A battery pack and vehicle

Abstract

This application provides a battery pack and a vehicle. The battery pack includes: a housing with an inner cavity for accommodating battery cells; a vent valve disposed on the housing and enabling communication between the inside and outside of the housing; an airbag that isolates the inner cavity of the housing from the external environment and is connected to the vent valve to communicate with the external environment or the inner cavity of the housing; and a fire extinguishing medium filled in the inner cavity of the housing and / or the airbag for extinguishing fires in the battery cells. The battery pack with the above structure, by adding an airbag to isolate the inner cavity from the external environment, can achieve pressure balance between the inside and outside of the housing while preventing communication between the inner cavity and the external environment. This prevents water vapor from the external environment from entering the inner cavity of the housing, thereby preventing condensation from affecting the electrical components inside the battery pack, improving the safety and durability of the battery pack. Furthermore, the pre-filling of the sealed inner cavity of the housing with a fire extinguishing medium reduces the risk of thermal runaway propagation in the battery pack.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery pack and a vehicle. Background Technology

[0002] As the power battery of a vehicle, the battery pack is susceptible to pressure differences when external or internal air pressure changes (heating or cooling of the internal gas). These differences can lead to deformation of the battery pack casing, affecting its performance and lifespan. Currently, the common method for balancing the internal and external air pressure of the battery pack is to install a vent valve on the casing. When the pressures inside and outside the battery pack are inconsistent, the vent valve facilitates air exchange.

[0003] However, when the battery pack is in an environment with high humidity, water vapor in the air can enter the battery pack through ventilation. This water vapor condenses inside the battery pack, increasing the risk of short circuits and corrosion of internal electrical components, severely impacting the battery pack's safety and durability. Furthermore, the process of exchanging air with the external environment to balance the internal and external air pressure also allows oxygen from the environment to enter the battery pack. In the event of thermal runaway, oxygen can act as a combustion promoter, increasing the risk of the thermal runaway spreading. Utility Model Content

[0004] In view of this, this application provides a battery pack that improves safety and durability and reduces the risk of thermal runaway propagation. Furthermore, this application also provides a vehicle incorporating this battery pack.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A battery pack, comprising:

[0007] The housing has an internal cavity to accommodate the battery cells;

[0008] A vent valve is installed on the housing and enables communication between the inside and outside of the housing;

[0009] An airbag isolates the inner cavity of the box from the external environment of the box, and is connected to the vent valve so that it can communicate with the external environment of the box or with the inner cavity of the box through the vent valve;

[0010] Fire extinguishing medium is filled in the inner cavity of the housing and / or the airbag to extinguish the fire in the battery cell.

[0011] Optionally, in the above-mentioned battery pack, the airbag is disposed in the inner cavity of the housing and communicates with the external environment of the housing through the vent valve.

[0012] Optionally, in the above-mentioned battery pack, the fire extinguishing medium is an insulating fire extinguishing medium, and it fills the inner cavity of the box.

[0013] Optionally, in the above-mentioned battery pack, the airbag is disposed outside the housing and communicates with the inner cavity of the housing through the vent valve.

[0014] Optionally, in the above-mentioned battery pack, the fire extinguishing medium is a gaseous fire extinguishing medium, and it is filled in the inner cavity of the box and / or the airbag.

[0015] Optionally, in the above battery pack, the airbags are configured as multiple, including a top airbag located between the top cover of the housing and the battery cell, and a side airbag located between the side frame of the housing and the battery cell.

[0016] Optionally, in the above battery pack, the vent valve is disposed on the side frame of the housing, the side airbag is aligned with and connected to the vent valve, and the top airbag is connected to the side airbag through a first air duct.

[0017] Optionally, in the above battery pack, there are multiple top airbags, which are connected in series through a second air duct, or the multiple top airbags are connected to the side airbags through multiple first air ducts respectively.

[0018] Optionally, in the above battery pack, the planar area of ​​the top airbag is larger than the planar area of ​​the side airbag, and the thickness of the top airbag is smaller than the thickness of the side airbag.

[0019] A vehicle includes a power battery, which is a battery pack as described in any of the preceding claims.

[0020] The battery pack provided in this application, in addition to the ventilation valve on the casing to allow for air exchange between the inner and outer spaces of the casing, also includes an airbag. The opening of the airbag is connected to the ventilation valve, meaning that the internal space of the airbag serves as the space that the ventilation valve can connect to (this space refers to the space located inside or outside the casing). When the airbag is outside the casing, its internal space can connect to the inner cavity of the casing through the ventilation valve, thus isolating the inner cavity from the external environment. Conversely, when the airbag is inside the casing, its internal space can connect to the external environment of the casing through the ventilation valve, again isolating the inner cavity from the external environment. This allows for pressure balancing ventilation to occur between the airbag and the inner cavity of the casing, or between the airbag and the external environment of the casing. This prevents water vapor from the external environment from entering the inner cavity of the casing and affecting the electrical components inside the battery pack, thus improving the safety and durability of the battery pack. Furthermore, because the inner cavity of the enclosure is isolated from the external environment, it not only prevents oxygen from the external environment from entering the inner cavity of the enclosure, but also allows fire extinguishing media to be filled in the sealed inner cavity of the enclosure, thereby reducing the risk of thermal runaway of the battery pack. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the airbag in the battery pack provided in an embodiment of this application, showing the arrangement of the airbag inside the housing.

[0023] Figure 2 This is a schematic diagram of a structure in which the top airbag and the side airbags are connected in series.

[0024] Figure 3 This is a schematic diagram of the top airbag structure;

[0025] Figure 4 for Figure 3 A schematic diagram of the local structure in its natural state;

[0026] Figure 5 for Figure 3 A schematic diagram of the local structure in the compressed state;

[0027] Figure 6 for Figure 3 A schematic diagram of the local structure in the expansion state;

[0028] Figure 7 This is a schematic diagram of the structure of the airbag installed outside the box.

[0029] exist Figures 1-7 middle:

[0030] 1-Box body, 2-Battery cell, 3-Ventilation valve, 4-Airbag, 5-First air duct, 6-Second air duct;

[0031] 101 - Frame, 102 - Top cover;

[0032] 401 - Top airbag, 402 - Side airbag. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0034] like Figures 1-7 As shown, this application embodiment provides a battery pack that can be used as a power battery for electric vehicles. This battery pack mainly includes a housing 1, a vent valve 3, an airbag 4, and a fire extinguishing medium. The housing 1 is the outer shell of the entire battery pack, used to enclose the inner cavity for housing and installing the battery cells 2, and to protect the battery cells 2. The housing 1 specifically includes a base plate, a frame 101, and a top cover 102 (for better protrusion of the airbag 4, this application only...). Figure 1The diagram shows a frame 101, with a base plate below the battery cell 2 and a top cover above the battery cell 2. The frame 101 is a circumferentially closed structure, surrounding the outside of the battery cell 2 and connecting the base plate and the top cover. A vent valve 3 is installed on the housing 1, specifically on the frame 101, penetrating the frame wall of the frame 101 to achieve communication between the inside and outside of the housing 1, allowing air exchange between the inside and outside of the housing 1 to achieve pressure balance. The specific structure of the vent valve 3 can be found in existing technology. An airbag 4 is an elastic component capable of expansion and contraction, balancing the pressure inside and outside of the housing 1 through expansion for intake and compression for exhaust. The opening of the airbag 4 is connected to the vent valve on the housing 1. The vent valve 3 is positioned at point 3 so that it acts as a switch to control the opening and closing of the airbag 4. Since the vent valve 3 controls the connection between the inside and outside of the housing 1, i.e., the vent valve 3 controls the connection between the spaces on both sides of the housing wall, by connecting the airbag 4 to the vent valve 3 in the above manner, the airbag 4 can cover the vent valve 3 on one side of the housing wall. This results in one side of the space connected by the vent valve 3 being the internal space of the airbag 4, while the other side is either the internal space of the housing wall (i.e., the inner cavity of the housing 1) or the external space (i.e., the external environment where the housing 1 is located). In other words, the two spaces connected by the vent valve 3 are the internal space of the airbag 4 and the internal cavity of the housing 1 (e.g., the inner cavity of the housing 1). Figure 7 (as shown), or the internal space of the airbag 4 and the external environment of the box 1 (such as... Figure 1 As shown in the figure, in both cases, the inner cavity of the housing 1 where the battery cell 2 is located is not connected to the external environment of the housing 1. The extinguishing medium (not shown in the figure) is used to extinguish the battery cell 2 when thermal runaway occurs. It can be filled in different spaces depending on the different settings of the airbag 4, such as filling the inner cavity of the housing 1 and / or filling the internal space of the airbag 4. Specifically, due to the isolation of the airbag 4, the inner cavity of the housing 1 is no longer directly connected to the external environment of the housing 1 through the vent valve 3. That is, the inner cavity of the battery pack that accommodates and installs the battery cell 2 is a sealed inner cavity formed by the housing 1 and the airbag 4. Therefore, the extinguishing medium can be pre-filled into the inner cavity so that it can extinguish the battery cell 2 in time when thermal runaway occurs.

[0035] The battery pack with the above-described structure, by adding an airbag 4, can not only achieve pressure balance inside and outside the housing 1, but also prevent the inner cavity of the housing 1 from communicating with the external environment. This prevents water vapor from entering the inner cavity of the housing 1, thus preventing the condensate formed by the water vapor from affecting the electrical components inside the battery pack, improving the safety and durability of the battery pack. Furthermore, since the inner cavity of the housing 1 is isolated from the external environment by the airbag 4, it can not only prevent oxygen from entering the inner cavity of the housing 1, but also pre-fill the sealed inner cavity of the housing 1 with fire extinguishing medium, thereby reducing the risk of thermal runaway of the battery pack.

[0036] In one alternative embodiment, such as Figure 1 As shown, the airbag 4 is placed inside the cavity of the box 1, and the internal space of the airbag 4 is connected to the external environment of the box 1 through the vent valve 3. As described above, the space connected to the airbag 4 through the vent valve 3 can be chosen in different ways. When the space connected to the airbag 4 through the vent valve 3 is the external environment of the box 1, the airbag 4 needs to be placed inside the cavity of the box 1, occupying a partial space within the cavity. This is necessary to achieve a balance of air pressure inside and outside the box 1. Specifically, if the air pressure inside the cavity of the box 1 is the same as the air pressure of the external environment, the airbag 4 inside the cavity of the box 1 will maintain a certain pressure. Figure 4 As shown in the natural state, it neither expands nor contracts; if the air pressure inside the chamber 1 is greater than the air pressure of the external environment, then the air bladder 4 inside the chamber 1 will... Figure 5 As shown, it will be compressed under greater air pressure, causing the gas inside the airbag 4 to be discharged into the external environment through the vent valve 3. The volume of the airbag 4 decreases, and the gas inside the chamber 1 has a larger diffusion space, thus reducing the air pressure inside the chamber 1. If the air pressure inside the chamber 1 is lower than the external air pressure, the greater air pressure from the external environment will enter the internal space of the airbag 4 through the vent valve 3, such as... Figure 6 As shown, the airbag 4 inflates, increasing its volume and occupying more space within the housing 1. This compresses the gas inside the housing 1, increasing the air pressure. Thus, pressure balance is achieved inside and outside the housing 1. This arrangement, placing the airbag 4 inside the housing 1, integrates the battery pack, optimizes its structure, and not only provides protection for the airbag 4 within the housing 1, improving battery pack reliability, but also facilitates the installation and use of the battery pack in the vehicle.

[0037] Optionally, in addition to the airbag 4 being located inside the housing 1, the extinguishing medium is further made into an insulating extinguishing medium and filled into the inner cavity of the housing 1. In this configuration, because the inner cavity of the housing 1 is enclosed by the housing 1 and the airbag 4 to form a sealed space, the extinguishing medium can be pre-filled into the inner cavity of the housing 1 during the battery pack manufacturing process without leakage. This allows the extinguishing medium and the battery pack's cells 2, BDU (Battery Disconnect Unit / Battery Energy Distribution Unit), MBS (Battery Management System), and other electrical components to be located in the same space. This allows the cells 2 to be in an oxygen-free environment, reducing the heat generated when thermal runaway occurs, enabling timely extinguishing of the fire in the cells 2, and reducing the risk of thermal runaway spread. Since the extinguishing medium is pre-filled into the space where the electrical components are located, it must be an insulating extinguishing medium to avoid affecting the normal operation of the components. Specifically, the extinguishing medium can be a gas, such as nitrogen, carbon dioxide, or an inert gas. Alternatively, the extinguishing medium can be filled in other spaces and then enter the inner cavity of the housing 1 when the battery cell 2 experiences thermal runaway. For example, the extinguishing medium can be filled in the airbag 4 located inside the housing 1. When the battery cell 2 experiences thermal runaway, the airbag 4 will burn through, allowing the extinguishing medium to enter the inner cavity of the housing 1. In this case, to prevent the extinguishing medium from leaking through the vent valve 3 due to the airbag 4 exchanging air with the external environment, the extinguishing medium filled in the airbag 4 is preferably a non-gaseous medium, such as dry powder, foam, or other liquid media.

[0038] In another alternative embodiment, such as Figure 7 As shown, the airbag 4 is positioned outside the housing 1 and connected to the inner cavity of the housing 1 via the vent valve 3 and the air duct. In this configuration, the airbag 4 can be positioned above the top cover 102 of the housing 1 or below the bottom plate. If the air pressure inside the housing 1 is greater than the air pressure inside the airbag 4, the gas inside the housing 1 will be discharged through the vent valve 3 into the airbag 4 located outside the housing 1. Figure 6 As the expansion increases, the air pressure inside the chamber 1 decreases. If the air pressure inside the chamber 1 is lower than the air pressure inside the airbag 4, the gas in the airbag 4 will enter the chamber 1 through the vent valve 3. Figure 5As shown, the reduction in gas inside the airbag 4 leads to a decrease in its volume, thereby increasing the air pressure inside the housing 1. This method of placing the airbag 4 outside the housing 1 avoids the airbag 4 occupying the internal space of the housing 1, prevents the addition of the airbag 4 from affecting other components of the battery pack, and allows for more space inside the housing 1 to optimize the structural layout. In addition, the airbag 4 placed outside the housing 1 is not limited by the space inside the housing 1, and its structural dimensions can be designed more flexibly.

[0039] With the airbag 4 located outside the housing 1, the extinguishing medium can be filled in the inner cavity of the housing 1 and / or in the airbag 4. That is, it can be filled only in the inner cavity, or only in the airbag 4, or both the inner cavity and the airbag 4 can be filled. In order to ensure that the extinguishing medium filled in the airbag 4 can enter the inner cavity through the vent valve 3 during air exchange, the extinguishing medium needs to be a gaseous extinguishing medium, such as nitrogen, carbon dioxide, inert gas, etc.

[0040] In this application, when the airbag 4 is placed in the inner cavity of the box 1, there are many different options for the placement position, number of airbags, and shape of the airbag 4.

[0041] In optional embodiments, such as Figures 1-3 As shown, multiple airbags 4 are configured, including a top airbag 401 located between the top cover of the housing 1 and the battery cell 2, and a side airbag 402 located between the frame 101 of the housing 1 and the battery cell 2. In existing battery pack structures, there are gaps between the battery cell 2 and the top cover, and between the battery cell 2 and the frame 101. When setting the airbags 4, these gaps can be fully utilized to minimize or avoid modifications to other battery pack structures. Based on this, this application sets multiple airbags 4, with each airbag 4 occupying a different gap space to best adapt to the existing battery pack structure. Specifically, a top airbag 401 is placed in the gap between the top cover and the battery cell 2, and a side airbag 402 is placed between the battery cell 2 and the frame 101. Furthermore, due to the planar area between the battery cell 2 and the top cover (this planar area refers to...), the airbags 401 are positioned in the gap between the top cover and the battery cell 2, and the side airbags 402 are placed between the battery cell 2 and the frame 101. Figure 1The area of ​​the XY plane shown is relatively large, so multiple top airbags 401 can be laid flat in this gap. Similarly, since there are gaps between the frame 101 and the battery cell 2 on all four circumferential walls, multiple side airbags 402 can also be provided, located in multiple gaps around the perimeter, and / or multiple side airbags 402 can be laid flat in each gap around the perimeter. This not only makes full use of the unused space inside the housing 1, avoiding changes to the structural layout of the battery pack, but also allows for the provision of more airbags 4, improving ventilation. Of course, in optional embodiments, the number and position of the battery cell 2 in the housing can be changed, or the volume of the housing 1 can be changed to specifically reserve space for the airbags 4.

[0042] In addition, the airbag 4 can be set in many other different ways, such as setting only one airbag 4, because there is also a gap between the battery cell 2 and the bottom plate of the housing 1, so the only airbag 4 can be set between the battery cell 2 and the bottom plate.

[0043] like Figure 1 As shown, the vent valve 3 is installed on the frame 101 of the housing 1, the side airbag 402 is aligned with and connected to the vent valve 3, and the top airbag 401 is connected to the side airbag 402 through the first air guide pipe 5. In this configuration, based on the side airbag 402 between the battery cell 2 and the frame 101, at least the part of the housing 1 that is aligned with the vent valve 3 on the frame 101 is provided with a side airbag 402. This allows for direct communication between the airbag 4 and the vent valve 3, improving the ventilation effect. At the same time, other parts in the gap between the battery cell 2 and the frame 101 can be provided with other side airbags 402 or no side airbags 402 may be provided. The top airbag 401 located between the battery cell 2 and the top cover is connected to the side airbag 402 through the first air guide tube 5, allowing the gas in the top airbag 401 and the gas in the side airbag 402 to circulate through the first air guide tube 5, ensuring the normal expansion and contraction of the top airbag 401. In addition, the side airbag 402 may not be provided at the part of the box 1 that is aligned with the air valve 3 on the frame 101. The top airbag 401 and / or the side airbag 402 provided in other parts are connected to the air valve 3 through the air guide tube.

[0044] As described above, when multiple top airbags 401 are configured, the multiple top airbags 401 are connected in series through the second air guide tube 6, or the multiple top airbags 401 are connected to the side airbags 402 respectively through multiple first air guide tubes 5. That is, as Figure 1 and Figure 2As shown, multiple top airbags 401 are connected in series via multiple second air ducts 6, and then the top airbags 401 located at the end of the series connection are connected to the side airbags 402 of the vent valve 3 via first air ducts 5. Alternatively, each top airbag 401 can be connected to the side airbag 402 of the vent valve 3 via a first air duct 5, so that all the top airbags 401 are arranged in parallel. Both connection methods can ensure that all airbags 401 are connected to the vent valve 3. The first air duct 5 and the second air duct 6 can be rigid pipes to avoid obstruction of gas flow due to accidental compression, or they can be flexible pipes, which facilitates flexible arrangement of the pipes inside the battery pack.

[0045] like Figures 1-3 As shown, the planar area of ​​the top airbag 401 (this planar area refers to...) Figure 1 or Figure 2 The area of ​​the XY plane shown is greater than the planar area of ​​the side airbag 402 (this planar area refers to...). Figure 1 or Figure 2 (As shown in the XZ plane area), the thickness of the top airbag 401 in the Z direction is less than the thickness of the side airbag 402 in the Y direction. This allows the added airbag 4 to better fit into the unused space within the housing 1, avoiding modifications to the existing structure of the battery pack and making the technical solution easier to implement.

[0046] In addition, based on the premise that it can be normally installed in an unused space, the planar shape of the airbag 4 can be Figure 2 and Figure 3 The rectangle shown can also be a circle, an ellipse, or other polygons.

[0047] And, as Figure 7 As shown, when the airbag 4 is located outside the box 1, the airbag 4 may also include the top airbag 401 mentioned above. Its shape, size and setting method (such as setting it parallel to the top cover 102 or the bottom plate, connecting it to the vent valve 3 through the first air duct 5, or connecting it to each other in series through the second air duct 6) can be the same as when it is located inside the box 1.

[0048] Based on the battery pack described above, this application also provides a vehicle that includes the aforementioned battery pack. The beneficial effects of the battery pack on the vehicle are described above and will not be repeated here.

[0049] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0050] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0051] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0052] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0053] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0054] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A battery pack, characterized by, include: The housing has an internal cavity to accommodate the battery cells; A vent valve is installed on the housing and enables communication between the inside and outside of the housing; An airbag isolates the inner cavity of the box from the external environment of the box, and is connected to the vent valve so that it can communicate with the external environment of the box or with the inner cavity of the box through the vent valve; Fire extinguishing medium is filled in the inner cavity of the housing and / or the airbag to extinguish the fire in the battery cell.

2. The battery pack according to claim 1, characterized in that, The airbag is located inside the cavity of the box and is connected to the external environment of the box through the vent valve.

3. The battery pack of claim 2, wherein, The extinguishing medium is an insulating extinguishing medium and is filled in the inner cavity of the box.

4. The battery pack of claim 1, wherein, The airbag is located on the outside of the box and is connected to the inner cavity of the box through the vent valve.

5. The battery pack of claim 4, wherein, The extinguishing medium is a gaseous extinguishing medium, and it is filled in the inner cavity of the box and / or the airbag.

6. The battery pack of claim 2, wherein, The airbags are configured in multiple ways, including a top airbag located between the top cover of the housing and the battery cell, and a side airbag located between the side frame of the housing and the battery cell.

7. The battery pack of claim 6, wherein, The vent valve is located on the side frame of the housing, the side airbag is aligned with and connected to the vent valve, and the top airbag is connected to the side airbag through the first air guide tube.

8. The battery pack of claim 7, wherein, The top airbags are multiple, and the multiple top airbags are connected in series through a second air guide tube, or the multiple top airbags are respectively connected to the side airbags through multiple first air guide tubes.

9. The battery pack of any one of claims 6-8, wherein, The planar area of ​​the top airbag is larger than that of the side airbag, and the thickness of the top airbag is smaller than that of the side airbag.

10. A vehicle comprising a power battery, characterized by The power battery is the battery pack according to any one of claims 1-9.

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