CN218414923U

CN218414923U - Single battery shell, single battery, battery and electric equipment

Info

Publication number: CN218414923U
Application number: CN202222252545.4U
Authority: CN
Inventors: 苏华圣; 岳嵩; 李全坤; 邢承友; 王鹏
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-08-25
Filing date: 2022-08-25
Publication date: 2023-01-31
Anticipated expiration: 2032-08-25

Abstract

The embodiment of the application provides a single battery shell, a single battery, a battery and electric equipment. The housing of the battery cell includes: the shell is a hollow structure with an opening end, the side wall of the shell is enclosed to form the opening end, and the side wall is provided with at least one pressure relief area which surrounds the whole circumference along the circumferential direction of the side wall. The single battery shell, the single battery, the battery and the electric equipment provided by the embodiment of the application can improve the safety of the battery.

Description

Single battery shell, single battery, battery and electric equipment

Technical Field

The application relates to the technical field of batteries, in particular to a single battery shell, a single battery, a battery and electric equipment.

Background

Energy conservation and emission reduction are the key points of sustainable development of the automobile industry. Under such circumstances, electric vehicles are an important component of sustainable development of the automobile industry due to their energy saving and environmental protection advantages. In the case of electric vehicles, battery technology is an important factor in the development thereof.

In addition to improving the performance of batteries, safety issues are also a considerable problem in the development of battery technology. If the safety problem of the battery cannot be guaranteed, the battery cannot be used. Therefore, how to enhance the safety of the battery is a technical problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a single battery shell, a single battery, a battery and electric equipment, and can improve the safety of the battery.

In a first aspect, a battery cell housing is provided, including: the shell is a hollow structure with an opening end, the side wall of the shell is enclosed to form the opening end, and the side wall is provided with at least one pressure relief area which surrounds the whole circumference along the circumferential direction of the side wall.

Therefore, in the case of the battery cell according to the embodiment of the present application, the side wall of the case is likely to be pressed by the adjacent battery cell or the case or other parts of the battery during the use of the battery. If the pressure relief region is located in a local circumferential region of the side wall of the housing, or the pressure relief regions are distributed perpendicular to the circumferential direction of the side wall, since the region where the pressure relief region is located is weaker than the region where the pressure relief region is not located, and is more likely to deform, the deformation of the side wall in the circumferential direction is not uniform, and thus the battery cell is deformed non-uniformly. For example, uneven deformation of the cylindrical battery cell may cause poor roundness of the battery cell, which may affect welding of the case, thereby reducing strength and safety of the battery cell. Therefore, the pressure relief area of this application embodiment encircles the whole week along the circumference of lateral wall, can make the circumference of the free casing of battery warp comparatively evenly, and then improves free intensity of battery and security.

In addition, if the pressure relief area is disposed in a local area of the side wall of the housing, or the pressure relief area is distributed perpendicular to the circumferential direction of the side wall, the pressure relief area needs to be installed in a specific direction when a plurality of battery cells are assembled, so as to avoid blocking the pressure relief area. Therefore, the installation difficulty is increased, the pressure relief area can be shielded due to installation errors, the internal pressure of the pressure relief area is released, and the safety of the battery monomer is reduced. And the pressure release district of this application encircles whole week along the circumference of the lateral wall of casing, consequently when the equipment battery is single, has reduced the requirement of the free mounted position of battery, has improved the free installation flexibility ratio of battery, easily avoids sheltering from the pressure release district, and then can in time release the free internal pressure of battery of thermal runaway, improves the security of battery.

In some embodiments, the wall thickness of the relief area is less than the wall thickness of other regions of the sidewall. The strength of the pressure relief area is relatively weak, so that the processing is convenient, when the battery monomer is out of control due to heat, the internal temperature or pressure of the battery monomer reaches a preset value, and the shell is damaged at the pressure relief area so as to relieve the internal pressure or temperature.

In some embodiments, a surface of the pressure relief region facing the interior of the housing is flush with a surface of the other region facing the interior of the housing. If not, the pressure relief area is recessed relative to other areas due to the small wall thickness of the pressure relief area, and the electrolyte included in the housing is corrosive, and if the electrolyte accumulates in the pressure relief area, the electrolyte may corrode and damage the pressure relief area, and the pressure relief area may fail.

In some embodiments, the wall thickness T1 of the relief zone satisfies: t1 is more than or equal to 0.2T, wherein T is the wall thickness of the other area. The wall thickness of the pressure relief area is smaller than that of other areas, so that the pressure relief area is damaged when the pressure or the temperature inside the battery cell reaches a threshold value, the internal pressure is relieved, and the temperature is reduced in time. Conversely, the wall thickness of the pressure relief area may not be too thin to prevent the housing from having insufficient strength to affect the structural strength of the cell.

In some embodiments, the height H1 of the pressure relief zone is in the range of [0.1mm,5mm ], and the height direction of the pressure relief zone is perpendicular to the open end.

The height of the pressure relief area is not suitable to be too small so as to avoid increasing the processing difficulty, and the pressure relief area is also prevented from being damaged due to too small area, so that the pressure relief area can not timely relieve pressure. Conversely, the height of the pressure relief area should not be too large, so as to avoid the insufficient strength of the whole shell, and avoid the shell from being damaged by external force.

In some embodiments, the different regions of the relief zone are of equal height. The height of the pressure release area is equal along the circumferential direction of the side wall, so that the processing is convenient, different sizes are not required to be additionally arranged, the stress of the side wall around the pressure release area is uniform, and the roundness of the side wall is ensured.

In some embodiments, the pressure relief region comprises at least one weakened region having a wall thickness that is less than a wall thickness of a region of the pressure relief region other than the weakened region. The battery pack can avoid insufficient strength of the shell due to the fact that the wall thickness of all regions of the pressure relief area is set to be too thin, and can enable the pressure relief area to be damaged at the weak area with smaller wall thickness when the pressure or the temperature inside the battery cell reaches a threshold value, and can timely relieve the internal pressure.

In some embodiments, the pressure relief area includes a plurality of the weak areas uniformly distributed along the circumferential direction of the side wall, so as to avoid uneven circumferential stress, uneven strength and uneven deformation of the side wall caused by uneven distribution of the weak areas, thereby reducing the structural strength of the battery cell.

In some embodiments, the side wall includes a securing region partially overlapping the pressure relief region, the securing region for securing the battery cell, the securing region not completely covering a plurality of the weakened regions in a first cross-section of the side wall, the first cross-section passing through the pressure relief region and parallel to the open end.

Through setting up the fixed area and not totally covering the weak area on the pressure release district, it is sheltered from by the fixed area to have partial weak area on the pressure release district at least for the weak area can in time be destroyed when battery monomer thermal runaway, the inside pressure of battery monomer of releasing and in time cooling, the security that improves the battery.

In some embodiments, the housing is a cylinder, and in the first cross section, the angle of the central angle of the circular arc in which the region other than the fixing region is located is larger than the angle of the central angle of the circular arc between any two adjacent weak regions of the pressure relief region.

Like this, no matter how this battery monomer of axis rotation of following battery monomer installs, the fixed area can not shelter from and cover all weak areas on the pressure release district, the nimble installation of battery monomer of being convenient for on the one hand, need not set up specific mounted position or direction, on the other hand can avoid the weak area to be sheltered from to make the weak area can in time be destroyed when battery monomer thermal runaway, the pressure and the timely cooling of the battery monomer inside of releasing improve the security of battery.

In some embodiments, the length L1 of the weakened area along the circumference of the sidewall is satisfied; l1 is more than or equal to 0.1mm and less than or equal to 0.2L, wherein L is the perimeter of the side wall. If the length of the weak area is set too small along the axis of the side wall, the processing difficulty is increased, and the difficulty of damaging the pressure relief area in the weak area is increased; conversely, if the length of the weak region is set too large, the strength of the side wall of the case may be reduced, thereby affecting the strength and safety of the battery cell.

In some embodiments, the sidewall is provided with a plurality of such relief zones. When the battery monomer generates thermal runaway, high temperature or high pressure is usually generated locally, if only one pressure relief area is arranged on the side wall, the situation that the pressure relief area is far away from the high-temperature high-pressure area may exist, and then the pressure relief area cannot be damaged in time. Therefore, can be provided with a plurality of pressure release regions on the lateral wall, especially in direction of height X, when the size of lateral wall is great, set up a plurality of pressure release regions and can guarantee that different regions produce high temperature or high pressure, the nearest pressure release region of corresponding distance can in time be destroyed, and then in time releases internal pressure and in time cools down, improves the security of battery.

In some embodiments, a plurality of the pressure relief zones are symmetrically distributed with respect to a second cross section of the sidewall, the second cross section passing through a center point of the sidewall and being parallel to the open end.

Like this, on the one hand can be so that the free bulk strength of battery is comparatively even, and on the other hand also can be so that when different regions produced high temperature or high pressure, there was the most recent pressure release district of distance that corresponds with it, and this pressure release district can in time be destroyed, and then in time releases internal pressure and in time cools down, improves the security of battery.

In some embodiments, the housing is a cylinder.

In some embodiments, the case has two of the open ends, which are opposite bottom surfaces of the case, to facilitate quick installation of the internal electrode assembly.

In a second aspect, a battery cell is provided, including: the housing of the first aspect; and the cover plate is used for covering the opening end.

In a third aspect, a battery is provided, including: a plurality of battery cells comprising the housing of the first aspect.

In a fourth aspect, there is provided an electrical device comprising: a plurality of battery cells, the battery cells including the housing of the first aspect, the battery cells being configured to provide electrical energy to the electrical device.

In some embodiments, the powered device is a vehicle, a watercraft, or a spacecraft.

Drawings

FIG. 1 is a schematic illustration of a vehicle according to an embodiment of the present disclosure;

fig. 2 is a schematic view of a partial structure of a battery according to an embodiment of the present disclosure;

fig. 3 is an exploded view of a battery cell according to an embodiment of the present disclosure;

fig. 4 is a schematic view of a side wall of a housing of a battery cell as disclosed in an embodiment of the present application;

FIG. 5 is a schematic illustration of a first cross-section of a sidewall disclosed in an embodiment of the present application;

FIG. 6 is a schematic view, partially in cross-section, of a battery as disclosed in an embodiment of the present application;

fig. 7 is a partial cross-sectional view of a battery cell and a fixing member according to an embodiment of the present disclosure.

In the drawings, the drawings are not necessarily to scale.

Detailed Description

Embodiments of the present application will be described in further detail below with reference to the drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the described embodiments.

In the description of the present application, it is to be noted that, unless otherwise specified, "a plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like, indicate an orientation or positional relationship that is merely for convenience in describing the application and to simplify the description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. "vertical" is not strictly vertical, but is within the tolerance of the error. "parallel" is not strictly parallel but within the tolerance of the error.

The following description is given with the directional terms as they are used in the drawings and not intended to limit the specific structure of the present application. In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood as appropriate by one of ordinary skill in the art.

In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.

In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiments of the present application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application. The battery cells are generally divided into three types in an encapsulation manner: the single battery of cylindricality battery, square battery monomer and laminate polymer battery monomer, this application embodiment is to this also not limited.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charging or discharging of battery monomer.

The battery monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive pole piece, a negative pole piece and an isolating membrane. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece comprises a positive pole current collector and a positive pole active substance layer, wherein the positive pole active substance layer is coated on the surface of the positive pole current collector, the positive pole current collector which is not coated with the positive pole active substance layer protrudes out of the positive pole current collector which is coated with the positive pole active substance layer, and the positive pole current collector which is not coated with the positive pole active substance layer is used as a positive pole lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece includes negative pole mass flow body and negative pole active substance layer, and the negative pole active substance layer coats in the surface of negative pole mass flow body, and the negative pole mass flow body protrusion in the negative pole mass flow body of coating the negative pole active substance layer not coating the negative pole active substance layer, and the negative pole mass flow body of not coating the negative pole active substance layer is as negative pole utmost point ear. The material of the negative electrode collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the isolation film may be polypropylene (PP) or Polyethylene (PE). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The development of battery technology should take into consideration various design factors, such as energy density, cycle life, discharge capacity, charge and discharge rate, and safety of battery. For the battery, the main safety hazard comes from the charging and discharging processes, and in order to improve the safety performance of the battery, a pressure relief mechanism is generally arranged on the battery cell. The pressure relief mechanism refers to an element or a component that is activated to relieve the internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a predetermined threshold. The predetermined threshold may be adjusted according to design requirements. The predetermined threshold may depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte and the separator in the battery cell. The pressure relief mechanism may employ, for example, a pressure-sensitive or temperature-sensitive element or component, i.e., the pressure relief mechanism is actuated when the internal pressure or temperature of the battery cell reaches a predetermined threshold, thereby forming a channel through which the internal pressure or temperature may be vented.

The term "activate" as used herein refers to the action of the pressure relief mechanism, such that the internal pressure and temperature of the battery cell are released. The actions generated by the pressure relief mechanism may include, but are not limited to: at least a portion of the pressure relief mechanism ruptures, is torn or melts, etc. After the pressure relief mechanism is actuated, high-temperature and high-pressure substances inside the battery cells are discharged outwards from the pressure relief mechanism as emissions. In this way, the cell can be depressurized under controlled pressure or temperature, so that a potentially more serious accident can be avoided.

Reference herein to emissions from the battery cell includes, but is not limited to: electrolyte, dissolved or split anode and cathode pole pieces, fragments of a separation film, high-temperature and high-pressure gas generated by reaction, flame and the like.

The pressure relief mechanism on the battery cell has an important influence on the safety of the battery. For example, when a short circuit, overcharge, or the like occurs in a battery cell, thermal runaway may occur inside the battery cell, and thus, pressure or temperature may suddenly rise. In this case, the internal pressure and temperature can be released outwards by the actuation of the pressure relief mechanism, so as to prevent the explosion and the fire of the battery cells.

Therefore, how to reasonably design the structure and the position of the pressure relief mechanism is crucial to the safety of the battery, and especially for battery cells with different shapes, the arrangement of the pressure relief mechanism may also affect the processing efficiency of the battery. For example, the current pressure relief mechanism is generally disposed at an end of a housing of a battery cell, and if a plurality of battery cells are stacked together or other components are stacked with the battery cell, the pressure relief mechanism located at the end of the battery cell may be shielded by other battery cells or components, so that pressure relief is not timely, and a safety accident occurs. For example, for a cylindrical battery cell, in order to improve the space utilization rate and energy density of the battery, how to reasonably set the position of the pressure relief mechanism to relieve the pressure in time should be considered, and meanwhile, the influence of the setting position of the pressure relief mechanism on the installation and fixation of the battery cell should be considered, so as to avoid reducing the processing and production efficiency of the battery.

Therefore, the embodiment of the application provides a single battery shell, a single battery, a battery and an electric device, which can solve the above problems. The shell of the embodiment of the application is a hollow structure with an opening end, the side wall of the shell is enclosed to form the opening end, and the side wall is provided with at least one pressure relief area which surrounds the whole circumference along the circumferential direction of the side wall. During use of the battery, the side walls of the housing of the battery cells are likely to be compressed by adjacent battery cells or the battery case or other components. If the pressure relief area is located in a local area of the side wall of the housing in the circumferential direction, the deformation is more likely to occur because the area provided with the pressure relief area is weaker than the area not provided with the pressure relief area, and then the deformation in the circumferential direction of the side wall is not uniform, which in turn causes non-uniform deformation of the battery cell. Therefore, the pressure relief area of the embodiment of the application surrounds the whole circumference along the circumferential direction of the side wall, so that the circumferential deformation of the shell of the battery cell is uniform.

In addition, if the pressure relief area is arranged in a local area of the side wall of the shell, when a plurality of battery monomers are assembled, the battery monomers need to be installed in a specific direction so as to avoid shielding the pressure relief area, so that the installation difficulty is increased, the pressure relief area is influenced to release internal pressure due to shielding of the pressure relief area, and the safety of the battery is further reduced. And the pressure release district of this application encircles whole week along the circumference of casing lateral wall, consequently when the equipment battery is single, has reduced the requirement of the free mounted position of battery, has improved the free installation flexibility ratio of battery, easily avoids sheltering from the pressure release district, and then can in time release the free internal pressure of battery of thermal runaway, improves the security of battery.

The technical scheme described in the embodiment of the application is suitable for various electric equipment using batteries.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range extending vehicle and the like; spacecraft include aircraft, rockets, space shuttles, spacecraft, and the like; electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above-mentioned electric devices.

For convenience of explanation, the following embodiments will be described by taking an electric device as an example of a vehicle.

For example, as shown in fig. 1, which is a schematic structural diagram of a vehicle 1 according to an embodiment of the present disclosure, the vehicle 1 may be a fuel-oil vehicle, a gas-fired vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid electric vehicle, or an extended range vehicle. The vehicle 1 may be provided with a motor 40, a controller 30 and a battery 10, the controller 30 being configured to control the battery 10 to supply power to the motor 40. For example, the battery 10 may be provided at the bottom or the head or tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, for example, the battery 10 may be used as an operation power supply of the vehicle 1 for a circuit system of the vehicle 1, for example, for power demand for operation at the start, navigation, and running of the vehicle 1. In another embodiment of the present application, the battery 10 may be used not only as an operation power source of the vehicle 1 but also as a driving power source of the vehicle 1 instead of or in part of fuel or natural gas to provide driving power to the vehicle 1.

In order to meet different power requirements, the battery may include a plurality of battery cells, wherein the plurality of battery cells may be connected in series or in parallel or in series-parallel, and the series-parallel refers to a mixture of series connection and parallel connection. The battery may also be referred to as a battery pack. Alternatively, a plurality of battery cells may be connected in series or in parallel or in series-parallel to form a battery module, and a plurality of battery modules may be connected in series or in parallel or in series-parallel to form a battery. That is to say, a plurality of battery cells may directly constitute a battery, or may first constitute a battery module, and then constitute a battery, which is not limited in this embodiment of the present application.

For example. Fig. 2 shows a schematic view of a part of the structure of the battery 10 according to the embodiment of the present application. As shown in fig. 2, the battery 10 of the embodiment of the present application may include a plurality of battery cells 20 to meet different power requirements. The shape of the battery cell 20 of the embodiment of the present application may be set according to practical applications. For example, the battery cell 20 may be a rectangular parallelepiped or a cylinder or other shape. For convenience of description, the present embodiment is mainly described by taking the cylindrical battery cell 20 as an example, but the present embodiment is not limited thereto.

In the embodiment of the present application, as shown in fig. 2, due to the shape characteristics of the cylindrical battery cell 20, in order to improve the installation efficiency of the battery 10, the battery 10 may further include a fixing member 11, and the fixing member 11 may be used to fix a plurality of battery cells 20. Specifically, the shape of the fixing member 11 may be set according to practical applications, for example, the shape of the fixing member 11 may be set according to factors such as the number and positions of the plurality of battery cells 20 to be mounted. For example, in fig. 2, the fixing member 11 is illustrated as an approximately rectangular parallelepiped, and the plurality of battery cells 20 may be fixed to the outer surface of the fixing member 11; in addition, the inside of the fixing part 11 may be provided as a hollow structure for accommodating other parts, but the embodiment of the present application is not limited thereto.

It should be understood that the battery 10 of the present embodiment may further include a case that may be used to house a plurality of battery cells 20. The inside hollow structure that is of the box of this application embodiment, a plurality of battery monomer 20 hold in the box. The bin may comprise two parts, herein referred to as a first bin portion and a second bin portion, respectively, which snap together. The shape of the first case portion and the second case portion may be determined according to the shape of the internally housed member, for example, may be determined according to the shape of a combination of a plurality of battery cells 20 internally housed, at least one of the first case portion and the second case portion having one opening. For example, only one of the first and second casing portions may be a hollow rectangular parallelepiped having an opening, and the other may be plate-shaped to cover the opening. For example, taking the case where the second case portion is a hollow rectangular parallelepiped and has one opening, and the first case portion is a plate-shaped case portion, the first case portion covers the opening of the second case portion to form a case having a closed chamber, which may be used to accommodate a plurality of battery cells 20. The plurality of battery cells 20 are connected in parallel or in series-parallel combination and then are arranged in a box body formed by buckling the first box body part and the second box body part.

For another example, the first case portion and the second case portion may be hollow cuboids, and each of the first case portion and the second case portion may have an opening surface, the opening of the first case portion and the opening of the second case portion are disposed opposite to each other, and the first case portion and the second case portion are engaged with each other to form a case having a closed cavity, and the closed cavity may be used to accommodate the plurality of battery cells 20.

Optionally, the battery 10 may further include a bus member, which may be used to electrically connect the plurality of battery cells 20, such as in parallel or in series-parallel. Specifically, the bus member may achieve electrical connection between the battery cells 20 by connecting the electrode terminals 231 of the battery cells 20. Further, the bus member may be fixed to the electrode terminals 231 of the battery cells 20 by welding.

Fig. 3 is an exploded schematic diagram of at least a part of the structure of the battery cell 20 according to the embodiment of the present application, for example, the battery cell 20 shown in fig. 3 may be any one of the battery cells 20 in the battery 10 shown in fig. 2. As shown in fig. 3, the battery cell 20 of the embodiment of the present application may include a case 21 and a cap plate 23. Specifically, the housing 21 has a hollow structure with an open end 211, and the cover plate 23 is used for covering the open end 211.

The case 21 according to the embodiment of the present disclosure may have a hollow structure including at least one open end 211, wherein the hollow structure may be used to accommodate the electrode assembly 24 of the battery cell 20, and the cover plate 23 is used to cover the open end 211 of the case 21. Specifically, if the housing 21 has a hollow structure with one open end 211, one cover plate 23 may be provided to cover the one open end 211 of the housing 21; if the housing 21 has a hollow structure with two open ends 211, for example, as shown in fig. 3, the housing 21 has two open ends 211 oppositely disposed, two cover plates 23 may be disposed, and the two cover plates 23 respectively cover the two open ends 211 of the housing 21.

The material of the housing 21 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The housing 21 may be in various shapes, such as a cylinder, a rectangular parallelepiped, or the like. Illustratively, in the various figures of the embodiments of the present application, the housing 21 is a cylinder; illustratively, the case 21 has two open ends 211, the two open ends 211 being two opposite bottom surfaces of the case 21, and such a structure with two open ends facilitates assembly of the inner electrode assembly 24, and the electrode assembly 24 can enter the case 21 through any one of the open ends 211, thereby improving the processing efficiency of the battery cell 20.

The cover plate 23 of the embodiment of the present application is a member that covers the open end 211 of the case 21 to isolate the internal environment of the battery cell 20 from the external environment. The cover 23 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the cover 23 may be made of the same material as or different from that of the case 21.

It will be appreciated that the shape of the cover plate 23 may be adapted to the shape of the housing 21. For example, when the case 21 has a rectangular parallelepiped structure, the cover plate 23 may have a plate-like structure that fits the case 21, or may have a hollow rectangular parallelepiped structure with one end open at 213, so that the cover plate 23 and the case 21 are closed to form the rectangular parallelepiped battery cell 20. For another example, as shown in fig. 3, when the housing 21 is a cylinder, the cover plate 23 may be a circular plate; or the cover plate 23 may also be a groove structure with a circular bottom wall, so that the cover plate 23 and the housing 21 are covered to form the cylindrical battery cell 20, which is not limited in the embodiment of the present application.

The battery cell 20 of the embodiment of the present application may further include an electrode assembly 24, and one or more electrode assemblies 24 may be disposed, and the embodiment of the present application is not limited thereto. The electrode assembly 24 is a component in the battery cell 20 where electrochemical reactions occur. The electrode assembly 24 may be a cylinder, a rectangular parallelepiped, or the like, and the shape of the electrode assembly 24 may be the same as or different from the outer shape of the battery cell 20. For example, if the electrode assembly 24 has a cylindrical structure, the housing of the battery cell 20 may also have a cylindrical structure; alternatively, if the electrode assembly 24 has a rectangular parallelepiped structure, the housing of the battery cell 20 may have a rectangular parallelepiped structure, so as to increase the space occupancy rate of the electrode assembly 24 in the battery cell.

As shown in fig. 3, the electrode assembly 24 according to the embodiment of the present application may include a tab 241 and a main portion, wherein the tab of the electrode assembly 24 may include a positive electrode tab and a negative electrode tab, the positive electrode tab may be formed by laminating a portion of the positive electrode sheet on which the positive electrode active material layer is not coated, the negative electrode tab may be formed by laminating a portion of the negative electrode sheet on which the negative electrode active material layer is not coated, and the main portion may be formed by laminating a portion of the positive electrode sheet on which the positive electrode active material layer is coated and a portion of the negative electrode sheet on which the negative electrode active material layer is coated or winding the same. Also, the two tabs of the electrode assembly 24 may be located on the same end face or different end faces of the electrode assembly 24, for example, as shown in fig. 3, the embodiment of the present application takes the case where the two tabs of the electrode assembly 24 are located on two oppositely disposed end faces, respectively. Also, correspondingly, the plurality of electrode terminals 231 of the battery cell 20 may be respectively disposed at the opposite end surfaces, for example, may be respectively disposed at the opposite cover plates 23, so that each tab 241 may be electrically connected to the corresponding one or more electrode terminals 231. For example, as shown in fig. 3, each tab 241 may be electrically connected to the corresponding two electrode terminals 231, but the embodiment of the present application is not limited thereto.

The housing 21 according to the embodiment of the present application will be described in detail with reference to the accompanying drawings. As shown in fig. 3, the housing 21 is a hollow structure having an open end 211, a sidewall 212 of the housing 21 encloses the open end 211, the sidewall 212 is provided with at least one pressure relief region 22, and the pressure relief region 22 surrounds the entire circumference of the sidewall 212.

It should be understood that the open end 211 of the embodiment of the present application refers to the end surface of the housing 21 where the opening is located. Correspondingly, the side wall 212 of the housing 21 of the embodiment of the present application can enclose the open end 211, that is, the side wall 212 of the housing 21 refers to the wall of the housing 21 adjacent to the open end 211. For example, for a cylindrical battery cell 20, the sidewall 212 of the housing 21 is a cylindrical side surface, and the open end 211 of the housing 21 refers to the bottom surface of the housing having an opening.

The side wall 212 of the present embodiment is provided with one or more pressure relief regions 22, and the pressure relief regions 22 may be configured to be broken when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold value to relieve the internal pressure or temperature of the battery cell 20. For example, the pressure relief region 22 may be provided with a pressure relief mechanism such that when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, the pressure relief mechanism of the pressure relief region 22 is activated, the pressure relief region 22 is broken, and the internal pressure or temperature of the battery cell 20 is relieved.

For convenience of explanation, the embodiment of the present application is described by taking any one of the relief regions 22 provided in the sidewall 212 as an example. Specifically, as shown in fig. 3, for any one of the pressure relief regions 22, the pressure relief region 22 surrounds the entire circumference of the sidewall 212 along the circumferential direction of the sidewall 212, wherein the "entire circumference" means that the number of the pressure relief region 22 surrounding the sidewall 212 along the circumferential direction of the sidewall 212 is an integer, for example, the pressure relief region 22 surrounds the sidewall 212 along the circumferential direction of the sidewall 212 for one, two or three weeks. For convenience of illustration, the pressure relief region 22 is disposed around the sidewall 212 along the circumferential direction of the sidewall 212 for a circle in the embodiments of the present application, but the embodiments of the present application are not limited thereto.

In addition, for convenience of explanation, the height direction X of the battery cell 20 is defined as a direction perpendicular to the open end 211 of the case 21, and then the circumferential direction of the side wall 212 is perpendicular to the height direction X of the battery cell 20. For example, as shown in fig. 3, for the cylindrical battery cell 20, the height direction X is the direction of the central axis of the cylindrical housing 21, and the circumferential direction of the sidewall 212 is perpendicular to the central axis of the housing 21.

In the present embodiment, the side wall 212 of the housing 21 of the battery cell 20 is likely to be pressed by the adjacent battery cell 20 or the case or other parts of the battery 10 during the use of the battery 10. If the pressure relief region 22 is located in a local region of the side wall 212 of the housing 21 in the circumferential direction, or the pressure relief regions 22 are distributed perpendicular to the circumferential direction of the side wall 212, since the region where the pressure relief region 22 is located is weaker than the region where the pressure relief region 22 is not located, and is more likely to deform, the deformation of the side wall 212 in the circumferential direction is not uniform, and thus the battery cell 20 is deformed non-uniformly. For example, the uneven deformation of the cylindrical battery cell 20 may cause poor roundness of the battery cell 20, which may affect the welding of the case 21, thereby reducing the strength and safety of the battery cell 20. Therefore, the pressure relief area 22 of the embodiment of the present application surrounds the entire circumference along the circumferential direction of the side wall 212, so that the circumferential deformation of the housing 21 of the battery cell 20 is uniform, and the strength and the safety of the battery cell 20 are improved.

In addition, if the pressure relief region 22 is provided in a partial region of the side wall 212 of the housing 21, or the pressure relief regions 22 are distributed perpendicular to the circumferential direction of the side wall 212, the battery cells 20 are mounted in a specific direction so as not to block the pressure relief region 22 when they are assembled. Therefore, the installation difficulty is increased, and the pressure relief area 22 may be shielded due to installation errors, so that the pressure relief area 22 is influenced to release internal pressure, and the safety of the battery 10 of the battery cell 20 is reduced. And the circumference of the lateral wall 212 of this application along casing 21 encircles whole week in pressure release district 22, consequently when assembling battery monomer 20, has reduced the requirement of battery monomer 20's mounted position, has improved battery monomer 20's installation flexibility ratio, easily avoids sheltering from pressure release district 22, and then can in time let out the internal pressure of thermal runaway's battery monomer 20, improves the security of battery 10.

It should be appreciated that the pressure relief zone 22 of the embodiments of the present application may be arranged in a variety of ways. For example, a material or an element or a component sensitive to pressure or temperature may be used at the pressure relief region 22, such as a pressure-sensitive material or a temperature-sensitive material, that is, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold value, the pressure relief region 22 may be damaged by sensing the temperature or pressure in time, so as to form a channel through which the internal pressure or temperature of the battery cell 20 can be relieved.

As another example, the pressure relief region 22 may be provided in other manners. In particular, the wall thickness of the relief area 22 is smaller than the wall thickness of the other region 2121 of the side wall 212. Specifically, the pressure relief area 22 may be a notch on the battery cell 20, such that the wall thickness of the housing 21 of the battery cell 20 at the pressure relief area 22 is smaller than the thickness of the other region 2121 of the side wall 212, i.e., the pressure relief area 22 is the smallest wall thickness of the side wall 212, so that the strength at the pressure relief area 22 is relatively weak. Thus, it is possible to facilitate the process, and when the internal temperature or pressure of the battery cell 20 reaches a predetermined value due to thermal runaway, the case 21 is broken at the relief area 22 to relieve the internal pressure or temperature. The embodiment of the present application is mainly described by taking the example of providing the pressure relief area 22 in the form of an indentation.

It should be understood that other regions 2121 of embodiments of the present application may include: the area of the sidewall 212 other than the venting zone 22, for example, the other area 2121 may refer primarily to the area of the sidewall 212 that is located around the venting zone 22. For example, as shown in fig. 3, if no other component is disposed on the side wall 212 and all other regions of the side wall 212 except the pressure relief region 22 have the same wall thickness, the other regions 2121 may be regions of the side wall 212 except the pressure relief region 22.

Fig. 4 shows a schematic view of the side wall 212 of the housing 21 of the battery cell 20 of the embodiment of the present application. As shown in fig. 4, a plurality of bleed zones 22 are provided on the sidewall 212. When thermal runaway of the battery cell 20 occurs, high temperature or high pressure is usually generated locally, and if only one pressure relief region 22 is provided on the side wall 212, the pressure relief region 22 may be far from the high temperature and high pressure region, so that the pressure relief region 22 cannot be damaged in time. Therefore, a plurality of pressure relief regions 22 may be disposed on the side wall 212, and particularly, in the height direction X, when the size of the side wall 212 is large, the plurality of pressure relief regions 22 may be disposed to ensure that the corresponding pressure relief region 22 closest to the side wall can be damaged in time when high temperature or high pressure is generated in different regions, so as to timely relieve the internal pressure and reduce the temperature, thereby improving the safety of the battery 10.

As shown in fig. 4, the plurality of pressure relief zones 22 are symmetrically distributed with respect to a second cross section 2124 of the sidewall 212, the second cross section 2124 passing through a center point of the sidewall 212 and being parallel to the open end 211. Specifically, the second cross section 2124 is perpendicular to the height direction X, and the second cross section 2124 passes through a center point of the sidewall 212, so that when the sidewall 212 is provided with a plurality of pressure relief regions 22, the plurality of pressure relief regions 22 are uniformly distributed in the height direction X. Like this, on the one hand can make battery monomer 20's bulk strength comparatively even, on the other hand also can make when different regions produce high temperature or high pressure, have the most recent pressure release district 22 of distance that corresponds with it, this pressure release district 22 can in time be destroyed, and then in time release internal pressure and in time cool down, improve the security of battery 10.

For example, fig. 4 illustrates two relief areas 22 provided on the side wall 212. Further, for the plurality of relief areas 22 provided on the side wall 212, the distance H2 between each relief area 22 and the nearest opening end 211 in the height direction X of the battery cell 20 may be set according to practical applications. For example, the H2 may be set according to the total height H of the side wall 212, e.g., H2 may be set to about 0.25 × H.

In the embodiment of the present application, for any one of the pressure release regions 22, the height H1 of the pressure release region 22 is in the range of [0.1mm,5mm ], and the height direction X of the pressure release region 22 is perpendicular to the open end 211. Specifically, the height direction of the pressure relief area 22 is the height direction X of the battery cell 20, and the height H1 of the pressure relief area 22 may be set according to practical applications. For example, the height H1 of the pressure relief area 22 should not be too small to avoid increasing the processing difficulty, and the pressure relief area 22 should not be too small to be damaged, so that the pressure relief area 22 cannot timely relieve pressure. Conversely, the height H1 of the pressure relief area 22 should not be too large to avoid the overall strength of the shell 21 being insufficient, and to avoid the shell 21 being damaged by external forces. For example, the height H1 of the pressure relief area 22 may be set to be generally 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

As shown in fig. 4, the different regions of the pressure relief area 22 of the present embodiment are of equal height. Specifically, the pressure relief area 22 is arranged at the same height along the circumferential direction of the side wall 212, which not only facilitates processing without additional arrangement of different sizes, but also enables the side wall 212 to have uniform stress around the pressure relief area 22 and ensures the roundness of the side wall 212. For example, when the pressure relief area 22 is processed by stamping, it can be ensured that the material extrusion is uniform during the stamping process, and the roundness of the shell 21 meets the use requirement.

Fig. 5 showsbase:Sub>A schematic cross-sectional view of the side wall 212 of the housing 21 according to an embodiment of the present application, wherein the cross-section may bebase:Sub>A first cross-section 2123 of the side wall 212, the first cross-section 2123 passing through the pressure relief area 22 and being parallel to the open end 211, for example, the first cross-section 2123 may bebase:Sub>A cross-section alongbase:Sub>A directionbase:Sub>A-base:Sub>A' as shown in fig. 4. As shown in fig. 4 and 5, the wall thickness of the pressure relief area 22 of the embodiment of the present application is smaller than the wall thickness of the other region 2121 of the side wall 212, wherein the wall thickness of the pressure relief area 22 can be set according to the actual application.

For example, as shown in fig. 4 and 5, the wall thickness T1 of the run-out region 22 satisfies: t1 < T0.2T ≦ T, where T is the wall thickness of the other regions 2121 of the sidewall 212. Specifically, the wall thickness T1 of the pressure relief region 22 is set smaller than the wall thickness T of the other region 2121, so that the pressure relief region 22 is destroyed when the pressure or temperature inside the battery cell 20 reaches a threshold value, and internal pressure is relieved and temperature is reduced in time. Conversely, the wall thickness T1 of the pressure relief area 22 may not be too thin to prevent the housing 21 from having insufficient strength and affecting the structural strength of the battery cell 20. For example, the wall thickness T1 of the pressure relief region 22 may be set to 0.21T, 0.4T, 0.6T or 0.8T in general.

In the present embodiment, as shown in fig. 4 and 5, the surface of the pressure relief area 22 facing the inside of the casing 21 is flush with the surface of the other area 2121 facing the inside of the casing 21. In particular, the wall thickness of the pressure relief zone 22 being smaller than the wall thickness of the other regions 2121 can be achieved in various ways. For example, a thinning process may be performed on the inner surface of the side wall 212 facing the inside of the battery cell 20, so that the pressure relief region 22 is recessed on the inner surface of the side wall 212 compared to the other region 2121, i.e., a groove in the side wall 212 opening toward the inside of the battery cell 20 serves as the pressure relief region 22. Since the electrolyte is contained in the casing 21, the electrolyte has certain corrosiveness, and if the electrolyte is accumulated in the groove serving as the pressure relief region 22, the electrolyte is likely to corrode and damage the pressure relief region 22, and the pressure relief region 22 is likely to fail. Therefore, thinning is not usually performed on the inner surface of the side wall 212, i.e., the surface of the pressure relief area 22 facing the inside of the housing 21 is flush with the surface of the other area 212 facing the inside of the housing 21; correspondingly, a thinning process may be performed on the surface of the sidewall 212 facing the exterior of the battery cell 20 to form the pressure relief region 22.

In the present embodiment, as shown in fig. 4 and 5, the bleeder 22 comprises at least one zone of weakness 221, the wall thickness of the zone of weakness 221 being smaller than the wall thickness of the area of the bleeder 22 other than the zone of weakness 221. Specifically, the weak region 221 may be provided in at least a partial region within the pressure relief region 22 to further reduce the wall thickness of the partial region of the pressure relief region 22, so that both insufficient strength of the case body 21 due to excessively thin wall thickness of the entire region of the pressure relief region 22 can be avoided, and when the pressure or temperature inside the battery cell 20 reaches a threshold value, the pressure relief region 22 can be broken at the weak region 221 having a smaller wall thickness, and the internal pressure can be relieved at that time.

As shown in fig. 4 and 5, the pressure relief area 22 includes a plurality of weakened areas 221 uniformly distributed along the circumferential direction of the side wall 212, so as to avoid uneven circumferential force, uneven strength, and uneven deformation of the side wall 212 caused by uneven distribution of the weakened areas 221, thereby affecting the structural strength of the battery cell 20. In particular, along the circumferential direction of the side wall 212, the pressure relief zone 22 comprises a plurality of weakened zones 221 distributed uniformly, comprising: the distance between each adjacent two of the plurality of weak regions 221 is equal and the length of the plurality of weak regions 221 is equal, but the distance between each adjacent two of the weak regions 212 and the length of each weak region 221 may be equal or different.

It should be understood that, for the cylindrical battery cell 20, each weakened area 221 corresponds to an arc along the circumferential direction of the side wall 212 on the first cross section 2123, and the distance between each two adjacent weakened areas 221 in the embodiment of the present application may refer to the length of the arc between the two adjacent weakened areas 221; and the length of each weak area 221 in the embodiment of the present application may refer to: the length of the arc in which the weakened area 221 is located.

It should be understood that the number of the weak areas 221 provided in the pressure relief area 22 in the embodiment of the present application may be set according to practical applications. When the number of the weak areas 221 is too small, if the length of each weak area 221 is small, the pressure relief area 22 may not be damaged in time, and the pressure relief efficiency is affected; if each weakened region 221 is of a greater length, it may result in greater strength differences in different regions of the pressure relief region 22, which in turn may result in uneven loading and uneven deformation of the sidewall 212. On the contrary, if the number of the weak regions 221 is set too much, the strength of the side wall 212 may be insufficient, affecting the safety of the battery cell 20. Therefore, the number of the weak areas 221 of the pressure relief area 22 is not easily set too much or much, for example, as shown in fig. 5, the pressure relief area 22 is provided with three weak areas 221; or four weakened areas 221 may be provided.

In the present embodiment, as illustrated in fig. 5, the length L1 of the weak region 221 in the circumferential direction of the side wall 212 is satisfied; l1 is more than or equal to 0.1mm and less than or equal to 0.2L, wherein L is the perimeter of the side wall 212. If the length L1 of the weakened region 221 is set too small along the axis of the side wall 212, the difficulty of processing increases, and the difficulty of breaking the pressure relief region 22 at the weakened region 221 increases; conversely, if the length L1 of the weak region 221 is set too large, the strength of the side wall 212 of the case 21 is reduced, thereby affecting the strength and safety of the battery cell 20.

It should be understood that the length L1 of the weak region 221 of the embodiment of the present application may also be set according to the assembly position of the battery cell 20. For example, if the battery cell 20 is blocked by other components during the installation, the location of the pressure relief region 22 and the location of the weak region 221 of the pressure relief region 22 should be properly set according to the blocked area of the battery cell 20, so as to prevent the weak region 221 of the pressure relief region 22 from being blocked and being damaged in time.

Fig. 6 shows a partial cross-sectional view of the battery 10 according to the embodiment of the present application, for example, fig. 6 may be a partial cross-sectional view of the battery 20 shown in fig. 2, which is perpendicular to the height direction Z of the battery cell 20, and further, for example, may be a cross-section passing through the bleeder region 22. As shown in fig. 6, as can be seen from fig. 2, each battery cell 20 may be fixed to the fixing member 11, and the fixing member 22 may block a partial region of each battery cell 20. Also, with the relief area 22 provided around the side wall 212, the fixing member 11 may block a partial area of the relief area 22 of each battery cell 20.

Fig. 7 shows a schematic partial cross-sectional view of the battery cell 20 and the fixing member 11 according to the embodiment of the present application, for example, the battery cell 20 in fig. 7 may be any one battery cell 20 of the plurality of battery cells 20 shown in fig. 6, and fig. 7 also shows a part of the fixing member 11 to show that the battery cell 20 and the fixing member 11 are partially fixed to each other.

As shown in fig. 7, the side wall 212 includes a fixing region 2122 partially overlapping the pressure relief region 22, and the fixing region 2122 is used for fixing the battery cell, that is, the region where the fixing member 11 contacts the side wall of the battery cell 20 is the fixing region 2122, and the fixing region 2122 at least partially overlaps the pressure relief region 22.

Since the fixed region 2122 at least partially overlaps the pressure relief region 22, there may be a situation where the weakened region 221 overlaps the fixed region 2122 for a plurality of weakened regions 221 disposed on the pressure relief region 22, and then the fixed region 2122 may affect the weakened region 221 to be damaged in time, thereby affecting the safety of the battery cell 20.

Thus, in the present embodiment, the fixed area 2122 does not completely cover the plurality of weakened areas 221 in the first cross-section 2123 of the sidewall 212, wherein the first cross-section 2123 passes through the relief area 22 and is parallel to the open end 211. In this way, by arranging the fixing region 2122 to not completely cover the whole weak region 221 on the pressure relief region 22, that is, at least a part of the weak region 221 on the pressure relief region 22 is not shielded and covered by the fixing region 2122, the weak region 221 can be timely destroyed when the battery cell 20 is out of control due to heat, the pressure inside the battery cell 20 is relieved, and the temperature is timely reduced, so that the safety of the battery 10 is improved.

In the embodiment, if the housing 21 is a cylinder, on the first cross section 2123 of the sidewall 212, the area excluding the fixing area 2122 is located at an angle larger than the angle of the central angle of the circular arc between any two adjacent weak areas 221 of the pressure relief area 22. Specifically, as shown in fig. 7, in the first cross section 2123 of the side wall 212, if the central angle of the arc where any one of the weak regions 221 of the pressure relief region 22 is located is α, and the central angle of the arc between any two adjacent weak regions 221 of the pressure relief region 22 is β, α and β satisfy: n × (α + β) =360 °, where n is the number of weakened areas 221 in the relief area 22, and when the relief area 22 is provided with a plurality of weakened areas 221, here, the plurality of weakened areas 221 are uniformly distributed in the relief area 22 in the circumferential direction of the side wall 212 as an example.

As shown in fig. 7, in the first cross-section 2123 of the sidewall 212, the central angle of the arc in which the region of the fixing region 2122 is located is θ, and the central angle of the arc in which the region other than the fixing region 2122 is located is equal to 360 ° - θ, so that the fixing region 2122 satisfies: 360-theta > beta, so that no matter how the battery cell 20 is rotated along the axis of the battery cell 20 for installation, the fixing region 2122 does not shield all the weak regions 221 on the pressure relief region 22, which facilitates flexible installation of the battery cell 20 without setting a specific installation position or direction, so that the fixing region 2122 does not completely cover the plurality of weak regions 221, and on the other hand, the weak regions 221 can be prevented from being shielded, so that the weak regions 221 can be damaged in time when the battery cell 20 is out of control due to heat, the pressure inside the battery cell 20 can be relieved, and the temperature can be reduced in time, and the safety of the battery 10 can be improved.

In the present embodiment, the side wall 212 of the housing 21 of the battery cell 20 is likely to be pressed by the adjacent battery cell 20 or the case or other parts of the battery 10 during the use of the battery 10. If the pressure relief region 22 is located in a local region of the side wall 212 of the housing 21 in the circumferential direction, or the pressure relief regions 22 are distributed perpendicular to the circumferential direction of the side wall 212, since the region where the pressure relief region 22 is located is weaker than the region where the pressure relief region 22 is not located, and is more likely to deform, the deformation of the side wall 212 in the circumferential direction is not uniform, and thus the battery cell 20 is not uniformly deformed. For example, the uneven deformation of the cylindrical battery cell 20 may cause poor roundness of the battery cell 20, which may affect the welding of the case 21, thereby reducing the strength and safety of the battery cell 20. Therefore, the pressure relief area 22 according to the embodiment of the present application surrounds the entire circumference along the circumferential direction of the side wall 212, so that the circumferential deformation of the housing 21 of the battery cell 20 is uniform, and the strength and the safety of the battery cell 20 are improved.

In addition, if the pressure relief region 22 is provided in a partial region of the side wall 212 of the housing 21, or the pressure relief regions 22 are distributed perpendicular to the circumferential direction of the side wall 212, the battery cells 20 are mounted in a specific direction so as not to block the pressure relief region 22 when they are assembled. Thus, the installation difficulty is increased, and the pressure relief area 22 may be shielded due to installation errors, so that the pressure relief area 22 is influenced to release the internal pressure, and the safety of the battery 10 of the battery cell 20 is reduced. And the pressure release area 22 of this application encircles whole week along the circumference of the lateral wall 212 of casing 21, consequently when assembling battery monomer 20, has reduced the requirement of battery monomer 20's mounted position, has improved battery monomer 20's installation flexibility ratio, easily avoids sheltering from pressure release area 22, and then can in time discharge the internal pressure of battery monomer 20 out of control, improves the security of battery 10.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. A housing (21) for a battery cell (20), characterized in that the housing (21) is a hollow structure with an open end (211), a side wall (212) of the housing (21) encloses the open end (211), the side wall (212) is provided with at least one pressure relief zone (22), and the pressure relief zone (22) surrounds the entire circumference of the side wall (212).

2. Housing (21) according to claim 1, characterized in that the wall thickness of the pressure relief zone (22) is smaller than the wall thickness of the other regions (2121) of the side wall (212).

3. A housing (21) according to claim 2, characterized in that the surface of the pressure relief zone (22) facing the interior of the housing (21) is flush with the surface of the further region (2121) facing the interior of the housing (21).

4. A housing (21) according to claim 2, wherein the wall thickness T1 of the pressure relief zone (22) is such that: t1 is not less than 0.2T, wherein T is the wall thickness of the other region (2121).

5. A housing (21) according to any of claims 1 to 4, characterized in that the height H1 of the pressure relief zone (22) ranges from [0.1mm,5mm ], the height direction of the pressure relief zone (22) being perpendicular to the open end (211).

6. A housing (21) according to claim 5, characterized in that the different areas of the pressure relief zone (22) are of equal height.

7. A shell (21) as claimed in any one of claims 1 to 4, characterized in that the pressure relief region (22) comprises at least one weakened region (221), the wall thickness of the weakened region (221) being smaller than the wall thickness of the region of the pressure relief region (22) other than the weakened region (221).

8. The housing (21) as claimed in claim 7, characterized in that the pressure relief zone (22) comprises a plurality of said weakened zones (221) evenly distributed along the circumference of the side wall (212).

9. Housing (21) according to claim 8, characterized in that the side wall (212) comprises a fixing region (2122) partially overlapping the pressure relief region (22), the fixing region (2122) being used for fixing of the battery cells,

said anchoring zone (2122) does not completely cover said plurality of weakened areas (221) on a first section (2123) of said side wall (212), said first section (2123) passing through said draining zone (22) and being parallel to said open end (211).

10. A housing (21) according to claim 9, wherein the housing (21) is cylindrical and the angle of the central angle of the circular arc of the first cross section (2123) is larger than the angle of the central angle of the circular arc between any two adjacent weakening areas (221) of the pressure relief area (22) except the fastening area (2122).

11. The housing (21) according to claim 7, wherein the length L1 of the weakened area (221) in the circumferential direction of the side wall (212) is satisfied; l1 is more than or equal to 0.1mm and less than or equal to 0.2L, wherein L is the perimeter of the side wall (212).

12. A housing (21) according to any of claims 1 to 4, characterized in that a plurality of said pressure relief zones (22) are provided on said side wall (212).

13. The housing (21) according to claim 12, wherein a plurality of said pressure relief zones (22) are symmetrically distributed with respect to a second section (2124) of said side wall (212), said second section (2124) passing through a central point of said side wall (212) and being parallel to said open end (211).

14. A housing (21) according to any of claims 1 to 4, characterized in that the housing (21) is a cylinder.

15. The housing (21) of claim 14, wherein the housing (21) has two of the open ends (211), the two open ends (211) being two opposing bottom surfaces of the housing (21).

16. A battery cell (20), comprising:

the housing (21) as defined in any one of claims 1 to 15;

and the cover plate (23) is used for covering the opening end (211).

17. A battery, comprising:

a plurality of battery cells (20), the battery cells (20) comprising a housing (21) as claimed in any one of claims 1 to 15.

18. An electrical device, comprising:

a plurality of battery cells (20), the battery cells (20) comprising a housing (21) according to any one of claims 1 to 15, the battery cells (20) being for providing electrical energy to the electrical consumer.