Cylindrical battery monomer, battery device and power utilization device

Abstract

The utility model discloses a cylindrical battery monomer, a battery device and a power utilization device. A cylindrical battery cell includes a housing, an electrode assembly, and a first current collecting member. The electrode assembly is arranged in the shell and comprises a first pole piece, an isolating membrane and a second pole piece; the first pole piece comprises a first current collector, the first current collector comprises a first coating area and first empty foil areas, the first empty foil areas with different winding layer numbers are mutually stacked to form a first tab stacking area, the first tab stacking area is provided with a first welding printing part, and the first welding printing part is connected with at least two layers of first empty foil areas. And the first current collecting component is connected with the first tab stacking area through the second welding printing part. On the same projection plane perpendicular to the axis direction, the orthographic projection of the first welding printing part and the orthographic projection of the first flow collecting component have an overlapping area, and the orthographic projection of the first welding printing part and the orthographic projection of the second welding printing part are not overlapped. According to the technical scheme provided by the invention, the charge-discharge performance and reliability of the battery device can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a cylindrical battery cell, a battery device, and an electrical device. Background Technology

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

[0003] In the development of battery technology, how to improve the charging and discharging performance and reliability of battery devices is a technical problem that urgently needs to be solved. Utility Model Content

[0004] This application provides a cylindrical battery cell, a battery device, and an electrical device. The technical solution provided by this application can improve the charging and discharging performance and reliability of the battery device.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, some embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, and a first current collector. The electrode assembly is disposed within the casing and has a wound structure. The electrode assembly includes a first electrode, a separator, and a second electrode, with the separator disposed between the first and second electrodes. The first electrode includes a first current collector, which includes a first coating area and a first empty foil area. The first coating area has a first active layer. At least a portion of the first empty foil area is bent towards the axial direction of the electrode assembly, and first empty foil areas with different winding layers are stacked to form a first tab stacked area. The first tab stacked area has a first solder mark, which connects at least two layers of the first empty foil area. The first current collector is located on one side of the electrode assembly along the axial direction and is connected to the first tab stacked area via a second solder mark. Specifically, on the same projection plane perpendicular to the axial direction, the orthographic projection of the first solder mark overlaps with the orthographic projection of the first current collector, while the orthographic projections of the first and second solder marks do not overlap.

[0007] In the above scheme, on the one hand, the first tab stack area is pre-welded so that at least two first empty foil areas are connected to each other through the first solder mark, which can shorten the electrical connection path between the multi-layer first empty foil areas, reduce the internal resistance of the first tab stack area, and improve the current carrying capacity of the cylindrical battery cell. On the other hand, there is an overlapping area between the first solder mark and the first current collector, which allows the multi-layer first empty foil areas to be electrically connected to the first current collector through the first solder mark, shortening the electrical connection path between the multi-layer first empty foil areas and the first current collector, further improving the current carrying capacity of the cylindrical battery cell. Furthermore, since the formation of the first solder mark will cause local unevenness in the first tab stack area, the first solder mark and the second solder mark are not overlapped, which can reduce the risk of poor soldering between the first current collector and the first tab stack area, affecting the welding quality of the first current collector and the first tab stack area, so that the cylindrical battery cell has high structural reliability, and thus the battery device has high charge and discharge performance and reliability.

[0008] According to some embodiments of this application, the first solder mark has a first end and a second end, the first end being farther away from the axis than the second end; the second solder mark has a third end and a fourth end, the third end being farther away from the axis than the fourth end. The distance from the second end to the axis is greater than or equal to the distance from the third end to the axis.

[0009] In the above scheme, the first soldering part is farther away from the axis of the electrode assembly than the second soldering part. On the one hand, it can pre-weld the multi-layer first empty foil area of ​​the outer ring of the first tab stacking area into one piece, shorten the electrical connection path of the outer ring of the first tab stacking area, effectively reduce the internal resistance of the first tab stacking area, and improve the overcurrent capacity of the cylindrical battery cell. On the other hand, it can reduce the interference of the first soldering part to the second soldering part, so that the first current collector can be effectively electrically connected to the first tab stacking area through the second soldering part, thereby enabling the cylindrical battery cell to have higher charge and discharge performance and reliability, and thus enabling the battery device to have higher charge and discharge performance and reliability.

[0010] According to some embodiments of this application, the distance between the first end and the outer peripheral surface of the electrode assembly is greater than or equal to 0 and less than or equal to 2 mm.

[0011] In the above scheme, by controlling the distance between the first end and the outer peripheral surface of the electrode assembly to between 0 and 2 mm, the first soldering part can effectively pre-weld the multi-layer first empty foil area of ​​the outer ring of the first tab stack area into one piece, shorten the electrical connection path of the outer ring of the first tab stack area, effectively reduce the internal resistance of the first tab stack area, which is conducive to improving the overcurrent capacity of the cylindrical battery cell, so that the cylindrical battery cell has high charge and discharge performance, and thus the battery device has high charge and discharge performance.

[0012] According to some embodiments of this application, the first tab stack region includes a first region covered by a first current collector and a second region located on the outer periphery of the first region. A portion of the first solder mark is located in the first region, and another portion is located in the second region.

[0013] In the above scheme, the first current collector is located in the first region, and the second region is located between the inner wall of the outer casing and the first region. This can reduce the risk of impact on the cylindrical battery cell being transmitted to the first current collector, causing the first current collector to puncture the outer casing, which is beneficial to improving the reliability of the cylindrical battery cell. At the same time, a part of the first solder mark is located in the first region, and another part is located in the second region. This can effectively shorten the electrical connection path between the empty foil area in the second region and the first current collector, which is beneficial to improving the charge and discharge performance of the cylindrical battery cell, and thus to improving the charge and discharge performance of the battery device.

[0014] According to some embodiments of this application, the first tab stack region further includes a third region located on the inner periphery of the first region. The first tab stack region also includes a third solder mark portion connecting at least two layers of first empty foil regions. A portion of the third solder mark portion is located in the first region, and another portion is located in the third region. On the same projection plane perpendicular to the axial direction, the orthographic projection of the third solder mark portion and the orthographic projection of the second solder mark portion do not overlap.

[0015] In the above scheme, the third soldering part can pre-weld the multi-layer first empty foil area in the third region into one piece, and part of the third soldering part is located in the first region and the other part is located in the third region. This allows the multi-layer first empty foil area in the third region to be electrically connected to the first current collector through the third soldering part, effectively shortening the electrical connection path between the empty foil area in the third region and the first current collector, which is beneficial to improving the charge and discharge performance of the cylindrical battery cell, and thus to improving the charge and discharge performance of the battery device. At the same time, since the formation of the third soldering part will cause local unevenness in the first tab stacked area, the third soldering part and the second soldering part are not overlapped, which can reduce the risk of poor welding between the first current collector and the first tab stacked area, affecting the welding quality of the first current collector and the first tab stacked area. This makes the cylindrical battery cell have high structural reliability, and thus makes the battery device have high charge and discharge performance and reliability.

[0016] According to some embodiments of this application, the second solder mark portion has a third end and a fourth end, the third end being farther away from the axis than the fourth end, and the third solder mark portion has a fifth end and a sixth end, the fifth end being farther away from the axis than the sixth end. The distance from the fifth end to the axis is less than or equal to the distance from the fourth end to the axis.

[0017] In the above scheme, the third soldering part is closer to the axis of the electrode assembly than the second soldering part. On the one hand, it can pre-weld the multi-layer first empty foil area of ​​the inner ring of the first tab stacking area into one piece, shorten the electrical connection path of the inner ring of the first tab stacking area, effectively reduce the internal resistance of the first tab stacking area, and improve the overcurrent capacity of the cylindrical battery cell. On the other hand, it can reduce the interference of the third soldering part to the second soldering part, so that the first current collector can be effectively electrically connected to the first tab stacking area through the second soldering part, thereby enabling the cylindrical battery cell to have higher charge and discharge performance and reliability, and thus enabling the battery device to have higher charge and discharge performance and reliability.

[0018] According to some embodiments of this application, there are multiple third solder marks, which are arranged at intervals along the circumferential direction of the electrode assembly.

[0019] In the above scheme, multiple third soldering sections are arranged at intervals along the circumference of the electrode assembly, which can effectively pre-weld the multi-layer first empty foil area into one piece, effectively shorten the electrical connection path of the inner ring of the first electrode stacking area, effectively reduce the internal resistance of the first electrode stacking area, which is conducive to improving the overcurrent capacity of the cylindrical battery cell and improving the charging and discharging performance of the battery device.

[0020] According to some embodiments of this application, there are multiple first solder marks, and the multiple first solder marks are arranged at intervals along the circumferential direction of the electrode assembly.

[0021] In the above scheme, multiple first soldering portions are arranged at intervals along the circumference of the electrode assembly, which can effectively pre-weld the multi-layer first empty foil area into one piece, effectively shorten the electrical connection path of the inner ring of the first electrode stacking area, effectively reduce the internal resistance of the first electrode stacking area, which is conducive to improving the overcurrent capacity of the cylindrical battery cell and improving the charging and discharging performance of the battery device.

[0022] According to some embodiments of this application, along the circumferential direction of the electrode assembly, the distance between two adjacent first solder marks is greater than or equal to 1 mm and less than or equal to 6 mm.

[0023] In the above scheme, by setting the distance between two adjacent first solder marks to be greater than or equal to 1 mm and less than or equal to 6 mm, the first electrode stacking area has multiple first solder marks with appropriate spacing. On the one hand, this helps to reduce the electrical connection path between the multiple layers of first empty foil areas. On the other hand, it can reduce the risk of affecting the electrolyte wetting of the electrode assembly due to the first solder marks being too densely arranged, so that the cylindrical battery cell has high charge and discharge performance and reliability.

[0024] According to some embodiments of this application, both the first solder mark and the second solder mark are strips extending radially along the electrode assembly. The first solder mark and the second solder mark are staggered along the circumferential direction of the electrode assembly.

[0025] In the above scheme, both the first and second solder marks are strips extending radially along the electrode assembly. Along the circumference of the electrode assembly, the first and second solder marks are located at different positions, which can effectively reduce the interference of the first solder mark on the second solder mark. This allows the first current collector to be effectively electrically connected to the first tab stacked area through the first and second solder marks, thereby enabling the cylindrical battery cell to have high charge and discharge performance and reliability, and thus enabling the battery device to have high charge and discharge performance and reliability.

[0026] According to some embodiments of this application, the diameter of the outer casing is greater than or equal to 46 mm.

[0027] In the above scheme, the cylindrical battery cell has a large outer diameter to achieve a high capacity and meet different power consumption needs. In the large-diameter cylindrical battery cell, the multiple layers of the first empty foil area in the first tab stacking area are pre-welded together by the first soldering part, and the first soldering part overlaps with the first current collector. The first soldering part and the second soldering part do not overlap. On the one hand, this can effectively improve the charge and discharge performance of the large-diameter cylindrical battery cell, and on the other hand, it can effectively reduce the risk of reliability reduction caused by poor soldering of the second soldering part.

[0028] According to some embodiments of this application, the density of the first tab stack region is 5% to 70%.

[0029] In the above scheme, by setting the density of the first tab stack region to 5%~70%, the first tab stack region can have a suitable stacking thickness. On the one hand, this ensures that the electrode assembly is stably located in the outer shell nickel, reducing the risk of the electrical connection path between the first tab stack region and the first current collector being broken due to the electrode assembly moving within the shell. On the other hand, it can reduce the risk of excessive pressure generated during the electrode assembly insertion process due to excessive stacking thickness, which could affect the structural integrity of the electrode assembly. Furthermore, it provides sufficient welding depth for the formation of the first solder mark, reducing the risk of burn-through and damage to the separator structure.

[0030] According to some embodiments of this application, along the axial direction, the depth of the first solder mark is less than the thickness of the first tab stack region.

[0031] In the above scheme, the depth of the first solder mark is less than the thickness of the first tab stacked area, which can reduce the impact of the first solder mark on the separator, reduce the risk of local damage to the separator due to the heat generated by the first solder mark, and make the cylindrical battery cell have high reliability.

[0032] According to some embodiments of this application, the size of the first current collector is smaller than the size of the electrode assembly along the radial direction of the electrode assembly.

[0033] In the above scheme, by setting the size of the first current collector to be smaller than the size of the electrode assembly along the radial direction of the electrode assembly, the risk of the cylindrical battery cell being punctured by the displacement of the first current collector relative to the outer casing due to external force can be reduced, thus making the cylindrical battery cell have higher reliability.

[0034] According to some embodiments of this application, the second electrode includes a second current collector, the second current collector includes a second coating area and a second empty foil area, the second coating area is provided with a second active layer, at least a portion of the second empty foil area is bent toward the axial direction of the electrode assembly, and the second empty foil areas with different winding layers are stacked on each other to form a second electrode tab stack area, the second electrode tab stack area has a fourth solder mark, the fourth solder mark connects at least two layers of second empty foil areas.

[0035] The cylindrical battery cell also includes a second current collector, which is located on the side of the electrode assembly opposite to the first current collector along the axial direction. The second current collector is connected to the second tab stacked area through a fifth solder joint.

[0036] Among them, on the same projection plane perpendicular to the axis direction, the orthographic projection of the fourth solder mark overlaps with the orthographic projection of the second current collector, while the orthographic projections of the fourth solder mark and the fifth solder mark do not overlap.

[0037] In the above scheme, on the one hand, the second tab stacked area is pre-welded so that at least two second empty foil areas are interconnected through the fourth solder mark, which can shorten the electrical connection path between the multi-layer second empty foil areas, reduce the internal resistance of the second tab stacked area, and improve the current carrying capacity of the cylindrical battery cell. On the other hand, there is an overlapping area between the fourth solder mark and the second current collector, which allows the multi-layer second empty foil areas to be electrically connected to the second current collector through the fourth solder mark, shortening the electrical connection path between the multi-layer second empty foil areas and the second current collector, further improving the current carrying capacity of the cylindrical battery cell. Furthermore, since the formation of the fourth solder mark will cause local unevenness in the second tab stacked area, the fourth solder mark and the fifth solder mark are not overlapped, which can reduce the risk of poor soldering between the second current collector and the second tab stacked area, affecting the welding quality of the second current collector and the second tab stacked area, so that the cylindrical battery cell has high structural reliability, and thus the battery device has high charge and discharge performance and reliability.

[0038] Secondly, some embodiments of this application provide a battery device, which includes the cylindrical battery cell provided in the first aspect.

[0039] Thirdly, some embodiments of this application provide an electrical device, which includes a cylindrical battery cell provided in the first aspect, or a battery device provided in the second aspect.

[0040] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of a vehicle in some embodiments of this application;

[0043] Figure 2 This is an exploded perspective view of the battery device in some embodiments of this application;

[0044] Figure 3 This is a three-dimensional schematic diagram of a cylindrical battery cell provided in some embodiments of this application;

[0045] Figure 4 An exploded perspective view of a cylindrical battery cell provided in some embodiments of this application;

[0046] Figure 5 A perspective view of the electrode assembly and the first current collector provided in some embodiments of this application;

[0047] Figure 6 A top view of the electrode assembly and the first current collector is provided for some embodiments of this application;

[0048] Figure 7 This is a schematic diagram of the structure of the electrode assembly and the first current collector provided in some embodiments of this application;

[0049] Figure 8 for Figure 7 Enlarged view of point A in the middle.

[0050] Icons: 1000 - Vehicle; 100 - Battery Unit; 200 - Controller; 300 - Motor; 10 - Cylindrical Battery Cell; 20 - Housing; 21 - First Housing Body; 22 - Second Housing Body; 11 - Outer Shell; 110 - Housing; 111 - Cover; 12 - Electrode Assembly; 120 - First Electrode; 121 - Separator; 122 - Second Electrode; 13 - First Current Collector; 130 - First Coating Area; 131 - First Empty Foil Area; 14 - First active layer; 15-First tab stacked region; 150-First solder mark; 1500-First end; 1501-Second end; 15a-First region; 15b-Second region; 15c-Third region; 151-Third solder mark; 1510-Fifth end; 1511-Sixth end; 16-First current collector; 160-Second solder mark; 1600-Third end; 1601-Fourth end; z-Axis direction; y-Circumferential direction of electrode assembly. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0053] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0054] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0055] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0056] In the embodiments of this application, the same reference numerals denote 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 this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0057] In this application, "multiple" means two or more (including two).

[0058] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0059] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0060] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, serves to prevent short circuits to some extent while allowing active ions to pass through.

[0061] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0062] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0063] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be 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. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0064] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides 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, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM1), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM6), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0065] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0066] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0067] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can 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.).

[0068] 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.

[0069] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0070] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0071] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0072] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0073] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0074] As an example, the material of the separator may include at least one of glass fiber, nonwoven 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 it may be attached to the surfaces of the positive and negative electrodes.

[0075] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0076] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0077] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0078] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0079] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0080] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0081] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0082] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0083] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0084] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0085] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0086] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0087] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0088] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0089] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0090] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0091] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0092] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0093] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0094] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0095] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. The energy storage device includes energy storage containers, energy storage cabinets, etc. In some embodiments, one or more energy storage devices may constitute at least part of an energy storage system.

[0096] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, and discharge capacity. Furthermore, the charge and discharge performance of the battery device must also be taken into account.

[0097] In related technologies, a cylindrical battery cell includes a casing, an electrode assembly, and a current collector. The electrode assembly has a wound structure and includes a positive electrode sheet, a separator, and a negative electrode sheet, with the separator disposed between the positive and negative electrode sheets. Taking the positive electrode sheet as an example, the positive electrode sheet includes a positive current collector, which includes a coated area and an empty foil area. The coated area has a positive active layer. At least a portion of the empty foil area is bent towards the central axis of the electrode assembly, and empty foil areas with different winding layers are stacked on top of each other to form a tab stack area. The tab stack area is welded to the current collector to realize the output and input of electrical energy.

[0098] However, the tab stacked region is formed by stacking several layers of empty foil regions. The electrical connection path within the tab stacked region passes through different numbers of empty foil regions, resulting in a long electrical connection path, high internal resistance, and reduced current carrying capacity. This leads to low charge and discharge performance of the cylindrical battery cell. Furthermore, in related technologies, to reduce the risk of the current collector puncturing the casing due to impact deformation during collision testing or use, the current collector is smaller than both the casing and the electrode assembly. The smaller size of the current collector further lengthens the electrical connection path between some layers of empty foil regions and the current collector, impacting the charge and discharge performance of the cylindrical battery cell.

[0099] In view of this, to improve the problem of low charge and discharge performance of a single battery cell caused by long electrical connection paths and high internal resistance in the tab stacked area, some embodiments of this application provide a cylindrical battery cell, which includes a casing, an electrode assembly, and a first current collector. The electrode assembly is disposed within the casing and has a wound structure. The electrode assembly includes a first electrode, a separator, and a second electrode, with the separator disposed between the first and second electrodes. The first electrode includes a first current collector, which includes a first coating area and a first empty foil area. The first coating area has a first active layer. At least a portion of the first empty foil area is bent towards the axial direction of the electrode assembly, and first empty foil areas with different winding layers are stacked to form a first tab stacked area. The first tab stacked area has a first solder mark connecting at least two layers of the first empty foil area. The first current collector is located on one side of the electrode assembly along the axial direction and is connected to the first tab stacked area via a second solder mark. Among them, on the same projection plane perpendicular to the axis direction, the orthographic projection of the first solder mark and the orthographic projection of the first current collector have an overlapping area, while the orthographic projections of the first solder mark and the second solder mark do not overlap.

[0100] In the above scheme, on the one hand, the first tab stack area is pre-welded so that at least two first empty foil areas are connected to each other through the first solder mark, which can shorten the electrical connection path between the multi-layer first empty foil areas, reduce the internal resistance of the first tab stack area, and improve the current carrying capacity of the cylindrical battery cell. On the other hand, there is an overlapping area between the first solder mark and the first current collector, which allows the multi-layer first empty foil areas to be electrically connected to the first current collector through the first solder mark, shortening the electrical connection path between the multi-layer first empty foil areas and the first current collector, further improving the current carrying capacity of the cylindrical battery cell. Furthermore, since the formation of the first solder mark will cause local unevenness in the first tab stack area, the first solder mark and the second solder mark are not overlapped, which can reduce the risk of poor soldering between the first current collector and the first tab stack area, affecting the welding quality of the first current collector and the first tab stack area, so that the cylindrical battery cell has high structural reliability, and thus the battery device has high charge and discharge performance and reliability.

[0101] The cylindrical battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.

[0102] The technical solutions described in the embodiments of this application are applicable to battery devices, energy storage devices using battery devices, and electrical devices using battery devices.

[0103] Energy storage devices may include energy storage containers, energy storage cabinets, etc. For example, an energy storage cabinet may include a cabinet and one or more battery cells and / or battery devices mounted on the cabinet.

[0104] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be new energy vehicles, including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The electrical devices in the embodiments of this application include, but are not limited to, those mentioned above.

[0105] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0106] Figure 1 This is a schematic diagram of a vehicle in some embodiments of this application.

[0107] The electrical device is a vehicle 1000. Inside the vehicle 1000, a controller 200, a motor 300, and a battery device 100 can be installed. The controller 200 controls the battery device 100 to supply power to the motor 300. For example, the battery device 100 can be installed at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source for the vehicle's electrical system, such as for the power needs of starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the vehicle's operating power source but also as the vehicle's driving power source, replacing or partially replacing fuel or natural gas to provide driving power to the vehicle.

[0108] Please refer to Figure 2 , Figure 2 This is an exploded perspective view of the battery device 100 in some embodiments of this application. The battery device 100 includes a housing 20 and cylindrical battery cells 10, which are housed within the housing 20.

[0109] The housing 20 provides an assembly space for the cylindrical battery cell 10, and the housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, which overlap each other, and together define an assembly space for accommodating the battery cell. The second housing body 22 may be a hollow structure open at one end, and the first housing body 21 may be a plate-like structure, with the first housing body 21 covering the open side of the second housing body 22 so that the first housing body 21 and the second housing body 22 together define the assembly space; alternatively, the first housing body 21 and the second housing body 22 may both be hollow structures open on one side, with the open side of the first housing body 21 covering the open side of the second housing body 22.

[0110] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as cylinder, cuboid or cube.

[0111] In the battery device 100, there can be one or more cylindrical battery cells 10 disposed within the housing 20. When there are multiple cylindrical battery cells 10 disposed within the housing 20, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that the multiple cylindrical battery cells 10 are connected in both series and parallel configurations. The multiple cylindrical battery cells 10 can be directly connected in series, in parallel, or in a mixed configuration together, and then the entire assembly of the multiple cylindrical battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also be composed of multiple cylindrical battery cells 10 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 20.

[0112] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple cylindrical battery cells 10 to achieve electrical connection between the multiple cylindrical battery cells 10.

[0113] For example, the housing 20 is provided with multiple battery cell assemblies, each battery cell assembly including multiple cylindrical battery cells 10, which are connected in series with each other via a busbar. In some embodiments, the multiple battery cell assemblies can be connected in series with each other via a busbar.

[0114] Each cylindrical battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0115] Some embodiments of this application provide a cylindrical battery cell 10; please refer to [link to relevant documentation]. Figures 3-8 , Figure 3 This is a three-dimensional schematic diagram of a cylindrical battery cell 10 provided in some embodiments of this application. Figure 4 This is an exploded perspective view of the cylindrical battery cell 10 provided in some embodiments of this application. Figure 5 This is a perspective view of the electrode assembly 12 and the first current collector 16 provided in some embodiments of this application. Figure 6 A top view of the electrode assembly 12 and the first current collector 16 is provided for some embodiments of this application. Figure 7 This is a schematic diagram of the structure of the electrode assembly 12 and the first current collector 16 provided in some embodiments of this application. Figure 8 for Figure 7 Enlarged view of point A in the middle.

[0116] The cylindrical battery cell 10 includes a casing 11, an electrode assembly 12, and a first current collector 16. The electrode assembly 12 is disposed within the casing 11 and has a wound structure. The electrode assembly 12 includes a first electrode 120, a separator 121, and a second electrode 122, with the separator 121 disposed between the first electrode 120 and the second electrode 122. The first electrode 120 includes a first current collector 13, which includes a first coating area 130 and a first empty foil area 131. The first coating area 130 is provided with a first active layer 14. At least a portion of the first empty foil area 131 is bent toward the axis of the electrode assembly 12, and the first empty foil areas 131 with different winding layers are stacked on top of each other to form a first tab stack area 15. The first tab stack area 15 has a first solder mark 150, which connects at least two layers of the first empty foil area 131. The first current collector 16 is located on one side of the electrode assembly 12 along the axial direction z of the electrode assembly 12. The first current collector 16 is connected to the first tab stack region 15 through the second solder mark 160. Specifically, on the same projection plane perpendicular to the axial direction z, the orthographic projection of the first solder mark 150 and the orthographic projection of the first current collector 16 overlap, but the orthographic projections of the first solder mark 150 and the second solder mark 160 do not overlap.

[0117] The cylindrical battery cell 10 includes a housing 11, which is a component for housing the electrode assembly 12. The housing 11 can also be used to house an electrolyte, such as an electrolyte solution. In some embodiments, the housing 11 is cylindrical in shape.

[0118] Please see Figure 3 and Figure 4 In some embodiments, the housing 11 includes a housing 110 and a cover 111. The housing 110 has an internal cavity for accommodating the electrode assembly 12, and the housing 110 has an opening communicating with the cavity. The cover 111 closes to the opening of the housing 110 to form a closed space for accommodating the electrode assembly 12 and the electrolyte (e.g., electrolyte solution).

[0119] The housing 110 is cylindrical in shape. In some embodiments, the housing 110 may be made of metal or a combination of metal and non-metal. For example, the housing 110 may be made of metal, such as copper, iron, aluminum, steel, stainless steel or aluminum alloy.

[0120] In some embodiments, the cover 111 may be made of metal or a combination of metal and non-metal. For example, the cover 111 may be made of metal, such as copper, iron, aluminum, steel, or aluminum alloy. In other embodiments, the cover 111 may be made of non-metallic materials, such as plastic or ceramic.

[0121] In some embodiments, the material of the cover 111 and the material of the housing 110 may be the same, and the two are connected to each other. Optionally, the connection relationship between the cover 111 and the housing 110 is diverse, including but not limited to welding, bonding, riveting, and other connection methods.

[0122] In some embodiments, the housing 11 may be provided with electrode terminals, which are electrically connected to the tabs of the electrode assembly 12 to realize the input and output of electrical energy. Optionally, the electrode terminals may be electrically connected to the tab stacked area of ​​the electrode assembly 12 via a current collector. The electrode terminals may be provided on the side wall of the cover 111, the housing 110, or the end wall of the housing 110 opposite to the cover 111. Exemplarily, electrode terminals are provided on the end wall, and the electrode terminals are electrically connected to the tabs via a current collector.

[0123] In some embodiments, the housing 11 may be energized, meaning the housing 11 may be connected to the tab stack region of the electrode assembly 12 to enable the input and output of electrical energy. Exemplarily, the cover 111 is electrically connected to the tab stack region of the electrode assembly 12 via a current collector.

[0124] The electrode assembly 12 includes a first electrode 120, a second electrode 122, and a separator 121. The separator 121 is disposed between the first electrode 120 and the second electrode 122. The electrode assembly 12 has a wound structure, with the first electrode 120, the second electrode 122, and the separator 121 wound together around the axis of the electrode assembly 12. The first electrode 120 and the second electrode 122 have opposite polarities, that is, one of the first electrode 120 and the second electrode 122 is a positive electrode, and the other is a negative electrode. Some embodiments of this application are illustrated using the first electrode 120 as the positive electrode and the second electrode 122 as the negative electrode.

[0125] The first electrode 120 includes a first current collector 13 and a first active layer 14. The first current collector 13 includes a first coated area 130 and a first empty foil area 131, which are arranged along the axial direction z. In some embodiments, the first empty foil area 131 is located at one end of the first current collector 13 along the axial direction z.

[0126] A first active layer 14 is disposed on the first coating area 130. Optionally, the first active layer 14 is disposed on at least one side of the first coating area 130 along its thickness direction. For example, the first active layer 14 is disposed on one side of the first coating area 130 along its thickness direction. Or, for example, the first active layer 14 is disposed on both sides of the first coating area 130 along its thickness direction.

[0127] After the first electrode 120, the separator 121, and the second electrode 122 are wound into a wound structure, the entire first empty foil region 131 or a portion of the first empty foil region 131 is bent towards the axial direction z of the electrode assembly 12, and the first empty foil regions 131 with different winding layers are stacked on top of each other to form the first tab stacked region 15. In the wound structure, the electrode assembly 12 includes a main region and the first tab stacked region 15. The main region can be understood as the region of the electrode assembly 12 containing the active material.

[0128] The first empty foil region 131 with different winding layers can be understood as the winding structure including multiple layers of first empty foil region 131, such as the first layer of first empty foil region 131 to the nth layer of first empty foil region 131. All of the first layer of first empty foil region 131 to the nth layer of first empty foil region 131 are bent toward the axis of electrode assembly 12 and attached to the end of the main body region along the axial direction z to form the first tab stacked region 15.

[0129] Optionally, the shape of the first electrode stacked region 15 can be circular.

[0130] Optionally, the first empty foil area 131 with different winding layers can be formed into the first tab stack area 15 by a flattening process. In some embodiments where the first empty foil area 131 with different winding layers can be formed into the first tab stack area 15 by a flattening process, the first empty foil area 131 is strip-shaped along the winding direction, and its size is equal to or smaller than the size of the coating area. The first empty foil area 131 is flattened by a flattening roller so that the first empty foil area with different winding layers is bent toward the axis.

[0131] Optionally, the first empty foil area 131 with different winding layers can be formed into the first tab stack area 15 by a smoothing process. In some embodiments where the first empty foil area 131 with different winding layers can be formed into the first tab stack area 15 by a smoothing process, along the winding direction, the first empty foil area 131 may include a plurality of spaced sub-tabs, and along the radial direction of the electrode assembly 12, the sub-tabs with different winding layers can be bent toward the axis of the electrode assembly 12 by applying a radial load with a smoothing roller. Optionally, in the first electrode sheet 120 of the same layer, a gap can be formed between two adjacent sub-tabs, and the sub-tabs of another layer of first electrode sheet 120 adjacent to the first electrode sheet 120 can cover the gap.

[0132] Optionally, in the first tab stacking region 15, the first empty foil regions 131 with different winding layers can overlap each other in the axial direction z, or they can overlap each other in the radial direction of the electrode assembly 12.

[0133] During the manufacturing process of electrode assembly 12, at least two layers of first empty foil regions 131 in the first tab stack region 15 are pre-soldered to form a first solder mark 150. The first solder mark 150 can connect at least two layers of first empty foil regions 131, so that current can pass through the at least two layers of first empty foil regions 131 from the first solder mark 150.

[0134] Optionally, the forming process of the first solder mark 150 includes, but is not limited to, ultrasonic welding, laser welding, etc.

[0135] Optionally, the first soldering part 150 may have various shapes, including but not limited to strip, ring, wave and other shapes.

[0136] Optionally, the first soldering section 150 can connect two, three, or more layers of first empty foil areas 131 in the first tab stacking area 15. For example, the first soldering section 150 can connect all the layers of first empty foil areas 131 in the first tab stacking area 15.

[0137] The number of first solder joints 150 is unlimited, including one, two or more.

[0138] In some embodiments where the first empty foil area 131 with different winding layers can be formed into the first tab stack area 15 by a flattening process, the number of first soldering portions 150 can be one, and one first soldering portion connects at least two or all layers of the first empty foil area 131.

[0139] In some embodiments where the first empty foil region 131 with different winding layers can be formed into the first tab stack region 15 by a smoothing process, the number of first soldering portions 150 can be multiple, the first empty foil region 131 includes multiple sets of sub-tabs, each set of sub-tabs is bent radially toward the axis along the electrode assembly, and the number of first soldering portions 150 can correspond to the number of sets of sub-tabs, so that at least two layers or all layers of sub-tabs in each set of sub-tabs are interconnected.

[0140] Along the axial direction z, the first current collector 16 and the first tab stack region 15 are disposed on the same side. The first current collector 16 is welded to the first tab stack region 15 to form a second solder mark 160. Optionally, the first current collector 16 can be connected to the wall of the housing 11, so that the first tab stack region 15 is electrically connected to the wall of the housing 11 through the first current collector 16. Optionally, the first current collector 16 can be electrically connected to an electrode terminal disposed on the housing 11, so that the first tab stack region 15 is electrically connected to the electrode terminal through the first current collector 16.

[0141] Optionally, the first current collector 16 may be in other shapes such as disc, sheet, or strip.

[0142] Optionally, the first current collector 16 may be made of metal, including but not limited to metals such as copper, iron, aluminum, steel or aluminum alloys.

[0143] Optionally, the forming process of the second solder mark 160 includes, but is not limited to, ultrasonic welding, laser welding, etc.

[0144] Optionally, the second soldering part 160 can have various shapes, including but not limited to strip, ring, wave and other shapes.

[0145] The second soldering section 160 can connect the first current collector 16 to at least one first empty foil area 131 in the first tab stack region 15. Optionally, the second soldering section 160 can connect the first current collector 16 to two, three or more first empty foil areas 131 in the first tab stack region 15.

[0146] Please see Figures 4-8 When viewed along the axial direction z, the first solder mark 150 and the first current collector 16 overlap at least partially, and the first solder mark 150 and the second solder mark 160 are misaligned and do not overlap.

[0147] Optionally, when viewed along the axial direction z, the first current collector 16 covers the entire first solder mark 150. Alternatively, when viewed along the axial direction z, the first current collector 16 covers a portion of the first solder mark 150, with another portion of the first solder mark 150 located outside the area where the first current collector 16 is located.

[0148] In the above scheme, on the one hand, the first tab stacked region 15 is pre-welded so that at least two first empty foil regions 131 are interconnected through the first soldering part 150, which can shorten the electrical connection path between the multi-layer first empty foil regions 131, reduce the internal resistance of the first tab stacked region 15, and improve the overcurrent capacity of the cylindrical battery cell 10; on the other hand, there is an overlapping area between the first soldering part 150 and the first current collector 16, so that the multi-layer first empty foil regions 131 can be electrically connected to the first current collector 16 through the first soldering part 150, shortening the electrical connection path between the multi-layer first empty foil regions 131 and the first current collector 16. The electrical connection path between components 16 further enhances the current carrying capacity of the cylindrical battery cell 10. On the other hand, the formation of the first solder mark 150 will cause local unevenness in the first tab stacked area 15. The first solder mark 150 and the second solder mark 160 are not overlapped, which can reduce the risk of poor soldering between the first current collector 16 and the first tab stacked area 15, affecting the welding quality of the first current collector 16 and the first tab stacked area 15. This makes the cylindrical battery cell 10 have high structural reliability, and thus makes the battery device 100 have high charge and discharge performance and reliability.

[0149] According to some embodiments of this application, the first solder joint 150 has a first end 1500 and a second end 1501, the first end 1500 being further away from the axis than the second end 1501; the second solder joint 160 has a third end 1600 and a fourth end 1601, the third end 1600 being further away from the axis than the fourth end 1601. The distance from the second end 1501 to the axis is greater than or equal to the distance from the third end 1600 to the axis.

[0150] Please see Figure 6 The first end 1500 can be the end of the first solder mark 150 furthest from the axis of the electrode assembly 12. The second end 1501 can be the end of the first solder mark 150 closest to the axis of the electrode assembly 12. The third end 1600 can be the end of the second solder mark 160 furthest from the axis of the electrode assembly 12. The fourth end 1601 can be the end of the second solder mark 160 closest to the axis of the electrode assembly 12.

[0151] The distance from the second end 1501 to the axis is greater than or equal to the distance from the third end 1600 to the axis. This can be understood as the first soldering part 150 being farther away from the axis of the electrode assembly 12 than the second soldering part 160. Along the radial direction of the electrode assembly 12, the distance between the second end 1501 and the third end 1600 is greater than or equal to 0.

[0152] In the above scheme, the first soldering part 150 is farther away from the axis of the electrode assembly 12 than the second soldering part 160. On the one hand, it can pre-weld the multi-layer first empty foil area 131 of the outer ring of the first tab stacking area 15 into one piece, shorten the electrical connection path of the outer ring of the first tab stacking area 15, effectively reduce the internal resistance of the first tab stacking area 15, and improve the overcurrent capacity of the cylindrical battery cell 10. On the other hand, it can reduce the interference of the first soldering part 150 on the second soldering part 160, so that the first current collector 16 can be effectively electrically connected to the first tab stacking area 15 through the second soldering part 160, thereby enabling the cylindrical battery cell 10 to have higher charge and discharge performance and reliability, and thus enabling the battery device 100 to have higher charge and discharge performance and reliability.

[0153] According to some embodiments of this application, the distance between the first end 1500 and the outer peripheral surface of the electrode assembly 12 is greater than or equal to 0 and less than or equal to 2 mm.

[0154] Please see Figure 6 The distance between the first end 1500 and the outer peripheral surface of the electrode assembly 12 can be understood as the minimum distance from the first end 1500 to the outer peripheral surface of the electrode assembly 12. The value of the distance P between the first end 1500 and the outer peripheral surface of the electrode assembly 12 can be 0, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm...2mm or any value between two adjacent values.

[0155] Optionally, the distance between the first end 1500 and the outer peripheral surface of the electrode assembly 12 can be measured by: obtaining the cross-sectional shape of the cylindrical battery cell through CT testing, and then using image analysis to obtain the distance P between the first end 1500 and the outer peripheral surface of the electrode assembly 12.

[0156] Optionally, the distance between the first end 1500 and the outer peripheral surface of the electrode assembly 12 can be measured by: disassembling the cylindrical battery cell to obtain the electrode assembly 12, and directly measuring the distance P between the first end 1500 and the outer peripheral surface of the electrode assembly 12.

[0157] In the above scheme, by controlling the distance between the first end 1500 and the outer peripheral surface of the electrode assembly 12 to between 0 and 2 mm, the first soldering part 150 can effectively pre-weld the multi-layer first empty foil area 131 of the outer ring of the first tab stacking area 15 into one piece, shorten the electrical connection path of the outer ring of the first tab stacking area 15, effectively reduce the internal resistance of the first tab stacking area 15, which is conducive to improving the overcurrent capacity of the cylindrical battery cell 10, so that the cylindrical battery cell 10 has high charge and discharge performance, and thus the battery device 100 has high charge and discharge performance.

[0158] According to some embodiments of this application, the first tab stack region includes a first region 15a covered by a first current collector and a second region 15b located on the outer periphery of the first region 15a. A portion of the first solder mark 150 is located in the first region 15a, and another portion is located in the second region 15b.

[0159] The first electrode stacked region includes a first region 15a and a second region 15b. The location of the first region 15a corresponds to the location of the first current collector 16. On the same projection plane perpendicular to the axial direction z, the orthographic projection of the first current collector 16 and the orthographic projection of the first region 15a coincide. The second region 15b is located on the outer periphery of the first region 15a.

[0160] In some embodiments, the area of ​​the first tab stack region is larger than the size of the first current collector 16, the first current collector 16 is disposed on the first tab stack region, there is a distance between the first current collector 16 and the edge of the first tab stack region, and the area between the first current collector 16 and the edge of the first tab stack region is the second region 15b.

[0161] Please see Figure 6 The first current collector 16 can be an annular disk structure. The first region 15a is an annular region corresponding to the first current collector 16, and the second region 15b is an annular region located on the outer periphery of the first region 15a.

[0162] A portion of the first solder mark 150 is located in the first region 15a, and another portion of the first solder mark 150 is located in the second region 15b. This can be understood as a portion of the first solder mark 150 coinciding with the first current collector 16, and the other portion of the first solder mark 150 being located outside the first current collector 16.

[0163] In the above scheme, the first current collector 16 is located in the first region 15a, and the second region 15b is located between the inner wall of the outer casing 11 and the first region 15a. This reduces the risk of the cylindrical battery cell 10 being impacted and transmitted to the first current collector 16, causing the first current collector 16 to puncture the outer casing 11, thus improving the reliability of the cylindrical battery cell 10. At the same time, a portion of the first solder mark 150 is located in the first region 15a, and another portion is located in the second region 15b. This effectively shortens the electrical connection path between the empty foil area in the second region 15b and the first current collector 16, which is beneficial to improving the charging and discharging performance of the cylindrical battery cell 10, and thus to improving the charging and discharging performance of the battery device 100.

[0164] According to some embodiments of this application, the first tab stack region further includes a third region 15c, which is located on the inner periphery of the first region 15a. The first tab stack region 15 also includes a third solder mark 151, which connects at least two layers of first empty foil regions 131. A portion of the third solder mark 151 is located in the first region 15a, and another portion is located in the third region 15c. On the same projection plane perpendicular to the axial direction z, the orthographic projection of the third solder mark 151 and the orthographic projection of the second solder mark 160 do not overlap.

[0165] In some embodiments, the first tab stack region further has a third region 15c, which is not covered by the first current collector 16 and is located on the inner periphery of the first current collector 16.

[0166] Optionally, the electrode assembly 12 has a winding center hole, the middle part of the first current collector 16 has a through hole, and the area between the hole wall of the through hole of the first current collector 16 and the hole wall of the winding center hole is the third region 15c.

[0167] During the manufacturing process of electrode assembly 12, at least two layers of first empty foil regions 131 in the first tab stack region 15 are pre-soldered in the first region 15a and the third region 15c to form a third solder mark 151. The third solder mark 151 can connect at least two layers of first empty foil regions 131, so that current can pass through the at least two layers of first empty foil regions 131 from the third solder mark 151.

[0168] Optionally, the forming process of the third solder mark 151 includes, but is not limited to, ultrasonic welding process, laser welding process, etc.

[0169] Optionally, the third soldering part 151 can have various shapes, including but not limited to strip, ring, wave and other shapes.

[0170] Optionally, the third soldering section 151 can connect two, three, or more layers of the first empty foil area 131 in the first tab stack area 15. For example, the third soldering section 151 can connect all the layers of the first empty foil area 131 in the first tab stack area 15.

[0171] When viewed along the axial direction z, the third solder mark 151 at least partially overlaps with the first current collector 16, and the third solder mark 151 and the second solder mark 160 are misaligned and do not overlap.

[0172] In the above scheme, the third soldering part 151 can pre-solder the multilayer first empty foil area 131 of the third region 15c into one piece, and a part of the third soldering part 151 is located in the first region 15a, and another part is located in the third region 15c. This allows the multilayer first empty foil area 131 of the third region 15c to be electrically connected to the first current collector 16 through the third soldering part 151, effectively shortening the electrical connection path between the empty foil area in the third region 15c and the first current collector 16, which is beneficial to improving the charge and discharge performance of the cylindrical battery cell 10. This is beneficial to improving the charging and discharging performance of the battery device 100. At the same time, since the formation of the third solder mark 151 will cause local unevenness in the first tab stacked area 15, and the third solder mark 151 and the second solder mark 160 are not overlapped, the risk of poor soldering between the first current collector 16 and the first tab stacked area 15, which affects the welding quality of the first current collector 16 and the first tab stacked area 15, is reduced. This makes the cylindrical battery cell 10 have high structural reliability, and thus the battery device 100 has high charging and discharging performance and reliability.

[0173] According to some embodiments of this application, the second solder mark portion 160 has a third end 1600 and a fourth end 1601, with the third end 1600 being further away from the axis than the fourth end 1601. The third solder mark portion 151 has a fifth end 1510 and a sixth end 1511, with the fifth end 1510 being further away from the axis than the sixth end 1511. The distance from the fifth end 1510 to the axis is less than or equal to the distance from the fourth end 1601 to the axis.

[0174] Please see Figure 6 The third end 1600 can be the end of the second solder mark 160 furthest from the axis of the electrode assembly 12. The fourth end 1601 can be the end of the second solder mark 160 closest to the axis of the electrode assembly 12. The fifth end 1510 can be the end of the third solder mark 151 furthest from the axis of the electrode assembly 12. The sixth end 1511 can be the end of the third solder mark 151 closest to the axis of the electrode assembly 12.

[0175] The fact that the distance from the fifth end 1510 to the axis is less than or equal to the distance from the fourth end 1601 to the axis can be understood as the third solder mark 151 being closer to the axis of the electrode assembly 12 than the second solder mark 160. Along the radial direction of the electrode assembly 12, the distance between the fifth end 1510 and the fourth end 1601 is greater than or equal to 0.

[0176] In the above scheme, the third soldering part 151 is closer to the axis of the electrode assembly 12 than the second soldering part 160. On the one hand, it can pre-weld the multi-layer first empty foil area 131 of the inner ring of the first tab stacking area 15 into one piece, shorten the electrical connection path of the inner ring of the first tab stacking area 15, effectively reduce the internal resistance of the first tab stacking area 15, and improve the overcurrent capacity of the cylindrical battery cell 10. On the other hand, it can reduce the interference of the third soldering part 151 on the second soldering part 160, so that the first current collector 16 can be effectively electrically connected to the first tab stacking area 15 through the second soldering part 160, thereby enabling the cylindrical battery cell 10 to have higher charge and discharge performance and reliability, and thus enabling the battery device 100 to have higher charge and discharge performance and reliability.

[0177] According to some embodiments of this application, there are multiple third solder marks 151, and the multiple third solder marks 151 are arranged at intervals along the circumferential y-direction of the electrode assembly.

[0178] Please see Figure 6 In some embodiments, the first tab stack region 15 is provided with a plurality of third solder marks 151, which are arranged at intervals along the circumferential y-direction of the electrode assembly.

[0179] Optionally, the third solder mark 151 is a strip-shaped structure extending radially along the electrode assembly 12. The length direction of the third solder mark 151 may be parallel to the radial direction of the electrode assembly 12, and a plurality of third solder marks 151 are arranged at intervals along the circumferential y-axis of the electrode assembly.

[0180] In the above scheme, multiple third soldering portions 151 are arranged at intervals along the circumferential y-axis of the electrode assembly, which can effectively pre-weld the multilayer first empty foil area 131 into one piece, effectively shorten the electrical connection path of the inner ring of the first tab stacked area 15, effectively reduce the internal resistance of the first tab stacked area 15, which is beneficial to improving the overcurrent capacity of the cylindrical battery cell 10 and improving the charging and discharging performance of the battery device 100.

[0181] According to some embodiments of this application, there are multiple first solder pads 150, and the multiple first solder pads 150 are arranged at intervals along the circumferential y-direction of the electrode assembly.

[0182] Please see Figure 6 In some embodiments, the first tab stacking region 15 is provided with a plurality of first solder marks 150, and the plurality of first solder marks 150 are arranged at intervals along the circumferential y-direction of the electrode assembly.

[0183] Optionally, the first solder mark 150 is a strip-shaped structure extending radially along the electrode assembly 12. The length direction of the first solder mark 150 may be parallel to the radial direction of the electrode assembly 12, and a plurality of first solder marks 150 are arranged at intervals along the circumferential y-axis of the electrode assembly.

[0184] In the above scheme, multiple first soldering portions 150 are arranged at intervals along the circumferential y-axis of the electrode assembly, which can effectively pre-weld the multilayer first empty foil area 131 into one piece, effectively shorten the electrical connection path of the inner ring of the first tab stack area 15, effectively reduce the internal resistance of the first tab stack area 15, which is beneficial to improving the overcurrent capacity of the cylindrical battery cell 10 and improving the charging and discharging performance of the battery device 100.

[0185] According to some embodiments of this application, along the circumferential direction y of the electrode assembly, the distance between two adjacent first solder pads 150 is greater than or equal to 1 mm and less than or equal to 6 mm.

[0186] Along the circumferential direction y of the electrode assembly, the distance between two adjacent first solder pads 150 can be the minimum distance between two adjacent first solder pads 150, which can be the distance between the second ends 1501 of two adjacent first solder pads 150. See also... Figure 6 Along the circumferential direction y of the electrode assembly, the distance Q between two adjacent first solder pads 150 can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm or any value between two adjacent values.

[0187] Optionally, the method for measuring the distance between two adjacent first solder marks 150 along the circumferential direction y of the electrode assembly can be: disassembling the cylindrical battery cell to obtain the electrode assembly 12, and directly measuring the distance Q between two adjacent first solder marks 150.

[0188] In the above scheme, by setting the distance between two adjacent first soldering portions 150 to be greater than or equal to 1 mm and less than or equal to 6 mm, the first electrode stacking area 15 has multiple first soldering portions 150 with appropriate spacing. On the one hand, this helps to reduce the electrical connection path between the multilayer first empty foil areas 131. On the other hand, it can reduce the risk of affecting the electrolyte wetting of the electrode assembly 12 due to the excessively dense arrangement of the first soldering portions 150, so that the cylindrical battery cell 10 has high charge and discharge performance and reliability.

[0189] According to some embodiments of this application, both the first solder mark 150 and the second solder mark 160 are strips extending radially along the electrode assembly 12. The first solder mark 150 and the second solder mark 160 are staggered along the circumferential direction y of the electrode assembly.

[0190] Please see Figure 6 The first solder mark 150 is a strip extending radially along the electrode assembly 12, and the direction in which the first solder mark 150 has the largest size is parallel to the radial direction of the electrode assembly 12. The second solder mark 160 is a strip extending radially along the electrode assembly 12, and the direction in which the second solder mark 160 has the largest size is parallel to the radial direction of the electrode assembly 12.

[0191] In some embodiments, the size of the second solder mark 160 is larger than the size of the first solder mark 150 along the radial direction of the electrode assembly 12. In some embodiments, the width of the second solder mark 160 is equal to the width of the first solder mark 150.

[0192] The staggered arrangement of the first solder mark 150 and the second solder mark 160 along the circumferential direction y of the electrode assembly can be understood as follows: along the radial direction of the electrode assembly 12, the first solder mark 150 extends to the axis of the electrode assembly 12, and the extended portion does not interfere with the second solder mark 160.

[0193] In the above scheme, the first solder mark 150 and the second solder mark 160 are both strips extending radially along the electrode assembly 12, and the first solder mark 150 and the second solder mark 160 are located at different positions along the circumferential direction y of the electrode assembly. This can effectively reduce the interference of the first solder mark 150 on the second solder mark 160, so that the first current collector 16 is effectively electrically connected to the first tab stacked region 15 through the first solder mark 150 and the second solder mark 160. This enables the cylindrical battery cell 10 to have high charge and discharge performance and reliability, and thus enables the battery device 100 to have high charge and discharge performance and reliability.

[0194] Optionally, the diameter of the outer casing 11 is greater than or equal to 46 mm. The outer casing 11 can be understood as the outer diameter of the outer casing 11.

[0195] In some embodiments, the diameter of the cylindrical battery cell 10 is greater than or equal to 46 mm. Exemplarily, the diameter of the cylindrical battery cell 10 can be 46 mm, 50 mm, 60 mm, or other values ​​greater than or equal to 46 mm.

[0196] In the above scheme, the cylindrical battery cell 10 has a large outer diameter to achieve a high capacity and meet different power consumption needs. In the cylindrical battery cell 10 with a large outer diameter, the multi-layer first empty foil area 131 in the first tab stacking area 15 is pre-welded together by the first soldering part 150, and the first soldering part 150 and the first current collector 16 have an overlapping area. The first soldering part 150 and the second soldering part 160 do not overlap. On the one hand, this can effectively improve the charge and discharge performance of the cylindrical battery cell 10 with a large outer diameter, and on the other hand, it can effectively reduce the risk of reliability reduction caused by poor soldering of the second soldering part 160.

[0197] Optionally, the diameter of the housing 11 is less than or equal to 46 mm. For example, the diameter of the housing 11 can be 32 mm.

[0198] According to some embodiments of this application, the density of the first tab lamination region 15 is 5% to 70%.

[0199] In some embodiments, the density of the first tab lamination region 15 can be 5%, 6%, 7%, 8%...68%, 69%, 70% or any value between two adjacent values.

[0200] Optionally, the density of the first tab stacked region 15 can be calculated using a local method. The formula for calculating the density of the first tab stacked region 15 includes Y=ND / (n(GAP+D)). Where Y refers to the density of the first tab stacked region 15, N refers to the total width of the first empty foil region 131 (the dimension of the first empty foil region 131 along the axial direction z when the first electrode sheet 120 is unfolded), GAP refers to the spacing between two adjacent rings of the first empty foil region 131, D refers to the thickness of the first empty foil region 131, and n refers to the width of the unbent portion of the first empty foil region 131.

[0201] Optionally, the density of the first tab stacked region 15 can be calculated using the overall method. The formula for calculating the density of the first tab stacked region 15 includes Y = LND / nπ(R²-r²). Where Y refers to the density of the first tab stacked region 15, L refers to the length of the first empty foil region 131 (the dimension of the first empty foil region 131 along the winding direction when the first electrode 120 is unfolded), N refers to the total width of the first empty foil region 131 (the dimension of the first empty foil region 131 along the axial direction z when the first electrode 120 is unfolded), D refers to the thickness of the first empty foil region 131, n refers to the width of the unbent portion of the first empty foil region 131, R refers to the radius of the electrode assembly 12, r refers to the radius of the central hole of the electrode assembly 12, and π is pi.

[0202] In the above scheme, by setting the density of the first tab stack region 15 to 5%~70%, the first tab stack region 15 can have a suitable stacking thickness. On the one hand, this ensures that the electrode assembly 12 is stably located in the outer casing 11, reducing the risk of the electrical connection path between the first tab stack region 15 and the first current collector 16 being broken due to the electrode assembly 12 moving within the outer casing 11. On the other hand, it can reduce the risk of excessive pressure generated during the insertion of the electrode assembly 12 into the casing due to excessive stacking thickness, which could affect the structural integrity of the electrode assembly 12. Furthermore, it provides sufficient welding depth for the formation of the first solder mark 150, reducing the risk of solder burn-through and damage to the structure of the separator 121.

[0203] According to some embodiments of this application, along the axial direction z, the depth of the first solder mark 150 is less than the thickness of the first tab stack region 15.

[0204] Along the axial direction z, the depth of the first solder mark 150 being less than the thickness of the first tab stack region 15 can be understood as the first solder mark 150 not extending through the side of the first tab stack region 15 away from the first current collector 16. For example, the first solder mark 150 has an upper end and a lower end along the axial direction z, with the upper end closer to the first current collector 16 than the lower end. The upper end may protrude from the surface of the first tab stack region 15 facing the first current collector 16, while the lower end does not protrude from the surface of the first tab stack region 15 away from the first current collector 16.

[0205] Optionally, along the axial direction z, there is at least one first empty foil area 131 between the first soldering part 150 and the main body area.

[0206] In the above scheme, the depth of the first solder mark 150 is less than the thickness of the first tab stacking region 15, which can reduce the impact of the first solder mark 150 on the separator 121, reduce the risk of local damage to the separator 121 due to the heat generated by the first solder mark 150, and make the cylindrical battery cell 10 have high reliability.

[0207] According to some embodiments of this application, the size of the first current collector 16 is smaller than the size of the electrode assembly 12 along the radial direction of the electrode assembly 12.

[0208] In some embodiments, the distance between the outer contour of the first current collector 16 and the inner peripheral wall of the housing 110 is greater than the distance between the outer contour of the electrode assembly 12 and the inner peripheral wall of the housing 110.

[0209] In some embodiments, when viewed along the axial direction z, the outline of the first tab stacked region 15 is circular, the outline of the electrode assembly 12 is circular, and the outer diameter of the first current collector 16 is smaller than the outer diameter of the electrode assembly 12.

[0210] In some embodiments, when viewed along the axial direction z, the outline shape of the first tab stack region 15 is circular, the outline shape of the first current collector 16 is circular, the outline of the electrode assembly 12 is circular, the outer diameter of the first tab stack region 15 is smaller than the outer diameter of the electrode assembly 12, and the outer diameter of the first current collector 16 is smaller than the outer diameter of the first tab stack region 15.

[0211] In the above scheme, by setting the size of the first current collector 16 to be smaller than the size of the electrode assembly 12 along the radial direction of the electrode assembly 12, the risk of the cylindrical battery cell 10 being punctured by the displacement of the first current collector 16 relative to the outer casing 11 due to external force can be reduced, thus making the cylindrical battery cell 10 have higher reliability.

[0212] According to some embodiments of this application, the second electrode 122 includes a second current collector, the second current collector includes a second coating area and a second empty foil area, the second coating area is provided with a second active layer, at least a portion of the second empty foil area is bent in the axial direction z of the electrode assembly 12, and the second empty foil areas with different winding layers are stacked on each other to form a second electrode tab stack area, the second electrode tab stack area has a fourth solder mark, the fourth solder mark connects at least two layers of second empty foil areas;

[0213] The cylindrical battery cell 10 also includes a second current collector, which is located on the side of the electrode assembly 12 opposite to the first current collector 16 along the axial direction z. The second current collector is connected to the second tab stacked area through a fifth solder mark.

[0214] Among them, on the same projection plane perpendicular to the axis direction z, the orthographic projection of the fourth solder mark and the orthographic projection of the second current collector have an overlapping area, while the orthographic projections of the fourth solder mark and the fifth solder mark do not overlap.

[0215] In the wound structure, the electrode assembly 12 includes a main body region, a first tab stacked region 15, and a second tab stacked region. Along the axial direction z, the first tab stacked region 15 and the second tab stacked region are located at opposite ends of the main body region. The second tab stacked region is formed by stacking second empty foil regions of different numbers on top of each other.

[0216] During the manufacturing process of electrode assembly 12, at least two layers of second empty foil regions in the second tab stack region are pre-soldered to form a fourth solder mark. The fourth solder mark can connect at least two layers of second empty foil regions, allowing current to pass through the at least two layers of second empty foil regions via the fourth solder mark.

[0217] Optionally, the forming process of the fourth solder mark includes, but is not limited to, ultrasonic welding, laser welding, etc.

[0218] Optionally, the shape of the fourth soldering part can be varied, including but not limited to other shapes such as strip, ring, and wave.

[0219] Optionally, the fourth soldering section can connect two, three, or more layers of second empty foil areas in the second tab stack area. For example, the second soldering section 160 can connect all layers of second empty foil areas in the second tab stack area.

[0220] Along the axial direction z, the second current collector and the second tab stacked region are disposed on the same side. The second current collector is welded to the second tab stacked region to form a fifth solder mark. Optionally, the second current collector can be connected to the wall of the housing 11 so that the second tab stacked region is electrically connected to the wall of the housing 11 through the second current collector. Optionally, the second current collector can be electrically connected to an electrode terminal disposed on the housing 11 so that the second tab stacked region is electrically connected to the electrode terminal through the second current collector.

[0221] Alternatively, the second current collector can be in other shapes such as disc, sheet, or strip.

[0222] Optionally, the second current collector may be made of metal, including but not limited to metals such as copper, iron, aluminum, steel or aluminum alloys.

[0223] Optionally, the forming process of the fifth solder mark includes, but is not limited to, ultrasonic welding, laser welding, etc.

[0224] Optionally, the fifth solder joint can have various shapes, including but not limited to strip, ring, wave, and other shapes.

[0225] The fifth soldering section can connect the second current collector to at least one layer of the second empty foil region in the second tab stack area. Optionally, the fifth soldering section can connect the second current collector to two, three, or more layers of the first empty foil region 131 in the second tab stack area.

[0226] When viewed along the axial direction z, the fourth solder mark overlaps at least partially with the second current collector, and the fourth and fifth solder marks are staggered and do not overlap.

[0227] Optionally, when viewed along the axial direction z, the second current collector covers the entire fourth solder joint. Alternatively, when viewed along the axial direction z, the second current collector covers a portion of the fourth solder joint, with another portion of the fourth solder joint located outside the area where the second current collector is located.

[0228] In the above scheme, on the one hand, the second tab stacked area is pre-welded so that at least two second empty foil areas are interconnected through the fourth solder mark, which can shorten the electrical connection path between the multi-layer second empty foil areas, reduce the internal resistance of the second tab stacked area, and improve the current carrying capacity of the cylindrical battery cell 10; on the other hand, there is an overlapping area between the fourth solder mark and the second current collector, so that the multi-layer second empty foil areas can be electrically connected to the second current collector through the fourth solder mark, shortening the electrical connection path between the multi-layer second empty foil areas and the second current collector, further improving the current carrying capacity of the cylindrical battery cell 10; furthermore, since the formation of the fourth solder mark will cause local unevenness in the second tab stacked area, the fourth solder mark and the fifth solder mark are not overlapped, which can reduce the risk of poor soldering between the second current collector and the second tab stacked area, affecting the welding quality of the second current collector and the second tab stacked area, so that the cylindrical battery cell 10 has high structural reliability, and thus the battery device 100 has high charge and discharge performance and reliability.

[0229] Some embodiments of this application also provide a battery device 100, please refer to [link to relevant documentation]. Figure 2 The battery device 100 includes cylindrical battery cells 10.

[0230] For example, the battery device 100 includes a housing 20 and cylindrical battery cells 10, the cylindrical battery cells 10 being housed within the housing 20. In the battery device 100, there may be one or more cylindrical battery cells 10 disposed within the housing 20. When there are multiple cylindrical battery cells 10 disposed within the housing 20, the multiple cylindrical battery cells 10 may be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that some of the multiple cylindrical battery cells 10 are connected in series and others in parallel.

[0231] Some embodiments of this application also provide an electrical device; please refer to [link / reference]. Figure 1 The electrical device includes a cylindrical battery cell 10 or a battery device 100.

[0232] For example, the electrical device is a vehicle, and the cylindrical battery cell 10 and / or battery device 100 can serve as the operating power source for the vehicle's electrical system, for example, for the power requirements of starting, navigation and operation of the vehicle.

[0233] This application provides a cylindrical battery cell 10. Please refer to [link to relevant documentation]. Figures 3-8 .

[0234] The cylindrical battery cell 10 includes a housing 11, an electrode assembly 12, and a first current collector 16. The electrode assembly 12 is disposed inside the housing 11 and has a wound structure. The electrode assembly 12 includes a first electrode 120, a separator 121, and a second electrode 122, with the separator 121 disposed between the first electrode 120 and the second electrode 122. The first electrode 120 includes a first current collector 13, which includes a first coated area 130 and a first empty foil area 131. The first coated area 130 is provided with a first active layer 14. At least a portion of the first empty foil area 131 is bent in the axial direction z of the electrode assembly 12, and the first empty foil areas 131 with different winding layers are stacked on top of each other to form a first tab stack area 15. The first tab stack area 15 has a first solder mark 150 and a third solder mark 151. The first solder mark 150 connects at least two layers of the first empty foil area 131, and the third solder mark 151 connects at least two layers of the first empty foil area 131. A first current collector 16 is located on one side of the electrode assembly 12 along the axial direction z, and the first current collector 16 is connected to the first tab stack area 15 through a second solder mark 160.

[0235] Optionally, the first current collector 16 is a current collector disk. Along the radial direction of the electrode assembly, the size of the current collector disk is smaller than the size of the electrode assembly 12, and the size of the electrode assembly 12 is smaller than the size of the outer shell.

[0236] The first electrode stacked region 15 includes a first region 15a, a second region 15b, and a third region 15c. The first region 15a is covered by a current collector, the second region 15b is located on the outer periphery of the first region 15a, and the third region 15c is located on the inner periphery of the first region 15a.

[0237] Optionally, a portion of the first solder mark 150 is located in the first region 15a, and another portion of the first solder mark 150 is located in the second region 15b. The first solder mark 150 and the second solder mark 160 do not overlap, and the first solder mark 150 is further away from the axis of the electrode assembly 12 than the second solder mark 160.

[0238] Optionally, a portion of the third solder mark 151 is located in the first region 15a, and another portion of the first solder mark 150 is located in the third region 15c. The third solder mark 151 and the second solder mark 160 do not overlap, and the second solder mark 160 is further away from the axis of the electrode assembly 12 than the third solder mark 151.

[0239] In the above scheme, on the one hand, the first tab stacked region 15 is pre-welded so that at least two first empty foil regions 131 are interconnected through the first soldering part 150 and the third soldering part 151, which can shorten the electrical connection path between the multi-layer first empty foil regions 131, reduce the internal resistance of the first tab stacked region 15, and improve the overcurrent capacity of the cylindrical battery cell 10; on the other hand, the first soldering part 150 and the first current collector 16 have overlapping areas, and the third soldering part 151 and the first current collector 16 have overlapping areas, so that the multi-layer first empty foil regions 131 can be electrically connected to the first current collector 16 through the first soldering part 150 and the third soldering part 151, shortening the multi-layer first empty foil regions 131. The electrical connection path between the first current collector 16 and the first current collector 16 further enhances the current carrying capacity of the cylindrical battery cell 10. On the other hand, the formation of the first solder mark 150 and the third solder mark 151 will cause local unevenness in the first tab stacked area 15. The non-overlapping arrangement of the first solder mark 150 and the second solder mark 160, and the non-overlapping arrangement of the third solder mark 151 and the second solder mark 160 can reduce the risk of poor soldering between the first current collector 16 and the first tab stacked area 15, which affects the welding quality of the first current collector 16 and the first tab stacked area 15. This makes the cylindrical battery cell 10 have high structural reliability, and thus makes the battery device 100 have high charge and discharge performance and reliability.

[0240] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cylindrical battery cell, characterized by, include: shell; An electrode assembly is disposed within the housing. The electrode assembly has a wound structure and includes a first electrode, a separator, and a second electrode. The separator is disposed between the first electrode and the second electrode. The first electrode includes a first current collector, which includes a first coating area and a first empty foil area. The first coating area is provided with a first active layer. The first empty foil area is located on one side of the first coating area along the axial direction of the electrode assembly. At least a portion of the first empty foil area is bent toward the axial direction of the electrode assembly, and first empty foil areas with different winding layers are stacked on top of each other to form a first tab stack area. The first tab stack area has a first solder mark, which connects at least two layers of the first empty foil area. The first current collector is located on one side of the electrode assembly along the axial direction, and the first current collector is connected to the first tab stack area through the second solder mark. Specifically, on the same projection plane perpendicular to the axis, the orthographic projection of the first solder mark overlaps with the orthographic projection of the first current collector, while the orthographic projections of the first solder mark and the second solder mark do not overlap.

2. The cylindrical battery cell according to claim 1, characterized in that, The first solder mark has a first end and a second end, the first end being farther away from the axis than the second end; the second solder mark has a third end and a fourth end, the third end being farther away from the axis than the fourth end. The distance from the second end to the axis is greater than or equal to the distance from the third end to the axis.

3. The cylindrical battery cell according to claim 2, characterized in that, The distance between the first end and the outer peripheral surface of the electrode assembly is greater than or equal to 0 and less than or equal to 2 mm.

4. The cylindrical battery cell according to claim 1, characterized in that, The first electrode stacked region includes a first region covered by the first flow collector and a second region located on the outer periphery of the first region; A portion of the first solder mark is located in the first region, and another portion is located in the second region.

5. The cylindrical battery cell according to claim 4, characterized in that, The first electrode stacked region also has a third region, which is located on the inner peripheral side of the first region; The first tab stack area also has a third solder mark, which connects at least two layers of the first empty foil area. A portion of the third solder mark is located in the first region, and another portion is located in the third region. On the same projection plane perpendicular to the axis, the orthographic projection of the third solder mark and the orthographic projection of the second solder mark do not overlap.

6. The cylindrical battery cell according to claim 5, characterized in that, The second solder mark has a third end and a fourth end, the third end being further away from the axis than the fourth end; the third solder mark has a fifth end and a sixth end, the fifth end being further away from the axis than the sixth end. The distance from the fifth end to the axis is less than or equal to the distance from the fourth end to the axis.

7. The cylindrical battery cell according to claim 5, characterized in that, The number of the third solder marks is multiple, and the multiple third solder marks are arranged at intervals along the circumference of the electrode assembly.

8. The cylindrical battery cell according to claim 2, characterized in that, Both the first solder mark and the second solder mark are strips extending radially along the electrode assembly; Along the circumferential direction of the electrode assembly, the first solder mark and the second solder mark are staggered.

9. The cylindrical battery cell according to claim 1, characterized in that, The number of the first solder marks is multiple, and the multiple first solder marks are arranged at intervals along the circumference of the electrode assembly.

10. The cylindrical battery cell according to claim 9, characterized in that, Along the circumferential direction of the electrode assembly, the distance between two adjacent first solder marks is greater than or equal to 1 mm and less than or equal to 6 mm.

11. The cylindrical battery cell according to claim 1, characterized in that, The density of the first electrode lamination region is 5% to 70%.

12. The cylindrical battery cell according to claim 1, characterized in that, Along the axial direction, the depth of the first solder mark is less than the thickness of the first tab stack region.

13. The cylindrical battery cell according to claim 1, characterized in that, Along the radial direction of the electrode assembly, the size of the first current collector is smaller than the size of the electrode assembly.

14. The cylindrical battery cell according to any one of claims 1-13, characterized in that, The second electrode includes a second current collector, the second current collector includes a second coating area and a second empty foil area, the second coating area is provided with a second active layer, at least a portion of the second empty foil area is bent toward the axial direction of the electrode assembly, and the second empty foil areas with different winding layers are stacked on each other to form a second tab stack area, the second tab stack area has a fourth solder mark, the fourth solder mark connects at least two layers of the second empty foil area; The cylindrical battery cell further includes a second current collector, which is located on the side of the electrode assembly opposite to the first current collector along the axial direction. The second current collector is connected to the second tab stacked area through a fifth solder mark. Specifically, on the same projection plane perpendicular to the axis, the orthographic projection of the fourth solder mark overlaps with the orthographic projection of the second current collector, while the orthographic projections of the fourth solder mark and the fifth solder mark do not overlap.

15. A battery device, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-14.

16. An electrical appliance, characterized in that, Includes the cylindrical battery cell according to any one of claims 1-14, or the battery device according to claim 15.

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