according to actual application, and the present application is not limited.

[0056] In some embodiments, as shown in FIG. 4, the gas collection assembly 300 further comprises a gas flow assembly 302 and a backup power supply 303; wherein the gas flow assembly 302 is electrically connected to the battery monitoring circuit 100 and the backup power supply 303, and the gas flow assembly 302 is configured to sequentially discharge the gas inside the battery pack through the breather valve 30 and the gas collection pipeline 301.

[0057] In this embodiment, the gas flow assembly 302 can prevent the fan, and the power required for the operation of the gas flow assembly 302 can be provided by the battery pack. At the same time, the gas flow assembly 302 can be opened after the thermal runaway of the battery cell 20 in the battery pack, so as to reduce the internal air pressure of the gas collection pipeline 301, thereby sequentially discharging the exhaust gas generated by the thermal runaway through the breather valve 30 and the gas collection pipeline 301, and preventing the exhaust gas from being directly discharged into the air, thereby reducing the harm to the environment and the human body.

[0058] At the same time, the gas flow collection assembly can also be configured with a backup power supply 303, thereby providing power for the gas flow assembly 302 through the backup power supply 303 when the battery pack cannot provide power for the gas flow assembly 302, ensuring that the gas flow assembly 302 can continue to operate to reduce the internal air pressure of the gas collection pipeline 301, thereby sequentially discharging the exhaust gas generated by the thermal runaway through the breather valve 30 and the gas collection pipeline 301, and preventing the exhaust gas from being directly discharged into the air, thereby reducing the harm to the environment and the human body.

[0059] In some embodiments, the gas collection assembly 300 further comprises a control circuit, which is electrically connected to the cell monitoring module 101, the airflow assembly 302 and the backup power supply 303 respectively.

[0060] In this embodiment, the cell monitoring module 101 turns on the airflow assembly 302 through the control circuit, and when the battery pack cannot provide power for the airflow assembly 302, the backup power supply 303 can supply power for the airflow assembly 302 through the control circuit, so as to ensure that the airflow assembly 302 can be turned on after the cell 20 in the battery pack is in thermal runaway, so as to reduce the internal gas pressure of the gas collection pipeline 301, so that the exhaust gas generated by the thermal runaway can be sequentially discharged by the air permeable valve 30 and the gas collection pipeline 301.

[0061] In some embodiments, as shown in FIG. 5, the control circuit comprises a first switch 304, a second switch 305, a third switch 306 and a fourth switch 307, one end of the first switch 304 is electrically connected to the positive electrode V+ of the power supply, the other end of the first switch 304 is electrically connected to the airflow assembly 302, the negative electrode V- of the power supply is electrically connected to the airflow assembly 302, one end of the second switch 305 is electrically connected to the cell monitoring module 101, the other end of the second switch 305 is electrically connected to the negative electrode V- of the power supply and the airflow assembly 302 respectively, one end of the third switch 306 is electrically connected to the battery management system and one end of the second switch 305, the other end of the third switch 306 is electrically connected to the positive electrode of the backup power supply 303, one end of the fourth switch 307 is electrically connected to one end of the third switch 306, the other end of the fourth switch 307 is electrically connected to the airflow assembly 302, and the negative electrode of the backup power supply 303 is electrically connected to the airflow assembly 302.

[0062] In this embodiment, the power supply can be provided by the battery pack. When it is needed to turn on the airflow assembly 302, the cell monitoring module 101 controls the first switch 304 and the second switch 305 to be closed, and uses the power supply to supply power for the airflow assembly 302; when the power supply cannot supply power for the airflow assembly 302, the cell monitoring module 101 controls the third switch 306 and the fourth switch 307 to be closed, so as to realize that the backup power supply 303 is used to supply power for the airflow assembly 302.

[0063] In some embodiments, the control circuit comprises a relay, the relay comprises a coil, and the relay is provided with at least four contacts, which are a first contact, a second contact, a third contact and a fourth contact, the first contact and the second contact can be used as a group of normally open contacts, and can be understood as a first switch; the coil can be understood as a second switch; the third contact and the fourth contact can be used as a group of normally open contacts, and can be understood as a third switch.

[0064] Specifically, one end of the coil is electrically connected to the slave board of the battery management system, the other end of the coil is electrically connected to the negative electrode of the first power supply, the first contact is electrically connected to the positive electrode of the first power supply, the second contact is electrically connected to the airflow assembly, the third contact is electrically connected to one end of the coil and one end of the fourth switch respectively, and the fourth contact is electrically connected to the positive electrode of the second power supply.

[0065] When it is necessary to start the airflow assembly, the slave board of the battery management system sends a starting signal to the coil, so that the coil conducts electricity, so that the coil closes the first contact and the second contact, and closes the third contact and the fourth contact, thereby the first power supply (which can be understood as a battery pack) and the second power supply (which can be understood as a backup power supply) can simultaneously supply power to the airflow assembly. When the first power supply and the second power supply simultaneously supply power to the airflow assembly, diodes are arranged at the first power supply and the second power supply to prevent reverse current.

[0066] In some embodiments, the application also provides a battery pack comprising the thermal runaway management system 10 of the battery pack mentioned in the application.

[0067] In this embodiment, the battery pack is provided with a battery management system (BMS). The battery management system can ensure the safe, reliable and efficient operation of the battery under various charging and discharging and environmental conditions. The battery management system can prolong the service life of the battery and improve its performance by monitoring and managing the state parameters of the battery in real time, such as voltage, current, temperature, etc. At the same time, the battery pack can control the thermal runaway management system 10 through the battery management system, which can effectively improve the safety and reliability of the battery pack.

[0068] It can be understood that the thermal runaway management system and the battery management system provided by the embodiments of the application are examples. The thermal runaway management system and the battery management system described in the embodiments of the application are used to more clearly illustrate the technical solutions of the embodiments of the application, and do not constitute a limitation on the technical solutions provided by the embodiments of the application. Those skilled in the art can know that the technical solutions provided by the embodiments of the application are also applicable to similar technical problems as the system evolves and new business scenarios appear.

[0069] It should be noted that the order of the following embodiments is not limited as the preferred order of the embodiments. The thermal runaway management method will be described in detail below. At the same time, the thermal runaway management method provided by the application can be executed by the thermal runaway management system or the battery management system.

[0070] Please refer to FIG. 6, which is a flowchart of the thermal runaway management method provided by the application. As shown in FIG. 6, the thermal runaway management method comprises steps S110-S130.

[0071] S110, acquire first temperature information collected by a cell monitoring module at a cell in the battery pack, second temperature information collected by a temperature monitoring circuit at the cell, and first collection information collected by a fire-fighting assembly in the battery pack.

[0072] In this embodiment, the first temperature information can be the temperature collected by the cell monitoring module at the cell in the battery pack, the second temperature information can be the temperature collected by the temperature monitoring circuit at the cell in the battery pack, and the first collection information can be the smoke information collected by the fire-fighting assembly inside the battery pack. The cell monitoring module can be a slave board of a battery management system, and the temperature monitoring circuit can be a circuit additionally arranged to monitor the temperature of the cell in the battery pack.

[0073] Specifically, the application can directly acquire the first temperature information by using the cell monitoring module, and can also collect the second temperature information of the cell by using the temperature monitoring circuit. Through the first temperature information and the second temperature information, the accuracy of the temperature collected from the cell position can be ensured, and in the event of failure of one of them, the temperature of the cell in the thermal runaway state can be ensured.

[0074] When the cell in the battery pack is in thermal runaway, the first temperature information, the second temperature information, and the first collection information can be acquired, and it can be determined whether at least one of the first temperature information, the second temperature information, and the first collection information is abnormal. If it is abnormal, it can be determined that the cell in the battery pack is in thermal runaway, and the cell in thermal runaway can be determined, and thermal runaway processing such as fire extinguishing processing can be performed to prevent the thermal runaway of the cell from spreading to other cells, thereby effectively improving the safety and reliability of the battery pack.

[0075] S120, if at least one of the first temperature information, the second temperature information, and the first collection information is abnormal, determine the thermal runaway area in the battery pack.

[0076] In this embodiment, the cell in thermal runaway in the battery pack is specifically the position information of the cell in thermal runaway in the battery pack. After it is monitored that at least one of the first temperature information, the second temperature information, and the first collection information is abnormal, the position information of the cell in thermal runaway in the battery pack can be determined through at least one of the first temperature information, the second temperature information, and the first collection information.

[0077] For example, if the first temperature information is abnormal, the position information of the cell in thermal runaway in the battery pack can be determined through the first temperature information corresponding line, or the corresponding second temperature information can be determined through the first temperature information corresponding line, and the position information of the cell in thermal runaway in the battery pack can be determined through the second temperature information corresponding line.

[0078] In some embodiments, if at least one of the first temperature information, the second temperature information, and the first collection information is abnormal, the thermal runaway region in the battery pack is determined, comprising: if at least two of the first temperature information, the second temperature information, and the first collection information are abnormal, the thermal runaway region in the battery pack is determined.

[0079] Specifically, in order to ensure that the battery cell thermal runaway is misjudged, the present application can determine whether the battery cell in the battery pack is in thermal runaway by determining whether at least two of the first temperature information, the second temperature information, and the first collection information are abnormal, and then determine the thermal runaway region and perform thermal runaway processing, such as fire extinguishing processing, to prevent the thermal runaway of the battery cell from spreading to other battery cells, thereby effectively improving the safety and reliability of the battery pack.

[0080] For example, if the first temperature information and the second temperature information are abnormal, it can be determined that the battery cell in the battery pack is in thermal runaway; or if the first temperature information and the first collection information are abnormal, it can be determined that the battery cell in the battery pack is in thermal runaway; or if the second temperature information and the first collection information are abnormal, it can be determined that the battery cell in the battery pack is in thermal runaway; or if the first temperature information, the second temperature information, and the first collection information are abnormal, it can be determined that the battery cell in the battery pack is in thermal runaway.

[0081] In some embodiments, the temperature monitoring circuit includes a thermal switch; before determining the thermal runaway region in the battery pack, further comprising: if the first temperature information is that the temperature of the battery cell is higher than a preset temperature, it is determined that the battery cell is in thermal runaway; if the second temperature information is that the thermal switch is disconnected, it is determined that the battery cell at the thermal switch is in thermal runaway; if the first collection information is a preset first information, it is determined that the battery cell in the battery pack is in thermal runaway.

[0082] In the present embodiment, the temperature monitoring circuit includes a plurality of thermal switches, each battery cell corresponds to a thermal switch, the first temperature information is the temperature information monitored by the battery cell monitoring module at the battery cell, if the temperature information shows that the temperature of the battery cell is higher than a preset temperature, it can be determined that the battery cell at the corresponding position is in thermal runaway; the second temperature information is the on-off information of the thermal switch in the temperature monitoring circuit, if the on-off information shows that the thermal switch is disconnected, it can be determined that the battery cell at the corresponding position is in thermal runaway; the first collection information is the smoke information monitored by the smoke alarm in the fire-fighting assembly in the battery pack, if the smoke information shows that the smoke concentration in the battery pack is higher than a preset threshold, i.e. the first collection information is the first information, it can be determined that the battery cell in the battery pack is in thermal runaway.

[0083] In some embodiments, the temperature monitoring circuit includes a thermal switch; before determining the thermal runaway region in the battery pack, further comprising: if the first temperature information is that the temperature of the battery cell is higher than a preset temperature, it is determined whether the second temperature information is that the thermal switch is disconnected; if the second temperature information is that the thermal switch is disconnected, it is determined that the battery cell at the thermal switch is in thermal runaway.

[0084] This application can determine thermal runaway of battery cells within a battery pack by checking whether the first and second temperature information are abnormal. Specifically, if the first temperature information indicates that the cell temperature is higher than a preset temperature, it can be determined that the cell has most likely experienced thermal runaway. To avoid false positives, the second temperature information can be used to determine whether the thermal switch is open. That is, the cell monitoring module detects whether there is current or voltage at the thermal switch to determine whether the thermal switch is open. If it is open, thermal runaway of the cell at the corresponding location can be determined.

[0085] In some embodiments, before determining the thermal runaway region within the battery pack, the method further includes: if the first temperature information indicates that the temperature of the cell is higher than a preset temperature, determining whether the first collected information is a preset first information; if the first collected information is the preset first information, determining the cell in the battery pack that is experiencing thermal runaway.

[0086] Specifically, this application can also determine whether there is an abnormality in the thermal runaway of the battery cell within the battery pack based on the first temperature information and the first collected information. Similarly, if the first temperature information indicates that the temperature of the battery cell is higher than a preset temperature, it can be determined that the battery cell has most likely experienced thermal runaway. To avoid misjudgment, the thermal runaway of the battery cell can be further determined by the first collected information of the fire suppression component within the battery pack. Specifically, it can be determined whether the first collected information is the preset first information. If it is the first information, then the thermal runaway of the battery cell can be determined.

[0087] In some embodiments, the temperature monitoring circuit includes a thermal switch; before determining the thermal runaway region within the battery pack, it further includes: if the second temperature information is the thermal switch's open information, determining whether the first collected information is a preset first information; if the first collected information is the preset first information, determining the thermally runaway cell within the battery pack.

[0088] Specifically, this application can also determine whether there is an abnormality in the thermal runaway of the battery cell within the battery pack based on the second temperature information and the first collected information. If the second temperature information is the opening information of the thermal switch, it can be determined that the battery cell has most likely experienced thermal runaway. To avoid misjudgment, the thermal runaway of the battery cell can be further determined by the first collected information of the fire suppression component within the battery pack. Specifically, it can be determined whether the first collected information is the preset first information. If it is the first information, then the thermal runaway of the battery cell can be determined.

[0089] It should be noted that after obtaining the first temperature information, the second temperature information, and the first acquisition information, this application can first use any one of them to determine whether the cell has thermal runaway. At the same time, in order to further improve the accuracy of thermal runaway, the other two or one can be used for confirmation.

[0090] In some embodiments, determining the thermal runaway region in the battery pack comprises: obtaining position information of the battery cell; and determining the thermal runaway region in the battery pack according to the position information.

[0091] In the embodiment, after determining the battery cell that has thermal runaway in the battery pack, the thermal runaway region in the battery pack can be determined directly according to the position information of the battery cell, and then the fire extinguishing module corresponding to the region can be used to perform fire extinguishing to prevent the thermal runaway of the battery cell from spreading to other battery cells, thereby effectively improving the safety and reliability of the battery pack.

[0092] In some embodiments, determining the thermal runaway region in the battery pack comprises: if the first collection information is the first information, obtaining position information of the smoke detector corresponding to the first information; and determining the battery cell that has thermal runaway in the battery pack according to the position information.

[0093] In the embodiment, the fire-fighting assembly comprises a plurality of smoke detectors, and each battery cell can correspond to a smoke detector. When it is determined that the smoke information shows that the smoke concentration in the battery pack is higher than a preset threshold, i.e., the first collection information is the first information, it can be determined that there is a battery cell that has thermal runaway in the battery pack. In order to determine the position of the battery cell that has thermal runaway in the battery pack, the position information of the smoke detector that has smoke alarm in the battery pack can be obtained, and then the position of the battery cell that has thermal runaway in the battery pack can be determined according to the position information of the smoke detector, so that the fire extinguishing module can be used to extinguish the fire of the battery cell that has thermal runaway to prevent the thermal runaway of the battery cell from spreading to other battery cells, thereby effectively improving the safety and reliability of the battery pack.

[0094] In some embodiments, determining the battery cell that has thermal runaway in the battery pack according to the position information comprises: obtaining first temperature information or / and second temperature information at the position corresponding to the smoke detector; and determining the battery cell that has thermal runaway in the battery pack according to the first temperature information or / and the second temperature information.

[0095] Specifically, after the smoke detector alarms, the battery cell that has thermal runaway can be further determined according to the first temperature information or / and the second temperature information at the position corresponding to the smoke detector, so as to avoid the situation of misjudgment of thermal runaway, thereby improving the accuracy of determining the battery cell that has thermal runaway.

[0096] S130, controlling the fire-fighting assembly to perform fire extinguishing in the thermal runaway region, and controlling the gas collection assembly to collect the gas inside the battery pack.

[0097] Specifically, after determining that the thermal runaway occurs in the battery cell in the battery pack and the thermal runaway region, the fire extinguishing assembly can be controlled to perform fire extinguishing in the thermal runaway region, and the gas collection assembly can be controlled to collect the gas inside the battery pack. Not only can the thermal runaway in the battery pack be controlled in time, but also the waste gas generated by the thermal runaway can be treated in time after the thermal runaway of the battery cell is triggered, thereby effectively improving the safety and reliability of the battery pack.

[0098] In some embodiments, the temperature monitoring circuit includes a plurality of thermal switches, each battery cell corresponding to a thermal switch, the battery pack is provided with a gas valve, and the gas collection assembly includes an air flow assembly and a gas collection pipeline; wherein the control of the gas collection assembly to collect the gas inside the battery pack includes: starting the air flow assembly to reduce the pressure inside the gas collection pipeline; after a preset first time, obtaining the on-off information of the thermal switch at the battery cell that does not have thermal runaway in the battery pack; if the on-off information is the off information of the thermal switch, opening the gas valve to sequentially discharge the gas in the battery pack through the gas valve and the gas collection pipeline.

[0099] In this embodiment, the gas collection pipeline is arranged outside the battery pack, one end of the gas valve is in communication with one end of the gas collection pipeline, the air flow assembly is arranged at the other end of the gas collection pipeline, and the other end of the gas valve is in communication with the inside of the battery pack.

[0100] In the process of controlling the gas collection assembly to collect the gas inside the battery pack, the air flow assembly can be started first to reduce the pressure inside the gas collection pipeline. Since the battery cells in the battery pack have thermal runaway, the pressure inside the battery pack is large, so a large pressure difference can be formed on both sides of the gas valve, thereby making it easier to open the gas valve to quickly discharge the harmful gas generated in the battery pack.

[0101] At the same time, since the thermal runaway may spread in the battery pack, and when the thermal runaway spreads in the battery pack, the gas valve may still be in a closed state, it is necessary to confirm whether the battery cell that does not have thermal runaway has thermal runaway after a preset first time. However, the battery cell monitoring module may not be able to monitor the state of other battery cells that do not have thermal runaway. Therefore, the on-off information of the thermal switch at the battery cell that does not have thermal runaway is used to determine whether the battery cell that does not have thermal runaway has thermal runaway, and to determine whether the thermal runaway spreads to other battery cells. If the thermal switch at the battery cell that does not have thermal runaway is off, it can be determined that the thermal runaway spreads to other battery cells, and the gas valve needs to be opened immediately to quickly and timely discharge the gas in the battery pack through the gas valve and the gas collection pipeline.

[0102] The breather valve is a device for balancing the pressure inside and outside the sealed equipment and preventing moisture, dust and other contaminants from entering. Its main function is to maintain good air permeability while preventing the intrusion of water droplets, drizzle, fine impurities and chemicals.

[0103] In some embodiments, the gas collection assembly 300 further comprises a control circuit, and the control circuit comprises a first switch; the starting of the airflow assembly comprises: controlling the first switch to be closed to start the airflow assembly.

[0104] Specifically, the battery pack is preferably selected to provide power for the airflow assembly, that is, the battery pack can be controlled to supply power to the airflow assembly by controlling the first switch to be closed, so that the airflow assembly is started, so that the gas generated by the thermal runaway of the battery pack can be discharged in a targeted manner.

[0105] In some embodiments, the gas collection assembly 300 further comprises a breather valve, and the control circuit further comprises a second switch, a third switch and a fourth switch; wherein the control of the first switch to be closed to start the airflow assembly comprises: controlling the second switch to be in a power-on state; and according to the power-on state of the second switch, controlling the first switch and the third switch to be closed to start the airflow assembly.

[0106] In this embodiment, the gas collection assembly 300 is further provided with a second power supply, i.e. a backup power supply, and the control circuit comprises a relay and a fourth switch. The coil of the relay can be used as the second switch, and the relay is provided with at least two groups of normally open contacts. One group of normally open contacts is used as the first switch, and the other group of normally open contacts can be used as the third switch. When the battery management system controls the coil to be conductive, the first switch and the third switch are closed. At this time, since the fourth switch is arranged between the positive electrode of the second power supply and the airflow assembly, the fourth switch can be in a disconnected state first, so that the battery pack supplies power to the airflow assembly.

[0107] After the first switch and the third switch are controlled to be closed to start the airflow assembly, if the battery pack cannot supply power to the airflow assembly due to thermal runaway, the fourth switch can be closed to start the breather valve and the airflow assembly.

[0108] It should be noted that the other group of normally open contacts of the relay is used as the third switch in order to continuously supply power to the coil of the relay through the third switch after the third switch is closed. This not only enables the first power supply to supply power to the airflow assembly through the first switch, but also enables the second power supply to continuously supply power to the airflow assembly through the third switch, so that the airflow assembly does not appear to be powered off in the started state.

[0109] In some embodiments, the application can also directly control the fourth switch to close to open the valve of the air vent valve in advance to realize the simultaneous power supply of the first power supply and the second power supply to the airflow assembly while energizing the coil of the relay to control the first switch and the third switch to be turned on.

[0110] In some embodiments, after opening the air vent valve to sequentially discharge the gas in the battery pack through the air vent valve and the gas collection pipeline, the method further comprises: after a preset second time, acquiring second collection information of the fire-fighting assembly in the battery pack; if the second collection information is preset second information, opening the balance valve and controlling the airflow assembly to stop working.

[0111] In the embodiment, the second collection information can be smoke information collected by the fire-fighting assembly in the battery pack. When the second collection information is the second information after the second time, the balance valve is opened and the airflow assembly is controlled to stop working. The second information is information that the smoke concentration in the battery pack does not exceed the preset concentration. If the second collection information is the second information, it can be determined that the thermal runaway of the battery cell in the battery pack is controlled.

[0112] The second information can be information that the smoke concentration in the battery pack is lower than the preset concentration, that is, when the second collection information in the battery pack is that the smoke concentration in the battery pack is lower than the preset concentration, the balance valve can be opened to balance the air pressure inside and outside the battery pack to avoid secondary damage to the battery pack. The second information can also be information that the air pressure in the battery pack is lower than the preset air pressure, that is, when the first collection information in the battery pack is that the air pressure in the battery pack is lower than the preset air pressure, it can be determined that basically no gas is generated in the battery pack at this time, and the case of the battery pack reaches the limit and is about to deform. Therefore, the balance valve needs to be opened to balance the air pressure inside and outside the battery pack to avoid secondary damage to the battery pack.

[0113] At the same time, after determining that the thermal runaway battery cell is controlled, the application can open the balance valve and control the airflow assembly to stop working to regulate the air pressure in the battery pack and avoid secondary damage to the battery pack due to deformation. The balance valve is arranged on the case where the battery pack is located and communicates with the inside of the battery pack. The balance valve can be divided into three types: static balance valve, dynamic balance valve and pressure-independent balance valve.

[0114] The thermal runaway management method provided in the application, by acquiring the first temperature information of the battery cell monitoring module at the battery cell in the battery pack, the second temperature information of the temperature monitoring circuit at the battery cell, and the first collection information of the fire-fighting assembly in the battery pack, when at least one of the first temperature information, the second temperature information and the first collection information is abnormal, the thermal runaway area in the battery pack is determined, and the fire-fighting assembly is controlled to execute extinguishing in the interior of the battery pack and the gas collection assembly is controlled to collect the gas in the interior of the battery pack. Not only the monitoring of the thermal runaway of the battery cell is realized, but also the thermal runaway diffusion in the battery pack can be timely controlled, and after the thermal runaway of other battery cells is triggered, the waste gas generated by the thermal runaway can be timely treated, so that the safety and reliability of the battery pack are effectively improved.

Claims

1. A thermal runaway management system (10), comprising: a battery monitoring circuit (100) disposed inside a battery pack and electrically connected to a battery cell (20) in the battery pack; a fire extinguishing assembly (200) disposed inside the battery pack and electrically connected to the battery monitoring circuit (100); a gas collection assembly (300) electrically connected to the battery monitoring circuit (100) and in communication with the inside of the battery pack; wherein the battery monitoring circuit (100) is configured to at least monitor a temperature of the battery cell (20) and control the fire extinguishing assembly (200) to perform fire extinguishing inside the battery pack and control the gas collection assembly (300) to collect gas inside the battery pack.

2. The thermal runaway management system (10) of claim 1, wherein, The battery monitoring circuit (100) comprises: a battery cell monitoring module (101) electrically connected to the battery cell (20); a temperature monitoring circuit (102) electrically connected to the battery cell monitoring module (101) and configured to monitor a temperature of the battery cell (20); The battery cell monitoring module (101) is configured to monitor a state of the battery and control the fire extinguishing assembly (200) to perform fire extinguishing inside the battery pack and control the gas collection assembly (300) to collect gas inside the battery pack.

3. The thermal runaway management system (10) of claim 2, wherein, The battery cell monitoring module (101) comprises a slave module of a battery management system to which the battery pack belongs.

4. The thermal runaway management system (10) of claim 2, wherein, The temperature monitoring circuit (102) comprises a thermal switch; One end of the thermal switch is electrically connected to one end of the battery cell (20), and the other end of the thermal switch is electrically connected to the battery cell monitoring module (101).

5. The thermal runaway management system (10) according to any one of claims 1-4, wherein, The fire extinguishing assembly (200) comprises a smoke detector (201) and a fire extinguishing module (202); The smoke detector (201) and the fire extinguishing module (202) are electrically connected to the battery monitoring circuit (100), the smoke detector (201) is configured to detect smoke inside the battery pack, and the fire extinguishing module (202) is configured to perform fire extinguishing inside the battery pack.

6. The thermal runaway management system (10) of claim 5, wherein, The fire extinguishing assembly (200) further comprises a fire control module (203); The fire control module (203) is electrically connected to the battery monitoring circuit (100), the smoke detector (201), and the fire extinguishing module (202), respectively, and the fire control module (203) is configured to control the fire extinguishing module (202) to perform fire extinguishing inside the battery pack.

7. The thermal runaway management system (10) according to any one of claims 1-6, wherein, The gas collection assembly (300) comprises a gas collection pipeline (301), and the battery pack is provided with a gas permeable valve (30); wherein the gas collection pipeline (301) is disposed outside the battery pack; one end of the gas collection pipeline (301) is in communication with one end of the gas permeable valve (30), and the other end of the gas permeable valve (30) is in communication with the inside of the battery pack.

8. The thermal runaway management system (10) of claim 7, wherein, The battery pack is further provided with a balance valve, one end of the balance valve is in communication with the inside of the battery pack, and the other end of the balance valve is in communication with the outside of the battery pack.

9. The thermal runaway management system (10) of claim 7, wherein, The gas collection assembly (300) further comprises an air flow assembly (302) and a backup power supply (303); The airflow assembly (302) is electrically connected to the battery monitoring circuit (100) and the backup power supply (303), and is configured to sequentially discharge the gas inside the battery pack through the gas permeable valve (30) and the gas collection pipeline (301).

10. A thermal runaway management method applied to a battery pack, the battery pack comprising a thermal runaway management system (10), the thermal runaway management system (10) comprising a cell monitoring module (101), a temperature monitoring circuit (102), a fire extinguishing assembly (200) and a gas collection assembly (300); the method comprising: obtaining first temperature information collected by the cell monitoring module (101) at a cell (20) in the battery pack, second temperature information collected by the temperature monitoring circuit (102) at the cell (20), and first collection information collected by the fire extinguishing assembly (200) in the battery pack; if at least one of the first temperature information, the second temperature information and the first collection information is abnormal, determining a thermal runaway area in the battery pack; controlling the fire extinguishing assembly (200) to perform fire extinguishing at the thermal runaway area, and controlling the gas collection assembly (300) to collect the gas inside the battery pack.

11. The thermal runaway management method of claim 10, wherein, The temperature monitoring circuit (102) comprises a thermal sensitive switch; Before the determination of the thermal runaway area in the battery pack, further comprising: if the first temperature information is that the temperature of the cell (20) is higher than a preset temperature, determining whether the second temperature information is disconnection information of the thermal sensitive switch; if the second temperature information is the disconnection information, determining that the cell (20) at the thermal sensitive switch is in thermal runaway.

12. The thermal runaway management method of claim 10, wherein, The temperature monitoring circuit (102) comprises a thermal sensitive switch; Before the determination of the thermal runaway area in the battery pack, further comprising: if the first temperature information is that the temperature of the cell (20) is higher than a preset temperature, determining whether the first collection information is preset first information; if the first collection information is the preset first information, determining that the cell (20) is in thermal runaway.

13. The thermal runaway management method of claim 10, wherein, The temperature monitoring circuit (102) comprises a thermal sensitive switch; Before the determination of the thermal runaway area in the battery pack, further comprising: if the second temperature information is disconnection information of the thermal sensitive switch, determining whether the first collection information is preset first information; if the first collection information is the preset first information, determining that the cell (20) is in thermal runaway.

14. The thermal runaway management method of claim 10, wherein, The determination of the thermal runaway area in the battery pack comprises: obtaining position information of the cell (20); determining the thermal runaway area in the battery pack according to the position information.

15. The thermal runaway management method of any one of claims 10-14, wherein, The temperature monitoring circuit (102) comprises a plurality of thermal sensitive switches, each of the cells (20) corresponds to one of the thermal sensitive switches, the battery pack is provided with a gas permeable valve (30), and the gas collection assembly (300) comprises an airflow assembly (302) and a gas collection pipeline (301); The control of the gas collection assembly (300) to collect the gas inside the battery pack comprises: start the airflow assembly (302) to reduce the pressure inside the gas collection pipeline (301); after a preset first time, obtaining the on-off information of the thermal switch at the cell (20) in the battery pack that does not appear thermal runaway; if the on-off information is the off information of the thermal switch, opening the gas permeable valve (30) to sequentially discharge the gas in the battery pack from the gas permeable valve (30) and the gas collection pipeline (301).

16. The thermal runaway management method of claim 15, wherein, The battery pack is also provided with a balance valve; after the opening of the gas permeable valve (30) to sequentially discharge the gas in the battery pack from the gas permeable valve (30) and the gas collection pipeline (301), further comprising: after a preset second time, obtaining the second collection information of the fire-fighting assembly (200) in the battery pack; if the second collection information is a preset second information, opening the balance valve and controlling the airflow assembly (302) to stop working.

17. A battery pack comprising the thermal runaway management system (10) of any one of claims 1-9.

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