Battery monomer, battery and electric equipment

Abstract

The invention provides a battery monomer, a battery and electric equipment, and relates to the field of batteries. The battery cell includes a housing, an electrode assembly, and an electrode terminal. The housing has a wall portion, and the wall portion is provided with a lead-out hole. The electrode assembly is housed within the housing. The electrode terminal comprises a first terminal part and a second terminal part, and the first terminal part and the second terminal part are made of different materials and are compounded with each other. The first terminal part penetrates through the lead-out hole, and the second terminal part is electrically connected with the electrode assembly. Wherein the first terminal part comprises a first limiting part, and the first limiting part is configured to limit the first terminal part to be separated from the lead-out hole in the direction away from the electrode assembly in the thickness direction of the wall part. And when the first terminal part is subjected to outward pulling force, the first limiting part can limit the electrode terminal to be separated from the lead-out hole. The composite interface of the first terminal part and the second terminal part is not easy to be subjected to external force, and the first terminal part and the second terminal part are not easy to separate, so that the service life of the battery monomer is relatively long.

Description

Battery cells, batteries and electrical equipment Technical Field

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

[0002] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including performance parameters such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery life must be considered. However, current batteries have a relatively short lifespan.

[0003] Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a battery cell, a battery, and an electrical device, which are intended to improve the problem of short battery life in the related art.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and an electrode terminal, the shell having a wall portion, the wall portion being provided with a lead-out hole; the electrode assembly is accommodated in the shell; the electrode terminal includes a first terminal portion and a second terminal portion, the first terminal portion and the second terminal portion being made of different materials and composite with each other, the first terminal portion being passed through the lead-out hole, and the second terminal portion being electrically connected to the electrode assembly; wherein the first terminal portion includes a first limiting portion, and along the thickness direction of the wall portion, the first limiting portion is configured to limit the first terminal portion from detaching from the lead-out hole in a direction away from the electrode assembly.

[0006] In the above technical solution, the electrode terminal of the battery cell includes a first terminal portion and a second terminal portion made of different materials, so that the first terminal portion can be welded to the current collecting member and the second terminal portion can be welded to the electrode assembly. The first terminal portion has a first limiter portion. When the first terminal portion is subjected to an outward pulling force, the first limiter portion can prevent the first terminal portion from being separated from the lead-out hole in a direction away from the electrode assembly. In this way, the composite interface of the first terminal portion and the second terminal portion is not easily affected by external forces, and the first terminal portion and the second terminal portion are not easily separated, thereby extending the life of the battery cell.

[0007] As an optional technical solution of an embodiment of the present application, along the thickness direction of the wall portion, the first limiting portion is located on the side of the wall portion facing the electrode assembly, and the projection of the first limiting portion and the projection of the wall portion at least partially overlap.

[0008] In the above technical solution, along the thickness direction of the wall portion, the first stopper is located on the side of the wall portion facing the electrode assembly. The projection of the first stopper and the projection of the wall portion at least partially overlap. When the first terminal portion is subjected to an outward pulling force, the first stopper can abut against the wall portion to prevent the first terminal portion from separating from the lead-out hole in a direction away from the electrode assembly. In this way, the composite interface between the first terminal portion and the second terminal portion is not easily affected by external forces, and thus the first terminal portion and the second terminal portion are not easily separated, thereby extending the life of the battery cell.

[0009] As an optional technical solution of an embodiment of the present application, the first terminal portion and the second terminal portion are combined to form a composite interface, and the composite interface intersects with the outer surface of the electrode terminal at a junction position; the battery cell also includes a sealant, which seals the junction position.

[0010] In the above technical solution, since the first and second terminal portions are made of different materials, chemical corrosion may occur if the electrolyte enters the composite interface. Therefore, by providing a sealant to seal the interface, the risk of electrolyte entering the composite interface is reduced, thereby reducing the risk of chemical corrosion and extending the life of the battery cell.

[0011] As an optional technical solution of an embodiment of the present application, a groove is provided on the side of the second terminal portion facing the first terminal portion, the first limiting portion is at least partially accommodated in the groove, and the groove side surface of the groove and the outer peripheral surface of the first limiting portion are combined to form the composite interface.

[0012] In the above technical solution, a groove is provided on the side of the second terminal portion facing the first terminal portion, so that the side surface of the groove and the outer peripheral surface of the first limiting portion can form a composite interface. In this way, the electrolyte can only enter the composite interface from the side of the second terminal portion facing away from the electrode assembly, making it more difficult for the electrolyte to enter the composite interface, and the composite interface is less susceptible to corrosion by the electrolyte.

[0013] As an optional technical solution of an embodiment of the present application, the second terminal portion includes a first part and a second part. Along the thickness direction, the first part and the first terminal portion are stacked, and the second part is arranged around the first limiting portion. The first part and the second part jointly define the groove, and the seal is at least partially located between the second part and the wall portion so that the seal seals the junction position.

[0014] In the above technical solution, the electrolyte can only enter the junction position through the gap between the second part and the wall portion. Therefore, by at least partially arranging the seal between the second part and the wall portion, the electrolyte cannot enter the junction position through the gap between the second part and the wall portion, thereby achieving sealing of the junction position.

[0015] As an optional technical solution of an embodiment of the present application, part of the sealing member is located between the first limiting portion and the wall portion, so that the sealing member covers the boundary position.

[0016] In the above technical solution, the sealing member is partially located between the first limiting portion and the wall portion, and at the same time, the sealing member is partially located between the second portion and the wall portion, thereby covering the interface position and achieving a better sealing effect on the interface position.

[0017] As an optional technical solution of the embodiment of the present application, part of the sealing member extends into the outlet hole.

[0018] In the above technical solution, part of the sealing member extends into the lead-out hole, which can, on the one hand, position the sealing member so as to facilitate installation of the sealing member, and, on the other hand, can also seal the first terminal portion and the wall portion.

[0019] As an optional technical solution of an embodiment of the present application, along the thickness direction, the first limiting portion has a first surface facing the wall portion, and the first outer edge of the first surface is arranged around the lead-out hole, and the second portion has a second surface facing the wall portion, and the second outer edge of the second surface is arranged around the composite interface; along the direction perpendicular to the thickness direction, the minimum distance between the first outer edge and the hole wall of the lead-out hole is A, and the minimum distance between the second outer edge and the composite interface is B, satisfying: A / B≥1 / 3.

[0020] In the above technical solution, the minimum distance between the first outer edge and the wall of the lead-out hole, perpendicular to the thickness direction, is greater than or equal to 1 / 3 the minimum distance between the second outer edge and the composite interface. When the first terminal portion is subjected to outward tension, the second portion can also abut against the seal, distributing the force applied to the first stopper and further reducing the risk of deformation of the first stopper. Furthermore, the ratio A / B ≥ 1 / 3 prevents the first stopper from being too small, providing it with greater strength to resist deformation.

[0021] As an optional technical solution of an embodiment of the present application, the first surface and the second surface are flush.

[0022] In the above technical solution, when the first surface and the second surface are flush, the composite interface is not easily affected by external forces, and the first terminal portion and the second terminal portion are not easily separated, thereby extending the life of the battery cell.

[0023] As an optional technical solution of an embodiment of the present application, the seal includes a first sealing portion, which is located between the second portion and the wall portion along the thickness direction; along the direction perpendicular to the thickness direction, the minimum distance between the outer peripheral surface of the first sealing portion and the composite interface is C, satisfying: C ≥ 1 mm.

[0024] In the above technical solution, in order to make the first sealing part cooperate with the insulating part, a notch may be provided on the first sealing part. By making C ≥ 1mm, the first sealing part can be ensured to have a better sealing effect, reduce the risk of electrolyte entering the composite interface, and extend the service life of the battery cell.

[0025] As an optional technical solution of an embodiment of the present application, the seal includes a first sealing portion, which is located between the second portion and the wall portion; the first sealing portion has a third surface facing the wall portion and a fourth surface facing the second portion, the third outer edge of the third surface is arranged around the composite interface, and the fourth outer edge of the fourth surface surrounds the third outer edge.

[0026] In the above technical solution, the edge of the first sealing portion may be formed into a stepped, inclined, or curved shape to facilitate mating with the insulating member. By arranging the fourth outer edge around the third outer edge, that is, the area of ​​the fourth surface is larger than the area of ​​the third surface, the sealing effect can be improved to a certain extent.

[0027] As an optional technical solution of an embodiment of the present application, along the thickness direction, the first limiting portion has a first surface facing the wall portion, and the first outer edge of the first surface is arranged around the lead-out hole. Along the direction perpendicular to the thickness direction, the minimum distance between the first outer edge and the hole wall of the lead-out hole is A, satisfying: A≥1mm.

[0028] In the above technical solution, the minimum distance between the first outer edge and the wall of the lead-out hole, along a direction perpendicular to the thickness direction, is greater than or equal to 1 mm, ensuring that the projection of the first stopper and the projection of the wall have sufficient overlapping area along the thickness direction of the wall. When the first terminal portion is subjected to an outward pulling force, the first stopper has sufficient area to contact the wall portion to prevent the electrode terminal from dislodging from the lead-out hole. If A is less than 1 mm, the area of ​​contact between the first stopper and the wall portion is small when the first terminal portion is subjected to an outward pulling force, and the first stopper may deform, causing the electrode terminal to dislodge from the lead-out hole.

[0029] As an optional technical solution of the embodiment of the present application, the first terminal portion includes a main body portion, the main body portion is inserted into the lead-out hole, and the first limiting portion protrudes from the outer peripheral surface of the main body portion.

[0030] In the above technical solution, by making the first limiting portion protrude from the outer peripheral surface of the main body, the strength of the main body is not easily weakened, so that the first terminal portion is not easily damaged when subjected to external force.

[0031] As an optional technical solution of an embodiment of the present application, the first terminal portion also includes a main body portion and a second limiting portion, the main body portion is passed through the lead-out hole, the main body portion connects the first limiting portion and the second limiting portion, and along the thickness direction, the first limiting portion and the second limiting portion are respectively located on both sides of the wall portion, and the projection of the second limiting portion and the projection of the wall portion at least partially overlap.

[0032] In the above technical solution, the main body connects the first and second stoppers. The first stopper restricts the electrode terminal from escaping the lead-out hole in a direction away from the electrode assembly, while the second stopper restricts the electrode terminal from escaping the lead-out hole in a direction toward the electrode assembly. This reduces the risk of the electrode terminal escaping the lead-out hole, helps ensure the normal output or input of electrical energy from the battery cell, and prolongs the life of the battery cell.

[0033] As an optional technical solution of an embodiment of the present application, the battery cell includes a seal, and along the thickness direction of the wall, the seal is at least partially located on the side of the wall facing the electrode assembly, and the projection of the seal and the projection of the wall at least partially overlap, and the first limiting portion is located on the side of the seal facing the electrode assembly, and the projection of the first limiting portion and the projection of the seal at least partially overlap.

[0034] In the above technical solution, when the first terminal portion is subjected to an outward pulling force, the first limiting portion can abut against the sealing member, and the sealing member can abut against the wall portion, thereby limiting the first terminal portion from disengaging from the lead-out hole in a direction away from the electrode assembly. In this way, the composite interface between the first terminal portion and the second terminal portion is less susceptible to external forces, and thus the first terminal portion and the second terminal portion are less likely to separate, thereby extending the life of the battery cell. While abutting against and limiting the first limiting portion, the sealing member also seals the first terminal portion and the wall portion, achieving multiple functions in one component, which helps simplify the structure of the battery cell.

[0035] As an optional technical solution of an embodiment of the present application, along the thickness direction, the projection of the first limiting portion and the projection of the wall portion do not overlap.

[0036] In the above technical solution, along the thickness direction, the projection of the first limiting portion partially overlaps with the projection of the seal, the projection of the seal partially overlaps with the projection of the wall portion, and the projection of the first limiting portion does not overlap with the projection of the seal, so that the size of the first limiting portion can be reduced.

[0037] As an optional technical solution of an embodiment of the present application, along the thickness direction, the first limiting portion is located on a side of the sealing member facing the electrode assembly.

[0038] In the above technical solution, the first limiting portion is arranged on the side of the sealing member facing the electrode assembly. When the first terminal portion is subjected to an outward pulling force, the first limiting portion can be more stably supported against the sealing member.

[0039] In a second aspect, an embodiment of the present application further provides a battery, which includes the above-mentioned battery cell.

[0040] In a third aspect, an embodiment of the present application further provides an electric device, which includes the above-mentioned battery, and the battery is used to provide electrical energy to the electric device. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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.

[0042] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0043] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0044] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0045] FIG4 is an exploded view of a battery cell provided in some embodiments of the present application;

[0046] FIG5 is a schematic structural diagram of an end cap provided in some embodiments of the present application;

[0047] FIG6 is a schematic top view of an end cap provided in some embodiments of the present application;

[0048] FIG7 is a cross-sectional view of the DD position in FIG6;

[0049] FIG8 is an enlarged view of position E in FIG7 ;

[0050] FIG9 is a schematic top view of end caps provided in other embodiments of the present application;

[0051] FIG10 is a cross-sectional view of the FF position in FIG9;

[0052] FIG11 is an enlarged view of position G in FIG10 ;

[0053] FIG12 is a cross-sectional view of an end cap provided in some other embodiments of the present application;

[0054] FIG13 is a schematic top view of end caps provided in some other embodiments of the present application;

[0055] FIG14 is a cross-sectional view taken along line HH in FIG13 ;

[0056] FIG15 is an enlarged view of position I in FIG14 .

[0057] Icons: 10-case; 11-upper case; 12-lower case; 20-battery cell; 21-housing; 211-wall; 212-end cover; 2121-lead-out hole; 213-shell; 214-insulating member; 22-electrode assembly; 221-ear; 23-electrode terminal; 231-first terminal portion; 2312-main body; 2313-second limiting portion; 2311-first limiting portion; 232-second terminal portion; 2321-first part; 2322-second part; 233-conductive member; 24-seal; 241-third sealing portion; 242-second sealing portion; 243-first sealing portion; 100-battery; 200-controller; 300-motor; 1000-vehicle. DETAILED DESCRIPTION

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] The term "plurality" used in this application refers to two or more (including two).

[0065] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0066] 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.

[0067] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of 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. The positive active material layer is coated on the surface of the positive electrode collector. The portion of the positive electrode collector not coated with the positive active material layer protrudes from the portion coated with the positive active material layer. The portion of the positive electrode collector not coated with the positive active material layer serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive active material can 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. The negative active material layer is coated on the surface of the negative electrode collector. The portion of the negative electrode collector not coated with the negative active material layer protrudes from the portion coated with the negative active material layer. The portion of the negative electrode collector not coated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative active material can be carbon or silicon, among others. To ensure high current flow without melting, multiple positive tabs are stacked together, and multiple negative tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the present invention is not limited thereto.

[0068] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0069] The development of battery technology requires simultaneous consideration of multiple design factors, including performance parameters such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery life must be considered. However, current batteries have a relatively short lifespan.

[0070] The inventors noted that metals of the same material are easier to weld. The electrode terminal includes a first terminal portion and a second terminal portion, the first terminal portion and the second terminal portion being made of different materials. The first terminal portion can be made of the same material as the current collecting member to facilitate welding thereto. The second terminal portion can be made of the same material as the current collecting member to facilitate welding thereto. The first and second terminal portions are composited and disposed on the end cap.

[0071] The inventors further discovered that, with conventional electrode terminals, the first terminal portion is susceptible to external forces. When the first terminal portion is subjected to an outward pull, the second terminal portion abuts against the end cap, causing the second terminal portion to be subjected to an inward reaction force. The junction where the first and second terminal portions meet is relatively fragile. When an external force pulls the first terminal portion outward and a reaction force pulls the second terminal portion inward, the first and second terminal portions can easily break apart at the junction, damaging the battery cell and shortening the life of the battery cell 20.

[0072] In view of this, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and an electrode terminal. The shell has a wall portion, and the wall portion is provided with a lead-out hole. The electrode assembly is accommodated in the shell. The electrode terminal includes a first terminal portion and a second terminal portion, and the first terminal portion and the second terminal portion are made of different materials and are composite with each other. The first terminal portion is passed through the lead-out hole, and the second terminal portion is electrically connected to the electrode assembly. The first terminal portion includes a first limiting portion, and along the thickness direction of the wall portion, the first limiting portion is located on the side of the wall portion facing the electrode assembly, and the projection of the first limiting portion and the projection of the wall portion at least partially overlap.

[0073] The electrode terminal of the battery cell includes a first terminal portion and a second terminal portion made of different materials, so as to facilitate welding the first terminal portion to the current collecting member and welding the second terminal portion to the electrode assembly. Along the thickness direction of the wall portion, the first terminal portion has a first limiting portion located on the side of the wall portion facing the electrode assembly. The projection of the first limiting portion and the projection of the wall portion at least partially overlap, so that when the first terminal portion is subjected to outward pulling force, the first limiting portion can abut against the wall portion (it can be abutted against the wall portion through an intermediate component) to limit the first terminal portion from escaping from the lead-out hole in the direction away from the electrode assembly. In this way, the composite interface of the first terminal portion and the second terminal portion is not easily affected by external forces, so the first terminal portion and the second terminal portion are not easily separated, which prolongs the life of the battery cell.

[0074] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0075] Electrically powered devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Electric tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0076] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0077] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0078] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0079] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 being housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include an upper housing 11 and a lower housing 12, with the upper housing 11 and the lower housing 12 covering each other, and the upper housing 11 and the lower housing 12 jointly defining a storage space for accommodating the battery cell 20. The lower housing 12 can be a hollow structure with one end open, and the upper housing 11 can be a plate-like structure, with the upper housing 11 covering the open side of the lower housing 12, so that the upper housing 11 and the lower housing 12 jointly define a storage space. The upper housing 11 and the lower housing 12 can also be hollow structures with one end open, with the open side of the upper housing 11 covering the open side of the lower housing 12. Of course, the box body 10 formed by the upper box body 11 and the lower box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0080] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0081] Each battery cell 20 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0082] Please refer to Figures 3 and 4. Figure 3 is an exploded view of a battery cell 20 provided in some embodiments of the present application. Figure 4 is an exploded view of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery 100. As shown in Figures 3 and 4, a battery cell 20 includes a housing 21 and an electrode assembly 22.

[0083] The housing 21 includes an end cap 212 and a shell 213. The shell 213 has an accommodation space with one end open for accommodating the electrode assembly 22. The end cap 212 is connected to the shell 213 and closes the opening.

[0084] The end cap 212 refers to a component that covers the opening of the shell 213 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 213 to match the shell 213. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as an aluminum alloy), so that the end cap 212 is not easily deformed when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. Optionally, the battery cell 20 also includes a pressure relief mechanism, which is provided on the end cap 212. The pressure relief mechanism is used to open when the internal pressure or temperature of the battery cell 20 reaches the detonation pressure to release the internal pressure of the battery cell 20. In some embodiments, the battery cell 20 further includes an insulating member 214 disposed inside the end cap 212. The insulating member 214 can be used to isolate the electrical connection components within the housing 213 from the end cap 212 to reduce the risk of short circuits. Exemplarily, the insulating member 214 can be made of plastic, rubber, or the like.

[0085] The housing 213 is a component that cooperates with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 213 and the end cap 212 can be separate components. An opening can be provided in the housing 213, and the end cap 212 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 213 can be integrated. Specifically, the end cap 212 and the housing 213 can form a common joint surface before other components are inserted into the housing. When the interior of the housing 213 is to be enclosed, the end cap 212 is placed over the housing 213. The housing 213 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 213 can be determined based on the specific shape and size of the electrode assembly 22. The housing 213 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0086] The electrode assembly 22 is the component where the electrochemical reaction occurs in the battery cell 20. One or more electrode assemblies 22 may be contained within the housing 21. The electrode assembly 22 is primarily formed by winding or stacking a positive electrode sheet and a negative electrode sheet, typically with a separator disposed between the positive and negative electrode sheets.

[0087] In some embodiments, the electrode assembly is provided with tabs that conduct current from the electrode assembly. The tabs include a positive tab and a negative tab. The positive tab and the negative tab can be located together at one end of the electrode assembly or separately at two ends of the electrode assembly.

[0088] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to the tab. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via a current collecting member. The electrode terminal may be provided on an end cap or on the housing.

[0089] Please refer to Figures 3, 4, 5, 6, 7 and 8. Figure 5 is a schematic structural diagram of the end cap 212 provided in some embodiments of the present application. Figure 6 is a schematic top view of the end cap 212 provided in some embodiments of the present application. Figure 7 is a cross-sectional view of the DD position in Figure 6. Figure 8 is an enlarged view of the E position in Figure 7. An embodiment of the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22 and an electrode terminal 23. The shell 21 has a wall portion 211, and the wall portion 211 is provided with a lead-out hole 2121. The electrode assembly 22 is accommodated in the shell 21. The electrode terminal 23 includes a first terminal portion 231 and a second terminal portion 232. The first terminal portion 231 and the second terminal portion 232 are made of different materials and are composite with each other. The first terminal portion 231 is inserted into the lead-out hole 2121, and the second terminal portion 232 is electrically connected to the electrode assembly 22. The first terminal portion 231 includes a first limiting portion 2311 , and along the thickness direction of the wall portion 211 , the first limiting portion 2311 is configured to limit the first terminal portion 231 from escaping from the lead-out hole 2121 in a direction away from the electrode assembly 22 .

[0090] The outer shell 21 has multiple walls, such as a bottom wall, side walls, and a top wall. The wall portion 211 specifically refers to the wall on which the electrode terminal 23 is provided. For example, if the electrode terminal 23 is provided on the bottom wall, the wall portion 211 refers to the bottom wall of the shell 213. For another example, if the electrode terminal 23 is provided on the top wall, the wall portion 211 refers to the top wall of the shell 213. For another example, if a side wall is provided with an electrode terminal 23, the wall portion 211 refers to the side wall. For another example, if the end cover 212 is provided with the electrode terminal 23, the wall portion 211 may also refer to the end cover 212. In other words, the wall portion 211 may be either a wall on the shell 213 or the end cover 212. In this embodiment, the electrode terminal 23 is provided on the end cover 212 as an example, that is, in this embodiment, the end cover 212 is the wall portion 211.

[0091] The lead-out hole 2121 is a through hole formed in the wall portion 211 . The lead-out hole 2121 is used to provide the electrode terminal 23 . The electrode terminal 23 connects the electrode assembly 22 in the housing 21 and the current collecting member outside the housing 21 through the lead-out hole 2121 .

[0092] The electrode terminal 23 is disposed on the wall portion 211 . The electrode terminal 23 can be used to electrically connect to the electrode assembly 22 to output or input electrical energy of the battery cell 20 .

[0093] The first terminal portion 231 is the portion of the electrode terminal 23 that is used to connect to the busbar component. The material of the first terminal portion 231 can be the same as the material of the busbar component to facilitate welding with the busbar component. For example, the material of the first terminal portion 231 can be aluminum. Optionally, a conductive member 233 is provided at one end of the first terminal portion 231 away from the second terminal portion 232 in the thickness direction. By providing the conductive member 233 and connecting to the busbar component through the conductive member 233, the connection area between the first terminal portion 231 and the busbar component is increased, thereby improving the stability of the connection.

[0094] The second terminal portion 232 is the portion of the electrode terminal 23 used to connect to the electrode assembly 22. The material of the second terminal portion 232 can be the same as that of the current collecting member or the tab 221 to facilitate welding to the current collecting member or the tab 221. For example, the material of the second terminal portion 232 can be copper.

[0095] “The first terminal portion 231 and the second terminal portion 232 are made of different materials” means that the first terminal portion 231 and the second terminal portion 232 are made of different metal materials or metal alloys. For the same metal alloys with different components, they can be considered to be made of the same material.

[0096] The composite can be made by solid-liquid bonding, solid-phase bonding, hot rolling, diffusion pressing, surfacing, and hot rolling.

[0097] The first stopper 2311 is a portion of the first terminal portion 231. The first stopper 2311 is located within the housing 21. Along the thickness direction of the wall portion 211, the first stopper 2311 can be positioned relative to the wall portion 211 or other components. When the first terminal portion 231 is subjected to an outward pulling force, the first stopper 2311 can abut against the wall portion 211 or other components, thereby preventing the first terminal portion 231 from disengaging from the lead-out hole 2121 in a direction away from the electrode assembly 22.

[0098] The thickness direction of the wall portion 211 may be the Y direction as shown in FIG. 8 .

[0099] The electrode terminal 23 of the battery cell 20 includes a first terminal portion 231 and a second terminal portion 232 made of different materials, so that the first terminal portion 231 can be welded to the current collecting member and the second terminal portion 232 can be welded to the electrode assembly 22. The first terminal portion 231 has a first limiting portion 2311. When the first terminal portion 231 is subjected to an outward pulling force, the first limiting portion 2311 can limit the first terminal portion 231 from being separated from the lead-out hole 2121 in a direction away from the electrode assembly 22. In this way, the composite interface of the first terminal portion 231 and the second terminal portion 232 is not easily affected by external forces, and thus the first terminal portion 231 and the second terminal portion 232 are not easily separated, thereby extending the life of the battery cell 20.

[0100] 3, 4, 5, 6, 7, and 8, in some embodiments, along the thickness direction of the wall portion 211, the first limiting portion 2311 is located on the side of the wall portion 211 facing the electrode assembly 22. The projection of the first limiting portion 2311 and the projection of the wall portion 211 at least partially overlap.

[0101] The phrase "the projection of the first limiting portion 2311 at least partially overlaps with the projection of the wall portion 211" includes both partial overlap and complete overlap. The complete overlap of the projection of the first limiting portion 2311 with the projection of the wall portion 211 can also be understood as meaning that the projection of the first limiting portion 2311 on the wall portion 211 completely falls within the wall portion 211 along the thickness direction.

[0102] Along the thickness direction of the wall portion 211, the first stop portion 2311 is located on the side of the wall portion 211 facing the electrode assembly 22. The projection of the first stop portion 2311 and the projection of the wall portion 211 at least partially overlap, so that when the first terminal portion 231 is subjected to an outward pulling force, the first stop portion 2311 can abut against the wall portion 211 (the first stop portion 2311 can abut against the wall portion 211 directly, or the first stop portion 2311 can abut against the wall portion 211 indirectly through an intermediate component), thereby limiting the first terminal portion 231 from disengaging from the lead-out hole 2121 in a direction away from the electrode assembly 22. In this way, the composite interface between the first terminal portion 231 and the second terminal portion 232 is not easily affected by external forces, and thus the first terminal portion 231 and the second terminal portion 232 are not easily separated, thereby extending the life of the battery cell 20.

[0103] Referring to Figures 3, 4, 5, 6, 7, and 8, in some embodiments, along the thickness direction, the first limiting portion 2311 has a first surface facing the wall portion 211, and a first outer edge of the first surface is disposed around the outlet hole 2121. Along a direction perpendicular to the thickness direction, the minimum distance A between the first outer edge and the wall surface of the outlet hole 2121 satisfies the following: A ≥ 1 mm.

[0104] The direction perpendicular to the thickness direction may be the radial direction of the lead-out hole 2121. Referring to Figure 8 , the direction perpendicular to the thickness direction may be the X direction shown in the figure.

[0105] The first surface is the surface of the first stopper 2311 that faces the wall portion 211 along the thickness direction. The first stopper 2311 can be disc-shaped, and the first outer edge of the first surface is disposed outside the outlet hole 2121. Optionally, the first stopper 2311 and the outlet hole 2121 are coaxially disposed. In this case, the distance from each position on the first outer edge to the wall of the outlet hole 2121 is equal.

[0106] In some embodiments, the first limiting portion 2311 and the outlet hole 2121 are not coaxially arranged. In this case, the distances from various positions on the first outer edge to the wall of the outlet hole 2121 are not necessarily equal.

[0107] In conjunction with FIG. 8 , the first surface is the upper surface of the first limiting portion 2311 .

[0108] A represents the minimum distance between the first outer edge and the wall of the lead-out hole 2121 in a direction perpendicular to the thickness direction. The minimum distance between the first outer edge and the wall of the lead-out hole 2121 in a direction perpendicular to the thickness direction can be: A = 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0109] By ensuring that the minimum distance between the first outer edge and the wall surface of the lead-out hole 2121 along a direction perpendicular to the thickness direction is greater than or equal to 1 mm, the projection of the first limiting portion 2311 and the projection of the wall portion 211 along the thickness direction of the wall portion 211 have sufficient overlapping area. When the first terminal portion 231 is subjected to an outward pulling force, the first limiting portion 2311 can have sufficient area to abut against the wall portion 211 to prevent the electrode terminal 23 from separating from the lead-out hole 2121. If A is less than 1 mm, when the first terminal portion 231 is subjected to an outward pulling force, the area of ​​abutment between the first limiting portion 2311 and the wall portion 211 is small, and the first limiting portion 2311 may deform, causing the electrode terminal 23 to separate from the lead-out hole 2121.

[0110] 3 , 4 , 5 , 6 , 7 and 8 , in some embodiments, the first terminal portion 231 includes a body portion 2312 , which is disposed through the lead-out hole 2121 . The first position-limiting portion 2311 protrudes from the outer circumference of the body portion 2312 .

[0111] The main body 2312 is the portion of the first terminal 231 that passes through the lead-out hole 2121. The first position-limiting portion 2311 may be a fan-shaped structure protruding from the outer circumference of the main body 2312, or an annular structure protruding from the outer circumference of the main body 2312.

[0112] By making the first limiting portion 2311 protrude from the outer circumference of the main body 2312 , the strength of the main body 2312 is not easily weakened, so that the first terminal portion 231 is not easily damaged when subjected to external force.

[0113] In other embodiments, a receiving groove is formed on the body portion 2312, and the wall portion 211 extends into the receiving groove. Along the thickness direction of the wall portion 211, the groove wall of the receiving groove located on the side of the wall portion 211 facing the electrode assembly constitutes the first limiting portion 2311. In this manner, the volume of the electrode terminal 23 is reduced.

[0114] 3, 4, 5, 6, 7, and 8, in some embodiments, the first terminal portion 231 further includes a body portion 2312 and a second limiting portion 2313. The body portion 2312 is disposed through the lead-out hole 2121 and connects the first limiting portion 2311 and the second limiting portion 2313. Along the thickness direction, the first limiting portion 2311 and the second limiting portion 2313 are respectively located on either side of the wall portion 211, and the projection of the second limiting portion 2313 at least partially overlaps with the projection of the wall portion 211.

[0115] The main body 2312 is a portion of the first terminal portion 231 that passes through the lead-out hole 2121 . The main body 2312 connects the first limiting portion 2311 and the second limiting portion 2313 .

[0116] The second position-limiting portion 2313 is located outside the housing 21 and is disposed opposite the wall portion 211 along the thickness direction. Thus, along the thickness direction, the first position-limiting portion 2311 and the second position-limiting portion 2313 are respectively located on either side of the wall portion 211, and the projections of the first position-limiting portion 2311 and the wall portion 211 at least partially overlap, and the projections of the second position-limiting portion 2313 and the wall portion 211 at least partially overlap.

[0117] The main body 2312 connects the first limiting portion 2311 and the second limiting portion 2313. The first limiting portion 2311 can limit the electrode terminal 23 from being separated from the lead-out hole 2121 in a direction away from the electrode assembly 22, while the second limiting portion 2313 can limit the electrode terminal 23 from being separated from the lead-out hole 2121 in a direction toward the electrode assembly 22. This reduces the risk of the electrode terminal 23 being separated from the lead-out hole 2121, helps ensure that the battery cell 20 can normally output or input electrical energy, and prolongs the life of the battery cell 20.

[0118] In some embodiments, the first terminal portion 231 and the second terminal portion 232 are combined to form a composite interface, which intersects the outer surface of the electrode terminal 23 at an interface. The battery cell 20 further includes a seal 24 that seals the interface.

[0119] The composite interface is the connection interface between the first terminal portion 231 and the second terminal portion 232. The junction position is the position where the composite interface intersects the outer contour of the electrode terminal 23.

[0120] "Seal 24 seals the interface" means that seal 24 can prevent electrolyte from entering the composite interface. For example, seal 24 can be positioned along the path where electrolyte enters the composite interface to reduce the risk of electrolyte entering the composite interface. In other words, seal 24 does not necessarily cover the interface.

[0121] The sealing member 24 is a structure capable of achieving a sealing effect, such as a sealant, a sealing gasket, a sealing sheet or a sealing ring, etc. The sealing member 24 seals the interface to reduce the risk of electrolyte entering the composite interface.

[0122] Because the first terminal portion 231 and the second terminal portion 232 are made of different materials, chemical corrosion may occur if electrolyte enters the composite interface. Therefore, by providing a sealant 24 to seal the interface, the risk of electrolyte entering the composite interface is reduced, thereby reducing the risk of chemical corrosion and extending the life of the battery cell 20.

[0123] 3 , 4 , 5 , 6 , 7 and 8 , in some embodiments, the sealing member 24 is configured to seal the first terminal portion 231 and the wall portion 211 .

[0124] The sealing member 24 may be partially disposed between the first terminal portion 231 and the wall portion 211 to seal the first terminal portion 231 and the wall portion 211 .

[0125] The seal 24 seals the first terminal portion 231 and the wall portion 211 while sealing the interface. One component realizes multiple functions, which helps to simplify the structure of the battery cell 20 .

[0126] Referring to Figures 3, 4, 5, 6, 7 and 8, in some embodiments, the seal 24 includes a third sealing portion 241, which is arranged between the first limiting portion 2311 and the wall portion 211 to seal the first terminal portion 231 and the wall portion 211.

[0127] The third sealing portion 241 may be annular. The third sealing portion 241 is disposed between the first limiting portion 2311 and the wall portion 211 , thereby reducing the risk of the electrolyte entering the lead-out hole 2121 .

[0128] If the electrolyte wants to enter the outlet hole 2121, it needs to pass between the first limiting portion 2311 and the wall portion 211. By setting the third sealing portion 241 to seal the first limiting portion 2311 and the wall portion 211, the electrolyte is restricted from entering the outlet hole 2121, thereby achieving sealing of the first terminal portion 231 and the wall portion 211.

[0129] 3 , 4 , 5 , 6 , 7 and 8 , in some embodiments, the seal 24 further includes a second sealing portion 242 , which is connected to the third sealing portion 241 , and at least partially extends into the outlet hole 2121 .

[0130] The second sealing portion 242 extends into the outlet hole 2121 and is disposed between the body 2312 and the wall 211 to seal the body 2312 and the wall 211. The second sealing portion 242 may be a cylindrical structure and sleeved on the outside of the body 2312.

[0131] By providing the second sealing portion 242, which at least partially extends into the lead-out hole 2121, the second sealing portion 242 can position the sealing member 24 to facilitate installation of the sealing member 24. On the other hand, the second sealing portion 242 can also seal the first terminal portion 231 and the wall portion 211.

[0132] In some embodiments, a groove is provided on the side of the second terminal portion 232 facing the first terminal portion 231, and the first limiting portion 2311 is at least partially accommodated in the groove. The groove side surface and the outer peripheral surface of the first limiting portion 2311 form a composite interface.

[0133] Along the thickness direction, the surface of the first retaining portion 2311 facing the electrode assembly 22 and the bottom surface of the groove combine to form a first connection interface. The outer peripheral surface of the first retaining portion 2311 and the side surface of the groove combine to form a second connection interface. In the present embodiment, the composite interface specifically refers to the second connection interface.

[0134] A groove is provided on the side of the second terminal portion 232 facing the first terminal portion 231, so that a composite interface is formed between the side of the groove and the outer peripheral surface of the first limiting portion 2311. In this way, the electrolyte can only enter the composite interface from the side of the second terminal portion 232 facing away from the electrode assembly 22, making it more difficult for the electrolyte to enter the composite interface, and the composite interface is less susceptible to corrosion by the electrolyte.

[0135] Please refer to Figures 9, 10 and 11. Figure 9 is a top view schematic diagram of the end cover 212 provided in other embodiments of the present application. Figure 10 is a cross-sectional view of the FF position in Figure 9. Figure 11 is an enlarged view of the G position in Figure 10. In other embodiments, the first terminal portion 231 and the second terminal portion 232 are stacked in the thickness direction, and the junction position is located on the outer peripheral surface of the electrode terminal 23. Optionally, the second terminal portion 232 is a plate-like structure, and the thickness direction is perpendicular to the composite interface. In this way, it is more convenient to composite the first terminal portion 231 and the second terminal portion 232, and the composite quality is better, so that the first terminal portion 231 and the second terminal portion 232 are not easy to separate.

[0136] Please refer to Figures 3, 4, 5, 6, 7, 8 and 12. Figure 12 is a cross-sectional view of an end cap provided in some other embodiments of the present application. In some embodiments, the second terminal portion 232 includes a first portion 2321 and a second portion 2322. Along the thickness direction, the first portion 2321 is stacked with the first terminal portion 231, and the second portion 2322 is surrounded by the first limiting portion 2311. The first portion 2321 and the second portion 2322 jointly define a groove. The seal 24 is at least partially located between the second portion 2322 and the wall portion 211 so that the seal 24 seals the interface.

[0137] In the thickness direction, the first portion 2321 is located on the side of the first limiting portion 2311 facing the electrode assembly 22 in the second terminal portion 232. The first portion 2321 is stacked with the first terminal portion 231 and is closer to the electrode assembly 22 in the thickness direction.

[0138] The second portion 2322 is located on the periphery of the first portion 2321 to define a groove together. In this way, the interface is located on the side of the second terminal portion 232 away from the electrode assembly 22 in the thickness direction, making it more difficult for the electrolyte to enter the composite interface.

[0139] Referring to FIG. 8 , in some embodiments, a portion of the sealing member 24 is located between the second portion 2322 and the wall portion 211 , and another portion of the sealing member 24 is located outside the second portion 2322 and the wall portion 211 .

[0140] Referring to FIG. 12 , in some further embodiments, the sealing member 24 is completely located between the second portion 2322 and the wall portion 211 .

[0141] The electrolyte can only enter the junction position through the gap between the second part 2322 and the wall portion 211. Therefore, by at least partially arranging the seal 24 between the second part 2322 and the wall portion 211, the electrolyte cannot enter the junction position through the gap between the second part 2322 and the wall portion 211, thereby achieving sealing of the junction position.

[0142] 3 , 4 , 5 , 6 , 7 and 8 , in some embodiments, a portion of the seal 24 is located between the first limiting portion 2311 and the wall portion 211 , so that the seal 24 covers the interface.

[0143] The sealing member 24 is partially located between the first limiting portion 2311 and the wall portion 211 , and simultaneously, the sealing member 24 is partially located between the second portion 2322 and the wall portion 211 , thereby covering the interface position and achieving a better sealing effect on the interface position.

[0144] Referring to Figures 3, 4, 5, 6, 7, and 8, in some embodiments, along the thickness direction, the first limiting portion 2311 has a first surface facing the wall portion 211, with a first outer edge of the first surface disposed around the outlet hole 2121. The second portion 2322 has a second surface facing the wall portion 211, with a second outer edge of the second surface disposed around the composite interface. Along a direction perpendicular to the thickness direction, the minimum distance between the first outer edge and the wall of the outlet hole 2121 is A, and the minimum distance between the second outer edge and the composite interface is B, satisfying the following: A / B ≥ 1 / 3.

[0145] The second surface is the surface of the second portion 2322 facing the wall portion 211 along the thickness direction. The second portion 2322 is disposed around the outside of the first limiting portion 2311, and the second outer edge of the second surface is also disposed around the composite interface.

[0146] In conjunction with FIG. 8 , the second surface is the upper surface of the second portion 2322 .

[0147] B represents the minimum distance between the second outer edge and the composite interface along the direction perpendicular to the thickness direction.

[0148] A / B represents the ratio of the minimum distance between the first outer edge and the wall of the lead-out hole 2121 to the minimum distance between the second outer edge and the composite interface, along a direction perpendicular to the thickness direction. Because the first outer edge and the composite interface coincide with each other, A / B can also represent the ratio of the minimum distance between the composite interface and the wall of the lead-out hole 2121 to the minimum distance between the second outer edge and the composite interface, along a direction perpendicular to the thickness direction.

[0149] Along the direction perpendicular to the thickness direction, the ratio of the minimum distance between the first outer edge and the hole wall of the lead-out hole 2121 to the minimum distance between the second outer edge and the composite interface can be: A / B = 1 / 3, 1 / 2, 2 / 3, 3 / 4, 4 / 5, 5 / 6, etc.

[0150] In a direction perpendicular to the thickness, the minimum distance between the first outer edge and the wall of the lead-out hole 2121 is greater than or equal to 1 / 3 times the minimum distance between the second outer edge and the composite interface. When the first terminal portion 231 is subjected to outward tension, the second portion 2322 can also abut against the seal 24, distributing the force applied to the first limiting portion 2311 and further reducing the risk of deformation of the first limiting portion 2311. Furthermore, the ratio A / B ≥ 1 / 3 prevents the first limiting portion 2311 from being too small, providing greater strength to resist deformation.

[0151] 3 , 4 , 5 , 6 , 7 and 8 , in some embodiments, the first surface and the second surface are flush.

[0152] “The first surface and the second surface are flush” means that the first surface and the second surface are in the same plane.

[0153] When the first surface and the second surface are flush, the composite interface is not easily affected by external forces, and the first terminal portion 231 and the second terminal portion 232 are not easily separated, thereby extending the life of the battery cell 20 .

[0154] In other embodiments, the first surface and the second surface are not flush, and the size of the seal 24 can be adjusted so that the first surface abuts against the wall 211 through the seal 24 , and the second surface abuts against the wall 211 through the seal 24 .

[0155] In some embodiments, the seal 24 includes a first sealing portion 243, which is located along the thickness direction between the second portion 2322 and the wall portion 211. Along a direction perpendicular to the thickness direction, the minimum distance C between the outer periphery of the first sealing portion 243 and the composite interface satisfies: C ≥ 1 mm.

[0156] Please refer to FIG. 8 , in which the dotted line indicates the boundary between the third sealing portion 241 and the first sealing portion 243 .

[0157] Along the direction perpendicular to the thickness direction, the minimum distance between the outer peripheral surface of the first sealing portion 243 and the composite interface can be: C=1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc.

[0158] In order to make the first sealing part 243 match with the insulating part 214, a notch may be provided on the first sealing part 243. By making C ≥ 1 mm, the first sealing part 243 can be ensured to have a better sealing effect, reduce the risk of electrolyte entering the composite interface, and extend the service life of the battery cell 20.

[0159] In some embodiments, the seal 24 includes a first sealing portion 243, which is located between the second portion 2322 and the wall portion 211. The first sealing portion 243 has a third surface facing the wall portion 211 and a fourth surface facing the second portion 2322, wherein a third outer edge of the third surface surrounds the composite interface, and a fourth outer edge of the fourth surface surrounds the third outer edge.

[0160] In the embodiment of the present application, the third surface is the upper surface of the first sealing portion 243 and is in contact with the wall portion 211 . The fourth surface is the lower surface of the first sealing portion 243 and is in contact with the second portion 2322 .

[0161] The fourth outer edge of the fourth surface surrounds the third outer edge, such that the area of ​​the fourth surface is greater than the area of ​​the third surface. One end of the first sealing portion 243 can be formed into a step, an inclined surface, or a curved surface. In this case, C represents the distance between the third outer edge and the composite interface along a direction perpendicular to the thickness direction.

[0162] Of course, in the embodiment where the third surface and the fourth surface have the same area, C represents the distance between the third outer edge and the composite interface or the distance between the fourth outer edge and the composite interface along the direction perpendicular to the thickness direction.

[0163] In addition, in the embodiment where the area of ​​the third surface is greater than the area of ​​the fourth surface, C represents the distance between the fourth outer edge and the composite interface along a direction perpendicular to the thickness direction.

[0164] Along the direction perpendicular to the thickness direction, the distance between the third outer edge and the composite interface can be: C = 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc.

[0165] The edge of the first sealing portion 243 may form a step, a slope or a curved surface, etc., so as to cooperate with the insulating member 214. The portion of the first sealing portion 243 without a step has a better sealing effect. The position of the third surface corresponds to the portion without a step. By making C ≥ 1mm, the first sealing portion 243 is ensured to have a better sealing effect, reducing the risk of electrolyte entering the composite interface and extending the service life of the battery cell 20. In addition, the area of ​​the fourth surface is larger than that of the third surface, which can also improve the sealing effect to a certain extent.

[0166] Please refer to Figures 13, 14 and 15. Figure 13 is a top view of the end cap 212 provided in some other embodiments of the present application. Figure 14 is a cross-sectional view of the HH position in Figure 13. Figure 15 is an enlarged view of the I position in Figure 14. In some other embodiments, the battery cell 20 includes a seal 24. Along the thickness direction of the wall portion 211, the seal 24 is at least partially located on the side of the wall portion 211 facing the electrode assembly 22, and the projection of the seal 24 and the projection of the wall portion 211 at least partially overlap. The projection of the first limiting portion 2311 and the projection of the seal 24 at least partially overlap.

[0167] The phrase “the projection of the seal 24 at least partially overlaps with the projection of the wall 211” includes both partial overlap and complete overlap. The complete overlap of the projection of the seal 24 and the projection of the wall 211 can also be understood as meaning that the projection of the seal 24 on the wall 211 completely falls within the wall 211 along the thickness direction.

[0168] “The projection of the first limiting portion 2311 and the projection of the seal 24 at least partially overlap” includes that the projection of the first limiting portion 2311 and the projection of the seal 24 partially overlap and that the projection of the first limiting portion 2311 and the projection of the seal 24 completely overlap.

[0169] When the first terminal portion 231 is subjected to an outward pulling force, the first limiting portion 2311 can abut against the sealing member 24, and the sealing member 24 can abut against the wall portion 211 to limit the first terminal portion 231 from separating from the lead-out hole 2121 in a direction away from the electrode assembly 22. In this way, the composite interface between the first terminal portion 231 and the second terminal portion 232 is not easily affected by external forces, and thus the first terminal portion 231 and the second terminal portion 232 are not easily separated, which extends the life of the battery cell 20. While abutting against and limiting the first limiting portion 2311, the sealing member 24 also seals the first terminal portion 231 and the wall portion 211. One component performs multiple functions, which is conducive to simplifying the structure of the battery cell 20. In some embodiments, along the thickness direction, the projection of the first limiting portion 2311 and the projection of the wall portion 211 do not overlap.

[0170] “Along the thickness direction, the projection of the first limiting portion 2311 and the projection of the wall portion 211 do not overlap” means that along the thickness direction, the projection of the first limiting portion 2311 and the projection of the wall portion 211 are staggered.

[0171] Along the thickness direction, the projection of the first limiting portion 2311 partially overlaps with the projection of the seal 24, the projection of the seal 24 partially overlaps with the projection of the wall portion 211, and the projection of the first limiting portion 2311 does not overlap with the projection of the seal 24. In this way, the size of the first limiting portion 2311 can be reduced.

[0172] In some embodiments, along the thickness direction, the first limiting portion 2311 is located on a side of the sealing member 24 facing the electrode assembly 22 .

[0173] The first limiting portion 2311 is disposed on the side of the sealing member 24 facing the electrode assembly 22 . When the first terminal portion 231 is subjected to an outward pulling force, the first limiting portion 2311 can be more stably supported against the sealing member 24 .

[0174] In other embodiments, the first limiting portion 2311 may also be snapped onto the sealing member 24 so that the projection of the first limiting portion 2311 along the thickness direction and the projection of the sealing member 24 along the thickness direction at least partially overlap.

[0175] In yet other embodiments, along the thickness direction of the wall portion 211, the seal 24 is at least partially located on the side of the wall portion 211 facing the electrode assembly 22, with the projection of the seal 24 at least partially overlapping the projection of the wall portion 211. A receiving groove is defined in the body portion 2312, into which the seal 24 extends. Along the thickness direction of the wall portion 211, the groove wall located on the side of the seal 24 facing the electrode assembly forms the first stop 2311. This approach reduces the size of the electrode terminal 23.

[0176] The embodiment of the present application further provides a battery 100 , which includes the above-mentioned battery cell 20 .

[0177] An embodiment of the present application further provides an electric device, which includes the above-mentioned battery 100, and the battery 100 is used to provide electric energy to the electric device.

[0178] According to some embodiments of the present application, please refer to Figures 3 to 8.

[0179] An embodiment of the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22 and an electrode terminal 23. The shell 21 has a wall portion 211, and the wall portion 211 is provided with a lead-out hole 2121. The electrode assembly 22 is accommodated in the shell 21. The electrode terminal 23 includes a first terminal portion 231 and a second terminal portion 232, and the first terminal portion 231 and the second terminal portion 232 are made of different materials and are composite with each other. The first terminal portion 231 is passed through the lead-out hole 2121, and the second terminal portion 232 is electrically connected to the electrode assembly 22. Among them, the first terminal portion 231 includes a first limiting portion 2311, and along the thickness direction of the wall portion 211, the first limiting portion 2311 is located on the side of the wall portion 211 facing the electrode assembly 22, and the projection of the first limiting portion 2311 and the projection of the wall portion 211 at least partially overlap. The electrode terminal 23 of the battery cell 20 includes a first terminal portion 231 and a second terminal portion 232 made of different materials, facilitating welding of the first terminal portion 231 to the current collecting member and the second terminal portion 232 to the electrode assembly 22. Along the thickness of the wall portion 211, the first terminal portion 231 has a first stopper 2311 located on the side of the wall portion 211 facing the electrode assembly 22. The projection of the first stopper 2311 at least partially overlaps with the projection of the wall portion 211. This allows the first stopper 2311 to abut against the wall portion 211 when the first terminal portion 231 is subjected to an outward pull, thereby preventing the first terminal portion 231 from separating from the lead-out hole 2121 in a direction away from the electrode assembly 22. This prevents the interface between the first and second terminal portions 231, 232, from being affected by external forces, making separation difficult. This extends the life of the battery cell 20.

[0180] The first terminal portion 231 and the second terminal portion 232 are combined to form a composite interface, and the composite interface intersects with the outer surface of the electrode terminal 23 at the junction. The battery cell 20 also includes a sealant 24, which seals the junction. Since the first terminal portion 231 and the second terminal portion 232 are made of different materials, if the electrolyte enters the composite interface, chemical corrosion will occur. Therefore, by providing the sealant 24 to seal the junction, the risk of the electrolyte entering the composite interface is reduced, thereby reducing the risk of chemical corrosion and improving the life of the battery cell 20.

[0181] 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, wherein: include: The housing has a wall portion, wherein the wall portion is provided with an outlet hole; an electrode assembly, contained in the housing; The electrode terminal comprises a first terminal portion and a second terminal portion, the first terminal portion and the second terminal portion are made of different materials and are composite with each other, the first terminal portion is inserted through the lead-out hole, and the second terminal portion is electrically connected to the electrode assembly; The first terminal portion includes a first limiting portion, and along a thickness direction of the wall portion, the first limiting portion is configured to limit the first terminal portion from being separated from the lead-out hole in a direction away from the electrode assembly.

2. The battery cell according to claim 1, wherein: Along the thickness direction of the wall portion, the first limiting portion is located on a side of the wall portion facing the electrode assembly, and a projection of the first limiting portion and a projection of the wall portion at least partially overlap.

3. The battery cell according to claim 2, wherein: The first terminal portion and the second terminal portion are combined to form a composite interface, and the composite interface intersects with the outer surface of the electrode terminal at a junction position; The battery cell further includes a sealing member, which seals the interface position.

4. The battery cell according to claim 3, wherein: A groove is provided on a side of the second terminal portion facing the first terminal portion, the first limiting portion is at least partially accommodated in the groove, and a groove side surface of the groove and an outer peripheral surface of the first limiting portion are combined to form the composite interface.

5. The battery cell according to claim 4, wherein: The second terminal portion includes a first part and a second part. Along the thickness direction, the first part and the first terminal portion are stacked, and the second part is surrounded by the first limiting portion. The first part and the second part jointly define the groove, and the seal is at least partially located between the second part and the wall portion so that the seal seals the interface position.

6. The battery cell according to claim 5, wherein: A portion of the sealing member is located between the first limiting portion and the wall portion, so that the sealing member covers the interface position.

7. The battery cell according to claim 6, wherein: A portion of the sealing member extends into the outlet hole.

8. The battery cell according to any one of claims 5 to 7, wherein: Along the thickness direction, the first limiting portion has a first surface facing the wall portion, a first outer edge of the first surface is arranged around the lead-out hole, and the second portion has a second surface facing the wall portion, a second outer edge of the second surface is arranged around the composite interface; Along the direction perpendicular to the thickness direction, the minimum distance between the first outer edge and the hole wall of the lead-out hole is A, and the minimum distance between the second outer edge and the composite interface is B, satisfying: A / B≥1 / 3.

9. The battery cell according to claim 8, wherein: The first surface and the second surface are flush.

10. The battery cell according to any one of claims 5 to 9, wherein: The sealing member comprises a first sealing portion, and along the thickness direction, the first sealing portion is located between the second portion and the wall portion; Along the direction perpendicular to the thickness direction, the minimum distance between the outer peripheral surface of the first sealing portion and the composite interface is C, satisfying: C ≥ 1 mm.

11. The battery cell according to any one of claims 5 to 10, wherein: The seal comprises a first sealing portion, which is located between the second portion and the wall portion; the first sealing portion has a third surface facing the wall portion and a fourth surface facing the second portion, a third outer edge of the third surface is arranged around the composite interface, and a fourth outer edge of the fourth surface surrounds the third outer edge.

12. The battery cell according to any one of claims 2 to 11, wherein: Along the thickness direction, the first limiting portion has a first surface facing the wall portion, and the first outer edge of the first surface is arranged around the lead-out hole. Along the direction perpendicular to the thickness direction, the minimum distance between the first outer edge and the hole wall of the lead-out hole is A, satisfying: A≥1mm.

13. The battery cell according to any one of claims 1 to 12, wherein: The first terminal portion includes a main body portion, the main body portion is penetrated through the lead-out hole, and the first limiting portion protrudes from an outer peripheral surface of the main body portion.

14. The battery cell according to any one of claims 1 to 13, wherein: The first terminal portion also includes a main body portion and a second limiting portion, the main body portion is inserted through the lead-out hole, the main body portion connects the first limiting portion and the second limiting portion, and along the thickness direction, the first limiting portion and the second limiting portion are respectively located on both sides of the wall portion, and the projection of the second limiting portion and the projection of the wall portion at least partially overlap.

15. The battery cell according to claim 1, 13 or 14, wherein: The battery cell includes a seal, which is at least partially located on a side of the wall facing the electrode assembly along the thickness direction of the wall, a projection of the seal and a projection of the wall at least partially overlap, and a projection of the first limiting portion and a projection of the seal at least partially overlap.

16. The battery cell according to claim 15, wherein: Along the thickness direction, a projection of the first limiting portion and a projection of the wall portion do not overlap.

17. The battery cell according to claim 15 or 16, wherein: Along the thickness direction, the first limiting portion is located on a side of the sealing component facing the electrode assembly.

18. A battery, wherein: Comprising a battery cell according to any one of claims 1-17.

19. An electrical device, wherein: The battery according to claim 18 is used to provide electrical energy to the electrical device.

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