Battery pack with emergency protection function

Abstract

The application discloses a battery pack with an emergency protection function, which comprises a box body with a mounting cavity, a battery cell installed in the mounting cavity, a box cover used for sealing the mounting cavity and having a sealed storage cavity in which fire extinguishing material is stored, a detection device configured to detect the pressure and / or smoke in the mounting cavity and / or the temperature of the battery cell, a triggering device configured to connect the mounting cavity and the storage cavity, and a BMS electrically connected with the detection device and the triggering device, wherein the BMS controls the triggering device to connect the mounting cavity and the storage cavity according to the detection result of the detection device, so that the fire extinguishing material in the storage cavity diffuses into the mounting cavity. The battery pack has a simple and compact overall structure, the fire extinguishing material is released quickly, and the purpose of rapid cooling and rapid fire extinguishing can be effectively achieved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery pack with emergency protection function. Background Technology

[0002] When a single cell in a battery pack experiences thermal runaway, the heat can easily spread to the entire module or battery pack, potentially leading to fire or explosion. Since battery packs are typically installed in small, enclosed spaces (such as the underside of a car), it is difficult to effectively cool and extinguish a fire from the outside once a localized thermal runaway occurs. Therefore, it is necessary to incorporate an emergency protection structure inside the battery pack.

[0003] Although existing battery packs are equipped with fire suppression systems, they have drawbacks such as taking up a lot of space and slow diffusion, which makes it impossible to cool down and extinguish fires quickly (the large space occupied will result in a high lid and many gaps inside the battery pack, which in turn will lead to a high oxygen content inside the battery pack). Summary of the Invention

[0004] In order to overcome at least one of the defects of the prior art, the present invention provides a battery pack with emergency protection function, which has a simple and compact overall structure and releases fire extinguishing material quickly, effectively achieving the purpose of rapid cooling and rapid fire extinguishing.

[0005] The technical solution adopted by this invention to solve its problem is:

[0006] A battery pack with emergency protection function includes:

[0007] The enclosure has a mounting cavity;

[0008] The battery cell is installed in the mounting cavity;

[0009] The lid fits onto the box body to seal the mounting cavity. The lid has a sealed storage cavity containing fire extinguishing materials.

[0010] The detection device is configured to detect the pressure and / or smoke and / or temperature of the battery cell within the mounting cavity;

[0011] A triggering device is configured to connect the mounting cavity and the storage cavity;

[0012] The BMS is electrically connected to the detection device and the triggering device, respectively. The BMS controls the triggering device to open the installation cavity and the storage cavity based on the detection result of the detection device, so that the extinguishing material in the storage cavity can be diffused into the installation cavity.

[0013] The battery pack provided by this invention has a storage cavity inside its cover, which contains fire extinguishing material. A detection device converts the pressure and / or smoke triggering status and / or cell temperature detected in the mounting cavity into detection signals and sends them to the BMS. When the pressure in the mounting cavity reaches a danger threshold, and / or the smoke detection is triggered, and / or the cell temperature reaches a danger threshold, the BMS sends a command to the triggering device, which then controls the triggering device to open the storage cavity of the cover, making the mounting cavity and the storage cavity interconnected. At this time, the fire extinguishing material will be released from the storage cavity of the cover and will quickly diffuse into the mounting cavity to absorb heat and cool down, while isolating oxygen to prevent the battery pack from catching fire and exploding.

[0014] In the above solution, the fire extinguishing material is stored directly in the storage cavity of the cover, replacing the existing method of using a gas tank combined with a conduit or a separate fire extinguishing bag. This method is simpler and more compact, reduces production costs, occupies less space, and allows the entire battery pack to be made thinner. Furthermore, the gap between the inner surface of the cover and the battery cell can be kept small, thus minimizing the overall empty space inside the battery pack. The fire extinguishing material can be quickly released to fill the entire battery pack, thereby rapidly expelling air and isolating oxygen, effectively achieving the purpose of rapid cooling and rapid fire extinguishing.

[0015] Furthermore, the side wall of the box cover facing the installation cavity includes a fixed part and a movable part connected together. The triggering device drives the movable part to at least partially disengage from the fixed part, thereby connecting the installation cavity and the storage cavity. In this way, by using the triggering device to drive the movable part to disengage from the fixed part, the box cover is broken, thus achieving connection between the installation cavity and the storage cavity. This prevents the storage cavity from resealing due to factors such as triggering device malfunction during the cooling and extinguishing process, ensuring the continuous and effective release of the extinguishing material.

[0016] Furthermore, the triggering device is an electromagnetic relay, which is installed inside the mounting cavity. The electromagnetic relay's magnetic force acts on the movable part, thereby using magnetic attraction to detach the movable part from the fixed part. The electromagnetic relay is small in size and can be installed in the gap between the side wall of the enclosure and the battery cell. Moreover, the electromagnetic relay only needs to be energized for a short time to detach the movable part from the fixed part, further avoiding the impact of triggering device failure during the cooling and fire extinguishing process.

[0017] Furthermore, the movable part is in the shape of a long, thin sheet, and the electromagnetic relay is positioned at one end along the length of the movable part. In this way, the movable part can be opened by tearing it open from one end with less electromagnetic force and a larger opening can be made.

[0018] Furthermore, the movable part is in the shape of a circular thin sheet, and the electromagnetic relay corresponds to the center position of the movable part.

[0019] Furthermore, the box cover includes an outer main cover plate and an inner layer plate. The outer main cover plate is recessed in the direction away from the box body to form a cavity. The periphery of the inner layer plate is connected to the circumferential sidewall of the cavity to divide at least part of the cavity into a storage cavity. The inner layer plate includes a fixed part and a movable part to specifically form the storage cavity, and the movable part serves as a part of the sidewall of the storage cavity facing the installation cavity. The overall structure of the box cover is simple and easy to manufacture.

[0020] Furthermore, the fixed part and the movable part are integrally formed, and the fixed part and the movable part are connected by grooves to form a connection boundary between them.

[0021] Furthermore, the fixed part and the movable part are welded or glued together, and the strength of the fixed part and the movable part at the connection is less than the strength of the fixed part itself and the strength of the movable part itself.

[0022] Thus, in all the above-mentioned connection schemes for fixed and movable parts, it can be ensured that when the movable part is subjected to force, failure will first begin from the connection boundary or connection point between the fixed and movable parts.

[0023] Furthermore, the extinguishing material is compressed carbon dioxide. In this way, the compressed carbon dioxide can vaporize and cool down, preventing further spread of thermal runaway, and can also isolate oxygen to prevent the battery pack from catching fire and exploding.

[0024] Furthermore, the detection device includes a pressure sensor and / or a temperature sensor and / or a smoke detector.

[0025] Furthermore, it also includes at least two explosion-proof valves with different pressure thresholds, which are located in the enclosure. In this way, when the triggering device releases the extinguishing material on the enclosure cover (especially compressed carbon dioxide), the pressure in the installation cavity will increase rapidly. At this time, the different explosion-proof valves in the battery pack will open in sequence to prevent the pressure value in the installation cavity from becoming too high.

[0026] Furthermore, the lid is provided with a filling hole, which connects to the storage cavity for filling with fire extinguishing material, thereby enabling the filling of fire extinguishing material during the production process.

[0027] In summary, the battery pack with emergency protection function provided by this invention has the following technical effects:

[0028] 1) Simple and compact structure, rapid cooling and fire extinguishing: The fire extinguishing material is stored directly in the storage cavity of the cover. The installation cavity and storage cavity are connected by a triggering device to release the fire extinguishing material. Its structure is simpler and more compact, reducing production costs and occupying less space. The entire battery pack can be made thinner, and the gap between the inner surface of the cover and the battery cell can be kept to a small value. This keeps the overall empty space inside the battery pack small, and the fire extinguishing material can be released quickly to fill the entire battery pack, so as to quickly remove air and isolate oxygen. It can effectively achieve the purpose of rapid cooling and rapid fire extinguishing, so as to solve the problems of bulky battery pack structure, large number of parts, and slow cooling and fire extinguishing in the existing technology.

[0029] 2) High stability: The triggering device drives the moving part to disengage from the fixed part, thereby breaking the cover to open the installation cavity and the storage cavity. This avoids the storage cavity from being sealed again due to factors such as triggering device failure during the cooling and fire extinguishing process, ensuring the continuous and effective release of the fire extinguishing material. At the same time, the use of an electromagnetic relay as the triggering device reduces its space occupation and its power-on working time, further reducing the impact of triggering device failure.

[0030] 3) High safety: By setting multiple explosion-proof valves with different pressure thresholds in the enclosure, when the triggering device releases the compressed carbon dioxide on the enclosure cover, multiple explosion-proof valves in the battery pack will open in sequence to prevent the pressure in the installation cavity from becoming too high. At the same time, the vaporized carbon dioxide can displace the air in the installation cavity and be discharged from the battery pack through the explosion-proof valves, effectively isolating external oxygen from entering and ensuring the safety of the battery pack. Attached Figure Description

[0031] Figure 1 This is an exploded schematic diagram of the battery pack according to an embodiment of the present invention;

[0032] Figure 2 This is a perspective sectional view of the lid of the box in an embodiment of the present invention when it has a first type of movable part;

[0033] Figure 3 This is one of the cross-sectional schematic diagrams of the battery pack according to an embodiment of the present invention;

[0034] Figure 4 This is a second cross-sectional schematic diagram of the battery pack according to an embodiment of the present invention;

[0035] Figure 5 This is a perspective sectional view of the lid of the box in an embodiment of the present invention when it has a second type of movable part.

[0036] The meanings of the reference numerals in the attached figures are as follows:

[0037] 1. Enclosure; 101. Mounting cavity; 2. Battery cell; 3. Enclosure cover; 301. Storage cavity; 302. Filling hole; 31. Outer main body cover plate; 32. Inner layer plate; 321. Fixing part; 322. Moving part; 4. Detection device; 5. Triggering device; 6. Explosion-proof valve. Detailed Implementation

[0038] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings.

[0039] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0041] See Figure 1 and Figure 3 The present invention discloses a battery pack with emergency protection function, including: a housing 1, a battery cell 2, a housing cover 3, a detection device 4, a triggering device 5, a BMS (not shown in the figure) and multiple explosion-proof valves 6.

[0042] The housing 1 serves as the main carrier and can be used to install various components. The housing 1 has an installation cavity 101. Multiple battery cells 2 can be combined to form a battery cell module and installed in the installation cavity 101. Of course, the specific number of battery cells 2 is not limited. One battery cell 2 or multiple battery cells 2 are also acceptable, but it is preferable to have multiple battery cells 2 forming a battery cell module. The housing cover 3 covers the housing 1 to seal the installation cavity 101. The housing cover 3 has a sealed storage cavity 301, which stores fire extinguishing materials.

[0043] The BMS can be electrically connected to the detection device 4, which is configured to detect the pressure and / or smoke and / or temperature of the battery cell 2 within the mounting cavity 101 and transmit detection signals to the BMS. Specifically, the detection device 4 may include a pressure sensor and / or a temperature sensor and / or a smoke detector. The pressure sensor may be mounted on the housing 1 or the cover 3 to detect whether the pressure within the mounting cavity 101 reaches a dangerous threshold. The temperature sensor may be mounted on the battery cell 2 to detect whether the temperature of a single battery cell reaches a dangerous threshold. The smoke detector may be mounted on the housing 1 or the cover 3 to detect whether smoke is present within the mounting cavity 101.

[0044] The BMS can also be electrically connected to the triggering device 5, which is configured to connect the mounting cavity 101 and the storage cavity 301. When the detection device 4 detects a hazardous situation (such as the pressure in the mounting cavity 101 or the temperature of the battery cell reaching a dangerous threshold, or the smoke detection being triggered), the BMS controls the triggering device 5 to connect the mounting cavity 101 and the storage cavity 301 based on the detection result of the detection device 4, so that the fire extinguishing material in the storage cavity 301 can diffuse to the mounting cavity 101 to absorb heat and cool down, while isolating oxygen to prevent the battery pack from catching fire and exploding.

[0045] In the above solution, the fire extinguishing material is directly stored in the storage cavity 301 of the cover 3, replacing the existing gas tank combined with a conduit or the independent fire extinguishing bag. Its structure is simpler and more compact, reducing production costs and occupying less space. The entire battery pack can be made thinner, and the gap between the inner surface of the cover 3 and the battery cell 2 can be kept at a small value, thereby keeping the overall empty space inside the battery pack small. The fire extinguishing material can be quickly released to fill the entire battery pack, so as to quickly remove air and isolate oxygen. It can effectively achieve the purpose of rapid cooling and rapid fire extinguishing, thus solving the problems of bulky battery pack structure, large number of parts, and slow cooling and fire extinguishing in the existing technology.

[0046] Preferably, the extinguishing material is a non-flammable compressed gas, or a mixture of a non-flammable compressed gas and powder. Specifically, the extinguishing material can be compressed carbon dioxide, or a mixture of compressed nitrogen and dry powder.

[0047] It should be noted that, for ease of understanding, the following description of this embodiment will use the detection device 4 as a pressure sensor and compressed carbon dioxide as the extinguishing material.

[0048] See Figure 2Specifically, three explosion-proof valves 6 are provided, each with a different pressure threshold. The explosion-proof valves 6 can be installed on the housing 1 to connect to the installation cavity 101. The purpose of providing multiple explosion-proof valves 6 is to facilitate the opening of different numbers of valves 6 according to changes in the pressure within the installation cavity 101, controlling the pressure relief rate and preventing excessive pressure within the installation cavity. Specifically, the three explosion-proof valves 6 are arranged sequentially on one side wall of the housing 1.

[0049] Preferably, the pressure threshold of any explosion-proof valve 6 is greater than the trigger pressure value of the pressure sensor, so as to avoid the pressure sensor from failing to detect pressure and to ensure that the release of fire extinguishing material comes first and the pressure relief comes later.

[0050] It should be noted that the number of explosion-proof valves 6 can also be two, four, five, etc., to satisfy the function of controlling the pressure relief speed of the installation cavity 101 by opening the explosion-proof valves 6 in sequence.

[0051] By combining the above schemes, when the pressure in the mounting cavity 101 reaches the preset trigger pressure value of the pressure sensor, the triggering device 5 is activated. The triggering device 5 connects the mounting cavity 101 with the storage cavity 301 to vaporize and release the compressed carbon dioxide on the cover 3. The pressure in the mounting cavity 101 will increase rapidly. At this time, multiple explosion-proof valves 6 in the battery pack will open in sequence to release pressure and prevent the pressure in the mounting cavity 101 from becoming too high. At the same time, the vaporized carbon dioxide can displace the air in the mounting cavity 101 and discharge it from the battery pack through the explosion-proof valves 6, effectively isolating external oxygen from entering and ensuring the safety of the battery pack.

[0052] As a further explanation, as compressed carbon dioxide begins to vaporize and release, the pressure inside the installation cavity 101 begins to increase. When the pressure inside the cavity reaches the pressure threshold of the first explosion-proof valve 6, the first explosion-proof valve 6 opens to perform a first-stage pressure relief. As the compressed carbon dioxide continues to vaporize and release, when the rate of increase in the pressure inside the cavity remains greater than the rate of first-stage pressure relief, the second and third explosion-proof valves 6 will open sequentially as the pressure inside the cavity accumulates, until the rate of increase in the pressure inside the cavity is less than or equal to the current pressure relief rate.

[0053] Of course, some explosion-proof valves 6 can have the same pressure threshold to control the pressure release rate when the pressure in the mounting cavity 101 reaches the pressure threshold of that part of the explosion-proof valve 6. For example, there are two explosion-proof valves 6 with the minimum pressure threshold, so that the initial pressure release rate of the explosion-proof valves 6 can be faster in the initial stage of extinguishing material release.

[0054] See Figure 3In this embodiment, the side wall of the cover 3 facing the mounting cavity 101 includes a fixed part 321 and a movable part 322 connected together. The triggering device 5 drives the movable part 322 to at least partially disengage from the fixed part 321, so that the mounting cavity 101 is connected to the storage cavity 301. When the battery cell 2 is installed in the mounting cavity 101 of the housing 1, a gap can be maintained between the battery cell 2 and the circumferential side wall of the mounting cavity 101. Preferably, the position of the movable part 322 corresponds to this gap so that it is not obstructed by the battery cell 2 when it disengages from the fixed part 321.

[0055] Combination Figure 2 Specifically, the lid 3 may include an outer main cover plate 31 and an inner layer plate 32. The outer main cover plate 31 is recessed in the direction away from the box body 1 to form a cavity. The inner layer plate 32 may be located in the cavity, and the periphery of the inner layer plate 32 is connected to the circumferential sidewall of the cavity to divide at least part of the cavity into a storage cavity 301. The inner layer plate 32 includes a fixed part 321 and a movable part 322. Thus, the sidewall of the storage cavity 301 includes the bottom wall and circumferential sidewall of the cavity of the outer main cover plate 31 and the inner layer plate 32. During installation, the outer main cover plate 31 is connected to the box 1, and the mounting cavity 101 is connected to the outer cavity of the outer main cover plate 31 (the inner cavity of the outer main cover plate 31 constitutes the aforementioned storage cavity 301). The inner layer plate 32 is isolated between the mounting cavity 101 and the storage cavity 301. When the movable part 322 is opened, the storage cavity 301 is connected to the outer cavity of the outer main cover plate 31, and thus indirectly connected to the mounting cavity 101.

[0056] By combining the above solutions, the triggering device 5 drives the movable part 322 to disengage from the fixed part 321, thereby breaking the cover 3 and thus connecting the installation cavity 101 and the storage cavity 301. This prevents the storage cavity 301 from being sealed again due to factors such as the failure of the triggering device 5 during the cooling and fire extinguishing process, ensuring the continuous and effective release of the fire extinguishing material. At the same time, by forming the storage cavity 301 in the cover 3 in the above manner, the overall structure of the cover 3 can be made simple and easy to manufacture.

[0057] See Figure 2 As an example, the inner layer plate 32 specifically includes a fixed part 321 and two movable parts 322. The fixed part 321 is rectangular with a large area, while the movable parts 322 are long strips. The length of the fixed part 321 is equal to the length of the movable parts 322. One side of the two movable parts 322 in the width direction is fixedly connected to the two opposite sides in the width direction of the fixed part 321. The two opposite sides in the length direction of the fixed part 321 are fixedly connected to the sidewalls of the cavity of the outer main body cover plate 31. The other sides of the movable parts 322 are fixedly connected to the sidewalls of the cavity of the outer main body cover plate 31. That is, in this example, the movable parts 322 are located outside the fixed part 321.

[0058] See Figure 5 As another example, the inner layer plate 32 specifically includes a fixed part 321 and two movable parts 322. The fixed part 321 is rectangular with a large area, while the movable parts 322 are circular thin sheets. The length and width of the fixed part 321 are adapted to the length and width of the cavity of the outer main body cover plate 31, that is, the circumferential side of the fixed part 321 is fixedly connected to the circumferential sidewall of the cavity of the outer main body cover plate 31. The fixed part 321 has two holes corresponding to the shape of the movable parts 322. The periphery of the movable parts 322 is fixedly connected to the periphery of the holes of the fixed part 321. That is, in this example, the movable parts 322 are located inside the fixed part 321.

[0059] Of course, in addition to the two shapes of the movable part 322 described above, the movable part 322 can also be square, rhomboid, pentagonal, hexagonal, elliptical, etc.

[0060] Understandably, when the movable part 322 is a long, thin strip, the movable part 322 can also be located inside the fixed part 321. In this case, the length of the movable part 322 needs to be less than the length of the fixed part 321 so that the two ends of the length of the movable part 322 do not protrude from the fixed part 321.

[0061] It is understandable that the number of active parts 322 can also be one, three, four, etc., and this embodiment does not specifically limit the number of active parts 322.

[0062] In this embodiment, the fixed connection between the fixed part 321 and the movable part 322 can be one of the following:

[0063] (1) The fixed part 321 and the movable part 322 are integrally formed, and the fixed part 321 and the movable part 322 are connected by grooves to form a connection boundary between them;

[0064] (2) The fixed part 321 and the movable part 322 are welded or glued together, and the strength of the fixed part 321 and the movable part 322 at the connection is less than the strength of the fixed part 321 itself and the strength of the movable part 322 itself.

[0065] In addition, it is necessary to control that the connection strength between the fixed part 321 and the outer main body cover plate 31 is greater than the connection strength between the fixed part 321 and the movable part 322; while when the movable part 322 needs to be connected to the outer main body cover plate 31, the connection strength between the movable part 322 and the outer main body cover plate 31 must be less than the strength of the fixed part 321 itself, the strength of the movable part 322 itself, and the connection strength between the fixed part 321 and the outer main body cover plate 31. These strength differences can all be achieved through design.

[0066] It should also be noted that the strength of the outer main body cover plate 31 itself, the strength of the fixing part 321 itself, the strength of the moving part 322 itself, the connection strength between the fixing part 321 and the outer main body cover plate 31, the connection strength between the moving part 322 and the outer main body cover plate 31, and the connection strength between the fixing part 321 and the moving part 322 all need to meet the required strength when storing fire extinguishing materials in the storage cavity 301, and these can also be achieved through design.

[0067] Thus, in all the above-mentioned connection schemes of the fixed part 321 and the movable part 322, it can be ensured that when the movable part 322 is subjected to force, the damage will first start from the connection boundary or connection point between the fixed part 321 and the movable part 322.

[0068] See Figure 3 and Figure 4 In this embodiment, preferably, the triggering device 5 is an electromagnetic relay, and the number of electromagnetic relays can be equal to the number of movable parts 322 so as to drive the movable parts 322 accordingly. Specifically, the electromagnetic relay is installed in the mounting cavity 101, and the electromagnetic relay's magnetic force acts on the movable part 322, thereby using magnetic attraction to make the movable part 322 disengage from the fixed part 321.

[0069] Understandably, the movable part 322 is made of a magnetic metal material so that the movable part 322 can be magnetically attracted by the electromagnetic relay.

[0070] The advantage of using an electromagnetic relay as the triggering device 5 is that the electromagnetic relay is small in size and can be installed in the gap between the side wall of the box 1 and the battery cell 2. Moreover, the electromagnetic relay only needs to be energized for a short time to separate the movable part 322 from the fixed part 321, which further avoids the impact of the triggering device 5 failure during the cooling and fire extinguishing process.

[0071] Based on the use of an electromagnetic relay as the triggering device 5, when the movable part 322 is in the shape of a long, thin sheet, the electromagnetic relay corresponds to one end of the movable part 322 along its length. Therefore, opening the movable part 322 by tearing it from one end requires less electromagnetic force and allows for a larger opening. See details in [reference needed]. Figure 4 The state shown.

[0072] Based on the use of an electromagnetic relay as the triggering device 5, when the movable part is in the shape of a circular thin sheet, the electromagnetic relay corresponds to the center position of the movable part 322.

[0073] In other preferred embodiments, the triggering device 5 may also use methods such as pushing the movable part 322, hammering the movable part 322, or pulling the movable part 322 to disengage the movable part 321. The specific structure of the triggering device 5 may be changed according to the driving method, which will not be described in this embodiment.

[0074] Of course, it is best to keep the cover 3 free of pipes and wires to facilitate the disassembly and assembly of the cover 3.

[0075] See Figure 2 or Figure 4 In this embodiment, to facilitate the filling of fire extinguishing material during production, preferably, the cover 3 is provided with a filling hole 302, which connects to the storage cavity 301 for filling with fire extinguishing material. Specifically, the filling hole 302 can be located on the outer main cover plate 31, the fixed part 321, or the movable part 322, as long as it can connect to the storage cavity 301. Of course, it is preferable that the filling hole 302 is located on the fixed part 321 and avoids the battery cell 2; after the fire extinguishing material is filled, the filling hole 302 still needs to be sealed. The sealing method is not limited and can be achieved by using sealing bolts, one-way valves, etc.

[0076] The specific working process of the battery pack provided by this invention is as follows:

[0077] (1) When cell 2 experiences thermal runaway, it causes the pressure or temperature to rise or smoke to appear in the mounting cavity 101. The detection device 4 detects the dangerous situation and outputs a detection signal to the BMS. The BMS sends a command to power on the electromagnetic relay.

[0078] (2) After the electromagnetic relay is powered on, it generates a magnetic attraction force that acts on the movable part 322 at the corresponding position in the box cover 3, thereby attracting the movable part 322 down to detach from the fixed part 321, thereby damaging the box cover 3 and making the mounting cavity 101 and the storage cavity 301 connected.

[0079] (3) The compressed carbon dioxide begins to vaporize rapidly and diffuses from the storage chamber 301 to the installation chamber 101 to absorb heat, cools the battery pack, and prevents thermal runaway from spreading further. At the same time, the carbon dioxide gas fills the battery pack, which plays a role in isolating oxygen and preventing fire.

[0080] (4) When the pressure inside the installation cavity 101 is too high, multiple explosion-proof valves 6 open in sequence to release pressure in stages.

[0081] In summary, the battery pack provided by this invention can effectively achieve rapid cooling and rapid fire extinguishing. It has the characteristics of simple and compact structure, rapid cooling and fire extinguishing, high stability, and high safety. It also solves the problems of bulky battery pack structure, large number of parts, and slow cooling and fire extinguishing in the prior art.

[0082] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A battery pack with emergency protection function, characterized in that, include: The housing (1) has a mounting cavity (101); Battery cell (2) is installed in the mounting cavity (101); A lid (3) is fitted onto the box body (1) to seal the mounting cavity (101). The lid (3) has a sealed storage cavity (301) containing fire extinguishing materials. The detection device (4) is configured to detect the pressure and / or smoke and / or temperature of the battery cell (2) within the mounting cavity (101); A triggering device (5) is configured to connect the mounting cavity (101) and the storage cavity (301); The BMS is electrically connected to the detection device (4) and the triggering device (5) respectively. The BMS controls the triggering device (5) to connect the mounting cavity (101) and the storage cavity (301) according to the detection result of the detection device (4), so that the fire extinguishing material in the storage cavity (301) can diffuse to the mounting cavity (101). The side wall of the cover (3) facing the mounting cavity (101) includes a fixed part (321) and a movable part (322) connected to each other. The triggering device (5) drives the movable part (322) to at least partially disengage from the fixed part (321) so that the mounting cavity (101) is connected to the storage cavity (301). The triggering device (5) is an electromagnetic relay, which is installed in the mounting cavity (101) and the electromagnetic relay acts magnetically on the movable part (322). The lid (3) includes an outer main cover plate (31) and an inner layer plate (32). The outer main cover plate (31) is recessed in a direction away from the box body (1) to form a cavity. The periphery of the inner layer plate (32) is connected to the circumferential sidewall of the cavity to divide at least part of the cavity into the storage cavity (301). The inner layer plate (31) includes a fixed part (321) and a movable part (322). The fixed part (321) and the movable part (322) are integrally formed, and the fixed part (321) and the movable part (322) are connected to each other by grooves.

2. The battery pack with emergency protection function according to claim 1, characterized in that, The movable part (322) is in the shape of a long strip and a thin sheet, and the electromagnetic relay is located at one end of the movable part (322) along its length.

3. The battery pack with emergency protection function according to claim 1, characterized in that, The movable part (322) is in the shape of a circular thin sheet, and the electromagnetic relay corresponds to the center position of the movable part (322).

4. The battery pack with emergency protection function according to claim 1, characterized in that, The fixed part (321) and the movable part (322) are welded or glued together, and the strength of the fixed part (321) and the movable part (322) at the connection is less than the strength of the fixed part (321) itself and the strength of the movable part (322) itself.

5. The battery pack with emergency protection function according to any one of claims 1 to 4, characterized in that, The extinguishing material is compressed carbon dioxide.

6. The battery pack with emergency protection function according to any one of claims 1 to 4, characterized in that, The detection device (4) includes a pressure sensor and / or a temperature sensor and / or a smoke detector.

7. The battery pack with emergency protection function according to any one of claims 1 to 4, characterized in that, It also includes at least two explosion-proof valves (6) with different pressure thresholds, the explosion-proof valves (6) being disposed in the housing (1).

8. The battery pack with emergency protection function according to any one of claims 1 to 4, characterized in that, The box cover (3) is provided with a filling hole (302), which is connected to the storage cavity (301) for filling fire extinguishing material.

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