Battery cell, battery and electric device

Abstract

A battery cell (10), a battery (100) and an electric device. The battery cell (10) comprises a casing (1), an electrode assembly and binding members (2). The casing (1) has a cavity, and the electrode assembly is arranged in the cavity. The binding members (2) surround at least part of the casing (1) to provide an expansion binding force to the casing (1), thereby restraining the deformation of the casing (1) during thermal runaway of the battery cell (10); in addition, the overall structural strength of the battery cell (10) can also be improved, thereby reducing the risk of the casing (1) rupturing due to a rapid increase in the air pressure in the cavity, and improving the reliability of the battery cell (10).

Description

Battery cells, batteries and electrical devices

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202420969145.1, filed on May 7, 2024, entitled “Battery Cell, Battery and Electrical Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of battery technology, and in particular relates to a battery cell, a battery, and an electrical device. Background Technology

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0005] As battery energy density increases, the heat generated by thermal runaway in individual battery cells becomes increasingly significant. Existing battery cell casings are struggling to withstand the temperatures and pressures generated by thermal runaway, leading to casing cracks or even explosions. Therefore, improving the structural strength of battery cells has become a pressing issue.

[0006] Summary of the Invention

[0007] In view of the above problems, this application provides a battery cell, a battery, and an electrical device that can reduce the risk of the casing cracking due to a rapid increase in air pressure inside the cavity and improve the reliability of the battery cell.

[0008] In a first aspect, this application provides a battery cell including a housing, an electrode assembly, and a restraining member. The housing has a cavity, the electrode assembly is disposed in the cavity, and the restraining member surrounds at least a portion of the housing to provide an expansion restraining force to the housing.

[0009] In this embodiment, a restraining member is provided around at least a portion of the outer casing to provide an expansion restraining force to the outer casing when the battery cell experiences thermal runaway, thereby suppressing the deformation of the outer casing during the thermal runaway of the battery cell, reducing the risk of the outer casing cracking due to a rapid increase in air pressure inside the cavity, and improving the reliability of the battery cell.

[0010] In some embodiments, the restraint member encloses a restraint space, and the outer casing is disposed within the restraint space. The restraint member is circumferentially pressed against the outer casing. By disposing the outer casing within the restraint space formed by the restraint member, the restraint member can be disposed at least around the periphery of the outer casing, thereby strengthening the overall structural strength of the battery casing's external structure by circumferentially restraining the outer casing with the restraint member.

[0011] In some embodiments, the housing includes a shell and an end cap. The shell has a cavity and an opening communicating with the cavity in a first direction. The end cap closes to the opening and seals the cavity. There are two or more restraints, which press against the shell and / or the end cap respectively. This restraints the battery shell and the connection between the shell and the end cap, thereby reducing the risk of the shell side exploding or the shell separating from the end cap when the battery cell experiences thermal runaway, and improving the reliability of the battery cell.

[0012] In some embodiments, two or more restraining members are spaced apart along a first direction and press against the casing circumferentially. This allows the casing to be restrained circumferentially in different regions along the first direction by the two or more restraining members, thereby reducing the risk of the casing side exploding in the event of thermal runaway of a single battery cell.

[0013] In some embodiments, two or more restraining members are spaced apart along a second direction and circumferentially pressed against the housing and end cap, the second direction intersecting the first direction. This allows the housing and end cap to be restrained circumferentially at different connection areas along the second direction by two or more restraining members, thereby reducing the risk of separation between the housing and end cap in the event of thermal runaway of a single battery cell.

[0014] In some embodiments, among the two or more restraining members, some restraining members are disposed circumferentially against the housing, and some restraining members are disposed circumferentially against the housing and the end cap. By simultaneously providing a first restraining member and a second restraining member on the housing, it is possible to restrain the housing circumferentially and also restrain the connection between the housing and the end cap circumferentially, thereby reducing the risk of the housing side exploding and the housing separating from the end cap in the event of thermal runaway of the battery cell, and improving the reliability of the battery cell.

[0015] In some embodiments, the restraint member is configured as a restraint strap, which surrounds to form a restraint space and is disposed against the housing in a circumferential direction to circumferentially restrain the housing.

[0016] In some embodiments, the restraint straps are wrapped around the outer casing once, or the restraint straps overlap and wrap around the outer casing more than twice, to meet the requirements for restraining the outer casing and the strength requirements of the external structure of the battery cell.

[0017] In some embodiments, the restraint member is configured as an elastic sleeve, which includes an end face and a side face surrounding the end face. The end face and the side face enclose a restraint space, and the elastic sleeve restrains the outer shell circumferentially by pressing the side face against the outer shell in the circumferential direction.

[0018] In some embodiments, the housing is further provided with a pressure relief mechanism, which is connected to the cavity. The restraint member is arranged to avoid the pressure relief mechanism so that in the event of thermal runaway, the battery cell can be depressurized in a directional manner through the pressure relief mechanism, thereby improving the reliability of the battery cell.

[0019] In some embodiments, the protrusion distance of the restraint member on the side facing away from the cavity relative to the outer shell is 0.2mm to 1mm, which can provide a certain strength and reduce the space occupied by the battery, thereby increasing the energy density of the battery.

[0020] Secondly, embodiments of this application provide a battery, including the battery cell of the first aspect.

[0021] Thirdly, embodiments of this application provide an electrical device including a battery as described in the second aspect, the battery being used to provide electrical energy.

[0022] According to the embodiments of this application, a battery cell is surrounded by a restraining member in at least a portion of the outer casing. In the event of thermal runaway of the battery cell, the restraining member provides an expansion restraining force to the outer casing to suppress the deformation of the outer casing during thermal runaway of the battery cell. Furthermore, by combining the restraining member with the outer casing to form the outer layer structure of the battery cell, the overall structural strength of the battery cell can be improved, thereby further reducing the risk of the outer casing cracking due to a rapid increase in air pressure inside the cavity and improving the reliability of the battery cell.

[0023] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0025] Figure 1 is a schematic diagram of the vehicle structure provided in some embodiments of this application;

[0026] Figure 2 is an exploded view of a battery provided in some embodiments of this application;

[0027] Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0028] Figure 4 is a schematic diagram of the structure of a battery cell provided in some other embodiments of this application;

[0029] Figure 5 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0030] Figure 6 is a structural schematic diagram of a battery cell provided in some embodiments of this application from another angle.

[0031] The accompanying drawings are not necessarily drawn to scale.

[0032] Marker explanation:

[0033] 100 batteries, 200 controllers, 300 motors;

[0034] 10 individual battery cells, 20 battery casings;

[0035] 1. Outer shell, 11. Housing, 12. End cap, 2. Restraint, 2a. First restraint, 2b. Second restraint, 3. Pressure relief mechanism;

[0036] X is the second direction, and Z is the first direction. Detailed Implementation

[0037] 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.

[0038] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0039] 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", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0040] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0041] 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 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.

[0042] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0044] As battery energy density increases, the heat generated by thermal runaway also increases. Traditional aluminum casings are generally unable to withstand the heat generated by thermal runaway and are often melted through. Therefore, related technologies use steel casings for individual battery cells to withstand some of the energy generated by thermal runaway in high-energy-density batteries. However, even with steel casings, some individual battery cells still cannot withstand the temperature and pressure generated by thermal runaway, causing localized cracks in the casing or even complete explosion, resulting in serious consequences.

[0045] Based on the above considerations, in order to reduce the risk of partial cracking of the battery cell casing during thermal runaway, this application provides a battery cell in which at least part of the battery cell casing is surrounded by a restraining member to provide an expansion restraining force to the casing, so that the casing can withstand the gas pressure generated during thermal runaway of the battery cell.

[0046] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0047] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. This application does not impose any special limitations on the above-mentioned electrical devices.

[0048] It should be understood that the technical solutions described in the embodiments of this application are applicable to all electrical devices including batteries and those using batteries, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0049] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0050] A battery 100 is installed inside the vehicle, and the battery 100 can be located at the bottom, front, or rear of the vehicle. The battery 100 can be used to power the vehicle, for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller 200 and a motor 300, the controller 200 being used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle during starting, navigation, and driving.

[0051] Please refer to Figure 2, which is an exploded schematic diagram of the battery 100 provided in some embodiments of this application.

[0052] The battery 100 mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells 10 to provide higher voltage and capacity, wherein a battery cell 10 is the smallest unit constituting the battery 100. The battery 100 generally also includes a battery housing 20 for encapsulating one or more battery cells 10. The battery housing 20 can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells 10.

[0053] Multiple battery cells 10 can be connected in series, parallel, or in a hybrid manner via connectors. A hybrid connection means that multiple battery cells 10 can be connected in both series and parallel configurations. Multiple battery cells 10 can be directly connected in series, parallel, or in a hybrid manner, and then the entire assembly of the multiple battery cells 10 can be housed within the battery casing 20. Alternatively, multiple battery cells 10 can first be connected in series, parallel, or in a hybrid manner to form a battery module 100, and then the multiple battery modules can be connected in series, parallel, or in a hybrid manner via connectors to form a whole, which is then housed within the battery casing 20.

[0054] Optionally, the battery cell 10 can be a secondary battery or a primary battery. A secondary battery refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used. Battery cells include, but are not limited to, lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-metal hydride battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0055] As an example, the battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, but is not limited thereto. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0056] Please refer to Figure 3, which is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application.

[0057] This application provides a battery cell 10, including a housing 1, an electrode assembly, and a restraining member 2. The housing 1 has a cavity, the electrode assembly is disposed in the cavity, and the restraining member 2 surrounds at least a portion of the housing 1 to provide an expansion restraining force to the housing 1.

[0058] The battery cell 10 provided in this application embodiment has a restraining member 2 surrounding at least a portion of the outer casing 1. In the event of thermal runaway of the battery cell 10, the restraining member 2 provides an expansion restraining force to the outer casing 1 to suppress the deformation of the outer casing 1 during thermal runaway of the battery cell 10. Furthermore, by combining the restraining member 2 with the outer casing 1 to form the outer layer structure of the battery cell 10, the overall structural strength of the battery cell 10 can be improved, thereby further reducing the risk of the outer casing 1 cracking due to a rapid increase in air pressure inside the cavity and improving the reliability of the battery cell 10.

[0059] In this embodiment, the outer shell 1 is used to form an internal environment, which can be used to accommodate electrode components, electrolyte, and other components. The outer shell 1 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the outer shell 1 can be determined according to the specific shape and size of the electrode components.

[0060] The outer casing 1 can be made of various materials, specifically metal materials, such as steel, to withstand the temperature generated by the thermal runaway of the battery cell 10, and also to give the outer casing 1 itself a certain strength to partially withstand the gas pressure generated by the thermal runaway of the battery cell 10.

[0061] The restraint member 2 surrounds at least a portion of the outer casing 1 and provides an expansion restraint force to the outer casing 1. This means that for some battery cells 10, due to the limited strength of the outer casing 1, when the battery cell 10 experiences thermal runaway, the outer casing 1 may expand and deform in the direction away from the cavity. Therefore, by surrounding the side of the outer casing 1 away from the cavity with the restraint member 2, the expansion of the outer casing 1 can be suppressed to a certain extent. Furthermore, by combining the restraint member 2 with the outer casing 1 to form the outer layer structure of the battery cell 10, the overall structural strength of the battery cell 10 can be improved. The restraint member 2 and the outer casing 1 work together to withstand the gas pressure generated by the thermal runaway of the battery cell 10, thereby further reducing the risk of the outer casing 1 cracking and improving the reliability of the battery cell 10.

[0062] Optionally, the restraint 2 can be made of non-metallic materials to improve structural strength while reducing the weight of the battery cell 10, making it easier to promote and apply.

[0063] Optionally, the restraint component 2 is an insulating component, meaning that the entire restraint component 2 is made of insulating material, such as rubber or plastic. The restraint component 2 has good insulation properties, thereby reducing the risk of short circuits in the battery cell 10 caused by the restraint component 2.

[0064] In some alternative embodiments, the restraint member 2 encloses to form a restraint space, the outer shell 1 is disposed within the restraint space, and the restraint member 2 is disposed against the outer shell 1 in a circumferential direction.

[0065] By placing the outer shell 1 within the binding space formed by the binding member 2, the binding member 2 can be set at least around the periphery of the outer shell 1, thereby binding the outer shell 1 in a circumferential manner through the binding member 2, which strengthens the overall structural strength of the external structure of the battery casing 11, makes it easier to set the binding member 2, and also allows the binding member 2 to simultaneously press against multiple surfaces of the outer shell 1 in a circumferential direction, making the binding force on the outer shell 1 more uniform and stable.

[0066] Referring to Figure 3, in some optional embodiments, the number of restraints 2 is two or more, and the two or more restraints 2 respectively surround different areas of the outer shell 1 to locally reinforce the weak areas of the outer shell 1, improve the overall structural strength of the battery cell 10, and further reduce the risk of the battery cell 10 cracking from the weak areas of the outer shell 1 when thermal runaway occurs.

[0067] Furthermore, compared to binding the entire area of ​​the outer casing 1, reinforcing only the weakest areas of the outer casing 1 reduces the material used in the binding component 2, lowers costs, and also reduces the weight of the battery cell 10.

[0068] The housing 1 mainly includes a housing 11 and an end cap 12. The housing 11 and the end cap 12 can be independent components. The housing 11 has a cavity to form the internal environment of the electrode assembly. The housing 11 is provided with an opening along the first direction Z.

[0069] End cap 12 refers to a component that covers the opening of housing 11 to isolate the internal environment of battery cell 10 from the external environment. In any case, the shape of end cap 12 can be adapted to the shape of housing 11 to fit it. Optionally, end cap 12 can be made of a material with a certain degree of hardness and strength, so that end cap 12 is less prone to deformation under pressure and impact, enabling battery cell 10 to have higher structural strength and improved safety performance.

[0070] In some alternative embodiments, two or more restraints 2 are respectively pressed against the housing 11 and / or the end cap 12. Since in practical applications, the weakest areas of the outer casing 1 and the main stress areas during thermal runaway are the battery housing 11 and the connection between the battery housing 11 and the end cap 12, by pressing two or more restraints 2 against the housing 11 and / or the end cap 12, the battery housing 11 and the connection between the housing 11 and the end cap 12 can be restrained, thereby reducing the risk of the housing 11 bursting open on the side or the housing 11 separating from the end cap 12 when the battery cell 10 experiences thermal runaway, and improving the reliability of the battery cell 10.

[0071] For the battery cell 10, the specific arrangement of the restraint member 2 can be adjusted according to the actual stress on the battery cell 10.

[0072] Referring to Figure 3, in some optional embodiments, two or more restraint members 2 are spaced apart along the first direction Z and are arranged to press against the housing 11 in the circumferential direction. That is, by restraining the strength of different regions of the housing 11 along the first direction Z by two or more restraint members 2 in the circumferential direction, the risk of the side of the housing 11 exploding when the battery cell 10 experiences thermal runaway is reduced.

[0073] Among them, two or more binding members 2 can be set with different structural strengths, such as different thicknesses or made of different materials, so as to provide different sizes of expansion binding force to different regions of the shell 11 along the first direction Z in a more targeted manner, thereby improving the overall structural strength of the battery cell 10.

[0074] As an optional embodiment, the number of restraint members 2 can be set to two and evenly distributed on the housing 11 along the first direction Z. Of course, the number of restraint members 2 can also be set to three, five or even more, and the specific number of restraint members 2 can also be adjusted according to the dimension of each restraint member 2 along the first direction Z and the dimension of the housing 11 along the first direction Z.

[0075] Please refer to Figure 4, which shows a schematic diagram of the structure of a battery cell 10 provided in some other embodiments of this application. In some alternative embodiments, two or more restraining members 2 are spaced apart along a second direction X and are arranged to press against the housing 11 and the end cap 12 in a circumferential direction, the second direction X intersecting the first direction Z. That is, by restraining different connection areas of the housing 11 and the end cap 12 along the second direction X by two or more restraining members 2 in a circumferential direction, the risk of separation of the housing 11 and the end cap 12 in the event of thermal runaway of the battery cell 10 can be reduced.

[0076] As an optional embodiment, the number of restraint members 2 can be set to two and evenly distributed along the second direction X on the end cap 12 to reinforce the connection between the housing 11 and the end cap 12. Of course, the number of restraint members 2 can also be set to three, five or even more, and the specific number of restraint members 2 can be adjusted according to the dimension of each restraint member 2 along the second direction X and the dimension of the housing 11 or the end cap 12 along the second direction X.

[0077] Please refer to Figure 5, which shows a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application. In some alternative embodiments, among the two or more restraining members 2, some restraining members 2 are arranged to press against the housing 11 in the circumferential direction, and some restraining members 2 are arranged to press against the housing 11 and the end cap 12 in the circumferential direction.

[0078] For ease of description, the restraint member 2 is divided into a first restraint member 2a and a second restraint member 2b. The first restraint member 2a is disposed to press against the housing 11 in the circumferential direction, and the second restraint member 2b is disposed to press against the housing 11 and the end cap 12 in the circumferential direction.

[0079] By simultaneously providing a first restraining member 2a and a second restraining member 2b on the outer casing 1, it is possible to restrain the casing 11 in a circumferential manner, and at the same time restrain the connection between the casing 11 and the end cap 12 in a circumferential manner. This reduces the risk of the casing 11 bursting open on the side and the casing 11 separating from the end cap 12 when the battery cell 10 experiences thermal runaway, thereby improving the reliability of the battery cell 10.

[0080] Optionally, the number of first restraint members 2a is two or more, and the two or more first restraint members 2a are distributed at intervals along the first direction Z, and / or the number of second restraint members 2b is two or more, and the two or more second restraint members 2b are distributed at intervals along the second direction X. That is, by increasing the number of first restraint members 2a and second restraint members 2b, the expansion restraint force on the housing 11 itself and the connection between the housing 11 and the end cap 12 is further increased, the risk of the housing 11 bursting open from the side and the housing 11 separating from the end cap 12 is further reduced, and the reliability of the battery cell 10 is improved.

[0081] As an optional embodiment, the number of first restraint members 2a can be set to two and evenly distributed on the housing 11 along the first direction Z, and the number of second restraint members 2b can also be set to two and evenly distributed on the end cap 12 along the second direction X, with the first restraint members 2a and the second restraint members 2b intersecting each other.

[0082] Please refer to Figure 6, which shows a structural schematic diagram of the battery cell 10 provided in some embodiments of this application from another angle. In some optional embodiments, a pressure relief mechanism 3 is also provided on the outer casing 1, the pressure relief mechanism 3 is connected to the cavity, and the restraint member 2 is disposed to avoid the pressure relief mechanism 3.

[0083] By providing a pressure relief mechanism 3 on the outer casing 1, pressure can be released when the internal air pressure of the battery cell 10 increases rapidly due to thermal runaway, thereby reducing the risk of the battery cell 10 exploding. Furthermore, by ensuring that the restraint member 2 avoids the pressure relief mechanism 3, the impact of the restraint member 2 on the pressure relief mechanism 3 is reduced, allowing the pressure relief mechanism 3 to open and release pressure normally.

[0084] It is understood that by providing the restraint member 2 around at least part of the outer casing 1, the compressive strength of the external structure of the battery cell 10 should be greater than the opening pressure of the pressure relief mechanism 3, so that in the event of thermal runaway, the battery cell 10 can be depressurized in a directional manner through the pressure relief mechanism 3, thereby improving the reliability of the battery cell 10.

[0085] Optionally, the pressure relief mechanism 3 can be configured as an explosion-proof valve.

[0086] Please refer to Figure 6. In order to enclose and form a binding space by the binding member 2, in some embodiments, the binding member 2 is set as a binding strap, which surrounds to form the binding space and is disposed against the outer shell 1 in the circumferential direction.

[0087] As an optional implementation, the restraining member 2 can be configured as a restraining strap, which is wrapped around the periphery of the outer casing 1 of the battery cell 10 in a circumferential direction to restrain the casing 1. The restraining strap should be positioned to avoid the pressure relief mechanism 3, thereby increasing the overall structural strength of the battery cell 10 while achieving directional pressure relief.

[0088] When the restraint 2 is set as a restraint strap, it can be wrapped around the outer shell 1 once or multiple times according to the structural strength requirements of the battery cell 10. The number of wrappings can be adjusted according to the actual structure of the battery cell 10, as long as it can meet the restraint requirements of the outer shell 1 and the strength requirements of the external structure of the battery cell 10.

[0089] Optionally, the binding strap can be made of carbon fiber, nylon, polypropylene, etc. By using carbon fiber filaments, nylon cable ties, etc., the weight of the battery cell 10 can be reduced while enhancing strength, making it more convenient for practical applications.

[0090] It is understandable that, in addition to setting the restraint 2 as a restraint strap, the restraint 2 can also be set as other conventional replacements, such as setting the restraint 2 as a frame, which surrounds the battery cell 10 to restrain the outer casing 1 in the circumferential direction.

[0091] In addition, besides setting the restraint member 2 as a restraint strap, in some other embodiments, the restraint member 2 can be set as an elastic sleeve, which includes an end face and a side face surrounding the end face. The end face and the side face enclose a restraint space, and the elastic sleeve presses against the outer shell 1 in the circumferential direction through the side face.

[0092] As an optional implementation, the restraint member 2 can also be configured as an elastic sleeve, which includes an end face and a side face. Taking the configuration of the elastic sleeve pressing against the housing 11 in the circumferential direction as an example, the end face of the elastic sleeve can be made to cooperate with the end cap 12 of the housing 1, and the side face of the elastic sleeve can be made to cooperate with the housing 11 of the housing 1, so as to provide an expansion restraint force to the housing 11.

[0093] It is understandable that when the pressure relief mechanism 3 on the outer casing 1 is located within the confinement space, a vent can be provided at the corresponding position on the end face and / or side of the elastic sleeve to expose the pressure relief mechanism 3 through the vent, thereby increasing the overall structural strength of the battery cell 10 while achieving directional pressure relief.

[0094] In some alternative embodiments, the protrusion distance of the restraint member 2 relative to the outer shell 1 on the side of the cavity facing away from the cavity is 0.2 mm to 1 mm.

[0095] It should be noted that the protrusion distance of the restraining member 2 relative to the outer shell 1 on the surface opposite to the cavity refers to the thickness of the restraining member 2. The outer shell 1 includes a housing 11 and an end cap 12; therefore, for the housing 11, it refers to the protrusion distance of the restraining member 2 relative to the housing 11 on the surface opposite to the cavity. Since the end cap 12 includes a cover and functional components such as electrode terminals and injection holes disposed on the cover, for the end cap 12, it refers to the protrusion distance of the restraining member 2 relative to the cover on the surface opposite to the cavity.

[0096] By making the thickness of the restraint member 2 greater than or equal to 0.2 mm, a certain strength effect can be achieved to better meet the structural strength requirements of the battery cell 10. By making the thickness of the restraint member 2 less than or equal to 1 mm, the space occupied by the battery can be reduced, thereby increasing the energy density of the battery 100.

[0097] Please refer to Figures 1 to 6. The structure of the battery cell 10 in this application embodiment will be described below using a specific example.

[0098] The battery cell 10 in this embodiment includes a housing 1, an electrode assembly, a restraint member 2, and a pressure relief mechanism 3 disposed on the housing 1. The housing 1 includes a shell 11 and an end cap 12. The restraint member 2 is a restraint strap, which is disposed around the pressure relief mechanism 3 and wrapped around the periphery of the housing 1.

[0099] Specifically, the restraining member 2 includes a first restraining member 2a and a second restraining member 2b. There are two first restraining members 2a, spaced apart along the first direction Z and pressing against the housing 11 circumferentially. There are also two second restraining members 2b, spaced apart along the second direction X and pressing against the housing 11 and the end cap 12 circumferentially. By providing the first restraining members 2a and the second restraining members 2b, the housing 11 can be circumferentially restrained, and the connection between the housing 11 and the end cap 12 can also be restrained circumferentially, thereby enhancing the overall structural strength of the battery cell 10, reducing the risk of the housing 11 bursting open from the side and the housing 11 separating from the end cap 12, and achieving directional pressure relief.

[0100] According to some embodiments of this application, this application also provides a battery 100, including a battery cell 10 of any of the above schemes.

[0101] According to some embodiments of this application, this application also provides an electrical device including a battery 100 of any of the above schemes, and the battery 100 is used to provide electrical energy to the electrical device.

[0102] The electrical device can be any of the aforementioned devices or systems that use battery 100.

[0103] 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 single battery cell, comprising: The outer shell has a cavity; Electrode assembly, disposed in the cavity; A restraint member surrounds at least a portion of the housing to provide an expansion restraint force to the housing.

2. The battery cell according to claim 1, wherein, The restraint members enclose and form a restraint space, the outer shell is disposed within the restraint space, and the restraint members are disposed against the outer shell in a circumferential direction.

3. The battery cell according to claim 2, wherein, The outer casing includes a housing and an end cap. The housing has the cavity and an opening communicating with the cavity in a first direction. The end cap covers the opening and seals the cavity. The number of restraints is two or more, and the two or more restraints respectively press against the housing and / or the end cap.

4. The battery cell according to claim 3, wherein, Two or more of the aforementioned restraints are spaced apart along the first direction and press against the housing along the circumferential direction.

5. The battery cell according to claim 3, wherein, Two or more of the aforementioned restraints are spaced apart along a second direction and pressed against the housing and the end cap along the circumferential direction, wherein the second direction intersects the first direction.

6. The battery cell according to claim 3, wherein, Of the two or more restraining members, some of the restraining members are disposed along the circumferential direction to press against the housing, and some of the restraining members are disposed along the circumferential direction to press against the housing and the end cap.

7. The battery cell according to any one of claims 2 to 6, wherein, The restraint member is configured as a restraint strap, which surrounds to form the restraint space and is disposed against the outer shell in the circumferential direction.

8. The battery cell according to claim 7, wherein, The restraint straps may wrap around the outer shell once, or the restraint straps may overlap and wrap around the outer shell more than twice.

9. The battery cell according to any one of claims 2 to 6, wherein, The restraint member is configured as an elastic sleeve, the elastic sleeve includes an end face and a side face surrounding the end face, the end face and the side face enclose the restraint space, and the elastic sleeve presses against the outer shell along the circumferential direction through the side face.

10. The battery cell according to any one of claims 1 to 6, wherein, The outer shell is also provided with a pressure relief mechanism, which is connected to the cavity, and the restraint member is arranged to avoid the pressure relief mechanism.

11. The battery cell according to any one of claims 1 to 6, wherein, The protrusion distance of the restraint member relative to the outer shell on the side of the cavity is 0.2mm to 1mm.

12. A battery comprising a battery cell as described in any one of claims 1 to 11.

13. An electrical device comprising the battery of claim 12, the battery being used to provide electrical energy.

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