Electrode assembly, battery cell, battery, and electrical device

Abstract

An electrode assembly (100), a battery cell (201), a battery (200), and an electrical device (1000). The electrode assembly (100) comprises a first electrode plate (10), a second electrode plate (20) and a separator (30), the separator (30) isolating the first electrode plate (10) from the second electrode plate (20), and the first electrode plate (10), the second electrode plate (20) and the separator (30) being wound to form an integral body. In an innermost ring of the electrode assembly (100), the first electrode plate (10) is disposed closer to an inner side of the electrode assembly relative to the second electrode plate (20). The first electrode plate (10) comprises a body (11), and a tab (12) connected to the body (11). The body (11) is formed having a notch (13) extending along a width direction of the first electrode plate (10). The notch (13) and the tab (12) are disposed at an interval along a winding path of the electrode assembly (100).

Description

Electrode assemblies, battery cells, batteries and electrical equipment

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202322756585.7 filed with the State Intellectual Property Office of China on October 13, 2023, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery manufacturing technology, and in particular to an electrode assembly, a battery cell, a battery, and an electrical device. Background Art

[0004] During battery manufacturing, the first and second electrode sheets, along with the separator, are combined and wound around a winding needle to form an electrode assembly. During this winding process, the innermost electrode sheet of the first and second electrode sheets is at a higher risk of wrinkling.

[0005] Summary of the Invention

[0006] The present application provides an electrode assembly, a battery cell, a battery and an electrical device, which can solve the problem of a high risk of wrinkling of the electrode sheets in the inner circle during the winding process.

[0007] The electrode assembly of the embodiment of the present application includes a first electrode plate, a second electrode plate and a diaphragm, the diaphragm isolates the first electrode plate and the second electrode plate, the first electrode plate, the second electrode plate and the diaphragm are wound into one body, in the innermost circle of the electrode assembly, the first electrode plate is close to the inner side of the electrode assembly relative to the second electrode plate, the first electrode plate includes a body and a pole ear connected to the body, the body is formed with a notch extending along the width direction of the first pole plate, the notch and the pole ear are arranged at intervals along the winding path of the electrode assembly.

[0008] In the electrode assembly of the embodiment of the present application, by providing a notch on the first electrode sheet near the inner side of the electrode assembly, the thickness of a portion of the first electrode sheet is reduced, thereby reducing the stress experienced by the portion of the first electrode sheet during winding. Furthermore, since the risk of stress concentration is higher in areas other than the tabs during winding, the notch is spaced apart from the tabs along the winding path of the electrode assembly. This effectively reduces the stress experienced by specific areas of the first electrode sheet during winding, thereby reducing the risk of wrinkling the first electrode sheet.

[0009] In certain embodiments, there are a plurality of notches, and the plurality of notches are arranged at intervals along the winding path of the electrode assembly.

[0010] In this way, the spacing of the multiple notches can more evenly distribute the stress on the electrode assembly, which helps reduce the stress on multiple areas of the first electrode sheet during winding, thereby further reducing the risk of wrinkling the first electrode sheet.

[0011] In certain embodiments, the width of the notch gradually increases from the outer circle to the inner circle of the electrode assembly.

[0012] It can be understood that the risk of wrinkling on the inner side of the winding path of the electrode assembly is greater than that on the outer side. Therefore, the width of the notch is set to gradually increase from the outer side to the inner side of the winding path of the electrode assembly, which can adapt to the stress in different areas of the first electrode sheet, thereby more effectively reducing the risk of wrinkling in different areas of the first electrode sheet.

[0013] In certain embodiments, the spacing between adjacent notches along the winding path of the electrode assembly is equal. In this way, the equally spaced notches are easy to manufacture, thereby reducing manufacturing costs.

[0014] In some embodiments, the widths of the notches are equal. In this way, notches with equal widths are easy to manufacture, thereby reducing manufacturing costs.

[0015] In certain embodiments, the spacing between at least some adjacent notches gradually decreases from the outside to the inside of the winding path of the electrode assembly.

[0016] It can be understood that the risk of wrinkling on the inner side of the winding path of the electrode assembly is greater than that on the outer side. Therefore, the spacing between at least some adjacent notches is set to gradually decrease from the outer side to the inner side of the winding path of the electrode assembly, which can adapt to the stress in different areas of the first electrode sheet, thereby more effectively reducing the risk of wrinkling in different areas of the first electrode sheet.

[0017] In some embodiments, there are multiple pole tabs, and the multiple pole tabs are arranged at intervals along the winding path of the electrode assembly. There are multiple notches and multiple notch groups are formed. Each notch group includes multiple notches, and each notch group is located between adjacent pole tabs.

[0018] It can be understood that the provision of multiple notch groups can disperse stress, thereby reducing the risk of wrinkling in the first pole piece. The stress is more concentrated in the area between adjacent tabs, so the probability of wrinkling is higher. Providing all notch groups between adjacent tabs can reduce the risk of wrinkling in the area between adjacent tabs.

[0019] In some embodiments, along the winding path of the electrode assembly, the spacing between adjacent notches in the same notch group is equal. In this way, the equally spaced notches are easy to manufacture, thereby reducing manufacturing costs.

[0020] In certain embodiments, along the winding path of the electrode assembly, the spacing between adjacent notches in the same notch group is a first spacing, and the spacing between adjacent notch groups is a second spacing, which is greater than the first spacing.

[0021] In this way, by setting the second spacing to be larger than the first spacing, it is possible to ensure that the notch groups are arranged in areas where stress is relatively concentrated, thereby avoiding the arrangement of too many notches, thereby improving manufacturing efficiency and reducing manufacturing costs.

[0022] In some embodiments, the notch is located at a bend in the electrode assembly. As such, stress is more concentrated at the bend in the electrode assembly, and thus the probability of wrinkling is higher. Placing the notch at the bend in the electrode assembly can effectively reduce the probability of wrinkling.

[0023] The battery cell according to the embodiment of the present application includes the electrode assembly described in any of the above embodiments.

[0024] The battery according to the embodiment of the present application includes a plurality of battery cells according to the above embodiment.

[0025] The electric device according to the embodiment of the present application includes the battery cell described in the above embodiment or the battery described in the above embodiment.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] FIG1 is a schematic diagram of the structure of an electrical device provided in some embodiments of the present application;

[0029] FIG2 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0030] FIG3 is a disassembled diagram of a battery cell provided in some embodiments of the present application;

[0031] FIG4 is a cross-sectional view of an electrode assembly in a wound state provided by some embodiments of the present application;

[0032] FIG5 is a cross-sectional view of an electrode assembly provided in some embodiments of the present application in a flattened state;

[0033] FIG6 is a schematic structural diagram of a first pole piece provided in some embodiments of the present application;

[0034] FIG7 is a cross-sectional view of an electrode assembly in a flattened state provided by some embodiments of the present application;

[0035] FIG8 is a cross-sectional view of an electrode assembly in a wound state provided by some embodiments of the present application;

[0036] FIG9 is a schematic structural diagram of a first pole piece provided in some embodiments of the present application;

[0037] FIG10 is a schematic structural diagram of a first pole piece provided in some embodiments of the present application.

[0038] Explanation of the accompanying figures: Electrical device 1000; battery 200; controller 300; motor 400; battery cell 201; battery case 500; shell 202; electrode assembly 100; first pole piece 10; second pole piece 20; diaphragm 30; first diaphragm 31; second diaphragm 32; body 11; tab 12; notch 13; first notch 130; second notch 131; third notch 132; fourth notch 133; fifth notch 134; sixth notch 135; notch group 14; first notch group 140; second notch group 141; coating 15. DETAILED DESCRIPTION

[0039] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0041] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0042] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0044] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0045] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply 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 on the embodiments of the present application.

[0046] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0047] Currently, market developments indicate that power batteries are becoming increasingly widely used. Power batteries are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in aerospace and other fields. As power battery applications continue to expand, market demand is also growing.

[0048] During battery manufacturing, the first and second electrode sheets, along with the separator, are wound onto a winding needle to form the electrode assembly. Before entering the winding needle, the first and second electrode sheets are of equal length. However, this equal length can lead to lithium deposition. Specifically, lithium ions are transferred to areas outside the electrode sheets rather than between them, potentially forming lithium crystals and causing wear and punctures in the electrode sheets.

[0049] To address issues like lithium deposition, it's necessary to ensure that the inner-circle electrode of the first and second electrode pieces is shorter than the outer-circle electrode piece. For example, when the first electrode piece is in the inner circle, the length of the first electrode piece must be shorter than the length of the second electrode piece. However, because the two electrode pieces are equal in length before entering the winding needle, the inner-circle electrode piece is at a higher risk of wrinkling after entering the winding needle. To address this issue, this application provides the following technical solution.

[0050] The electrical devices of the embodiments of the present application include battery cells or batteries in any of the following embodiments. Specifically, the electrical devices may use batteries or battery cells as a power source, and the electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0051] For the convenience of explanation, the following embodiments take a vehicle as an example of an electrical device according to an embodiment of the present application.

[0052] Please refer to Figure 1, which is a schematic diagram of the structure of an electric device 1000 provided in some embodiments of the present application. A battery 200 is installed inside the vehicle. Battery 200 can be located at the bottom, front, or rear of the vehicle. Battery 200 can be used to power the vehicle, for example, as the vehicle's operating power source.

[0053] The vehicle may further include a controller 300 and a motor 400 . The controller 300 is used to control the battery 200 to supply power to the motor 400 , for example, to meet the vehicle's power requirements for starting, navigating, and driving.

[0054] In the embodiment of the present application, the battery 200 can not only serve as the operating power source of the vehicle, but also serve as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0055] Please refer to Figure 2, which is a schematic diagram of the structure of a battery 200 provided in some embodiments of the present application. The battery 200 according to the embodiments of the present application includes a plurality of battery cells 201 according to any of the following embodiments. In the embodiments of the present application, the battery cells 201 may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., although the embodiments of the present application are not limited thereto.

[0056] The battery cell 201 can be cylindrical, flat, rectangular, or other shapes, and the embodiments of the present application do not limit this. The battery cell 201 is generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0057] The battery 200 generally includes a battery case 500 for encapsulating one or more battery cells 201. Multiple batteries can be housed in the battery case 500, which can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells 201. As the carrier of the battery module, the battery case 500 plays a key role in the safe operation and protection of the battery module. The battery case 500 must meet the strength and stiffness requirements and the protection level requirements of the electrical equipment casing, while providing collision protection. The shape of the battery case 500 can be a rectangular parallelepiped, a cube, etc. The battery case 500 can be cast with materials such as steel plates and aluminum alloys; new lightweight materials can also be used, such as glass fiber reinforced composite materials, carbon fiber reinforced composite materials, etc.

[0058] Please refer to Figure 3, which is a disassembled view of a battery cell 201 provided in some embodiments of the present application. In certain embodiments, the battery cell 201 includes a housing 202 and an electrode assembly 100, wherein the electrode assembly 100 is disposed in the housing 202.

[0059] The electrode assembly 100 is a component where electrochemical reactions occur in the battery cell 201. One or more electrode assemblies 100 may be contained within the housing 202 of the battery cell 201.

[0060] Please refer to Figures 4, 5 and 6. Figure 4 is a cross-sectional view of the electrode assembly 100 provided in some embodiments of the present application in a wound state; Figure 5 is a cross-sectional view of the electrode assembly 100 provided in some embodiments of the present application in a flattened state; Figure 6 is a structural schematic diagram of the first electrode sheet 10 provided in some embodiments of the present application.

[0061] The electrode assembly 100 of the embodiment of the present application includes a first electrode plate 10, a second electrode plate 20 and a diaphragm 30. The diaphragm 30 isolates the first electrode plate 10 and the second electrode plate 20. The first electrode plate 10, the second electrode plate 20 and the diaphragm 30 are wound into one body. In the innermost circle of the electrode assembly 100, the first electrode plate 10 is close to the inner side of the electrode assembly 100 relative to the second electrode plate 20. The first electrode plate 10 includes a main body 11 and a pole ear 12 connected to the main body 11. The main body 11 is formed with a notch 13 extending along the width direction of the first electrode plate 10. The notch 13 and the pole ear 12 are arranged at intervals along the winding path of the electrode assembly 100.

[0062] Specifically, the first electrode sheet 10 can be an anode electrode sheet or a cathode electrode sheet, and the second electrode sheet 20 can also be an anode electrode sheet or a cathode electrode sheet. Taking the example where the first electrode sheet 10 is a cathode electrode sheet and the second electrode sheet 20 is an anode electrode sheet, the cathode electrode sheet is closer to the inner side of the electrode assembly 100 relative to the anode electrode sheet. The anode electrode sheet can be formed on both sides of a layer of copper foil, and the cathode electrode sheet can be formed on both sides of a layer of aluminum foil. When the wound electrode assembly 100 is unfolded, along the length direction of the unfolded electrode assembly 100, the end regions of the first electrode sheet 10 and the second electrode sheet 20 are not aligned. Furthermore, the length of the first electrode sheet 10 is shorter than the length of the second electrode sheet 20.

[0063] The separator 30 may include a first separator 31 and a second separator 32. The second electrode sheet 20 may be disposed between the first separator 31 and the second separator 32. The first electrode sheet 10 may be disposed on the side of the second separator 32 facing away from the second electrode sheet 20. After entering the winding needle for winding, the length of the first electrode sheet 10 may be less than the length of the second electrode sheet 20. The wound electrode assembly 100 includes a stacked multi-turn structure, each turn of which includes at least one turn of the first electrode sheet 10, one turn of the second electrode sheet 20, and one turn of the separator 30.

[0064] The body 11 is the main component of the electrode assembly 100. The edge of the body 11 may be provided with a tab 12. The body 11 and the tab 12 may be separate or integral. For example, the body 11 and the tab 12 may be integral, specifically by laser cutting the first electrode sheet 10 to obtain the body 11 and the tab 12 connected to the body 11.

[0065] The notch 13 is a material thinning area on the outer surface of the body 11 near the inner side of the electrode assembly 100. The notch 13 can be a groove or a thin line. The notch 13 can be formed on the outer surface of the first electrode sheet 10 by laser cutting, stamping cutting, etc. The notch 13 can be formed on the outer surface of the body 11 near the inner side of the electrode assembly 100. The shape of the notch 13 can be a regular shape, such as a square, an oval, etc., or an irregular shape. The shortest distance between the notch 13 and the edge of the body 11 can be set according to requirements. For example, the shortest distance d1 between the notch 13 and the edge of the body 11 can be 1 / 300 to 1 / 70 of the width W1 of the body 11. Furthermore, the shortest distance d1 between the notch 13 and the edge of the body 11 can be 1 mm to 2 mm. Within this range, the stress in the area where the notch 13 is provided on the first electrode sheet 10 can be released, thereby effectively reducing the probability of wrinkling of the first electrode sheet 10, and the first electrode sheet 10 is not easy to break.

[0066] In some embodiments, a coating 15 may be provided on the side of the notch 13 close to the tab 12 . The coating 15 may be made of aluminum oxide, etc. The coating 15 may press against the edge of the tab 12 , thereby reducing the probability of burrs and other defects when laser cutting the tab 12 or the notch 13 .

[0067] It is understood that the winding path of the electrode assembly 100 refers to the path formed by the outer surface of the first electrode sheet 10 or the second electrode sheet 20 when the electrode assembly 100 is in a wound state. When the wound electrode assembly 100 is unfolded, the winding path of the electrode assembly 100 can be a path formed along the length direction of the electrode assembly 100.

[0068] In the electrode assembly 100 of the embodiment of the present application, by providing a notch 13 on the first electrode sheet 10 near the inner side of the electrode assembly 100, the thickness of a portion of the first electrode sheet 10 is reduced, thereby reducing the stress experienced by the portion of the first electrode sheet 10 during winding. Furthermore, since the risk of stress concentration is higher in areas other than the tab 12 during winding, the notch 13 is spaced apart from the tab 12 along the winding path of the electrode assembly 100. This effectively reduces the stress experienced by a specific area of ​​the first electrode sheet 10 during winding, thereby reducing the risk of wrinkling the first electrode sheet 10.

[0069] 5 and 7 , FIG7 is a cross-sectional view of an electrode assembly 100 in a flattened state according to some embodiments of the present application. In some embodiments, there are multiple notches 13 , which are spaced apart along the winding path of the electrode assembly 100 .

[0070] Specifically, the number of notches 13 can be two, three, four or even more, and can be set according to specific requirements. The spacing between the multiple notches 13 can be equal or unequal, and can be set according to the probability of wrinkling of the first pole piece 10 during winding.

[0071] In this way, the spacing of the plurality of notches 13 can more evenly distribute the stress on the electrode assembly 100. This helps reduce the stress on multiple regions of the first electrode sheet 10 during winding, thereby further reducing the risk of wrinkling the first electrode sheet 10.

[0072] Referring to FIG. 6 , in some embodiments, the width of the notch 13 gradually increases from the outer circumference to the inner circumference of the electrode assembly 100 .

[0073] Specifically, the electrode assembly 100 may be wound multiple times. Along the thickness direction of the electrode assembly 100, the heads of the first electrode sheet 10 and the second electrode sheet 20 may be located at the inner circle, and the tails of the first electrode sheet 10 and the second electrode sheet 20 may be located at the outer circle. The head refers to the portion where winding begins, and the tail refers to the portion where winding ends.

[0074] The width of the notch 13 can gradually increase in a linear manner or in a nonlinear manner. For example, from the inner circle to the outer circle of the electrode assembly 100, the width W2 of the first circle notch 13 is 6 to 8 mm, the width W3 of the second circle notch 13 is 4 to 6 mm, and the width W4 of the third and fourth circles notch 13 is 2 to 4 mm. Within these ranges, the probability of wrinkling of the first electrode sheet 10 can be effectively reduced. Among them, the first to fourth circles refer to the first four circles close to the inner circle after the electrode assembly 100 is wound, and the first circle is the innermost circle. It is worth noting that the numerical values ​​here are only examples for ease of understanding and cannot be used as a limitation on the implementation methods of this application.

[0075] It can be understood that the risk of wrinkling on the inner side of the winding path of the electrode assembly 100 is greater than that on the outer side. Therefore, the width of the notch 13 is set to gradually increase from the outer side to the inner side of the winding path of the electrode assembly 100, which can adapt to the stress in different areas of the first electrode sheet 10, thereby more effectively reducing the risk of wrinkling in different areas of the first electrode sheet 10.

[0076] Referring to FIG. 6 , in certain embodiments, the spacing d2 between adjacent notches 13 along the winding path of the electrode assembly 100 is equal. The spacing d2 between adjacent notches 13 refers to the spacing between the edges of adjacent notches 13. Specifically, when the electrode assembly 100 is in a flattened state, the spacing d2 between adjacent notches 13 along the length of the electrode assembly 100 is equal; when the electrode assembly 100 is in a wound state, the spacing d2 between adjacent notches 13 remains equal. In this way, the equally spaced notches 13 are easy to manufacture, thereby reducing manufacturing costs.

[0077] Please refer to Figures 7, 8 and 9. Figure 8 is a cross-sectional view of the electrode assembly 100 in a wound state provided in some embodiments of the present application; Figure 9 is a structural schematic diagram of the first electrode sheet 10 provided in some embodiments of the present application.

[0078] In some embodiments, the widths of the notches 13 are equal. Specifically, the widths of the plurality of notches 13 can be set according to the magnitude of the stress on the inner side of the winding path of the electrode assembly 100. For example, the width of each notch 13 can be set to W5 = 8 mm. It is worth noting that the numerical values ​​here are only examples for ease of understanding and cannot be used as limitations on the embodiments of the present application. In this way, notches 13 of equal width are easy to manufacture, thereby reducing manufacturing costs.

[0079] Referring to FIG. 9 , in some embodiments, the spacing between at least some adjacent notches 13 gradually decreases from the outside to the inside of the winding path of the electrode assembly 100 .

[0080] Specifically, along the outer side to the inner side of the winding path of the electrode assembly 100, the distances between adjacent notches 13 may be d3, d4, d5, and d6, respectively, wherein d3 is greater than d4, d4 is greater than d5, and d5 is greater than d6.

[0081] It can be understood that the risk of wrinkling on the inner side of the winding path of the electrode assembly 100 is greater than that on the outer side. Therefore, the spacing between at least some adjacent notches 13 is set to gradually decrease from the outer side to the inner side of the winding path of the electrode assembly 100, which can adapt to the stress in different areas of the first electrode sheet 10, thereby more effectively reducing the risk of wrinkling in different areas of the first electrode sheet 10.

[0082] Please refer to Figure 10, which is a schematic diagram of the structure of the first electrode sheet 10 provided in some embodiments of the present application. In certain embodiments, there are multiple electrode tabs 12, which are spaced apart along the winding path of the electrode assembly 100. There are multiple notches 13, which are formed into multiple notch groups 14, each notch group 14 including multiple notches 13, and each notch group 14 is located between adjacent electrode tabs 12.

[0083] Specifically, the number of tabs 12 can be two, three, four, or even more. The spacing between the multiple tabs 12 can be set according to the performance requirements of the electrode assembly 100, and this application does not limit this. Each notch group 14 can include two, three, four, or even more notches 13. For example, each notch group 14 can include three notches 13, and the three notches 13 can be arranged between adjacent tabs 12.

[0084] It can be understood that the provision of multiple score groups 14 can disperse stress, thereby reducing the risk of wrinkling of the first pole piece 10. The stress in the area between adjacent pole tabs 12 is relatively concentrated, so the probability of wrinkling is relatively high. Providing all score groups 14 between adjacent pole tabs 12 can reduce the risk of wrinkling in the area between adjacent pole tabs 12.

[0085] Referring to FIG. 10 , in certain embodiments, adjacent notches 13 within the same notch group 14 are spaced equally along the winding path of electrode assembly 100. Specifically, along the winding path of electrode assembly 100, notch group 14 may include a first notch group 140, which may include a first notch 130, a second notch 131, and a third notch 132, arranged in sequence. The spacing between first notch 130 and second notch 131 may be equal to the spacing between second notch 131 and third notch 132. Thus, equally spaced notches 13 are easier to manufacture, thereby reducing manufacturing costs.

[0086] Referring to FIG. 10 , in some embodiments, along the winding path of the electrode assembly 100 , the spacing between adjacent notches 13 in the same notch group 14 is a first spacing L1 , and the spacing between adjacent notch groups 14 is a second spacing L2 , which is greater than the first spacing L1 .

[0087] Specifically, along the winding path of electrode assembly 100, score group 14 may further include a second score group 141 spaced apart from first score group 140. Second score group 141 may include a fourth score 133, a fifth score 134, and a sixth score 135, respectively, arranged in sequence. Third score 132 and fourth score 133 are adjacent scores 13 between first score group 140 and second score group 141. The spacing between second score 131 and third score 132 is a first spacing L1, and the spacing between third score 132 and fourth score 133 is a second spacing L2, which is greater than first spacing L1.

[0088] Thus, by setting the second spacing L2 to be larger than the first spacing L1 , it is possible to ensure that the notch groups 14 are arranged in areas where stress is relatively concentrated, thereby avoiding the provision of excessive notches 13 , thereby improving manufacturing efficiency and reducing manufacturing costs.

[0089] Referring to Figures 4 and 8 , in certain embodiments, the notch 13 is located at a bend in the electrode assembly 100. Specifically, the electrode assembly 100 includes multiple bends, and the notch 13 may be located at a bend where stress is concentrated. For example, the notch 13 may be located at the first two bends from the inner side to the outer side of the winding path of the electrode assembly 100.

[0090] In this way, the stress at the bend of the electrode assembly 100 is more concentrated, so the probability of wrinkling is higher. Setting the notch 13 at the bend of the electrode assembly 100 can effectively reduce the probability of wrinkling of the first electrode sheet 10.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An electrode assembly, wherein: The electrode assembly includes a first electrode sheet, a second electrode sheet and a diaphragm, wherein the diaphragm separates the first electrode sheet from the second electrode sheet, and the first electrode sheet, the second electrode sheet and the diaphragm are wound together to form an integral body. In the innermost circle of the electrode assembly, the first electrode sheet is closer to the inner side of the electrode assembly relative to the second electrode sheet. The first pole piece includes a body and a pole lug connected to the body, the body is formed with a notch extending along a width direction of the first pole piece, and the notch and the pole lug are arranged at intervals along a winding path of the electrode assembly.

2. The electrode assembly according to claim 1, wherein: The number of the notches is plural, and the notches are arranged at intervals along the winding path of the electrode assembly.

3. The electrode assembly according to claim 2, wherein: The width of the notch gradually increases from the outer circle to the inner circle of the electrode assembly.

4. The electrode assembly according to claim 3, wherein: Along the winding path of the electrode assembly, the spacings between adjacent notches are equal.

5. The electrode assembly according to claim 2, wherein: The widths of the notches are equal.

6. The electrode assembly according to claim 5, wherein: Along the outer side to the inner side of the winding path of the electrode assembly, the intervals between at least some of the adjacent notches gradually decrease.

7. The electrode assembly according to any one of claims 1 to 6, wherein: There are multiple pole tabs, which are spaced apart along the winding path of the electrode assembly. There are multiple notches, which form multiple notch groups. Each notch group includes multiple notches, and each notch group is located between adjacent pole tabs.

8. The electrode assembly according to claim 7, wherein: Along the winding path of the electrode assembly, the intervals between adjacent notches in the same notch group are equal.

9. The electrode assembly according to claim 8, wherein: Along the winding path of the electrode assembly, the spacing between adjacent notches in the same notch group is a first spacing, and the spacing between adjacent notch groups is a second spacing, and the second spacing is greater than the first spacing.

10. The electrode assembly according to any one of claims 1 to 9, wherein: The notch is located at a bend of the electrode assembly.

11. A battery cell, wherein: The battery cell comprises the electrode assembly according to any one of claims 1 to 10.

12. A battery, wherein: The battery comprises a plurality of battery cells according to claim 11 .

13. An electrical device, wherein: The electrical equipment comprises the battery cell according to claim 11 or the battery according to claim 12.

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