Battery cell, manufacturing method and system thereof, battery and electric device

Abstract

The embodiments of the present application provide a battery cell, a manufacturing method and a manufacturing system thereof, a battery, and an electrical device. The battery cell includes: an electrode assembly, including a first and a second tab with opposite polarities, the electrode assembly also including a main body, the first and second tabs protruding from the main body; a shell for accommodating the electrode assembly, the shell including a barrel and a cover connected to the barrel, the barrel is arranged around the periphery of the electrode assembly, the cover is provided with an electrode lead-out hole, at least a portion of the cover is used to electrically connect the first connecting member and the first tab of the battery; and an electrode terminal for electrically connecting the second connecting member and the second tab of the battery, the electrode terminal is insulated and arranged on the cover and installed in the electrode lead-out hole, one of the cover and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell. The present application can improve the current capacity of the battery cell and simplify the structure of the battery cell.

Description

[0001] This application is a divisional application of the invention patent application with the application date of August 23, 2021, application number 202180024771.2, and name “Battery Cell, Manufacturing Method and Manufacturing System, Battery and Electrical Device”. Technical Field

[0002] The present application relates to the field of battery technology, and more particularly, to a battery cell and a manufacturing method and system thereof, a battery, and an electrical device. Background Art

[0003] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

[0004] In the development of battery technology, how to improve the current capacity of battery cells and simplify the structure of battery cells is a research direction in battery technology. Summary of the Invention

[0005] The present application provides a battery cell and a manufacturing method and system thereof, a battery, and an electrical device, which can improve the current capacity of the battery cell and simplify the structure of the battery cell.

[0006] In a first aspect, an embodiment of the present application provides a battery cell for a battery, comprising:

[0007] The electrode assembly includes a first electrode tab and a second electrode tab with opposite polarities, and the electrode assembly also includes a main body, the first electrode tab and the second electrode tab protruding from the main body;

[0008] a housing for accommodating the electrode assembly, the housing comprising a barrel and a cover connected to the barrel, the barrel being disposed around the periphery of the electrode assembly, the cover being provided with an electrode lead-out hole, at least a portion of the cover being used to electrically connect the first connecting member and the first tab of the battery; and

[0009] The electrode terminal is used to electrically connect the second connecting member and the second tab of the battery. The electrode terminal is insulated and arranged on the cover body and installed in the electrode lead-out hole. One of the cover body and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell.

[0010] In the above solution, by using the cover and electrode terminals as the output terminals, the battery cell structure can be simplified while ensuring the battery cell's current capacity. The cover and electrode terminals are located at the same end of the battery cell, allowing the first and second connecting members to be assembled to the same side of the battery cell. This simplifies the assembly process and improves the efficiency of assembling multiple battery cells into groups.

[0011] In some embodiments, the cover and the barrel are integrally formed. The integrally formed structure can omit the connection process of the cover and the barrel.

[0012] In some embodiments, the cover and the cylinder are split structures.

[0013] In some embodiments, the cover and the cylinder are connected by welding, riveting or bonding.

[0014] In some embodiments, the cover includes a connecting portion, the connecting portion is provided with an electrode lead-out hole, and at least a portion of the connecting portion is used to connect the first connecting member and the first electrode tab.

[0015] In the above solution, the bent portion can release stress during the molding process of the shell, reduce stress concentration, and lower the risk of shell rupture.

[0016] In some embodiments, the connecting portion includes a main body and a first recess. The main body is disposed around the periphery of the first recess and is configured to connect the first connecting member and the first tab. The first recess is recessed from the outer surface of the main body in a direction facing the electrode assembly. The electrode lead-out hole extends through the bottom wall of the first recess and connects the first recess to the interior of the housing. The battery cell also includes a first insulating member. The first recess is configured to accommodate at least a portion of the first insulating member. The portion of the first insulating member accommodated in the first recess is attached to the sidewalls and / or bottom wall of the first recess.

[0017] In the above solution, the provision of the first recess allows for positioning of the first insulating member, simplifying the assembly process. The first recess can accommodate at least a portion of the first insulating member, thereby reducing the size of the outer surface of the first insulating member protruding from the main body, thereby reducing the maximum size of the battery cell and improving energy density.

[0018] In some embodiments, the thickness of the main body is greater than the wall thickness of the barrel. The main body is used to connect to the first connecting member, so it needs to be thicker to ensure the connection strength between the main body and the first connecting member. Furthermore, a thicker main body can better support components such as the electrode terminals. The barrel primarily isolates the electrode assembly from the outside world and can be relatively thin to reduce the overall weight of the battery cell.

[0019] In some embodiments, the difference between the thickness D1 of the main body and the wall thickness D2 of the cylinder satisfies: 0.1 mm ≤ D1 - D2 ≤ 2 mm.

[0020] If D1-D2 is less than 0.1mm, then the thickness of the main body is too small or the thickness of the barrel is too large. A smaller thickness of the main body will result in insufficient strength, while a larger thickness of the barrel will result in excessive weight, affecting energy density. If D1-D2 is greater than 2mm, the difference in the amount of stretching of the main body and the barrel during the stretching process will be too large, and the barrel will be easily damaged during the stretching process. Therefore, in the embodiment of the present application, D1 and D2 meet the following requirements: 0.1mm ≤ D1-D2 ≤ 2mm.

[0021] In some embodiments, the barrel is cylindrical, the electrode lead-out hole is a circular hole, and the central axis of the barrel and the central axis of the electrode lead-out hole are arranged to coincide with each other.

[0022] In the above solution, the electrode lead-out hole is used to define the position of the electrode terminal. In this embodiment, the central axis of the electrode lead-out hole is aligned with the central axis of the barrel, so that at least part of the electrode terminal is located at the center of the cover. This reduces the requirements for the position accuracy of the electrode terminal when multiple battery cells are assembled into a group, simplifies the assembly process, and improves assembly efficiency.

[0023] In some embodiments, the inner radius L1 of the cylinder and the width L2 of the main body satisfy: 0.2≤L2 / L1≤0.8, and the width L2 of the main body is the difference between the outer radius and the inner radius of the main body.

[0024] In the above solution, assuming the inner radius L1 of the cylinder is constant, the width L2 of the main body is negatively correlated with the radius of the electrode lead-out hole. If the width L2 of the main body is too small, the main body's current capacity will be insufficient; if the width L2 of the main body is too large, the radius of the electrode lead-out hole will be too small, resulting in insufficient current capacity for the electrode terminals. The inventors have found through experiments that when the inner radius L1 of the cylinder and the width L2 of the main body satisfy the following relationship: 0.2 ≤ L2 / L1 ≤ 0.8, the current capacity of the main body and the current capacity of the electrode terminals can be better balanced, meeting the current capacity requirements of the battery cells.

[0025] In some embodiments, the main body is used to be welded with the first connecting member and a first welding area is formed on the main body. The first welding area is spaced apart from the first end of the bending portion, and the first end is used to connect to the main body.

[0026] In the above solution, the first welding area is spaced apart from the first end of the bent portion to reduce the risk of welding to the bent portion due to process errors during welding, reduce the possibility of cold welding, and ensure the connection strength between the main body and the first connecting member.

[0027] In some embodiments, the welding depth D3 of the first welding region and the thickness D1 of the body portion satisfy: 0.1≤D3 / D1≤0.8.

[0028] In the above scheme, if the value of D3 / D1 is too small, the volume of the first welding area will be too small, which will result in insufficient connection strength between the main body and the first connecting member and low flow capacity. Therefore, in this embodiment, the value of D3 / D1 is greater than or equal to 0.1 to ensure the connection strength and flow capacity between the main body and the first connecting member. If the value of D3 / D1 is too large, the power required for welding will also be too high, and the high temperature generated during welding will easily burn other components. In addition, if the value of D3 / D1 is too large, it will also increase the risk of the main body being melted through. After the main body is melted through, it is more likely to burn other components in the shell. Therefore, in the embodiment of the present application, the value of D3 / D1 is less than or equal to 0.8 to reduce the temperature during welding and reduce the risk of burning other components.

[0029] In some embodiments, the battery cell also includes a second insulating component, which includes an insulating body and an insulating protrusion protruding from the outer periphery of the insulating body. The insulating body is against the side of the main body facing the electrode assembly, and the insulating protrusion is provided on the side of the bending portion facing the electrode assembly. The surface of the insulating protrusion facing away from the electrode assembly is closer to the electrode assembly than the surface of the insulating body facing away from the electrode assembly, so as to form a second recess for avoiding the bending portion.

[0030] In the above solution, the insulating body can separate at least a portion of the main body from the electrode assembly, and the insulating protrusion can separate at least a portion of the bent portion from the electrode assembly. Thus, when the battery cell vibrates, this embodiment can reduce the risk of contact between the electrode assembly and the main body, as well as the risk of contact between the electrode assembly and the bent portion, thereby improving safety. In this embodiment, the second recess is provided to avoid interference between the bent portion and the second insulating member.

[0031] In some embodiments, the insulating protrusion extends beyond the second end portion of the bent portion in a direction facing the electrode assembly, and the second end portion is used to connect to the barrel.

[0032] In the above solution, the outer surface of the insulating protrusion is spaced apart from the inner surface of the bent portion to avoid interference between the insulating protrusion and the bent portion. The size of the insulating protrusion protruding from the insulating body is not affected by the bent portion, which can improve the isolation effect of the insulating protrusion.

[0033] In some embodiments, the inner surface of the insulating body is formed with a third recessed portion that is recessed away from the electrode assembly, and at least a portion of the electrode terminal is accommodated in the third recessed portion. The provision of the third recessed portion can reduce the space occupied by the second insulating member and the electrode terminal, thereby increasing the energy density of the battery cell.

[0034] In some embodiments, the thickness of the insulating body is greater than that of the main body. During welding of the main body and the first connecting member, heat is transferred to the insulating body. In this embodiment, the insulating body is made thicker than the main body to extend the heat transfer path and reduce the impact of heat on other components. The greater thickness of the insulating body in this embodiment ensures insulation even if the portion of the insulating body near the first welding area is burned.

[0035] In some embodiments, a protrusion is formed on the connecting portion at a position opposite the first recess, extending from the inner surface of the main body in a direction facing the electrode assembly. The connecting portion also includes a fourth recess, which is recessed from the top surface of the protrusion to the inner surface of the main body in a direction away from the electrode assembly. The battery cell also includes a second insulating member, the fourth recess being configured to accommodate at least a portion of the second insulating member, and the portion of the second insulating member accommodated in the fourth recess being attached to the sidewalls and / or bottom wall of the fourth recess.

[0036] In the above solution, by providing the convex portion, the thickness of the bottom wall of the first recess can be increased, thereby improving the strength of the bottom wall of the first recess and enabling the bottom wall of the first recess to effectively support the electrode terminal. The second insulating member can cover the main body from the inside to separate the electrode assembly from the main body, reducing the risk of contact and conduction between the electrode assembly and the main body when the battery cell vibrates, thereby improving safety performance. By providing the fourth recess, the second insulating member can be positioned, simplifying the assembly process. The fourth recess can accommodate at least a portion of the second insulating member, thereby fully utilizing the internal space of the housing and improving energy density.

[0037] In some embodiments, the cover body further includes a bending portion, the bending portion includes a first end portion for connecting to the connecting portion and a second end portion for connecting to the cylinder body, and the thickness of the bending portion gradually decreases from the first end portion to the second end portion.

[0038] In the above solution, the thickness of the bent portion changes gradually to adapt to the thickness difference between the connecting portion and the cylinder, smoothly connecting the cylinder and the connecting portion, reducing the risk of steps forming on the inner and outer surfaces of the shell and reducing stress concentration.

[0039] In some embodiments, the second tab is provided at one end of the electrode assembly facing the cover, and the first tab is provided at the other end of the electrode assembly facing away from the cover. The barrel is used to connect the first tab and the cover so that the first tab is electrically connected to the cover.

[0040] In the above solution, the first electrode tab and the second electrode tab are arranged at both ends of the electrode assembly, which can reduce the risk of conduction between the first electrode tab and the second electrode tab and increase the flow area of ​​the first electrode tab and the flow area of ​​the second electrode tab.

[0041] In some embodiments, the first tab is the negative electrode tab, and the housing is made of steel. The housing is electrically connected to the negative electrode tab, meaning the housing is in a low-potential state. The steel housing is less susceptible to corrosion by the electrolyte in this low-potential state, thus reducing safety risks.

[0042] In some embodiments, the cylinder has an opening at one end facing away from the cover, and the battery cell further includes a cover plate for closing the opening.

[0043] In a second aspect, an embodiment of the present application provides a battery, comprising: a battery cell according to any embodiment of the first aspect; a first connecting member connected to the cover; and a second connecting member connected to the electrode terminal.

[0044] In a third aspect, an embodiment of the present application provides an electrical device, comprising the battery of the second aspect, the battery being used to provide electrical energy.

[0045] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, comprising:

[0046] A housing and an electrode terminal are provided. The housing includes a cylinder and a cover connected to the cylinder. The cover is provided with an electrode lead-out hole. The cylinder has an opening at one end facing away from the cover. The electrode terminal is insulated and arranged on the cover and mounted in the electrode lead-out hole.

[0047] Providing an electrode assembly, the electrode assembly comprising a first electrode tab and a second electrode tab with opposite polarities;

[0048] Installing the electrode assembly into the housing so that the barrel surrounds the periphery of the electrode assembly and the second tab is electrically connected to the electrode terminal;

[0049] Providing a cover plate and connecting the cover plate to the barrel to close the opening of the barrel, and electrically connecting the first electrode tab to the cover plate so that the first electrode tab is electrically connected to the cover body via the cover plate and the barrel;

[0050] Among them, at least a portion of the cover is used to electrically connect the first connecting member and the first pole ear of the battery, the electrode terminal is used to electrically connect the second connecting member and the second pole ear of the battery, one of the cover and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell, and the electrode assembly also includes a main body, and the first pole ear and the second pole ear protrude from the main body.

[0051] In a fifth aspect, an embodiment of the present application provides a battery cell manufacturing system, comprising:

[0052] The first providing device is used to provide a housing and an electrode terminal, wherein the housing includes a cylinder and a cover connected to the cylinder, the cover is provided with an electrode lead-out hole, the cylinder has an opening at one end facing away from the cover, and the electrode terminal is insulated and arranged on the cover and mounted in the electrode lead-out hole;

[0053] A second providing device is used to provide an electrode assembly, wherein the electrode assembly includes a first electrode tab and a second electrode tab with opposite polarities;

[0054] a first assembly device for installing the electrode assembly into the housing so that the barrel is disposed around the periphery of the electrode assembly and the second tab is electrically connected to the electrode terminal;

[0055] A second assembly device is used to provide a cover plate, connect the cover plate to the barrel to close the opening of the barrel, and electrically connect the first electrode tab to the cover plate so that the first electrode tab is electrically connected to the cover plate via the cover plate and the barrel;

[0056] Among them, at least a portion of the cover is used to electrically connect the first connecting member and the first pole ear of the battery, the electrode terminal is used to electrically connect the second connecting member and the second pole ear of the battery, one of the cover and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell, and the electrode assembly also includes a main body, and the first pole ear and the second pole ear protrude from the main body. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] 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 of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0058] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0059] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0060] Figure 3 for Figure 2 An exploded schematic diagram of the battery module shown;

[0061] Figure 4 A partial cross-sectional schematic diagram of a battery provided in some embodiments of the present application;

[0062] Figure 5 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0063] Figure 6 for Figure 4 An enlarged schematic diagram of the battery shown at box A;

[0064] Figure 7 A partial cross-sectional schematic diagram of a battery cell housing provided in some embodiments of the present application;

[0065] Figure 8 for Figure 6 An enlarged schematic diagram of the battery shown at circle B;

[0066] Figure 9 A schematic structural diagram of a second insulating member of a battery cell provided in some embodiments of the present application;

[0067] Figure 10 for Figure 6 An enlarged schematic diagram of the battery shown at circle C;

[0068] Figure 11 A schematic structural diagram of an electrode terminal of a battery cell provided in some embodiments of the present application;

[0069] Figure 12 A schematic flow chart of a method for manufacturing a battery cell according to some embodiments of the present application;

[0070] Figure 13 A schematic block diagram of a battery cell manufacturing system provided in some embodiments of the present application.

[0071] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0072] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0073] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0074] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0075] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0076] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0077] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0078] The term "plurality" used in this application refers to two or more (including two).

[0079] 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.

[0080] 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. A battery generally includes a housing that encloses one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0081] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer, with the positive active material layer coated on the surface of the positive current collector. The positive current collector includes a positive current collector portion and a positive electrode tab protruding from the positive current collector portion. The positive current collector portion is coated with the positive active material layer, while at least a portion of the positive electrode tab is not coated with the positive active material layer. For example, in lithium-ion batteries, the positive current collector can be made of aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, among others. The negative electrode sheet includes a negative current collector and a negative active material layer, with the negative active material layer coated on the surface of the current collector. The negative current collector includes a negative current collecting portion and a negative electrode tab protruding from the negative current collecting portion. The negative current collecting portion is coated with the negative active material layer, while at least a portion of the negative electrode tab is uncoated with the negative active material layer. The negative current collector can be made of copper, and the negative active material layer includes a negative active material, such as carbon or silicon. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0082] In a battery, multiple battery cells are electrically connected via a busbar. To simplify the battery structure, the inventors arranged the positive and negative output electrodes of the battery cells at the same end of the battery cells, making it easier for the busbar to connect to the positive and negative output electrodes.

[0083] Battery cells are typically equipped with electrode terminals, which serve as output terminals. The inventors have attempted to place two electrode terminals at the same end of a battery cell, serving as the positive and negative output terminals of the battery cell, respectively. However, the inventors have discovered that for smaller battery cells, if two electrode terminals are placed at the same end, a relatively large distance between the two electrode terminals is required to facilitate assembly of the electrode terminals with the current collector. This compresses the size of the electrode terminals themselves, resulting in a smaller flow area for the electrode terminals, which in turn affects the flow capacity of the battery cell.

[0084] In view of this, an embodiment of the present application provides a technical solution, which uses the cover of the shell as the output pole and locates the cover and the electrode terminal at the same end of the battery cell, which can simplify the structure of the battery cell and ensure the current capacity of the battery cell.

[0085] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0086] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0087] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0088] Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application. Figure 1 As shown, a battery 2 is provided inside the vehicle 1, and the battery 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery 2 can be used to power the vehicle 1, for example, the battery 2 can be used as an operating power source for the vehicle 1.

[0089] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0090] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0091] Figure 2 Schematic diagram of the explosion of the battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a box 5 and a battery cell ( Figure 2 The battery cells are housed in the box body 5 .

[0092] The housing 5 is used to accommodate battery cells and can have various structures. In some embodiments, the housing 5 can include a first housing portion 51 and a second housing portion 52. The first housing portion 51 and the second housing portion 52 overlap each other and together define a storage space 53 for accommodating the battery cells. The second housing portion 52 can be a hollow structure with one end open. The first housing portion 51 is a plate-like structure, and the first housing portion 51 overlaps the open side of the second housing portion 52 to form the housing 5 with the storage space 53. The first housing portion 51 and the second housing portion 52 can also each be a hollow structure with one end open. The open side of the first housing portion 51 overlaps the open side of the second housing portion 52 to form the housing 5 with the storage space 53. Of course, the first housing portion 51 and the second housing portion 52 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0093] In order to improve the sealing performance after the first box body 51 and the second box body 52 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 51 and the second box body 52 .

[0094] Assuming that the first box portion 51 covers the top of the second box portion 52 , the first box portion 51 can also be referred to as an upper box cover, and the second box portion 52 can also be referred to as a lower box.

[0095] In battery 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery module can be housed within housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 6, and then multiple battery modules 6 can be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within housing 5.

[0096] Figure 3 for Figure 2 An exploded diagram of the battery module is shown.

[0097] In some embodiments, as Figure 3 As shown, there are multiple battery cells 7, which are first connected in series, in parallel, or in mixed series to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed series to form a whole, which is accommodated in a box.

[0098] The multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0099] Figure 4 A partial cross-sectional schematic diagram of a battery provided in some embodiments of the present application; Figure 5An exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 6 for Figure 4 An enlarged schematic diagram of the battery shown at box A; Figure 7 A partial cross-sectional schematic diagram of a battery cell housing provided in some embodiments of the present application; Figure 8 for Figure 6 An enlarged schematic diagram of the battery shown at circle B.

[0100] like Figures 4 to 8 As shown, the battery cell 7 of the embodiment of the present application includes: an electrode assembly 10, including a first pole tab 11 and a second pole tab 12 with opposite polarities; a shell 20, used to accommodate the electrode assembly 10, the shell 20 includes a barrel 21 and a cover 22 connected to the barrel 21, the barrel 21 is arranged around the outer periphery of the electrode assembly 10, the cover 22 is provided with an electrode lead-out hole 221, at least a portion of the cover 22 is used to electrically connect the first connecting member 81 and the first pole tab 11 of the battery 2; and an electrode terminal 30, used to electrically connect the second connecting member 82 and the second pole tab 12 of the battery 2, the electrode terminal 30 is insulated and arranged on the cover 22 and installed in the electrode lead-out hole 221, one of the cover 22 and the electrode terminal 30 is the positive output pole of the battery cell 7, and the other is the negative output pole of the battery cell 7.

[0101] The electrode assembly 10 includes a first electrode plate, a second electrode plate, and a separator, wherein the separator is used to separate the first electrode plate and the second electrode plate. The polarity of the first electrode plate and the second electrode plate are opposite. In other words, one of the first electrode plate and the second electrode plate is a positive electrode plate, and the other of the first electrode plate and the second electrode plate is a negative electrode plate.

[0102] The first pole piece, the second pole piece and the separator are all strip-shaped structures, and the first pole piece, the second pole piece and the separator are wound together to form a wound structure. The wound structure can be a cylindrical structure, a flat structure or a structure of other shapes.

[0103] From the appearance of the electrode assembly 10, the electrode assembly 10 includes a main body 13, a first electrode tab 11, and a second electrode tab 12. The first electrode tab 11 and the second electrode tab 12 protrude from the main body 13. The first electrode tab 11 is the portion of the first electrode sheet not coated with the active material layer, and the second electrode tab 12 is the portion of the second electrode sheet not coated with the active material layer. The first electrode tab 11 and the second electrode tab 12 are used to draw current from the main body 13.

[0104] The first electrode tab 11 and the second electrode tab 12 may extend from the same side of the main body 13 , or may extend from opposite sides thereof.

[0105] The first electrode tab 11 and the second electrode tab 12 may be respectively disposed on both sides of the main body 13 along the first direction X. In other words, the first electrode tab 11 and the second electrode tab 12 are respectively disposed at both ends of the electrode assembly 10 along the first direction X.

[0106] Optionally, the first pole tab 11 is wound around the central axis of the electrode assembly 10 in multiple turns, and the first pole tab 11 includes multiple turns of pole tab layers. After the winding is completed, the first pole tab 11 is generally cylindrical, and a gap is left between two adjacent turns of pole tab layers. The embodiment of the present application can process the first pole tab 11 to reduce the gap between the pole tab layers, so as to facilitate the connection of the first pole tab 11 with other conductive structures. For example, the embodiment of the present application can flatten the first pole tab 11 so that the end area of ​​the first pole tab 11 away from the main body 13 is gathered and gathered together; the flattening process forms a dense end face at the end of the first pole tab 11 away from the main body 13, reduces the gap between the pole tab layers, and facilitates the connection of the first pole tab 11 with other conductive structures. Alternatively, the embodiment of the present application can also fill the conductive material between two adjacent turns of pole tab layers to reduce the gap between the pole tab layers.

[0107] Optionally, the second electrode tab 12 is wound multiple times around the central axis of the electrode assembly 10, and the second electrode tab 12 includes multiple electrode tab layers. Exemplarily, the second electrode tab 12 is also flattened to reduce gaps between the electrode tab layers of the second electrode tab 12.

[0108] The housing 20 is a hollow structure, forming a space within it for accommodating the electrode assembly 10. The shape of the housing 20 can be determined based on the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is cylindrical, a cylindrical housing can be used; if the electrode assembly 10 is rectangular, a rectangular housing can be used. Optionally, both the electrode assembly 10 and the housing 20 are cylindrical; accordingly, the barrel 21 is cylindrical, and the cover 22 is a circular plate-like structure.

[0109] The cover 22 is electrically connected to the barrel 21 , and the cover 22 and the barrel 21 may have the same polarity.

[0110] The cover 22 and the barrel 21 can be an integral structure, that is, the housing 20 is an integrally formed component. Of course, the cover 22 and the barrel 21 can also be two components provided separately and then connected together by welding, riveting, bonding, etc.

[0111] The housing 20 is a hollow structure with one end open. Specifically, the end of the barrel 21 facing away from the cover 22 has an opening 211. The battery cell 7 also includes a cover plate 40, which covers the opening of the barrel 21 to seal the opening 211. The cover plate 40 can have various structures, for example, a plate-like structure.

[0112] The electrode lead-out hole 221 passes through the cover 22 to facilitate the electrical energy in the electrode assembly 10 to be led out of the housing 20. For example, the electrode lead-out hole 221 passes through the cover 22 along the first direction X.

[0113] The central axis of the electrode assembly 10 is a virtual straight line, which is parallel to the first direction X. The central axis of the electrode assembly 10 may pass through the electrode lead-out hole 221 or may be staggered with the electrode lead-out hole 221 , which is not limited in this embodiment.

[0114] The first tab 11 is electrically connected to the cover 22 . The first tab 11 can be directly electrically connected to the cover 22 or indirectly electrically connected to the cover 22 through other conductive structures. For example, the first tab 11 can be electrically connected to the cover 22 through the barrel 21 .

[0115] The second electrode tab 12 is electrically connected to the electrode terminal 30. The second electrode tab 12 may be directly electrically connected to the electrode terminal 30 or indirectly electrically connected to the electrode terminal 30 through other conductive structures.

[0116] The electrode terminal 30 is insulated from the cover 22 . Therefore, the electrode terminal 30 and the cover 22 may have different polarities, and the electrode terminal 30 and the cover 22 may serve as different output poles.

[0117] The electrode terminal 30 is fixed to the cover 22 . The electrode terminal 30 can be fixed as a whole to the outside of the cover 22 , or can extend into the interior of the housing 20 through the electrode lead-out hole 221 .

[0118] When the first tab 11 is a negative tab and the second tab 12 is a positive tab, the cover 22 is the negative output terminal of the battery cell 7, and the electrode terminal 30 is the positive output terminal of the battery cell 7. When the first tab 11 is a positive tab and the second tab 12 is a negative tab, the cover 22 is the positive output terminal of the battery cell 7, and the electrode terminal 30 is the negative output terminal of the battery cell 7.

[0119] In the battery 2 , a plurality of battery cells 7 are electrically connected by a busbar. The busbar includes a first connecting member 81 for connecting to the cover 22 of the battery cell 7 and a second connecting member 82 for connecting to the electrode terminal 30 of the battery cell 7 .

[0120] The first connecting member 81 can be connected to the cover 22 by welding, bonding, or other means to achieve electrical connection between the first connecting member 81 and the cover 22. The second connecting member 82 can be connected to the electrode terminal 30 by welding, bonding, riveting, or other means to achieve electrical connection between the second connecting member 82 and the electrode terminal 30.

[0121] Illustratively, the first connecting member 81 connects the cover 22 of one battery cell 7 and the electrode terminal 30 of another battery cell 7 , while the second connecting member 82 connects the electrode terminal 30 of the one battery cell 7 and the cover 22 of yet another battery cell 7 , so that the first connecting member 81 and the second connecting member 82 connect the three battery cells 7 in series.

[0122] In this embodiment, by using the cover 22 and electrode terminal 30 as the output terminal, the structure of the battery cell 7 can be simplified while ensuring the current carrying capacity of the battery cell 7. The cover 22 and electrode terminal 30 are located at the same end of the battery cell 7. In this way, the first connecting member 81 and the second connecting member 82 can be assembled to the same side of the battery cell 7, which simplifies the assembly process and improves the efficiency of assembling multiple battery cells 7 into groups.

[0123] In some embodiments, the cover 22 and the barrel 21 are integrally formed. This can eliminate the need for a connection process between the cover 22 and the barrel 21. The housing 20 can be formed by a stretching process.

[0124] The electrode lead-out hole 221 in the embodiment of the present application is formed after the shell 20 is stretched.

[0125] The inventors have tried rolling the open end of the shell so that it folds inward and forms a flange structure. The flange structure presses the cover plate to fix the cover plate. The inventors installed the electrode terminals on the cover plate and used the flange structure and electrode terminals as the two output poles of the battery cell. However, the larger the size of the flange structure, the higher the risk of curling and wrinkling after forming. If the flange structure curls and wrinkles, it will cause the surface of the flange structure to be uneven, and when the flange structure is welded to the external connecting member, there will be problems with poor welding. Therefore, the size of the flange structure is relatively limited, resulting in insufficient current capacity of the battery cell.

[0126] In this embodiment, an electrode lead-out hole 221 for mounting the electrode terminal 30 is formed in the cover 22 by a perforation process, thereby positioning the positive and negative output electrodes at the end of the battery cell 7 facing away from the opening of the housing 20. The cover 22 is formed during the molding process of the housing 20, and even after the electrode lead-out hole 221 is formed, its flatness is maintained, thereby ensuring the connection strength between the cover 22 and the first connecting member 81. Furthermore, the flatness of the cover 22 is not constrained by its own size, allowing the cover 22 to be larger, thereby improving the current carrying capacity of the battery cell 7.

[0127] In some embodiments, the cover body 22 includes a connecting portion 222 and a bending portion 223 , the connecting portion 222 is provided with an electrode lead-out hole 221 , and at least a portion of the connecting portion 222 is used to connect the first connecting member 81 and the first electrode tab 11 , and the bending portion 223 is used to connect the cylinder 21 and the connecting portion 222 .

[0128] This embodiment does not impose any restrictions on the thickness of the connecting portion 222 , the thickness of the bending portion 223 , and the wall thickness of the cylinder 21 , and the thicknesses of the three can be determined according to requirements.

[0129] The connecting portion 222 is an annular plate-like structure that extends along the circumference of the electrode lead-out hole 221 to surround the electrode lead-out hole 221. The connecting portion 222 having a plate-like structure can better fit with the first connecting member 81, thereby ensuring the connection strength and flow area between the two.

[0130] The first connecting member 81 may be connected to the connecting portion 222 by welding, bonding or other methods to achieve electrical connection between the first connecting member 81 and the cover 22 .

[0131] In the embodiment of the present application, the bent portion 223 can release stress during the molding process of the shell 20, reduce stress concentration, and lower the risk of the shell 20 breaking.

[0132] In some embodiments, the connecting portion 222 includes a main body 2221 and a first recess 2222. The main body 2221 is disposed around the periphery of the first recess 2222 and is used to connect the first connecting member 81 and the first electrode tab 11. The first recess 2222 is recessed from the outer surface 222b of the main body in a direction facing the electrode assembly 10. The electrode lead-out hole 221 extends through the bottom wall of the first recess 2222 and connects the first recess 2222 with the interior of the housing 20. The battery cell 7 also includes a first insulating member 61. The first recess 2222 is configured to accommodate at least a portion of the first insulating member 61. The portion of the first insulating member 61 accommodated in the first recess 2222 is attached to the sidewalls and / or bottom wall of the first recess 2222.

[0133] The body 2221 has an inner surface 222a and an outer surface 222b disposed opposite to each other along its thickness direction. The inner surface 222a of the body faces the electrode assembly 10. The outer surface 222b of the body can be flat to facilitate contact with the first connecting member 81.

[0134] The electrode terminal 30 is fixed to the connecting portion 222. For example, the bottom wall of the first recess 2222 can be used to cooperate with and fix the electrode terminal 30.

[0135] The first insulating member 61 is used to insulate at least a portion of the electrode terminal 30 from the connecting portion 222. For example, at least a portion of the first insulating member 61 is sandwiched between the bottom wall of the first recess 2222 and the electrode terminal 30 to insulate the bottom wall of the first recess 2222 from the electrode terminal 30 and reduce the risk of short circuits.

[0136] In this embodiment, a portion of the first insulating member 61 may be accommodated in the first recess 2222 , or the entire first insulating member 61 may be accommodated in the first recess 2222 .

[0137] The portion of the first insulating member 61 accommodated in the first recess 2222 may be attached only to the side walls of the first recess 2222 , only to the bottom wall of the first recess 2222 , or to both the bottom wall and the side walls of the first recess 2222 .

[0138] "Attachment" refers to the contacting of two components. The two components can be attached and fixed, or simply attached without being fixed. For example, the electrode terminal 30 and the bottom wall of the first recess 2222 clamp the portion of the first insulating member 61 housed in the first recess 2222 from both sides. The portion of the first insulating member 61 housed in the first recess 2222 is attached to the bottom wall of the first recess 2222 due to the clamping force. Of course, the portion of the first insulating member 61 housed in the first recess 2222 can also be attached to the bottom wall of the first recess 2222 using an adhesive.

[0139] In this embodiment, the first recess 2222 is provided to position the first insulating member 61, simplifying the assembly process. The first recess 2222 can accommodate at least a portion of the first insulating member 61, thereby reducing the size of the outer surface 222b of the first insulating member 61 protruding from the main body, thereby reducing the maximum size of the battery cell 7 and improving the energy density.

[0140] In some embodiments, the outer surface 222 b of the body portion is exposed, which is not covered by the electrode terminal 30 and the first insulating member 61 .

[0141] In some embodiments, the thickness of the main body 2221 is greater than the wall thickness of the cylinder 21 .

[0142] The main body 2221 is used to connect to the first connecting member 81, so it needs to be relatively thick to ensure the connection strength between the main body 2221 and the first connecting member 81. Furthermore, the thicker main body 2221 can better support components such as the electrode terminal 30. The barrel 21 primarily isolates the electrode assembly 10 from the outside world and can be relatively thin to reduce the overall weight of the battery cell 7.

[0143] For example, the body portion 2221 is welded to the first connecting member 81. If the body portion 2221 is thin, it is easy to be melted through during welding; therefore, the body portion 2221 of the embodiment of the present application has a thicker thickness.

[0144] In some embodiments, the difference between the thickness D1 of the main body 2221 and the wall thickness D2 of the cylinder 21 satisfies: 0.1 mm ≤ D1 - D2 ≤ 2 mm.

[0145] If D1-D2 is less than 0.1mm, then the thickness of the main body 2221 is too small or the thickness of the cylinder 21 is too large. The smaller thickness of the main body 2221 will cause the strength of the main body 2221 to be insufficient, while the larger thickness of the cylinder 21 will cause the weight of the cylinder 21 to be too large, affecting the energy density.

[0146] The housing 20 is usually formed by stretching a flat plate. If D1-D2 is greater than 2 mm, the difference between the stretching amount of the main body 2221 and the stretching amount of the barrel 21 is too large during the stretching process, and the barrel 21 is easily damaged during the stretching process.

[0147] Therefore, in the embodiment of the present application, D1 and D2 satisfy the following relationship: 0.1 mm ≤ D1 - D2 ≤ 2 mm.

[0148] Optionally, the value of D1-D2 is 0.1 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm or 2 mm.

[0149] In some embodiments, the barrel 21 is cylindrical, the electrode lead-out hole 221 is a circular hole, and the central axis of the barrel 21 and the central axis of the electrode lead-out hole 221 are arranged to coincide with each other.

[0150] The “overlapping arrangement” does not require that the central axis of the cylinder 21 and the central axis of the electrode lead-out hole 221 absolutely completely overlap, and there may be deviations allowed by the process.

[0151] The electrode lead-out hole 221 is used to define the position of the electrode terminal 30. In this embodiment, the central axis of the electrode lead-out hole 221 is aligned with the central axis of the barrel 21, so that at least a portion of the electrode terminal 30 is located at the center of the cover 22. This reduces the requirement for the positional accuracy of the electrode terminal 30 when multiple battery cells 7 are assembled into a group, simplifies the assembly process, and improves assembly efficiency.

[0152] In some embodiments, the inner radius L1 of the cylinder 21 and the width L2 of the body 2221 satisfy: 0.2≤L2 / L1≤0.8, and the width L2 of the body 2221 is the difference between the outer radius of the body 2221 and the inner radius of the body 2221 .

[0153] The main body 2221 is a circular ring structure, and the width L2 is the ring width of the circular ring structure.

[0154] The electrode assembly 10 is generally cylindrical in structure, and the inner radius L1 of the cylinder 21 is positively correlated with the radius of the electrode assembly 10. The larger the value of L1, the larger the volume and capacity of the electrode assembly 10, and the higher the requirement for the current carrying capacity of the battery cell 7.

[0155] The width L2 of the main body 2221 and the radius of the electrode lead-out hole 221 are both related to the flow capacity of the battery cell 7. The larger the width L2, the larger the connection area between the first connecting member 81 and the main body 2221, and the higher the flow capacity between the first connecting member 81 and the main body 2221. The radius of the electrode lead-out hole 221 directly affects the flow area of ​​the electrode terminal 30 and correspondingly affects the flow capacity between the electrode terminal 30 and the second connecting member 82. In short, the width L2 of the main body 2221 and the radius of the electrode lead-out hole 221 both affect the flow capacity of the battery cell 7.

[0156] However, given a constant inner radius L1 of the cylinder 21, the width L2 of the main body 2221 is negatively correlated with the radius of the electrode lead-out hole 221. If the width L2 of the main body 2221 is too small, the flow capacity of the main body 2221 will be insufficient; on the other hand, if the width L2 of the main body 2221 is too large, the radius of the electrode lead-out hole 221 will be too small, resulting in insufficient flow capacity for the electrode terminal 30. The inventors have conducted experiments and found that when the inner radius L1 of the cylinder 21 and the width L2 of the main body 2221 satisfy the following relationship: 0.2 ≤ L2 / L1 ≤ 0.8, the flow capacity of the main body 2221 and the flow capacity of the electrode terminal 30 can be better balanced, meeting the flow capacity requirements of the battery cell 7.

[0157] In some embodiments, the inner radius L1 of the cylinder 21 and the width L2 of the main body 2221 satisfy: 0.3≤L2 / L1≤0.7.

[0158] Optionally, the value of L2 / L1 is 0.3, 0.4, 0.5, 0.6 or 0.7.

[0159] In some embodiments, the main body 2221 is used to be welded with the first connecting member 81 and form a first welding area W11 on the main body 2221 . The first welding area W11 is spaced apart from the first end 223a of the bending portion 223 . The first end 223a is used to connect the main body 2221 .

[0160] The main body 2221 is welded to the first connecting member 81 to form a first weld portion W1. For example, during welding, a laser is applied to the surface of the first connecting member 81 facing away from the main body 2221, and the laser melts and connects a portion of the first connecting member 81 and a portion of the main body 2221 to form the first weld portion W1.

[0161] The first welding portion W1 includes a first welding area W11 formed on the body portion 2221 and a second welding area W12 formed on the first connection member 81 .

[0162] The bending portion 223 includes a first end 223a and a second end 223b opposite to each other. The first end 223a is connected to the main body 2221, and the second end 223b is connected to the cylinder 21. The bending portion 223 is bent as a whole, and its inner and outer surfaces are generally curved.

[0163] In the embodiment of the present application, the first welding area W11 is spaced apart from the first end 223a of the bending portion 223 to reduce the risk of welding to the bending portion 223 due to process errors during the welding process, reduce the possibility of cold welding, and ensure the connection strength between the main body 2221 and the first connecting member 81.

[0164] In some embodiments, the welding depth D3 of the first welding region W11 and the thickness D1 of the body portion 2221 satisfy: 0.1≤D3 / D1≤0.8.

[0165] The welding depth D3 refers to the dimension of the first welding region W11 in the thickness direction of the main body portion 2221 .

[0166] The smaller the value of D3 / D1, the smaller the portion of the main body 2221 that needs to be melted during welding, and the lower the power required for welding; conversely, the larger the value of D3 / D1, the larger the portion of the main body 2221 that needs to be melted during welding, and the higher the power required for welding.

[0167] If the value of D3 / D1 is too small, the volume of the first welding area W11 will be too small, which will lead to insufficient connection strength and low flow capacity between the main body 2221 and the first connecting member 81. Therefore, in this embodiment, the value of D3 / D1 is greater than or equal to 0.1 to ensure the connection strength and flow capacity between the main body 2221 and the first connecting member 81.

[0168] If the value of D3 / D1 is too large, the welding power required will be too high, and the high temperature generated during welding can easily burn other components, such as the second insulating member described later. Furthermore, an excessively large value of D3 / D1 increases the risk of melting through the main body 2221, which can easily burn other components within the housing 20. Therefore, in this embodiment of the present application, the value of D3 / D1 is set to be less than or equal to 0.8 to reduce the welding temperature and the risk of burning other components.

[0169] Optionally, the value of D3 / D1 is 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7.

[0170] In some embodiments, a protrusion 2223 is formed on the connection portion 222 at a position opposite the first recess 2222, protruding from the inner surface 222a of the body portion in a direction facing the electrode assembly 10. The connection portion 222 also includes a fourth recess 2224, which is recessed from the top end surface 222c of the protrusion 2223 to the inner surface 222a of the body portion in a direction away from the electrode assembly 10. The battery cell 7 also includes a second insulating member 60. The fourth recess 2224 is configured to accommodate at least a portion of the second insulating member 60. The portion of the second insulating member 60 accommodated in the fourth recess 2224 is attached to the sidewalls and / or bottom wall of the fourth recess 2224.

[0171] The first concave portion 2222 and the convex portion 2223 may be formed by punching the cover body 22 .

[0172] The top surface 222c of the protrusion 2223 is the surface of the protrusion 2223 facing the electrode assembly 10. The fourth recess 2224 is an annular recess disposed around the protrusion 2223. The bottom surface of the fourth recess 2224 is the inner surface 222a of the body.

[0173] The portion of the second insulating member 60 accommodated in the fourth recess 2224 may be attached only to the side walls of the fourth recess 2224 , only to the bottom wall of the fourth recess 2224 , or to both the side walls and the bottom wall of the fourth recess 2224 .

[0174] By providing the convex portion 2223, this embodiment can increase the thickness of the bottom wall of the first recess 2222 to improve the strength of the bottom wall of the first recess 2222, so that the bottom wall of the first recess 2222 can effectively support the electrode terminal 30. The second insulating member 60 can cover the main body 2221 from the inside to separate the electrode assembly 10 from the main body 2221, reducing the risk of contact and conduction between the electrode assembly 10 and the main body 2221 when the battery cell 7 vibrates, thereby improving safety performance. By providing the fourth recess 2224, the second insulating member 60 can be positioned to simplify the assembly process. The fourth recess 2224 can accommodate at least a portion of the second insulating member 60, so that the internal space of the shell 20 can be fully utilized to improve energy density.

[0175] In some embodiments, one of the first insulating member 61 and the second insulating member 60 is used to seal the electrode lead-out hole 221. In other embodiments, the battery cell 7 further includes a sealing ring 62, which is sleeved on the electrode terminal 30 and is used to seal the electrode lead-out hole 221. Optionally, a portion of the sealing ring 62 extends into the electrode lead-out hole 221 to separate the hole wall of the electrode lead-out hole 221 from the electrode terminal 30.

[0176] In some embodiments, the bending portion 223 includes a first end 223a for connecting to the connecting portion 222 and a second end 223b for connecting to the cylinder 21. The thickness of the bending portion 223 gradually decreases from the first end 223a to the second end 223b.

[0177] The thickness of the first end portion 223 a of the bent portion 223 is equal to the thickness of the main body 2221 , and the thickness of the second end portion 223 b of the bent portion 223 is equal to the thickness of the cylinder 21 .

[0178] The embodiment of the present application gradually changes the thickness of the bending portion 223 to adapt to the thickness difference between the connecting portion 222 and the cylinder 21, smoothly connecting the cylinder 21 and the connecting portion 222, reducing the risk of steps forming on the inner and outer surfaces of the shell 20, and reducing stress concentration.

[0179] In some embodiments, the second tab 12 is disposed at one end of the electrode assembly 10 facing the cover 22, and the first tab 11 is disposed at the other end of the electrode assembly 10 facing away from the cover 22. The barrel 21 is used to connect the first tab 11 and the cover 22 so that the first tab 11 is electrically connected to the cover 22.

[0180] The barrel 21 may be directly electrically connected to the first electrode tab 11 or may be electrically connected to the first electrode tab 11 through other components. For example, the first electrode tab 11 is electrically connected to the barrel 21 through the cover plate 40 .

[0181] In the embodiment of the present application, the first electrode tab 11 and the second electrode tab 12 are arranged at both ends of the electrode assembly 10 , which can reduce the risk of conduction between the first electrode tab 11 and the second electrode tab 12 and increase the flow area of ​​the first electrode tab 11 and the flow area of ​​the second electrode tab 12 .

[0182] In some embodiments, the first electrode tab 11 is a negative electrode tab, and the base material of the shell 20 is steel.

[0183] The housing 20 is electrically connected to the negative electrode tab, that is, the housing 20 is in a low potential state. The steel housing 20 is not easily corroded by the electrolyte in the low potential state, thereby reducing safety risks.

[0184] In some embodiments, the battery cell 7 further includes a current collecting member 50 for connecting the second electrode tab 12 and the electrode terminal 30 .

[0185] The current collecting member 50 can be connected to the second electrode tab 12 by welding, abutting, or bonding, and connected to the electrode terminal 30 by welding, abutting, bonding, riveting, etc., thereby achieving electrical connection between the second electrode tab 12 and the electrode terminal 30.

[0186] In the first direction X, the electrode terminal 30 is disposed opposite the middle region of the second electrode tab 12. If the electrode terminal 30 and the second electrode tab 12 were directly connected, the conductive path between the edge region of the second electrode tab 12 and the electrode terminal 30 would be longer, resulting in uneven current density in the second electrode sheet of the electrode assembly 10, increased internal resistance, and affected current handling and charging efficiency of the battery cell 7.

[0187] The current collecting component 50 of the embodiment of the present application can have a larger connection area with the second pole tab 12, and the current of the second pole tab 12 can be collected into the electrode terminal 30 through the current collecting component 50. In this way, the current collecting component 50 can reduce the difference in the conductive path between different areas of the second pole tab 12 and the electrode terminal 30, improve the uniformity of the current density of the second pole sheet, reduce the internal resistance, and improve the flow capacity and charging efficiency of the battery cell 7.

[0188] Figure 9 A schematic structural diagram of the second insulating component of a battery cell provided in some embodiments of the present application.

[0189] like Figure 8 and Figure 9 As shown, in some embodiments, the battery cell 7 also includes a second insulating component 60, which includes an insulating body 63 and an insulating protrusion 64 protruding from the outer periphery of the insulating body 63, the insulating body 63 abuts against the side of the main body 2221 facing the electrode assembly 10, and the insulating protrusion 64 is provided on the side of the bending portion 223 facing the electrode assembly 10, and the surface of the insulating protrusion 64 facing away from the electrode assembly 10 is closer to the electrode assembly 10 than the surface of the insulating body 63 facing away from the electrode assembly 10, so as to form a second recess 65 for avoiding the bending portion 223.

[0190] The insulating body 63 has an inner surface and an outer surface disposed opposite each other, with the inner surface 631 of the insulating body facing the electrode assembly 10. The insulating protrusion 64 has an inner surface and an outer surface disposed opposite each other, with the inner surface 641 of the insulating protrusion facing the electrode assembly 10. In the first direction X, the outer surface 642 of the insulating protrusion is closer to the electrode assembly 10 than the outer surface 632 of the insulating body.

[0191] In the thickness direction of the main body 2221 , the insulating body 63 and the main body 2221 at least partially overlap, and the insulating protrusion 64 and the bent portion 223 at least partially overlap.

[0192] The insulating protrusion 64 is an annular structure surrounding the outer side of the insulating body 63. The second recess 65 surrounds the outer side of the insulating body 63.

[0193] The insulating body 63 rests against the surface of the main body 2221 facing the electrode assembly 10 and covers the first welding area W11. If the main body 2221 is melted through due to an operational error during welding of the first connecting member 81 and the main body 2221, the insulating body 63 acts as a stopper, reducing the risk of weld beads falling onto the electrode assembly 10 and mitigating safety hazards.

[0194] In this embodiment, the insulating body 63 can separate at least a portion of the main body 2221 from the electrode assembly 10, and the insulating protrusion 64 can separate at least a portion of the bent portion 223 from the electrode assembly 10. Thus, when the battery cell 7 vibrates, this embodiment can reduce the risk of contact between the electrode assembly 10 and the main body 2221, as well as the risk of contact between the electrode assembly 10 and the bent portion 223, thereby improving safety. In this embodiment, the second recess 65 is provided to avoid interference between the bent portion 223 and the second insulating member 60.

[0195] In some embodiments, the insulating protrusion 64 extends beyond the second end portion 223 b of the bent portion 223 in a direction facing the electrode assembly 10 , and the second end portion 223 b is used to connect to the barrel 21 .

[0196] In the first direction X, the outer surface 642 of the insulating protrusion is closer to the electrode assembly 10 than the second end portion 223 b.

[0197] This embodiment can separate the outer surface 642 of the insulating protrusion from the inner surface of the bent portion 223, preventing interference between the insulating protrusion 64 and the bent portion 223. The size of the insulating protrusion 64 protruding from the insulating body 63 is not affected by the bent portion 223, which can improve the isolation effect of the insulating protrusion 64.

[0198] In some embodiments, the inner surface 641 of the insulating protrusion is flush with the inner surface 631 of the insulating body.

[0199] In some embodiments, a third recess 66 is formed on the inner surface 631 of the insulating body and is recessed in a direction away from the electrode assembly 10 . At least a portion of the electrode terminal 30 is received in the third recess 66 .

[0200] In this embodiment, by providing the third recess 66 , the space occupied by the second insulating member 60 and the electrode terminal 30 can be reduced, thereby improving the energy density of the battery cell 7 .

[0201] In some embodiments, the thickness of the insulating body 63 is greater than the thickness of the main body 2221 .

[0202] During welding of the main body 2221 and the first connecting member 81, heat is transferred to the insulating body 63. In this embodiment, the thickness of the insulating body 63 is greater than that of the main body 2221 to extend the heat transfer path and reduce the impact of heat on other components. The greater thickness of the insulating body 63 in this embodiment ensures that even if the portion of the insulating body 63 near the first welding region W11 is burned, the insulation effect is maintained.

[0203] Figure 10 for Figure 6 An enlarged schematic diagram of the battery shown at circle C; Figure 11 A schematic structural diagram of the electrode terminals of a battery cell provided in some embodiments of the present application.

[0204] like Figure 10 and Figure 11 As shown, the electrode terminal 30 includes a terminal body 31, the terminal body 31 includes a columnar portion 311, a first limiting portion 312 and a second limiting portion 313, at least a portion of the columnar portion 311 is located in the electrode lead-out hole 221, the first limiting portion 312 and the second limiting portion 313 are both connected to and protrude from the outer wall of the columnar portion 311, the first limiting portion 312 and the second limiting portion 313 are respectively arranged on the outer side and the inner side of the connecting portion along the first direction X, and are used to clamp a portion of the connecting portion.

[0205] The terminal body 31 has an inner surface and an outer surface disposed opposite each other, with the inner surface 314 of the terminal body facing the electrode assembly 10. The columnar portion 311 is provided with a fifth recess 311 a, which is recessed from the outer surface 315 of the terminal body in a direction facing the electrode assembly 10. The bottom of the fifth recess 311 a forms a transition portion 311 b, which is used for welding to the current collecting member 50.

[0206] When the electrode assembly and the current collecting member 50 are installed into the shell through the opening of the cylinder and the current collecting member 50 is pressed against the transition part 311b, the external welding equipment can weld the transition part 311b and the current collecting member 50 from the side of the transition part 311b away from the current collecting member 50.

[0207] In this embodiment, the thickness of the transition portion 311b is reduced by providing the fifth recess 311a, which can reduce the welding power required for welding the transition portion 311b to the current collecting member 50, reduce heat generation, and reduce the risk of burning other components (such as the first insulating member and the second insulating member).

[0208] In some embodiments, the electrode terminal 30 further includes a sealing plate 32, which is used to seal the opening of the fifth recess 311a. The sealing plate 32 can be located entirely outside the fifth recess 311a or partially within the fifth recess 311a, as long as the sealing plate 32 can seal the opening of the fifth recess 311a. The sealing plate 32 protects the transition portion 311b from the outside, reducing the entry of external impurities into the fifth recess 311a, reducing the risk of damage to the transition portion 311b by external impurities, and improving the sealing performance of the battery cell 7.

[0209] In some embodiments, the fifth recess 311 a is a stepped recess, and at least a portion of the sealing plate 32 is received in the fifth recess 311 a and supported by a stepped surface of the fifth recess 311 a.

[0210] In some embodiments, the sealing plate 32 is welded to the second connecting member 82 to form a second weld portion W2. The second weld portion W2 can reduce the contact resistance between the sealing plate 32 and the second connecting member 82, thereby improving the current flow capacity.

[0211] In some embodiments, at least a portion of the sealing plate 32 protrudes beyond the outer surface 315 of the terminal body.

[0212] When welding the second connecting member 82 and the sealing plate 32 is required, the second connecting member 82 is first attached to the upper surface of the sealing plate 32 (i.e., the outer surface of the sealing plate 32 facing away from the transition portion 311b), and then the second connecting member 82 and the sealing plate 32 are welded.

[0213] At least part of the sealing plate 32 protrudes from the outer surface 315 of the terminal body to prevent the outer surface 315 of the terminal body from interfering with the fit between the sealing plate 32 and the second connecting member 82 , thereby ensuring that the second connecting member 82 and the sealing plate 32 fit tightly together.

[0214] Figure 12 A schematic flow chart of a method for manufacturing a battery cell provided in some embodiments of the present application.

[0215] like Figure 12 As shown, the manufacturing method of the battery cell provided in the embodiment of the present application includes:

[0216] S100, providing a housing and an electrode terminal, wherein the housing includes a cylinder and a cover connected to the cylinder, the cover is provided with an electrode lead-out hole, the cylinder has an opening at one end facing away from the cover, and the electrode terminal is insulated and disposed on the cover and mounted in the electrode lead-out hole;

[0217] S200, providing an electrode assembly, the electrode assembly comprising a first electrode tab and a second electrode tab with opposite polarities;

[0218] S300, installing the electrode assembly into the housing so that the barrel surrounds the outer periphery of the electrode assembly, and the second tab is electrically connected to the electrode terminal;

[0219] S400, providing a cover plate, and connecting the cover plate to the barrel to close the opening of the barrel, and electrically connecting the first electrode tab to the cover plate, so that the first electrode tab is electrically connected to the cover plate via the cover plate and the barrel;

[0220] Among them, at least a portion of the cover is used to electrically connect the first connecting member and the first pole ear of the battery, the electrode terminal is used to electrically connect the second connecting member and the second pole ear of the battery, and one of the cover and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell.

[0221] It should be noted that the relevant structure of the battery cell manufactured by the above-mentioned method for manufacturing the battery cell can refer to the battery cells provided in the above-mentioned embodiments.

[0222] When assembling a battery cell based on the above-mentioned battery cell manufacturing method, it is not necessary to follow the above-mentioned steps in sequence. In other words, the steps can be performed in the order mentioned in the embodiment, or in a different order than the order mentioned in the embodiment, or several steps can be performed simultaneously. For example, steps S100 and S200 can be performed in any order and can be performed simultaneously.

[0223] Figure 13 A schematic block diagram of a battery cell manufacturing system provided in some embodiments of the present application.

[0224] like Figure 13 As shown, the battery cell manufacturing system 90 of the embodiment of the present application includes:

[0225] A first providing device 91 is used to provide a housing and electrode terminals. The housing includes a cylinder and a cover connected to the cylinder. The cover is provided with an electrode lead-out hole. The cylinder has an opening at one end facing away from the cover. The electrode terminal is insulated and disposed on the cover and mounted in the electrode lead-out hole.

[0226] A second providing device 92 is used to provide an electrode assembly, wherein the electrode assembly includes a first electrode tab and a second electrode tab with opposite polarities;

[0227] The first assembly device 93 is used to install the electrode assembly into the housing so that the barrel is arranged around the periphery of the electrode assembly and the second tab is electrically connected to the electrode terminal;

[0228] A second assembly device 94 is used to provide a cover plate, connect the cover plate to the barrel to close the opening of the barrel, and electrically connect the first tab to the cover plate so that the first tab is electrically connected to the cover plate via the cover plate and the barrel;

[0229] Among them, at least a portion of the cover is used to electrically connect the first connecting member and the first pole ear of the battery, the electrode terminal is used to electrically connect the second connecting member and the second pole ear of the battery, and one of the cover and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell.

[0230] The relevant structures of the battery cells manufactured by the above manufacturing system can refer to the battery cells provided in the above embodiments.

[0231] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0232] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell for a battery, characterized in that: The battery cell comprises: An electrode assembly comprising a first electrode tab and a second electrode tab with opposite polarities, the electrode assembly further comprising a main body, the first electrode tab and the second electrode tab protruding from the main body; a housing for accommodating the electrode assembly, the housing comprising a barrel and a cover connected to the barrel, the barrel being disposed around the periphery of the electrode assembly, the cover being provided with an electrode lead-out hole, at least a portion of the cover being used to electrically connect the first connecting member and the first tab of the battery; and an electrode terminal for electrically connecting the second connecting member and the second tab of the battery, the electrode terminal being insulated and disposed on the cover and mounted in the electrode lead-out hole, one of the cover and the electrode terminal being the positive output electrode of the battery cell, and the other being the negative output electrode of the battery cell; Wherein, the cover body includes a connecting portion, the connecting portion is provided with the electrode lead-out hole, the connecting portion includes a main body portion, the main body portion is located outside the electrode lead-out hole, the main body portion is used to electrically connect the first connecting member and the first electrode ear, and the thickness of the main body portion is greater than the thickness of the cylinder.

2. The battery cell according to claim 1, wherein: The cover body and the cylinder body are formed as an integral structure.

3. The battery cell according to claim 1, wherein: The cover body and the cylinder body are split structures.

4. The battery cell according to claim 3, characterized in that The cover body and the cylinder body are connected by welding, riveting or bonding.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The difference between the thickness D1 of the main body and the wall thickness D2 of the cylinder satisfies: 0.1 mm ≤ D1 - D2 ≤ 2 mm.

6. The battery cell according to any one of claims 1 to 4, characterized in that: The difference between the thickness D1 of the main body and the wall thickness D2 of the cylinder satisfies: 0.2 mm ≤ D1 - D2 ≤ 1.8 mm.

7. The battery cell according to any one of claims 1 to 4, characterized in that: The barrel is cylindrical, the electrode lead-out hole is a circular hole, and the central axis of the barrel and the central axis of the electrode lead-out hole are arranged to coincide with each other.

8. The battery cell according to claim 7, characterized in that The inner radius L1 of the cylinder and the width L2 of the main body satisfy: 0.2≤L2 / L1≤0.8, and the width L2 of the main body is the difference between the outer radius of the main body and the inner radius of the main body.

9. The battery cell according to claim 8, characterized in that The inner radius L1 of the cylinder and the width L2 of the main body satisfy: 0.3≤L2 / L1≤0.

7.

10. The battery cell according to any one of claims 1 to 4, characterized in that: The cover body further includes a bending portion, the main body is used to be welded with the first connecting member and form a first welding area on the main body, the first welding area is spaced apart from the first end of the bending portion, and the first end is used to connect the main body.

11. The battery cell according to claim 10, characterized in that The welding depth D3 of the first welding region and the thickness D1 of the main body satisfy the following: 0.1≤D3 / D1≤0.

8.

12. The battery cell according to claim 11, characterized in that The welding depth D3 of the first welding region and the thickness D1 of the main body satisfy the following: 0.2≤D3 / D1≤0.

7.

13. The battery cell according to any one of claims 1 to 4, characterized in that: The connecting portion further includes a first recess, the main body being disposed around an outer periphery of the first recess, the first recess being recessed from an outer surface of the main body in a direction facing the electrode assembly, and the electrode lead-out hole penetrating a bottom wall of the first recess and connecting the first recess with the interior of the housing; The battery cell further includes a first insulating member, the first recess is configured to accommodate at least a portion of the first insulating member, and the portion of the first insulating member accommodated in the first recess is attached to a side wall and / or a bottom wall of the first recess.

14. The battery cell according to claim 13, characterized in that The cover body also includes a bending portion, and the battery cell also includes a second insulating component, which includes an insulating body and an insulating protrusion protruding from the outer periphery of the insulating body. The insulating body is against the side of the main body facing the electrode assembly, and the insulating protrusion is provided on the side of the bending portion facing the electrode assembly. The surface of the insulating protrusion facing away from the electrode assembly is closer to the electrode assembly than the surface of the insulating body facing away from the electrode assembly, so as to form a second recess for avoiding the bending portion.

15. The battery cell according to claim 14, characterized in that The insulating protrusion extends beyond the second end portion of the bent portion in a direction facing the electrode assembly, and the second end portion is used to connect to the barrel.

16. The battery cell according to claim 14, characterized in that A third recessed portion is formed on an inner surface of the insulating body and is recessed in a direction away from the electrode assembly. At least a portion of the electrode terminal is received in the third recessed portion.

17. The battery cell according to claim 14, characterized in that The thickness of the insulating body is greater than the thickness of the main body.

18. The battery cell according to claim 14, characterized in that A convex portion is formed on the connecting portion at a position opposite to the first concave portion, protruding from the inner surface of the main body portion in a direction facing the electrode assembly; The connecting portion further includes a fourth recessed portion, the fourth recessed portion being recessed from the top surface of the protruding portion in a direction away from the electrode assembly to the inner surface of the main body portion; The battery cell further includes a second insulating member, the fourth recess is configured to receive at least a portion of the second insulating member, and the portion of the second insulating member received in the fourth recess is attached to a side wall and / or a bottom wall of the fourth recess.

19. The battery cell according to any one of claims 1 to 4, characterized in that: The cover body further includes a bending portion, which includes a first end portion for connecting to the connecting portion and a second end portion for connecting to the cylinder body. The thickness of the bending portion gradually decreases from the first end portion to the second end portion.

20. The battery cell according to any one of claims 1 to 4, characterized in that: The second electrode tab is provided at one end of the electrode assembly facing the cover body, and the first electrode tab is provided at the other end of the electrode assembly facing away from the cover body; The barrel is used to connect the first tab and the cover, so that the first tab is electrically connected to the cover.

21. The battery cell according to any one of claims 1 to 4, characterized in that: The first electrode tab and the second electrode tab extend from the same side of the main body.

22. The battery cell according to any one of claims 1 to 4, characterized in that: The electrode terminal includes a terminal body, which includes a columnar portion, a first limiting portion and a second limiting portion. At least a portion of the columnar portion is located in the electrode lead-out hole. The first limiting portion and the second limiting portion are both connected to and protrude from the outer side wall of the columnar portion. The first limiting portion and the second limiting portion are respectively arranged on the outer side and the inner side of the connecting portion along the first direction, and are used to clamp a portion of the connecting portion. The central axis of the electrode assembly is a virtual straight line, which is parallel to the first direction.

23. The battery cell according to claim 22, characterized in that The terminal body has an inner surface and an outer surface arranged opposite to each other, the inner surface of the terminal body faces the electrode assembly, the columnar portion is provided with a fifth recess, the fifth recess is recessed from the outer surface of the terminal body in a direction facing the electrode assembly, and the bottom of the fifth recess forms a transition portion, which is used to be welded to the current collecting component.

24. The battery cell according to claim 23, characterized in that The electrode terminal further includes a sealing plate for closing an opening of the fifth recess.

25. The battery cell according to claim 24, characterized in that The fifth recess is a stepped recess, and at least a portion of the sealing plate is accommodated in the fifth recess and supported by a stepped surface of the fifth recess.

26. The battery cell according to claim 24, characterized in that The sealing plate is used to be welded to the second connecting member to form a second welding portion.

27. The battery cell according to claim 24, characterized in that At least a portion of the sealing plate protrudes from an outer surface of the terminal body.

28. The battery cell according to any one of claims 1 to 4, characterized in that: The first electrode tab is a negative electrode tab, and the base material of the shell is steel.

29. The battery cell according to any one of claims 1 to 4, characterized in that: The cylinder has an opening at one end facing away from the cover, and the battery cell further includes a cover plate for closing the opening.

30. A battery, characterized in that: include: The battery cell according to any one of claims 1 to 29; a first connecting member connected to the cover; as well as The second connecting member is connected to the electrode terminal.

31. An electrical device, characterized in that: A battery according to claim 30 is included for providing electrical energy.

32. A method for manufacturing a battery cell, characterized in that: include: A housing and an electrode terminal are provided, wherein the housing includes a cylindrical body and a cover connected to the cylindrical body, the cover includes a connecting portion, the connecting portion is provided with an electrode lead-out hole, the connecting portion includes a main body, the main body is located outside the electrode lead-out hole, the thickness of the main body is greater than the thickness of the cylindrical body, the cylindrical body has an opening at one end facing away from the cover, and the electrode terminal is insulated and disposed on the cover and mounted in the electrode lead-out hole; Providing an electrode assembly, the electrode assembly comprising a first electrode tab and a second electrode tab of opposite polarity; Installing the electrode assembly into the housing so that the barrel surrounds the periphery of the electrode assembly and the second tab is electrically connected to the electrode terminal; Providing a cover plate, and connecting the cover plate to the barrel to close the opening of the barrel, and electrically connecting the first tab to the cover plate, so that the first tab is electrically connected to the cover via the cover plate and the barrel; Among them, the main body of the cover body is used to electrically connect the first connecting member and the first pole lug of the battery, and the electrode terminal is used to electrically connect the second connecting member and the second pole lug of the battery. One of the cover body and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell. The electrode assembly also includes a main body, and the first pole lug and the second pole lug protrude from the main body.

33. A battery cell manufacturing system, characterized in that: include: A first providing device is configured to provide a housing and an electrode terminal, wherein the housing comprises a cylindrical body and a cover connected to the cylindrical body, the cover comprising a connecting portion, the connecting portion being provided with an electrode lead-out hole, the connecting portion comprising a main body, the main body being located outside the electrode lead-out hole, the main body being thicker than the cylindrical body, the cylindrical body having an opening at one end facing away from the cover, the electrode terminal being insulated and disposed on the cover and mounted in the electrode lead-out hole; A second providing device is used to provide an electrode assembly, wherein the electrode assembly includes a first electrode tab and a second electrode tab with opposite polarities; a first assembling device for installing the electrode assembly into the housing so that the barrel is disposed around the periphery of the electrode assembly and the second tab is electrically connected to the electrode terminal; a second assembling device, configured to provide a cover plate, connect the cover plate to the barrel to close the opening of the barrel, and electrically connect the first tab to the cover plate, so that the first tab is electrically connected to the cover via the cover plate and the barrel; Among them, the main body of the cover body is used to electrically connect the first connecting member and the first pole lug of the battery, and the electrode terminal is used to electrically connect the second connecting member and the second pole lug of the battery. One of the cover body and the electrode terminal is the positive output pole of the battery cell, and the other is the negative output pole of the battery cell. The electrode assembly also includes a main body, and the first pole lug and the second pole lug protrude from the main body.

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