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

Abstract

The present application provides a battery cell, a manufacturing method and system thereof, a battery, and an electrical device. The battery cell includes: an electrode assembly, including a first tab, the first tab being arranged around the central axis of the electrode assembly; a housing for accommodating the electrode assembly, the housing including a barrel and a cover connected to the barrel, the barrel being arranged around the outer circumference of the electrode assembly, the cover being provided with an electrode lead-out hole, the central axis extending in a first direction and passing through the electrode lead-out hole, the first tab including a first annular portion, the projection of the first annular portion in the first direction not overlapping with the projection of the electrode lead-out hole in the first direction; an electrode terminal including a columnar portion and a first connecting portion connected to the columnar portion, the columnar portion being at least partially located within the electrode lead-out hole, the first connecting portion being at least partially located between the cover and the first annular portion and being used to connect the first annular portion to electrically connect the first tab and the electrode terminal. The present application can improve the current carrying capacity of the battery cell.

Description

Technical Field

[0001] 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

[0002] 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.

[0003] In the development of battery technology, how to improve the current capacity of battery cells is a technical problem that needs to be solved urgently. Summary of the Invention

[0004] 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 carrying capacity of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising:

[0006] The electrode assembly includes a first tab, wherein the first tab is disposed around a central axis of the electrode assembly;

[0007] 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, the central axis of which extends along a first direction and passes through the electrode lead-out hole, the first electrode tab comprising a first annular portion, the first annular portion being disposed opposite the cover, and a projection of the first annular portion in the first direction not overlapping a projection of the electrode lead-out hole in the first direction;

[0008] The electrode terminal includes a columnar portion and a first connecting portion connected to the columnar portion, wherein the columnar portion is at least partially located in the electrode lead-out hole, and at least partially the first connecting portion is located between the cover body and the first annular portion and is used to connect the first annular portion to electrically connect the first tab and the electrode terminal.

[0009] In the above scheme, the first annular portion of the first electrode tab is connected by extending the first connecting portion between the cover body and the first annular portion, so that the current in the electrode assembly can flow to the electrode terminal through the first annular portion, thereby shortening the conductive path, reducing the internal resistance, and improving the current flow capacity and charging efficiency of the battery cell.

[0010] In some embodiments, the first connecting portion is an annular structure surrounding the outer side of the columnar portion, and at least a portion of the first connecting portion is welded to the first annular portion to form a first welding portion.

[0011] In the above solution, the first welding portion can reduce the contact resistance between the electrode terminal and the first annular portion, thereby improving the current carrying capacity.

[0012] In some embodiments, the first welding portion is annular and disposed around the columnar portion.

[0013] In the above solution, the annular first welding portion has a larger flow area, which can improve the uniformity of the current density of the first pole piece, reduce the internal resistance, and improve the flow capacity.

[0014] In some embodiments, there are a plurality of first welding portions, and the plurality of first welding portions are spaced apart along the circumference of the columnar portion.

[0015] In the above solution, the multiple first welding portions can increase the flow area, improve the uniformity of the current density of the first electrode, reduce the internal resistance, and improve the flow capacity.

[0016] In some embodiments, the first connecting portion includes: a first abutting portion, which abuts and is welded to the first annular portion to form a first welding portion, and a gap is formed between the first abutting portion and the cover body for avoiding the first welding portion; and a second abutting portion, which is used to connect the first abutting portion and the columnar portion and abut against the cover body.

[0017] In the above solution, a gap is formed between the first abutting portion and the cover body so that the first welding portion avoids the cover body, thereby reducing the risk of the cover body being crushed and improving safety performance.

[0018] In some embodiments, a surface of the first abutting portion facing the cover body is farther away from the cover body than a surface of the second abutting portion facing the cover body, so as to form a gap for avoiding the first welding portion.

[0019] In some embodiments, a surface of the first abutting portion facing the electrode assembly is provided with a protrusion, which abuts against the first annular portion. A groove is formed on a surface of the first abutting portion facing away from the electrode assembly in an area corresponding to the protrusion, and a portion between a top surface of the protrusion and a bottom surface of the groove is used for welding to the first annular portion to form a first weld.

[0020] In the above solution, the protrusion can better fit the first annular portion, reducing the risk of poor welding. The groove can reduce the thickness of the portion between the top surface of the protrusion and the bottom surface of the groove, thereby reducing the power required for welding, reducing heat generation, and reducing the risk of burns to the electrode assembly.

[0021] In some embodiments, a surface of the second abutting portion facing the electrode assembly abuts against the first annular portion.

[0022] In the above solution, part of the current can be transmitted through the fitting portion between the second inner surface and the end surface of the first annular portion, thereby improving the current carrying capacity.

[0023] In some embodiments, the first abutting portion surrounds the outer side of the second abutting portion, and a thickness of the first abutting portion is smaller than a thickness of the second abutting portion.

[0024] In the above solution, the second abutment portion is used to abut against the cover body and requires a greater thickness to reduce deformation of the second abutment portion during assembly. The first abutment portion is used for welding to the first annular portion and can have a smaller thickness, which can reduce the power required for welding, reduce heat generation, and reduce the risk of burns to the electrode assembly.

[0025] In some embodiments, the columnar portion and the first connecting portion are integrally formed.

[0026] In the above solution, the connection process between the columnar portion and the first connection portion can be omitted, the structure of the electrode terminal can be simplified, the resistance of the electrode terminal can be reduced, and the current carrying capacity can be improved.

[0027] In some embodiments, the first electrode tab further includes a second annular portion, the first annular portion surrounds the outside of the second annular portion, the second annular portion is arranged opposite to the electrode lead-out hole along the first direction, and at least a portion of the second annular portion abuts against the columnar portion.

[0028] In the above solution, the second annular portion is provided to improve the flow capacity. The second annular portion can also radially support the first annular portion, thereby reducing the risk of the first annular portion being crushed and deformed during welding, and improving the welding stability of the first annular portion and the first connecting portion.

[0029] In some embodiments, the columnar portion is welded to the second annular portion to form a second welded portion.

[0030] In the above solution, the second welding portion can reduce the contact resistance between the columnar portion and the second annular portion, thereby improving the current carrying capacity.

[0031] In some embodiments, a surface of the columnar portion facing the electrode assembly is flush with a surface of the first connecting portion facing the electrode assembly.

[0032] In the above solution, the surface of the columnar portion facing the electrode assembly and the surface of the first connecting portion facing the electrode assembly can simultaneously abut against the first electrode tab to increase the contact area between the first electrode tab and the electrode terminal and improve the current carrying capacity.

[0033] In some embodiments, the central axis coincides with the axis of the electrode lead-out hole.

[0034] In the above solution, the electrode lead-out hole is generally opened in the middle of the cover, and correspondingly, the electrode terminal is also installed in the middle of the cover. When multiple battery cells are assembled into a group, the positioning accuracy requirements for the electrode terminal can be reduced, simplifying the assembly process.

[0035] In some embodiments, the electrode terminal further includes a retaining portion connected to and protruding from an outer sidewall of the columnar portion. The retaining portion is located on a side of the cover body away from the first connecting portion. The first connecting portion and the retaining portion are configured to clamp a portion of the cover body in a first direction. The first connecting portion and the retaining portion clamp a portion of the cover body from both sides to secure the electrode terminal to the cover body.

[0036] In some embodiments, the battery cell further includes a first insulating member and a second insulating member, wherein at least a portion of the first insulating member is sandwiched between the stopper and the cover, and at least a portion of the second insulating member is sandwiched between the first connecting portion and the cover. The first insulating member and the second insulating member are used to insulate the electrode terminal from the cover.

[0037] In some embodiments, the first insulating member and the second insulating member are integrally formed; alternatively, the first insulating member and the second insulating member are provided separately and abut against each other.

[0038] In some embodiments, one of the first insulating member and the second insulating member is used to seal the electrode lead-out hole.

[0039] In some embodiments, a plurality of protrusion structures are provided on the outer periphery of the limiting portion, and the plurality of protrusion structures are arranged at intervals along the circumference of the columnar portion.

[0040] In the above solution, there is a groove structure between adjacent protrusion structures. This solution reduces the difficulty of folding the first limiting portion and reduces stress concentration on the first limiting portion by providing the groove structure and the protrusion structure.

[0041] In some embodiments, the limiting portion is a flange structure formed by folding outward from the end of the columnar portion away from the electrode assembly.

[0042] In some embodiments, the columnar portion is provided with a first through hole, the first through hole communicating with the interior space of the housing and the exterior space of the housing. The electrode terminal further includes a sealing plate connected to the columnar portion and used to seal the first through hole.

[0043] In the above solution, the first through hole can be used in multiple molding processes, for example, the first through hole can be used in the injection process, the formation process, or other processes. After the battery cell is formed, the sealing plate can reduce the risk of electrolyte leakage through the first through hole and improve the sealing performance.

[0044] In some embodiments, the first through hole is used to inject electrolyte into the interior space of the housing.

[0045] In some embodiments, the columnar portion has a first recessed portion that is recessed from a surface of the columnar portion facing away from the electrode assembly in a direction toward the electrode assembly. The columnar portion forms a second connecting portion at the bottom of the first recessed portion, and the first through-hole extends through the second connecting portion to connect the first recessed portion with the interior space of the housing. At least a portion of the sealing plate is received in the first recessed portion and seals the opening of the first recessed portion.

[0046] In the above solution, at least a portion of the sealing plate is accommodated within the first recess. This reduces the overall size of the electrode terminal in the first direction, reduces the space occupied by the electrode terminal, and improves energy density. During assembly, the first recess also positions the sealing plate, simplifying the assembly process.

[0047] In some embodiments, the first electrode tab further includes a second annular portion, the first annular portion surrounding an outer side of the second annular portion, the second annular portion being disposed opposite the electrode lead-out hole along the first direction, and at least a portion of the second annular portion abutting against the second connecting portion. The second connecting portion is welded to the second annular portion to form a second weld.

[0048] In the above solution, the second welded portion can reduce the contact resistance between the second connecting portion and the second annular portion, thereby improving the current carrying capacity. In this solution, the thickness of the second connecting portion is reduced by providing the first recess. This reduces the welding power required to weld the second connecting portion to the second annular portion, reduces heat generation, and reduces the risk of burns to other components.

[0049] In some embodiments, the second connecting portion includes a second recess, the bottom wall of the second recess is formed with a second welding portion, and the second recess is configured to be recessed from the outer surface of the second connecting portion in a direction facing the electrode assembly so that a gap is formed between the outer surface of the second connecting portion and the bottom wall of the second recess.

[0050] During battery cell production, external devices must mate with the second connection portion. Due to the uneven surface of the second welding portion, if an external device is pressed against the second welding portion, it could be easily crushed. This embodiment provides a second recess to create a gap between the outer surface of the second connecting portion and its bottom wall. This allows the outer surface of the second connecting portion to support the external device, separating it from the second welding portion and reducing the risk of crushing the external device.

[0051] In some embodiments, a gap is provided between the sealing plate and the second connecting portion for avoiding the second welding portion.

[0052] In the above solution, a gap is provided between the sealing plate and the second connecting portion to avoid direct contact between the sealing plate and the second welding portion, thereby reducing shaking of the sealing plate during assembly and ensuring sealing effect.

[0053] In some embodiments, a step surface is provided on a sidewall of the first recess, and the step surface is used to support the sealing plate.

[0054] In the above solution, when assembling the sealing plate, the stepped surface can support and position the sealing plate, thereby simplifying the assembly process. The first recess has a stepped structure, so that the sealing plate rests on the stepped surface to form a gap between the sealing plate and the second connecting portion.

[0055] In some embodiments, the sealing plate is used to be welded to the busbar component of the battery to form a third welding portion.

[0056] In the above solution, the third welding portion can reduce the contact resistance between the sealing plate and the current collecting component, thereby improving the current carrying capacity.

[0057] In some embodiments, at least a portion of the sealing plate protrudes from the outer surface of the cylindrical portion.

[0058] In the above solution, at least part of the sealing plate protrudes from the outer surface of the columnar portion to avoid the outer surface of the columnar portion interfering with the fit between the sealing plate and the flow collecting component, thereby ensuring that the flow collecting component and the sealing plate are tightly connected.

[0059] In some embodiments, the electrode assembly has a wound structure, and the electrode assembly has a second through-hole at the center of the winding. The second through-hole extends through the electrode assembly along a first direction, and the second through-hole is arranged opposite the first through-hole along the first direction, so that electrolyte can flow into the interior of the electrode assembly through the second through-hole. During the injection process, the electrolyte can flow through the first through-hole into the second through-hole. The electrolyte flowing into the second through-hole can soak the electrode assembly from the inside, thereby improving the soaking efficiency of the electrode assembly.

[0060] In some embodiments, the projection of the first through hole along the first direction is located within the projection of the second through hole along the first direction, which can reduce the obstruction of the first through hole by the first tab and allow the electrolyte to flow smoothly into the second through hole.

[0061] In some embodiments, the cover and the barrel are formed as an integral structure. This can eliminate the need for a connecting step between the cover and the barrel. The housing can be formed by a stretching process.

[0062] In some embodiments, the electrode assembly further includes a second tab disposed about a central axis of the electrode assembly. The first tab and the second tab are disposed at opposite ends of the electrode assembly along a first direction. The barrel is configured to connect the second tab to the cover to electrically connect the second tab to the cover.

[0063] In the above solution, the cover and electrode terminal have different polarities. In this case, one of the cover and electrode terminal can serve as the positive output terminal of the battery cell, while the other can serve as the negative output terminal of the battery cell. In this embodiment, the positive and negative output terminals are placed on the same side of the battery cell, which simplifies the connection process between multiple battery cells.

[0064] In some embodiments, the second 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.

[0065] 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.

[0066] In a second aspect, an embodiment of the present application provides a battery comprising a plurality of battery cells according to any one embodiment of the first aspect and a busbar component, wherein the busbar component is used to electrically connect at least two battery cells.

[0067] 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.

[0068] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, comprising:

[0069] An electrode assembly is provided, the electrode assembly comprising a first electrode tab, the first electrode tab being arranged around a central axis of the electrode assembly, the first electrode tab comprising a first annular portion;

[0070] Providing an electrode terminal including a columnar portion and a first connecting portion connected to the columnar portion;

[0071] connecting at least a portion of the first connecting portion to the first annular portion to electrically connect the first tab and the electrode terminal;

[0072] A housing is provided, the housing comprising a cylinder and a cover connected to the cylinder, the cylinder having an opening at one end away from the cover, and the cover having an electrode lead-out hole;

[0073] Installing the electrode assembly and the electrode terminal into the housing, and extending the columnar portion out of the cover through the electrode lead-out hole;

[0074] providing a cover plate and connecting the cover plate to the cylinder to close the opening of the cylinder;

[0075] In which, the cylinder is arranged around the outer circumference of the electrode assembly, the central axis extends along the first direction and passes through the electrode lead-out hole, the first annular portion is arranged opposite to the cover body, and the projection of the first annular portion in the first direction does not overlap with the projection of the electrode lead-out hole in the first direction, and at least part of the first connecting portion is located between the cover body and the first annular portion and is connected to the first annular portion.

[0076] In some embodiments, the manufacturing method of a battery cell further includes: compressing an end of the columnar portion facing away from the electrode assembly so that the end extends outward and forms a retaining structure, wherein the retaining structure is used to secure the electrode terminal to the cover. The retaining structure and the first connecting portion can clamp a portion of the cover from both sides to secure the electrode terminal to the cover.

[0077] In other embodiments, the manufacturing method of the battery cell further includes: folding outwardly an end of the columnar portion facing away from the electrode assembly to form a flange structure to secure the electrode terminal to the cover. The flange structure and the first connecting portion can clamp a portion of the cover from both sides to secure the electrode terminal to the cover.

[0078] In a fifth aspect, an embodiment of the present application provides a battery cell manufacturing system, comprising:

[0079] A first providing device is used to provide an electrode assembly, the electrode assembly including a first electrode tab, the first electrode tab is arranged around the central axis of the electrode assembly, and the first electrode tab includes a first annular portion;

[0080] A second providing device is used to provide an electrode terminal, including a columnar portion and a first connecting portion connected to the columnar portion;

[0081] a first assembling device for connecting at least a portion of the first connecting portion to the first annular portion to electrically connect the first tab to the electrode terminal;

[0082] A third providing device is used to provide a housing, the housing comprising a cylinder and a cover connected to the cylinder, the cylinder having an opening at one end facing away from the cover, and the cover having an electrode lead-out hole;

[0083] a second assembling device for installing the electrode assembly and the electrode terminal into the housing and allowing the columnar portion to extend to the outside of the cover through the electrode lead-out hole;

[0084] a fourth providing device for providing a cover plate and connecting the cover plate to the cylinder to close the opening of the cylinder;

[0085] In which, the cylinder is arranged around the outer circumference of the electrode assembly, the central axis extends along the first direction and passes through the electrode lead-out hole, the first annular portion is arranged opposite to the cover body, and the projection of the first annular portion in the first direction does not overlap with the projection of the electrode lead-out hole in the first direction, and at least part of the first connecting portion is located between the cover body and the first annular portion and is connected to the first annular portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] 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.

[0087] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0088] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0089] Figure 3 for Figure 2 A schematic structural diagram of the battery module shown;

[0090] Figure 4 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0091] Figure 5 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application;

[0092] Figure 6 for Figure 5 A partial enlarged schematic diagram of a battery cell is shown;

[0093] Figure 7 This is a schematic structural diagram of the electrode assembly and electrode terminals of a battery cell after welding in some embodiments of the present application;

[0094] Figure 8 Schematic diagram of the structure of the electrode assembly and electrode terminal of the battery cell after welding in some other embodiments of the present application;

[0095] Figure 9 for Figure 6 An enlarged schematic diagram of a battery cell shown at box B;

[0096] Figure 10 A schematic top view of an electrode terminal of a battery cell provided in some embodiments of the present application;

[0097] Figure 11 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application;

[0098] Figure 12 for Figure 11 A schematic structural diagram of the electrode terminal shown;

[0099] Figure 13 A schematic diagram of the structure of a battery cell connected to a busbar component according to some embodiments of the present application;

[0100] Figure 14 A schematic flow chart of a method for manufacturing a battery cell according to some embodiments of the present application;

[0101] Figure 15 A schematic block diagram of a battery cell manufacturing system provided in some embodiments of the present application. DETAILED DESCRIPTION

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] The term "plurality" used in this application refers to two or more (including two).

[0109] 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.

[0110] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0111] A battery cell comprises an electrode assembly and an electrolyte. The electrode assembly comprises a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer, which is coated on the surface of the positive electrode collector. The positive electrode collector comprises a positive current collector portion and a positive tab, which is coated with the positive active material layer, while the positive tab is not. For lithium-ion batteries, for example, the positive current collector may be made of aluminum, and the positive active material layer comprises a positive active material, which may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer, which is coated on the surface of the negative electrode collector. The negative electrode collector comprises a negative current collector portion and a negative tab, which is coated with the negative active material layer, while the negative tab is not. The negative electrode current collector may be made of copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon or silicon, etc. The separator may be made of PP (polypropylene) or PE (polyethylene), etc.

[0112] The battery cell also includes a shell for accommodating the electrode assembly. The shell is provided with electrode lead-out holes for installing electrode terminals. The electrode terminals are used to be electrically connected to the electrode assembly to realize charging and discharging of the electrode assembly.

[0113] The electrode assembly's electrode sheet includes an electrical generating part and a tab connected to the electrical generating part. Taking the positive electrode sheet as an example, the electrical generating part includes a positive current collecting part and an active material layer coated on the positive current collecting part. The electrode assembly generally inputs and outputs current through the tab, and in a wound electrode assembly, the tab and the electrical generating part are both multi-turn structures. As the number of turns increases from the inside to the outside, the circumference of each turn of the electrical generating part and the tab gradually increases, and correspondingly, the internal resistance of each turn also gradually increases.

[0114] The housing includes a cover body disposed opposite to the tab, and an electrode lead-out hole is provided on the cover body. The electrode lead-out hole is usually provided in the middle of the cover body, and accordingly, the electrode terminal is also installed in the middle of the cover body.

[0115] The inventors noticed that due to the limitations of the position of the electrode lead-out hole, the electrode terminal is usually connected to the inner ring area of the tab to achieve electrical connection between the electrode terminal and the tab. This results in a longer conductive path and a larger internal resistance between the outer ring area of the electricity generating part and the electrode terminal, affecting the current capacity and charging efficiency of the battery cell.

[0116] In view of this, an embodiment of the present application provides a technical solution, which extends a portion of the electrode terminal between the cover body and the first annular portion and connects to the electrode ear, so that the electrode terminal is connected to the portion of the electrode ear that is outside the electrode lead-out hole, so as to shorten the conductive path between the electrode ear and the electrode terminal, reduce the internal resistance, and improve the current carrying capacity.

[0117] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0118] 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.

[0119] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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 .

[0124] 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.

[0125] 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 .

[0126] 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.

[0127] 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.

[0128] Figure 3 for Figure 2 The schematic diagram of the battery module is shown.

[0129] 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.

[0130] Multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar 8 to achieve parallel, series, or mixed connection of multiple battery cells 7 in the battery module 6. There can be one or more busbars, each of which is used to electrically connect at least two battery cells 7.

[0131] Figure 4 An exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 5 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 6 for Figure 5 A partially enlarged schematic diagram of a battery cell is shown.

[0132] like Figures 4 to 6As shown, the battery cell 7 of the embodiment of the present application includes an electrode assembly 10, a housing 20, and an electrode terminal 30. The electrode assembly 10 includes a first tab 11, which is arranged around the central axis A of the electrode assembly 10. The housing 20 is used to accommodate the electrode assembly 10. The housing 20 includes a barrel 21 and a cover 22 connected to the barrel 21. The barrel 21 is arranged around the outer circumference of the electrode assembly 10. The cover 22 is provided with an electrode lead-out hole 221. The central axis A extends along the first direction X and passes through the electrode lead-out hole 221. The first tab 11 includes a first annular portion 112, which is arranged opposite to the cover 22. The projection of the first annular portion 112 in the first direction X does not overlap with the projection of the electrode lead-out hole 221 in the first direction X. The electrode terminal 30 includes a columnar portion 31 and a first connecting portion 32 connected to the columnar portion 31. The columnar portion 31 is at least partially located in the electrode lead-out hole 221. At least partially, the first connecting portion 32 is located between the cover body 22 and the first annular portion 112 and is used to connect the first annular portion 112 to electrically connect the first tab 11 and the electrode terminal 30.

[0133] 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.

[0134] The first pole piece, the second pole piece and the separator are all strip-shaped structures, and are wound together around the central axis A to form a wound structure. The wound structure can be a cylindrical structure, a flat structure or a structure of other shapes.

[0135] From the appearance of the electrode assembly 10, the electrode assembly 10 includes a main body 12, a first electrode tab 11, and a second electrode tab 13. The first electrode tab 11 and the second electrode tab 13 protrude from the main body 12. 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 13 is the portion of the second electrode sheet not coated with the active material layer.

[0136] The first electrode tab 11 and the second electrode tab 13 may extend from the same side of the main body 12 or from opposite sides thereof. For example, the first electrode tab 11 and the second electrode tab 13 are respectively disposed on opposite sides of the main body 12 along the first direction X. In other words, the first electrode tab 11 and the second electrode tab 13 are respectively disposed at both ends of the electrode assembly 10 along the first direction X. The first electrode tab 11 is located at the end of the electrode assembly 10 facing the cover 22, and the second electrode tab 13 is located at the end of the electrode assembly 10 facing away from the cover 22.

[0137] Optionally, the first pole tab 11 is wound around the central axis A of the electrode assembly 10 in multiple turns. In other words, 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. In the embodiment of the present application, the first pole tab 11 can be processed to reduce the gap between the pole tab layers to facilitate the connection of the first pole tab 11 with other conductive structures. For example, in the embodiment of the present application, the first pole tab 11 can be flattened to make the end area of the first pole tab 11 away from the main body 12 gather and gather together; the flattening process forms a dense end face at the end of the first pole tab 11 away from the main body 12, reducing the gap between the pole tab layers, and facilitating the connection of the first pole tab 11 with the electrode terminal 30. Alternatively, in the embodiment of the present application, a conductive material can be filled between two adjacent turns of pole tab layers to reduce the gap between the pole tab layers.

[0138] Optionally, the second electrode tab 13 is wound multiple times around the central axis A of the electrode assembly 10, and the second electrode tab 13 includes multiple electrode tab layers. Exemplarily, the second electrode tab 13 is also flattened to reduce gaps between the electrode tab layers of the second electrode tab 13.

[0139] 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.

[0140] 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.

[0141] The housing 20 is a hollow structure with one end open. Specifically, the barrel 21 has an opening 211 at one end facing away from the cover 22. The battery cell 7 also includes a cover plate 50, which covers the opening of the barrel 21 to seal the opening 211. The cover plate 50 can have various structures, for example, a plate-like structure.

[0142] 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.

[0143] The central axis A is a virtual straight line parallel to the first direction X, which passes through the electrode lead-out hole 221. The central axis A of the electrode assembly 10 and the axis of the electrode lead-out hole 221 may or may not coincide with each other.

[0144] The electrode terminals 30 are used to connect to the busbar components to achieve electrical connection between the battery cells 7 .

[0145] The electrode terminal 30 may be insulated and disposed on the cover 22 , or may be electrically connected to the cover 22 . This embodiment of the present application does not limit this, as long as the first electrode tab 11 and the second electrode tab 13 are prevented from being electrically conductive.

[0146] The housing 20 may be positively charged, negatively charged, or uncharged.

[0147] The first electrode tab 11 may be a positive electrode tab or a negative electrode tab.

[0148] The first annular portion 112 is an annular structure disposed around the central axis A and is located outside the electrode lead-out hole 221 along the second direction. The radius of each electrode tab layer in the first annular portion 112 is greater than the radius of the electrode lead-out hole 221. The second direction is the radial direction of the first electrode tab 11.

[0149] In this embodiment, the cover 22 refers to a solid portion, which is disposed opposite to the first annular portion 112 in the first direction X. The cover 22 covers the first annular portion 112 in the first direction X.

[0150] The first electrode tab 11 may be entirely located outside the electrode lead-out hole 221 along the second direction, that is, the first electrode tab 11 only includes the first annular portion 112. Of course, a portion of the first electrode tab 11 may also be disposed opposite the electrode lead-out hole 221 along the first direction X, that is, the projection of the first electrode tab 11 in the first direction X partially overlaps with the projection of the electrode lead-out hole 221 in the first direction X.

[0151] The electrode terminal 30 is mounted in the electrode lead-out hole 221 and covers the electrode lead-out hole 221. The columnar portion 31 may extend to the outside of the housing 20 through the electrode lead-out hole 221 to lead out the electrical energy of the electrode assembly 10.

[0152] The electrode terminal 30 is fixed to the cover 22. The electrode terminal 30 can be fixed to the cover 22 by its own structure, for example, by welding, riveting or other means, or by other fixing members.

[0153] The first connecting portion 32 may be connected to the first annular portion 112 by welding, abutting, or bonding.

[0154] At least a portion of the first connecting portion 32 overlaps with the first annular portion 112 in the first direction X, so that the first connecting portion 32 is connected to the first annular portion 112 .

[0155] The first connecting portion 32 protrudes from and connects to the outer wall of the columnar portion 31. There may be one or more first connecting portions 32. For example, the first connecting portion 32 may be an annular structure surrounding the outer side of the columnar portion 31. Alternatively, there may be multiple first connecting portions 32, and the multiple first connecting portions 32 may be spaced apart along the circumference of the columnar portion 31.

[0156] The columnar portion 31 and the first connecting portion 32 may be an integrally formed structure. Of course, the columnar portion 31 and the first connecting portion 32 may also be two components provided separately and then connected together by welding, riveting, bonding, or the like.

[0157] In the battery cell 7 of the embodiment of the present application, the first annular portion 112 of the first electrode tab 11 is connected by the first connecting portion 32 extending between the cover body 22 and the first annular portion 112, so that the current in the electrode assembly 10 can flow to the electrode terminal 30 through the first annular portion 112, thereby shortening the conductive path, reducing the internal resistance, and improving the current flow capacity and charging efficiency of the battery cell 7.

[0158] The outer circle area of the electrical generating part of the first electrode piece corresponds to the first annular part 112. The current in the outer circle part can flow to the electrode terminal 30 through the first annular part 112, thereby shortening the conductive path; and the inner circle area of the electrical generating part of the first electrode piece has a smaller circumference, so the conductive path between the inner circle area and the first annular part 112 is also relatively small. Therefore, this embodiment can shorten the conductive path and reduce the internal resistance.

[0159] In some embodiments, the central axis A coincides with the axis of the electrode lead-out hole 221 .

[0160] This embodiment does not require that the central axis A completely coincide with the axis of the electrode lead-out hole 221 ; there may be a deviation between the two that is permitted by the process.

[0161] In this embodiment, the electrode lead-out hole 221 is generally opened in the middle of the cover 22. Accordingly, the electrode terminal 30 is also installed in the middle of the cover 22. When multiple battery cells 7 are assembled into a group, the positioning accuracy requirement of the electrode terminal 30 can be reduced, simplifying the assembly process.

[0162] Exemplarily, the axis of the electrode lead-out hole 221 coincides with the axis of the cover 22, and the cover 22 is an annular structure disposed around the axis of the electrode lead-out hole 221. Optionally, the electrode lead-out hole 221 is a circular hole, and the cover 22 is an annular structure.

[0163] Exemplarily, the axis of the electrode terminal 30 coincides with the axis of the electrode lead-out hole 221 .

[0164] 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.

[0165] In some embodiments, the electrode assembly 10 further includes a second electrode tab 13, which is disposed around the central axis A of the electrode assembly 10. The first electrode tab 11 and the second electrode tab 13 are respectively disposed at both ends of the electrode assembly 10 along the first direction X. The barrel 21 is used to connect the second electrode tab 13 and the cover 22 to electrically connect the second electrode tab 13 and the cover 22.

[0166] The barrel 21 may be directly electrically connected to the second electrode tab 13 or may be electrically connected to the second electrode tab 13 through other components. For example, the second electrode tab 13 is electrically connected to the barrel 21 through the cover plate 50 .

[0167] The cover 22 and the electrode terminal 30 have different polarities. In this case, one of the cover 22 and the electrode terminal 30 can serve as the positive output terminal of the battery cell 7, while the other can serve as the negative output terminal of the battery cell 7. In this embodiment, the positive and negative output terminals are arranged on the same side of the battery cell 7, which simplifies the connection process between multiple battery cells 7.

[0168] The electrode lead-out hole 221 in the embodiment of the present application is formed after the shell 20 is stretched.

[0169] The inventors have tried to roll the open end of the cylinder so that the open end of the cylinder is folded 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 current collecting component, 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.

[0170] In this embodiment, a hole-forming process is used to form electrode lead-out holes 221 on the cover 22 for mounting the electrode terminals 30. This allows the positive and negative output electrodes to be positioned at the end of the battery cell 7 facing away from the opening of the barrel 21. The cover 22 is formed during the molding process of the housing 20. Even after the electrode lead-out holes 221 are formed, the flatness of the cover 22 is maintained, ensuring the connection strength between the cover 22 and the current collector. Furthermore, the flatness of the cover 22 is not constrained by its own dimensions, allowing it to be larger, thereby improving the current handling capacity of the battery cell 7.

[0171] In some embodiments, the second electrode tab 13 is a negative electrode tab, and the base material of the shell 20 is steel.

[0172] 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.

[0173] In some embodiments, the columnar portion 31 and the first connecting portion 32 are integrally formed.

[0174] In this embodiment, the connection process between the columnar portion 31 and the first connection portion 32 can be omitted, thereby simplifying the structure of the electrode terminal 30 , reducing the resistance of the electrode terminal 30 , and improving the current carrying capacity.

[0175] In some embodiments, the first connection portion 32 is an annular structure surrounding the outer side of the columnar portion 31 , and at least a portion of the first connection portion 32 is welded to the first annular portion 112 to form a first welding portion W1 .

[0176] In the second direction, the first welding portion W1 is located outside the electrode lead-out hole 221 .

[0177] When assembling the battery cell 7, the first annular portion 112 of the first tab 11 of the electrode assembly 10 can be welded to the first connecting portion 32 of the electrode terminal 30, and then the electrode assembly 10 and the electrode terminal 30 are placed together in the shell 20, and the columnar portion 31 is extended from the electrode lead-out hole 221.

[0178] The shape of the first welding portion W1 can be linear, C-shaped, ring-shaped, spiral, V-shaped or other shapes, which is not limited in this embodiment.

[0179] There may be one or more first welding portions W1 .

[0180] The first welding portion W1 can reduce the contact resistance between the electrode terminal 30 and the first annular portion 112 and improve the current carrying capacity.

[0181] In some embodiments, a cross-section of the first electrode tab 11 perpendicular to the first direction X is annular. The outer radius of the first electrode tab 11 is R, and the minimum spacing between the first weld portion W1 and the central axis A in the second direction is D, and both satisfy the following relationship: 0.2≤D / R≤0.8, where the second direction is the radial direction of the first electrode tab 11.

[0182] After being flattened, the first tab 11 is generally cylindrical in shape. The cross section of the first tab 11 perpendicular to the first direction X is not required to be an absolute circular ring, and a certain deviation is allowed.

[0183] The first weld W1 is used to transmit current between the electrode terminal 30 and the first tab 11, and its position has a direct impact on the conductive path of each part of the first tab 11. If D / R is less than 0.2, the spacing between the first weld W1 and the outermost tab layer is too large, resulting in a large difference between the current path between the outermost tab layer and the electrode terminal 30 and the current path between the innermost tab layer and the electrode terminal 30, causing uneven current density in the first electrode sheet of the electrode assembly 10 and increasing internal resistance. If D / R is greater than 0.8, the spacing between the first weld W1 and the innermost tab layer is too large, resulting in a large difference between the current path between the outermost tab layer and the electrode terminal 30 and the current path between the innermost tab layer and the electrode terminal 30, causing uneven current density in the first electrode sheet and increasing internal resistance.

[0184] In the embodiment of the present application, the values of D and R are set to 0.2≤D / R≤0.8, which can reduce the difference in current paths between parts at different positions of the first electrode tab 11 and the electrode terminal 30, improve the uniformity of the current density of the first electrode sheet of the electrode assembly 10, reduce the internal resistance, and improve the overcurrent capacity.

[0185] Optionally, 0.3≤D / R≤0.7. Exemplarily, the value of D / R is 0.3, 0.4, 0.5, 0.6 or 0.7.

[0186] In some embodiments, the total number of turns of the tab layer of the first tab 11 is N1, and the total number of turns of the tab layer connected to the first welding portion W1 is N2, and both satisfy: 0.3≤N2 / N1≤0.7.

[0187] The first weld W1 connects the N2 tab layers together, allowing current between the N2 tab layers to flow directly through the first weld W1 to the electrode terminal 30 without passing through other tab layers. Setting N2 / N1 ≥ 0.3 effectively improves current flow capacity and reduces differences in current paths between different parts of the first tab 11 and the electrode terminal 30. If N2 / N1 > 0.7, the first connecting portion 32 will be too large and the columnar portion 31 too small in the radial direction of the first tab 11, affecting the flow area of the electrode terminal 30.

[0188] Alternatively, the value of N2 / N1 may be 0.3, 0.4, 0.5, 0.6 or 0.7.

[0189] Figure 7 This is a schematic structural diagram of the electrode assembly and electrode terminals of a battery cell after welding in some embodiments of the present application; Figure 8 Schematic diagram of the structure of the electrode assembly and electrode terminal of the battery cell after welding according to other embodiments of the present application.

[0190] like Figure 7As shown, in some embodiments, the first welding portion W1 is annular and disposed around the columnar portion 31 .

[0191] The annular first welding portion W1 has a larger flow area, which can improve the uniformity of the current density of the first pole piece, reduce the internal resistance, and improve the flow capacity.

[0192] In some embodiments, in the radial direction of the first electrode tab 11 , a ratio of a size of the first welding portion W1 (ie, a width of the annular first welding portion W1 ) to an outer radius of the first electrode tab 11 is 0.3-0.7.

[0193] like Figure 8 As shown, in other embodiments, there are multiple first welding portions W1 , and the multiple first welding portions W1 are arranged at intervals along the circumference of the columnar portion 31 .

[0194] The first welding portion W1 may be a linear structure extending along the radial direction of the first electrode tab 11 , or may be a V-shaped structure, or may be other structures.

[0195] The multiple first welding portions W1 can increase the flow area, improve the uniformity of the current density of the first electrode, reduce the internal resistance, and improve the flow capacity.

[0196] Figure 9 for Figure 6 An enlarged schematic diagram of a battery cell shown at box B; Figure 10 Schematic top view of the electrode terminals of a battery cell provided in some embodiments of the present application.

[0197] Reference Figure 6 、 Figure 9 and Figure 10 In some embodiments, the first connecting portion 32 includes a first abutting portion 321 and a second abutting portion 322. The first abutting portion 321 abuts against and is welded to the first annular portion 112 to form a first welding portion W1. A gap is formed between the first abutting portion 321 and the cover 22 to avoid the first welding portion W1. The second abutting portion 322 is used to connect the first abutting portion 321 and the columnar portion 31 and abut against the cover 22.

[0198] The gap avoiding the first welding portion W1 is located on the side of the first welding portion W1 away from the first annular portion 112 . The gap can separate the component (eg, the cover 22 ) located on the side of the first welding portion W1 away from the first annular portion 112 from the first welding portion W1 .

[0199] In this embodiment, the gap can be formed by reducing the thickness of the first abutting portion 321, or by providing a groove on the first abutting portion 321; of course, the present application is not limited to these two methods, and other methods can also be used to form the gap for avoiding the first welding portion W1.

[0200] The second abutting portion 322 may directly abut against the cover 22 or indirectly abut against the cover 22 via other components. When the housing 20 and the electrode terminal 30 are assembled, the second abutting portion 322 may function as a position limiter.

[0201] Optionally, the second abutting portion 322 is an annular structure surrounding the outer side of the columnar portion 31 .

[0202] The surface of the first abutting portion 321 facing the first annular portion 112 abuts against and contacts the first annular portion 112 , so that current can be transmitted through the contact surface between the first abutting portion 321 and the first annular portion 112 to improve the current carrying capacity.

[0203] When assembling the electrode terminal 30 and the electrode assembly 10, the first abutting portion 321 of the electrode terminal 30 is first abutted against the first pole tab 11, and then a laser is irradiated on the surface of the first abutting portion 321 facing away from the first pole tab 11. The laser welds the first abutting portion 321 and the first annular portion 112 to form a first welding portion W1.

[0204] The surface of the first weld portion W1 is uneven, and if the first weld portion W1 directly contacts other components, these components may be damaged. In this embodiment, a gap is formed between the first abutting portion 321 and the cover 22 to allow the first weld portion W1 to avoid the cover 22 or other components between the first abutting portion 321 and the cover 22, thereby reducing the risk of crushing the cover 22 and other components and improving safety.

[0205] In some embodiments, a surface of the first abutting portion 321 facing the cover 22 is farther away from the cover 22 than a surface of the second abutting portion 322 facing the cover 22 , so as to form a gap for avoiding the first welding portion W1 .

[0206] The first abutting portion 321 has a first inner surface 321a and a first outer surface 321b opposite to each other in the first direction X, and the first outer surface 321b faces the cover 22. The second abutting portion 322 has a second inner surface 322a and a second outer surface 322b opposite to each other in the first direction X, and the second outer surface 322b faces the cover 22.

[0207] In the first direction X, the first outer surface 321b is farther away from the cover body 22 than the second outer surface 322b. This embodiment does not limit the relative positions of the first inner surface 321a and the second inner surface 322a. For example, the first inner surface 321a can be flush with the second inner surface 322a.

[0208] Optionally, the first abutting portion 321 is a flat plate structure as a whole, and the first inner surface 321 a and the first outer surface 321 b are both planes.

[0209] In some embodiments, a protrusion 323 is provided on the surface of the first abutting portion 321 facing the electrode assembly 10, and the protrusion 323 abuts against the first annular portion 112. A groove 324 is formed on the surface of the first abutting portion 321 facing away from the electrode assembly 10 in an area corresponding to the protrusion 323. The portion between the top surface of the protrusion 323 and the bottom surface of the groove 324 is used for welding to the first annular portion 112 to form a first weld W1.

[0210] When assembling the electrode terminal 30 and the electrode assembly 10, the protrusion 323 of the electrode terminal 30 is first pressed against the first annular portion 112 before welding. The protrusion 323 can better fit the first annular portion 112, reducing the risk of poor welding.

[0211] The protrusion 323 protrudes relative to the first inner surface 321a toward the first annular portion 112. In some embodiments, the protrusion 323 can press against the first annular portion 112 and embed into the first annular portion 112, with the first inner surface 321a pressing against the end surface of the first annular portion 112. This allows some current to be transmitted through the interface between the first inner surface 321a and the end surface of the first annular portion 112, thereby improving current handling capacity.

[0212] The groove 324 is recessed relative to the first outer surface 321b in a direction facing the first annular portion 112. In this embodiment, the provision of the groove 324 can reduce the thickness of the portion between the top surface of the protrusion 323 and the bottom surface of the groove 324, thereby reducing the power required for welding, reducing heat generation, and reducing the risk of burns to the electrode assembly 10.

[0213] In this embodiment, a gap for avoiding the first welding portion W1 is formed by providing the groove 324 .

[0214] In some embodiments, a fixing sheet (not shown) may be disposed within the groove 324 to cover the first welding portion W1 and secure any metal particles remaining on the first welding portion W1, thereby reducing the risk of metal particles falling into the electrode assembly 10 and causing a short circuit. The fixing sheet may be an insulating patch, an insulating adhesive layer, or other structures.

[0215] In some embodiments, the surface of the second abutting portion 322 facing the electrode assembly 10 abuts against the first annular portion 112 .

[0216] The second inner surface 322a of the second abutting portion 322 abuts against and contacts the first annular portion 112 , and part of the current can also be transmitted through the fitting portion between the second inner surface 322a and the end surface of the first annular portion 112 , thereby improving the current flow capacity.

[0217] In some embodiments, the first abutting portion 321 surrounds the outer side of the second abutting portion 322 , and the thickness of the first abutting portion 321 is smaller than the thickness of the second abutting portion 322 .

[0218] The second abutting portion 322 is used to abut against the cover 22 and requires a greater thickness to reduce deformation of the second abutting portion 322 during assembly. The first abutting portion 321 is used for welding to the first annular portion 112 and can have a smaller thickness to reduce the power required for welding, reduce heat generation, and reduce the risk of burns to the electrode assembly 10.

[0219] In some embodiments, the first electrode tab 11 further includes a second annular portion 111 , the first annular portion 112 surrounds the outside of the second annular portion 111 , the second annular portion 111 is arranged opposite to the electrode lead-out hole 221 along the first direction X, and at least a portion of the second annular portion 111 abuts against the columnar portion 31 .

[0220] The second annular portion 111 is disposed opposite the electrode lead-out hole 221 along the first direction X, meaning that the projection of the second annular portion 111 along the first direction X is located within the projection of the electrode lead-out hole 221 along the first direction X, and the contour of the projection of the second annular portion 111 along the first direction X coincides with the contour of the projection of the electrode lead-out hole 221 along the first direction X. Exemplarily, the second annular portion 111 is disposed around the central axis A.

[0221] The first annular portion 112 is connected to the second annular portion 111 and is an annular structure surrounding the outside of the second annular portion 111. The outline of the projection of the electrode lead-out hole 221 onto the first electrode tab 11 along the first direction X can be considered to coincide with the outline of the boundary line between the second annular portion 111 and the first annular portion 112.

[0222] At least a portion of the second annular portion 111 abuts against the columnar portion 31 , so that part of the current can be transmitted to the electrode terminal 30 through the abutment between the second annular portion 111 and the columnar portion 31 .

[0223] This embodiment improves flow capacity by providing the second annular portion 111. The second annular portion 111 can also radially support the first annular portion 112, thereby reducing the risk of crushing and deforming the first annular portion 112 during welding, and improving the welding stability of the first annular portion 112 and the first connecting portion 32.

[0224] In some embodiments, the columnar portion 31 is welded to the second annular portion 111 to form a second welded portion. The second welded portion can reduce the contact resistance between the columnar portion 31 and the second annular portion 111, thereby improving the current carrying capacity.

[0225] In some embodiments, a surface of the columnar portion 31 facing the electrode assembly 10 is flush with a surface of the first connecting portion 32 facing the electrode assembly 10 .

[0226] In this embodiment, the surface of the columnar portion 31 facing the electrode assembly 10 and the surface of the first connecting portion 32 facing the electrode assembly 10 can simultaneously abut against the first electrode tab 11 to increase the contact area between the first electrode tab 11 and the electrode terminal 30 and improve the current flow capacity.

[0227] In some embodiments, the electrode terminal 30 also includes a limiting portion 33, which is connected to and protrudes from the outer wall of the columnar portion 31. The limiting portion 33 is located on the side of the cover body 22 away from the first connecting portion 32. The first connecting portion 32 and the limiting portion 33 are used to clamp a portion of the cover body 22 in the first direction X.

[0228] In the first direction X, at least a portion of the limiting portion 33 overlaps with the cover 22, and at least a portion of the first connecting portion 32 overlaps with the cover 22. The columnar portion 31 passes through the electrode lead-out hole 221 to connect the limiting portion 33 and the first connecting portion 32 located on both sides of the cover 22.

[0229] The limiting portion 33 and the first connecting portion 32 clamp a portion of the cover 22 from both sides to fix the electrode terminal 30 to the cover 22. The limiting portion 33 and the first connecting portion 32 can clamp the cover 22 directly or indirectly through other components.

[0230] Optionally, the columnar portion 31 is cylindrical, and the limiting portion 33 and the first connecting portion 32 are both annular.

[0231] In some embodiments, the columnar portion 31 , the limiting portion 33 and the first connecting portion 32 are integrally formed.

[0232] In some embodiments, the limiting portion 33 and the second abutting portion 322 overlap in the first direction X. Thus, the limiting portion 33 and the second abutting portion 322 are used to clamp a portion of the cover 22 in the first direction X to fix the electrode terminal 30 to the cover 22. For example, to ensure the connection strength between the electrode terminal 30 and the cover 22 and reduce deformation of the second abutting portion 322, the thickness of the second abutting portion 322 can be greater than the thickness of the first abutting portion 321.

[0233] In some embodiments, the battery cell 7 further includes a first insulating member 60 and a second insulating member 70. At least a portion of the first insulating member 60 is sandwiched between the stopper 33 and the cover 22, and at least a portion of the second insulating member 70 is sandwiched between the first connecting portion 32 and the cover 22. The first insulating member 60 and the second insulating member 70 are used to insulate and isolate the electrode terminal 30 from the cover 22.

[0234] The first insulating member 60 and the second insulating member 70 are both annular structures disposed around the columnar portion 31 .

[0235] The first insulating member 60 can insulate and isolate the limiting portion 33 from the cover 22 , and the second insulating member 70 can insulate and isolate the first connecting portion 32 from the cover 22 .

[0236] In some embodiments, one of the first insulating member 60 and the second insulating member 70 separates the columnar portion 31 from the cover 22. For example, a portion of the first insulating member 60 extends into the electrode lead-out hole 221 to separate the hole wall of the electrode lead-out hole 221 from the columnar portion 31.

[0237] In some embodiments, at least a portion of the second insulating member 70 is clamped between the cover 22 and the second abutting portion 322. In other words, the second abutting portion 322 abuts against the cover 22 via the second insulating member 70.

[0238] The second abutting portion 322 can be used to support and fix the second insulating member 70 and separate the second insulating member 70 from the first welding portion W1 to prevent the first welding portion W1 from crushing the second insulating member 70. Optionally, the first abutting portion 321 is spaced apart from the second insulating member 70.

[0239] In some embodiments, the first insulating member 60 and the second insulating member 70 are integrally formed. Alternatively, in other embodiments, the first insulating member 60 and the second insulating member 70 are provided separately and abut against each other.

[0240] In some embodiments, one of the first insulating member 60 and the second insulating member 70 is used to seal the electrode lead-out hole 221. In some examples, the stopper 33 and the cover 22 press the first insulating member 60, compressing and sealing the electrode lead-out hole 221 from the outside. In other examples, the first connecting portion 32 and the cover 22 press the second insulating member 70, compressing and sealing the electrode lead-out hole 221 from the inside.

[0241] In some embodiments, the battery cell 7 further includes a sealing ring 80, which is sleeved on the columnar portion 31 and is used to seal the electrode lead-out hole 221. Optionally, a portion of the sealing ring 80 extends into the electrode lead-out hole 221 to separate the hole wall of the electrode lead-out hole 221 from the columnar portion 31.

[0242] In some embodiments, a plurality of protrusion structures 331 are provided on the outer periphery of the limiting portion 33 , and the plurality of protrusion structures 331 are arranged at intervals along the circumference of the columnar portion 31 .

[0243] Optionally, the plurality of protrusion structures 331 may be arranged at equal intervals along the circumference of the columnar portion 31 .

[0244] The limiting portion 33 is a flange structure formed by folding outward from the end of the columnar portion 31 away from the electrode assembly 10 .

[0245] Before the electrode terminal 30 is assembled into the housing 20, the retaining portion 33 of the electrode terminal 30 is generally cylindrical and located at the upper end of the columnar portion 31. The outer wall of the retaining portion 33 is flush with the outer wall of the columnar portion 31. When assembling the electrode terminal 30 and the housing 20, the retaining portion 33 is passed through the electrode lead-out hole 221 and then squeezed to fold outward, and the electrode terminal 30 is riveted to the cover 22.

[0246] Before the stopper 33 is folded, a plurality of spaced grooves 332 are formed at its upper end. After the stopper 33 is folded, a plurality of spaced protrusions 331 are formed along the circumference of the columnar portion 31. The grooves 332 are formed between adjacent protrusions 331. This embodiment utilizes the provision of the grooves 332 and protrusions 331 to reduce the difficulty of folding the stopper 33 and reduce stress concentration on the stopper 33.

[0247] Figure 11 A partial cross-sectional schematic diagram of a battery cell provided in some other embodiments of the present application; Figure 12 for Figure 11 Schematic diagram of the structure of the electrode terminal shown.

[0248] like Figure 11 and Figure 12 As shown, in some embodiments, the columnar portion 31 is provided with a first through hole 311, which communicates with the interior space of the housing 20 and the exterior space of the housing 20. The electrode terminal 30 further includes a sealing plate 34, which is connected to the columnar portion 31 and is used to seal the first through hole 311.

[0249] The first through hole 311 passes through the columnar portion 31 along the first direction. There can be one or more first through holes 311.

[0250] During the molding process of the battery cell 7 , the first through hole 311 may be used in multiple molding steps. For example, the first through hole 311 may be used in a liquid injection step, a formation step, or other steps.

[0251] The sealing plate 34 can seal the first through hole 311. After the battery cell 7 is formed, the sealing plate 34 can reduce the risk of electrolyte leakage through the first through hole 311 and improve the sealing performance.

[0252] Specifically, the first through hole 311 is used to inject electrolyte into the interior space of the housing 20 . When injection is required, the injection head of the injection device presses against the columnar portion 31 , and then injects electrolyte into the housing 20 through the first through hole 311 .

[0253] During the formation process of the battery cell 7 , gas is generated in the housing 20 . The first through hole 311 can also be used to communicate with an external negative pressure device to extract the gas in the housing 20 .

[0254] In some embodiments, the axis of the first through hole 311 coincides with the axis of the electrode lead-out hole 221 .

[0255] In some embodiments, the columnar portion 31 has a first recess 312, which is recessed from the surface of the columnar portion 31 facing away from the electrode assembly 10 and toward the electrode assembly 10. The columnar portion 31 forms a second connecting portion 313 at the bottom of the first recess 312. The first through-hole 311 passes through the second connecting portion 313 to connect the first recess 312 with the interior space of the housing 20. At least a portion of the sealing plate 34 is accommodated in the first recess 312 and closes the opening of the first recess 312.

[0256] In this embodiment, at least a portion of the sealing plate 34 is accommodated within the first recess 312. This reduces the overall size of the electrode terminal 30 in the first direction, reduces the space occupied by the electrode terminal 30, and improves energy density. During assembly of the sealing plate 34, the first recess 312 also positions the sealing plate 34, thereby simplifying the assembly process.

[0257] In some embodiments, the sealing plate 34 is welded to the sidewall of the first recess 312 to close the opening of the first recess 312 .

[0258] In some embodiments, the first electrode tab 11 further includes a second annular portion 111. The first annular portion 112 surrounds the outer side of the second annular portion 111. The second annular portion 111 is arranged opposite to the electrode lead-out hole 221 along the first direction X, and at least a portion of the second annular portion 111 abuts against the second connecting portion 313. The second connecting portion 313 is welded to the second annular portion 111 to form a second weld W2.

[0259] The projection of the second connection portion 313 along the first direction X is located within the projection of the electrode lead-out hole 221 along the first direction X.

[0260] The second weld portion W2 can reduce the contact resistance between the second connection portion 313 and the second annular portion 111, thereby improving the current carrying capacity. In this embodiment, the first recess 312 is provided to reduce the thickness of the second connection portion 313. This can reduce the welding power required to weld the second connection portion 313 to the second annular portion 111, reduce heat generation, and reduce the risk of burns to other components (such as the first and second insulating components).

[0261] During the welding process, the second connecting portion 313 is affected by welding stress. The first through hole 311 of this embodiment can relieve stress, thereby reducing the risk of deformation and cracking of the second connecting portion 313 during welding and ensuring the connection strength between the second connecting portion 313 and the second annular portion 111.

[0262] In some embodiments, the thickness of the second connection portion 313 is 0.5 mm-10 mm.

[0263] In some embodiments, the second connection portion 313 includes a second recess 314, the bottom wall of the second recess 314 is formed with a second welding portion W2, and the second recess 314 is configured to be recessed from the outer surface 313b of the second connection portion in a direction facing the electrode assembly so that a gap is formed between the outer surface 313b of the second connection portion and the bottom wall of the second recess 314.

[0264] In this embodiment, a second recess 314 is formed on the second connecting portion 313 to form a step structure on the second connecting portion 313 .

[0265] The portion between the bottom wall of the second recess 314 and the inner surface 313a of the second connecting portion is welded to the second annular portion 111 to form a second weld W2. The first through hole 311 extends from the bottom wall of the second recess 314 to the inner surface 313a of the second connecting portion to penetrate the second connecting portion 313.

[0266] During the production of battery cells 7, external devices need to be mated to the second connecting portion 313. Due to the uneven surface of the second welding portion W2, if an external device is pressed against the second welding portion W2, it can be easily crushed by the second welding portion W2. In this embodiment, the second recess 314 is provided to form a gap between the outer surface 313b of the second connecting portion and the bottom wall of the second recess 314. This allows the outer surface 313b of the second connecting portion to support the external device, separating it from the second welding portion W2 and reducing the risk of crushing the external device.

[0267] The external equipment may be a liquid injection device, a gas extraction device, a welding device, or a device for the battery cell 7 .

[0268] For example, when injecting liquid, the injection head presses against the outer surface 313b of the second connecting part. The outer surface 313b of the second connecting part can support the injection head and cooperate with the injection head to achieve sealing, thereby reducing the risk of electrolyte leakage to the outside of the battery cell 7.

[0269] In some embodiments, a gap is provided between the sealing plate 34 and the second connecting portion 313 to avoid the second welding portion W2 .

[0270] The surface of the second welding portion W2 is uneven. If the sealing plate 34 presses against the second welding portion W2, it will cause the sealing plate 34 to wobble during assembly, affecting the sealing effect. In this embodiment, a gap is provided between the sealing plate 34 and the second connecting portion 313 to avoid direct contact between the sealing plate 34 and the second welding portion W2, thereby reducing the shaking of the sealing plate 34 during assembly and ensuring the sealing effect.

[0271] In some embodiments, the sealing plate 34 may rest against the second connecting portion 313 , and the second recess 314 on the second connecting portion 313 forms a gap between the sealing plate 34 and the second connecting portion 313 .

[0272] In some other embodiments, a step surface 312 a is provided on the sidewall of the first recess 312 , and the step surface 312 a is used to support the sealing plate 34 .

[0273] The first recess 312 is a stepped recess that is larger on the outside and smaller on the inside.

[0274] When assembling the sealing plate 34, the stepped surface 312a can support and position the sealing plate 34, thereby simplifying the assembly process. The first recess 312 has a stepped structure, so that the sealing plate 34 abuts against the stepped surface 312a to form a gap between the sealing plate 34 and the second connecting portion 313.

[0275] In some embodiments, the electrode assembly 10 is a winding structure, and the electrode assembly 10 has a second through hole 14 at the center of the winding. The second through hole 14 passes through the electrode assembly 10 along the first direction. The second through hole 14 and the first through hole 311 are arranged opposite to each other along the first direction so that the electrolyte can flow into the interior of the electrode assembly 10 through the second through hole 14.

[0276] The electrode assembly is formed by winding the first electrode sheet, the second electrode sheet and the separator on a winding tool. After the winding is formed, the winding tool is removed from the electrode assembly. After the winding tool is removed, a second through hole 14 is formed in the middle of the electrode assembly.

[0277] The axis of the second through hole 14 coincides with the central axis of the electrode assembly. The second through hole 14 extends along the first direction through the first electrode tab 11, the main body 12, and the second electrode tab 13. The second annular portion 111 of the first electrode tab 11 is a circular ring-shaped structure surrounding the outside of the second through hole 14, and the first annular portion 112 is a circular ring-shaped structure surrounding the outside of the second annular portion 111.

[0278] During the injection process, the electrolyte can flow into the second through hole 14 through the first through hole 311 . The electrolyte flowing into the second through hole 14 can infiltrate the electrode assembly from the inside, thereby improving the infiltration efficiency of the electrode assembly.

[0279] In some embodiments, the projection of the first through hole 311 along the first direction X is located within the projection of the second through hole 14 along the first direction X. This can reduce the obstruction of the first tab 11 on the first through hole 311 , allowing the electrolyte to flow smoothly into the second through hole 14 .

[0280] In some embodiments, the first through hole 311 and the second through hole 14 are coaxially arranged. The aperture of the second through hole 14 can be greater than or equal to the aperture of the first through hole 311.

[0281] Figure 13 This is a schematic structural diagram of the battery cells and the busbar components provided in some embodiments of the present application after being connected.

[0282] like Figure 13 As shown, in some embodiments, the sealing plate 34 is used to be welded to the busbar component 8 of the battery to form a third welding portion W3.

[0283] In the battery, the battery cells 7 are electrically connected via the current collecting member 8. The third welding portion W3 can reduce the contact resistance between the sealing plate 34 and the current collecting member 8, thereby improving the current carrying capacity.

[0284] Optionally, in the battery, the busbar member 8 connects the sealing plate 34 of one battery cell 7 and the cover of another battery cell to connect the two battery cells in series.

[0285] In some embodiments, at least a portion of the sealing plate 34 protrudes from the outer surface 31 a of the cylindrical portion.

[0286] When the collector component 8 and the sealing plate 34 need to be welded, the collector component 8 is first attached to the upper surface of the sealing plate 34 (ie, the outer surface of the sealing plate 34 facing away from the second connection portion), and then the collector component 8 and the sealing plate 34 are welded.

[0287] At least part of the sealing plate 34 protrudes from the outer surface 31 a of the columnar portion to prevent the outer surface 31 a of the columnar portion from interfering with the fit between the sealing plate 34 and the flow collecting component 8 , thereby ensuring that the flow collecting component 8 and the sealing plate 34 are tightly connected.

[0288] Figure 14 A schematic flow chart of a method for manufacturing a battery cell provided in some embodiments of the present application.

[0289] like Figure 14 As shown, the manufacturing method of the battery cell of the embodiment of the present application includes:

[0290] S100, providing an electrode assembly, the electrode assembly comprising a first electrode tab, the first electrode tab being disposed around a central axis of the electrode assembly, and the first electrode tab comprising a first annular portion;

[0291] S200, providing an electrode terminal, including a columnar portion and a first connecting portion connected to the columnar portion;

[0292] S300, connecting at least a portion of the first connecting portion to the first annular portion to electrically connect the first tab and the electrode terminal;

[0293] S400, providing a housing, the housing comprising a cylinder and a cover connected to the cylinder, the cylinder having an opening at one end facing away from the cover, and the cover having an electrode lead-out hole;

[0294] S500, installing the electrode assembly and the electrode terminal into the housing, and extending the columnar portion to the outside of the cover through the electrode lead-out hole;

[0295] S600, providing a cover plate, and connecting the cover plate to the cylinder to close the opening of the cylinder;

[0296] In which, the cylinder is arranged around the outer circumference of the electrode assembly, the central axis extends along the first direction and passes through the electrode lead-out hole, the first annular portion is arranged opposite to the cover body, and the projection of the first annular portion in the first direction does not overlap with the projection of the electrode lead-out hole in the first direction, and at least part of the first connecting portion is located between the cover body and the first annular portion and is connected to the first annular portion.

[0297] In some embodiments, the method for manufacturing a battery cell further includes step S510: squeezing the end of the columnar portion away from the electrode assembly to extend the end outward and form a limiting structure, which is used to fix the electrode terminal to the cover.

[0298] In this embodiment, the limiting structure and the first connecting portion can clamp a portion of the cover body from both sides to fix the electrode terminal to the cover body.

[0299] Optionally, step S510 may be performed after step S500 and before step S600.

[0300] In some other embodiments, the method for manufacturing a battery cell further includes step S520: folding outwardly the end of the columnar portion away from the electrode assembly to form a flange structure to fix the electrode terminal to the cover.

[0301] In this embodiment, the flange structure and the first connecting portion can clamp a portion of the cover from both sides to fix the electrode terminal to the cover.

[0302] Optionally, step S520 may be performed after step S500 and before step S600.

[0303] 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.

[0304] 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.

[0305] Figure 15 A schematic block diagram of a battery cell manufacturing system provided in some embodiments of the present application.

[0306] like Figure 15 As shown, the battery cell manufacturing system 9 of the embodiment of the present application includes:

[0307] A first providing device 91 is used to provide an electrode assembly, wherein the electrode assembly includes a first electrode tab, which is arranged around the central axis of the electrode assembly and includes a first annular portion;

[0308] A second providing device 92 is used to provide an electrode terminal, including a columnar portion and a first connecting portion connected to the columnar portion;

[0309] a first assembling device 93 for connecting at least a portion of the first connecting portion to the first annular portion to electrically connect the first tab to the electrode terminal;

[0310] The third providing device 94 is used to provide a housing, the housing comprising a cylinder and a cover connected to the cylinder, the cylinder having an opening at one end facing away from the cover, and the cover having an electrode lead-out hole;

[0311] The second assembly device 95 is used to install the electrode assembly and the electrode terminal into the housing, and to extend the columnar portion to the outside of the cover through the electrode lead-out hole;

[0312] a fourth providing device 96 for providing a cover plate and connecting the cover plate to the cylinder to close the opening of the cylinder;

[0313] In which, the cylinder is arranged around the outer circumference of the electrode assembly, the central axis extends along the first direction and passes through the electrode lead-out hole, the first annular portion is arranged opposite to the cover body, and the projection of the first annular portion in the first direction does not overlap with the projection of the electrode lead-out hole in the first direction, and at least part of the first connecting portion is located between the cover body and the first annular portion and is connected to the first annular portion.

[0314] The relevant structures of the battery cells manufactured by the manufacturing system 9 can refer to the battery cells provided in the above embodiments.

[0315] 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.

[0316] 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, comprising: An electrode assembly includes a first electrode tab, wherein the first electrode tab is arranged around a central axis of the electrode assembly; a shell for accommodating the electrode assembly, the shell comprising a barrel and a cover connected to the barrel, the barrel being arranged around the outer circumference of the electrode assembly, the cover being provided with an electrode lead-out hole, the central axis extending along a first direction and passing through the electrode lead-out hole, the first electrode tab comprising a first annular portion, the first annular portion being arranged opposite to the cover, and a projection of the first annular portion in the first direction not overlapping with a projection of the electrode lead-out hole in the first direction, the shell being a cylinder; an electrode terminal comprising a columnar portion and a first connecting portion connected to the columnar portion, wherein the columnar portion is at least partially located within the electrode lead-out hole, and at least a portion of the first connecting portion is located between the cover and the first annular portion and is used to connect the first annular portion to electrically connect the first tab to the electrode terminal; The first connecting portion is an annular structure surrounding the outer side of the columnar portion, and at least a portion of the first connecting portion is welded to the first annular portion to form a first welding portion; The first connecting portion includes: a first abutting portion abutting against and welded to the first annular portion to form the first welding portion, a gap being formed between the first abutting portion and the cover body for avoiding the first welding portion; and a second abutting portion, used to connect the first abutting portion and the columnar portion and abut against the cover body; A surface of the first abutting portion facing the cover body is farther away from the cover body than a surface of the second abutting portion facing the cover body, so as to form a gap for avoiding the first welding portion.

2. The battery cell according to claim 1, wherein: The first welding portion is annular and arranged around the columnar portion; or, there are multiple first welding portions, and the multiple first welding portions are arranged at intervals along the circumference of the columnar portion.

3. The battery cell according to claim 1, wherein: A convex portion is provided on a surface of the first abutting portion facing the electrode assembly, and the convex portion abuts against the first annular portion; The first abutment portion has a groove formed in an area corresponding to the protrusion on a surface facing away from the electrode assembly, and a portion between the top surface of the protrusion and the bottom surface of the groove is used for welding with the first annular portion to form the first welding portion.

4. The battery cell according to claim 1, wherein: A surface of the second abutting portion facing the electrode assembly abuts against the first annular portion.

5. The battery cell according to claim 1, wherein The first abutting portion surrounds the outer side of the second abutting portion, and the thickness of the first abutting portion is smaller than the thickness of the second abutting portion.

6. The battery cell according to any one of claims 1 to 5, wherein: The columnar portion and the first connecting portion are integrally formed.

7. The battery cell according to any one of claims 1 to 5, wherein: The first electrode tab further includes a second annular portion, the first annular portion surrounds the outside of the second annular portion, the second annular portion is arranged opposite to the electrode lead-out hole along the first direction, and at least a portion of the second annular portion abuts against the columnar portion.

8. The battery cell according to claim 7, wherein: The columnar portion is welded to the second annular portion to form a second welded portion.

9. The battery cell according to claim 7, wherein: A surface of the columnar portion facing the electrode assembly is flush with a surface of the first connecting portion facing the electrode assembly.

10. The battery cell according to any one of claims 1 to 5, wherein: The central axis coincides with the axis of the electrode lead-out hole.

11. The battery cell according to any one of claims 1 to 5, wherein: The electrode terminal also includes a limiting portion, which is connected to and protrudes from the outer wall of the columnar portion. The limiting portion is located on the side of the cover body away from the first connecting portion. The first connecting portion and the limiting portion are used to clamp a portion of the cover body in the first direction.

12. The battery cell according to claim 11, wherein: The battery cell further includes a first insulating member and a second insulating member, wherein at least a portion of the first insulating member is clamped between the limiting portion and the cover, and at least a portion of the second insulating member is clamped between the first connecting portion and the cover; The first insulating member and the second insulating member are used to insulate and isolate the electrode terminal from the cover.

13. The battery cell according to claim 12, wherein: The first insulating member and the second insulating member are formed as an integral structure; or, The first insulating member and the second insulating member are provided separately and abut against each other.

14. The battery cell according to claim 12, wherein: One of the first insulating member and the second insulating member is used to seal the electrode lead-out hole.

15. The battery cell according to claim 11, wherein A plurality of protrusion structures are provided on the outer periphery of the limiting portion, and the plurality of protrusion structures are arranged at intervals along the circumference of the columnar portion.

16. The battery cell according to claim 15, wherein: The limiting portion is a flange structure formed by folding outward from the end of the columnar portion away from the electrode assembly.

17. The battery cell according to claim 1, wherein The columnar portion is provided with a first through hole, wherein the first through hole is connected to the inner space of the housing and the outer space of the housing; The electrode terminal further includes a sealing plate connected to the columnar portion and configured to seal the first through-hole.

18. The battery cell according to claim 17, wherein: The first through hole is used to inject electrolyte into the inner space of the shell.

19. The battery cell according to claim 17, wherein: The columnar portion has a first recessed portion, the first recessed portion being recessed from a surface of the columnar portion facing away from the electrode assembly in a direction facing the electrode assembly; The columnar portion forms a second connecting portion at the bottom of the first recess, and the first through hole passes through the second connecting portion to connect the first recess with the internal space of the housing; At least a portion of the sealing plate is accommodated in the first recess and closes an opening of the first recess.

20. The battery cell according to claim 19, wherein The first electrode tab further includes a second annular portion, the first annular portion surrounds the outside of the second annular portion, the second annular portion is arranged opposite to the electrode lead-out hole along the first direction, and at least a portion of the second annular portion abuts against the second connecting portion; The second connecting portion is welded to the second annular portion to form a second welding portion.

21. The battery cell according to claim 20, wherein: The second connecting portion includes a second recess, the bottom wall of which is formed with the second welding portion, and the second recess is configured to be recessed from the outer surface of the second connecting portion in a direction facing the electrode assembly so that a gap is formed between the outer surface of the second connecting portion and the bottom wall of the second recess.

22. The battery cell according to claim 20, wherein A gap is provided between the sealing plate and the second connecting portion for avoiding the second welding portion.

23. The battery cell according to claim 19, wherein A step surface is provided on the side wall of the first recess, and the step surface is used to support the sealing plate.

24. The battery cell according to claim 17, wherein The sealing plate is used to be welded to the busbar component of the battery to form a third welding portion.

25. The battery cell according to claim 24, wherein At least a portion of the sealing plate protrudes from the outer surface of the columnar portion.

26. The battery cell according to claim 17, wherein: The electrode assembly is a winding structure, and the electrode assembly has a second through hole at the center of the winding. The second through hole passes through the electrode assembly along the first direction. The second through hole is arranged opposite to the first through hole along the first direction so that the electrolyte can flow into the interior of the electrode assembly through the second through hole.

27. The battery cell according to claim 26, wherein: A projection of the first through hole along the first direction is located within a projection of the second through hole along the first direction.

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

29. The battery cell according to claim 1, wherein The electrode assembly further includes a second electrode tab, which is arranged around the central axis of the electrode assembly; The first electrode tab and the second electrode tab are respectively provided at two ends of the electrode assembly along the first direction; The barrel is used to connect the second electrode tab and the cover so that the second electrode tab and the cover are electrically connected.

30. The battery cell according to claim 29, wherein The second electrode tab is a negative electrode tab, and the base material of the shell is steel.

31. The battery cell according to claim 1, wherein 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.

32. A battery comprising a plurality of battery cells according to any one of claims 1 to 31 and a busbar component, wherein the busbar component is used to electrically connect at least two of the battery cells.

33. An electrical device comprising the battery according to claim 32, wherein the battery is used to provide electrical energy.

34. A method for manufacturing a battery cell, comprising: Providing an electrode assembly, the electrode assembly comprising a first electrode tab, the first electrode tab being arranged around a central axis of the electrode assembly, the first electrode tab comprising a first annular portion; Providing an electrode terminal, the electrode terminal comprising a columnar portion and a first connecting portion connected to the columnar portion; connecting at least a portion of the first connecting portion to the first annular portion to electrically connect the first tab to the electrode terminal; Providing a housing, the housing comprising a cylinder and a cover connected to the cylinder, the cylinder having an opening at one end away from the cover, and the cover having an electrode lead-out hole; Installing the electrode assembly and the electrode terminal into the housing, and allowing the columnar portion to extend to the outside of the cover through the electrode lead-out hole; providing a cover plate, and connecting the cover plate to the cylinder to close the opening of the cylinder; The barrel is arranged around the outer circumference of the electrode assembly, the central axis extends along a first direction and passes through the electrode lead-out hole, the first annular portion is arranged opposite to the cover, and a projection of the first annular portion in the first direction does not overlap with a projection of the electrode lead-out hole in the first direction, and at least a portion of the first connecting portion is located between the cover and the first annular portion and is connected to the first annular portion; The first connecting portion is an annular structure surrounding the outer side of the columnar portion, and at least a portion of the first connecting portion is welded to the first annular portion to form a first welding portion; The first connecting portion includes: a first abutting portion abutting against and welded to the first annular portion to form the first welding portion, a gap being formed between the first abutting portion and the cover body for avoiding the first welding portion; and a second abutting portion, used to connect the first abutting portion and the columnar portion and abut against the cover body; A surface of the first abutting portion facing the cover body is farther away from the cover body than a surface of the second abutting portion facing the cover body, so as to form a gap for avoiding the first welding portion.

35. The manufacturing method according to claim 34, further comprising: The end portion of the columnar portion facing away from the electrode assembly is squeezed to extend outward and form a limiting structure, wherein the limiting structure is used to fix the electrode terminal to the cover.

36. The manufacturing method according to claim 34, further comprising: The end of the columnar portion facing away from the electrode assembly is folded outward to form a flange structure to fix the electrode terminal to the cover.

37. A battery cell manufacturing system comprising: A first providing device is used to provide an electrode assembly, wherein the electrode assembly includes a first electrode tab, the first electrode tab is arranged around the central axis of the electrode assembly, and the first electrode tab includes a first annular portion; a second providing device for providing an electrode terminal, wherein the electrode terminal includes a columnar portion and a first connecting portion connected to the columnar portion; a first assembling device for connecting at least a portion of the first connecting portion to the first annular portion to electrically connect the first tab to the electrode terminal; A third providing device is used to provide a housing, the housing comprising a barrel and a cover connected to the barrel, the barrel having an opening at one end away from the cover, the cover having an electrode lead-out hole, and the housing being a cylinder; a second assembling device for installing the electrode assembly and the electrode terminal into the housing and allowing the columnar portion to extend to the outside of the cover through the electrode lead-out hole; a fourth providing device for providing a cover plate and connecting the cover plate to the cylinder to close the opening of the cylinder; The barrel is arranged around the outer circumference of the electrode assembly, the central axis extends along a first direction and passes through the electrode lead-out hole, the first annular portion is arranged opposite to the cover, and a projection of the first annular portion in the first direction does not overlap with a projection of the electrode lead-out hole in the first direction, and at least a portion of the first connecting portion is located between the cover and the first annular portion and is connected to the first annular portion; The first connecting portion is an annular structure surrounding the outer side of the columnar portion, and at least a portion of the first connecting portion is welded to the first annular portion to form a first welding portion; The first connecting portion includes: a first abutting portion abutting against and welded to the first annular portion to form the first welding portion, a gap being formed between the first abutting portion and the cover body for avoiding the first welding portion; and a second abutting portion, used to connect the first abutting portion and the columnar portion and abut against the cover body; A surface of the first abutting portion facing the cover body is farther away from the cover body than a surface of the second abutting portion facing the cover body, so as to form a gap for avoiding the first welding portion.

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