Battery monomer, battery device and electric equipment

Abstract

The invention discloses a battery monomer, a battery device and electric equipment. The battery cell includes a housing, a first electrode terminal, an electrode assembly, and a first adapter. The shell comprises a wall part; the first electrode terminal is arranged on the wall part; the electrode assembly is contained in the shell and comprises a main body part and a first tab, and at least part of the first tab protrudes out of the first end face of the main body part in 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, away from the main body part, of the first tab in the first direction and abuts against the first tab, a first concave part is arranged on the side, in the first direction, of the first adapter, and the bottom wall of the first concave part is welded to the first tab. The bottom wall of the first concave part is relatively thin, so that the first concave part can be conveniently welded with the first tab, the pseudo soldering risk is not easy to generate, the welding difficulty can be reduced, the requirement on the welding power is reduced, the risk of burning the main body part in the welding operation is reduced, and the reliability of the battery monomer is improved.

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 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 conducive to improving reliability.

[0005] According to a first aspect of the present application, a battery cell is provided, comprising a housing, a first electrode terminal, an electrode assembly, and a first adapter. The housing comprises a wall portion; the first electrode terminal is disposed on the wall portion; the electrode assembly is housed within the housing, the electrode assembly comprising a main body portion and a first tab, at least a portion of the first tab protruding from a first end face of the main body portion along a first direction. The 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 tab facing away from the main body portion along the first direction and abutting against the first tab. A first recess is provided on one side of the first adapter along the first direction, the bottom wall of the first recess being welded to the first tab. The first recess is recessed into the surface of the first adapter, and compared to the bottom wall of the first recess, at least another portion of the first adapter is relatively thicker, which is beneficial for improving the flow capacity. The bottom wall of the first recess is relatively thin, which facilitates welding to the first tab, is less likely to cause a cold weld, and can reduce the difficulty of welding and the welding power requirement, thereby reducing the risk of burning the main body during welding and improving the reliability of the battery cell.

[0006] In some embodiments, the first adapter is welded to the first tab to form a weld portion, and the weld portion is exposed on a side of the first adapter facing away from the first tab along the first direction. Thus, a penetration weld can be performed on the bottom wall of the first recess and the first tab from the side of the first adapter facing away from the first tab along the first direction, thereby forming the weld portion. This helps further reduce the difficulty of welding and the risk of burning the main body during the welding operation.

[0007] In some embodiments, the first adapter is welded to the first tab to form a weld, and the sidewall of the first recess is spaced apart from the weld. This reduces the likelihood of welding the first tab to a thicker portion of the first adapter due to welding tolerances, thereby reducing the risk of cold welds and improving weld strength and reliability.

[0008] In some embodiments, the minimum distance d between the sidewall of the first recess and the weld portion is 0.1 mm ≤ d ≤ 3 mm. When d is greater than or equal to 0.1 mm, the weld portion is not too close to the first recess, which helps reduce the risk of a cold weld. When d is less than or equal to 3 mm, the size of the first recess can be reduced, thereby reducing the adverse effects of the first recess on the structural strength and current carrying capacity of the first adapter.

[0009] In some embodiments, the first tab includes multiple tab layers, at least some of which include an extension and a bent portion. The extension is connected between the main body and the bent portion, and the bent portion is bent relative to the extension. Adjacent bent portions are stacked along a first direction, and the bent portions of at least some of the tab layers abut against and are welded to the first adapter. On the one hand, the multiple bent portions are stacked with a small gap between the stacking layers, which helps reduce the risk of a poor weld between the first adapter and the first tab. On the other hand, the extension can separate the bent portion and the main body by a certain distance in the first direction, which can reduce the welding heat transferred to the main body during the welding of the bent portion to the first adapter, thereby reducing the risk of burning the main body.

[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 being arranged along a second direction perpendicular to the first direction; along the second direction, the bent portions of the first tab layers bend toward the second tab layers, and the bent portions of the second tab layers bend toward the first tab layers. The bent portions of the first tab layers and the second tab layers bend toward each other, and the bending directions of the plurality of tab layers are relatively regular. The first tab is relatively compact and flat overall, which helps reduce interlayer gaps at the bent portions and improves the welding effect between the first tab and the first adapter.

[0011] In some embodiments, there are multiple first recesses, at least some of which are spaced apart along the second direction; at least some of the bent portions of the first tab layer and at least some of the bent portions of the second tab layer are welded to the bottom walls of different first recesses. This allows for multiple welds to be formed between the first tab and the first adapter, increasing the path for current flow, reducing internal resistance, and lowering the risk of connection failure between the first tab and the first adapter due to a cold weld at one of the welds. Furthermore, this reduces the maximum number of stacked bent portions of the multiple tab layers, thereby reducing the space occupied by the first tab in the first direction and facilitating increased energy density in the battery cell.

[0012] In some embodiments, the bent portion has a stacked region stacked with at least two other bent portions along a first direction. The stacked regions of all bent portions form the stacked portion of the first tab, which abuts against and is welded to the first adapter. As a result, the stacked portion has a relatively high structural strength and a relatively large thickness. The stacked portion is not easily penetrated during welding to the first adapter, which helps reduce heat transfer to the main body and reduces the risk of burns to the main body.

[0013] In some embodiments, within a projection plane perpendicular to the first direction, the orthographic projection of the first recess lies within the orthographic projection of the stacked portion. Thus, each region of the first tab corresponding to the bottom wall of the first recess has at least three layers of bends, which reduces the likelihood of the first adapter being welded to portions of the first tab other than the stacked portion, thereby reducing the risk of cold solder joints or welding through the first tab.

[0014] In some embodiments, in the stacked portion, the maximum number of stacked bend portions is m, the total number of tab layers is n, and 15% ≤ m / n ≤ 30%. When m / n is greater than or equal to 15%, the stacked portion has relatively greater structural strength and thickness, which helps reduce the risk of welding through the stacked portion and burning the main body. When m / n is less than or equal to 30%, the stacked portion is not excessively large along the first direction, which helps reduce the space occupied by the first tab in the first direction and improve the energy density of the battery cell.

[0015] In some embodiments, the first recess is formed on a side of the first adapter that faces away from the first tab along the first direction. Thus, while still meeting welding requirements, the size of the first recess can be reduced, thereby minimizing the impact 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 tabs, and each first tab is welded to the bottom wall of one or more corresponding first recesses. This facilitates the bending operation of the first tab, reduces the difficulty of bending the first tab, and improves the tightness and flatness of the bent first tab.

[0017] In some embodiments, the first adapter includes a first adapter body and a plurality of first protrusions, wherein the plurality of first protrusions and the plurality of first tabs are arranged in a one-to-one correspondence, and two adjacent first protrusions are connected by at least a portion of the first adapter body. The first adapter body and the first protrusions are both arranged on a side of the first tab facing away from the main body along a first direction. In the direction from the first tab to the main body, the first protrusions extend beyond a first surface of the first adapter body facing the first tab, and each first protrusion abuts against a corresponding first tab. Each first protrusion is provided with at least one first recess on one side along the first direction, and the thickness of the bottom wall of the first recess is less than the thickness of the first adapter body. Thus, by appropriately deforming the first adapter body, each first tab can be tightly abutted against the corresponding first protrusion, thereby improving the welding effect between the first tab and each first protrusion and reducing the risk of connection failure between the first tab and the first protrusion due to cold welding.

[0018] In some embodiments, a second recess is provided on a side of the first adapter facing away from the first tab. The second recess corresponds to the first recess, and the first recess is recessed from the bottom surface of the second recess. This can appropriately reduce the thickness of the first recess, reduce the weight of the first recess, and reduce the space occupied by the first recess along the first direction.

[0019] In some embodiments, the first protrusion includes a protruding body and a weakened portion. The weakened portion is disposed correspondingly to the first recess, and at least a portion of the weakened portion forms the bottom wall of the first recess. The thickness of the protruding body is equal to the thickness of the first adapter body. Thus, the thickness of the protruding body is neither too thick to occupy excessive space nor too thin to affect flow.

[0020] In some embodiments, the thickness of the first adapter body is T, 0.5 mm ≤ T ≤ 5 mm. When T is greater than or equal to 0.5 mm, the thickness of the first adapter body is not too thin to affect its current carrying capacity, which helps reduce heat generation and the internal resistance of the battery cell. When T is less than or equal to 5 mm, the thickness of the first adapter body is not too thick, which can reduce the space occupied by the first adapter body, which helps increase 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 protrusion disposed around the first recess and projecting beyond a surface of the first protrusion along the first direction. The second protrusion can enhance the overall strength of the first adapter around the first recess, thereby reducing the impact of the first recess on the overall strength of the first adapter.

[0022] In some embodiments, the first recess and the second protrusion are both located on the side of the first protrusion facing away from the first tab. The second protrusion protrudes in the first direction beyond the second surface of the first protrusion facing away from the first tab. Along the direction from the main body toward the first tab, the second protrusion does not extend beyond the surface of the first adapter body facing away from the electrode assembly. This allows the space in the second recess to accommodate the second protrusion, reducing the additional space occupied by the second protrusion in the first direction, thereby improving space utilization and increasing the energy density of the battery cell.

[0023] In some embodiments, the wall portion is located on one side of the electrode assembly along the 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, connecting the first adapter body and the second adapter body via the connecting portion. The projection of the connecting portion along the second direction is an arc, and the first, second, and third directions are perpendicular to each other. The arc-shaped connecting portion helps reduce the possibility of cracking or splitting during the bending process of the first adapter.

[0025] In some embodiments, the connection portion has an inner surface facing the electrode assembly, the projection of the inner surface along the second direction being an arc, and the radius of the circle corresponding to the projection of the inner surface being r, where 0.2 mm ≤ r ≤ 20 mm. When r is greater than or equal to 0.2 mm, the inner side of the connection portion is less likely to form an angle, thereby reducing the risk of cracking or fissures in the connection portion. When r is less than or equal to 20 mm, the connection portion is not excessively large, thereby reducing the space required for arranging the connection portion, reducing space waste within the battery cell, and thereby improving the energy density of the battery cell.

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

[0027] According to a second aspect of the present application, the present application provides a battery device comprising a plurality of battery cells provided according to any embodiment of the first aspect.

[0028] According to a third aspect of the present application, the present application provides an electrical device, which includes a battery device provided according to any embodiment 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 exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0030] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application; Figure 2A schematic diagram of the exploded structure of a battery device provided in some embodiments of the present application; Figure 3 A schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application; Figure 4 for Figure 3 A schematic cross-sectional view of a battery cell shown; Figure 5 for Figure 4 Schematic diagram of the enlarged structure of area A in the middle; Figure 6 for Figure 3 A schematic structural diagram of the first adapter of the battery cell shown; Figure 7 for Figure 3 A schematic structural diagram of the electrode assembly and the first adapter of the battery cell after welding; Figure 8 for Figure 7 Schematic diagram of the enlarged structure of the middle area B; Figure 9 for Figure 3 A schematic front view of the first adapter of the battery cell shown; Figure 10 for Figure 9 Schematic diagram of the enlarged structure of area C in the middle.

[0031] The reference numerals of the specific embodiments are as follows: Vehicle 1, controller 3, motor 4, battery device 2; Box body 5, first box body part 5a, second box body part 5b, accommodating space 5c; Battery cell 6, electrode assembly 10, main body 11, first end face 11a, second end face 11b, first electrode tab 12, electrode tab layer 121, extension portion 1211, bend portion 1212, stacking region 1212a, first electrode tab layer 121a, second electrode tab layer 121b, third electrode tab layer 121c, stacking portion 122, second electrode tab 13, outer shell 20, housing 21, wall portion 211, end cap 22, first electrode terminal 31, second electrode terminal 32, first adapter 40, First recess 41, first adapter body 42, adapter portion 421, first surface 42a, third surface 42b, first protrusion 43, protruding body 431, weak portion 432, second surface 43a, second recess 44, bottom surface 44a, second protrusion 45, second adapter 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 DESCRIPTION

[0032] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0034] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0036] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0037] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0038] The term "plurality" used in this application refers to two or more (including two).

[0039] 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.

[0040] In the embodiment of the present application, the battery cell may be a secondary battery cell. A secondary battery cell refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0041] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present application are not limited to this.

[0042] A battery cell generally consists of an electrode assembly, a casing, and electrode terminals. The electrode assembly is housed within the casing, and the electrode terminals are located within the casing. The casing encapsulates the electrode assembly and other components, including the electrolyte. The electrode assembly includes tabs, which are electrically connected to the electrode terminals via adapters or directly. The electrode terminals serve to electrically connect the electrode assembly to circuits external to the battery cell, enabling charging or discharging of the battery cell.

[0043] The electrode assembly consists of a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator is placed between the positive and negative electrodes to prevent short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0044] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0045] In some embodiments, the negative electrode may be a negative electrode sheet, which 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.

[0046] In some embodiments, a separator is disposed between the positive electrode and the negative electrode.

[0047] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0048] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0049] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0050] In some embodiments, the electrode assembly is a laminate structure.

[0051] 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 multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0052] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0053] A battery device generally includes a housing for enclosing one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0054] As an example, a battery cell assembly may be a battery module, which is composed of multiple battery cells arranged and fixed to form an independent module. As an example, a battery module may be formed by bundling multiple battery cells with cable ties. The battery cell assembly may be housed in a case by securing the battery module within the case. As an example, the case may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, forming an enclosed space within the case to accommodate the battery cell assembly.

[0055] 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.

[0056] In some embodiments, the battery device may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0057] In a battery cell, the electrode assembly and the electrode terminal are usually electrically connected through an adapter. The adapter is welded to the electrode terminal and the electrode assembly's tab and acts as an intermediate overcurrent. In order to meet the overcurrent requirements, the thickness of the adapter cannot usually be too thin. However, if the thickness of the adapter is thicker, a higher welding power is required between the adapter and the tab to reduce the risk of cold welding. For tabs formed by flattening or smoothing, the tabs are close to the separator. When the welding power between the tabs and the adapter is high, 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.

[0058] In view of this, an embodiment of the present application provides a technical solution, wherein at least a portion of a first adapter is disposed on a side of the first tab facing away from the main body along a first direction, abutting against the first tab, and a first recess is provided on one side of the first adapter along the first direction, with the bottom wall of the first recess welded to the first tab. Compared to the bottom wall of the first recess, at least another portion of the first adapter is relatively thicker, which helps improve current flow capacity. The bottom wall of the first recess is relatively thin, which facilitates welding to the first tab, reduces the risk of cold welding, and reduces the welding power requirement, which helps reduce the risk of burning the main body during welding and improves the reliability of the battery cell.

[0059] The technical solutions provided in the embodiments of the present application are applicable to battery cells, battery devices, and electrical equipment using the battery devices.

[0060] The battery device disclosed in the embodiments of the present application can be used in various energy storage systems that use the battery device as a power source or use the battery device as an energy storage element. The power-consuming device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0061] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0062] Figure 1 Schematic diagram of the structure of the vehicle provided by some embodiments of the present application. 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, or an extended-range vehicle. A battery device 2 is provided inside vehicle 1. Battery device 2 can be located at the bottom, head, or tail of vehicle 1. Battery device 2 can be used to power vehicle 1. For example, battery device 2 can serve as an operating power source for vehicle 1. Vehicle 1 can also include a controller 3 and a motor 4. Controller 3 is used to control battery device 2 to power motor 4, for example, to meet the power requirements of vehicle 1 during startup, navigation, and driving.

[0063] In some embodiments of the present application, the battery device 2 can serve not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0064] Figure 2 Schematic diagram of the exploded structure of the battery device provided in some embodiments of the present application. Figure 2The battery device 2 includes a housing 5 and a battery cell 6, and the battery cell 6 is accommodated in the housing 5. The housing 5 is used to provide a storage space for the battery cell 6, and the housing 5 can adopt various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b, and the first housing portion 5a and the second housing portion 5b cover each other, and the first housing portion 5a and the second housing portion 5b jointly define a storage space 5c for accommodating the battery cell 6. The second housing portion 5b can be a hollow structure with one end open, and the first housing portion 5a can be a plate-shaped structure, and the first housing portion 5a covers the open side of the second housing portion 5b, so that the first housing portion 5a and the second housing portion 5b jointly define the storage space 5c; the first housing portion 5a and the second housing portion 5b can also be hollow structures with one side open, and the open side of the first housing portion 5a covers the open side of the second housing portion 5b. Of course, the box body 5 formed by the first box body portion 5a and the second box body portion 5b can be in various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0065] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0066] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0067] In the battery device 2, there may be multiple battery cells 6, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections within the battery cells 6. Multiple battery cells 6 may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery unit 6 is housed within the housing 5. Alternatively, the battery device 2 may comprise multiple battery cells 6 that are first connected in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single unit housed within the housing 5. The battery device 2 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 6.

[0068] For example, the battery cell 6 may be the smallest unit constituting the battery device 2 .

[0069] Figure 3 Schematic diagram of the exploded structure of the battery cell provided in some embodiments of the present application. Figure 3 The battery cell 6 includes a housing 20 and an electrode assembly 10 , and the electrode assembly 10 is disposed in the housing 20 .

[0070] The housing 20 is used to encapsulate the electrode assembly 10 and the electrolyte and other components. The housing 20 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0071] In some embodiments, the housing 20 is a hollow structure, and a space is formed inside the housing to accommodate the electrode assembly 10 and the electrolyte. 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 rectangular parallelepiped structure, a rectangular housing can be used.

[0072] The housing 20 can be made of a variety of materials, for example, metal or plastic. Alternatively, the housing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the housing 20 can be made of steel, aluminum, plastic (e.g., polypropylene), composite metal (e.g., copper-aluminum composite), or aluminum-plastic film.

[0073] As an example, the housing 20 includes a shell 21 and an end cover 22 . The shell 21 has an opening, and the end cover 22 is used to cover the opening.

[0074] The housing 21 is a component used to cooperate with the end cover 22 to form an internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0075] The housing 21 and the end cap 22 may be separate components. For example, an opening may be provided on the housing 21 , and the end cap 22 may be placed over the opening to form an internal cavity of the battery cell 6 .

[0076] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from that of the housing 21.

[0077] The end cover 22 can be connected to the housing 21 by welding, bonding, clamping or other methods.

[0078] The housing 21 may be open at one end or at both ends. For example, the housing 21 is open at one end, and a single end cap 22 is provided to cover the opening of the housing 21. As another example, the housing 21 may be open at both ends, and two end caps 22 are provided, each of which covers the two openings of the housing 21.

[0079] Figure 4 for Figure 3 A schematic cross-sectional view of a battery cell is shown, Figure 5 for Figure 4 Schematic diagram of the enlarged structure of area A in the middle. Figure 6 for Figure 3 The schematic structural diagram of the first adapter of the battery cell shown in FIG. Figure 7 for Figure 3 The schematic diagram of the structure of the battery cell electrode assembly and the first adapter 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 the first adapter of the battery cell shown, Figure 10 for Figure 9 Schematic diagram of the enlarged structure of area C in the middle.

[0080] 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 arranged 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 tab 12, and at least a portion of the first pole tab 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 arranged on a side of the first pole tab 12 away from the main body 11 along the first direction X, and is against the first pole tab 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 tab 12.

[0081] The wall portion 211 may be the end cover 22 or one of the walls of the housing 21 .

[0082] In some examples, the first electrode tab 12 may be a positive electrode tab, and accordingly, the first electrode terminal 31 may be a positive electrode terminal. In other examples, the first electrode tab 12 may be a negative electrode tab, and accordingly, the first electrode terminal 31 may be a negative electrode terminal.

[0083] There may be one or more first electrode tabs 12 .

[0084] The first tab 12 may entirely protrude from the first end surface 11 a of the main body 11 , or only a portion of the first tab 12 may protrude from the first end surface 11 a of the main body 11 , while the other portion of the first tab 12 may be inserted into the main body 11 .

[0085] The first adapter 40 can be connected to the first electrode terminal 31 by welding, bonding, or other suitable means. Optionally, the first adapter 40 is welded to the first electrode terminal 31 by laser welding, ultrasonic welding, or other suitable welding means to improve the connection strength and stability between the first adapter 40 and the first electrode terminal 31.

[0086] The first adapter 40 can be arranged as a whole on the side of the first pole tab 12 away from the main body 11; or only a part of the first adapter 40 can be arranged on the side of the first pole tab 12 away from the main body 11, and the other part of the first adapter 40 can be arranged between the main body 11 and the wall 211 along the third direction Z, and the third direction Z is perpendicular to the first direction X.

[0087] At least a portion of the first adapter 40 located on the side of the first pole tab 12 away from the main body 11 can abut against the first pole tab 12, that is, at least a portion of the first adapter 40 located on the side of the first pole tab 12 away from the main body 11 abuts against and directly contacts the first pole tab 12, which can reduce the gap between the first adapter 40 and the first pole tab 12 and improve the welding quality between the two.

[0088] In some examples, the first recess 41 may be formed on a side of the first adapter 40 facing away from the first tab 12 along the first direction X. The first recess 41 is recessed into a surface of the first adapter 40 facing away from the first tab 12. The first tab 12 may abut against a surface of the first adapter 40 facing the first tab 12.

[0089] In other examples, the first recess 41 may also be formed on a side of the first adapter 40 facing the first tab 12 along the first direction X. The first recess 41 is recessed in the surface of the first adapter 40 facing the first tab 12. At least a portion of the first tab 12 is accommodated in the first recess 41 and abuts against the bottom surface of the first recess 41.

[0090] Along the first direction X, the projection of the first recess 41 may be circular, rectangular, or other suitable shapes.

[0091] The bottom wall of the first recess 41 refers to the portion 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 the portion of the first adapter 40 corresponding to the first recess 41 forms the bottom wall of the first recess 41 .

[0092] The first recess 41 may be formed by stamping, machining or other suitable processes.

[0093] The first recess 41 is recessed in the surface of the first adapter 40. Compared with the bottom wall of the first recess 41, at least other parts of the first adapter 40 are relatively thick, which is beneficial to improving the current flow capacity; the bottom wall of the first recess 41 is relatively thin, which is convenient for welding with the first pole ear 12, 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.

[0094] In some embodiments, the first adapter 40 and the first tab 12 are welded to form a welding portion 50 . The welding portion 50 is exposed on a side of the first adapter 40 along the first direction X away from the first tab 12 .

[0095] The number of the welding portion 50 may be one or more.

[0096] 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 compatible with the projection shape of the first recess 41 .

[0097] 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 .

[0098] The weld portion 50 is exposed on the side of the first adapter 40 that is away from the first tab 12 along the first direction X. This means that the weld portion 50 can be exposed from the side of the first adapter 40 that is away from the first tab 12 along the first direction X. Thus, through-welding can be performed on the bottom wall of the first recess 41 and the first tab 12 from the side of the first adapter 40 that is away from the first tab 12 along the first direction X, thereby forming the weld portion 50. This helps to further reduce the difficulty of welding and the risk of burning the main body 11 during the welding operation.

[0099] In some embodiments, the first adapter 40 and the first tab 12 are welded to form a welding portion 50 , and a sidewall of the first recess 41 is spaced apart from the welding portion 50 .

[0100] The sidewall 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 sidewall of the first recess 41 can 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.

[0101] The first recess 41 may have one or more side walls.

[0102] In some examples, the projection of the first recess 41 along the first direction X may be rectangular, and the first recess 41 may have four sequentially connected sidewalls. In other examples, the projection of the first recess 41 along the first direction X may be circular, and the first recess 41 may have an annular sidewall.

[0103] Each sidewall of the first recess 41 is spaced apart from the welding portion 50. In other words, each sidewall 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 sidewall of the first recess 41 do not overlap. This reduces the possibility of welding between the first tab 12 and the thicker portion of the first adapter 40 due to welding tolerances, thereby reducing the risk of cold welding and improving welding strength and reliability.

[0104] In some embodiments, the minimum distance between the sidewall of the first recess 41 and the welding portion 50 is d, and 0.1 mm≤d≤3 mm.

[0105] The weld portion 50 may have a regular or irregular outer contour, and the vertical distances between various regions of the outer contour of the weld portion 50 and the corresponding sidewalls of the first recess 41 may vary. The minimum distance between the sidewall of the first recess 41 and the weld portion 50 refers to the minimum value of the vertical distances between various regions of the outer contour of the weld portion 50 and the corresponding sidewalls of the first recess 41, that is, the vertical distance between the portion of the weld portion 50 closest to the sidewall of the first recess 41 and that sidewall.

[0106] Optionally, d can 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 in between any two of them.

[0107] In the embodiment 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 cold welding; in the embodiment 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 flow capacity of the first adapter 40.

[0108] In some embodiments, the first tab 12 includes multiple tab layers 121, and at least some of the tab layers 121 include an extension portion 1211 and a bent portion 1212. The extension portion 1211 is connected between the main body 11 and the bent portion 1212, and the bent portion 1212 is bent relative to the extension portion 1211. 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 and are welded to the first adapter 40.

[0109] Each tab layer 121 may include an extension 1211 and a bend 1212, or only some of the tab layers 121 may include the extension 1211 and the bend 1212, while the remaining tab layers 121 may include only the extension 1211. Exemplarily, the electrode assembly 10 has a wound structure, with the outer multi-turn tab layer 121 including the extension 1211 and the bend 1212, and the inner multi-turn tab layer 121 including only the extension 1211. Alternatively, tab layers 121 having both the extension 1211 and the bend 1212 and tab layers 121 having only the extension 1211 may be alternately arranged in the arrangement direction of the multiple tab layers 121.

[0110] The extension portion 1211 is a portion of the tab layer 121 that is directly connected to the main body 11. Optionally, the extension portion 1211 may extend along the first direction X.

[0111] The bent portion 1212 is connected to the protruding portion 1211 and is bent relative to the protruding 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 that the bent portions 1212 of adjacent tab layers 121 are stacked along the first direction X.

[0112] The bent portions 1212 of adjacent tab layers 121 are stacked along the first direction X. This means that the projections of the bent portions 1212 of adjacent tab layers 121 along the first direction X at least partially overlap, and the overlapping portions of the bent portions 1212 of adjacent tab layers 121 are in direct contact with each other. Adjacent tab layers 121 can be connected to each other through the stacking of the bent portions 1212.

[0113] The bent portions 1212 of the multiple tab layers 121 can be staggered along the arrangement direction of the multiple tab layers 121, so that the bent portions 1212 of the multiple tab layers 121 can directly abut against the first adapter 40, thereby being directly connected to the first adapter 40, which is beneficial to increase the current flow path.

[0114] At least part of the bent portion 1212 of the tab layer 121 is welded to the first adapter 40 . The portion of the bent portion 1212 welded to 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 .

[0115] Optionally, the extension portion 1211 of each tab layer 121 is not welded to the first adapter 40 .

[0116] In the embodiment of the present application, at least a portion of the tab layer 121 is configured to have a protruding portion 1211 and a bent portion 1212, and the first adapter 40 is welded to the bent portion 1212 of at least a portion of the tab layer 121. On the one hand, multiple bent portions 1212 are stacked with a small stacking gap, which is beneficial to reducing the risk of poor welding between the first adapter 40 and the first tab 12; on the other hand, the protruding portion 1211 can space the bent portion 1212 and the main body 11 by a certain distance in the first direction X, which can reduce the welding heat transferred to the main body 11 during the welding process of the bent portion 1212 and the first adapter 40, thereby reducing the risk of burning the main body 11.

[0117] In some embodiments, the plurality of tab layers 121 include a plurality of first tab layers 121 a and a plurality of second tab layers 121 b , and the plurality of first tab layers 121 a and the plurality of second tab layers 121 b are arranged along a second direction Y, where the second direction Y is perpendicular to the first direction X. The bent portion 1212 of the first tab layer 121 a bends along the second direction Y toward the second tab layer 121 b , and the bent portion 1212 of the second tab layer 121 b bends along the second direction Y toward the first tab layer 121 a .

[0118] 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 .

[0119] The plurality of first tab layers 121 a and the plurality of second tab layers 121 b may be spaced apart along the second direction Y. Optionally, the plurality of tab layers 121 further include a plurality of third tab layers 121 c, which are located between the plurality of first tab layers 121 a and the plurality of second tab layers 121 b along the second direction Y. The third tab layer 121 c may include only the protruding portion 1211.

[0120] Each first tab layer 121 a includes a protruding portion 1211 and a bent portion 1212 , and the bent portions 1212 of the first tab layers 121 a have the same bending trend.

[0121] Each second tab layer 121 b includes a protruding portion 1211 and a bent portion 1212 , and the bent portions 1212 of the plurality of second tab layers 121 b have the same bending trend.

[0122] In some examples, the bent portion 1212 of a portion of the first tab layer 121a and the bent portion 1212 of a portion of the second tab layer 121b may overlap along the first direction X. In other examples, the bent portion 1212 of the first tab layer 121a and the bent portion 1212 of the second tab layer 121b do not overlap in the first direction X.

[0123] At least a portion 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 weld portion 50, and at least a portion 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 weld portion 50. The weld portion 50 formed by welding the first tab layer 121a to the first adapter 40 and the weld portion 50 formed by welding the second tab layer 121b to the first adapter 40 may be directly connected or not directly connected.

[0124] The bending portion 1212 of the first tab layer 121a and the bending portion 1212 of the second tab layer 121b are bent toward each other. The bending directions of the multiple tab layers 121 are relatively regular, and the first tab 12 is relatively compact and flat as a whole, which is beneficial to reducing the inter-layer gap of the bending portion 1212 and improving the welding effect between the first tab 12 and the first adapter 40.

[0125] In some embodiments, there may be a plurality of first recesses 41 , and at least some of the plurality of first recesses 41 are spaced apart along the second direction Y. At least some of the bent portions 1212 of the first tab layer 121 a and at least some of the bent portions 1212 of the second tab layer 121 b are welded to the bottom walls of different first recesses 41 .

[0126] Optionally, in a projection plane perpendicular to the first direction X, the orthographic projection of the first tab layer 121 a and the orthographic projection of the second tab layer 121 b do not overlap.

[0127] Optionally, the two first recesses 41 are spaced apart along the second direction Y. At least a portion 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 portion of the bent portion 1212 of the second tab layer 121b is welded to the bottom wall of the other first recess 41. The welded portion 50 formed by welding the first tab layer 121a and the first adapter 40 is not directly connected to the welded portion 50 formed by welding the second tab layer 121b and the first adapter 40.

[0128] The first pole tab layer 121a can be welded to the first adapter 40 separately, and the second pole tab layer 121b can be welded to the first adapter 40 separately. On the one hand, multiple welding parts 50 can be formed between the first pole tab 12 and the first adapter 40, which increases the flow path of current, helps to reduce internal resistance, and reduces the risk of connection failure between the first pole tab 12 and the first adapter 40 due to a cold weld in one of the welding parts 50; on the other hand, it can also reduce the maximum number of stacked layers of the bending parts 1212 of the multiple pole tab layers 121, thereby reducing the space occupied by the first pole tab 12 in the first direction X, which is beneficial to improving the energy density of the battery cell 6.

[0129] In some embodiments, the bending portion 1212 has a stacking area 1212a stacked with at least two other bending portions 1212 along the first direction X. The stacking areas 1212a of all the bending portions 1212 form the stacking portion 122 of the first tab 12. The stacking portion 122 abuts against and is welded to the first adapter 40.

[0130] Along the first direction X, the projection of the stacking region 1212a of each bending portion 1212 overlaps with the projections of at least two other bending portions 1212. In other words, any region of the stacking portion 122 has at least three layers stacked along the first direction X.

[0131] The number of layers of the bending portion 1212 of the stacking portion 122 is greater than or equal to 3. The stacking portion 122 has a relatively high structural strength and a relatively large thickness. The stacking portion 122 and the first adapter 40 are not easily welded through during welding, which is beneficial to reducing the heat transferred to the main body 11 and reducing the risk of the main body 11 being burned.

[0132] In some embodiments, within a projection plane perpendicular to the first direction X, the orthographic projection of the first recess 41 is located within the orthographic projection of the laminated 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 reduces the likelihood of the first adapter 40 being welded to portions of the first tab 12 other than the laminated portion 122, thereby reducing the risk of cold solder joints or welding through the first tab 12.

[0133] In some embodiments, within a projection plane perpendicular to the first direction X, the orthographic projection of the laminated portion 122 exceeds the orthographic projection of the first recessed portion 41. In other words, the projected area of ​​the laminated portion 122 is larger than the projected area of ​​the first recessed portion 41, and the projection of the laminated portion 122 covers the projection of the first recessed portion 41. Thus, the laminated portion 122 has a relatively large area, which can accommodate relative positional variations between the first tab 12 and the first adapter 40 due to manufacturing and assembly tolerances, thereby reducing the possibility of affecting the welding effect between the first tab 12 and the first adapter 40.

[0134] In some embodiments, in the stacking portion 122 , the maximum number of stacked layers of the bending portion 1212 is m, the total number of layers of the tab layer 121 is n, and 15%≤m / n≤30%.

[0135] Optionally, m / n may be 15%, 16%, 17%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, or any other value therebetween.

[0136] In the embodiment of the present application, m / n is set to be greater than or equal to 15%. This provides the laminate portion 122 with relatively greater structural strength and thickness, which helps reduce the risk of the laminate portion 122 being welded through and damaging the main body 11. In the embodiment of the present application, m / n is set to be less than or equal to 30%. This prevents the laminate portion 122 from being excessively large along the first direction X, which helps reduce the space occupied by the first tab 12 in the first direction X and improves the energy density of the battery cell 6.

[0137] In some embodiments, the first recess 41 is formed on a side of the first adapter 40 that is away from the first tab 12 along the first direction X.

[0138] If the first recess 41 is provided on a side of the first adapter 40 facing the first tab 12 along the first direction X, the first tab 12 abuts against the bottom surface of the first recess 41 . The first recess 41 requires a relatively large space to accommodate at least a portion of the first tab 12 to reduce interference between the first tab 12 and the first adapter 40 .

[0139] In the embodiment of the present application, the first recess 41 is arranged on the side of the first adapter 40 away from the first pole tab 12 along the first direction X. The first pole tab 12 can be abutted against the surface of the first adapter 40 facing the first pole tab 12 along the first direction X. On the premise of meeting the welding requirements, the size of the first recess 41 can be reduced, which is conducive to reducing the impact of the setting of the first recess 41 on the structural strength and flow area of ​​the first adapter 40.

[0140] In some embodiments, there are multiple first recesses 41 and multiple first electrode tabs 12 , and each first electrode tab 12 is welded to the bottom wall of one or more corresponding first recesses 41 .

[0141] In some examples, the first recesses 41 and the first tabs 12 are arranged in a one-to-one correspondence, and the first tab 12 is welded to the bottom wall of a corresponding first recess 41 .

[0142] In other examples, the first recesses 41 and the first tabs 12 are arranged in a many-to-one correspondence, and the first tabs 12 are welded to the bottom walls of the corresponding first recesses 41 .

[0143] Optionally, there may be two first electrode tabs 12 . The two first electrode tabs 12 may be arranged along the third direction Z. Accordingly, there are at least two first recesses 41 .

[0144] Optionally, the multiple first tab layers 121 a of each first tab 12 may be welded to the bottom wall of one first recess 41 , and the multiple second tab layers 121 b of each first tab 12 may be welded to the bottom wall of another first recess 41 .

[0145] In the embodiment of the present application, a plurality of first electrode tabs 12 and a plurality of first recesses 41 are provided to facilitate the bending operation of the first electrode tab 12 , reduce the difficulty of bending the first electrode tab 12 , and improve the firmness and flatness of the first electrode tab 12 after bending.

[0146] 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 are disposed in a one-to-one correspondence with the plurality of first tabs 12 . Both the first adapter body 42 and the first protrusions 43 are disposed on a side of the first tab 12 facing away from the main body 11 along the first direction X. Along the direction from the first tab 12 to the main body 11 , the first protrusions 43 extend beyond a first surface 42a of the first adapter body 42 facing the first tab 12 , and each first protrusion 43 abuts against a corresponding first tab 12 . Each first protrusion 43 is provided with at least one first recess 41 on one side along the first direction X. The bottom wall of the first recess 41 is thinner than the thickness of the first adapter body 42 .

[0147] 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 .

[0148] In some other examples, the first transition body 42 includes a plurality of transition portions 421 arranged at intervals. Two adjacent transition portions 421 are connected by a first protrusion 43.

[0149] 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 alternately arranged.

[0150] In some examples, the first recess 41 may be provided on a side of the first protrusion 43 facing away from the first tab 12, and the first tab 12 abuts against the surface of the corresponding first protrusion 43 facing the first 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 tab 12, and the first tab 12 abuts against the bottom wall of the corresponding first recess 41 along the first direction X.

[0151] 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.

[0152] The first protrusion 43 may include the bottom wall of the first recess 41 and other portions connected to the bottom wall of the first recess 41. The other portions of the first protrusion 43 may have a uniform thickness or a unequal thickness. The average thickness of the other portions of the first protrusion 43 may be the same as or different from the thickness of the first adapter body 42.

[0153] The first adapter body 42 is thicker than the bottom wall of the first recess 41 , which is beneficial for improving the current flow capacity of the first adapter 40 and reducing the internal resistance of the battery cell 6 .

[0154] Due to manufacturing tolerances, the dimensions of the multiple first tabs 12 protruding from the first end surface 11a along the first direction X may be different. If the multiple first tabs 12 abut against the straight first adapter 40, some of the first tabs 12 and the first adapter 40 may have poor contact or a small contact surface, affecting the welding effect between the first tabs 12 and the first adapter 40.

[0155] In the embodiment of the present application, a plurality of first protrusions 43 are respectively provided corresponding to the plurality of first pole tabs 12. By connecting two adjacent first protrusions 43 through at least a portion of the first adapter body 42, the first adapter body 42 can be appropriately deformed so that each first pole tab 12 is tightly abutted against the corresponding first protrusion 43, which is beneficial to improving the welding effect between the first pole tab 12 and each first protrusion 43 and reducing the risk of connection failure between the first pole tab 12 and the first protrusion 43 due to cold welding.

[0156] In some embodiments, a second recess 44 is defined on a side of the first adapter 40 facing away from the first tab 12 . The second recess 44 corresponds to the first protrusion 43 , and the first recess 41 is recessed from a bottom surface 44 a of the second recess 44 .

[0157] The second recess 44 can be recessed in the third surface 42 b of the first adapter body 42 facing away from the first tab 12 . A first protrusion 43 is formed on the portion of the first adapter 40 along the first direction X corresponding to the second recess 44 .

[0158] The first recess 41 may be formed on a side of the first adapter 40 facing away from the first tab 12 . The first recess 41 is recessed into the bottom surface 44 a toward the first tab 12 .

[0159] Optionally, along the first direction X, the dimension of the first recess 41 sunken into the bottom surface 44 a may be the same as the dimension of the first protrusion 43 protruding from the first surface 42 a , so that the thickness of the first protrusion 43 is the same as the thickness of the first adapter body 42 .

[0160] In the embodiment of the present application, by providing the second concave portion 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 along the first direction X can be reduced.

[0161] In some embodiments, the first protrusion 43 includes a protruding body 431 and a weak portion 432. The weak portion 432 is arranged corresponding to the first recess 41. At least part of the weak portion 432 forms the bottom wall of the first recess 41. The thickness of the protruding body 431 is equal to the thickness of the first adapter body 42.

[0162] Optionally, the protruding body 431 may be a structure of uniform thickness.

[0163] In some examples, the cross-sectional shape of the first recess 41 perpendicular to the third direction Z may be a rectangle, and the weak portion 432 integrally forms the bottom wall of the first recess 41 .

[0164] In other examples, the cross-sectional shape of the first recess 41 perpendicular to the third direction Z may be a trapezoid, a portion of the weak portion 432 forms the bottom wall of the first recess 41 , and another portion of the weak portion 432 forms the side wall of the first recess 41 .

[0165] The thickness of the protruding body 431 is equal to the thickness of the first adapter body 42 . The thickness of the protruding body 431 is not too large to occupy too much space, nor is it too small to affect the flow.

[0166] In some embodiments, the thickness of the first adapter body 42 is T, and 0.5 mm ≤ T ≤ 5 mm.

[0167] 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 therebetween.

[0168] In the embodiment of the present application, T is set to be greater than or equal to 0.5 mm. This prevents the thickness of the first adapter body 42 from being too small to affect its current carrying capacity, thereby reducing heat generation and lowering the internal resistance of the battery cell 6. In the embodiment of the present application, T is set to be less than or equal to 5 mm. This prevents the thickness of the first adapter body 42 from being too large, thereby reducing the space occupied by the first adapter body 42, thereby improving the energy density of the battery cell 6 and reducing the weight of the battery cell 6.

[0169] In some embodiments, the first adapter 40 includes a second protrusion 45 . The second protrusion 45 is disposed around the first recess 41 . The second protrusion 45 protrudes from a surface of the first protrusion 43 along the first direction X.

[0170] Alternatively, the first concave portion 41 may be formed by a stamping process. During the stamping process, a portion of material corresponding to the first concave portion 41 is extruded to the periphery of the first concave portion 41 , and the second convex portion 45 may be formed by solidifying the extruded material during the stamping process.

[0171] Along the first direction X, the first recess 41 and the second protrusion 45 may be located on the same side of the first protrusion 43. In some examples, the first recess 41 and the second protrusion 45 are both located on the side of the first protrusion 43 facing away from the first electrode tab 12. In other examples, the first recess 41 and the second protrusion 45 are both located on the side of the first protrusion 43 facing the first electrode tab 12.

[0172] The second protrusion 45 is disposed around the first recess 41 . The second protrusion 45 can enhance the overall strength of the first adapter 40 around the first recess 41 and reduce the influence of the first recess 41 on the overall strength of the first adapter 40 .

[0173] In some embodiments, the first recess 41 and the second protrusion 45 are both located on the side of the first protrusion 43 facing away from the first electrode tab 12 , and the second protrusion 45 protrudes from a second surface 43 a of the first protrusion 43 facing away from the first electrode tab 12 along the first direction X. Along the direction from the main body 11 toward the first electrode tab 12 , the second protrusion 45 does not extend beyond the surface of the first adapter body 42 facing away from the electrode assembly 10 . In other words, the second protrusion 45 can be entirely accommodated within the second recess 44 and does not extend outside the second recess 44 .

[0174] The second protrusion 45 is located on the side of the first protrusion 43 facing away from the first electrode tab 12 . The first protrusion 43 and the second protrusion 45 protrude in opposite directions along the first direction X, which helps to reduce the space occupied by the first protrusion 43 and the second protrusion 45 in the first direction X.

[0175] The second protrusion 45 does not extend beyond the first adapter body 42 , and the space of the second recess 44 can be used to accommodate the second protrusion 45 , thereby reducing the extra space occupied by the second protrusion 45 in the first direction X, thereby improving space utilization and increasing the energy density of the battery cell 6 .

[0176] 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 body 46 , which is located between the electrode assembly 10 and the wall portion 211 along the third direction Z and is connected to the first electrode terminal 31 .

[0177] Optionally, the first adapter 40 is L-shaped as a whole.

[0178] The second adapter body 46 may be directly connected to the first adapter body 42 , or may be indirectly connected to the first adapter body 42 through other structures.

[0179] The thickness of the second adapter body 46 can be the same as or different from the thickness of the first adapter body 42. Optionally, the thickness of the second adapter body 46 is the same as the thickness of the first adapter body 42, and the second adapter body 46 and the first adapter body 42 can be formed from a plate through a bending process.

[0180] The second transfer body 46 can be connected to the first electrode terminal 31 by riveting, welding, bonding or other appropriate methods.

[0181] The second adapter body 46 is provided with a third recess 461, which is recessed into the surface of the second adapter body 46 along the third direction Z. The third recess 461 can be located on the side of the second adapter body 46 facing the electrode assembly 10, or on the side of the second adapter body 46 facing away from the electrode assembly 10. The portion of the second adapter body 46 corresponding to the third recess 461 is relatively weak, forming the fuse of the first adapter 40. This allows for a timely fuse to open when excessive current flows within the battery cell 6, thereby providing circuit breaker protection.

[0182] In some embodiments, the first adapter 40 includes a connecting portion 47 , and the first adapter body 42 and the second adapter body 46 are connected by the connecting portion 47 . The projection of the connecting portion 47 along the second direction Y is an arc. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0183] The thickness of the connecting portion 47 may be the same as or different from the thickness of the first adapter body 42. The thickness of the connecting portion 47 may be the same as or different from the thickness of the second adapter body 46.

[0184] Alternatively, the connecting portion 47 may be formed by a bending process, during which a portion of the material forming the connecting portion 47 is stretched, thereby making at least a portion of the connecting portion 47 thinner than the thickness of the first adapter body 42 and the thickness of the second adapter body 46 .

[0185] The connecting portion 47 can be smoothly connected to the first adapter body 42 , and the connecting portion 47 can be smoothly connected to the second adapter body 46 .

[0186] The connecting portion 47 may include an inner surface 47 a facing the electrode assembly 10 and an outer surface 47 b facing away from the electrode assembly 10 , and both the inner surface 47 a and the outer surface 47 b are arc-shaped surfaces.

[0187] The embodiment of the present application uses the arc-shaped connecting portion 47 to help reduce the possibility of cracking or splitting during the bending process of the first adapter 40 .

[0188] In some embodiments, the connecting 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, and the radius of the circle corresponding to the projection of the inner surface 47 a is r, 0.2 mm≤r≤20 mm.

[0189] Optionally, r can be 0.2 mm, 0.5 mm, 0.7 mm, 1 mm, 0.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 5 mm, 7 mm, 10 mm, 15 mm, 20 mm or any value therebetween.

[0190] The projection of the outer surface 47b of the connecting portion 47 along the second direction Y is also arc-shaped, 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. Therefore, the connecting portion 47 can be a structure of uniform thickness.

[0191] In the embodiment of the present application, r is set to be greater than or equal to 0.2 mm. This prevents the inner side of the connection portion 47 from forming an angle, which helps reduce the risk of cracking or splitting the connection portion 47. In the embodiment of the present application, r is set to be less than or equal to 20 mm. This prevents the connection portion 47 from being too large, reduces the space required for arranging the connection portion 47, reduces space waste within the battery cell 6, and helps increase the energy density of the battery cell 6.

[0192] In some embodiments, the first adapter 40 is an integrally formed structure, which helps to simplify the assembly process.

[0193] 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 each other along the first direction X.

[0194] 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 electrode tab 13 facing away from the main body 11 along the first direction X, and abuts against the second electrode tab 13. A fourth recess 61 is defined on one side of the second adapter 60 along the first direction X. The bottom wall of the fourth recess 61 is welded to the second electrode tab 13.

[0195] The structure of the second adapter 60 may be similar to that of the first adapter 40 , and will not be described in detail here.

[0196] The connection relationship between the second adapter 60 and the second tab 13 is similar to the connection relationship between the first adapter 40 and the first tab 12 , and will not be described again here.

[0197] 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 flow 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.

[0198] 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.

[0199] According to the third aspect of the present application, an embodiment of the present application further provides an electric device, which includes the battery device provided by any embodiment of the second aspect of the present application. The electric device can be any of the aforementioned devices or systems using battery cells.

[0200] The embodiment of the present application provides a battery cell 6, which includes an electrode assembly 10, a housing 20, a first electrode terminal 31, and a first adapter 40. The first adapter 40 is an integrally formed structure. The housing 20 includes a wall portion 211, and the first electrode terminal 31 is disposed on the wall portion 211. The electrode assembly 10 is housed within the housing 20. The electrode assembly 10 includes a main body 11 and a first electrode tab 12. At least a portion of the first electrode tab 12 protrudes from a first end surface 11a of the main body 11 along a first direction X. The first adapter 40 is connected to the first electrode terminal 31. At least a portion of the first adapter 40 is disposed on a side of the first electrode tab 12 that faces away from the main body 11 along the first direction X and abuts against the first electrode tab 12. A first recess 41 is provided on one side of the first adapter 40 along the first direction X. The bottom wall of the first recess 41 is welded to the first electrode tab 12 to form a weld 50. The minimum distance between the weld 50 and the sidewall 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 disposed on a side of the first electrode tab 12 facing away from the main body 11 along the first direction X. The second adapter body 46 is disposed between the electrode assembly 10 and the wall portion 211 along the third direction Z. 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, and the radius of the circle corresponding to the projection of the inner surface 47a is greater than 0.2 mm.

[0201] The first concave portion 41 can be formed by machining or stamping. When the first concave portion 41 is formed by stamping, the first adapter 40 further includes a second convex portion 45 that surrounds the first concave portion 41 and protrudes from the surface of the first convex portion 43 along the first direction X.

[0202] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, 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 pole ear away from the main body along the first direction and abuts against the first pole ear. 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 pole ear.

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 first adapter body and a plurality of first protrusions, wherein 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; At least one first recess is provided on one side of each first protrusion along the first direction, and the thickness of the bottom wall of the first recess is smaller than the thickness of the first adapter body.

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.

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