Battery cell, battery, electrical equipment, and manufacturing method and equipment for battery cell

Abstract

The present application provides a battery cell, a battery, an electrical device, a method for manufacturing a battery cell, and an apparatus, and relates to the field of batteries. The battery cell includes a shell, an electrode assembly, and an end cap. The shell includes a side wall and a bottom wall, the side wall being arranged around the bottom wall, and the side wall and the bottom wall together defining a receiving cavity with an opening at one end. The electrode assembly is arranged in the receiving cavity. The end cap is used to cover the opening. The side wall includes a main body and an end portion, the main body being connected to the bottom wall, and the end portion being connected to an end of the main body away from the bottom wall. The outer peripheral surface of the end cap is welded to the inner surface of the end portion. A first step surface is formed between the inner surface of the end portion and the inner surface of the main body portion, and the first step surface is configured to limit the movement of the end cap in a direction close to the bottom wall. A first step surface is formed on the inner surface of the shell of the battery cell, and the first step surface can position the end cap when installing the end cap, and can also shield the laser when welding the outer peripheral surface of the end cap to the inner surface of the end portion to prevent the laser from burning the electrode assembly.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to a battery cell, a battery, an electrical device, and a method and equipment for manufacturing a battery cell. Background Art

[0002] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. Currently, there are two main methods for battery packaging: crimping the end cap and housing, and laser welding the end cap and housing. Batteries packaged with welded packaging have a low yield rate. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a battery cell, a battery, an electrical device, a method for manufacturing a battery cell, and an apparatus, which are intended to improve the problem of low yield of welded packaged batteries.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and an end cover. The shell includes a side wall and a bottom wall, the side wall is arranged around the bottom wall, and the side wall and the bottom wall together define a receiving cavity with an opening at one end. The electrode assembly is arranged in the receiving cavity. The end cover is used to cover the opening. The side wall includes a main body and an end portion, the main body portion is connected to the bottom wall, the end portion is connected to an end of the main body portion away from the bottom wall, and the outer peripheral surface of the end portion is welded to the inner surface of the end portion. A first step surface is formed between the inner surface of the end portion and the inner surface of the main body portion, and the first step surface is configured to limit the movement of the end cover in a direction close to the bottom wall.

[0005] In the above technical solution, the side walls and bottom wall of the housing define a cavity for accommodating the electrode assembly. The electrode assembly is housed within the cavity, and the end cap seals the opening of the cavity, isolating the electrode assembly from the external environment. A first stepped surface is formed between the inner surface of the end portion of the housing and the inner surface of the main body. The end cap faces the first stepped surface. The first stepped surface not only positions the end cap during installation but also shields the laser beam during welding between the outer circumference of the end cap and the inner surface of the end portion, preventing the laser beam from irradiating and potentially burning the electrode assembly.

[0006] As an optional technical solution of the embodiment of the present application, the end cover is supported on the first step surface.

[0007] In the above technical solution, since metal vapor is generated during laser welding, the end cover is held against the first step surface so that there is no gap between the end cover and the first step surface. This limits the metal vapor from entering the receiving cavity, thereby preventing the metal vapor from damaging the electrode assembly in the receiving cavity.

[0008] As an optional technical solution of an embodiment of the present application, the end cover includes an end cover body, an edge portion and a connecting portion, the end cover body is connected to the edge portion through the connecting portion, the outer peripheral surface of the edge portion is connected to the inner surface of the end portion, the connecting portion extends from the end cover body radially outward along the shell and toward the bottom wall, and the edge portion extends from the connecting portion in a direction away from the bottom wall.

[0009] In the above technical solution, the end cover body and the edge portion are connected by a connecting portion, and the connecting portion extends from the end cover body radially outward along the shell and toward the bottom wall, and the edge portion extends from the connecting portion in a direction away from the bottom wall. This is equivalent to forming a recess on the side of the end cover close to the bottom wall, so that the space enclosed by the end cover and the main body is increased, which is beneficial to increasing the energy density of the battery cell.

[0010] As an optional technical solution of an embodiment of the present application, along the direction away from the bottom wall, the side of the end cover body away from the bottom wall does not exceed the end.

[0011] In the above technical solution, by ensuring that the side of the end cover body away from the bottom wall does not exceed the end, the battery cells are made more regular, and when the battery cells are installed in the box, the space in the box will not be wasted. For example, if the side of the end cover body away from the bottom wall exceeds the end, when the battery cells are installed in the box, there will be an unusable gap between the box and the end, which will waste space in the box.

[0012] As an optional technical solution of the embodiment of the present application, the side of the end cover body away from the bottom wall is flush with the end portion.

[0013] In the above technical solution, by aligning the side of the end cap body away from the bottom wall with the end portion, the battery cells are more neatly arranged, eliminating wasted space within the box when the battery cells are installed. Furthermore, when the side of the end cap body away from the bottom wall is aligned with the end portion, the end cap body and the end portion can jointly support the battery cells, preventing them from tipping over. Furthermore, when the end cap is installed on the end portion, positioning is more precise.

[0014] As an optional technical solution in an embodiment of the present application, the end portion includes a first portion and a second portion. The second portion is connected to the main body via the first portion, and the first portion extends from the main body in a direction away from the bottom wall. The outer peripheral surface of the end cap is welded to the inner surface of the first portion. The second portion extends radially inward from the first portion along the housing and covers the weld between the end cap and the first portion.

[0015] In the above technical solution, the welding position is more likely to rust due to contact with moisture in the air. By extending the second part radially inward from the first part to shield the welding position between the end cover and the first part, the welding position is protected, the possibility of the welding position contacting with moisture in the air is reduced, and the service life of the battery cell is extended.

[0016] As an optional technical solution of the embodiment of the present application, a protrusion is formed on one end of the second part away from the first part, and the protrusion is hooked on a side of the edge portion facing the connecting portion.

[0017] In the above technical solution, by making the second part cover the welding position between the end cover and the first part, and making the protrusion hook on the side of the edge portion facing the connecting portion, the shielding effect of the welding position between the end cover and the first part is improved, and the possibility of the welding position contacting with moisture in the air is further reduced, thereby extending the service life of the battery cell.

[0018] As an optional technical solution of the embodiment of the present application, the inner surface of the end portion is provided with a notch, and the notch is located between the first part and the second part.

[0019] In the above technical solution, a notch is provided between the first and second parts. During manufacturing, the first and second parts can be formed by bending the end portion at the location of the notch. The notch facilitates consistent positioning of the first and second parts of multiple housings produced, ensuring process consistency. Furthermore, by adjusting the location of the notch, the size of the second part can also be adjusted.

[0020] As an optional technical solution of an embodiment of the present application, the battery cell further includes a sealing layer, which is located between the second portion and the edge portion.

[0021] In the above technical solution, a sealing layer is provided between the second portion and the edge portion to isolate the welding position from the air, thereby preventing the welding position from coming into contact with moisture in the air and rusting, thereby extending the service life of the battery cell.

[0022] As an optional technical solution of an embodiment of the present application, the angle between the connecting portion and the edge portion is α, which satisfies 30°≤α≤65°.

[0023] In the above technical solution, if the angle α between the connection portion and the edge portion is less than 30°, the connection portion will block the current collecting tray of the battery cell. If the angle α between the connection portion and the edge portion is greater than 65°, the distance between the end cap body and the bottom wall is small, that is, the space enclosed by the end cap and the body is small, and the energy density of the battery cell is low.

[0024] In a second aspect, an embodiment of the present application further provides a battery comprising a battery cell according to any one of the above items.

[0025] As an optional technical solution in an embodiment of the present application, the outer surface of the end portion protrudes from the outer surface of the main body to form a second stepped surface between the outer surface of the end portion and the outer surface of the main body. The battery also includes a thermal management component disposed on the second stepped surface and in contact with the outer surface of the main body.

[0026] In the above technical solution, the outer surface of the end portion is made to protrude from the outer surface of the main body, thereby forming a second stepped surface between the outer surface of the end portion and the outer surface of the main body. The second stepped surface can be used to place and position the thermal management component. Furthermore, the thermal management component is placed on the second stepped surface so that it can contact the outer surface of the main body, facilitating heat exchange between the thermal management component and the electrode assembly within the main body, thereby controlling the temperature of the electrode assembly.

[0027] As an optional technical solution of an embodiment of the present application, the width of the second step surface in the radial direction of the shell is less than half the thickness of the thermal management component.

[0028] In the above technical solution, by making the width of the second stepped surface in the radial direction of the housing less than half the thickness of the thermal management component, it is easier to install the thermal management component between two battery cells, allowing the thermal management component to simultaneously adhere to the main bodies of both battery cells. If the width of the second stepped surface in the radial direction of the housing is greater than half the width of the thermal management component, the thermal management component, when installed between the two battery cells, will only fully contact the main body of one battery cell, while a gap will exist between the thermal management component and the main body of the other battery cell.

[0029] In a third aspect, an embodiment of the present application further provides an electrical device, which includes the above-mentioned battery, and the battery is used to provide electrical energy.

[0030] Fourthly, an embodiment of the present application further provides a method for manufacturing a battery cell, which includes: providing a shell, the shell including side walls and a bottom wall, the side walls being arranged around the bottom wall, the side walls and the bottom wall jointly defining a receiving cavity with an opening at one end, the side walls including a main body and an end portion, the main body being connected to the bottom wall, the end portion being connected to an end of the main body away from the bottom wall, and a first step surface being formed between an inner surface of the end portion and an inner surface of the main body portion; providing an electrode assembly; providing an end cover; loading the electrode assembly into the receiving cavity from the opening, covering the opening with the end cover, and limiting the end cover from moving toward the bottom wall by the first step surface; and welding the outer peripheral surface of the end cover to the inner surface of the end portion along the axial direction of the shell.

[0031] In a fifth aspect, an embodiment of the present application further provides a manufacturing device for a battery cell, and the manufacturing device for the battery cell includes: a first providing device, a second providing device, a third providing device, a first assembly device, and a second assembly device. The first providing device is used to provide a shell, and the shell includes a side wall and a bottom wall. The side wall is arranged around the bottom wall, and the side wall and the bottom wall together define a receiving cavity with an opening at one end. The side wall includes a main body and an end portion, the main body portion is connected to the bottom wall, and the end portion is connected to an end of the main body portion away from the bottom wall, and a first step surface is formed between the inner surface of the end portion and the inner surface of the main body portion. The second providing device is used to provide an electrode assembly. The third providing device is used to provide an end cover. The first assembly device is used to load the electrode assembly into the receiving cavity from the opening, cover the end cover on the opening, and limit the end cover from moving in a direction close to the bottom wall by the first step surface. The second assembly device is used to weld the outer peripheral surface of the end cover to the inner surface of the end portion along the axial direction of the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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.

[0033] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0034] Figure 2 An exploded view of a battery provided in accordance with some embodiments of the present application;

[0035] Figure 3 An overall schematic diagram of a battery cell provided in some embodiments of the present application;

[0036] Figure 4 A schematic front view of a battery cell provided in some embodiments of the present application;

[0037] Figure 5 for Figure 4 Cross-sectional view at position V-V;

[0038] Figure 6 for Figure 5 Enlarged view of the middle VI position;

[0039] Figure 7 A schematic front view of a battery cell provided in some other embodiments of the present application;

[0040] Figure 8 for Figure 7 Cross-sectional view at position VIII-VIII;

[0041] Figure 9 for Figure 8 Enlarged view of the middle IX position;

[0042] Figure 10 A schematic front view of a battery cell provided in some other embodiments of the present application;

[0043] Figure 11 for Figure 10 Cross-sectional view at position Ⅺ-Ⅺ;

[0044] Figure 12 for Figure 11 Enlarged view of the middle XII position;

[0045] Figure 13 A schematic front view of a battery cell provided in some further embodiments of the present application;

[0046] Figure 14 for Figure 13 Cross-sectional view at position XIV-XIV;

[0047] Figure 15 for Figure 14 A magnified view of the XV position in the middle;

[0048] Figure 16 A schematic top view of multiple electrode assemblies provided in some embodiments of the present application;

[0049] Figure 17 for Figure 16 Cross-sectional view at position XVII-XVII;

[0050] Figure 18 for Figure 17 A magnified view of position XVIII in the middle;

[0051] Figure 19 A schematic diagram of a method for manufacturing a battery cell according to some embodiments of the present application;

[0052] Figure 20 A schematic diagram of a battery cell manufacturing device provided in some embodiments of the present application.

[0053] Icons: 10-box body; 11-upper box part; 12-lower box part; 20-battery cell; 21-end cover; 211-end cover body; 212-connecting part; 213-edge part; 22-shell; 221-bottom wall; 222-side wall; 2221-main body; 2222-end; 2222a-first part; 2222b-second part; 2223-first step surface; 2224-second step surface; 2225-protrusion; 23-electrode assembly; 30-thermal management component; 100-battery; 200-controller; 300-motor; 410-first providing device; 420-second providing device; 430-third providing device; 440-first assembling device; 450-second assembling device; 1000-vehicle. DETAILED DESCRIPTION

[0054] 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.

[0055] 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.

[0056] 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.

[0057] References to "embodiments" herein 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.

[0058] 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, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0059] 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).

[0060] 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.

[0061] 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.

[0062] In the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application are not limited to this.

[0063] 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.

[0064] A battery cell consists of an electrode assembly and an electrolyte (e.g., electrolyte solution). The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by allowing metal ions to move between the positive and negative electrode sheets. The separator is placed between the positive and negative electrode sheets to insulate them and prevent short circuits.

[0065] The battery cell further includes a shell and an end cover. The shell has an opening. The end cover covers the opening to form a closed space isolated from the outside space. The closed space is used to accommodate the electrode assembly, electrolyte and other functional components.

[0066] Currently, market developments indicate that batteries are increasingly being 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 cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0067] During the production process, the electrode assembly must be placed in the housing, and then the end caps must be attached to the housing. Currently, there are two main methods for battery packaging: crimping the end caps to the housing, and laser welding the end caps to the housing. Batteries packaged with welded packaging have a low yield rate.

[0068] After research, the inventors found that the reason for the low yield rate of welded packaged batteries is that the laser will irradiate the electrode assembly during welding, burning the electrode assembly. Specifically, one end of the shell is closed and the other end is open, and the electrode assembly is accommodated in the shell. When welding the end cap to the shell, it is necessary to first cover the end cap on the open end of the shell so that the outer peripheral surface of the end cap is close to the inner peripheral surface of the shell to close the open end of the shell. In this way, when the outer peripheral surface of the end cap is laser welded to the inner peripheral surface of the shell along the axial direction of the shell, the laser will directly penetrate into the shell along the gap between the outer peripheral surface of the end cap and the inner peripheral surface of the shell, and irradiate the electrode assembly inside the shell, thereby burning the electrode assembly and causing damage or destruction to the electrode assembly.

[0069] Based on the above considerations, the inventors conducted in-depth research and designed a battery cell, forming a first step surface on the inner wall of the shell, so that the first step surface is opposite to the end cover. In this way, when welding the outer peripheral surface of the end cover and the inner peripheral surface of the shell, the first step surface can block the laser to prevent the laser from irradiating the electrode assembly and burning the electrode assembly.

[0070] The shell includes a side wall and a bottom wall. The side wall is arranged around the bottom wall. The side wall and the bottom wall together define a receiving cavity with an opening at one end. The electrode assembly is arranged in the receiving cavity. The end cover is used to cover the opening. The side wall includes a main body and an end portion. The main body is connected to the bottom wall. The end portion is connected to the end of the main body away from the bottom wall. The outer peripheral surface of the end cover is welded to the inner surface of the end portion. A first step surface is formed between the inner surface of the end portion and the inner surface of the main body. The first step surface is configured to limit the movement of the end cover in a direction close to the bottom wall so as to position the end cover when the end cover is installed.

[0071] The battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, electrical equipment such as vehicles, ships, or aircraft.

[0072] The embodiments of the present application provide an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0073] 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.

[0074] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, to meet the power requirements for starting, navigating and driving the vehicle 1000.

[0075] In some embodiments of the present application, the battery 100 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.

[0076] Please refer to Figure 2 , Figure 2This is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10, battery cells 20, and a thermal management component 30. The battery cells 20 are housed within the housing 10, and the thermal management component 30 is attached to the battery cells 20. The housing 10 is used to provide a storage space for the battery cells 20 and can have various structures. In some embodiments, the housing 10 can include an upper housing portion 11 and a lower housing portion 12. The upper housing portion 11 and the lower housing portion 12 overlap each other, and the upper housing portion 11 and the lower housing portion 12 together define a storage space for the battery cells 20. The lower housing portion 12 can be a hollow structure with one end open, and the upper housing portion 11 can be a plate-like structure. The upper housing portion 11 overlaps the open side of the lower housing portion 12, so that the upper housing portion 11 and the lower housing portion 12 together define a storage space. Alternatively, the upper housing portion 11 and the lower housing portion 12 can each be a hollow structure with one end open, with the open side of the upper housing portion 11 overlapping the open side of the lower housing portion 12. Of course, the box body 10 formed by the upper box part 11 and the lower box part 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0077] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 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 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0078] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0079] Please refer to Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , Figure 3 This is a schematic diagram of a battery cell 20 provided in some embodiments of the present application. Figure 4 This is a schematic front view of a battery cell 20 provided in some embodiments of the present application. Figure 5 for Figure 4 The battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0080] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism, such as a pressure relief valve, for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this is not particularly limited in the present embodiment. In some embodiments, an insulating member can be provided on the inside of the end cap 21 to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Exemplary insulating members can be plastic, rubber, etc.

[0081] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 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.

[0082] The electrode assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs. One or more electrode assemblies 23 may be contained within the housing 22. The electrode assembly 23 is primarily formed by winding or stacking positive and negative electrode sheets, and a separator is typically provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active materials constitute the main body of the electrode assembly 23, while the portions of the positive and negative electrode sheets without active materials each constitute a tab. The positive and negative electrode tabs may be located together at one end of the main body or separately at both ends of the main body.

[0083] Please refer to Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , Figure 6 for Figure 5 An enlarged view of position VI in the middle. An embodiment of the present application provides a battery cell 20 comprising an end cap 21, a housing 22, and an electrode assembly 23. The housing 22 comprises sidewalls 222 and a bottom wall 221. The sidewalls 222 surround the bottom wall 221 and together define a receiving cavity with an opening at one end. The electrode assembly 23 is disposed within the receiving cavity. The end cap 21 covers the opening. The sidewall 222 comprises a main body 2221 and an end 2222. The main body 2221 is connected to the bottom wall 221, and the end 2222 is connected to the end of the main body 2221 away from the bottom wall 221. The outer circumferential surface of the end cap 21 is welded to the inner surface of the end 2222. A first step surface 2223 is formed between the inner surface of the end 2222 and the inner surface of the main body 2221. The first step surface 2223 is configured to restrict movement of the end cap 21 toward the bottom wall 221.

[0084] The bottom wall 221 and the side wall 222 may be integrally formed.

[0085] The end portion 2222 is located at one end of the side wall 222 away from the bottom wall 221. The opening of the housing 22 is formed at the end portion 2222, and the opening is opposite the bottom wall 221. The side wall 222 includes an inner surface and an outer surface. The inner surface is relatively close to the central axis of the housing 22, and the outer surface is relatively far from the central axis of the housing 22. The inner surface of the side wall 222 includes the inner surface of the end portion 2222 and the inner surface of the main body 2221.

[0086] The inner surface of the end portion 2222 is away from the central axis of the shell 22 relative to the inner surface of the main body 2221, so as to form a first step surface 2223 between the inner surface of the end portion 2222 and the inner surface of the main body 2221, and the first step surface 2223 connects the inner surface of the end portion 2222 and the inner surface of the main body 2221.

[0087] The end cover 21 is connected to the side wall 222 to close the opening of the receiving cavity to form an internal environment of the battery cell 20 .

[0088] The outer peripheral surface of the end cap 21 is the surface farthest from the central axis of the end cap 21 . The end cap 21 has a first surface facing the electrode assembly 23 . The central axis of the end cap 21 is perpendicular to the first surface and passes through the center of the first surface.

[0089] For example, the housing 22 is cylindrical, and the shape of the end cover 21 is adapted to the housing 22. Figure 3 , with reference Figure 4The end portion 2222 and the main body portion 2221 are both cylindrical, the axis of the end portion 2222 coincides with the axis of the main body portion 2221, and the inner diameter of the end portion 2222 is larger than the inner diameter of the main body portion 2221. Then, in the radial direction of the shell 22, there is a step between the inner surface of the main body portion 2221 and the inner surface of the end portion 2222, forming a first step surface 2223, which is a circular surface facing the opening.

[0090] During assembly, the first step surface 2223 limits the end cover 21 from moving toward the bottom wall 221 to position the end cover 21 , thereby facilitating assembly and improving assembly accuracy and efficiency.

[0091] When welding the end cover 21 to the end portion 2222, the laser is irradiated in a direction parallel to the central axis of the end cover 21, thereby welding the outer peripheral surface of the end cover 21 to the inner surface of the end portion 2222. The first step surface 2223 blocks the propagation direction of the laser to prevent the laser from directly irradiating the electrode assembly 23 and causing damage to the electrode assembly 23.

[0092] In addition, due to the limiting effect of the first step surface 2223, the end cover 21 can be prevented from excessively squeezing the electrode assembly 23, thereby preventing the electrode assembly 23 from being damaged by excessive force, resulting in powder loss (i.e., the active material on the electrode sheet falling off) and causing lithium plating problems, thereby improving the safety performance of the battery cell 20.

[0093] In some embodiments of the present application, the end cover 21 is supported on the first step surface 2223 .

[0094] “The end cover 21 is pressed against the first step surface 2223 ” means that the end cover 21 is pressed against the first step surface 2223 and has a certain contact force with the first step surface 2223 so that there is no gap between the end cover 21 and the first step surface 2223 , thereby allowing the end cover 21 to close the accommodating cavity of the shell 22 .

[0095] When the battery cell 20 is arranged with the bottom wall 221 at the bottom and the end cover 21 at the top, the end cover 21 abuts against the first step surface 2223 , and the first step surface 2223 supports the end cover 21 .

[0096] Since metal vapor is generated during laser welding, by holding the end cover 21 against the first step surface 2223, there is no gap between the end cover 21 and the first step surface 2223, thereby limiting the metal vapor from entering the receiving cavity and preventing the metal vapor from damaging the electrode assembly 23 in the receiving cavity.

[0097] In some embodiments of the present application, the end cover 21 includes an end cover body 211, an edge portion 213 and a connecting portion 212. The end cover body 211 is connected to the edge portion 213 through the connecting portion 212. The outer peripheral surface of the edge portion 213 is connected to the inner surface of the end portion 2222. The connecting portion 212 extends from the end cover body 211 radially outward along the shell 22 and toward the bottom wall 221, and the edge portion 213 extends from the connecting portion 212 in a direction away from the bottom wall 221.

[0098] Please refer to Figure 6 The edge portion 213 is the portion of the end cap 21 near the edge of the end cap 21 that connects to the inner surface of the end portion 2222. The end cap body 211 is the main portion of the end cap 21 near the center of the end cap 21 that seals the housing 22. The connecting portion 212 is the portion of the end cap 21 that connects the edge portion 213 and the end cap body 211. The outer circumference of the edge portion 213 is the outer circumference of the end cap 21.

[0099] For example, the end cap body 211 is disc-shaped, the edge portion 213 is cylindrical, and the connecting portion 212 extends obliquely upward from the end cap body 211 and is connected to the upper end of the edge portion 213, so that the projection of the edge portion 213 on the plane where the end cap body 211 lies falls outside the end cap body 211. In the axial direction of the housing 22, the distance between the end cap body 211 and the bottom wall 221 is greater than the distance between the edge portion 213 and the bottom wall 221.

[0100] The end cover body 211 and the edge portion 213 are connected by the connecting portion 212, and the axial upper edge portion 213 of the shell 22 is closer to the bottom wall 221 than the end cover body 211. This is equivalent to forming a recess on the side of the end cover 21 close to the bottom wall 221, so that the space enclosed by the end cover 21 and the shell 22 is increased, which is beneficial to increasing the energy density of the battery cell 20.

[0101] In some embodiments of the present application, along a direction away from the bottom wall 221 , a side of the end cover body 211 away from the bottom wall 221 does not exceed the end portion 2222 .

[0102] The side of the end cover body 211 away from the bottom wall 221 does not extend beyond the end portion 2222, which means that the surface of the end cover body 211 away from the bottom wall 221 is close to the bottom wall 221 relative to the surface of the end portion 2222 away from the bottom wall 221, or that the surface of the end cover body 211 away from the bottom wall 221 is flush with the surface of the end portion 2222 away from the bottom wall 221.

[0103] By ensuring that the side of the end cover body 211 away from the bottom wall 221 does not exceed the end 2222, the battery cell 20 is made more regular. When the battery cell 20 is installed in the box body 10, the space inside the box body 10 will not be wasted. For example, if the side of the end cover body 211 away from the bottom wall 221 exceeds the end 2222, when the battery cell 20 is installed in the box body 10, there will be an unusable gap between the box body 10 and the end 2222, which will waste the space inside the box body 10.

[0104] In some embodiments of the present application, a side of the end cover body 211 away from the bottom wall 221 is flush with the end portion 2222 .

[0105] That is, the surface of the end cover body 211 away from the bottom wall 221 is flush with the surface of the end 2222 away from the bottom wall 221, making the appearance of the battery cell 20 beautiful.

[0106] By aligning the side of the end cap body 211 away from the bottom wall 221 with the end 2222, the battery cells 20 are more neatly arranged, eliminating wasted space within the box 10 when the battery cells 20 are installed. Furthermore, when the side of the end cap body 211 away from the bottom wall 221 is aligned with the end 2222, the end cap body 211 and the end 2222 can jointly support the battery cells 20, preventing them from tipping over. Furthermore, positioning the end cap 21 is simplified when it is mounted on the end 2222.

[0107] In some embodiments of this application, please refer to Figure 6 The outer surface of the end portion 2222 protrudes from the outer surface of the main body 2221, and a first stepped surface 2223 is formed on the inner surface of the shell 22. The first stepped surface 2223 can be formed by bending the sidewall 222. The sidewall 222 is bent along the radial direction of the shell 22 so that the end portion 2222 protrudes from the main body 2221, thereby forming the first stepped surface 2223 at the bent position (the first stepped surface 2223 is located on the inner surface of the shell 22). Specifically, the sidewall 222 is bent so that the sidewall 222 first extends radially and then axially of the shell 22. The portion extending axially of the shell 22 after the bending is the end portion 2222, and the first stepped surface 2223 is formed on the portion extending radially of the shell 22. Bending the sidewall 222 to form the first stepped surface 2223 at the bent position facilitates processing of the shell 22.

[0108] In some embodiments of the present application, the shell 22 may also be cast, that is, the bottom wall 221 , the main body 2221 and the end portion 2222 are integrally formed.

[0109] Please refer to Figure 7 、 Figure 8 and Figure 9 , Figure 7 This is a schematic front view of a battery cell 20 provided in some other embodiments of the present application. Figure 8 for Figure 7 The cross-sectional view at position VIII-VIII, Figure 9 for Figure 8 In other embodiments of the present application, the first step surface 2223 can also be formed by thinning the side wall 222. Specifically, the thickness of the side wall 222 is thinned at the end 2222 to form the first step surface 2223 at the connection position between the end 2222 and the main body 2221.

[0110] “The thickness of the side wall 222 is thinned at the end portion 2222 ” means that the thickness of the main body 2221 is greater than the thickness of the end portion 2222 , and the inner diameter of the end portion 2222 is greater than the inner diameter of the main body 2221 , and the outer diameter of the end portion 2222 is equal to the outer diameter of the main body 2221 .

[0111] By thinning the shell 22 at the end 2222, the inner diameter of the end 2222 is made larger than the inner diameter of the main body 2221 to form a first step surface 2223, and the outer diameter of the end 2222 is equal to the outer diameter of the main body 2221. In this way, no steps will be formed on the outer peripheral surface of the shell 22, and the impact on other structures is relatively small (for example, there is no need to modify the existing box 10).

[0112] It should be noted that the housing 22 of the same structure can be manufactured by casting. The embodiment of the present application only provides one manufacturing method, and the above manufacturing method should not be considered as a limitation of the present application.

[0113] Optionally, the first step surface 2223 is parallel to an end of the electrode assembly 23 close to the end cover 21 .

[0114] In some embodiments of the present application, the thickness of the main body 2221 and the end cap 21 is 0.25 mm, and the length of the first step surface 2223 is between 0.05 and 0.2 mm, for example, 0.1 mm. In embodiments where the end portion 2222 is formed by thinning the side wall 222, the thickness of the end portion 2222 can be 0.15 mm. It should be noted that the thickness of the end portion 2222 must meet the strength requirements of the battery cell 20 and ensure that it can limit the end cap 21 to prevent damage to the end portion 2222 when the internal pressure of the battery cell 20 increases.

[0115] Please refer to Figure 10 、 Figure 11 and Figure 12 , Figure 10 This is a schematic front view of a battery cell 20 provided in some embodiments of the present application. Figure 11 for Figure 10The cross-sectional view at the Ⅺ-Ⅺ position, Figure 12 for Figure 11 An enlarged view of the center XII position. In an embodiment where the outer surface of the end portion 2222 protrudes from the outer surface of the main body and a first stepped surface 2223 is formed on the inner surface of the housing 22, the end portion 2222 includes a first portion 2222a and a second portion 2222b. The second portion 2222b is connected to the main body 2221 via the first portion 2222a. The first portion 2222a extends from the main body 2221 away from the bottom wall 221. The outer circumferential surface of the end cap 21 is welded to the inner surface of the first portion 2222a. The second portion 2222b extends radially inward from the first portion 2222a in the housing 22 and covers the weld between the end cap 21 and the first portion 2222a.

[0116] The shell 22 is cylindrical, and the first part 2222a extends along the axial direction of the shell 22. One end of the first part 2222a is connected to the main body 2221, and the other end of the first part 2222a is connected to the second part 2222b. The inner circumference of the first part 2222a is used for welding with the outer circumference of the end cover 21, specifically with the outer circumference of the edge part 213.

[0117] The second portion 2222b extends radially toward the central axis of the shell 22 , and one end of the second portion 2222b is connected to an end of the first portion 2222a away from the main body 2221 to shield the welding position between the end cover 21 and the first portion 2222a .

[0118] The welding position is more likely to rust due to contact with moisture in the air. By extending the second part 2222b from the first part 2222a radially inward along the shell 22, the welding position between the end cover 21 and the first part 2222a is shielded, the welding position is protected, the possibility of the welding position contacting moisture in the air is reduced, and the service life of the battery cell 20 is extended.

[0119] In some embodiments of the present application, a protrusion 2225 is formed at one end of the second portion 2222 b away from the first portion 2222 a , and the protrusion 2225 is hooked on a side of the edge portion 213 facing the connecting portion 212 .

[0120] A recess is formed between the inner surface of the edge portion 213 and the outer surface of the connecting portion 212. A protrusion 2225 is formed on one end of the second portion 2222b away from the first portion 2222a. The protrusion 2225 extends into the recess and hooks on the side of the edge portion 213 facing the connecting portion 212.

[0121] By making the second part 2222b cover the welding position between the end cover 21 and the first part 2222a, and making the protrusion 2225 hook on the side of the edge portion 213 facing the connecting portion 212, the shielding effect of the welding position between the end cover 21 and the first part 2222a is improved, further reducing the possibility of the welding position contacting moisture in the air, and extending the service life of the battery cell 20.

[0122] In some embodiments of the present application, a notch is provided on the inner surface of the end portion 2222 , and the notch is located between the first portion 2222 a and the second portion 2222 b .

[0123] The notch refers to a mark carved on the inner wall surface of the end portion 2222 , that is, a thinner area of the end portion 2222 , so as to reduce the difficulty of bending the end portion 2222 .

[0124] By providing a notch between the first portion 2222a and the second portion 2222b, the first portion 2222a and the second portion 2222b can be formed by bending the end portion 2222 at the location of the notch during manufacturing. The notch facilitates consistent positioning of the first portion 2222a and the second portion 2222b across multiple housings 22, ensuring process consistency. Furthermore, by adjusting the location of the notch, the size of the second portion 2222b can also be adjusted.

[0125] Optionally, a notch is provided between the protrusion 2225 and the second portion 2222b. During manufacturing, the second portion 2222b and the protrusion 2225 can be formed by bending the end portion 2222 at the location of the notch. The notch ensures that the second portions 2222b and protrusions 2225 of multiple housings 22 are positioned consistently across the production process, ensuring process consistency. Furthermore, by adjusting the location of the notch, the size of the protrusion 2225 can also be adjusted.

[0126] In some embodiments of the present application, the battery cell 20 further includes a sealing layer, which is located between the second portion 2222 b and the edge portion 213 .

[0127] The sealing layer is a structure capable of achieving a sealing effect. Optionally, the sealing layer is formed by applying glue between the second portion 2222b and the edge portion 213.

[0128] A sealing layer is provided between the second portion 2222 b and the edge portion 213 to isolate the welding position from the air, thereby preventing the welding position from coming into contact with moisture in the air and rusting, thereby extending the service life of the battery cell 20 .

[0129] In other embodiments of the present application, a sealing layer is provided between the edge portion 213 and the protrusion 2225. The sealing layer is formed by applying glue between the edge portion 213 and the protrusion 2225 to isolate the welding position from the air, prevent the welding position from coming into contact with moisture in the air and rusting, thereby extending the service life of the battery cell 20.

[0130] Please refer to Figure 13 、 Figure 14 and Figure 15 , Figure 13 This is a schematic front view of a battery cell 20 provided in some further embodiments of the present application. Figure 14 for Figure 13 The cross-sectional view at position XIV-XIV in the middle, Figure 15 for Figure 14 An enlarged view of the XV position in the middle. In the embodiment where the first stepped surface 2223 is formed by thinning the opposite sidewall 222, the end portion 2222 includes a first portion 2222a and a second portion 2222b. The second portion 2222b is connected to the main body 2221 via the first portion 2222a. The first portion 2222a extends from the main body 2221 away from the bottom wall 221. The outer circumferential surface of the end cap 21 is welded to the inner surface of the first portion 2222a. The second portion 2222b extends radially inward from the first portion 2222a in the housing 22 and covers the weld between the end cap 21 and the first portion 2222a.

[0131] The first portion 2222a extends axially along the housing 22. One end of the first portion 2222a is connected to the main body 2221, and the other end of the first portion 2222a is connected to the second portion 2222b. The inner circumference of the first portion 2222a is welded to the outer circumference of the end cover 21, specifically to the outer circumference of the edge portion 213. The second portion 2222b extends radially along the housing 22. One end of the second portion 2222b is connected to the end of the first portion 2222a away from the main body 2221. The second portion 2222b is used to shield the welding position between the end cover 21 and the first portion 2222a.

[0132] The welding position is more likely to rust due to contact with moisture in the air. By extending the second part 2222b from the first part 2222a radially inward along the shell 22, the welding position between the end cover 21 and the first part 2222a is shielded, the welding position is protected, the possibility of the welding position contacting moisture in the air is reduced, and the service life of the battery cell 20 is extended.

[0133] In some embodiments of the present application, a protrusion 2225 is formed at one end of the second portion 2222 b away from the first portion 2222 a , and the protrusion 2225 is hooked on a side of the edge portion 213 facing the connecting portion 212 .

[0134] Specifically, a recess is formed between the inner surface of the edge portion 213 and the outer surface of the connecting portion 212. A protrusion 2225 is formed on one end of the second portion 2222b away from the first portion 2222a. The protrusion 2225 extends into the recess to hook on the side of the edge portion 213 facing the connecting portion 212.

[0135] By making the second part 2222b cover the welding position between the end cover 21 and the first part 2222a, and making the protrusion 2225 hook on the side of the edge portion 213 facing the connecting portion 212, the shielding effect of the welding position between the end cover 21 and the first part 2222a is improved, further reducing the possibility of the welding position contacting moisture in the air, and extending the service life of the battery cell 20.

[0136] In some embodiments of the present application, the angle α between the connecting portion 212 and the edge portion 213 satisfies 30°≤α≤65°.

[0137] like Figure 6 As shown, the angle α between the connecting portion 212 and the edge portion 213 is the angle between the outer surface of the connecting portion 212 and the inner surface of the edge portion 213. The angle α between the connecting portion 212 and the edge portion 213 affects the degree of inclination of the connecting portion 212. The larger the angle α between the connecting portion 212 and the edge portion 213, the smaller the inclination of the connecting portion 212, which brings the end cover body 211 closer to the bottom wall 221. The smaller the angle α between the connecting portion 212 and the edge portion 213, the greater the inclination of the connecting portion 212, which brings the connecting portion 212 closer to the axis of the housing 22.

[0138] If the angle α between the connection portion 212 and the edge portion 213 is less than 30°, the connection portion 212 is too close to the axis of the housing 22 and may block the current collecting plate of the battery cell 20. If the angle α between the connection portion 212 and the edge portion 213 is greater than 65°, the distance between the end cap body 211 and the bottom wall 221 is small, that is, the space enclosed by the end cap 21 and the body 2221 is small, and the energy density of the battery cell 20 is low.

[0139] Optionally, the angle α between the connection portion 212 and the edge portion 213 is 54.8°. At this time, the energy density of the battery cell 20 is relatively large, and there is a large gap between the connection portion 212 and the current collecting plate of the battery cell 20, which will not block the current collecting plate of the battery cell 20. It should be noted that the angle α between the connection portion 212 and the edge portion 213 will also affect the distance between the end cover body 211 and the lower end of the edge portion 213. If the angle α between the connection portion 212 and the edge portion 213 is too small, the distance between the end cover body 211 and the lower end of the edge portion 213 is short, which will cause the protrusion 2225 to be unable to hook on the side of the edge portion 213 facing the connection portion 212. Optionally, the distance between the end cover body 211 and the lower end of the edge portion 213 is greater than 0.25 mm to allow the protrusion 2225 to hook on the side of the edge portion 213 facing the connection portion 212. For example, the distance between the end cap body 211 and the lower end of the edge portion 213 is greater than 0.5 mm.

[0140] The embodiment of the present application further provides a battery 100 , which includes the battery cell 20 described in any one of the above items.

[0141] Please refer to Figure 16 、 Figure 17 and Figure 18 , Figure 16 Schematic top view of multiple electrode assemblies 23 provided in some embodiments of the present application, Figure 17 for Figure 16 The cross-sectional view at position XVII-XVII, Figure 18 for Figure 17 An enlarged view of position XVIII in FIG. In some embodiments of the present application, the outer surface of the end portion 2222 protrudes from the outer surface of the main body 2221, forming a second stepped surface 2224 between the outer surface of the end portion 2222 and the outer surface of the main body 2221. The battery 100 also includes a thermal management component 30, which is positioned on the second stepped surface 2224 and contacts the outer surface of the main body 2221.

[0142] The sidewall 222 is bent radially of the housing 22 so that the end portion 2222 protrudes from the main body 2221, forming a second stepped surface 2224 at the bent position (the second stepped surface 2224 is located on the outer surface of the housing 22). Specifically, the sidewall 222 is bent so that it first extends radially and then axially of the housing 22. The portion extending axially of the housing 22 after the bend is the end portion 2222, while the second stepped surface 2224 is formed on the portion extending radially of the housing 22. It should be noted that the first stepped surface 2223 is located on the inner surface of the housing 22, while the second stepped surface 2224 is located on the outer surface of the housing 22. The outer diameter of the end portion 2222 is greater than the outer diameter of the main body 2221, and the second stepped surface 2224 connects the outer surface of the end portion 2222 and the outer surface of the main body 2221.

[0143] The thermal management component 30 is used to regulate the temperature of the battery cells 20. It can heat and / or cool the battery cells 20 to regulate their temperature, ensuring they operate at a suitable temperature and improving their performance. In some embodiments, the thermal management component 30 is an electric heating plate. In other embodiments, the thermal management component 30 is a water-cooled plate with a wavy cross-section. The water-cooled plate is positioned on the second stepped surface 2224 and adjacent to the outer wall of the housing 22 of the battery cells 20. Specifically, the battery cells 20 are arranged in a staggered array, with each cell 20 fitting within a recessed portion of the water-cooled plate. To increase the contact area between the water-cooled plate and the battery cells 20, the curvature of the recessed portion of the water-cooled plate is equal to the radius of the housing 22. The length of the water-cooled plate is less than or equal to the length of the main body 2221, ensuring that the water-cooled plate does not extend beyond the height of the battery cells 20.

[0144] By making the outer surface of the end portion 2222 protrude from the outer surface of the main body 2221, a second stepped surface 2224 is formed between the outer surface of the end portion 2222 and the outer surface of the main body 2221. The second stepped surface 2224 can be used to place and position the thermal management component 30. Furthermore, placing the thermal management component 30 on the second stepped surface 2224 allows the thermal management component 30 to contact the outer surface of the main body 2221, facilitating heat exchange between the thermal management component 30 and the electrode assembly 23 within the main body 2221, thereby controlling the temperature of the electrode assembly 23.

[0145] In some embodiments of the present application, the width of the second step surface 2224 in the radial direction of the housing 22 is less than half the thickness of the thermal management component 30 .

[0146] The width of the second step surface 2224 in the radial direction of the housing 22 is the difference between the outer diameter of the end portion 2222 and the outer diameter of the main body 2221 , that is, the length by which the end portion 2222 protrudes from the main body 2221 in the radial direction of the housing 22 .

[0147] By making the radial width of the second stepped surface 2224 of the housing 22 less than half the thickness of the thermal management component 30, it is easier to place the thermal management component 30 between two battery cells 20, allowing the thermal management component 30 to simultaneously adhere to the body portions 2221 of both battery cells 20. When the radial width of the second stepped surface 2224 of the housing 22 is greater than half the width of the thermal management component 30, the thermal management component 30 disposed between the two battery cells 20 can only fully contact the body portion 2221 of one battery cell 20, while a gap exists between the thermal management component 30 and the body portion 2221 of the other battery cell 20.

[0148] An embodiment of the present application further provides an electrical device, which includes the above-mentioned battery 100, and the battery 100 is used to provide electrical energy.

[0149] Please refer to Figure 19 The present embodiment further provides a method for manufacturing a battery cell 20. The method for manufacturing a battery cell 20 includes:

[0150] Step S1: Provide a shell 22, the shell 22 includes a side wall 222 and a bottom wall 221, the side wall 222 is arranged around the bottom wall 221, the side wall 222 and the bottom wall 221 together define a receiving cavity with an opening at one end, the side wall 222 includes a main body 2221 and an end 2222, the main body 2221 is connected to the bottom wall 221, the end 2222 is connected to the end of the main body 2221 away from the bottom wall 221, and a first step surface 2223 is formed between the inner surface of the end 2222 and the inner surface of the main body 2221.

[0151] Step S2: providing an electrode assembly 23;

[0152] Step S3: providing an end cap 21;

[0153] Step S4: insert the electrode assembly 23 into the receiving cavity through the opening, cover the opening with the end cap 21, and restrict the end cap 21 from moving toward the bottom wall 221 by the first step surface 2223;

[0154] Step S5 : welding the outer peripheral surface of the end cover 21 and the inner surface of the end portion 2222 along the axial direction of the shell 22 .

[0155] Please refer to Figure 20The embodiment of the present application also provides a manufacturing device for a battery cell 20. The manufacturing device for the battery cell 20 includes: a first providing device 410, a second providing device 420, a third providing device 430, a first assembly device 440, and a second assembly device 450. The first providing device 410 is used to provide a shell 22. The shell 22 includes a side wall 222 and a bottom wall 221. The side wall 222 is arranged around the bottom wall 221. The side wall 222 and the bottom wall 221 together define a receiving cavity with an opening at one end. The side wall 222 includes a main body 2221 and an end 2222. The main body 2221 is connected to the bottom wall 221. The end 2222 is connected to the end of the main body 2221 away from the bottom wall 221. A first step surface 2223 is formed between the inner surface of the end 2222 and the inner surface of the main body 2221. The second providing device 420 is used to provide the electrode assembly 23. The third providing device 430 is used to provide the end cap 21. The first assembly device 440 is used to install the electrode assembly 23 into the receiving cavity through the opening, cover the end cap 21 on the opening, and restrict the end cap 21 from moving toward the bottom wall 221 via the first step surface 2223. The second assembly device 450 is used to weld the outer peripheral surface of the end cap 21 to the inner surface of the end portion 2222 along the axial direction of the housing 22.

[0156] According to some embodiments of this application, please refer to Figures 3 to 15 .

[0157] The battery cell 20 includes an end cap 21, a shell 22, and an electrode assembly 23. The shell 22 includes a side wall 222 and a bottom wall 221. The side wall 222 is arranged around the bottom wall 221. The side wall 222 and the bottom wall 221 together define a receiving cavity with an opening at one end. The electrode assembly 23 is arranged in the receiving cavity. The end cap 21 is used to cover the opening. Among them, the side wall 222 includes a main body 2221 and an end 2222. The main body 2221 is connected to the bottom wall 221, and the end 2222 is connected to the end of the main body 2221 away from the bottom wall 221. The outer peripheral surface of the end cap 21 is welded to the inner surface of the end 2222. A first step surface 2223 is formed between the inner surface of the end 2222 and the inner surface of the main body 2221. The first step surface 2223 is configured to limit the movement of the end cap 21 in the direction close to the bottom wall 221.

[0158] The sidewalls 222 and bottom wall 221 of the housing 22 define a receiving cavity for accommodating the electrode assembly 23. The electrode assembly 23 is accommodated within the receiving cavity, and the end cap 21 seals the opening of the receiving cavity to isolate the electrode assembly 23 from the external environment. A first stepped surface 2223 is formed between the inner surface of the end portion 2222 of the housing 22 and the inner surface of the main body 2221. The end cap 21 faces the first stepped surface 2223. The first stepped surface 2223 not only positions the end cap 21 during installation, but also shields the laser when welding the outer circumference of the end cap 21 to the inner surface of the end portion 2222, thereby preventing the laser from irradiating the electrode assembly 23 and burning it.

[0159] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: A housing, the housing comprising side walls and a bottom wall, the side walls being arranged around the bottom wall, the side walls and the bottom wall jointly defining a receiving cavity having an opening at one end; an electrode assembly, disposed in the receiving cavity; an end cap, for covering the opening; The shell is cylindrical, and the shape of the end cover is adapted to the shell; The side wall includes a main body and an end portion, the main body is connected to the bottom wall, and the end portion is connected to an end of the main body away from the bottom wall. The outer peripheral surface of the end cover is welded to the inner surface of the end portion, and a first step surface is formed between the inner surface of the end portion and the inner surface of the main body, and the first step surface is configured to limit the movement of the end cover toward the bottom wall. The end cover includes an end cover body, an edge portion and a connecting portion, the end cover body is connected to the edge portion through the connecting portion, the outer peripheral surface of the edge portion is connected to the inner surface of the end portion, the connecting portion extends from the end cover body along the radial direction of the shell outward and toward the bottom wall, and the edge portion extends from the connecting portion in a direction away from the bottom wall.

2. The battery cell according to claim 1, wherein: The end cover is supported on the first step surface.

3. The battery cell according to claim 1, wherein: Along a direction away from the bottom wall, a side of the end cover body away from the bottom wall does not exceed the end portion.

4. The battery cell according to claim 3, characterized in that A side of the end cover body away from the bottom wall is flush with the end portion.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The end portion includes a first part and a second part, the second part is connected to the main body through the first part, the first part extends from the main body in a direction away from the bottom wall, the outer peripheral surface of the end cover is welded to the inner surface of the first part, and the second part extends from the first part inwardly along the radial direction of the shell and covers the welding position of the end cover and the first part.

6. The battery cell according to claim 5, characterized in that A protrusion is formed on one end of the second portion away from the first portion, and the protrusion is hooked on a side of the edge portion facing the connecting portion.

7. The battery cell according to claim 5, characterized in that The inner surface of the end portion is provided with a notch, and the notch is located between the first portion and the second portion.

8. The battery cell according to claim 5, characterized in that The battery cell further includes a sealing layer located between the second portion and the edge part.

9. The battery cell according to any one of claims 1 to 4, characterized in that: An included angle α between the connecting portion and the edge portion satisfies 30°≤α≤65°.

10. A battery, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 9.

11. The battery according to claim 10, characterized in that The outer surface of the end portion protrudes from the outer surface of the main body portion to form a second step surface between the outer surface of the end portion and the outer surface of the main body portion; The battery further includes a heat management component disposed on the second step surface and in contact with an outer surface of the body portion.

12. The battery according to claim 11, characterized in that A width of the second step surface in a radial direction of the housing is less than half a thickness of the heat management component.

13. An electrical device, characterized in that: The battery according to any one of claims 10 to 12 is used to provide electrical energy.

14. A method for manufacturing a battery cell, characterized in that: The manufacturing method of the battery cell includes: A housing is provided, the housing comprising a side wall and a bottom wall, the side wall being arranged around the bottom wall, the side wall and the bottom wall jointly defining a receiving cavity having an opening at one end, the side wall comprising a main body portion and an end portion, the main body portion being connected to the bottom wall, the end portion being connected to an end of the main body portion away from the bottom wall, and a first step surface being formed between an inner surface of the end portion and an inner surface of the main body portion; providing an electrode assembly; providing an end cover, the end cover comprising an end cover body, an edge portion, and a connecting portion, the end cover body being connected to the edge portion via the connecting portion, the outer peripheral surface of the edge portion being connected to the inner surface of the end portion, the connecting portion extending radially outward from the end cover body and toward the bottom wall of the housing, and the edge portion extending away from the bottom wall from the connecting portion; Inserting the electrode assembly into the receiving cavity through the opening, covering the opening with the end cover, and limiting the end cover from moving toward the bottom wall by the first step surface; The outer peripheral surface of the end cover and the inner surface of the end portion are welded along the axial direction of the shell.

15. A battery cell manufacturing device, characterized in that: The manufacturing equipment of the battery cell includes: A first providing device is configured to provide a housing, the housing comprising a side wall and a bottom wall, the side wall being disposed around the bottom wall, the side wall and the bottom wall jointly defining a receiving cavity having an opening at one end, the side wall comprising a main body portion and an end portion, the main body portion being connected to the bottom wall, the end portion being connected to an end of the main body portion away from the bottom wall, a first step surface being formed between an inner surface of the end portion and an inner surface of the main body portion; a second providing device for providing an electrode assembly; A third providing device is configured to provide an end cover, the end cover comprising an end cover body, an edge portion, and a connecting portion, the end cover body being connected to the edge portion via the connecting portion, an outer peripheral surface of the edge portion being connected to an inner surface of the end portion, the connecting portion extending radially outward from the end cover body toward the bottom wall of the housing, and the edge portion extending away from the bottom wall from the connecting portion; a first assembling device, configured to install the electrode assembly into the receiving cavity through the opening, cover the opening with the end cap, and restrict movement of the end cap toward the bottom wall via the first step surface; The second assembling device is used to weld the outer peripheral surface of the end cover and the inner surface of the end portion along the axial direction of the shell.

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