Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and an electric equipment, wherein the battery monomer comprises a shell, a space is formed in the shell, the shell comprises a first wall part, the first wall part is provided with a pressure relief mechanism; an electrode assembly is arranged in the space; a bottom support plate is arranged in the space and is arranged between the first wall part and the electrode assembly along a third direction to support the electrode assembly; wherein the bottom support plate comprises a plate body and a first support part, the plate body has a first area and a second area arranged along a second direction, the normal projection of the pressure relief mechanism on the plate body along the third direction is located in the first area, at least one first support part is arranged on the side of the second area facing the first wall part, and the size of the first support part along the first direction is less than L1, so that a gap is formed between the plate body and the first wall part, and the gap is communicated with the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. The application can improve the reliability of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0002] With the development of battery technology, battery devices are being applied in more and more fields, gradually replacing traditional fossil fuels in areas such as automotive power. To effectively release the pressure inside the battery cell casing, a pressure relief mechanism is installed on the battery cell casing.

[0003] In related technologies, the electrode assembly is supported on the pressure relief mechanism. The distance between the pressure relief mechanism and the electrode assembly is extremely small, which makes it difficult for high-pressure gas inside the casing to reach the pressure relief mechanism. When the battery cell experiences thermal runaway, the pressure relief mechanism may be blocked by the bottom plate, which may cause fire, explosion and other risks, resulting in low reliability of the battery cell. Summary of the Invention

[0004] In view of the above problems, this application provides battery cells, battery devices and electrical equipment to reduce or eliminate the risk of fire and explosion caused by thermal runaway of battery cells, thereby improving the reliability of battery cells.

[0005] In a first aspect, this application provides a battery cell, comprising: a housing having a receiving space, the housing including a first wall portion, the first wall portion having a pressure relief mechanism, the dimension of the pressure relief mechanism along a first direction being defined as L1, and the dimension along a second direction perpendicular to the first direction being defined as L2, wherein L1 > L2; an electrode assembly disposed within the receiving space; and a bottom support plate disposed within the receiving space and disposed along a third direction between the first wall portion and the electrode assembly for supporting the electrode assembly, the third direction being perpendicular to both the first and second directions; wherein the bottom support plate includes a plate body and a first support portion, the plate body having a first region and a second region arranged along the second direction, the orthographic projection of the pressure relief mechanism along the third direction onto the plate body being located within the first region, and at least one first support portion being provided on the side of the second region facing the first wall portion, the side of the first support portion away from the plate body abutting against the first wall portion, the dimension of the first support portion along the first direction being less than L1, so as to form a gap between the second region of the plate body and the first wall portion, the gap connecting the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. By placing the base plate between the first wall portion where the pressure relief mechanism is located and the electrode assembly, and with the orthographic projection of the pressure relief mechanism along a third direction onto the plate body located within the first region of the plate body, the first and second regions of the plate body are arranged along a second direction. Simultaneously, at least one first support portion is provided on the side of the second region of the plate body facing the first wall portion, and the dimension of the first support portion along the first direction is smaller than the dimension L1 of the pressure relief mechanism along the first direction, thus forming a gap between the second region of the plate body and the first wall portion. This gap connects the space located on the side of the plate body opposite to the pressure relief mechanism and the pressure relief mechanism. Since the dimension L1 of the pressure relief mechanism along the first direction is larger than its dimension L2 along the second direction, providing at least one first support portion in the second region of the plate body can lift the base plate. The plate's support stability reduces or eliminates the risk of the bottom support plate sagging or collapsing towards the pressure relief mechanism, thereby reducing the possibility of the bottom support plate blocking the pressure relief mechanism. This can reduce or eliminate the risk of fire or explosion caused by the bottom support plate blocking the pressure relief mechanism when the battery cell experiences thermal runaway, thus improving the reliability of the battery cell. On the other hand, since the second region of the plate body and the pressure relief mechanism are arranged along the second direction, the high-pressure gas flow rate from the space on the side of the plate body away from the pressure relief mechanism to the pressure relief mechanism can be increased, allowing the pressure inside the containment space to be released quickly. This maintains the pressure balance inside and outside the battery cell, reducing or eliminating the risk of fire or explosion when the battery cell experiences thermal runaway, further improving the reliability of the battery cell.

[0006] In some embodiments, a plurality of first support portions are provided on the side of the second region facing the first wall portion, and the plurality of first support portions are spaced apart along a first direction. By arranging the plurality of first support portions spaced apart along the first direction to form a plurality of gaps spaced apart along the first direction between the plate body and the first wall portion, it is possible not only to further improve the discharge efficiency and stability of high-pressure gas in the space of the plate body away from the pressure relief mechanism, enabling the pressure relief mechanism to continuously and efficiently relieve pressure, thus helping to improve pressure relief efficiency, but also to reduce the noise of high-pressure gas discharge and improve user experience.

[0007] In some embodiments, the sum of the dimensions of a plurality of first support portions spaced apart along a first direction is defined as L3, and the dimension of the first support portion along a third direction is defined as h, where 0.21 ≤ h × (L1 - L3) / L1 ≤ 1.11. By making the product of the ratio between the difference between the dimension L1 of the pressure relief mechanism along the first direction and the sum of the dimensions L3 of the plurality of first support portions spaced apart along the first direction and the dimension L1 of the pressure relief mechanism along the first direction and the dimension h of the first support portion along the third direction satisfy: 0.21 ≤ h × (L1 - L3) / L1 ≤ 1.11, the sum of the flow areas of the gap in the first direction and the third direction is larger, so that the high-pressure gas generated when the battery cell experiences thermal runaway can reach the pressure relief mechanism more smoothly. This enables the pressure relief rate of the pressure relief mechanism to be much greater than the pressure rise rate inside the second accommodating cavity, thereby reducing the risk of battery cell fire and explosion.

[0008] In some embodiments, the plate body has two second regions, which are located on opposite sides of the first region along the second direction. A first support portion is provided on the side of each second region facing the first wall. By distributing the two second regions on opposite sides of the first region along the second direction, and simultaneously providing the first support portion on the side of each second region facing the first wall, the supporting force can be evenly distributed on the base plate, reducing or eliminating the risks of the base plate swaying, tilting, sagging towards the pressure relief mechanism, or collapsing. This allows the base plate to stably support the electrode assembly, thereby reducing the risk of displacement or damage to the battery cells and further improving the reliability of the battery device. Furthermore, the formation of multiple spaces connecting the plate body to the side facing away from the pressure relief mechanism and the gap in the pressure relief mechanism on opposite sides of the first region along the second direction increases the exhaust path and exhaust area inside the battery cells, making exhaust smoother and improving exhaust efficiency.

[0009] In some embodiments, the first support portion includes a composite layer protruding from the side of the plate body facing the first wall portion. The composite layer has better high-temperature resistance, ensuring that the first support portion will not be damaged by the heat flowing through it when the battery cell experiences thermal runaway. This reduces or eliminates the risk of the base plate shaking, tilting, sagging towards the pressure relief mechanism, or collapsing due to heat damage to the first support portion. It also allows high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism to be normally discharged to the pressure relief mechanism, thereby suppressing the chain reaction caused by the thermal runaway of the battery cell and ensuring that the base plate can provide sufficient safety protection when the battery cell experiences thermal runaway.

[0010] In some embodiments, the side of the plate body closest to the electrode assembly abuts against the electrode assembly. By abutting the side of the plate body closest to the electrode assembly against the electrode assembly, the plate body can be stably supported on the plate body, so that the electrode assembly will not be displaced or deformed during the use of the battery device. Therefore, the plate body can provide support and protection for the electrode assembly. Furthermore, it allows the high-pressure gas and heat in the battery cell to quickly flow through the gap between the second region and the first wall of the plate body to the pressure relief mechanism, reducing or preventing the gas and heat from remaining between the electrode assembly and the plate body.

[0011] In some embodiments, the distance between the first support and the pressure relief mechanism along the second direction is d, where d ≥ 2 mm. By making the distance d between the first support and the pressure relief mechanism in the second direction greater than or equal to 2 mm, on the one hand, the risk of the first support blocking the pressure relief mechanism can be reduced, allowing high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism to reach the pressure relief mechanism smoothly; on the other hand, since the pressure and temperature near the pressure relief mechanism are relatively high, by making the first support and the pressure relief mechanism a certain distance apart, the risk of air pressure and heat damaging the first support can be reduced, thereby reducing the risk of the pressure relief mechanism being blocked due to the bottom plate shaking, tilting, or sagging or collapsing towards the pressure relief mechanism.

[0012] In some embodiments, a first through hole is provided in the first region; and / or a second through hole is provided in the region of the second region where no first support is provided. By providing a first through hole in the first region of the plate body and / or a second through hole in the second region of the plate body, both the first and second through holes connect to the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. This ensures that when a battery cell experiences thermal runaway, the high-pressure gas in the space located on the side of the plate body away from the pressure relief mechanism will not accumulate on the side of the bottom plate away from the first wall, thus mitigating the aggravation of thermal runaway.

[0013] In some embodiments, the plate body further includes a third region and a fourth region, which are located on opposite sides of the first region along a first direction. A second support portion is provided on the side of the third region facing the first wall and / or the side of the fourth region facing the first wall, the second support portion being spaced apart from the first support portion, and the side of the second support portion facing away from the plate body abutting against the first wall. By providing a second support portion on the side of the third region and / or the fourth region facing the first wall, and having the side of the second support portion facing away from the plate body abutting against the first wall, the support capacity and protection effect of the base plate for the electrode assembly can be improved, reducing the risk of the electrode assembly shaking or displacement.

[0014] In some embodiments, the housing further includes a second wall and a third wall disposed opposite to each other in a second direction, with a first wall connected between the second wall and the third wall; in a third region, a first channel is formed between the second support and the second wall and / or between the second support and the third wall, the first channel connecting the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism; in a fourth region, a second channel is formed between the second support and the second wall and / or between the second support and the third wall, the second channel connecting the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. By providing the first and second channels to increase the exhaust path and exhaust area inside the battery cell, the high-pressure gas in the space located on the side of the plate body away from the pressure relief mechanism can flow to the pressure relief mechanism not only through the gap between the second region of the plate body and the first wall, but also through the first and second channels, which can further improve the pressure release rate inside the containment space, further reduce the probability of fire, explosion, and other risks caused by thermal runaway of the battery cell, and further improve the reliability of the battery cell, thereby further improving the reliability of the battery device.

[0015] In some embodiments, the second support portion includes a first sub-support portion and a second sub-support portion spaced apart along a second direction, with a third channel formed between the first and second sub-support portions. The third channel connects the space located on the side of the plate body opposite to the pressure relief mechanism and the pressure relief mechanism. By forming a third channel between the first and second sub-support portions, the exhaust path and exhaust area inside the battery cell are further increased, enabling a more effective increase in exhaust volume when thermal runaway occurs in the battery cell, further reducing the accumulation of pressure inside the containment space, thereby further reducing the impact of thermal runaway on the battery cell.

[0016] In some embodiments, a third through hole is provided in the area of ​​the third region and / or the fourth region where the second support is not provided. By providing a third through hole in the area of ​​the third region and / or the fourth region where the second support is not provided, the third through hole connects the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. This allows high-pressure gas in the space located on the side of the plate body away from the pressure relief mechanism to flow to the pressure relief mechanism through the third through hole when thermal runaway occurs in a single battery cell. This further reduces the gas pressure on the side of the bottom plate away from the first wall, and can further mitigate thermal runaway.

[0017] In some embodiments, the area S1 of the pressure relief mechanism in the preset plane and the area S2 of the first wall in the preset plane satisfy: S1 / S2≥0.5; the preset plane is parallel to the first direction and the second direction. By ensuring that the area S1 of the pressure relief mechanism in the preset plane and the area S2 of the first wall in the preset plane satisfy: S1 / S2≥0.5, the area of ​​the pressure relief mechanism is larger, which can more effectively release the pressure and heat inside the containment space, thereby reducing the air pressure and temperature inside the containment space, reducing the risk of fire or explosion of the electrode assembly, and further improving the reliability of the battery device.

[0018] Secondly, this application provides a battery device, which includes a housing and a battery cell as described in any of the above embodiments, with the battery cell disposed within the housing.

[0019] Thirdly, this application provides an electrical device, which includes the aforementioned battery device. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0021] Figure 1 This is a schematic diagram of the structure of an embodiment of the electrical equipment provided in this application;

[0022] Figure 2 This is an exploded structural diagram of an embodiment of the battery device provided in this application;

[0023] Figure 3 This is a schematic diagram of the exploded partial structure of an embodiment of the battery cell provided in this application;

[0024] Figure 4 This is a schematic diagram of the structure of the base plate of the battery device provided in this application in the first embodiment;

[0025] Figure 5This is a schematic diagram of the structure of the base plate of the battery device provided in this application, representing the second embodiment.

[0026] Figure 6 This is a schematic diagram of the structure of the base plate of the battery device provided in this application, in the third embodiment.

[0027] Figure 7 This is a schematic diagram of the structure of the fourth embodiment of the base plate of the battery device provided in this application;

[0028] Figure 8 This is a schematic diagram of the fifth embodiment of the base plate of the battery device provided in this application.

[0029] The reference numerals in the detailed embodiments are as follows:

[0030] Vehicle 1000a, battery cell 20, casing 21, accommodating space 21a, first wall 211, second wall 212, third wall 213, opening 2111, pressure relief mechanism 22, base plate 24, plate body 241, first region 2411, second region 2412, third region 2413, fourth region 2414, first support 242, composite layer 2421, second support 243, first sub-support 2431, second sub-support 2 432, gap 242a, first gap 242a1, second gap 242a2, first through hole 2411a, second through hole 2412a, third through hole 2413a, first channel 244, second channel 245, third channel 246, protective film 25, explosion-proof valve 30, heat insulation pad 40, busbar component 50, protective component 60, battery device 100a, controller 200a, motor 300a, housing 10, first part 11, second part 12. Detailed Implementation

[0031] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0032] 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 application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0033] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0035] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 the embodiments of this application and simplifying the description, and are not intended to 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 the embodiments of this application.

[0036] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate heat exchange medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] With the development of battery technology, battery devices are being applied in more and more fields, gradually replacing traditional fossil fuels in areas such as automotive power. To effectively release the pressure inside the battery cell casing, a pressure relief mechanism is installed on the casing. This mechanism can quickly respond and release the high-pressure gas inside the casing when thermal runaway occurs, reducing the internal pressure and thus minimizing the accumulation of heat and pressure. However, if the electrode assembly is directly supported by the pressure relief mechanism, the distance between the mechanism and the assembly will be extremely small, making it difficult for the high-pressure gas inside the casing to escape smoothly.

[0039] In related technologies, a base plate is supported between the pressure relief mechanism and the electrode assembly to increase the distance between them, facilitating the arrival of high-pressure gas inside the casing at the pressure relief mechanism and its discharge. However, in existing systems, the support portion of the base plate is located outside both ends of the base plate along the length of the pressure relief mechanism. When the pressure relief mechanism is long, the area of ​​the base plate corresponding to the pressure relief mechanism is prone to drooping or collapsing towards it, posing a risk of blocking the pressure relief mechanism. When a battery cell experiences thermal runaway, the base plate may block the pressure relief mechanism, potentially leading to fire or explosion, thus resulting in low reliability of the battery device.

[0040] Based on the above considerations, this application provides battery cells, battery devices, and electrical equipment. The battery cell includes a housing, an electrode assembly, and a base plate. The housing forms an accommodating space and includes a first wall portion. The first wall portion is provided with a pressure relief mechanism. The dimension of the pressure relief mechanism along a first direction is defined as L1, and the dimension along a second direction perpendicular to the first direction is defined as L2, wherein L1 > L2. The electrode assembly is disposed within the accommodating space. The base plate is disposed within the accommodating space and is disposed between the first wall portion and the electrode assembly along a third direction for supporting the electrode assembly. The third direction is perpendicular to both the first and second directions. The base plate includes a plate body and a first support portion. The plate body has a first region and a second region arranged along the second direction. The orthographic projection of the pressure relief mechanism along the third direction onto the plate body is located within the first region. At least one first support portion is provided on the side of the second region facing the first wall portion. The side of the first support portion away from the plate body abuts against the first wall portion. The dimension of the first support portion along the first direction is less than L1, so as to form a gap between the second region of the plate body and the first wall portion. The gap connects the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. The side of the first support portion away from the plate body abuts against the first wall portion.

[0041] By placing the base plate between the first wall portion where the pressure relief mechanism is located and the electrode assembly, and with the orthographic projection of the pressure relief mechanism along a third direction onto the plate body located within the first region of the plate body, the first and second regions of the plate body are arranged along a second direction. Simultaneously, at least one first support portion is provided on the side of the second region of the plate body facing the first wall portion, and the dimension of the first support portion along the first direction is smaller than the dimension L1 of the pressure relief mechanism along the first direction, thus forming a gap between the second region of the plate body and the first wall portion. This gap connects the space located on the side of the plate body opposite to the pressure relief mechanism and the pressure relief mechanism. Since the dimension L1 of the pressure relief mechanism along the first direction is larger than its dimension L2 along the second direction, providing at least one first support portion in the second region of the plate body can lift the base plate. The support stability of the plate reduces or eliminates the risk of the area corresponding to the pressure relief mechanism sagging or collapsing towards the pressure relief mechanism, thereby reducing the possibility of the bottom plate blocking the pressure relief mechanism. This can reduce or eliminate the risk of fire and explosion caused by the bottom plate blocking the pressure relief mechanism when the battery cell experiences thermal runaway, thus improving the reliability of the battery cell. On the other hand, since the second area of ​​the plate body and the pressure relief mechanism are arranged along the second direction, the rate at which high-pressure gas flows from the space on the side of the plate body away from the pressure relief mechanism to the pressure relief mechanism can be increased, allowing the pressure inside the containment space to be released quickly. This maintains the pressure balance inside and outside the battery cell, reducing or eliminating the risk of fire and explosion when the battery cell experiences thermal runaway, further improving the reliability of the battery cell.

[0042] The battery cell, battery device, and electrical equipment disclosed in this application can be used in electrical equipment that uses the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical equipment can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0043] For ease of explanation, the following embodiments will be described using a vehicle 1000a as an example of an electrical device according to an embodiment of this application.

[0044] Please refer to Figure 1The vehicle 1000a can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery device 100a is installed inside the vehicle 1000a, and the battery device 100a can be located at the bottom of the vehicle 1000a. The battery device 100a can be used to power the vehicle 1000a; for example, the battery device 100a can serve as the operating power source for the vehicle 1000a. The vehicle 1000a may also include a controller 200a and a motor 300a. The controller 200a is used to control the battery device 100a to supply power to the motor 300a, for example, to meet the power needs of the vehicle 1000a during starting, navigation, and driving.

[0045] In some embodiments of this application, the battery device 100a can not only serve as the operating power source for the vehicle 1000a, but also as the driving power source for the vehicle 1000a, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000a.

[0046] In some embodiments, the battery device 100a may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0047] Please refer to Figure 2 The battery device 100a mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells 20, which are connected in series, parallel, or mixed connection via busbars 50. Two adjacent busbars 50 are provided with protective components 60. The protective components 60 may be insulating components, and they can reduce or eliminate the risk of short circuits caused by direct contact between two adjacent busbars 50, thereby improving the reliability of the battery device 100a.

[0048] In some embodiments, a heat insulation pad 40 is provided between two adjacent battery cells 20. The heat insulation pad 40 can not only reduce or eliminate heat transfer between two adjacent battery cells 20, reducing the risk of one battery cell 20 being affected by excessive temperature, but also fix the battery cells 20 so that they do not swing during use, reducing or eliminating the risk of interference between two adjacent battery cells 20.

[0049] In this embodiment of the application, the battery cell 20 can be a secondary battery, which refers to a battery cell 20 that can be used again after being discharged by recharging to activate the active materials.

[0050] The battery cell 20 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0051] In some embodiments, the battery device 100a includes a housing 10 and a battery cell 20, wherein the battery cell 20 is disposed within the housing 10.

[0052] In some embodiments, the housing 10 may be part of the chassis structure of the vehicle 1000a. For example, a portion of the housing 10 may be at least a part of the chassis of the vehicle 1000a, or a portion of the housing 10 may be at least a part of the crossbeams and longitudinal beams of the vehicle 1000a.

[0053] Please continue to refer to Figure 2 The housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first part 11 and a second part 12, which overlap each other, and together define a receiving cavity 10a for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure, with the first part 11 covering the open side of the second part 12 so that the first part 11 and the second part 12 together define the receiving cavity 10a; the first part 11 and the second part 12 may also be hollow structures with one side open, with the open side of the first part 11 covering the open side of the second part 12. Of course, the housing 10 formed by the first part 11 and the second part 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0054] In some embodiments, an explosion-proof valve 30 is provided on the first part 11. The explosion-proof valve 30 can automatically open when the pressure in the accommodating cavity 10a exceeds the safe range, so as to release the high-pressure gas in the accommodating cavity 10a, thereby reducing or eliminating the risk of fire or explosion caused by excessive internal pressure in the accommodating cavity 10a.

[0055] In some embodiments, please refer to Figures 2 to 5The battery cell 20 includes a housing 21, an electrode assembly, and a base plate 24. The housing 21 forms an accommodating space 21a and includes a first wall portion 211. The first wall portion 211 is provided with a pressure relief mechanism 22. The pressure relief mechanism 22 has a dimension L1 along a first direction XX and a dimension L2 along a second direction YY perpendicular to the first direction XX, wherein L1 > L2. The electrode assembly is disposed within the accommodating space 21a. The base plate 24 is disposed within the accommodating space 21a and is disposed between the first wall portion 211 and the electrode assembly along a third direction ZZ to support the electrode assembly. The third direction ZZ is perpendicular to both the first direction XX and the second direction YY. The base plate 24 includes a plate body 241 and a first support portion 24. 2. The plate body 241 has a first region 2411 and a second region 2412 arranged along the second direction YY. The orthographic projection of the pressure relief mechanism 22 along the third direction ZZ on the plate body 241 is located in the first region 2411. The second region 2412 is provided with at least one first support portion 242 on the side facing the first wall portion 211. The side of the first support portion 242 away from the plate body 241 abuts against the first wall portion 211. The size of the first support portion 242 along the first direction XX is less than L1, so as to form a gap 242a between the second region 2412 and the first wall portion 211 of the plate body 241. The gap 242a connects the space 21a located on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22.

[0056] The housing 21 is a component used to house the electrode assembly. The housing 21 can be a hollow structure with an opening at one end, located on a different side from the first wall portion 211. The battery cell 20 also includes an end cap assembly, which covers the opening and connects to the housing 21 to form a receiving space 21a for housing the electrode assembly. The receiving space 21a is filled with an electrolyte, such as a liquid electrolyte solution. The housing 21 can take various shapes, such as a cube, cuboid, cylinder, or prism. This embodiment uses a cuboid shape as an example for illustration.

[0057] The electrode assembly is the component in the battery cell 20 where the electrochemical reaction occurs. The battery cell 20 includes one or more electrode assemblies. Each electrode assembly has a positive electrode, a negative electrode, and a separator. The positive electrode, negative electrode, and separator are wound or stacked to form the electrode assembly, with the separator located between the positive and negative electrode. The portions of the positive and negative electrode with active material constitute the main body of the electrode assembly, while the portions of the positive electrode without active material constitute the positive electrode tab, and the portions of the negative electrode without active material constitute the negative electrode tab. The positive and negative electrode tabs can be located together at one end of the main body or separately at both ends. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the positive and negative electrode tabs connect to the electrode terminals to form a current loop.

[0058] In some embodiments, a pressure relief mechanism 22 is provided on the housing 21. The pressure relief mechanism 22 is used to release the internal pressure of the battery cell 20.

[0059] As an example, the internal pressure or temperature of the battery cell 20 is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold, the pressure relief mechanism 22 is activated or a weak structure provided in the pressure relief mechanism 22 is destroyed, thereby forming an opening or channel for the release of internal pressure or temperature. The threshold design varies depending on the design requirements. The threshold may depend on one or more of the materials of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 20.

[0060] As an example, the pressure relief mechanism 22 can be integrally formed with the housing 21, for example, by making grooves on the housing 21 to form a weak structure, which serves as the pressure relief mechanism 22.

[0061] The pressure relief mechanism 22 can also be separately disposed from and connected to the housing 21, for example, by welding it to the housing 21 or by connecting it through other components. As an example, the pressure relief mechanism 22 is provided with grooves to form a weak structure.

[0062] As an example, the pressure relief mechanism 22 can take the form of an explosion-proof valve, a balancing valve, a gas valve, a pressure relief valve, or a safety valve.

[0063] In some embodiments, the pressure relief mechanism 22 is disposed on the first wall portion 211 of the housing, which may be the bottom wall or side wall of the housing 21. The bottom support plate 24 may be disposed between the bottom wall of the housing 21 and the electrode assembly, or between the side wall of the housing 21 and the electrode assembly. This application uses the example of the first wall portion 211 being the bottom wall of the housing 21 and the bottom support plate 24 being disposed between the bottom wall of the housing 21 and the electrode assembly for illustration.

[0064] In some embodiments, such as Figure 3 As shown, the first wall portion 211 has an opening 2111. The opening 2111 connects the receiving cavity 10a and the receiving space 21a. A pressure relief mechanism 22 is provided at the opening 2111 of the first wall portion 211. The pressure relief mechanism 22 can respond quickly to thermal runaway of the battery cell 20 and release high-pressure gas in the space on the side of the plate body 241 opposite to the pressure relief mechanism 22 to the receiving cavity 10a, thereby reducing the pressure in the receiving space 21a and reducing the accumulation of heat and gas pressure.

[0065] The plane containing the first wall portion 211 is parallel to the first direction XX and the second direction YY. The pressure relief mechanism 22 extends along the first direction XX, and the dimension of the pressure relief mechanism 22 along the first direction XX is L1. The dimension of the pressure relief mechanism 22 along the second direction YY is L2. The first dimension L1 of the pressure relief mechanism 22 is greater than the second dimension L2.

[0066] The electrode assembly, the base plate 24, and the first wall portion 211 are arranged sequentially in the third direction ZZ. The base plate 24 not only supports the electrode assembly but also increases the distance between the electrode assembly and the first wall portion 211, preventing the electrode assembly from blocking the pressure relief mechanism 22.

[0067] The pressure relief mechanism 22 corresponds to the first region 2411 of the plate body 241. The second region 2412 of the plate body 241 corresponds to the region on at least one side of the first wall portion 211 along the second direction YY where the pressure relief mechanism 22 is not provided. The first support portion 242 provided on the side of the second region 2412 facing the first wall portion 211 is spaced apart from the pressure relief mechanism 22, so that the first support portion 242 will not damage the pressure relief mechanism 22 or affect the normal pressure relief of the pressure relief mechanism 22.

[0068] In some embodiments, such as Figure 3 As shown, the battery device 100a also includes a protective film 25. The protective film 25 is disposed on the side of the pressure relief mechanism 22 facing away from the base plate 24. The protective film 25 is used to protect the pressure relief mechanism and can reduce the impact of dust and other impurities on the pressure relief mechanism 22.

[0069] In some embodiments, the first support portion 242 is integrally formed on the side of the plate body 241 facing the first wall portion 211; or the first support portion 242 is fixedly connected to the side of the plate body 241 facing the first wall portion 211. The first support portion 242 is fixedly connected to the plate body 241 by means including but not limited to adhesive bonding or welding.

[0070] In some embodiments, the base plate 24 may be selected from a metallic or non-metallic material. When the base plate 24 is selected from a metallic material, the material of the base plate 24 may be aluminum, copper, aluminum alloy, aluminum-manganese alloy, or stainless steel, but is not limited thereto. When the base plate 24 is selected from a non-metallic material, the material of the base plate 24 may be polyethylene, polypropylene, polyimide, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, or propylene-tetrafluoroethylene copolymer, but is not limited thereto.

[0071] This application places a base plate 24 between the first wall portion 211 where the pressure relief mechanism 22 is located and the electrode assembly. The orthographic projection of the pressure relief mechanism 22 along the third direction YY onto the plate body 241 is located within the first region 2411 of the plate body 241. The first region 2411 and the second region 2412 of the plate body 241 are arranged along the second direction YY. At the same time, at least one first support portion 242 is provided on the side of the second region 2412 of the plate body 241 facing the first wall portion 211. The dimension of the first support portion 242 along the first direction XX is smaller than the dimension L1 of the pressure relief mechanism 22 along the first direction XX, so as to form a gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211. The gap 242a connects the space located on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22. On the one hand, since the dimension L1 of the pressure relief mechanism 22 along the first direction XX is larger than its dimension L2 along the second direction YY, the second region 2412 of the plate body 241... Region 2412 is provided with at least one first support 242, which can improve the support stability of the base plate 24, reduce or eliminate the risk of the area corresponding to the base plate 24 and the pressure relief mechanism 22 sagging or collapsing towards the pressure relief mechanism 22, thereby reducing the possibility of the base plate 24 blocking the pressure relief mechanism 22. When the battery cell 20 experiences thermal runaway, it can reduce or eliminate the risk of fire or explosion caused by the base plate 24 blocking the pressure relief mechanism 22, thereby improving the reliability of the battery cell 20. On the other hand, since the second region 2412 of the plate body 241 and the pressure relief mechanism 22 are arranged along the second direction YY, the high pressure gas in the space of the plate body 241 away from the pressure relief mechanism 22 can be increased to the speed at which the high pressure gas flows to the pressure relief mechanism 22, so that the pressure inside the accommodating space 21a can be released quickly, thereby maintaining the pressure balance inside and outside the battery cell 20. This can reduce or eliminate the risk of fire or explosion caused by the battery cell 20 when thermal runaway occurs, thereby further improving the reliability of the battery cell 20.

[0072] In some embodiments, a plurality of first support portions 242 are provided on the side of the second region 2412 facing the first wall portion 211, and the plurality of first support portions 242 are spaced apart along the first direction XX.

[0073] By arranging multiple first support portions 242 at intervals along the first direction XX to form multiple gaps 242a at intervals along the first direction XX between the plate body 241 and the first wall portion 211, it is possible not only to further improve the discharge efficiency and stability of high-pressure gas in the space of the plate body 241 away from the pressure relief mechanism 22, enabling the pressure relief mechanism 22 to continuously and efficiently relieve pressure, thus helping to improve pressure relief efficiency, but also to reduce the noise of high-pressure gas discharge and improve user experience.

[0074] In some embodiments, such as Figure 1As shown, the sum of the dimensions of a plurality of first support portions 242 spaced apart along the first direction XX is defined as L3, and the dimension of the first support portion 242 along the third direction ZZ is h, where 0.21≤h×(L1-L3) / L1≤1.11.

[0075] The dimension of the first support portion 242 along the third direction ZZ is the thickness of the first support portion 242.

[0076] Wherein, 0.21≤h×(L1-L3) / L1≤1.11 means that the difference between the dimension L1 of the pressure relief mechanism 22 along the first direction XX and the sum of the dimensions L3 of the plurality of first support parts 242 spaced along the first direction XX along the first direction XX and the dimension L1 of the pressure relief mechanism 22 along the first direction XX, and the product of the dimension h of the first support part 242 along the third direction ZZ is greater than or equal to 0.21 and less than or equal to 1.11.

[0077] The ratio between the difference between the dimension L1 of the pressure relief mechanism 22 along the first direction XX and the sum L3 of the dimensions L3 of the plurality of first support parts 242 spaced apart along the first direction XX, and the dimension L1 of the pressure relief mechanism 22 along the first direction XX, and the product of this ratio with the dimension h of the first support part 242 along the third direction ZZ, can be 0.21, 0.25, 0.28, 0.3, 0.322, 0.351, 0.388, 0.4, 0.42, 0.455, 0.467, 0.49, or 0.5. The values ​​are 0.52, 0.545, 0.56, 0.58, 0.6, 0.615, 0.63, 0.65, 0.675, 0.691, 0.7, 0.735, 0.75, 0.77, 0.785, 0.8, 0.825, 0.85, 0.88, 0.9, 0.93, 0.95, 0.968, 0.98, 1, 1.11, etc. The specific product can be selected according to actual needs, as long as the above products are within the range of 0.21 to 1.11.

[0078] By making the ratio between the difference between the dimension L1 of the pressure relief mechanism 22 along the first direction XX and the sum of the dimensions L3 of the multiple first support parts 242 spaced apart along the first direction XX and the dimension L1 of the pressure relief mechanism 22 along the first direction XX, and the product of the dimension h of the first support part 242 along the third direction ZZ, satisfying: 0.21≤h×(L1-L3) / L1≤1.11, the sum of the flow areas of the gap 242a in the first direction XX and the third direction ZZ is larger, so that the high-pressure gas generated when the battery cell 20 experiences thermal runaway can reach the pressure relief mechanism 22 more smoothly. This enables the pressure relief rate of the pressure relief mechanism 22 to be much greater than the pressure rise rate inside the second accommodating cavity, thereby reducing the risk of fire and explosion of the battery cell 20.

[0079] In some embodiments, please continue to refer to Figures 4 to 5 The plate body 241 has two second regions 2412, which are located on opposite sides of the first region 2411 along the second direction YY. Each of the two second regions 2412 is provided with a first support portion 242 on the side facing the first wall portion 211.

[0080] In some embodiments, the first support portion 242 on the two second regions 2412 corresponds one-to-one.

[0081] In some embodiments, the first support portions 242 on the two second regions 2412 are staggered.

[0082] By distributing two second regions 2412 on opposite sides of the first region 2411 along the second direction YY, and simultaneously setting the first support portion 242 on the side of the two second regions 2412 facing the first wall portion 211, on the one hand, the supporting force can be evenly distributed on the base plate 24, reducing or eliminating the risks of the base plate 24 swaying, tilting, sagging or collapsing towards the pressure relief mechanism 22, thereby enabling the base plate 24 to stably support the electrode assembly, thereby reducing the risk of displacement or damage to the battery cell 20, and further improving the reliability of the battery device 100a; on the other hand, by forming a space on the side of the connecting plate body 241 away from the pressure relief mechanism 22 and multiple gaps 242a of the pressure relief mechanism 22 on opposite sides of the first region 2411 along the second direction YY, the exhaust path and exhaust area inside the battery cell 20 can be increased, making the exhaust smoother and improving the exhaust efficiency.

[0083] In some embodiments, please continue to refer to Figure 4 The first support portion 242 includes a composite layer 2421, which protrudes from the plate body 241 on the side facing the first wall portion 211.

[0084] In some embodiments, the composite layer 2421 may be composed of two or more polymer materials such as polyethylene, polypropylene, polyimide, and polytetrafluoroethylene, but the material of the composite layer 2421 is not limited to the above-mentioned polymer materials.

[0085] In some embodiments, the composite layer 2421 may be composed of two or more metal materials such as copper, aluminum, aluminum alloy, aluminum-manganese alloy, and stainless steel, but the material of the composite layer 2421 is not limited to the above-mentioned metal materials.

[0086] The composite layer 2421 has better high temperature resistance, so that the first support part 242 will not be damaged by the heat flowing through it when the battery cell 20 experiences thermal runaway. It can reduce or eliminate the risk of the bottom plate 24 shaking, tilting, or sagging or collapsing towards the pressure relief mechanism 22 due to the heat damage to the first support part 242. It can also allow the high pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 to be discharged normally to the pressure relief mechanism 22, thereby suppressing the chain reaction caused by the thermal runaway of the battery cell 20, so that the bottom plate 24 can provide sufficient safety protection when the battery cell 20 experiences thermal runaway.

[0087] In some embodiments, the side of the plate body 241 closest to the electrode assembly abuts against the electrode assembly.

[0088] The side of the plate body 241 closest to the electrode assembly is flat.

[0089] By bringing the side of the plate body 241 close to the electrode assembly into contact with the electrode assembly, the plate body 241 can be stably supported on the plate body 241, so that the electrode assembly will not be displaced or deformed during the use of the battery device 100a. Therefore, the plate body 241 can play a supporting and protective role for the electrode assembly. In addition, the high-pressure gas and heat in the battery cell 20 can be quickly circulated to the pressure relief mechanism 22 through the gap 242a between the second region 2412 and the first wall 211 of the plate body 241, reducing or avoiding the residual gas and heat between the electrode assembly and the plate body 241.

[0090] In some embodiments, please continue to refer to Figure 5 Along the second direction YY, the distance between the first support 242 and the pressure relief mechanism 22 is d, where d ≥ 2mm.

[0091] Along the second direction YY, the distance d between the first support 242 and the pressure relief mechanism 22 can be 2mm, 2.15mm, 2.35mm, 2.5mm, 2.75mm, 2.9mm, 3mm, 3.15mm, 3.33mm, 3.5mm, 3.65mm, 3.88mm, 4mm, 4.33mm, 4.5mm, 4.85mm, 5mm, etc. The specific value of the above distance can be selected according to actual needs, as long as the above distance is greater than or equal to 2mm.

[0092] By ensuring that the distance d between the first support 242 and the pressure relief mechanism 22 in the second direction YY is greater than or equal to 2mm, on the one hand, the risk of the first support 242 blocking the pressure relief mechanism 22 can be reduced, allowing high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 to reach the pressure relief mechanism 22 smoothly; on the other hand, since the pressure near the pressure relief mechanism 22 is relatively high and the temperature is also relatively high, by keeping the first support 242 and the pressure relief mechanism 22 at a certain distance, the risk of air pressure and heat damaging the first support 242 can be reduced, thereby reducing the risk of the pressure relief mechanism 22 being blocked due to the bottom plate 24 shaking, tilting, or sagging or collapsing towards the pressure relief mechanism 22.

[0093] In some embodiments, please refer to Figure 6 The first region 2411 is provided with a first through hole 2411a; and / or the second region 2412 is provided with a second through hole 2412a in the region where the first support 242 is not provided.

[0094] The first through hole 2411a and the second through hole 2412a both penetrate the plate body 241 along the third direction ZZ and connect the accommodating space 21a and the pressure relief mechanism 22.

[0095] In some embodiments, the first region 2411 is provided with a first through hole 2411a, the shape of the first through hole 2411a may be the same as the shape of the pressure relief mechanism 22, and the first through hole 2411a may correspond to the pressure relief mechanism 22.

[0096] In some embodiments, the first region 2411 is provided with a plurality of first through holes 2411a, which are spaced apart along a first direction XX. The shape of the first through holes 2411a can be circular, elliptical, square or other shapes.

[0097] In some embodiments, a second through hole 2412a is provided between two adjacent first support portions 242. The number of through holes between two adjacent first support portions 242 can be one or more. The shape of the second through hole 2412a can be circular, elliptical, square, or other shapes.

[0098] By providing a first through hole 2411a on the first region 2411 of the plate body 241 and / or providing a second through hole 2412a on the second region 2412 of the plate body 241, both the first through hole 2411a and the second through hole 2412a are connected to the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22, when the battery cell 20 experiences thermal runaway, the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 will not accumulate on the side of the bottom support plate 24 away from the first wall 211, which can help alleviate the aggravation of thermal runaway.

[0099] In some embodiments, please refer to Figure 7 The plate body 241 also includes a third region 2413 and a fourth region 2414, which are located on opposite sides of the first region 2411 along the first direction XX. A second support portion 243 is provided on the side of the third region 2413 facing the first wall portion 211 and / or the side of the fourth region 2414 facing the first wall portion 211. The second support portion 243 is spaced apart from the first support portion 242, and the side of the second support portion 243 away from the plate body 241 abuts against the first wall portion 211.

[0100] The second support portion 243 is integrally formed on the side of the third region 2413 and / or the fourth region 2414 facing the first wall portion 211; or the second support portion 243 is fixedly connected to the side of the third region 2413 and / or the fourth region 2414 facing the first wall portion 211. The methods by which the second support portion 243 is fixedly connected to the third region 2413 and / or the fourth region 2414 include, but are not limited to, adhesive bonding or welding.

[0101] By providing a second support portion 243 on the side of the third region 2413 and / or the fourth region 2414 facing the first wall portion 211, and having the side of the second support portion 243 away from the plate body 241 abutting against the first wall portion 211, the support capacity and protection effect of the bottom support plate 24 for the electrode assembly can be improved, reducing the risk of the electrode assembly shaking or displacement.

[0102] In some embodiments, please continue to refer to Figure 3 and Figure 7The housing 21 also includes a second wall portion 212 and a third wall portion 213 disposed opposite to each other in the second direction YY, with a first wall portion 211 connected between the second wall portion 212 and the third wall portion 213; in the third region 2413, a first channel 244 is formed between the second support portion 243 and the second wall portion 212 and / or between the second support portion 243 and the third wall portion 213, the first channel 244 connecting the space located on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22; in the fourth region 2414, a second channel 245 is formed between the second support portion 243 and the second wall portion 212 and / or between the second support portion 243 and the third wall portion 213, the second channel 245 connecting the space located on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22.

[0103] Specifically, the first channel 244 corresponds to the second region 2412 in the first direction XX. The second channel 245 corresponds to the second region 2412 in the first direction XX.

[0104] In some embodiments, the first channel 244 and the second channel 245 are directly connected to the pressure relief mechanism 22, or they are connected to the pressure relief mechanism 22 through the gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211.

[0105] By setting the first channel 244 and the second channel 245 to increase the exhaust path and exhaust area inside the battery cell 20, the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 can flow to the pressure relief mechanism 22 not only through the gap 242a between the second region 2412 and the first wall 211 of the plate body 241, but also through the first channel 244 and the second channel 245. This can further improve the pressure release rate inside the accommodating space 21a, further reduce the probability of fire, explosion and other risks when the battery cell 20 experiences thermal runaway, and further improve the reliability of the battery cell 20, thereby further improving the reliability of the battery device 100a.

[0106] In some embodiments, please refer to Figure 8 The second support portion 243 includes a first sub-support portion 2431 and a second sub-support portion 2432 arranged at intervals along the second direction YY. A third channel 246 is formed between the first sub-support portion 2431 and the second sub-support portion 2432. The third channel 246 connects the space located on the side of the plate body 241 opposite to the pressure relief mechanism 22 and the pressure relief mechanism 22.

[0107] The second support portion 243 located in the third region 2413 and the second support portion 243 located in the fourth region 2414 both include a first sub-support portion 2431 and a second sub-support portion 2432, and a third channel 246 is formed between the first sub-support portion 2431 and the second sub-support portion 2432 in each region, and the third channel 246 corresponds to the first region 2411.

[0108] In some embodiments, the third channel 246 connects to the pressure relief mechanism 22 through the gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211; and / or the third channel 246 connects to the pressure relief mechanism 22 through the space between the first support portion 242 and the second support portion 243.

[0109] By forming a third channel 246 between the first sub-support 2431 and the second sub-support 2432, the exhaust path and exhaust area inside the battery cell 20 are further increased, so that the exhaust volume can be increased more effectively when the battery cell 20 experiences thermal runaway, further reducing the accumulation of pressure inside the containment space 21a, thereby further reducing the impact of thermal runaway on the battery cell 20.

[0110] In some embodiments, please continue to refer to Figure 7 The third through hole 2413a is provided in the area of ​​the third region 2413 and / or the fourth region 2414 where the second support 243 is not provided.

[0111] The third through hole 2413a penetrates the plate body 241 along the third direction ZZ and connects the receiving space 21a and the pressure relief mechanism 22. The shape of the third through hole 2413a can be circular, elliptical, square or other shapes.

[0112] In some embodiments, the plate body 241 is provided with a third through hole 2413a in the region corresponding to the first channel 244 and / or in the region corresponding to the second channel 245.

[0113] In some embodiments, a third through hole 2413a is provided on the side of the second support portion 243 located in the third region 2413 facing the second region 2412 and / or on the side of the second support portion 243 located in the fourth region 2414 facing the second region 2412. The third through hole 2413a may correspond to the second region 2412. Of course, the third through hole 2413a may also correspond to the first region 2411.

[0114] By providing a third through hole 2413a in the area where the second support 243 is not provided in the third region 2413 and / or the fourth region 2414, the third through hole 2413a connects the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22, so that when the battery cell 20 experiences thermal runaway, the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 can flow to the pressure relief mechanism 22 through the third through hole 2413a, further reducing the gas pressure on the side of the bottom support plate 24 away from the first wall 211, which can further alleviate the thermal runaway.

[0115] In some embodiments, the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall portion 211 in the preset plane satisfy: S1 / S2≥0.5; the preset plane is parallel to the first direction XX and the second direction YY.

[0116] Wherein, S1 / S2≥0.5 means that the ratio between the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall portion 211 in the preset plane is greater than or equal to 0.5.

[0117] In some embodiments, the pressure relief mechanism 22 and the first wall portion 211 are located on the same plane, and the plane on which the pressure relief mechanism 22 and the first wall portion 211 are located is a preset plane.

[0118] In some embodiments, the pressure relief mechanism 22 and the first wall portion 211 are not on the same plane, and the plane where the pressure relief mechanism 22 is located and the plane where the first wall portion 211 is located are parallel to a preset plane.

[0119] The ratio between the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall portion 211 in the preset plane can be 0.5, 0.52, 0.535, 0.555, 0.58, 0.6, 0.615, 0.64, 0.66, 0.685, 0.7, 0.73, 0.75, 0.778, 0.79, 0.8, 0.825, 0.86, 0.88, 0.9, etc. The specific ratio can be selected according to actual needs, as long as the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall portion 211 in the preset plane satisfy: S1 / S2≥0.5.

[0120] In some embodiments, please refer to Figure 3 The dimension of the first wall portion 211 along the first direction XX is the third dimension L4. When the first dimension L1 of the pressure relief mechanism 22 along the first direction XX approaches the third dimension L4 of the first wall portion 211 along the first direction XX, the setting of the third region 2413 and the fourth region 2414 can be cancelled. At this time, the plate body 241 only has the first region 2411 and the second region 2412 arranged along the second direction YY.

[0121] By ensuring that the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall portion 211 in the preset plane satisfy S1 / S2≥0.5, the area of ​​the pressure relief mechanism 22 is larger, which can more effectively release the pressure and heat inside the containment space 21a, thereby reducing the air pressure and temperature inside the containment space 21a, reducing the risk of fire and explosion of the electrode assembly, and further improving the reliability of the battery device 100a.

[0122] In some embodiments, such as Figures 3 to 5 As shown, the battery cell 20 includes a housing 21, an electrode assembly, and a base plate 24. The housing 21 forms a receiving space 21a and includes a first wall portion 211. The first wall portion 211 is provided with a pressure relief mechanism 22. The pressure relief mechanism 22 has a dimension L1 along a first direction XX and a dimension L2 along a second direction YY perpendicular to the first direction XX, wherein L1 > L2. The electrode assembly is disposed within the receiving space 21a. The base plate 24 is disposed within the receiving space 21a and is arranged along a third direction ZZ between the first wall portion 211 and the electrode assembly to support the electrode assembly. The third direction ZZ is perpendicular to both the first direction XX and the second direction YY. The base plate 24 includes a plate body 241 and a first support portion 242. The plate body 241 has a first region 2411 and a second region 2412 arranged along the second direction YY. The pressure relief mechanism 22... The orthographic projection of the first support portion 242 along the third direction ZZ onto the plate body 241 is located within the first region 2411. The second region 2412 is provided with at least one first support portion 242 on the side facing the first wall portion 211. The side of the first support portion 242 away from the plate body 241 abuts against the first wall portion 211. The dimension of the first support portion 242 along the first direction XX is less than L1 to form a gap 242a between the second region 2412 and the first wall portion 211 of the plate body 241. The gap 242a connects the space 21a located on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22. The sum of the dimensions of the multiple first support portions 242 spaced apart along the first direction XX is defined as L3, and the dimension of the first support portion 242 along the third direction ZZ is h, where 0.21≤h×(L1-L3) / L1≤1.11.

[0123] In some embodiments, the plate body 241 further includes a third region 2413 and a fourth region 2414, the third region 2413 and the fourth region 2414 being located on opposite sides of the first region 2411 along the first direction XX; a second support portion 243 is provided on the side of the third region 2413 facing the first wall portion 211 and / or on the side of the fourth region 2414 facing the first wall portion 211, the second support portion 243 being spaced apart from the first support portion 242, and the side of the second support portion 243 facing away from the plate body 241 abutting against the first wall portion 211.

[0124] In some embodiments, such as Figure 6 As shown, the first region 2411 is provided with a first through hole 2411a; the second region 2412, where the first support part 242 is not provided, is provided with a second through hole 2412a.

[0125] In some embodiments, such as Figure 7 As shown, the first region 2411 is provided with a first through hole 2411a; the second region 2412, where the first support 242 is not provided, is provided with a second through hole 2412a; the third region 2413 and the fourth region 2414, where the second support 243 is not provided, are provided with a third through hole 2413a; in the third region 2413, a first channel 244 is formed between the second support 243 and the second wall 212 and / or between the second support 243 and the third wall 213, the first channel 244 connecting the receiving space 21a and the pressure relief mechanism 22; in the fourth region 2414, a second channel 245 is formed between the second support 243 and the second wall 212 and / or between the second support 243 and the third wall 213, the second channel 245 connecting the receiving space 21a and the pressure relief mechanism 22.

[0126] In some embodiments, such as Figure 8 As shown, the second support portion 243 includes a first sub-support portion 2431 and a second sub-support portion 2432 arranged at intervals along the second direction YY. A third channel 246 is formed between the first sub-support portion 2431 and the second sub-support portion 2432. The third channel 246 connects the accommodating space 21a and the pressure relief mechanism 22.

[0127] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0128] In some embodiments, please refer to Figures 3 to 5The battery cell 20 includes a housing 21, an electrode assembly, and a bottom support plate 24. The housing 21 forms an accommodating space 21a, the electrode assembly is disposed in the accommodating space 21a, and a built-in heating film is placed in the accommodating space 21a. The housing 21 includes a first wall portion 211, the first wall portion 211 is provided with a pressure relief mechanism 22, and the bottom support plate 24 is disposed between the first wall portion 211 and the electrode assembly. The base plate 24 includes a plate body 241 and a first support portion 242. The plate body 241 has a first region 2411 and a second region 2412 arranged along the second direction YY. The orthographic projection of the pressure relief mechanism 22 along the third direction ZZ on the plate body 241 is located in the first region 2411. The plate body 241 has two second regions 2412, which are located on opposite sides of the first region 2411 along the second direction YY. The first support portion 242 is provided on the side of each of the two second regions 2412 facing the first wall portion 211, and the first support portions 242 on the two second regions 2412 correspond one-to-one.

[0129] To investigate the impact of different values ​​of h×(L1-L3) / L1 on the battery cell 20, multiple comparative experiments were conducted to test and compare the relevant parameters of the battery cell 20. In these comparative experiments, Examples 1-20 were set up, in which multiple first support parts 242 were spaced apart along a first direction XX, each first support part 242 having a dimension of 15mm along the first direction XX, a dimension of 3mm along a second direction YY, a first dimension of the pressure relief mechanism 22 along the first direction XX of L1 (L1 = 95mm), the sum of the dimensions of the multiple first support parts 242 spaced apart along the first direction XX of L3, and a dimension of h along a third direction ZZ of the first support part 242. The number, position, and spacing of the first support parts 242 along the first direction XX were adjusted to regulate the values ​​of L1-L3, thereby adjusting the value of h×(L1-L3) / L1. Other structures and experimental conditions were the same in all examples. The experiment used prismatic battery cells 20 with the same dimensions (31mm*238mm*117mm) and energy density (760Wh / L) for testing. Before testing, battery cells 20 were fully discharged. A 1.5mm diameter opening was drilled in the top cover of battery cell 20. One end of a gas tube with a diameter matching the opening was inserted into the opening. AB glue was applied between the inner wall of the opening and the outer wall of the gas tube for sealing. The other end of the gas tube was connected to a pressure sensor to detect the pressure inside the containment space 21a. During testing, battery cell 20 was fully charged. Then, a 40V, 10A power supply was applied to the built-in heating film to trigger battery cell 20, causing thermal runaway. The state of battery cell 20 after failure and the pressure value inside containment space 21a were observed.

[0130] The specific data is shown in Table 1 below:

[0131]

[0132]

[0133] Table 1

[0134] As shown in Table 1 above, when 0.47 ≤ h × (L1 - L3) / L1 ≤ 0.79, the maximum air pressure inside the containment space 21a is ≤ 0.6 MPa, and the shell 21 remains intact. This indicates that when the value of h × (L1 - L3) / L1 is within the range of 0.47 to 0.79, the pressure relief mechanism 22 has the highest pressure relief efficiency, and the shell 21 remains intact. By limiting the value of h × (L1 - L3) / L1 to the optimal range, the exhaust path and exhaust area from the containment space 21a to the pressure relief mechanism 22 can be better improved, allowing the pressure inside the containment space 21a to be released rapidly.

[0135] This application further proposes a battery device 100a, which includes a housing 10 and a battery cell 20 as described in any of the above embodiments, wherein the battery cell 20 is disposed within the housing 10.

[0136] In the technical solutions of this application embodiment, the specific structure of the battery cell 20 refers to the above embodiments. Since the battery device 100a provided in this application adopts all the technical solutions of all the above embodiments of the battery cell 20, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described in detail here.

[0137] According to some embodiments of this application, the battery device 100a described above can be used in electrical equipment. With this configuration, the base plate 24 is positioned between the first wall portion 211 where the pressure relief mechanism 22 is located and the electrode assembly. The orthographic projection of the pressure relief mechanism 22 along the third direction YY onto the plate body 241 is located within the first region 2411 of the plate body 241. The first region 2411 and the second region 2412 of the plate body 241 are arranged along the second direction YY. At the same time, at least one first support portion 242 is provided on the side of the second region 2412 of the plate body 241 facing the first wall portion 211. The dimension of the first support portion 242 along the first direction XX is smaller than the dimension L1 of the pressure relief mechanism 22 along the first direction XX, so that a gap 242a is formed between the second region 2412 of the plate body 241 and the first wall portion 211. The gap 242a connects the space located on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22. On the one hand, since the dimension L1 of the pressure relief mechanism 22 along the first direction XX is larger than its dimension L2 along the second direction YY, the first region 2411 of the plate body 241 faces the first wall portion 211. The second region 2412 is provided with at least one first support 242, which can improve the support stability of the base plate 24, reduce or eliminate the risk of the area corresponding to the base plate 24 and the pressure relief mechanism 22 sagging or collapsing towards the pressure relief mechanism 22, thereby reducing the possibility of the base plate 24 blocking the pressure relief mechanism 22. When the battery cell 20 experiences thermal runaway, it can reduce or eliminate the risk of fire or explosion caused by the base plate 24 blocking the pressure relief mechanism 22, thereby improving the reliability of the battery cell 20. On the other hand, since the second region 2412 of the plate body 241 and the pressure relief mechanism 22 are arranged along the second direction YY, the high pressure gas in the space of the plate body 241 away from the pressure relief mechanism 22 can be increased to the speed at which the high pressure gas flows to the pressure relief mechanism 22, so that the pressure inside the accommodating space 21a can be released quickly, thereby maintaining the pressure balance inside and outside the battery cell 20. This can reduce or eliminate the risk of fire or explosion caused by the battery cell 20 when thermal runaway occurs, thereby further improving the reliability of the battery cell 20.

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, The battery cell includes: The housing has a receiving space. The housing includes a first wall portion and a pressure relief mechanism. The dimension of the pressure relief mechanism along a first direction is defined as L1, and the dimension along a second direction perpendicular to the first direction is defined as L2, wherein L1 > L2. An electrode assembly is disposed within the accommodating space; A base plate is disposed within the receiving space and is arranged along a third direction between the first wall and the electrode assembly to support the electrode assembly. The third direction is perpendicular to the first direction and the second direction, respectively. The base plate includes a plate body and a first support portion. The plate body has a first region and a second region arranged along the second direction. The orthographic projection of the pressure relief mechanism on the plate body along the third direction is located in the first region. At least one first support portion is provided on the side of the second region facing the first wall portion. The side of the first support portion away from the plate body abuts against the first wall portion. The dimension of the first support portion along the first direction is less than L1, so as to form a gap between the second region of the plate body and the first wall portion. The gap connects the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism.

2. The battery cell according to claim 1, characterized in that, The second region has a plurality of first support portions on the side facing the first wall portion, and the plurality of first support portions are spaced apart along the first direction.

3. The battery cell according to claim 2, characterized in that, The sum of the dimensions of a plurality of first support portions spaced apart along the first direction is defined as L3, and the dimension of the first support portion along the third direction is h, wherein 0.21≤h×(L1-L3) / L1≤1.

11.

4. The battery cell according to claim 1, characterized in that, The plate body has two second regions, which are located on opposite sides of the first region along the second direction. The first support portion is provided on the side of each of the two second regions facing the first wall portion.

5. The battery cell according to claim 1, characterized in that, The first support portion includes a composite layer, which protrudes from the side of the plate body facing the first wall portion.

6. The battery cell according to claim 1, characterized in that, The plate body abuts against the electrode assembly on the side closest to the electrode assembly.

7. The battery cell according to claim 1, characterized in that, Along the second direction, the distance between the first support and the pressure relief mechanism is d, where d ≥ 2 mm.

8. The battery cell according to claim 1, characterized in that, The first region is provided with a first through hole; and / or the area of ​​the second region where the first support is not provided is provided with a second through hole.

9. The battery cell according to any one of claims 1 to 8, characterized in that, The plate body further includes a third region and a fourth region, the third region and the fourth region being located on opposite sides of the first region along the first direction; The third region is provided with a second support portion on the side facing the first wall portion and / or the fourth region is provided with a second support portion on the side facing the first wall portion. The second support portion is spaced apart from the first support portion, and the side of the second support portion away from the plate body abuts against the first wall portion.

10. The battery cell according to claim 9, characterized in that, The housing further includes a second wall portion and a third wall portion disposed opposite to each other in the second direction, wherein the first wall portion is connected between the second wall portion and the third wall portion; In the third region, a first channel is formed between the second support and the second wall and / or between the second support and the third wall, the first channel connecting the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism; In the fourth region, a second channel is formed between the second support and the second wall and / or between the second support and the third wall, the second channel connecting the space located on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism.

11. The battery cell according to claim 9, characterized in that, The second support portion includes a first sub-support portion and a second sub-support portion spaced apart along the second direction. A third channel is formed between the first sub-support portion and the second sub-support portion. The third channel connects the space located on the side of the plate body opposite to the pressure relief mechanism and the pressure relief mechanism.

12. The battery cell according to claim 9, characterized in that, The third region and / or the fourth region where the second support is not provided are provided with a third through hole.

13. The battery cell according to claim 1, characterized in that, The area S1 of the pressure relief mechanism in the preset plane and the area S2 of the first wall in the preset plane satisfy: S1 / S2≥0.5; The preset plane is parallel to the first direction and the second direction.

14. A battery device, characterized in that, The battery device includes a housing and a battery cell as described in any one of claims 1 to 13, wherein the battery cell is disposed within the housing.

15. An electrical appliance, characterized in that, The electrical equipment includes: The battery device as claimed in claim 14.

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