Tab assembly, battery cell and battery

Abstract

The utility model discloses a tab assembly, electric core and battery, tab assembly is used for electric core, and electric core includes pole piece, and the tab assembly includes: a plurality of first tab first tab alternate lamination, and the first tab of two adjacent is bonded with the conductive adhesive layer arranged between the two, and the conductive adhesive layer between the two sides of first tab is bonded, and second tab is connected with at least one of first tab and conductive adhesive layer. In the tab assembly of the utility model, a plurality of first tabs are bonded through the conductive adhesive layer, and the conductive adhesive layer between the two sides of first tab is bonded simultaneously, and the operation is simple, and the connecting effect is good, stable.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a tab assembly, a battery cell and a battery. Background Technology

[0002] Lithium-ion batteries, which contain lithium elements (including metallic lithium, lithium alloys, lithium ions, lithium polymers, etc.) in an electrochemical system, are widely used in consumer electronics and other fields due to their outstanding advantages such as high energy density, long cycle life and low self-discharge rate.

[0003] In the electrode lead-out structure technology of lithium battery cells, multiple stacked first tabs (also known as "dummy tabs" in the industry) are usually set up, and multiple first tabs are connected to second tabs (also known as "true tabs" in the industry) to realize the function of cell current lead-out.

[0004] In the specific connection process, multiple first tabs are often welded together using a roll welding process to achieve connection and conduct electricity at the same time. However, this process has drawbacks: the tabs of the entire length need to be welded, which is challenging in terms of processing difficulty and processing effect. Uncontrollable abnormalities such as weld breakage, light transmission, and poor welding are prone to occur, affecting the safety of the battery cell. Utility Model Content

[0005] The main purpose of this utility model is to propose an electrode tab assembly, which aims to solve the technical problems of difficult processing, poor connection effect, and instability caused by the current use of roll welding to connect multiple first electrodes in battery cell electrodes.

[0006] To achieve the above objectives, this utility model proposes a tab assembly for a battery cell, wherein the battery cell includes electrode plates, and the tab assembly includes:

[0007] Multiple first tabs are integrally formed with or connected to the current collector of the electrode sheet;

[0008] Multiple conductive adhesive layers are alternately stacked with the multiple first tabs, and two adjacent first tabs are bonded to the conductive adhesive layer disposed between them, and the conductive adhesive layers on both sides of the first tabs are bonded to each other.

[0009] The second tab is connected to at least one of the first tab and the conductive adhesive layer.

[0010] In some embodiments, along the length of the first tab, one end of the conductive adhesive layer extends beyond the first tab to form an adhesion with the adjacent conductive adhesive layer.

[0011] In some embodiments, the first electrode tab is provided with a through hole along its thickness direction, and the conductive adhesive layers on both sides of the first electrode tab pass through the through hole to form an adhesive bond.

[0012] In some embodiments, the number of through holes is multiple; and / or,

[0013] The projection of the through hole onto the thickness direction of the first electrode includes one of the following: circular, elliptical, polygonal, and sector-shaped.

[0014] In some embodiments, along the stacking direction of the first tab and the conductive adhesive layer, the through holes of adjacent first tabs are aligned or staggered.

[0015] In some embodiments, along the length direction of the first electrode tab, one end of the second electrode tab is opposite to a first electrode tab and is bonded to the conductive adhesive layers on both sides of the opposite first electrode tab.

[0016] In some embodiments, the plurality of conductive adhesive layers include a first conductive adhesive layer and a second conductive adhesive layer, wherein the first conductive adhesive layer and the second conductive adhesive layer are respectively located as the two outermost opposite layers in the plurality of conductive adhesive layers;

[0017] A first protective layer is provided on the side of the first conductive adhesive layer opposite to the first electrode tab to which it is bonded, and a second protective layer is provided on the side of the second conductive adhesive layer opposite to the first electrode tab to which it is bonded.

[0018] In some embodiments, one end of the second electrode tab is overlapped and welded to the first electrode tab bonded to the first conductive adhesive layer;

[0019] Along the length of the first conductive adhesive layer, one end of the first protective layer extends beyond the first conductive adhesive layer to cover the solder mark formed by welding the second electrode tab to the first electrode tab.

[0020] This utility model also proposes a battery cell, which includes a first electrode, a second electrode, a separator, and a tab assembly as described above. The separator is disposed between the first electrode and the second electrode, and the second electrode has the opposite polarity to the first electrode.

[0021] The number of electrode tabs is one, and the current collector of the first electrode sheet is integrally formed or connected to the plurality of first electrodes in the electrode tab assembly; or, the number of electrode tabs is two, and the current collector of the first electrode sheet is integrally formed or connected to the plurality of first electrodes in one of the two electrode tab assemblies, and the current collector of the second electrode sheet is integrally formed or connected to the plurality of first electrodes in the other of the two electrode tab assemblies.

[0022] The present invention also proposes a battery comprising a casing and a battery cell as described above, wherein the battery cell is disposed in the casing.

[0023] This utility model's electrode assembly includes multiple conductive adhesive layers, which are alternately stacked with multiple first electrodes. A second electrode is connected to at least one of the first electrodes and the conductive adhesive layers. Adjacent first electrodes are bonded to the conductive adhesive layer located between them. The conductive adhesive layer ensures smooth current conduction while connecting the first electrodes. Compared to traditional roll welding, this method is simpler to operate and effectively avoids welding abnormalities such as weld breaks, light transmission, and incomplete welds caused by the welding process, resulting in a better connection. Furthermore, while the first electrode is bonded to the conductive adhesive layer, the conductive adhesive layers on both sides are bonded to each other, improving the connection stability between the first electrodes and ensuring the safety of the battery cell. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the battery cell structure in one embodiment of the present invention;

[0025] Figure 2 for Figure 1 A schematic diagram of the battery cell in the embodiment when its tab assembly is in a folded state;

[0026] Figure 3 This is a schematic diagram of the battery cell structure in another embodiment of the present invention;

[0027] Figure 4 for Figure 3 A schematic diagram of the battery cell in the embodiment when its tab assembly is in a folded state;

[0028] Figure 5 This is a schematic diagram of the battery cell structure in another embodiment of the present invention;

[0029] Figure 6 This is a partial structural diagram of the first electrode of the electrode assembly in one embodiment of the present invention;

[0030] Figure 7 This is a partial structural diagram of the first electrode of the electrode assembly in another embodiment of the present invention; Reference numerals are explained as follows:

[0031] 100 Electrode assembly 110 First pole ear 120 conductive adhesive layer 130 Second pole ear 111 Through hole 121 First conductive adhesive layer 122 Second conductive adhesive layer 141 First protective layer 142 Second protective layer 200 First Pole Film 300 Second pole plate 400 diaphragm

[0032] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0034] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0035] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0036] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0037] Reference Figures 1 to 4 This utility model embodiment proposes an electrode assembly 100 for use in a battery cell, the battery cell including electrode plates (positive electrode plates or negative electrode plates), wherein the electrode assembly 100 includes:

[0038] Multiple first tabs 110 are integrally formed with or connected to the current collector of the electrode sheet;

[0039] Multiple conductive adhesive layers 120 are alternately stacked with multiple first tabs 110, and two adjacent first tabs 110 are bonded to the conductive adhesive layer 120 disposed between them, and the conductive adhesive layers 120 on both sides of the first tab 110 are bonded to each other.

[0040] The second tab 130 is connected to at least one of the first tab 110 and the conductive adhesive layer 120.

[0041] Specifically, the first tab 110 is adapted to the current collector of the electrode plate, and the material is the same as the current collector (e.g., when the positive current collector is aluminum foil, the first tab 110 is aluminum; when the negative current collector is copper foil, the first tab 110 is copper or nickel-plated copper). The number and size parameters (such as thickness, width, length, etc.) of the first tab 110 can be set according to actual needs.

[0042] The first electrode 110 is connected to the current collector in one of the following two ways:

[0043] Firstly, it is integrally molded by cutting one side of the current collector into multiple spaced protrusions to form the first tab 110, without the need for additional connection processes. Secondly, it is fixedly connected by using conductive adhesive bonding or welding to fix the independent first tab 110 to the lead-out end of the current collector, ensuring the continuity of current conduction.

[0044] The number of conductive adhesive layers 120 is adapted to the stacked structure of the first tabs 110. For example, when n first tabs 110 are stacked along the thickness direction, n+1 conductive adhesive layers 120 are provided to form an alternating stacked structure of "conductive adhesive layer 120 - first tab 110 - conductive adhesive layer 120", or n-1 conductive adhesive layers 120 are provided to form an alternating stacked structure of "first tab 110 - conductive adhesive layer 120 - first tab 110", and the conductive adhesive layers 120 on both sides of the first tab 110 are mutually bonded. The conductive adhesive layer 120 can be composed of a resin matrix and conductive filler, and any commonly available conductive adhesive type can be used. This embodiment does not limit this.

[0045] The quantity and dimensional parameters (such as thickness, width, and length) of the conductive adhesive layer 120 can be set according to actual needs. For example, the width of the conductive adhesive layer 120 is 1mm to 3mm larger than the width of the first tab 110, ensuring that the conductive adhesive layers 120 on both sides of the first tab 110 can overlap and bond through the excess portion, forming a covering fixation for the first tab 110. The conductive adhesive layer 120 not only achieves electrical connection between the first tabs 110, but also, through its alternating layering and bonding structure, allows multiple first tabs 110 to form a whole. When the battery cell expands and contracts during charging and discharging, the adhesiveness of the conductive adhesive layer 120 can buffer mechanical stress, preventing separation between the first tabs 110. Using the conductive adhesive layer 120 for connection, no complex welding equipment or parameter control is required; the connection of the first tabs 110 can be achieved simply by hot pressing or room temperature bonding, making the operation simple.

[0046] The second electrode 130 has an elongated structure and is made of a material compatible with the first electrode 110. The connection method of the second electrode 130 in the electrode assembly 100 can be at least one of the following:

[0047] First, the second tab 130 is connected to the outermost first tab 110, specifically by welding or bonding with conductive adhesive; second, the second tab 130 is connected to the outermost conductive adhesive layer 120, and the second tab 130 and the conductive adhesive layer 120 are tightly bonded by a hot pressing process to achieve current conduction.

[0048] In this embodiment, the tab assembly 100 is provided with multiple conductive adhesive layers 120. The multiple conductive adhesive layers 120 and multiple first tabs 110 are alternately stacked. The second tab 130 is connected to at least one of the first tabs 110 and the conductive adhesive layers 120. Two adjacent first tabs 110 are bonded to the conductive adhesive layer 120 disposed between them. The conductive adhesive layer 120 can ensure smooth current conduction while connecting the first tabs 110. Compared with the traditional roll welding process, the operation is simple and can effectively avoid welding abnormalities such as weld breakage, light transmission, and poor welding caused by the welding process, resulting in a good connection effect. Furthermore, while the first tab 110 is bonded to the conductive adhesive layer 120, the conductive adhesive layers 120 on both sides of it are bonded to each other, which can improve the connection stability between the first tabs 110 and ensure the safety of the battery cell.

[0049] In some embodiments, refer to Figures 1 to 4 Along the length direction of the first tab 110, one end of the conductive adhesive layer 120 extends beyond the first tab 110 and forms an adhesive bond with the adjacent conductive adhesive layer 120.

[0050] In this embodiment, based on the above-mentioned tab assembly 100, the design of the stacked structure of the conductive adhesive layer 120 and the first tab 110 is further optimized: along the length direction of the first tab 110 (the end of the first tab 110 near the current collector is defined as the "connection end", and the free end away from the current collector is defined as the "extension end"), the extension end of the conductive adhesive layer 120 extends beyond the extension end of the first tab 110, and the extended portion forms a tight bond with the extended portion of the adjacent conductive adhesive layer 120.

[0051] The extended portions of two adjacent conductive adhesive layers 120 form an "overlap area" along the thickness direction of the first tab 110. The width of the overlap area is the same as the width of the conductive adhesive layer 120 (e.g., 5mm to 20mm), and the overlap length is equal to the extended length of the conductive adhesive layer 120 (e.g., 1mm to 3mm). The extended portions are bonded using the same process as the main body of the conductive adhesive layer 120.

[0052] The conductive adhesive layer 120 can extend beyond the length of the first tab 110 by 1mm to 3mm. For example, when the length of the first tab 110 is 10mm to 20mm, the extension length is preferably 1mm to 2mm; when the length of the first tab 110 is 20mm to 30mm, the extension length is preferably 2mm to 3mm. This ensures that the extension meets the bonding strength requirements while avoiding material waste or interference with other structures due to excessive extension.

[0053] During assembly, transportation, or use, the battery cell may be subjected to minor mechanical shocks (such as drops or vibrations). In a conventional tab assembly 100, the extended end of the first tab 110 is unrestrained, and impacts can easily cause the tab edge to lift. The end-wrapping structure of the conductive adhesive layer 120 can fix the extended end of the first tab 110, making its edge form an integral part with the conductive adhesive layer 120, thus preventing the tab edge from lifting.

[0054] In addition to the above-mentioned bonding method, the bonding between two adjacent conductive adhesive layers 120 can also be:

[0055] In some embodiments, refer to Figure 5 The first electrode 110 has a through hole 111 extending through it along its thickness direction, and the conductive adhesive layers 120 on both sides of the first electrode 110 pass through the through hole 111 to form an adhesive bond.

[0056] In this embodiment, the first tab 110 is provided with a through hole 111. The through hole 111 is provided through the thickness direction of the first tab 110 (the direction perpendicular to the tab plane). When stacked, the conductive adhesive layers 120 on both sides of the first tab 110 can pass through the through hole 111 for bonding, that is, the cross-tab bonding of the conductive adhesive layers 120 on both sides is realized.

[0057] In some embodiments, refer to Figures 5 to 7 The number of through holes 111 is multiple; and / or,

[0058] The projection of the through hole 111 in the thickness direction of the first electrode 200 includes one of the following: circle, ellipse, polygon and sector.

[0059] In this embodiment, optionally, the number of through holes 111 can be two or more, depending on actual needs. The through holes 111 are linearly distributed at equal intervals along the length of the first tab 110, and are centrally or symmetrically distributed along the width (deviation from the center ≤1mm), avoiding stress concentration caused by dense local through holes 111 (e.g., only one through hole 111 is provided within 5mm of the edge to prevent edge cracking). By providing multiple through holes 111, adjacent conductive adhesive layers 120 are bonded at each through hole 111, which helps to improve the bonding strength and enhance the connection stability.

[0060] Optionally, the shape of the projection of the through-hole 111 in the thickness direction of the first electrode 200 can be set according to actual needs, such as a circle, ellipse, polygon (e.g., triangle, rectangle, hexagon, etc.), or sector. All shapes can be achieved through laser processing, requiring only adjustment of the motion trajectory of the laser galvanometer. When there are multiple through-holes 111, the shapes of the multiple through-holes 111 can be selected from circles, ellipses, polygons, and sectors, and can be the same or different, depending on actual needs.

[0061] In some embodiments, along the stacking direction of the first tab 110 and the conductive adhesive layer 120, the through holes 111 between adjacent first tabs 110 are aligned or misaligned.

[0062] In this embodiment, along the stacking direction (the direction perpendicular to the plane of the first tab 110, which is regarded as the Z-axis direction), the through holes 111 of adjacent first tabs 110 are arranged to enhance the vertical current conduction efficiency by alignment. Specifically, along the stacking direction, the projections of the through holes 111 of two adjacent first tabs 110 completely overlap or the deviation is ≤0.05mm, forming a vertical through channel, so that the bonding points of the conductive adhesive of adjacent layers can be continuously connected along the Z-axis direction.

[0063] Alternatively, by setting staggered settings to disperse interlayer stress and adapt to the expansion and contraction of the core, specifically, along the stacking direction, the projections of the through holes 111 of two adjacent first tabs 110 do not overlap and there is a gap, for example, the center-to-center distance of the projection is ≥ 1.2 times the maximum outer diameter of the through hole 111, forming an array of staggered bonding points.

[0064] In some embodiments, refer to Figure 1 and Figure 2 Along the length of the first tab 110, one end of the second tab 130 is opposite to the first tab 110 and is bonded to the conductive adhesive layer 120 on both sides of the first tab 110.

[0065] In this embodiment, along the length of the first tab 110 (defined as the "proximal end" of the first tab 110 near the current collector and the "distal end" away from the current collector), one end of the second tab 130 (denoted as the "connecting end") is positioned opposite a target first tab 110 (denoted as the "target tab"), and this connecting end is simultaneously bonded tightly to the conductive adhesive layers 120 on both sides of the target tab, forming a sandwich-like connection structure in which the target tab is sandwiched between the second tab 130 and the conductive adhesive layers 120 on both sides. By simultaneously bonding the second tab 130 to the conductive adhesive layers 120 on both sides, the connection strength can be improved, the risk of detachment can be reduced, the current conduction path can be optimized, the current distribution can be more uniform, and local overheating can be reduced.

[0066] In some embodiments, refer to Figure 3 and Figure 4 The plurality of conductive adhesive layers 120 include a first conductive adhesive layer 121 and a second conductive adhesive layer 122, wherein the first conductive adhesive layer 121 and the second conductive adhesive layer 122 are respectively located as the two outermost layers of the plurality of conductive adhesive layers.

[0067] A first protective layer 141 is provided on the side of the first conductive adhesive layer 121 facing away from the first electrode tab 110 to which it is bonded, and a second protective layer 142 is provided on the side of the second conductive adhesive layer 122 facing away from the first electrode tab 110 to which it is bonded.

[0068] In this embodiment, based on the original tab assembly 100 (containing multiple first tabs 110 and alternately stacked conductive adhesive layers), the design of the two outermost conductive adhesive layers (defined as "first conductive adhesive layer 121" closer to the outer side of the battery core and "second conductive adhesive layer 122" farther from the outer side of the core) is optimized. Specifically, a first protective layer 141 is provided on the side of the first conductive adhesive layer 121 opposite to the first tab 110 it is bonded to, and a second protective layer 142 is provided on the side of the second conductive adhesive layer 122 opposite to the first tab 110 it is bonded to, forming a composite protective structure of "protective layer - outermost conductive adhesive layer - first tab 110 - inner conductive adhesive layer". The protective layer can be made of PET material, which has excellent electrical insulation properties. The protective layer is used to insulate the outermost first conductive layer from other objects (such as the casing) and avoid the risk of short circuits. Furthermore, the protective layer can be a "non-adhesive first tab 110 side" that only covers the outermost conductive adhesive layer, without contacting the inner first tab 110 or the inner conductive adhesive layer, so as to avoid affecting the current conduction and adhesion stability of the inner layer.

[0069] In some embodiments, refer to Figure 3 and Figure 4 One end of the second electrode 130 is overlapped and welded to the first electrode 110 bonded to the first conductive adhesive layer 121;

[0070] Along the length of the first conductive adhesive layer 121, one end of the first protective layer 141 extends beyond the first conductive adhesive layer 121 to cover the solder mark H formed by welding the second tab 130 and the first tab 110.

[0071] In this embodiment, along the length of the first tab 110, one end (welding end) of the second tab 130 is overlapped with the first tab 110 bonded to the first conductive adhesive layer 121 (denoted as "welding tab, i.e., the bonding tab of the first conductive adhesive layer 121) and fixedly connected by welding. Simultaneously, one end of the first protective layer 141 is extended beyond the edge of the first conductive adhesive layer 121, completely covering the weld mark H formed by welding. By covering the weld mark H between the second tab 130 and the first tab 110 with the protective layer, tiny weld slags on the surface of the weld mark are encapsulated, preventing them from piercing the diaphragm 400 and causing short circuits, thus improving safety.

[0072] This utility model embodiment also proposes a battery cell, referring to... Figure 1 and Figure 2 The battery cell includes a first electrode 200, a second electrode 300, a diaphragm 400, and a tab assembly 100 as described above. The diaphragm 400 is disposed between the first electrode 200 and the second electrode 300, and the second electrode 300 has the opposite polarity to the first electrode 200.

[0073] The number of tab assemblies 100 is one, and the current collector of the first electrode 200 is integrally formed with or connected to a plurality of first electrodes 110 in the tab assembly 100; or, the number of tab assemblies 100 is two, and the current collector of the first electrode 200 is integrally formed with or connected to a plurality of first electrodes 110 in one of the two tab assemblies 100, and the current collector of the second electrode 300 is integrally formed with or connected to a plurality of first electrodes 110 in the other of the two tab assemblies 100.

[0074] The specific structure of the tab assembly 100 is as described in the above embodiments. Since this battery cell adopts all the technical solutions of all the above embodiments, it has at least all the technical effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. The battery cell involved can be a wound battery cell or a stacked battery cell, and the tab assembly 100 proposed in this solution is applicable to both types of battery cells.

[0075] This utility model embodiment also proposes a battery, which includes a casing and a battery cell as described above, with the battery cell disposed within the casing. The specific structure of the battery cell is the same as described in the above embodiments. Since this battery adopts all the technical solutions of all the above embodiments, it possesses at least all the technical effects brought about by the technical solutions of the above embodiments. The battery may be a lithium battery.

[0076] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A tab assembly for a battery cell, the battery cell comprising electrode plates, characterized in that, The electrode assembly includes: Multiple first tabs are integrally formed with or connected to the current collector of the electrode sheet; Multiple conductive adhesive layers are alternately stacked with the multiple first tabs, and two adjacent first tabs are bonded to the conductive adhesive layer disposed between them, and the conductive adhesive layers on both sides of the first tabs are bonded to each other. The second tab is connected to at least one of the first tab and the conductive adhesive layer.

2. The electrode assembly according to claim 1, characterized in that, Along the length of the first electrode tab, one end of the conductive adhesive layer extends beyond the first electrode tab to form an adhesion with the adjacent conductive adhesive layer.

3. The electrode assembly according to claim 1, characterized in that, The first electrode tab has a through hole extending through its thickness direction, and the conductive adhesive layers on both sides of the first electrode tab pass through the through hole to form an adhesive bond.

4. The electrode assembly according to claim 3, characterized in that, The number of through holes is multiple; and / or, The projection of the through hole onto the thickness direction of the first electrode tab includes one of the following: circular, elliptical, polygonal, and fan-shaped.

5. The electrode assembly according to claim 3, characterized in that, Along the stacking direction of the first electrode tab and the conductive adhesive layer, the through holes of adjacent first electrodes tabs are aligned or staggered.

6. The electrode assembly according to claim 1, characterized in that, Along the length of the first electrode tab, one end of the second electrode tab is opposite to one of the first electrode tabs and is bonded to the conductive adhesive layers on both sides of the opposite first electrode tab.

7. The electrode assembly according to claim 1, characterized in that, The plurality of conductive adhesive layers includes a first conductive adhesive layer and a second conductive adhesive layer, wherein the first conductive adhesive layer and the second conductive adhesive layer are respectively located as the two outermost opposite layers in the plurality of conductive adhesive layers. A first protective layer is provided on the side of the first conductive adhesive layer opposite to the first electrode tab to which it is bonded, and a second protective layer is provided on the side of the second conductive adhesive layer opposite to the first electrode tab to which it is bonded.

8. The electrode assembly according to claim 7, characterized in that, One end of the second electrode tab is overlapped and welded to the first electrode tab that is bonded to the first conductive adhesive layer; Along the length of the first conductive adhesive layer, one end of the first protective layer extends beyond the first conductive adhesive layer to cover the solder mark formed by welding the second electrode tab to the first electrode tab.

9. A battery cell, characterized in that, The assembly includes a first electrode, a second electrode, a diaphragm, and a tab assembly as described in any one of claims 1 to 8, wherein the diaphragm is disposed between the first electrode and the second electrode, and the second electrode has the opposite polarity to the first electrode. The number of electrode tabs is one, and the current collector of the first electrode sheet is integrally formed or connected to the plurality of first electrodes in the electrode tab assembly; or, the number of electrode tabs is two, and the current collector of the first electrode sheet is integrally formed or connected to the plurality of first electrodes in one of the two electrode tab assemblies, and the current collector of the second electrode sheet is integrally formed or connected to the plurality of first electrodes in the other of the two electrode tab assemblies.

10. A battery, characterized in that, It includes a housing and a battery cell as described in claim 9, wherein the battery cell is disposed in the housing.

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