Battery monomer, battery device and electric equipment

Abstract

The utility model provides a battery monomer, a battery device and electric equipment, the battery monomer comprises a shell and an electrode assembly, the shell has an accommodating space, the electrode assembly is located in the accommodating space, the electrode assembly comprises a first pole piece, a second pole piece and an isolating membrane, and the isolating membrane is clamped between the first pole piece and the second pole piece; the first pole piece, the isolating membrane and the second pole piece are wound to form an electrode assembly, the first pole piece is provided with a plurality of first tabs which are arranged in a stacked mode, the first tabs comprise first inner tabs and first outer tabs, and the first inner tabs are closer to the winding center of the electrode assembly than the first outer tabs; a plurality of first tabs are arranged between the first inner tab and the first outer tab, the width of the first inner tab is larger than that of the first outer tab, and the width of any one of the first tabs between the first inner tab and the first outer tab is smaller than or equal to that of the first inner tab and larger than that of the first outer tab. According to the invention, the yield of the battery monomers can be improved.

Description

Technical Field

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

[0002] Battery cells 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, improving the yield rate of individual battery cells is a key research direction. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance that can improve the yield rate of battery cells.

[0005] This application provides a battery cell including a casing and an electrode assembly. The casing has a receiving space, and the electrode assembly is located in the receiving space. The electrode assembly includes a first electrode, a second electrode, and a separator. The separator is sandwiched between the first electrode and the second electrode. The first electrode, the separator, and the second electrode are wound to form the electrode assembly. The first electrode has a plurality of first tabs stacked on top of each other. The plurality of first tabs include a first inner tab and a first outer tab. The first inner tab is closer to the winding center of the electrode assembly than the first outer tab. A plurality of first tabs are provided between the first inner tab and the first outer tab. The width of the first inner tab is greater than the width of the first outer tab, and the width of any first tab located between the first inner tab and the first outer tab is less than or equal to the width of the first inner tab and greater than the width of the first outer tab.

[0006] In the above technical solution, the battery cell of this embodiment sets the width of the first inner electrode tab to be greater than the width of the first outer electrode tab, and the width of any first electrode tab located between the first inner electrode tab and the first outer electrode tab is less than or equal to the width of the first inner electrode tab and greater than the width of the first outer electrode tab. In this way, the width of the first outer electrode tab is smaller, reducing the possibility of misalignment with the first inner electrode tab in the thickness direction of the electrode assembly. This improves the problem of assembly failure due to misalignment between the first electrode tab and other components (such as the lower plastic) in the battery cell, reduces the defect rate of the electrode assembly, and improves the yield rate and production efficiency of the battery cell.

[0007] In some embodiments, the plurality of first electrodes located between the first inner electrode and the first outer electrode include a first group of electrodes and a second group of electrodes located between the first group of electrodes and the first outer electrode. The first group of electrodes includes a plurality of first electrodes of the same width, and the second group of electrodes includes at least two first electrodes. The width of any one of the first electrodes in the second group of electrodes is less than the width of any one of the first electrodes in the first group of electrodes.

[0008] In the above technical solution, the first set of electrodes is configured to include multiple first electrodes of the same width. The multiple stacked first electrodes can have a large overlapping area, which facilitates the connection of the first electrodes with other components and has little impact on the current carrying capacity of the first electrodes, thus reducing the heat generation problem.

[0009] In some embodiments, in the second set of tabs, the width of the plurality of first tabs decreases sequentially from the first inner tab to the first outer tab.

[0010] In the above technical solution, the width of the multiple first tabs is set to decrease one by one, so that the width of the first outer tab and the first tab adjacent to the first outer tab is smaller, which further reduces the possibility of misalignment between the first tab near the outer ring and the first inner tab in the thickness direction of the electrode assembly after winding, reduces the defect rate of the electrode assembly, and improves the yield rate and production efficiency of the battery cell.

[0011] In some embodiments, in the second set of electrodes, the widths of the plurality of first electrodes are arranged in an arithmetic sequence from the first inner electrode to the first outer electrode.

[0012] In the above technical solution, the positional change of the first electrode tab of the second set of electrodes after being affected by the thickness is easy to control, reducing the possibility of misalignment, reducing the defect rate of electrode assembly, and improving the yield rate of battery cells and production efficiency.

[0013] In some embodiments, in the second group of electrodes, at least a portion of the first electrodes are divided into multiple groups, each group of first electrodes including multiple first electrodes of the same width, and the width of the first electrodes in the multiple groups decreases sequentially from the first inner electrode to the first outer electrode.

[0014] In the above technical solution, by setting the width of the first electrode tab to decrease in small increments, the impact of the reduction in the width of the first electrode tab on the connection area can be reduced, that is, the impact on the current carrying capacity can be reduced.

[0015] In some embodiments, the widths of the first electrodes of a plurality of groups are arranged in an arithmetic sequence from the first inner electrode to the first outer electrode.

[0016] In the above technical solution, the positional change of the second set of tabs after being affected by thickness is easy to control, reducing the possibility of misalignment, reducing the defect rate of electrode components, and improving the yield rate of battery cells and production efficiency.

[0017] In some embodiments, the second electrode sheet has a plurality of stacked second tabs, the polarity of which is opposite to that of the first tab. The plurality of second tabs includes a second inner tab and a second outer tab. The second inner tab is closer to the winding center of the electrode assembly than the second outer tab. A plurality of second tabs are provided between the second inner tab and the second outer tab. The width of the second inner tab is greater than the width of the second outer tab, and the width of any second tab located between the second inner tabs and the second outer tab is less than or equal to the width of the second inner tab and greater than the width of the second outer tab.

[0018] In the above technical solution, the battery cell of this embodiment sets the width of the second inner electrode tab to be greater than the width of the second outer electrode tab, and the width of any second electrode tab located between the second inner electrode tab and the second outer electrode tab is less than or equal to the width of the second inner electrode tab and greater than the width of the second outer electrode tab. In this way, the width of the second outer electrode tab is smaller, reducing the possibility of misalignment with the second inner electrode tab in the thickness direction of the electrode assembly. This improves the problem of assembly failure due to misalignment between the second electrode tab and other components in the battery cell, reduces the defect rate of the electrode assembly, and improves the yield rate and production efficiency of the battery cell.

[0019] In some embodiments, a plurality of first tabs and a plurality of second tabs are located at the same end of the electrode assembly.

[0020] The above technical solution facilitates the subsequent wiring of individual battery cells.

[0021] In some embodiments, the plurality of first tabs and the plurality of second tabs are all located on the same side of the winding center in the thickness direction of the electrode assembly.

[0022] In the above technical solution, while meeting the overcurrent requirements, it facilitates the bending of the first and second tabs, thereby connecting them with the adapters inside the battery cell, such as by welding.

[0023] In some embodiments, the width of the first inner electrode ear is L1, and the width of the first outer electrode ear is L2, where L1 and L2 satisfy: 3 / 4 ≤ L2 / L1 < 1.

[0024] In the above technical solution, limiting the value of L2 / L1 to greater than or equal to 3 / 4 can reduce the impact on the connection area of ​​the first electrode tab and the current carrying capacity, and facilitate subsequent welding and other processes.

[0025] In some embodiments, L1 and L2 satisfy: 3 / 4 ≤ L2 / L1 ≤ 7 / 8.

[0026] In the above technical solution, the value of L2 / L1 is limited to less than or equal to 7 / 8, so as to further reduce the possibility of misalignment between the first outer tab and the first inner tab in the thickness direction of the electrode assembly, reduce the defect rate of the electrode assembly, and improve the yield rate and production efficiency of the battery cell.

[0027] In some embodiments, the first inner electrode is the first electrode closest to the winding center, and / or the first outer electrode is the first electrode farthest from the winding center.

[0028] In the above technical solution, by setting the first inner tab to be closest to the winding center, the first inner tab has the largest width among all the first tabs, thus reserving space for subsequent misalignment of the first tabs and reducing the possibility of misalignment. The farthest first tab usually misaligns more severely; therefore, setting the first outer tab to be farthest from the winding center reduces the possibility of misalignment of the outermost first tab after winding, reducing the defect rate of the electrode assembly and improving the yield rate and production efficiency of the battery cells.

[0029] Secondly, embodiments of this application also provide a battery device, including the aforementioned battery cell.

[0030] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery cell or battery device, wherein the battery cell is used to provide electrical energy or store electrical energy. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0032] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0033] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0034] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0035] Figure 4 A schematic diagram of a structure of an electrode assembly in a battery cell that is not affected by thickness, provided in some embodiments of this application;

[0036] Figure 5Another structural schematic diagram of the electrode assembly in a battery cell provided in some embodiments of this application;

[0037] Figure 6 This is another structural schematic diagram of an electrode assembly in a battery cell that is not affected by thickness, provided in some embodiments of this application;

[0038] Figure 7 for Figure 6 The diagram shows the structure of the electrode assembly affected by thickness.

[0039] Figure 8 This is another schematic diagram of an electrode assembly in a battery cell that has not been misaligned, provided in some embodiments of this application.

[0040] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0041] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Battery cell assembly; 6. Battery cell; 7. Housing;

[0042] 51. Outer shell; 511. Housing; 512. End cap;

[0043] 52. Electrode assembly; 521. First electrode; 5211. First tab; 5212. First inner tab; 5213. First outer tab; 5214. First set of tabs; 5215. Second set of tabs; 522. Second electrode; 5221. Second tab; 5222. Second inner tab; 5223. Second outer tab; 5224. Third set of tabs; 5225. Fourth set of tabs; 523. Separating membrane;

[0044] 53. Insulating components. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this application, "multiple" means two or more (including two).

[0052] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0053] A single battery cell includes electrode components and an electrolyte. The electrode components include a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, which is coated on the surface of the positive current collector. The positive current collector includes a positive electrode coating area and a positive electrode tab connected to the coating area. The coating area is coated with the positive active material layer, while the tab is not. Taking a lithium-ion battery cell as an example, the positive current collector can be made of aluminum, and the positive active material layer includes the positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being coated on the surface of the negative electrode current collector. The negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area. The negative electrode coating area is coated with the negative electrode active material layer, while the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes negative electrode active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0054] During the winding process of a single battery cell, a winding device is typically used to wind the positive electrode sheet, the negative electrode sheet, and the separator to form an electrode assembly. The positive electrode sheet has multiple positive electrode tabs, and the negative electrode sheet has multiple negative electrode tabs. After winding, the multiple positive electrode tabs are stacked and aligned, and the multiple negative electrode tabs are stacked and aligned, which facilitates subsequent connection and assembly.

[0055] However, the thickness of the positive electrode, the negative electrode, and the separator are not fixed and may be thinner or thicker than expected. This change in thickness can cause misalignment of the subsequently wound tabs, altering the position of the outermost few turns of the tabs. Consequently, the finished electrode assembly may interfere with other components within the housing (such as the part in the lower plastic between the positive and negative tabs), making assembly impossible and reducing the production yield and efficiency of the electrode assembly.

[0056] In view of this, this application provides a battery cell in which the width of the first inner tab is set to be greater than the width of the first outer tab, and the width of any first tab located between the first inner tabs and between the first outer tabs is less than or equal to the width of the first inner tab and greater than the width of the first outer tab. In this way, the width of the first outer tab is smaller, reducing the possibility of misalignment after winding, reducing the defect rate of the electrode assembly, and improving the yield and production efficiency of the battery cell.

[0057] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0058] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0059] Figure 1 This is a structural schematic diagram of vehicle 1 provided in some embodiments of this application.

[0060] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0061] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0062] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0063] Figure 2 This is a schematic diagram of the structure of the battery device 2 provided in some embodiments of this application.

[0064] like Figure 2 As shown, the battery device 2 may include one or more battery cell assemblies 5 for providing voltage and capacity. The battery cell assembly 5 may include multiple battery cells 6, which are connected in series, parallel, or mixed connection via a busbar.

[0065] In some embodiments, the battery cell assembly 5 is typically formed by arranging multiple battery cells 6; as an example, the battery cell assembly 5 can be a battery module, which is formed by arranging and fixing multiple battery cells 6 into a single module. As an example, a battery module can be formed by bundling multiple battery cells 6 together with cable ties.

[0066] In some embodiments, the battery device 2 may be a battery pack, which includes a housing 7 and one or more battery cell assemblies 5, the battery cell assemblies 5 being housed in the housing 7.

[0067] As an example, the battery cell assembly 5 can be a battery module, and the battery cell assembly 5 can be housed in the housing 7 by fixing the battery module in the housing 7.

[0068] As an example, the battery cell assembly 5 can also be housed in the housing 7 by directly fixing multiple battery cells 6 to the housing 7.

[0069] As an example, the housing 7 may include a first housing and a second housing. The first housing and the second housing are fastened together to form a closed space inside the housing 7 to house the battery cell assembly 5. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 7 may be a top cover or a bottom plate.

[0070] As an example, the housing 7 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 7 forms an enclosed space to accommodate the battery cell assembly 5.

[0071] As an example, the box body 7 can be part of the chassis structure of the vehicle 1. For example, the top cover of the box body 7 can be at least part of the floor of the vehicle 1, or the frame of the box body 7 can be at least part of the crossbeams and longitudinal beams of the vehicle 1.

[0072] In some embodiments, battery device 2 refers to energy storage device, which includes a housing 7, with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0073] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application; Figure 4 A schematic diagram of a structure of an electrode assembly in a battery cell that is not affected by thickness, provided in some embodiments of this application; Figure 5 Another structural schematic diagram of the electrode assembly in a battery cell provided in some embodiments of this application; Figure 6 This is another structural schematic diagram of the electrode assembly in a battery cell that is not affected by thickness, as provided in some embodiments of this application. Figure 7 for Figure 6 The diagram shows the structure of the electrode assembly affected by thickness.

[0074] like Figures 3-7 As shown, this application also provides a battery cell 6, which includes a housing 51 and an electrode assembly 52. ​​The housing 51 has a receiving space, and the electrode assembly 52 is located in the receiving space. The electrode assembly 52 includes a first electrode 521, a second electrode 522, and a separator 523. The separator 523 is sandwiched between the first electrode 521 and the second electrode 522. The first electrode 521, the separator 523, and the second electrode 522 are wound to form the electrode assembly 52. ​​The first electrode 521 has a plurality of first tabs 5211 stacked on top of each other. The plurality of first tabs 5211 include a first inner tab 5212 and a first outer tab 5213. The first inner tab 5212 is compared with the first outer tab 5213. An outer electrode tab 5213 is closer to the winding center of the electrode assembly 52. ​​A plurality of first electrodes tabs 5211 are provided between the first inner electrode tab 5212 and the first outer electrode tab 5213. The width of the first inner electrode tab 5212 is greater than the width of the first outer electrode tab 5213. The width of any first electrode tab 5211 located between the first inner electrode tab 5212 and the first outer electrode tab 5213 is less than or equal to the width of the first inner electrode tab 5212 and greater than the width of the first outer electrode tab 5213.

[0075] The outer casing 51 is a component used to form the internal environment of the battery cell 6, which can accommodate the electrode assembly 52, electrolyte, and other components. The outer casing 51 may include a housing 511 and an end cap 512. The housing 511 and end cap 512 can be independent components, or an opening may be provided on the housing 511, with the end cap 512 closing the opening to form the internal environment of the battery cell 6. The housing 511 may be cuboid in shape. Specifically, the shape of the housing 511 can be determined according to the specific shape and size of the electrode assembly 52. ​​The housing 511 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0076] End cap 512 refers to a component that covers the opening of housing 511 to isolate the internal environment of battery cell 6 from the external environment. The shape of end cap 512 may be adapted to the shape of housing 511 to fit the housing 511. Functional components such as electrode terminals may be provided on end cap 512. Electrode terminals can be used for electrical connection with electrode assembly 52 to output or input electrical energy to battery cell 6. In some embodiments, end cap 512 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 6 reaches a threshold. The material of end cap 512 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating member 53 may be provided on the inner side of end cap 512. The insulating member 53 can be used to isolate the electrical connection components within housing 511 from end cap 512 to reduce the risk of short circuits. For example, the insulating member 53 may be plastic, rubber, etc.

[0077] Electrode assembly 52 is the component in a battery cell where electrochemical reactions occur. The casing may contain one or more electrode assemblies 52. In this embodiment, the electrode assembly 52 is mainly formed by winding positive and negative electrode sheets, with a separator between them. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 52, while the portions without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or at opposite ends. During charging and discharging, the positive and negative active materials react with the electrolyte, and the tabs connect to electrode leads (such as electrode terminals or the casing) to form a current loop.

[0078] The first electrode 521 is a component of the electrode assembly 52. ​​The first electrode 521 includes a first current collector and a first active material layer. The first active material layer is coated on the surface of the first current collector, and the first current collector without the first active material layer protrudes beyond the first current collector coated with the first active material layer. The first current collector without the first active material layer serves as the first tab 5211. The first electrode 521 can be either a positive electrode or a negative electrode. When the first electrode 521 is a positive electrode, the second electrode 522 is a negative electrode, and the first tab 5211 is a positive tab; when the first electrode 521 is a negative electrode, the first tab 5211 is a negative tab, and the second electrode 522 is a positive electrode.

[0079] The letter L indicates the width of the first tab 5211, the letter X indicates the length direction of the electrode assembly 52, and the letter Y indicates the thickness direction of the electrode assembly 52. ​​The width L of the first tab 5211 refers to the dimension of the first tab 5211 in the length direction X of the electrode assembly 52. ​​For example, along the length direction X of the electrode assembly 52, at the same position on one side edge of the first tab 5211, the distance between one side of the first tab 5211 and the other side of the first tab 5211.

[0080] In this embodiment, the first inner electrode tab 5212 is close to the winding center. It may be the first inner electrode tab 5212 closest to the winding center, or it may not be the first inner electrode tab 5212 closest to the winding center.

[0081] In this embodiment, the first outer electrode 5213 is far from the winding center. It may be the first outer electrode 5213 that is farthest from the winding center, or it may not be the first outer electrode 5213 that is farthest from the winding center.

[0082] In this embodiment, the width of either the first inner electrode ear 5212 or the first outer electrode ear 5213 is less than or equal to the width of the first inner electrode ear 5212, including the following solutions:

[0083] The width of either the first inner pole ear 5211 or the first outer pole ear 5213 is smaller than the width of the first inner pole ear 5212;

[0084] The width of any one of the first pole ears 5211 between the first inner pole ear 5212 and the first outer pole ear 5213 is equal to the width of the first inner pole ear 5212;

[0085] A portion of the first electrode ear 5211 between the first inner electrode ear 5212 and the first outer electrode ear 5213 has a width equal to the width of the first inner electrode ear 5212, while the other portion of the first electrode ear 5211 has a width smaller than the width of the first inner electrode ear 5212.

[0086] Along the arrangement direction from the first inner electrode tab 5212 to the first outer electrode tab 5213, the width variation trend of the first electrode tab 5211 located between the first inner electrode tab 5212 and the first outer electrode tab 5213 in this embodiment can be as follows:

[0087] The width of the multiple first tabs 5211 decreases sequentially.

[0088] Alternatively, the width of the multiple first tabs 5211 may change in the following manner: first unchanged, then decreasing, then unchanged again.

[0089] Alternatively, the width of the multiple first tabs 5211 may decrease first and then remain constant.

[0090] For example, Figure 7 This can represent the change in the shape of the electrode tab due to the thinner electrode sheet during clockwise winding, such as... Figure 7 As shown, even if the position of the first outer tab 5213 near the outer ring changes, it does not become misaligned with the first inner tab 5212 near the winding center.

[0091] In this embodiment, the battery cell 6 has a wider first inner tab 5212 than the wider first outer tab 5213. Furthermore, the width of any first tab 5211 located between the first inner tab 5212 and the first outer tab 5213 is less than or equal to the width of the first inner tab 5212 and greater than the width of the first outer tab 5213. This results in a smaller width for the first outer tab 5213, reducing the likelihood of misalignment with the first inner tab 5212 in the thickness direction of the electrode assembly. This improves the problem of assembly failure due to misalignment between the first tab 5211 and other components (such as the insulating component 53) in the battery cell 6, reducing the defect rate of the electrode assembly 52, and increasing the yield and production efficiency of the battery cell 6.

[0092] In some embodiments, the plurality of first electrodes 5211 located between the first inner electrode 5212 and the first outer electrode 5213 include a first group of electrodes 5214 and a second group of electrodes 5215 located between the first group of electrodes 5214 and the first outer electrode 5213. The first group of electrodes 5214 includes a plurality of first electrodes 5211 with the same width, and the second group of electrodes 5215 includes at least two first electrodes 5211. The width of any one of the first electrodes 5211 in the second group of electrodes 5215 is smaller than the width of any one of the first electrodes 5211 in the first group of electrodes 5214.

[0093] For example, the widths of the second set of tabs 5215 are all the same.

[0094] If the first set of tabs 5214 is configured to include multiple first tabs 5211 of the same width, the multiple stacked first tabs 5211 can have a large overlapping area, which facilitates the connection of the first tabs 5211 with other components, and has little impact on the current carrying capacity of the first tabs 5211, thus reducing the heat generation problem.

[0095] Figure 8 This is another schematic diagram of an electrode assembly in a battery cell that has not been misaligned, provided in some embodiments of this application.

[0096] Please see Figure 8 In some embodiments, in the second set of tabs 5215, the width of the plurality of first tabs 5211 decreases sequentially in the direction from the first inner tab 5212 to the first outer tab 5213.

[0097] In this embodiment, the width of the multiple first tabs 5211 decreases one by one, and they can decrease in an arithmetic sequence, that is, the decrease is the same. The decrease in the width of the multiple first tabs 5211 can also become larger or smaller.

[0098] The width of the multiple first tabs 5211 is set to decrease one by one, so that the width of the first outer tab 5213 and the first tab 5211 adjacent to the first outer tab 5213 is smaller, which further reduces the possibility of misalignment between the first tab 5211 near the outer ring and the first inner tab 5212 in the thickness direction of the electrode assembly after winding, thereby reducing the defect rate of the electrode assembly 52 and improving the yield rate and production efficiency of the battery cell 6.

[0099] In some embodiments, in the second set of tabs 5215, the widths of a plurality of first tabs 5211 are arranged in an arithmetic sequence from the first inner tab 5212 to the first outer tab 5213.

[0100] From the first inner electrode 5212 to the first outer electrode 5213, the width of the multiple first electrodes 5211 in the second group of electrodes 5215 decreases by the same amount. The first outer electrode 5213 may or may not be arranged in an arithmetic sequence with the first electrodes 5211 adjacent to it in the second group of electrodes 5215.

[0101] With this configuration, the positional change of the first tab 5211 of the second set of tabs 5215 after being affected by the thickness is easier to control, reducing the possibility of misalignment, reducing the defect rate of the electrode assembly 52, and improving the yield rate and production efficiency of the battery cell 6.

[0102] Please continue reading. Figure 6 and Figure 7 In some embodiments, in the second group of electrodes 5215, at least a portion of the first electrodes 5211 are divided into multiple groups, and each group of first electrodes 5211 includes multiple first electrodes 5211 of the same width. From the first inner electrode 5212 to the first outer electrode 5213, the width of the first electrodes 5211 in the multiple groups decreases sequentially.

[0103] In this embodiment, the number of first electrodes 5211 in each group can be two, three, or four, etc. The number of first electrodes 5211 in each group can be the same or different. Optionally, the number of first electrodes 5211 in each group is the same.

[0104] In this embodiment, the width of the first tab 5211 decreases in groups, and it can decrease in an arithmetic sequence, that is, the decrease is the same. The width of the first tab 5211 in multiple groups can also decrease more or less.

[0105] By setting the width of the first tab 5211 to decrease in increments of each group, the impact of the reduction in the width of the first tab 5211 on the connection area can be reduced, which in turn reduces the impact on the current carrying capacity.

[0106] In some embodiments, the widths of the first electrodes 5211 of a plurality of groups are arranged in an arithmetic sequence from the first inner electrode 5212 to the first outer electrode 5213.

[0107] From the first inner electrode 5212 to the first outer electrode 5213, the width of the first electrode 5211 decreases by the same amount in each group.

[0108] In this embodiment, the first outer electrode 5213 can be arranged in an arithmetic sequence with multiple groups of first electrodes 5211, or it can be arranged in a different arithmetic sequence.

[0109] With this configuration, the positional changes of the second set of tabs 5215 after being affected by thickness are easier to control, reducing the possibility of misalignment, decreasing the defect rate of electrode assembly 52, and improving the yield rate of battery cells and production efficiency.

[0110] In some embodiments, the second electrode 522 has a plurality of stacked second tabs 5221, the second tabs 5221 having opposite polarities to the first tabs 5211. The plurality of second tabs 5221 includes a second inner tab 5222 and a second outer tab 5223. The second inner tab 5222 is closer to the winding center of the electrode assembly 52 than the second outer tab 5223. A plurality of second tabs 5221 are provided between the second inner tab 5222 and the second outer tab 5223. The width of the second inner tab 5222 is greater than the width of the second outer tab 5223, and the width of any second tab 5221 located between the second inner tab 5222 and the second outer tab 5223 is less than or equal to the width of the second inner tab 5222 and greater than the width of the second outer tab 5223.

[0111] In this embodiment, the second inner electrode tab 5222 is close to the winding center. It may be the second inner electrode tab 5222 that is closest to the winding center, or it may not be the second inner electrode tab 5222 that is closest to the winding center.

[0112] In this embodiment, the second outer electrode 5223 is far from the winding center. It may be the second outer electrode 5223 that is farthest from the winding center, or it may not be the second outer electrode 5223 that is farthest from the winding center.

[0113] The width of the second tab 5221 refers to the dimension of the second tab 5221 in the length direction X of the electrode assembly 52. ​​For example, along the length direction X of the electrode assembly 52, at the same position on one side edge of the second tab 5221, the distance between one side of the second tab 5221 and the other side of the second tab 5221.

[0114] In this embodiment, the width of any one of the second electrode tabs 5221 between the second inner electrode tab 5222 and the second outer electrode tab 5223 is less than or equal to the width of the second inner electrode tab 5222, including the following schemes:

[0115] The width of any one of the second pole ears 5221 between the second inner pole ear 5222 and the second outer pole ear 5223 is smaller than the width of the second inner pole ear 5222;

[0116] The width of any of the second pole ears 5221 between the second inner pole ear 5222 and the second outer pole ear 5223 is equal to the width of the second inner pole ear 5222;

[0117] The width of a portion of the second pole ear 5221 between the second inner pole ear 5222 and the second outer pole ear 5223 is equal to the width of the second inner pole ear 5222, while the width of another portion of the second pole ear 5221 is less than the width of the second inner pole ear 5222.

[0118] Along the arrangement direction from the second inner electrode tab 5222 to the second outer electrode tab 5223, the width variation trend of the second electrode tab 5221 located at the second inner electrode tab 5222 and the second outer electrode tab 5223 in this embodiment can be as follows:

[0119] The width of the multiple second tabs 5221 decreases sequentially.

[0120] Alternatively, the width of the multiple second tabs 5221 may change in the following manner: first unchanged, then decreasing, and then unchanged again.

[0121] Alternatively, the width of the multiple second tabs 5221 may first decrease and then remain constant.

[0122] For example, Figure 7 This can represent the change in the shape of the electrode tab due to the thinner electrode sheet during clockwise winding, such as... Figure 7 As shown, even if the position of the second outer tab 5223 near the outer ring changes, it does not become misaligned with the second inner tab 5222 near the winding center.

[0123] In this embodiment, the width of the second inner tab 5222 of the battery cell 6 is set to be greater than the width of the second outer tab 5223, and the width of any second tab 5221 located between the second inner tab 5222 and the second outer tab 5223 is less than or equal to the width of the second inner tab 5222 and greater than the width of the second outer tab 5223. In this way, the width of the second outer tab 5223 is smaller, reducing the possibility of misalignment with the second inner tab 5222 in the thickness direction of the electrode assembly. This improves the problem of assembly failure of the second tab 5221 with other components in the battery cell 6, reduces the defect rate of the electrode assembly 52, and improves the yield rate and production efficiency of the battery cell.

[0124] In some embodiments, the plurality of second electrodes 5221 located between the second inner electrode 5222 and the second outer electrode 5223 include a third group of electrodes 5224 and a fourth group of electrodes 5225 located between the third group of electrodes 5224 and the second outer electrode 5223. The third group of electrodes 5224 includes a plurality of second electrodes 5221 of the same width, and the fourth group of electrodes 5225 includes at least two second electrodes 5221. The width of any second electrode 5221 in the fourth group of electrodes 5225 is less than the width of any second electrode 5221 in the third group of electrodes 5224.

[0125] In some embodiments, in the fourth set of tabs 5225, the width of the plurality of second tabs 5221 decreases sequentially in the direction from the second inner tab 5222 to the second outer tab 5223.

[0126] In some embodiments, in the fourth set of tabs 5225, the widths of a plurality of second tabs 5221 are arranged in an arithmetic sequence from the second inner tab 5222 to the second outer tab 5223.

[0127] In some embodiments, in the fourth group of electrodes 5225, at least a portion of the second electrodes 5221 are divided into multiple groups, and each group of second electrodes 5221 includes multiple second electrodes 5221 of the same width. From the second inner electrode 5222 to the second outer electrode 5223, the width of the second electrodes 5221 of the multiple groups decreases sequentially.

[0128] In some embodiments, the widths of the second pole ears 5221 of a plurality of groups are arranged in an arithmetic sequence from the second inner pole ear 5222 to the second outer pole ear 5223.

[0129] In some embodiments, a plurality of first tabs 5211 and a plurality of second tabs 5221 are located at the same end of the electrode assembly 52.

[0130] In this embodiment, the plurality of first tabs 5211 and the plurality of second tabs 5221 are all disposed at the same end of the electrode assembly 52 in the direction of the winding axis.

[0131] This setup facilitates the wiring of the subsequent battery cell 6.

[0132] In some embodiments, the plurality of first tabs 5211 and the plurality of second tabs 5221 are all located on the same side of the winding center in the thickness direction of the electrode assembly 52.

[0133] In this embodiment, the thickness direction Y, length direction X, and winding axis direction of the electrode assembly 52 are perpendicular to each other.

[0134] This configuration, while meeting the overcurrent requirements, facilitates the bending of the first tab 5211 and the second tab 5221, thereby connecting them to the adapter within the battery cell 6, such as by welding.

[0135] In some embodiments, the width of the first inner electrode 5212 is L1, and the width of the first outer electrode 5213 is L2, where L1 and L2 satisfy: 3 / 4 ≤ L2 / L1 < 1.

[0136] Optionally, the value of L2 / L1 can be 3 / 4, 13 / 16, 7 / 8, or 15 / 16.

[0137] Limiting the value of L2 / L1 to greater than or equal to 3 / 4 can reduce the impact on the connection area and current carrying capacity of the first electrode tab 5211, and facilitate subsequent welding and other processes.

[0138] In some embodiments, L1 and L2 satisfy: 3 / 4 ≤ L2 / L1 ≤ 7 / 8.

[0139] Optionally, the value of L2 / L1 can be 3 / 4, 13 / 16, or 7 / 8.

[0140] The value of L2 / L1 is limited to less than or equal to 7 / 8 to further reduce the possibility of misalignment between the first outer tab 5213 and the first inner tab 5212 in the thickness direction of the electrode assembly 52, thereby reducing the defect rate of the electrode assembly 52 and improving the yield rate and production efficiency of the battery cells.

[0141] In some embodiments, the first inner electrode 5212 is the first electrode closest to the winding center, and / or the first outer electrode 5213 is the first electrode farthest from the winding center.

[0142] In this embodiment, the first inner tab 5212 is closest to the winding center, that is, the first inner tab 5212 is the first tab 5211 of the innermost ring of the first pole piece 521.

[0143] In this embodiment, the first outer tab 5213 is furthest from the winding center, that is, the first outer tab 5213 is the first tab 5211 of the outermost ring of the first pole piece 521.

[0144] By setting the first inner tab 5212 to be closest to the winding center, the first inner tab 5212 has the largest width among all the first tabs 5211, thus reserving space for the misalignment of the subsequent first tabs 5211 and reducing the possibility of misalignment of the first tab 5211.

[0145] The first tab 5211, which is furthest away, is usually more misaligned. Therefore, setting the first outer tab 5213 to be furthest from the winding center can reduce the possibility of misalignment of the first tab 5211 on the outermost ring after winding, reduce the defect rate of the electrode assembly 52, and improve the yield rate and production efficiency of the battery cell 6.

[0146] In some embodiments, this application also provides a battery device 2, including the battery cell 6 described above.

[0147] This application embodiment also provides an electrical device, including the above-mentioned battery cell 6 or battery device 2, wherein the battery cell 6 is used to provide electrical energy or store electrical energy.

[0148] Please see Figures 4-7This application provides a battery cell 6, which includes a housing 51 and an electrode assembly 52. ​​The housing 51 has a receiving space, and the electrode assembly 52 is located in the receiving space. The electrode assembly 52 includes a first electrode 521, a second electrode 522, and a separator 523. The separator 523 is sandwiched between the first electrode 521 and the second electrode 522. The first electrode 521, the separator 523, and the second electrode 522 are wound together to form the electrode assembly 52. ​​The first electrode 521 has a plurality of first tabs 5211 stacked together. The plurality of first tabs 5211 include a first inner tab 5212 and a first outer tab 5213. The first inner tab 5212 is compared with the first outer tab 5213. An outer electrode tab 5213 is closer to the winding center of the electrode assembly 52. ​​A plurality of first electrodes tabs 5211 are provided between the first inner electrode tab 5212 and the first outer electrode tab 5213. The width of the first inner electrode tab 5212 is greater than the width of the first outer electrode tab 5213. The width of any first electrode tab 5211 located between the first inner electrode tab 5212 and the first outer electrode tab 5213 is less than or equal to the width of the first inner electrode tab 5212 and greater than the width of the first outer electrode tab 5213. The plurality of first electrodes 5211 located between the first inner electrode 5212 and the first outer electrode 5213 include a first group of electrodes 5214 and a second group of electrodes 5215 located between the first group of electrodes 5214 and the first outer electrode 5213. The first group of electrodes 5214 includes a plurality of first electrodes 5211 of the same width, and the second group of electrodes 5215 includes at least two first electrodes 5211. The width of any one of the first electrodes 5211 in the second group of electrodes 5215 is smaller than the width of any one of the first electrodes 5211 in the first group of electrodes 5214. In the second group of electrodes 5215, at least a portion of the first electrodes 5211 are divided into multiple subgroups, and each subgroup of first electrodes 5211 includes a plurality of first electrodes 5211 of the same width. From the first inner electrode 5212 to the first outer electrode 5213, the width of the first electrodes 5211 in the multiple subgroups decreases sequentially. From the first inner tab 5212 to the first outer tab 5213, the widths of the multiple groups of first tabs 5211 are arranged in an arithmetic sequence. The multiple first tabs 5211 and multiple second tabs 5221 are located at the same end of the electrode assembly 52. ​​Both the multiple first tabs 5211 and multiple second tabs 5221 are located on the same side of the winding center in the thickness direction of the electrode assembly 52. ​​The first inner tab 5212 is the first tab closest to the winding center, and the first outer tab 5213 is the first tab farthest from the winding center.

[0149] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: The outer shell has a storage space; An electrode assembly is located in the receiving space. The electrode assembly includes a first electrode, a second electrode, and a separator. The separator is sandwiched between the first electrode and the second electrode. The first electrode, the separator, and the second electrode are wound to form the electrode assembly. The first electrode has a plurality of stacked first tabs, each including a first inner tab and a first outer tab. The first inner tab is closer to the winding center of the electrode assembly than the first outer tab. A plurality of first tabs are provided between the first inner tab and the first outer tab. Wherein, the width of the first inner electrode ear is greater than the width of the first outer electrode ear, and the width of any first electrode ear located between the first inner electrode ear and the first outer electrode ear is less than or equal to the width of the first inner electrode ear and greater than the width of the first outer electrode ear.

2. The battery cell according to claim 1, characterized in that, The plurality of first electrodes located between the first inner electrode and the first outer electrode include a first group of electrodes and a second group of electrodes located between the first group of electrodes and the first outer electrode. The first group of electrodes includes a plurality of first electrodes of the same width, and the second group of electrodes includes at least two first electrodes. The width of any one of the first electrodes in the second group of electrodes is less than the width of any one of the first electrodes in the first group of electrodes.

3. The battery cell according to claim 2, characterized in that, In the second set of tabs, the width of each of the first tabs decreases sequentially from the first inner tab to the first outer tab.

4. The battery cell according to claim 3, characterized in that, In the second set of electrodes, the widths of the multiple first electrodes are arranged in an arithmetic sequence from the first inner electrode to the first outer electrode.

5. The battery cell according to claim 2, characterized in that, In the second group of electrodes, at least a portion of the first electrodes are divided into multiple groups, and each group of first electrodes includes multiple first electrodes of the same width. From the first inner electrode to the first outer electrode, the width of the first electrodes in the multiple groups decreases sequentially.

6. The battery cell according to claim 5, characterized in that, From the first inner electrode to the first outer electrode, the widths of the first electrodes of multiple groups are arranged in an arithmetic sequence.

7. The battery cell according to any one of claims 1-6, characterized in that, The second electrode has a plurality of stacked second tabs, the polarity of which is opposite to that of the first electrode. The plurality of second tabs includes a second inner tab and a second outer tab. The second inner tab is closer to the winding center of the electrode assembly than the second outer tab. A plurality of second tabs are provided between the second inner tab and the second outer tab. The width of the second inner electrode ear is greater than the width of the second outer electrode ear, and the width of any second electrode ear located between the second inner electrode ears and between the second outer electrode ears is less than or equal to the width of the second inner electrode ear and greater than the width of the second outer electrode ear.

8. The battery cell according to claim 7, characterized in that, Multiple first tabs and multiple second tabs are located at the same end of the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The plurality of first tabs and the plurality of second tabs are all located on the same side of the winding center in the thickness direction of the electrode assembly.

10. The battery cell according to any one of claims 1-6, characterized in that, The width of the first inner electrode ear is L1, and the width of the first outer electrode ear is L2. The L1 and L2 satisfy: 3 / 4 ≤ L2 / L1 < 1.

11. The battery cell according to claim 10, characterized in that, The L1 and L2 satisfy the following condition: 3 / 4 ≤ L2 / L1 ≤ 7 / 8.

12. The battery cell according to any one of claims 1-6, characterized in that, The first inner electrode tab is the first electrode tab closest to the winding center, and / or the first outer electrode tab is the first electrode tab farthest from the winding center.

13. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-12.

14. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-12 or a battery device as described in claim 13, wherein the battery cell is used to provide electrical energy or store electrical energy.

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