Electrode assembly and manufacturing method thereof, battery cell, battery device, and electric device

Abstract

The invention relates to the technical field of batteries, and particularly discloses an electrode assembly and a manufacturing method thereof, a battery monomer, a battery device and a power utilization device.The manufacturing method comprises the steps that in the die cutting procedure of a first pole piece, a notch is cut in the side edge of the first pole piece at the downstream of each first tab group; the notch is provided with a first end and a second end positioned at the downstream of the first end along the conveying direction of the first pole piece; in the winding process, the first pole piece is closer to the winding axis than the second pole piece with the opposite polarity, and the second end of each notch in the first pole piece is cut off, so that the second end of each notch serves as the winding starting end of the first pole piece of the next electrode assembly to be wound. By adopting the manufacturing method provided by the invention, the possibility that the innermost ring of the electrode assembly is brought out by the winding part to be in contact with the second tab during needle withdrawing is reduced, and the adverse effect of needle withdrawing action on the quality of the electrode assembly is further reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to an electrode assembly and its manufacturing method, a battery cell, a battery device, and an electrical device. Background Technology

[0002] Electrode assemblies are the components in a battery cell where electrochemical reactions occur. They are mainly divided into wound electrode assemblies and stacked electrode assemblies. Among them, wound electrode assemblies are formed by winding anode plates, separators, and cathode plates in layers around a winding component. When the wound electrode assembly is unloaded, a problem of poor needle removal can easily occur. That is, when the winding component is pulled out from the center of the electrode assembly, the innermost ring of the electrode assembly is easily pulled out, which affects the quality of the electrode assembly and reduces the safety performance of the battery. Summary of the Invention

[0003] In view of the above problems, this application provides an electrode assembly and its manufacturing method, a battery cell, a battery device and an electrical device, to reduce the adverse effects of the pin-pulling action on the quality of the electrode assembly, thereby improving the safety performance of the battery.

[0004] The first aspect of this application discloses a method for manufacturing an electrode assembly, comprising:

[0005] The first electrode sheet is die-cut. In the die-cutting process of the first electrode sheet, a first electrode ear group is cut out from the side of the first electrode sheet or multiple first electrode ear groups are cut out at intervals along the length direction of the first electrode sheet. And along the conveying direction of the first electrode sheet, downstream of each first electrode ear group, a notch is cut out from the side edge of the first electrode sheet. The notch is located on the same side of the first electrode sheet as the first electrode ear group. The first electrode ear group includes a first electrode ear or multiple first electrode ear groups at intervals along the length direction of the first electrode sheet. The notch has a first end and a second end downstream of the first end along the conveying direction of the first electrode sheet.

[0006] The first electrode, the separator, and the second electrode are wound around the winding axis. The first electrode is closer to the winding axis than the second electrode. During the winding process, the second end of each notch on the first electrode is cut off, so that the second end of each notch serves as the winding end of the first electrode of the already wound electrode assembly and the winding start end of the first electrode of the next electrode assembly to be wound. The polarities of the first electrode and the second electrode are opposite.

[0007] The electrode assembly manufacturing method of this embodiment involves cutting a notch on the same side of the first tab on the first electrode sheet during the die-cutting process. The notch has a first end and a second end downstream of the first end along the conveying direction of the first electrode sheet. Then, during the winding process, the first electrode sheet is cut along the second end of the notch, and the first electrode sheet is closer to the winding axis than the second electrode sheet. This results in the innermost ring of the electrode assembly manufactured by the electrode assembly manufacturing method of this embodiment being the first electrode sheet, and the width of the winding start end of the first electrode sheet is reduced. In this way, when the winding member is pulled out from the center of the wound electrode assembly for unloading, the portion of the innermost ring of the electrode assembly carried out by the winding member is reduced. Even if the winding start end of the first electrode sheet is close to the second tab of the second electrode sheet, the possibility of the innermost ring of the electrode assembly being carried out and contacting the second tab, thereby causing a short circuit in the battery, is reduced. This reduces the adverse impact of the pin-pulling action on the quality of the electrode assembly and is beneficial to improving battery safety.

[0008] In some embodiments of this application, the method of manufacturing the electrode assembly further includes: in the die-cutting process of the first electrode sheet, upstream of each first electrode tab group, a positioning hole is also cut out on the side of the first electrode sheet, the positioning hole being located on the same side of the first electrode sheet as the first electrode tab group.

[0009] The target image of the first electrode is acquired downstream of the cutting station of the first electrode.

[0010] After the positioning hole is identified based on the target image, a notch is cut out on the side of the first electrode at a preset distance downstream of the first electrode lug and from the positioning hole, along the conveying direction of the first electrode.

[0011] With this setup, in the die-cutting process of the first electrode, by cutting out a positioning hole upstream of the first electrode lug, and then by identifying the positioning hole, it is easier to determine the cutting point of the notch at a preset distance from the positioning hole, which is also beneficial to accurately find the cutting position of the notch on the first electrode.

[0012] In some embodiments of this application, the method for manufacturing the electrode assembly further includes: after identifying the positioning hole based on the target image, counting the first electrode tab downstream of the target image acquisition station;

[0013] In response to the number of first electrodes reaching a preset value, a first electrode group is confirmed to be cut out.

[0014] This setup, after identifying the positioning hole, allows for the counting of the first electrode tabs that have already been die-cut, ensuring that the first electrode sheet is cut to form a notch only after the first electrode tab group has been cut, thus improving the accuracy of the die-cutting process.

[0015] In some embodiments of this application, the first electrode is an anode electrode and the second electrode is a cathode electrode. The manufacturing method of the electrode assembly in this embodiment is applicable to electrode assemblies where the innermost ring is an anode electrode. When the winding start end of the anode electrode is close to the cathode tab, the notch can correspond to the cathode tab when the electrode assembly is unloaded during the winding process, reducing the possibility of the inner ring of the anode electrode contacting the cathode tab and causing a short circuit in the battery.

[0016] The second aspect of this application provides an electrode assembly manufactured according to any of the electrode assembly manufacturing methods proposed in the first aspect of this application. The electrode assembly is a wound structure and includes: a first electrode, a second electrode, and a separator. The polarity of the first electrode and the polarity of the second electrode are opposite. The separator is disposed between the first electrode and the second electrode to isolate the first electrode and the second electrode. The first electrode has a first tab and a notch on the same side. The notch has a first end and a second end along the length direction of the first electrode. The second end is the winding start end of the first electrode and is located at the innermost side of the wound structure.

[0017] In some embodiments of this application, the dimension W2 of the second end along the width direction of the first electrode is greater than or equal to the dimension W1 of the first end along the width direction of the first electrode.

[0018] When the pin is pulled out, the winding component usually pulls out a corner of the innermost ring of the electrode assembly. Along the winding direction, the axial dimension of the pulled-out portion of the innermost ring gradually decreases from the starting end to the ending end of the winding. In this embodiment, by designing W2 ≥ W1, the dimension W2 of the second end of the notch along the width direction of the first electrode sheet is larger. This reduces the possibility that the starting end of the innermost ring (i.e., the first electrode sheet) of the wound electrode assembly will be pulled out and come into contact with the second electrode tab, thereby reducing the possibility of a battery short circuit leading to a safety accident.

[0019] In some embodiments of this application, the size of the notch gradually increases along the width direction of the first electrode from the first end to the second end. Thus, W2 is the maximum size of the notch along the width direction of the first electrode. Without changing other parameters and ensuring the notch corresponds to the second tab, the volume of the removed portion of the first electrode can be minimized, resulting in less removal of the active material layer of the first electrode, which is beneficial for achieving better quality of the electrode assembly.

[0020] In some embodiments of this application, the dimension of the notch along the length direction of the first electrode is greater than the dimension of the second end along the width direction of the first electrode, and the dimension of the first end along the width direction of the first electrode is 0 mm.

[0021] With all other parameters being equal, the volume of the portion of the first electrode to be removed is minimized as much as possible compared to the implementation scheme where W1 > 0 mm.

[0022] In some embodiments of this application, the dimension of the second end along the width direction of the first electrode is 2% to 4% of the width of the first electrode, and the dimension of the notch along the length direction of the first electrode is 10% to 20% of the width of the first electrode. In this way, the size of the notch is approximately matched with the size of the innermost ring of the electrode assembly without notch die-cut in the related art, which is carried out by the winding component, thereby minimizing the possibility of the innermost ring contacting the second electrode tab when the needle is pulled out.

[0023] In some embodiments of this application, the dimension of the notch along the length direction of the first electrode is greater than or equal to 5 mm and less than or equal to 100 mm; and / or, the dimension of the second end along the width direction of the first electrode is greater than or equal to 1 mm and less than or equal to 20 mm.

[0024] A third aspect of this application provides a battery cell comprising: a housing and any of the electrode assemblies provided in the second aspect of this application.

[0025] The fourth aspect of this application provides a battery device comprising any of the battery cells proposed in the third aspect of this application.

[0026] The fifth aspect of this application provides an electrical device comprising: any of the battery devices proposed in the fourth aspect of this application, the battery device being used to provide electrical energy.

[0027] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0028] Figure 1 A schematic flowchart illustrating a method for manufacturing an electrode assembly according to one embodiment of this application is shown.

[0029] Figure 2 A schematic diagram of a die-cutting machine is shown for the die-cutting process of a method for manufacturing an electrode assembly according to one embodiment of this application.

[0030] Figure 3 The diagram illustrates a die-cutting process in a method for manufacturing an electrode assembly according to one embodiment of this application.

[0031] Figure 4 A partial schematic diagram of a first electrode sheet in the form of a roll formed by a die-cutting process in a method for manufacturing an electrode assembly according to one embodiment of this application is shown.

[0032] Figure 5A schematic diagram of a winding machine is shown for the winding process of a method for manufacturing an electrode assembly according to one embodiment of this application.

[0033] Figure 6 A schematic diagram of the first electrode of an electrode assembly according to one embodiment of this application is shown.

[0034] Figure 7 A schematic diagram of an electrode assembly according to one embodiment of this application is shown.

[0035] Figure 8 This is a schematic diagram of a first electrode with various shaped notches according to at least one embodiment of this application;

[0036] Figure 9 An exploded view of a battery cell according to one embodiment of this application is shown schematically.

[0037] Figure 10 A schematic diagram of a battery device according to one embodiment of this application is shown;

[0038] Figure 11 A schematic diagram of an electrical device according to one embodiment of this application is shown.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1000, vehicles;

[0041] 100. Battery device;

[0042] 10. Battery cell assembly; 11. Battery cell; 12. Electrode assembly; 121. First electrode; 1211. First tab; 1212. Notch; 1213. Positioning hole; 122. Second electrode; 1221. Second tab; 123. Separator; 13. Housing;

[0043] 20. Box body; 21. First part; 22. Second part;

[0044] 200. Controller;

[0045] 300. Motor;

[0046] 2000. Die-cutting machine; 210. Unwinding mechanism; 220. Rewinding mechanism; 230. Cutting mechanism; 240. Image acquisition mechanism; 250. Overhead roller; 251. Encoder;

[0047] 3000, Winding machine; 310, Winding component; 320, Cutting mechanism; 330, Feeding mechanism; 340, Traction mechanism. Detailed Implementation

[0048] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0050] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0051] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0052] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0053] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0054] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0055] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0056] It is understood that the embodiments described herein may be combined with other embodiments.

[0057] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0058] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0059] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0060] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0061] The battery manufacturing process with wound electrode assemblies typically includes the following steps: Step 1, slurry preparation, which mainly involves mixing electrode active materials, binders, solvents, etc., and thoroughly stirring and dispersing them to form a slurry; Step 2, coating, which involves uniformly coating the slurry prepared in Step 1 onto the surface of the current collector to form an active material layer, and then drying it to form an electrode sheet; Step 3, rolling and slitting, which involves rolling and slitting the electrode sheet prepared in Step 2 to cut the wider current collector into multiple narrower current collectors; Step 4, die-cutting, which involves processing the electrode sheet prepared in Step 3... The produced electrode sheets are punched into specified sizes and shapes to die-cut tabs in the blank areas not covered by the active material layer; Step 5, winding process, the anode electrode sheet, separator, and cathode electrode sheet are stacked and wound in a certain order to form an electrode assembly; Step 6, assembly process, the electrode assembly produced in Step 5 is installed into the housing to form a battery cell without electrolyte; Step 7, electrolyte injection process, a specified amount of electrolyte is injected into the battery cell; Step 8, battery sealing process, the gas inside the battery cell is extracted in a vacuum environment and sealed.

[0062] It should be noted that in the coating, rolling, and die-cutting processes, corresponding material rolls are obtained through winding for use in the next process. In step 4, the anode sheet with the anode tabs and the cathode sheet with the cathode tabs die-cut are provided to the winding component in the form of material rolls to form an electrode assembly. The anode and cathode tabs can conduct current from the electrode assembly. Furthermore, depending on the arrangement of the anode sheet, the separator, and the cathode sheet, the winding component can sequentially wind in the anode sheet, separator, cathode sheet, and separator in one rotation, meaning the anode sheet enters the winding component first, and the innermost ring of the wound electrode assembly is the anode sheet. Alternatively, the winding component can sequentially wind in the cathode sheet, separator, anode sheet, and separator in one rotation, meaning the cathode sheet enters the winding component first, and the innermost ring of the wound electrode assembly is the cathode sheet. Alternatively, the winding component can be wound in sequence as follows: the separator, anode plate, separator, cathode plate, or the separator, cathode plate, separator, anode plate, with the separator entering the winding component first.

[0063] When the anode or cathode electrode enters the winding component first, the innermost ring of the wound electrode assembly is the electrode sheet. During unloading, the winding component easily pulls out the innermost ring of the electrode sheet as it is pulled from the center of the electrode assembly. In some related technologies, the starting end of the winding of the innermost anode electrode in the wound electrode assembly is close to the cathode tab of the cathode electrode. Thus, during needle removal, the portion of the anode electrode pulled out by the winding component can easily come into contact with the cathode tab. This can easily cause a short circuit in the battery containing this electrode assembly, potentially leading to a fire and resulting in low battery safety. For similar reasons, when the innermost ring of the wound electrode assembly is the cathode electrode, and the starting end of the winding of the cathode electrode is close to the anode tab of the anode electrode, the cathode electrode is easily pulled out by the winding component during needle removal and comes into contact with the anode tab of the anode electrode.

[0064] In this application, a notch is cut into the side of the first electrode sheet during the die-cutting process, with the notch on the same side as the first electrode tab. In the subsequent winding process, the first electrode sheet forms the innermost ring of the wound electrode assembly. Furthermore, during the winding process, the first electrode sheet is cut at the second end of the notch, making the second end of the notch the starting end of the winding of the innermost ring of the wound electrode assembly. That is, it is equivalent to cutting off the portion of the innermost ring of the electrode assembly (i.e., the first electrode sheet) that might otherwise be carried out by the winding component, creating a notch at the position that might otherwise be carried out by the winding component. This reduces the possibility that the starting end of the winding of the first electrode sheet might be carried out and come into contact with the second electrode tab, causing a short circuit, when the needle is pulled out.

[0065] In some embodiments of this application, such as Figure 1 As shown, this application proposes a method for manufacturing an electrode assembly, which includes the following steps.

[0066] S10, the first electrode 121 is die-cut. In the die-cutting process of the first electrode 121, a first electrode ear group is cut out from the side of the first electrode 121 or multiple first electrode ear groups are cut out in sequence along the length direction of the first electrode 121. Along the conveying direction of the first electrode 121, downstream of each first electrode ear group, a notch 1212 is cut out from the side edge of the first electrode 121. The notch 1212 is located on the same side of the first electrode ear group as the first electrode 121. The first electrode ear group includes a first electrode ear 1211 or multiple first electrode ear 1211 arranged at intervals along the length direction of the first electrode 121. The notch 1212 has a first end and a second end located downstream of the first end along the conveying direction of the first electrode 121.

[0067] S20, the first electrode 121, the separator 123, and the second electrode 122 are wound around the winding axis. The first electrode 121 is closer to the winding axis than the second electrode 122. In the winding process, the second end of each notch 1212 on the first electrode 121 is cut off, so that the second end of each notch 1212 serves as the winding end of the first electrode 121 of the already wound electrode assembly 12 and the winding start end of the first electrode 121 of the next electrode assembly 12 to be wound. The first electrode 121 and the second electrode 122 have opposite polarities.

[0068] Specifically, the die-cutting process of S10 can be performed by die-cutting machine 2000. Please refer to... Figure 2 The die-cutting machine 2000 involved in this application includes at least an unwinding mechanism 210, a cutting mechanism 230, and a winding mechanism 220 arranged sequentially along the conveying direction of the first electrode 121. The unwinding mechanism 210 is used to carry and release the first electrode 121 in the form of a roll. The cutting mechanism 230 is used to cut the first electrode 121, and the winding mechanism 220 is used to wind up the die-cut first electrode 121. The cutting mechanism 230 can be a cutter or a laser cutting head. The laser cutting head can emit a laser beam, which is projected onto the first electrode 121 along its thickness direction, causing the first electrode 121 to be heated and melted. As the laser beam moves, the first electrode 121 is cut. The following description uses a laser cutting head as an example of the cutting mechanism 230.

[0069] Taking a first electrode group with two electrodes as an example, please combine... Figure 3 The specific implementation process of S10 may include steps a to g. Among them, the laser beam in Figure 2 The arrow shown in the image is a thick dashed line, indicating the conveying direction of the first electrode 121 during the die-cutting process. Figure 2 and Figure 3 It is indicated by a solid line with a hollow arrow.

[0070] Step a, control the laser beam to move so as to cut a first side edge along the width direction of the first pole piece 121;

[0071] Step b: Control the laser beam to turn off, and the first electrode 121 moves along the conveying direction with a preset length;

[0072] Step c: Control the laser beam to move so as to cut a second side edge from the side edge of the first electrode 121 along the width direction; wherein the first side edge and the second side edge are two opposite sides of the first electrode tab 1211.

[0073] Step d: Control the laser beam to move from the root of the second side along the length of the first electrode 121 and move a distance equal to the distance between two adjacent first electrode tabs 1211.

[0074] Step e, return to step a, until a preset number of first electrode tabs 1211 are cut out, and the preset number of first electrode tabs form a first electrode tab group;

[0075] Step f: Control the laser beam to move so as to cut a notch 1212 on the side of the first electrode 121 along the width direction, and the notch 1212 has a first end and a second end along the conveying direction of the first electrode 121, with the second end located downstream of the first end.

[0076] Step g, return to step a, until two first electrode tabs and two notches 1212 are formed by cutting, resulting in the first electrode plate 121. Figure 4 As shown.

[0077] In S10, the die-cut first electrode sheet 121 is wound up along the winding direction r, wherein the first electrode tab 1211, which is die-cut first, is wound up first during the winding process. It can be understood that the first electrode sheet 121 has at least one first electrode tab group and at least one notch 1212 on its side along the width direction. The notch 1212 and the first electrode tab group are located on the same side of the first electrode sheet, and the first electrode tab group protrudes from the notch 1212. The notch 1212 is specifically located on the side edge of the electrode body of the first electrode sheet 121. The number K of the first electrode tab groups is equal to the number K of the notches 1212, where K is a positive integer. Along the conveying direction of the first electrode sheet 121 in the die-cutting process, each first electrode tab group has a notch 1212 downstream. When the number of first electrode tab groups is greater than or equal to 2, there is a notch 1212 between any two adjacent first electrode tab groups.

[0078] Taking the number of first electrode groups as one as an example, the specific implementation process of S10 may include the above steps a to f.

[0079] It is understood that the first electrode sheet 121 in the form of a roll obtained in S10 is cut into K first electrode sheets 121 in S20 for the production of K electrode assemblies 12. Specifically, when K≥2, the portion of the first electrode sheet 121 in the form of a roll located between the second ends of two adjacent notches 1212 (i.e., located at...) Figure 4 The portion between the cut lines (shown by the thick dashed line) is the first electrode 121 of an electrode assembly 12.

[0080] The opposite polarity of the first electrode 121 and the second electrode 122 means that one of the first electrode 121 and the second electrode 122 is the anode electrode and the other is the cathode electrode.

[0081] Specifically, the winding process of S20 can be achieved using a winding machine 3000. Please refer to... Figure 5The winding machine 3000 involved in this application includes at least four feeding mechanisms 330, a winding component 310, a cutting mechanism 320, and a traction mechanism 340. The four feeding mechanisms 330 are disposed on the material receiving side of the winding component 310, and are respectively used to provide the winding component 310 with a first electrode 121, a separator 123, a second electrode 122, and a separator 123. The first electrode 121 is closer to the winding axis than the second electrode 122, so when the winding component 310 rotates one revolution, the first electrode 121 enters the winding component 310 before the second electrode 122. After the winding component 310 rotates a preset number of revolutions to obtain the wound electrode assembly 12, the cutting mechanism 320 cuts the first electrode 121 along its width direction at the second end of each notch 1212. The cutting line can be referenced... Figure 4 The thick dashed lines shown indicate that the first electrode sheet is cut. It can be seen that the portion between the second ends of every two adjacent notches 1212 on the first electrode sheet 121 in the form of a roll constitutes a first electrode sheet 121 of a wound electrode assembly 12. Each first electrode sheet 121 has a first tab group and a notch 1212, as shown... Figure 6 As shown, each first electrode 121, the separator 123, and the second electrode 122 are stacked and wound together to form an electrode assembly 12, as shown. Figure 7 As shown. The unwinding direction of the first electrode 121 in roll form during S20 (in...) Figure 4 (shown as a hollow arrow in dashed line) The second end of each notch 1212 is opposite to the winding direction r of the first electrode 121 in S10. Therefore, the second end of each notch 1212 is delivered to the winding member 310 before the first end, such that the second end of the notch 1212 is the winding end of the first electrode 121 of the already wound electrode assembly 12 and the winding start end of the first electrode 121 of the next electrode assembly 12 to be wound.

[0082] The specific process of S20 may include steps i to iv. Step i: The winding component 310 rotates a preset number of times to form the electrode assembly 12. Step ii: The cutting structure cuts the first electrode sheet, the separator 123, and the second electrode sheet 122, with the cut position of the first electrode sheet 121 (in roll form) being the second end of the notch 1212. Step iii: The unloading robot grips the wound electrode assembly 12, the winding component 310 retracts axially to be pulled out from the center of the electrode assembly 12, and the unloading robot then transfers the wound electrode assembly 12 to the next process. Step iv: The traction mechanism 340 pulls the cut-off winding start end of the first electrode sheet 121 and the second electrode sheet 122 back to the winding component 310, returning to step i for the next winding cycle. In step i, as the winding component 310 rotates, the predetermined number of first electrodes 1211 in the first electrode group are stacked sequentially until the electrode assembly 12 is wound into shape. The traction mechanism 340 can pull the winding start end to the winding component 310 by clamping or by vacuum adsorption.

[0083] In general, each electrode assembly 12 has a first electrode tab 121 with a first tab group and a notch 1212. In S10, the first tab group is cut and formed first and is wound up first. In S20, the second end of the notch 1212 enters the winding member 310 first. Combined with the fact that the first electrode tab 121 is closer to the winding axis than the second electrode tab 122, the innermost circle of the wound electrode assembly 12 is the first electrode tab 121, and the second end of the notch 1212 on the first electrode tab 121 is the winding start end.

[0084] Therefore, in the manufacturing method of the electrode assembly 12 of this embodiment, a notch 1212 is cut on the same side of the first tab 1211 on the electrode body of the first electrode 121 in the die-cutting process, and the first electrode 121 is cut off along the second end of the notch 1212 in the winding process. The first electrode 121 is closer to the winding axis than the second electrode 122, so that the innermost ring of the electrode assembly 12 manufactured by the manufacturing method of the electrode assembly 12 of this embodiment is the first electrode 121, and a portion of the winding start end of the first electrode 121 is cut off. In this way, when the winding component 310 is pulled out from the center of the wound electrode assembly 12 for unloading, the portion of the innermost ring of the electrode assembly 12 that is carried out by the winding component 310 is reduced. At this time, even if the winding start end of the first electrode 121 is close to the second tab 1221 of the second electrode 122, since a portion of the winding start end of the first electrode 121 is cut off, the size of the winding start end of the first electrode 121 along its width direction is reduced. Therefore, the notch 1212 corresponds to the second tab 1221, which can reduce the possibility that the innermost ring of the electrode assembly 12 will be carried out to contact the second tab 1221 and thus cause a short circuit in the battery. That is, it reduces the adverse effect of the pin pulling action on the quality of the electrode assembly 12 and is conducive to improving the safety of the battery.

[0085] In some embodiments of this application, the first electrode 121 is an anode electrode, and the second electrode 122 is a cathode electrode. That is, the innermost ring of the electrode assembly 12 prepared using the manufacturing method of the electrode assembly 12 of this embodiment is an anode electrode. Even when the winding start end of the anode electrode is close to the cathode tab, during the unloading of the wound electrode assembly 12 in the winding process, the portion of the inner ring of the anode electrode carried out by the winding member 310 is reduced, and the notch 1212 corresponds to the cathode tab. This reduces the possibility of the inner ring of the anode electrode carried out by the winding member 310 contacting the cathode tab and causing a short circuit in the battery, and reduces the adverse impact of the pin-pulling action on the quality of the electrode assembly 12. In some embodiments of this application, the first electrode 121 is a cathode electrode, and the second electrode 122 is an anode electrode. That is, the innermost ring of the electrode assembly 12 prepared using the manufacturing method of the electrode assembly 12 of this embodiment is a cathode electrode.

[0086] Please refer to some embodiments of this application. Figure 3The manufacturing method of electrode assembly 12 may further include: in the die-cutting process of the first electrode 121, upstream of each first electrode tab group, a positioning hole 1213 is cut out on the side of the first electrode 121, the positioning hole 1213 and the first electrode tab group being located on the same side of the first electrode 121. Furthermore, a target image of the first electrode 121 is acquired downstream of the cutting station of the first electrode 121; after identifying the positioning hole 1213 based on the target image, a notch 1212 is cut out on the side of the first electrode 121 downstream of the first electrode tab group and at a preset distance from the positioning hole 1213, along the conveying direction of the first electrode 121.

[0087] Specifically, the implementation of S10 can be achieved by cutting out the positioning hole 1213 before step a. Alternatively, as... Figure 4 As shown, the specific implementation process of S10 above can also be after step a and before step b, cutting out the positioning hole 1213, that is, after cutting out the first side, first cutting out to form the positioning hole 1213, and then cutting out the second side to form the first tab 1211.

[0088] In this example, as Figure 2 As shown, the die-cutting machine 2000 used to implement step S10 also includes an image acquisition mechanism 240. Along the conveying direction of the first electrode 121, the image acquisition mechanism 240 is located downstream of the cutting mechanism 230, used to acquire images of the first electrode 121 and analyze the acquired images. For example, the image acquisition mechanism 240 can be a macro camera or an infrared camera, etc. Thus, the first electrode 121 travels along the conveying direction, and at its first position, it reaches the cutting mechanism 230 where a positioning hole 1213 is cut out. The first electrode 121 continues to travel forward, reaching its first position at the image acquisition mechanism 240, where the image acquisition mechanism 240 acquires an image of the first electrode 121 and identifies the positioning hole 1213. The first electrode 121 continues to travel forward, and then a first electrode lug is cut out. Finally, at a preset distance from the positioning hole 1213, a notch 1212 is cut out on the side of the first electrode 121.

[0089] In this embodiment, the die-cutting process of the first electrode 121 involves cutting a positioning hole 1213 upstream of the first electrode lug. By identifying the positioning hole 1213, the cutting point of the notch 1212 at a preset distance from the positioning hole 1213 can be easily determined. This facilitates accurately locating the cutting position of the notch 1212 on the first electrode 121. Furthermore, since the positioning hole 1213 is formed upstream of the first electrode lug, it can also serve as a starting position marker for cutting the first electrode 121 to form the first electrode lug and the notch 1212. In other words, it marks the starting position of the portion of the first electrode 121 in the form of a roll for each electrode assembly 12 during the die-cutting process.

[0090] It should be noted that the die-cutting machine 2000 used to implement step S10 should also be configured such that the distance L between the image acquisition mechanism 240 and the cutting mechanism 230 is less than the dimension d of the first electrode tab 1211 along the conveying direction, so that after the positioning hole 1213 is cut out, before the second position of the first electrode 121 reaches the cutting mechanism 230, the first position moves to the image acquisition mechanism 240 first, so that after the positioning hole 1213 is acquired and identified, the second position is conveyed to the cutting mechanism 230, and the first electrode tab 1211 is cut out at the second position, so that the positioning hole 1213 can play a positioning role and a starting position mark role.

[0091] In the manufacturing method of electrode assembly 12 disclosed herein, the shape and size of positioning hole 1213 are not limited; for example, positioning hole 1213 may be shaped as follows: Figure 4 The elliptical shape shown can also be rectangular, triangular, or other shapes. The elliptical positioning hole 1213 has smooth walls, resulting in low stress concentration and thus contributing to high quality of the manufactured electrode assembly 12.

[0092] In some examples, the die-cutting machine 2000 used to implement step S10 further includes a guide roller 250 and an encoder 251. The guide roller 250 is located downstream of the unwinding mechanism 210 and upstream of the winding mechanism 220. The rotation axis of the guide roller 250 is parallel to the rotation axes of the unwinding mechanism 210 and the winding mechanism 220, for transporting the first electrode 121 and changing the transport direction of the first electrode 121. The encoder 251 is mounted on the guide roller 250 and can count the number of rotations of the guide roller 250. The diameter of the guide roller 250 is a fixed value. In this example, after identifying the positioning hole 1213, the tape length can be calculated based on the counting result of the encoder 251 and the diameter of the guide roller 250. When the tape length of the first electrode 121 reaches a preset distance, the side of the first electrode 121 is cut to form a notch 1212. The preset distance represents the distance between the positioning hole 1213 and the notch 1212 in the length direction of the first electrode 121. Along the length direction of the first electrode 121, the distance between the positioning hole 1213 and the first end of the notch 1212 is the first distance, and the distance between the positioning hole 1213 and the second end of the notch 1212 is the second distance. The first distance is less than the second distance, and the preset distance can be greater than or equal to the first distance and less than or equal to the second distance.

[0093] In other examples, encoder 251 may also count the number of rotations of the unwinding mechanism 210 drum or the winding mechanism 220 drum. Alternatively, encoder 251 may be replaced by a proximity switch to count the number of rotations of roller 250.

[0094] In some embodiments of this application, the manufacturing method of the electrode assembly 12 may further include: after identifying the positioning hole 1213 based on the target image, counting the first electrode tab 1211 downstream of the target image acquisition station; and confirming that a first electrode tab group has been cut out in response to the number of the first electrode tab 1211 reaching a preset value.

[0095] In this example, the die-cutting machine 2000 used to implement step S10 should also include a counting element, which is used to detect and count the first tab 1211. The counting element can be implemented as an encoder 251 or an infrared counting sensor; this embodiment does not impose specific limitations on this. Along the conveying direction of the first electrode 121, the cutting mechanism 230, the image acquisition mechanism 240, and the counting element are arranged sequentially, so the counting element can count the die-cut first tab 1211 after it has been die-cut.

[0096] In this embodiment, the manufacturing method, after identifying the positioning hole 1213 (i.e., after identifying the starting position mark of the first electrode 121), counts the die-cut first tabs 1211 to ensure that the first electrode 121 is cut to form a notch 1212 after the first tab group is cut. Therefore, in this embodiment, die-cutting the first electrode 121 to form the notch 1212 requires not only that the first electrode 121 be moved to a predetermined distance from the positioning hole 1213, but also that the number of cut first tabs 1211 reaches a predetermined number so that the predetermined number of first tabs 1211 can be stacked into a first tab group in the subsequent winding process. That is, the conditions for the cutting mechanism 230 to punch out the notch 1212 are increased, which helps to improve the accuracy of the die-cutting process.

[0097] Taking the cutting mechanism 230 as a laser cutting head as an example, in step S10, specifically, the laser cutting head is controlled to cut the first electrode 121 along the cutting path to create a notch 1212. It can be understood that the cutting path includes at least one longitudinal path, the extension direction of which is parallel to or at an angle to the length direction of the first electrode 121, such that the notch 1212 formed by the cutting has a first end and a second end along the length direction of the first electrode 121. This angle is acute and can be 15°, 30°, 45°, 60°, etc.

[0098] As disclosed in the manufacturing method of electrode assembly 12, the shape and size of notch 1212 are diverse, and this application does not impose specific limitations on the shape and size of notch 1212. It is understood that the cutting path will determine the shape and size of notch 1212, so the cutting path can be reasonably designed according to requirements and actual working conditions.

[0099] In some embodiments of this application, the dimension W2 of the second end along the width direction of the first electrode 121 can be greater than or equal to the dimension W1 of the first end along the width direction of the first electrode 121. Correspondingly, when the cutting path includes a longitudinal path at an angle to the length direction of the first electrode 121, along the conveying direction of the first electrode 121, this longitudinal path gradually moves away from the side where the first electrode tab group is located on the first electrode 121. Implementation methods of this embodiment include, but are not limited to, the following possibilities.

[0100] In some embodiments, please combine Figure 8 As shown in (a), the cutting path includes a longitudinal path, the extension direction of which is parallel to the length direction of the first electrode 121. In this embodiment, the specific process of cutting the notch 1212 is as follows: the laser cutting head is controlled to move from point A on the side edge of the first electrode 121 along the width direction of the first electrode 121 to point B, then the laser cutting head is controlled to move from point B along the longitudinal path to point C, and then the laser cutting head is controlled to move from point C along the width direction of the first electrode 121 to point D on the side edge of the first electrode 121. Wherein, along the conveying direction of the first electrode 121, point A is upstream of point D. It can be seen that the notch 1212 cut in this embodiment is rectangular, W1 = W2.

[0101] In some embodiments, please continue reading Figure 4 and Figure 6 As shown, the cutting path includes a longitudinal path, the extension direction of which forms an angle with the length direction of the first electrode 121. That is, the longitudinal path is inclined to the length direction of the first electrode 121, and along the conveying direction of the first electrode 121, the longitudinal path gradually moves away from the side where the first electrode tab group is located on the first electrode 121. In this embodiment, the specific process of cutting the notch 1212 is as follows: control the laser cutting head to move from point E on the side edge of the first electrode 121 along the width direction of the first electrode 121 to point F, then control the laser cutting head to move from point F along the longitudinal path to point G, and then control the laser cutting head to move from point G along the width direction of the first electrode 121 to point H on the side edge of the first electrode 121. Among them, along the conveying direction of the first electrode 121, point E is located upstream of point H. As can be seen, in this embodiment, when point F is aligned with the root of the first tab 1211 along the length of the first electrode 121, the cut notch 1212 forms a right-angled triangle, W1 < W2, and W1 = 0 mm. It should be noted that, considering processing errors, measurement errors, etc., the 0 mm referred to in this article can fluctuate within the range of process errors, and is not limited to an absolute zero value in a mathematical sense.

[0102] In some embodiments, please combine Figure 8 As shown in (b), the cutting path includes a longitudinal path, the extension direction of which forms an angle with the length direction of the first electrode 121. This embodiment and... Figure 6 The examples shown are similar, the difference being: Figure 6 In the example shown, point F is aligned with the root of the first tab 1211 along the length of the first electrode 121. In this example, there is a gap between point F and the root of the first tab 1211 along the width of the first electrode 121, making the cut notch 1212 trapezoidal, with 0mm < W1 < W2.

[0103] In some embodiments, please combine Figure 8 As shown in (c), the cutting path includes two longitudinal paths, namely the first path and the second path. The extension direction of the first path is parallel to the length direction of the first electrode 121. The downstream end of the first path is connected to the upstream end of the second path. The extension direction of the second path forms an angle with the length direction of the first electrode 121, and along the conveying direction of the first electrode 121, the second path gradually moves away from the side where the first electrode tab group is located on the first electrode 121. In this embodiment, the specific process of cutting the notch 1212 is as follows: control the laser cutting head to move from point I on the side edge of the first electrode 121 along the width direction of the first electrode 121 to point J, then control the laser cutting head to move from point J along the first path to point K, continue to control the laser cutting head to move from point K along the second path to point L, and then control the laser cutting head to move from point L along the width direction of the first electrode 121 to point M on the side edge of the first electrode 121. In the transmission direction of the first electrode 121, I is located upstream of M, so that the cut notch 1212 is a combination of trapezoid and rectangle, W3 = W1 < W2, and W3 is the vertical distance between K and I in the width direction of the first electrode 121.

[0104] In some embodiments, please combine Figure 8As shown in (d), the cutting path includes two longitudinal paths, namely the third path and the fourth path. The extension direction of the third path forms an angle with the length direction of the first electrode 121, and along the conveying direction of the first electrode 121, the third path gradually moves away from the side where the first electrode tab group is located on the first electrode 121. The downstream end of the third path is connected to the upstream end of the fourth path, and the extension direction of the fourth path is parallel to the length direction of the first electrode 121. In this embodiment, the specific process of cutting the notch 1212 is as follows: control the laser cutting head to move from point N on the side edge of the first electrode 121 along the width direction of the first electrode 121 to point O, then control the laser cutting head to move from point O along the third path to point P, continue to control the laser cutting head to move from point P along the fourth path to point Q, and then control the laser cutting head to move from point Q along the width direction of the first electrode 121 to point R on the side edge of the first electrode 121. In the transmission direction of the first electrode 121, N is located upstream of Q, so that the cut notch 1212 is trapezoidal, 0mm = W1 < W2 = W4, and W4 is the vertical distance between P and R in the width direction of the first electrode 121.

[0105] Understandably, practical experience shows that since the electrode assembly 12 has a wound structure, and both the first electrode 121 and the second electrode 122 are spiral-shaped, the corner end of the innermost ring (i.e., the first electrode 121) where the winding begins is carried out by the winding component 310 when the needle is pulled out. Specifically, along the winding direction, the dimension of the portion of the innermost ring carried out along the axial direction of the electrode assembly 12 gradually decreases from the winding beginning end to the winding end end. When flattened, the portion of the innermost ring carried out by the winding component 310 is a triangle, and usually an isosceles right triangle. That is, the innermost ring's winding beginning end is carried out the most by the winding component 310, so the probability of the innermost ring's winding beginning end contacting the second electrode tab 1221 is the greatest. For ease of understanding, let's assume that when the first electrode 121 is not die-cut with a notch 1212, the width of the innermost ring's winding beginning end carried out by the winding component 310 is W'.

[0106] As described above, by designing the cutting path reasonably, the dimension W2 of the second end of the notch 1212 of the first electrode 121 along the width direction of the first electrode 121 is greater than or equal to the dimension W1 of the first end along the width direction of the first electrode 121. Therefore, compared with the technical solution where the notch 1212 is not die-cut or W2 is less than W1, in this embodiment, the dimension W2 of the second end of the notch 1212 along the width direction of the first electrode 121 is larger. Thus, the width of the innermost ring (i.e., the first electrode 121) of the wound electrode assembly 12 is greatly reduced when it is unloaded. Therefore, the possibility of the innermost ring (i.e., the first electrode 121) of the wound electrode assembly 12 being carried out and contacting the second tab 1221 is reduced, thereby reducing the possibility of a battery short circuit leading to a safety accident.

[0107] Please continue to refer to this. Figure 6 and Figure 8 As shown in (b), the cutting path is configured such that the dimension of the notch 1212 along the width direction of the first electrode 121 gradually increases from the first end to the second end. In other words, W1 < W2, and the dimension W2 of the second end of the notch 1212 along the width direction of the first electrode 121 is the maximum dimension of the notch 1212 along the width direction of the first electrode 121.

[0108] With this design, when the dimension W2 of the second end of the notch 1212 is equal to W', compared with the technical solution of W2=W1, in this embodiment, W2 is the maximum dimension of the notch 1212 along the width direction of the first electrode 121. This can greatly reduce the possibility of the winding start end contacting the second electrode tab 1221, and also make the volume of the innermost ring (i.e. the first electrode 121) of the electrode assembly 12 as small as possible. As a result, less of the active material layer of the first electrode 121 is removed, which is beneficial to make the electrode assembly 12 have better quality.

[0109] Based on the embodiment where the dimension of the notch 1212 gradually increases from the first end to the second end along the width direction of the first electrode 121, such as Figure 4 and Figure 6 As shown, W1 can be equal to 0 mm. Or, as... Figure 8 As shown in (b), W1 can also be greater than 0 mm. In contrast, in the embodiment where W1 equals 0 mm with other parameters being the same, the volume of the innermost ring (i.e., the first electrode 121) of the electrode assembly 12 is less, so the active material layer of the first electrode 121 is less removed, which is beneficial to making the electrode assembly 12 have better quality.

[0110] Furthermore, such as Figure 4 and Figure 6 As shown, the dimension l of the notch 1212 along the length direction of the first electrode 121 is greater than the dimension W2 of the second end along the width direction of the first electrode 121. That is, the notch 1212 is also an unequal-sided right triangle.

[0111] As described above, for electrode assembly 12 without notch 1212, when the winding member 310 is pulled out from the center of the wound electrode assembly 12, it usually brings out the innermost ring, which is an isosceles right triangle. In this embodiment, by constructing l to be greater than W2, the shape of the cut-out portion of the innermost ring (i.e., notch 1212) matches the shape of the portion of the innermost ring of the electrode assembly 12 brought out by the winding member 310. In this way, the cut-out portion of the innermost ring (i.e., the first electrode 121) is exactly the same as the portion brought out, so that the winding start end does not move out and contact the second electrode tab 1221, the volume of the cut-out portion of the innermost ring (i.e., the first electrode 121) of the electrode assembly 12 can be reduced to the maximum extent, which is beneficial to the electrode assembly 12 having better quality.

[0112] In some embodiments of this application, the dimension W2 of the second end along the width direction of the first electrode 121 can be the width W of the first electrode 121. 总 2% to 4%, the dimension l of the notch 1212 along the length direction of the first electrode 121 is the width W of the first electrode 121. 总 10% to 20%.

[0113] After extensive practical verification, based on the fact that the notch 1212 is an irregular right-angled triangle and the shape of the notch 1212 matches the shape of the innermost ring of the electrode assembly 12 that is brought out by the winding component 310, the value range of W2 is [W 总 ×2%, W 总 ×4%], the range of values ​​for l is [W 总 ×10%, W 总 When the size of the notch 1212 is approximately matched with the size of the portion of the innermost ring of the electrode assembly 12 without the notch 1212 being brought out by the winding component 310 in the related art, the possibility of the innermost ring contacting the second tab 1221 during needle removal can be minimized.

[0114] It is understandable that the width W of the first electrode 121 总 The value range of l is usually [50mm, 500mm]. Correspondingly, the value range of l is [50mm×10%, 500mm×20%], that is, the value range of l is [5mm, 100mm]; the value range of W2 is [50mm×2%, 500mm×4%], that is, the value range of W2 is [1mm, 20mm].

[0115] Wherein, l can be any value from 5mm, 10mm, 15mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, and W2 can be any value from 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, as long as l > W2.

[0116] In one embodiment of this application, l can be a value from [10mm, 100mm], and W2 can be a value from [1mm, 10mm]. In this embodiment, l and W2 can also satisfy the following relationship: W2 = l × 10%.

[0117] In one embodiment of this application, l can be specifically selected from values ​​in [5mm, 100mm], while W2 can be specifically selected from values ​​in [3mm, 20mm].

[0118] The second aspect of this application discloses an electrode assembly 12, which is manufactured using the method for manufacturing the electrode assembly 12 described in the first aspect above, wherein the electrode assembly 12 has a wound structure. Specifically, as shown... Figure 7 As shown, the electrode assembly 12 of this embodiment includes a first electrode 121, a second electrode 122, and a separating membrane 123. The polarity of the first electrode 121 is opposite to that of the second electrode 122. The separating membrane 123 is disposed between the first electrode 121 and the second electrode 122 to isolate the first electrode 121 and the second electrode 122. The innermost ring of the electrode assembly 12 is the first electrode 121. The first electrode 121 has a first tab and a notch 1212 on the same side. The notch 1212 has a first end and a second end along the length direction of the first electrode 121. The second end is the starting end of the winding of the first electrode 121 and is located at the innermost side of the winding structure. In other words, the second end is close to the center of the electrode assembly 12. That is, along the winding direction, the second end is upstream of the first end and enters the winding member 310 before the first end.

[0119] The first electrode group includes a preset number of first electrodes 1211. The preset number can be 1 or greater than or equal to 2. In this case, the preset number of first electrodes 1211 are arranged sequentially along the length direction of the first electrode plate 121.

[0120] The first electrode 121 includes an electrode body and a first tab 1211. The electrode body is coated with an active material layer, while the first tab 1211 is not coated with an active material layer. The first tab 1211 protrudes from the edge of the electrode body, and the notch 1212 is specifically located on the electrode body of the first electrode 121.

[0121] In this embodiment, the electrode assembly 12 has a notch 1212 at one end of the innermost ring (i.e., the first electrode 121) near the winding axis. When the winding member 310 pulls out from the center of the wound electrode assembly 12 for unloading, the notch 1212 corresponds to the second tab 1221. This reduces the possibility that the innermost ring of the electrode assembly 12 may be pulled out and come into contact with the second tab 1221, thereby causing a short circuit in the battery. In other words, it reduces the adverse effects of the needle-pulling action on the quality of the electrode assembly 12 and is beneficial to improving the safety of the battery.

[0122] A second aspect of this application provides a battery cell 11, comprising: a housing 13 and an electrode assembly 12 as described above, the electrode assembly 12 being disposed within the housing 13.

[0123] The housing 13 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 13 can be determined according to the specific shape and size of the electrode assembly 12. The material of the housing 13 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0124] The battery cell 11 has an electrode assembly 12 manufactured by the manufacturing method of the electrode assembly 12 of the first aspect described above. The beneficial effects of the battery cell 11 are the same as those of the manufacturing method of the electrode assembly 12 of the first aspect described above, and will not be repeated here.

[0125] A third aspect of this application provides a battery device 100, comprising: a battery cell 11 as described above.

[0126] The battery device 100 has an electrode assembly 12 manufactured by the manufacturing method of the electrode assembly 12 of the first aspect described above. The beneficial effects of the battery device 100 are the same as those of the manufacturing method of the electrode assembly 12 of the first aspect described above, and will not be repeated here.

[0127] The battery device 100 described in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using the battery cells 11 and battery device 100 described in this application.

[0128] In some embodiments of this application, such as Figure 10As shown, the battery device 100 may further include a housing 20, within which multiple battery cell assemblies 10 are housed. The housing 20 is used to house the battery cell assemblies 10 to prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy material such as aluminum alloy or iron alloy, a polymer material such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0129] To meet different power demands, the battery cell assembly 10 may include multiple battery cells 11, where each battery cell 11 is the smallest unit constituting the battery cell assembly 10. Multiple battery cells 11 may be connected in series and / or in parallel via electrode terminals for various applications. Battery cells 11 may include, but are not limited to, lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries. Furthermore, the shape of the battery cells may include, but is not limited to, cylindrical, flat, cuboid, or other shapes.

[0130] In some embodiments, such as Figure 2 As shown, the housing 20 may include a first part 21 and a second part 22, which overlap each other, and together define a space for accommodating the battery cell assembly 10. The second part 22 may be a hollow structure with one end open, and the first part 21 may be a plate-like structure, with the first part 21 covering the open side of the second part 22 so that the first part 21 and the second part 22 together define a space for accommodating the battery cell assembly 10; the first part 21 and the second part 22 may also be hollow structures with one side open, with the open side of the first part 21 covering the open side of the second part 22.

[0131] The fourth aspect of this application provides an electrical device comprising: the battery device described in the third aspect above.

[0132] The electrical device has an electrode assembly manufactured by the method of manufacturing the electrode assembly of the first aspect described above. The beneficial effects of the electrical device are the same as those of the method of manufacturing the electrode assembly of the first aspect described above, and will not be repeated here.

[0133] In this application embodiment, the power-consuming device using a battery as a power source can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0134] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical devices described above, but can also be applied to all battery devices including housings and electrical devices using battery devices. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0135] Please refer to Figure 11 The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0136] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0137] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0138] In the embodiments of this application, such as Figure 1 As shown, this application proposes a method for manufacturing an electrode assembly 12, the specific implementation process of which includes the following steps.

[0139] use Figure 2The die-cutting machine 2000 shown implements the die-cutting process: It performs die-cutting on the anode sheet. In this process, the sides of the anode sheet are alternately cut to form anode tab groups and a notch 1212 until M anode tab groups and M notches 1212 are formed, where M is a positive integer and M≥2, such that there is a notch 1212 between each pair of adjacent anode tab groups. Each anode tab group includes K anode tabs, where K is a positive integer, and the number of anode tabs in each group can be the same or different. Furthermore, along the conveying direction of the anode sheet, the notch 1212 has a first end and a second end downstream of the first end. The anode sheet die-cut in this process is wound along the winding direction r, so that the anode sheet is provided to the next process (i.e., the winding process) in the form of a coil.

[0140] use Figure 5 The winding machine 3000 shown implements the winding process: It winds the anode electrode, separator 123, and cathode electrode around a winding axis. The anode electrode is closer to the winding axis than the cathode electrode, and is cut along the second end of each notch 1212. The portion of the anode electrode between the second ends of two adjacent notches 1212 serves as the anode electrode of a wound electrode assembly 12, and the anode electrode is the innermost ring of the electrode assembly 12. The second end of the notch 1212 is the winding end of the already wound anode electrode of the electrode assembly 12 and the winding start end of the next anode electrode of the electrode assembly 12 to be wound. The anode electrode obtained in the die-cutting process is unwound in the opposite direction to the winding direction r.

[0141] In the die-cutting process, before cutting out the anode tab assembly, elliptical positioning holes 1213 are also cut out on the side of the anode sheet. The die-cutting machine 2000 also includes an image acquisition mechanism 240, a guide roller 250, an encoder 251, and an infrared counting sensor. The image acquisition mechanism 240 is located downstream of the cutting mechanism 230, the guide roller 250 is located between the unwinding mechanism 210 and the winding mechanism 220, the encoder 251 is located on the guide roller 250 and is used to count the number of rotations of the guide roller 250, and the infrared counting sensor is located downstream of the image acquisition mechanism 240.

[0142] In the die-cutting process, the first electrode 121 travels along the conveyor direction. At its first position, the first electrode 121 reaches the cutting mechanism 230 where a positioning hole 1213 is cut. The first electrode 121 continues to travel forward, reaching the image acquisition mechanism 240 at its first position. The image acquisition mechanism 240 acquires an image of the first electrode 121 and identifies the positioning hole 1213. Upon identification of the positioning hole 1213, the encoder 251 begins counting. The first electrode 121 continues to travel forward, reaching the cutting mechanism 230 at its second position where a second electrode tab 1221 is cut. When the first electrode 121 travels to the second electrode tab 1221 and reaches the infrared counting sensor, the infrared counting sensor detects the second electrode tab 1221 and counts. When the infrared counting sensor detects a preset number, and the travel length calculated based on the encoder 251's counting result and the diameter of the roller 250 is a preset distance, a notch 1212 is cut into the side of the anode electrode.

[0143] The cutting mechanism 230 of the die-cutting machine 2000 is a laser cutting head. In the die-cutting process, the laser cutting head is controlled to cut the anode sheet along the cutting path to create a notch 1212. The cutting path includes a first transverse path, a longitudinal path, and a second transverse path connected in sequence. Both the first and second transverse paths are parallel to the width direction of the anode sheet. The longitudinal path forms an angle with the length direction of the anode sheet and gradually moves away from the side where the anode tabs are located along the conveying direction of the anode sheet. Specifically, the laser cutting head moves from point E along the first transverse path to point F, then from point F along the longitudinal path to point G, and then from point G along the second transverse path to point H. Thus, the notch 1212 formed on the anode sheet is a right-angled triangle.

[0144] The dimension W2 of the second end of the notch 1212 along the width direction of the anode plate ranges from [1mm, 20mm], and the dimension l of the notch 1212 along the length direction of the anode plate ranges from [5mm, 100mm].

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for manufacturing an electrode assembly, characterized in that, include: The first electrode sheet is die-cut. In the die-cutting process of the first electrode sheet, a first electrode tab group is cut out from the side of the first electrode sheet, or multiple first electrode tab groups are cut out sequentially at intervals along the length direction of the first electrode sheet. And along the conveying direction of the first electrode sheet, downstream of each first electrode tab group, a notch is cut out from the side edge of the first electrode sheet. The notch is located on the same side of the first electrode sheet as the first electrode tab group. The first electrode tab group includes a first electrode tab or multiple first electrode tabs at intervals along the length direction of the first electrode sheet. The notch has a first end and a second end located downstream of the first end along the conveying direction of the first electrode sheet. The first electrode, the separator, and the second electrode are wound around a winding axis. The first electrode is closer to the winding axis than the second electrode. During the winding process, the second end of each notch on the first electrode is cut off, so that the second end of each notch serves as the winding end of the first electrode of the already wound electrode assembly and the winding start end of the first electrode of the next electrode assembly to be wound. The first electrode and the second electrode have opposite polarities.

2. The method for manufacturing the electrode assembly according to claim 1, characterized in that, Also includes: In the die-cutting process of the first electrode sheet, a positioning hole is also cut on the side of the first electrode sheet upstream of each first electrode tab group. The positioning hole is located on the same side of the first electrode sheet as the first electrode tab group. The target image of the first electrode is acquired downstream of the cutting station of the first electrode. After the positioning hole is identified based on the target image, a notch is cut out on the side of the first electrode sheet along the conveying direction of the first electrode sheet, downstream of the first electrode ear group and at a preset distance from the positioning hole.

3. The method for manufacturing the electrode assembly according to claim 2, characterized in that, Also includes: After the positioning hole is identified based on the target image, the first electrode is counted downstream of the target image acquisition station; In response to the number of the first electrode tabs reaching a preset value, a first electrode tab group is confirmed to be cut out.

4. The method for manufacturing an electrode assembly according to any one of claims 1 to 3, characterized in that, The first electrode is an anode electrode, and the second electrode is a cathode electrode.

5. An electrode assembly, manufactured by the method of manufacturing the electrode assembly according to any one of claims 1 to 4, characterized in that, The electrode assembly has a wound structure and includes a first electrode, a second electrode, and a separator. The polarity of the first electrode and the second electrode are opposite. The separator is disposed between the first electrode and the second electrode to isolate the first electrode and the second electrode. The first electrode sheet has a first tab group and a notch on the same side. The notch has a first end and a second end along the length direction of the first electrode sheet. The second end is the winding start end of the first electrode sheet and is located at the innermost side of the winding structure.

6. The electrode assembly according to claim 5, characterized in that, The dimension of the second end along the width direction of the first electrode is greater than or equal to the dimension of the first end along the width direction of the first electrode.

7. The electrode assembly according to claim 6, characterized in that, From the first end to the second end, the size of the notch gradually increases along the width direction of the first electrode.

8. The electrode assembly according to claim 7, characterized in that, The dimension of the notch along the length direction of the first electrode is greater than the dimension of the second end along the width direction of the first electrode, and the dimension of the first end along the width direction of the first electrode is 0 mm.

9. The electrode assembly according to claim 8, characterized in that, The second end has a dimension along the width direction of the first electrode that is 2% to 4% of the width of the first electrode, and the notch has a dimension along the length direction of the first electrode that is 10% to 20% of the width of the first electrode.

10. The electrode assembly according to claim 9, characterized in that, The dimension of the notch along the length of the first electrode is greater than or equal to 5 mm and less than or equal to 100 mm; And / or, the dimension of the second end along the width direction of the first electrode is greater than or equal to 1 mm and less than or equal to 20 mm.

11. A single battery cell, characterized in that, include: The housing and the electrode assembly according to any one of claims 5 to 10, wherein the electrode assembly is disposed within the housing.

12. A battery device, characterized in that, include: The battery cell according to claim 11.

13. An electrical appliance, characterized in that, include: The battery device according to claim 12 is used to provide electrical energy.

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