Battery monomer, battery, electric equipment, and manufacturing method and equipment of battery monomer

Abstract

The invention provides a battery monomer, a battery, electric equipment, and a manufacturing method and equipment of the battery monomer, and relates to the field of batteries. The battery monomer comprises a shell, an electrode assembly and an end cover, the shell comprises a side wall and a bottom wall, the side wall is arranged around the bottom wall in a surrounding mode, and the side wall and the bottom wall jointly define a containing cavity with an opening in one end. The electrode assembly is arranged in the accommodating cavity. The end cover is used for covering the opening. The side wall comprises a body part and an end part, the body part is connected to the bottom wall, and the end part is connected to the end, away from the bottom wall, of the body part. And the outer peripheral surface of the end cover is welded with the inner surface of the end part. A first step surface is formed between the inner surface of the end part and the inner surface of the body part, and the first step surface is configured to limit the end cover to move in the direction close to the bottom wall. The first step surface is formed on the inner surface of the shell of the battery monomer, and the first step surface can position the end cover when the end cover is mounted, and can shield laser when the outer peripheral surface of the end cover and the inner surface of the end part are welded, so that the laser is prevented from burning the electrode assembly.

Description

This application is a divisional application of the invention patent application with the application date of October 20, 2021, the application number of 202180089593.1, and the name of "Battery cell, battery, electric device, manufacturing method and equipment of battery cell". TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a battery cell, a battery, an electric device, a manufacturing method and equipment of a battery cell. BACKGROUND

[0002] Batteries are widely used in the field of new energy, such as electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automobile industry. At present, there are two main ways of battery packaging, one is the connection of the end cover and the shell by rolling and sealing, and the other is the laser welding of the end cover and the shell. The yield of the welded battery is low. SUMMARY

[0003] The purpose of the embodiments of the present application is to provide a battery cell, a battery, an electric device, a manufacturing method and equipment of a battery cell, which aims to improve the problem of low yield of welded batteries.

[0004] In a first aspect, the embodiments of the present application provide a battery cell, which comprises a shell, an electrode assembly and an end cover. The shell comprises a side wall and a bottom wall, the side wall is arranged around the bottom wall, and the side wall and the bottom wall jointly 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 comprises a body part and an end part, the body part is connected to the bottom wall, the end part is connected to one end of the body part away from the bottom wall, and the outer peripheral surface of the end cover is welded to the inner surface of the end part. A first step surface is formed between the inner surface of the end part and the inner surface of the body part, and the first step surface is configured to limit the movement of the end cover towards the bottom wall.

[0005] In the above technical solution, the side wall and the bottom wall of the shell surround a receiving cavity for accommodating the electrode assembly, the electrode assembly is accommodated in the receiving cavity, and the end cover seals the opening of the receiving cavity to isolate the electrode assembly from the external environment. A first step surface is formed between the inner surface of the end part of the shell and the inner surface of the body part, the end cover is opposite to the first step surface, the first step surface not only can position the end cover when the end cover is installed, but also can shield the laser when the outer peripheral surface of the end cover and the inner surface of the end part are welded, so as to prevent the electrode assembly from being burned by the laser.

[0006] As an optional technical solution of the embodiments of the present application, the end cover abuts against the first step surface.

[0007] In the technical scheme, metal vapor is generated during laser welding, and the end cover is abutted against the first step surface, so that no gap is formed between the end cover and the first step surface, thereby limiting the metal vapor from entering the accommodation cavity and avoiding damage to the electrode assembly in the accommodation cavity.

[0008] As an optional technical scheme of the embodiment, the end cover comprises an end cover body, an edge portion and a connecting portion, the end cover body is connected with the edge portion through the connecting portion, the outer peripheral surface of the edge portion is connected with the inner surface of the end portion, the connecting portion extends from the end cover body outward in the radial direction of the shell and towards the bottom wall, and the edge portion extends from the connecting portion away from the bottom wall.

[0009] In the technical scheme, the end cover body and the edge portion are connected through the connecting portion, and the connecting portion extends from the end cover body outward in the radial direction of the shell and towards the bottom wall, and the edge portion extends from the connecting portion away from the bottom wall, which is equivalent to forming a recess on one side of the end cover close to the bottom wall, so that the space surrounded by the end cover and the body portion is increased, which is beneficial to increasing the energy density of the battery monomer.

[0010] As an optional technical scheme of the embodiment, in the direction away from the bottom wall, the side of the end cover body away from the bottom wall does not exceed the end portion.

[0011] In the technical scheme, by making the side of the end cover body away from the bottom wall not exceeding the end portion, the battery monomer is more regular, and when the battery monomer is installed in the box, the space in the box is not wasted. For example, if the side of the end cover body away from the bottom wall exceeds the end portion, when the battery monomer is installed in the box, there is a gap between the box and the end portion that cannot be utilized, which wastes the space in the box.

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

[0013] In the technical scheme, by making the side of the end cover body away from the bottom wall flush with the end portion, the battery monomer is more regular, and when the battery monomer is installed in the box, the space in the box is not wasted. Moreover, when the side of the end cover body away from the bottom wall is flush with the end portion, the end cover body and the end portion can jointly support the battery monomer, so that the battery monomer is not prone to tilting. In addition, when the end cover is installed on the end portion, the positioning is more accurate.

[0014] As an optional technical scheme of the embodiment, the end portion comprises a first portion and a second portion, the second portion is connected to the body portion through the first portion, and the first portion extends from the body portion away from the bottom wall. The outer peripheral surface of the end cover is welded to the inner surface of the first portion. The second portion extends from the first portion inward in the radial direction of the shell and covers the welding position of the end cover and the first portion.

[0015] In the technical solution, the welding position is more likely to be contacted with moisture in the air and rusted, the second part is extended from the first part along the radial direction of the shell inwardly to shield the welding position of the end cover and the first part, the welding position is protected, the possibility of the welding position being contacted with moisture in the air is reduced, and the service life of the battery monomer is prolonged.

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

[0017] In the technical solution, the welding position of the end cover and the first part is shielded by the second part, the protrusion is hooked on the side of the edge portion facing the connecting portion, the shielding effect of the welding position of the end cover and the first part is improved, the possibility of the welding position being contacted with moisture in the air is further reduced, and the service life of the battery monomer is prolonged.

[0018] As an optional technical solution of the embodiment, 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 technical solution, the notch is arranged between the first part and the second part, the end portion is bent at the position of the notch during manufacturing to form the first part and the second part. By arranging the notch, the positions of the first part and the second part of the plurality of shells produced are easily ensured to be consistent, and the consistency of the process is ensured. Moreover, by adjusting the position of the notch, the size of the second part can also be adjusted.

[0020] As an optional technical solution of the embodiment, the battery monomer further comprises a sealing layer, and the sealing layer is located between the second part and the edge portion.

[0021] In the technical solution, the sealing layer is arranged between the second part and the edge portion to isolate the welding position from the air, so as to avoid the welding position being contacted with moisture in the air and rusted, and the service life of the battery monomer is prolonged.

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

[0023] In the technical solution, if the included angle α between the connecting portion and the edge portion is less than 30°, the connecting portion will block the current collecting disc of the battery monomer. If the included angle α between the connecting portion and the edge portion is greater than 65°, the distance between the end cover body and the bottom wall is small, that is, the space surrounded by the end cover and the body portion is small, and the energy density of the battery monomer is small.

[0024] In a second aspect, the embodiment also provides a battery, which comprises the battery monomer in any one of the above.

[0025] As an optional technical solution of the embodiment of the application, the outer surface of the end portion protrudes from the outer surface of the body portion to form a second stepped surface between the outer surface of the end portion and the outer surface of the body portion. The battery further comprises a thermal management component, which is arranged on the second stepped surface and in contact with the outer surface of the body portion.

[0026] In the above technical solution, by making the outer surface of the end portion protrude from the outer surface of the body portion, a second stepped surface is formed between the outer surface of the end portion and the outer surface of the body portion, and the second stepped surface can be used to arrange and position the thermal management component. Moreover, by arranging the thermal management component on the second stepped surface, the thermal management component can be in contact with the outer surface of the body portion, so as to facilitate heat exchange between the thermal management component and the electrode assembly in the body portion, thereby controlling the temperature of the electrode assembly.

[0027] As an optional technical solution of the embodiment of the application, the width of the second stepped 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 shell less than half the thickness of the thermal management component, the thermal management component can be arranged between two battery monomers, so that the thermal management component is simultaneously attached to the body portions of the two battery monomers. When the width of the second stepped surface in the radial direction of the shell is greater than half the width of the thermal management component, the thermal management component arranged between the two battery monomers can only be in full contact with the body portion of one battery monomer, and there will be a gap between the body portion of the other battery monomer.

[0029] In a third aspect, the embodiment of the application further provides a power consumption device, which comprises the battery described above and is used to provide electric energy.

[0030] In a fourth aspect, the embodiment of the application further provides a manufacturing method of a battery monomer, which comprises the following steps: providing a shell, the shell comprising a side wall and a bottom wall, the side wall being arranged around the bottom wall, the side wall and the bottom wall together defining a receiving cavity having an opening at one end, the side wall comprising a body portion and an end portion, the body portion being connected to the bottom wall, the end portion being connected to one end of the body portion away from the bottom wall, and a first stepped surface being formed between the inner surface of the end portion and the inner surface of the body portion; providing an electrode assembly; providing an end cover; loading the electrode assembly into the receiving cavity from the opening, covering the end cover on the opening, and limiting the movement of the end cover in the direction close to the bottom wall through the first stepped surface; and welding the outer peripheral surface of the end cover and the inner surface of the end portion in the axial direction of the shell.

[0031] In a fifth aspect, the embodiments of the present application further provide a battery cell manufacturing device, which comprises a first providing device, a second providing device, a third providing device, a first assembling device and a second assembling device. The first providing device is configured to provide a shell, which comprises a side wall and a bottom wall, the side wall is arranged around the bottom wall, and the side wall and the bottom wall jointly define a receiving cavity with an opening at one end. The side wall comprises a body portion and an end portion, the body portion is connected to the bottom wall, the end portion is connected to one end of the body portion away from the bottom wall, and a first step surface is formed between an inner surface of the end portion and an inner surface of the body portion. The second providing device is configured to provide an electrode assembly. The third providing device is configured to provide an end cover. The first assembling device is configured to load the electrode assembly into the receiving cavity from the opening, cover the end cover on the opening, and limit the movement of the end cover towards the bottom wall through the first step surface. The second assembling device is configured to weld the outer circumferential surface of the end cover and the inner surface of the end portion along the axial direction of the shell. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

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

[0034] Figure 2 An exploded view of a battery is provided for some embodiments of the present application;

[0035] Figure 3 A whole schematic diagram of a battery cell is provided for some embodiments of the present application;

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

[0037] Figure 5 A sectional view of the position I-I in FIG. 1 is provided for some embodiments of the present application; Figure 4 An enlarged view of the position VI in FIG. 1 is provided for some embodiments of the present application;

[0038] Figure 6 A sectional view of the position VIII-VIII in FIG. 1 is provided for some embodiments of the present application; Figure 5 A front view schematic diagram of a battery cell is provided for some embodiments of the present application;

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

[0040] Figure 8 A sectional view of the position I-I in FIG. 1 is provided for some embodiments of the present application; Figure 7 An enlarged view of the position VI in FIG. 1 is provided for some embodiments of the present application;

[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] Icon: 10 - box; 11 - upper box portion; 12 - lower box portion; 20 - battery cell; 21 - end cap; 211 - end cap body; 212 - connecting portion; 213 - edge portion; 22 - case; 221 - bottom wall; 222 - side wall; 2221 - body portion; 2222 - end portion; 2222a - first portion; 2222b - second portion; 2223 - first step surface; 2224 - second step surface; 2225 - protrusion; 23 - electrode assembly; 30 - thermal management member; 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 embodiments of the present application will be described below in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, but cannot be used to limit the protection scope of the present application.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising," "having," and "including" and any variations thereof are intended to cover a non-exclusive inclusion; the terms "consisting essentially of and "consisting of are intended to cover a non-exclusive inclusion of the recited elements.

[0056] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0057] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0058] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are A, A and B, and B. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0059] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0060] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular 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 explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing", and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0062] In the present application, the battery cell can include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium-sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, etc. The embodiments of the present application are not limited thereto.

[0063] The battery referred to in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application can include a battery module or a battery pack, etc. The battery generally includes a box for packaging one or more battery cells. The box can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cell.

[0064] The battery cell includes an electrode assembly and an electrolyte (e.g., an electrolyte solution), and the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The separator is used to be disposed between the positive electrode sheet and the negative electrode sheet to insulate the positive electrode sheet and the negative electrode sheet and avoid short circuit.

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

[0066] At present, from the development of market situation, the application of battery is more and more widely. The battery is not only applied to the energy storage power system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, military equipment, aerospace and other fields. With the continuous expansion of the application field of battery, the demand of its market is also increasing.

[0067] In the production process, the electrode assembly needs to be installed in the shell, and then the end cover is connected to the shell. At present, there are two ways for battery packaging, one is that the end cover and the shell are connected by roll sealing, and the other is that the end cover and the shell are laser welded. The yield of the battery packaged by welding is low.

[0068] The inventor found that the reason why the yield of the battery packaged by welding is low is that the laser will irradiate on the electrode assembly during welding, and burn 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 cover to the shell, the end cover needs to be covered on the open end of the shell, so that the outer peripheral surface of the end cover 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 cover and the inner peripheral surface of the shell are laser welded along the axial direction of the shell, the laser will directly enter the shell through the gap between the outer peripheral surface of the end cover and the inner peripheral surface of the shell, and irradiate on the electrode assembly in the shell, and then burn the electrode assembly, causing damage or destruction of the electrode assembly.

[0069] Based on the above consideration, the inventor designs a battery cell after in-depth research, a first step surface is formed on the inner wall of the shell, so that the first step surface is opposite to the end cover. In this way, when the outer peripheral surface of the end cover and the inner peripheral surface of the shell are welded, the first step surface can block the laser to prevent the laser from irradiating on 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, and the side wall and the bottom wall jointly define a receiving cavity having 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 body portion and an end portion, the body portion is connected to the bottom wall, the end portion is connected to one end of the body portion away from the bottom wall, and the outer peripheral surface of the end cover is welded to the inner surface of the end portion. The first step surface is formed between the inner surface of the end portion and the inner surface of the body portion, and the first step surface is configured to limit the movement of the end cover towards the bottom wall to position the end cover when the end cover is installed.

[0071] The battery cell disclosed in the embodiments of the present application can be used in electric equipment such as vehicles, ships or aircraft, but is not limited thereto.

[0072] The embodiments of the present application provide a power consumption device using a battery as a power supply. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, and the like. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, an electric aircraft toy, and the like. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0073] The following embodiments are described by taking a power consumption device of an embodiment of the present application as a vehicle 1000 for example for convenience of description.

[0074] Please refer to Figure 1 , Figure 1 A structural schematic diagram of the vehicle 1000 is provided for some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile. The new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile. The vehicle 1000 is internally provided with a battery 100. The battery 100 can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can 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 working power demand of the vehicle 1000 during starting, navigation, and driving.

[0075] In some embodiments of the present application, the battery 100 can not only be used as an operating power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0076] Please refer to Figure 2 , Figure 2An exploded view of a battery 100 is provided for some embodiments of the present application. The battery 100 includes a box 10, battery cells 20 and a thermal management component 30. The battery cells 20 are accommodated in the box 10, and the thermal management component 30 is attached to the battery cells 20. The box 10 is used to provide an accommodation space for the battery cells 20, and the box 10 can adopt various structures. In some embodiments, the box 10 can include an upper box portion 11 and a lower box portion 12. The upper box portion 11 and the lower box portion 12 are mutually covered, and together define an accommodation space for accommodating the battery cells 20. The lower box portion 12 can be a hollow structure with one end open, and the upper box portion 11 can be a plate-shaped structure. The upper box portion 11 covers the open side of the lower box portion 12, so that the upper box portion 11 and the lower box portion 12 together define the accommodation space. Alternatively, the upper box portion 11 and the lower box portion 12 can both be hollow structures with one side open, and the open side of the upper box portion 11 covers the open side of the lower box portion 12. Of course, the box 10 formed by the upper box portion 11 and the lower box portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0077] In the battery 100, the battery cells 20 can be multiple. The multiple battery cells 20 can be connected in series, in parallel or in a mixed manner. The mixed manner means that the multiple battery cells 20 are connected in series and in parallel. The multiple battery cells 20 can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery cells 20 is accommodated in the box 10. Of course, the battery 100 can also be that the multiple battery cells 20 are first connected in series, in parallel or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, in parallel or in a mixed manner to form a whole, and the whole is accommodated in the box 10. The battery 100 can further include other structures. For example, the battery 100 can further include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0078] Each battery cell 20 can be a secondary battery or a primary battery. The battery cell 20 can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can have a cylindrical shape, a flat shape, a cuboid shape or other shapes, etc.

[0079] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , Figure 3 A whole schematic view of a battery cell 20 is provided for some embodiments of the present application, Figure 4 A front view schematic view of a battery cell 20 is provided for some embodiments of the present application, Figure 5 is a sectional view of the position V-V in Figure 4 . The battery cell 20 includes an end cover 21, a shell 22, an electrode assembly 23 and other functional components.

[0080] The end cover 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 21 can be adapted to the shape of the shell 22 to fit the shell 22. Optionally, the end cover 21 can be made of a material with certain hardness and strength, such as aluminum alloy, so that the end cover 21 is less likely to deform when subjected to extrusion collision, and the battery cell 20 can have higher structural strength and improved safety performance. In some embodiments, the end cover 21 can also be provided with a pressure relief mechanism, such as a pressure relief valve, for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cover 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the present application does not make special limitations on this. In some embodiments, an insulating member can also be provided on the inner side of the end cover 21, which can be used to isolate the electrical connection components in the shell 22 from the end cover 21 to reduce the risk of short circuit. For example, the insulating member can be plastic, rubber, etc.

[0081] The shell 22 is a component for fitting the end cover 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte and other components. The shell 22 and the end cover 21 can be independent components, and an opening can be provided on the shell 22, and the end cover 21 is covered on the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 21 and the shell 22 can also be integrated, specifically, the end cover 21 and the shell 22 can form a common connecting surface before other components enter the shell, and when it is necessary to seal the inside of the shell 22, the end cover 21 is covered on the shell 22. The shell 22 can be various shapes and various sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the present application does not make special limitations on this.

[0082] The electrode assembly 23 is a component in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 can be contained in the shell 22. The electrode assembly 23 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have a portion with active material constituting the main body of the electrode assembly 23, and a portion without active material constituting the tab of the positive electrode sheet and the negative electrode sheet, respectively. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or at two ends of the main body, respectively.

[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 body portion 2221 are both in a cylindrical shape, the axis of the end portion 2222 coincides with the axis of the body portion 2221, and the inner diameter of the end portion 2222 is larger than the inner diameter of the body portion 2221, so that in the radial direction of the shell 22, there is a gap between the inner surface of the body portion 2221 and the inner surface of the end portion 2222, forming a first step surface 2223, and the first step surface 2223 is a circular ring surface facing the opening.

[0090] When assembling, the first step surface 2223 limits the movement of the end cover 21 towards the bottom wall 221, so as to position the end cover 21, thereby facilitating assembly, improving assembly accuracy and assembly efficiency.

[0091] When welding the end cover 21 to the end portion 2222, the laser is parallel to the central axis direction of the end cover 21, so as to weld the outer peripheral surface of the end cover 21 to the inner surface of the end portion 2222, and the first step surface 2223 blocks the propagation direction of the laser, so as to avoid direct irradiation of the laser on the electrode assembly 23 and 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 pressing the electrode assembly 23, so as to avoid damage to the electrode assembly 23 due to excessive force, and to avoid the problem of lithium precipitation caused by the falling of active substances on the electrode plate, thereby improving the safety performance of the battery monomer 20.

[0093] In some embodiments of the present application, the end cover 21 abuts against the first step surface 2223.

[0094] The "end cover 21 abuts 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, and the end cover 21 seals the accommodation cavity of the shell 22.

[0095] When the battery monomer 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 abutting 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, so that the metal vapor is limited from entering the accommodation cavity, and damage to the electrode assembly 23 in the accommodation cavity is avoided.

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

[0098] Please refer to Figure 6 The edge portion 213 is a portion of the end cover 21 close to an edge of the end cover 21 and used to connect with the inner surface of the end portion 2222. The end cover body 211 is a portion of the end cover 21 close to a middle portion of the end cover 21 and used to close a main portion of the shell 22. The connecting portion 212 is a portion of the end cover 21 connecting the edge portion 213 and the end cover body 211. The outer peripheral surface of the edge portion 213 is the outer peripheral surface of the end cover 21.

[0099] Exemplarily, the end cover body 211 is in a disc shape, the edge portion 213 is in a cylindrical shape, and the connecting portion 212 extends obliquely upward from the end cover body 211 and is connected to an upper end of the edge portion 213, so that a projection of the edge portion 213 on a plane where the end cover body 211 is located falls outside the end cover body 211. In an axial direction of the shell 22, the distance between the end cover body 211 and the bottom wall 221 is farther 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 through the connecting portion 212, and in the axial direction of the shell 22, the edge portion 213 is closer to the bottom wall 221 than the end cover body 211, which is equivalent to forming a recess on a 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 monomer 20.

[0101] In some embodiments of the present application, in 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 exceed the end portion 2222 means that a surface of the end cover body 211 away from the bottom wall 221 is close to the bottom wall 221 relative to a surface of the end portion 2222 away from the bottom wall 221, or 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 making the side of the end cover body 211 away from the bottom wall 221 not exceeding the end portion 2222, the battery monomer 20 is more regular, and when the battery monomer 20 is installed in the box body 10, the space in the box body 10 is not wasted. For example, if the side of the end cover body 211 away from the bottom wall 221 exceeds the end portion 2222, when the battery monomer 20 is installed in the box body 10, there is a gap between the box body 10 and the end portion 2222 that cannot be utilized, and the space in the box body 10 is wasted.

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

[0105] The side of the end cover body 211 away from the bottom wall 221 is flush with the end portion 2222, that is, 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, so that the appearance of the battery monomer 20 is beautiful.

[0106] By making the side of the end cover body 211 away from the bottom wall 221 flush with the end portion 2222, the battery monomer 20 is more regular, and when the battery monomer 20 is installed in the box body 10, the space in the box body 10 is not wasted. Moreover, when the side of the end cover body 211 away from the bottom wall 221 is flush with the end portion 2222, the end cover body 211 and the end portion 2222 can jointly support the battery monomer 20, so that the battery monomer 20 is not easy to tilt. In addition, when the end cover 21 is installed on the end portion 2222, the positioning is simpler.

[0107] In some embodiments of the present application, please refer to Figure 6 , the outer surface of the end portion 2222 protrudes from the outer surface of the body portion 2221, and the inner surface of the shell 22 is formed with a first step surface 2223. The first step surface 2223 can be formed by bending the side wall 222, and the side wall 222 is bent along the radial direction of the shell 22 so that the end portion 2222 protrudes from the body portion 2221 to form the first step surface 2223 at the bending position (the first step surface 2223 is located on the inner surface of the shell 22). Specifically, the side wall 222 is bent so that the side wall 222 first extends in the radial direction of the shell 22 and then extends in the axial direction of the shell 22. The portion of the side wall 222 that extends in the axial direction of the shell 22 after bending is the end portion 2222, and the first step surface 2223 is formed on the portion of the side wall 222 that extends in the radial direction of the shell 22. By bending the side wall 222, the first step surface 2223 is easily formed at the bending position, which facilitates the processing of the shell 22.

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

[0109] Please refer to Figure 7 ,Figure 8 and Figure 9 , Figure 7 a front view of the battery cell 20 provided by some embodiments of the present application, Figure 8 is Figure 7 a sectional view of the position VIII-VIII in FIG. 8, Figure 9 is Figure 8 an enlarged view of the position IX in FIG. 8. In some 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 portion 2222 to form the first step surface 2223 at the position where the end portion 2222 and the body portion 2221 are connected.

[0110] The "thickness of the side wall 222 is thinned at the end portion 2222" means that the thickness of the body portion 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 body portion 2221, and the outer diameter of the end portion 2222 is equal to the outer diameter of the body portion 2221.

[0111] By thinning the shell 22 at the end portion 2222, the inner diameter of the end portion 2222 is greater than the inner diameter of the body portion 2221 to form the first step surface 2223, and the outer diameter of the end portion 2222 is equal to the outer diameter of the body portion 2221, so that the outer circumferential surface of the shell 22 does not form a step, and has less influence on other structures (for example, there is no need to modify the existing box 10).

[0112] It should be noted that the shell 22 with the same structure can also be manufactured by casting. The embodiments of the present application only provide a manufacturing method, and the above manufacturing method should not be considered as a limitation on the present application.

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

[0114] In some embodiments of the present application, the thickness of the body portion 2221 and the end cover 21 is 0.25 mm, and the length of the first step surface 2223 is between 0.05-0.2 mm, for example, 0.1 mm. In the embodiment in which 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 needs to meet the strength requirement of the battery cell 20, and ensure that the end cover 21 can be limited, so as to avoid 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 a front view of the battery cell 20 provided by some embodiments of the present application, Figure 11 is Figure 10A sectional view of the position XI-XI, Figure 12 For Figure 11 An enlarged view of the position XII. In the embodiment in which the outer surface of the end portion 2222 protrudes from the outer surface of the body, and the inner surface of the shell 22 is formed with the first stepped surface 2223, the end portion 2222 includes a first portion 2222a and a second portion 2222b, the second portion 2222b is connected to the body portion 2221 through the first portion 2222a, and the first portion 2222a extends from the body portion 2221 in a direction away from the bottom wall 221. The outer peripheral surface of the end cover 21 is welded to the inner surface of the first portion 2222a. The second portion 2222b extends from the first portion 2222a in a direction radially inward of the shell 22 and covers the welding position of the end cover 21 and the first portion 2222a.

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

[0117] The second portion 2222b extends along the radial direction of the shell 22 towards the central axis of the shell 22, and one end of the second portion 2222b is connected to the end of the first portion 2222a away from the body portion 2221, so as to shield the welding position of the end cover 21 and the first portion 2222a.

[0118] The welding position is more likely to be in contact with moisture in the air and rust. By extending the second portion 2222b from the first portion 2222a in a direction radially inward of the shell 22, the welding position of the end cover 21 and the first portion 2222a is shielded, the welding position is protected, the possibility of the welding position being in contact with moisture in the air is reduced, and the service life of the battery monomer 20 is prolonged.

[0119] In some embodiments of the present application, the end of the second portion 2222b away from the first portion 2222a is formed with a protrusion 2225, and the protrusion 2225 is hooked on the side of the edge portion 213 towards 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. The end of the second portion 2222b away from the first portion 2222a is formed with a protrusion 2225, and the protrusion 2225 extends into the recess and is hooked on the side of the edge portion 213 towards the connecting portion 212.

[0121] By shielding the welding position of the end cover 21 and the first portion 2222a by the second portion 2222b, the hooking of the protrusion 2225 towards the side of the edge portion 213 facing the connecting portion 212, the shielding effect of the welding position of the end cover 21 and the first portion 2222a is improved, the possibility of the welding position contacting moisture in the air is further reduced, and the service life of the battery monomer 20 is prolonged.

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

[0123] The notch refers to the trace of the inner wall surface of the end portion 2222, that is, the thin area of the thickness 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 position of the notch during manufacturing. By providing the notch, it is easy to ensure that the positions of the first portion 2222a and the second portion 2222b of the plurality of housings 22 produced are consistent, thereby ensuring the consistency of the process. Moreover, by adjusting the position of the notch, the size of the second portion 2222b can also be adjusted.

[0125] Optionally, a notch is also 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 position of the notch. By providing the notch, it is easy to ensure that the positions of the second portion 2222b and the protrusion 2225 of the plurality of housings 22 produced are consistent, thereby ensuring the consistency of the process. Moreover, by adjusting the position of the notch, the size of the protrusion 2225 can also be adjusted.

[0126] In some embodiments of the present application, the battery monomer 20 further comprises a sealing layer between the second portion 2222b and the edge portion 213.

[0127] The sealing layer is a structure that can achieve a sealing effect. Optionally, the sealing layer is formed by gluing between the second portion 2222b and the edge portion 213.

[0128] By providing a sealing layer between the second portion 2222b and the edge portion 213, the welding position is isolated from the air, thereby avoiding rust caused by the welding position contacting moisture in the air, and prolonging the service life of the battery monomer 20.

[0129] In some embodiments of the present application, a sealing layer is arranged between the edge portion 213 and the protrusion 2225, and the sealing layer is formed by coating glue between the edge portion 213 and the protrusion 2225 to isolate the welding position from air and avoid the welding position from contacting moisture in the air to rust, thereby prolonging the service life of the battery monomer 20.

[0130] Please refer to Figure 13 , Figure 14 and Figure 15 , Figure 13 the front view schematic diagram of the battery monomer 20 provided in some embodiments of the present application, Figure 14 is Figure 13 the sectional view of the position XIV-XIV in FIG. 22, Figure 15 is Figure 14 the enlarged view of the position XV in FIG. 22. In the embodiment in which the first step surface 2223 is formed by thinning the side wall 222, the end portion 2222 includes a first portion 2222a and a second portion 2222b, the second portion 2222b is connected to the body portion 2221 through the first portion 2222a, and the first portion 2222a extends from the body portion 2221 in a direction away from the bottom wall 221. The outer circumferential surface of the end cover 21 is welded to the inner surface of the first portion 2222a. The second portion 2222b extends from the first portion 2222a in the radial direction of the shell 22 and covers the welding position of the end cover 21 and the first portion 2222a.

[0131] The first portion 2222a extends in the axial direction of the shell 22, one end of the first portion 2222a is connected to the body portion 2221, and the other end of the first portion 2222a is connected to the second portion 2222b. The inner circumferential surface of the first portion 2222a is used for welding with the outer circumferential surface of the end cover 21, specifically the outer circumferential surface of the edge portion 213. The second portion 2222b extends in the radial direction of the shell 22, and one end of the second portion 2222b is connected to the end of the first portion 2222a away from the body portion 2221. The second portion 2222b is used to shield the welding position of the end cover 21 and the first portion 2222a.

[0132] The welding position is more likely to contact moisture in the air to rust. By extending the second portion 2222b from the first portion 2222a in the radial direction of the shell 22, the welding position of the end cover 21 and the first portion 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 monomer 20 is prolonged.

[0133] In some embodiments of the present application, the end of the second portion 2222b away from the first portion 2222a is formed with a protrusion 2225, and the protrusion 2225 is hooked on the 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 included angle a between the connecting portion 212 and the edge portion 213 is 54.8°. At this time, the energy density of the battery cell 20 is larger, and the connecting portion 212 has a larger gap with the current collecting plate of the battery cell 20 and does not block the current collecting plate of the battery cell 20. It should be noted that the included angle a between the connecting portion 212 and the edge portion 213 also affects the distance between the end cover body 211 and the lower end of the edge portion 213. If the included angle a between the connecting 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 can cause the protrusion 2225 to be unable to hook on the side of the edge portion 213 facing the connecting 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, so as to allow the protrusion 2225 to hook on the side of the edge portion 213 facing the connecting portion 212. For example, the distance between the end cover body 211 and the lower end of the edge portion 213 is greater than 0.5 mm.

[0140] The embodiments of the present application also provide a battery 100, which comprises the battery cell 20 in any of the above embodiments.

[0141] Please refer to Figure 16 , Figure 17 and Figure 18 , Figure 16 the top view of the plurality of electrode assemblies 23 provided in some embodiments of the present application, Figure 17 the sectional view of the XVII-XVII position in Figure 16 , and Figure 18 the enlarged view of the XVIII position in Figure 17 . In some embodiments of the present application, the outer surface of the end portion 2222 protrudes from the outer surface of the body portion 2221 to form a second stepped surface 2224 between the outer surface of the end portion 2222 and the outer surface of the body portion 2221. The battery 100 further comprises a thermal management component 30, which is arranged on the second stepped surface 2224 and in contact with the outer surface of the body portion 2221.

[0142] The side wall 222 is radially bent along the shell 22 so that the end portion 2222 protrudes from the body portion 2221 to form a second step surface 2224 at the bent position (the second step surface 2224 is located on the outer surface of the shell 22). Specifically, the side wall 222 is bent so that the side wall 222 first extends radially towards the shell 22 and then extends axially towards the shell 22, and the portion of the side wall 222 extending axially along the shell 22 is the end portion 2222, and the second step surface 2224 is formed on the portion of the side wall 222 extending radially along the shell 22. It should be noted that the first step surface 2223 is located on the inner surface of the shell 22, and the second step surface 2224 is located on the outer surface of the shell 22. The outer diameter of the end portion 2222 is greater than the outer diameter of the body portion 2221, and the second step surface 2224 connects the outer surface of the end portion 2222 and the outer surface of the body portion 2221.

[0143] The thermal management component 30 is a component for adjusting the temperature of the battery monomer 20, and the thermal management component 30 can heat and / or cool the battery monomer 20 to adjust the temperature of the battery monomer 20 so that the battery monomer 20 works in a suitable temperature environment and improves the performance of the battery monomer 20. In some embodiments, the thermal management component 30 is an electric heating plate. In other embodiments, the thermal management component 30 is a water cooling plate, the cross section of the water cooling plate is wavy, the water cooling plate is placed on the second step surface 2224 and close to the outer wall of the shell 22 of the plurality of battery monomers 20. Specifically, the plurality of battery monomers 20 are arranged in a staggered array, and each battery monomer 20 is attached to a concave portion of the water cooling plate. In order to increase the contact area between the water cooling plate and the battery monomer 20, the curvature of the concave portion of the water cooling plate is equal to the radius of the shell 22. The length of the water cooling plate is less than or equal to the length of the body portion 2221, so that the water cooling plate does not exceed the battery monomer 20 in the height direction of the battery monomer 20.

[0144] By protruding the outer surface of the end portion 2222 from the outer surface of the body portion 2221 to form the second step surface 2224 between the outer surface of the end portion 2222 and the outer surface of the body portion 2221, the second step surface 2224 can place the thermal management component 30 and position the thermal management component 30. And placing the thermal management component 30 on the second step surface 2224 makes the thermal management component 30 contact the outer surface of the body portion 2221, which facilitates the thermal management component 30 to exchange heat with the electrode assembly 23 in the body portion 2221 to control 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 shell 22 is less than half the thickness of the thermal management component 30.

[0146] The width of the second stepped surface 2224 in the radial direction of the shell 22 is the difference between the outer diameter of the end portion 2222 and the outer diameter of the body portion 2221. That is, in the radial direction of the shell 22, the length of the end portion 2222 protrudes from the body portion 2221.

[0147] By making the width of the second stepped surface 2224 in the radial direction of the shell 22 less than half the thickness of the thermal management component 30, the thermal management component 30 is facilitated to be arranged between two battery monomers 20 so that the thermal management component 30 simultaneously fits the body portions 2221 of the two battery monomers 20. When the width of the second stepped surface 2224 in the radial direction of the shell 22 is greater than half the width of the thermal management component 30, the thermal management component 30 arranged between two battery monomers 20 can only be in full contact with the body portion 2221 of one battery monomer 20, and there will be a gap between the body portion 2221 of the other battery monomer 20.

[0148] The embodiments of the present application also provide a battery 100, which comprises the battery monomer 20.

[0149] Please refer to Figure 19 The embodiments of the present application also provide a manufacturing method of the battery monomer 20, which comprises:

[0150] Step S1: providing a shell 22, the shell 22 comprising a side wall 222 and a bottom wall 221, the side wall 222 being arranged around the bottom wall 221, the side wall 222 and the bottom wall 221 together defining a receiving cavity with an opening at one end, the side wall 222 comprising a body portion 2221 and an end portion 2222, the body portion 2221 being connected to the bottom wall 221, the end portion 2222 being connected to one end of the body portion 2221 away from the bottom wall 221, and a first stepped surface 2223 being formed between the inner surface of the end portion 2222 and the inner surface of the body portion 2221.

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

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

[0153] Step S4: loading the electrode assembly 23 into the receiving cavity from the opening, covering the end cover 21 on the opening, and limiting the movement of the end cover 21 towards the bottom wall 221 by the first stepped surface 2223;

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

[0155] Please refer to Figure 20The application further provides a battery cell 20 manufacturing device, which comprises a first providing device 410, a second providing device 420, a third providing device 430, a first assembling device 440 and a second assembling device 450. The first providing device 410 is configured to provide a shell 22, which comprises a side wall 222 and a bottom wall 221, the side wall 222 is arranged around the bottom wall 221, and the side wall 222 and the bottom wall 221 jointly define a receiving cavity with an opening at one end. The side wall 222 comprises a body part 2221 and an end part 2222, the body part 2221 is connected to the bottom wall 221, the end part 2222 is connected to one end of the body part 2221 away from the bottom wall 221, and a first step surface 2223 is formed between the inner surface of the end part 2222 and the inner surface of the body part 2221. The second providing device 420 is configured to provide an electrode assembly 23. The third providing device 430 is configured to provide an end cover 21. The first assembling device 440 is configured to load the electrode assembly 23 into the receiving cavity from the opening, cover the end cover 21 on the opening, and limit the movement of the end cover 21 towards the bottom wall 221 through the first step surface 2223. The second assembling device 450 is configured to weld the outer peripheral surface of the end cover 21 and the inner surface of the end part 2222 along the axial direction of the shell 22.

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

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

[0158] The side wall 222 and the bottom wall 221 of the shell 22 enclose a receiving cavity for accommodating the electrode assembly 23, the electrode assembly 23 is accommodated in the receiving cavity, and the end cover 21 closes the opening of the receiving cavity to isolate the electrode assembly 23 from the external environment. A first step surface 2223 is formed between the inner surface of the end portion 2222 of the shell 22 and the inner surface of the body portion 2221, the end cover 21 is opposite to the first step surface 2223, the first step surface 2223 can not only position the end cover 21 when the end cover 21 is installed, but also shield the laser when the outer circumferential surface of the end cover 21 is welded with the inner surface of the end portion 2222, so as to avoid that the electrode assembly 23 is burned by the laser. The preferred embodiments of the present application have been described above with the aid of drawings, but the present application covers any variations and modifications within the spirit and scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope 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; In which, 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 in a direction close to 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: The inner diameter of the end portion is greater than the inner diameter of the main body portion, and the outer diameter of the main body portion is less than or equal to the outer diameter of the end portion.

4. The battery cell according to claim 1, wherein: 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.

5. The battery cell according to claim 5, characterized in that: 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.

6. The battery cell according to claim 5, characterized in that A side of the end cover body away from the bottom wall is flush with the end portion.

7. The battery cell according to claim 6, characterized in that One end of the edge portion facing away from the bottom wall is flush with the end portion.

8. The battery cell according to any one of claims 5 to 7, characterized in that: The edge portion and the end portion are both cylindrical structures.

9. The battery cell according to claim 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.

10. The battery cell according to claim 9, 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.

11. The battery cell according to claim 9, 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.

12. The battery cell according to claim 9, characterized in that The battery cell further includes a sealing layer located between the second portion and the edge part.

13. The battery cell according to any one of claims 4 to 7, characterized in that: An included angle α between the connecting portion and the edge portion satisfies 30°≤α≤65°.

14. A battery, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 13.

15. The battery according to claim 14, 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.

16. The battery according to claim 15, 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.

17. An electrical device, characterized in that: The battery according to any one of claims 14 to 16 is used to provide electrical energy.

18. A method for manufacturing a battery cell, characterized in that: The manufacturing method of the battery cell includes: A housing is provided, the housing being cylindrical and comprising a side wall and a bottom wall, the side wall being disposed around the bottom wall and jointly defining a receiving cavity having an opening at one end, the side wall comprising 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; providing an electrode assembly; Providing an end cover, wherein the shape of the end cover is adapted to the housing; 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.

19. 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 being cylindrical and 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 used to provide an end cover, wherein the shape of the end cover is adapted to the housing; 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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