Battery cell, battery device, and electric device

Abstract

The application is suitable for the technical field of batteries, and provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises: a shell; an electrode terminal installed on the shell; an electrode assembly accommodated in the shell, the electrode assembly having a tab; an adapter comprising a first connecting portion, a second connecting portion and a bending portion, the first connecting portion being electrically connected with the tab, the second connecting portion being electrically connected with the electrode terminal; and the bending portion being arranged between the first connecting portion and the second connecting portion, the bending portion being bent towards one side of the adapter and formed with a groove. The battery monomer provided by the application can reduce the risk of tab fracture and improve the cycle life of the battery monomer.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. In this context, electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the automotive industry's sustainable development. And for electric vehicles, battery technology is a crucial factor in their development.

[0003] In the development of battery technology, improving the cycle life of individual battery cells is an important research direction. Utility Model Content

[0004] In view of this, embodiments of this application provide a battery cell, a battery device, and an electrical device that can extend the cycle life of the battery cell.

[0005] An embodiment of the first aspect of this application provides a battery cell, comprising: a housing; electrode terminals mounted on the housing; an electrode assembly housed within the housing, the electrode assembly having tabs; and an adapter, comprising a first connecting portion, a second connecting portion, and a bending portion, the first connecting portion being electrically connected to the tabs, the second connecting portion being electrically connected to the electrode terminals; the bending portion being disposed between the first connecting portion and the second connecting portion, the bending portion being bent toward one side of the adapter and forming a groove, the groove penetrating at least one side of the adapter.

[0006] In the battery cell provided in this application embodiment, the adapter includes a bent portion with a groove. The groove wall is easily deformed under force to release stress. The bent portion is located between the first connecting portion and the second connecting portion. The deformation of the bent portion does not easily affect the first and second connecting portions, and the adapter piece can still be stably connected to the tab and the electrode terminal. Therefore, during the use of the battery cell, the groove is easy to stretch and deform, releasing stress, reducing the pulling force on the tab, effectively reducing the risk of tab breakage, and improving the cycle life of the battery cell.

[0007] In some embodiments, the first connecting portion, the bending portion, and the second connecting portion are sequentially arranged along a first direction; the bending portion includes a first sub-part and a second sub-part arranged opposite to each other along the first direction, and a bottom connected between the first sub-part and the second sub-part, the first sub-part, the second sub-part, and the connecting portion forming a groove; the first sub-part is bent to connect with the first connecting portion, the second sub-part is bent to connect with the second connecting portion, and the bottom protrudes relative to the first connecting portion; the groove penetrates at least one side of the adapter along a second direction, and the second direction intersects with the first direction.

[0008] By adopting the above technical solution, the first sub-part is easy to deform, thereby increasing the size of the groove and reducing the risk of the electrode tab tearing; the groove penetrates at least one side of the adapter along the second direction, making the groove easy to deform under a small force.

[0009] In some embodiments, the bottom protrudes toward the side of the adapter opposite to the electrode terminals.

[0010] By adopting the above technical solution, the space between the adapter and the electrode assembly can be used to accommodate the groove without affecting the original design capacity of the battery cell.

[0011] In some embodiments, the groove has an inner width at the bottom, which is greater than or equal to twice the minimum bending radius of the bend.

[0012] By adopting the above technical solution, the adapter piece can be made into a groove through a bending process, and the bent part is not easy to crack or generate internal cracks.

[0013] In some embodiments, the groove has an inner width at the bottom, the inner width being greater than or equal to the thickness of the bend.

[0014] By adopting the above technical solution, a groove can be made on the adapter through a bending process. The bent part is easy to form and is not prone to cracking or internal cracks.

[0015] In some embodiments, the groove has an inner width A at the bottom, the bend has an outer width C at the bottom, and the thickness of the bend is E, where C = A + 2 * E.

[0016] By adopting the above technical solution, the outer width of the groove is smaller, and the applicability of the adapter is wider.

[0017] In some embodiments, the first connecting portion is welded to the electrode tab and forms a first weld mark, and the minimum distance from the outer wall surface of the first sub-part to the first weld mark is greater than or equal to 2 mm.

[0018] By adopting the above technical solution, the manufacturability requirements of battery cells can be met, the first solder mark and the bending part are less likely to affect each other, and the reliability of welding between the tab and the adapter is improved.

[0019] In some embodiments, the second connection portion is welded to the electrode terminal and a second solder mark is formed thereon, and the minimum distance from the outer wall surface of the second sub-part to the second solder mark is greater than or equal to 4 mm.

[0020] By adopting the above technical solution, the manufacturability requirements of battery cells can be met, the second solder mark and the bending part are less likely to affect each other, and the reliability of welding between electrode terminals and adapters is improved.

[0021] In some embodiments, the housing includes an end cap assembly and a housing, the end cap assembly covering the housing, the end cap assembly including an end cap and an insulating member, the insulating member being disposed on the side of the end cap facing the electrode assembly, the electrode assembly further including a main body portion, and an electrode tab being disposed on one side of the main body portion, wherein FD≥0.5mm, where D is the total height of the adapter and F is the distance from the main body portion to the insulating member.

[0022] By adopting the above technical solution, the total height of the adapter matches the space after the tab is bent, without affecting the original design capacity of the battery cell; the adapter can effectively utilize the space between the main body and the insulating part, and reduce the risk of the adapter damaging the electrode and the risk of the adapter being inserted into the main body.

[0023] In some embodiments, the outer surface of the bottom is provided with an insulating layer.

[0024] By adopting the above technical solution, the insulating layer can insulate and separate the groove from the main body of the electrode assembly, so as to prevent the bent part from being inserted into the electrode assembly and causing defects in extreme cases.

[0025] In some embodiments, the thickness of the bent portion is less than the thickness of the first connecting portion, and the thickness of the bent portion is less than the thickness of the second connecting portion.

[0026] By adopting the above technical solution, the bending part has a smaller thickness compared to other parts of the adapter, which facilitates bending or stamping of the bending part to form a groove while meeting the current carrying capacity.

[0027] In some embodiments, the housing includes two first walls disposed opposite each other along a first direction, wherein the first wall is the wall with the largest area in the housing.

[0028] By adopting the above technical solution, the two first walls are arranged opposite each other along the first direction, and the bent part is located between the first connecting part and the second connecting part along the first direction. When the electrode assembly expands, the groove can deform and stretch along the first direction, which effectively reduces the tensile force on the electrode tab and reduces the risk of electrode tab cracking.

[0029] In some embodiments, the adapter includes two first connecting portions and two bending portions. The two first connecting portions are respectively disposed on both sides of the adapter along a first direction, and each bending portion is disposed between the second connecting portion and the first connecting portion.

[0030] By adopting the above technical solution, the adapter is provided with two first connecting parts and two bending parts. In this way, the groove of each bending part can be stretched and deformed under force, reducing the tensile force on the two electrodes connected to the adapter.

[0031] An embodiment of the second aspect of this application provides a battery device comprising a battery cell as provided in the first aspect.

[0032] The embodiments of the third aspect of this application provide an electrical device, such as a battery cell of the first aspect or a battery device of the second aspect.

[0033] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0036] Figure 2 This is an exploded view of a battery device provided in an embodiment of this application;

[0037] Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application;

[0038] Figure 4 This is a cross-sectional view of a battery cell provided in an embodiment of this application;

[0039] Figure 5 This is a front view of the adapter and electrode provided in an embodiment of this application;

[0040] Figure 6 yes Figure 5 Side view of the adapter and electrode shown;

[0041] Figure 7 yes Figure 4 A cross-sectional view of another state of the battery cell shown;

[0042] Figure 8 This is a schematic diagram of the structure of an adapter provided in another embodiment of this application.

[0043] The markings in the diagram mean:

[0044] 1000, Vehicle; 1001, Battery assembly; 200, Housing; 210, Upper housing; 220, Lower housing; 1002, Controller; 1003, Motor; 100, Battery cell; 10, Housing; 101, First wall; 11, Shell; 12, End cap assembly; 121, End cap; 122, Insulator; 13, Electrode terminal; 14, Pressure relief mechanism; 20, Electrode assembly; 21, Main body; 22, Electrode tab; 30, Adapter; 31, First connecting part; 311, First weld mark; 32, Second connecting part; 321, Second weld mark; 33, Bending part; 331, Groove; 3311, First sub-part; 3312, Second sub-part; 3313, Bottom; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0045] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0047] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0050] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0051] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0052] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0053] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0054] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0055] A battery cell typically includes a casing, electrode terminals, and an adapter. The casing contains a cavity for housing the electrode assembly. The electrode terminals are located on the casing and are electrically connected to the tabs of the electrode assembly to extract the electrical energy generated by the assembly. The adapter connects the tabs and electrode terminals to provide an electrical connection.

[0056] During the use of a battery cell, the charging and discharging process causes the electrode assembly to expand, and the tabs to be stretched. In severe cases, this stretching can exceed the breaking strain of the tabs, causing them to break and resulting in battery cell failure.

[0057] During manufacturing, the total thickness of the electrode assembly is typically only considered to be less than the inner width of the outer shell, and the length of the tabs is designed based on the unexpanded state. However, during use, charging and discharging cause the electrode assembly to expand, and the tabs are subjected to tensile forces, especially the outermost tabs and the adjacent layers of tabs. The expanded length is significantly greater than the length during manufacturing, and in severe cases, it may exceed the metal fracture strain of the tabs, causing them to break. However, if the designed length of the tabs exceeds the necessary range (i.e., there is redundancy), the tabs will be too long, making tab shaping and control difficult. If not properly controlled, there is a probability that the redundant tab portion will insert into the electrode sheet, causing an internal short circuit risk.

[0058] In view of this, the present application provides a battery cell, which includes a housing, electrode terminals, electrode assemblies and an adapter. The adapter includes a first connecting portion, a second connecting portion and a bending portion. The first connecting portion is electrically connected to the tabs, and the second connecting portion is electrically connected to the electrode terminals. The bending portion is disposed between the first connecting portion and the second connecting portion, and the bending portion is bent toward one side of the adapter and forms a groove.

[0059] When the electrode assembly expands, the tabs are stretched, causing the grooves to deform and release stress, reducing the risk of tab tearing and extending the cycle life of the battery cell. Furthermore, this embodiment eliminates the need for excessively long tabs, improving the tab breakage problem without increasing the tab length. It also prevents the tabs from inserting into the electrode plates due to excessive length, reducing the risk of internal short circuits.

[0060] The technical solutions described in the embodiments of this application are applicable to battery devices, energy storage devices, and electrical devices that use battery devices.

[0061] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0062] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0063] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. Electrical devices include, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. Spacecraft include, for example, airplanes, rockets, space shuttles, and spacecraft.

[0064] The energy storage device provided in this application includes one or more battery clusters to improve the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices, which are connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0065] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices.

[0066] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0067] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet.

[0068] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0069] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 1001 is disposed inside the vehicle 1000, and the battery device 1001 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 1001 can be used to power the vehicle 1000; for example, the battery device 1001 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 1002 and a motor 1003. The controller 1002 is used to control the battery device 1001 to supply power to the motor 1003, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0070] In some embodiments of this application, the battery device 1001 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0071] refer to Figure 2 , Figure 2This is an exploded structural diagram of a battery device 1001 provided in some embodiments of this application. The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via busbars.

[0072] In some embodiments, multiple battery cells in the battery device 1001 can be electrically connected through a busbar to achieve parallel, series, or mixed connection of multiple battery cells in the battery device 1001.

[0073] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0074] In some embodiments, the battery device 1001 may be a battery pack, which includes a housing 200 and one or more battery cell assemblies housed in the housing 200.

[0075] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing 200 by fixing the battery module in the housing 200.

[0076] As an example, the battery cell assembly can also be housed in the housing 200 by directly fixing multiple battery cells to the housing 200.

[0077] As an example, the housing 200 may include an upper housing 210 and a lower housing 220. The upper housing 210 and the lower housing 220 are fastened together to form a closed receiving cavity inside the housing 200 to house the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed.

[0078] As an example, the housing 200 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 200 forms a closed receiving cavity to accommodate the battery cell assembly.

[0079] As an example, the housing 200 can be part of the chassis structure of the vehicle 1000. For example, the top cover of the housing 200 can be at least part of the floor of the vehicle 1000, or the frame of the housing 200 can be at least part of the crossbeams and longitudinal beams of the vehicle 1000.

[0080] In some embodiments, battery device 1001 refers to an energy storage device, which includes a housing 200, and at least one side of the housing 200 has a door. The energy storage device includes energy storage containers, energy storage cabinets, etc.

[0081] Please refer to Figure 3 The battery cell 100 is the smallest unit that makes up the battery device. The battery cell 100 includes a housing 10, an electrode assembly 20, and other functional components. The housing 10 is provided with functional components such as electrode terminals 13 and a pressure relief mechanism 14. The electrode terminals 13 are connected to the tabs of the electrode assembly 20 to realize the input and output of electrical energy, and the pressure relief mechanism 14 is used to release the internal pressure of the battery cell. Figure 3 The X direction in the diagram indicates the width of the battery cell 100, the Y direction indicates the length of the battery cell 100, and the Z direction indicates the height of the battery cell 100.

[0082] The outer casing 10 is used to enclose a receiving space, which can be used to house the electrode assembly 20, the electrolyte, and other components. The outer casing 10 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the outer casing 10 can be determined according to the specific shape and size of the electrode assembly. The outer casing 10 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0083] Electrode assembly 20 is the component in the battery cell 100 where electrochemical reactions occur. The casing 10 may contain one or more electrode assemblies 20. Electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the body of the electrode assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the body or separately at both ends of the body. During the charging and discharging process of the battery device, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0084] An embodiment of the first aspect of this application provides a battery cell 100. Please refer to... Figures 3 to 7 The battery cell 100 includes a housing 10, electrode terminals 13, electrode assembly 20, and adapter 30. The electrode terminals 13 are installed in the housing 10, and the electrode assembly 20 is housed in the housing 10. The electrode assembly 20 has tabs 22. The adapter 30 includes a first connecting portion 31, a second connecting portion 32, and a bending portion 33. The first connecting portion 31 is electrically connected to the tabs 22, and the second connecting portion 32 is electrically connected to the electrode terminals 13. The bending portion 33 is disposed between the first connecting portion 31 and the second connecting portion 32. The bending portion 33 bends toward the side of the adapter 30 and forms a groove 331.

[0085] The outer casing 10 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite casing 10), or aluminum-plastic film, etc. In some embodiments, the outer casing 10 can be a sealed structure or a non-sealed structure.

[0086] In some embodiments, the housing 10 includes an end cap assembly 12 and a housing 11, the housing 11 having an opening, and the end cap assembly 12 covering the opening. The housing 11 may have one or more openings. The end cap assembly 12 may also be provided one or more.

[0087] The housing 10 is provided with at least one electrode terminal 13. For example, the number of electrode terminals 13 can be two, which are a positive electrode terminal and a negative electrode terminal, respectively. The electrode terminals 13 can be provided on the end cap assembly 12 or on the housing 11.

[0088] The number of electrode assemblies 20 can be one or more. The electrode assembly 20 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked. The electrode assembly 20 includes tabs 22, which can conduct current from the electrode assembly 20. The tabs 22 include a positive tab and a negative tab.

[0089] In some embodiments, the electrode assembly 20 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0090] In some embodiments, the electrode assembly 20 has a stacked structure.

[0091] In some embodiments, the electrode assembly 20 may be cylindrical, flat, or polygonal in shape.

[0092] The adapter 30 is a component used to electrically connect the tab 22 to the electrode terminal 13. The adapter 30 can be made of conductive materials such as metal. Optionally, the adapter 30 can be made of the same material as the tab 22 it is connected to. For example, the adapter 30 can be made of copper, aluminum, etc.

[0093] The adapter 30 includes a first connecting portion 31, a second connecting portion 32, and a bending portion 33. The first connecting portion 31 is the part of the adapter 30 used to connect the electrode tab 22. The first connecting portion 31 and the electrode tab 22 can be connected by welding to form a first solder mark 311. The area of ​​the first solder mark 311 is less than or equal to the area of ​​the first connecting portion 31. The first connecting portion 31 can be a flat sheet or other shapes.

[0094] The second connecting portion 32 is the part of the adapter 30 used to connect to the electrode terminal 13. The second connecting portion 32 and the electrode terminal 13 can be welded together to form a second solder mark 321. The area of ​​the second solder mark 321 is less than or equal to the area of ​​the second connecting portion 32. The second connecting portion 32 can be a flat sheet or other shapes. For example, the second connecting portion 32 has a protrusion on the part corresponding to the electrode terminal 13, and the protrusion protrudes towards the side of the electrode terminal 13.

[0095] The bending portion 33 is a bending structure in the adapter 30. The bending portion 33 has a groove 331. The bending portion 33 can be formed in the adapter 30 by stamping, bending and other processes. That is to say, the adapter 30 can be an integral part. The groove 331 is formed by stamping, bending and other processes on the bending portion 33.

[0096] The groove 331 has an opening and a bottom, with the bottom facing the opening. The bottom of the groove 331 protrudes towards the thickness direction of the adapter 30, and the adapter 30 is connected to the tab 22 and the electrode terminal 13 on both sides along its thickness direction. Optionally, such as Figure 4 As shown, the bottom of the groove 331 protrudes towards the side of the adapter 30 near the electrode terminal 13. In other embodiments, the bottom of the groove 331 may also protrude towards the side of the adapter 30 near the electrode terminal 13.

[0097] In some embodiments, the adapter 30 may be an integrally formed structure, and the bending portion 33 may be manufactured by processes such as bending and stamping.

[0098] During the use of the battery cell 100, the charging and discharging of the battery cell 100 may cause the electrode assembly 20 to expand, which causes the tab 22 to be subjected to a pulling force. The groove wall of the groove 331 can be stretched and deformed, which increases the width of the groove 331. Through torque amplification, the adapter 30 is deformed and extended to release stress. In this way, the pulling force of the tab 22 can be reduced or even eliminated, effectively reducing the risk of tab 22 breakage.

[0099] In the battery cell 100 provided in this application embodiment, the adapter 30 includes a bending portion 33, and the bending portion 33 forms a groove 331. The groove wall of the groove 331 is easily deformed under force to release stress. The bending portion 33 is located between the first connecting portion 31 and the second connecting portion 32. The deformation of the bending portion 33 does not easily affect the first connecting portion 31 and the second connecting portion 32, so that the adapter piece can still be stably connected to the tab 22 and the electrode terminal 13. Therefore, during the use of the battery cell 100, the groove 331 is easy to stretch and deform, releasing stress, reducing the tensile force of the tab 22, effectively reducing the risk of tab 22 breakage, and improving the cycle life of the battery cell 100. At the same time, this application embodiment does not require the tab 22 to be designed too long. The problem of tab 22 breakage is improved without increasing the design length of the tab 22. The tab 22 will not be inserted into the electrode sheet due to excessive length, reducing the risk of internal short circuit.

[0100] In some embodiments, the first connecting portion 31, the bending portion 33, and the second connecting portion 32 are sequentially arranged along the first direction X; the bending portion 33 includes a first sub-part 3311 and a second sub-part 3312 arranged opposite to each other along the first direction X, and a bottom portion 3313 connected between the first sub-part 3311 and the second sub-part 3312. The first sub-part 3311, the second sub-part 3312, and the bottom portion 3313 form a groove 331. The first sub-part 3311 is bent and connected to the first connecting portion 31, and the second sub-part 3312 is bent and connected to the second connecting portion 32. The bottom portion 3313 protrudes relative to the first connecting portion 31; the groove 331 penetrates at least one side of the adapter 30 along the second direction Y. The second direction Y intersects the first direction X and is perpendicular to the thickness direction of the adapter 30.

[0101] For example, the first direction X is perpendicular to the second direction Y. The first direction X can be the thickness direction of the battery cell 100, and the second direction Y can be the length direction of the battery cell 100. Along the first direction X, the bending portion 33 is provided between the first connecting portion 31 and the second connecting portion 32.

[0102] The groove 331 includes a first sub-part 3311, a second sub-part 3312, and a bottom 3313. The first sub-part 3311 and the second sub-part 3312 are spaced apart to form a slot, and the slot is opposite to the bottom 3313. The first sub-part 3311 is bent and connected to the first connecting part 31, wherein the first sub-part 3311 and the first connecting part 31 can be bent and connected perpendicularly or at other angles; the second sub-part 3312 is bent and connected to the second connecting part 32, wherein the second sub-part 3312 and the second connecting part 32 can be bent and connected perpendicularly or at other angles.

[0103] The groove 331 extends through at least one side of the adapter 30 along the second direction Y, making it easy for the pulling force of the tab 22 to deform the groove 331. For example, as... Figure 5 As shown, in some embodiments, the groove 331 penetrates both sides of the adapter 30 along the second direction Y, facilitating the deformation of the groove 331; for example... Figure 8 As shown, in some other embodiments, the groove 331 may also extend through one side of the adapter 30 along the second direction Y.

[0104] Please refer to Figure 4 In the initial state, the first sub-part 3311 is approximately perpendicular to the first connecting part 31; please refer to... Figure 7 When the electrode assembly 20 expands, the tab 22 is subjected to tensile force, the angle between the first sub-part 3311 and the first connecting part 31 increases, the width of the groove 331 increases, and the adapter 30 deforms to release stress.

[0105] By adopting the above technical solution, the bending portion 33 includes a first sub-portion 3311, a second sub-portion 3312, and a bottom portion 3313. The first sub-portion 3311 is bent and connected to the first connecting portion 31. When the tab 22 connected to the first connecting portion 31 is subjected to tensile force due to the deformation of the electrode assembly 20, the first sub-portion 3311 is prone to deformation, thereby increasing the size of the groove 331. The adapter 30 releases stress through deformation, reducing the risk of the tab 22 tearing and improving the cycle life of the battery cell 100. At the same time, since the angle between the first sub-portion 3311 and the bottom of the groove increases, the size of the groove 331 can be increased, allowing stress to be released. The second sub-portion 3312 is less prone to deformation under force, thus less likely to affect the connection reliability between the adapter 30 and the electrode terminal 13. In addition, the groove 331 penetrates at least one side of the adapter 30 along the second direction Y, making the groove 331 easy to deform under a small force, further reducing the risk of the tab 22 tearing.

[0106] In some embodiments, the first sub-part 3311 is smoothly connected to the bottom 3313, and / or the second sub-part 3312 is smoothly connected to the bottom 3313. The bent portion 33 can be manufactured by processes such as bending and stamping, so that the bottom 3313 is smoothly connected to the first sub-part 3311 and / or the second sub-part 3312. By adopting the above technical solution, the smooth transition connection can distribute stress evenly, which is beneficial for the deformation of the groove 331 to release stress.

[0107] In some embodiments, the first sub-part 3311 is perpendicular to the first connecting part 31 and the bottom part 3313, respectively, and / or the second sub-part 3312 is perpendicular to the second connecting part 32 and the bottom part 3313, respectively. By adopting the above technical solution, it is beneficial to effectively utilize space and control the manufacturing accuracy of the groove 331.

[0108] In some embodiments, the bottom 3313 protrudes toward the side of the adapter 30 opposite to the electrode terminal 13.

[0109] The electrode assembly 20 also includes a main body 21, with an electrode tab 22 disposed at one end of the main body 21. The electrode tab 22 is bent and connected to the adapter 30. Therefore, there is a gap between the adapter 30 and the main body 21.

[0110] By protruding the bottom 3313 toward the side opposite to the electrode terminal 13, the space between the adapter 30 and the main body 21 can be used to accommodate the bent part 33, saving space and improving the space utilization of the battery cell 100 without affecting the original design capacity of the battery cell 100.

[0111] Please refer to Figure 4 In some embodiments, the groove 331 has an inner width at the bottom 3313, the inner width being greater than or equal to twice the minimum bending radius of the bend 33.

[0112] like Figure 4 , Figure 6 As shown, the groove 331 has an inner width A at the bottom 3313, and the dimension of A is greater than or equal to twice the minimum bending radius of the bent portion 33.

[0113] The inner width A of the groove 331 at the bottom 3313 refers to the width of the groove 331 located at the bottom 3313 along the first direction X. Figure 4 As shown, in some embodiments, both the first sub-part 3311 and the second sub-part 3312 are perpendicular to the bottom 3313, so the inner width A of the groove 331 at the bottom 3313 is equal to the inner width of the groove 331 at the opening; in other embodiments, such as Figure 7 As shown, if the first sub-part 3311 and / or the second sub-part 3312 are connected to the bottom 3313 at an obtuse angle before the groove 331 is stretched and deformed, then the inner width A of the groove 331 at the bottom 3313 is less than the inner width of the groove 331 at the opening.

[0114] Figure 6 The bending radius R1 of the bent part is shown. The minimum bending radius of the bent part 33 refers to the minimum value of the inner diameter of the bent part 33.

[0115] By adopting the above technical solution, the adapter piece can be made into a groove 331 by bending process. The inner width of the groove 331 at the bottom 3313 is greater than or equal to twice the minimum bending radius, and the bending part 33 is not easy to crack or generate internal cracks.

[0116] In other embodiments, the groove 331 can be manufactured by a one-piece stamping process, in which case A is related to the manufacturing capability of the stamping head; compared with the one-piece stamping process, the groove 331 obtained by the bending process can save the total width and improve the applicability.

[0117] In some embodiments, the groove 331 has an inner width A at the bottom 3313, the inner width A being greater than or equal to the thickness of the bend 33.

[0118] For example, the thickness of the bend 33 is E. Since the inner width A is greater than or equal to twice the minimum bending radius of the bend 33, and the bending radius can typically be from 0.5*E to 1*E, A is not less than E.

[0119] By adopting the above technical solution, the inner width of the groove 331 is greater than or equal to the thickness of the bending part 33. The groove 331 can be made on the adapter 30 by bending process. The bending part 33 is easy to form and is not easy to crack or generate internal cracks.

[0120] In some embodiments, the groove 331 has an outer width at the bottom 3313, the outer width being greater than or equal to the thickness of the bend 33.

[0121] Please refer to Figure 4 The groove 331 has an inner width A at the bottom 3313, the bent part 33 has an outer width A at the bottom 3313, and the thickness of the bent part 33 is E, C=A+2*E.

[0122] Figure 4 The thickness H of the adapter 30 and the thickness E of the bending portion 33 are illustrated. Optionally, the thickness E of the bending portion 33 can be equal to the thickness of the adapter 30, that is, the bending portion 33, the first connecting portion 31, and the second connecting portion 32 all have the same thickness. The thickness of the adapter 30 can be designed according to the current carrying capacity of the battery cell 100. The thickness of the adapter 30 can be uniform throughout, or the thickness can vary locally (e.g., locally thickened or thinned). For example, the thickness of the bending portion 33 can be slightly smaller than the thickness of other parts, which is more conducive to deformation without affecting the current carrying capacity. The thickness of the bending portion 33 affects the size of A and C, and needs to meet the minimum bending radius requirement to prevent internal cracks from occurring during bending.

[0123] By satisfying the above relationship, the outer width C of the bent portion 33 is related to the inner width A of the groove 331 and the thickness E of the bent portion 33. The groove 331 can be manufactured by an overall bending process. The outer width of the bent portion 33 is relatively small, and the adapter 30 has a wide range of applications.

[0124] Please refer to Figure 4 and Figure 5 In some embodiments, the first connecting portion 31 is welded to the tab 22 and a first solder mark 311 is formed thereon, and the minimum distance from the outer wall surface of the first sub-part 3311 to the first solder mark 311 is greater than or equal to 2 mm.

[0125] The first connecting part 31 is welded to the electrode tab 22 to form a first weld mark 311. Optionally, the first connecting part 31 can be ultrasonically welded to the electrode tab 22, in which case the first weld mark 311 is an ultrasonic weld mark. For example, the first weld mark 311 is rectangular.

[0126] The first sub-part 3311 has an outer wall surface, which is the wall surface of the first sub-part 3311 facing away from the interior of the groove 331. Along the first direction X, the minimum distance from the outer wall surface of the first sub-part 3311 to the first weld mark 311 is B, where B ≥ 2 mm. For example, the value of B can be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc. The value of B takes into account the positioning tolerance and necessary structural buffering when the ultrasonic welding head is pressed down. The specific value needs to take into account the overall design dimensions of the battery cell 100 and the spacing dimensions of the first weld marks 311 on both sides of the adapter 30.

[0127] It is understood that if the first sub-part 3311 can be perpendicularly connected to the bottom 3313, then the distance from both ends of the outer wall surface of the first sub-part 3311 to the first solder mark 311 is equal; if the first sub-part 3311 and the bottom 3313 can be obliquely connected, then the distance from both ends of the outer wall surface of the first sub-part 3311 to the first solder mark 311 is unequal, and the minimum distance is the distance from the position of the outer wall surface near the first solder mark 311 to the first solder mark 311. Furthermore, the first solder mark 311 can be a regular shape or an irregular shape. If the edge of the first solder mark 311 near the bend 33 is oblique to the first direction X, then the minimum distance is the distance from the outer wall surface of the first sub-part 3311 to the position of the first solder mark 311 near the bend 33.

[0128] Taking into account factors such as welding positioning tolerance, by ensuring that the minimum distance from the outer wall surface of the first sub-part 3311 to the first weld mark 311 is greater than or equal to 2mm, the manufacturability requirements of the battery cell 100 can be met. The first weld mark 311 and the bending part 33 are less likely to affect each other, thus improving the reliability of welding between the tab 22 and the adapter 30.

[0129] Please refer to Figure 4 In some embodiments, the second connection portion 32 is welded to the electrode terminal 13 and a second solder mark 321 is formed thereon, and the minimum distance from the outer wall surface of the second sub-part 3312 to the second solder mark 321 is greater than or equal to 4 mm.

[0130] The second connecting part 32 and the electrode terminal 13 can be laser welded to form a second solder mark 321, which can be circular or other shapes. Figure 4 The diagram illustrates the distance G from the outer wall surface of the second sub-part 3312 to the second solder mark 321 in the first direction X. The minimum value of distance G is greater than or equal to 4 mm. For example, the value of G can be 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc. The maximum value of distance G can be set according to the overall dimensions of the adapter 30.

[0131] Taking into account factors such as welding positioning tolerance and electrode terminal 13 size, by ensuring that the minimum distance from the outer wall surface of the second sub-part 3312 to the second weld mark 321 is greater than or equal to 4mm, the manufacturability requirements of the battery cell 100 can be met. The second weld mark 321 and the bending part 33 are less likely to interfere with each other, thus improving the reliability of welding between the electrode terminal 13 and the adapter 30.

[0132] In some embodiments, the housing 10 includes an end cap assembly 12 and a housing 11. The end cap assembly 12 covers the housing 11. The end cap assembly 12 includes an end cap 121 and an insulating member 122. The insulating member 122 is disposed on the side of the end cap 121 facing the electrode assembly 20. The electrode assembly 20 also includes a main body 21. An electrode tab is disposed on one side of the main body. Wherein, FD ≥ 0.5 mm, D is the total height of the adapter 30, and F is the distance from the main body 21 to the insulating member 122.

[0133] The end cap assembly 12 includes an end cap 121 and an insulating member 122. The end cap 121 covers the opening of the housing 11, and the electrode terminal 13 passes through the end cap 121. The insulating member 122 is located on the side of the end cap 121 facing the electrode assembly 20. The insulating member 122 can insulate and separate the end cap 121 from the electrode assembly 20, and the insulating member 122 can support the electrode assembly 20, reducing the risk of the electrode assembly 20 moving upward. The insulating member 122 can be a plastic part.

[0134] The electrode assembly 20 includes a main body 21 and a tab 22, with the tab 22 located on the side of the main body 21 near the end cap 121. The main body 21 includes multiple layers of positive and negative electrode sheets, which are wound or stacked.

[0135] The third direction Z is the height direction of the battery cell 100. Along the third direction Z, the end cap assembly 12 is connected to one side of the housing 11. The bottom of the groove 331 protrudes towards the electrode assembly 20. The total height D of the adapter 30 is the total height of the adapter 30 in the third direction Z, that is, the total height between the upper surface of the adapter 30 near the end cap assembly 12 and the lower surface of the groove bottom. In some embodiments, the first connecting portion 31 and the second connecting portion 32 are flush.

[0136] The distance F between the main body 21 and the insulating member 122 is the distance between the main body 21 and the insulating member 122 along the third direction Z.

[0137] The difference between F and D is greater than or equal to 0.5mm. For example, the range of the difference between F and D is 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, etc. The design value of the total height of the adapter 30 takes into account factors such as the height tolerance of the main body 21 and the thickness tolerance of the insulating part 122, so as to reduce the risk of the adapter 30 damaging the electrode and the risk of the adapter 30 being inserted into the main body 21.

[0138] The bottom of the groove 331 is spaced apart from the main body 21 of the electrode assembly 20. Optionally, the difference between F and D can be less than or equal to 4mm, which can be set according to the overall size of the battery cell 100.

[0139] By satisfying the above relationships, the total height of the adapter 30 is less than the distance from the main body 21 to the insulating member 122. The total height of the adapter 30 matches the space after the tab 22 is bent, without affecting the original design capacity of the battery cell 100. The design value of the total height of the adapter 30 takes into account the height tolerance of the main body 21 and the thickness tolerance of the insulating member 122. In this way, the adapter 30 can effectively utilize the space between the main body 21 and the insulating member 122, and reduce the risk of the adapter 30 damaging the electrode and the risk of the adapter 30 being inserted into the main body 21.

[0140] In some embodiments, D≤F-α-β, where α is the maximum tolerance of the height of the main body 21 and β is the thickness tolerance of the insulating member 122. The maximum tolerance α of the height of the main body 21 is the upper limit of the tolerance for the misalignment of the electrode in the height direction in the main body 21.

[0141] The total height D of the adapter 30 can be set with reference to the distance F from the main body 21 to the insulating member 122, the maximum tolerance a of the height of the main body 21, and the thickness tolerance of the insulating member 122. This allows the adapter 30 to reduce the risk of electrode deformation by using the bending portion 33 of appropriate height. At the same time, the adapter 30 is less likely to damage the electrode or be inserted into the main body 21.

[0142] In some embodiments, the outer surface of the bottom 3313 is provided with an insulating layer (not shown).

[0143] The bottom 3313 protrudes towards the side of the electrode assembly 20, and an insulating layer is provided on the outer surface of the bottom 3313. The insulating layer may be insulating tape or insulating coating.

[0144] In this way, the insulating layer can insulate and separate the groove 331 from the main body 21 of the electrode assembly 20, so as to prevent the bent part 33 from being inserted into the electrode assembly 20 in extreme cases and causing defects.

[0145] In some embodiments, the thickness of the bent portion 33 is less than the thickness of the first connecting portion 31, and the thickness of the bent portion 33 is less than the thickness of the second connecting portion 32.

[0146] The thicknesses of the first connecting portion 31 and the second connecting portion 32 can be equal or different. The thickness of the bent portion 33 is E, and the thicknesses of the first connecting portion 31 and the second connecting portion 32 are H. In some embodiments, E is less than H.

[0147] The thickness of the bent portion 33 is less than the thickness of the first connecting portion 31 and the second connecting portion 32. That is, the bent portion 33 has a smaller thickness than other parts of the adapter 30. While meeting the current carrying capacity, it is convenient for the bent portion 33 to be bent or stamped to form the groove 331.

[0148] In some embodiments, the housing 10 includes two first walls 101 disposed opposite to each other along the first direction X, the first wall 101 being the wall with the largest area in the housing 10; the first connecting portion 31, the bending portion 33 and the second connecting portion 32 are disposed sequentially along the first direction X.

[0149] The outer casing 10 includes a housing 11 and an end cap assembly 12. The first wall 101 is the largest wall in the housing 11, and the first wall 101 can be referred to as the "large surface" of the battery cell 100. The two first walls 101 are arranged opposite each other along the first direction X. When the electrode assembly 20 expands, the expansion force of the first wall 101 is greater than the expansion force of the other walls.

[0150] The electrode assembly 20 includes a main body 21 and a tab 22, which is folded over and welded to the first connecting part 31. During charging and discharging, the electrode assembly 20 easily expands along the first direction X, thereby pulling the tab 22 along the first direction X. Since the bending part 33 is located between the first connecting part 31 and the second connecting part 32 along the first direction X, the bending part 33 can deform in the first direction X to release stress and reduce the tensile force on the tab 22.

[0151] By adopting the above technical solution, the two first walls 101 are arranged opposite each other along the first direction X, and the bent part 33 is arranged between the first connecting part 31 and the second connecting part 32 along the first direction X. When the electrode assembly 20 expands, the groove 331 can deform and stretch along the first direction X, which effectively reduces the tensile force on the tab 22 and reduces the risk of the tab 22 cracking.

[0152] In some embodiments, the adapter 30 includes two first connecting portions 31 and two bending portions 33. The two first connecting portions 31 are respectively disposed on both sides of the adapter 30 along the first direction X, and each bending portion 33 is disposed between the second connecting portion 32 and the first connecting portion 31.

[0153] like Figure 3As shown, the number of electrode assemblies 20 can be at least two, and the tabs 22 of at least two electrode assemblies 20 are respectively connected to two first connecting portions 31. For example, the number of electrode assemblies 20 and adapters 30 are both two, and the two adapters 30 are respectively connected to the positive electrode terminal and the negative electrode terminal; each electrode assembly 20 includes a positive tab and a negative tab, the positive tabs of the two electrode assemblies 20 are respectively connected to the two first connecting portions 31 on one adapter 30, and the negative tabs of the two electrode assemblies 20 are respectively connected to the two first connecting portions 31 on another adapter 30.

[0154] In other embodiments, the number of electrode assemblies 20 may also be one, with the tabs 22 on both sides of the electrode assembly 20 along the first direction X respectively connected to two first connecting portions 31.

[0155] By adopting the above technical solution, the adapter 30 is provided with two first connecting parts 31 and two bending parts 33. In this way, the groove 331 of each bending part 33 can be stretched and deformed under force, reducing the tensile force on the two tabs 22 connected to the adapter 30.

[0156] In some embodiments, the electrode terminal 13 has two terminals, namely a positive electrode terminal and a negative electrode terminal; the number of adapters 30 is two, one adapter 30 connects the positive tab of the electrode assembly 20 to the positive electrode terminal, and the other adapter 30 connects the negative tab of the electrode assembly 20 to the negative electrode terminal.

[0157] The adapter 30 can have various shapes. For example, such as Figure 5 As shown, the adapter 30 is a rectangular sheet; for example, as... Figure 8 As shown, the adapter 30 includes two first connecting portions 31 and a second connecting portion 32 disposed between the two first connecting portions 31. The two first connecting portions 31 are spaced apart in a first direction X, and a bent portion 33 is disposed between the first connecting portions 31 and the second connecting portion 32. The first connecting portions 31 and the second connecting portion 32 are partially offset in a second direction Y, where the second direction Y intersects the first direction X. Please refer to... Figure 3 and Figure 8 In the battery cell 100, the second connecting portion 32 protrudes relative to the first connecting portion 31 in the second direction Y, so as to connect the second connecting portion 32 to the electrode terminal 13.

[0158] Please refer to Figures 3 to 8Some embodiments of this application provide a battery cell 100, including a housing 10; electrode terminals 13 mounted on the housing 10; an electrode assembly 20 housed within the housing 10, the electrode assembly 20 having tabs 22; and an adapter 30 including a first connecting portion 31, a second connecting portion 32, and a bending portion 33. The first connecting portion 31 is electrically connected to the tabs 22, and the second connecting portion 32 is electrically connected to the electrode terminals 13. The bending portion 33 is disposed between the first connecting portion 31 and the second connecting portion 32, and the bending portion 33 forms a groove 331. The first connecting portion 31, the bending portion 33, and the second connecting portion 32 are connected along the first... The direction X is arranged sequentially; the bending portion 33 includes a first sub-part 3311 and a second sub-part 3312 arranged opposite to each other along the first direction X, and a bottom 3313 connected between the first sub-part 3311 and the second sub-part 3312. The first sub-part 3311 is bent and connected to the first connecting portion 31, and the second sub-part 3312 is bent and connected to the second connecting portion 32. The bottom 3313 protrudes relative to the first connecting portion 31 towards the side closer to the electrode assembly 20; the groove 331 penetrates at least one side of the adapter 30 along the second direction Y. The second direction Y intersects with the first direction X and is perpendicular to the thickness direction of the adapter 30.

[0159] The second aspect of this application provides a battery device 1001, including a battery cell as provided in the first aspect.

[0160] A third aspect of this application provides an electrical device, including a battery cell as in the first aspect, or a battery device 1001 as in the second aspect.

[0161] The electrical device can be any of the aforementioned devices or systems that utilize battery device 1001.

[0162] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: shell; Electrode terminals are mounted on the housing; An electrode assembly, housed within the housing, the electrode assembly having tabs; The adapter includes a first connecting portion, a second connecting portion, and a bending portion. The first connecting portion is electrically connected to the tab, and the second connecting portion is electrically connected to the electrode terminal. The bending portion is disposed between the first connecting portion and the second connecting portion. The bending portion is bent toward one side of the adapter and forms a groove. The groove penetrates at least one side of the adapter.

2. The battery cell as described in claim 1, characterized in that, The first connecting portion, the bent portion, and the second connecting portion are arranged sequentially along a first direction; The bending portion includes a first sub-part and a second sub-part disposed opposite to each other along the first direction, and a bottom connected between the first sub-part and the second sub-part, wherein the first sub-part, the second sub-part and the bottom form the groove; The first sub-part is bent and connected to the first connecting part, and the second sub-part is bent and connected to the second connecting part. The bottom protrudes relative to the first connecting part. The groove penetrates at least one side of the adapter along a second direction, the second direction intersects with the first direction, and the second direction is perpendicular to the thickness direction of the adapter.

3. The battery cell as described in claim 2, characterized in that, The bottom protrudes towards the side of the adapter that is away from the electrode terminal.

4. The battery cell as described in claim 2, characterized in that, The groove has an inner width at the bottom, which is greater than or equal to twice the minimum bending radius of the bend.

5. The battery cell as described in claim 2, characterized in that, The groove has an inner width at the bottom, the inner width being greater than or equal to the thickness of the bend.

6. The battery cell as described in claim 2, characterized in that, The groove has an inner width A at the bottom, the bend has an outer width C at the bottom, and the thickness of the bend is E, where C = A + 2 * E.

7. The battery cell as described in claim 2, characterized in that, The first connecting part is welded to the electrode tab and a first weld mark is formed thereon. The minimum distance from the outer wall surface of the first sub-part to the first weld mark is greater than or equal to 2mm.

8. The battery cell as described in claim 2, characterized in that, The second connecting part is welded to the electrode terminal and a second solder mark is formed thereon. The minimum distance from the outer wall surface of the second sub-part to the second solder mark is greater than or equal to 4mm.

9. The battery cell as described in claim 3, characterized in that, The outer casing includes an end cap assembly and a housing. The end cap assembly covers the housing and includes an end cap and an insulating member. The insulating member is located on the side of the end cap facing the electrode assembly. The electrode assembly also includes a main body and an electrode tab is located on one side of the main body. FD ≥ 0.5 mm, D is the total height of the adapter, and F is the distance from the main body to the insulating member.

10. The battery cell as described in claim 3, characterized in that, The outer surface of the bottom is provided with an insulating layer.

11. The battery cell according to any one of claims 1-9, characterized in that, The thickness of the bent portion is less than the thickness of the first connecting portion, and the thickness of the bent portion is less than the thickness of the second connecting portion.

12. The battery cell according to any one of claims 2-9, characterized in that, The outer shell includes two first walls disposed opposite each other along the first direction, wherein the first wall is the wall with the largest area in the outer shell.

13. The battery cell as described in claim 12, characterized in that, The adapter includes two first connecting portions and two bending portions. The two first connecting portions are respectively disposed on both sides of the adapter along the first direction, and each bending portion is disposed between the second connecting portion and the first connecting portion.

14. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-13, or a battery device as described in claim 14.

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