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

Abstract

The present application relates to the field of battery technology, and specifically to a battery cell, a battery, an electrical device, and a method and device for manufacturing a battery cell. The battery cell includes: a housing including a wall portion; an electrode terminal, the electrode terminal being disposed on the wall portion, the electrode terminal having an injection hole extending axially therethrough, the injection hole including a first hole segment and a second hole segment, the second hole segment being closer to the interior of the battery cell than the first hole segment, and the aperture of the second hole segment being smaller than the aperture of the first hole segment; and a seal, the seal being used to seal the injection hole, the seal including a body and a limiting protrusion, the body being in sealing engagement with the first hole segment, the body including a first surface and a second surface facing axially opposite each other, the first surface facing the interior of the battery cell, the second surface facing away from the interior of the battery cell, the limiting protrusion being formed on the first surface and engaging with the second hole segment to prevent the body from being easily tilted or displaced, thereby improving the sealing performance and thereby increasing the service life and safety of the battery cell.

Description

Technical Field

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

[0002] In the pursuit of energy conservation and emission reduction, batteries are widely used in electrical equipment such as mobile phones, computers, and electric vehicles to provide power for these equipment. The service life and safety of batteries are extremely important to the performance of these equipment. Summary of the Invention

[0003] The present application aims to provide a battery cell, a battery, an electrical device, and a method and equipment for manufacturing the battery cell, so as to improve the service life and safety of the battery.

[0004] The embodiment of the present application is implemented as follows:

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising: a shell comprising a wall portion; an electrode terminal, the electrode terminal being arranged on the wall portion, the electrode terminal having an injection hole extending axially therethrough, the injection hole comprising a first hole segment and a second hole segment, the second hole segment being closer to the interior of the battery cell than the first hole segment, the aperture of the second hole segment being smaller than the aperture of the first hole segment; and a seal, the seal being used to seal the injection hole, the seal comprising a main body and a limiting protrusion, the main body being sealingly matched with the first hole segment, the main body comprising a first surface and a second surface opposite to each other along the axial direction, the first surface facing the interior of the battery cell, the second surface facing away from the interior of the battery cell, the limiting protrusion being formed on the first surface and matching with the second hole segment.

[0006] In the technical solution of the present application, the main body and the limiting protrusion are connected as a whole to form a seal. Under the obstruction of the inner wall of the second hole segment, the limiting protrusion is not easy to shift or tilt, so that the main body is also not easy to tilt and shift, ensuring that the main body and the first hole segment are sealed together, thereby improving the sealing of the injection hole, alleviating the problem of battery cell leakage, and achieving increased service life and safety of the battery cell.

[0007] In one embodiment of the present application, the body further includes an outer peripheral surface connecting the first surface and the second surface, and the outer peripheral surface is welded to the hole wall of the first hole segment.

[0008] In the above technical solution, the seal and the electrode terminal are connected by welding, which has a fast processing speed and can improve production efficiency.

[0009] In one embodiment of the present application, the second surface includes a central area and an edge area, the central area is used to connect to the conduit component, and a first groove is provided on the second surface, the first groove is arranged around the periphery of the central area, and the edge area is arranged around the periphery of the first groove.

[0010] In the above technical solution, the seal is not only used to seal the injection hole, but also used to realize the electrical connection between the electrode terminal and the busbar component. A first groove is set between the central area and the edge area of ​​the second surface, and the edge area is connected to the first outer peripheral surface of the main body. The first groove separates the central area and the edge area. The first groove is used to release the welding stress of the first outer peripheral surface and the inner wall of the first hole section to prevent deformation of the central area, and can ensure that the central area is flat. It is not easy to have a cold weld when welding the flat central area and the busbar component, and can ensure the stable overcurrent of the electrode terminal and the busbar component.

[0011] On the other hand, by configuring the central area of ​​the second surface for connecting the busbar component, the area of ​​the portion of the electrode terminal originally used for connecting the busbar component (i.e., the side of the electrode terminal facing away from the battery cell) can be reduced, so that the aperture of the injection hole can be set larger, thereby effectively improving the injection efficiency.

[0012] In one embodiment of the present application, a projection of the limiting protrusion on the second surface along the axial direction is located within the central area.

[0013] In the above technical solution, by setting the position of the limiting protrusion to correspond to the position of the central area, the structural strength of the central area is enhanced, further playing a role in preventing the central area from being deformed.

[0014] In one embodiment of the present application, the edge region is recessed relative to the central region along the axial direction toward the interior of the battery cell.

[0015] In the above technical solution, by setting the edge area of ​​the main body to be concave relative to the adjacent central area, the weld is prevented from being higher than the central area in the axial direction, which plays a role in protecting the weld and also prevents the raised weld from interfering with the convergence component, so as not to affect the connection between the convergence component and the central area.

[0016] In one embodiment of the present application, the electrode terminal includes a first end surface, the first end surface is perpendicular to the axial direction and faces away from the interior of the battery cell, and the central area is flush with the first end surface.

[0017] In the above technical solution, the seal does not occupy additional space outside the battery cell, and the central area of ​​the seal is not lower than the first end face, which is conducive to the central area fitting with the surface of the convergence component, ensuring that the connection between the central area and the convergence component is stable and reliable, and improving the current flow capacity.

[0018] In one embodiment of the present application, the outer peripheral surface is a first conical surface whose diameter gradually decreases along the axial direction and toward the interior of the battery cell, and the hole wall of the first hole segment is a second conical surface matching the first conical surface.

[0019] In the above technical solution, by setting the outer peripheral surface of the main body and the hole wall of the first hole section as conical surfaces, the conical surfaces have the function of guiding the seal into the injection hole, which is convenient for assembly; during laser welding, the second conical surface can also block and reflect the laser propagating along the axial direction, so as to alleviate the problem of the laser entering the interior of the battery cell through the gap between the seal and the injection hole, thereby avoiding burning the functional components inside the battery cell.

[0020] In one embodiment of the present application, a second groove is provided at the center of the second surface.

[0021] In the above technical solution, the second groove can be used as a support position or marking position for the welding equipment. The welding equipment uses the second groove as a fulcrum or center of the circle to rotate its welding head along the outer ring of the edge area to complete the welding of the main body and the electrode terminal, making welding convenient.

[0022] In one embodiment of the present application, the second groove is hemispherical.

[0023] In the above technical solution, the inner wall of the second groove is a spherical surface. When the second groove serves as a support position for the welding equipment, it is beneficial for the welding equipment to rotate in the second groove, ensuring smooth welding operation and further facilitating welding.

[0024] In one embodiment of the present application, the liquid injection hole also includes a third hole segment, which is closer to the interior of the battery cell than the second hole segment, has a hole diameter smaller than the hole diameter of the second hole segment, and the limiting protrusion covers the third hole segment.

[0025] In the above technical solution, by setting the third hole segment, when the electrolyte overflows from the third hole segment, the second hole segment can accommodate the overflowed electrolyte, and the electrolyte is not easy to overflow to the first hole segment, effectively alleviating the corrosion of the electrolyte weld and improving the sealing effect.

[0026] In one embodiment of the present application, the limiting protrusion includes a third surface, which is the side of the limiting protrusion facing the interior of the battery cell along the axial direction; a transition connection surface is formed between the hole wall of the second hole segment and the hole wall of the third hole segment, and the transition connection surface is opposite to the third surface and has a gap.

[0027] In the above technical solution, by setting a gap between the third surface and the transition connection surface, the axial length of the limiting protrusion and the length of the second hole segment are allowed to have a certain manufacturing tolerance to prevent over-positioning, so as to ensure that the outer peripheral surface of the main body and the hole wall of the first hole segment are in contact, and to ensure that the first surface of the main body can be in contact with the step surface, thereby improving the sealing between the main body and the electrode terminal.

[0028] In one embodiment of the present application, the battery cell further includes an electrode assembly, and a first pole tab is formed at one end of the electrode assembly facing the wall portion; the transition connection surface includes a connected main body area and a welding area, the welding area is used to weld to the first pole tab, the main body area is connected to the hole wall of the second hole segment, and the welding area is connected to the hole wall of the third hole segment, a first gap is provided between the main body area and the third surface, and a second gap is provided between the welding area and the third surface, and the second gap is larger than the first gap.

[0029] In the above technical solution, the welding area is recessed axially toward the interior of the battery cell relative to the main area, so that the welding area is further away from the third surface of the limiting protrusion, so that the weld formed in the welding area avoids the limiting protrusion, so as not to affect the positioning accuracy of the seal and ensure the sealing performance of the seal.

[0030] In a second aspect, an embodiment of the present application provides a battery, which includes the aforementioned battery cell.

[0031] The battery provided in the embodiment of the present application has a good sealing property for the battery cells, is not prone to leakage, and has a high service life and safety of the battery.

[0032] In a third aspect, an embodiment of the present application provides an electrical device, which includes the aforementioned battery.

[0033] The battery of the electrical equipment provided in this application has a long service life and high safety, and the electrical equipment has good durability and is safe to use.

[0034] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, comprising: providing a shell, the shell comprising a wall portion; providing an electrode terminal, the electrode terminal having an injection hole extending axially therethrough, the injection hole comprising a first hole segment and a second hole segment, the aperture of the second hole segment being smaller than the aperture of the first hole segment; providing a seal, the seal comprising a main body and a limiting protrusion, the main body comprising a first surface and a second surface relative to each other, the limiting protrusion being formed on the first surface; arranging the electrode terminal on the wall portion so that the second hole segment is closer to the interior of the battery cell than the first hole segment, and sealing the injection hole with the seal so that the main body is sealed in cooperation with the first hole segment, and the limiting protrusion is cooperated with the second hole segment.

[0035] In a fifth aspect, an embodiment of the present application provides a manufacturing device for a battery cell, which includes: a first providing device for providing a shell, the shell including a wall portion; a second providing device for providing an electrode terminal, the electrode terminal having an injection hole extending along its axial direction, the injection hole including a first hole segment and a second hole segment, the aperture of the second hole segment being smaller than the aperture of the first hole segment; a third providing device for providing a seal, the seal including a main body and a limiting protrusion, the main body including a first surface and a second surface relative to each other, the limiting protrusion being formed on the first surface; an assembling device for arranging the electrode terminal on the wall portion so that the second hole segment is closer to the interior of the battery cell than the first hole segment, and for sealing the injection hole with the seal so that the main body is sealed and matched with the first hole segment, and the limiting protrusion is matched with the second hole segment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A schematic diagram of a vehicle provided in accordance with an embodiment of the present application;

[0038] Figure 2 An exploded view of a battery provided in one embodiment of the present application;

[0039] Figure 3 A schematic diagram of the external structure of a battery cell provided in one embodiment of the present application;

[0040] Figure 4 A top view of a battery cell provided in one embodiment of the present application;

[0041] Figure 5 A schematic diagram of the internal structure of a battery cell provided in one embodiment of the present application;

[0042] Figure 6 for Figure 5 A partial enlarged view of

[0043] Figure 7 An exploded view of an electrode terminal and a seal is provided for one embodiment of the present application;

[0044] Figure 8 An exploded view of a battery cell provided in one embodiment of the present application;

[0045] Figure 9A schematic flow chart of a method for manufacturing a battery cell according to an embodiment of the present application;

[0046] Figure 10 A schematic block diagram of a battery cell manufacturing device provided in one embodiment of the present application.

[0047] Icons: 1000-vehicle; 100-battery; 200-motor; 300-controller; 101-housing; 1011-first housing portion; 1012-second housing portion; 102-battery cell; 1-housing; 11-bottom wall; 12-side wall; 13-end cover; 2-electrode terminal; 21-first end face; 22-second end face; 23-injection hole; 231-first hole section; 232-second hole section; 233-third hole section; 234-step surface; 235-transition connection surface; 2351-main body area; 2352-welding area; 2361-first gap; 2362-second Gap; 3-seal; 31-body; 311-first surface; 312-second surface; 3121-center area; 3122-edge area; 3123-first groove; 3124-second groove; 313-first peripheral surface; 32-limiting protrusion; 321-third surface; 322-second peripheral surface; 4-electrode assembly; 41-first pole ear; 42-second pole ear; 5-first adapter; 6-second adapter; 7-manufacturing equipment; 71-first providing device; 72-second providing device; 73-third providing device; 74-assembling device; P-axial; R-radial. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] The term "and / or" in this application simply describes an association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0053] 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.

[0054] The term "plurality" used in this application refers to two or more (including two).

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The battery cell further includes a housing for accommodating the electrode assembly, and electrode terminals mounted on the housing. The electrode terminals are used to be electrically connected to the electrode assembly to enable charging and discharging of the electrode assembly.

[0059] The battery cell also has an injection hole that connects the inside and outside of the battery cell and is used to inject electrolyte from the outside to the inside. After the electrode assembly, electrode terminals, and casing are assembled, electrolyte is injected into the casing through the injection hole. After the first charge and discharge (i.e., after formation), the injection hole is sealed with a sealant.

[0060] The injection hole is often located in the housing. After injection is complete, a sealant (such as a sealing pin) is riveted to the housing to seal the injection hole. This riveting can easily cause the housing to deform due to stress, leading to a reduced seal at the injection hole and leakage. To prevent deformation, a sheet-like sealant can be placed inside the injection hole. However, sheet-like sealants are prone to tilting, warping, or shifting, leading to a reduced seal at the injection hole and leakage. Leakage from a battery cell can severely reduce the battery's lifespan and safety.

[0061] In order to solve the problem of battery cell leakage and improve the service life and safety of the battery cell, the present application provides a solution: an injection hole is set at the electrode terminal, the injection hole passes through the electrode terminal along the axial direction P, and a seal is connected to the electrode terminal to seal the injection hole. The electrode terminal has a large axial thickness and high strength, is not easy to deform, and is not easy to affect the sealing; at the same time, the injection hole is configured to include a first hole segment and a second hole segment, the second hole segment is closer to the interior of the battery cell than the first hole segment, and the aperture of the second hole segment is smaller than the aperture of the first hole segment. The seal is configured to include a main body and a limiting protrusion, wherein the main body is sealed with the first hole segment, and the limiting protrusion is formed on the side of the main body facing the interior of the battery cell. The limiting protrusion cooperates with the second hole segment to prevent the main body from tilting, ensure that the outer peripheral surface of the main body is in contact with the hole wall of the second hole segment, thereby improving the sealing at the injection hole, alleviating the problem of battery cell leakage, and improving the service life and safety of the battery cell.

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

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

[0064] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0065] The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. Figure 1As shown, a battery 100, a controller 300, and a motor 200 may be provided inside the vehicle 1000, and the controller 300 is used to control the battery 100 to supply power to the motor 200. For example, the battery 100 may be provided at the bottom, front, or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may be used as an operating power source for the vehicle 1000 and for the circuit system of the vehicle 1000, for example, for the starting, navigation, and operating power requirements of the vehicle 1000. In another embodiment of the present application, the battery 100 may not only be used as an operating power source for the vehicle 1000, but may also be used as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0066] In order to meet different power requirements, such as Figure 2 As shown, the battery 100 may include multiple battery cells 102, wherein the multiple battery cells 102 are connected in series, in parallel, or in a hybrid connection. Hybrid connection refers to a mixture of series and parallel connections. The battery 100 may also be referred to as a battery pack 100. Optionally, the multiple battery cells 102 may be first connected in series, in parallel, or in a hybrid connection to form a battery module, and the multiple battery modules may then be connected in series, in parallel, or in a hybrid connection to form the battery 100. In other words, the multiple battery cells 102 may directly form the battery 100, or they may first form battery modules, which may then form the battery 100.

[0067] The battery 100 may further include a housing 101 (or housing), the interior of the housing 101 being a hollow structure, and a plurality of battery cells 102 being accommodated in the housing 101. The housing 101 may include two portions for accommodating (see Figure 2 ), here referred to as the first box body part 1011 and the second box body part 1012, respectively, the first box body part 1011 and the second box body part 1012 are buckled together. The shape of the first box body part 1011 and the second box body part 1012 can be determined according to the shape of the combination of multiple battery cells 102, and the first box body part 1011 and the second box body part 1012 can both have an opening. For example, the first box body part 1011 and the second box body part 1012 can both be hollow rectangular parallelepipeds and each has only one open face. The opening of the first box body part 1011 and the opening of the second box body part 1012 are arranged opposite to each other, and the first box body part 1011 and the second box body part 1012 are buckled together to form a box body 101 with a closed chamber. Of the first box body part 1011 and the second box body part 1012, one can also be a rectangular parallelepiped with an opening, and the other can be a cover structure to close the opening of the rectangular parallelepiped. The plurality of battery cells 102 are connected in parallel, in series or in a mixed combination and are placed in the box body 101 formed by buckling the first box body portion 1011 and the second box body portion 1012 .

[0068] The following describes in detail any battery cell 102. Figure 3 、 Figure 4 and Figure 5 As shown, the battery cell 102 includes a housing 1, an electrode terminal 2 and a seal 3. The housing 1 includes a wall portion, and the electrode terminal 2 is provided on the wall portion. Figure 6 and Figure 7 As shown, the electrode terminal 2 has a liquid injection hole 23 passing through it along its axial direction P, and the liquid injection hole 23 includes a first hole segment 231 and a second hole segment 232. The second hole segment 232 is closer to the interior of the battery cell 102 than the first hole segment 231, and the aperture of the second hole segment 232 is smaller than the aperture of the first hole segment 231; the seal 3 is used to seal the liquid injection hole 23, and the seal 3 includes a main body 31 and a limiting protrusion 32. The main body 31 is sealed with the first hole segment 231, and the main body 31 includes a first surface 311 and a second surface 312 opposite to each other along the axial direction P. The first surface 311 faces the interior of the battery cell 102, and the second surface 312 faces away from the interior of the battery cell 102. The limiting protrusion 32 is formed on the first surface 311 and cooperates with the second hole segment 232.

[0069] The interior of the housing 1 forms a space for accommodating the electrode assembly 4. The shape of the housing 1 can be determined based on the specific shape of the electrode assembly 4. For example, if the electrode assembly 4 has a cylindrical structure, the housing 1 can be a cylindrical shell; if the electrode assembly 4 has a rectangular parallelepiped structure, the housing 1 can be a rectangular parallelepiped shell. For example, both the electrode assembly 4 and the housing 1 are cylindrical.

[0070] The housing 1 includes a shell and an end cap 13. The shell includes a side wall 12 and a bottom wall 11. The side wall 12 is arranged around the bottom wall 11. One end of the side wall 12 is connected to the bottom wall 11, and the other end of the side wall 12 forms an opening opposite to the bottom wall 11. The end cap 13 covers the opening to form a closed space, which is the space for accommodating the electrode assembly 4. The wall portion is the bottom wall 11 or the end cap 13. The drawings in this specification show an embodiment in which the wall portion is the bottom wall 11. In other embodiments, the wall portion can also be the end cap 13.

[0071] In some embodiments, an electrode lead-out hole is provided in the wall portion, through which the electrode terminal 2 is inserted. An elastic seal 3 fills the gap between the outer circumference of the electrode terminal 2 and the inner wall of the through-hole to achieve a seal. Optionally, the elastic seal 3 is made of an insulating elastic polymer material to insulate the wall portion from the electrode terminal 2. In other embodiments, a localized area of ​​the wall portion may be thickened to form the electrode terminal 2.

[0072] The axial direction P of the electrode terminal 2 is perpendicular to the wall portion, and the electrode terminal 2 has a first end and a second end in its axial direction P, the first end has a first end face 21, and the second end has a second end face 22, and the first end face 21 and the second end face 22 are opposite to each other along the axial direction P, wherein the first end extends out of the outer shell 1 so that the first end face 21 faces away from the interior of the battery cell 102, and the second end is located in the outer shell 1 so that the second end face 22 faces the interior of the battery cell 102.

[0073] The injection hole 23 extends from the first end to the second end of the electrode terminal 2 and passes through the first end surface 21 and the second end surface 22, respectively, to achieve communication between the interior and exterior of the battery cell 102. The injection hole 23 is a stepped hole, including a first hole segment 231 and a second hole segment 232. The first hole segment 231 has a relatively large hole diameter, while the second hole segment 232 has a relatively small hole diameter. The hole wall of the first hole segment 231 and the hole wall of the second hole segment 232 are connected by a stepped surface 234, which faces away from the interior of the battery cell 102.

[0074] The sealing member 3 includes a body 31 and a limiting protrusion 32 . The body 31 is used to connect to the electrode terminal 2 to seal the liquid injection hole 23 . The limiting protrusion 32 is used to prevent the body 31 from tilting or shifting.

[0075] The outer surface of the body 31 includes a first surface 311, a second surface 312, and a first outer peripheral surface 313. The first surface 311 and the second surface 312 are opposite each other along the axial direction P. The first surface 311 faces the interior of the battery cell 102, while the second surface 312 faces away from the interior of the battery cell 102. In other words, the second surface 312 is the side of the body 31 exposed to the outside of the battery cell 102. The first outer peripheral surface 313 is connected around the central axis of the body 31 and connects the first surface 311 and the second surface 312. The central axis of the body 31 extends along the axial direction P. The first outer peripheral surface 313 of the body 31 is in contact with and connected to the wall of the first hole segment 231 to achieve a seal.

[0076] The phrase "the position-limiting protrusion 32 is formed on the first surface 311" means that the position-limiting protrusion 32 protrudes from the first surface 311 along the axial direction P toward the interior of the battery cell 102. The position-limiting protrusion 32 includes a second outer peripheral surface 322 and a third surface 321. The third surface 321 faces away from the first surface 311 of the body 31 and toward the interior of the battery cell 102. The second outer peripheral surface 322 connects the third surface 321 and the first surface 311 of the body 31.

[0077] The limiting protrusion 32 extends to the second hole section 232 to achieve engagement with the second hole section 232. The limiting protrusion 32 and the second hole section 232 may be an interference fit or a clearance fit. In other words, the second outer peripheral surface 322 of the limiting protrusion 32 and the hole wall of the second hole section 232 may be completely in contact with each other, or there may be a gap.

[0078] When the second outer peripheral surface 322 of the limiting protrusion 32 is completely fitted with the hole wall of the second hole section 232 , the limiting protrusion 32 also has a certain sealing effect to prevent the electrolyte from entering the second hole section 232 , thereby improving the sealing performance and further alleviating the problem of electrolyte leakage.

[0079] When there is a gap between the second outer peripheral surface 322 of the limiting protrusion 32 and the hole wall of the second hole segment 232, it facilitates the limiting protrusion 32 to enter the second hole segment 232, allowing the aperture of the second hole segment 232 and the diameter of the limiting protrusion 32 to have a certain manufacturing tolerance, and also allowing the direction of the limiting protrusion 32 entering the second hole segment 232 to be slightly tilted relative to the axial direction P. Even if it is slightly tilted, it is not easy to get stuck and can return to a coaxial state with the second hole segment 232 under the action of gravity.

[0080] In the embodiment of the present application, the main body 31 and the limiting protrusion 32 are connected as a whole to form a seal 3. Under the obstruction of the inner wall of the second hole section 232, the limiting protrusion 32 and the main body 31 cannot move out of the injection hole 23 along the radial direction R (that is, it is not easy to shift), and the limiting protrusion 32 is not easy to tilt, so that the main body 31 is not easy to tilt, effectively preventing the main body 31 from tilting, ensuring that the outer peripheral surface of the main body 31 and the hole wall of the first hole section 231 are in contact, thereby improving the sealing of the injection hole 23, alleviating the problem of leakage of the battery cell 102, and improving the service life and safety of the battery cell 102.

[0081] It should be noted that the axial direction P referred to herein refers to the extension direction of the central axis of the electrode terminal 2, and the radial direction R referred to herein refers to the direction perpendicular to the central axis of the electrode terminal 2. In this embodiment, the injection hole 23 is coaxially provided with the electrode terminal 2, that is, the injection hole 23 is located at the axis of the electrode terminal 2. In other embodiments, the injection hole 23 may not be located at the axis of the electrode terminal 2, and the extension direction of the injection hole 23 may only be parallel to the axial direction P of the electrode terminal 2.

[0082] In this embodiment, the body 31 and the limiting protrusion 32 are coaxially arranged, and the sealing member 3 and the electrode terminal 2 and the liquid injection hole 23 are all coaxial.

[0083] There are many ways to connect the body 31 and the electrode terminal 2, such as bonding, welding, etc. Exemplarily, a conductive adhesive is provided between the first outer peripheral surface 313 of the body 31 and the hole wall of the first hole section 231 .

[0084] According to some embodiments of the present application, the first outer peripheral surface 313 of the body 31 and the hole wall of the first hole section 231 are welded.

[0085] There are many welding methods, such as penetration welding, hot melt welding, butt welding, etc. For example, the seal 3 is placed in the injection hole 23, the first outer peripheral surface 313 of the body 31 is aligned with the hole wall of the first hole section 231, and butt welding is performed at the alignment interface.

[0086] The welding method has the characteristics of fast processing speed and can improve production efficiency.

[0087] According to some embodiments of the present application, the second surface 312 includes a central area 3121 and an edge area 3122. The central area 3121 is used to connect with the conduit component. A first groove 3123 is provided on the second surface 312. The first groove 3123 is arranged around the periphery of the central area 3121, and the edge area 3122 is arranged around the periphery of the first groove 3123.

[0088] The busbar is a component of the battery 100 for achieving electrical connection (eg, parallel connection, series connection, or hybrid connection) between the plurality of battery cells 102. Specifically, the busbar can achieve electrical connection between the battery cells 102 by connecting the electrode terminals 2 of the battery cells 102.

[0089] In the above scheme, the seal 3 not only serves as a component for sealing the injection hole 23, but also is used to realize the electrical connection between the electrode terminal 2 and the busbar component. A first groove 3123 is set between the central area 3121 and the edge area 3122 of the second surface 312, and the edge area 3122 is connected to the first outer peripheral surface 313 of the main body 31. The first groove 3123 separates the central area 3121 and the edge area 3122. The first groove 3123 is used to release the welding stress between the first outer peripheral surface 313 and the inner wall of the first hole section 231 to prevent the central area 3121 from deforming, ensure that the central area 3121 is flat, and it is not easy to have a cold weld when welding the central area 3121 and the busbar component, thereby ensuring that the connection between the central area 3121 and the busbar component is stable and reliable, and has good current capacity.

[0090] On the other hand, by configuring the central area 3121 of the second surface 312 for connecting the busbar component, the area of ​​the first end surface 21 of the electrode terminal 2 can be reduced, so the aperture of the injection hole 23 can be set larger, thereby effectively improving the injection efficiency.

[0091] According to some embodiments of the present application, a projection of the limiting protrusion 32 on the second surface 312 along the axial direction P is located within the central area 3121 .

[0092] The position of the limiting protrusion corresponds to the position of the central area 3121, which strengthens the structural strength of the central area 3121 and further prevents the central area 3121 from deformation.

[0093] According to some embodiments of the present application, the edge region 3122 is recessed toward the interior of the battery cell 102 along the axial direction P relative to the central region 3121 .

[0094] By setting the edge area 3122 of the main body 31 to be recessed relative to the adjacent central area 3121, the recess can accommodate the weld between the main body 31 and the electrode terminal 2, preventing the weld from protruding above the central area 3121 along the axial direction P, thereby protecting the weld and preventing the raised weld from interfering with the busbar component, thereby avoiding affecting the connection between the busbar component and the central area 3121.

[0095] According to some embodiments of the present application, the first end surface 21 of the electrode terminal 2 is perpendicular to the axial direction P and faces away from the interior of the battery cell 102 , and the central area 3121 is flush with the first end surface 21 .

[0096] By setting the central area 3121 to be flush with the first end face 21, the central area 3121 is not higher than the first end face 21 in the axial direction P, and does not occupy additional space outside the battery cell 102. The central area 3121 is also not lower than the first end face 21, which is conducive to the central area 3121 fitting with the surface of the convergence component, ensuring that the connection between the central area 3121 and the convergence component is stable and reliable, and improving the current flow capacity.

[0097] According to some embodiments of the present application, the first outer peripheral surface 313 of the body 31 is a first conical surface whose diameter gradually decreases along the axial direction P and toward the interior of the battery cell 102, and the hole wall of the first hole segment 231 is a second conical surface matching the first conical surface.

[0098] like Figure 7 As shown, the body 31 is shaped like a frustum, with the central axis of the frustum extending along the axial direction P. The area of ​​the first surface 311 is smaller than the area of ​​the second surface 312. The first outer peripheral surface 313 is a first conical surface, which means that the first outer peripheral surface 313 is a trumpet-shaped curved surface. The smaller end of the first outer peripheral surface 313 is connected to the first surface 311, and the larger end of the second outer peripheral surface 322 is connected to the second surface 312. In the axial direction P, the smaller end of the first outer peripheral surface 313 is relatively close to the interior of the battery cell 102, and the larger end of the first outer peripheral surface 313 is relatively close to the exterior of the battery cell 102.

[0099] The first hole segment 231 is a second conical surface, which means that the hole wall of the first hole segment 231 is a trumpet-shaped curved surface. The first hole segment 231 is a trumpet-shaped hole. The larger end of the first hole segment 231 is relatively close to the outside of the battery cell 102, and the smaller end of the first hole segment 231 is relatively close to the inside of the battery cell 102 and connected to the second hole segment 232.

[0100] By setting the outer peripheral surface of the main body 31 and the hole wall of the first hole section 231 as conical surfaces, the conical surface has the function of guiding the seal 3 into the injection hole 23, which is convenient for assembly; during laser welding, the second conical surface can also block and reflect the laser propagating along the axial direction P, so as to alleviate the problem of the laser entering the interior of the battery cell 102 through the gap between the seal 3 and the injection hole 23, and avoid burning the functional components inside the battery cell 102.

[0101] The matching of the first conical surface and the second conical surface means that the first conical surface and the second conical surface are in contact with each other. Since the first conical surface and the second conical surface are in contact with each other, the gap between them is smaller, which can further prevent the laser from being reflected and transmitted between the first conical surface and the second conical surface, thereby further alleviating the problem of the laser entering the interior of the battery cell 102 through the gap between the seal 3 and the injection hole 23.

[0102] In other embodiments, the shape of the main body 31 may also be a prism, the first surface 311 and the second surface 312 are the two opposite bottom surfaces of the prism, the first surface 311 is the smaller bottom surface of the prism, the second surface 312 is the larger bottom surface of the prism, and the first outer peripheral surface 313 of the main body 31 is the side surface of the prism; the internal space of the first hole segment 231 is prism-shaped, and the side wall 12 of the first hole segment 231 matches the first outer peripheral surface 313.

[0103] According to some embodiments of the present application, Figure 4 、 Figure 5 、 Figure 6 As shown, a second groove 3124 is provided at the center of the second surface 312 .

[0104] The central area 3121 is circular, the edge area 3122 and the first groove 3123 are both annular, the central area 3121, the first groove 3123 and the edge area 3122 are concentrically arranged, and the second groove 3124 is arranged in the central area 3121 and at the center of the circle of the central area 3121.

[0105] The second groove 3124 can serve as a support or marking position for the welding equipment. The welding equipment can complete the welding of the body 31 and the electrode terminal 2 by rotating the welding head along the outer ring of the edge area 3122 using the second groove 3124 as a fulcrum or center. The second groove 3124 is provided to facilitate welding.

[0106] According to some embodiments of the present application, the second groove 3124 is hemispherical.

[0107] like Figure 7 As shown, the second groove 3124 is hemispherical, and the inner wall of the second groove 3124 is spherical. When the second groove 3124 is used as a supporting position for the welding equipment, it is beneficial for the welding equipment to rotate in the second groove 3124.

[0108] According to some embodiments of the present application, Figure 7 As shown, the liquid injection hole 23 also includes a third hole segment 233 , which is closer to the interior of the battery cell 102 than the second hole segment 232 . The aperture of the third hole segment 233 is smaller than that of the second hole segment 232 , and the limiting protrusion 32 covers the third hole segment 233 .

[0109] The first hole section 231, the second hole section 232, and the third hole section 233 are connected in sequence, and their diameters decrease in sequence. The hole wall of the first hole section 231 and the hole wall of the second hole section 232 are connected by a transition surface (i.e., step surface 234), and the hole wall of the second hole section 232 and the hole wall of the third hole section 233 are connected by another transition surface (i.e., transition connecting surface 235). The end of the first hole section 231 facing away from the second hole section 232 extends to the first end surface 21, and the end of the third hole section 233 facing away from the second hole section 232 extends to the second end surface 22.

[0110] By providing the third hole section 233 , when the electrolyte overflows from the third hole section 233 , the second hole section 232 can accommodate the overflowed electrolyte, and the electrolyte is not easy to overflow into the first hole section 231 , thereby effectively alleviating the corrosion of the weld by the electrolyte and improving the sealing effect.

[0111] According to some embodiments of the present application, the third surface 321 is opposite to the transition connection surface 235 and has a gap therebetween.

[0112] The third surface 321 faces the interior of the battery cell 102, and the transition connection surface 235 faces the exterior of the battery cell 102. The gap between the third surface 321 and the transition connection surface 235 means that the third surface 321 and the transition connection surface 235 are not in contact and have a certain spacing distance in the axial direction P.

[0113] By setting a gap between the third surface 321 and the transition connection surface 235, a certain manufacturing tolerance is allowed between the length of the limiting protrusion 32 in the axial direction P and the length of the second hole segment 232 to prevent over-positioning, so as to ensure that the outer peripheral surface of the main body 31 and the hole wall of the first hole segment 231 are in contact with each other, and that the first surface 311 of the main body 31 can be in contact with the step surface 234, thereby improving the sealing between the main body 31 and the electrode terminal 2.

[0114] According to some embodiments of the present application, the battery cell 102 also includes an electrode assembly 4, and a first pole ear 41 is formed at one end of the electrode assembly 4 facing the wall; the transition connection surface 235 includes a connected main body area 2351 and a welding area 2352, the welding area 2352 is used to weld with the first pole ear 41, the main body area 2351 is connected to the hole wall of the second hole segment 232, and the welding area 2352 is connected to the hole wall of the third hole segment 233, there is a first gap 2361 between the main body area 2351 and the third surface 321, there is a second gap 2362 between the welding area 2352 and the third surface 321, and the second gap 2362 is larger than the first gap 2361.

[0115] The electrode assembly 4 includes a first electrode piece, a second electrode piece and an isolating member, and the isolating member is used to separate the first electrode piece and the second electrode piece. The polarity of the first electrode piece and the second electrode piece is opposite. In other words, one of the first electrode piece and the second electrode piece is a positive electrode piece, and the other of the first electrode piece and the second electrode piece is a negative electrode piece. The first electrode piece, the second electrode piece and the isolating member are prior art. Although not shown in the drawings of the present application specification, those skilled in the art should understand their specific structure. The first electrode tab 41 and the second electrode tab 42 can extend from the same side of the electrode assembly 4, or they can extend from opposite sides respectively. For example, as Figure 5 and Figure 8 As shown, the first tab 41 and the second tab 42 are located at opposite ends of the electrode assembly 4. The end of the electrode assembly 4 with the first tab 41 faces the wall, while the end of the electrode assembly 4 with the second tab 42 faces away from the wall. That is, in this embodiment, the end of the electrode assembly 4 with the first tab 41 faces the bottom wall 11, while the end of the electrode assembly 4 with the second tab 42 faces the end cap 13. The first tab 41 is electrically connected to the electrode terminal 2, and the second tab 42 is electrically connected to the end cap 13. The electrical connection can be made by contact, conductive adhesive, direct welding, or indirect welding.

[0116] Take the indirect welding of the first tab 41 and the electrode terminal 2 as an example. Figure 8 As shown, the battery cell 102 also includes a first adapter 5, which is welded to the first pole tab 41. After the electrode assembly 4 is installed in the shell 1, the first adapter 5 contacts the second end face 22 of the electrode terminal 2, and the welding head of the welding equipment is applied to the welding area 2352 to weld the electrode terminal 2 and the first adapter 5, thereby realizing the electrical connection between the first pole tab 41 and the electrode terminal 2.

[0117] Since the second gap 2362 is larger than the first gap 2361, the welding area 2352 is recessed relative to the main body area 2351 along the axial direction P toward the interior of the battery cell 102, so that the welding area 2352 is further away from the third surface 321 of the limiting protrusion, so that the weld formed by the welding area 2352 avoids the limiting protrusion, so as not to affect the positioning accuracy of the seal 3 and ensure the sealing performance of the seal 3.

[0118] In some embodiments, the battery cell 102 further includes a second adapter 6 , which is welded to the second tab 42 . After the electrode assembly 4 is installed in the housing 1 , the second adapter 6 is in contact with the end cap 13 for electrical conduction or welding.

[0119] Second, as Figure 2 As shown, the embodiment of the present application provides a battery 100, which includes at least one battery cell 102 described in the above embodiments. The battery 100 provided in the embodiment of the present application has good sealing performance and is not prone to leakage, thereby increasing the service life and safety of the battery 100.

[0120] In a third aspect, the embodiment of the present application provides an electrical device, which may be but is not limited to Figure 1 The vehicle 1000 shown has an electric device including the above-mentioned battery 100. The battery 100 of the electric device has a long service life and high safety, and the electric device has good durability and is safe to use.

[0121] In a fourth aspect, the present invention provides a method for manufacturing a battery cell 102, such as Figure 9 As shown, the manufacturing method includes:

[0122] S1, providing a housing 1, wherein the housing 1 includes a wall portion;

[0123] S2. Provide an electrode terminal 2. The electrode terminal 2 has an injection hole 23 extending therethrough along its axial direction P. The injection hole 23 includes a first hole segment 231 and a second hole segment 232. The diameter of the second hole segment 232 is smaller than that of the first hole segment 231.

[0124] S3, providing a sealing member 3, the sealing member 3 including a body 31 and a limiting protrusion 32, the body 31 including a first surface 311 and a second surface 312 opposite to each other, the limiting protrusion 32 being formed on the first surface 311;

[0125] S4, set the electrode terminal 2 on the wall so that the second hole segment 232 is closer to the interior of the battery cell 102 than the first hole segment 231, and seal the liquid injection hole 23 with the seal 3 so that the body 31 is sealed with the first hole segment 231, and the limiting protrusion 32 is matched with the second hole segment 232.

[0126] It should be noted that the relevant structure of the battery cell 102 manufactured by the above-mentioned method for manufacturing the battery cell 102 can refer to the battery cell 102 provided in the above-mentioned embodiments.

[0127] When assembling the battery cell 102 according to the manufacturing method of the battery cell 102, it is not necessary to follow the above 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 embodiment, or several steps can be performed simultaneously. For example, steps S1, S2, and S3 can be performed in any order and can be performed simultaneously.

[0128] In a fifth aspect, the present application provides a manufacturing device 7 for a battery cell 102, such as Figure 10 As shown, the manufacturing equipment 7 includes a first providing device 71 , a second providing device 72 , a third providing device 73 and an assembling device 74 .

[0129] The first providing device 71 is used to provide a housing 1 , wherein the housing 1 includes a wall portion.

[0130] The second providing device 72 is used to provide the electrode terminal 2 , which has a liquid injection hole 23 extending through the electrode terminal 2 along its axial direction P. The liquid injection hole 23 includes a first hole segment 231 and a second hole segment 232 . The aperture of the second hole segment 232 is smaller than that of the first hole segment 231 .

[0131] The third providing device 73 is used to provide a sealing member 3 . The sealing member 3 includes a body 31 and a limiting protrusion 32 . The body 31 includes a first surface 311 and a second surface 312 opposite to each other. The limiting protrusion 32 is formed on the first surface 311 .

[0132] The assembly device 74 is used to set the electrode terminal 2 on the wall so that the second hole segment 232 is closer to the interior of the battery cell 102 than the first hole segment 231, and is used to seal the liquid injection hole 23 with the seal 3 so that the main body 31 is sealed with the first hole segment 231 and the limiting protrusion 32 is matched with the second hole segment 232.

[0133] The relevant structure of the battery cell 102 manufactured by the above-mentioned manufacturing equipment 7 can refer to the battery cell 102 provided in the above-mentioned embodiments.

[0134] 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.

[0135] According to some embodiments of this application, please refer to Figure 3-Figure 8As shown, an embodiment of the present application provides a cylindrical battery cell 102, which includes a housing 1, an electrode assembly 4, an electrode terminal 2, and a seal 3. The housing 1 includes a shell and an end cap 13. The shell includes a side wall 12 and a bottom wall 11. The side wall 12 is arranged around the bottom wall 11. One end of the side wall 12 is connected to the bottom wall 11, and the other end of the side wall 12 forms an opening opposite to the bottom wall 11. The end cap 13 covers the opening to form a storage space. The electrode assembly 4 is arranged in the storage space of the housing 1. The electrode assembly 4 is formed with a first electrode tab 41 and a second electrode tab 42 at both ends along the axial direction P. The end of the electrode assembly 4 with the first electrode tab 41 faces the bottom wall 11, and the end of the electrode assembly 4 with the second electrode tab 42 faces the end cap 13. The electrode terminal 2 is insulated and mounted on the bottom wall 11, that is, a sealing ring made of insulating material is provided between the electrode terminal 2 and the bottom wall 11. The electrode terminal 2 is electrically connected to the first tab 41, and the end cap 13 is electrically connected to the second tab 42, enabling electrical energy to be input and output from the battery cell. The electrode terminal 2 has an injection hole 23 extending along its axial direction P. This is used to inject liquid into the interior of the battery cell 102 (i.e., the accommodation space within the housing 1). The injection hole 23 includes a first hole segment 231 and a second hole segment 232. The second hole segment 232 is closer to the interior of the battery cell 102 than the first hole segment 231, and the aperture of the second hole segment 232 is smaller than that of the first hole segment 231. The seal 3 is used to seal the liquid injection hole 23. The seal 3 includes a main body 31 and a limiting protrusion 32. The main body 31 is sealed and matched with the first hole segment 231. The main body 31 includes a first surface 311 and a second surface 312 that are opposite to each other along the axial direction P. The first surface 311 faces the interior of the battery cell 102, and the second surface 312 faces away from the interior of the battery cell 102. The limiting protrusion 32 is formed on the first surface 311 and matches the second hole segment 232. The battery cell 102 provided in the embodiment of the present application has a liquid injection hole 23 arranged on the electrode terminal 2, and no additional hole is required on the outer shell 1, which effectively improves the structural strength of the outer shell 1 and makes the outer shell 1 not easily deformed; the thickness of the electrode terminal 2 is greater than that of the outer shell 1, and the electrode terminal 2 is not easily deformed when the liquid injection hole 23 is closed; at the same time, under the obstruction of the inner wall of the second hole section 232, the limiting protrusion 32 and the main body 31 are not easily displaced or tilted, which effectively prevents the main body 31 from tilting and ensures that the outer peripheral surface of the main body 31 fits the hole wall of the second hole section 232; thereby, the sealing performance of the liquid injection hole 23 is improved from many aspects, the problem of liquid leakage of the battery cell 102 is alleviated, and the service life and safety of the battery cell 102 are improved.

[0136] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: A housing including a wall portion, wherein the housing is cylindrical in shape; an electrode terminal, the electrode terminal being disposed on the wall portion, the electrode terminal having an injection hole extending axially therethrough, the injection hole comprising a first hole segment and a second hole segment, the second hole segment being closer to the interior of the battery cell than the first hole segment, and having a smaller hole diameter than the first hole segment; and a seal member, the seal member being used to seal the liquid injection hole, the seal member comprising a body and a limiting protrusion, the body being in sealing engagement with the first hole segment, the body comprising a first surface and a second surface opposing each other along the axial direction, the first surface facing the interior of the battery cell, the second surface facing away from the interior of the battery cell, the limiting protrusion being formed on the first surface and engaging with the second hole segment; In which, the main body also includes an outer peripheral surface connecting the first surface and the second surface, the outer peripheral surface is welded to the hole wall of the first hole segment, the second surface includes a central area and an edge area, and a first groove is provided on the second surface, the first groove is provided around the periphery of the central area, and the edge area is provided around the periphery of the first groove.

2. The battery cell according to claim 1, wherein: The central area is used for connecting with the current collecting component.

3. The battery cell according to claim 2, characterized in that: The projection of the limiting protrusion on the second surface along the axial direction is located in the central area.

4. The battery cell according to claim 3, characterized in that The edge region is recessed relative to the central region along the axial direction toward the interior of the battery cell.

5. The battery cell according to claim 3, characterized in that: The electrode terminal includes a first end surface, the first end surface is perpendicular to the axial direction and faces away from the interior of the battery cell, and the central area is flush with the first end surface.

6. The battery cell according to claim 2, characterized in that The outer peripheral surface is a first conical surface whose diameter gradually decreases along the axial direction and toward the interior of the battery cell, and the hole wall of the first hole segment is a second conical surface matching the first conical surface.

7. The battery cell according to claim 1, characterized in that A second groove is provided at the center of the second surface.

8. The battery cell according to claim 7, characterized in that The second groove is hemispherical.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The liquid injection hole further includes a third hole segment, which is closer to the interior of the battery cell than the second hole segment. The aperture of the third hole segment is smaller than that of the second hole segment, and the limiting protrusion covers the third hole segment.

10. The battery cell according to claim 9, characterized in that: The limiting protrusion includes a third surface, which is the side of the limiting protrusion facing the interior of the battery cell along the axial direction; a transition connection surface is formed between the hole wall of the second hole segment and the hole wall of the third hole segment, and the transition connection surface is opposite to the third surface and has a gap.

11. The battery cell according to claim 10, characterized in that The battery cell further includes an electrode assembly, wherein a first electrode tab is formed at one end of the electrode assembly facing the wall portion; The transition connection surface includes a connected main body area and a welding area, the welding area is used to weld with the first tab, the main body area is connected to the hole wall of the second hole segment, and the welding area is connected to the hole wall of the third hole segment. There is a first gap between the main body area and the third surface, and there is a second gap between the welding area and the third surface, and the second gap is larger than the first gap.

12. A battery, characterized in that: The battery comprises the battery cell according to any one of claims 1 to 11.

13. An electrical device, characterized in that: The electric device comprises the battery according to claim 12.

14. A method for manufacturing a battery cell, characterized in that: include: providing a housing comprising a wall portion; Providing an electrode terminal, the electrode terminal having an injection hole extending axially therethrough, the injection hole comprising a first hole segment and a second hole segment, wherein the second hole segment has a smaller hole diameter than the first hole segment; A sealing member is provided, the sealing member comprising a body and a limiting protrusion, the body comprising a first surface and a second surface opposite to each other, the limiting protrusion being formed on the first surface; The electrode terminal is arranged on the wall portion so that the second hole segment is closer to the interior of the battery cell than the first hole segment. The injection hole is sealed with the sealing member so that the body is sealed with the first hole segment and the limiting protrusion is matched with the second hole segment.

15. A battery cell manufacturing device, characterized in that: include: a first providing device for providing a housing, wherein the housing includes a wall portion; A second providing device is used to provide an electrode terminal, wherein the electrode terminal has an injection hole extending axially therethrough, the injection hole comprising a first hole segment and a second hole segment, wherein the second hole segment has a smaller hole diameter than the first hole segment; A third providing device is used to provide a sealing member, wherein the sealing member includes a body and a limiting protrusion, the body includes a first surface and a second surface opposite to each other, and the limiting protrusion is formed on the first surface; An assembly device is used to arrange the electrode terminal on the wall portion so that the second hole segment is closer to the interior of the battery cell than the first hole segment, and to seal the liquid injection hole with the sealing member so that the body is sealed with the first hole segment and the limiting protrusion is matched with the second hole segment.

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