Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode terminal, an adapter and an electrode assembly, the electrode terminal is arranged on the shell. The adapter is arranged in the shell. The electrode assembly is arranged in the shell and comprises a main body part and an electrode lug, the electrode lug protrudes out of the end face, facing one side of the adapter, of the main body part, the electrode lug and the adapter are welded to form a welding mark, the electrode lug and the electrode terminal are connected through the adapter, the size of the welding mark in the width direction of the electrode lug is H, the size of the welding mark in the extending direction of the electrode lug is D, and D and H meet the condition that H / D is larger than or equal to 10 and smaller than or equal to 500. And the extension direction, the width direction and the thickness direction of the tab are vertical to each other. The reliability of the battery monomer can be improved.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and rechargeable alkaline zinc-manganese battery cells, among others.

[0003] In the development of battery technology, improving the reliability of individual battery cells has always been a research direction. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can improve the reliability of the battery cell.

[0005] In a first aspect, this application provides a battery cell, which includes a housing, electrode terminals, an adapter, and an electrode assembly. The electrode terminals are disposed in the housing. The adapter is disposed within the housing. The electrode assembly is disposed within the housing and includes a main body and a tab. The tab protrudes from the end face of the main body facing the adapter. The tab is welded to the adapter to form a solder mark. The tab and the electrode terminal are connected through the adapter. The dimension of the solder mark along the width direction of the tab is H, and the dimension of the solder mark along the extension direction of the tab is D. D and H satisfy: 10 ≤ H / D ≤ 500, and the extension direction, width direction, and thickness direction of the tab are perpendicular to each other.

[0006] In the above solution, by reducing the size of the solder mark along the extension direction of the tab, the area occupied by the solder mark in the extension direction of the tab is reduced, the overall extension size of the tab is reduced, the possibility of the tab being folded over and inserted into the main body is reduced, and the possibility of thermal runaway caused by internal short circuit of the battery cell is reduced. At the same time, the size of the solder mark along the width direction of the tab is increased to increase the connection area between the tab and the adapter, improve the overcurrent capacity of the battery cell, and improve the reliability of the battery cell.

[0007] In some embodiments, the dimension of the solder mark along the extension direction of the tab is 0.5mm≤D≤20mm.

[0008] In the above scheme, by setting the size of the solder mark along the extension direction of the tab to be greater than or equal to 0.5 mm, the total area of ​​the solder mark is increased, and the current carrying capacity between the adapter and the tab is improved. By setting the size of the solder mark along the extension direction of the tab to be less than or equal to 20 mm, the possibility of the tab being folded and inserted into the main body is reduced, the possibility of internal short circuit in the battery cell is reduced, the possibility of thermal runaway in the battery cell is reduced, and the reliability of the battery cell is improved.

[0009] In some embodiments, the projection shape of the solder mark on the tab is rectangular, triangular, or trapezoidal to improve the applicability of the soldering device to the connection of the adapter and the tab, and to increase the design flexibility of the battery cell.

[0010] In some embodiments, the dimension of the end of the electrode facing the main body in the width direction is greater than the dimension of the end of the electrode away from the main body in the width direction.

[0011] In the above scheme, the above settings help to reduce the weight of the end of the tab away from the main body, thereby reducing the possibility of the end of the tab away from the main body folding over, reducing the possibility of thermal runaway caused by internal short circuit in the battery cell, and improving the reliability of the battery cell.

[0012] In some embodiments, the battery cell further includes electrode terminals, and the adapter includes a first adapter portion and a second adapter portion. The first adapter portion is electrically connected to the tab, and the second adapter portion is electrically connected to the electrode terminal. The dimension of the solder mark at the end away from the second adapter portion in the width direction is greater than the dimension of the solder mark at the end near the second adapter portion in the width direction.

[0013] In the above scheme, the shape of the solder mark is adapted to the shape where the dimension of the first end of the tab along the width direction is larger than the dimension of the second end along the width direction, thereby maximizing the area occupied by the solder mark in the tab, increasing the overall area of ​​the solder mark, improving the current carrying capacity between the adapter and the tab, and improving the overall performance of the battery cell.

[0014] In some embodiments, the solder mark and the second transition portion are at least partially overlapped along the extending direction.

[0015] In the above scheme, the above settings help to shorten the distance between the solder mark and the second adapter, shorten the current path, and improve the overall current carrying capacity of the battery cell.

[0016] In some embodiments, the solder mark includes a first sub-solder mark and a second sub-solder mark, the first sub-solder mark and the second sub-solder mark are spaced apart along the extension direction, the first sub-solder mark is located on the side of the second sub-solder mark away from the main body, and the dimension of the first sub-solder mark along the width direction is smaller than the dimension of the second sub-solder mark along the width direction.

[0017] In the above scheme, the above settings make the shape of the solder mark adapt to the shape of the first end of the electrode tab having a larger dimension in the width direction than the second end, while simplifying the shape of the solder mark, so that the welding device can be modularized and production costs can be reduced.

[0018] In some embodiments, at least one of the first sub-solder mark and the second sub-solder mark is symmetrically arranged with respect to the central axis of the electrode tab along the extension direction.

[0019] In the above scheme, the distance between the two sides of the first sub-weld and / or the second sub-weld along the width direction is the same as the distance between the two sides of the tab along the width direction, thereby improving the connection stability of the weld to the tab and the adapter, reducing the possibility of the tab separating from the adapter due to insufficient local connection strength, and improving the reliability of the battery cell.

[0020] In some embodiments, the tab further includes a bend, through which the solder mark is connected to the body portion.

[0021] In the above scheme, the above settings help to reduce the space occupied by the tabs within the battery cell, thereby increasing the energy density of the battery cell.

[0022] In some embodiments, the dimension of the tab along the width direction is L, and L and H satisfy the relationship 1 / 3≤H / L≤2 / 3.

[0023] In the above scheme, the ratio of the width dimension of the solder mark to the width dimension of the electrode tab is set to be greater than or equal to 1 / 3, thereby maximizing the width dimension of the solder mark to increase the overall area of ​​the solder mark and improve the current carrying capacity; the ratio of the width dimension of the solder mark to the width dimension of the electrode tab is set to be less than or equal to 2 / 3, thereby reducing the possibility of electrode tab cracking or even breakage during the welding process and improving the preparation yield.

[0024] Secondly, embodiments of this application provide a battery device, including the battery cell in any of the foregoing embodiments.

[0025] Thirdly, embodiments of this application provide an electrical device, including the battery device in any of the foregoing embodiments, the battery device being used to provide electrical energy to the electrical device.

[0026] 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

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application 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.

[0028] Figure 1 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the exploded structure of a battery provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of a battery module provided in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the exploded structure of a single battery cell provided in an embodiment of this application;

[0032] Figure 5 This is a top view of a single battery cell provided in an embodiment of this application;

[0033] Figure 6 This is a schematic diagram of the flattened structure of the tabs in a single battery cell provided in an embodiment of this application;

[0034] Figure 7 yes Figure 6 A schematic diagram of an enlarged structure of P;

[0035] Figure 8 yes Figure 6 A schematic diagram of another enlarged structure of P;

[0036] Figure 9 yes Figure 6 A schematic diagram of another enlarged structure of P;

[0037] Figure 10 yes Figure 6 A schematic diagram of another enlarged structure of P;

[0038] Figure 11 yes Figure 6 A schematic diagram of another enlarged structure of P;

[0039] Figure 12 This is a schematic cross-sectional view of a battery cell provided in an embodiment of this application;

[0040] Figure 13 yes Figure 12 A schematic diagram of an enlarged structure of Q.

[0041] Marker description

[0042] 1000, vehicles;

[0043] 100, Battery assembly; 200, Controller; 300, Motor; 400, Housing; 410, First housing section; 420, Second housing section; 430, Receiving section; 500, Battery module;

[0044] 110. Battery cell;

[0045] 10. Outer shell; 11. Housing; 12. End cap;

[0046] 20. Electrode terminals;

[0047] 30. Adapter; 31. First adapter; 32. Second adapter; 33. Fuse;

[0048] 40. Electrode assembly; 41. Main body; 42. Electrode tab;

[0049] 50. Weld stamp; 50a. Compacted zone; 50b. Uncompacted zone; 51. First sub-weld stamp; 52. Second sub-weld stamp;

[0050] X, extension direction; Y, width direction; Z, thickness direction. Detailed Implementation

[0051] 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.

[0052] 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.

[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] 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.

[0056] 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.

[0057] 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.

[0058] 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).

[0059] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to 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.

[0060] In the description of the embodiments of this application, unless otherwise expressly specified and limited, 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.

[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] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0064] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0065] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0066] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0067] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0068] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0069] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0070] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0071] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0072] The battery apparatus 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 connected in series, parallel, or mixed connections via a busbar.

[0073] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0074] 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 another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0075] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0076] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0077] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0078] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0079] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0080] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0081] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0082] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0083] In some embodiments, a single battery cell typically includes an electrode assembly, electrode terminals, and a housing. The electrode assembly is electrically connected to the outside via the electrode terminals. The housing accommodates the electrode assembly and provides support for it.

[0084] Electrode assemblies typically feature tabs, which are usually connected to the electrode terminals of individual battery cells via adapters to lead current to the outside of the battery cell. The tabs and adapters are welded together using a welding device. Currently, the welding area limits the reduction of the tab height, resulting in excessively tall tabs that are prone to folding. This can cause the tabs to be inserted upside down into the electrode assembly, leading to internal short circuits within the battery cell, potentially triggering thermal runaway and reducing the reliability of the battery cell.

[0085] Based on the above-mentioned technical problems, this application provides a technical solution that reduces the area occupied by the solder stamp along the extension direction of the tab, thereby reducing the overall extension size of the tab, reducing the possibility of the tab being folded over and inserted into the main body, and reducing the possibility of thermal runaway caused by internal short circuit in the battery cell. At the same time, it increases the size of the solder stamp along the width direction of the tab to increase the connection area between the tab and the adapter, improve the overcurrent capacity of the battery cell, and improve the reliability of the battery cell.

[0086] The technical solutions described in this application are applicable to batteries and electrical devices that use batteries. Electrical devices include, for example, mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools. Spacecraft include, for example, airplanes, rockets, space shuttles, and spacecraft. Electric toys include, for example, stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include, for example, 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.

[0087] The battery cells described in this application are not limited to the electrical devices described above, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0088] Please see Figure 1 , Figure 1 This is a schematic diagram of a vehicle structure provided in an embodiment 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 100 can be installed inside the vehicle 1000; specifically, for example, the battery device 100 can be installed at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200, for example, is used to control the battery to supply power to the motor 300. The battery can be used for starting the vehicle 1000, navigation, etc. Of course, the battery device 100 can also be used to drive the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide propulsion for the vehicle 1000.

[0089] Figure 2 This is a schematic diagram of the exploded structure of a battery provided in an embodiment of this application. For example... Figure 2 As shown, the battery device 100 includes a housing 400 and battery cells (not shown in the figure), with the battery cells housed within the housing 400.

[0090] The housing 400 is used to house individual battery cells, and the housing 400 can have various structures. In some embodiments, the housing 400 may include a first housing portion 410 and a second housing portion 420, which overlap each other, and together define a receiving portion 430 for housing the individual battery cells. The second housing portion 420 may be a hollow structure with one end open, and the first housing portion 410 may be a plate-like structure, with the first housing portion 410 covering the open side of the second housing portion 420 to form a housing with the receiving portion 430; alternatively, both the first housing portion 410 and the second housing portion 420 may be hollow structures with one side open, with the open side of the first housing portion 410 covering the open side of the second housing portion 420 to form a housing 400 with the receiving portion 430. Of course, the first housing portion 410 and the second housing portion 420 can have various shapes, such as cylinders, cuboids, etc.

[0091] In the battery device 100, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells is housed within the housing 400. Alternatively, multiple battery cells can first be connected in series, in parallel, or in a mixed configuration to form a battery module 500, and then the multiple battery modules 500 can be connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 400.

[0092] Figure 3 This is a schematic diagram of the structure of a battery module provided in an embodiment of this application.

[0093] In some embodiments, such as Figure 3 As shown, there are multiple battery cells 110. These multiple battery cells 110 are first connected in series, parallel, or in a mixed manner to form a battery module 500. The multiple battery modules 500 are then connected in series, parallel, or in a mixed manner to form a whole, which is housed in the casing.

[0094] Figure 4 This is a schematic diagram of the exploded structure of a battery cell provided in an embodiment of this application.

[0095] Please see Figure 4 In some embodiments, the battery cell 110 includes a housing 10 and an electrode assembly 40, the electrode assembly 40 being housed within the housing 10. The housing 10 is a hollow structure, with an internal space for accommodating the electrode assembly 40 and the electrolyte. The shape of the housing 10 can be determined according to the specific shape of the electrode assembly 40. For example, if the electrode assembly 40 is a cuboid structure, a cuboid housing 10 can be used.

[0096] The outer casing 10 is a hollow structure, forming an internal space for accommodating the electrode assembly 40 and the electrolyte. The shape of the outer casing 10 can be determined according to the specific shape of the electrode assembly 40. For example, if the electrode assembly 40 has a cuboid structure, a cuboid outer casing 10 can be used.

[0097] In some embodiments, the housing 10 includes a housing 11 and an end cap 12. The housing 11 has an opening, and the end cap 12 is connected to the housing 11 and closes the opening. The housing 11 is a component for engaging with the end cap 12 to form an internal cavity of the battery cell 110. The formed internal cavity can be used to accommodate the electrode assembly 40, electrolyte, and other components.

[0098] The housing 11 and the end cap 12 can be separate components. For example, an opening can be provided on the housing 11, and the end cap 12 can be used to close the opening to form an internal cavity for the battery cell 110.

[0099] The housing 11 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 11 can be determined according to the specific shape and size of the electrode assembly 40. The material of the housing 11 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not impose any special limitations on this.

[0100] The shape of the end cap 12 can be adapted to the shape of the housing 11 to fit the housing 11. The material of the end cap 12 can be the same as or different from the material of the housing 11. Optionally, the end cap 12 can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 12 is not easily deformed when subjected to compression and impact, so that the battery cell 110 can have higher structural strength and improve reliability.

[0101] The end cap 12 is connected to the housing 11 by welding, bonding, snap-fitting or other means.

[0102] The housing 11 may be open at one end or open at both ends. In some examples, the housing 11 may be a structure with an opening on one side, and one end cap 12 is provided to cover the housing 11. In other examples, the housing 11 may also be a structure with openings on both sides, and two end caps 12 are provided, with the two end caps 12 respectively covering the two openings of the housing 11.

[0103] Electrode assembly 40 is a component in the battery cell 110 where electrochemical reactions occur. The housing 11 may contain one or more electrode assemblies 40.

[0104] In some embodiments, the electrode assembly 40 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell 110, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive and negative electrode.

[0105] In some embodiments, the electrode assembly 40 further includes a separator membrane disposed between the positive electrode and the negative electrode, which can prevent short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0106] In some embodiments, the positive electrode sheet may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector. Exemplarily, the portion of the positive current collector without the positive electrode film layer may serve as a positive electrode tab 42.

[0107] As an example, the positive electrode current collector has two surfaces opposite each other in its own thickness direction Z, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector. Optionally, the positive electrode film layer may include a positive electrode active material layer.

[0108] In some embodiments, the negative electrode sheet may include a negative current collector and a negative electrode film layer disposed on at least one surface of the negative current collector. Exemplarily, the portion of the negative current collector without the negative electrode film layer may serve as a negative electrode tab 42. Optionally, the negative electrode film layer may include a negative electrode active material layer.

[0109] In some embodiments, the electrode assembly 40 includes a main body 41, a positive electrode tab, and a negative electrode tab. The positive and negative electrode tabs extend from the main body 41.

[0110] As an example, the positive electrode sheet has a portion coated with a positive electrode film layer for the positive current collector, a portion coated with a negative electrode film layer for the negative current collector, a positive electrode film layer, a negative electrode film layer, and a separator forming a main body 41. The positive electrode tab and the negative electrode tab can be led out from the same end of the main body 41, or they can be led out from both ends of the main body 41 respectively.

[0111] In some embodiments, the electrode assembly 40 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0112] In some embodiments, the battery cell 110 includes a first electrode terminal 20 and a second electrode terminal 20 that are insulated from each other. The first electrode terminal 20 is electrically connected to the positive electrode tab, and the second electrode terminal 20 is electrically connected to the negative electrode tab. The first electrode terminal 20 and the second electrode terminal 20 are used for electrical connection to an external circuit to enable charging or discharging of the battery cell 110.

[0113] As an example, the first electrode terminal 20 may be a separately formed component that is mounted on the housing 10. Alternatively, the first electrode terminal 20 may also be part of the housing 10.

[0114] As an example, the second electrode terminal 20 may be a separately formed component that is mounted on the housing 10. Alternatively, the second electrode terminal 20 may also be part of the housing 10.

[0115] In some embodiments, both the first electrode terminal 20 and the second electrode terminal 20 are disposed on the end cap 12. As an example, the end cap 12, the first electrode terminal 20 and the second electrode terminal 20 can be pre-assembled together and then assembled with the electrode assembly 40 and the housing 11.

[0116] Figure 5 This is a top view structural diagram of a battery cell provided in an embodiment of this application. Figure 6 This is a schematic diagram of the structure of a battery cell after the tabs have been flattened, as provided in an embodiment of this application. Figure 7 yes Figure 6 A schematic diagram of an enlarged structure of P. Figure 5 The housing and electrode terminals are not shown.

[0117] like Figures 4 to 7 As shown, this application embodiment provides a battery cell 110, which includes a housing 10, electrode terminals 20, an adapter 30, and an electrode assembly 40. The electrode terminals 20 are disposed within the housing 10. The adapter 30 is disposed within the housing 10. The electrode assembly 40 is disposed within the housing 10 and includes a main body 41 and a tab 42. The tab 42 protrudes from the end face of the main body 41 facing the adapter 30. The tab 42 is welded to the adapter 30 to form a solder mark 50. The tab 42 and the electrode terminals 20 are connected through the adapter 30. The dimension of the solder mark 50 along the width direction Y of the tab 42 is H, and the dimension of the solder mark 50 along the extension direction X of the tab 42 is D. D and H satisfy: 10 ≤ H / D ≤ 500. The extension direction X, the width direction Y, and the thickness direction Z of the tab 42 are all perpendicular to each other.

[0118] As an example, electrode terminals 20 are disposed on end caps 12 of housing 10, and tabs 42 may protrude from the end face of main body 41 facing end cap 12. Alternatively, tabs 42 may also protrude from the end face of main body 41 facing side wall of housing 11, with a portion of adapter 30 located between tabs 42 and side of housing 11, and another portion of adapter 30 located between main body 41 and end cap 12.

[0119] In some examples, the electrode assembly 40 is a wound structure, with the positive and negative electrode sheets wound into a wound structure.

[0120] In some examples, the electrode assembly 40 can be cylindrical, flat, or polygonal, etc.

[0121] In some examples, the tab 42 and the adapter 30 can be ultrasonically welded to form a solder mark 50. Optionally, the number of solder marks 50 may include one or more.

[0122] In some examples, the tab 42 includes a first tab 42 and a second tab 42 with opposite polarities, the adapter 30 includes a first adapter 30 and a second adapter 30, and the electrode terminal 20 includes a first electrode terminal 20 and a second electrode terminal 20 with opposite polarities. The first tab 42 is electrically connected to the first electrode terminal 20 via the first adapter 30, and the second tab 42 is electrically connected to the second electrode terminal 20 via the second adapter 30. The first tab 42 and the first adapter 30 are soldered to form a first solder mark 50, and the second tab 42 and the second adapter 30 solder mark 50 form a second solder mark 50. Optionally, the shape of the first solder mark 50 and the shape of the second solder mark 50 can be the same or different.

[0123] Optionally, the area of ​​the first solder mark 50 and the area of ​​the second solder mark 50 can be the same or different.

[0124] As an example, the positive electrode sheet includes a positive electrode tab, the negative electrode sheet includes a negative electrode tab, the positive electrode tab is formed by multiple layers of positive electrode tabs stacked together, and the negative electrode tab 42 is formed by multiple layers of negative electrode tabs stacked together.

[0125] Taking the electrode assembly 40 as a winding structure as an example, the extension direction X of the tab 42 can be the direction away from the main body 41 after the tab 42 is flattened, the width direction Y of the tab 42 can be the extension direction X of the main body 41 after the tab 42 is flattened, and the thickness direction Z of the tab 42 can be the stacking direction of the multi-layer tab layers.

[0126] In some examples, the ratio of the dimension of the solder mark 50 along the width direction Y of the tab 42 to the dimension of the solder mark 50 along the extension direction X of the tab 42 is 10, 11, 12, 15, 20, 22, 25, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 200, 250, 300, 350, 400, 450 or 500.

[0127] Optionally, the ratio of the dimension of the solder mark 50 along the width direction Y of the tab 42 to the dimension of the solder mark 50 along the extension direction X of the tab 42 is 20 to 100.

[0128] When the shape of the solder mark 50 is polygonal, the dimension of the solder mark 50 along the width direction Y of the tab 42 is the maximum dimension of the solder mark 50 along the width direction Y of the tab 42, and the dimension of the solder mark 50 along the extension direction X of the tab 42 is the maximum dimension of the solder mark 50 along the extension direction X of the tab 42.

[0129] It is understandable that the dimension of the solder mark 50 along the width direction Y of the tab 42 is greater than the dimension of the solder mark 50 along the extension direction X of the tab 42. This makes the width dimension of the tab 42 greater than the extension dimension of the tab 42, thereby reducing the possibility of the tab 42 folding over. At the same time, it increases the contact area between the tab 42 and the adapter 30, thereby improving the current flow capacity between the tab 42 and the adapter 30.

[0130] This embodiment of the application reduces the size of the solder mark 50 along the extension direction X of the tab 42, thereby reducing the area occupied by the solder mark 50 in the extension direction X of the tab 42, reducing the overall extension size of the tab 42, reducing the possibility of the tab 42 folding over and being inserted into the main body 41, and reducing the possibility of thermal runaway caused by internal short circuit in the battery cell 110. At the same time, it increases the size of the solder mark 50 along the width direction Y of the tab 42 to increase the connection area between the tab 42 and the adapter 30, improve the overcurrent capacity of the battery cell 110, and improve the reliability of the battery cell 110.

[0131] like Figures 4 to 7 As shown, in some alternative embodiments, the dimension of the solder mark 50 along the extension direction X of the tab 42 is 0.5mm≤D≤20mm.

[0132] In some examples, the dimension of the solder mark 50 along the extension direction X of the tab 42 is 0.5mm, 0.6mm, 0.8mm, 1mm, 1.5mm, 2.5mm, 5mm, 10mm or 20mm.

[0133] In this embodiment, the size of the solder mark 50 along the extension direction X of the tab 42 is set to be greater than or equal to 0.5 mm to increase the total area of ​​the solder mark 50 and improve the current carrying capacity between the adapter 30 and the tab 42. The size of the solder mark 50 along the extension direction X of the tab 42 is set to be less than or equal to 20 mm to reduce the possibility of the tab 42 being folded and inserted into the main body 41, reduce the possibility of internal short circuit in the battery cell 110, reduce the possibility of thermal runaway in the battery cell 110, and improve the reliability of the battery cell 110.

[0134] Figure 8 yes Figure 6 Another enlarged structural diagram of P.

[0135] like Figure 8 As shown, in some alternative embodiments, the projection shape of the solder mark 50 on the tab 42 is rectangular, triangular or trapezoidal to improve the applicability of the welding device to the connection of the adapter 30 and the tab 42, and to improve the design flexibility of the battery cell 110.

[0136] Understandably, in some welding processes, such as ultrasonic welding, the weld mark 50 includes a compacted zone 50a and a non-compacted zone 50b. The compacted zone 50a is the area where the material is highly compressed and undergoes plastic deformation under the action of ultrasonic vibration and pressure during the welding process; the non-compacted zone 50b is the area that is not significantly compressed or only slightly compressed during the welding process. For example, the compacted zone 50a of the weld mark 50 forms a protruding structure, and the non-compacted zone 50b of the weld mark 50 forms a planar structure. Taking the projection of the weld mark 50 onto the tab 42 as a trapezoid as an example, the trapezoid has multiple protruding structures forming a compacted zone 50a and non-compacted zones 50b located around the compacted zone 50a.

[0137] Figure 9 yes Figure 6 Another enlarged structural diagram of P.

[0138] like Figures 4 to 9 As shown, in some alternative embodiments, the dimension of the end of the tab 42 facing the main body 41 along the width direction Y is greater than the dimension of the end of the tab 42 away from the main body 41 along the width direction Y.

[0139] For example, after the tab 42 is flattened, the end of the tab 42 facing the main body 41 is the first end, and the end of the tab 42 away from the main body 41 is the second end. The dimension of the first end along the width direction Y is greater than the dimension of the second end along the width direction Y. Optionally, the dimension along the width direction Y from the first end to the second end can be gradually reduced or can be reduced in a stepwise manner.

[0140] In some examples, the shape of the tab 42 after being flattened along the thickness direction Z is trapezoidal.

[0141] In this embodiment of the application, the above-mentioned arrangement helps to reduce the weight of the end of the tab 42 away from the main body 41, thereby reducing the possibility of the end of the tab 42 away from the main body 41 folding over, reducing the possibility of thermal runaway caused by internal short circuit in the battery cell 110, and improving the reliability of the battery cell 110.

[0142] like Figure 4 , Figure 5 as well as Figure 8 As shown, in some optional embodiments, the battery cell 110 further includes an electrode terminal 20, and the adapter 30 includes a first adapter portion 31 and a second adapter portion 32. The first adapter portion 31 is electrically connected to the tab 42, and the second adapter portion 32 is electrically connected to the electrode terminal 20. The dimension of the solder mark 50 at the end away from the second adapter portion 32 along the width direction Y is greater than the dimension of the solder mark 50 at the end near the second adapter portion 32 along the width direction Y.

[0143] In some examples, electrode terminal 20 includes one tab 42 of the same polarity, and the number of first adapters 31 may be one. In other examples, electrode terminal 20 includes two or more tabs 42 of the same polarity, and the number of first adapters 31 may be two or more, so that the first adapters 31 and the tabs 42 of the same polarity are electrically connected in a one-to-one correspondence.

[0144] In some examples, two or more first adapters 31 may be connected to a second adapter 32.

[0145] In some examples, a fusion section 33 may be provided between the first transition section 31 and the second transition section 32, and the solder mark 50 and the fusion section 33 are at least partially overlapped along the extension direction X.

[0146] In some examples, the dimension of the first adapter 31 along the width direction Y is greater than the dimension of the first adapter 31 along the extension direction X.

[0147] In some examples, the dimension of the first adapter 30 along the width direction Y is larger than the dimension of the second adapter 32 along the width direction Y.

[0148] For example, the end of the solder mark 50 furthest from the second transition portion 32 is the third end, and the end of the solder mark 50 closest to the second transition portion 32 is the fourth end. The dimension of the third end along the width direction Y is greater than the dimension of the fourth end along the width direction Y. Optionally, the dimension from the third end to the fourth end along the width direction Y can gradually decrease or decrease in a stepwise manner.

[0149] In some examples, the solder mark 50 is trapezoidal, triangular or other shapes along the thickness direction Z of the tab 42.

[0150] In these alternative embodiments, the above-described configuration allows the shape of the solder mark 50 to be adapted to a shape where the dimension of the first end of the tab 42 along the width direction Y is greater than the dimension of the second end along the width direction Y. This maximizes the area occupied by the solder mark 50 in the tab 42, increases the overall area of ​​the solder mark 50, improves the current flow capacity between the adapter 30 and the tab 42, and improves the overall performance of the battery cell 110.

[0151] like Figures 4 to 8 As shown, in some alternative embodiments, the solder mark 50 and the second transition portion 32 are at least partially overlapped along the extension direction X.

[0152] In some examples, the solder mark 50 and the second transition portion 32 partially overlap along the extension direction X. In other examples, the projection of the second transition portion 32 along the extension direction X lies within the projection of the solder mark 50 along the extension direction X.

[0153] The above-described configuration in this embodiment of the application helps to shorten the distance between the solder mark 50 and the second adapter 32, shorten the current path, and improve the overall current carrying capacity of the battery cell 110.

[0154] like Figure 4 , Figure 5 as well as Figure 9 As shown, in some optional embodiments, the solder mark 50 includes a first sub-solder mark 51 and a second sub-solder mark 52, the first sub-solder mark 51 and the second sub-solder mark 52 are spaced apart along the extension direction X, the first sub-solder mark 51 is located on the side of the second sub-solder mark 52 away from the main body portion 41, and the size of the first sub-solder mark 51 along the width direction Y is smaller than the size of the second sub-solder mark 52 along the width direction Y.

[0155] In some examples, the number of first sub-solder marks 51 may include one or more.

[0156] In some examples, the number of second sub-solder marks 52 may include one or more.

[0157] In some examples, the shape of the first sub-solder mark 51 and the shape of the second sub-solder mark 52 may be the same or different. For example, both the first sub-solder mark 51 and the second sub-solder mark 52 may be rectangular.

[0158] In some examples, the dimensions of the first sub-solder mark 51 along the extension direction X and the second sub-solder mark 52 along the extension direction X may be the same or different. For example, the dimension of the first sub-solder mark 51 along the extension direction X may be smaller than the dimension of the second sub-solder mark 52 along the extension direction X.

[0159] In some examples, the number of second sub-solder marks 52 may include multiple second sub-solder marks 52, and the sum of the dimensions of the multiple second sub-solder marks 52 along the width direction Y is greater than the dimension of the first sub-solder mark 51 along the width direction Y.

[0160] As an example, after the tab 42 is flattened, the first sub-solder mark 51 is located on the side of the second sub-solder mark 52 away from the main body 41. The first sub-solder mark 51 can be located at the end of the tab 42 away from the main body 41, and the second sub-solder mark 52 can be located at the end of the tab 42 close to the main body 41.

[0161] Optionally, the first sub-weld mark 51 and the second sub-weld mark 52 can be formed by a single welding process, or they can be formed by two welding processes.

[0162] Optionally, the welding process of the first sub-weld 51 and the welding process of the second sub-weld 52 can be the same or different.

[0163] In these alternative embodiments, the above-described configuration allows the shape of the solder mark 50 to be adapted to a shape where the dimension of the first end of the tab 42 along the width direction Y is greater than the dimension of the second end along the width direction Y. This simplifies the shape of the solder mark 50, enabling the welding device to be modularized and reducing production costs.

[0164] Figure 10 yes Figure 6 Another enlarged structural diagram of P. Figure 11 yes Figure 6 Another enlarged structural diagram of P.

[0165] like Figures 9 to 11 As shown, in some alternative embodiments, at least one of the first sub-solder mark 51 and the second sub-solder mark 52 is symmetrically arranged with respect to the central axis of the tab 42 along the extension direction X.

[0166] In some examples, the first sub-solder mark 51 is symmetrically arranged with respect to the central axis of the extension direction X of the tab 42, and the second sub-solder mark 52 is symmetrically arranged with respect to the central axis of the extension direction X of the tab 42. In other examples, the first sub-solder mark 51 is symmetrically arranged with respect to the central axis of the extension direction X of the tab 42, and the end of the second sub-solder mark 52 away from the second transition portion 32 in the width direction Y is flush with the end of the first sub-solder mark 51 away from the second transition portion 32 in the width direction Y. In still other examples, the second sub-solder mark 52 is symmetrically arranged with respect to the central axis of the extension direction X of the tab 42.

[0167] In these alternative embodiments, the above-described configuration ensures that the two sides of the first sub-weld 51 and / or the second sub-weld 52 are at the same distance from the two sides of the tab 42 along the width direction Y, thereby improving the connection stability of the solder 50 to the tab 42 and the adapter 30, reducing the possibility of the tab 42 partially separating from the adapter due to insufficient local connection strength, and improving the reliability of the battery cell 110.

[0168] Figure 12 This is a cross-sectional structural diagram of a battery cell provided in an embodiment of this application. Figure 13 yes Figure 12 A schematic diagram of an enlarged structure of Q.

[0169] like Figure 12 and Figure 13 As shown, in some alternative embodiments, the tab 42 further includes a bend, through which the solder mark 50 is connected to the main body 41.

[0170] It is understood that the tabs are formed by stacking multiple tab layers. For example, the positive tab is formed by stacking multiple positive tab layers, and the negative tab is formed by stacking multiple negative tab layers. Exemplarily, after the multiple tab layers are stacked, they are brought closer together, and then the stacked multiple tab layers are welded to the adapter 30. After welding, the multiple tab layers are bent so that the multiple tab layers and the adapter 30 are bent and positioned opposite the end face of the main body 41. The bent multiple tab layers form a bent portion, and the end of the multiple tab layers away from the main body 41 is welded to the adapter 30 to form a weld mark 50.

[0171] In these alternative embodiments, the above-described arrangement helps to reduce the space occupied by the tab 42 within the battery cell 110, thereby increasing the energy density of the battery cell 110.

[0172] like Figures 4 to 7 As shown, in some optional embodiments, the tab 42 has a dimension L along the width direction Y, and L and H satisfy the relationship 1 / 3≤H / L≤2 / 3.

[0173] As an example, the ratio of the dimension of the solder mark 50 along the width direction Y to the dimension of the tab 42 along the width direction Y is 1 / 3, 1 / 2, 4 / 9, 5 / 9 or 2 / 3.

[0174] In this embodiment, the ratio of the dimension of the solder mark 50 along the width direction Y to the dimension of the tab 42 along the width direction Y is set to be greater than or equal to 1 / 3, thereby maximizing the dimension of the solder mark 50 in the width direction Y to increase the overall area of ​​the solder mark 50 and improve the current carrying capacity; the ratio of the dimension of the solder mark 50 along the width direction Y to the dimension of the tab 42 along the width direction Y is set to be less than or equal to 2 / 3 to reduce the possibility of the tab 42 cracking or even breaking during the soldering process and improve the preparation yield.

[0175] Secondly, embodiments of this application provide a battery device 100, including the battery cell 110 in any of the foregoing embodiments.

[0176] Thirdly, embodiments of this application provide an electrical device, including the battery device 100 in any of the foregoing embodiments, the battery device being used to provide electrical energy to the electrical device.

[0177] According to some embodiments of this application, please refer to Figures 4 to 7 The battery cell includes a housing 10, electrode terminals 20, an adapter 30, and an electrode assembly 40. The electrode terminals 20 are disposed within the housing 10. The adapter 30 is disposed within the housing. The electrode assembly 40 is disposed within the housing 10 and includes a main body 41 and tabs 42. The tabs protrude from the end face of the main body 41 facing the adapter 30. The tabs 42 are welded to the adapter 30 to form a solder mark 50. The tabs 42 and the electrode terminals 20 are connected via the adapter 30. The solder mark 50 has a dimension H along the width direction Y of the tab 42 and a dimension D along the extension direction X of the tab 42. D and H satisfy: 10 ≤ H / D ≤ 500. The extension direction X, the width direction Y, and the thickness direction Z of the tab 42 are all perpendicular to each other.

[0178] The projection shape of the solder mark 50 on the tab 42 is rectangular, triangular or trapezoidal.

[0179] The dimension of the end of the tab 42 facing the main body 41 along the width direction Y is greater than the dimension of the end of the tab 42 away from the main body 41 along the width direction Y.

[0180] The battery cell 110 also includes an electrode terminal 20. The adapter 30 includes a first adapter portion 31 and a second adapter portion 32. The first adapter portion 31 is electrically connected to the tab 42, and the second adapter portion 32 is electrically connected to the electrode terminal 20. The dimension of the solder mark 50 in the width direction Y at the end away from the second adapter portion 32 is greater than the dimension of the solder mark 50 in the width direction Y at the end near the second adapter portion 32.

[0181] The dimension of the tab 42 along the width direction Y is L, and L and H satisfy the relationship 1 / 3≤H / L≤2 / 3.

[0182] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not 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 or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery monomer comprises: a shell; an electrode terminal arranged in the shell; an adapter arranged in the shell; an electrode assembly arranged in the shell, the electrode assembly comprising a main body and a tab, the tab protruding from an end face of the main body on a side facing the adapter, the tab being welded with the adapter and forming a welding mark, the welding mark and the electrode terminal being connected through the adapter, a dimension of the welding mark along a width direction of the tab being H, a dimension of the welding mark along an extension direction of the tab being D, D and H satisfying 10≤H / D≤500, the extension direction, the width direction and a thickness direction of the tab being perpendicular to each other.

2. The battery cell of claim 1, wherein, The dimension of the welding mark along the extension direction of the tab is 0.5mm≤D≤20mm.

3. The battery cell of claim 1, wherein, A projection shape of the welding mark on the tab is a rectangle, a triangle or a trapezoid.

4. The battery cell of claim 1, wherein, A dimension of an end of the tab on the side facing the main body along the width direction is greater than a dimension of an end of the tab on the side away from the main body along the width direction.

5. The battery cell of claim 4, wherein, The battery monomer further comprises an electrode terminal, the adapter comprises a first adapter part and a second adapter part, the first adapter part being electrically connected with the tab, the second adapter part being electrically connected with the electrode terminal, a dimension of an end of the welding mark on the side away from the second adapter part along the width direction is greater than a dimension of an end of the welding mark on the side close to the second adapter part along the width direction.

6. The battery cell of claim 5, wherein, Along the extension direction, the welding mark and the second adapter part are at least partially overlapped.

7. The battery cell of claim 4, wherein, The welding mark comprises a first sub-welding mark and a second sub-welding mark, the first sub-welding mark and the second sub-welding mark being arranged at intervals along the extension direction, the first sub-welding mark being located on a side of the second sub-welding mark away from the main body, a dimension of the first sub-welding mark along the width direction is smaller than a dimension of the second sub-welding mark along the width direction.

8. The battery cell of claim 7, wherein, At least one of the first sub-welding mark and the second sub-welding mark is symmetrically arranged with respect to a central axis of the tab along the extension direction.

9. The battery cell of claim 1, wherein, The tab further comprises a bending part, the welding mark being connected with the main body through the bending part.

10. The battery cell of claim 1, wherein, A dimension of the tab along the width direction is L, L and H satisfying 1 / 3≤H / L≤2 / 3.

11. A battery device characterized by comprising: The battery device comprises the battery monomer as claimed in any one of claims 1 to 10.

12. An electrical device, characterized by The battery device as claimed in claim 11 is used to provide electric energy for the electric device.

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