Battery cell, battery device, and electrical equipment

Abstract

The present application discloses a battery cell, a battery device and an electrical device. The battery cell includes a shell, a first electrode terminal, an electrode assembly and a first adapter. The shell includes a wall portion; the first electrode terminal is arranged on the wall portion; the electrode assembly is accommodated in the shell, and the electrode assembly includes a main body and a first pole ear, and at least a portion of the first pole ear protrudes from a first end face of the main body along a first direction. The first adapter is connected to the first electrode terminal, and at least a portion of the first adapter is arranged on a side of the first pole ear away from the main body along the first direction, and abuts against the first pole ear. A first recess is provided on one side of the first adapter along the first direction, and the bottom wall of the first recess is welded to the first pole ear. The bottom wall of the first recess is relatively thin, which is convenient for welding with the first pole ear, and is not prone to the risk of cold welding. It can also reduce the difficulty of welding and the requirement for welding power, which is conducive to reducing the risk of burning the main body during welding operations and improving the reliability of the battery cell.

Description

Technical Field

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

[0002] Batteries are widely used in electronic devices, such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0003] In the development of battery technology, how to improve the reliability of battery cells is a research direction in battery technology. Summary of the invention

[0004] The present application provides a battery cell, a battery device and an electrical equipment, which are beneficial to improving reliability.

[0005] According to the first aspect of the present application, the present application provides a battery cell, which includes a shell, a first electrode terminal, an electrode assembly and a first adapter. The shell includes a wall portion; the first electrode terminal is arranged on the wall portion; the electrode assembly is accommodated in the shell, and the electrode assembly includes a main body and a first pole ear, and at least part of the first pole ear protrudes from the first end surface of the main body along the first direction. The first adapter is connected to the first electrode terminal, at least part of the first adapter is arranged on the side of the first pole ear away from the main body along the first direction, and abuts against the first pole ear, and the first adapter is provided with a first recess on one side of the first direction, and the bottom wall of the first recess is welded to the first pole ear. The first recess is recessed in the surface of the first adapter, and compared with the bottom wall of the first recess, the other at least part of the first adapter is relatively thick, which is conducive to improving the current capacity; the bottom wall of the first recess is relatively thin, which is convenient for welding with the first pole ear, and is not easy to produce the risk of cold welding, and can reduce the difficulty of welding, reduce the requirements for welding power, and is conducive to reducing the risk of burning the main body during welding operation, and improving the reliability of the battery cell.

[0006] In some embodiments, the first adapter is welded to the first pole tab to form a welding portion, and the welding portion is exposed on a side of the first adapter away from the first pole tab along the first direction. Thus, the bottom wall of the first recess and the first pole tab can be penetrated and welded from the side of the first adapter away from the first pole tab along the first direction to form a welding portion, which is conducive to further reducing the difficulty of welding and reducing the risk of burning the main body during welding operation.

[0007] In some embodiments, the first adapter is welded to the first pole tab to form a welding portion, and the side wall of the first recess is spaced apart from the welding portion. Thus, the possibility of welding the first pole tab to the thicker portion of the first adapter due to welding tolerance can be reduced, which is beneficial to reducing the risk of cold welding and improving welding strength and reliability.

[0008] In some embodiments, the minimum distance between the side wall of the first recess and the welding portion is d, where 0.1 mm ≤ d ≤ 3 mm. Since d is greater than or equal to 0.1 mm, the welding portion is not too close to the first recess, which is beneficial to reducing the risk of false soldering. Since d is less than or equal to 3 mm, the size of the first recess can be reduced, and the adverse effects of the setting of the first recess on the structural strength and current-carrying capacity of the first adapter can be reduced.

[0009] In some embodiments, the first tab includes a plurality of tab layers. At least some of the tab layers include an extending portion and a bent portion. The extending portion is connected between the main body portion and the bent portion. The bent portion is bent relative to the extending portion. The adjacent bent portions are stacked along the first direction. The bent portions of at least some of the tab layers abut against the first adapter and are welded to the first adapter. On the one hand, the plurality of bent portions are stacked, and the stacking gap is small, which is beneficial to reducing the risk of false soldering between the first adapter and the first tab. On the other hand, the extending portion can make the bent portion and the main body portion have a certain distance in the first direction, and the welding heat transferred to the main body portion during the welding process between the bent portion and the first adapter can be reduced, and the risk of burning the main body portion can be reduced.

[0010] In some embodiments, the plurality of tab layers include a plurality of first tab layers and a plurality of second tab layers. The plurality of first tab layers and the plurality of second tab layers are arranged along the second direction, and the second direction is perpendicular to the first direction. Along the second direction, the bent portion of the first tab layer is bent toward the second tab layer, and the bent portion of the second tab layer is bent toward the first tab layer. The bent portions of the first tab layer and the second tab layer are bent toward each other, and the bending directions of the plurality of tab layers are relatively regular. The first tab is relatively compact and flat as a whole, which is beneficial to reducing the interlayer gap of the bent portion and improving the welding effect between the first tab and the first adapter.

[0011] In some embodiments, there are a plurality of first recesses, and at least some of the plurality of first recesses are spaced along the second direction; the bent portions of at least some of the first tab layers and the bent portions of at least some of the second tab layers are respectively welded to the bottom walls of different first recesses. On the one hand, a plurality of welding portions can be formed between the first tab and the first adapter, increasing the current flow path, which is beneficial to reducing the internal resistance and reducing the risk of connection failure between the first tab and the first adapter caused by false soldering of one of the welding portions. On the other hand, the maximum number of stacked bent portions of the plurality of tab layers can also be reduced, thereby reducing the space occupied by the first tab in the first direction, which is beneficial to improving the energy density of the battery cell.

[0012] In some embodiments, the bent portion has a stacking area stacked with at least two other bent portions along the first direction, and the stacking areas of all the bent portions form a stacking portion of the first pole lug, and the stacking portion abuts against and is welded to the first adapter. As a result, the stacking portion has a relatively high structural strength and a relatively large thickness, and the stacking portion and the first adapter are not easily welded through when being welded, which is beneficial to reducing the heat transferred to the main body and reducing the risk of the main body being burned.

[0013] In some embodiments, in a projection plane perpendicular to the first direction, the orthographic projection of the first recess is located within the orthographic projection of the stacking portion. Thus, each region corresponding to the first pole tab and the bottom wall of the first recess has at least three layers of bending portions, which can reduce the possibility of the first adapter being welded to other parts of the first pole tab except the stacking portion, and is conducive to reducing the risk of cold welding or the first pole tab being welded through.

[0014] In some embodiments, in the stacked portion, the maximum number of layers of the bent portion is m, the total number of layers of the tab layer is n, and 15%≤m / n≤30%. When m / n is greater than or equal to 15%, the stacked portion has a relatively large structural strength and thickness, which is beneficial to reducing the risk of the stacked portion being welded through and burning the main body. When m / n is less than or equal to 30%, the size of the stacked portion along the first direction is not too large, which is beneficial to reducing the space occupied by the first tab in the first direction and improving the energy density of the battery cell.

[0015] In some embodiments, the first recess is formed on a side of the first adapter away from the first pole lug along the first direction. Thus, the size of the first recess can be reduced while meeting welding requirements, which is conducive to reducing the impact of the setting of the first recess on the structural strength and flow area of ​​the first adapter.

[0016] In some embodiments, there are multiple first recesses and multiple first pole tabs, and each first pole tab is welded to the bottom wall of the corresponding one or more first recesses. This facilitates the bending operation of the first pole tab, reduces the bending difficulty of the first pole tab, and improves the compactness and flatness of the first pole tab after bending.

[0017] In some embodiments, the first adapter includes a first adapter body and a plurality of first protrusions, the plurality of first protrusions and the plurality of first pole ears are arranged in one-to-one correspondence, two adjacent first protrusions are connected by at least part of the first adapter body, the first adapter body and the first protrusions are both arranged on the side of the first pole ear away from the main body along the first direction; along the direction of the first pole ear pointing to the main body, the first protrusion exceeds the first surface of the first adapter body facing the first pole ear, and each first protrusion abuts against a corresponding first pole ear; each first protrusion is provided with at least one first concave portion on one side along the first direction, and the thickness of the bottom wall of the first concave portion is less than the thickness of the first adapter body. Thus, each first pole ear can be tightly abutted against the corresponding first protrusion by appropriate deformation of the first adapter body, which is conducive to improving the welding effect between the first pole ear and each first protrusion, and reducing the risk of connection failure between the first pole ear and the first protrusion caused by cold welding.

[0018] In some embodiments, a second concave portion is provided on a side of the first adapter that faces away from the first tab, the second concave portion is provided corresponding to the first convex portion, and the first concave portion is recessed from the bottom surface of the second concave portion. Thus, the thickness of the first convex portion can be appropriately reduced, the weight of the first convex portion can be reduced, and the space occupied by the first convex portion along the first direction can be reduced.

[0019] In some embodiments, the first convex portion includes a protruding body and a weak portion, the weak portion is arranged corresponding to the first concave portion, at least part of the weak portion forms the bottom wall of the first concave portion, and the thickness of the protruding body is equal to the thickness of the first adapter body. Thus, the thickness of the protruding body is not too large to occupy too much space, and the thickness of the protruding body is not too small to affect the flow.

[0020] In some embodiments, the thickness of the first adapter body is T, 0.5mm≤T≤5mm. When T is greater than or equal to 0.5mm, the thickness of the first adapter body is not too small to affect its current capacity, which is beneficial to reduce heat generation and reduce the internal resistance of the battery cell. When T is less than or equal to 5mm, the thickness of the first adapter body is not too large, which can reduce the space occupied by the first adapter body, which is beneficial to improve the energy density of the battery cell and reduce the weight of the battery cell.

[0021] In some embodiments, the first adapter includes a second convex portion, the second convex portion is arranged around the first concave portion, and the second convex portion protrudes from the surface of the first convex portion along the first direction. The second convex portion can enhance the overall strength of the first adapter around the first concave portion and reduce the influence of the arrangement of the first concave portion on the overall strength of the first adapter.

[0022] In some embodiments, both the first concave portion and the second convex portion are located on a side of the first convex portion facing away from the first tab, and the second convex portion protrudes from a second surface of the first convex portion facing away from the first tab along a first direction; along a direction from the main body portion towards the first tab, the second convex portion does not extend beyond a surface of the first adapter body facing away from the electrode assembly. Thus, the space of the second concave portion can be utilized to accommodate the second convex portion, reducing the extra space occupied by the second convex portion in the first direction, which is beneficial to improving the space utilization rate and enhancing the energy density of the battery cell.

[0023] In some embodiments, the wall portion is located on a side of the electrode assembly along a third direction, and the first direction is perpendicular to the third direction; the first adapter includes a second adapter body, and along the third direction, the second adapter body is located between the electrode assembly and the wall portion and is connected to the first electrode terminal.

[0024] In some embodiments, the first adapter includes a connecting portion, and the first adapter body and the second adapter body are connected through the connecting portion. The projection of the connecting portion along a second direction is arc-shaped, and the first direction, the second direction, and the third direction are perpendicular to each other pairwise. With the arc-shaped connecting portion, it is beneficial to reduce the possibility of cracking or the appearance of cracks during the bending process of the first adapter.

[0025] In some embodiments, the connecting portion has an inner surface facing the electrode assembly, and the projection of the inner surface along the second direction is circular arc-shaped. The radius of the circle corresponding to the projection of the inner surface is r, and 0.2 mm ≤ r ≤ 20 mm. When r is greater than or equal to 0.2 mm, it is not easy to form an included angle inside the connecting portion, which is beneficial to reducing the risk of cracking or the appearance of cracks in the connecting portion. When r is less than or equal to 20 mm, the connecting portion will not be too large, which can reduce the space required for arranging the connecting portion and reduce the space waste inside the battery cell, being beneficial to enhancing the energy density of the battery cell.

[0026] In some embodiments, the first adapter is an integrally formed structure, which is beneficial to simplifying the assembly process.

[0027] According to a second aspect of the present application, the present application provides a battery device, which includes a plurality of battery cells provided according to any one of the embodiments of the first aspect.

[0028] According to a third aspect of the present application, the present application provides an electrical equipment, which includes the battery device provided according to any one of the embodiments of the second aspect, and the battery device is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The features, advantages, and technical effects of the exemplary embodiments of the present application will be described below with reference to the drawings.

[0030] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application;

[0031] Figure 2Exploded structural schematic diagram of the battery device provided by some embodiments of the present application;

[0032] Figure 3 Exploded structural schematic diagram of the battery cell provided by some embodiments of the present application;

[0033] Figure 4 For Figure 3 Cross-sectional schematic diagram of the battery cell shown;

[0034] Figure 5 For Figure 4 Enlarged structural schematic diagram of area A in;

[0035] Figure 6 For Figure 3 Structural schematic diagram of the first adapter of the battery cell shown;

[0036] Figure 7 For Figure 3 Structural schematic diagram after welding the electrode assembly and the first adapter of the battery cell shown;

[0037] Figure 8 For Figure 7 Enlarged structural schematic diagram of area B in;

[0038] Figure 9 For Figure 3 Front view schematic diagram of the first adapter of the battery cell shown;

[0039] Figure 10 For Figure 9 Enlarged structural schematic diagram of area C in.

[0040] Reference numerals in the specific embodiments are as follows:

[0041] Vehicle 1, controller 3, motor 4, battery device 2;

[0042] Box body 5, first box body part 5a, second box body part 5b, accommodation space 5c;

[0043] Battery cell 6, electrode assembly 10, main body 11, first end face 11a, second end face 11b, first tab 12, tab layer 121, protruding portion 1211, bent portion 1212, stacked area 1212a, first tab layer 121a, second tab layer 121b, third tab layer 121c, stacked portion 122, second tab 13, housing 20, shell 21, wall portion 211, end cap 22, first electrode terminal 31, second electrode terminal 32, first adapter 40, first recess 41, first adapter main body 42, adapter portion 421, first surface 42a, third surface 42b, first protrusion 43, protruding main body 431, weak portion 432, second surface 43a, second recess 44, bottom surface 44a, second protrusion 45, second adapter main body 46, third recess 461, connecting portion 47, inner surface 47a, outer surface 47b, welding portion 50, second adapter 60, fourth recess 61, first direction X, second direction Y, third direction Z. Detailed implementation mode

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0046] Referring to "embodiment" in the present application means that a specific feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0047] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0049] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0050] The term “plurality” used in this application refers to two or more (including two).

[0051] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0052] In the embodiment of the present application, the battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0053] The battery cells can be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc., which are not limited in the embodiments of the present application.

[0054] A battery cell generally includes an electrode assembly, a housing, and an electrode terminal. The electrode assembly is contained in the housing, and the electrode terminal is disposed in the housing. The housing is used to encapsulate the electrode assembly and components such as the electrolyte. The electrode assembly includes a tab, which is electrically connected to the electrode terminal through an adapter or directly electrically connected to the electrode terminal. The electrode terminal can be used to electrically connect the electrode assembly to a circuit outside the battery cell to realize charging or discharging of the battery cell.

[0055] The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) intercalate and deintercalate between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and allow the active ions to pass through.

[0056] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet 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.

[0057] In some embodiments, the negative electrode may be a negative electrode sheet, and 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.

[0058] In some embodiments, the separator is disposed between the positive electrode and the negative electrode.

[0059] In some embodiments, the separator is a separator membrane. The present application does not particularly limit the type of the separator membrane, and any well-known porous structure separator membrane with good chemical stability and mechanical stability can be selected.

[0060] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0061] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0062] In some embodiments, the electrode assembly is a laminated structure.

[0063] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel, or in a hybrid connection through a bus bar component.

[0064] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0065] The battery device generally includes a box for encapsulating one or more battery cells. The box can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0066] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by cable ties. The battery cell assembly may be accommodated in the box by fixing the battery module in the box. As an example, the box 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 a closed space is formed inside the box to accommodate the battery cell assembly.

[0067] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0068] In some embodiments, the battery device may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0069] In a battery cell, the electrode assembly and the electrode terminal are usually electrically connected through an adapter, which is welded to the electrode terminal and the electrode assembly's pole ear and serves as an intermediate current transfer. In order to meet the overcurrent requirements, the thickness of the adapter is usually not too thin. However, if the thickness of the adapter is thicker, a larger welding power is required between the adapter and the pole ear to reduce the risk of cold welding. For the pole ear formed by flattening or smoothing, the pole ear is close to the separator. When the welding power between the pole ear and the adapter is large, it is easy to burn the separator, causing the risk of short circuit between the positive and negative poles, affecting the reliability of the battery cell.

[0070] In view of this, the embodiment of the present application provides a technical solution, which is to arrange at least part of the first adapter on the side of the first pole ear away from the main body along the first direction and against the first pole ear, and to arrange a first recess on the side of the first adapter along the first direction, and the bottom wall of the first recess is welded to the first pole ear. Compared with the bottom wall of the first recess, the other at least part of the first adapter is relatively thick, which is conducive to improving the current capacity; the bottom wall of the first recess is relatively thin, which is convenient for welding with the first pole ear, and is not easy to produce the risk of cold welding, and can reduce the requirements for welding power, which is conducive to reducing the risk of burning the main body during welding operation and improving the reliability of the battery cell.

[0071] The technical solution provided in the embodiments of the present application is applicable to battery cells, battery devices, and electrical equipment using the battery devices.

[0072] The battery device disclosed in the embodiments of the present application can be used in electrical equipment that uses the battery device as a power source or various energy storage systems that use the battery device as an energy storage element. The electrical equipment can be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, spacecraft, and so on. Among them, the electric toys can include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0073] For the convenience of description, the following embodiments will be described by taking the electrical equipment as a vehicle as an example.

[0074] Figure 1 It is a schematic structural diagram of a vehicle provided by some embodiments of the present application. Refer to Figure 1 , vehicle 1 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc. A battery device 2 is provided inside vehicle 1. The battery device 2 can be arranged at the bottom, head, or tail of vehicle 1. The battery device 2 can be used to supply power to vehicle 1. For example, the battery device 2 can be used as the operating power source of vehicle 1. Vehicle 1 can also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4. For example, it is used for the working power requirements during the start, navigation, and driving of vehicle 1.

[0075] In some embodiments of the present application, the battery device 2 can not only be used as the operating power source of vehicle 1, but also as the driving power source of vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for vehicle 1.

[0076] Figure 2 It is a schematic exploded view of a battery device provided by some embodiments of the present application. Refer to Figure 2, the battery device 2 includes a box body 5 and battery cells 6, and the battery cells 6 are accommodated in the box body 5. Among them, the box body 5 is used to provide an accommodation space for the battery cells 6, and the box body 5 can adopt various structures. In some embodiments, the box body 5 may include a first box body part 5a and a second box body part 5b, the first box body part 5a and the second box body part 5b cover each other, and the first box body part 5a and the second box body part 5b jointly define an accommodation space 5c for accommodating the battery cells 6. The second box body part 5b may be a hollow structure with one end open, and the first box body part 5a may be a plate-like structure. The first box body part 5a covers the open side of the second box body part 5b so that the first box body part 5a and the second box body part 5b jointly define the accommodation space 5c; the first box body part 5a and the second box body part 5b may also both be hollow structures with one side open, and the open side of the first box body part 5a covers the open side of the second box body part 5b. Of course, the box body 5 formed by the first box body part 5a and the second box body part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0077] To improve the sealing performance after the connection between the first box body part 5a and the second box body part 5b, a sealing member, such as sealant, sealing ring, etc., may also be provided between the first box body part 5a and the second box body part 5b.

[0078] Assume that the first box body part 5a covers the top of the second box body part 5b. The first box body part 5a may also be referred to as the upper box cover, and the second box body part 5b may also be referred to as the lower box body.

[0079] In the battery device 2, there may be multiple battery cells 6, and the multiple battery cells 6 may be connected in series, parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 6. The multiple battery cells 6 may be directly connected in series, parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 6 is accommodated in the box body 5; of course, in the battery device 2, multiple battery cells 6 may also be first connected in series, parallel, or in a mixed connection to form a battery module form, and then multiple battery modules are connected in series, parallel, or in a mixed connection to form a whole and are accommodated in the box body 5. The battery device 2 may also include other structures. For example, the battery device 2 may further include a busbar component for realizing the electrical connection among the multiple battery cells 6.

[0080] Exemplarily, the battery cell 6 may be the smallest unit constituting the battery device 2.

[0081] Figure 3 is a schematic exploded view of a battery cell provided in some embodiments of the present application. Refer to Figure 3 , the battery cell 6 includes a housing 20 and an electrode assembly 10, and the electrode assembly 10 is disposed inside the housing 20.

[0082] The housing 20 is used to encapsulate components such as the electrode assembly 10 and the electrolyte. The housing 20 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing), or an aluminum plastic film, etc.

[0083] In some embodiments, the housing 20 is a hollow structure, and an accommodation space for accommodating the electrode assembly 10 and the electrolyte is formed inside it. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cuboid structure, a cuboid housing can be selected.

[0084] The material of the housing 20 can be various. For example, the material of the housing 20 can be metal or plastic. Optionally, the material of the housing 20 can be copper, iron, aluminum, steel, aluminum alloy, etc. Exemplarily, the housing 20 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing), or an aluminum plastic film, etc.

[0085] As an example, the housing 20 includes a housing body 21 and an end cap 22. The housing body 21 has an opening, and the end cap 22 is used to cover the opening.

[0086] The housing body 21 is a component used to cooperate with the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, the electrolyte, and other components.

[0087] The housing body 21 and the end cap 22 can be independent components. Exemplarily, an opening can be provided on the housing body 21, and the end cap 22 is covered at the opening to form the internal cavity of the battery cell 6.

[0088] The shape of the end cap 22 can be adapted to the shape of the housing body 21 to cooperate with the housing body 21. The material of the end cap 22 can be the same as or different from the material of the housing body 21.

[0089] The end cap 22 can be connected to the housing body 21 by welding, bonding, clamping, or other means.

[0090] The housing body 21 can have an opening at one end or at both ends. Exemplarily, the housing body 21 is a structure with an opening on one side, and the end cap 22 is provided as one and covers the opening of the housing body 21. As another example, the housing body 21 can also be a structure with openings on both sides, and the end caps 22 are provided as two, and the two end caps 22 respectively cover the two openings of the housing body 21.

[0091] Figure 4 For Figure 3 the cross-sectional schematic view of the battery cell shown, Figure 5 For Figure 4 the enlarged structural schematic view of region A in Figure 6 For Figure 3 the structural schematic view of the first adapter of the battery cell shown, Figure 7 ForFigure 3 The schematic diagram of the structure of the electrode assembly and the first adapter of the battery cell after welding is shown, Figure 8 for Figure 7 Schematic diagram of the enlarged structure of area B in the middle. Figure 9 for Figure 3 A front view schematic diagram of a first adapter of a battery cell is shown, Figure 10 for Figure 9 Schematic diagram of the enlarged structure of area C in the middle.

[0092] Reference Figures 3 to 10 The embodiment of the present application provides a battery cell 6, which includes an electrode assembly 10, a shell 20, a first electrode terminal 31 and a first adapter 40. The shell 20 includes a wall portion 211. The first electrode terminal 31 is disposed on the wall portion 211. The electrode assembly 10 is accommodated in the shell 20, and the electrode assembly 10 includes a main body 11 and a first pole ear 12, and at least a portion of the first pole ear 12 protrudes from a first end surface 11a of the main body 11 along the first direction X. The first adapter 40 is connected to the first electrode terminal 31, and at least a portion of the first adapter 40 is disposed on a side of the first pole ear 12 away from the main body 11 along the first direction X, and abuts against the first pole ear 12. A first recess 41 is provided on one side of the first adapter 40 along the first direction X, and a bottom wall of the first recess 41 is welded to the first pole ear 12.

[0093] The wall portion 211 may be the end cover 22 , or may be one of the shell walls of the shell 21 .

[0094] In some examples, the first electrode tab 12 may be a positive electrode tab, and accordingly, the first electrode terminal 31 is a positive electrode terminal. In other examples, the first electrode tab 12 may also be a negative electrode tab, and accordingly, the first electrode terminal 31 is a negative electrode terminal.

[0095] The number of the first electrode tab 12 may be one or more.

[0096] The first electrode tab 12 may protrude entirely from the first end surface 11 a of the main body 11 , or only a portion of the first electrode tab 12 may protrude from the first end surface 11 a of the main body 11 , and the other portion of the first electrode tab 12 may be inserted into the main body 11 .

[0097] The first adapter 40 can be connected to the first electrode terminal 31 by welding, bonding or other suitable methods. Optionally, the first adapter 40 is welded to the first electrode terminal 31 by laser welding, ultrasonic welding or other suitable welding methods to improve the connection strength and stability between the first adapter 40 and the first electrode terminal 31.

[0098] The first adapter 40 can be integrally disposed on the side of the first tab 12 facing away from the main body 11; alternatively, only a part of the first adapter 40 can be disposed on the side of the first tab 12 facing away from the main body 11, and the other part of the first adapter 40 can be disposed, for example, between the main body 11 and the wall 211 along the third direction Z, where the third direction Z is perpendicular to the first direction X.

[0099] At least a part of the first adapter 40 located on the side of the first tab 12 facing away from the main body 11 can abut against the first tab 12. That is, at least a part of the first adapter 40 located on the side of the first tab 12 facing away from the main body 11 abuts against and directly contacts the first tab 12, which can reduce the gap between the first adapter 40 and the first tab 12 and improve the welding efficiency between the two.

[0100] In some examples, the first recess 41 can be formed on the side of the first adapter 40 facing away from the first tab 12 along the first direction X, and the first recess 41 is recessed from the surface of the first adapter 40 facing away from the first tab 12. The first tab 12 can abut against the surface of the first adapter 40 facing the first tab 12.

[0101] In other examples, the first recess 41 can also be formed on the side of the first adapter 40 facing the first tab 12 along the first direction X, and the first recess 41 is recessed from the surface of the first adapter 40 facing the first tab 12. At least a part of the first tab 12 is received in the first recess 41 and abuts against the bottom surface of the first recess 41.

[0102] Along the first direction X, the projection of the first recess 41 can be circular, rectangular, or other suitable shapes.

[0103] The bottom wall of the first recess 41 refers to the part of the first adapter 40 corresponding to the bottom surface of the first recess 41 in the first direction X. In other words, at least a part of the first adapter 40 corresponding to the first recess 41 forms the bottom wall of the first recess 41.

[0104] The first recess 41 can be formed by stamping, machining, or other suitable processes.

[0105] The first recess 41 is recessed from the surface of the first adapter 40. Compared with the bottom wall of the first recess 41, at least some other parts of the first adapter 40 are relatively thick, which is beneficial to improving the current-carrying capacity; the bottom wall of the first recess 41 is relatively thin, which is convenient for welding with the first tab 12, not prone to the risk of false soldering, and can reduce the welding difficulty and the requirement for welding power, which is beneficial to reducing the risk of burning the main body 11 during the welding operation and improving the reliability of the battery cell 6.

[0106] In some embodiments, the first adapter 40 and the first electrode tab 12 are welded to form a welding portion 50 , and the welding portion 50 is exposed at a side of the first adapter 40 along the first direction X away from the first electrode tab 12 .

[0107] The number of the welding part 50 may be one or more.

[0108] The projection of the welding portion 50 along the first direction X may be substantially rectangular, circular, annular or other shapes. Optionally, the projection shape of the welding portion 50 may be matched with the projection shape of the first recessed portion 41 .

[0109] The welding portion 50 is directly connected to the first electrode tab 12 and the bottom wall of the first recess 41 , and current can be transmitted between the first electrode tab 12 and the first adapter 40 through the welding portion 50 .

[0110] The welding portion 50 is exposed on the side of the first adapter 40 away from the first pole tab 12 along the first direction X, which means that the welding portion 50 can be exposed from the side of the first adapter 40 away from the first pole tab 12 along the first direction X. Thus, the bottom wall of the first recess 41 and the first pole tab 12 can be penetrated and welded from the side of the first adapter 40 away from the first pole tab 12 along the first direction X, thereby forming the welding portion 50, which is conducive to further reducing the difficulty of welding and reducing the risk of burning the main body 11 during the welding operation.

[0111] In some embodiments, the first adapter 40 and the first electrode tab 12 are welded to form a welding portion 50 , and a side wall of the first recess 41 is spaced apart from the welding portion 50 .

[0112] The side wall of the first recess 41 refers to the portion of the first adapter 40 corresponding to the side surface of the first recess 41, that is, the side wall of the first recess 41 may be the portion of the first adapter 40 surrounding the outer periphery of the first recess 41. The side surface of the first recess 41 is connected to the bottom surface of the first recess 41.

[0113] The first recessed portion 41 may have one or more side walls.

[0114] In some examples, the projection of the first recess 41 along the first direction X may be rectangular, and the first recess 41 has four side walls connected in sequence. In other examples, the projection of the first recess 41 along the first direction X may be circular, and the first recess 41 has an annular side wall.

[0115] Each side wall of the first recess 41 is spaced from the welding portion 50. In other words, each side wall of the first recess 41 is not directly connected to the welding portion 50. Along the first direction X, the projection of the welding portion 50 and the projection of the side wall of the first recess 41 do not overlap. Thus, the possibility of welding the first tab 12 to the thicker portion of the first adapter 40 due to welding tolerance can be reduced, which is beneficial to reducing the risk of false soldering and improving the welding strength and reliability.

[0116] In some embodiments, the minimum distance between the side wall of the first recess 41 and the welding portion 50 is d, where 0.1 mm ≤ d ≤ 3 mm.

[0117] The welding portion 50 may have a regular or irregular outer contour, and the vertical distances between the regions of the outer contour of the welding portion 50 and the corresponding side walls of the first recess 41 may not be equal. The minimum distance between the side wall of the first recess 41 and the welding portion 50 refers to the minimum value among the vertical distances between the regions of the outer contour of the welding portion 50 and the corresponding side walls of the first recess 41, that is, the vertical distance between the portion of the welding portion 50 closest to the side wall of the first recess 41 and the side wall.

[0118] Optionally, d may be 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm or any value between any two of them.

[0119] In the embodiments of the present application, d is set to be greater than or equal to 0.1 mm, so that the welding portion 50 is not too close to the first recess 41, which is beneficial to reducing the risk of false soldering; in the embodiments of the present application, d is set to be less than or equal to 3 mm, which can reduce the size of the first recess 41 and reduce the adverse effects of the setting of the first recess 41 on the structural strength and current-carrying capacity of the first adapter 40.

[0120] In some embodiments, the first tab 12 includes a plurality of tab layers 121, and at least some of the tab layers 121 include a protruding portion 1211 and a bent portion 1212. The protruding portion 1211 is connected between the main body portion 11 and the bent portion 1212, and the bent portion 1212 is bent relative to the protruding portion 1211. The adjacent bent portions 1212 are stacked along the first direction X, and the bent portions 1212 of at least some of the tab layers 121 abut against the first adapter 40 and are welded to the first adapter 40.

[0121] Each tab layer 121 may include an extension portion 1211 and a bent portion 1212, or only some of the tab layers 121 may include the extension portion 1211 and the bent portion 1212, and the remaining tab layers 121 may only include the extension portion 1211, for example. Exemplarily, the electrode assembly 10 is a wound structure, and the outermost several turns of tab layers 121 include the extension portion 1211 and the bent portion 1212, while the innermost several turns of tab layers 121 only include the extension portion 1211. Alternatively, the tab layers 121 having both the extension portion 1211 and the bent portion 1212 and the tab layers 121 having only the extension portion 1211 may also be alternately arranged in the arrangement direction of the plurality of tab layers 121.

[0122] The extension portion 1211 is the part of the tab layer 121 for directly connecting with the main body portion 11. Optionally, the extension portion 1211 may extend along the first direction X.

[0123] The bent portion 1212 is connected to the extension portion 1211 and is bent relative to the extension portion 1211. The bent portion 1212 may be bent once or multiple times. The bending direction of the bent portion 1212 forms a certain angle with the first direction X. The bending trends of the bent portions 1212 of some adjacent tab layers 121 may be substantially the same, so as to facilitate the stacking of the bent portions 1212 of the adjacent tab layers 121 along the first direction X.

[0124] The stacked arrangement of the bent portions 1212 of the adjacent tab layers 121 along the first direction X means that the projections of the bent portions 1212 of the adjacent tab layers 121 along the first direction X at least partially overlap, and at least part of the overlapping bent portions 1212 of the adjacent tab layers 121 are in direct contact. The adjacent tab layers 121 may be connected to each other through the stacking of the bent portions 1212.

[0125] The bent portions 1212 of the plurality of tab layers 121 may be offset from each other by a part along the arrangement direction of the plurality of tab layers 121, so that the bent portions 1212 of the plurality of tab layers 121 can all directly abut against the first adapter 40 and thus be directly connected to the first adapter 40, which is beneficial to increasing the current flow path.

[0126] The bent portions 1212 of at least some of the tab layers 121 are welded to the first adapter 40. The part of the bent portion 1212 for welding with the first adapter 40 may or may not abut against the first adapter 40, but may be stacked with the bent portions 1212 of other tab layers 121.

[0127] Optionally, the extension portions 1211 of each tab layer 121 are not welded to the first adapter 40.

[0128] In the embodiments of the present application, at least part of the tab layer 121 is provided with a protruding portion 1211 and a bent portion 1212, and the first adapter 40 is welded to the bent portion 1212 of at least part of the tab layer 121. On the one hand, a plurality of bent portions 1212 are stacked, and the stacking gap is small, which is conducive to reducing the risk of poor soldering between the first adapter 40 and the first tab 12. On the other hand, the protruding portion 1211 can make the bent portion 1212 and the main body portion 11 spaced apart by a certain distance in the first direction X, which can reduce the soldering heat transferred to the main body portion 11 during the soldering process between the bent portion 1212 and the first adapter 40, and reduce the risk of burning the main body portion 11.

[0129] In some embodiments, the plurality of tab layers 121 include a plurality of first tab layers 121a and a plurality of second tab layers 121b. The plurality of first tab layers 121a and the plurality of second tab layers 121b are arranged along the second direction Y, and the second direction Y is perpendicular to the first direction X. The bent portion 1212 of the first tab layer 121a is bent along the second direction Y toward the second tab layer 121b, and the bent portion 1212 of the second tab layer 121b is bent along the second direction Y toward the first tab layer 121a.

[0130] Optionally, the electrode assembly 10 may be a flat structure, and the second direction Y may be the thickness direction of the electrode assembly 10.

[0131] The plurality of first tab layers 121a and the plurality of second tab layers 121b may be arranged at intervals along the second direction Y. Optionally, the plurality of tab layers 121 further include a plurality of third tab layers 121c. Along the second direction Y, the plurality of third tab layers 121c are located between the plurality of first tab layers 121a and the plurality of second tab layers 121b. The third tab layer 121c may only include the protruding portion 1211.

[0132] Each first tab layer 121a includes a protruding portion 1211 and a bent portion 1212, and the bending trends of the bent portions 1212 of the plurality of first tab layers 121a are the same.

[0133] Each second tab layer 121b includes a protruding portion 1211 and a bent portion 1212, and the bending trends of the bent portions 1212 of the plurality of second tab layers 121b are the same.

[0134] In some examples, the bent portions 1212 of some of the first tab layers 121a and the bent portions 1212 of some of the second tab layers 121b may be stacked along the first direction X. In other examples, the bent portions 1212 of the first tab layer 121a and the bent portions 1212 of the second tab layer 121b do not overlap in the first direction X.

[0135] At least a part of the bent portion 1212 of the first tab layer 121a abuts against the first adapter 40 and is welded to form at least one welding portion 50. At least a part of the bent portion 1212 of the second tab layer 121b abuts against the first adapter 40 and is welded to form at least one welding portion 50. The welding portion 50 formed by welding the first tab layer 121a and the first adapter 40 and the welding portion 50 formed by welding the second tab layer 121b and the first adapter 40 may be directly connected or may not be directly connected.

[0136] The bent portions 1212 of the first tab layer 121a and the second tab layer 121b are bent towards each other. The bending directions of the multiple tab layers 121 are relatively regular. The first tab 12 is relatively tight and flat as a whole, which is beneficial to reducing the interlayer gap of the bent portion 1212 and improving the welding effect between the first tab 12 and the first adapter 40.

[0137] In some embodiments, there may be multiple first recesses 41, and at least a part of the multiple first recesses 41 are arranged at intervals along the second direction Y. At least a part of the bent portion 1212 of the first tab layer 121a and at least a part of the bent portion 1212 of the second tab layer 121b are respectively welded to the bottom walls of different first recesses 41.

[0138] Optionally, in the projection plane perpendicular to the first direction X, the orthographic projection of the first tab layer 121a and the orthographic projection of the second tab layer 121b do not overlap.

[0139] Optionally, two first recesses 41 are arranged at intervals along the second direction Y. At least a part of the bent portion 1212 of the first tab layer 121a is welded to the bottom wall of one of the first recesses 41, and at least a part of the bent portion 1212 of the second tab layer 121b is welded to the bottom wall of the other first recess 41. The welding portion 50 formed by welding the first tab layer 121a and the first adapter 40 and the welding portion 50 formed by welding the second tab layer 121b and the first adapter 40 are not directly connected.

[0140] The first tab layer 121a can be welded to the first adapter 40 separately, and the second tab layer 121b can be welded to the first adapter 40 separately. On the one hand, multiple welding portions 50 can be formed between the first tab 12 and the first adapter 40, increasing the current flow paths, which is beneficial to reducing the internal resistance and reducing the risk of connection failure between the first tab 12 and the first adapter 40 caused by a virtual weld in one of the welding portions 50. On the other hand, it can also reduce the maximum number of stacked layers of the bent portions 1212 of the multiple tab layers 121, thereby reducing the space occupied by the first tab 12 in the first direction X and being beneficial to improving the energy density of the battery cell 6.

[0141] In some embodiments, the bent portion 1212 has a stacked area 1212a that is stacked with at least two other bent portions 1212 along the first direction X. The stacked areas 1212a of all the bent portions 1212 form a stacked portion 122 of the first tab 12. The stacked portion 122 abuts against the first adapter 40 and is welded to the first adapter 40.

[0142] Along the first direction X, the projections of the stacked areas 1212a of the respective bent portions 1212 overlap with the projections of at least two other bent portions 1212. In other words, any region of the stacked portion 122 has at least a three-layer structure stacked along the first direction X.

[0143] The number of layers of the bent portions 1212 in the stacked portion 122 is greater than or equal to 3. The stacked portion 122 has relatively high structural strength and relatively large thickness. When the stacked portion 122 and the first adapter 40 are welded, it is not easily welded through, which is beneficial to reducing the heat transferred to the main body portion 11 and reducing the risk of the main body portion 11 being burned.

[0144] In some embodiments, in the projection plane perpendicular to the first direction X, the orthographic projection of the first recess 41 is located within the orthographic projection of the stacked portion 122. In other words, each region of the first tab 12 corresponding to the bottom wall of the first recess 41 has at least three layers of bent portions 1212, which can reduce the possibility of the first adapter 40 being welded to other parts of the first tab 12 except the stacked portion 122, and is beneficial to reducing the risk of false soldering or the first tab 12 being welded through.

[0145] In some embodiments, in the projection plane perpendicular to the first direction X, the orthographic projection of the stacked portion 122 extends beyond the orthographic projection of the first recess 41. In other words, the projected area of the stacked portion 122 is larger than the projected area of the first recess 41, and the projection of the stacked portion 122 covers the projection of the first recess 41. Thus, the stacked portion 122 has a relatively large area, can adapt to the relative position change between the first tab 12 and the first adapter 40 caused by manufacturing tolerances and assembly tolerances, and reduces the possibility of affecting the welding effect of the first tab 12 and the first adapter 40.

[0146] In some embodiments, in the stacked portion 122, the maximum number of layers of the stacked bent portions 1212 is m, and the total number of layers of the tab layer 121 is n, where 15% ≤ m / n ≤ 30%.

[0147] Optionally, m / n can be 15%, 16%, 17%, 18%, 20%, 22%, 24%, 26%, 28%, 30% or any value between any two of them.

[0148] In the embodiments of the present application, m / n is set to be greater than or equal to 15%. The stacked portion 122 has relatively high structural strength and thickness, which is beneficial to reducing the risk of the stacked portion 122 being burned through by welding and damaging the main body portion 11. In the embodiments of the present application, m / n is set to be less than or equal to 30%. The size of the stacked portion 122 in the first direction X is not too large, which is beneficial to reducing the space occupied by the first tab 12 in the first direction X and improving the energy density of the battery cell 6.

[0149] In some embodiments, the first recess 41 is formed on a side of the first adapter 40 facing away from the first tab 12 in the first direction X.

[0150] If the first recess 41 is provided on a side of the first adapter 40 facing the first tab 12 in the first direction X, the first tab 12 abuts against the bottom surface of the first recess 41. The first recess 41 needs relatively large space to accommodate at least part of the first tab 12, so as to reduce the interference between the first tab 12 and the first adapter 40.

[0151] In the embodiments of the present application, the first recess 41 is provided on a side of the first adapter 40 facing away from the first tab 12 in the first direction X. The first tab 12 can abut against the surface of the first adapter 40 facing the first tab 12 in the first direction X. On the premise of meeting the welding requirements, the size of the first recess 41 can be reduced, which is beneficial to reducing the influence of the arrangement of the first recess 41 on the structural strength and current-carrying area of the first adapter 40.

[0152] In some embodiments, both the first recess 41 and the first tab 12 are multiple. Each first tab 12 is welded to the bottom wall of the corresponding one or more first recesses 41.

[0153] In some examples, the first recess 41 and the first tab 12 are arranged in a one-to-one correspondence, and the first tab 12 is welded to the bottom wall of the corresponding one first recess 41.

[0154] In other examples, the first recess 41 and the first tab 12 are arranged in a many-to-one correspondence, and the first tab 12 is welded to the bottom walls of the corresponding multiple first recesses 41.

[0155] Optionally, there may be two first tabs 12. The two first tabs 12 can be arranged along the third direction Z. Correspondingly, there are at least two first recesses 41.

[0156] Optionally, the multiple first tab layers 121a of each first tab 12 can be welded to the bottom wall of one first recess 41, and the multiple second tab layers 121b of each first tab 12 can be welded to the bottom wall of another first recess 41.

[0157] In the embodiment of the present application, the first pole tab 12 and the first recess 41 are both provided in plurality, so as to facilitate the bending operation of the first pole tab 12 , reduce the difficulty of bending the first pole tab 12 , and improve the compactness and flatness of the first pole tab 12 after bending.

[0158] In some embodiments, the first adapter 40 includes a first adapter body 42 and a plurality of first protrusions 43, two adjacent first protrusions 43 are connected by at least a portion of the first adapter body 42, the plurality of first protrusions 43 and the plurality of first pole tabs 12 are arranged one by one, and the first adapter body 42 and the first protrusions 43 are both arranged on the side of the first pole tab 12 away from the main body 11 along the first direction X. Along the direction from the first pole tab 12 to the main body 11, the first protrusion 43 exceeds the first surface 42a of the first adapter body 42 facing the first pole tab 12, and each first protrusion 43 abuts against a corresponding first pole tab 12. Each first protrusion 43 is provided with at least one first recess 41 on one side along the first direction X, and the thickness of the bottom wall of the first recess 41 is less than the thickness of the first adapter body 42.

[0159] In some examples, there are two first protrusions 43 , and the first adapter body 42 may be a continuous structure. The first adapter body 42 is disposed between the two first protrusions 43 .

[0160] In some other examples, the first adapter body 42 includes a plurality of adapter parts 421 arranged at intervals. Two adjacent adapter parts 421 are connected by a first protrusion 43 .

[0161] Optionally, the plurality of first electrode tabs 12 may be arranged at intervals along the third direction Z, and the plurality of first protrusions 43 may be arranged at intervals along the third direction Z. Along the third direction Z, the plurality of transition portions 421 and the plurality of first protrusions 43 are arranged alternately.

[0162] In some examples, the first recess 41 may be provided on a side of the first protrusion 43 facing away from the first pole tab 12, and the first pole tab 12 abuts against the surface of the corresponding first protrusion 43 facing the first pole tab 12 along the first direction X. In other examples, the first recess 41 may also be provided on a side of the first protrusion 43 facing the first pole tab 12, and the first pole tab 12 abuts against the bottom wall of the corresponding first recess 41 along the first direction X.

[0163] The first adapter body 42 may be a structure of uniform thickness, and the bottom wall of the first recess 41 may also be a structure of uniform thickness.

[0164] The first convex portion 43 may include the bottom wall of the first concave portion 41 and other parts connected to the bottom wall of the first concave portion 41. The other parts of the first convex portion 43 may be of equal thickness or unequal thickness. The average thickness of the other parts of the first convex portion 43 may be the same as or different from the thickness of the first adapter body 42.

[0165] The first transfer body 42 is thicker than the bottom wall of the first recess 41, which is beneficial to improving the current-carrying capacity of the first transfer member 40 and reducing the internal resistance of the battery cell 6.

[0166] Due to manufacturing tolerances, the dimensions of the plurality of first tabs 12 protruding from the first end face 11a in the first direction X may not be the same. If the plurality of first tabs 12 abut against the flat first transfer member 40, there may be a phenomenon of poor contact or a small contact surface between some of the first tabs 12 and the first transfer member 40, which affects the welding effect between the first tabs 12 and the first transfer member 40.

[0167] In the embodiments of the present application, a plurality of first convex portions 43 are respectively provided corresponding to the plurality of first tabs 12, and at least a part of the first transfer body 42 connects two adjacent first convex portions 43. By appropriate deformation of the first transfer body 42, each of the first tabs 12 can be closely abutted against the corresponding first convex portion 43, which is beneficial to improving the welding effect between the first tabs 12 and each first convex portion 43 and reducing the risk of connection failure between the first tabs 12 and the first convex portions 43 caused by virtual soldering.

[0168] In some embodiments, a second recess 44 is provided on a side of the first transfer member 40 facing away from the first tab 12. The second recess 44 is provided corresponding to the first convex portion 43, and the first recess 41 is recessed from the bottom surface 44a of the second recess 44.

[0169] The second recess 44 may be recessed in a third surface 42b of the first transfer body 42 facing away from the first tab 12. A portion of the first transfer member 40 corresponding to the second recess 44 in the first direction X forms the first convex portion 43.

[0170] The first recess 41 may be formed on a side of the first transfer member 40 facing away from the first tab 12, and the first recess 41 is recessed from the bottom surface 44a in a direction approaching the first tab 12.

[0171] Optionally, along the first direction X, the dimension of the first recess 41 recessed from the bottom surface 44a may be the same as the dimension of the first convex portion 43 protruding beyond the first surface 42a, so that the thickness of the first convex portion 43 is the same as the thickness of the first transfer body 42.

[0172] In the embodiments of the present application, by providing the second recess 44 corresponding to the first convex portion 43, the thickness of the first convex portion 43 can be appropriately reduced, the weight of the first convex portion 43 can be reduced, and the space occupied by the first convex portion 43 in the first direction X can be reduced.

[0173] In some embodiments, the first convex portion 43 includes a protruding main body 431 and a weak portion 432. The weak portion 432 is provided corresponding to the first recess 41, at least a part of the weak portion 432 forms the bottom wall of the first recess 41, and the thickness of the protruding main body 431 is equal to the thickness of the first transfer body 42.

[0174] Optionally, the protruding body 431 may have a uniform thickness structure.

[0175] In some examples, the cross-sectional shape of the first recess 41 perpendicular to the third direction Z may be rectangular, and the weak portion 432 integrally forms the bottom wall of the first recess 41.

[0176] In other examples, the cross-sectional shape of the first recess 41 perpendicular to the third direction Z may be trapezoidal. A part of the weak portion 432 forms the bottom wall of the first recess 41, and another part of the weak portion 432 forms the side wall of the first recess 41.

[0177] The thickness of the protruding body 431 is equal to the thickness of the first transition body 42. The thickness of the protruding body 431 is not too large to occupy too much space, and the thickness of the protruding body 431 is not too small to affect the current flow.

[0178] In some embodiments, the thickness of the first transition body 42 is T, and 0.5 mm ≤ T ≤ 5 mm.

[0179] Optionally, T may be 0.5 mm, 0.7 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.5 mm, 3 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm or any value between any two of them.

[0180] In the embodiments of the present application, T is set to be greater than or equal to 0.5 mm, so that the thickness of the first transition body 42 is not too small to affect its current-carrying capacity, which is beneficial to reducing heat generation and reducing the internal resistance of the battery cell 6. In the embodiments of the present application, T is set to be less than or equal to 5 mm, so that the thickness of the first transition body 42 is not too large, the space occupied by the first transition body 42 can be reduced, which is beneficial to improving the energy density of the battery cell 6 and reducing the weight of the battery cell 6.

[0181] In some embodiments, the first adapter 40 includes a second convex portion 45. The second convex portion 45 is disposed around the first recess 41, and the second convex portion 45 protrudes from the surface of the first convex portion 43 along the first direction X.

[0182] Optionally, the first recess 41 may be formed by a stamping process. During the stamping process, the corresponding part of the material of the first recess 41 is extruded to the periphery of the first recess 41, and the second convex portion 45 may be formed after the extruded material is solidified during the stamping process.

[0183] Along the first direction X, the first concave portion 41 and the second convex portion 45 can be located on the same side of the first convex portion 43. In some examples, both the first concave portion 41 and the second convex portion 45 are located on the side of the first convex portion 43 facing away from the first tab 12. In other examples, both the first concave portion 41 and the second convex portion 45 are located on the side of the first convex portion 43 facing the first tab 12.

[0184] The second convex portion 45 is disposed around the first concave portion 41. The second convex portion 45 can enhance the overall strength of the first adapter 40 around the first concave portion 41 and reduce the influence of the setting of the first concave portion 41 on the overall strength of the first adapter 40.

[0185] In some embodiments, both the first concave portion 41 and the second convex portion 45 are located on the side of the first convex portion 43 facing away from the first tab 12, and the second convex portion 45 protrudes from the second surface 43a of the first convex portion 43 facing away from the first tab 12 along the first direction X. Along the direction from the main body portion 11 to the first tab 12, the second convex portion 45 does not extend beyond the surface of the first adapter main body 42 facing away from the electrode assembly 10. In other words, the second convex portion 45 can be entirely accommodated in the second concave portion 44, and the second convex portion 45 does not extend outside the second concave portion 44.

[0186] The second convex portion 45 is located on the side of the first convex portion 43 facing away from the first tab 12, and the protruding directions of the first convex portion 43 and the second convex portion 45 along the first direction X are opposite, which is beneficial to reducing the overall space occupied by the first convex portion 43 and the second convex portion 45 in the first direction X.

[0187] The second convex portion 45 does not extend beyond the first adapter main body 42. The space of the second concave portion 44 can be used to accommodate the second convex portion 45, reducing the extra space occupied by the second convex portion 45 in the first direction X, which is beneficial to improving the space utilization rate and enhancing the energy density of the battery cell 6.

[0188] In some embodiments, the wall portion 211 is located on one side of the electrode assembly 10 along the third direction Z, and the first direction X is perpendicular to the third direction Z. The first adapter 40 includes a second adapter main body 46. Along the third direction Z, the second adapter main body 46 is located between the electrode assembly 10 and the wall portion 211 and is connected to the first electrode terminal 31.

[0189] Optionally, the first adapter 40 is integrally L-shaped.

[0190] The second adapter main body 46 can be directly connected to the first adapter main body 42 or indirectly connected to the first adapter main body 42 through other structures.

[0191] The thickness of the second transfer body 46 and the thickness of the first transfer body 42 may be the same or different. Optionally, the thickness of the second transfer body 46 is the same as that of the first transfer body 42, and the second transfer body 46 and the first transfer body 42 can be formed by bending a plate-shaped member.

[0192] The second transfer body 46 can be connected to the first electrode terminal 31 by riveting, welding, bonding or other suitable means.

[0193] The second transfer body 46 is provided with a third recess 461, and the third recess 461 is recessed from the surface of the second transfer body 46 along the third direction Z. The third recess 461 can be provided on the side of the second transfer body 46 facing the electrode assembly 10, or can be provided on the side of the second transfer body 46 facing away from the electrode assembly 10. The portion of the second transfer body 46 corresponding to the third recess 461 is relatively weak and can form a fusing portion of the first transfer member 40, so as to be able to fuse in time when the current inside the battery cell 6 is too large, thereby playing a role in open-circuit protection.

[0194] In some embodiments, the first transfer member 40 includes a connecting portion 47, and the first transfer body 42 and the second transfer body 46 are connected by the connecting portion 47. The projection of the connecting portion 47 along the second direction Y is arc-shaped, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other in pairs.

[0195] The thickness of the connecting portion 47 and the thickness of the first transfer body 42 may be the same or different. The thickness of the connecting portion 47 and the thickness of the second transfer body 46 may be the same or different.

[0196] Optionally, the connecting portion 47 can be formed by a bending process. During the bending process, a part of the material used to form the connecting portion 47 will be subjected to a tensile force, so that the thickness of at least part of the connecting portion 47 is less than the thickness of the first transfer body 42 and the thickness of the second transfer body 46.

[0197] The connecting portion 47 can be smoothly connected to the first transfer body 42, and the connecting portion 47 can be smoothly connected to the second transfer body 46.

[0198] The connecting portion 47 may include an inner surface 47a facing the electrode assembly 10 and an outer surface 47b facing away from the electrode assembly 10, and both the inner surface 47a and the outer surface 47b are arc-shaped surfaces.

[0199] In the embodiment of the present application, through the arc-shaped connecting portion 47, it is beneficial to reduce the possibility of cracking or the appearance of cracks during the bending process of the first transfer member 40.

[0200] In some embodiments, the connection portion 47 has an inner surface 47 a facing the electrode assembly 10 , the projection of the inner surface 47 a along the second direction Y is an arc shape, the radius of the circle corresponding to the projection of the inner surface 47 a is r, and 0.2 mm≤r≤20 mm.

[0201] Optionally, r can be 0.2mm, 0.5mm, 0.7mm, 1mm, 0.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 5mm, 7mm, 10mm, 15mm, 20mm or any value therebetween.

[0202] The projection of the outer surface 47b of the connecting portion 47 along the second direction Y is also an arc shape, and the center of the circle corresponding to the projection of the inner surface 47a coincides with the center of the circle corresponding to the projection of the outer surface 47b, so that the connecting portion 47 can be a uniform thickness structure.

[0203] In the embodiment of the present application, r is set to be greater than or equal to 0.2 mm, and the inner side of the connection portion 47 is not easy to form an angle, which is conducive to reducing the risk of cracking or cracking of the connection portion 47. In the embodiment of the present application, r is set to be less than or equal to 20 mm, and the connection portion 47 is not too large, which can reduce the space required for arranging the connection portion 47, reduce the space waste in the battery cell 6, and help improve the energy density of the battery cell 6.

[0204] In some embodiments, the first adapter 40 is an integrally formed structure, which helps to simplify the assembly process.

[0205] In some embodiments, the electrode assembly 10 includes a second electrode tab 13 , at least a portion of which protrudes from a second end surface 11 b of the main body 11 along the first direction X. The second end surface 11 b and the first end surface 11 a are disposed opposite to each other along the first direction X.

[0206] In some embodiments, the battery cell 6 includes a second electrode terminal 32 and a second adapter 60, the second electrode terminal 32 is disposed on the wall portion 211, the second adapter 60 is connected to the second electrode terminal 32, at least a portion of the second adapter 60 is disposed on a side of the second pole tab 13 away from the main body portion 11 along the first direction X, and abuts against the second pole tab 13. A fourth recess 61 is disposed on one side of the second adapter 60 along the first direction X, and a bottom wall of the fourth recess 61 is welded to the second pole tab 13.

[0207] The structure of the second adapter 60 may be similar to that of the first adapter 40 , and will not be described in detail herein.

[0208] The connection relationship between the second adapter 60 and the second electrode tab 13 is similar to the connection relationship between the first adapter 40 and the first electrode tab 12 , and will not be described in detail here.

[0209] Compared with the fourth recess 61, at least other parts of the second adapter 60 are relatively thick, which is beneficial to improving the current carrying capacity; the bottom wall of the fourth recess 61 is relatively thin, which is convenient for welding with the second pole ear 13, and is not prone to the risk of cold welding. It can also reduce the difficulty of welding and the requirements for welding power, which is beneficial to reducing the risk of burning the main body 11 during welding operations and improving the reliability of the battery cell 6.

[0210] According to the second aspect of the present application, an embodiment of the present application further provides a battery device, wherein the battery device 2 includes a plurality of battery cells 6 provided according to any embodiment of the first aspect of the present application.

[0211] According to the third aspect of the present application, an embodiment of the present application further provides an electric device, the electric device comprising the battery device provided according to any embodiment of the second aspect of the present application. The electric device may be any of the above-mentioned devices or systems using battery cells.

[0212] The embodiment of the present application provides a battery cell 6, which includes an electrode assembly 10, a shell 20, a first electrode terminal 31 and a first adapter 40. The first adapter 40 is an integrally formed structure. The shell 20 includes a wall portion 211, and the first electrode terminal 31 is disposed on the wall portion 211. The electrode assembly 10 is accommodated in the shell 20, and the electrode assembly 10 includes a main body 11 and a first pole ear 12, and at least a portion of the first pole ear 12 protrudes from the first end surface 11a of the main body 11 along the first direction X. The first adapter 40 is connected to the first electrode terminal 31, and at least a portion of the first adapter 40 is disposed on a side of the first pole ear 12 away from the main body 11 along the first direction X, and abuts against the first pole ear 12. The first adapter 40 is provided with a first recess 41 on one side of the first direction X, and the bottom wall of the first recess 41 is welded to the first pole ear 12 to form a welding portion 50. The minimum distance between the welding portion 50 and the side wall of the first recess 41 is greater than or equal to 0.1 mm. The first adapter 40 includes a first adapter body 42, a first protrusion 43, and a second adapter body 46. The first adapter body 42 and the first protrusion 43 are arranged on the side of the first electrode tab 12 away from the main body 11 along the first direction X. Along the third direction Z, the second adapter body 46 is arranged between the electrode assembly 10 and the wall portion 211. The thickness of the first adapter body 42 is greater than or equal to 0.5 mm. The first adapter body 42 and the second adapter body 46 are connected by an arc-shaped connecting portion 47. The connecting portion 47 has an inner surface 47a facing the electrode assembly 10. The projection of the inner surface 47a along the second direction Y is an arc shape, and the radius of the circle corresponding to the projection of the inner surface 47a is greater than 0.2 mm.

[0213] The first concave portion 41 can be formed by machining or stamping processes. When the first concave portion 41 is formed by a stamping process, the first adapter 40 further includes a second convex portion 45. The second convex portion 45 is disposed around the first concave portion 41, and the second convex portion 45 protrudes from the surface of the first convex portion 43 along the first direction X.

[0214] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing, including a wall portion; A first electrode terminal is provided on the wall portion; An electrode assembly, contained in the housing, comprising a main body and a first electrode tab, wherein at least a portion of the first electrode tab protrudes from a first end surface of the main body along a first direction; as well as A first adapter is connected to the first electrode terminal, at least a portion of the first adapter is disposed on a side of the first electrode tab away from the main body along the first direction and abuts against the first electrode tab, a first recess is disposed on one side of the first adapter along the first direction, and a bottom wall of the first recess is welded to the first electrode tab; The first adapter includes a first adapter body, and the thickness of the bottom wall of the first recess is smaller than the thickness of the first adapter body.

2. The battery cell according to claim 1, characterized in that: The first adapter and the first pole tab are welded to form a welding portion, and the welding portion is exposed on a side of the first adapter away from the first pole tab along the first direction.

3. The battery cell according to claim 1, characterized in that: The first adapter and the first electrode tab are welded to form a welding portion, and the side wall of the first recess is spaced apart from the welding portion.

4. The battery cell according to claim 3, characterized in that: A minimum distance between a side wall of the first recess and the welding portion is d, and 0.1 mm≤d≤3 mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The first pole lug includes multiple pole lug layers, at least part of the pole lug layers include a protruding portion and a bent portion, the protruding portion is connected between the main body and the bent portion, the bent portion is bent relative to the protruding portion, adjacent bent portions are stacked along the first direction, and the bent portions of at least part of the pole lug layers are abutted against and welded to the first adapter.

6. The battery cell according to claim 5, characterized in that: The plurality of tab layers include a plurality of first tab layers and a plurality of second tab layers, the plurality of first tab layers and the plurality of second tab layers are arranged along a second direction, and the second direction is perpendicular to the first direction; Along the second direction, the bent portion of the first pole tab layer is bent toward the second pole tab layer, and the bent portion of the second pole tab layer is bent toward the first pole tab layer.

7. The battery cell according to claim 6, characterized in that: There are a plurality of first recesses, and at least some of the plurality of first recesses are arranged at intervals along the second direction; At least a portion of the bent portion of the first tab layer and at least a portion of the bent portion of the second tab layer are respectively welded to different bottom walls of the first recessed portion.

8. The battery cell according to claim 5, characterized in that: The bending portion has a stacking area stacked with at least two other bending portions along the first direction, and the stacking areas of all the bending portions form a stacking portion of the first pole tab, and the stacking portion abuts against and is welded to the first transition member.

9. The battery cell according to claim 8, characterized in that: In a projection plane perpendicular to the first direction, the orthographic projection of the first recessed portion is located within the orthographic projection of the stacked portion.

10. The battery cell according to claim 8, characterized in that: In the stacked portion, the maximum number of stacked layers of the bent portion is m, the total number of stacked tab layers is n, and 15%≤m / n≤30%.

11. The battery cell according to any one of claims 1 to 4, characterized in that: The first recess is formed on a side of the first adapter away from the first electrode tab along the first direction.

12. The battery cell according to any one of claims 1 to 4, characterized in that: There are a plurality of the first recesses and the first pole tabs, and each of the first pole tabs is welded to the bottom wall of the corresponding one or more first recesses.

13. The battery cell according to claim 12, characterized in that: The first adapter comprises a plurality of first protrusions, the plurality of first protrusions and the plurality of first tabs are arranged in one-to-one correspondence, two adjacent first protrusions are connected by at least a portion of the first adapter body, and the first adapter body and the first protrusions are both arranged on a side of the first tab away from the main body along the first direction; Along the direction from the first pole lug to the main body, the first protrusions extend beyond the first surface of the first adapter body facing the first pole lug, and each of the first protrusions abuts against a corresponding one of the first pole lugs; Each of the first protrusions is provided with at least one first concave portion on one side along the first direction.

14. The battery cell according to claim 13, characterized in that: A second recess is provided on a side of the first adapter facing away from the first pole ear. The second recess is arranged corresponding to the first protrusion, and the first recess is recessed from a bottom surface of the second recess.

15. The battery cell according to claim 13, characterized in that: The first convex portion includes a protruding body and a weakened portion, the weakened portion is arranged corresponding to the first concave portion, at least part of the weakened portion forms a bottom wall of the first concave portion, and the thickness of the protruding body is equal to the thickness of the first adapter body.

16. The battery cell according to claim 13, characterized in that: The thickness of the first adapter body is T, 0.5 mm≤T≤5 mm.

17. The battery cell according to claim 13, characterized in that: The first adapter includes a second convex portion, the second convex portion is arranged around the first concave portion, and the second convex portion protrudes from a surface of the first convex portion along the first direction.

18. The battery cell according to claim 17, characterized in that: The first concave portion and the second convex portion are both located on a side of the first convex portion facing away from the first pole lug, and the second convex portion protrudes from a second surface of the first convex portion facing away from the first pole lug along the first direction; Along the direction from the main body to the first electrode tab, the second protrusion does not extend beyond the surface of the first transfer body away from the electrode assembly.

19. The battery cell according to claim 13, characterized in that: The wall portion is located on one side of the electrode assembly along a third direction, and the first direction is perpendicular to the third direction; The first adapter includes a second adapter body. Along the third direction, the second adapter body is located between the electrode assembly and the wall portion and is connected to the first electrode terminal.

20. The battery cell according to claim 19, characterized in that: The first adapter includes a connecting portion, the first adapter body and the second adapter body are connected by the connecting portion, the projection of the connecting portion along the second direction is an arc, and the first direction, the second direction and the third direction are perpendicular to each other.

21. The battery cell according to claim 20, characterized in that: The connecting portion has an inner surface facing the electrode assembly, the projection of the inner surface along the second direction is an arc shape, the radius of the circle corresponding to the projection of the inner surface is r, and 0.2mm≤r≤20mm.

22. The battery cell according to any one of claims 1 to 4, characterized in that: The first adapter is an integrally formed structure.

23. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 22.

24. An electrical equipment, characterized in that: Comprising a battery device according to claim 23, the battery device is used to provide electrical energy.

Images