Fire extinguishing device and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a fire extinguishing device and a battery pack, the fire extinguishing device is installed inside a shell of the battery pack, the fire extinguishing device comprises a shell, a packaging piece and a blasting assembly, the shell is provided with a storage cavity and an installation cavity, the end, away from the storage cavity, of the installation cavity is open, and the storage cavity is used for storing fire extinguishing media; the packaging piece is installed on the shell and used for isolating the storage cavity from the installation cavity, the blasting assembly is connected to the open end of the installation cavity, and the blasting assembly and the packaging piece are arranged in a spaced mode. The fire extinguishing device can be triggered and release the fire extinguishing medium when the internal pressure of the battery pack is increased, a sensor and control software are not needed, the manufacturing cost is low, and the reliability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a fire extinguishing device and a battery pack. Background Art

[0002] As the sales and ownership of electric vehicles increase, the thermal safety performance of electric vehicle power batteries, as core components, involves personal safety. Therefore, many thermal safety control solutions have emerged, among which the addition of fire extinguishing devices in battery packs is becoming more and more widely used. Currently, commonly used fire extinguishing devices often integrate pressure sensors and smoke sensors, etc., which detect the pressure and smoke status in the battery pack and use software strategies to control the triggering of the fire protection switch to trigger fire protection; however, fire protection devices using sensors and software control solutions are expensive, poor in economic efficiency, and rely on control software to start, which is dependent on electronic control and has reliability issues. Utility Model Content

[0003] The first object of the utility model is to provide a fire extinguishing device, which can be triggered and release a fire extinguishing medium when the internal pressure of a battery pack increases, does not require sensors and control software, has low manufacturing costs and high reliability.

[0004] The second object of the utility model is to provide a battery pack, which can cool down the battery cells and extinguish the fire in time when the battery cells are in thermal runaway, and the battery pack does not require sensor detection and software control during the fire extinguishing process, and has high reliability.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a fire extinguishing device, which is installed inside the shell of a battery pack, and comprises: a shell, wherein the shell has a storage cavity and an installation cavity, wherein the installation cavity is open at one end away from the storage cavity, and the storage cavity is used to store a fire extinguishing medium; a packaging component, wherein the packaging component is installed on the shell and is used to isolate the storage cavity and the installation cavity; and a blasting component, wherein the blasting component is connected to the open end of the installation cavity and is spaced apart from the packaging component; wherein the blasting component can destroy the packaging component so that the storage cavity and the installation cavity are connected, and the fire extinguishing medium in the storage cavity can diffuse from the storage cavity through the installation cavity into the shell.

[0007] In some embodiments, the shell includes a storage shell and a mounting shell, the storage shell defines the storage cavity, the mounting shell defines the mounting cavity, the storage shell is provided with a pressure relief hole, and the packaging component is installed on the storage shell or the mounting shell to encapsulate the pressure relief hole.

[0008] In some specific embodiments, the shell includes a storage shell, and the storage shell is used to define the storage cavity, the storage shell includes a tank body and a cover body, one end of the tank body is open and the other end is closed, and the cover body is sealingly connected to the open end of the tank body; a one-way valve is provided on the cover body or the tank body, and the fire extinguishing medium is filled into the storage cavity from the one-way valve.

[0009] In some more specific embodiments, the cover body includes a cover plate and a plug-in ring, the plug-in ring is inserted into the tank body, and the cover plate is sealingly connected to the end surface of the open end of the tank body.

[0010] In some embodiments, the explosion assembly includes an explosion-proof component and a movable component, the explosion-proof component is connected to the inner wall of the installation cavity, the movable component is connected to the explosion-proof component, and the explosion-proof component can be ruptured under the action of pressure difference so that the movable component destroys the packaging component.

[0011] In some specific embodiments, the movable part has a flange portion and a piercing portion connected to the flange portion, a surface of the flange portion facing away from the piercing portion is connected to the explosion-proof part, and the piercing portion is arranged toward the packaging part.

[0012] In some specific embodiments, the fire extinguishing device further includes a guide member, one end of which is connected to the packaging member, and the other end of which is spaced apart from the explosion-proof member, and the guide member is used to limit the movement direction of the movable member.

[0013] In some specific embodiments, the explosion-proof component has a bottom wall and a peripheral wall arranged around the bottom wall, the peripheral wall is connected to the inner peripheral wall of the installation cavity, and the bottom wall is provided with a notch, which is located radially inward of the connection position between the peripheral wall and the bottom wall.

[0014] In some embodiments, a mounting portion is provided on the outer wall of the shell, and the fire extinguishing device is fixed in the outer shell of the battery pack by a connector passing through the mounting portion.

[0015] The utility model discloses a battery pack, comprising a shell, a battery cell and the fire extinguishing device as described above, wherein the fire extinguishing device and the battery cell are both arranged in the shell, and when the battery cell has thermal runaway, the fire extinguishing medium in the fire extinguishing device can diffuse to the shell.

[0016] The beneficial effects of the fire extinguishing device of the utility model are as follows: since the blasting assembly is connected to the open end of the installation cavity, that is, of the two surfaces of the blasting assembly arranged opposite to each other, one surface contacts the gas in the battery pack shell, and the other surface contacts the gas in the installation cavity, when the battery cell of the battery pack has thermal runaway, the battery cell will release a large amount of gas so that the air pressure inside the shell suddenly increases, so that there is a pressure difference between the inside of the shell and the installation cavity, and this pressure difference can cause the blasting assembly to rupture and destroy the packaging component isolating the storage cavity and the installation cavity, so that the storage cavity and the installation cavity are connected, and the fire extinguishing medium stored in the storage cavity can diffuse from the storage cavity through the installation cavity into the shell, cooling the battery cell and extinguishing the fire. Therefore, the fire extinguishing device of the utility model is triggered by the pressure difference change between the inside of the battery pack shell and the installation cavity during operation, so as to realize the release of the fire extinguishing medium, without the need for sensors and control software, with high reliability and low manufacturing cost.

[0017] The battery pack of the utility model has the beneficial effects as follows: due to the fire extinguishing device described above, the battery pack can cool down the battery cells and extinguish the fire in time when the battery cells are in thermal runaway, and the battery pack fire extinguishing process does not require sensor detection and software control, and has high reliability.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a fire extinguishing device according to an embodiment of the utility model;

[0020] Figure 2 It is another structural schematic diagram of the fire extinguishing device of the embodiment of the utility model;

[0021] Figure 3 It is an exploded schematic diagram of a fire extinguishing device according to an embodiment of the utility model;

[0022] Figure 4 It is an exploded schematic diagram of the lower half structure of the fire extinguishing device of the embodiment of the utility model;

[0023] Figure 5 It is an exploded schematic diagram of the upper part of the structure of the fire extinguishing device of the embodiment of the utility model;

[0024] Figure 6 yes Figure 5 A schematic structural diagram of the structure shown in another direction.

[0025] Reference numerals:

[0026] 100, housing; 110, storage housing; 111, tank body; 1111, mounting portion; 112, cover body; 1121, cover plate; 11211, pressure relief hole; 1122, plug-in ring; 120, mounting housing;

[0027] 200, packaging;

[0028] 300, blasting assembly; 310, explosion-proof component; 311, bottom wall; 3111, notch; 312, peripheral wall; 320, movable part; 321, flange; 322, piercing part; 3221, connecting rod; 3222, cone head;

[0029] 400. Guide member; 500. Check valve. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0034] The utility model discloses a fire extinguishing device, which is installed inside the shell of a battery pack. Figure 1 and Figure 2 As shown, the fire extinguishing device includes a housing 100, a packaging member 200 and an explosion assembly 300. The housing 100 has a storage cavity and an installation cavity, and the installation cavity is open at one end away from the storage cavity. The storage cavity is used to store the fire extinguishing medium. The packaging member 200 is installed on the housing 100 and is used to isolate the storage cavity and the installation cavity. The explosion assembly 300 is connected to the open end of the installation cavity and is spaced apart from the packaging member 200.

[0035] It is understandable that, since the blasting assembly 300 is connected to the open end of the installation cavity, that is, of the two surfaces of the blasting assembly 300 that are arranged opposite to each other, one surface is in contact with the gas in the shell, and the other surface is in contact with the gas in the installation cavity, when the battery cell of the battery pack has thermal runaway, the battery cell will release a large amount of gas, causing the air pressure inside the shell to suddenly increase, so that there is a pressure difference between the inside of the shell and the installation cavity, and this pressure difference can cause the blasting assembly 300 to rupture and destroy the package 200 that isolates the storage cavity and the installation cavity, so that the storage cavity and the installation cavity are connected, and the fire extinguishing medium stored in the storage cavity can be diffused from the storage cavity through the installation cavity into the shell, cooling the battery cell and extinguishing the fire. The fire extinguishing device of this embodiment completely relies on the pressure difference between the inside of the shell and the installation cavity to realize the release of the fire extinguishing medium of the fire extinguishing device during operation, without the need for sensors and control software, with high reliability and low manufacturing cost.

[0036] Optionally, the fire extinguishing medium may be liquid nitrogen, liquid carbon dioxide or inert gas, etc. In the actual working process, the fire extinguishing medium can fill the entire shell, which can cool down the battery cell on the one hand, and prevent the air in the external environment from entering the shell to ignite the combustible gas emitted by the battery cell on the other hand, extinguish the fire of the battery cell that has thermal runaway, and prevent the spread of thermal runaway and explosion. Of course, in other embodiments of the utility model, the fire extinguishing medium can be selected according to actual needs and is not limited to the above limitations.

[0037] refer to Figure 2As shown, the housing 100 includes a storage shell 110 and a mounting shell 120. The storage shell 110 defines a storage cavity, and the mounting shell 120 defines a mounting cavity. The storage shell 110 is provided with a pressure relief hole 11211, and the packaging member 200 is installed on the storage shell 110 or the mounting shell 120 to encapsulate the pressure relief hole 11211. It can be understood that the housing 100 is split into two parts, the storage shell 110 and the mounting shell 120. In the actual assembly process, the fire extinguishing medium is filled into the storage shell 110, and the blasting assembly 300 is arranged on the mounting shell 120, and then the storage shell 110 and the mounting shell 120 are assembled. This assembly method of first forming small modules and then splicing is conducive to improving production efficiency.

[0038] Optionally, the installation shell 120 and the storage shell 110 can be connected by sealing adhesive, welding, or screws or other connectors in conjunction with sealing rings. Thus, the connection between the installation shell 120 and the storage shell 110 can be facilitated, and the sealing of the connection between the installation shell 120 and the storage shell 110 can be ensured, thereby avoiding the phenomenon of fire extinguishing medium leakage caused by poor sealing of the connection between the two.

[0039] Optionally, the cross-sectional shapes of the mounting shell 120 and the storage shell 110 are both circular. It is understandable that, since the fire extinguishing device needs to be installed in the outer shell of the battery pack, the entire fire extinguishing device is cylindrical in shape, which is convenient for installation and occupies a relatively small space. Of course, in other embodiments of the utility model, the cross-sectional shapes of the mounting shell 120 and the storage shell 110 can also be set to other shapes according to actual needs, such as elliptical, polygonal, etc.

[0040] refer to Figure 3 as well as Figure 4 As shown, the storage shell 110 includes a tank body 111 and a cover body 112. One end of the tank body 111 is open and the other end is closed. The cover body 112 is sealed and connected to the open end of the tank body 111. The pressure relief hole 11211 is provided on the cover body 112. A one-way valve 500 is provided on the cover body 112 or the tank body 111, and the fire extinguishing medium is filled into the storage cavity from the one-way valve 500. It can be understood that the fire extinguishing medium is filled into the storage cavity from the one-way valve 500. The one-way valve 500 can prevent the fire extinguishing medium in the storage cavity from leaking from the filling position to the outside of the storage cavity, ensuring that the fire extinguishing medium can be stably stored in the storage cavity. At the same time, since the cover body 112 is arranged toward the mounting shell 120, the pressure relief hole 11211 is provided on the cover body 112. When the packaging member 200 is damaged, the fire extinguishing medium can diffuse more quickly into the mounting cavity and fill the outer shell of the battery pack, which is conducive to ensuring the fire extinguishing effect.

[0041] Optionally, the pressure relief hole 11211 is disposed at the center of the cover 112. Thus, the fire extinguishing medium can further quickly diffuse into the installation cavity and fill the outer shell of the battery pack. Of course, in other embodiments of the present invention, the pressure relief hole 11211 can also be disposed at other positions of the cover 112.

[0042] Optionally, the package 200 is a tempered glass bonded to the cover 112, and the diameter of the tempered glass is slightly smaller than the diameter of the cover 112. It is understandable that the tempered glass can withstand high impact forces on a large surface, but will burst instantly when subjected to large stress locally. The use of tempered glass to block the pressure relief hole 11211 is not only convenient for force triggering, but also ensures that the pressure relief hole 11211 can be tightly sealed during normal operation. Of course, it should be additionally explained here that in other embodiments of the utility model, the material of the package 200, the connection relationship with the cover 112, and the size relationship with the cover 112 can be adjusted according to actual needs and are not limited to the above description.

[0043] It should be noted that the cover 112 is sealed to the open end of the tank 111 , and the sealing connection may be by adhesive bonding, welding, or other connection methods, which may be selected according to actual needs.

[0044] For further reference, Figure 3 and Figure 4 As shown, the cover body 112 includes a cover plate 1121 and a plug ring 1122, the plug ring 1122 is inserted into the tank body 111, and the cover plate 1121 is sealed and connected to the end surface of the open end of the tank body 111. It can be understood that in the actual assembly process, the plug ring 1122 is inserted into the tank body 111, so that the cover body 112 stops on the end surface of the open end of the tank body 111, and the outer wall of the tank body 111 is flush with the outer peripheral wall of the cover plate 1121, and finally the cover body 112 is connected to the tank body 111 by a sealing connection method such as welding or bonding. This can improve the connection stability between the cover body 112 and the tank body 111 on the one hand, and prevent the cover body 112 from falling off the tank body 111. On the other hand, it can ensure the sealing of the connection between the cover body 112 and the tank body 111, and prevent the fire extinguishing medium from leaking from the connection position between the two.

[0045] refer to Figure 5-Figure 6As shown, the explosion assembly 300 includes an explosion-proof component 310 and a movable component 320, the explosion-proof component 310 is connected to the inner peripheral wall of the installation cavity, and the movable component 320 is connected to the explosion-proof component 310, and the explosion-proof component 310 can be broken under the action of pressure difference, so that the movable component 320 destroys the package 200. It can be understood that the explosion-proof component 310 has the characteristics of constant pressure explosion. When designing a fire extinguishing device, the explosion-proof component 310 can be selected according to the needs of fire extinguishing, so as to ensure that when the battery cell is thermally controlled, the explosion-proof component 310 can be stably broken under the action of pressure difference to drive the movable component 320 to destroy the package 200. It should be supplemented that the explosion-proof component 310 needs to be easy to break, and the movable component 320 needs to be relatively hard and easy to puncture the package 200. The two can be separated into two connected parts and the materials of the two can be selected according to actual needs, so as to ensure that the explosion-proof component 310 can be stably broken under the action of pressure difference, and the movable component 320 can be stably destroyed.

[0046] Optionally, the explosion-proof component 310 is an explosion-proof film, and the movable component 320 is a metal component. Of course, the specific materials of the explosion-proof component 310 and the movable component 320 can also be selected according to actual needs.

[0047] Further, refer to Figure 5-Figure 6 As shown, the movable part 320 has a flange part 321 and a piercing part 322 connected to the flange part 321, the surface of the flange part 321 away from the piercing part 322 is connected to the explosion-proof part 310, and the piercing part 322 is arranged toward the packaging part 200. It can be understood that the flange part 321 has a large area, and the connection with the explosion-proof part 310 can ensure the stable connection between the movable part 320 and the explosion-proof part 310, so as to ensure that the movable part 320 can be stably driven to move when the explosion-proof part 310 ruptures under the action of the pressure difference, and the piercing part 322 has a small area, and the pressure acting on the packaging part 200 is large, which is conducive to destroying the packaging part 200.

[0048] Optionally, the piercing portion 322 includes a connecting rod 3221 and a cone head 3222, wherein the connecting rod 3221 is used to connect the flange portion 321, and the cone head 3222 is used to pierce the package 200. Of course, in other embodiments of the utility model, the piercing portion 322 can directly adopt a structure such as a screw or a thumbtack. It should be supplemented that in some embodiments, the movable member 320 is an integral structure, that is, the flange portion 321 and the piercing portion 322 are an integrally formed structure, and in some embodiments, the movable member 320 is a split structure, and the piercing portion 322 is fixed to the flange portion 321 by welding, bonding, etc., which can be selected according to actual needs.

[0049] Optionally, the explosion-proof component 310 has a bottom wall 311 and a peripheral wall 312 arranged around the bottom wall 311, the peripheral wall 312 is connected to the inner peripheral wall of the installation cavity, and the bottom wall 311 is provided with a notch 3111, and the notch 3111 is located radially inside the connection position between the peripheral wall 312 and the bottom wall 311. It is understandable that the peripheral wall 312 can be connected to the inner peripheral wall of the installation cavity by gluing or the like, which can ensure that the explosion-proof component 310 is stably connected to the installation shell 120, and the notch 3111 is provided on the bottom wall 311, which can more conveniently realize the rupture of the explosion-proof component 310 under the action of the pressure difference, so as to ensure the fire extinguishing process. Further, the notch 3111 is located on the circumferential outer side of the outer peripheral wall of the flange part 321. It is understandable that since the bottom wall 311 is connected to the flange part 321, the notch 3111 and the flange part 321 are avoided, which can avoid the flange part 321 from having an adverse effect on the normal rupture of the bottom wall 311.

[0050] Furthermore, the fire extinguishing device further comprises a guide member 400, one end of which is connected to the packaging member 200, and the other end of which is spaced apart from the explosion-proof member 310, and the guide member 400 is used to limit the movement direction of the piercing portion 322. It is understandable that in the actual working process, when the explosion-proof member 310 is destroyed under the pressure difference and drives the movement of the movable member 320, if the movement direction of the movable member 320 is skewed, it is easy for the piercing portion 322 to fail to stably pierce the packaging member 200. In this embodiment, the additional guide member 400 can limit the movement direction of the piercing portion 322, ensuring that the piercing portion 322 can stably pierce the packaging member 200. Optionally, the guide member 400 is a metal guide tube, and the inner diameter of the guide tube is slightly larger than the outer diameter of the piercing portion 322, thereby facilitating the guide member 400 to be inserted into the piercing portion 322 during the installation process and ensuring the limiting effect of the guide member 400 and the piercing portion 322.

[0051] refer to Figure 1 As shown, a mounting portion 1111 is provided on the outer wall of the housing 100, and the fire extinguishing device is fixed in the housing of the battery pack by a connector passing through the mounting portion 1111. It can be understood that the fire extinguishing device is fixed in the housing of the battery pack by a connector passing through the mounting portion 1111, which can facilitate the installation of the fire extinguishing device inside the housing of the battery pack and prevent the fire extinguishing device from shaking in the housing, thereby ensuring the stability of the fire extinguishing device. The connector can be a screw or a pin.

[0052] Optionally, there are multiple mounting portions 1111, and the multiple mounting portions 1111 are arranged at intervals along the outer wall of the shell 100. In this way, the installation stability of the fire extinguishing device can be further improved. It should be supplemented that the mounting portion 1111 can be arranged on the storage shell 110 or on the mounting shell 120, and the specific selection can be made according to actual needs. In addition, in other embodiments of the utility model, the fire extinguishing device can also be directly welded or bonded to the outer shell of the battery pack, and is not limited to the connection scheme of the connector in this embodiment.

[0053] The working principle of the fire extinguishing device of this embodiment is described in detail below.

[0054] After the thermal runaway of the battery pack is triggered, the pressure in the outer shell suddenly increases due to the gas production of the battery cells. The explosion-proof part 310 contacts the air in the outer shell on one side and contacts the air in the installation cavity on the other side. At this time, there is a pressure difference between the inside of the outer shell and the installation cavity. After reaching a certain set pressure, the explosion-proof part 310 will rupture along the notch 3111 on the bottom wall 311. After the explosion-proof part 310 ruptures, the piercing part 322 can slide inside the guide part 400, and finally the cone head 3222 impacts and pierces the package 200 made of tempered glass. Due to the characteristic that tempered glass will instantly rupture as a whole after being subjected to local pressure, the pressure relief hole 11211 on the top of the storage shell 110 will instantly open, and the fire extinguishing medium such as inert gas will be smoothly discharged from the storage cavity into the installation cavity, and quickly fill the battery pack, dilute the combustible gas in the battery pack and cool the battery pack, so as to extinguish the battery pack.

[0055] The utility model discloses a battery pack, including a shell (not shown), a battery cell and the fire extinguishing device mentioned above. The fire extinguishing device and the battery cell are both arranged in the shell. When the battery cell has thermal runaway, the fire extinguishing medium in the fire extinguishing device can diffuse to the shell. Due to the fire extinguishing device mentioned above, the battery pack can cool down the battery cell and extinguish the fire in time when the battery cell has thermal runaway. In addition, the battery pack does not need sensor detection and software control during the fire extinguishing process, and has high reliability.

[0056] It should be noted that, in the embodiments of the present invention, the type of battery cell and the shape of the shell can be selected according to actual needs, and other structures inside the shell can be obtained according to the prior art, and other necessary structures of the battery pack are not limited here.

[0057] In the description of this specification, the description of reference terms such as "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0058] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A fire extinguishing device, characterized in that: The fire extinguishing device is installed inside the housing of the battery pack, and the fire extinguishing device includes: A housing (100), the housing (100) comprising a storage cavity and an installation cavity, the installation cavity being open at one end away from the storage cavity, and the storage cavity being used to store a fire extinguishing medium; A packaging component (200), the packaging component (200) being mounted on the housing (100) and used to isolate the storage cavity and the mounting cavity; A blasting assembly (300), the blasting assembly (300) being connected to the open end of the installation cavity and spaced apart from the packaging component (200); wherein: The explosion assembly (300) can destroy the packaging component (200) so that the storage cavity and the installation cavity are in communication, and the fire extinguishing medium in the storage cavity can diffuse from the storage cavity through the installation cavity into the housing.

2. The fire extinguishing device according to claim 1, characterized in that: The shell (100) includes a storage shell (110) and a mounting shell (120), the storage shell (110) defines the storage cavity, the mounting shell (120) defines the mounting cavity, the storage shell (110) is provided with a pressure relief hole (11211), and the packaging component (200) is installed on the storage shell (110) or the mounting shell (120) to encapsulate the pressure relief hole (11211).

3. The fire extinguishing device according to claim 1, characterized in that: The housing (100) comprises a storage shell (110) and is used to define the storage cavity. The storage shell (110) comprises a tank body (111) and a cover body (112). One end of the tank body (111) is open and the other end is closed. The cover body (112) is sealed to the open end of the tank body (111). A one-way valve (500) is provided on the cover body (112) or the tank body (111). The fire extinguishing medium is filled into the storage cavity from the one-way valve (500).

4. The fire extinguishing device according to claim 3, characterized in that: The cover body (112) comprises a cover plate (1121) and an insert ring (1122); the insert ring (1122) is inserted into the tank body (111); and the cover plate (1121) is sealingly connected to the end surface of the open end of the tank body (111).

5. The fire extinguishing device according to claim 1, characterized in that: The explosion assembly (300) comprises an explosion-proof component (310) and a movable component (320), wherein the explosion-proof component (310) is connected to the inner peripheral wall of the installation cavity, and the movable component (320) is connected to the explosion-proof component (310), and the explosion-proof component (310) can be ruptured under the action of a pressure difference, so that the movable component (320) destroys the packaging component (200).

6. The fire extinguishing device according to claim 5, characterized in that: The movable part (320) comprises a flange part (321) and a piercing part (322) connected to the flange part (321); a surface of the flange part (321) facing away from the piercing part (322) is connected to the explosion-proof part (310); and the piercing part (322) is arranged toward the packaging part (200).

7. The fire extinguishing device according to claim 5, characterized in that: The fire extinguishing device further comprises a guide member (400), one end of which is connected to the packaging member (200) and the other end of which is spaced apart from the explosion-proof member (310). The guide member (400) is used to limit the movement direction of the movable member (320).

8. The fire extinguishing device according to claim 5, characterized in that: The explosion-proof component (310) comprises a bottom wall (311) and a peripheral wall (312) arranged around the bottom wall (311); the peripheral wall (312) is connected to the inner peripheral wall of the installation cavity; the bottom wall (311) is provided with a notch (3111); the notch (3111) is located radially inward of a connection position between the peripheral wall (312) and the bottom wall (311).

9. The fire extinguishing device according to any one of claims 1 to 8, characterized in that: An installation portion (1111) is provided on the outer wall of the shell (100), and the fire extinguishing device is fixed inside the outer shell of the battery pack via a connecting piece passing through the installation portion (1111).

10. A battery pack, characterized in that: The invention comprises a shell, a battery cell and a fire extinguishing device as described in any one of claims 1 to 9, wherein the fire extinguishing device and the battery cell are both arranged in the shell, and when the battery cell has thermal runaway, the fire extinguishing medium in the fire extinguishing device can diffuse to the shell.

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