Battery cells, battery devices and power-consuming devices

Abstract

The present application provides a battery cell, a battery device and an electrical device, wherein the electrode assembly of the battery cell comprises a main body and a plurality of first pole ears, wherein the plurality of first pole ears are connected to the same end of the main body, wherein the first pole ears comprise a connection area and a gathering area, wherein the connection area connects the gathering area and the main body, and the gathering areas of the plurality of first pole ears are stacked and welded along a first direction to form a gathering part; the electrode lead-out part is connected to the gathering part; along the first direction, the two gathering areas farthest apart in the gathering part are first gathering areas, and at least one surface of at least one first gathering area is provided with a conductive adhesive layer, which has a binding effect on the first gathering area, and can reduce the risk of the first gathering area cracking at the welding position due to being subjected to welding energy, thereby reducing the risk of failure of the battery cell and improving the reliability of the battery cell.

Description

Technical Field

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

[0002] Batteries are widely used in new energy vehicles, electronic equipment and other fields. As the demand for batteries increases, higher requirements are placed on battery reliability. As the market's requirements for battery life increase, the requirements for battery reliability are also increasing. Summary of the invention

[0003] The embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can improve the reliability of the battery cell.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, comprising an electrode assembly and an electrode lead-out portion; the electrode assembly comprises a main body and a plurality of first pole tabs, the plurality of first pole tabs being connected to the same end of the main body, the first pole tab comprising a connection area and a gathering area, the connection area connecting the gathering area and the main body, the gathering areas of the plurality of first pole tabs being stacked and welded along a first direction to form a gathering portion; the electrode lead-out portion is connected to the gathering portion; wherein, along the first direction, the two gathering areas in the gathering portion that are farthest apart are first gathering areas, and at least one surface of at least one of the first gathering areas is provided with a conductive adhesive layer.

[0005] In the above technical solution, the two most distant gathering areas in the gathering part are the first gathering areas, and at least one surface of at least one first gathering area is provided with a conductive adhesive layer. When the plurality of gathering areas are welded to form the gathering part, and / or when the gathering part is welded to the electrode lead-out part, one of the two first gathering areas is closest to the welding equipment, and the welding energy borne by the first gathering area is the largest. When the first gathering area provided with the conductive adhesive layer is closest to the welding equipment during welding, the conductive adhesive layer has a binding effect on the first gathering area, which can reduce the risk of the first gathering area cracking at the welding position due to the welding energy, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell. Even if the first gathering area is cracked at the welding position due to the welding energy, since the conductive adhesive has conductive properties, the conductive adhesive can play a conductive role, so as to provide a current path inside the cracked part component, alleviate the problem of power drop caused by the cracking of the first gathering area and reduce the risk of battery cell failure, thereby improving the reliability of the battery cell. Even if the first gathering area is cracked at the welding position due to welding energy, the conductive adhesive layer can solidify the cracked first gathering area, and alleviate the degree of change in the shape of the first gathering area after the first gathering area is cracked at the welding position, for example, it can alleviate the degree of warping of the first gathering area after the first gathering area is cracked at the welding position, and reduce the risk of reliability problems of the battery cell caused by excessive change in the shape of the first gathering area after the first gathering area is cracked, thereby further improving the reliability of the battery cell. In some embodiments of the first aspect of the present application, along the first direction, the gathering portion has two opposite first outer surfaces, one of the first gathering areas has one first outer surface, and at least one of the first outer surfaces is provided with the conductive adhesive layer.

[0006] In the above technical solution, at least one first outer surface is provided with a conductive adhesive layer. When the first outer surface provided with the conductive adhesive layer is closest to the welding equipment during welding, the conductive adhesive layer has a binding effect on the first gathering area, which can further reduce the risk of the first gathering area cracking at the welding position due to the welding energy, thereby reducing the risk of failure of the battery cell and improving the reliability of the battery cell.

[0007] In some embodiments of the first aspect of the present application, along the first direction, two opposite surfaces of at least one of the first gathering areas are provided with the conductive adhesive layer.

[0008] In the above technical solution, along the first direction, two opposite surfaces of at least one first gathering area are provided with conductive adhesive layers, and the conductive adhesive layers on both sides of the first gathering area can provide better binding effect for the first gathering area. When the first gathering area provided with the conductive adhesive layer is closest to the welding equipment during welding, the risk of cracking of the first gathering area at the welding position due to welding energy can be further reduced, thereby reducing the risk of further battery cell failure and improving the reliability of the battery cell.

[0009] In some embodiments of the first aspect of the present application, the number of the gathering areas in the gathering portion is m, and among the n continuously stacked gathering areas, the conductive adhesive layer is arranged between two adjacent gathering areas, and the n gathering areas include at least one of the first gathering areas, and m≥n≥2.

[0010] In the above technical solution, among the n continuously stacked gathering areas, a conductive adhesive layer is arranged between two adjacent gathering areas, the n gathering areas include at least one first gathering area, m≥n≥2, and the gathering area continuously arranged with the first gathering area is provided with a conductive adhesive layer, which can reduce the risk of cracking of other gathering areas close to the first gathering area during welding, further reduce the risk of failure of the battery cell, and further improve the reliability of the battery cell.

[0011] In some embodiments of the first aspect of the present application, n=2 or n=3.

[0012] In the above technical solution, n=2 or n=3, which can ensure that a maximum of three continuously stacked gathering areas including a first gathering area are provided with a conductive adhesive layer, thereby reducing the risk of cracking of other gathering areas close to the first gathering area during welding, and can also alleviate the problem of the gathering part being too large in size due to the provision of a conductive adhesive layer, as well as the problem of the conductive adhesive layer occupying too much internal space of the battery cell, which is conducive to the battery cell having a higher energy density.

[0013] In some embodiments of the first aspect of the present application, the thickness of the conductive adhesive layer is 1 μm to 15 μm.

[0014] In the above technical solution, the thickness of the conductive adhesive layer is greater than or equal to 1 μm, and the conductive adhesive layer has a good binding effect on the first gathering area, which can reduce the risk of the first gathering area cracking at the welding position due to the welding energy, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell. The thickness of the conductive adhesive layer is less than or equal to 15 μm, and the thickness of the conductive adhesive layer is controlled to alleviate the problem of the gathering part being too large due to setting the thickness of the conductive adhesive layer too large, and alleviate the problem of the conductive adhesive layer occupying too much internal space of the battery cell, which is conducive to the battery cell having a higher energy density.

[0015] In some embodiments of the first aspect of the present application, the thickness of the conductive adhesive layer is 2 μm to 10 μm.

[0016] In the above technical solution, the thickness of the conductive adhesive layer is greater than or equal to 2μm, and the conductive adhesive layer has a better binding effect on the first gathering area, which can further reduce the risk of the first gathering area cracking at the welding position due to the welding energy, thereby further reducing the risk of battery cell failure and improving the reliability of the battery cell. The thickness of the conductive adhesive layer is less than or equal to 10μm, which further controls the thickness of the conductive adhesive layer, further alleviates the problem of the size of the gathering part being too large due to setting the thickness of the conductive adhesive layer too large, and further alleviates the problem of the conductive adhesive layer occupying too much internal space of the battery cell, which is conducive to the battery cell having a higher energy density.

[0017] In some embodiments of the first aspect of the present application, the conductive adhesive layer is a graphite conductive adhesive layer, a metal particle type conductive adhesive layer, a nano-silver type conductive adhesive layer or a nano-carbon tube type conductive adhesive layer.

[0018] In the above technical solution, the graphite conductive adhesive layer, the metal particle conductive adhesive layer, the nano silver conductive adhesive layer and the nano carbon tube conductive adhesive layer all have good bonding properties, can provide good binding force to the gathering area, and reduce the risk of cracking during welding of the gathering area. The graphite conductive adhesive layer, the metal particle conductive adhesive layer, the nano silver conductive adhesive layer and the nano carbon tube conductive adhesive layer also have good conductivity. When the gathering area is cracked at the welding position due to welding energy, they can play a good conductive role, so as to provide a current path inside the cracked part of the component, effectively alleviate the problem of power drop caused by cracking of the first gathering area and reduce the risk of battery cell failure, thereby improving the reliability of the battery cell.

[0019] In some embodiments of the first aspect of the present application, in a projection plane perpendicular to the first direction, the orthographic projection of the conductive adhesive layer is a rectangle or a circle.

[0020] In the above technical solution, in the projection plane perpendicular to the first direction, the orthographic projection of the conductive adhesive layer is a rectangle or a circle, which makes the molding of the conductive adhesive layer simpler.

[0021] In some embodiments of the first aspect of the present application, along the first direction, a portion of the electrode lead-out portion is stacked with the gathering portion, and in the two first gathering areas, at least one surface of the first gathering area close to the electrode lead-out portion is provided with the conductive adhesive layer.

[0022] In the above technical solution, at least one surface of the first gathering area close to the electrode lead-out part is provided with a conductive adhesive layer, which facilitates welding of the electrode lead-out part and the gathering area from the side of the electrode lead-out part away from the first gathering area closest to the electrode lead-out part. When welding the electrode lead-out part and the gathering area from the side of the electrode lead-out part away from the first gathering area closest to the electrode lead-out part, the first gathering area close to the electrode lead-out part is restrained by the conductive adhesive layer, and the first gathering area close to the electrode lead-out part is at risk of cracking at the welding position due to the welding energy, thereby improving the reliability of welding the electrode lead-out part and the gathering area from the side of the electrode lead-out part away from the first gathering area closest to the electrode lead-out part, thereby reducing the risk of battery cell failure and improving the reliability of battery cells.

[0023] In some embodiments of the first aspect of the present application, along the first direction, a portion of the electrode lead-out portion is stacked with the gathering portion, and in the two first gathering areas, at least one surface of the first gathering area away from the electrode lead-out portion is provided with the conductive adhesive layer.

[0024] In the above technical scheme, in the two first gathering areas, at least one surface of the first gathering area away from the electrode lead-out portion is provided with a conductive adhesive layer, so as to facilitate welding the electrode lead-out portion and the gathering area on the side of the gathering area away from the electrode lead-out portion. When welding the electrode lead-out portion and the gathering area from the side of the gathering area away from the electrode lead-out portion, the first gathering area away from the electrode lead-out portion is restrained by the conductive adhesive layer. The first gathering area away from the electrode lead-out portion is at risk of cracking at the welding position due to the welding energy, thereby improving the reliability of welding the electrode lead-out portion and the gathering area from the side of the gathering area away from the back of the electrode lead-out portion, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell.

[0025] In some embodiments of the first aspect of the present application, the electrode assembly includes a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab each include a plurality of the first electrode tabs, and the thickness of the conductive adhesive layer in the first gathering area of ​​the gathering portion of the positive electrode tab is greater than the thickness of the conductive adhesive layer in the first gathering area of ​​the gathering portion of the negative electrode tab.

[0026] In the above technical solution, both the positive electrode tab and the negative electrode tab include a plurality of first tabs. In the positive electrode tab and the negative electrode tab, when the first gathering area provided with the conductive adhesive layer is closest to the welding equipment during welding, the conductive adhesive layer has a binding effect on the first gathering area, which can reduce the risk of the first gathering area cracking at the welding position due to welding energy, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell. Even if the first gathering area cracks at the welding position due to welding energy, the conductive adhesive layer can solidify the cracked first gathering area, alleviate the degree of morphological change of the first gathering area after the first gathering area cracks at the welding position, for example, alleviate the degree of warping of the first gathering area after the first gathering area cracks at the welding position, reduce the risk of reliability problems of the battery cell due to excessive morphological changes of the first gathering area after the first gathering area cracks, and further improve the reliability of the battery cell. The thickness of the conductive adhesive layer in the first gathering area of ​​the gathering part of the positive electrode tab is greater than the thickness of the conductive adhesive layer in the first gathering area of ​​the gathering part of the negative electrode tab, which can provide greater binding force for the gathering area of ​​the positive electrode tab and can alleviate the problem of the first tab of the positive electrode tab being more prone to cracking during welding to a certain extent.

[0027] In some embodiments of the first aspect of the present application, the electrode assembly includes a positive electrode tab and a negative electrode tab, and the positive electrode tab or the negative electrode tab includes a plurality of the first electrode tabs; the battery cell includes two electrode lead-out portions, one electrode lead-out portion is connected to the gathered portions of the plurality of the first electrode tabs of the positive electrode tab, and the other electrode lead-out portion is connected to the gathered portions of the plurality of the first electrode tabs of the negative electrode tab.

[0028] In the above technical solution, both the positive electrode tab and the negative electrode tab include a plurality of first tabs. In the positive electrode tab and the negative electrode tab, when the first gathering area provided with the conductive adhesive layer is closest to the welding equipment during welding, the conductive adhesive layer has a binding effect on the first gathering area, which can reduce the risk of the first gathering area cracking at the welding position due to welding energy, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell. Even if the first gathering area cracks at the welding position due to welding energy, the conductive adhesive layer can solidify the cracked first gathering area, alleviate the degree of morphological change of the first gathering area after the first gathering area cracks at the welding position, for example, alleviate the degree of warping of the first gathering area after the first gathering area cracks at the welding position, reduce the risk of reliability problems of the battery cell due to excessive morphological changes of the first gathering area after the first gathering area cracks, and further improve the reliability of the battery cell. One electrode lead-out portion is connected to the gathered portion of the first plurality of positive electrode tabs, and the other electrode lead-out portion is connected to the gathered portion of the first plurality of negative electrode tabs, so as to facilitate leading out the electrodes of the battery cell, thereby facilitating charging and discharging of the battery cell.

[0029] In a second aspect, an embodiment of the present application provides a battery device, comprising a battery cell provided by any of the above embodiments.

[0030] In the above technical solution, the battery cell provided by any of the above embodiments has good reliability, and the electrical device including the battery cell also has good reliability.

[0031] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any of the above embodiments or a battery device provided by the above embodiments.

[0032] In the above technical solutions, the battery cells and battery devices provided by any of the above embodiments have good reliability, which is beneficial to improving the power consumption reliability of the power consumption devices powered by the battery cells and battery devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0035] Figure 2 An exploded view of a battery device provided in some embodiments of the present application;

[0036] Figure 3 An exploded view of a battery cell provided for some embodiments of the present application;

[0037] Figure 4 An axonometric view of a battery cell provided for some embodiments of the present application;

[0038] Figure 5 for Figure 4 A1-A1 sectional view;

[0039] Figure 6 for Figure 5 A schematic diagram of the structure of the electrode assembly;

[0040] Figure 7 A schematic diagram of the structure of an electrode assembly provided in some other embodiments of the present application;

[0041] Figure 8 for Figure 5 A schematic diagram of the structure of the electrode assembly in FIG. 1 (showing the thickness of the conductive adhesive layer);

[0042] Fig. 9 A schematic diagram of the structure of a conductive adhesive layer in a gathered area provided in some embodiments of the present application;

[0043] Fig.10 A schematic diagram of the structure of the conductive adhesive layer in the gathered area provided in some other embodiments of the present application;

[0044] Fig.11 A schematic diagram of the coordination of the gathering portion and the electrode lead-out portion provided in some embodiments of the present application;

[0045] Fig.12 Schematic diagram of the coordination of the folded portion and the electrode lead-out portion provided in other embodiments of the present application.

[0046] Icons: 1000-vehicle; 100-battery device; 10-housing; 11-first housing; 12-second housing; 20-battery cell; 21-housing; 211-shell; 2111-opening; 212-end cover; 22-electrode assembly; 221-main body; 222a-positive pole ear; 222b-negative pole ear; 222-first pole ear; 2221-connecting area; 2222'-folding part; 2222-folding area; 22221-first folding area; 22222-first intermediate folding area; Q1-first outer surface; Q2-second surface; 23-electrode terminal; 24-current collecting member; 25-electrode lead-out portion; 26-conductive adhesive layer; 200-controller; 300-motor; X-first direction. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0049] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0050] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0052] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0053] The term “plurality” used in this application refers to two or more (including two).

[0054] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0055] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0056] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to reduce the risk of short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0057] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0058] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0059] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0060] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0061] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0062] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0063] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0064] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

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

[0066] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0067] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0068] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical stability and mechanical stability.

[0069] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0070] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0071] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0072] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0073] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0074] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0075] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0076] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0077] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0078] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0079] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0080] In some embodiments, the electrode assembly is a laminate structure.

[0081] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0082] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet is folded to form a plurality of stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0083] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded sections.

[0084] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0085] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0086] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0087] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0088] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate the electrode assembly 22 and components such as the electrolyte. The housing may 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.

[0089] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery cell, such as a hexagonal battery cell.

[0090] The battery apparatus 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, in parallel or in mixed connection through a busbar.

[0091] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module.

[0092] As an example, a battery module may be formed by bundling a plurality of battery cells by cable ties.

[0093] In some embodiments, the battery device may be a battery pack, which may include a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0094] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0095] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0096] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0097] As an example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0098] As an example, the box body can be used as a part of the chassis structure of the vehicle. For example, the top cover of the box body can become at least a part of the floor of the vehicle, or the frame of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0099] In some embodiments, the battery device refers to an energy storage device, which includes a box body, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0100] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important part of the development of new energy today. The development of battery technology must consider many design factors at the same time, such as performance parameters such as energy density, cycle life, discharge capacity, and charge and discharge rate. In addition, the reliability of the battery must also be considered.

[0101] The electrode assembly of the battery cell includes a positive electrode tab and a negative electrode tab. The positive electrode tab includes a plurality of positive electrode tabs, each of which has a positive electrode gathering area, and the positive electrode gathering areas of the plurality of positive electrode tabs are stacked to form a positive electrode gathering part; the negative electrode tab includes a plurality of negative electrode tabs, each of which has a negative electrode gathering area, and the negative electrode gathering areas of the plurality of negative electrode tabs are stacked to form a negative electrode gathering part. The positive electrode gathering areas can be welded to form a positive electrode gathering part, and the negative electrode gathering areas can be welded to form a negative electrode gathering part. The positive electrode gathering part and the electrode lead-out part (such as a current collecting component) can be welded, and the negative electrode gathering part and the electrode lead-out part (such as a current collecting component) can be welded. When welding multiple positive electrode gathering areas to form a positive electrode gathering portion, and / or welding the positive electrode gathering portion to the electrode lead-out portion and welding multiple negative electrode gathering areas to form a negative electrode gathering portion, and / or welding the negative electrode gathering portion to the electrode lead-out portion, the positive electrode gathering areas closer to the welding equipment among the multiple positive electrode gathering areas are subjected to greater welding energy, and the positive electrode gathering areas closer to the welding equipment are more likely to crack, and the negative electrode gathering areas closer to the welding equipment among the multiple negative electrode gathering areas are subjected to greater welding energy, and the negative electrode gathering areas closer to the welding equipment are more likely to crack, which can easily lead to battery cell failure after the gathering areas are cracked, thereby reducing the reliability of the battery cell.

[0102] Based on the above considerations, in order to solve the problem that the pole ear is easy to crack during welding, an embodiment of the present application provides a battery cell, the battery cell includes an electrode assembly and an electrode lead-out portion; the electrode assembly includes a main body and a plurality of first pole ears, the plurality of first pole ears are connected to the same end of the main body, the first pole ear includes a connecting area and a gathering area, the connecting area connects the gathering area and the main body, the gathering areas of the plurality of first pole ears are stacked and welded along a first direction to form a gathering part; the electrode lead-out portion is connected to the gathering part; wherein, along the first direction, the two gathering areas in the gathering part that are farthest apart are first gatherings, and at least one surface of at least one first gathering area is provided with a conductive adhesive layer.

[0103] The two furthest-separated gathering areas in the gathering part are the first gathering areas, and at least one surface of at least one first gathering area is provided with a conductive adhesive layer. When the plurality of gathering areas are welded to form the gathering part, and / or when the gathering part is welded to the electrode lead-out part, one of the two first gathering areas is closest to the welding equipment, and the welding energy borne by the first gathering area is the largest. When the first gathering area provided with the conductive adhesive layer is closest to the welding equipment during welding, the conductive adhesive layer has a binding effect on the first gathering area, which can reduce the risk of the first gathering area cracking at the welding position due to the welding energy, thereby reducing the risk of battery cell failure and improving the reliability of the battery cell. Even if the first gathering area is cracked at the welding position due to the welding energy, since the conductive adhesive has conductive properties, the conductive adhesive can play a conductive role, so as to provide a current path inside the cracked part of the component, alleviate the problem of power drop caused by the cracking of the first gathering area and reduce the risk of battery cell failure, thereby improving the reliability of the battery cell. Even if the first gathering area is cracked at the welding position due to welding energy, the conductive adhesive layer can solidify the cracked first gathering area, and alleviate the degree of morphological change of the first gathering area after the first gathering area is cracked at the welding position. For example, it can alleviate the degree of warping of the first gathering area after the first gathering area is cracked at the welding position, reduce the risk of reliability problems of the battery cell 20 caused by excessive degree of morphological change of the first gathering area after the first gathering area is cracked, and further improve the reliability of the battery cell.

[0104] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery cells and battery devices, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0105] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0106] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 is provided with a battery device 100 inside, and the battery device 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000, for example, the battery device 100 can be used as an operating power source of the vehicle 1000.

[0107] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery device 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0108] In some embodiments of the present application, the battery device 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0109] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 may include a case 10 and a battery cell 20 . The case 10 is used to accommodate the battery cell 20 .

[0110] Among them, a closed space for accommodating the battery cell 20 is formed inside the box 10. The box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first box 11 and a second box 12, and the first box 11 and the second box 12 are buckled with each other. The first box 11 and the second box 12 can be in various shapes, such as a cuboid, a cylinder, etc. The first box 11 can be a hollow structure with one side open, and the second box 12 can also be a hollow structure with one side open. The open side of the second box 12 is buckled with the open side of the first box 11 to form a box 10 with a closed space. It is also possible that the first box 11 is a hollow structure with one side open, and the second box 12 is a plate-like structure. The second box 12 is buckled on the open side of the first box 11, so as to form a box 10 with a accommodating space.

[0111] In the battery device 100, there may be one or more battery cells 20. If there are more than one battery cell 20, the battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 20 are connected in series and in parallel. A battery module may be formed by connecting a plurality of battery cells 20 in series, in parallel, or in a mixed connection, and then the plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole and accommodated in the box 10. Alternatively, all the battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by all the battery cells 20 is accommodated in the box 10.

[0112] In some embodiments, the battery device 100 may further include a busbar component (not shown in the figure), and the multiple battery cells 20 may be electrically connected through the busbar component to achieve series connection, parallel connection, or mixed connection of the multiple battery cells 20. The busbar component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0113] Please refer to Figure 3 and Figure 4 , Figure 3 An exploded view of a battery cell 20 provided in some embodiments of the present application; Figure 4 for Figure 3The battery cell 20 is shown in an isometric view. The battery cell 20 may include a housing 21 and an electrode assembly 22 , wherein the electrode assembly 22 is accommodated in the housing 21 .

[0114] In some embodiments, the housing 21 may include a shell 211 and an end cap 212, wherein the shell 211 has an opening 2111, and the end cap 212 closes the opening 2111 of the shell 211. The closing here means covering or closing, which may be sealed or unsealed.

[0115] The shell 211 is a component for accommodating the electrode assembly 22. The shell 211 may be a hollow structure with an opening 2111 formed at one end, or a hollow structure with openings 2111 formed at opposite ends. The shell 211 may be in various shapes, such as a cylindrical shape, a rectangular parallelepiped shape, etc. The material of the shell 211 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The electrode assembly 22 may be partially located in the shell 211, or may be completely located in the shell 211.

[0116] The end cap 212 and the shell 211 together define a receiving space for accommodating the electrode assembly 22 and other components. The end cap 212 can be connected to the shell 211 by welding, crimping, etc. to close the opening 2111 of the shell 211. The shape of the end cap 212 can be adapted to the shape of the shell 211. For example, the shell 211 is a rectangular parallelepiped structure, and the end cap 212 is a rectangular plate structure adapted to the shell 211. For another example, the shell 211 is a cylindrical structure, and the end cap 212 is a circular plate structure adapted to the shell 211. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 212 and the shell 211 can be the same or different.

[0117] In the embodiment where the housing 211 forms an opening 2111 at one end, one end cap 212 may be provided accordingly. In the embodiment where the housing 211 forms openings 2111 at two opposite ends, two end caps 212 may be provided accordingly, and the two end caps 212 respectively close the two openings 2111 of the housing 211, and the two end caps 212 and the housing 211 together define a receiving space.

[0118] In some embodiments, the battery cell 20 may further include an electrode terminal 23, which is disposed on the housing 21, and is used to electrically connect to the tab of the electrode assembly 22 to input or output the electrical energy of the battery cell 20. The electrode terminal 23 may be disposed on the shell 211 of the housing 21, or may be disposed on the end cover 212 of the housing 21. The electrode terminal 23 may be directly connected to the tab, for example, the electrode terminal 23 is welded to the tab. The electrode terminal 23 may also be indirectly connected to the tab, for example, the electrode terminal 23 is indirectly connected to the tab through a current collecting member 24. The current collecting member 24 may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0119] As an example, Figure 3 and Figure 4 As shown, an opening 2111 is formed at one end of the shell 211, and there is one end cap 212 in the shell 21, and one end cap 212 closes one opening 2111 of the shell 211. Two electrode terminals 23 are provided on the end cap 212, and the two electrode terminals 23 are respectively a positive electrode terminal 23 and a negative electrode terminal 23. A positive electrode tab 222a and a negative electrode tab 222b are formed at one end of the electrode assembly 22 facing the end cap 212, and the positive electrode terminal 23 is electrically connected to the positive electrode tab 222a, and the negative electrode terminal 23 is electrically connected to the negative electrode tab 222b.

[0120] Please refer to Figure 5 and Figure 6 , Figure 5 for Figure 4 A1-A1 cross-sectional view, Figure 6 for Figure 5 A schematic diagram of the structure of the electrode assembly 22 in the embodiment of the present application. The embodiment of the present application provides a battery cell 20, the battery cell 20 includes an electrode assembly 22 and an electrode lead-out portion 25; the electrode assembly 22 includes a main body 221 and a plurality of first pole tabs 222, the plurality of first pole tabs 222 are connected to the same end of the main body 221, the first pole tab 222 includes a connection area 2221 and a gathering area 2222, the connection area 2221 connects the gathering area 2222 and the main body 221, the gathering areas 2222 of the plurality of first pole tabs 222 are stacked and welded along a first direction X to form a gathering part 2222'; the electrode lead-out portion 25 is connected to the gathering part 2222'; wherein, along the first direction X, the two gathering areas 2222 in the gathering part 2222' that are farthest apart are first gathering areas 22221, and at least one surface of at least one first gathering area 22221 is provided with a conductive adhesive layer 26.

[0121] The electrode assembly 22 includes a positive electrode sheet, a negative electrode sheet and a separator, and the separator is used to insulate and separate the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the negative electrode sheet and the separator are stacked in a certain order to form a laminated electrode assembly 22. The positive electrode sheet, the negative electrode sheet and the separator are stacked in a certain order and wound around a winding axis to form a wound electrode assembly 22. Figure 5 and Figure 6 , the electrode assembly 22 is shown as a wound structure.

[0122] The positive electrode sheet includes a positive current collecting layer, a positive active material layer and a positive electrode tab 222a. Along the thickness direction of the positive electrode sheet, a positive active position layer is provided on at least one side of the positive current collecting layer. The positive electrode tab 222a is connected to one end of the positive electrode tab 222a along the positive electrode sheet, and the positive electrode tab 222a and the positive current collecting layer together form a positive current collector of the positive electrode sheet. The positive current collecting layer and the positive electrode tab 222a can be integrally formed, for example, by die-cutting the same current collector to form an integral positive current collecting layer and positive electrode tab 222a, which facilitates the manufacturing and forming of the positive electrode sheet and is conducive to improving production efficiency.

[0123] The positive electrode current collecting layer and the positive electrode tab 222a can also be separate structures. For example, different current collectors are die-cut separately to form separate positive electrode current collecting layer and positive electrode tab 222a, and then the positive electrode current collecting layer and the positive electrode tab 222a are connected as a whole through conductive glue, welding and other connection methods to form a positive electrode current collector of the positive electrode sheet, so that the structural setting of the positive electrode current collector is more flexible.

[0124] In some embodiments, the positive electrode current collector layer and the positive electrode active material layer together form a positive electrode body of the positive electrode sheet.

[0125] In other embodiments, the positive electrode current collector layer includes a first region provided with a positive electrode active material layer and a second region not provided with a positive electrode active material layer, the first region and the second region are arranged and connected along the width direction of the positive electrode plate, the positive electrode tab 222a is connected to the end of the second region away from the first region, and the surface of the second region facing the positive electrode active material layer is provided with an insulating member, and the insulating member is used to reduce the risk of burrs generated when die-cutting the negative electrode tab 222b piercing the separator and causing a short circuit. The positive electrode current collector layer, the positive electrode active material layer and the insulating layer together form the positive electrode body of the positive electrode plate.

[0126] The negative electrode sheet includes a negative current collecting layer, a negative active material layer and a negative electrode tab 222b. Along the thickness direction of the negative electrode sheet, a negative active position layer is provided on at least one side of the negative current collecting layer. The negative electrode tab 222b is connected to one end of the negative electrode tab 222b along the negative electrode sheet, and the negative electrode tab 222b and the negative current collecting layer together form a negative current collector of the negative electrode sheet. The negative current collecting layer and the negative electrode tab 222b can be integrally formed, for example, by die-cutting the same current collector to form an integral negative current collecting layer and negative electrode tab 222b, which facilitates the manufacturing and forming of the negative electrode sheet and is conducive to improving production efficiency.

[0127] The negative electrode current collecting layer and the negative electrode tab 222b can also be separate structures. For example, different current collectors are die-cut separately to form separate negative electrode current collecting layer and negative electrode tab 222b, and then the negative electrode current collecting layer and the negative electrode tab 222b are connected as a whole through conductive glue, welding and other connection methods to form a negative electrode current collector of the negative electrode sheet, so that the structural setting of the negative electrode current collector is more flexible.

[0128] In some embodiments, the negative electrode current collector layer and the negative electrode active material layer together form a negative electrode body of the negative electrode sheet.

[0129] The negative electrode body, the positive electrode body, and the separator form a main body portion 221 of the electrode assembly 22 .

[0130] like Figure 6 As shown, in some embodiments, the positive electrode tab 222a or the negative electrode tab 222b includes multiple first electrode tabs 222, and the first electrode tab 222 is a part of the positive electrode tab 222a or the first electrode tab 222 is a part of the negative electrode tab 222b. It can be understood that multiple first electrode tabs 222 together form the positive electrode tab 222a, or multiple first electrode tabs 222 together form the negative electrode tab 222b.

[0131] In other embodiments, the positive electrode tab 222a and the negative electrode tab 222b both include a plurality of first electrode tabs 222 . It can be understood that the positive electrode tab 222a is formed by a plurality of first electrode tabs 222 , and the negative electrode tab 222b is formed by a plurality of first electrode tabs 222 .

[0132] like Figure 5 , Figure 6 As shown, in the positive electrode tab 222a and / or the negative electrode tab 222b, the connection parts of the plurality of first tabs 222 are stacked. After the positive electrode tab 222a is bent, the connection part of the first tab 222 of the positive electrode tab 222a is the bent part connecting the gathered area 2222 and the main body 221. After the negative electrode tab 222b is bent, the connection part of the first tab 222 of the negative electrode tab 222b is the bent part connecting the gathered area 2222 and the main body 221.

[0133] There may be no connection between the connection parts of the plurality of first electrode tabs 222. The connection parts of two adjacent first electrode tabs 222 may be in contact, or there may be a gap between them, or they may be in contact in some areas and there may be a gap in other areas.

[0134] In the positive electrode tab 222a and / or the negative electrode tab 222b, the gathered areas 2222 of the plurality of first tabs 222 are stacked and welded along the first direction X to form a gathered portion 2222'. The gathered areas 2222 are welded so that the first tabs 222 are electrically connected. The gathered areas 2222 of the plurality of first tabs 222 can be welded by laser welding, ultrasonic welding, etc. to form the gathered portion 2222'. The first direction X can be any direction, for example, Figure 5 and Figure 6 , the first direction X is parallel to the extending direction of the winding axis of the electrode assembly 22 .

[0135] The electrode lead-out portion 25 is a component electrically connected to the electrode assembly 22. If the electrode lead-out portion 25 is connected to the gathered portion 2222' of the plurality of first pole tabs 222 of the positive pole tab 222a, the electrode lead-out portion 25 forms the positive electrode of the battery cell 20. If the electrode lead-out portion 25 is connected to the gathered portion 2222' of the plurality of first pole tabs 222 of the negative pole tab 222b, the electrode lead-out portion 25 forms the negative electrode of the battery cell 20, and the battery cell 20 can be charged or discharged through the electrode lead-out portion 25. The electrode lead-out portion 25 may be in various forms. For example, the electrode lead-out portion 25 may be an electrode terminal 23, that is, the electrode terminal 23 is connected to the gathering portion 2222'; for example, the electrode lead-out portion 25 may include a current collecting component 24 and an electrode terminal 23, and the electrode terminal 23 and the gathering portion 2222' are connected via the current collecting component 24; for another example, the electrode lead-out portion 25 may be a shell 211, and the gathering portion 2222' is connected to the shell 211. Figure 3 FIG. 2 shows a case where the electrode lead portion 25 is an electrode terminal 23. Figure 5 2 shows a case where the electrode lead-out portion 25 includes the electrode terminal 23 and the current collecting member 24 .

[0136] The battery cell 20 has two electrode lead-out portions 25, one electrode lead-out portion 25 is electrically connected to the positive electrode tab 222a to form the positive electrode of the battery cell 20, and the other electrode lead-out portion 25 is electrically connected to the negative electrode tab 222b to form the negative electrode of the battery cell 20. The two electrode lead-out portions 25 may have the same structure, for example, both electrode lead-out portions 25 are electrode terminals 23, or both electrode lead-out portions 25 include current collecting members 24 and electrode terminals 23. The two electrode lead-out portions 25 may also have different structures, for example, one electrode lead-out portion 25 is a shell 211, and the other electrode lead-out portion 25 includes a current collecting member 24 and an electrode terminal 23; or one electrode lead-out portion 25 is a shell 211, and the other electrode lead-out portion 25 is an electrode terminal 23; or one electrode lead-out portion 25 is an electrode terminal 23, and the other electrode lead-out portion 25 includes a current collecting member 24 and an electrode terminal 23.

[0137] The conductive adhesive layer 26 may be formed by coating slurry on the gathered area 2222 and then solidifying it. The conductive adhesive layer 26 may also be a solid colloid bonded to the gathered area 2222, such as adhesive tape.

[0138] A conductive adhesive layer 26 may be provided on the surface of one of the two first gathering areas 22221. Then, when welding to form the gathering portion 2222' or welding to connect the gathering portion 2222' and the electrode lead-out portion 25, the first gathering area 22221 provided with the conductive adhesive layer 26 can be made closer to the welding equipment than other gathering areas 2222, thereby reducing the risk of cracking of the gathering area 2222 closest to the welding equipment during welding.

[0139] The surfaces of the two first gathering areas 22221 can be both provided with a conductive adhesive layer 26. When welding to form the gathering portion 2222' or welding to connect the gathering portion 2222' and the electrode lead portion 25, any one of the first gathering areas 22221 can be selected to be closer to the welding equipment according to actual needs to facilitate welding.

[0140] The conductive adhesive layer 26 is disposed on the surface of the first gathered area 22221 in the thickness direction, that is, the conductive adhesive layer 26 is disposed on the surface of the first gathered area 22221 in the first direction X. Along the first direction X, the first gathered area 22221 may be provided with the conductive adhesive layer 26 on only one surface, which can reduce the risk of cracking of the first gathered area 22221 during welding, and can also alleviate the problem of the gathered portion 2222' being too large in size due to the provision of the conductive adhesive layer 26, and alleviate the problem of the conductive adhesive layer 26 occupying too much internal space of the battery cell 20, which is conducive to the battery cell 20 having a higher energy density.

[0141] Along the first direction X, the first gathering area 22221 may also be provided with a conductive adhesive layer 26 on two opposite surfaces, which can further reduce the risk of cracking of the first gathering area 22221 at the welding position due to welding energy, thereby reducing the risk of further failure of the battery cell 20 and improving the reliability of the battery cell 20.

[0142] The conductive adhesive layer 26 is an adhesive having a certain conductivity after being cured or dried.

[0143] The conductive adhesive layer 26 includes a resin matrix, and commonly used adhesive systems include thermosetting adhesives such as epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane, acrylic resin, etc. These adhesives form a molecular skeleton structure of the conductive adhesive layer 26 after curing, provide mechanical properties and bonding performance guarantees, and form channels for the conductive filler particles. Since epoxy resin can be cured at room temperature or below 150°C and has a rich formula design performance, the epoxy resin-based conductive adhesive layer 26 is dominant.

[0144] The conductive adhesive layer 26 requires that the conductive particles themselves have good conductive properties and a particle size within a suitable range, and can be added to the matrix of the conductive adhesive layer 26 to form a conductive path. The conductive filler can be gold, silver, copper, aluminum, zinc, iron, nickel powder, graphite and some conductive compounds.

[0145] The conductive fillers of the conductive adhesive layer 26 generally include three categories: carbon, metal, and metal oxide. For example, the conductive fillers may be metal powders with low resistivity such as Au, Ag, Cu, and Ni.

[0146] The two furthest apart gathering areas 2222 in the gathering portion 2222' are the first gathering areas 22221, and at least one surface of at least one first gathering area 22221 is provided with a conductive adhesive layer 26. When a plurality of gathering areas 2222 are welded to form a gathering portion 2222', and / or when the gathering portion 2222' is welded to the electrode lead-out portion 25, one of the two first gathering areas 22221 is closest to the welding equipment, and the welding energy borne by the first gathering area 22221 is the largest. When the first gathering area 22221 provided with the conductive adhesive layer 26 is closest to the welding equipment during welding, the conductive adhesive layer 26 has a binding effect on the first gathering area 22221, which can reduce the risk of the first gathering area 22221 cracking at the welding position due to the welding energy, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20. Even if the first gathered area 22221 is cracked at the welding position due to welding energy, the conductive adhesive has conductive properties and can play a conductive role, so as to provide a current path inside the cracked part of the component, thereby alleviating the problem of power drop caused by the cracking of the first gathered area 22221 and reducing the risk of failure of the battery cell 20, thereby improving the reliability of the battery cell 20. Even if the first gathered area 22221 is cracked at the welding position due to welding energy, the conductive adhesive layer 26 can solidify the cracked first gathered area 22221, and alleviate the degree of morphological change of the first gathered area 22221 after the first gathered area 22221 is cracked at the welding position, for example, it can alleviate the degree of warping of the first gathered area 22221 after the first gathered area 22221 is cracked at the welding position, and reduce the risk of reliability problems of the battery cell 20 caused by excessive morphological changes of the first gathered area 22221 after the first gathered area 22221 is cracked, thereby further improving the reliability of the battery cell 20.

[0147] like Figure 6 , Figure 7 As shown, in some embodiments, along the first direction X, the gathered portion 2222 ′ has two opposite first outer surfaces Q1 , a first gathered area 22221 has a first outer surface Q1 , and at least one first outer surface Q1 is provided with a conductive adhesive layer 26 .

[0148] The two first outer surfaces Q1 are respectively the two surfaces of the gathering portion 2222' that are farthest apart along the first direction X. One first outer surface Q1 is a surface of a first gathering area 22221 away from another first gathering area 22221 in the first direction X, and the other first outer surface Q1 is a surface of another first gathering area 22221 away from one first gathering area 22221 in the first direction X. Figure 6 FIG. 2 shows a situation where only the first outer surface Q1 of one first gathering area 22221 is provided with the conductive adhesive layer 26 . Figure 7 FIG. 2 shows the situation where the first outer surfaces Q1 of the two first gathered areas 22221 are both provided with a conductive adhesive layer 26 .

[0149] At least one first outer surface Q1 is provided with a conductive adhesive layer 26. When the first outer surface Q1 provided with the conductive adhesive layer 26 is closest to the welding equipment during welding, the conductive adhesive layer 26 has a binding effect on the first gathering area 22221, which can further reduce the risk of the first gathering area 22221 cracking at the welding position due to the welding energy, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20.

[0150] like Figure 6 , Figure 7 As shown, in some embodiments, along the first direction X, two opposite surfaces of at least one first gathering area 22221 are both provided with a conductive adhesive layer 26 .

[0151] The first gathering area 22221 further includes a second surface Q2. Along the first direction X, the first outer surface Q1 and the second surface Q2 of the same first gathering area 22221 are arranged opposite to each other.

[0152] The plurality of gathered areas 2222 also include a first intermediate gathered area 22222 adjacent to the first gathered area 22221. In some embodiments, the conductive adhesive layer 26 disposed on the second surface Q2 is connected to the second intermediate gathered area 2222 along the first direction X away from the surface of the second surface Q2, so that the conductive adhesive layer 26 disposed on the second surface Q2 can not only restrain the first gathered area 22221, but also restrain the first intermediate pole ear, and can simultaneously reduce the risk of cracking of the first gathered area 22221 and the first intermediate gathered area 22222 during welding.

[0153] like Figure 6 , Figure 7 As shown, two surfaces of a first gathering area 22221 opposite to each other along the first direction X may be provided with a conductive adhesive layer 26 .

[0154] In some other embodiments, two surfaces of the two first gathered areas 22221 that are opposite to each other along the first direction X may be provided with a conductive adhesive layer 26 .

[0155] Along the first direction X, two opposite surfaces of at least one first gathering area 22221 are provided with a conductive adhesive layer 26. The conductive adhesive layers 26 on both sides of the first gathering area 22221 can provide a better binding effect for the first gathering area 22221. When the first gathering area 22221 provided with the conductive adhesive layer 26 is closest to the welding equipment during welding, the risk of cracking of the first gathering area 22221 at the welding position due to the welding energy can be further reduced, thereby reducing the risk of further failure of the battery cell 20 and improving the reliability of the battery cell 20.

[0156] In some embodiments, the number of the gathering areas 2222 in the gathering portion 2222' is m, and in the n continuously stacked gathering areas 2222, a conductive adhesive layer 26 is disposed between two adjacent gathering areas 2222, and the n gathering areas 2222 include at least one first gathering area 22221, and m≥n≥2.

[0157] The two opposite surfaces of the conductive adhesive layer 26 between two adjacent gathering areas 2222 along the first direction X are respectively connected to the two adjacent gathering areas 2222, that is, the two adjacent gathering areas 2222 share a conductive adhesive layer 26, and the conductive adhesive layer 26 can provide constraints for the two adjacent gathering areas 2222 at the same time, and can reduce the risk of cracking of the two adjacent gathering areas 2222 at the same time.

[0158] A conductive adhesive layer 26 may be disposed between every two adjacent gathered areas 2222 , and then n=m.

[0159] A conductive adhesive layer 26 may also be provided between some adjacent gathered areas 2222 , and then n<m. Figure 6 The case where n<m is shown in FIG.

[0160] In the n continuously stacked gathering areas 2222, a conductive adhesive layer 26 is arranged between two adjacent gathering areas 2222, and the n gathering areas 2222 include at least one first gathering area 22221, m≥n≥2, and the gathering area 2222 continuously arranged with the first gathering area 22221 is provided with a conductive adhesive layer 26, which can reduce the risk of cracking of other gathering areas 2222 close to the first gathering area 22221 during welding, further reduce the risk of failure of the battery cell 20, and further improve the reliability of the battery cell 20.

[0161] In some embodiments, n=2 or n=3. Figure 6 The case where n=3 and m=4 is shown in FIG.

[0162] n=2 or n=3, which can ensure that a maximum of three continuously stacked gathering areas 2222 including a first gathering area 22221 are all provided with a conductive adhesive layer 26, thereby reducing the risk of cracking of other gathering areas 2222 close to the first gathering area 22221 during welding, and can also alleviate the problem of the gathering portion 2222' being too large in size due to the provision of the conductive adhesive layer 26, and alleviate the problem of the conductive adhesive layer 26 occupying too much internal space of the battery cell 20, which is beneficial for the battery cell 20 to have a higher energy density.

[0163] In some embodiments, the thickness of the conductive adhesive layer 26 is 1 μm-15 μm.

[0164] The thickness of the conductive adhesive layer 26 is the distance between two opposite surfaces of the conductive adhesive layer 26 in the first direction X. The thickness of any conductive adhesive layer 26 is 1 μm to 15 μm. In the case where the gathered portion 2222' is provided with a plurality of conductive adhesive layers 26, the thicknesses of the conductive adhesive layers 26 may be the same or different. Figure 8 As shown, the thicknesses of the three conductive adhesive layers 26 in the positive electrode tab 222a are H1, H2, and H3, respectively, 1 μm ≤ H1 ≤ 15 μm, 1 μm ≤ H2 ≤ 15 μm, 1 μm ≤ H3 ≤ 15 μm, and H1, H2, and H3 may be the same or different. The thicknesses of the three conductive adhesive layers 26 in the negative electrode tab 222b are H4, H5, and H6, respectively, 1 μm ≤ H4 ≤ 15 μm, 1 μm ≤ H5 ≤ 15 μm, and 1 μm ≤ H6 ≤ 15 μm, and H4, H5, and H6 may be the same or different.

[0165] Exemplarily, the thickness of the conductive adhesive layer 26 may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, etc.

[0166] The thickness of the conductive adhesive layer 26 is greater than or equal to 1 μm, and the conductive adhesive layer 26 has a good binding effect on the first gathered area 22221, which can reduce the risk of the first gathered area 22221 cracking at the welding position due to welding energy, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20. The thickness of the conductive adhesive layer 26 is less than or equal to 15 μm, and the thickness of the conductive adhesive layer 26 is controlled to alleviate the problem of the size of the gathered portion 2222' being too large due to setting the thickness of the conductive adhesive layer 26 too large, and alleviate the problem of the conductive adhesive layer 26 occupying too much internal space of the battery cell 20, which is conducive to the battery cell 20 having a higher energy density.

[0167] Furthermore, the thickness of the conductive adhesive layer 26 is 2 μm-10 μm.

[0168] Illustratively, the thickness of the conductive adhesive layer 26 may be 2 μm, 2.3 μm, 2.5 μm, 2.8 μm, 3.3 μm, 3.5 μm, 3.5 μm, 4.5 μm, 5.5 μm, 6.5 μm, 7.5 μm, 8.5 μm, 9.5 μm, 10 μm, etc.

[0169] The thickness of the conductive adhesive layer 26 is greater than or equal to 2 μm, and the conductive adhesive layer 26 has a better binding effect on the first gathered area 22221, which can further reduce the risk of the first gathered area 22221 cracking at the welding position due to welding energy, thereby further reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20. The thickness of the conductive adhesive layer 26 is less than or equal to 10 μm, which further controls the thickness of the conductive adhesive layer 26, further alleviates the problem of the gathered portion 2222' being too large due to the setting of the conductive adhesive layer 26 being too thick, and further alleviates the problem of the conductive adhesive layer 26 occupying too much internal space of the battery cell 20, which is conducive to the battery cell 20 having a higher energy density.

[0170] In some embodiments, the conductive adhesive layer 26 is a graphite conductive adhesive layer, a metal particle conductive adhesive layer, a nano-silver conductive adhesive layer, or a nano-carbon tube conductive adhesive layer.

[0171] Graphite conductive adhesive is a conductive adhesive made with graphite as a conductive additive. Graphite conductive adhesive has the advantages of low cost and low relative density.

[0172] Metal particle conductive adhesive refers to a conductive adhesive formed by combining metal particles such as copper, nickel, and iron with organic colloids. Metal particle conductive adhesive has low cost and is easy to process into various shapes.

[0173] The main components of nano-silver conductive adhesive are silver powder and organic solvent, which has excellent conductivity, corrosion resistance and weather resistance.

[0174] Nano-carbon tube conductive adhesive has excellent conductivity, flexibility, heat resistance and cold resistance, as well as good chemical stability.

[0175] The graphite conductive adhesive layer, the metal particle conductive adhesive layer, the nano silver conductive adhesive layer and the nano carbon tube conductive adhesive layer all have good bonding properties, and can provide good binding force to the gathering area 2222, reducing the risk of cracking during welding of the gathering area 2222. The graphite conductive adhesive layer, the metal particle conductive adhesive layer, the nano silver conductive adhesive layer and the nano carbon tube conductive adhesive layer also have good conductivity, and can play a good conductive role in the case where the gathering area 2222 is cracked at the welding position due to welding energy, so as to provide a current path inside the cracked part of the component, effectively alleviating the problem of power drop caused by cracking of the first gathering area 22221 and reducing the risk of failure of the battery cell 20, thereby improving the reliability of the battery cell 20.

[0176] like Fig. 9 , Fig.10 As shown, in some embodiments, in a projection plane perpendicular to the first direction X, the orthographic projection of the conductive adhesive layer 26 is a rectangle or a circle.

[0177] It can be understood that, in the projection plane perpendicular to the first direction X, the outline of the orthographic projection of the conductive adhesive layer 26 is a rectangle or a circle.

[0178] In the projection plane perpendicular to the first direction X, the orthographic projection of the conductive adhesive layer 26 is a rectangle or a circle, which makes the formation of the conductive adhesive layer 26 easier.

[0179] In other embodiments, in the projection plane perpendicular to the first direction X, the orthographic projection of the conductive adhesive layer 26 may also be other shapes, such as polygons other than rectangles, or other irregular shapes.

[0180] like Fig.11 As shown, in some embodiments, along the first direction X, a portion of the electrode lead portion 25 is stacked with the gathering portion 2222 ′, and in the two first gathering areas 22221 , at least one surface of the first gathering area 22221 close to the electrode lead portion 25 is provided with a conductive adhesive layer 26 .

[0181] Take the example that the first direction X is parallel to the extension direction of the winding axis of the electrode assembly 22. Fig.11 As shown, part of the electrode lead-out portion 25 is arranged on the side of the gathered portion 2222' away from the main body 221, at least one surface of the first gathered area 22221 farthest from the main body 221 is provided with a conductive adhesive layer 26, and the first gathered portion 2222' farthest from the main body 221 is the first gathered area 22221 close to the electrode lead-out portion 25. When the gathered portion 2222' and the electrode lead-out portion 25 are connected by welding, welding can be performed from the side of the electrode lead-out portion 25 away from the gathered portion 2222', which is more convenient.

[0182] At least one surface of the first gathering area 22221 close to the electrode lead-out portion 25 is provided with a conductive adhesive layer 26, so as to facilitate welding the electrode lead-out portion 25 and the gathering portion 2222' from the side of the electrode lead-out portion 25 away from the first gathering area 22221 closest to the electrode lead-out portion 25. When welding the electrode lead-out portion 25 and the gathering portion 2222' from the side of the electrode lead-out portion 25 away from the first gathering area 22221 closest to the electrode lead-out portion 25, the first gathering area 22221 close to the electrode lead-out portion 25 is restrained by the conductive adhesive layer 26, and the risk of cracking of the first gathering area 22221 close to the electrode lead-out portion 25 at the welding position due to the welding energy is reduced, thereby improving the reliability of welding the electrode lead-out portion 25 and the gathering portion 2222' from the side of the electrode lead-out portion 25 away from the first gathering area 22221 closest to the electrode lead-out portion 25, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20.

[0183] like Fig.12As shown, in other embodiments, along the first direction X, a portion of the electrode lead portion 25 is stacked with the gathering portion 2222 ′, and in the two first gathering areas 22221 , at least one surface of the first gathering area 22221 away from the electrode lead portion 25 is provided with a conductive adhesive layer 26 .

[0184] Take the example that the first direction X is parallel to the extension direction of the winding axis of the electrode assembly 22. Fig.12 As shown, part of the electrode lead-out portion 25 is arranged on the side of the gathering portion 2222' facing the main body portion 221, at least one surface of the first gathering area 22221 farthest from the main body portion 221 is provided with a conductive adhesive layer 26, and the first gathering portion 2222' farthest from the main body portion 221 is the first gathering area 22221 farthest from the electrode lead-out portion 25. When the gathering portion 2222' and the electrode lead-out portion 25 are connected by welding, welding can be performed from the side of the gathering portion 2222' away from the electrode lead-out portion 25, which is more convenient.

[0185] In the two first gathering areas 22221, at least one surface of the first gathering area 22221 away from the electrode lead-out portion 25 is provided with a conductive adhesive layer 26, so as to facilitate welding the electrode lead-out portion 25 and the gathering portion 2222' at the side of the gathering portion 2222' away from the electrode lead-out portion 25. When welding the electrode lead-out portion 25 and the gathering portion 2222' from the side of the gathering portion 2222' away from the electrode lead-out portion 25, the first gathering area 22221 away from the electrode lead-out portion 25 is restrained by the conductive adhesive layer 26, and the risk of cracking of the first gathering area 22221 away from the electrode lead-out portion 25 at the welding position due to the welding energy is reduced, thereby improving the reliability of welding the electrode lead-out portion 25 and the gathering portion 2222' from the side of the gathering portion 2222' away from the back of the electrode lead-out portion 25, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20.

[0186] In some embodiments, the electrode assembly 22 includes a positive electrode tab 222a and a negative electrode tab 222b, each of the positive electrode tab 222a and the negative electrode tab 222b includes a plurality of first electrode tabs 222, and the thickness of the conductive adhesive layer 26 in the first gathering area 22221 of the gathering portion 2222' of the positive electrode tab 222a is greater than the thickness of the conductive adhesive layer 26 in the first gathering area 22221 of the gathering portion 2222' of the negative electrode tab 222b.

[0187] The thickness of the conductive adhesive layer 26 in the first gathered area 22221 of the gathered portion 2222' of the positive electrode tab 222a may only be greater than the thickness of the conductive adhesive layer 26 in the first gathered area 22221 of the gathered portion 2222' of the negative electrode tab 222b. The thickness of the conductive adhesive layer 26 in the first gathered area 22221 of the gathered portion 2222' of the positive electrode tab 222a may also be greater than the thickness of any conductive adhesive layer 26 in the gathered portion 2222' of the negative electrode tab 222b.

[0188] Exemplarily, the thickness of the gathering area 2222 of the positive electrode tab 222a is 15 μm, the thickness of the conductive adhesive layer 26 provided in the gathering area 2222 of the positive electrode tab 222a is 3 μm, the thickness of the gathering area 2222 of the negative electrode tab 222b is 6 μm, and the thickness of the conductive adhesive layer 26 provided in the gathering area 2222 of the negative electrode tab 222b is 2 μm.

[0189] The positive electrode tab 222a and the negative electrode tab 222b both include multiple first tabs 222. In the positive electrode tab 222a and the negative electrode tab 222b, when the first gathering area 22221 provided with the conductive adhesive layer 26 is closest to the welding equipment during welding, the conductive adhesive layer 26 has a binding effect on the first gathering area 22221, which can reduce the risk of cracking of the first gathering area 22221 at the welding position due to the welding energy, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20. Even if the first gathering area 22221 is cracked at the welding position due to welding energy, the conductive adhesive layer 26 can solidify the cracked first gathering area 22221, and alleviate the degree of morphological change of the first gathering area 22221 after the first gathering area 22221 is cracked at the welding position. For example, it can alleviate the degree of warping of the first gathering area 22221 after the first gathering area 22221 is cracked at the welding position, reduce the risk of reliability problems of the battery cell 20 caused by excessive degree of morphological change of the first gathering area 22221 after the first gathering area 22221 is cracked, and further improve the reliability of the battery cell 20. The thickness of the conductive adhesive layer 26 of the first gathering area 22221 of the gathering portion 2222' of the positive electrode tab 222a is greater than the thickness of the conductive adhesive layer 26 of the first gathering area 22221 of the gathering portion 2222' of the negative electrode tab 222b, which can provide a greater binding force for the gathering area 2222 of the positive electrode tab 222a, and to a certain extent alleviate the problem that the first tab 222 of the positive electrode tab 222a is more prone to cracking during welding.

[0190] like Fig.11 , Fig.12As shown, in some embodiments, the electrode assembly 22 includes a positive electrode tab 222a and a negative electrode tab 222b, and the positive electrode tab 222a or the negative electrode tab 222b includes a plurality of first tabs 222; the battery cell 20 includes two electrode lead-out portions 25, one electrode lead-out portion 25 is connected to the gathered portion 2222' of the plurality of first tabs 222 of the positive electrode tab 222a, and the other electrode lead-out portion 25 is connected to the gathered portion 2222' of the plurality of first tabs 222 of the negative electrode tab 222b.

[0191] One electrode lead-out portion 25 and the gathered portion 2222' of the plurality of first pole tabs 222 of the positive pole tab 222a can be connected by welding or by conductive adhesive, so that the electrode lead-out portion 25 and the positive pole tab 222a are electrically connected, and the other electrode lead-out portion 25 and the gathered portion 2222' of the plurality of first pole tabs 222 of the negative pole tab 222b can be connected by welding or by conductive adhesive, so that the electrode lead-out portion 25 and the negative pole tab 222b are electrically connected. The battery cell 20 is charged and discharged through the two electrode lead-out portions 25.

[0192] The positive electrode tab 222a and the negative electrode tab 222b both include multiple first tabs 222. In the positive electrode tab 222a and the negative electrode tab 222b, when the first gathering area 22221 provided with the conductive adhesive layer 26 is closest to the welding equipment during welding, the conductive adhesive layer 26 has a binding effect on the first gathering area 22221, which can reduce the risk of cracking of the first gathering area 22221 at the welding position due to the welding energy, thereby reducing the risk of failure of the battery cell 20 and improving the reliability of the battery cell 20. Even if the first gathered area 22221 is cracked at the welding position due to welding energy, the conductive adhesive layer 26 can solidify the cracked first gathered area 22221, and alleviate the degree of change in the shape of the first gathered area 22221 after the first gathered area 22221 is cracked at the welding position, for example, it can alleviate the degree of warping of the first gathered area 22221 after the first gathered area 22221 is cracked at the welding position, and reduce the risk of reliability problems of the battery cell 20 caused by excessive change in the shape of the first gathered area 22221 after the first gathered area 22221 is cracked, and further improve the reliability of the battery cell 20. One electrode lead-out portion 25 is connected to the gathered portions 2222' of the multiple first pole tabs 222 of the positive pole tab 222a, and the other electrode lead-out portion 25 is connected to the gathered portions 2222' of the multiple first pole tabs 222 of the negative pole tab 222b, so as to facilitate the lead-out of the electrodes of the battery cell 20, thereby facilitating the charging and discharging of the battery cell 20.

[0193] The embodiment of the present application further provides a battery device 100 , and the battery device 100 includes the battery cell 20 provided in any of the above embodiments.

[0194] The battery cell 20 provided in any of the above embodiments has good reliability, and the electrical device including the battery cell 20 also has good reliability.

[0195] The embodiment of the present application further provides an electrical device, which includes the battery cell 20 provided by any of the above embodiments or the battery device 100 provided by the above embodiments.

[0196] The battery cell 20 and the battery device 100 provided in any of the above embodiments have good reliability, which is beneficial to improving the power consumption reliability of the power consumption device powered by the battery cell 20 and the battery device 100.

[0197] The embodiment of the present application provides a battery cell 20, which includes an electrode assembly 22 and two electrode lead-out portions 25. The electrode assembly 22 includes a main body 221, a positive electrode tab 222a and a negative electrode tab 222b. The positive electrode tab 222a includes a plurality of first tabs 222, and the negative electrode tab 222b includes a plurality of first tabs 222. The plurality of first tabs 222 of the positive electrode tab 222a are connected to the same end of the main body 221, and the plurality of first tabs 222 of the negative electrode tab 222b are connected to the same end of the main body 221. The first tab 222 includes a connection area 2221 and a retracted area 2222, and the connection area 2221 connects the retracted area 2222 and the main body 221. The gathered areas 2222 of the plurality of first pole tabs 222 of the positive pole tab 222a are stacked and welded along the first direction X to form a gathered portion 2222'; the gathered areas 2222 of the plurality of first pole tabs 222 of the negative pole tab 222b are stacked and welded along the first direction X to form a gathered portion 2222'. The gathered portion 2222' of the positive pole tab 222a and a portion of one electrode lead-out portion 25 are stacked and welded along the first direction X, and the gathered portion 2222' of the negative pole tab 222b and a portion of another electrode lead-out portion 25 are stacked and welded along the first direction X. A conductive adhesive layer 26 is arranged between two adjacent gathering areas 2222 of the three continuously stacked gathering areas 2222 in each gathering portion 2222' close to the electrode lead-out portion 25, and two sides of the conductive adhesive layer 26 are respectively connected to the two gathering areas 2222. The three continuously stacked gathering areas 2222 close to the electrode lead-out portion 25 include a first gathering area 22221 closest to the electrode lead-out portion 25, and a conductive adhesive layer 26 is also arranged on the surface of the first gathering area 22221 facing the electrode lead-out portion 25.

[0198] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0199] The above embodiments are only used to illustrate the technical solutions of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, comprising a main body and a plurality of first pole tabs, wherein the plurality of first pole tabs are connected to the same end of the main body, the first pole tab comprises a connection area and a gathering area, the connection area connects the gathering area and the main body, and the gathering areas of the plurality of first pole tabs are stacked and welded along a first direction to form a gathering portion; An electrode lead-out portion connected to the gathering portion; Wherein, along the first direction, the two gathering areas in the gathering portion that are farthest apart are first gathering areas, and at least one surface of at least one of the first gathering areas is provided with a conductive adhesive layer.

2. The battery cell according to claim 1, characterized in that: Along the first direction, the gathering portion has two opposite first outer surfaces, one of the first gathering areas has one first outer surface, and at least one of the first outer surfaces is provided with the conductive adhesive layer.

3. The battery cell according to claim 1, characterized in that: Along the first direction, two opposite surfaces of at least one of the first gathering areas are both provided with the conductive adhesive layer.

4. The battery cell according to claim 1, characterized in that: The number of the gathering areas in the gathering portion is m. Among the n continuously stacked gathering areas, the conductive adhesive layer is arranged between two adjacent gathering areas. The n gathering areas include at least one of the first gathering areas, and m≥n≥2.

5. The battery cell according to claim 4, characterized in that: n=2 or n=3.

6. The battery cell according to claim 1, characterized in that: The thickness of the conductive adhesive layer is 1 μm to 15 μm.

7. The battery cell according to claim 6, characterized in that: The thickness of the conductive adhesive layer is 2 μm to 10 μm.

8. The battery cell according to claim 1, characterized in that: The conductive adhesive layer is a graphite conductive adhesive layer, a metal particle conductive adhesive layer, a nano silver conductive adhesive layer or a nano carbon tube conductive adhesive layer.

9. The battery cell according to claim 1, characterized in that: On a projection plane perpendicular to the first direction, the orthographic projection of the conductive adhesive layer is a rectangle or a circle.

10. The battery cell according to any one of claims 1 to 9, characterized in that: Along the first direction, a portion of the electrode lead-out portion is stacked with the gathering portion, and in the two first gathering areas, at least one surface of the first gathering area close to the electrode lead-out portion is provided with the conductive adhesive layer.

11. The battery cell according to any one of claims 1 to 9, characterized in that: Along the first direction, a portion of the electrode lead-out portion is stacked with the gathering portion, and in the two first gathering areas, at least one surface of the first gathering area away from the electrode lead-out portion is provided with the conductive adhesive layer.

12. The battery cell according to any one of claims 1 to 9, characterized in that: The electrode assembly includes a positive electrode tab and a negative electrode tab, each of the positive electrode tab and the negative electrode tab includes a plurality of the first electrode tabs, and the thickness of the conductive adhesive layer in the first gathering area of ​​the gathering portion of the positive electrode tab is greater than the thickness of the conductive adhesive layer in the first gathering area of ​​the gathering portion of the negative electrode tab.

13. The battery cell according to any one of claims 1 to 9, characterized in that: The electrode assembly includes a positive electrode tab and a negative electrode tab, and the positive electrode tab or the negative electrode tab includes a plurality of the first electrode tabs.

14. The battery cell according to any one of claims 1 to 9, characterized in that: The electrode assembly comprises a positive electrode tab and a negative electrode tab, and each of the positive electrode tab and the negative electrode tab comprises a plurality of the first electrode tabs; The battery cell includes two electrode lead-out portions, one of which is connected to the gathered portions of the first plurality of positive electrode tabs, and the other of which is connected to the gathered portions of the first plurality of negative electrode tabs.

15. A battery device, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 14.

16. An electrical device, characterized in that: The method comprises the battery cell according to any one of claims 1 to 14 or the battery device according to claim 15.

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