Battery cell, battery, electrical device, electrode assembly and manufacturing method thereof

Abstract

A battery cell, a battery, an electrical device, an electrode assembly and a manufacturing method thereof. The electrode assembly includes: a main body portion (100), including a positive electrode tab (10A), a negative electrode tab (10B) and a separator (10C), the positive electrode tab (10A), the separator (10C) and the negative electrode tab (10B) are wound into a wound structure along a winding direction (r); a plurality of positive electrode ears (20), respectively connected to at least two positive electrode tab winding layers and arranged at intervals along the winding direction (r); a plurality of negative electrode ears (30), respectively connected to at least two negative electrode tab winding layers and arranged at intervals along the winding direction (r). The plurality of positive electrode ears (20) and the plurality of negative electrode ears (30) are located at the same side end of the main body portion (100) in a direction perpendicular to the winding direction (r), and the lengths of the positive electrode ears (20) respectively connected to the respective positive electrode tab winding layers and the negative electrode ears (30) respectively connected to the respective negative electrode tab winding layers increase along the winding direction (r).

Description

[0001] This application is a divisional application of a patent application with an international filing date of April 28, 2022, an international application number of PCT / CN2022 / 089733, a Chinese application number of 202280034760.7, and an invention title of "Battery Cell, Battery, Electrical Equipment, Electrode Assembly and Manufacturing Method Thereof". Technical Field

[0002] The present disclosure relates to the technical field of batteries, and in particular to a battery cell, a battery, an electrical equipment, an electrode assembly and a manufacturing method thereof. Background Art

[0003] A rechargeable battery cell, which can be referred to as a secondary battery cell, is a battery cell that can be activated by charging after discharging so as to be used continuously. Rechargeable battery cells are widely used in electronic devices, such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0004] As a key component of a battery cell, there are some battery performance or safety problems related to the tab during the formation of the electrode assembly. Summary of the Invention

[0005] In one aspect of the present disclosure, there is provided an electrode assembly, including:

[0006] A main body part, including a positive electrode plate, a negative electrode plate and a separator disposed between the positive electrode plate and the negative electrode plate, the positive electrode plate, the separator and the negative electrode plate being wound into a wound structure along a winding direction;

[0007] A plurality of positive electrode tabs, respectively connected to at least two positive electrode plate winding layers in the wound structure and arranged at intervals along the winding direction; and

[0008] A plurality of negative electrode tabs, respectively connected to at least two negative electrode plate winding layers in the wound structure and arranged at intervals along the winding direction;

[0009] Wherein, the plurality of positive electrode tabs and the plurality of negative electrode tabs are located at the same side end of the main body part in a direction perpendicular to the winding direction, the length of the positive electrode tab respectively connected to each positive electrode plate winding layer increases along the winding direction, and the length of the negative electrode tab respectively connected to each negative electrode plate winding layer increases along the winding direction.

[0010] A plurality of positive electrode tabs connected to the positive electrode plate and a plurality of negative electrode tabs connected to the negative electrode plate are arranged on the same side of the winding structure. In this way, the current collector plates corresponding to the positive electrode tabs and the current collector plates corresponding to the negative electrode tabs can respectively collect current and output it from the same side. Compared with the structure in the related art where the tabs extend from both ends of the winding structure, in this embodiment, the electronic path from the electrode plate to the electrode post can be shortened, so that the tabs do not need to guide the current through the housing, eliminating the adverse effects of the housing resistance on the internal resistance of the battery and the adverse effects of the housing heat generation on the internal heat dissipation of the battery, thereby reducing the internal resistance of the battery, improving the heat dissipation of the battery, and enhancing the battery power and fast charging ability.

[0011] By making the lengths of the positive electrode tabs and the negative electrode tabs connected to each layer of the electrode plate winding layer increase along the winding direction, when the positive electrode tabs after the electrode plate is wound are bent and smoothed, they can overlap and approach each other inward according to the curvature of the corresponding electrode plate winding layer, and when the negative electrode tabs after the electrode plate is wound are bent and smoothed, they can overlap and approach each other inward according to the curvature of the corresponding electrode plate winding layer, so as to respectively form a neater positive electrode tab group and negative electrode tab group, which is convenient for separating the positive and negative electrodes and is beneficial to subsequent tab welding. Moreover, the separated positive electrode tabs and the separated negative electrode tabs are not prone to generate wrinkles when being bent and smoothed, thereby reducing the risk of short circuit caused by tab breakage or wrinkles inserting into the electrode plate.

[0012] In some embodiments, the winding structure is a cylindrical winding structure wound around a winding axis.

[0013] Compared with the cylindrical winding structure adopted by cylindrical batteries in the related art, where the positive electrode tabs and the negative electrode tabs extend from both ends respectively, in this embodiment, the positive electrode tabs and the negative electrode tabs are located on the same side of the cylindrical winding structure, which can effectively reduce the internal resistance of the battery and improve the heat dissipation of the battery. Moreover, as the perimeter of the electrode plate winding layer of the cylindrical winding structure gradually decreases from the outside to the inside, the lengths of the corresponding tabs of each layer also decrease accordingly. In this way, the tabs of each layer will be neater after being smoothed towards the center of the circle, which is convenient for separating the positive and negative electrodes and is beneficial to subsequent tab welding. In addition, the intervals between the tabs respectively connected by each electrode plate winding layer can enable the positive electrode tabs and the negative electrode tabs after winding to be partitioned, reducing the risk of short circuit caused by the ineffective separation of two groups of electrode plates with opposite polarities after being smoothed.

[0014] In some embodiments, the angular range of the plurality of positive electrode tabs at the end of the main body portion with respect to the winding axis does not overlap with the angular range of the plurality of negative electrode tabs at the end of the main body portion with respect to the winding axis.

[0015] By making the angular ranges of the plurality of positive electrode tabs and the plurality of negative electrode tabs on the same side of the cylindrical winding structure not overlap, the risk of short circuit caused by the ineffective separation of two groups of electrode plates with opposite polarities after being smoothed can be effectively reduced.

[0016] In some embodiments, at least one of the plurality of positive electrode tabs has at least one first notch on a side away from the positive electrode plate, and the at least one first notch divides the positive electrode tab into a plurality of positive electrode tab segments along the winding direction; and / or at least one of the plurality of negative electrode tabs has at least one second notch on a side away from the negative electrode plate, and the at least one second notch divides the negative electrode tab into a plurality of negative electrode tab segments along the winding direction.

[0017] By providing the first notch on the side of the positive electrode tab to obtain the divided plurality of positive electrode tab segments, the positive electrode tab is not easily wrinkled when flattened, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part being inserted between the electrode plates. Similarly, by providing the second notch on the side of the negative electrode tab to obtain the divided plurality of negative electrode tab segments, the negative electrode tab is not easily wrinkled when flattened, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part being inserted between the electrode plates.

[0018] In some embodiments, the widths of the respective positive electrode tab segments in the winding direction are the same, and the number of positive electrode tab segments in the positive electrode tabs respectively connected to the respective positive electrode plate winding layers increases along the winding direction; the widths of the respective negative electrode tab segments in the winding direction are the same, and the number of negative electrode tab segments in the negative electrode tabs respectively connected to the respective negative electrode plate winding layers increases along the winding direction.

[0019] Using positive electrode tab segments with the same width can reduce the processing difficulty of the positive electrode tab and make the flattened positive electrode tab group neater. Correspondingly, the length of the corresponding positive electrode tab is also changed by the change in the number of positive electrode tab segments connected to each positive electrode plate winding layer. Similarly, using negative electrode tab segments with the same width can reduce the processing difficulty of the negative electrode tab and make the flattened negative electrode tab group neater. Correspondingly, the length of the corresponding negative electrode tab is also changed by the change in the number of negative electrode tab segments connected to each negative electrode plate winding layer.

[0020] In some embodiments, the plurality of positive electrode tabs and the plurality of negative electrode tabs satisfy at least one of the following:

[0021] The end positions of the positive electrode tabs respectively connected to the respective positive electrode plate winding layers and located at the most upstream in the winding direction are all in the same plane;

[0022] The end positions of the positive electrode tabs respectively connected to the respective positive electrode plate winding layers and located at the most downstream in the winding direction are all in the same plane;

[0023] The end positions of the negative electrode tabs respectively connected to the respective negative electrode plate winding layers and located at the most upstream in the winding direction are all in the same plane;

[0024] The end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer, which are located at the most downstream in the winding direction, are all in the same plane.

[0025] Aligning the end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer, which are located at the most upstream in the winding direction, to the same plane is beneficial for ensuring the neatness of the end on this side when flattening each layer of positive electrode tabs inward, facilitating the separation of the positive and negative electrodes, and being beneficial for subsequent tab welding. Similarly, aligning the end positions of the positive electrode tabs at the most downstream to the same plane, aligning the end positions of the negative electrode tabs at the most upstream to the same plane, and aligning the end positions of the negative electrode tabs at the most downstream to the same plane can all ensure the neatness of the corresponding side ends, facilitate the separation of the positive and negative electrodes, and be beneficial for subsequent tab welding.

[0026] In some embodiments, the end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer, which are located at the most upstream and the most downstream in the winding direction, are all in the same plane; and / or the end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer, which are located at the most upstream and the most downstream in the winding direction, are all in the same plane.

[0027] By aligning the end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer, which are located at the most upstream and the most downstream in the winding direction, to the same plane, a positive electrode tab group with an overall bow shape can be formed. After flattening this bow-shaped positive electrode tab group inward, both ends can be kept neat, thereby effectively separating it from the negative electrode tab group and also facilitating its welding to the current collector plate. Similarly, by aligning the end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer, which are located at the most upstream and the most downstream in the winding direction, to the same plane, a negative electrode tab group with an overall bow shape can be formed. After flattening this bow-shaped negative electrode tab group inward, both ends can be kept neat, thereby effectively separating it from the negative electrode tab group and also facilitating its welding to the current collector plate.

[0028] In some embodiments, the end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer, which are located at the most upstream in the winding direction, and the end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer, which are located at the most upstream in the winding direction, are all in the same plane;

[0029] The end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer, which are located at the most downstream in the winding direction, and the end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer, which are located at the most downstream in the winding direction, are all in the same plane.

[0030] By aligning the end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer at the most upstream position in the winding direction and the end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer at the most downstream position to the same plane, and by aligning the end positions of the positive electrode tabs respectively connected to each positive electrode tab winding layer at the most downstream position in the winding direction and the end positions of the negative electrode tabs respectively connected to each negative electrode tab winding layer at the most upstream position to the same plane, a positive electrode tab group and a negative electrode tab group that are fan-shaped as a whole and symmetric to each other can be formed. The tab groups in this structure have good consistency and are more likely to maintain the uniformity of the welding effect during welding.

[0031] In some embodiments, the winding structure is a cylindrical winding structure wound around a winding axis, and the plurality of positive electrode tabs and the plurality of negative electrode tabs are symmetric with respect to the winding axis or symmetric with respect to a plane passing through the winding axis.

[0032] To improve the consistency when the positive and negative electrode tabs are respectively welded to the current collector plate, the plurality of positive electrode tabs and the plurality of negative electrode tabs can be symmetric with respect to the winding axis, or the plurality of positive electrode tabs and the plurality of negative electrode tabs can be symmetric with respect to a plane passing through the winding axis. In this way, the uniformity of the welding effect is improved by the morphological consistency of the flattened positive electrode tab group and negative electrode tab group.

[0033] In some embodiments, the electrode assembly further includes: an insulating member disposed at an end of the main body portion on the side connecting the plurality of positive electrode tabs and the plurality of negative electrode tabs and located between the plurality of positive electrode tabs and the plurality of negative electrode tabs.

[0034] To more effectively separate the positive electrode tabs and negative electrode tabs on the same side of the main body portion, an insulating member is provided between the plurality of positive electrode tabs and the plurality of negative electrode tabs to achieve effective separation of the two and reduce the risk of short circuit.

[0035] In some embodiments, the insulating member includes an insulating plastic block.

[0036] By using an insulating plastic block with a certain volume to isolate the positive electrode tabs and negative electrode tabs, on the one hand, it can effectively insulate between the positive electrode tabs and negative electrode tabs and avoid short circuit between the two. On the other hand, it can form a certain supporting effect at the end of the main body portion, so that it can withstand a certain extrusion force when the battery end is pressed, and reduce the risk of decarburization at the edge of the electrode sheet caused by the pressure on the main body portion.

[0037] In some embodiments, the winding structure is a cylindrical winding structure wound around a winding axis, and the cylindrical winding structure has a first central hole penetrating axially, and the insulating member has a second central hole communicating with the first central hole along the winding axis.

[0038] By providing a first central hole and a second central hole on the insulating member and the cylindrical winding structure respectively, the perfusion of the electrolyte in the battery cell can be achieved.

[0039] In some embodiments, both the first central hole and the second central hole are circular holes, and the diameter D1 of the first central hole is greater than or equal to the diameter D2 of the second central hole.

[0040] When using a second central hole with a diameter not greater than that of the first central hole, even if the tab enters or passes through the second central hole from the upper surface of the insulating member after being flattened, it is not easy to further contact the electrode sheet radially outside the first central hole, thereby effectively reducing the risk of short circuit.

[0041] In some embodiments, the positive electrode sheet includes a positive current collector and a positive active material film layer covering the surface of the positive current collector, the plurality of positive tabs are connected to the first side edge of the positive current collector extending along the winding direction, the negative electrode sheet includes a negative current collector and a negative active material film layer covering the surface of the negative current collector, and the plurality of negative tabs are connected to the second side edge of the negative current collector extending along the winding direction.

[0042] In some embodiments, at least one positive tab among the plurality of positive tabs has at least one first notch on the side away from the positive electrode sheet, the at least one first notch divides the positive tab into a plurality of positive tab segments along the winding direction, and the root of the at least one first notch is located on the front side of the separator in the first direction;

[0043] At least one negative tab among the plurality of negative tabs has at least one second notch on the side away from the negative electrode sheet, the at least one second notch divides the negative tab into a plurality of negative tab segments along the winding direction, and the root of the at least one second notch is located on the front side of the separator in the first direction;

[0044] Wherein, the first direction is the extending direction of the plurality of positive tabs relative to the positive electrode sheet or the extending direction of the plurality of negative tabs relative to the negative electrode sheet, and the first direction is perpendicular to the winding direction.

[0045] If the opposite side edge of the first side edge in the opposite direction of the first direction is used as a reference, the heights of the roots of the first notch and the second notch are greater than the height of the separator. Since the roots of the first notch and the second notch are usually the positions where the tab segments are bent and flattened, when the tab segments are flattened and welded to the current collecting plate, the tab segments heated during welding can keep a certain distance from the separator, thereby reducing the possibility of the separator being scalded during welding, and further preventing short circuit caused by the separator being scalded.

[0046] In some embodiments, the electrode assembly further includes:

[0047] a positive current collector disk, located on a side of the plurality of positive electrode tabs away from the main body portion, and fixedly connected to the flattened plurality of positive electrode tabs by welding; and

[0048] a negative current collector disk, located on a side of the plurality of negative electrode tabs away from the main body portion, and fixedly connected to the flattened plurality of negative electrode tabs by welding;

[0049] Wherein, the plurality of positive electrode tabs are bent and flattened towards the center of the end portion facing the main body portion at the root of the at least one first notch, the plurality of negative electrode tabs are bent and flattened towards the center of the end portion facing the main body portion at the root of the at least one second notch, a first distance d1 between the root of the at least one first notch and the separator in the first direction is greater than or equal to 1.5 times the thickness t1 of the positive current collector disk, and a second distance d2 between the root of the at least one second notch and the separator in the first direction is greater than or equal to 1.5 times the thickness t2 of the negative current collector disk.

[0050] Since the thickness of the current collector disk is related to the heat during welding, the thicker the current collector disk, the higher the heat during welding. Correspondingly, making the first distance between the root of the first notch and the separator in the first direction greater than 1.5 times the thickness of the positive current collector disk, and making the second distance between the root of the second notch and the separator in the first direction greater than 1.5 times the thickness of the negative current collector disk can effectively reduce the possibility of the separator being scalded during welding of the current collector disk, thereby preventing short circuit caused by the separator being scalded.

[0051] In some embodiments, the roots of the first notches between adjacent positive electrode tab segments and the roots of the second notches between adjacent negative electrode tab segments are located in the same plane perpendicular to the first direction.

[0052] If the opposite side of the first side in the opposite direction of the first direction is used as a reference, by setting the roots of the first notch and the second notch at the same height, the positive electrode tabs and the negative electrode tabs can be made to be as much as possible in the same plane when welded after being flattened, thereby ensuring that no false welding phenomenon is likely to occur during welding.

[0053] In some embodiments, at least one of the plurality of positive electrode tabs has at least one first notch on a side away from the positive electrode plate, and the at least one first notch divides the positive electrode tab into a plurality of positive electrode tab segments along the winding direction, and the number of positive electrode tab segments of the positive electrode tabs respectively connected to each positive electrode plate winding layer continuously increases or increases in stages along the winding direction; and / or

[0054] At least one of the plurality of negative electrode tabs has at least one second notch on a side away from the negative electrode plate, and the at least one second notch divides the negative electrode tab into a plurality of negative electrode tab segments along the winding direction, and the number of negative electrode tab segments of the negative electrode tabs respectively connected to the respective negative electrode plate winding layers continuously increases or increases in stages along the winding direction.

[0055] In some embodiments, at least one of the plurality of positive electrode tabs has at least one first notch on a side away from the positive electrode plate, and the at least one first notch divides the positive electrode tab into a plurality of positive electrode tab segments along the winding direction, and a first notch of one of the two positive electrode tabs respectively connected to adjacent positive electrode plate winding layers is radially opposite to a positive electrode tab segment of the other positive electrode tab or is radially opposite to a first notch of the other positive electrode tab; and / or

[0056] At least one of the plurality of negative electrode tabs has at least one second notch on a side away from the negative electrode plate, and the at least one second notch divides the negative electrode tab into a plurality of negative electrode tab segments along the winding direction, and a second notch of one of the two negative electrode tabs respectively connected to adjacent negative electrode plate winding layers is radially opposite to a negative electrode tab segment of the other negative electrode tab or is radially opposite to a second notch of the other negative electrode tab.

[0057] In one aspect of the present disclosure, a battery cell is provided, including the foregoing electrode assembly. The battery cell using the foregoing electrode assembly has better performance.

[0058] In one aspect of the present disclosure, a battery is provided, including the foregoing battery cell. The battery using the foregoing battery cell has better performance.

[0059] In one aspect of the present disclosure, an electrical device is provided, including the foregoing battery. The electrical device using the foregoing battery has better performance.

[0060] In one aspect of the present disclosure, a method for manufacturing an electrode assembly is provided, including:

[0061] Providing a separator, a positive electrode plate connected with a positive electrode full tab, and a negative electrode plate connected with a negative electrode full tab;

[0062] Die-cutting the positive electrode full tab into a plurality of positive electrode tabs arranged at intervals along the length direction of the positive electrode plate, and die-cutting the negative electrode full tab into a plurality of negative electrode tabs arranged at intervals along the length direction of the negative electrode plate;

[0063] Wind the positive electrode sheet, the separator, and the negative electrode sheet into the main body of the electrode assembly, and place the plurality of positive electrode tabs and the plurality of negative electrode tabs at the same side end of the main body in a direction perpendicular to the winding direction of the main body;

[0064] Bend and flatten the plurality of positive electrode tabs and the plurality of negative electrode tabs;

[0065] Wherein, when die-cutting the positive full tabs and the negative full tabs, the length of the positive electrode tabs respectively connected to the respective winding layers of the positive electrode sheets of the main body in the winding direction increases along the winding direction, and the length of the negative electrode tabs respectively connected to the respective winding layers of the negative electrode sheets of the main body in the winding direction increases along the winding direction.

[0066] By using a die-cutting process to arrange the plurality of positive electrode tabs formed on the positive electrode sheet and the plurality of negative electrode tabs formed on the negative electrode sheet on the same side of the winding structure, the current collector plates corresponding to the positive electrode tabs and the current collector plates corresponding to the negative electrode tabs can respectively collect current and output it from the same side. Compared with the structure in the related art where the tabs protrude from both ends of the winding structure, in this embodiment, the electron path from the electrode sheet to the pole column can be shortened, so that the tabs do not need to conduct current through the housing, eliminating the adverse effects of the housing resistance on the internal resistance of the battery and the adverse effects of the housing heat generation on the internal heat dissipation of the battery, thereby reducing the internal resistance of the battery, improving the heat dissipation of the battery, and enhancing the battery power and fast charging ability.

[0067] By increasing the lengths of the positive electrode tabs and the negative electrode tabs connected to the respective winding layers of the pole piece in the winding direction, when the respective positive electrode tabs after winding the pole piece are bent and flattened, they can overlap and approach each other inward according to the curvature of the corresponding winding layer of the pole piece, and when the respective negative electrode tabs after winding the pole piece are bent and flattened, they can overlap and approach each other inward according to the curvature of the corresponding winding layer of the pole piece, so as to respectively form a neater positive electrode tab group and negative electrode tab group, which is convenient for separating the positive and negative electrodes, and is beneficial to subsequent tab welding, and the separated positive electrode tabs and the separated negative electrode tabs are not prone to generate wrinkles when bent and flattened, thereby reducing the risk of tab breakage or wrinkles inserting into the pole piece and causing a short circuit.

[0068] In some embodiments, the manufacturing method further includes:

[0069] Fix an insulating member between the plurality of positive electrode tabs and the plurality of negative electrode tabs, so that the tab group formed by overlapping the plurality of positive electrode tabs and the tab group formed by overlapping the plurality of negative electrode tabs are isolated by the insulating member.

[0070] By arranging an insulating member between the plurality of positive electrode tabs and the plurality of negative electrode tabs on the same side of the main body, effective separation between the two can be achieved, further reducing the risk of short circuit.

[0071] In some embodiments, the manufacturing method further includes:

[0072] Welding the positive current collector plate to the smoothed multiple positive electrode tabs, and welding the negative current collector plate to the smoothed multiple negative electrode tabs.

[0073] By respectively welding the positive current collector plate and the negative current collector plate to the smoothed multiple positive electrode tabs and the smoothed multiple negative electrode tabs, an electrode assembly structure with the positive current collector plate and the negative current collector plate on the same side of the main body can be obtained.

[0074] In some embodiments, during the process of die-cutting the multiple positive electrode tabs, at least one first notch is die-cut on the side of at least one positive electrode tab away from the positive electrode plate, so as to divide the positive electrode tab into multiple positive electrode tab segments along the winding direction through the at least one first notch; and / or

[0075] During the process of die-cutting the multiple negative electrode tabs, at least one second notch is die-cut on the side of at least one negative electrode tab away from the negative electrode plate, so as to divide the negative electrode tab into multiple negative electrode tab segments along the winding direction through the at least one second notch.

[0076] Obtaining multiple separated positive electrode tab segments by die-cutting the side of the positive electrode tab with the first notch can make the positive electrode tab not easily wrinkle during smoothing, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part inserting between the electrode plates. Similarly, obtaining multiple separated negative electrode tab segments by die-cutting the side of the negative electrode tab with the second notch can make the negative electrode tab not easily wrinkle during smoothing, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part inserting between the electrode plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments of the present disclosure will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained according to the drawings without creative efforts.

[0078] Referring to the drawings, the present disclosure can be more clearly understood according to the following detailed description, where:

[0079] Figure 1 is a schematic structural diagram of some embodiments of the electrical device according to the present disclosure;

[0080] Figure 2 is a schematic structural diagram of some embodiments of the battery according to the present disclosure;

[0081] Figure 3 is a schematic cross-sectional view of a wound structure formed according to some embodiments of the electrode assembly of the present disclosure;

[0082] Figure 4 is a schematic unfolded view of the positive electrode tab according to some embodiments of the electrode assembly of the present disclosure;

[0083] Figure 5 is a schematic unfolded view of the negative electrode tab according to some embodiments of the electrode assembly of the present disclosure;

[0084] Figure 6 is a schematic structural view according to some embodiments of the electrode assembly of the present disclosure;

[0085] Figure 7 and Figure 8 respectively are Figure 6 a schematic view of the end portion provided with an insulating member and a schematic view of the end portion without the insulating member in a top view angle of the embodiment;

[0086] Figure 9 is a schematic structural view according to some other embodiments of the electrode assembly of the present disclosure;

[0087] Figure 10 is Figure 9 a schematic view of the end portion without the insulating member in a top view angle of the embodiment;

[0088] Figure 11 and Figure 12 respectively are Figure 6 the embodiment and Figure 9 a schematic view of the coverage range of the electrode tab and the insulating member at the end portion of the main body portion in the embodiment;

[0089] Figure 13 is a schematic view of the arrangement of the positive electrode tab, the negative electrode tab, and the separator according to some embodiments of the electrode assembly of the present disclosure;

[0090] Figure 14 A schematic structural view according to still some other embodiments of the electrode assembly of the present disclosure;

[0091] Figure 15 is a schematic view of the arrangement of the positive electrode tab, the negative electrode tab, the separator, and the insulating member according to some embodiments of the electrode assembly of the present disclosure;

[0092] Figure 16 is a schematic flow chart according to some embodiments of the manufacturing method of the electrode assembly of the present disclosure.

[0093] It should be understood that the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components.

[0094] Description of the Reference Numerals in the Drawings

[0095] 10: Battery cell; 10A: Positive electrode tab; 10B: Negative electrode tab; 10C: Separator; 100: Winding structure; 11: Positive current collector; 12: Positive active material film layer; 13: Negative current collector; 14: Negative active material film layer; 15: Insulating film layer; 16: First side; 17: Second side; 18: Third side; 121: Positive coating edge; 151: Insulating film layer coating edge; 153: Negative coating edge;

[0096] 20: Positive electrode ear; 21: Positive electrode ear segment; 22: First notch; 23: Root of the first notch;

[0097] 30: Negative electrode ear; 31: Negative electrode ear segment; 32: Second notch; 33: Root of the second notch;

[0098] 40: Insulating part; 41: Second central hole; 42: Front end of the insulating part;

[0099] 51: Positive current collecting plate; 52: Negative current collecting plate; 53: First electrode terminal; 54: Second electrode terminal;

[0100] 60: Battery; 61: Box body; 62: Cover;

[0101] 70: Vehicle. Detailed Embodiments

[0102] The following further describes in detail the embodiments of the present disclosure in conjunction with the drawings and examples. The detailed descriptions and drawings of the following examples are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure, that is, the present disclosure is not limited to the described embodiments.

[0103] In the description of the present disclosure, it should be noted that unless otherwise specified, the meaning of "a plurality" is two or more; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0104] The orientation terms used in the following description are all the directions shown in the figures, and do not limit the specific structure of the present disclosure. In the description of the present disclosure, it should also be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0105] The following will describe in detail some embodiments of the present invention with reference to the accompanying drawings. Without conflict, the features in the following embodiments can be combined with each other.

[0106] In some related technologies, the electrode assembly in a cylindrical battery cell has tabs protruding from both ends of the winding structure. One of the tabs protruding from one end is electrically connected to the housing and is guided by the housing to the same side as the tab protruding from the other end. It has been found through research that such a cylindrical battery cell will have an increased internal resistance of the entire battery due to the housing resistance tabs, and the overcurrent in the housing will generate heat, affecting the heat dissipation inside the battery, thereby affecting the performance of the battery.

[0107] In view of this, the embodiments of the present disclosure provide a battery cell, a battery, an electrical device, an electrode assembly, and a manufacturing method thereof, which can improve the performance of the battery.

[0108] The electrode assembly of the embodiments of the present disclosure can be applied to various battery cells. The battery cell can include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present disclosure do not limit this. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, and the embodiments of the present application do not limit this either. Generally, the battery cell is divided into a cylindrical battery cell, a square battery cell, and a soft-pack battery cell according to the packaging method, and the embodiments of the present application do not limit this either.

[0109] The battery cell of the embodiments of the present disclosure can be applied to various batteries. The battery can be used to supply power to electrical devices such as vehicles, for example, to provide a power source for vehicle control or a power source for driving. The battery can include a housing and a battery module. The housing is used to provide an accommodation space for the battery module, and the battery module is installed in the housing. The housing can be made of a metal material. The battery module can include a plurality of battery cells connected in series, parallel, or in a hybrid connection. The battery cell is the smallest unit that makes up the battery. The battery cell includes an electrode assembly capable of undergoing an electrochemical reaction.

[0110] The battery according to the embodiments of the present disclosure is applicable to various electrical devices that use batteries. The electrical devices can be mobile phones, portable devices, laptops, battery cars, electric vehicles, ships, spacecrafts, electric toys, and electric tools, etc. For example, spacecrafts include airplanes, rockets, space shuttles, and spaceships, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers. The embodiments of the present invention do not particularly limit the above-mentioned electrical devices.

[0111] Figure 1 is a schematic structural diagram of some embodiments of the electrical device according to the present disclosure. For convenience, the electrical device is taken as a vehicle as an example for illustration. Refer to Figure 1 , inside the vehicle 70, there is a battery 60, and the battery 60 is arranged at the bottom, head, or tail of the vehicle. The battery 60 powers the vehicle. For example, the battery 60 serves as the operating power source of the vehicle. This battery 60 can be used as the power source for devices such as new energy vehicles, ships, and intelligent electrical cabinets. The battery 60 can also be used as a power supply component to provide the required electrical energy for various electrical components of the device.

[0112] Figure 2 is a schematic structural diagram of some embodiments of the battery according to the present disclosure. Refer to Figure 2 , in some embodiments, the battery 60 includes a box body 61, a cover 62, and one or more battery cells 10 arranged in the box body 61. To facilitate observing the multiple battery cells 10 inside the box body 61, Figure 2 only a part of the cover 62 is shown. The battery cells 10 are electrically connected to each other, such as in series, parallel, or a combination of series and parallel, to achieve the required electrical performance parameters of the battery 60. The multiple battery cells 10 are arranged in rows, and one row or multiple rows of battery cells 10 can be arranged in the box according to needs.

[0113] In some embodiments, the battery cells 10 of the battery 60 can be arranged along at least one of the length direction and the width direction of the box body. At least one row or one column of battery cells 10 can be arranged according to actual needs. According to needs, one layer or multiple layers of battery cells 10 can also be arranged in the height direction of the battery 60.

[0114] In some embodiments, multiple battery cells 10 can be first connected in series, parallel, or a combination of series and parallel to form battery modules, and then multiple battery modules are connected in series, parallel, or a combination of series and parallel to form a whole and are accommodated in the box body 61. In other embodiments, all the battery cells 10 are directly connected in series, parallel, or a combination of series and parallel together, and then the whole formed by all the battery cells 10 is accommodated in the box body.

[0115] The battery cell 10 may include a housing, an end cap, and an electrode assembly. The housing has a cavity for accommodating the electrode assembly, and the end of the housing may be configured to be open for setting the end cap assembly. The electrode assembly is installed in the cavity of the housing. In addition to the electrode assembly, the end cap, and the housing, the battery cell 10 also includes an electrolyte.

[0116] Figure 3 It is a schematic cross-sectional view of a winding structure formed according to some embodiments of the electrode assembly of the present disclosure. Figure 4 It is a developed view of the positive electrode tab in some embodiments of the electrode assembly according to the present disclosure. Figure 5 It is a developed view of the negative electrode tab in some embodiments of the electrode assembly according to the present disclosure.

[0117] Figure 6 It is a schematic structural view of some embodiments of the electrode assembly according to the present disclosure.

[0118] Reference Figure 3 , in some embodiments, the electrode assembly includes: a main body portion 100, a plurality of positive electrode tabs 20, and a plurality of negative electrode tabs 30. The main body portion 100 includes: a positive electrode tab 10A, a negative electrode tab 10B, and a separator 10C disposed between the positive electrode tab 10A and the negative electrode tab 10B. The positive electrode tab 10A, the separator 10C, and the negative electrode tab 10B are wound along the winding direction r to form a winding structure, for example, forming Figure 3 a laminated structure of the negative electrode tab 10B, the separator 10C, the positive electrode tab 10A, the separator 10C... formed radially along the winding mechanism. The winding structure can form a cylindrical winding structure after winding. Correspondingly, the housing adopted by the battery cell including this electrode assembly is a cylindrical housing structure.

[0119] The battery cell 10 mainly operates by the movement of metal ions between the positive electrode tab and the negative electrode tab. The material of the separator 10C can be PP (polypropylene) or PE (polyethylene), etc.

[0120] Reference Figure 4 and Figure 6 , a plurality of positive electrode tabs 20 are respectively connected to at least two positive electrode tab winding layers in the winding structure and are arranged at intervals along the winding direction r. Reference Figure 5 and Figure 6 , a plurality of negative electrode tabs 30 are respectively connected to at least two negative electrode tab winding layers in the winding structure and are arranged at intervals along the winding direction r. The plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30 are located at the same side end of the main body portion 100 in the direction perpendicular to the winding direction r.

[0121] A plurality of positive electrode tabs connected to the positive electrode plate and a plurality of negative electrode tabs connected to the negative electrode plate are arranged on the same side of the winding structure, so that the current collectors of the positive electrode plate and the negative electrode plate can respectively collect current and output it from the same side. Compared with the structure in the related art where the tabs extend from both ends of the winding structure, in this embodiment, the electronic path from the electrode plate to the electrode post can be shortened, the tabs do not need to conduct current through the housing, and the adverse effects of the housing resistance on the internal resistance of the battery and the adverse effects of the housing heat generation on the internal heat dissipation of the battery are eliminated, thereby reducing the internal resistance of the battery, improving the heat dissipation of the battery, and enhancing the battery power and fast charging ability.

[0122] Reference Figures 4 - 6 , the length b1 of the positive electrode tab 20 connected to each positive electrode plate winding layer in the winding direction r increases along the winding direction r, and the length b2 of the negative electrode tab 30 connected to each negative electrode plate winding layer in the winding direction r increases along the winding direction r.

[0123] By making the lengths of the positive electrode tabs and the negative electrode tabs connected to each layer of the electrode plate winding layer increase along the winding direction, when the positive electrode tabs after the electrode plate is wound are bent and flattened, they can overlap and approach each other inward according to the curvature of the corresponding electrode plate winding layer, and when the negative electrode tabs after the electrode plate is wound are bent and flattened, they can overlap and approach each other inward according to the curvature of the corresponding electrode plate winding layer, so as to respectively form a neater positive electrode tab group and negative electrode tab group, which is convenient for separating the positive and negative electrodes, is beneficial to subsequent tab welding, and the separated positive electrode tabs and the separated negative electrode tabs are not prone to generating wrinkles when bent and flattened, thereby reducing the risk of tab breakage or wrinkles inserting into the electrode plate and causing a short circuit.

[0124] Figure 7 And Figure 8 Are respectively Figure 6 Schematic diagrams of the end part of the embodiment with an insulating member and the end part of the embodiment without the insulating member from a top view angle. Figure 9 Is a schematic structural diagram of some other embodiments of the electrode assembly according to the present disclosure. Figure 10 Is Figure 9 Schematic diagram of the end part of the embodiment without the insulating member from a top view angle. Figure 11 And Figure 12 Are respectively Figure 6 Embodiment and Figure 9 Schematic diagrams of the coverage ranges of the electrode tabs and the insulating member at the end part of the main body in the embodiment.

[0125] Reference Figure 6 And Figure 9, in some embodiments, the winding structure is a cylindrical winding structure wound around a winding axis ax. Compared with the cylindrical winding structure used in cylindrical batteries in the related art, where the positive electrode tab and the negative electrode tab extend from both ends respectively, in this embodiment, the positive electrode tab and the negative electrode tab are located on the same side of the cylindrical winding structure, which can effectively reduce the internal resistance of the battery and improve the heat dissipation of the battery. Moreover, as the circumference of the electrode sheet winding layers of the cylindrical winding structure gradually decreases from the outside to the inside, the corresponding tab lengths of each layer also decrease accordingly. In this way, after the tabs of each layer are smoothed towards the center of the circle, they will be more aligned, which is convenient for separating the positive and negative electrodes and is beneficial for subsequent tab welding.

[0126] In addition, the intervals between the tabs respectively connected to the respective electrode sheet winding layers can enable the wound positive electrode tabs and negative electrode tabs to be partitioned, reducing the risk of short circuit caused by the ineffective separation of two sets of electrode sheets with opposite polarities after smoothing.

[0127] In Figures 6 - 12 , the angular ranges of the plurality of positive electrode tabs 20 at the end of the main body 100 relative to the winding axis ax do not overlap with the angular ranges of the plurality of negative electrode tabs 30 at the end of the main body 100 relative to the winding axis ax. By making the angular ranges of the plurality of positive electrode tabs and the plurality of negative electrode tabs on the same side of the cylindrical winding structure not overlap, the risk of short circuit caused by the ineffective separation of two sets of electrode sheets with opposite polarities after smoothing can be effectively reduced.

[0128] To more effectively separate the positive electrode tab and the negative electrode tab located on the same side of the main body, referring to Figure 6 , Figure 7 , Figure 11 and Figure 12 , in some embodiments, the electrode assembly further includes: an insulating member 40. The insulating member 40 is disposed at the end of the main body 100 on the side connecting the plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30 and is located between the plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30. In this way, by arranging an insulating member between the plurality of positive electrode tabs and the plurality of negative electrode tabs, the effective separation of the two can be achieved, reducing the risk of short circuit.

[0129] In some embodiments, the insulating member 40 includes an insulating plastic block. The shape and size of the insulating plastic hole can be determined according to the coverage range of the positive electrode tab and the negative electrode tab. By using an insulating plastic block with a certain volume to isolate the positive electrode tab and the negative electrode tab, on the one hand, the insulation between the positive electrode tab and the negative electrode tab can be effectively achieved, avoiding short circuit between the two; on the other hand, a certain supporting effect can be formed at the end of the main body, so that when the battery end is compressed, it can withstand a certain extrusion force, reducing the risk of carbon removal at the edge of the electrode sheet caused by the compression of the main body.

[0130] For a cylindrical winding structure wound around a winding axis ax, refer to Figure 7 and Figure 8 , in some embodiments, the cylindrical winding structure has a first central hole 110 penetrating axially therethrough, and the insulating member 40 has a second central hole 41 communicating with the first central hole 110 along the winding axis ax. By providing the first central hole and the second central hole on the insulating member and the cylindrical winding structure respectively, the perfusion of the electrolyte in the battery cell can be realized.

[0131] In some embodiments, both the first central hole 110 and the second central hole 41 are circular holes, and the diameter D1 of the first central hole 110 is greater than or equal to the diameter D2 of the second central hole 41. When using a second central hole with a diameter not greater than that of the first central hole, even if the tab is flattened and enters or passes through the second central hole from the upper surface of the insulating member, it is not easy to further contact the electrode tab radially outside the first central hole, thereby effectively reducing the risk of short circuit.

[0132] Refer to Figure 11 and Figure 12 , in some embodiments, the plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30 satisfy at least one of the following: the end positions of the positive electrode tabs 20 respectively connected to the respective positive electrode tab winding layers that are located at the most upstream in the winding direction r are all located in the same plane (for example, the first plane S1); the end positions of the positive electrode tabs 20 respectively connected to the respective positive electrode tab winding layers that are located at the most downstream in the winding direction r are all located in the same plane (for example, the second plane S2); the end positions of the negative electrode tabs 30 respectively connected to the respective negative electrode tab winding layers that are located at the most upstream in the winding direction r are all located in the same plane (for example, the third plane S3); the end positions of the negative electrode tabs 30 respectively connected to the respective negative electrode tab winding layers that are located at the most downstream in the winding direction r are all located in the same plane (for example, the fourth plane S4).

[0133] In this embodiment, the end positions of the positive electrode tabs respectively connected to the respective positive electrode tab winding layers that are located at the most upstream in the winding direction are aligned to the same plane, which is beneficial to ensuring the neatness of the end portions on this side when flattening the positive electrode tabs inward, facilitating the separation of the positive and negative electrodes, and being beneficial to subsequent tab welding. Similarly, aligning the most downstream end portions of the positive electrode tabs to the same plane, aligning the most upstream end portions of the negative electrode tabs to the same plane, and aligning the most downstream end portions of the negative electrode tabs to the same plane can all ensure the neatness of the corresponding side end portions, facilitate the separation of the positive and negative electrodes, and be beneficial to subsequent tab welding.

[0134] Refer to Figure 11, in some embodiments, the positive electrode tabs 20 respectively connected to each positive electrode sheet winding layer are located in the same plane at the end position located most upstream and the end position located most downstream in the winding direction r. For example, the first plane S1 and the second plane S2 are coplanar. By aligning the end positions located most upstream and the end positions located most downstream in the winding direction of the positive electrode tabs respectively connected to each positive electrode sheet winding layer to the same plane, a positive electrode tab group having an overall bow shape can be formed. After this bow-shaped positive electrode tab group is smoothed inward, both ends can be kept neat, thereby effectively separating from the negative electrode tab group and also facilitating the welding of itself with the current collector plate.

[0135] Similarly, the negative electrode tabs 30 respectively connected to each negative electrode sheet winding layer are located in the same plane at the end position located most upstream and the end position located most downstream in the winding direction r. For example, the third plane S3 and the fourth plane S4 are coplanar. By aligning the end positions located most upstream and the end positions located most downstream in the winding direction of the negative electrode tabs respectively connected to each negative electrode sheet winding layer to the same plane, a negative electrode tab group having an overall bow shape can be formed. After this bow-shaped negative electrode tab group is smoothed inward, both ends can be kept neat, thereby effectively separating from the negative electrode tab group and also facilitating the welding of itself with the current collector plate.

[0136] Reference Figure 12 , in some embodiments, the end position located most upstream in the winding direction r of the positive electrode tabs 20 respectively connected to each positive electrode sheet winding layer and the end position located most upstream in the winding direction r of the negative electrode tabs 30 respectively connected to each negative electrode sheet winding layer are located in the same plane. For example, the first plane S1 and the third platform S3 are coplanar. The end position located most downstream in the winding direction r of the positive electrode tabs 20 respectively connected to each positive electrode sheet winding layer and the end position located most downstream in the winding direction r of the negative electrode tabs 30 respectively connected to each negative electrode sheet winding layer are located in the same plane. For example, the second plane S2 and the fourth platform S4 are coplanar.

[0137] In this embodiment, by aligning the end position located most upstream in the winding direction of the positive electrode tabs respectively connected to each positive electrode sheet winding layer and the end position located most downstream of the negative electrode tabs respectively connected to each negative electrode sheet winding layer to the same plane, and aligning the end position located most downstream in the winding direction of the positive electrode tabs respectively connected to each positive electrode sheet winding layer and the end position located most upstream of the negative electrode tabs respectively connected to each negative electrode sheet winding layer to the same plane, a positive electrode tab group and a negative electrode tab group that are overall fan-shaped and symmetric to each other can be formed. The tab groups in this structure have good consistency and are more likely to maintain the uniformity of the welding effect during welding.

[0138] For a cylindrical winding structure wound around a winding axis ax, in order to improve the consistency when the positive and negative tab ears are respectively welded to the current collector plate, referring to Figures 6 - 12 , in some embodiments, the plurality of positive tab ears 20 and the plurality of negative tab ears 30 are symmetric with respect to the winding axis ax, or symmetric with respect to a plane passing through the winding axis ax. In this way, the uniformity of the welding effect is improved by the morphological consistency of the flattened positive tab ear group and negative tab ear group.

[0139] Referring to Figure 11 and Figure 12 , in some embodiments, the end positions of the positive tab ears 20 respectively connected to the respective positive electrode sheet winding layers, which are located at the most upstream in the winding direction r, are all located in a first plane S1, and the end positions of the positive tab ears 20 respectively connected to the respective positive electrode sheet winding layers, which are located at the most downstream in the winding direction r, are all located in a second plane S2. The included angle range θ1 from the first plane S1 to the second plane S2 in the circumferential direction can satisfy: θ1 = K1*(C / L), and θ1 ≤ 180 degrees. C is the capacity of the battery using the electrode assembly, L is the total length of the negative electrode sheet 10B, and K1 is a first proportional parameter.

[0140] The end positions of the negative tab ears 30 respectively connected to the respective negative electrode sheet winding layers, which are located at the most upstream in the winding direction r, are all located in a third plane S3, and the end positions of the negative tab ears 30 respectively connected to the respective negative electrode sheet winding layers, which are located at the most downstream in the winding direction r, are all located in a fourth plane S4. The included angle range θ2 from the third plane S3 to the fourth plane S4 in the circumferential direction can satisfy: θ2 = K2*(C / L), and θ2 ≤ 180 degrees. C is the capacity of the battery using the electrode assembly, L is the total length of the negative electrode sheet 10B, and K2 is a second proportional parameter.

[0141] The value of the aforementioned included angle range is not greater than 180 degrees. If it exceeds 180 degrees, it is easy for the flattened negative tab ear or positive tab ear to contact the tab ear of the other polarity, resulting in a short - circuit risk. The included angle range corresponding to the tab ear group, the total length L of the negative electrode sheet, and the battery capacity C are all related to the current density flowing through the tab ear. When the battery capacity C is constant, the longer the total length L of the negative electrode sheet, the less the unit charge amount corresponding to the circumferential perimeter. Therefore, when the allowable current density is satisfied, a tab ear group with a smaller included angle range can be used; when the total length L of the negative electrode sheet is constant, the larger the battery capacity C, the more the unit charge amount corresponding to the circumferential perimeter. In order to avoid too high a current density flowing through the tab ear, resulting in over - current heating, a tab ear group with a larger included angle range can be used.

[0142] In some embodiments, the unit of the capacity C of the electrode assembly is ampere - hour, the unit of the total length L of the negative electrode sheet 10B is millimeter, and the first proportional parameter K1 is greater than or equal to The second proportional parameter K2 is greater than or equal to By defining suitable value ranges for the first proportional parameter K1 and the second proportional parameter K2, the temperature of the tab can be maintained within an allowable range during charging, avoiding overheating and affecting the performance of the chemical substances in the battery using the electrode assembly.

[0143] Referring to the foregoing embodiments, when the electrode assembly is used in a lithium secondary battery, since side reactions or even decomposition of the lithium salt, solvent, positive electrode active material, and negative electrode active material will occur at high temperatures, it is usually controlled below 80 °C, preferably below 60 °C, during normal use of the electrode assembly. In an experimental example, the capacity C of the battery assembly is 45 ampere-hours, and the total length L of the negative electrode tab is 4827 mm. According to Calculation is carried out, and both θ1 and θ2 are approximately equal to 112 degrees. Therefore, when the actual included angle range θ1 and θ2 adopt 120 degrees greater than 112 degrees, the corresponding K1 and K2 are greater than The measured temperature at the root of the tab during fast charging is 50 °C, meeting the requirements that the tab temperature of this kind of battery is lower than 60 °C and 80 °C.

[0144] Referring to the foregoing embodiments, in another experimental example, the capacity C of the battery assembly is 32.5 ampere-hours, and the total length L of the negative electrode tab is 4585 mm. According to Calculation is carried out, and both θ1 and θ2 are approximately equal to 85 degrees. Therefore, when the actual included angle range θ1 and θ2 adopt 90 degrees greater than 85 degrees, the corresponding K1 and K2 are greater than The measured temperature at the root of the tab during fast charging is 52 °C, meeting the requirements that the tab temperature of this kind of battery is lower than 60 °C and 80 °C.

[0145] Referring to the foregoing embodiments, in a comparative experimental example, the capacity C of the battery assembly is 30 ampere-hours, and the total length L of the negative electrode tab is 4585 mm. According to Calculation is carried out, and both θ1 and θ2 are approximately equal to 78 degrees. Therefore, when the actual included angle range θ1 and θ2 adopt 30 degrees less than 78 degrees, the corresponding K1 and K2 are less than The measured temperature at the root of the tab during fast charging is 80 °C, not meeting the requirements that the tab temperature of this kind of battery is lower than 60 °C and 80 °C.

[0146] It can be seen from the above experimental examples and comparative experimental examples that by selecting a suitable included angle range θ1 and θ2, the temperature of the tab during fast charging can be reduced, avoiding the influence of excessive tab temperature on the performance of the chemical substances in the battery, reducing the battery life, and causing battery failure.

[0147] Figure 13It is a schematic diagram showing the arrangement of the positive electrode tab, negative electrode tab and separator in some embodiments of the electrode assembly according to the present disclosure. Refer to Figure 4 and Figure 13 , in some embodiments, at least one positive electrode tab 20 among the plurality of positive electrode tabs 20 has at least one first notch 22 on a side away from the positive electrode sheet 10A, and the at least one first notch 22 divides the positive electrode tab 20 into a plurality of positive electrode tab segments 21 along the winding direction r.

[0148] By providing the first notch on the side of the positive electrode tab to obtain the divided positive electrode tab segments, it is possible to prevent the positive electrode tab from being easily wrinkled when flattened, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part being inserted between the electrode sheets.

[0149] At least one negative electrode tab 30 among the plurality of negative electrode tabs 30 may have at least one second notch 32 on a side away from the negative electrode sheet 10B, and the at least one second notch 32 divides the negative electrode tab 30 into a plurality of negative electrode tab segments 31 along the winding direction r. By providing the second notch on the side of the negative electrode tab to obtain the divided negative electrode tab segments, it is possible to prevent the negative electrode tab from being easily wrinkled when flattened, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part being inserted between the electrode sheets.

[0150] In some other embodiments, the positive electrode tab may not have the first notch and is continuous in the winding direction r without being divided into a plurality of positive electrode tab segments; the negative electrode tab may also not have the second notch and is continuous in the winding direction r without being divided into a plurality of negative electrode tab segments.

[0151] In some embodiments, the widths of the respective positive electrode tab segments 21 in the winding direction r are the same, and the number of positive electrode tab segments 21 in the positive electrode tab 20 connected to the respective positive electrode sheet winding layers may increase along the winding direction r. For example, the number of positive electrode tab segments 21 corresponding to the inner positive electrode sheet winding layer is less than the number of positive electrode tab segments 21 corresponding to the outer positive electrode sheet winding layer. This change in number can be continuous or can change in stages. By using positive electrode tab segments 21 with the same width, the processing difficulty of the positive electrode tab can be reduced, and the flattened positive electrode tab group can be made neater. Correspondingly, the length b1 of the corresponding positive electrode tab is also changed by changing the number of positive electrode tab segments 21 connected to the respective positive electrode sheet winding layers.

[0152] The widths of all the negative electrode tab segments 31 in the winding direction r are the same, and the number of negative electrode tab segments 31 in the negative electrode tab 30 connected to each negative electrode tab winding layer increases along the winding direction r. For example, the number of negative electrode tab segments 31 corresponding to the inner negative electrode tab winding layer is less than the number of negative electrode tab segments 31 corresponding to the outer negative electrode tab winding layer. This change in quantity can be continuous or stepwise. By using negative electrode tab segments 31 with the same width, the processing difficulty of the negative electrode tab can be reduced, and the flattened negative electrode tab group can be made neater. Correspondingly, the change in the length b2 of the corresponding negative electrode tab is achieved by changing the number of negative electrode tab segments 31 connected to each negative electrode tab winding layer.

[0153] Reference Figure 13 , in some embodiments, the positive electrode tab 10A includes a positive electrode current collector 11 and a positive electrode active material film layer 12 covering the surface of the positive electrode current collector 11. The plurality of positive electrode tabs 20 are connected to the first side edge 16 of the positive electrode current collector 11 extending along the winding direction r. The positive electrode active material film layer 12 continuously extends from the surface of the positive electrode current collector 11 to a partial surface of the plurality of positive electrode tabs 20.

[0154] Taking a lithium-ion battery as an example, the material of the positive electrode current collector 11 can be aluminum, and the positive electrode active material film layer 12 can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. In some embodiments, the plurality of positive electrode tabs 20 can be welded to the first side edge of the positive electrode current collector 11. The plurality of positive electrode tabs 20 can also be formed by die-cutting the positive electrode current collector 11.

[0155] Generally speaking, the edge part of the positive electrode active material film layer is thinner, and the thinner positive electrode active material film layer may cause too large a gap between the electrode tabs, making it difficult to retain the electrolyte, resulting in poor local electrolyte infiltration effect and easy occurrence of lithium deposition problems. When die-cutting and other methods are used to cut out the positive electrode tabs on the positive electrode tab, by cutting off the side edge of the positive electrode tab provided with the positive electrode active material film layer, a state can be formed in which the positive electrode active material film layer continuously extends from the surface of the positive electrode current collector to a partial surface of the positive electrode tab. Correspondingly, the thickness of the positive electrode active material film layer covering the side edge of the positive electrode tab adjacent to the positive electrode tab is more consistent with other positions of the positive electrode tab, making it easier to retain the electrolyte, obtaining a better electrolyte infiltration effect, and reducing the risk of lithium deposition.

[0156] The negative electrode tab 10B includes a negative current collector 13, a negative active material film layer 14 covering the surface of the negative current collector 13, and an insulating film layer 15 covering the surface of the negative current collector 13. The plurality of negative electrode tabs 30 are connected to the second side edge 17 of the negative current collector 13 extending along the winding direction r. The insulating film layer 15 (such as a ceramic insulating layer, etc.) is located on the front side of the negative active material film layer 14 in the first direction a and continuously extends from the surface of the negative current collector 13 to a partial surface of the plurality of negative electrode tabs 30. The insulating layer 15 can prevent burrs on the cut edge of the anode tab from piercing the separator and causing a short circuit with the cathode tab.

[0157] The material of the negative current collector 13 can be copper, and the negative active material film layer 14 can be carbon or silicon, etc. In some embodiments, the plurality of negative electrode tabs 30 can be welded to the second side edge 17 of the negative current collector 13. The plurality of negative electrode tabs 30 can also be formed by die-cutting the negative current collector 13.

[0158] See Figure 13 , the first direction a is the extending direction of the plurality of positive electrode tabs 20 relative to the positive electrode tab 10A or the extending direction of the plurality of negative electrode tabs 30 relative to the negative electrode tab 10B, and the first direction is perpendicular to the winding direction r.

[0159] Similar to the structure where the positive active material film layer on the positive electrode tab is thinner at the edge portion, the edge portion of the insulating film layer is also thinner, and the thinner insulating film layer may cause an excessive gap between the tabs, making it difficult to retain the electrolyte, resulting in poor local electrolyte infiltration effect and prone to lithium plating problems. When die-cutting and other methods are used to cut out the negative electrode tabs on the negative electrode tab, by cutting off the side edge of the negative electrode tab provided with the insulating film layer, a state can be formed where the insulating film layer continuously extends from the surface of the negative current collector to a partial surface of the negative electrode tab. Correspondingly, the thickness of the insulating film layer covering the side edge of the negative electrode tab adjacent to the negative electrode tab is more consistent with other positions of the negative electrode tab, making it easier to retain the electrolyte, obtaining a better electrolyte infiltration effect, and reducing the risk of lithium plating.

[0160] In Figure 13 , in the first direction a, the foremost ends of the extending portions of the positive active material film layer 12 at the plurality of positive electrode tabs 20 are all located on the front side of the first side edge 16. For the preparation method of forming the positive electrode tab by die-cutting, the first side edge 16 is equivalent to the die-cut edge of the positive electrode tab 10A, and the foremost end of the extending portion of the positive active material film layer 12 on the positive electrode tab 20 is defined as the positive coating edge 121.

[0161] If the opposite side of the first side 16 in the opposite direction of the first direction a is used as a reference, the height of the positive electrode coating film edge 121 is greater than the die-cut edge of the positive electrode plate 10A. In this way, when die-cutting, the part of the positive electrode plate that is outside the positive electrode tab and lower than the positive electrode coating film edge 121 by a certain height can be cut off, so as to cut off the part of the positive electrode plate corresponding to the thinned part of the edge of the positive electrode active material film layer, which can reduce the possible electrolyte deficiency problem in this part and reduce the risk of local lithium deposition.

[0162] In Figure 13 it, in the first direction a, the first side 16 is located behind the second side 17. For the preparation method of forming the positive electrode tab and the negative electrode tab by die-cutting, the first side 16 is equivalent to the die-cut edge of the positive electrode plate 10A, and the second side 17 is equivalent to the die-cut edge of the negative electrode plate 10B. If the opposite side of the first side 16 in the opposite direction of the first direction a is used as a reference, the height of the die-cut edge of the positive electrode plate is less than the height of the die-cut edge of the negative electrode plate. In this way, when the negative electrode tab is flattened, if the ear fold inserts in the direction of the electrode plate, the negative electrode plate will first overlap with the insulating coating on the negative electrode plate, and it is not easy to first overlap with the positive electrode active material film layer on the positive electrode plate, thereby reducing the short-circuit risk.

[0163] In Figure 13 it, in the first direction a, the front end of the extension part of the positive electrode active material film layer 12 on the plurality of positive electrode tabs 20 is located behind the front end of the extension part of the insulating film layer 15 on the plurality of negative electrode tabs 30. The front end of the extension part of the positive electrode active material film layer 12 on the positive electrode tab 20 is defined as the positive electrode coating film edge 121, and the front end of the extension part of the insulating film layer 15 on the negative electrode tab 30 is defined as the insulating film layer coating film edge 151.

[0164] If the opposite side of the first side 16 in the opposite direction of the first direction a is used as a reference, the height of the positive electrode coating film edge 121 is less than the height of the insulating film layer coating film edge 151. In this way, when the end of the electrode assembly is pressed, the insulating layer will be pressed first before the positive electrode active material film layer, which can reduce the risk of decarbonization of the positive electrode active material film layer during pressing, thereby causing a short circuit.

[0165] In some embodiments, at least one positive electrode tab 20 among the plurality of positive electrode tabs 20 has at least one first notch 22 on a side edge away from the positive electrode plate 10A. The at least one first notch 22 divides the positive electrode tab 20 into a plurality of positive electrode tab segments 21 along the winding direction r. The root 23 of the at least one first notch 22 is located on the front side of the separator 10C in the first direction. At least one negative electrode tab 30 among the plurality of negative electrode tabs 30 has at least one second notch 32 on a side edge away from the negative electrode plate 10B. The at least one second notch 32 divides the negative electrode tab 30 into a plurality of negative electrode tab segments 31 along the winding direction r. The root 33 of the at least one second notch 32 is located on the front side of the separator 10C in the first direction.

[0166] If the opposite side edge of the first side edge in the opposite direction of the first direction is used as a reference, the heights of the root of the first notch and the root of the second notch are greater than the height of the separator. Since the roots of the first notch and the second notch are usually the positions where the tab segments are bent and flattened, when the tab segments are flattened and welded to the current collector plate, the tab segments heated during welding can maintain a certain distance from the separator, thereby reducing the possibility of the separator being scalded during welding, and further preventing short circuits caused by the separator being scalded.

[0167] Figure 14 Schematic structural diagram according to still other embodiments of the electrode assembly of the present disclosure. Refer to Figure 14 , in some embodiments, the electrode assembly further includes: a positive current collector plate 51 and a negative current collector plate 52. The positive current collector plate 51 is located on a side of the plurality of positive electrode tabs 20 away from the main body portion 100 and is fixedly connected to the plurality of flattened positive electrode tabs 20 by welding. The negative current collector plate 52 is located on a side of the plurality of negative electrode tabs 30 away from the main body portion 100 and is fixedly connected to the plurality of flattened negative electrode tabs 30 by welding. In Figure 14 , the positive current collector plate 51 can be electrically connected to any one of the first electrode terminal 53 and the second electrode terminal 54, and the negative current collector plate 52 can be electrically connected to the other one of the first electrode terminal 53 and the second electrode terminal 54.

[0168] Refer to 13 and Figure 14 , the plurality of positive electrode tabs 20 are bent and flattened at the end center of the root 23 of the at least one first notch 22 toward the main body portion 100, and the plurality of negative electrode tabs 30 are bent and flattened at the end center of the root 33 of the at least one second notch 32 toward the main body portion 100.

[0169] The root 23 of the at least one first notch 22 and the separator 10C (i.e., the third side 18 of the separator 10C) have a first distance d1 in the first direction a that is greater than or equal to 1.5 times the thickness t1 of the positive current collector plate 51, i.e., d1≥1.5*t1. The root 33 of the at least one second notch 32 and the separator 10C (i.e., the third side 18 of the separator 10C) have a second distance d2 in the first direction a that is greater than or equal to 1.5 times the thickness t2 of the negative current collector plate 52, i.e., d2≥1.5*t2.

[0170] Since the thickness of the current collector plate is related to the heat during welding, the thicker the current collector plate, the higher the heat during welding. Correspondingly, making the first distance between the root of the first notch and the separator in the first direction greater than 1.5 times the thickness of the positive current collector plate, and making the second distance between the root of the second notch and the separator in the first direction greater than 1.5 times the thickness of the negative current collector plate can effectively reduce the possibility of the separator being scalded when welding the current collector plate, thereby preventing short circuits caused by the separator being scalded.

[0171] In some embodiments, the roots of the first notches 22 between adjacent positive tab segments 21 and the roots of the second notches 32 between adjacent negative tab segments 31 are located in the same plane perpendicular to the first direction. If the opposite side of the first side 16 in the opposite direction of the first direction a is used as a reference, by setting the roots 23 of the first notches 22 and the roots 33 of the second notches 32 at the same height, the positive and negative tabs can be made to be as close as possible in the same plane when welded after being smoothed, thus ensuring that welding is not prone to occur with poor welding.

[0172] Figure 15 It is a schematic diagram of the arrangement of the positive electrode plate, negative electrode plate, separator, and insulating member in some embodiments of the electrode assembly according to the present disclosure. Figure 15 The arrangement position of the insulating member 40 relative to the unfolded positive electrode plate 10A, negative electrode plate 10B, and separator 10C is schematically drawn. It can be seen that the insulating member 40 is located between the positive tab 20 and the negative tab 30, and in the first direction a, the distance between the root 23 of the at least one first notch 22 and the second side 17 is the third distance d3, and the distance between the root 33 of the at least one second notch 32 and the second side 17 is the fourth distance d4.

[0173] In the first direction a, the insulating member 40 is located on the front side of the second side edge 17, and the distance between the foremost end 42 of the insulating member 40 and the second side edge 17 is the fifth distance d5. The distance between the foremost end of the extended portion of the plurality of positive electrode tabs 20 (i.e., the positive electrode coating edge 121) of the positive electrode active material film layer 12 and the second side edge 17 is the sixth distance d6. The third distance d3, the fourth distance d4, the fifth distance d5, and the sixth distance d6 satisfy: d5 < d6, d3 < d5, d4 < d5.

[0174] In the first direction, the roots of the first notch and the second notch are more forward than the insulating member. In this way, when welding the current collector plate, the current collector plate will first contact and weld with the flattened tabs, thus effectively avoiding the phenomenon of false soldering. In addition, the foremost end of the insulating member in the first direction is more forward than the foremost end of the positive electrode active material film layer at the positive electrode tab. In this way, when the electrode assembly is pressed, the insulating member will be pressed before the positive electrode active material film layer, thereby reducing the risk of decarburization of the positive electrode active material film layer during pressing, which may cause a short circuit.

[0175] Figure 16 is a schematic flowchart of some embodiments of the manufacturing method of the electrode assembly according to the present disclosure. The foregoing embodiments of the electrode assembly can be obtained by Figure 16 the manufacturing method shown. Refer to Figure 16 , in some embodiments, the manufacturing method of the electrode assembly includes: step S1, step S2, step S3, and step S4. In step S1, a separator 10C, a positive electrode tab 10A connected with a positive electrode full tab, and a negative electrode tab 10B connected with a negative electrode full tab are provided. The positive electrode tab 10A and the negative electrode tab 10B can be obtained by processes such as pulping, coating, rolling, and slitting.

[0176] In step S2, the positive electrode full tab is die-cut into a plurality of positive electrode tabs 20 arranged at intervals along the length direction of the positive electrode tab 10A, and the negative electrode full tab is die-cut into a plurality of negative electrode tabs 30 arranged at intervals along the length direction of the negative electrode tab 10B. The die-cutting of the positive electrode full tab and the negative electrode full tab can be performed by a tab die-cutting device.

[0177] When die-cutting the positive electrode full tab and the negative electrode full tab, the length b1 of the positive electrode tab 20 respectively connected to each positive electrode tab winding layer of the main body portion 100 in the winding direction r increases along the winding direction r, and the length b2 of the negative electrode tab 30 respectively connected to each negative electrode tab winding layer of the main body portion 100 in the winding direction r increases along the winding direction r.

[0178] In step S3, the positive electrode tab 10A, the separator 10C, and the negative electrode tab 10B are wound into the main body 100 of the electrode assembly, and the plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30 are located at the same side end of the main body 100 in a direction perpendicular to the winding direction r of the main body 100. During winding, the positive electrode tabs 20 and the negative electrode tabs 30 are staggered from each other so that they are respectively located in different regions at the end of the main body 100.

[0179] In step S4, the plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30 are bent and flattened so that the plurality of positive electrode tabs 20 overlap each other and the plurality of negative electrode tabs 30 overlap each other.

[0180] In this embodiment, a plurality of positive electrode tabs formed on the positive electrode tab and a plurality of negative electrode tabs formed on the negative electrode tab are arranged on the same side of the winding structure through a die-cutting process. In this way, the current collector plates corresponding to the positive electrode tabs and the current collector plates corresponding to the negative electrode tabs can respectively collect current and output it from the same side. Compared with the structure in the related art where the electrode tabs extend from both ends of the winding structure, this embodiment can shorten the electron path from the electrode tab to the pole column, so that the electrode tabs do not need to guide the current through the housing, eliminating the adverse effects of the housing resistance on the internal resistance of the battery and the adverse effects of the housing heat generation on the internal heat dissipation of the battery, thereby reducing the internal resistance of the battery, improving the heat dissipation of the battery, and enhancing the battery power and fast charging ability.

[0181] By making the lengths of the positive electrode tabs and the negative electrode tabs connected to each layer of the electrode tab winding layer increase along the winding direction, it can be ensured that after the electrode tabs are wound, each positive electrode tab can overlap and approach each other inward according to the curvature of the corresponding electrode tab winding layer when being bent and flattened, and each negative electrode tab can overlap and approach each other inward according to the curvature of the corresponding electrode tab winding layer when being bent and flattened, so as to respectively form a neater positive electrode tab group and a negative electrode tab group, which is convenient for separating the positive and negative electrodes and is beneficial to subsequent electrode tab welding. Moreover, the separated positive electrode tabs and the separated negative electrode tabs are not likely to generate wrinkles when being bent and flattened, thereby reducing the risk of short circuit caused by electrode tab breakage or wrinkles being inserted into the electrode tab.

[0182] Reference Figure 16 , in some embodiments, the manufacturing method further includes: step S5. Step S5 can be executed after step S4. In step S5, the positive current collector plate 51 is welded to the plurality of positive electrode tabs 20 that have been flattened, and the negative current collector plate 52 is welded to the plurality of negative electrode tabs 30 that have been flattened. By welding the positive current collector plate and the negative current collector plate to the plurality of flattened positive electrode tabs and the plurality of flattened negative electrode tabs respectively, an electrode assembly structure with a positive current collector plate and a negative current collector plate on the same side of the main body can be obtained.

[0183] In the above embodiments, the manufacturing method further includes: fixing an insulating member 40 between the plurality of positive electrode tabs 20 and the plurality of negative electrode tabs 30, so that the tab group formed by overlapping the plurality of positive electrode tabs 20 and the tab group formed by overlapping the plurality of negative electrode tabs 30 are isolated by the insulating member 40. In this embodiment, by providing an insulating member between the plurality of positive electrode tabs and the plurality of negative electrode tabs on the same side of the main body portion, effective separation between the two can be achieved, further reducing the risk of short circuit. The step of providing the insulating member can be performed before step S4 to prevent the flattened positive electrode sheet and the flattened negative electrode sheet from contacting each other and causing a short circuit.

[0184] In some embodiments, during the process of die-cutting the plurality of positive electrode tabs 20, at least one first notch 22 is die-cut on the side of at least one positive electrode tab 20 away from the positive electrode sheet 10A, so as to divide the positive electrode tab 20 into a plurality of positive electrode tab segments 21 along the winding direction r through the at least one first notch 22. Obtaining the divided plurality of positive electrode tab segments by die-cutting the side of the positive electrode tab can make the positive electrode tab not easily wrinkle during flattening, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part inserting between the electrode sheets.

[0185] In some embodiments, during the process of die-cutting the plurality of negative electrode tabs 30, at least one second notch 32 is die-cut on the side of at least one negative electrode tab 30 away from the negative electrode sheet 10B, so as to divide the negative electrode tab 30 into a plurality of negative electrode tab segments 31 along the winding direction r through the at least one second notch 32. Obtaining the divided plurality of negative electrode tab segments by die-cutting the side of the negative electrode tab can make the negative electrode tab not easily wrinkle during flattening, reducing the risk of tab breakage caused by wrinkles and the risk of short circuit caused by the wrinkled part inserting between the electrode sheets.

[0186] Based on the various embodiments of the above electrode assembly of the present disclosure, embodiments of the present disclosure further provide a battery cell, including the aforementioned electrode assembly. The battery cell adopting the aforementioned electrode assembly has better performance, such as lower internal resistance, better heat dissipation, and better cycling performance, etc.

[0187] In one aspect of the present disclosure, there is provided a battery, including the aforementioned battery cell. The battery adopting the aforementioned battery cell has better performance, such as lower internal resistance, better heat dissipation, and better cycling performance, etc.

[0188] In one aspect of the present disclosure, there is provided an electrical device, including the aforementioned battery. The electrical device adopting the aforementioned battery has better performance.

[0189] Although the present disclosure has been described with reference to preferred embodiments, various modifications can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any manner. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electrode assembly, characterized in that, Comprising: A main body part (100), including a positive electrode tab (10A), a negative electrode tab (10B), and a separator (10C) disposed between the positive electrode tab (10A) and the negative electrode tab (10B), wherein the positive electrode tab (10A), the separator (10C), and the negative electrode tab (10B) are wound into a wound structure along a winding direction (r); A plurality of positive electrode tabs (20), respectively connected to at least two positive electrode tab winding layers in the wound structure, and spaced apart along the winding direction (r), at least one of the plurality of positive electrode tabs (20) having at least one first notch (22) on a side away from the positive electrode tab (10A), the at least one first notch (22) separating the positive electrode tab (20) into a plurality of positive electrode tab segments (21) along the winding direction (r); A plurality of negative electrode tabs (30), respectively connected to at least two negative electrode tab winding layers in the wound structure, and spaced apart along the winding direction (r), at least one of the plurality of negative electrode tabs (30) having at least one second notch (32) on a side away from the negative electrode tab (10B), the at least one second notch (32) separating the negative electrode tab (30) into a plurality of negative electrode tab segments (31) along the winding direction (r); wherein, the plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30) are located at the same side end of the main body part (100) in a direction perpendicular to the winding direction (r), the length of the positive electrode tab (20) connected to each positive electrode tab winding layer in the winding direction (r) increases along the winding direction (r), and the length of the negative electrode tab (30) connected to each negative electrode tab winding layer in the winding direction (r) increases along the winding direction (r); The electrode assembly further comprises: A positive current collector plate (51), located on a side of the plurality of positive electrode tabs (20) away from the main body part (100), and fixedly connected to the plurality of flattened positive electrode tabs (20) by welding; A negative current collector plate (52), located on a side of the plurality of negative electrode tabs (30) away from the main body part (100), and fixedly connected to the plurality of flattened negative electrode tabs (30) by welding; Among them, the plurality of positive electrode tabs (20) are bent and flattened towards the end center of the main body portion (100) at the root of the at least one first notch (22), and the plurality of negative electrode tabs (30) are bent and flattened towards the end center of the main body portion (100) at the root of the at least one second notch (32). The first distance d1 between the root of the at least one first notch (22) and the separator (10C) in the first direction is greater than or equal to 1.5 times the thickness t1 of the positive current collector plate (51). The second distance d2 between the root of the at least one second notch (32) and the separator (10C) in the first direction is greater than or equal to 1.5 times the thickness t2 of the negative current collector plate (52). The first direction is the extending direction of the plurality of positive electrode tabs (20) relative to the positive electrode plate (10A) or the extending direction of the plurality of negative electrode tabs (30) relative to the negative electrode plate (10B), and the first direction is perpendicular to the winding direction (r).

2. The electrode assembly according to claim 1, characterized in that, The winding structure is a cylindrical winding structure wound around a winding axis (ax).

3. The electrode assembly according to claim 2, characterized in that, The angular range of the plurality of positive electrode tabs (20) at the end of the main body portion (100) relative to the winding axis (ax) does not overlap with the angular range of the plurality of negative electrode tabs (30) at the end of the main body portion (100) relative to the winding axis (ax).

4. The electrode assembly according to claim 1, wherein The widths of the respective positive electrode tab segments (21) in the winding direction (r) are the same, and the number of positive electrode tab segments (21) in the positive electrode tabs (20) respectively connected to the respective positive electrode plate winding layers increases along the winding direction (r). The widths of the respective negative electrode tab segments (31) in the winding direction (r) are the same, and the number of negative electrode tab segments (31) in the negative electrode tabs (30) respectively connected to the respective negative electrode plate winding layers increases along the winding direction (r).

5. The electrode assembly according to claim 1, wherein The plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30) satisfy at least one of the following: The end positions of the positive electrode tabs (20) respectively connected to the respective positive electrode plate winding layers that are located most upstream in the winding direction (r) are all in the same plane; The end positions of the positive electrode tabs (20) respectively connected to the respective positive electrode plate winding layers that are located most downstream in the winding direction (r) are all in the same plane; The end positions of the negative electrode tabs (30) respectively connected to the respective negative electrode plate winding layers that are located most upstream in the winding direction (r) are all in the same plane; The end positions of the negative electrode tabs (30) respectively connected to the respective negative electrode plate winding layers that are located most downstream in the winding direction (r) are all in the same plane.

6. The electrode assembly according to claim 5, characterized in that The end positions of the positive electrode tabs (20) respectively connected to the respective positive electrode plate winding layers that are located most upstream and most downstream in the winding direction (r) are all in the same plane; and / or The end positions of the negative electrode tabs (30) respectively connected to the respective negative electrode plate winding layers that are located most upstream and most downstream in the winding direction (r) are all in the same plane.

7. The electrode assembly according to claim 5, characterized in that, The end positions of the positive electrode tabs (20) respectively connected to the respective positive electrode sheet winding layers, which are the most upstream in the winding direction (r), and the end positions of the negative electrode tabs (30) respectively connected to the respective negative electrode sheet winding layers, which are the most upstream in the winding direction (r), are all located in the same plane; The end positions of the positive electrode tabs (20) respectively connected to the respective positive electrode sheet winding layers, which are the most downstream in the winding direction (r), and the end positions of the negative electrode tabs (30) respectively connected to the respective negative electrode sheet winding layers, which are the most downstream in the winding direction (r), are all located in the same plane.

8. The electrode assembly according to claim 1, characterized in that, The winding structure is a cylindrical winding structure wound around a winding axis (ax), and the plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30) are symmetric with respect to the winding axis (ax), or symmetric with respect to a plane passing through the winding axis (ax).

9. The electrode assembly according to claim 1, characterized in that, It further includes: An insulating member (40), which is provided at an end of the main body portion (100) on the side connecting the plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30), and is located between the plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30).

10. The electrode assembly according to claim 9, characterized in that, The insulating member (40) includes an insulating plastic block.

11. The electrode assembly according to claim 9, wherein, The winding structure is a cylindrical winding structure wound around a winding axis (ax), the cylindrical winding structure has a first central hole (110) penetrating axially, and the insulating member (40) has a second central hole (41) communicating with the first central hole (110) along the winding axis (ax).

12. The electrode assembly according to claim 11, wherein, Both the first central hole (110) and the second central hole (41) are circular holes, and the diameter D1 of the first central hole (110) is greater than or equal to the diameter D2 of the second central hole (41).

13. The electrode assembly according to claim 1, wherein, The positive electrode sheet (10A) includes a positive electrode current collector (11) and a positive electrode active material film layer (12) covering the surface of the positive electrode current collector (11), the plurality of positive electrode tabs (20) are connected to a first side edge (16) of the positive electrode current collector (11) extending along the winding direction (r), the negative electrode sheet (10B) includes a negative electrode current collector (13) and a negative electrode active material film layer (14) covering the surface of the negative electrode current collector (13), and the plurality of negative electrode tabs (30) are connected to a second side edge (17) of the negative electrode current collector (13) extending along the winding direction (r).

14. The electrode assembly according to claim 13, characterized in that, The root of the at least one first notch (22) is located on the front side of the separator (10C) in the first direction; The root of the at least one second notch (32) is located on the front side of the separator (10C) in the first direction.

15. The electrode assembly according to claim 14, wherein, The roots of the first notches (22) between adjacent positive electrode tab segments (21) and the roots of the second notches (32) between adjacent negative electrode tab segments (31) are located in the same plane perpendicular to the first direction.

16. The electrode assembly according to claim 1, wherein The number of positive electrode tab segments (21) in the positive electrode tabs (20) respectively connected to the respective positive electrode sheet winding layers continuously increases or increases in stages along the winding direction (r); and / or The number of negative electrode tab segments (31) in the negative electrode tabs (30) respectively connected to the respective negative electrode tab winding layers continuously increases or increases in stages along the winding direction (r).

17. The electrode assembly according to claim 1, wherein, One first notch (22) of one of the two positive electrode tabs (20) respectively connected to adjacent positive electrode tab winding layers is disposed radially opposite to the positive electrode tab segment (21) of the other positive electrode tab (20) or is disposed radially opposite to the first notch (22) of the other positive electrode tab (20); and / or One second notch (32) of one of the two negative electrode tabs (30) respectively connected to adjacent negative electrode tab winding layers is disposed radially opposite to the negative electrode tab segment (31) of the other negative electrode tab (30) or is disposed radially opposite to the second notch (32) of the other negative electrode tab (30).

18. A battery cell, characterized in that, Comprising: The electrode assembly according to any one of claims 1-17.

19. A battery, characterized in that, Comprising the battery cell according to claim 18.

20. An electrical device, characterized in that, Comprising the battery according to claim 19.

21. A manufacturing method of an electrode assembly, characterized in that, Comprising: Providing a separator (10C), a positive electrode tab (10A) connected with a positive electrode full tab, and a negative electrode tab (10B) connected with a negative electrode full tab; Die-cutting the positive electrode full tab into a plurality of positive electrode tabs (20) arranged at intervals along the length direction of the positive electrode tab (10A), and die-cutting the negative electrode full tab into a plurality of negative electrode tabs (30) arranged at intervals along the length direction of the negative electrode tab (10B); Winding the positive electrode tab (10A), the separator (10C) and the negative electrode tab (10B) into a main body portion (100) of the electrode assembly, and making the plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30) located at the same side end portion of the main body portion (100) in a direction perpendicular to the winding direction (r) of the main body portion (100); Bending and flattening the plurality of positive electrode tabs (20) and the plurality of negative electrode tabs (30); Wherein, when die-cutting the positive electrode full tab and the negative electrode full tab, the length of the positive electrode tab (20) respectively connected to each positive electrode tab winding layer of the main body portion (100) increases along the winding direction (r), and the length of the negative electrode tab (30) respectively connected to each negative electrode tab winding layer of the main body portion (100) increases along the winding direction (r); Wherein, in the process of die-cutting the plurality of positive electrode tabs (20), at least one side edge of at least one positive electrode tab (20) on the side away from the positive electrode tab (10A) is die-cut to form at least one first notch (22), so as to divide the positive electrode tab (20) into a plurality of positive electrode tab segments (21) along the winding direction (r) through the at least one first notch (22); During the die-cutting of the multiple negative electrode tabs (30), at least one second notch (32) is die-cut on the side of at least one negative electrode tab (30) away from the negative electrode plate (10B), so as to divide the negative electrode tab (30) into multiple negative electrode tab segments (31) along the winding direction (r) through the at least one second notch (32); The manufacturing method further includes: Welding the positive current collector plate (51) to the smoothed multiple positive electrode tabs (20), and welding the negative current collector plate (52) to the smoothed multiple negative electrode tabs (30); Wherein, the first distance d1 between the root of the at least one first notch (22) and the separator (10C) in the first direction is greater than or equal to 1.5 times the thickness t1 of the positive current collector plate (51), the second distance d2 between the root of the at least one second notch (32) and the separator (10C) in the first direction is greater than or equal to 1.5 times the thickness t2 of the negative current collector plate (52), the first direction is the extending direction of the multiple positive electrode tabs (20) relative to the positive electrode plate (10A) or the extending direction of the multiple negative electrode tabs (30) relative to the negative electrode plate (10B), and the first direction is perpendicular to the winding direction (r).

22. The manufacturing method according to claim 21, wherein, It further includes: Fixing an insulating member (40) between the multiple positive electrode tabs (20) and the multiple negative electrode tabs (30), so that the ear group formed by the overlapping of the multiple positive electrode tabs (20) and the ear group formed by the overlapping of the multiple negative electrode tabs (30) are isolated by the insulating member (40).

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