Tab assembly, battery cell and battery

Abstract

The utility model provides a tab assembly, a battery cell and a battery, and relates to the technical field of batteries, the tab assembly comprises a plurality of first empty foil layers, a plurality of second empty foil layers and a switching piece, the first empty foil layers and the second empty foil layers are arranged along a first direction, the thickness direction of each of the first empty foil layers and the second empty foil layers is the first direction, and the thickness direction of each of the first empty foil layers and the second empty foil layers is the second direction. The heights of the multiple first empty foil layers are gradually increased one by one, the heights of the multiple second empty foil layers are gradually decreased one by one, in the first direction, the projection of any first empty foil layer and the projection of the adjacent second empty foil layer are arranged in a staggered mode in the second direction, and the first direction, the second direction and the height direction are perpendicular in pairs; all the first empty foil layers are suitable for being connected with the same adapter piece, and all the second empty foil layers are suitable for being connected with the same adapter piece. According to the invention, convenient connection between the plurality of empty foil layers and the switching sheet can be realized, the contact area between the empty foil layers and the switching sheet is increased, the current conduction performance of the empty foil layers is improved, the overall structure is simple, and the practicability is high.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a tab assembly, a battery cell, and a battery. Background Art

[0002] A composite current collector is generally a multilayer stack formed by a metal layer-polymer layer-metal layer structure. When the composite current collector is applied to lithium-ion batteries, it can effectively improve the battery's performance against needle puncture, extrusion, and heavy object impact. At the same time, because the polymer material is relatively light, the weight of the current collector can be reduced and the energy density of the battery can be increased. Therefore, the composite current collector is widely used because of its ultra-thin and ultra-light characteristics, and the high safety of the batteries produced.

[0003] In the related art, the polymer macromolecular layer in the composite current collector itself is not conductive. Therefore, it is necessary to weld the upper and lower metal layers of the composite current collector to the metal tabs in order to converge the current on the current collector. However, since the metal conductive layer is relatively thin, when the composite current collector is welded by laser and ultrasonic methods, the welding strength between the multiple layers of tabs is relatively weak, resulting in a large resistance in the tab area and a decrease in the current conduction ability. Summary of the Invention

[0004] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of one aspect of the present application proposes a tab assembly, which can realize convenient connection between multiple empty foil layers and adapter plates, increase the contact area between the empty foil layers and the adapter plates, improve the current conduction performance of the empty foil layers, and has a simple overall structure and strong practicality.

[0006] Another aspect of the present application provides a battery cell.

[0007] According to yet another aspect of the present application, a battery is provided.

[0008] According to an embodiment of the present application, a tab assembly includes a first empty foil layer, a second empty foil layer and a transition piece, wherein the first empty foil layer and the second empty foil layer are both in plurality and are arranged along a first direction, the thickness direction of each of the first empty foil layer and the second empty foil layer is the first direction, the heights of the plurality of first empty foil layers increase one by one, and the heights of the plurality of second empty foil layers decrease one by one, along the first direction, the projection of any first empty foil layer and the projection of the adjacent second empty foil layer are staggered along the second direction, and the first direction, the second direction and the height direction are perpendicular to each other; all the first empty foil layers are suitable for being connected to the same transition piece, and all the second empty foil layers are suitable for being connected to the same transition piece.

[0009] According to the tab assembly of the embodiment of the present application, a plurality of first empty foil layers arranged along the first direction and with increasing heights form a stepped first empty foil area, and a plurality of second empty foil layers arranged along the first direction and with decreasing heights form a stepped second empty foil area. The stepped structure of the first empty foil area and the second empty foil area enables all the empty foil layers (first empty foil layer or second empty foil layer) arranged in the same direction to be exposed one by one along the height direction, so that all the empty foil layers in the same direction are connected to the same adapter. Therefore, compared with the related art, the present application can realize convenient connection between multiple empty foil layers and the adapter, increase the contact area between the empty foil layer and the adapter, improve the current conduction performance of the empty foil layer, and has a simple overall structure and strong practicality.

[0010] In some embodiments, the adapter sheet has a butting portion, and the butting portion is adapted to abut against at least a portion of any one of each of the first hollow foil layers and each of the second hollow foil layers in the first direction.

[0011] It can be understood that the docking portion enables the adapter to contact the corresponding first empty foil area or the second empty foil area, facilitating the subsequent welding operation between the adapter and the empty foil layer to ensure the connection quality between the two and the reliability of current extraction.

[0012] In some embodiments, the docking portion includes a plurality of docking layers arranged along the height direction, the docking layers corresponding one-to-one to any one of the first empty foil layer and the second empty foil layer, and the thickness direction of the docking layer is consistent with the height direction to form a stepped first docking area or second docking area on the docking portion, so that the docking portion can be in good contact with the corresponding first empty foil area or second empty foil area to ensure the connection reliability between the adapter and the empty foil layer.

[0013] In some embodiments, the thickness of all the docking layers is the same, and when the docking portion abuts against all the first empty foil layers, the thickness of the docking layer is equal to the height difference between any two adjacent first empty foil layers, or, when the docking portion abuts against all the second empty foil layers, the thickness of the docking layer is equal to the height difference between any two adjacent second empty foil layers.

[0014] It is understandable that designing the thickness of the butt joint layer to be equal to the height difference between any two adjacent first hollow foil layers or any two adjacent second hollow foil layers further ensures the contact area between the adapter and the hollow foil layer and improves the connection quality between the two.

[0015] In some embodiments, along the second direction, the widths of all the docking layers are the same, the widths of all the first empty foil layers are the same, and the widths of all the second empty foil layers are the same. The width of the docking layer is equal to the width of the abutting first empty foil layer or the width of the second empty foil layer, so that the adapter sheet and the empty foil layer are completely fitted together, further increasing the contact area between the two.

[0016] In some embodiments, there is one adapter sheet having a first surface and a second surface arranged opposite to each other along the first direction, at least a portion of each first hollow foil layer is connected to the first surface, and at least a portion of each second hollow foil layer is connected to the second surface.

[0017] It can be understood that the method of connecting all the first empty foil layers and all the second empty foil layers to the two wall surfaces corresponding to the same adapter plate respectively realizes the centralized conduction of current on all the empty foil layers by one adapter plate, further simplifies the tab assembly, and ensures the current conductivity of the empty foil layer.

[0018] In some embodiments, there are two adapters, wherein one adapter is connected to at least a portion of each of the first hollow foil layers, and the other adapter is connected to at least a portion of each of the second hollow foil layers.

[0019] It can be understood that by connecting all first empty foil layers and all second empty foil layers to a switching piece respectively, the current on different empty foil layers can be derived separately, which expands the flexibility of current deriving on different empty foil layers in the tab assembly.

[0020] In some embodiments, the height difference between any two adjacent first hollow foil layers is Δh1, and 0.5 mm ≤ Δh1 ≤ 2 mm.

[0021] In some embodiments, the height difference between any two adjacent second hollow foil layers is Δh2, and 0.5 mm ≤ Δh2 ≤ 2 mm.

[0022] In some embodiments, the number of the first empty foil layers is the same as the number of the second empty foil layers.

[0023] In some embodiments, all the first hollow foil layers have the same thickness, all the second hollow foil layers have the same thickness, and the thickness of the first hollow foil layer is the same as the thickness of the second hollow foil layer.

[0024] In some embodiments, the first hollow foil layer with the highest height among all the first hollow foil layers is the same height as the second hollow foil layer with the highest height among all the second hollow foil layers.

[0025] In some embodiments, the first hollow foil layer with the lowest height among all the first hollow foil layers is the same height as the second hollow foil layer with the lowest height among all the second hollow foil layers.

[0026] In some embodiments, on a projection plane perpendicular to the first direction, a distance between a projection of the first hollow foil layer and a projection of the second hollow foil layer along the second direction is a, and a≤2 mm.

[0027] A battery cell according to an embodiment of the present application includes a tab assembly and a composite current collector, wherein the tab assembly is the tab assembly described in any of the above embodiments, and there are multiple composite current collectors that are arranged and connected along a first direction, all of the composite current collectors are connected to the tab assembly, and the composite current collector corresponds one-to-one to each of the first empty foil layer and the second empty foil layer in the tab assembly, so as to facilitate the current of all the composite current collectors to be derived from the tab assembly.

[0028] According to the battery cell of the embodiment of the present application, the tab assembly is designed to be a structure capable of enabling all empty foil layers (the first empty foil layer or the second empty foil layer) in the same direction to conduct current from the same adapter sheet, which can increase the contact area between the empty foil layer and the adapter sheet and improve the current conduction performance of the empty foil layer. Therefore, compared with the related technology, the battery cell using this tab assembly can simultaneously connect multiple composite current collectors in series, reducing the resistance of the composite current collector, making the circuit conduction performance of the composite current collector better, and facilitating the current inside the battery cell to be directed to the external circuit.

[0029] A battery according to an embodiment of the present application includes the battery cell described above.

[0030] The technical advantages of the battery according to the embodiment of the present application are the same as the technical advantages of the above-mentioned battery cell, which will not be repeated here.

[0031] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of a tab assembly according to an embodiment of the present application.

[0033] Figure 2 It is a structural schematic diagram of the tab assembly according to an embodiment of the present application when no adapter is installed.

[0034] Figure 3 yes Figure 2 Schematic diagram of the left view structure.

[0035] Figure 4 yes Figure 2 Schematic diagram of the right view structure.

[0036] Figure 5 It is a schematic structural diagram of the adapter in the tab assembly according to an embodiment of the present application.

[0037] Figure 6 yes Figure 5 Schematic diagram of the left view structure.

[0038] Figure 7 yes Figure 5 Schematic diagram of the right view structure.

[0039] Figure 8 This is a schematic diagram of the connection structure between the composite current collector and the tab in the battery cell according to an embodiment of the present application (the adapter is not shown in the figure).

[0040] Figure 9 Schematic diagram of the structure of a battery according to an embodiment of the present application.

[0041] Figure numerals: 1. first empty foil layer, 2. second empty foil layer, 3. adapter, 31. docking portion, 311. docking layer, 32. first surface, 33. second surface, 4. composite current collector. DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present application, but should not be understood as limiting the present application.

[0043] like Figures 1 to 7 As shown, a tab assembly of an embodiment of the present application includes a first empty foil layer 1, a second empty foil layer 2 and a adapter 3, wherein there are multiple first empty foil layers 1 and second empty foil layers 2 and they are arranged along the first direction, the thickness direction of each of the first empty foil layer 1 and the second empty foil layer 2 is the first direction, the heights of the multiple first empty foil layers 1 increase one by one, and the heights of the multiple second empty foil layers 2 decrease one by one, along the first direction, the projection of any first empty foil layer 1 and the projection of the adjacent second empty foil layer 2 are staggered along the second direction, and the first direction, the second direction and the height direction are perpendicular to each other; all first empty foil layers 1 are suitable for being connected to the same adapter 3, and all second empty foil layers 2 are suitable for being connected to the same adapter 3.

[0044] According to the tab assembly of the embodiment of the present application, a plurality of first empty foil layers 1 arranged along the first direction and with increasing heights form a stepped first empty foil area, and a plurality of second empty foil layers 2 arranged along the first direction and with decreasing heights form a stepped second empty foil area, wherein the stepped structure of the first empty foil area and the second empty foil area can enable all the empty foil layers (first empty foil layer 1 or second empty foil layer 2) arranged in the same direction to be exposed one by one along the height direction, so that all the empty foil layers in the same direction are connected to the same adapter 3. Therefore, compared with the related art, the present application can realize convenient connection between multiple empty foil layers and the adapter 3, increase the contact area between the empty foil layer and the adapter 3, improve the current conduction performance of the empty foil layer, and the overall structure is simple and practical.

[0045] Specifically, the first direction may be the front-to-back direction in the figure. The second direction may be the left-to-right direction in the figure. The height direction may be the up-down direction in the figure. The heights of the multiple first empty foil layers 1 increase in a step-by-step manner from the front to the back. The heights of the multiple second empty foil layers 2 decrease in a step-by-step manner from the front to the back. The first empty foil layer 1 and the second empty foil layer 2 may be respectively connected to different conductive metal layers of the battery cell. The adapter 3 may be a metal adapter 3. The material of the metal adapter 3 may not be limited to one or more of conductive metals such as copper, aluminum, nickel, zinc, tin, titanium and silver, and those skilled in the art may make adaptive adjustments according to actual conditions.

[0046] like Figures 5 to 7 As shown, in some embodiments, the adapter sheet 3 has a butting portion 31 , and the butting portion 31 is adapted to abut against at least a portion of any one of each first hollow foil layer 1 and each second hollow foil layer 2 in a first direction.

[0047] It can be understood that the docking portion 31 enables the adapter plate 3 to contact the corresponding first empty foil area or the second empty foil area, facilitating the subsequent welding operation between the adapter plate 3 and the empty foil layer to ensure the connection quality between the two and ensure the reliability of current extraction.

[0048] Specifically, when the first empty foil layer 1 and the second empty foil layer 2 are both connected to the same adapter plate 3, a docking portion 31 may be provided on the front and rear of the adapter plate 3, or a docking portion 31 may be provided on either the front or rear of the adapter plate 3. Furthermore, when the first empty foil layer 1 and the second empty foil layer 2 are each connected to a different adapter plate 3, a docking portion 31 may be provided on each region of the adapter plate 3 that is in contact with the first empty foil layer 1 or the second empty foil layer 2.

[0049] like Figures 5 to 7As shown, in some embodiments, the docking portion 31 includes a plurality of docking layers 311 arranged along the height direction, and the docking layers 311 correspond one-to-one to any one of the first empty foil layer 1 and the second empty foil layer 2. The thickness direction of the docking layer 311 is consistent with the height direction to form a stepped first docking area or a second docking area on the docking portion 31, so that the docking portion 31 can be in good contact with the corresponding first empty foil area or the second empty foil area to ensure the connection reliability between the adapter 3 and the empty foil layer.

[0050] Specifically, when the docking portion 31 abuts the first hollow foil region, the lengths of the multiple docking layers 311 in the front-to-back direction decrease in a step-like manner from top to bottom. When the docking portion 31 abuts the second hollow foil region, the lengths of the multiple docking layers 311 in the front-to-back direction decrease in a step-like manner from top to bottom. The docking portion 31 is not limited to a stepped groove structure directly formed on the first surface 32 or the second surface 33 of the adapter plate 3, or a stepped boss structure directly formed on the first surface 32 or the second surface 33 of the adapter plate 3.

[0051] like Figures 5 to 7 As shown, in some embodiments, the thickness of all the butt joint layers 311 is the same, and when the butt joint portion 31 abuts against all the first empty foil layers 1, the thickness of the butt joint layer 311 is equal to the height difference between any two adjacent first empty foil layers 1, or, when the butt joint portion 31 abuts against all the second empty foil layers 2, the thickness of the butt joint layer 311 is equal to the height difference between any two adjacent second empty foil layers 2.

[0052] It is understandable that the thickness of the docking layer 311 is designed to be equal to the height difference between any two adjacent first empty foil layers 1 or any two adjacent second empty foil layers 2, which further ensures the contact area between the adapter 3 and the empty foil layer and improves the connection quality between the two.

[0053] like Figure 5 As shown, in some embodiments, along the second direction, the widths of all the butt joint layers 311 are the same, the widths of all the first empty foil layers 1 are the same, and the widths of all the second empty foil layers 2 are the same. The width of the butt joint layer 311 is equal to the width of the abutting first empty foil layer 1 or the width of the second empty foil layer 2, so that the adapter sheet 3 is completely fitted with the empty foil layer, further increasing the contact area between the two.

[0054] It should be noted that when die-cutting the empty foil areas, each empty foil area is provided with at least a first empty foil area and a second empty foil area, ensuring that the height of the first empty foil layer 1 in the first empty foil area increases sequentially, and the height of the second empty foil layer 2 in the second empty foil area decreases sequentially, and an adapter sheet 3 is inserted between the two cut empty foil areas. Ultrasonic welding can be used for the first empty foil area and the second empty foil area to tightly connect the adapter sheet 3 with each corresponding empty foil layer to form a conductive path.

[0055] like Figure 1 As shown, in some embodiments, there is one adapter plate 3, which has a first surface 32 and a second surface 33 arranged opposite to each other along a first direction, at least a portion of each first empty foil layer 1 is connected to the first surface 32, and at least a portion of each second empty foil layer 2 is connected to the second surface 33.

[0056] It can be understood that by respectively connecting all first empty foil layers 1 and all second empty foil layers 2 to the two wall surfaces corresponding to the same adapter 3, the centralized conduction of current on all empty foil layers by one adapter 3 is achieved, which further simplifies the tab assembly and ensures the current conductivity of the empty foil layer.

[0057] Specifically, the first surface 32 of the adapter sheet 3 corresponds to the rear surface of the adapter sheet 3 in the figure, and the second surface 33 of the adapter sheet 3 corresponds to the front surface of the adapter sheet 3 in the figure. The first hollow foil layer 1 and the first surface 32, as well as the second hollow foil layer 2 and the second surface 33, can be tightly connected by ultrasonic welding to form a conductive path therebetween.

[0058] In some embodiments, there are two adapter plates 3 (not shown in the figure), one adapter plate 3 is connected to at least a portion of each first empty foil layer 1, and the other adapter plate 3 is connected to at least a portion of each second empty foil layer 2.

[0059] It can be understood that by connecting all first empty foil layers 1 and all second empty foil layers 2 to a switching plate 3 respectively, the current on different empty foil layers can be derived separately, which expands the flexibility of current extraction on different empty foil layers in the tab assembly.

[0060] like Figure 3 and Figure 4 As shown, in some embodiments, the height difference between any two adjacent first hollow foil layers 1 is Δh1, 0.5 mm ≤ Δh1 ≤ 2 mm, wherein the height difference Δh1 can be, for example, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0061] like Figure 3 and Figure 4 As shown, in some embodiments, the height difference between any two adjacent second hollow foil layers 2 is Δh2, 0.5 mm ≤ Δh2 ≤ 2 mm, wherein the height difference Δh2 can be, for example, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0062] like Figures 2 to 4 As shown, in some embodiments, the number of the first empty foil layers 1 is the same as the number of the second empty foil layers 2 .

[0063] like Figures 2 to 4 As shown, in some embodiments, the thickness of all first hollow foil layers 1 is the same, the thickness of all second hollow foil layers 2 is the same, and the thickness of the first hollow foil layer 1 is the same as the thickness of the second hollow foil layer 2 .

[0064] like Figures 2 to 4 As shown, in some embodiments, the first hollow foil layer 1 with the highest height among all the first hollow foil layers 1 is the same height as the second hollow foil layer 2 with the highest height among all the second hollow foil layers 2 .

[0065] like Figures 2 to 4 As shown, in some embodiments, the first hollow foil layer 1 with the lowest height among all the first hollow foil layers 1 is the same height as the second hollow foil layer 2 with the lowest height among all the second hollow foil layers 2 .

[0066] It should be noted that the first empty foil layer 1 and the second empty foil layer 2 adopt the above-mentioned structural parameters. For example, the first empty foil area and the second empty foil area can be designed to have the same structure, and the specifications of the two are the same, but the opening directions of the two are opposite, so as to reduce the overall processing difficulty of the tab assembly and ensure production efficiency.

[0067] like Figure 2 As shown, in some embodiments, on a projection plane perpendicular to the first direction, a distance between a projection of the first hollow foil layer 1 and a projection of the second hollow foil layer 2 along the second direction is a, a≤2 mm, wherein the distance a can be, for example, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm, 1 mm, 0.8 mm, 0.6 mm, 0.4 mm, 0.2 mm, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0068] like Figure 8 As shown, a battery cell of an embodiment of the present application includes a tab assembly and a composite current collector 4, the tab assembly is the tab assembly of any of the above embodiments, there are multiple composite current collectors 4 and they are arranged and connected along a first direction, all composite current collectors 4 are connected to the tab assembly, and the composite current collectors 4 correspond one-to-one to each of the first empty foil layer 1 and the second empty foil layer 2 in the tab assembly, so as to facilitate the current of all composite current collectors 4 to be derived from the tab assembly.

[0069] According to the battery cell of the embodiment of the present application, the tab assembly is designed to be a structure capable of enabling all empty foil layers (the first empty foil layer 1 or the second empty foil layer 2) in the same direction to derive current from the same adapter 3, which can increase the contact area between the empty foil layer and the adapter 3 and improve the current conduction performance of the empty foil layer. Therefore, compared with the related technology, the battery cell using this tab assembly can simultaneously connect multiple composite current collectors 4 in series, reducing the resistance of the composite current collector 4, making the circuit conduction performance of the composite current collector 4 better, and facilitating the current inside the battery cell to be directed to the external circuit.

[0070] Specifically, the composite current collector 4 includes a coated area and a non-coated area. The first empty foil layer 1 and the second empty foil layer 2 in the tab assembly of the present application belong to the non-coated area in the composite current collector 4. The composite current collector 4 generally includes a base film layer and a first conductive metal layer and a second conductive metal layer arranged on both sides of the base film layer. The first empty foil layer 1 in the tab assembly of the present application is connected to the first conductive metal layer, that is, it is led out from the first conductive metal layer; the second empty foil layer 2 is connected to the second conductive metal layer, that is, it is led out from the second conductive metal layer, wherein a plurality of first empty foil layers 1 correspond one-to-one to a plurality of first conductive metal layers in the composite current collectors 4, a plurality of second empty foil layers 2 correspond one-to-one to a plurality of second conductive metal layers in the composite current collectors 4, and all first empty foil layers 1 and all second empty foil layers 2 are connected to the adapter 3, so that the tab assembly can realize the current extraction of all composite current collectors 4 (that is, battery cells).

[0071] It should be noted that the thickness of the base film layer can range from 2μm to 20μm. For example, the thickness of the base film layer can be 2μm, 4μm, 6μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, etc., but it is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable. The present application does not limit the specific material of the base film layer. The base film layer can be composed of one or more polymers and their derivative materials such as polyethylene, polypropylene, polyethylene terephthalate, polyethylene terephthalate, poly(p-phenylene terephthalamide), polyimide, etc., and those skilled in the art can make adaptive adjustments according to actual conditions.

[0072] In addition, the thickness range of the first conductive metal layer and the second conductive metal layer can be 0.5μm to 3μm. For example, the thickness of the two can be 0.5μm, 0.7μm, 0.9μm, 1μm, 1.3μm, 1.6μm, 1.9μm, 2μm, 2.3μm, 2.6μm, 3μm, etc., but are not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable. There is no limitation on the specific materials of the two. They can be composed of one or more of metals such as copper, aluminum, nickel, zinc, titanium and silver and alloys thereof. Those skilled in the art can make adaptive adjustments according to actual conditions.

[0073] like Figure 9 As shown, a battery according to an embodiment of the present application includes the above battery cells.

[0074] The technical advantages of the battery according to the embodiment of the present application are the same as the technical advantages of the above-mentioned battery cell, which will not be repeated here.

[0075] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0077] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0078] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0079] In this application, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0080] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A tab assembly, characterized in that: include: A first hollow foil layer (1) and a second hollow foil layer (2), wherein the first hollow foil layer (1) and the second hollow foil layer (2) are both in plurality and arranged along a first direction, the thickness direction of each of the first hollow foil layer (1) and the second hollow foil layer (2) is in the first direction, the heights of the plurality of first hollow foil layers (1) increase one by one, and the heights of the plurality of second hollow foil layers (2) decrease one by one, along the first direction, the projection of any first hollow foil layer (1) and the projection of the adjacent second hollow foil layer (2) are staggered along the second direction, and the first direction, the second direction and the height direction are perpendicular to each other; as well as A transfer plate (3), all of the first empty foil layers (1) are suitable for being connected to the same transfer plate (3), and all of the second empty foil layers (2) are suitable for being connected to the same transfer plate (3).

2. The tab assembly according to claim 1, wherein: The adapter plate (3) has a butt joint portion (31), and the butt joint portion (31) is suitable for abutting against at least a portion of any one of each of the first empty foil layers (1) and each of the second empty foil layers (2) in the first direction.

3. The tab assembly according to claim 2, characterized in that: The docking portion (31) comprises a plurality of docking layers (311) arranged along the height direction, the docking layers (311) corresponding one-to-one to any one of the first hollow foil layer (1) and the second hollow foil layer (2), and the thickness direction of the docking layers (311) is consistent with the height direction; And / or, the thickness of all the butt joint layers (311) is the same, and when the butt joint portion (31) abuts against all the first hollow foil layers (1), the thickness of the butt joint layer (311) is equal to the height difference between any two adjacent first hollow foil layers (1), or, when the butt joint portion (31) abuts against all the second hollow foil layers (2), the thickness of the butt joint layer (311) is equal to the height difference between any two adjacent second hollow foil layers (2).

4. The tab assembly according to claim 1, wherein: There is one adapter plate (3), the adapter plate (3) having a first surface (32) and a second surface (33) arranged opposite to each other along the first direction, at least a portion of each first hollow foil layer (1) is connected to the first surface (32), and at least a portion of each second hollow foil layer (2) is connected to the second surface (33); Alternatively, there are two adapter plates (3), one of which is connected to at least a portion of each first hollow foil layer (1), and the other adapter plate (3) is connected to at least a portion of each second hollow foil layer (2).

5. The tab assembly according to any one of claims 1 to 4, characterized in that: The height difference between any two adjacent first hollow foil layers (1) is Δh1, 0.5mm≤Δh1≤2mm; And / or, the height difference between any two adjacent second hollow foil layers (2) is Δh2, 0.5mm≤Δh2≤2mm.

6. The tab assembly according to claim 5, characterized in that: The number of the first empty foil layers (1) is the same as the number of the second empty foil layers (2); And / or, the thickness of all the first hollow foil layers (1) is the same, the thickness of all the second hollow foil layers (2) is the same, and the thickness of the first hollow foil layer (1) is the same as the thickness of the second hollow foil layer (2).

7. The tab assembly according to claim 5, characterized in that: The first hollow foil layer (1) with the highest height among all the first hollow foil layers (1) is the same height as the second hollow foil layer (2) with the highest height among all the second hollow foil layers (2); And / or, the first hollow foil layer (1) with the lowest height among all the first hollow foil layers (1) has the same height as the second hollow foil layer (2) with the lowest height among all the second hollow foil layers (2).

8. The tab assembly according to claim 5, characterized in that: On a projection plane perpendicular to the first direction, a distance between a projection of the first hollow foil layer (1) and a projection of the second hollow foil layer (2) along the second direction is a, and a≤2mm.

9. A battery cell, characterized in that: include: A tab assembly, wherein the tab assembly is the tab assembly according to any one of claims 1 to 8; and A composite current collector (4), wherein the composite current collector (4) is provided in plurality and arranged and connected along a first direction, all the composite current collectors (4) are connected to the tab assembly, and the composite current collector (4) corresponds one-to-one to each of the first empty foil layer (1) and the second empty foil layer (2) in the tab assembly, so as to facilitate the current of all the composite current collectors (4) to be derived from the tab assembly.

10. A battery, characterized in that: The battery comprises the battery cell according to claim 9.

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