Casing, battery cell, battery and electric device

Abstract

A casing (10), a battery cell (20), a battery (100) and an electric device. A first notch (11) and a second notch (12) are formed on the same wall of the casing (10), the second notch (12) is located on one side of the first notch (11) in the direction of width, the projections of the first notch (11) and the second notch (12) in the direction of thickness of the casing (10) are spaced apart from each other, and the thickness of the casing (10) at the first notch (11) is less than the thickness of the casing (10) at the second notch (12). When the pressure inside the casing is extremely large, the casing (10) can preferentially crack at the first notch (11) and is folded at the second notch (12) to form an opening for pressure relief, thereby reducing the risk of explosion of the battery cell (20).

Description

Casing, battery cells, batteries and electrical devices Technical Field

[0001] The present application relates to the field of batteries, and in particular to a housing, a battery cell, a battery, and an electrical device. Background Art

[0002] In the prior art, as the battery ages, the gas formed inside the battery casing increases, causing the pressure inside the battery casing to increase. When the pressure inside the battery casing is too high, the battery may explode. To reduce the risk of battery explosion, the battery casing is provided with a notch. When the pressure inside the battery casing is too high, the battery casing preferentially cracks at the notch, thereby releasing the pressure. In the related art, the opening formed by the cracking of the notch in the battery casing is small, which is not conducive to the discharge of gas.

[0003] Summary of the Invention

[0004] In view of the above problems, the present application provides a housing, a battery cell, a battery and an electrical device, which can make the cracked opening of the housing larger, thereby facilitating gas discharge.

[0005] In a first aspect, the present application provides a shell for a battery cell, wherein a first notch and a second notch are formed on the same wall of the shell, the second notch is located on one side in the width direction of the first notch, the projections of the first notch and the second notch in the thickness direction of the shell are spaced apart from each other, the thickness of the shell at the first notch is a first thickness, the thickness of the shell at the second notch is a second thickness, and the first thickness (H1) is less than the second thickness (H2).

[0006] In the technical solution of the embodiment of the present application, a first notch is provided on one wall of the outer shell of the battery cell. After the battery or battery cell has been used for a period of time and the pressure inside the outer shell increases, the outer shell preferentially cracks from the first notch to release the internal pressure. A second notch is provided on the same wall on one side in the width direction of the first notch. The projections of the first notch and the second notch in the thickness direction of the outer shell are spaced apart from each other, and the thickness of the outer shell at the first notch is smaller than the thickness of the outer shell at the second notch. This design allows the outer shell to fold over at the second notch when it cracks at the first notch. In this way, a larger opening can be formed between the first notch and the second notch as a pressure relief vent, and gas can be quickly discharged from the opening, thereby timely reducing the pressure inside the battery or battery cell and further reducing the risk of battery explosion.

[0007] In some embodiments, the housing includes a bottom wall and a side wall connected to the bottom wall, an opening is formed on a side of the side wall away from the bottom wall, and a first notch and a second notch are formed on the bottom wall.

[0008] The electrode assembly in the battery cell expands preferentially toward the side wall, so arranging the first score and the second score on the bottom wall can reduce the risk of the first score being squeezed and broken by the electrode assembly.

[0009] In some embodiments, the housing includes an inner surface and an outer surface, the first score is disposed on the outer surface, and the second score is disposed on the inner surface.

[0010] In this way, by setting the first notch on the outer surface of the shell and the second notch on the inner surface of the wall where the first notch is located, the wall thickness retained at the first notch can be on a different side from the wall thickness retained at the second notch, thereby increasing the strength of the shell and preventing the shell from cracking when the internal pressure is normal.

[0011] In some embodiments, the distance between the first score and the second score is the same everywhere along the width direction of the first score.

[0012] In this way, when the shell that has been cracked at the first notch is turned over at the second notch, the force is evenly distributed, which is conducive to forming a pressure relief hole.

[0013] In some embodiments, the first score is arranged parallel to the second score.

[0014] In this way, a larger pressure relief hole can be easily formed when the shell is split at the first notch and turned over at the second notch.

[0015] In some embodiments, along the arrangement direction of the first notch and the second notch, the distance between the first notch and the second notch is a first distance, and the ratio of the first distance to the size of the shell in the arrangement direction is in the range of 1 / 8-1 / 3.

[0016] In this way, by setting the arrangement distance of the first score and the second score on the shell to match the size of the shell, the cracked part of the shell between the first score and the second score can be easily folded around the second score relative to the bottom wall, and the pressure relief hole formed can effectively exhaust gas.

[0017] In some embodiments, the length of the second score is greater than that of the first score, and along the extension direction of the first score, an end of the second score exceeds an end of the first score.

[0018] In this way, the shell cracks at the first notch, and the end of the second notch exceeds the end of the first notch along the extension direction of the first notch. The crack easily extends from the end of the first notch to the second notch, which is conducive to forming a pressure relief port.

[0019] In some embodiments, along the width direction of the first score, a second score is provided on both sides of the first score.

[0020] In this way, the shell cracks at the first notch, and the crack extends from the first notch to the second notch on both sides of the first notch. The shell flips over at the two second notches, easily forming a pressure relief hole with the second notches on both sides of the first notch as the boundary, further expanding the area of ​​the pressure relief hole and improving the efficiency of shell pressure relief.

[0021] In some embodiments, the second notches located on both sides of the first notch are arranged symmetrically with respect to the first notch.

[0022] In this way, the second notch symmetrical to the first notch makes the folding time and path of both sides of the first notch roughly the same, and the force is evenly applied, which is conducive to forming a pressure relief hole.

[0023] In some embodiments, the length of the first score is parallel or perpendicular to the edge of the wall where the first score is located.

[0024] In this way, the first notch can guide the shell to form a crack parallel to or perpendicular to the edge of the wall where the first notch is located, which is conducive to the extension of the crack and the formation of a pressure relief port.

[0025] In some embodiments, the center of the first score coincides with the center of the wall in which the first score is located.

[0026] In this way, the first notch can guide the shell to crack preferentially at the center of the wall where the first notch is located, which is conducive to gas discharge. At the same time, the wall where the first notch is located has sufficient margin to crack to form a pressure relief hole, making the pressure relief hole area as large as possible and improving the pressure reduction efficiency.

[0027] In some embodiments, the width of the first notch decreases from the surface of the housing toward the bottom of the first notch.

[0028] In this way, the shape of the shell retained at the first notch tends to become sharper from the shell surface to the bottom of the first notch, which promotes stress concentration at the first notch and guides the shell to preferentially crack and release pressure at the bottom of the first notch. In addition, the wall where the first notch is located can be integrally formed using a stamping process to form a shell with the first notch, which improves molding efficiency and increases the strength of the resulting shell.

[0029] In some embodiments, the first notch is formed with a step surface that is substantially parallel to the surface of the housing.

[0030] The first score is formed with multiple stepped surfaces of varying widths extending from the surface of the housing toward the bottom of the first score. These stepped surfaces can be formed through multiple stamping operations, resulting in a more efficient manufacturing process for the wall where the first score is located. Furthermore, the multiple stepped surfaces, which are substantially parallel to the surface of the housing, can reduce stamping forces and increase the lifespan of the punch.

[0031] In some embodiments, the width of the second notch decreases from the surface of the housing toward the bottom of the second notch.

[0032] This helps guide the shell to fold over from the second score after it breaks at the first score, thereby opening the shell to form a pressure relief hole.

[0033] In some embodiments, the second notch is formed with a bottom surface, a first side surface and a second side surface, the angle formed by the first side surface and the bottom surface is a first angle, the angle formed by the second side surface and the bottom surface is a second angle, and the second angle is greater than or equal to the first angle.

[0034] In this way, the inclination angle of the side of the second notch close to the edge of the shell is greater than the inclination angle of the side close to the first notch, so that when the first notch cracks, the part of the shell between the first and second notches is more likely to fold at the second notch, forming a larger pressure relief port area.

[0035] In some embodiments, the first thickness is in a range of 0.08 mm to 0.33 mm.

[0036] Thus, the range of the first thickness can correspond to the range of the shell thickness, which is conducive to guiding the shell to crack preferentially at the first score when the internal pressure of the shell is excessive. At the same time, the first thickness within the corresponding range can ensure that the wall where the first score is located is sufficiently strong when the internal pressure of the shell is normal.

[0037] In some embodiments, a third score is formed on the housing, the third score is connected to the first score, and the length of the third score is shorter than the length of the first score.

[0038] In this way, when the shell cracks at the first notch due to excessive pressure inside the shell, the crack path can continue to extend along the third notch, which is conducive to increasing the crack area.

[0039] In some embodiments, the third score extends from the first score toward the second score.

[0040] This way, the third notch connects to the first, guiding the shell to crack along the first and third notches without excessive tearing and damaging the entire shell. Furthermore, the cracked portion of the shell remains attached to the wall where the first notch was located, reducing the risk of flying fragments that could connect to the positive and negative terminals of the battery cell and cause a short circuit.

[0041] In some embodiments, the third score connects ends of the first score.

[0042] In this way, the shell can be opened from the connection between the first score and the third score toward both sides along the marks of the first score and the third score, and folded at the second score. Such an extension direction is conducive to forming a pressure relief port.

[0043] In some embodiments, there are multiple third notches, and each end of the first notch is connected to a third notch.

[0044] In this way, the plurality of third notches can serve as cracking paths, further increasing the cracking range and improving the efficiency of pressure relief of the battery cells.

[0045] In some embodiments, the junction between the first notch and the third notch is passivated.

[0046] In this way, by passivating the connection between the first notch and the third notch, the shape of the retained shell is not too sharp, thereby dissipating the stress and preventing the shell from cracking under normal pressure.

[0047] In some embodiments, the width of the third score is equal to the width of the first score.

[0048] This is conducive to the shell continuing to crack along the third score after cracking at the first score.

[0049] In a second aspect, the present application provides a battery cell comprising the housing in the above embodiment.

[0050] In some embodiments, the battery cell includes an end cover and a battery cell assembly. The housing is formed with an opening, the end cover covers the opening, and the battery cell assembly is disposed in the housing.

[0051] In a third aspect, the present application provides a battery comprising the battery cell in the above embodiment.

[0052] In a fourth aspect, the present application provides an electrical device, which includes the battery or battery cell in the above embodiment, and the battery or battery cell is used to provide electrical energy.

[0053] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0055] FIG1 is a schematic structural diagram of a vehicle according to some embodiments of the present application;

[0056] FIG2 is a schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0057] FIG3 is a schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0058] FIG4 is a schematic structural diagram of a housing in some embodiments of the present application;

[0059] FIG5 is a schematic structural diagram of a housing according to some embodiments of the present application as viewed from the Y direction;

[0060] FIG6 is a schematic structural diagram of a housing according to some embodiments of the present application taken along the Z direction;

[0061] FIG7 is a schematic diagram of the cross-sectional structure of a housing along the AA direction according to some embodiments of the present application;

[0062] FIG8 is a partial cross-sectional enlarged structural schematic diagram of the housing of FIG7 ;

[0063] FIG9 is a schematic structural diagram of a housing according to some other embodiments of the present application as viewed from the Z direction;

[0064] FIG10 is a schematic diagram of the cross-sectional structure of the housing along the Z direction according to some further embodiments of the present application;

[0065] FIG11 is an enlarged structural diagram of part B of the housing of FIG8 ;

[0066] FIG12 is an enlarged structural diagram of portion C of the housing of FIG8 ;

[0067] FIG13 is an enlarged structural diagram of portion E of the housing in FIG6 .

[0068] The figure numbers in the specific implementation manner are as follows: vehicle 1000, motor 300, controller 400; battery 100, housing 210, first part 211, second part 212, battery cell 20, battery cell assembly 20, end cover 30; outer shell 10, first notch 11, step surface 111, slope surface 112, second notch 12, bottom surface 120, first side surface 121, second side surface 122, opening 101, bottom wall 110, side wall 120, inner surface 130, outer surface 140, third notch 13. DETAILED DESCRIPTION

[0069] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0071] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0072] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0073] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0074] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0075] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0076] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0077] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0078] When a battery is in use, gas forms inside the battery casing. As the gas builds up, the pressure inside the casing increases. When the pressure reaches a certain level, the casing can explode due to the excessive pressure, resulting in a non-directional explosion. The ruptured battery casing may fly off, potentially causing property and personal injury. Furthermore, flying fragments of the battery casing can cause the positive and negative electrodes to overlap, resulting in a short circuit and compromising the safety of the battery.

[0079] In order to reduce the risk of battery explosion and improve the safety of battery use, the battery casing is provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery reaches a threshold. For example, notches are provided on the surface of the casing to guide the casing to crack at the notches when the internal pressure is too high, thereby releasing the pressure and preventing the casing from being blown away. At the same time, the gas accumulated inside the battery can be discharged from the pressure relief port formed by the cracking at the notches, thereby reducing the pressure inside the battery. However, the pressure relief port formed by a single notch provided on the casing has a small area, which is not conducive to the discharge of gas. In addition, as the battery is charged and discharged, the battery cell will expand, causing the casing that wraps the battery cell to deform, pulling the pressure relief mechanism provided on the casing, causing the weak area of ​​the pressure relief mechanism to be easily torn, affecting the explosion-proof effect.

[0080] Based on the above considerations, in order to address the problem that the pressure relief vent formed by the notches on the outer shell is not conducive to the discharge of gas from the battery, an embodiment of the present application provides an outer shell for a battery cell. By providing a first notch and a second notch located to one side of the width direction of the first notch on a certain wall of the outer shell, when the pressure inside the battery cell reaches a threshold, the outer shell of the battery cell can crack at the first notch, and the cracked portion of the outer shell folds relative to the outer shell surface at the second notch, forming a pressure relief vent bounded by at least the first and second notches. In such an outer shell, when the internal pressure of the battery cell is excessive, a sufficiently large pressure relief vent can be formed, effectively discharging the gas accumulated in the battery cell, improving the pressure relief efficiency, and further reducing the risk of battery explosion.

[0081] The battery cells disclosed in the embodiments of the present application can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. Electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, among others.

[0082] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0083] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 200 is provided inside the vehicle 1000, and the battery 200 can be provided at the bottom, head or tail of the vehicle 1000. The battery 200 can be used to power the vehicle 1000. For example, the battery 200 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 400 and a motor 300. The controller 400 is used to control the battery 200 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0084] In some embodiments of the present application, the battery 200 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0085] Please refer to Figure 2, which is an exploded view of a battery 200 provided in some embodiments of the present application. The battery 200 includes a housing 210 and a battery cell 100, with the battery cell 100 being housed within the housing 210. The housing 210 is used to provide a storage space for the battery cell 100, and the housing 210 can adopt a variety of structures. In some embodiments, the housing 210 can include a first portion 211 and a second portion 212, which cover each other and together define a storage space for accommodating the battery cell 100. The second portion 212 can be a hollow structure with an opening 101 at one end, and the first portion 211 can be a plate-like structure. The first portion 211 covers the opening 101 side of the second portion 212, so that the first portion 211 and the second portion 212 jointly define a storage space. The first portion 211 and the second portion 212 can also be hollow structures with an opening 101 at one end, with the opening 101 side of the first portion 211 covering the opening 101 side of the second portion 212. Of course, the box 210 formed by the first portion 211 and the second portion 212 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0086] In the battery 200, there may be multiple battery cells 100, and the multiple battery cells 100 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 100. The multiple battery cells 100 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 200 structure may be housed within the housing 210. Of course, the battery 200 may also be a battery module formed by first connecting multiple battery cells 100 in series, in parallel, or in a hybrid connection, and then the multiple battery modules 200 may be connected in series, in parallel, or in a hybrid connection to form a complete battery 200 structure and housed within the housing 210. The battery 200 may also include other structures, for example, the battery 200 may also include a busbar component for electrically connecting the multiple battery cells 100.

[0087] Each battery cell 100 may be a secondary battery 200 or a primary battery 200; it may also be a lithium-sulfur battery 200, a sodium-ion battery 200, or a magnesium-ion battery 200, but is not limited thereto. The battery cell 100 may be cylindrical, flat, rectangular, or in other shapes.

[0088] Please refer to Figure 3, which is a schematic diagram of the exploded structure of a battery cell 100 provided in some embodiments of the present application. A battery cell 100 is the smallest unit that makes up a battery 200. As shown in Figure 3, a battery cell 100 includes an end cap 30, a housing 10, a cell assembly 20, and other functional components.

[0089] The end cap 30 refers to a component that covers the opening 101 of the outer shell 10 to isolate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the end cap 30 can be adapted to the shape of the outer shell 10 to match the outer shell 10. Optionally, the end cap 30 can be made of a material with a certain hardness and strength (such as an aluminum alloy). In this way, the end cap 30 is not easily deformed when squeezed or collided, so that the battery cell 100 can have a higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on the end cap 30. The electrode terminals can be used to electrically connect to the battery cell assembly 20 for outputting or inputting electrical energy from the battery cell 100. The material of the end cap 30 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the end cap 30. The insulating member can be used to isolate the electrical connection components in the outer shell 10 from the end cap 30 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0090] The outer shell 10 is a component that cooperates with the end cap 30 to form the internal environment of the battery cell 100. This internal environment can be used to accommodate the battery cell assembly 20, electrolyte, and other components. The outer shell 10 and the end cap 30 can be separate components. An opening 101 can be provided in the outer shell 10, and the end cap 30 is placed over the opening 101 to form the internal environment of the battery cell 100. Alternatively, the end cap 30 and the outer shell 10 can be integrated. Specifically, the end cap 30 and the outer shell 10 can form a common connection surface before other components are inserted into the outer shell. When the interior of the outer shell 10 needs to be sealed, the end cap 30 is placed over the outer shell 10. The outer shell 10 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the outer shell 10 can be determined based on the specific shape and size of the battery cell assembly 20. The outer shell 10 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0091] The battery cell assembly 20 is a component in the battery cell 100 where electrochemical reactions occur. One or more battery cell assemblies 20 may be contained in the housing 10. The battery cell assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active substances constitute the main body of the battery cell assembly 20, and the parts of the positive and negative electrode sheets without active substances each constitute a tab. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 200, the positive electrode active substance and the negative electrode active substance react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0092] According to some embodiments of the present application, referring to FIG4 and further referring to FIG5 to FIG8 , FIG7 is a schematic diagram of the cross-sectional structure of the housing 10 along the AA direction according to some embodiments of the present application, and FIG8 is an enlarged schematic diagram of the cross-sectional structure of a wall of the housing 10 of FIG7 provided with a first notch 11 and a second notch 12. The present application provides a housing 10 for a battery cell 100, wherein the same wall of the housing 10 is formed with a first notch 11 and a second notch 12, the second notch 12 being located to one side in the width direction of the first notch 11, the projections of the first notch 11 and the second notch 12 in the thickness direction of the housing 10 being spaced apart from each other, the thickness of the housing 10 at the first notch 11 being a first thickness, the thickness of the housing 10 at the second notch 12 being a second thickness, and the first thickness (H1) being less than the second thickness (H2).

[0093] As shown in the figure, the X direction is the length direction of the housing 10, the Y direction is the width direction of the housing 10, and the Z direction is the thickness direction of the housing 10, or the height direction of the housing 10. The length, width, and height of the battery cell 100 are consistent with the length, width, and height of the housing 10.

[0094] In some embodiments, the housing 10 is a rectangular parallelepiped, having two opposing faces in each of the length, width, and height directions, with the length, width, and height directions of the housing 10 being perpendicular to each other. The housing 10 may have four sidewalls 120 in the length and width directions: front, rear, left, and right. It may have only one solid wall in the height direction, and an opening 101 opposite the solid wall. Components such as the battery cell assembly 20 and the electrolyte can enter and be contained within the housing 10 through the opening 101.

[0095] Specifically, the first notch 11 and the second notch 12 can both be provided on a wall of the housing 10 in the X, Y, or Z directions. The wall thickness of the housing 10 outside the first notch 11 and the second notch 12 can be relatively uniform, and the thickness D of the largest surface of the housing 10 can range from 0.6 mm to 1.0 mm. The first notch 11 can be formed by recessing from the outer surface 140 of the housing 10 toward the inner surface 130, or recessing from the inner surface 130 toward the outer surface 140. The second notch 12 can also be formed by recessing from the outer surface 140 toward the inner surface 130, or recessing from the inner surface 130 toward the outer surface 140. The first notch 11 and the second notch 12 can extend along a straight or curved path, extending in the direction of the length of the first notch 11 or the second notch 12. The width of the first notch 11 is much smaller than the length of the first notch 11, and the width of the second notch 12 is also much smaller than the length of the second notch 12.

[0096] As shown in Figure 8, the distance between the deepest part of the first notch 11 and the opposite surface of the surface where the first notch 11 is located is the first thickness H1. The distance between the deepest part of the second notch 12 and the opposite surface of the surface where the second notch 12 is located is the second thickness H2. The first thickness H1 is smaller than the second thickness H2, and both the first thickness H1 and the second thickness H2 are smaller than the thickness D of the large wall of the shell 10. H1<H2<D. It can be understood that the shell 10 has lower strength at thin-walled parts and is prone to bending or cracking, and the smaller the wall thickness, the lower the strength. The first thickness H1 can be the minimum wall thickness on the shell 10, so that when the internal pressure of the shell 10 is too high, the shell 10 will preferentially crack at the first notch 11, and the first notch 11 is more likely to form a crack that causes the shell 10 to crack.

[0097] As shown in FIG6 or FIG9 , second score 12 is located to one side of first score 11 in the width direction, and the paths of first score 11 and second score 12 may be parallel. The projections of first score 11 and second score 12 in the thickness direction of housing 10 are spaced apart. As shown in FIG6 , first score 11 and second score 12 may be located at approximately the same position in the length direction of housing 10, while being spaced a certain distance apart in the width direction of housing 10. As shown in FIG9 , first score 11 and second score 12 may be spaced a certain distance apart in the length direction of housing 10, while being located at approximately the same position in the width direction of housing 10.

[0098] First thickness H1 is less than second thickness H2, and second thickness H2 is less than thickness D of the major surface of housing 10. When the pressure inside housing 10 reaches a threshold, housing 10 first breaks at first score 11. After breaking at first score 11, the broken portion of housing 10 bends along second score 12. The broken portion of housing 10 can flip around second score 12 toward the outside or toward the inside of housing 10, thereby forming a pressure relief vent between first score 11 and second score 12.

[0099] By providing a first notch 11 on one wall of the outer shell 10 of the battery cell 100, when the internal pressure of the battery 200 or battery cell 100 increases after a period of use, the outer shell 10 preferentially ruptures at the first notch 11, releasing the internal pressure. A second notch 12 is provided on the same wall, to one side of the first notch 11 in the width direction. The projections of the first notch 11 and the second notch 12 in the thickness direction of the outer shell 10 are spaced apart from each other, and the thickness of the outer shell 10 at the first notch 11 is smaller than the thickness of the outer shell 10 at the second notch 12. This design allows the outer shell 10 to fold over at the second notch 12 when it ruptures at the first notch 11, thereby forming a larger pressure relief vent between the first notch 11 and the second notch 12. Gas can be quickly discharged from the pressure relief vent, thereby promptly reducing the internal pressure of the battery 200 or battery cell 100 and further reducing the risk of battery 200 explosion.

[0100] Referring to Figures 3 to 5, in some embodiments, the housing 10 includes a bottom wall 110 and a side wall 120 connected to the bottom wall 110. An opening 101 is formed on a side of the side wall 120 away from the bottom wall 110, and a first notch 11 and a second notch 12 are formed on the bottom wall 110.

[0101] Specifically, the bottom wall 110 is a wall of the housing 10 located at the bottom of the battery cell assembly 20 in the height direction. The bottom wall 110 may be opposite the opening 101. The side walls 120 are walls surrounding the housing 10 in the length and width directions. The bottom wall 110 and side walls 120 of the housing 10 may be integrally formed, for example, by stamping, die-casting, etc.

[0102] In some embodiments, the first notch 11 and the second notch 12 may also be formed on one of the sidewalls 120 facing the front, rear, left, or right.

[0103] It is understood that as the positive and negative active materials of the battery 200 intercalate or release ions during the charge and discharge cycles, the cell assembly 20 expands due to side reactions in the cell system, as well as the exfoliation of graphite sheets. This causes the positive and negative electrode sheets to swell outward. Since the electrode sheets are typically arranged parallel to the sidewalls 120 of the housing 10, the cell assembly 20 expands toward the sidewalls 120.

[0104] Therefore, disposing the first notch 11 and the second notch 12 on the bottom wall 110 can reduce the risk of the first notch 11 and the second notch 12 being squeezed and broken by the electrode assembly.

[0105] In some embodiments, the housing 10 includes an inner surface 130 and an outer surface 140 , the first score 11 is disposed on the outer surface 140 , and the second score 12 is disposed on the inner surface 130 .

[0106] Specifically, the outer shell 10 forms the internal environment of the battery cell 100, and the battery cell assembly 20 is accommodated within the outer shell 10. The side of the outer shell 10 facing the battery cell assembly 20 is the inner surface 130. The surface of the outer shell 10 facing the external environment of the battery cell 100 is the outer surface 140. The wall thickness of the outer shell 10 can be defined as the distance between the inner surface 130 and the outer surface 140.

[0107] For example, the first score 11 is provided on the outer surface 140 of the bottom wall 110, with the bottom surface 120 of the first score 11 being relatively close to the inner surface 130. The second score 12 is provided on the inner surface 130 of the bottom wall 110, with the bottom surface 120 of the second score 12 being relatively close to the outer surface 140. The bottom wall 110 retains a certain thickness near the inner surface 130 at the first score 11, and retains a certain thickness near the outer surface 140 at the second score 12. The bottom wall 110 is thinner at the first score 11 and the second score 12, while the thinner walls of the first score 11 and the second score 12 are distributed on both the inner and outer sides of the bottom wall 110, which helps to disperse stress on the bottom wall 110 and increase the strength of the housing 10.

[0108] In this way, by setting the first score 11 on the outer surface 140 of the shell 10 and the second score 12 on the inner surface 130 of the wall where the first score 11 is located, the wall thickness retained at the first score 11 can be on a different side from the wall thickness retained at the second score 12, thereby increasing the strength of the shell 10 and preventing the shell 10 from cracking when the internal pressure is normal.

[0109] In some embodiments, first score 11 and second score 12 can be both located on the outer surface 140 of the same wall, or on the inner surface 130 of the same wall. Referring to FIG. 10 , first score 11 and second score 12 are both located on outer surface 140 of bottom wall 110, with bottom wall 110 having a smaller thickness near inner surface 130 at the locations of first score 11 and second score 12. In this embodiment, the first and second thicknesses are such that, under normal pressure within housing 10, the first and second score 11 and 12 locations are sufficiently strong and prevent cracking.

[0110] Please refer to FIG. 6 again. In some embodiments, along the width direction of the first score 11 , the distance between the first score 11 and the second score 12 is the same everywhere.

[0111] Specifically, the second notch 12 is provided on one side in the width direction of the first notch 11, and the width direction of the second notch 12 is consistent with the width direction of the second notch 12. Along the width direction of the first notch 11, the distance between the first notch 11 and the second notch 12 is equal everywhere, and the distance between the width center of the first notch 11 and the width center of the second notch 12 can be equal at all positions of the first notch 11. After the shell 10 is cracked at the first notch 11, a pressure relief vent of equal width can be formed between the first notch 11 and the second notch 12, and the width of the cracked portion of the shell 10 is equal. The cracked portion of the shell 10 detaches from the shell 10 at the first notch 11 and flips around the second notch 12, and the flipped portion of the shell 10 is evenly stressed.

[0112] In this way, the housing 10 that is cracked at the first notch 11 is evenly stressed when it is turned over at the second notch 12 , which is beneficial to the formation of the pressure relief vent.

[0113] In some embodiments, the first notch 11 and the second notch 12 are arranged in parallel.

[0114] Specifically, the first notch 11 and the second notch 12 may both extend in a straight line, and the first notch 11 and the second notch 12 extend in the same direction. The direction in which the first notch 11 and the second notch 12 extend is the longitudinal direction of the first notch 11 and the second notch 12, and the longitudinal directions of the first notch 11 and the second notch 12 are consistent. The first notch 11 and the second notch 12 are parallel, and the distance between the first notch 11 and the second notch 12 is equal at all locations in the longitudinal direction.

[0115] In this way, the shell 10 is cracked at the first score 11, and the part of the shell 10 that is cracked between the first score 11 and the second score 12 can have a relatively equal boundary, and the width of the boundary is roughly equal to the distance between the first score 11 and the second score 12, so that a larger pressure relief hole can be easily formed when the shell 10 is flipped at the second score 12.

[0116] In some embodiments, along the arrangement direction of the first notch 11 and the second notch 12, the distance between the first notch 11 and the second notch 12 is a first distance, and the ratio of the first distance to the size of the housing 10 in the arrangement direction is in the range of 1 / 8-1 / 3.

[0117] Specifically, as shown in Figures 6 and 8, the first notch 11 and the second notch 12 can be arranged along the width direction of the shell 10. As shown in Figure 9, the first notch 11 and the second notch 12 can also be arranged along the width direction of the shell 10. In some other embodiments, the first notch 11 and the second notch 12 can also be arranged along the height direction of the shell 10.

[0118] For example, referring to FIG8 , first notches 11 and second notches 12 are arranged on bottom wall 110 along the width of housing 10. The distance in the Y direction between the closest point of first notch 11 to second notch 12 and the closest point of second notch 12 to first notch 11 is a first distance m. The width of housing 10 is n, and the ratio of the first distance to the width of housing 10, m / n, is in the range of 1 / 8 < m / n < 1 / 3. For example, the ratio of the first distance to the width of housing 10, m / n, can be 1 / 7, 1 / 6, 1 / 5, or 1 / 4.

[0119] The ratio of the first distance to the width of the shell 10 is less than 1 / 3 and greater than 1 / 8. The distance between the first notch 11 and the second notch 12 matches the size of the shell 10, so that the part of the shell 10 that is cracked between the first notch 11 and the second notch 12 can be easily folded around the second notch 12 relative to the bottom wall 110, and the pressure relief port formed can effectively exhaust gas.

[0120] In this way, by setting the arrangement distance between the first score 11 and the second score 12 on the shell 10, it is beneficial for the shell 10 to fold relative to the wall where the first score 11 is located after it is cracked.

[0121] Please refer to FIG. 6 again. In some embodiments, the length of the second notch 12 is greater than that of the first notch 11 . Along the extending direction of the first notch 11 , the end of the second notch 12 exceeds the end of the first notch 11 .

[0122] Specifically, the extension direction of the first score 11 is the longitudinal direction of the first score 11. The second score 12 may be parallel to the first score 11, and the extension direction of the second score 12 is the same as the extension direction of the first score 11. The midpoint of the first score 11 in the longitudinal direction and the midpoint of the second score 12 in the longitudinal direction are located at the same position in the longitudinal direction of the first score 11. The first score 11 and the second score 12 each have two ends in the longitudinal direction, and the two ends of the second score 12 in the longitudinal direction extend further than the two ends of the first score 11.

[0123] In this way, the shell 10 cracks at the first score 11, and the end of the second score 12 exceeds the end of the first score 11 along the extension direction of the first score 11. The crack easily extends from the end of the first score 11 to the second score 12, which is conducive to forming a pressure relief port.

[0124] Referring to FIG. 6 and FIG. 7 , in some embodiments, along the width direction of the first score 11 , second scores 12 are provided on both sides of the first score 11 .

[0125] Specifically, the width of the first score 11 is much smaller than its length, and the first score 11 is in the form of a thin strip or line. There can be one first score 11, and there can be two second score 12 on the wall where the first score 11 is located. The first score 11 and the second score 12 are arranged on the bottom wall 110, with the first score 11 positioned between two second score 12 along the X or Y direction.

[0126] In this way, the shell 10 cracks at the first notch 11, and the crack extends from the first notch 11 to the second notch 12 on both sides of the first notch 11. The shell 10 flips over at the two second notches 12, easily forming a pressure relief port with the second notches 12 on both sides of the first notch 11 as the boundary, further expanding the area of ​​the pressure relief port and improving the pressure relief efficiency of the shell 10.

[0127] Referring to FIG. 6 and FIG. 8 , in some embodiments, the second notches 12 located on both sides of the first notch 11 are symmetrically arranged relative to the first notch 11 .

[0128] Specifically, the first score 11 can extend along a straight path, and the distance between the second score 12 on either side of the first score 11 and the first score 11 is constant along the direction of extension of the first score 11. The cracking path of the shell 10 from the first score 11 to the second score 12 on either side of the first score 11 can be the same. The shell 10 cracked between the first score 11 and the second score 12 on either side can form two substantially identical pieces, thereby allowing the second score 12 on either side of the first score 11 to fold over at the same time. During the cracking process of the shell 10 between the first score 11 and the second score 12, the forces acting on both sides of the first score 11 are substantially equal.

[0129] In this way, the second notch 12 symmetrical to the first notch 11 makes the folding time and path of both sides of the first notch 11 roughly the same, and the force is evenly applied, which is conducive to forming a pressure relief port.

[0130] Referring to FIG. 6 and FIG. 9 , in some embodiments, the length direction of the first score 11 is parallel or perpendicular to the edge of the wall where the first score 11 is located.

[0131] Specifically, as shown in FIG6 , the length direction of the first notch 11 is parallel to the long side of the wall where the first notch 11 is located, and is perpendicular to the short side of the wall where the first notch 11 is located. The width direction of the first notch 11 is consistent with the width direction of the housing 10, and the short side of the wall where the first notch 11 is located is the edge of the wall where the first notch 11 is located in the width direction of the housing 10. The second notch 12 can be provided on both sides of the first notch 11 along the width direction, parallel to the first notch 11, and the second notch 12 is also parallel to the long side of the wall where the first notch 11 is located, and perpendicular to the short side of the wall where the first notch 11 is located. In this embodiment, the length of the short side of the wall where the first notch 11 is located ranges from 20 mm to 40 mm or from 40 mm to 60 mm.

[0132] In some embodiments, as shown in FIG9 , the length direction of the first score 11 may also be parallel to the short side of the wall where the first score 11 is located, and perpendicular to the long side of the wall where the first score 11 is located. In this embodiment, the width direction of the first score 11 is consistent with the length direction of the housing 10, and the short side of the wall where the first score 11 is located has a length ranging from 40 mm to 60 mm or greater than 60 mm.

[0133] In this way, the first score 11 can guide the housing 10 to form a crack parallel to or perpendicular to the edge of the wall where the first score 11 is located, which is beneficial for the crack to extend and form a pressure relief port.

[0134] Continuing to refer to FIG. 6 , in some embodiments, the center of the first score 11 coincides with the center of the wall where the first score 11 is located.

[0135] Specifically, the wall where the first notch 11 is located can be a variety of shapes, such as a rectangle, a circle, an ellipse, or a polygon. For example, the housing 10 is a rectangular parallelepiped, and the first notch 11 is located on the bottom wall 110, which is parallel to the XY plane. The center of the projection of the first notch 11 along the Z direction coincides with the center of the projection of the bottom wall 110 along the Z direction. It is easy to understand that the projections of the first notch 11 and the bottom wall 110 along the Z direction are located on the XY plane, and the first notch 11 is located at the center of the bottom wall 110.

[0136] In this way, the first notch 11 can guide the shell 10 to crack preferentially at the center of the wall where the first notch 11 is located, which is conducive to gas discharge. At the same time, the wall where the first notch 11 is located has sufficient margin to crack to form a pressure relief hole, so that the area of ​​the pressure relief hole is as large as possible, thereby improving the pressure reduction efficiency.

[0137] 8 and 11 , FIG10 is an enlarged structural diagram of the cross section of the housing 10 in FIG8 at the first notch 11. In some embodiments, the width W1 of the first notch 11 decreases from the surface of the housing 10 toward the bottom of the first notch 11.

[0138] Specifically, the first score 11 is provided on the outer surface 140 of the bottom wall 110 and is recessed from the outer surface 140 of the bottom wall 110 toward the inner surface 130 of the bottom wall 110, with the bottom of the first score 11 being close to the inner surface 130 of the bottom wall 110. The cross-sectional shape of the first score 11 may be trapezoidal, as shown in FIG11 . The width W1 of the first score 11 is greatest on the outer surface 140 of the bottom wall 110 and smallest at the bottom of the first score 11. Furthermore, the width W1 of the first score 11 decreases from the outer surface 140 of the bottom wall 110 to the bottom of the first score 11. The width W1 of the first score 11 may gradually decrease from the outer surface 140 of the bottom wall 110 to the bottom of the first score 11, or may suddenly decrease at a location between the outer surface 140 of the bottom wall 110 and the bottom of the first score 11.

[0139] The width W1 of the first score 11 decreases from the surface to the bottom of the first score 11. Therefore, the shape of the shell 10 retained at the first score 11 becomes sharper from the surface toward the bottom of the first score 11. The width W1 of the first score 11 is smallest at the bottom of the first score 11, and the shape of the shell 10 retained at the bottom of the first score 11 is sharpest. This helps concentrate stress at the bottom of the first score 11, guiding the shell 10 to crack preferentially at the bottom of the first score 11, thereby relieving pressure on the shell 10.

[0140] The first notch 11 can be integrally formed with the wall where the first notch 11 is located by a stamping process to form a shell 10 with the first notch 11. The molding efficiency is high, and the strength of the first notch 11 on the shell 10 is large, ensuring that the shell 10 is not easy to break before the internal pressure reaches a threshold.

[0141] Continuing to refer to FIG. 11 , in some embodiments, the first notch 11 is formed with a step surface 111 , and the step surface 111 is substantially parallel to the surface of the housing 10 .

[0142] Specifically, a step surface 111 is formed between the bottom of the first score 11 and the surface where the first score 11 is located. The width of the step surface 111 is smaller than the width of the first score 11 on the surface of the housing 10, but larger than the width of the first score 11 at the bottom. The width W1 of the first score 11 can gradually decrease from the surface of the housing 10 to the step surface 111, suddenly decrease at the step surface 111, and then gradually decrease from the step surface 111 to the bottom of the first score 11. The bottom surface formed by the bottom of the first score 11 can be approximately parallel to the step surface 111 and also approximately parallel to the outer surface 140 and the inner surface 130 of the housing 10.

[0143] A slope 112 may be formed between the surface of the housing 10 and the step surface 111, connecting the surface of the housing 10 and the step surface 111. A slope 112 may also be formed between the step surface 111 and the bottom of the first notch 11, connecting the step surface 111 and the bottom of the first notch 11. The step surface 111 may be substantially parallel to the surface of the housing 10, while the slope 112 is inclined toward both the surface of the housing 10 and the step surface 111. It will be appreciated that when the angle formed between the slope 112 and the step surface 111 is 90°, the width W1 of the first notch 11 remains unchanged. The greater the deviation of the angle between the slope 112 and the step surface 111 from 90°, the more rapidly the width W1 of the first notch 11 changes.

[0144] The first score 11 is formed with multiple stepped surfaces 111 of varying widths extending from the surface of the housing 10 toward the bottom thereof. These stepped surfaces 111 can be formed through multiple stamping operations, resulting in a more efficient manufacturing process for the wall where the first score 11 is located. Furthermore, the multiple stepped surfaces 111, which are substantially parallel to the surface of the housing 10, can reduce stamping force and increase the lifespan of the punch.

[0145] By setting the width W1 of the first notch 11 to correspond to the size of the shell 10, it is beneficial to guide the wall where the first notch 11 is located to crack preferentially at the first notch 11 when the internal pressure of the shell 10 is too high, thereby effectively releasing the pressure of the shell 10.

[0146] 8 and 12 , FIG12 is an enlarged structural diagram of the cross section of the housing 10 in FIG8 at the second notch 12. In some embodiments, the width W2 of the second notch 12 decreases from the surface of the housing 10 toward the bottom of the second notch 12.

[0147] Specifically, the second notch 12 is provided on the inner surface 130 of the bottom wall 110 and is recessed toward the outer surface 140 of the bottom wall 110. The cross-sectional shape of the second notch 12 may be trapezoidal, with the long side of the trapezoidal cross-section formed on the inner surface 130 of the bottom wall 110 and the short side of the trapezoidal cross-section formed at the bottom of the second notch 12. The width W2 of the second notch 12 may gradually decrease from the inner surface 130 of the bottom wall 110 toward the bottom of the second notch 12. The outer shell 10 retained at the second notch 12 has a relatively sharp shape at the bottom of the second notch 12. When a force is applied to the outer shell 10, stress tends to concentrate at the bottom of the second notch 12 relative to the outer shell 10 surface.

[0148] This helps guide the housing 10 to fold at the second notch 12 , thereby opening the housing 10 to form a pressure relief vent.

[0149] By setting the width W2 of the second notch 12 to correspond to the width of the wall where the second notch 12 is located and the distance between the first notch 11 and the second notch 12 , it is beneficial for the housing 10 to be folded from the second notch 12 to form a pressure relief vent.

[0150] Please continue to refer to Figures 8 and 12. In some embodiments, the second notch 12 is formed with a bottom surface 120, a first side surface 121 and a second side surface 122. The angle formed by the first side surface 121 and the bottom surface 120 is a first angle α, and the angle formed by the second side surface 122 and the bottom surface 120 is a second angle β. The second angle β is greater than or equal to the first angle α, that is, α≤β.

[0151] Specifically, the cross-section of second score 12 can be trapezoidal. First side surface 121 is the side surface of second score 12 near the center of the wall where second score 12 is located. Second side surface 122 is the side surface of second score 12 near the edge of the wall where second score 12 is located. First score 11 is located at the center of the wall where second score 12 is located. First side surface 121 can also be the surface near the side of first score 11. When the internal pressure of housing 10 is excessive, it can crack and open along first score 11 toward first side surface 121.

[0152] The first angle α is the angle formed by the connection between the first side surface 121 and the bottom surface 120, and the second angle β is the angle formed by the connection between the second side surface 122 and the bottom surface 120. The first angle α is closer to the first notch 11 than the second angle. In some embodiments, the first notch 11 and the second notch 12 are disposed on the bottom wall 110 and are substantially parallel to the length of the housing 10. In this embodiment, the second angle β is closer to the long side of the bottom wall 110 than the first angle, and the first angle α is closer to the first notch 11 than the second angle β. The first angle α is greater than or equal to 90°, that is, 90°≤α≤β.

[0153] In this way, the inclination angle of the side of the second notch 12 close to the edge of the shell 10 is greater than the inclination angle of the side close to the first notch 11, so that when the first notch 11 cracks, the part of the shell between the first notch 11 and the second notch 12 is more easily folded at the second notch 12 due to the pressure released from the inside of the shell 10, forming a larger pressure relief port area.

[0154] In some embodiments, the first thickness H1 ranges from 0.08 mm to 0.33 mm.

[0155] Specifically, along the direction from the surface where the first notch 11 is located toward the surface of the housing 10 facing away from the first notch 11, the distance between the bottom of the first notch 11 and the surface of the housing 10 facing away from the first notch 11 is a first thickness H1. For example, if the first notch 11 is located on the outer surface 140 of the bottom wall 110, the first thickness H1 is the distance between the bottom of the first notch 11 and the inner surface 130 of the bottom wall 110 along the thickness direction of the housing 10.

[0156] For example, the first thickness H1 may be 0.08 mm, 0.11 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.24 mm, 0.27 mm, 0.3 mm, 0.33 mm, etc.

[0157] Thus, the range of first thickness H1 can correspond to the thickness of housing 10, which is conducive to guiding housing 10 to crack preferentially at first score 11 when the internal pressure of housing 10 is excessive. At the same time, the first thickness within the corresponding range can ensure that the wall where first score 11 is located is sufficiently strong when the internal pressure of housing 10 is normal.

[0158] In addition, the width of the first notch 11 , the width of the second notch 12 , the first thickness, and the second thickness can be set differently according to the different electrochemical systems of the battery cells 100 , so that the housing 10 can be applicable to a variety of battery cells 100 to meet diverse application requirements.

[0159] Please refer to FIG. 6 again. In some embodiments, the housing 10 is formed with a third notch 13 . The third notch 13 is connected to the first notch 11 . The length of the third notch 13 is smaller than that of the first notch 11 .

[0160] Specifically, the third notch 13 and the first notch 11 can be provided on the same surface. The third notch 13 can extend from a certain point on the first notch 11 along a straight path. The direction in which the third notch 13 extends can form a preset angle with the length direction of the first notch 11. For example, the first notch 11 and the third notch 13 form an angle of 120°. The position where the third notch 13 is connected to the first notch 11 can be at the end, midpoint or any position between the two ends of the first notch 11. The shape formed by the first notch 11 and the third notch 13 can be "Y"-shaped, "X"-shaped, Shape, etc.

[0161] The length of third score 13 is less than that of first score 11. The length of third score 13 is less than that of second score 12. The length of third score 13 can be approximately 1 / 2, 1 / 3, 2 / 5, 1 / 4, etc. of first score 11. Second score 12 is parallel to first score 11. Third score 13 is inclined relative to second score 12. The end of third score 13 away from first score 11 can extend beyond second score 12 in the length direction of first score 11.

[0162] The first score 11, the second score 12 and the third score 13 can be integrally formed on the same wall of the shell 10 by stamping. The shell 10 formed has greater strength at the first score 11, the second score 12 and the third score 13, so that the shell 10 will not rupture when the internal pressure is normal.

[0163] Thus, the third score 13 is connected to the first score 11, guiding the shell 10 to crack along the first score 11 and the third score 13 without excessive tearing and damaging the entire shell 10. At the same time, the cracked portion of the shell 10 remains attached to the wall where the first score 11 is located, reducing the risk of fragments flying out and even contacting the positive and negative terminals of the battery cell assembly 20, causing a short circuit.

[0164] In some embodiments, the third notch 13 extends from the first notch 11 toward the second notch 12 .

[0165] Specifically, the third score 13 extends from the junction of the first score 11 and the third score 13 to both sides of the width direction of the first score 11. The direction in which the third score 13 extends from the first score 11 to the second score 12 can form a predetermined angle with the length direction of the second score 12. For example, the third score 13 and the second score 12 form angles of 60° or 120°. The third score 13 can extend from the end, center, or any position between the ends of the first score 11 to near the end of the second score 12.

[0166] In this way, the shell 10 can be opened from the connection between the first score 11 and the third score 13 toward both sides along the marks of the first score 11 and the third score 13, and folded at the second score 12. Such an extension direction is conducive to forming a pressure relief port.

[0167] In some embodiments, the third score 13 connects ends of the first score 11 .

[0168] Please refer to Figures 6 and 13. Figure 13 is an enlarged schematic diagram of the structure of the housing 10 in Figure 6 at the junction of the third score 13 and the first score 11. The third score 13 can be a straight segment with two ends along the direction of extension of the third score 13. In some embodiments, one end of the third score 13 is connected to an end of the first score 11 along the length of the first score 11. The third score 13 can extend from the end of the first score 11 to the end of the second score 12.

[0169] In this way, the third score 13 connects to the crack path from the end of the first score 11 , which is beneficial for expanding the crack area of ​​the shell 10 .

[0170] Continuing to refer to FIG. 6 , in some embodiments, there are multiple third notches 13 , and each end of the first notch 11 is connected to a third notch 13 .

[0171] Specifically, the number of the first notch 11 is one, and the first notch 11 has two ends in the length direction. Two third notches 13 can be connected to each end of the first notch 11. In this embodiment, the number of the third notches 13 connected to the first notch 11 is four. The four third notches 13 can extend toward the upper left, upper right, lower right, and lower left of the first notch 11, respectively. The first notch 11 and the third notches 13 form a substantially The four third notches 13 may extend from the four ends of the second notch 12 on both sides of the first notch 11, and the ends of the third notches 13 away from the first notch 11 may be close to the ends of the second notch 12 in the corresponding extension direction.

[0172] In this way, the plurality of third notches 13 can all serve as cracking paths, further increasing the cracking range and improving the efficiency of pressure relief of the battery cell 100 .

[0173] Referring to FIG. 13 , in some embodiments, the connection between the first notch 11 and the third notch 13 is passivated.

[0174] Specifically, the connection between the first notch 11 and the third notch 13 can be rounded or passivated with a transition surface to prevent a sharp angle from being formed between the first notch 11 and the third notch 13. It is understood that the connection between the first notch 11 and the third notch 13 is more likely to form a sharp angle, leading to stress concentration.

[0175] In this way, the passivation treatment allows for a gentle transition between the first notch 11 and the third notch 13 , thereby dissipating stress and reducing the risk of cracking of the housing 10 under normal pressure, which may result in leakage of the battery cell 100 .

[0176] In some embodiments, the width of the third score 13 is equal to the width of the first score 11 .

[0177] Specifically, the width of the third notch 13 is within the same range as the width of the first notch 11. The third notch 13 and the first notch 11 can both be disposed on the outer surface 140 of the bottom wall 110. A platform surface (not shown) connected to the step surface 111 and parallel to the outer surface 140 can be formed between the outer surface 140 of the bottom wall 110 and the bottom of the third notch 13. The opening width of the third notch 13 at the platform surface can be greater than the width of the bottom of the third notch 13.

[0178] The cross-sectional shape of the third notch 13 may be completely consistent with the cross-sectional shape of the first notch 11 to facilitate stamping.

[0179] In this way, the shell 10 is facilitated to continue to crack along the trace of the third score 13 after cracking at the first score 11 .

[0180] According to some embodiments of the present application, the present application further provides a battery 200 , comprising the battery cell 100 described in any of the above solutions.

[0181] According to some embodiments of the present application, the present application further provides an electrical device, comprising the battery 200 described in any of the above schemes, and the battery 200 is used to provide electrical energy to the electrical device.

[0182] The power-consuming device may be any of the aforementioned devices or systems using the battery 200 .

[0183] According to some embodiments of the present application, a housing 10 for a battery cell 100 is provided. A first notch 11 and a second notch 12 are formed on the bottom wall 110 of the housing 10. The second notch 12 is located on either side of the first notch 11 along its width and is spaced apart from the first notch 11 in the width direction of the first notch 11. The thickness H1 of the housing 10 at the first notch 11 is less than the thickness H2 of the housing 10 at the second notch 12. When the internal pressure of the housing 10 is excessive, the housing 10 preferentially cracks at the first notch 11 due to its smaller thickness at the first notch 11, thereby relieving the pressure. The partially cracked housing 10 opens at the first notch 11 and, under the pressure from within the housing 10, folds over at the second notch 12, forming a pressure relief vent. This effectively discharges gas from the housing 10, further preventing the risk of explosion of the battery cell 100 due to excessive internal pressure.

[0184] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A housing for a battery cell, wherein, a first notch and a second notch are formed on the same wall of the housing, the second notch is located on one side in the width direction of the first notch, the projections of the first notch and the second notch in the thickness direction of the housing are spaced apart from each other, the thickness of the housing at the first notch is a first thickness, the thickness of the housing at the second notch is a second thickness, and the first thickness is less than the second thickness.

2. The housing according to claim 1, wherein, the housing includes a bottom wall and a side wall connected to the bottom wall, an opening is formed on a side of the side wall away from the bottom wall, and the first notch and the second notch are formed on the bottom wall.

3. The housing according to claim 1 or 2, wherein, the housing includes an inner surface and an outer surface, the first notch is provided on the outer surface, and the second notch is provided on the inner surface.

4. The housing according to any one of claims 1 - 3, wherein, along the width direction of the first notch, the distance between the first notch and the second notch is equal everywhere.

5. The housing according to claim 4, wherein, the first notch and the second notch are arranged in parallel.

6. The housing according to claim 4 or 5, wherein, along the arrangement direction of the first notch and the second notch, the distance between the first notch and the second notch is a first distance, and the ratio range of the first distance to the size of the housing in the arrangement direction is 1 / 8 - 1 / 3.

7. The housing according to any one of claims 4 - 6, wherein, the length of the second notch is greater than the length of the first notch, and along the extension direction of the first notch, the end of the second notch exceeds the end of the first notch.

8. The housing according to any one of claims 1 - 7, wherein, along the width direction of the first notch, the second notches are provided on both sides of the first notch.

9. The housing according to claim 8, wherein, the second notches respectively located on both sides of the first notch are symmetrically arranged with respect to the first notch.

10. The housing according to any one of claims 1 - 9, wherein, the length of the first notch is parallel or perpendicular to the edge of the wall where the first notch is located.

11. The housing according to any one of claims 1 - 10, wherein, the center of the first notch coincides with the center of the wall where the first notch is located.

12. The housing according to any one of claims 1 - 11, wherein, from the surface of the housing towards the bottom direction of the first notch, the width of the first notch shows a decreasing trend.

13. The housing according to claim 12, wherein, the first notch is formed with a stepped surface, and the stepped surface is substantially parallel to the surface of the housing.

14. The housing according to any one of claims 1 - 13, wherein, from the surface of the housing towards the bottom direction of the second notch, the width of the second notch shows a decreasing trend.

15. The housing according to claim 14, wherein, The second notch is formed with a bottom surface, a first side surface and a second side surface. An included angle formed by the first side surface and the bottom surface is a first included angle, and an included angle formed by the second side surface and the bottom surface is a second included angle. The second included angle is greater than or equal to the first included angle.

16. The outer shell according to any one of claims 1-15, wherein, The range of the first thickness is 0.08 mm - 0.33 mm.

17. The outer shell according to any one of claims 1-16, wherein, The outer shell is formed with a third notch, the third notch is connected to the first notch, and the length of the third notch is less than the length of the first notch.

18. The outer shell according to claim 17, wherein, The third notch extends from the first notch towards the second notch.

19. The outer shell according to claim 17 or 18, wherein, The third notch is connected to the end of the first notch.

20. The outer shell according to claim 19, wherein, The number of the third notches is multiple, and each end of the first notch is connected with a third notch.

21. The outer shell according to any one of claims 17-20, wherein, The connection between the first notch and the third notch is subjected to a passivation treatment.

22. The outer shell according to any one of claims 17-21, wherein, The width of the third notch is equal to the width of the first notch.

23. A battery cell, wherein, It includes the outer shell according to any one of claims 1-22.

24. The battery cell according to claim 23, wherein, The battery cell includes an end cover and a battery core assembly. The outer shell is formed with an opening, the end cover covers the opening, and the battery core assembly is arranged inside the outer shell.

25. A battery, wherein, It includes the battery cell according to claim 23 or 24.

26. An electrical equipment, wherein, It includes the battery cell according to claim 23 or 24, or the battery according to claim 25.

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