Explosion-proof device for lithium battery

Abstract

The lithium battery explosion-proof device comprises a lithium battery pack, a fire detection tube and a fire extinguishing storage tank, the lithium battery pack comprises a plurality of single batteries, each single battery is provided with an explosion-proof valve, the fire detection tube is communicated with the fire extinguishing storage tank, the fire detection tube is arranged outside the lithium battery pack, the fire detection tube is provided with a plurality of monitoring sections, and the number of the monitoring sections is the same as that of the single batteries; and each monitoring section is positively opposite to the anti-explosion valve of each single battery. Therefore, when the single battery is in thermal runaway, the internal pressure of the battery is increased, the anti-explosion valve bursts, high-temperature and high-pressure gas is sprayed out of the anti-explosion valve and is sprayed to the monitoring section of the fire trace tube opposite to the anti-explosion valve, and after the monitoring section is broken, the fire extinguishing medium of the fire extinguishing storage tank can be sprayed to the single battery along the monitoring section of the fire trace tube, so that rapid and accurate fire extinguishing is achieved; safety accident risks are reduced, and safe and stable operation of the lithium battery energy storage system is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of lithium battery safety technology, and more specifically, to a lithium battery explosion-proof device. Background Art

[0002] Lithium-ion battery energy storage systems, with their long lifespan and high efficiency, are widely used in power generation, grid, and user applications. However, issues such as material defects, poor manufacturing controls, control failures, and misuse can easily trigger thermal runaway in lithium-ion batteries, releasing large amounts of heat that can spread and cause serious safety incidents such as fires and explosions.

[0003] In terms of thermal runaway firefighting, the battery management system receives alarm signals and then controls the spraying of fire extinguishing media into the battery pack. However, the response speed is slow, and it is impossible to accurately locate the fire source and extinguish the fire, making it difficult to effectively prevent the spread of the fire and achieve the ideal safety protection effect.

[0004] Based on this, how to develop a new lithium battery safety structure to quickly and accurately extinguish fires, reduce the risk of safety accidents, and ensure the safe and stable operation of lithium battery energy storage systems is an issue that needs attention. Summary of the Invention

[0005] In view of the above problems, the present application provides a lithium battery explosion-proof device to quickly and accurately extinguish fires, reduce the risk of safety accidents, and ensure the safe and stable operation of lithium battery energy storage systems.

[0006] In order to achieve the above objectives, the following specific plans are proposed:

[0007] A lithium battery explosion-proof device, comprising a lithium battery pack, a fire detection tube and a fire extinguishing storage tank;

[0008] The lithium battery pack includes a plurality of single cells, each of which is provided with an explosion-proof valve;

[0009] The fire detection tube is connected to the fire extinguishing tank and is arranged outside the lithium battery pack. The fire detection tube is provided with a plurality of monitoring sections, the number of which is the same as that of the single cells. Each monitoring section is positively opposite to the explosion-proof valve of each single cell.

[0010] Optionally, the lithium battery explosion-proof device is used for:

[0011] For each single cell, when thermal runaway occurs in the single cell, the internal pressure of the single cell increases to a first pressure value. When the internal pressure of the single cell increases to the first pressure value, the explosion-proof valve of the single cell bursts and sprays high-temperature and high-pressure gas toward a target monitoring section that is directly opposite to the explosion-proof valve. The target monitoring section ruptures under the high-temperature and high-pressure gas and releases the fire extinguishing medium from the fire extinguishing tank toward the single cell.

[0012] Optionally, each explosion-proof valve is provided with a protruding structure.

[0013] Optionally, the lithium battery explosion-proof device is used for:

[0014] For each single cell, when thermal runaway occurs in the single cell, the internal pressure of the single cell increases to a first pressure value. When the internal pressure of the single cell increases to the first pressure value, the explosion-proof valve of the single cell bursts and sprays high-temperature and high-pressure gas toward the protruding structure. After the protruding structure bursts, the single cell continues to spray the high-temperature and high-pressure gas toward the target monitoring section. The target monitoring section ruptures under the high-temperature and high-pressure gas and releases the fire extinguishing medium from the fire extinguishing tank toward the single cell.

[0015] Optionally, the lithium battery explosion-proof device also includes a battery management system, a pole piece is connected between two adjacent single batteries, each pole piece includes a thermistor, each thermistor is connected to the battery management system, and the battery management system is connected to the lithium battery pack.

[0016] Optionally, the lithium battery explosion-proof device is used for:

[0017] For each thermistor, the battery management system monitors the resistance of the thermistor and calculates the voltage change rate of the two single batteries connected to the thermistor based on the resistance. When the voltage change rate exceeds a preset voltage change rate standard, the battery management system sends a power reduction operation instruction or a shutdown instruction to the lithium battery pack.

[0018] Optionally, the fire extinguishing medium stored in the fire extinguishing tank is in a high-pressure state, and the fire extinguishing tank is equipped with a pressure sensor for monitoring the internal pressure of the fire extinguishing tank. The pressure sensor is connected to the battery management system to transmit the internal pressure of the fire extinguishing tank to the battery management system in real time.

[0019] Optionally, the lithium battery explosion-proof device is used for:

[0020] For each single cell, when thermal runaway occurs in the single cell, the internal pressure of the single cell increases to a first pressure value. When the internal pressure of the single cell increases to the first pressure value, the explosion-proof valve of the single cell bursts and sprays high-temperature and high-pressure gas toward a target monitoring section that is directly opposite to the explosion-proof valve. The pressure inside the fire extinguishing tank increases under the action of the high-temperature and high-pressure gas. The battery management system transmits a pressure relief signal to the fire extinguishing tank based on a pressure increase signal of the pressure inside the tank. The fire extinguishing tank changes the high-pressure state of the fire extinguishing medium into a pressure relief state based on the pressure relief signal, so that the fire extinguishing medium is sprayed toward the single cell through the target monitoring section in a pressure relief manner.

[0021] Optionally, each monitoring section is provided with a support base.

[0022] Optionally, each thermistor is a positive temperature coefficient thermistor.

[0023] By means of the above technical solution, the lithium battery explosion-proof device of the present application includes a lithium battery pack, a fire detection tube and a fire extinguishing tank. The lithium battery pack includes a plurality of single cells, each of which is provided with an explosion-proof valve. The fire detection tube is connected to the fire extinguishing tank. The fire detection tube is arranged on the outside of the lithium battery pack. The fire detection tube is provided with a plurality of monitoring segments, which is the same as the number of single cells. Each monitoring segment is directly opposite to the explosion-proof valve of each single cell. It can be seen that when a single cell thermally runs away, the internal pressure of the battery increases, the explosion-proof valve bursts, and high-temperature and high-pressure gas is ejected from the explosion-proof valve and sprayed toward the monitoring segment of the fire detection tube arranged opposite to the explosion-proof valve. After the monitoring segment ruptures, the fire extinguishing medium of the fire extinguishing tank can be sprayed toward the single cell along the monitoring segment of the fire detection tube, thereby achieving rapid and accurate fire extinguishing, reducing the risk of safety accidents, and ensuring the safe and stable operation of the lithium battery energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0025] Figure 1 A schematic diagram of the structure of a lithium battery explosion-proof device provided in an embodiment of the present application;

[0026] Figure 2 Another structural diagram of the lithium battery explosion-proof device provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of an operating mode of the lithium battery explosion-proof device provided in an embodiment of the present application to cope with high battery temperatures.

[0028] In the attached figure, 1-fire detection tube, 2-support seat, 3-explosion-proof valve, 4-thermistor, 5-single battery, 6-lithium battery pack, 7-fire extinguishing tank. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] Figure 1 and Figure 2 An optional structure of a lithium battery explosion-proof device provided in an embodiment of the present application, such as Figure 1 As shown, the device structure may include:

[0031] Lithium battery pack 6, fire detection tube 1 and fire extinguishing tank 7.

[0032] Specifically, the lithium battery pack 6 may include a plurality of single cells 5. More specifically, the lithium battery pack 6 may include a casing, which is sealed and in which a plurality of single cells 5 may be disposed.

[0033] The fire detection tube 1 can be connected to the fire extinguishing tank 7, which can store fire extinguishing medium. Specifically, one end of the fire detection tube 1 can be connected to the inside of the fire extinguishing tank 7 so that the fire extinguishing medium flows into the inside of the fire detection tube 1.

[0034] Furthermore, each cell 5 is equipped with an explosion-proof valve 3 to prevent the cell 5 from exploding within a short period of time after a sudden thermal runaway. Specifically, if the temperature of the cell 5 rises sharply during charging or discharging, the internal resistance of the lithium battery pack 6 increases, and the battery voltage suddenly drops within a short period of time, the internal pressure of the cell 5 increases, causing the explosion-proof valve 3 to rupture, and high-temperature, high-pressure gas to be ejected from the explosion-proof valve, thereby preventing the cell 5 from exploding suddenly.

[0035] Furthermore, the fire detection tube 1 can be arranged outside the lithium battery pack 6. The fire detection tube 1 is provided with a plurality of monitoring sections, the same number as the single cells 5. Each monitoring section is directly opposite to the explosion-proof valve 3 of each single cell 5.

[0036] Among them, such as Figure 1 As shown, the fire detection tube 1 can be a multi-section curved structure, so that the fire detection tube 1 passes through each single battery 5, and the explosion-proof valve 3 of each single battery 5 is positively opposite to a monitoring section of the fire detection tube 1, so that after the explosion-proof valve 3 bursts, high-temperature and high-pressure gas can be ejected toward the monitoring section. When the monitoring section needs to spray the fire extinguishing medium, it can be accurately sprayed to the target single battery 5.

[0037] Based on the structure of the lithium battery explosion-proof device described in this embodiment, the lithium battery explosion-proof device provided in this application can include the following working processes in terms of thermal runaway fire protection:

[0038] For each single cell 5, when thermal runaway occurs in the single cell 5, the internal pressure of the single cell 5 increases to a first pressure value. When the internal pressure of the single cell 5 increases to the first pressure value, the explosion-proof valve 3 of the single cell 5 bursts and sprays high-temperature and high-pressure gas toward the target monitoring section that is positively opposite to the explosion-proof valve 3. The target monitoring section ruptures under the high-temperature and high-pressure gas and releases the fire extinguishing medium from the fire extinguishing tank 7 to the single cell 5.

[0039] The first pressure value may indicate a pressure threshold at which the explosion-proof valve 3 of the single battery 5 cannot withstand the internal pressure of the battery. When the internal pressure of the single battery 5 increases to the first pressure value, the explosion-proof valve 3 may burst due to being unable to withstand the internal pressure of the battery.

[0040] The lithium battery explosion-proof device provided in this embodiment includes a lithium battery pack, a fire detection tube, and a fire extinguishing tank. The lithium battery pack includes multiple single cells, each of which is equipped with an explosion-proof valve. The fire detection tube is connected to the fire extinguishing tank and is arranged on the outside of the lithium battery pack. The fire detection tube is provided with multiple monitoring segments, the same number as the single cells, and each monitoring segment is directly opposite the explosion-proof valve of each single cell. As can be seen, when a single cell thermally runs away, the internal pressure of the battery increases, the explosion-proof valve bursts, and high-temperature and high-pressure gas is ejected from the explosion-proof valve toward the monitoring segment of the fire detection tube arranged directly opposite the explosion-proof valve. After the monitoring segment ruptures, the fire extinguishing medium in the fire extinguishing tank can be sprayed along the monitoring segment of the fire detection tube toward the single cell, achieving rapid and accurate fire extinguishing, reducing the risk of safety accidents, and ensuring the safe and stable operation of the lithium battery energy storage system.

[0041] In some embodiments of the present application, the lithium battery explosion-proof device mentioned in the aforementioned embodiment is further described. The explosion-proof valve 3 of each single battery 5 of the lithium battery pack 6 of the lithium battery explosion-proof device may be provided with a protruding structure.

[0042] Specifically, since the monitoring section of the fire detection tube 1 is directly opposite to the explosion-proof valve 3, when the explosion-proof valve 3 bursts and ejects high-temperature and high-pressure gas, in order to avoid excessive damage to the monitoring section, the protruding structure can be used to buffer the impact force of the high-temperature and high-pressure gas when it is ejected.

[0043] Based on the structure of the lithium battery explosion-proof device described in this embodiment, the lithium battery explosion-proof device provided in this application can include the following working processes in terms of thermal runaway fire protection:

[0044] For each single cell 5, when thermal runaway occurs in the single cell 5, the internal pressure of the single cell 5 increases to a first pressure value. When the internal pressure of the single cell 5 increases to the first pressure value, the explosion-proof valve 3 of the single cell 5 bursts and sprays high-temperature and high-pressure gas toward the protruding structure. After the protruding structure bursts, the single cell 5 continues to spray the high-temperature and high-pressure gas toward the target monitoring section. The target monitoring section ruptures under the high-temperature and high-pressure gas and releases the fire extinguishing medium from the fire extinguishing tank 7 to the single cell 5.

[0045] It is understandable that when the explosion-proof valve 3 of the single battery 5 bursts and ejects high-temperature and high-pressure gas to the target monitoring section, the protruding structure of the explosion-proof valve 3 can slow down or offset part of the impact force of the high-temperature and high-pressure gas, thereby preventing the target monitoring section from being excessively damaged.

[0046] In some embodiments of the present application, the lithium battery explosion-proof device mentioned in the above embodiments is further introduced. The lithium battery explosion-proof device may also include a battery management system.

[0047] Specifically, such as Figure 1 As shown, a pole piece is connected between two adjacent single batteries, and each pole piece includes a thermistor 4.

[0048] The thermistor 4 may be a positive temperature coefficient (PTC) thermistor, which can increase its resistance under the influence of high temperature of the two connected single batteries 5 .

[0049] Furthermore, each thermistor 4 can be connected to a battery management system. The battery management system is connected to the lithium battery pack 6 to transmit battery system operating instructions to the lithium battery pack 6 in real time, so as to avoid thermal runaway of the battery system as much as possible.

[0050] Based on the structure of the lithium battery explosion-proof device described in this embodiment, the lithium battery explosion-proof device provided in this application may include the following response processes when the battery experiences high temperature:

[0051] For each thermistor 4, the battery management system monitors the resistance of the thermistor 4 and calculates the voltage change rate of the two single cells 5 connected to the thermistor 4 based on the resistance. When the voltage change rate exceeds the preset voltage change rate standard, the battery management system sends a power reduction operation instruction or a shutdown instruction to the lithium battery pack 6.

[0052] It is understandable that when the battery temperature rises sharply during the charge and discharge process, the resistance of thermistors 4 in the electrodes between adjacent cells 5 increases, increasing the internal resistance of the battery pack and causing the battery voltage to drop sharply within a short period of time. Consequently, the rate of change of the voltage of the two cells 5 increases. At this point, the battery management system can send a power reduction or shutdown command to the lithium battery pack 6 to prevent the battery from continuing to heat up and potentially developing thermal runaway. Furthermore, by leveraging the characteristics of positive temperature coefficient thermistors to detect changes in the electrical signal caused by battery temperature rise, the battery management system can monitor battery temperature and prevent thermal runaway, reducing the cost of the temperature sensing structure and increasing the speed of temperature signal acquisition.

[0053] In some embodiments of the present application, the lithium battery explosion-proof device mentioned in the above embodiments is further introduced. The fire extinguishing medium stored in the fire extinguishing tank 7 can be in a high-pressure state. The fire extinguishing tank 7 can be equipped with a pressure sensor for monitoring the internal pressure of the fire extinguishing tank 7. The pressure sensor can be connected to the battery management system to transmit the internal pressure of the fire extinguishing tank 7 to the battery management system in real time.

[0054] Based on the structure of the lithium battery explosion-proof device described in this embodiment, the lithium battery explosion-proof device provided in this application can determine whether the battery system is in thermal runaway by monitoring the pressure inside the fire extinguishing tank 7 through the battery management system. Specifically, the following process may be included:

[0055] For each single cell 5, when thermal runaway occurs in the single cell 5, the internal pressure of the single cell 5 increases to a first pressure value. When the internal pressure of the single cell 5 increases to the first pressure value, the explosion-proof valve 3 of the single cell 5 bursts and sprays high-temperature and high-pressure gas toward the target monitoring section that is positively opposite to the explosion-proof valve 3. The pressure inside the fire extinguishing tank 7 increases under the action of the high-temperature and high-pressure gas. The battery management system transmits a pressure relief signal to the fire extinguishing tank 7 based on the pressure increase signal of the pressure inside the tank. The fire extinguishing tank 7 changes the high-pressure state of the fire extinguishing medium to a pressure relief state based on the pressure relief signal, so that the fire extinguishing medium passes through the target monitoring section and is sprayed toward the single cell 5 in a pressure relief manner.

[0056] In some embodiments of the present application, the lithium battery explosion-proof device mentioned in the above embodiment is further introduced, such as Figure 1 As shown, each monitoring section of the fire detection tube 1 can be provided with a support base 2 .

[0057] It can be understood that a support base 2 is designed on the monitoring section to support the fire detection tube 1 and maintain the fire detection tube 1 horizontally without tilting. Therefore, it can ensure that when the sprayed fire extinguishing medium directly acts on the fire detection tube 1, it can prevent it from spreading to other single cells 5, thereby realizing the monitoring section to accurately extinguish the corresponding single cell 5.

[0058] In some embodiments of the present application, the process of how the lithium battery explosion-proof device responds to different conditions caused by high battery temperature is introduced, such as Figure 3 As shown, the process may include:

[0059] When the battery cells of the lithium battery pack 6 are at a high temperature and are controllable (controllable means that the battery cells do not experience thermal runaway), step S110 is executed.

[0060] Step S110 : The resistance of the thermistor increases.

[0061] Step S120: The battery management system detects, based on the resistance value of the thermistor, that a voltage change exceeds a preset change value.

[0062] Step S130: The battery management system sends a running instruction or a shutdown instruction to the lithium battery pack.

[0063] When the batteries of the lithium battery pack 6 are at high temperature and in thermal runaway, step S210 is executed.

[0064] Step S210: The explosion-proof valve of the single battery explodes and ejects high-temperature and high-pressure gas.

[0065] Step S220: The monitoring section of the fire detection tube sprays the fire extinguishing medium toward the single battery at a fixed point.

[0066] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0067] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referenced to each other.

[0068] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lithium battery explosion-proof device, characterized in that: Including lithium battery pack, fire detection tube and fire extinguishing tank; The lithium battery pack includes a plurality of single cells, each of which is provided with an explosion-proof valve; The fire detection tube is connected to the fire extinguishing tank and is arranged outside the lithium battery pack. The fire detection tube is provided with a plurality of monitoring sections, the number of which is the same as that of the single cells. Each monitoring section is positively opposite to the explosion-proof valve of each single cell.

2. The lithium battery explosion-proof device according to claim 1, characterized in that: The lithium battery explosion-proof device is used for: For each single cell, when thermal runaway occurs in the single cell, the internal pressure of the single cell increases to a first pressure value. When the internal pressure of the single cell increases to the first pressure value, the explosion-proof valve of the single cell bursts and sprays high-temperature and high-pressure gas toward a target monitoring section that is directly opposite to the explosion-proof valve. The target monitoring section ruptures under the high-temperature and high-pressure gas and releases the fire extinguishing medium from the fire extinguishing tank toward the single cell.

3. The lithium battery explosion-proof device according to claim 1, characterized in that: Each explosion-proof valve is provided with a protruding structure.

4. The lithium battery explosion-proof device according to claim 3, characterized in that: The lithium battery explosion-proof device is used for: For each single cell, when thermal runaway occurs in the single cell, the internal pressure of the single cell increases to a first pressure value. When the internal pressure of the single cell increases to the first pressure value, the explosion-proof valve of the single cell bursts and sprays high-temperature and high-pressure gas toward the protruding structure. After the protruding structure bursts, the single cell continues to spray the high-temperature and high-pressure gas toward the target monitoring section. The target monitoring section ruptures under the high-temperature and high-pressure gas and releases the fire extinguishing medium from the fire extinguishing tank toward the single cell.

5. The lithium battery explosion-proof device according to claim 1, characterized in that: The lithium battery explosion-proof device also includes a battery management system. A pole piece is connected between two adjacent single batteries. Each pole piece includes a thermistor. Each thermistor is connected to the battery management system, and the battery management system is connected to the lithium battery pack.

6. The lithium battery explosion-proof device according to claim 5, characterized in that: The lithium battery explosion-proof device is used for: For each thermistor, the battery management system monitors the resistance of the thermistor and calculates the voltage change rate of the two single batteries connected to the thermistor based on the resistance. When the voltage change rate exceeds a preset voltage change rate standard, the battery management system sends a power reduction operation instruction or a shutdown instruction to the lithium battery pack.

7. The lithium battery explosion-proof device according to claim 5, characterized in that: The fire extinguishing medium stored in the fire extinguishing tank is in a high-pressure state. The fire extinguishing tank is equipped with a pressure sensor for monitoring the internal pressure of the fire extinguishing tank. The pressure sensor is connected to the battery management system to transmit the internal pressure of the fire extinguishing tank to the battery management system in real time.

8. The lithium battery explosion-proof device according to claim 7, characterized in that: The lithium battery explosion-proof device is used for: For each single cell, when thermal runaway occurs in the single cell, the internal pressure of the single cell increases to a first pressure value. When the internal pressure of the single cell increases to the first pressure value, the explosion-proof valve of the single cell bursts and sprays high-temperature and high-pressure gas toward a target monitoring section that is directly opposite to the explosion-proof valve. The pressure inside the fire extinguishing tank increases under the action of the high-temperature and high-pressure gas. The battery management system transmits a pressure relief signal to the fire extinguishing tank based on a pressure increase signal of the pressure inside the tank. The fire extinguishing tank changes the high-pressure state of the fire extinguishing medium into a pressure relief state based on the pressure relief signal, so that the fire extinguishing medium is sprayed toward the single cell through the target monitoring section in a pressure relief manner.

9. The lithium battery explosion-proof device according to any one of claims 1 to 8, characterized in that: Each monitoring section is provided with a support base.

10. The lithium battery explosion-proof device according to any one of claims 5 to 8, characterized in that: Each thermistor is a positive temperature coefficient thermistor.

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