Electrode assembly, as well as related batteries, devices, manufacturing methods, and manufacturing apparatuses

Abstract

The present disclosure provides an electrode assembly, as well as related batteries, devices, manufacturing methods, and manufacturing apparatuses, including a plurality of first electrode plates and at least one second electrode plate, the polarity of the first electrode plates being opposite to that of the second electrode plates, the plurality of first electrode plates and the at least one second electrode plate being wound around a winding axis to form a wound structure, and the plurality of first electrode plates and the at least one second electrode plate being arranged in a superimposed state along a direction perpendicular to the winding axis. Each of the first electrode plates in the plurality of first electrode plates has a first current collector and a first active material layer disposed on a superposed surface of the first current collector, the first current collector having a first body portion on which the first active material layer is provided and at least one first tab protruding from the first body portion along the winding axis, the first tabs of the at least one first tab and the first body portion being arranged in parallel along the winding axis. The number of winding turns of the electrode assembly of the present disclosure can be reduced, and the amount of misalignment of the first tabs in the circumferential direction after winding can be reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of batteries, and in particular, to an electrode assembly, as well as related batteries, devices, manufacturing methods, and manufacturing apparatuses.

Background Art

[0002] Due to advantages such as small size, high energy density, high power density, multiple cycles, and long storage time, lithium-ion batteries are widely used in some electronic devices, electric transportation means, electric toys, and electric devices. For example, lithium-ion batteries are currently widely used in mobile phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] The electrode assembly is an important unit of a lithium-ion battery. Since the wound electrode assembly has the characteristics of a simple manufacturing process and high manufacturing efficiency, it is widely used in lithium-ion batteries.

[0004] However, in order to improve the volumetric energy density of lithium-ion batteries, the electrode assembly usually needs to be wound multiple times. When the electrode assembly is wound multiple times, the tabs are extremely likely to be misaligned, which affects the connection with the collector components.

Summary of the Invention

[0005] An object of the present disclosure is to provide an electrode assembly and related batteries, devices, manufacturing methods, and manufacturing apparatuses that improve the problem of tab misalignment caused by multiple windings.

[0006] A first aspect of the present disclosure provides an electrode assembly having a plurality of first electrode plates and at least one second electrode plate, wherein the polarity of the first electrode plates is opposite to that of the second electrode plate, and the plurality of first electrode plates and the at least one second electrode plate are wound around a winding axis to form a winding structure. In the winding structure, the plurality of first electrode plates and the at least one second electrode plate are arranged to overlap along a direction perpendicular to the winding axis. Each first electrode plate among the plurality of first electrode plates has a first current collector and a first active material layer disposed on a superimposed surface of the first current collector. The first current collector has a first main body portion provided with the first active material layer and at least one first tab protruding from the first main body portion along the direction of the winding axis. Each first tab among the at least one first tab and the first main body portion are arranged parallel to each other along the winding axis.

[0007] In some embodiments, each first electrode plate has a plurality of first tabs arranged at intervals.

[0008] In some embodiments, in the winding structure, each first electrode plate is provided with at least one tab on each of its circles.

[0009] In some embodiments, any two of all the first tabs overlap at least partially.

[0010] In some embodiments, the winding structure is flat and has a straight portion and turning portions disposed on both sides of the straight portion, and all the first tabs are disposed on the straight portion.

[0011] In some embodiments, the straight portion has a first straight small portion and a second straight small portion that are substantially parallel and symmetrically divided with respect to the winding axis, and all of the first tabs are arranged on the first straight small portion or the second straight small portion, or a part of all of the first tabs is arranged on the first straight small portion, and all of the remaining first tabs are arranged on the second straight small portion.

[0012] In some embodiments, the positions of the winding start ends of at least two of the plurality of first electrode plates are different, and / or the positions of the winding end ends of at least two of the plurality of first electrode plates are different.

[0013] In some embodiments, the electrode assembly has a plurality of second electrode plates, the positions of the winding start ends of at least two of the plurality of second electrode plates are different, and / or the positions of the winding end ends of at least two of the plurality of second electrode plates are different.

[0014] In some embodiments, the electrode assembly has a plurality of second electrode plates, the winding structure is flat, and has a straight portion and turning portions arranged on both sides of the straight portion, and the winding end of at least one of the plurality of first electrode plates is arranged in the turning portion, and / or the winding end of at least one of the plurality of second electrode plates is arranged in the turning portion.

[0015] In some embodiments, in different radial directions of the winding structure, the difference in the number of layers between the first electrode plate and the second electrode plate does not exceed a preset number of layers.

[0016] The second aspect of the present disclosure provides a battery having a case and the electrode assembly provided in any item of the first aspect of the present disclosure, wherein the electrode assembly is arranged in the case.

[0017] A third aspect of the present disclosure provides a battery module having a plurality of the batteries provided in the second aspect of the present disclosure.

[0018] A fourth aspect of the present disclosure provides a battery pack having a plurality of the battery modules provided in the third aspect of the present disclosure.

[0019] A fifth aspect of the present disclosure provides a device using a battery, the device having the battery provided in the second aspect of the present disclosure, the battery being configured to supply electrical energy.

[0020] A sixth aspect of the present disclosure is a method for manufacturing an electrode assembly, the method including: providing a plurality of first electrode plates and at least one second electrode plate, wherein polarities of the first electrode plates are opposite to polarities of the second electrode plate; winding the plurality of first electrode plates and the at least one second electrode plate around a winding axis to form a winding structure. In the winding structure, the plurality of first electrode plates and the at least one second electrode plate are arranged to overlap along a direction perpendicular to the winding axis. Each first electrode plate has a first current collector and a first active material layer disposed on a superimposed surface of the first current collector. The first current collector has a first main body portion provided with the first active material layer and at least one first tab protruding from the first main body portion along a direction of the winding axis. Each first tab and the first main body portion in the at least one first tab are arranged parallel to each other along the winding axis.

[0021] A seventh aspect of the present disclosure is a manufacturing apparatus for an electrode assembly, comprising an electrode plate arrangement mechanism configured to provide a plurality of first electrode plates and at least one second electrode plate, wherein the polarity of the first electrode plates is opposite to the polarity of the second electrode plate; an electrode plate arrangement mechanism, and a winding mechanism configured to wind the plurality of first electrode plates and the at least one second electrode plate around a winding shaft to form a winding structure. In the winding structure, the plurality of first electrode plates and the at least one second electrode plate are arranged to overlap along a direction perpendicular to the winding shaft. Each first electrode plate has a first current collector and a first active material layer disposed on the overlapping surface of the first current collector. The first current collector has a first main body portion provided with the first active material layer and at least one first tab protruding from the first main body portion along the direction of the winding shaft. Each first tab and the first main body portion in the at least one first tab are arranged parallel to each other along the winding shaft. A manufacturing apparatus is provided.

[0022] Based on the technical solution provided in the present disclosure, the electrode assembly has a plurality of first electrode plates, and the length of the first electrode plate is equal to being shortened. Further, since the number of windings of the electrode assembly is reduced, the amount of misalignment of the first tab in the circumferential direction after winding can be reduced, facilitating connection with the collector component. Also, the first tab and the first main body portion of the present disclosure are distributed parallel to each other along the winding shaft, whereby the area of the first current collector coated with the first active material layer is enlarged, and the energy density of the electrode assembly is further improved.

[0023] Other features and advantages of the present disclosure will become apparent from the detailed description of the exemplary embodiments of the present disclosure with reference to the following accompanying drawings.

Brief Description of the Drawings

[0024] The drawings described herein are used to provide a further understanding of the present disclosure and form a part of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are for explaining the present disclosure and do not unduly limit the present disclosure.

[0025]

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Embodiments for Carrying Out the Invention

[0026] To make the objectives, technical solutions, and effects of the embodiments of the present disclosure clearer, a clear and complete description of the technical solutions of the embodiments of the present disclosure is given below in combination with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part, not all, of the embodiments of the present disclosure. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present disclosure fall within the protection scope of the present disclosure.

[0027] Unless otherwise defined, all technical and scientific terms used in the text have the same meaning as understood by those skilled in the technical field of the present disclosure. In the text, the terms used in the application specification are for the purpose of explaining specific embodiments rather than limiting the present disclosure. The terms "including" and "having" and any variations thereof in the specification, claims, and the above brief description of the drawings of the present disclosure are intended to include non-exclusive inclusion. Terms such as "first" and "second" in the specification, claims, or the above drawings of the present disclosure are not for explaining a specific order or a primary or secondary relationship, but are used to distinguish different objects.

[0028] References to "embodiment" in this document mean that the specific features, structures, or properties described in combination with the embodiment may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in this specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive with other embodiments. One of ordinary skill in the art can explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0029] The term "and / or" in this document simply describes the occurrence relationship of the related objects and represents the existence of three relationships. For example, A and / or B can represent the situation where only A exists, where A and B exist simultaneously, and where only B exists. Furthermore, the symbol " / " in this document generally represents that the related objects before and after are in an "or" relationship.

[0030] The term "a plurality of" in the present disclosure refers to two or more. Similarly, "a plurality of groups" refers to two or more groups, and "a plurality of plates" refers to two or more plates.

[0031] The electrode assembly, method for manufacturing the same, battery, battery module, and battery pack described in the embodiments of the present disclosure are all applicable to various devices using batteries, such as mobile phones, notebook computers, battery cars, electric vehicles, ships, space vehicles, electric toys, and electric tools. For example, space vehicles include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include fixed or movable electric toys, such as game machines, electric vehicle toys, electric ship toys, electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools used in railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers.

[0032] The electrode assembly, battery, battery module, and battery pack described in the embodiments of the present disclosure are applicable not only to the above devices but also to all devices using batteries. However, for the sake of easy explanation, in the following embodiments, an electric vehicle will be taken as an example for explanation.

[0033] For example, FIG. 1 is a schematic structural diagram of a vehicle 100 according to an embodiment of the present disclosure. The vehicle 100 can be a vehicle powered by oil, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a battery electric vehicle, a hybrid electric vehicle, or an extended-range vehicle. The battery pack 200 can be disposed inside the vehicle 100. For example, the battery pack 200 can be disposed at the bottom, the front end, or the rear end of the vehicle 100. The battery pack 200 can be used as a power source for the vehicle 100. For example, the battery pack 200 can function as an operating power source for the vehicle 100 and can function as a circuit system for the vehicle 100. For example, the battery pack 200 can satisfy the power requirements of the vehicle 100 during startup, navigation, and operation of the vehicle 100. In other embodiments of the present disclosure, the battery pack 200 not only functions as an operating power source for the vehicle 100 but also functions as a driving power source for the vehicle 100 and can be used instead of or partially instead of fuel oil or natural gas to provide driving force to the vehicle 100.

[0034] To meet different requirements for electricity use, the battery pack 200 can include one battery module or a plurality of battery modules, and the plurality of battery modules can be connected in series, in parallel, or in series and in parallel. The series and parallel connections refer to a combination of series connection and parallel connection. For example, FIG. 2 is a schematic structural diagram of the battery pack 200 according to other embodiments of the present disclosure. The battery pack 200 has a first case 201, a second case 202, and a plurality of battery modules 300. The shapes of the first case 201 and the second case 202 are determined according to the shape formed by combining the plurality of battery modules 300. Both the first case 201 and the second case 202 are provided with openings. For example, both the first case 201 and the second case 202 can be hollow rectangular parallelepipeds with only one surface on each being the opening surface. That is, there is no case wall on its surface, and the inside and outside of the case communicate with each other. The first case 201 and the second case 202 are buckled to each other at the openings to form a closed case of the battery pack 200. After connecting the plurality of battery modules 300 in parallel, in series, or in series and in parallel, the plurality of battery modules 300 are arranged in the case formed after buckling the first case 201 to the second case 202.

[0035] In other embodiments of the present disclosure, when the battery pack 200 has the battery module 300, this battery module 300 is arranged in the case formed after buckling the first case 201 to the second case 202.

[0036] The electricity generated by one or more battery modules 300 penetrates the case through the conductive mechanism and is led out.

[0037] According to various power demands, the battery module 300 can also include one or more batteries. As shown in FIG. 3, the battery module 300 has a plurality of batteries 400. These plurality of batteries 400 can be connected in series, in parallel, or in series and parallel combinations to achieve high capacity or high power. For example, the battery 400 can be a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery 400 can be cylindrical, flat, rectangular, or other shapes.

[0038] In other embodiments of the present disclosure, a plurality of batteries 400 can be stacked on top of each other and connected in series, in parallel, or in series and parallel combinations. In other embodiments of the present disclosure, each battery 400 can be square, cylindrical, or other shapes. For example, FIG. 4 is a schematic structural diagram of the battery 400 according to other embodiments of the present disclosure. The battery 400 has one or more electrode assemblies 10, a case 20, and an end cover assembly 40. The shape of the case 20 can be determined according to the shape of the combined one or more electrode assemblies 10. For example, the case 20 can be a hollow rectangular parallelepiped, a cube, or a cylinder. Further, an opening is provided on one of the surfaces of the case 20 so that one or more electrode assemblies 10 can be placed inside the case 20. For example, when the case 20 is a hollow rectangular parallelepiped or a cube, one of the planes of the case 20 is an opening surface, that is, there is no case wall on that plane, and the inside and outside of the case 20 communicate with each other. If the case 20 is a hollow cylinder, the circular side surface of the case 20 is the opening surface, that is, there is no case wall on that circular side surface, and the inside and outside of the case 20 communicate with each other. The end cover assembly 40 is connected to the case 20 at the opening of the case 20 to form a closed case for containing the battery 400. The case 20 is filled with an electrolyte inside.

[0039] The end cover assembly 40 has an end cover 41, and a first terminal 42 and a second terminal 43 disposed on the end cover 41. The end cover 41 is substantially flat. The first terminal 42 and the second terminal 43 are disposed on the flat surface of the end cover 41 and penetrate the flat surface of the end cover 41. Corresponding to the first terminal 42 and the second terminal 43, a collector component 30 is provided. The collector component 30 is disposed between the end cover 41 and the electrode assembly 10.

[0040] For example, as shown in FIG. 4, each electrode assembly 10 is provided with a first tab 112 and a second tab 212. The first tab 112 of one or more electrode assemblies 10 is connected to the first terminal 42 via the collector component 30, and the second tab 212 of one or more electrode assemblies 10 is connected to the second terminal 43 via another collector component 30. Further, the electrode assembly 10 further has a welding protection plate 50 disposed between the tab and the corresponding collector component 30.

[0041] In other embodiments of the present disclosure, an explosion-proof valve 44 can be further provided on the flat surface of the end cover 41. The explosion-proof valve 44 can be a part of the flat surface of the end cover 41 and can also be welded to the flat surface of the end cover 41. The explosion-proof valve 44 has a nick. The depth of the nick is smaller than the thickness of other regions of the explosion-proof valve 44 except for the nick of the explosion-proof valve 44 in order to achieve the purpose of not penetrating the explosion-proof valve 44. That is, in the normal state, the explosion-proof valve 44 is combined with the end cover 41 in a sealed state. The end cover assembly 40 is connected to the case 20 at the opening of the case 20 via the end cover 41 to form a case for containing the battery 400. The space formed by the case is sealed and airtight. Inside the case, when the battery 400 generates excessive gas, the gas expands and the air pressure inside the case exceeds a preset value, the explosion-proof valve 44 cracks at the nick, the inside and outside of the case communicate, and the gas is released to the outside through the crack location of the explosion-proof valve 44 to avoid further explosion.

[0042] In the battery 400, one or more electrode assemblies 10 can be arranged according to actual usage requirements. As shown in FIG. 4, at least two independent electrode assemblies 10 are provided inside the battery 400.

[0043] In some embodiments, as shown in FIG. 5, the electrode assembly 10 has a plurality of first electrode plates 1 and at least one second electrode plate 2, and the polarity of the first electrode plate 1 is opposite to that of the second electrode plate 2. For example, the first electrode plate 1 is a positive electrode plate, the second electrode plate 2 is a negative electrode plate, and vice versa. The plurality of first electrode plates 1 and at least one second electrode plate 2 are wound around a winding axis K to form a winding structure. In this winding structure, the plurality of first electrode plates 1 and at least one second electrode plate 2 are arranged in a superimposed manner along a direction perpendicular to the winding axis K.

[0044] The number of the first electrode plates 1 and the second electrode plates 2 can be the same or different. In some embodiments, the total number of all the first electrode plates 1 and all the second electrode plates 2 is 3 or more. For example, the electrode assembly 10 has two, three, or four first electrode plates 1 and one, two, three, or four second electrode plates 2.

[0045] In other embodiments of the present disclosure, the shape of each first electrode plate 1 is substantially the same as that of each second electrode plate 2. For example, after flattening the winding structure, the first electrode plate 1 and the second electrode plate 2 are substantially strip-shaped. For example, the first electrode plate 1 and the second electrode plate 2 can be strip-shaped with a length of 5 to 20 m. The difference in the lengths of the first electrode plate 1 and the second electrode plate 2 is within a preset range, and the width dimensions are substantially the same. After the plurality of first electrode plates 1 and at least one second electrode plate 2 are superimposed, when the plurality of first electrode plates 1 and at least one second electrode plate 2 are wound along the strip direction, a winding structure can be obtained. This winding structure has a winding axis K, and the superimposed surface where the plurality of first electrode plates 1 are superimposed on at least one second electrode plate 2 is substantially parallel to the winding axis K.

[0046] In other embodiments of the present disclosure, the plurality of first electrode plates 1 and at least one second electrode plate 2 can be stacked in a plurality of forms. For example, when the plurality of first electrode plates 1 are two or more first electrode plates 1 and at least one second electrode plate 2 is also two or more second electrode plates 2, after flattening the winding structure, one first electrode plate 1 and one second electrode plate 2 can be alternately stacked in order. In another example, when the plurality of first electrode plates 1 are two or more first electrode plates 1 and at least one second electrode plate 2 is one second electrode plate 2, after flattening the winding structure, two or more first electrode plates 1 and one second electrode plate 2 can be alternately stacked in order.

[0047] When the plurality of first electrode plates 1 and at least one second electrode plate 2 are stacked, a separator 3 is further disposed between any adjacent one first electrode plate 1 and one second electrode plate 2. Since the separator 3 is configured to separate the adjacent first electrode plate 1 and second electrode plate 2, the adjacent first electrode plate 1 and second electrode plate 2 do not short-circuit each other.

[0048] In other embodiments of the present disclosure, electrode plates of different polarities are adjacent to each other. For example, that is, the fact that the first electrode plate 1 is adjacent to the second electrode plate 2 means that there is no electrode plate between the first electrode plate 1 and the second electrode plate 2 other than at least one layer of the separator 3. For example, there is no other first electrode plate 1 or second electrode plate 2 between the first electrode plate 1 and the second electrode plate 2. Also, it can be understood that the first electrode plate 1 and the second electrode plate 2 are most directly adjacent to each other. For example, based on one electrode plate having one polarity, that electrode plate having that polarity and the first layer of electrode plates having different polarities adjacent to that electrode plate having that polarity are called adjacent electrode plates.

[0049] In other embodiments of the present disclosure, the fact that two electrode plates of the same polarity are adjacent means that only one electrode plate of the other polarity exists between the two electrode plates of the same polarity. For example, the fact that two first electrode plates 1 are adjacent means that only one second electrode plate 2 exists between the two first electrode plates 1, and the fact that two second electrode plates 2 are adjacent means that only one first electrode plate 1 exists between the two second electrode plates 2. In other embodiments of the present disclosure, when no other electrode plates of different polarities exist between two electrode plates of the same polarity, the two electrode plates of the same polarity can be regarded as one electrode plate.

[0050] In other embodiments of the present disclosure, when no other electrode plates and separators of different polarities exist between two or more electrode plates of the same polarity, the two or more electrode plates of the same polarity can be regarded as one group of electrode plates. Therefore, during lamination, the group of electrode plates of the same polarity and another group of electrode plates of a different polarity or a single electrode plate are laminated alternately in sequence. For example, two or more first electrode plates constitute the first group of electrode plates, and two or more second electrode plates constitute the second group of electrode plates. The lamination can be as follows. The first group of electrode plates and the second group of electrode plates are laminated alternately in sequence, or the first group of electrode plates and a single second electrode plate are laminated alternately in sequence, or the second group of electrode plates and a single first electrode plate are laminated alternately in sequence.

[0051] Since a group of electrode plates of the same polarity can be regarded as one electrode plate, for the sake of easy explanation, one electrode plate described hereinafter can be not only one electrode plate, but also a group of electrode plates composed of a plurality of electrode plates of the same polarity.

[0052] However, regardless of the lamination method, at least one layer of separator 3 is disposed between adjacent electrode plates of different polarities.

[0053] In other embodiments of the present disclosure, the separator 3 has a separator base layer and a functional layer. The separator base layer can be at least one selected from polypropylene, polyethylene, ethylene-propylene copolymer, and polybutylene terephthalate. The functional layer can be a mixed layer of a ceramic oxide and a binder. In other embodiments of the present disclosure, after flattening the wound structure, the separator 3 is a thin film that exists separately, and is substantially strip-shaped, for example, strip-shaped with a length of 5 to 20 m. In other embodiments of the present disclosure, the separator 3 is coated on the surface of the first electrode plate 1 and / or the second electrode plate 2, that is, the separator 3 and the first electrode plate 1 and / or the second electrode plate 2 have an integral structure.

[0054] In other embodiments of the present disclosure, as shown in FIG. 5, in the wound structure, the first electrode plate 1 and the second electrode plate 2 are alternately and sequentially stacked. Here, A-A is the direction in which a plurality of first electrode plates 1 and at least one second electrode plate 2 are stacked, and K is the winding axis K of the wound structure.

[0055] In other embodiments of the present disclosure, as shown in FIG. 6, each first electrode plate 1 among the plurality of first electrode plates 1 has a first current collector 11 and a first active material layer 12 disposed on the overlapping surface of the first current collector 11. The first current collector 11 has a first main body portion 111 provided with the first active material layer 12 and at least one first tab 112 protruding from the first main body portion 111 along the winding axis K. The first tab 112 and the first main body portion 111 are arranged in parallel along the winding axis K. The second electrode plate 2 has a second current collector 21 and a second active material layer 22 disposed on the overlapping surface of the second current collector 21. The second current collector 21 has a second main body portion 211 provided with the second active material layer 22 and a second tab 212 protruding from the second main body portion 211 along the winding axis K.

[0056] In other embodiments of the present disclosure, when a plurality of first electrode plates 1 and at least one second electrode plate 2 are overlapped, that is, in a winding structure, the first tab 112 of the first electrode plate 1 and the second tab 212 of the second electrode plate 2 can be arranged on the same side along the winding axis K of the winding structure, and can also be arranged on different sides.

[0057] In other embodiments of the present disclosure, any two of all the first tabs 112 overlap at least partially. For example, a first tab 112 is provided on one electrode plate among the plurality of first electrode plates 1, and a first tab 112 is provided on another electrode plate among the plurality of first electrode plates 1, and these two first tabs 112 overlap at least partially. In another example, a plurality of first tabs 112 are provided on one electrode plate among the plurality of first electrode plates 1, and any two of the plurality of first tabs 112 overlap at least partially. In still another example, a plurality of first tabs 112 are provided on one electrode plate among the plurality of first electrode plates 1, and a plurality of first tabs 112 are provided on another electrode plate among the plurality of first electrode plates 1, and any first tab 112 of the one electrode plate and any first tab 112 of the other electrode plate overlap at least partially.

[0058] As can be seen from the above description, in order to obtain the same energy, the electrode assembly of this embodiment is equivalent to dividing a single first electrode plate with a length equal to the sum of the lengths of the plurality of first electrode plates 1 into the plurality of first electrode plates 1 and then winding these plurality of first electrode plates 1 in parallel. Since electrode plates of the same polarity are inside the electrode assembly of this embodiment and the internal resistance of the electrode assembly is reduced, the heat generation amount of the electrode assembly in the use process is reduced and the performance of the electrode assembly is improved.

[0059] In addition, when winding a single electrode plate whose length is equal to the total length of a plurality of first electrode plates 1, compared with the case of aligning a plurality of tabs on electrode plates of the same polarity, in the electrode assembly of the present embodiment, after overlapping and aligning the tabs on the plurality of first electrode plates 1 of the same polarity in parallel, winding is performed. Since the length of the electrode plate is shortened and the number of windings is reduced, the ability to control misplacement of the tabs in the winding process is improved, the misplacement amount between the plurality of first tabs 112 after winding is reduced, connection with the collector component becomes easier, the overcurrent capacity of the tabs is further improved, and the quality of the electrode assembly is improved.

[0060] Furthermore, in the related art, the region on the side of the first main body portion along the direction perpendicular to the winding axis K is not coated with the active material layer, and the tab is welded to that region. On the other hand, in the present embodiment, since the first tab 112 and the first main body portion 111 are distributed in parallel along the winding axis K and the first active material layer is disposed in the direction perpendicular to the winding axis K of the first main body portion, the region coated with the first active material layer 12 on the first current collector 11 is enlarged, and the energy density of the electrode assembly is further improved.

[0061] In other embodiments of the present disclosure, after flattening the winding structure, the structure of the first electrode plate 1 is as shown in FIG. 7. Each first electrode plate of the present embodiment has a plurality of first tabs 112, and by setting the plurality of first tabs 112, the overcurrent capacity can be improved.

[0062] In other embodiments of the present disclosure, the first tab 112 is formed by cutting the uncoated region of the first current collector 11. In the winding structure after winding, each first electrode plate 1 includes at least one first tab 112 on its circle. For example, each first electrode plate 1 is provided with one first tab 112 or two first tabs 112 on its circle.

[0063] In other embodiments of the present disclosure, after winding the electrode assembly 10 to form it, the plurality of first tabs 112 are laminated with each other and welded to the collector component 30.

[0064] In order to prevent the non-welded areas of the plurality of first tabs 112 from becoming dispersed after welding, on the one hand, since the first tabs 112 are thin, in the battery assembly process, the first tabs 112 are likely to be deformed and are compressed between the first electrode plate 11 and the second electrode plate 12, resulting in a risk of short circuit.

[0065] The first electrode plate 1 of the present embodiment is provided with an insulating layer 15 that serves as an insulating protection. For example, referring to FIG. 7, the insulating layer 15 is disposed on the surface of the root portion of the first tab 112, and the insulating layer 15 serves as an insulating protection. Even if the first tab 112 is inserted between the first electrode plate 1 and the second electrode plate 2, the insulating layer 15 can effectively separate the first tab 112 from the second electrode plate 2, reduce the risk of short circuit, and improve the safety performance.

[0066] Referring to FIG. 7, the insulating layer 15 has a first portion 15a and a second portion 15b. The first portion 15a is disposed (for example, coated) on the overlapping surface of the first main body portion 111 and is connected to the end portion of the first active material layer 12 adjacent to the first tab 112. The second portion 15b extends from the end portion of the first portion 15a that is away from the first active material layer 12 and is disposed (for example, coated) on the overlapping surface of the first tab 112. The second portion 15b can cover the root region of the first tab 112 adjacent to the first main body portion 111, effectively reducing the risk of contact between the root region of the first tab 112 and the first active material layer 12.

[0067] For example, the first active material layer 12 and the first portion 15a are distributed on the overlapping surface of the first main body portion 111 along both end sides of the winding axis K, and the first tab 112 and the first portion 15a are disposed on the same end side of the first main body portion 111. For example, the first tab 112 extends from the first portion 15a to the outside of the first main body portion 111 along the direction of the winding axis K.

[0068] For example, the fact that the first active material layer 12 and the first portion 15a are distributed on the overlapping surface of the first main body portion 111 along both end sides of the winding axis K means that the first active material layer 12 and the first portion 15a are substantially parallel regions on the overlapping surface of the first main body portion 111 and are distributed in two layers along the overlapping surface of the first main body portion 111 along the winding axis K. That is, it can also be understood that the first active material layer 12 and the first portion 15a are substantially parallel on the overlapping surface of the first main body portion 111 along the band direction of the first electrode plate 1 and are distributed in two layers.

[0069] The insulating layer 15 has an inorganic filler and a binder. The inorganic filler includes one or more of boehmite, aluminum oxide, magnesium oxide, titanium dioxide, zirconium oxide, silicon dioxide, silicon carbide, boron carbide, calcium carbonate, aluminum silicate, calcium silicate, potassium titanate, and barium sulfate. The binder has one or more of polyvinylidene fluoride, polyacrylonitrile, polyacrylic acid, polyacrylate, polyacrylate-acrylate, polyacrylonitrile-acrylic acid, and polyacrylonitrile-acrylate.

[0070] Any two of the first tabs in all of the first tabs of the present embodiment overlap at least partially. The number of windings of the electrode assembly 10 of the present embodiment is reduced, and the misalignment amount between the plurality of first tabs 112 after winding can be reduced. Thereby, the overcurrent capacity of the tabs is improved.

[0071] Before winding, the structure of the second electrode plate 2 is as shown in FIG. 8. The second electrode plate 12 of the present embodiment further has a third active material layer 23. The third active material layer 23 is disposed (for example, coated) in a region connected to the second active material layer 22 on the surface of the second tab 212. For example, the third active material layer 23 is disposed (for example, coated) on the surface of the root portion of the second tab 212. The third active material layer 23 and the second active material layer 22 are molded.

[0072] In the battery assembly process, regions of a plurality of second tabs 212 that are not coated with the third active material layer 23 are collected and welded to the collector component 30. The third active material layer 23 has a high elastic modulus and can effectively support the second tab 212, reducing the risk of the second tab 212 being inserted between the first electrode plate 1 and the second electrode plate 2.

[0073] Specifically, the first current collector 11 of the present embodiment is an aluminum foil, and the first active material layer 12 has a ternary material, lithium manganate, or lithium iron phosphate. The second current collector 21 is a copper foil, and the second active material layer 22 has graphite or silicon.

[0074] In the present embodiment, a plurality of first electrode plates 1 and a plurality of second electrode plates 2 are available. For example, by selecting the number of the first electrode plate 1 and the second electrode plate 2 to be 2 to 3, based on reducing the length of the electrode plate, winding can be reliably facilitated, and when the number of electrode plates is large, a dramatic increase in the required winding force can be prevented, or the dropout of the active material coated on the surface of the electrode plate can be prevented.

[0075] The winding structure of the electrode assembly of the present embodiment is flat and has a straight portion and turning portions disposed on both sides of the straight portion. The overlapping surfaces of the electrode plates in the straight portion are substantially parallel and substantially parallel to the winding axis K. The straight portion has a first straight small portion and a second straight small portion in a plane perpendicular to the winding axis K, and these are substantially parallel and symmetrically distributed with respect to the winding axis K. The two turning portions are respectively disposed on the first straight small portion and the second straight small portion and are on both sides of the straight portion.

[0076] All of the first tabs 112 in this embodiment are arranged on the straight portion. In this way, when a plurality of first tabs 112 are stacked, arranged, and connected, the contact area between the first tabs 112 increases, and the overcurrent capacity is improved. Further, since all of the first tabs 112 in this embodiment are arranged on the first straight small portion, when ensuring the overcurrent capacity of the first tabs 112, the thickness after the first tabs 112 are overlapped is reduced, and the space generated by the first tabs 112 is further reduced.

[0077] In an embodiment not shown in other drawings, all of the first tabs can also be arranged on the second straight small portion. Alternatively, a part of all of the first tabs is arranged on the first straight small portion, and the other part of the first tabs is arranged on the second straight small portion.

[0078] In other embodiments of the present disclosure, the electrode assembly 10 has a plurality of first electrode plates 1. The winding start positions of at least two of the plurality of first electrode plates 1 are different. Also, the winding end positions of at least two of the plurality of first electrode plates 1 are different. For example, the winding start positions of all of the first electrode plates 1 are different, and the winding end positions are also different.

[0079] In other embodiments of the present disclosure, the electrode assembly 10 has a plurality of second electrode plates 2. The winding start positions of at least two of the plurality of second electrode plates 2 are different. Also, the winding end positions of at least two of the plurality of second electrode plates 2 are different. For example, the winding start positions of all of the second electrode plates 2 are different, and the winding end positions are also different.

[0080] The electrode assembly 10 expands during the use process and applies a force to the case 20 after the expansion of the electrode assembly 10. On the other hand, the case 20 applies a reaction force to the electrode assembly 10. Regarding the electrode assembly 10 of the present disclosure, the number of layers of the first electrode plate 1 and the second electrode plate 2 has increased. With such a structure, it is possible to prevent the formation of a thick step at the winding end E of the plurality of first electrode plates 1 or the plurality of second electrode plates 2. When the outer layer of the winding structure receives the reaction force of the case 20, the problem of stress concentration at the winding end E of the electrode plate can be alleviated, and the winding structure receives uniform stress at different circumferential positions. Thereby, a large deformation of the winding structure is prevented, or the shedding of the active material in a partial region with a large stress is prevented, and the operating performance and reliability of the battery after long-term use are improved.

[0081] In other embodiments of the present disclosure, the electrode assembly has a plurality of first electrode plates 1 and a plurality of second electrode plates 2, and the positions of the winding start ends S of at least two of the plurality of first electrode plates 1 in the plurality of first electrode plates 1 are different. For example, the positions of the winding start ends S of all the first electrode plates 1 are different, and / or the positions of the winding start ends S' of at least two of the plurality of second electrode plates 2 in the plurality of second electrode plates 2 are different. For example, the positions of the winding start ends S' of all the second electrode plates 2 are different.

[0082] The electrode assembly 10 expands during the use process. Regarding the electrode assembly 10 of the present disclosure, the first winding start ends S of at least two first electrode plates 1 are set at different positions, and / or the second winding start ends S' of at least two second electrode plates 2 are set at different positions. That is, the first winding start ends S of at least two first electrode plates 1 are arranged in a staggered manner in the circumferential direction of the winding structure, and / or the second winding start ends S' of at least two second electrode plates 2 are arranged in a staggered manner in the circumferential direction of the winding structure. As a result, the positions of the winding start ends of the first electrode plate 1 and / or the second electrode plate 2 are different, which can prevent the formation of a large step at the winding start ends of the plurality of first electrode plates 1 or the plurality of second electrode plates 2, can alleviate the problem of stress concentration at the winding start ends of the electrode plates, and enable the winding structure to receive uniform stress at different circumferential positions. Thereby, a large deformation of the winding structure is prevented, or the shedding of the active material in a partial area with high stress is prevented, and the operating performance and reliability of the battery after long-term use are improved.

[0083] In other embodiments of the present disclosure, the winding end of at least one first electrode plate 1 among the plurality of first electrode plates 1 is arranged at the turning portion. The winding end of at least one second electrode plate 2 among the plurality of second electrode plates 2 is arranged at the turning portion.

[0084] When the winding ends of both the first electrode plate 1 and the second electrode plate 2 are arranged at the turning portion, the difference in the number of layers of the electrode plates between the first straight small portion and the second straight small portion can be reduced. When the electrode assembly 10 expands and contacts the case 20, and the inner wall of the case 20 exerts a reaction force on both sides of the electrode assembly 10, the stresses applied to the electrode plates of the first straight small portion and the second straight small portion are the same.

[0085] In other embodiments of the present disclosure, in different radial directions of the winding structure, the difference in the number of electrode plates does not exceed a preset number of layers. For example, the preset number of layers is less than or equal to the total number of a plurality of first electrode plates 1 and a plurality of second electrode plates 2. For example, after winding two first electrode plates 1 and two second electrode plates 2, in one of the radial directions of the winding structure, the number of electrode plates is 8, and in other radial directions of the winding structure, the number of electrode plates is at least 8 and at most 12. That is, the preset number of layers is less than or equal to the total number of two first electrode plates 1 and two second electrode plates 2 (in this case, the total is 4).

[0086] When the electrode assembly 10 expands and contacts the case 20, the case 20 applies a reaction force to the electrode assembly 10. When the difference in the number of electrode plates does not exceed the preset number of layers in different radial directions of the winding structure, the stress on the electrode assembly 10 at each point in the circumferential direction becomes more uniform, thereby preventing an increase in the performance difference at individual points of the electrode assembly 10 during the use process. For example, two first electrode plates 1 are arranged, two second electrode plates 2 are arranged, the preset number of layers is 4 or less, and the smaller the difference in the number of electrode plates, the more uniform the stress on the electrode assembly 10 at each point in the circumferential direction of the winding structure becomes.

[0087] The electrode assembly 10 can include at least two first electrode plates 1 and at least two second electrode plates 2. However, for the sake of simplicity of description, in the following embodiments, two first electrode plates 1 and two second electrode plates 2 will be taken as examples for description.

[0088] The outer shape of the winding structure of the electrode assembly 10 can be a cylindrical shape, a flat shape, an elliptical shape, a cubic shape, a rectangular parallelepiped shape, or any other shape. However, for the sake of simplicity of description, in the following, the winding structure of the electrode assembly 10 being a flat shape and a cylindrical shape will be taken as examples for description respectively.

[0089] FIG. 9 is a schematic structural view showing that the flat electrode assembly in another embodiment of the present disclosure is perpendicular to the cross-section of the winding axis K. The electrode assembly 120 has a first negative electrode plate 1201, a second negative electrode plate 1202, a first positive electrode plate 1203, a second positive electrode plate 1204, and a plurality of separators 1205. The first negative electrode plate 1201, the first positive electrode plate 1203, the second negative electrode plate 1202, and the second positive electrode plate 1204 are alternately stacked in order. The first negative electrode plate 1201 is separated from the first positive electrode plate 1203 by a separator 1205, the first positive electrode plate 1203 is separated from the second negative electrode plate 1202 by another separator 1205, and the second negative electrode plate 1202 is separated from the second positive electrode plate 1204 by another separator 1205. The first negative electrode plate 1201, the second negative electrode plate 1202, the first positive electrode plate 1203, the second positive electrode plate 1204, and the plurality of separators 1205 are all wound around the winding axis K after being stacked to form a flat winding structure.

[0090] In the electrode assembly 120 of this embodiment, regarding the structure and position of the tabs of the positive electrode plate and the tabs of the negative electrode plate, refer to the relevant contents of the first tab of the first electrode plate and the second tab of the second electrode plate described in the above embodiments of FIGS. 5 to 8. The content will not be repeated here.

[0091] In this embodiment, regarding the following specific conditions for different radial directions of the winding structure of the electrode assembly 120, that is, the difference in the number of electrode plate layers at different positions in the circumferential direction of the winding structure is not greater than the preset number of layers, also refer to the relevant contents described in the above embodiments of FIGS. 5 to 8. The content will not be repeated here.

[0092] In the winding structure, the innermost ring in the winding structure is the ring surrounded by the first negative electrode plate 1201, and the outermost ring of the winding structure is the ring surrounded by the second negative electrode plate 1202.

[0093] In this embodiment, the winding structure of the electrode assembly 120 has a straight portion 10A and turning portions 10B disposed on both sides of the straight portion 10A. The overlapping surfaces of the electrode plates in the straight portion 10A are substantially parallel planes, substantially parallel to the winding axis. Here, the plane is not strictly a plane and allows for a certain degree of error. In a plane perpendicular to the winding axis K, the straight portion 10A has a first straight small portion 10A1 and a second straight small portion 10A2, which are substantially parallel and symmetrically distributed with respect to the winding axis K. The two turning portions 10B are respectively disposed on the first straight small portion 10A1 and the second straight small portion 10A2, on both sides of the straight portion 10A.

[0094] In the winding structure of the electrode assembly, all the negative tabs of the first negative electrode plate 1201 and all the negative tabs of the second negative electrode plate 1202 can all be disposed in the straight portion 10A. For example, all the negative tabs are disposed in the first straight small portion 10A1, or all the negative tabs are disposed in the second straight small portion 10A2, or a part of the negative tabs is disposed in the first straight small portion 10A1, and all the remaining negative tabs are disposed in the second straight small portion 10A2. However, the negative tabs disposed in the same region overlap at least partially in a direction perpendicular to the winding axis. For example, they substantially overlap.

[0095] All the positive tabs of the first positive electrode plate 1203 and all the positive tabs of the second positive electrode plate 1204 can all be disposed in the straight portion 10A. For example, all the positive tabs are disposed in the first straight small portion 10A1, or all the positive tabs are disposed in the second straight small portion 10A2, or a part of the positive tabs is disposed in the first straight small portion 10A1, and all the remaining positive tabs are disposed in the second straight small portion 10A2. However, the positive tabs disposed in the same region overlap at least partially in a direction perpendicular to the winding axis. For example, they substantially overlap.

[0096] The positions of the first winding start ends S of the first positive electrode plate 1203 and the second positive electrode plate 1204 are the same. For example, the first winding start ends S of the first positive electrode plate 1203 and the second positive electrode plate 1204 are both arranged on the same linear small portion (for example, the first linear small portion 10A1) on the same side of the linear portion 10A, and the first winding start ends S of the first positive electrode plate 1203 and the second positive electrode plate 1204 are on the same plane.

[0097] Also, the positions of the second winding start ends S' of the first negative electrode plate 1201 and the second negative electrode plate 1202 are the same. For example, the second winding start ends S' of the first negative electrode plate 1201 and the second negative electrode plate 1202 are both arranged on the same linear small portion (for example, the first linear small portion 10A1) on the same side of the linear portion 10A, and the second winding start ends S' of the first negative electrode plate 1201 and the second negative electrode plate 1202 are on the same plane.

[0098] Along the reverse direction of the winding direction, the second winding start end S' of the first negative electrode plate 1201 exceeds the first winding start end S of the first positive electrode plate 1203. The second winding start end S' of the second negative electrode plate 1202 exceeds the first winding start end S of the second positive electrode plate 1204.

[0099] The positions of the first winding end E of the first positive electrode plate 1203 and the second positive electrode plate 1204 are the same. For example, the first winding end E of the first positive electrode plate 1203 and the second positive electrode plate 1204 are both arranged on the turning portion on the same side (for example, the first turning portion 10B1), and the first winding end E of the first positive electrode plate 1203 and the second positive electrode plate 1204 are on the same plane.

[0100] Also, the positions of the second winding ends E' of the first negative electrode plate 1201 and the second negative electrode plate 1202 are the same. For example, the second winding ends E' of the first negative electrode plate 1201 and the second negative electrode plate 1202 are both arranged in the turning portion on the same side (for example, the first turning portion 10B1), and are also arranged in the turning portion on the same side as the first winding end E of the first positive electrode plate 1203 and the second positive electrode plate 1204 (for example, the first turning portion 10B1), and the second winding ends E' of the first negative electrode plate 1201 and the second negative electrode plate 1202 are on the same plane.

[0101] Along the winding direction, the second winding end E' of the first negative electrode plate 1201 exceeds the first winding end E of the second positive electrode plate 1204. The second winding end E' of the second negative electrode plate 1202 exceeds the first winding end E of the first positive electrode plate 1203.

[0102] The winding structure of the above-described electrode assembly can approximately make up for the difference in the lengths of the plurality of electrode plates before winding, thereby facilitating winding.

[0103] FIG. 10 is a schematic structural view showing that in another embodiment of the present disclosure, the flat electrode assembly is perpendicular to the cross-section of the winding axis K. The electrode assembly 130 includes a first negative electrode plate 1301, a second negative electrode plate 1302, a first positive electrode plate 1303, a second positive electrode plate 1304, and a plurality of separators 1305. The first negative electrode plate 1301, the first positive electrode plate 1303, the second negative electrode plate 1302, and the second positive electrode plate 1304 are alternately stacked in order. The first negative electrode plate 1301 is separated from the first positive electrode plate 1303 by a separator 1305, the first positive electrode plate 1303 is separated from the second negative electrode plate 1302 by another separator 1305, and the second negative electrode plate 1302 is separated from the second positive electrode plate 1304 by another separator 1305. After the first negative electrode plate 1301, the second negative electrode plate 1302, the first positive electrode plate 1303, the second positive electrode plate 1304, and the plurality of separators 1305 are all stacked, they are wound around the winding axis K to form a flat winding structure.

[0104] In the winding structure of the electrode assembly, all the negative tabs of the first negative electrode plate 1301 and all the negative tabs of the second negative electrode plate 1302 can all be arranged in the straight portion 10A. For example, all the negative tabs are arranged in the first straight small portion 10A1, or all the negative tabs are arranged in the second straight small portion 10A2, or a part of the negative tabs is arranged in the first straight small portion 10A1, and all the remaining negative tabs are arranged in the second straight small portion 10A2. However, the negative tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding axis. For example, they substantially overlap.

[0105] All the positive tabs of the first positive electrode plate 1303 and all the positive tabs of the second positive electrode plate 1304 can all be arranged in the straight portion 10A. For example, all the positive tabs are arranged in the first straight small portion 10A1, or all the positive tabs are arranged in the second straight small portion 10A2, or a part of the positive tabs is arranged in the first straight small portion 10A1, and all the remaining positive tabs are arranged in the second straight small portion 10A2. However, the positive tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding axis. For example, they substantially overlap. The structure of the electrode assembly 130 of this embodiment is substantially the same as the structure of the electrode assembly described in the embodiment of FIG. 9. Hereinafter, the differences will be described.

[0106] In the winding structure of the electrode assembly 130 of this embodiment, the innermost ring in the winding structure is the ring surrounded by the first negative electrode plate 1301, and the outermost ring of the winding structure is the ring jointly surrounded by the first negative electrode plate 1301 and the second negative electrode plate 1302.

[0107] The first winding ends E of the first positive electrode plate 1303 and the second positive electrode plate 1304 are different. For example, the first winding ends E of the first positive electrode plate 1303 and the second positive electrode plate 1304 are arranged in the second turning portion 10B2 and the first turning portion 10B1 respectively.

[0108] Also, the positions of the second winding ends E' of the first negative electrode plate 1301 and the second negative electrode plate 1302 are different. For example, the second winding ends E' of the first negative electrode plate 1301 and the second negative electrode plate 1302 are respectively arranged in the first turning portion 10B1 and the second turning portion 10B2.

[0109] Along the winding direction, the second winding end E' of the first negative electrode plate 1301 exceeds the first winding end E of the second positive electrode plate 1304. Also, the second winding end E' of the second negative electrode plate 1302 exceeds the first winding end E of the first positive electrode plate 1303.

[0110] The above-described winding structure of the electrode assembly can reduce the step formed by the first positive electrode plate 1303 and the second positive electrode plate 1304 at the first winding end E, and can also reduce the step formed by the first negative electrode plate 1301 and the second negative electrode plate 1302 at the second winding end E'. As a result, when the electrode assembly expands and contacts the case, the local stress applied to the electrode plate at the winding end can be reduced, preventing cracking of the electrode plate or shedding of the active material, and improving the reliability of the long-term operation of the electrode assembly.

[0111] FIG. 11 is a schematic structural diagram showing that in another embodiment of the present disclosure, the flat electrode assembly is perpendicular to the cross-section of the winding axis K. The electrode assembly 140 has a first negative electrode plate 1401, a second negative electrode plate 1402, a first positive electrode plate 1403, a second positive electrode plate 1404, and a plurality of separators 1405. The first negative electrode plate 1401, the first positive electrode plate 1403, the second negative electrode plate 1402, and the second positive electrode plate 1404 are alternately stacked in order. The first negative electrode plate 1401 is separated from the first positive electrode plate 1403 by a separator 1405, the first positive electrode plate 1403 is separated from the second negative electrode plate 1402 by another separator 1405, and the second negative electrode plate 1402 is separated from the second positive electrode plate 1404 by another separator 1405. The first negative electrode plate 1401, the second negative electrode plate 1402, the first positive electrode plate 1403, the second positive electrode plate 1404, and the plurality of separators 1405 are all wound around the winding axis K after being stacked to form a flat winding structure.

[0112] In the winding structure of the electrode assembly, all the negative tabs of the first negative electrode plate 1401 and all the negative tabs of the second negative electrode plate 1402 can be arranged in the straight portion 10A. For example, all the negative tabs are arranged in the first straight small portion 10A1, or all the negative tabs are arranged in the second straight small portion 10A2, or a part of the negative tabs is arranged in the first straight small portion 10A1, and all the remaining negative tabs are arranged in the second straight small portion 10A2. However, the negative tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding axis. For example, they substantially overlap.

[0113] All the positive electrode tabs of the first positive electrode plate 1403 and all the positive electrode tabs of the second positive electrode plate 1404 can all be arranged on the straight part 10A. For example, all the positive electrode tabs are arranged on the first straight small part 10A1, or all the positive electrode tabs are arranged on the second straight small part 10A2, or some of the positive electrode tabs are arranged on the first straight small part 10A1, and all the remaining positive electrode tabs are arranged on the second straight small part 10A2. However, the positive electrode tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding axis. For example, they substantially overlap.

[0114] The structure of the electrode assembly 140 of this embodiment is substantially the same as the structure of the electrode assembly 120 described in the embodiment of FIG. 9. Hereinafter, the differences will be described.

[0115] In the winding structure of the electrode assembly 140 of this embodiment, the innermost ring in the winding structure is the ring surrounded by the first negative electrode plate 1401, and the outermost ring of the winding structure is the ring surrounded by the second negative electrode plate 1402.

[0116] In the winding structure of the electrode assembly of this embodiment, the positions of the second winding ends E' of the first negative electrode plate 1401 and the second negative electrode plate 1402 are different. For example, the second winding ends E' of the first negative electrode plate 1401 and the second negative electrode plate 1402 are all arranged in the same turning part (for example, the first turning part 10B1), and the second winding ends E' of the first negative electrode plate 1401 and the second negative electrode plate 1402 are not on the same plane.

[0117] The above-described winding structure of the electrode assembly 140 can reduce the difference in the number of electrode plate layers between the first straight small part 10A1 and the second straight small part 10A2. When the electrode assembly expands and contacts the case, and the inner wall of the case exerts a reaction force on both sides of the electrode assembly, the stresses applied to the electrode plates of the first straight small part 10A1 and the second straight small part 10A2 are the same.

[0118] FIG. 12 is a schematic structural diagram showing that in another embodiment of the present disclosure, the flat electrode assembly is perpendicular to the cross-section of the winding shaft K. The electrode assembly 150 includes a first negative electrode plate 1501, a second negative electrode plate 1502, a first positive electrode plate 1503, a second positive electrode plate 1504, and a plurality of separators 1505. The first negative electrode plate 1501, the first positive electrode plate 1503, the second negative electrode plate 1502, and the second positive electrode plate 1504 are alternately stacked in order. The first negative electrode plate 1501 is separated from the first positive electrode plate 1503 by a separator 1505, the first positive electrode plate 1503 is separated from the second negative electrode plate 1502 by another separator 1505, and the second negative electrode plate 1502 is separated from the second positive electrode plate 1504 by another separator 1505. After the first negative electrode plate 1501, the second negative electrode plate 1502, the first positive electrode plate 1503, the second positive electrode plate 1504, and the plurality of separators 1505 are all stacked, they are wound around the winding shaft K to form a flat winding structure.

[0119] In the winding structure of the electrode assembly, all the negative tabs of the first negative electrode plate 1501 and all the negative tabs of the second negative electrode plate 1502 can be arranged in the straight portion 10A. For example, all the negative tabs are arranged in the first straight small portion 10A1, or all the negative tabs are arranged in the second straight small portion 10A2, or a part of the negative tabs is arranged in the first straight small portion 10A1, and all the remaining negative tabs are arranged in the second straight small portion 10A2. However, the negative tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding shaft. For example, they substantially overlap.

[0120] All the positive electrode tabs of the first positive electrode plate 1503 and all the positive electrode tabs of the second positive electrode plate 1504 can all be arranged in the straight line portion 10A. For example, all the positive electrode tabs are arranged in the first straight small portion 10A1, or all the positive electrode tabs are arranged in the second straight small portion 10A2, or a part of the positive electrode tabs is arranged in the first straight small portion 10A1, and all the remaining positive electrode tabs are arranged in the second straight small portion 10A2. However, the positive electrode tabs arranged in the same region overlap at least partially in a direction perpendicular to the winding axis. For example, they substantially overlap.

[0121] The structure of the electrode assembly 150 of this embodiment is substantially the same as the structure of the electrode assembly 120 described in the embodiment of FIG. 9. Hereinafter, the differences will be described. In the winding structure of the electrode assembly of this embodiment, the innermost ring in the winding structure is a ring jointly surrounded by the first negative electrode plate 1501 and the second negative electrode plate 1502, and the outermost ring of the winding structure is a ring surrounded by the second negative electrode plate 1502.

[0122] In the winding structure of the electrode assembly 150 of this embodiment, the positions of the first winding start ends S of the first positive electrode plate 1503 and the second positive electrode plate 1504 are different. For example, the first winding start ends S of the first positive electrode plate 1503 and the second positive electrode plate 1504 are respectively arranged in the first straight small portion 10A1 and the second straight small portion 10A2, and the first winding start ends S of the first positive electrode plate 1503 and the second positive electrode plate 1504 are not on the same plane.

[0123] Also, the positions of the second winding start ends S of the first negative electrode plate 1501 and the second negative electrode plate 1502 are also different. For example, the second winding start ends S of the first negative electrode plate 1501 and the second negative electrode plate 1502 are respectively arranged in the first straight small portion 10A1 and the second straight small portion 10A2, and the second winding start ends S of the first negative electrode plate 1501 and the second negative electrode plate 1502 are not on the same plane.

[0124] The winding structure of the above-described electrode assembly can reduce the step formed by the first positive electrode plate 1503 and the second positive electrode plate 1504 at the first winding start end S, and can also reduce the step formed by the first negative electrode plate 1501 and the second negative electrode plate 1502 at the second winding start end S'. As a result, after the electrode assembly expands and contacts the case 20, the local stress applied to the electrode plate at the winding start end can be reduced, preventing cracking of the electrode plate or shedding of the active material, and improving the reliability of the long-term operation of the electrode assembly.

[0125] FIG. 13 is a schematic structural diagram showing that in another embodiment of the present disclosure, the flat electrode assembly is perpendicular to the cross-section of the winding axis K. The electrode assembly 160 includes a first negative electrode plate 1601, a second negative electrode plate 1602, a first positive electrode plate 1603, a second positive electrode plate 1604, and a plurality of separators 1605. The first negative electrode plate 1601, the first positive electrode plate 1603, the second positive electrode plate 1602, and the second positive electrode plate 1604 are alternately stacked in order. The first negative electrode plate 1601 is separated from the first positive electrode plate 1603 by a separator 1605, the first positive electrode plate 1603 is separated from the second negative electrode plate 1602 by another separator 1605, and the second negative electrode plate 1602 is separated from the second positive electrode plate 1604 by another separator 1605. After the first negative electrode plate 1601, the second negative electrode plate 1602, the first positive electrode plate 1603, the second positive electrode plate 1604, and the plurality of separators 1605 are all stacked, they are wound around the winding axis K to form a flat winding structure.

[0126] In the winding structure of the electrode assembly, all the negative tabs of the first negative electrode plate 1601 and all the negative tabs of the second negative electrode plate 1602 can all be arranged in the straight portion 10A. For example, all the negative tabs are arranged in the first straight small portion 10A1, or all the negative tabs are arranged in the second straight small portion 10A2, or a part of the negative tabs is arranged in the first straight small portion 10A1, and all the remaining negative tabs are arranged in the second straight small portion 10A2. However, the negative tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding axis. For example, they substantially overlap.

[0127] All the positive tabs of the first positive electrode plate 1603 and all the positive tabs of the second positive electrode plate 1604 can all be arranged in the straight portion 10A. For example, all the positive tabs are arranged in the first straight small portion 10A1, or all the positive tabs are arranged in the second straight small portion 10A2, or a part of the positive tabs is arranged in the first straight small portion 10A1, and all the remaining positive tabs are arranged in the second straight small portion 10A2. However, the positive tabs arranged in the same region overlap at least partially in the direction perpendicular to the winding axis. For example, they substantially overlap.

[0128] The structure of the electrode assembly 160 of this embodiment is substantially the same as the structure of the electrode assembly 120 described in the embodiment of FIG. 9. Hereinafter, the differences will be described. In the winding structure of the electrode assembly of this embodiment, the innermost ring in the winding structure is a ring jointly surrounded by the first negative electrode plate 1601 and the second negative electrode plate 1602, and the outermost ring of the winding structure is also a ring jointly surrounded by the first negative electrode plate 1601 and the second negative electrode plate 1602.

[0129] In the winding structure of the electrode assembly 160 of this embodiment, the positions of the first winding start ends S of the first positive electrode plate 1603 and the second positive electrode plate 1604 are different. For example, the first winding start ends S of the first positive electrode plate 1603 and the second positive electrode plate 1604 are respectively arranged on the first straight small portion 10A1 and the second straight small portion 10A2, and the first winding start ends S of the first positive electrode plate 1603 and the second positive electrode plate 1604 are not on the same plane.

[0130] Also, the positions of the second winding start ends S' of the first negative electrode plate 1601 and the second negative electrode plate 1602 are different. For example, the second winding start ends S' of the first negative electrode plate 1601 and the second negative electrode plate 1602 are respectively arranged on the first straight small portion 10A1 and the second straight small portion 10A2, and the second winding start ends S' of the first negative electrode plate 1601 and the second negative electrode plate 1602 are not on the same plane.

[0131] The positions of the first winding ends E of the first positive electrode plate 1603 and the second positive electrode plate 1604 are different. For example, the first winding ends E of the first positive electrode plate 1603 and the second positive electrode plate 1604 are respectively arranged on different turning portions 10B, and the first winding ends E of the first positive electrode plate 1603 and the second positive electrode plate 1604 are not on the same plane.

[0132] Also, the positions of the second winding ends E' of the first negative electrode plate 1601 and the second negative electrode plate 1602 are different. For example, the second winding ends E' of the first negative electrode plate 1601 and the second negative electrode plate 1602 are respectively arranged on two different turning portions 10B, and the second winding ends E' of the first negative electrode plate 1601 and the second negative electrode plate 1602 are not on the same plane.

[0133] The winding structure of the above-described electrode assembly can simultaneously reduce the step formed by the first positive electrode plate 1603 and the second positive electrode plate 1604 at the first winding start end S and the first winding end E, and can simultaneously reduce the step formed by the first negative electrode plate 1601 and the second negative electrode plate 1602 at the second winding start end S' and the second winding end E'. As a result, after the electrode assembly expands and contacts the case 20, the local stress applied to the electrode plates at the winding start end and the winding end is reduced, preventing cracking of the electrode plates or shedding of the active material, and improving the reliability of the long-term operation of the electrode assembly.

[0134] Based on the above embodiment, at different radial directions of the winding structure, that is, at different circumferential positions of the winding structure, the difference in the number of layers of the electrode plates does not exceed a preset number of layers. Here, the number of layers of the electrode plates refers to the total number of layers of the positive electrode plates and the negative electrode plates. Also, the preset number of layers is less than or equal to the sum of the number of multiple positive electrode plates and the number of multiple negative electrode plates.

[0135] When the electrode assembly expands and contacts the case 20, the case 20 applies a reaction force to the electrode assembly. As a result, the stress applied to each point in the circumferential direction of the electrode assembly becomes more uniform. Thereby, it is prevented that a large performance difference occurs at individual points in the electrode assembly during the use process. For example, when two positive electrode plates are arranged, two negative electrode plates are arranged, the preset number of layers is 4 or less, and the smaller the difference in the number of layers of the electrode plates, the more uniform the stress applied to the electrode assembly at each point in the circumferential direction.

[0136] FIGS. 14 to 17 are schematic structural diagrams of a cylindrical electrode assembly.

[0137] FIG. 14 is a schematic structural diagram showing that in another embodiment of the present disclosure, the cylindrical electrode assembly is perpendicular to the cross-section of the winding axis K. The electrode assembly 170 includes a first negative electrode plate 1701, a second negative electrode plate 1702, a first positive electrode plate 1703, a second positive electrode plate 1704, and a plurality of separators 1705. The first negative electrode plate 1701, the first positive electrode plate 1703, the second negative electrode plate 1702, and the second positive electrode plate 1704 are alternately and sequentially stacked. The first negative electrode plate 1701 is separated from the first positive electrode plate 1703 by a separator 1705, the first positive electrode plate 1703 is separated from the second negative electrode plate 1702 by another separator 1705, and the second negative electrode plate 1702 is separated from the second positive electrode plate 1704 by another separator 1705. After the first negative electrode plate 1701, the second negative electrode plate 1702, the first positive electrode plate 1703, the second positive electrode plate 1704, and the plurality of separators 1705 are all stacked, they are wound around the winding axis K to form a cylindrical winding structure.

[0138] In the electrode assembly of this embodiment, regarding the structure and position of the tabs of the positive electrode plate and the tabs of the negative electrode plate, refer to the relevant contents of the first tab of the first electrode plate and the second tab of the second electrode plate described in the above embodiments of FIGS. 5 to 8. This content will not be repeated here.

[0139] In the winding structure, the innermost ring in the winding structure is the ring surrounded by the first negative electrode plate 1701, and the outermost ring of the winding structure is the ring surrounded by the second negative electrode plate 1702.

[0140] The positions of the first winding start ends S of the first positive electrode plate 1703 and the second positive electrode plate 1704 are the same. For example, the first winding start ends S of the first positive electrode plate 1703 and the second positive electrode plate 1704 are both arranged in the same radial direction of the winding structure, and the first winding start ends S of the first positive electrode plate 1703 and the second positive electrode plate 1704 are on the same plane.

[0141] Also, the positions of the second winding start ends S′ of the first negative electrode plate 1701 and the second negative electrode plate 1702 are the same. For example, the second winding start ends S′ of the first negative electrode plate 1701 and the second negative electrode plate 1702 are both arranged in the same radial direction of the winding structure, and the second winding start ends S′ of the first negative electrode plate 1701 and the second negative electrode plate 1702 are on the same plane.

[0142] Along the reverse direction of the winding direction, the second winding start end S′ of the first negative electrode plate 1701 exceeds the first winding start end S of the first positive electrode plate 1704. The second winding start end S′ of the second negative electrode plate 1702 exceeds the first winding start end S of the second positive electrode plate 1703.

[0143] The positions of the first winding end E of the first positive electrode plate 1703 and the second positive electrode plate 1704 are the same. For example, the first winding end E of the first positive electrode plate 1703 and the second positive electrode plate 1704 are both arranged in the turning portion 10B on the same side, and the first winding end E of the first positive electrode plate 1703 and the second positive electrode plate 1704 are on the same plane.

[0144] Also, the positions of the second winding end E′ of the first negative electrode plate 1701 and the second negative electrode plate 1702 are the same. For example, the second winding end E′ of the first negative electrode plate 1701 and the second negative electrode plate 1702 are both arranged in the same turning region 10B, and the second winding end E′ of the first negative electrode plate 1701 and the second negative electrode plate 1702 are on the same plane.

[0145] Along the winding direction, the second winding end E′ of the first negative electrode plate 1701 exceeds the first winding end E of the second positive electrode plate 1704. Also, the second winding end E′ of the second negative electrode plate 1702 exceeds the first winding end E of the first positive electrode plate 1703.

[0146] The above-described winding structure can approximately equalize the lengths of the plurality of electrode plates before winding, thereby facilitating winding.

[0147] FIG. 15 is a schematic structural diagram showing that in another embodiment of the present disclosure, the cylindrical electrode assembly is perpendicular to the cross-section of the winding axis K. The electrode assembly 180 has a first negative electrode plate 1801, a second negative electrode plate 1802, a first positive electrode plate 1803, a second positive electrode plate 1804, and a plurality of separators 1805. The first negative electrode plate 1801, the first positive electrode plate 1803, the second negative electrode plate 1802, and the second positive electrode plate 1804 are alternately stacked in order. The first negative electrode plate 1801 is separated from the first positive electrode plate 1803 by a separator 1805, the first positive electrode plate 1803 is separated from the second negative electrode plate 1802 by another separator 1805, and the second negative electrode plate 1802 is separated from the second positive electrode plate 1804 by another separator 1805. The first negative electrode plate 1801, the second negative electrode plate 1802, the first positive electrode plate 1803, the second positive electrode plate 1804, and the plurality of separators 1805 are all wound around the winding axis K after being stacked to form a cylindrical winding structure.

[0148] The structure of the electrode assembly 180 in this embodiment is basically the same as the structure of the electrode assembly 170 described in the embodiment of FIG. 14. The differences will be described below. In the winding structure of this embodiment, the innermost ring of the winding structure is a ring jointly surrounded by the first negative electrode plate 1801 and the second negative electrode plate 1802, and the outermost ring of the winding structure is a ring surrounded by the first negative electrode plate 1801.

[0149] In the winding structure of this embodiment, the positions of the first winding start ends S of the first positive electrode plate 1803 and the second positive electrode plate 1804 are different. For example, the first winding start ends S of the first positive electrode plate 1803 and the second positive electrode plate 1804 are arranged in the relative radial direction of the winding structure, and the first winding start ends S of the first positive electrode plate 1803 and the second positive electrode plate 1804 are not in the same plane.

[0150] Also, the positions of the second winding start ends S′ of the first negative electrode plate 1801 and the second negative electrode plate 1802 are also different. For example, the second winding start end S′ of the first negative electrode plate 1801 and the second winding start end S′ of the second negative electrode plate 1802 are arranged in the relative radial direction of the winding structure, and the second winding start ends S′ of the first negative electrode plate 1801 and the second negative electrode plate 1802 are not on the same plane.

[0151] The above-described winding structure can reduce the step formed by the first positive electrode plate 1803 and the second positive electrode plate 1804 at the first winding start end S, and can also reduce the step formed by the first negative electrode plate 1801 and the second negative electrode plate 1802 at the second winding start end S′. As a result, after the electrode assembly expands and contacts the case 20, the local stress applied to the electrode plate at the winding start end can be reduced, preventing the electrode plate from cracking or the active material from falling off, and improving the reliability of the long-term operation of the electrode assembly.

[0152] FIG. 16 is a schematic structural diagram showing that a cylindrical electrode assembly is perpendicular to a cross section of a winding axis K in another embodiment of the present disclosure. The electrode assembly 190 includes a first negative electrode plate 1901, a second negative electrode plate 1902, a first positive electrode plate 1903, a second positive electrode plate 1904, and a plurality of separators 1905. The first negative electrode plate 1901, the first positive electrode plate 1903, the second negative electrode plate 1902, and the second positive electrode plate 1904 are alternately stacked in order. The first negative electrode plate 1901 is separated from the first positive electrode plate 1903 by a separator 1905, the first positive electrode plate 1903 is separated from the second negative electrode plate 1902 by another separator 1905, and the second negative electrode plate 1902 is separated from the second positive electrode plate 1904 by another separator 1905. After the first negative electrode plate 1901, the second negative electrode plate 1902, the first positive electrode plate 1903, the second positive electrode plate 1904, and the plurality of separators 1905 are all stacked, they are wound around the winding axis K to form a cylindrical winding structure.

[0153] The structure of this embodiment is substantially the same as the structure described in the embodiment of FIG. 15. Hereinafter, the differences will be described. In the winding structure of this embodiment, the innermost ring of the winding structure is a ring jointly surrounded by the first negative electrode plate 1901 and the second negative electrode plate 1902, and the outermost ring of the winding structure is a ring surrounded by the first negative electrode plate 1901.

[0154] In the winding structure of this embodiment, the positions of the first winding ends E of the first positive electrode plate 1903 and the second positive electrode plate 1904 are different. Also, the second winding ends E' of the first negative electrode plate 1901 and the second negative electrode plate 1902 are different.

[0155] Along the winding direction, the first negative electrode plate 1901 is arranged in the outermost layer, the end position of the second winding end E' exceeds the end position of the second winding end E' of the second negative electrode plate 1902, and the end position of the first winding end E of the first positive electrode plate 1903 exceeds the end position of the first winding end E of the second positive electrode plate 1904, for example, exceeding by half of the ring. The exceeding part is pushed inward along the radial direction until it contacts the electrode plate of the inner layer to improve the stability of the winding structure.

[0156] The above-described winding structure can simultaneously reduce the steps formed by the first positive electrode plate 1903 and the second positive electrode plate 1904 at the first winding start end S and the first winding end E, and can simultaneously reduce the steps formed by the first negative electrode plate 1901 and the second negative electrode plate 1902 at the second winding start end S' and the second winding end E'. As a result, after the electrode assembly expands and contacts the case 20, the local stress applied to the electrode plate at the winding start end and the winding end can be reduced, preventing cracking of the electrode plate or shedding of the active material, and improving the reliability of the long-term operation of the electrode assembly.

[0157] Furthermore, the number of layers of the winding structure in different radial directions can be the same. However, for a cylindrical winding structure, when the electrode assembly expands and contacts the case 20, the stress applied to each point along the circumferential direction is the same.

[0158] Figure 17 is a schematic structural diagram showing that in another embodiment of the present disclosure, the cylindrical electrode assembly is perpendicular to the cross-section of the winding axis K. The electrode assembly 200 has a first negative electrode plate 2001, a second negative electrode plate 2002, a first positive electrode plate 2003, a second positive electrode plate 2004, and a plurality of separators 2005. The first negative electrode plate 2001, the first positive electrode plate 2003, the second negative electrode plate 2002, and the second positive electrode plate 2004 are alternately and sequentially overlapped. The first negative electrode plate 2001 is separated from the first positive electrode plate 2003 by a separator 2005, the first positive electrode plate 2003 is separated from the second negative electrode plate 2002 by another separator 2005, and the second negative electrode plate 2002 is separated from the second positive electrode plate 2004 by another separator 2005. The first negative electrode plate 2001, the second negative electrode plate 2002, the first positive electrode plate 2003, the second positive electrode plate 2004, and the plurality of separators 2005 are all wound around the winding axis K after being overlapped to form a cylindrical winding structure.

[0159] The structure of the electrode assembly 200 of this embodiment is substantially the same as the structure of the electrode assembly 180 described in the embodiment of FIG. 15. The differences will be described below. In the winding structure of this embodiment, the innermost ring in the winding structure is a ring jointly surrounded by the first negative electrode plate 2001 and the second negative electrode plate 2002, and the outermost ring of the winding structure is also a ring jointly surrounded by the first negative electrode plate 2001 and the second negative electrode plate 2002.

[0160] Along the winding direction, the second negative electrode plate 2002 is arranged in the outermost layer, the end position of the second winding end E' exceeds the end position of the second winding end E' of the first negative electrode plate 2001, and the end position of the first winding end E of the second positive electrode plate 2004 exceeds the end position of the first winding end E of the first positive electrode plate 2003, for example, exceeding by half of the ring.

[0161] The above-described winding structure can simultaneously reduce the steps formed by the first positive electrode plate 2003 and the second positive electrode plate 2004 at the first winding start end S and the first winding end E, and can simultaneously reduce the steps formed by the first negative electrode plate 2001 and the second negative electrode plate 2002 at the second winding start end S' and the second winding end E'. As a result, after the electrode assembly expands and contacts the case 20, the local stress applied to the electrode plate at the winding start end and the winding end is reduced, preventing cracking of the electrode plate or shedding of the active material, and improving the reliability of the long-term operation of the electrode assembly.

[0162] Furthermore, the number of layers of the winding structure in different radial directions can be the same. However, for a cylindrical winding structure, when the electrode assembly expands and contacts the case 20, the stress applied to each point along the circumferential direction is the same.

[0163] Also, this structure can avoid the outermost layer of the electrode plate and the second layer from the last of the electrode plate bending at the winding end of the other electrode plate. As a result, all layers of the electrode plate are reliably in contact, and local stress is less likely to occur in the electrode plate. Thereby, cracking of the electrode plate or shedding of the active material can be prevented.

[0164] Second, the present disclosure further provides a method for manufacturing an electrode assembly. In some embodiments, the flowchart shown in FIG. 18 includes the following.

[0165] Step 101, providing a plurality of first electrode plates 1 and at least one second electrode plate 2. Here, the polarity of the first electrode plate 1 is opposite to the polarity of the second electrode plate 2.

[0166] Step 102, winding the plurality of first electrode plates 1 and at least one second electrode plate 2 around the winding shaft K to form a winding structure.

[0167] Here, in the winding structure, the first electrode plates 1 in the plurality of first electrode plates 1 and the second electrode plates 2 in at least one second electrode plate 2 are arranged to overlap along a direction perpendicular to the winding axis K. Each first electrode plate 1 has a first current collector 11 and a first active material layer 12 disposed on the overlapping surface of the first current collector 11. The first current collector has a first main body portion 111 provided with the first active material layer 12 and a first tab 112 protruding from the first main body portion 111 along the direction of the winding axis. The first tab 112 and the first main body portion 111 are arranged in parallel along the winding axis.

[0168] In this embodiment, by setting a plurality of first electrode plates 1, the number of windings of the electrode assembly 10 can be reduced. Therefore, the amount of misalignment in the circumferential direction of the first tab 112 after winding can be reduced, and the connection with the collector component 30 becomes easier.

[0169] Finally, the present disclosure further provides a manufacturing apparatus 500 for an electrode assembly. In some embodiments, as shown in FIG. 19, the manufacturing equipment 500 has the following.

[0170] An electrode plate arrangement mechanism configured to provide a plurality of first electrode plates 1 and at least one second electrode plate 2. Here, the polarity of the first electrode plate 1 is opposite to the polarity of the second electrode plate 2.

[0171] A winding mechanism configured to wind a plurality of first electrode plates 1 and at least one second electrode plate 2 around a winding shaft K to form a winding structure. Here, in the winding structure, the first electrode plates 1 among the plurality of first electrode plates 1 and the second electrode plates 2 among the at least one second electrode plate 2 are alternately arranged along a direction perpendicular to the winding shaft K. Each first electrode plate 1 has a first current collector 11 and a first active material layer 12 disposed on the overlapping surface of the first current collector 11. The first current collector 11 has a first main body portion 111 provided with the first active material layer 12 and a first tab 112 protruding from the first main body portion 111 along the direction of the winding shaft. The first tab 112 and the first main body portion 111 are distributed in parallel along the winding shaft. The winding mechanism 502 can provide a stable winding tension for the overlapping electrode plates.

[0172] The electrode assembly 10 manufactured by the manufacturing apparatus 500 of the electrode assembly can reduce the winding error in the winding process.

[0173] Finally, it should be noted that the above embodiments are not intended to limit the present disclosure, but are merely for explaining the technical solutions of the present disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can further modify a specific embodiment of the present disclosure or equivalently replace some of the technical features. Any modification or replacement that does not deviate from the spirit of the technical solution of the present disclosure shall fall within the scope of the technical solution claimed in the present disclosure.

Claims

1. It has a plurality of first electrode plates and at least one second electrode plate, the polarities of the first electrode plates are opposite to the polarities of the second electrode plates, and after the plurality of first electrode plates and the at least one second electrode plate are superimposed, they are wound around a winding shaft to form a winding structure. In the winding structure, the plurality of first electrode plates and the at least one second electrode plate are superimposed and arranged along a direction perpendicular to the winding shaft. Each first electrode plate in the plurality of first electrode plates has a first current collector and a first active material layer disposed on the superimposed surface of the first current collector. The first current collector has a first main body portion provided with the first active material layer and at least one first tab protruding from the first main body portion along the direction of the winding shaft. Each first tab in the at least one first tab and the first main body portion are arranged parallel to each other along the winding shaft. The positions of the winding start ends of at least two first electrode plates in the plurality of first electrode plates are different, and the winding start ends of at least two first electrode plates in the plurality of first electrode plates are arranged in a staggered pattern in the circumferential direction of the winding structure. Electrode assembly.

2. Each first electrode plate has a plurality of first tabs arranged at intervals. The electrode assembly according to Claim 1.

3. In the winding structure, each first electrode plate is provided with at least one tab on each of its circles. The electrode assembly according to Claim 1 or 2.

4. Any two first tabs among all the first tabs overlap at least partially. The electrode assembly according to any one of Claims 1 to 3.

5. The winding structure is flat and has a straight portion and turning portions arranged on both sides of the straight portion. All of the first tabs are arranged on the straight portion. The electrode assembly according to any one of Claims 1 to 4.

6. The straight portion has a first straight small portion and a second straight small portion that are substantially parallel and symmetrically divided with respect to the winding shaft. All of the first tabs are arranged on the first straight small portion or the second straight small portion, or A part of all of the first tabs is arranged on the first straight small portion, and the remaining all of the first tabs are arranged on the second straight small portion. The electrode assembly according to claim 5.

7. The positions of the winding ends of at least two of the plurality of first electrode plates are different. The electrode assembly according to any one of claims 1 to 6.

8. The electrode assembly has a plurality of second electrode plates, and the positions of the winding start ends of at least two of the plurality of second electrode plates are different, and / or the positions of the winding end ends of at least two of the plurality of second electrode plates are different. The electrode assembly according to any one of claims 1 to 7.

9. The electrode assembly has a plurality of second electrode plates, the winding structure is flat, and has a straight portion and turning portions arranged on both sides of the straight portion. The winding end of at least one of the plurality of first electrode plates is arranged in the turning portion, and / or the winding end of at least one of the plurality of second electrode plates is arranged in the turning portion. The electrode assembly according to any one of claims 1 to 8.

10. In different radial directions of the winding structure, the difference in the number of layers between the first electrode plate and the second electrode plate does not exceed a preset number of layers. The electrode assembly according to any one of claims 1 to 9.

11. The preset number of layers is less than or equal to the total number of all the first electrode plates and all the second electrode plates. The electrode assembly according to claim 10.

12. A case, The electrode assembly according to any one of claims 1 to 11, and the electrode assembly is arranged in the case. A battery.

13. A battery module having a plurality of the batteries according to claim 12.

14. A battery pack having a plurality of the battery modules according to claim 13.

15. A device using a battery, The device has the battery according to claim 12, and the battery is configured to supply electrical energy. A device.

16. A method for manufacturing an electrode assembly, A step of providing a plurality of first electrode plates and at least one second electrode plate, wherein the polarity of the first electrode plate is opposite to the polarity of the second electrode plate, A step of winding the plurality of first electrode plates and the at least one second electrode plate around a winding axis to form a winding structure after superimposing them. ​ In the winding structure, the plurality of first electrode plates and the at least one second electrode plate are arranged to overlap along a direction perpendicular to the winding axis. Each first electrode plate has a first current collector and a first active material layer disposed on the overlapping surface of the first current collector. The first current collector has a first main body portion provided with the first active material layer and at least one first tab protruding from the first main body portion along the direction of the winding axis. Each first tab in the at least one first tab and the first main body portion are arranged parallel to each other along the winding axis. The positions of the winding start ends of at least two of the plurality of first electrode plates are different, and the winding start ends of at least two of the plurality of first electrode plates are arranged in a stagger pattern in the circumferential direction of the winding structure. Manufacturing method.

17. An electrode assembly manufacturing apparatus, An electrode plate arrangement mechanism configured to provide a plurality of first electrode plates and at least one second electrode plate, wherein the polarity of the first electrode plate is opposite to the polarity of the second electrode plate, the electrode plate arrangement mechanism; A winding mechanism configured to wind the plurality of first electrode plates and the at least one second electrode plate around a winding axis to form a winding structure after overlapping them. In the winding structure, the plurality of first electrode plates and the at least one second electrode plate are arranged to overlap along a direction perpendicular to the winding axis. Each first electrode plate has a first current collector and a first active material layer disposed on the overlapping surface of the first current collector. The first current collector has a first main body portion provided with the first active material layer and at least one first tab protruding from the first main body portion along the direction of the winding axis. Each first tab in the at least one first tab and the first main body portion are arranged parallel to each other along the winding axis. The positions of the winding start ends of at least two of the plurality of first electrode plates are different, and the winding start ends of at least two of the plurality of first electrode plates are arranged in a stagger pattern in the circumferential direction of the winding structure. Manufacturing apparatus.

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