Battery cells, batteries and electrical equipment

Abstract

The embodiments of the present application provide a battery cell, a battery and an electrical device, which belong to the field of battery technology. Among them, the battery cell includes an electrode assembly and a shell. The shell accommodates the electrode assembly, and the shell has a wall portion. Along the thickness direction of the wall portion, the wall portion is arranged opposite to the electrode assembly. The wall portion is protruding with a first reinforcement portion, and the first reinforcement portion extends along the circumference of the wall portion. The wall portion includes a first area located on the outer peripheral side of the first reinforcement portion. The first area is formed with a weak portion, and the weak portion is configured to crack when the battery cell releases pressure. The first reinforcement portion strengthens the wall portion and enhances the strength of the weak portion. Since the weak portion is formed in the first area located on the outer peripheral side of the first reinforcement portion, when the wall portion is subjected to external force and the portion located on the inner peripheral side of the first reinforcement portion is deformed, the first reinforcement portion can reduce the influence of the external force on the weak portion, reduce the deformation of the weak portion, ensure the normal detonation pressure of the battery cell, and increase the service life of the battery cell.

Description

Technical Field

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

[0002] At present, with the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools, etc.

[0003] Battery cells, as energy storage elements, typically generate electrical energy through a chemical reaction between electrode components and electrolytes. In battery technology, not only the safety of battery cells must be considered, but also their service life. Therefore, improving the service life of battery cells is a pressing issue in battery technology. Summary of the Invention

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively increase the service life of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising an electrode assembly and a shell; the shell accommodates the electrode assembly, and the shell has a wall portion, and the wall portion is arranged opposite to the electrode assembly along the thickness direction of the wall portion; wherein, the wall portion is protruded with a first reinforcement portion, and the first reinforcement portion extends along the circumference of the wall portion, and the wall portion includes a first area located on the outer peripheral side of the first reinforcement portion, and the first area is formed with a weak portion, and the weak portion is configured to crack when the battery cell releases pressure.

[0006] In the above technical solution, the wall portion is provided with a protruding first reinforcement portion, which reinforces the wall portion and increases the strength of the weak portion. Because the weak portion is formed in the first region located on the outer periphery of the first reinforcement portion, when the wall portion is subjected to external forces and the portion located on the inner periphery of the first reinforcement portion deforms, the first reinforcement portion can reduce the impact of the external force on the weak portion, reducing deformation of the weak portion, ensuring the normal detonation pressure of the battery cell, and extending the service life of the battery cell.

[0007] In some embodiments, the wall portion further includes a second region located on the inner circumference of the first reinforcement portion, and the second region is provided with an injection hole. The injection hole is provided in the second region of the wall portion to facilitate the injection of electrolyte into the battery cell. When the electrolyte is injected into the battery cell through the injection hole, the second region is easily deformed toward the interior of the battery cell due to the extrusion force applied by the injection device. The first reinforcement portion can reduce the impact of the deformation of the second region on the weak portion, thereby reducing the deformation of the weak portion and reducing the risk of deformation of the weak portion during the process of injecting electrolyte into the battery cell through the injection hole, which may cause the weak portion to rupture before reaching the detonation pressure.

[0008] In some embodiments, the injection hole is coaxially arranged with the first reinforcement portion. Thus, when the electrolyte is injected into the battery cell through the injection hole, the first reinforcement portion is evenly stressed, which can further reduce deformation of the weak portion.

[0009] In some embodiments, the first reinforcement portion is protruding from the side of the wall portion facing the electrode assembly along the thickness direction of the wall portion. In this way, the first reinforcement portion faces the interior of the battery cell, reducing the excess external space occupied by the first reinforcement portion and reducing the volume of the battery cell.

[0010] In some embodiments, the first reinforcement abuts the electrode assembly along the thickness direction of the wall. When the wall is subjected to external force, causing the portion located on the inner circumference of the first reinforcement to deform toward the interior of the battery cell, the first reinforcement abuts the electrode assembly, thereby constraining the first reinforcement and reducing the risk of deformation of the weak portion.

[0011] In some embodiments, a first recess is provided along the thickness direction of the wall portion at a position corresponding to the first reinforcement portion on a side of the wall portion facing away from the electrode assembly. The provision of the first recess provides the first reinforcement portion with excellent buffering capacity. When the wall portion is subjected to external force, causing deformation of the portion located on the inner circumference of the first reinforcement portion, the first reinforcement portion provides an excellent buffering effect, preventing the external force from being transmitted to the weak portion, thereby further reducing deformation of the weak portion.

[0012] In some embodiments, the radial width of the first reinforcement portion along the wall portion is a1, the inner diameter of the first reinforcement portion is r1, and the radius of the wall portion is R, satisfying: 0.05≤a1 / R≤0.8; and / or, 0.05≤r1 / R≤0.8.

[0013] In some embodiments, the first region is provided with a protruding second reinforcement portion, which extends along the circumference of the wall portion; the first region includes a first connecting portion, which connects the first reinforcement portion and the second reinforcement portion, the first connecting portion being located on the outer periphery of the first reinforcement portion, and the second reinforcement portion being located on the outer periphery of the first connecting portion; wherein the weak portion is formed in the first connecting portion. The weak portion is formed in the first connecting portion connected between the first reinforcement portion and the second reinforcement portion, and the second reinforcement portion can also enhance the strength of the weak portion.

[0014] In some embodiments, the second reinforcement portion is protruding from a side of the first region facing the electrode assembly. Along the thickness of the wall portion, the second reinforcement portion has a first surface facing the electrode assembly. The first surface abuts the electrode assembly to achieve electrical connection between the wall portion and the electrode assembly. The abutment of the first surface with the electrode assembly not only achieves electrical connection between the wall portion and the electrode assembly, facilitating the output of electrical energy from the battery cells through the wall portion, but also provides support for the electrode assembly, improving the stability of the electrode assembly within the housing.

[0015] In some embodiments, along the direction of the wall portion pointing toward the electrode assembly, the first reinforcement portion does not extend beyond the first surface, thereby ensuring that the first surface can effectively abut against the electrode assembly.

[0016] In some embodiments, the first reinforcement portion has a second surface facing the electrode assembly along the thickness direction of the wall portion, and the second surface is flush with the first surface. This allows both the second surface and the first surface to abut the electrode assembly, thereby increasing the flow area and, at the same time, allowing the first reinforcement portion to abut the electrode assembly, reducing the effect of the force on the weak portion of the wall portion located on the inner circumference of the first reinforcement portion.

[0017] In some embodiments, the wall portion has a third surface that faces away from the electrode assembly and is farthest from the first surface along the thickness direction of the wall portion, and the first connecting portion is located between the first and third surfaces along the thickness direction of the wall portion. This places the first connecting portion between the first and third surfaces along the thickness direction of the wall portion, making it difficult for external forces to directly act on the first connecting portion, thereby effectively reducing the impact of external forces on the weak portion during the production and use of the battery cell.

[0018] In some embodiments, the first region further includes an edge portion connected to the second reinforcement portion and located on an outer periphery of the second reinforcement portion. A surface of the edge portion facing away from the electrode assembly along the thickness direction of the wall portion serves as a third surface. The edge portion protects the first connection portion, making it difficult for external forces to directly act on the first connection portion.

[0019] In some embodiments, along the thickness direction of the wall, the distance between the third surface and the first surface is H, the height of the protruding wall portion of the first reinforcement portion is h1, and the height of the protruding wall portion of the second reinforcement portion is h2, satisfying: 0.1≤h1 / H≤0.9; and / or, 0.1≤h2 / H≤0.9.

[0020] In some embodiments, a second recess is provided along the thickness direction of the wall portion at a position corresponding to the second reinforcement portion on a side of the first region facing away from the electrode assembly. The provision of the second recess provides the second reinforcement portion with excellent buffering capabilities. When an external force is applied to the area of the wall portion located outside the second reinforcement portion, the second reinforcement portion effectively buffers the force, preventing the external force from being transmitted to the weak portion, thereby further reducing deformation of the weak portion.

[0021] In some embodiments, the second reinforcement portion is welded to the electrode assembly to achieve electrical connection between the wall portion and the electrode assembly. Alternatively, the battery cell further includes a current collecting member disposed between the wall portion and the electrode assembly along the thickness of the wall portion, the current collecting member being connected to the electrode assembly, and the second reinforcement portion being welded to the current collecting member to achieve electrical connection between the wall portion and the electrode assembly. Whether the second reinforcement portion is welded to the electrode assembly or the current collecting member, both methods improve the stability of the electrical connection between the wall portion and the electrode assembly.

[0022] In some embodiments, along the radial direction of the wall portion, the width of the second reinforcement portion is a2, the radius of the wall portion is R, the distance from the outer edge of the second reinforcement portion to the outer edge of the wall portion is L1, and the spacing between the first reinforcement portion and the second reinforcement portion is L2, satisfying: 0.05≤a2 / R≤08; and / or, 002≤L1 / R≤08; and / or, 0.05≤L2 / R≤0.8.

[0023] In some embodiments, the first connecting portion partially protrudes along the thickness of the wall to form a third reinforcement portion. The third reinforcement portion extends circumferentially along the wall, and the weak portion is formed in the third reinforcement portion. The third reinforcement portion can enhance the strength of the first connecting portion and further reduce the impact of wall deformation on the weak portion.

[0024] In some embodiments, a width of the third reinforcement portion along the radial direction of the wall portion is a3, and a radius of the wall portion is R, satisfying: 0.05≤a3 / R≤0.8.

[0025] In some embodiments, the first region is provided with a notch, and a weakened portion is formed in the first region at the location of the notch. By providing the notch in the first region to form the weakened portion, the weakened portion is thinner than other regions, making it more susceptible to breakage, and the formation of the weakened portion is simple.

[0026] In some embodiments, the notch is disposed around the first reinforcement portion; the notch is a non-enclosed structure with a distance between the ends; or the notch is a closed structure with the ends connected. Thus, when the battery cell is depressurized, the wall portion can open in the area defined by the notch, providing the battery cell with a larger pressure relief area and improving pressure relief efficiency.

[0027] In some embodiments, the housing includes a shell and an end cap; the shell has an opening formed at one end, and the shell has a bottom wall opposite the opening; the end cap is connected to the shell and closes the opening; wherein one of the bottom wall and the end cap is a wall portion. The bottom wall of the shell can be used as the wall portion, so that the bottom wall of the shell has pressure relief capability; or the end cap of the shell can be used as the wall portion, so that the end cap has pressure relief capability.

[0028] In some embodiments, the battery cell further includes an electrode terminal disposed at an end of the housing opposite to the wall along the thickness direction of the wall, the electrode terminal being electrically connected to the electrode assembly, and conveniently outputting electrical energy from the battery cell through the electrode terminal.

[0029] In some embodiments, the electrode terminal has a first outer surface facing away from the electrode assembly along the thickness direction of the wall portion. The electrode terminal is provided with a groove that extends from the first outer surface toward the electrode assembly. The electrode terminal forms a second connecting portion at the location of the groove, and the second connecting portion is connected to the electrode assembly. The provision of the groove in the electrode terminal reduces the weight of the electrode terminal and lowers production costs. Furthermore, the provision of the groove in the electrode terminal makes the second connecting portion of the electrode terminal thinner, enabling external welding of the electrode terminal and improving the stability of the electrical connection between the electrode terminal and the electrode assembly.

[0030] In some embodiments, the battery cell further includes a sealing member connected to the electrode terminal and sealing the groove. Along the thickness direction of the wall portion, the sealing member has a second outer surface facing away from the electrode assembly, and the second outer surface is flush with the first outer surface. The second outer surface of the sealing member and the first outer surface of the electrode terminal can form a smooth interface, facilitating welding with other components and achieving large-area flow.

[0031] In a second aspect, an embodiment of the present application provides a battery, comprising a housing and a battery cell provided by any one embodiment of the first aspect, wherein the battery cell is housed in the housing.

[0032] In a third aspect, an embodiment of the present application further provides an electrical device, including a battery provided by any embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0035] Figure 2 An exploded view of a battery provided in accordance with some embodiments of the present application;

[0036] Figure 3 An exploded view of a battery cell provided in some embodiments of the present application;

[0037] Figure 4 for Figure 3A cross-sectional view of a battery cell is shown;

[0038] Figure 5 for Figure 4 A partial enlarged view of the battery cell shown;

[0039] Figure 6 for Figure 5 A schematic structural diagram of the wall portion shown;

[0040] Figure 7 Schematic diagram of the structure of the wall portion provided in some other embodiments of the present application;

[0041] Figure 8 for Figure 6 a top view of the wall portion shown;

[0042] Figure 9 Cross-sectional views of battery cells provided in some other embodiments of the present application;

[0043] Figure 10 for Figure 9 A partial enlarged view of the battery cell shown.

[0044] Icons: 1-shell; 11-shell; 111-bottom wall; 12-end cover; 13-wall; 131-first reinforcement; 1311-second surface; 132-first area; 1321-weak part; 1322-first connecting part; 1323-edge; 1324-third surface; 1325-third reinforcement; 1326-third recess; 1327-score; 133-second area; 1331-injection hole; 134-first recess; 135-second reinforcement; 1351-first surface; 136- Second recess; 2-electrode assembly; 21-ear; 21a-positive ear; 21b-negative ear; 3-electrode terminal; 31-first outer surface; 32-groove; 321-first groove; 322-second groove; 33-second connecting portion; 34-first inner surface; 4-current collecting member; 5-sealing member; 51-second outer surface; 10-battery cell; 20-casing; 201-first part; 202-second part; 100-battery; 200-controller; 300-motor; 1000-vehicle; Z-thickness direction. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only 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 drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0047] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the 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.

[0048] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0049] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0050] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0051] The term "plurality" used in this application refers to two or more (including two).

[0052] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0053] The battery referred to in the embodiments of this 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 this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0054] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The portion of the positive electrode collector not coated with the positive active material layer protrudes from the portion coated with the positive active material layer. The portion of the positive electrode collector not coated with the positive active material layer serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The portion of the negative electrode collector not coated with the negative active material layer protrudes from the portion coated with the negative active material layer. The portion of the negative electrode collector not coated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative active material can be carbon or silicon, among others. To ensure high current flow without melting, multiple positive tabs are stacked together, and multiple negative tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the present invention is not limited thereto.

[0055] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety must also be considered.

[0056] In a battery cell, a pressure relief mechanism may be provided in the battery cell to improve the safety of the battery cell. When the pressure inside the battery cell reaches the detonation pressure, the pressure inside the battery cell is released through the pressure relief mechanism.

[0057] In order to reduce the manufacturing cost of the pressure relief mechanism, a weak portion can be formed locally on the wall of the shell to form a pressure relief mechanism. When the pressure inside the battery cell reaches the detonation pressure, the weak portion will crack to achieve the purpose of pressure relief.

[0058] The inventors have noticed that for battery cells with a pressure relief mechanism formed by a weak portion of the wall, the weak portion is prone to abnormal rupture when the pressure inside the battery cell does not reach the detonation pressure, thereby reducing the service life of the battery cell.

[0059] The inventors further discovered that during normal use of a battery cell, the wall is susceptible to deformation due to external forces, causing deformation of the weak portion, which in turn reduces the strength of the weak portion and can lead to abnormal cracking of the weak portion. For example, the wall can be subjected to forces from other components outside the battery cell, causing the central area of the wall to deform toward the inside of the battery cell, thereby reducing the strength of the weak portion. In another example, as the pressure inside the battery cell increases with temperature, the wall can be subjected to forces from the gas inside the battery cell, causing the central area of the wall to deform toward the outside of the battery cell, thereby reducing the strength of the weak portion. This ultimately affects the service life of the battery cell.

[0060] In view of this, an embodiment of the present application provides a battery cell, in which a first reinforcement portion is protruded on the wall of the shell, and the first reinforcement portion extends along the circumference of the wall portion, so that the wall portion forms a first area on the outer peripheral side of the first reinforcement portion, and the weak portion is formed in the first area.

[0061] In such a battery cell, a first reinforcement protrudes from the wall, reinforcing the wall and increasing the strength of the weak portion. Because the weak portion is formed in the first region located on the outer periphery of the first reinforcement, when the wall is subjected to external forces, causing deformation of the portion located on the inner periphery of the first reinforcement, the first reinforcement can reduce the impact of the external force on the weak portion, minimizing deformation of the weak portion, ensuring the normal detonation pressure of the battery cell, and extending the battery cell's service life.

[0062] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0063] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0064] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0065] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed within the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, as the operating power source of the vehicle 1000.

[0066] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0067] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0068] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a housing 20 , wherein the battery cell 10 is accommodated in the housing 20 .

[0069] The housing 20 is a component that houses the battery cells 10 and provides a storage space for the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 can include a first portion 201 and a second portion 202, which overlap to define a storage space for the battery cells 10. The first portion 201 and the second portion 202 can have various shapes, such as a rectangular parallelepiped or a cylinder. The first portion 201 can be a hollow structure with one side open, and the second portion 202 can also be a hollow structure with one side open. The open side of the second portion 202 overlaps the open side of the first portion 201, forming the housing 20 with a storage space. Alternatively, the first portion 201 can be a hollow structure with one side open, and the second portion 202 can be a plate-like structure. The second portion 202 overlaps the open side of the first portion 201, forming the housing 20 with a storage space. The first portion 201 and the second portion 202 can be sealed by a sealing element, which can be a sealing ring, sealant, etc.

[0070] In the battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, the multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 10. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection to form a battery module, which can then be connected in series, parallel, or in a hybrid connection to form a single unit and housed within the housing 20. Alternatively, all battery cells 10 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by all battery cells 10 can be housed within the housing 20.

[0071] In some embodiments, the battery 100 may further include a busbar component, through which the multiple battery cells 10 can be electrically connected to each other, thereby enabling series connection, parallel connection, or hybrid connection of the multiple battery cells 10. The busbar component may be a metal conductor, such as copper, iron, aluminum, stainless steel, or aluminum alloy.

[0072] Please refer to Figure 3 and Figure 4 , Figure 3 An exploded view of a battery cell 10 provided in some embodiments of the present application is shown. Figure 4 for Figure 3 FIG2 is a cross-sectional view of a battery cell 10 . The battery cell 10 may include a housing 1 and an electrode assembly 2 .

[0073] The housing 1 is a component for accommodating the electrode assembly 2. The housing 1 may be in various shapes, such as a cylinder, a cuboid, etc. The housing 1 may include a shell 11 and an end cap 12.

[0074] The housing 11 may be a hollow structure with an opening at one end. The housing 11 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0075] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 and the shell 11 together define a sealed space for accommodating the electrode assembly 2, electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or rolling to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 1. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 1. For another example, the shell 11 is a cylinder, and the end cap 12 is a circular plate structure adapted to the shell 11. The material of the end cap 12 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0076] The electrode assembly 2 is the component within the battery cell 10 where the electrochemical reaction occurs. The electrode assembly 2 may include a positive electrode sheet, a negative electrode sheet, and a separator. The electrode assembly 2 may be a wound structure formed by winding the positive electrode sheet, separator, and negative electrode sheet, or a laminated structure formed by stacking the positive electrode sheet, separator, and negative electrode sheet. The electrode assembly 2 has tabs 21, which are divided into positive tabs 21a and negative tabs 21b. The positive tab 21a may be the portion of the positive electrode sheet not coated with the positive active material layer, and the negative tab 21b may be the portion of the negative electrode sheet not coated with the negative active material layer.

[0077] The battery cell 10 may also include an electrode terminal 3, which is used to electrically connect to the tab 21 of the electrode assembly 2 to output electrical energy from the battery cell 10. The electrode terminal 3 may be provided on the end cap 12 or on the outer casing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, by direct welding. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, by connecting the electrode terminal 3 and the tab 21 indirectly via a current collecting member 4. The current collecting member 4 may be a metal conductor, such as copper, iron, aluminum, steel, or an aluminum alloy.

[0078] like Figure 3 and Figure 4 As shown, taking the example of the electrode terminal 3 being arranged at the end of the housing 1 opposite to the end cover 12 , the positive tab 21 a is electrically connected to the electrode terminal 3 through one current collecting member 4 , and the negative tab 21 b is electrically connected to the housing 11 through another current collecting member 4 .

[0079] Please refer to Figure 5 , Figure 5 for Figure 4A partially enlarged view of a battery cell 10 is shown. An embodiment of the present application provides a battery cell 10 comprising a housing 1 and an electrode assembly 2. The housing 1 houses the electrode assembly 2, and the housing 1 has a wall portion 13. The wall portion 13 is provided with a first reinforcement portion 131 protruding from the wall portion 13. The first reinforcement portion 131 extends along the circumference of the wall portion 13. The wall portion 13 includes a first region 132 located on the outer peripheral side of the first reinforcement portion 131. The first region 132 is formed with a weak portion 1321. The weak portion 1321 is configured to rupture when the battery cell 10 releases pressure.

[0080] Wall 13 can be the end cap 12 of housing 1 or a wall disposed opposite end cap 12 of housing 11. Wall 13 can be circular or rectangular. If housing 1 is cylindrical, wall 13 is circular; if housing 1 is a cuboid, wall 13 is rectangular. For example, if housing 1 is cylindrical, the axial direction of housing 1 is the thickness direction Z of wall 13.

[0081] The wall portion 13 can be used as an electric energy output component of the battery cell 10. The wall portion 13 is electrically connected to the electrode assembly 2 to output the electric energy of the battery cell 10. For example, Figure 4 and Figure 5 In the embodiment, the wall portion 13 is the end cover 12 , and the end cover 12 is electrically connected to the tab 21 of the electrode assembly 2 through the current collecting member 4 .

[0082] A first reinforcement portion 131 is protruding from the wall portion 13. That is, the first reinforcement portion 131 is provided on the wall portion 13 and protrudes from the wall portion 13. Along the thickness direction Z of the wall portion 13, the first reinforcement portion 131 can be protruding from the side of the wall portion 13 facing the electrode assembly 2, so that the first reinforcement portion 131 faces the interior of the battery cell 10. The first reinforcement portion 131 can also be protruding from the side of the wall portion 13 facing away from the electrode assembly 2, so that the first reinforcement portion 131 faces the exterior of the battery cell 10.

[0083] The first reinforcement portion 131 may be an annular structure, such as a circular ring, a square ring, etc. Taking the circular wall portion 13 as an example, the first reinforcement portion 131 may extend along the circumference of the wall portion 13 to form a circular ring structure.

[0084] The first region 132 is the portion of the wall portion 13 located on the outer periphery of the first reinforcement portion 131. The outer periphery of the first reinforcement portion 131 is the outer side of the first reinforcement portion 131 in a direction perpendicular to the thickness Z of the wall portion 13. Taking the circular wall portion 13 as an example, the outer periphery of the first reinforcement portion 131 is the outer side of the first reinforcement portion 131 in the radial direction of the wall portion 13. The first region 132 is the annular portion of the wall portion 13 surrounding the outer side of the first reinforcement portion 131.

[0085] Weakened portion 1321 is the weaker portion of wall 13 and is more susceptible to rupture than other areas of wall 13. When the pressure inside battery cell 10 reaches the detonation pressure and requires pressure relief, weakened portion 1321 ruptures, allowing the discharge from inside battery cell 10 to escape, thereby relieving the pressure inside battery cell 10.

[0086] In the embodiment of the present application, the wall portion 13 is provided with a protruding first reinforcement portion 131. The first reinforcement portion 131 reinforces the wall portion 13 and increases the strength of the weak portion 1321. Because the weak portion 1321 is formed in the first region 132 located on the outer periphery of the first reinforcement portion 131, when the wall portion 13 is subjected to an external force and the portion located on the inner periphery of the first reinforcement portion 131 deforms, the first reinforcement portion 131 can reduce the impact of the external force on the weak portion 1321, reducing deformation of the weak portion 1321, ensuring the normal detonation pressure of the battery cell 10, and extending the service life of the battery cell 10.

[0087] In some embodiments, please refer to Figure 5 The wall portion 13 further includes a second region 133 located on the inner circumference of the first reinforcement portion 131 . The second region 133 is provided with a liquid injection hole 1331 . The liquid injection hole 1331 is provided in the second region 133 of the wall portion 13 to facilitate the injection of electrolyte into the battery cell 10 .

[0088] The second region 133 is the portion of the wall portion 13 located on the inner circumference of the first reinforcement portion 131. The first reinforcement portion 131 divides the wall portion 13 into two regions: a first region 132 located on the outer circumference of the first reinforcement portion 131, and a second region 133 located on the inner circumference of the first reinforcement portion 131. The second region 133 is the central region of the wall portion 13. The inner circumference of the first reinforcement portion 131 is the inner side of the first reinforcement portion 131 in the direction Z perpendicular to the thickness of the wall portion 13. For example, if the wall portion 13 is circular, the inner circumference of the first reinforcement portion 131 is the inner side of the first reinforcement portion 131 in the radial direction of the wall portion 13. The second region 133 is the portion of the wall portion 13 located on the inner side of the first reinforcement portion 131.

[0089] The injection hole 1331 is provided on the second region 133 to allow electrolyte to enter the interior of the battery cell 10. The injection hole 1331 can be located at the center of the second region 133 or offset from the center of the second region 133. After the electrolyte is injected into the battery cell 10 through the injection hole 1331, the injection hole 1331 can be sealed with a sealing nail.

[0090] When electrolyte is injected into the battery cell 10 through the injection hole 1331, the second area 133 is easily deformed toward the inside of the battery cell 10 due to the extrusion force applied by the injection device (such as an injection needle). The first reinforcement portion 131 can reduce the impact of the deformation of the second area 133 on the weak portion 1321, thereby reducing the deformation of the weak portion 1321 and reducing the risk of the weak portion 1321 being deformed during the process of injecting electrolyte into the battery cell 10 through the injection hole 1331, thereby reducing the risk of the weak portion 1321 cracking before reaching the detonation pressure.

[0091] In some embodiments, the liquid injection hole 1331 is coaxially arranged with the first reinforcement portion 131 .

[0092] It is understandable that the injection hole 1331 is disposed at the center of the second region 133. The provision of the injection hole 1331 enables the second region 133 to be an annular structure surrounding the inner side of the first reinforcement portion 131.

[0093] Taking the case where the injection hole 1331 is a circular hole and the first reinforcement portion 131 is annular as an example, the center line of the injection hole 1331 coincides with the center axis of the first reinforcement portion 131. The diameter of the injection hole 1331 may be 0.05 to 10 mm.

[0094] In this embodiment, the injection hole 1331 is coaxially arranged with the first reinforcement portion 131. When the electrolyte is injected into the battery cell 10 through the injection hole 1331, the second region 133 is deformed toward the inside of the battery cell 10 by force, and the first reinforcement portion 131 is uniformly stressed, thereby reducing the risk of deformation of the weak portion 1321 due to excessive local force on the first reinforcement portion 131, and can further reduce the deformation of the weak portion 1321.

[0095] In some embodiments, please refer to Figure 5 Along the thickness direction Z of the wall portion 13 , the first reinforcement portion 131 is protruded from the side of the wall portion 13 facing the electrode assembly 2 . Thus, the first reinforcement portion 131 faces the interior of the battery cell 10 , reducing the external space occupied by the first reinforcement portion 131 and reducing the volume of the battery cell 10 .

[0096] In some embodiments, please refer to Figure 5 Along the thickness direction Z of the wall portion 13 , the first reinforcement portion 131 abuts against the electrode assembly 2 .

[0097] It should be noted that the first reinforcement portion 131 can directly abut against the electrode assembly 2, for example, the first reinforcement portion 131 directly abuts against the electrode tab 21 of the electrode assembly 2; the first reinforcement portion 131 can also indirectly abut against the electrode assembly 2, for example, Figure 5 As shown, the first reinforcement portion 131 indirectly abuts against the electrode tab 21 of the electrode assembly 2 through the current collecting member 4 .

[0098] When the wall portion 13 is subjected to external force and the portion located on the inner circumference of the first reinforcement portion 131 is deformed toward the inside of the battery cell 10, since the first reinforcement portion 131 abuts against the electrode assembly 2, the electrode assembly 2 restricts the first reinforcement portion 131, reducing the risk of deformation of the weak portion 1321.

[0099] In some embodiments, please refer to Figure 5 Along the thickness direction Z of the wall portion 13 , a first recess 134 is provided at a position corresponding to the first reinforcement portion 131 on the side of the wall portion 13 away from the electrode assembly 2 .

[0100] The shape of the first recess 134 is the same as that of the first reinforcement 131. For example, if the first reinforcement 131 is annular, then the first recess 134 is also annular. The first recess 134 can be formed by stamping. After the first recess 134 is stamped, the first reinforcement 131 can be formed on the side of the wall 13 facing the electrode assembly 2.

[0101] In this embodiment, the setting of the first recess 134 enables the first reinforcement portion 131 to have excellent buffering ability. When the wall portion 13 is subjected to external force and the portion located on the inner circumferential side of the first reinforcement portion 131 is deformed, the first reinforcement portion 131 plays a good buffering role, preventing the external force from being transmitted to the weak portion 1321, thereby further reducing the deformation of the weak portion 1321.

[0102] In some embodiments, please refer to Figure 6 , Figure 6 for Figure 5 The schematic diagram of the structure of the wall portion 13 is shown. The radial width of the first reinforcement portion 131 along the wall portion 13 is a1, the inner diameter of the first reinforcement portion 131 is r1, and the radius of the wall portion 13 is R, which satisfies: 0.05≤a1 / R≤0.8; and / or, 0.05≤r1 / R≤0.8.

[0103] In this embodiment, the wall portion 13 is circular and the first reinforcement portion 131 is annular. Half of the difference between the outer diameter and the inner diameter of the first reinforcement portion 131 is the radial width of the first reinforcement portion 131 along the wall portion 13 .

[0104] a1 / R can be any value between 0.05 and 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. r1 / R can also be any value between 0.05 and 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0105] In some embodiments, please refer to Figure 5 and Figure 6The first region 132 is provided with a second reinforcement portion 135, which extends along the circumference of the wall portion 13. The first region 132 includes a first connecting portion 1322, which connects the first reinforcement portion 131 and the second reinforcement portion 135. The first connecting portion 1322 is located on the outer periphery of the first reinforcement portion 131, and the second reinforcement portion 135 is located on the outer periphery of the first connecting portion 1322. The weak portion 1321 is formed in the first connecting portion 1322.

[0106] The second reinforcement portion 135 is provided in the first region 132 and protrudes from the first region 132. Along the thickness direction Z of the wall portion 13, the second reinforcement portion 135 can be protruded from the side of the first region 132 facing the electrode assembly 2, so that the second reinforcement portion 135 faces the interior of the battery cell 10. The second reinforcement portion 135 can also be protruded from the side of the wall portion 13 facing away from the electrode assembly 2, so that the second reinforcement portion 135 faces the exterior of the battery cell 10.

[0107] The second reinforcement portion 135 surrounds the outer side of the first reinforcement portion 131. The second reinforcement portion 135 can be an annular structure, such as a circular ring, a square ring, etc. The second reinforcement portion 135 is coaxially arranged with the first reinforcement portion 131. For example, Figure 5 and Figure 6 As shown, the wall portion 13 is circular, and the second reinforcement portion 135 and the first reinforcement portion 131 are both annular. The second reinforcement portion 135 and the first reinforcement portion 131 are coaxially arranged.

[0108] The first connecting portion 1322 is the portion of the first region 132 that connects to the first reinforcement portion 131 and the second reinforcement portion 135 along a direction Z perpendicular to the thickness of the wall portion 13. The first connecting portion 1322 is connected to the second region 133 via the first reinforcement portion 131. For example, if both the first reinforcement portion 131 and the second reinforcement portion 135 are circular, the first connecting portion 1322 is an annular structure connecting the first reinforcement portion 131 and the second reinforcement portion 135.

[0109] For example, Figure 5 and Figure 6 As shown, the first connection portion 1322 and the second region 133 are both flat plate structures. Along the thickness direction Z of the wall portion 13 , the first connection portion 1322 is substantially flush with the second region 133 .

[0110] In this embodiment, the weak portion 1321 is formed at the first connecting portion 1322 connected between the first reinforcing portion 131 and the second reinforcing portion 135 . The second reinforcing portion 135 can also enhance the strength of the weak portion 1321 .

[0111] In some embodiments, please refer to Figure 5 and Figure 6The second reinforcement portion 135 is protruded from the side of the first area 132 facing the electrode assembly 2. Along the thickness direction Z of the wall portion 13, the second reinforcement portion 135 has a first surface 1351 facing the electrode assembly 2. The first surface 1351 abuts against the electrode assembly 2 to achieve electrical connection between the wall portion 13 and the electrode assembly 2.

[0112] The first surface 1351 is the end surface of the second reinforcement portion 135 facing the electrode assembly 2 along the thickness direction Z of the wall portion 13. The first surface 1351 can directly abut against the electrode assembly 2, for example, the first surface 1351 directly abuts against the electrode tab 21 of the electrode assembly 2 to achieve electrical connection between the wall portion 13 and the electrode assembly 2; the first surface 1351 can also indirectly abut against the electrode assembly 2, for example, Figure 5 As shown, the first surface 1351 directly abuts against the current collecting member 4 , and the current collecting member 4 directly abuts against the electrode tab 21 of the electrode assembly 2 , so as to achieve electrical connection between the wall portion 13 and the electrode assembly 2 .

[0113] The first surface 1351 of the second reinforcement portion 135 abuts against the electrode assembly 2. On the one hand, it realizes the electrical connection between the wall portion 13 and the electrode assembly 2, so as to output the electrical energy of the battery cell 10 through the wall portion 13; on the other hand, the second reinforcement portion 135 supports the electrode assembly 2, thereby improving the stability of the electrode assembly 2 inside the outer shell 1.

[0114] In some embodiments, please refer to Figure 5 and Figure 6 , along the direction of the wall portion 13 pointing to the electrode assembly 2 , the first reinforcement portion 131 does not exceed the first surface 1351 .

[0115] The direction in which the wall portion 13 points toward the electrode assembly 2 is the direction in which the wall portion 13 faces the electrode assembly 2 along the thickness direction Z.

[0116] In this embodiment, the first reinforcement portion 131 does not extend beyond the first surface 1351 , ensuring that the first surface 1351 can effectively abut against the electrode assembly 2 .

[0117] In some embodiments, along the thickness direction Z of the wall portion 13 , the first reinforcement portion 131 has a second surface 1311 facing the electrode assembly 2 , and the second surface 1311 is flush with the first surface 1351 .

[0118] Second surface 1311 is the end surface of the first reinforcement 131 facing the electrode assembly 2 along the thickness direction Z of the wall 13. Second surface 1311 is flush with first surface 1351, so that second surface 1311 and first surface 1351 are located in the same plane. Both second surface 1311 and first surface 1351 can abut against the electrode assembly 2. This increases the flow area. For example, if both second surface 1311 and first surface 1351 directly abut the current collecting member 4, and the current collecting member 4 directly abuts the tab 21 of the electrode assembly 2, then both second surface 1311 and first surface 1351 are in contact with the current collecting member 4, increasing the flow area between the current collecting member 4 and the wall 13. Furthermore, this allows the first reinforcement 131 to abut against the electrode assembly 2, reducing the impact of forces on the inner circumference of the wall 13 located on the first reinforcement 131 and the weak portion 1321.

[0119] In other embodiments, along the thickness direction Z of the wall portion 13 , the second surface 1311 may be further away from the electrode assembly 2 than the first surface 1351 .

[0120] In some embodiments, please refer to Figure 5 and Figure 6 Along the thickness direction Z of the wall 13 , the wall 13 has a third surface 1324 that is away from the electrode assembly 2 and is farthest from the first surface 1351 . Along the thickness direction Z of the wall 13 , the first connecting portion 1322 is located between the first surface 1351 and the third surface 1324 .

[0121] The third surface 1324 may be formed in the first region 132 or in the second region 133 .

[0122] In this embodiment, the first connection portion 1322 is positioned between the first surface 1351 and the third surface 1324 in the thickness direction Z of the wall portion 13, making it difficult for external forces to directly act on the first connection portion 1322. This effectively reduces the impact of external forces on the weak portion 1321 during the production and use of the battery cell 10. For example, when the housing 1 is placed on an object, the third surface 1324 of the wall portion 13 contacts the object, while the first connection portion 1322 is suspended in the air and is not directly in contact with the object and subjected to force, thereby protecting the weak portion 1321.

[0123] In some embodiments, please refer to Figure 5 and Figure 6 The first region 132 also includes an edge portion 1323, which is connected to the second reinforcement portion 135 and is located on the outer peripheral side of the second reinforcement portion 135. Along the thickness direction Z of the wall portion 13, the surface of the edge portion 1323 facing away from the electrode assembly 2 is the third surface 1324.

[0124] The edge portion 1323 can be a circular ring structure disposed around the second reinforcement portion 135. The outer diameter of the edge portion 1323 is equal to the diameter of the wall portion 13. Taking the wall portion 13 as the end cap 12 of the housing 1 as an example, the edge portion 1323 can be connected to the shell 11 of the housing 1, for example, by welding, so that the end cap 12 blocks the opening of the shell 11.

[0125] The edge portion 1323 protects the first connection portion 1322. When the housing 1 is placed on an object, the edge portion 1323 contacts the object, and the first connection portion 1322 is in a suspended state and does not directly contact the object and receive force, making it difficult for external force to directly act on the first connection portion 1322.

[0126] In some embodiments, please refer to Figure 6 Along the thickness direction Z of the wall portion 13, the distance between the third surface 1324 and the first surface 1351 is H, the height of the first reinforcement portion 131 protruding from the wall portion 13 is h1, and the height of the second reinforcement portion 135 protruding from the wall portion 13 is h2, satisfying: 0.1≤h1 / H≤0.9; and / or, 0.1≤h2 / H≤0.9.

[0127] h1 / H can be any value between 0.1 and 0.9, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9. h2 / H can also be any value between 0.1 and 0.9, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9.

[0128] h1 and h2 may be equal or different. In the embodiment where the first surface 1351 is flush with the second surface 1311 , h1 = h2.

[0129] In some embodiments, please refer to Figure 5 and Figure 6 Along the thickness direction Z of the wall portion 13 , a second recess 136 is provided at a position corresponding to the second reinforcement portion 135 on a side of the first region 132 away from the electrode assembly 2 .

[0130] The shape of the second recess 136 is the same as that of the second reinforcement 135. For example, if the second reinforcement 135 is annular, then the second recess 136 is also annular. The second recess 136 can be formed by stamping. After the second recess 136 is stamped, the second reinforcement 135 can be formed on the side of the first region 132 facing the electrode assembly 2.

[0131] The provision of the second recess 136 provides the second reinforcement 135 with excellent buffering capabilities. When the area of the wall 13 located on the outer periphery of the second reinforcement 135 is subjected to external forces, the second reinforcement 135 effectively buffers the area, preventing the external forces from being transmitted to the weak portion 1321, thereby further reducing deformation of the weak portion 1321. For example, using the wall 13 as the end cap 12 of the housing 1 as an example, when the wall 13 is assembled with the shell 11, the edge 1323 of the wall 13 will be subjected to the forces exerted by the shell 11. During this process, the buffering effect of the second reinforcement 135 can reduce deformation of the weak portion 1321.

[0132] In some embodiments, the second reinforcement portion 135 is welded to the electrode assembly 2 to achieve electrical connection between the wall portion 13 and the electrode assembly 2 .

[0133] Specifically, the first surface 1351 of the second reinforcement portion 135 directly contacts the electrode tab 21 of the electrode assembly 2 , and the second reinforcement portion 135 is welded to the electrode tab 21 of the electrode assembly 2 .

[0134] In this embodiment, welding the second reinforcement portion 135 to the electrode assembly 2 can effectively improve the stability of the electrical connection between the wall portion 13 and the electrode assembly 2 .

[0135] In the embodiment where the first region 132 is provided with the second recess 136 , the second recess 136 can be regarded as a welding groove. The provision of the second recess 136 can reduce the thickness of the second reinforcement 135 and enhance the firmness of the welding between the second reinforcement 135 and the tab 21 .

[0136] In the embodiment where the second region 133 is provided with an injection hole 1331, since the injection hole 1331 is provided in the second region 133 and the second protrusion is provided in the first region 132, the injection hole 1331 and the second protrusion are relatively far apart. Therefore, after the electrolyte is injected into the battery cell 10 through the injection hole 1331, the electrolyte remaining near the injection hole 1331 is unlikely to flow into the second recess 136, thereby less likely to affect the secure weld between the second reinforcement 135 and the tab 21. In the embodiment where the wall portion 13 is provided with a first recess 134, the first recess 134 can block the flow of electrolyte into the second groove 32, further reducing the risk of electrolyte remaining near the injection hole 1331 flowing into the second recess 136 and affecting the secure weld between the second reinforcement 135 and the tab 21.

[0137] In other embodiments, please refer to Figure 5 The battery cell 10 also includes a current collecting component 4, which is arranged between the wall portion 13 and the electrode assembly 2 along the thickness direction Z of the wall portion 13, and the current collecting component 4 is connected to the electrode assembly 2. The second reinforcement portion 135 is welded to the current collecting component 4 to achieve electrical connection between the wall portion 13 and the electrode assembly 2.

[0138] The shape of the current collecting member 4 may be the same as that of the wall portion 13 . For example, both the wall portion 13 and the current collecting member 4 may be circular.

[0139] Specifically, the current collecting member 4 is disposed between the electrode tab 21 and the wall portion 13 of the electrode assembly 2, and the current collecting member 4 is connected to the electrode tab 21. Exemplarily, the current collecting member 4 is welded to the electrode tab 21.

[0140] In this embodiment, the second reinforcement portion 135 is welded to the current collecting member 4 to improve the stability of the electrical connection between the wall portion 13 and the electrode assembly 2 .

[0141] In the embodiment where the second recess 136 is provided in the first region 132 , the provision of the second recess 136 can reduce the thickness of the second reinforcement portion 135 and enhance the firmness of welding between the second reinforcement portion 135 and the current collecting member 4 .

[0142] In the embodiment where the second region 133 is provided with an injection hole 1331, since the injection hole 1331 is provided in the second region 133 and the second protrusion is provided in the first region 132, the injection hole 1331 and the second protrusion are relatively far apart. Therefore, after the electrolyte is injected into the battery cell 10 through the injection hole 1331, the electrolyte remaining near the injection hole 1331 is unlikely to flow into the second recess 136, thereby less likely to affect the secure welding of the second reinforcement 135 to the current collecting member 4. In the embodiment where the wall portion 13 is provided with a first recess 134, the first recess 134 can block the flow of electrolyte into the second groove 32, further reducing the risk of electrolyte remaining near the injection hole 1331 flowing into the second recess 136 and affecting the secure welding of the second reinforcement 135 to the current collecting member 4.

[0143] In some embodiments, along the radial direction of the wall portion 13, the width of the second reinforcement portion 135 is a2, the radius of the wall portion 13 is R, the distance from the outer edge of the second reinforcement portion 135 to the outer edge of the wall portion 13 is L1, and the spacing between the first reinforcement portion 131 and the second reinforcement portion 135 is L2, satisfying: 0.05≤a2 / R≤0.8; and / or, 0.02≤L1 / R≤0.8; and / or, 0.05≤L2 / R≤0.8.

[0144] In this embodiment, the wall portion 13 is circular, and the second reinforcement portion 135 is annular. The radial width of the second reinforcement portion 135 along the wall portion 13 is half the difference between the outer and inner diameters of the second reinforcement portion 135. The distance between the outer edge of the first reinforcement portion 131 and the inner edge of the second reinforcement portion 135 is the spacing between the first reinforcement portion 131 and the second reinforcement portion 135. In embodiments where the first region 132 includes an edge portion 1323, the outer edge of the edge portion 1323 is the outer edge of the wall portion 13.

[0145] a2 / R can be any value between 0.05 and 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. L1 / R can be any value between 0.02 and 0.8, for example, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. L2 / R can be any value between 0.05 and 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0146] In some embodiments, please refer to Figure 7 , Figure 7 A structural schematic diagram of the wall portion 13 provided for other embodiments of the present application shows that along the thickness direction Z of the wall portion 13, the first connecting portion 1322 partially protrudes to form a third reinforcing portion 1325, the third reinforcing portion 1325 extends along the circumference of the wall portion 13, and the weak portion 1321 is formed in the third reinforcing portion 1325.

[0147] The third reinforcement portion 1325 can be an annular structure, such as a circular ring or a square ring. For example, if the wall portion 13 is circular, the third reinforcement portion 1325 can extend along the circumference of the wall portion 13 to form a circular ring structure. The third reinforcement portion 1325 can be coaxially arranged with the first reinforcement portion 131. The first connecting portion 1322 can form one or more third reinforcement portions 1325.

[0148] The first connecting portion 1322 has a third recess 1326 formed at a position corresponding to the third reinforcement portion 1325. The shape of the third recess 1326 is the same as that of the third reinforcement portion 1325. The third recess 1326 can be stamped. After the second recess 136 is stamped on one side of the first connecting portion 1322 along the thickness direction Z of the wall portion 13, the third reinforcement portion 1325 can be formed on the other side of the first connecting portion 1322.

[0149] Along the thickness direction Z of the wall portion 13, the first reinforcement portion 131, the second reinforcement portion 135 and the third reinforcement portion 1325 can be located on the same side of the wall portion 13, or on different sides. Figure 7 In the embodiment, the first reinforcement portion 131, the second reinforcement portion 135 and the third reinforcement portion 1325 are located on the same side of the wall portion 13 and all face the electrode assembly 2 ( Figure 7 not shown).

[0150] In the embodiment where the first connection portion 1322 is located between the first surface 1351 and the third surface 1324 along the thickness direction Z of the wall portion 13, since the third reinforcement portion 1325 is a part of the first connection portion 1322, the third reinforcement portion 1325 is also located between the first surface 1351 and the third surface 1324 along the thickness direction Z of the wall portion 13.

[0151] In this embodiment, the third reinforcing portion 1325 can enhance the strength of the first connecting portion 1322 , further reducing the influence of the deformation of the wall portion 13 under stress on the weak portion 1321 .

[0152] In other embodiments, the weak portion 1321 may also be formed in other areas of the first connecting portion 1322 except the third reinforcing portion 1325 .

[0153] In some embodiments, please refer to Figure 7 The width of the third reinforcement portion 1325 along the radial direction of the wall portion 13 is a3, and the radius of the wall portion 13 is R, which satisfies: 0.05≤a3 / R≤0.8.

[0154] In this embodiment, the wall portion 13 is circular and the third reinforcement portion 1325 is annular. Half of the difference between the outer diameter and the inner diameter of the third reinforcement portion 1325 is the radial width of the third reinforcement portion 1325 along the wall portion 13.

[0155] a3 / R can be any value between 0.05 and 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0156] In some embodiments, please refer to Figure 6 and Figure 7 The first region 132 is provided with a notch 1327 , and the first region 132 forms a weak portion 1321 at the location where the notch 1327 is provided.

[0157] After the notch 1327 is formed in the first region 132, the portion of the first region 132 remaining at the location of the notch 1327 becomes the weakened portion 1321. The shape of the weakened portion 1321 is the same as that of the notch 1327. The notch 1327 can have a variety of shapes, such as rectangular, circular, oval, annular, U-shaped, C-shaped, H-shaped, etc. The notch 1327 can be formed in a variety of ways, such as stamping, milling, etc.

[0158] By providing notches 1327 in the first region 132 to form a corresponding weak portion 1321 , the weak portion 1321 is thinner than other regions and is more easily broken. The forming method of the weak portion 1321 is simple.

[0159] In some embodiments, please refer to Figure 8 , Figure 8 for Figure 6 The top view of the wall portion 13 is shown. The notch 1327 is arranged around the first reinforcing portion 131, and the notch 1327 is a non-enclosed structure with a distance between the end portions.

[0160] Illustratively, notch 1327 is C-shaped.

[0161] When the battery cell 10 is depressurized, the area of the wall portion 13 defined by the notch 1327 can be flipped outward to open, so that the battery cell 10 has a larger depressurization area, thereby improving the depressurization efficiency.

[0162] In other embodiments, the notch 1327 is provided around the first reinforcement portion 131 , and the notch 1327 is a closed structure connected at both ends.

[0163] Exemplarily, notch 1327 is in the shape of a ring.

[0164] When the battery cell 10 is depressurized, the wall portion 13 can be opened outwardly in the area defined by the notch 1327 , so that the battery cell 10 has a larger depressurization area, thereby improving the depressurization efficiency.

[0165] In some embodiments, please refer to Figure 9 , Figure 9 This figure shows a cross-sectional view of a battery cell 10 according to another embodiment of the present invention. The housing 1 includes a shell 11 and an end cap 12. One end of the shell 11 forms an opening, and the shell 11 has a bottom wall 111 opposite the opening. The end cap 12 is connected to the shell 11 and closes the opening. One of the bottom wall 111 and the end cap 12 serves as a wall portion 13. If the bottom wall 111 of the shell 11 serves as the wall portion 13, the bottom wall 111 of the shell 11 has pressure relief capabilities. If the end cap 12 of the shell 1 serves as the wall portion 13, the end cap 12 has pressure relief capabilities.

[0166] For example, in Figure 9 In the embodiment, the end cover 12 serves as the wall portion 13 .

[0167] In some embodiments, please refer to Figure 9 The battery cell 10 further includes an electrode terminal 3 , which is disposed at an end of the housing 1 opposite to the wall 13 along a thickness direction Z of the wall 13 , and is electrically connected to the electrode assembly 2 .

[0168] The electrode terminal 3 and the electrode assembly 2 can be directly connected, for example, the electrode terminal 3 and the electrode tab 21 of the electrode assembly 2 are welded. Figure 9 As shown, the electrode terminal 3 and the electrode assembly 2 can also be indirectly connected through the current collecting member 4.

[0169] In the embodiment where the bottom wall 111 of the housing 11 serves as the wall portion 13, the electrode terminal 3 is provided on the end cover 12, and the electrode terminal 3 is riveted to the end cover 12 and is insulated from the end cover 12. Figure 9 As shown, in the embodiment where the end cap 12 serves as the wall portion 13 , the electrode terminal 3 is disposed on the bottom wall 111 of the housing 11 , and the electrode terminal 3 is riveted to the bottom wall 111 of the housing 11 and is insulated from the bottom wall 111 .

[0170] In this embodiment, the electrical energy of the battery cell 10 can be conveniently output through the electrode terminal 3 .

[0171] In some embodiments, please refer to Figure 10 , Figure 10 for Figure 9 A partial enlarged view of a portion A of a battery cell 10 is shown. Along the thickness direction Z of the wall portion 13, the electrode terminal 3 has a first outer surface 31 facing away from the electrode assembly 2. The electrode terminal 3 is provided with a groove 32 recessed from the first outer surface 31 in a direction approaching the electrode assembly 2. The electrode terminal 3 forms a second connecting portion 33 at the location where the groove 32 is provided. The second connecting portion 33 is connected to the electrode assembly 2.

[0172] The first outer surface 31 is the end surface of the electrode terminal 3 facing away from the electrode assembly 2 along the thickness direction Z of the wall portion 13. Along the thickness direction Z of the wall portion 13, the electrode terminal 3 also includes a first inner surface 34 opposite the first outer surface 31. The portion of the electrode terminal 3 located between the bottom surface of the groove 32 and the first inner surface 34 is the second connecting portion 33.

[0173] Exemplarily, the second connection portion 33 is indirectly connected to the tab 21 of the electrode assembly 2 via the current collecting member 4. The second connection portion 33 is welded to the current collecting member 4, and the current collecting member 4 is welded to the tab 21 of the electrode assembly 2. In embodiments where the second region 133 of the wall portion 13 is provided with an injection hole 1331, the injection hole 1331 is also provided in the electrode terminal 3 to avoid the situation where the injection hole 1331 is provided on the electrode terminal 3 and residual electrolyte near the injection hole 1331 causes a cold weld on the electrode terminal 3.

[0174] In this embodiment, the provision of the groove 32 on the electrode terminal 3 reduces the weight of the electrode terminal 3 and lowers production costs. Furthermore, the provision of the groove 32 on the electrode terminal 3 makes the second connecting portion 33 of the electrode terminal 3 thinner, enabling external welding of the electrode terminal 3 and improving the stability of the electrical connection between the electrode terminal 3 and the electrode assembly 2.

[0175] In some embodiments, please refer to Figure 10 The battery cell 10 further includes a blocking member 5 connected to the electrode terminal 3 and blocking the groove 32. Along the thickness direction Z of the wall portion 13, the blocking member 5 has a second outer surface 51 facing away from the electrode assembly 2, and the second outer surface 51 is flush with the first outer surface 31.

[0176] The blocking member 5 may be made of metal, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. The blocking member 5 and the electrode terminal 3 may be fixed by welding.

[0177] Exemplarily, the groove 32 includes a first groove 321 and a second groove 322, and the first groove 321 and the second groove 322 are arranged along the depth direction of the groove 32. The first groove 321 is recessed from the first outer surface 31 along the depth direction of the groove 32, and the second groove 322 is recessed from the bottom surface of the first groove 321 along the depth direction of the groove 32. The bottom surface of the second groove 322 is the bottom surface of the groove 32, and the sealing member 5 abuts against the bottom surface of the first groove 321 to seal the groove 32.

[0178] The second outer surface 51 of the plugging member 5 and the first outer surface 31 of the electrode terminal 3 form a smooth interface, facilitating welding with other components (such as a current collector) and achieving large-area flow. Furthermore, the flushness of the second outer surface 51 with the first outer surface 31 facilitates butt welding of the plugging member 5 to the electrode terminal 3.

[0179] An embodiment of the present application provides a battery 100 , including a housing 20 and a battery cell 10 provided in any one of the above embodiments, wherein the battery cell 10 is accommodated in the housing 20 .

[0180] An embodiment of the present application further provides an electrical device, including the battery 100 provided in any one of the above embodiments.

[0181] In addition, if Figure 4-Figure 6 As shown, an embodiment of the present application also provides a cylindrical battery 100, comprising an outer shell 1, an electrode assembly 2, an electrode terminal 3, and a current collecting member 4. The electrode assembly 2 is housed within the outer shell 1. The outer shell 1 comprises a shell body 11 and an end cap 12. The shell body 11 has an opening, and the end cap 12 closes the opening of the shell body 11. The end cap 12 is provided with a first reinforcement portion 131. The end cap 12 includes a first region 132 located on the outer periphery of the first reinforcement portion 131 and a second region 133 located on the inner periphery of the first reinforcement portion 131. A second reinforcement portion 135 is provided on the first region 132. Both the first reinforcement portion 131 and the second reinforcement portion 135 extend along the circumference of the end cap 12. The second region 133 includes a first connecting portion 1322 connecting the first reinforcement portion 131 and the second reinforcement portion 135. The first connecting portion 1322 is located on the outer periphery of the first reinforcement portion 131, and the second reinforcement portion 135 is located on the outer periphery of the first connecting portion 1322. The first connection portion 1322 is formed with a weak portion 1321, which is configured to rupture when the battery cell 10 releases pressure. The second region 133 is provided with a liquid injection hole 1331. The electrode terminal 3 is provided at the end of the housing 1 opposite the end cap 12. The positive tab 21a of the electrode assembly 2 is electrically connected to the electrode terminal 3 via a current collecting member 4, and the negative tab 21b of the electrode assembly 2 is electrically connected to the second reinforcement portion 135 via another current collecting member 4.

[0182] In such a battery cell 10, when the electrolyte is injected into the battery cell 10 through the injection hole 1331, the second region 133 is easily deformed toward the inside of the battery cell 10 due to the extrusion force applied by the injection device. The first reinforcement portion 131 can reduce the impact of the deformation of the second region 133 on the weak portion 1321, thereby reducing the deformation of the weak portion 1321, and reducing the risk of the weak portion 1321 being deformed during the process of injecting electrolyte into the battery cell 10 through the injection hole 1331, thereby increasing the service life of the battery cell 10.

[0183] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0184] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, wherein the electrode assembly is a wound structure; a housing for accommodating the electrode assembly, wherein the housing has a wall portion, and along a thickness direction of the wall portion, the wall portion is arranged opposite to the electrode assembly; The wall portion is provided with a protruding first reinforcement portion, the first reinforcement portion extends along the circumference of the wall portion, the wall portion includes a first area located on the outer circumference of the first reinforcement portion, the first area is formed with a weak portion, the weak portion is configured to rupture when the battery cell releases pressure, the first area is provided with a protruding second reinforcement portion, the second reinforcement portion extends along the circumference of the wall portion, the first area includes a first connecting portion, the first connecting portion connects the first reinforcement portion and the second reinforcement portion, the first connecting portion is located on the outer circumference of the first reinforcement portion, and the second reinforcement portion is located on the outer circumference of the first connecting portion; Wherein, the weak portion is formed at the first connecting portion.

2. The battery cell according to claim 1, wherein: The wall portion further includes a second region located on an inner circumferential side of the first reinforcement portion, and the second region is provided with a liquid injection hole.

3. The battery cell according to claim 2, characterized in that: The liquid injection hole is coaxially arranged with the first reinforcement portion.

4. The battery cell according to claim 1, wherein: Along the thickness direction of the wall portion, the first reinforcement portion is protruded on a side of the wall portion facing the electrode assembly.

5. The battery cell according to claim 4, characterized in that Along a thickness direction of the wall portion, the first reinforcement portion abuts against the electrode assembly.

6. The battery cell according to claim 4, characterized in that Along the thickness direction of the wall portion, a first recess is provided at a position corresponding to the first reinforcement portion on a side of the wall portion away from the electrode assembly.

7. The battery cell according to claim 1, wherein A width of the first reinforcement portion along the radial direction of the wall portion is a1, an inner diameter of the first reinforcement portion is r1, and a radius of the wall portion is R, which satisfies: 0.05≤a1 / R≤0.8; and / or 0.05≤r1 / R≤0.

8.

8. The battery cell according to claim 1, wherein: The second reinforcement portion is protruding from the side of the first area facing the electrode assembly. Along the thickness direction of the wall portion, the second reinforcement portion has a first surface facing the electrode assembly, and the first surface abuts against the electrode assembly to achieve electrical connection between the wall portion and the electrode assembly.

9. The battery cell according to claim 8, characterized in that Along the direction in which the wall portion points toward the electrode assembly, the first reinforcement portion does not extend beyond the first surface.

10. The battery cell according to claim 8, characterized in that The first reinforcement portion has a second surface facing the electrode assembly along a thickness direction of the wall portion, and the second surface is flush with the first surface.

11. The battery cell according to claim 8, characterized in that Along the thickness direction of the wall portion, the wall portion has a third surface that is away from the electrode assembly and farthest from the first surface. Along the thickness direction of the wall portion, the first connecting portion is located between the first surface and the third surface.

12. The battery cell according to claim 11, characterized in that The first region further includes an edge portion, the edge portion being connected to the second reinforcement portion and being located on an outer peripheral side of the second reinforcement portion; Along the thickness direction of the wall portion, a surface of the edge portion facing away from the electrode assembly is the third surface.

13. The battery cell according to claim 11, characterized in that Along the thickness direction of the wall, the distance between the third surface and the first surface is H, the height of the first reinforcement portion protruding from the wall is h1, and the height of the second reinforcement portion protruding from the wall is h2, satisfying: 0.1≤h1 / H≤0.9; and / or, 0.1≤h2 / H≤0.

9.

14. The battery cell according to claim 8, wherein Along the thickness direction of the wall portion, a second recess is provided at a position corresponding to the second reinforcement portion on a side of the first region away from the electrode assembly.

15. The battery cell according to claim 8, characterized in that The second reinforcement portion is welded to the electrode assembly to achieve electrical connection between the wall portion and the electrode assembly; or The battery cell further includes a current collecting member disposed between the wall portion and the electrode assembly along a thickness direction of the wall portion, the current collecting member being connected to the electrode assembly, and the second reinforcing portion being welded to the current collecting member to achieve electrical connection between the wall portion and the electrode assembly.

16. The battery cell according to claim 1, wherein Along the radial direction of the wall portion, the width of the second reinforcement portion is a2, the radius of the wall portion is R, the distance from the outer edge of the second reinforcement portion to the outer edge of the wall portion is L1, and the spacing between the first reinforcement portion and the second reinforcement portion is L2, satisfying: 0.05≤a2 / R≤0.8; and / or, 0.02≤L1 / R≤0.8; and / or, 0.05≤L2 / R≤0.

8.

17. The battery cell according to claim 1, characterized in that Along the thickness direction of the wall portion, the first connection portion partially protrudes to form a third reinforcement portion, the third reinforcement portion extends along the circumference of the wall portion, and the weak portion is formed in the third reinforcement portion.

18. The battery cell according to claim 17, wherein: The width of the third reinforcement portion along the radial direction of the wall portion is a3, and the radius of the wall portion is R, which satisfies: 0.05≤a3 / R≤0.

8.

19. The battery cell according to any one of claims 1 to 7, characterized in that: The first region is provided with a notch, and the first region forms the weak portion at a position where the notch is provided.

20. The battery cell according to claim 19, wherein The notch is arranged around the first reinforcement portion; The notch is a non-enclosed structure with a distance between the end portions; or The notch is a closed structure with both ends connected.

21. The battery cell according to any one of claims 1 to 7, characterized in that: The housing comprises: a shell having an opening formed at one end, the shell having a bottom wall opposite to the opening; an end cover connected to the housing and closing the opening; Wherein, one of the bottom wall and the end cover is the wall portion.

22. The battery cell according to any one of claims 1 to 7, characterized in that: The battery cell further includes an electrode terminal. The electrode terminal is disposed at an end of the housing opposite to the wall portion along a thickness direction of the wall portion. The electrode terminal is electrically connected to the electrode assembly.

23. The battery cell according to claim 22, characterized in that Along the thickness direction of the wall portion, the electrode terminal has a first outer surface facing away from the electrode assembly, and the electrode terminal is provided with a groove recessed from the first outer surface in a direction approaching the electrode assembly. The electrode terminal forms a second connecting portion at the position where the groove is provided, and the second connecting portion is connected to the electrode assembly.

24. The battery cell according to claim 23, characterized in that The battery cell further includes a blocking member connected to the electrode terminal and blocking the groove; along the thickness direction of the wall portion, the blocking member has a second outer surface facing away from the electrode assembly, and the second outer surface is flush with the first outer surface.

25. A battery, characterized in that: include: Box; The battery cell according to any one of claims 1 to 24, wherein the battery cell is accommodated in the box.

26. An electrical device, characterized in that: Comprising the battery of claim 25.

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