Battery monomer and manufacturing method thereof, battery device and electric equipment

Abstract

The invention relates to the technical field of batteries, in particular to a battery monomer and a manufacturing method thereof, a battery device and electric equipment. In the embodiment of the invention, the first ring section and the tail ring section of the main body part of the first pole piece are provided with the convex parts, and the stiffness of the convex parts is greater than that of the first tab, so that the bending resistance of the convex parts is greater than that of the first tab. In the embodiment of the invention, when the electrode assembly is manufactured, as the bending resistance of the convex part is greater than that of the first tab, the convex part can be in a more stable state relative to the first tab when the tension is changed, so that the rolling-in alignment degree and the rolling-up alignment degree of the electrode assembly can be determined by utilizing the convex part which is more difficult to bend; the detection accuracy of the in-roll alignment degree and the rolling alignment degree is improved, and then the detection accuracy of the alignment degree of the electrode assembly is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells and manufacturing methods thereof, battery devices and electrical equipment. Background Art

[0002] Currently, battery electrode assemblies are primarily manufactured through lamination or winding processes. During the production of wound electrode assemblies, alignment is a key indicator for measuring the relative position accuracy of the positive and negative electrode sheets during the winding process. Its quality directly impacts the performance, safety, and production consistency of the electrode assembly. Therefore, there is a need to improve the accuracy of electrode assembly alignment testing. Summary of the Invention

[0003] Based on this, the present application provides a battery cell and a manufacturing method thereof, a battery device and an electrical equipment to improve the detection accuracy of the alignment of the electrode assembly.

[0004] According to one aspect of the present application, a battery cell is provided, comprising an electrode assembly having a wound structure, comprising a first electrode sheet, a second electrode sheet, and a separator, wherein the separator separates the first electrode sheet from the second electrode sheet. The first electrode sheet comprises a main body, a plurality of first electrode tabs, and protrusions disposed on the first and last winding sections of the main body; along the winding axis of the electrode assembly, the plurality of first electrode tabs and all the protrusions are disposed on the same side of the main body, and the stiffness of the protrusions is greater than the stiffness of the first electrode tabs.

[0005] In the technical solution of the embodiment of the present application, a convex portion is provided on the first and last loop sections of the main body of the first pole piece, and the stiffness of the convex portion is made greater than the stiffness of the first pole piece, so that the bending resistance of the convex portion is greater than the bending resistance of the first pole piece. Since there is no tension constraint when the head and tail of the first pole piece are cut off, the actual relative position of the first pole piece and the second pole piece may change during winding, resulting in inaccurate results of the pole piece alignment detection. In the embodiment of the present application, when manufacturing the electrode assembly, since the bending resistance of the convex portion is greater than the bending resistance of the first pole piece, when the tension changes, the convex portion can be in a more stable state relative to the first pole piece, so that the convex portion that is less likely to bend can be used to determine the winding alignment and winding alignment of the electrode assembly, thereby improving the detection accuracy of the winding alignment and winding alignment, and further improving the detection accuracy of the electrode assembly alignment.

[0006] In some embodiments, the first pole piece also includes an insulating layer, the insulating layer includes a first insulating portion and a second insulating portion connected to the first insulating portion; the edge area of ​​one side of the main body portion having multiple first pole ears and a protrusion is the first area, and the root area of ​​the first pole ear adjacent to the main body portion is the second area; the first insulating portion is provided in the first area, and the second insulating portion is covered in the second area and covers at least part of the protrusion.

[0007] The insulating layer provides insulation protection. Even if the first tab is inserted between the first and second pole pieces, the insulating layer can separate the first tab and the second pole piece, thereby reducing the risk of short circuits and improving safety. Because the insulating layer has a certain thickness, the thickness of the area of ​​the first pole piece covered by the insulating layer can be increased, which can increase the moment of inertia of the section and thus increase the stiffness of the area of ​​the first pole piece covered by the insulating layer. This helps to further improve the stiffness of the protrusion, thereby further improving the detection accuracy of the winding alignment and winding alignment.

[0008] In some embodiments, the protrusion includes a first surface and a second surface arranged opposite to each other along the thickness direction of the protrusion; the thickness direction of the protrusion is perpendicular to the winding axis direction of the electrode assembly; wherein, the ratio of the area of ​​the first surface covered by the second insulating portion to the area of ​​the first surface is 0.8 to 1; and / or, the ratio of the area of ​​the second surface covered by the second insulating portion to the area of ​​the second surface is 0.8 to 1.

[0009] By controlling the area ratio of the first surface and / or the second surface of the protrusion covered by the second insulating portion, the stiffness of the protrusion can be further improved, thereby further improving the detection accuracy of the winding alignment and the winding alignment.

[0010] In some embodiments, a ratio of a surface area of ​​a region of the protrusion covered by the second insulating portion to a surface area of ​​the protrusion is 0.8 to 1.

[0011] By controlling the area ratio of the convex portion covered by the second insulating portion, the stiffness of the convex portion can be further improved, thereby further improving the detection accuracy of the winding alignment and the winding alignment.

[0012] In some embodiments, along the winding axis direction of the electrode assembly, the size of the protrusion is smaller than the size of the first electrode tab; and / or, along the winding direction of the electrode assembly, the size of the protrusion is smaller than the size of the first electrode tab.

[0013] By controlling the size of the protrusion along the winding axis direction of the electrode assembly and / or along the winding direction of the electrode assembly, the stiffness of the protrusion can be adjusted.

[0014] In some embodiments, a ratio of a dimension of the protrusion along the winding direction of the electrode assembly to a dimension of the protrusion along the winding axis direction of the electrode assembly is greater than or equal to 7.

[0015] By controlling the ratio of the size of the protrusion along the winding direction of the electrode assembly to the size along the winding axis direction of the electrode assembly, it is further beneficial to adjust the stiffness of the protrusion.

[0016] In some embodiments, the electrode assembly has a reference surface, and the winding axis of the electrode assembly is located on the reference surface; the reference surface has a first side and a second side arranged opposite to each other, multiple first tabs are located on the first side, and all protrusions are located on the second side.

[0017] By arranging the first pole tabs and the protrusions on different sides, all the first pole tabs can be arranged in the same area, which not only facilitates the connection of all the first pole tabs with the electrode terminals of the battery cells, but also helps to improve space utilization.

[0018] In some embodiments, orthographic projections of all the protrusions on the reference surface have overlapping portions with orthographic projections of the plurality of first tabs on the reference surface.

[0019] In this way, the protrusion can provide supporting force for the first pole ear, thereby reducing the risk of the first pole ear being inserted between the first pole piece and the second pole piece causing a short circuit when the electrode assembly is installed in the outer shell of the battery cell after the first pole ear is connected to the electrode terminal of the battery cell, thereby reducing the risk of pole ear redundancy and improving safety performance.

[0020] In some embodiments, the orthographic projection of any one of all the protrusions on the reference surface has an overlapping portion with the orthographic projection of any one of the multiple first pole ears on the reference surface; and / or, the number of ring segments of the main body is M, and the number of ring segments with protrusions is N; wherein 0.5≤N / M≤1, and N and M are both positive integers.

[0021] In this way, each protrusion can provide a supporting force acting on the first tab, thereby further improving the support effect on the first tab and further reducing the risk of tab redundancy. By controlling the number of ring segments provided by the protrusion, the protrusion can provide a certain supporting effect on the first tab.

[0022] In some embodiments, the middle circle segment of the main body is configured as at least one circle, and a convex portion is provided on at least one middle circle segment.

[0023] In this way, since at least one intermediate ring segment is provided with a protrusion, the protrusion provided on the intermediate ring segment can be used to verify the alignment of the intermediate ring segment, thereby further improving the accuracy of electrode assembly alignment detection. When the orthographic projection of the protrusion on the intermediate ring segment on the reference surface overlaps with the orthographic projection of the first electrode tab on the reference surface, the support performance of the protrusion on the first electrode tab is improved.

[0024] In some embodiments, the middle ring segment is provided as a plurality of rings, and each middle ring segment is provided with a convex portion.

[0025] In this way, the convex portion of each intermediate ring segment can be used to verify the alignment of the intermediate ring segments, thereby further improving the accuracy of detecting the alignment of the electrode assembly. When the orthographic projection of the convex portion on each intermediate ring segment on the reference surface overlaps with the orthographic projection of the first electrode tab on the reference surface, the support performance of the convex portion on the first electrode tab is further improved.

[0026] In some embodiments, along the winding direction of the electrode assembly, the same number of first electrode tabs are arranged between every two adjacent protrusions.

[0027] Since the distribution of the protrusion and the first electrode ear is periodic, not only can the tension of the electrode assembly formed by winding be more balanced along the circumference of the winding, thereby improving the stability of the winding molding, but it also facilitates the automated production of the first electrode ear and the protrusion.

[0028] In some embodiments, the protrusion is projected onto a surface perpendicular to the thickness direction of the protrusion as a first projection, and the thickness direction of the protrusion is perpendicular to the winding axis direction of the electrode assembly; the shapes of all first projections include at least one of a rectangle, a square, a rhombus, and a trapezoid.

[0029] In this way, by controlling the shape of the convex portion, the manufacturing convenience is improved while the convex portion has certain mechanical properties.

[0030] In some embodiments, along the winding direction of the electrode assembly, the size of the protrusion along the winding axis direction of the electrode assembly changes according to a first rule; the first rule includes one of unchanged, first decreasing and then increasing, first increasing and then decreasing, first decreasing and then increasing and then decreasing, and first increasing and then decreasing and then increasing.

[0031] When the first rule is constant, it is advantageous to ensure that the protrusion has certain mechanical properties while facilitating the production of the protrusion. When the first rule includes one of the following: first decreasing and then increasing, first increasing and then decreasing, first decreasing and then increasing, and then decreasing, or first increasing and then decreasing and then increasing, it is advantageous to control mechanical stress by changing the shape of the protrusion, thereby improving the reliability of the protrusion.

[0032] In some embodiments, along the winding axis direction of the electrode assembly, the size of the protrusion along the winding direction of the electrode assembly changes according to a second rule; the second rule includes one of unchanged, decreasing, increasing, first decreasing and then increasing, first increasing and then decreasing, first decreasing and then increasing and then decreasing, and first increasing and then decreasing and then increasing.

[0033] When the second rule is constant, it is advantageous to ensure that the protrusion has certain mechanical properties while facilitating the production of the protrusion. When the second rule includes one of decreasing, increasing, decreasing first then increasing, increasing first then decreasing, decreasing first then increasing then decreasing, or increasing first then decreasing then increasing, it is advantageous to control mechanical stress through the morphological changes of the protrusion, thereby improving the reliability of the protrusion.

[0034] In some embodiments, a dimension of the protrusion along the winding axis direction of the electrode assembly is 2 mm to 6 mm; and / or a dimension of the protrusion along the winding direction of the electrode assembly is 5 mm to 9 mm.

[0035] By controlling the height and / or width of the convex portion, not only is it easier to manufacture the convex portion, but the convex portion can also have a certain mechanical reliability and be adapted to the space limitations during the winding process.

[0036] In some embodiments, the first electrode is a positive electrode, and the second electrode is a negative electrode.

[0037] In this way, the positive electrode sheet can include a first tab and a protrusion. Since the overall rigidity of the positive electrode sheet is greater than that of the negative electrode sheet, this helps improve the stability of the protrusion, and thus helps improve the accuracy of alignment detection. Furthermore, since the negative electrode sheet is usually slightly larger than the positive electrode sheet, using the protrusion on the positive electrode sheet as the detection reference can more directly determine whether the negative electrode sheet effectively covers the positive electrode sheet.

[0038] According to another aspect of the present application, the present application provides a method for manufacturing a battery cell, comprising:

[0039] A first pole piece, a second pole piece, and a separator are provided; the first pole piece includes a main body, a plurality of first pole tabs, and protrusions respectively provided on a first loop section and an end loop section of the main body; along the width direction of the first pole piece, the plurality of first pole tabs and all the protrusions are provided on the same side of the main body, and the stiffness of the protrusions is greater than the stiffness of the first pole tabs;

[0040] stacking and winding the separator, the first pole piece, and the second pole piece to form an electrode assembly;

[0041] When the winding alignment and rewinding alignment of the first electrode sheet and the second electrode sheet both meet the qualified alignment conditions, the electrode assembly is loaded into the accommodating cavity of the shell to form a battery cell; wherein the winding alignment is determined based on the convex part of the first circle segment of the main body, and the rewinding alignment is determined based on the convex part of the last circle segment of the main body.

[0042] In the technical solution of the embodiment of the present application, a convex portion is provided on the first and last loop sections of the main body of the first pole piece, and the stiffness of the convex portion is made greater than the stiffness of the first pole piece, so that the bending resistance of the convex portion is greater than the bending resistance of the first pole piece. Since there is no tension constraint when the head and tail of the first pole piece are cut off, the actual relative position of the first pole piece and the second pole piece may change during winding, resulting in inaccurate results of the pole piece alignment detection. In the embodiment of the present application, when manufacturing the electrode assembly, since the bending resistance of the convex portion is greater than the bending resistance of the first pole piece, when the tension changes, the convex portion can be in a more stable state relative to the first pole piece, so that the convex portion that is less likely to bend can be used to determine the winding alignment and winding alignment of the electrode assembly, thereby improving the detection accuracy of the winding alignment and winding alignment, and further improving the detection accuracy of the electrode assembly alignment.

[0043] In some embodiments, the method for manufacturing a battery cell further includes:

[0044] Acquire a first image of the convex portion of the first winding section of the main body and the main body before the first pole piece is wound; determine a first distance between the convex portion of the first winding section of the main body and the main body in a width direction of the first pole piece based on the first image;

[0045] obtaining a second image of the convex portion of the first winding section of the main body and the main body wound onto the winding member after the first pole piece is wound; and determining, based on the second image, a second distance between the convex portion of the first winding section of the main body and the second pole piece in a width direction of the first pole piece;

[0046] Based on the difference between the first distance and the second distance, it is determined whether the incoming roll alignment satisfies an alignment qualification condition.

[0047] During the winding process of the first pole piece, the tension of the first pole piece will change. Since the convex portion of the first winding section of the main body can be in a more stable state, the first distance between the convex portion of the first winding section of the main body and the main body can be determined more accurately, which is conducive to improving the accuracy of the winding alignment detection.

[0048] In some embodiments, the method for manufacturing a battery cell further includes:

[0049] obtaining a third image of the convex portion of the last coil segment of the main body and the main body before the last coil segment of the main body is wound; and determining, based on the third image, a third distance between the convex portion of the last coil segment of the main body and the main body in the width direction of the first pole piece;

[0050] obtaining a fourth image of the convex portion of the last coil section of the main body and the main body wound onto the winding member after the last coil section of the main body is wound; and determining, based on the fourth image, a fourth distance between the convex portion of the first coil section of the main body and the second pole piece in a width direction of the first pole piece;

[0051] Based on the difference between the third distance and the fourth distance, it is determined whether the winding alignment satisfies an alignment qualification condition.

[0052] During the winding process of the first pole piece, the tension of the first pole piece changes. Since the convex portion of the last coil segment of the main body is in a more stable state, the third distance between the convex portion of the last coil segment of the main body and the main body is more accurately determined, which helps to improve the accuracy of the winding alignment detection.

[0053] In some embodiments, a convex portion is provided on the middle ring section of the main body; and the manufacturing method of the battery cell further includes:

[0054] Based on the verification alignment of the middle loop segments of the first and second pole pieces, a reference alignment of the middle loop segments of the first and second pole pieces is verified; wherein the reference alignment is determined based on the first tab of the middle loop segment located at the main body, and the verification alignment is determined based on the convex portion of the middle loop segment located at the main body;

[0055] When both the winding alignment and the rewinding alignment meet the alignment qualification conditions, and the reference alignment meets the verification qualification conditions, the electrode assembly is installed in the accommodating cavity of the shell to form a battery cell.

[0056] In this way, by verifying the alignment through the convex portion provided on the middle ring segment, the accuracy of the alignment of the middle ring segment can be further improved.

[0057] In some embodiments, a first pole piece, a second pole piece, and a separator are provided, including:

[0058] Providing the first pole piece strip;

[0059] The first pole piece strip is die-cut to form a plurality of first pole tabs and all protrusions to obtain the first pole piece.

[0060] In this way, the first electrode tab and the protrusion can be manufactured through the same process, which not only can utilize the structure of the first electrode piece to manufacture the protrusion, thereby improving the convenience of manufacturing the protrusion, but also helps to improve production efficiency.

[0061] In some embodiments, the method for manufacturing a battery cell further includes:

[0062] When the feeding end of the first pole piece is wound, a force is provided on the side of the feeding end of the first pole piece away from the winding piece, so that the feeding end of the first pole piece can be close to the winding piece.

[0063] In this way, by providing a force acting on the feeding end of the first electrode piece, the feeding end of the first electrode piece can be fed more stably and reliably, reducing the risk of wrinkles, bending, etc. at the feeding end of the first electrode piece, thereby helping to improve the performance of the electrode assembly.

[0064] According to another aspect of the present application, the present application provides a battery device, including the battery cell in any of the above embodiments; or, including the battery cell manufactured by the manufacturing method of the battery cell in any of the above embodiments.

[0065] The advantages possessed by the battery cell in any of the above embodiments and the battery cell manufactured by the manufacturing method of the battery cell in any of the above embodiments are also possessed by the battery device, which will not be described in detail here.

[0066] According to another aspect of the present application, the present application provides an electrical device, comprising the battery device in any of the above embodiments.

[0067] The advantages possessed by the battery device in any of the above embodiments are also possessed by the electrical equipment, which will not be described in detail here.

[0068] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0070] Figure 1 A schematic structural diagram of a vehicle in some embodiments of the present application;

[0071] Figure 2 Schematic diagram of the exploded structure of a battery device in some embodiments of the present application;

[0072] Figure 3 Schematic diagram of the exploded structure of a battery cell in some embodiments of the present application;

[0073] Figure 4 Schematic diagram of the three-dimensional structure of the electrode assembly in some embodiments of the present application;

[0074] Figure 5Schematic diagram of a top view of an electrode assembly in some other embodiments of the present application in a schematic situation;

[0075] Figure 6 This is a structural schematic diagram of the first pole piece in some embodiments of the present application in an unfolded state;

[0076] Figure 7 is a schematic top view of the electrode assembly in some other embodiments of the present application in another schematic situation;

[0077] Figure 8 This is a schematic structural diagram of the first pole piece in an unfolded state for comparison in some comparative examples of the present application;

[0078] Figure 9 Schematic diagram of the top view of the comparative electrode assembly in some comparative examples of the present application;

[0079] Figure 10 A schematic diagram of a comparative electrode assembly in some comparative embodiments of the present application in a state during the manufacturing process;

[0080] Figure 11 A schematic diagram of a comparative electrode assembly in some comparative examples of the present application in another state during the manufacturing process;

[0081] Figure 12 Schematic diagram of the structure of the first pole piece in some other embodiments of the present application in an unfolded state at one viewing angle;

[0082] Figure 13 Schematic diagram of the structure of the first pole piece in some other embodiments of the present application in an unfolded state from another viewing angle;

[0083] Figure 14 is a schematic cross-sectional structural diagram of a portion of the structure of a battery cell in some embodiments of the present application;

[0084] Figure 15 A schematic diagram of a partial structure of a battery cell in some embodiments of the present application;

[0085] Figure 16 Schematic diagram of a cross-sectional structure of a portion of a comparative battery cell in some comparative examples of the present application;

[0086] Figure 17 Schematic diagrams of partial structures of battery cells in some comparative examples of the present application;

[0087] Figure 18 Schematic diagram of a process for manufacturing a battery cell in some embodiments of the present application;

[0088] Figure 19A schematic diagram of an electrode assembly in some embodiments of the present application in a state during the manufacturing process;

[0089] Figure 20 is a schematic diagram of an electrode assembly in some embodiments of the present application in another state during the manufacturing process;

[0090] Figure 21 Schematic diagram of the process of steps SI, SJ, and SK in the method for manufacturing a battery cell in some embodiments of the present application;

[0091] Figure 22 A schematic diagram of a first image in some embodiments of the present application;

[0092] Figure 23 A schematic diagram of a portion of the first pole piece corresponding to the first image in some embodiments of the present application;

[0093] Figure 24 A schematic diagram of a second image in some embodiments of the present application;

[0094] Figure 25 A schematic diagram of a portion of a wound electrode assembly corresponding to the second image in some embodiments of the present application;

[0095] Figure 26 Schematic diagram of the process of steps SF, SG, and SH in the method for manufacturing a battery cell in some embodiments of the present application;

[0096] Figure 27 A schematic diagram of a portion of the first pole piece corresponding to the third image in some embodiments of the present application;

[0097] Figure 28 A schematic diagram of a portion of a wound electrode assembly corresponding to the fourth image in some embodiments of the present application;

[0098] Figure 29 Schematic diagram of the process of steps SO and SP in the method for manufacturing a battery cell in some embodiments of the present application;

[0099] Figure 30 This is a flowchart of steps S111 and S112 in some embodiments of the present application.

[0100] Description of reference numerals:

[0101] Vehicle 1;

[0102] Battery device 10, controller 20, motor 30;

[0103] Battery cell 100, outer shell 110, housing 111, end cap 112, electrode terminal 1121, electrode assembly 120, first electrode sheet 121, main body 1211, first coil segment Q1, last coil segment Q2, middle coil segment Q3, first electrode tab 1212, protrusion 1213, first surface m1, second surface m2, first insulating layer 1214, first insulating portion 12141, second insulating portion 12142, first region Z1, second region Z2, second electrode sheet 122, second electrode tab 1221, separator 123;

[0104] Box body 200, first box body portion 210, second box body portion 220;

[0105] Winding member 1000, image acquisition device 2000, first image acquisition component 2100, second image acquisition component 2200, cutting device 3000, conveying device 4000, image acquisition blind area W;

[0106] Compare the electrode assembly 120 ′, compare the first pole piece 121 ′, redundant area A;

[0107] First distance h1, second distance h2, third distance h3, fourth distance h4;

[0108] A first size d1, a second size d2, a third size d3, and a fourth size d4;

[0109] Reference surface E;

[0110] First direction F1, second direction F2, third direction F3, winding axis direction J1, winding direction J2, winding axis L. DETAILED DESCRIPTION

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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, B1 and / or B2 can represent three situations: B1 exists alone, B1 and B2 exist simultaneously, and B2 exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0116] 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).

[0117] 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.

[0118] 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.

[0119] Currently, market developments indicate that power batteries are becoming increasingly widely used. They 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 military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0120] During the winding process of the electrode assembly, the alignment of the electrode sheets needs to be checked. Typically, the relative positions of the positive and negative electrode sheets are measured before winding for alignment testing. However, since the head and tail of the electrode sheets are not tensioned when cut, the actual relative positions of the positive and negative electrode sheets may change during winding, resulting in inaccurate alignment test results.

[0121] Based on this, and to improve the accuracy of detecting the alignment of the electrode assembly, an embodiment of the present application provides a battery cell that provides protrusions on the first and last winding sections of the main body of the first electrode sheet, and utilizes these protrusions to improve the accuracy of detecting the alignment. Specifically, by configuring the stiffness of the protrusions on the first and last winding sections of the main body to be greater than the stiffness of the first electrode tab, the protrusions' ability to resist bending is improved, and alignment can be detected using the protrusions as a detection reference, thereby improving the accuracy of alignment detection.

[0122] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft. A power supply system comprising the battery cells disclosed in this application and other components can be used to improve the accuracy of electrode assembly alignment detection, thereby enhancing the performance, safety, and production consistency of the battery cells.

[0123] The present application provides an electrical device that uses a battery device as a power source. The electrical device is a device that uses electrical energy as an energy source and consumes electrical energy to achieve corresponding functions. For example, the electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0124] The electric device of the embodiment of the present application may include a device body and a power supply device, the power supply device is used to supply power to the device body, and the power supply device may include a battery cell or a battery pack. The device body refers to the main structure that consumes electric energy to achieve the corresponding function. For example, the electric device may be a mobile phone, the device body is the part that can achieve functions such as communication, and power is supplied to the part that can achieve functions such as communication through a battery cell or a battery pack. For example, the electric device may be a car, the device body is the part that can be used for people to sit on and can be driven on the road, and power is supplied to the part that can be used for people to sit on and can be driven on the road through a battery cell or a battery pack. The power supply device refers to a device that can output electric energy. For example, electric energy can be output by a battery pack composed of battery cells.

[0125] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0126] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the vehicle 1 in some embodiments of the present application. The vehicle 1 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 10 is provided inside the vehicle 1. The battery device 10 can be provided at the bottom, head or tail of the vehicle 1. The battery device 10 can be used to power the vehicle 1. For example, the battery device 10 can serve as an operating power source for the vehicle 1. The vehicle 1 can also include a controller 20 and a motor 30. The controller 20 is used to control the battery device 10 to power the motor 30, for example, for starting, navigating and operating power requirements of the vehicle 1 during driving.

[0127] In some embodiments of the present application, the battery device 10 can serve not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0128] In order to meet different power requirements, the battery device 10 may include a plurality of battery cells 100, and the battery cell 100 refers to the smallest unit that constitutes a battery module or a battery pack. A plurality of battery cells 100 can be connected in series and / or in parallel via electrode terminals for use in various applications. The batteries mentioned in this application include battery modules or battery packs. Among them, a plurality of battery cells 100 can be connected in series, in parallel, or in mixed connection, and mixed connection refers to a mixture of series and parallel connection. The battery device 10 may also be referred to as a battery pack. In the embodiment of the present application, a plurality of battery cells 100 may directly constitute a battery pack, or may first constitute a battery module, and then the battery module may constitute a battery pack.

[0129] Please refer to Figure 2 , Figure 2Schematic diagram of the exploded structure of the battery device 10 in some embodiments of the present application. Figure 2 In the embodiment, the battery device 10 may include a plurality of battery modules and a housing 200, and the plurality of battery modules are housed inside the housing 200. The housing 200 is used to house the battery cells 100 to reduce the risk of liquid or other foreign matter affecting the charging or discharging of the battery cells 100. The housing 200 may be a simple three-dimensional structure such as a single cuboid, cylinder or sphere, or a complex three-dimensional structure composed of a combination of simple three-dimensional structures such as cuboids, cylinders or spheres, and the embodiments of the present application do not limit this. The material of the housing 200 may be an alloy material such as aluminum alloy, iron alloy, or a polymer material such as polycarbonate, polyisocyanurate foam plastic, or a composite material such as glass fiber and epoxy resin, and the embodiments of the present application do not limit this.

[0130] In some embodiments, the housing 200 may include a first housing portion 210 and a second housing portion 220. The first housing portion 210 and the second housing portion 220 overlap each other, and the first housing portion 210 and the second housing portion 220 jointly define a space for accommodating the battery cells 100. The second housing portion 220 may be a hollow structure with one end open, and the first housing portion 210 may be a plate-like structure. The first housing portion 210 overlaps the open side of the second housing portion 220, so that the first housing portion 210 and the second housing portion 220 jointly define a space for accommodating the battery cells 100. The first housing portion 210 and the second housing portion 220 may also be hollow structures with one end open, with the open side of the first housing portion 210 overlapping the open side of the second housing portion 220.

[0131] The battery module may include a plurality of battery cells 100, and the plurality of battery cells 100 may be first connected in series, in parallel, or in a mixed connection to form a battery module, and the plurality of battery modules may then be connected in series, in parallel, or in a mixed connection to form a battery. In the present application, the battery cell 100 may include a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery device, etc., and the embodiments of the present application do not limit this. The battery cell 100 may be cylindrical, flat, rectangular, or in other shapes, etc., and the embodiments of the present application do not limit this. The battery cell 100 may be cylindrical, flat, rectangular, or in other shapes, etc., and the embodiments of the present application do not limit this. However, for the sake of simplicity, the following embodiments are all described using a square battery cell as an example.

[0132] Please refer to Figure 3 , Figure 3 Schematic diagram of the exploded structure of the battery cell 100 in some embodiments of the present application. The battery cell 100 refers to the smallest unit that constitutes the battery device 10. Figure 3 The battery cell 100 includes a housing 110 , an electrode assembly 120 and other functional components.

[0133] The outer shell 110 is a component used to form the internal environment of the battery cell 100. The outer shell 110 may include a shell 111 and an end cap 112. The shell 111 is a component used to cooperate with the end cap 112 to form the internal environment of the battery cell 100. The internal environment formed can be used to accommodate the electrode assembly 120, the electrolyte (not shown in the figure) and other components. The shell 111 and the end cap 112 can be independent components. An opening can be provided on the shell 111, and the end cap 112 is made to cover the opening to form the internal environment of the battery cell 100. Without limitation, the end cap 112 and the shell 111 can also be integrated. Specifically, the end cap 112 and the shell 111 can form a common connection surface before other components are inserted into the shell. When the interior of the shell 111 needs to be encapsulated, the end cap 112 is made to cover the shell 111. The shell 111 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 111 can be determined based on the specific shape and size of the electrode assembly 120. The housing 111 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular restrictions on this. The opening of the housing 111 can be located on the side or bottom of the housing 111, and this embodiment of the present application does not impose any particular restrictions on this.

[0134] The end cap 112 is a component that can be fitted over the opening of the housing 111 to isolate the internal environment of the battery cell 100 from the external environment. The shape of the end cap 112 can be adapted to the shape of the housing 111 to fit the housing 111. For example, the end cap 112 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 112 from deforming when subjected to compression or collision, giving the battery cell 100 greater structural strength and improved safety. Functional components such as electrode terminals 1121 can be provided on the end cap 112. The electrode terminals 1121 can be used to electrically connect to the electrode assembly 120 for outputting or inputting electrical energy into the battery cell 100. In some embodiments, the end cap 112 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold. In some embodiments, the end cap 112 can also be provided with an injection port for injecting electrolyte into the battery cell 100. Of course, the electrode terminal 1121 and the injection hole can also be provided on the shell 111. The material of the end cover 112 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the end cover 112, and the insulating member can be used to isolate the electrical connection components in the shell 111 from the end cover 112 to reduce the risk of short circuit. Exemplarily, the material of the insulating member can be plastic, rubber, etc. In some embodiments, a pressure relief mechanism can also be provided on the shell 111 and / or the end cover 112. The pressure relief mechanism is used to release the internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold value to improve the safety performance of the battery cell 100. The threshold design varies according to different design requirements. The threshold may depend on one or more materials of the electrode assembly 120 and the isolation member in the battery cell 100. The pressure relief mechanism may be in the form of an explosion-proof valve, an air valve, a pressure relief valve or a safety valve, and may specifically be a pressure-sensitive or temperature-sensitive element or structure, that is, when the internal pressure or temperature of the battery cell 100 reaches a threshold value, the pressure relief mechanism executes an action or a weak structure provided in the pressure relief mechanism is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released.

[0135] The electrode assembly 120 is a component where electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 120 may be contained within the housing 110.

[0136] The electrode assembly 120 is mainly formed by winding a positive electrode sheet and a negative electrode sheet, and an isolating member is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 120, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively at both ends of the main body, can be located at the top of the main body, or can be located on the side wall of the main body, and there is no specific limitation here. During the charge and discharge process of the battery device 10, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals 1121 to form a current loop. The isolating member is used to isolate the positive electrode sheet and the negative electrode sheet, and prevent the electrons in the battery cell 100 from passing freely, allowing the ions in the electrolyte to flow freely between the positive electrode sheet and the negative electrode sheet. The isolating member can be a thin film made of materials such as PE (polyethylene) and PP (polypropylene).

[0137] According to some embodiments of this application, please refer to Figures 4 to 6 , Figure 4 is a schematic diagram of the three-dimensional structure of the electrode assembly 120 in some embodiments of the present application. Figure 5 FIG. 1 is a schematic top view of the electrode assembly 120 in some other embodiments of the present application in a schematic situation. Figure 6 This is a schematic diagram of the structure of the first electrode sheet 121 in some embodiments of the present application in an unfolded state. The present application provides a battery cell 100, including an electrode assembly 120. The electrode assembly 120 has a wound structure and includes a first electrode sheet 121, a second electrode sheet 122, and a separator 123. The separator 123 separates the first electrode sheet 121 from the second electrode sheet 122. The first electrode sheet 121 includes a main body 1211, a plurality of first electrode tabs 1212, and protrusions 1213 respectively provided on the first coil section Q1 and the last coil section Q2 of the main body 1211. Along the winding axis J1 of the electrode assembly 120, the plurality of first electrode tabs 1212 and all the protrusions 1213 are provided on the same side of the main body 1211. The stiffness of the protrusions 1213 is greater than that of the first electrode tabs 1212.

[0138] The first electrode 121 and the second electrode 122 have opposite polarities. One of the first electrode 121 and the second electrode 122 is a positive electrode, and the other is a negative electrode. In the embodiment of the present application, the first electrode 121 can be a positive electrode, and the second electrode 122 can be a negative electrode. The positive electrode, negative electrode, separator 123, and main body 1211 can be understood with reference to the embodiments shown in the previous embodiments, and will not be described in detail here.

[0139] For example, in Figure 4In the illustrated embodiment, the first electrode sheet 121 includes a first electrode tab 1212, and the second electrode sheet 122 includes a second electrode tab 1221. The first electrode tab 1212 and the second electrode tab 1221 are located on the same side of the electrode assembly 120. The first electrode tab 1212 and the second electrode tab 1221 are respectively connected to different electrode terminals 1121 of the battery cell 100. The first direction F1, the second direction F2, and the third direction F3 can be considered the length, width, and height directions of the electrode assembly 120. That is, the first direction F1, the second direction F2, and the third direction F3 can be perpendicular to each other. It should be noted that the length, width, and height directions do not limit the size of the electrode assembly 120, but rather indicate that the electrode assembly 120 has certain dimensions in these three directions. The winding axis direction J1 of the electrode assembly 120 is the extension direction of the winding axis L of the electrode assembly 120. The extension direction of the winding axis L of the electrode assembly 120 can be the first direction F1. That is, the first electrode tab 1212 and the protrusion 1213 are disposed on one side of the main body 1211 along the first direction F1.

[0140] In the structure of the wound electrode assembly 120, a "segment" is a structural unit defined based on the order and positional characteristics of the winding process of the electrode sheet and separator 123, and is used to describe the winding sections at different locations. The number of segments corresponds to the number of turns of the electrode assembly 120. During the winding process of the electrode assembly 120, the segment forming the innermost turn of the continuous coil structure formed by rotational winding with the winding axis L as the reference is the first turn segment of the electrode assembly 120, and the segment forming the outermost turn is the last turn segment of the electrode assembly 120. When the number of turns of the electrode assembly 120 is greater than or equal to three, the electrode assembly 120 includes an intermediate turn segment connecting between the first turn segment and the last turn segment of the electrode assembly 120. When the electrode assembly 120 has multiple intermediate turn segments, all intermediate turn segments of the electrode assembly 120 are connected sequentially, with the intermediate turn segment of the first electrode assembly 120 connected to the first turn segment of the electrode assembly 120, and the intermediate turn segment of the last electrode assembly 120 connected to the last turn segment of the electrode assembly 120. The first circle segment Q1 of the main body 1211 is the part of the main body 1211 located in the first circle segment of the electrode assembly 120, the last circle segment Q2 of the main body 1211 is the part of the main body 1211 located in the last circle segment of the electrode assembly 120, and the middle circle segment Q3 of the main body 1211 is the part of the main body 1211 located in the middle circle segment of the electrode assembly 120.

[0141] For example, Figure 6 As an example, the main body 1211 includes a first circle segment Q1, a last circle segment Q2, and a plurality of middle circle segments Q3 connected between the first circle segment Q1 and the last circle segment Q2. Figure 6In the illustrated case, for ease of illustration, part of the middle coil segment Q3 is omitted, and the coil segments are distinguished by dotted lines. The dotted lines only illustrate the division of the coil segments and do not mean that there are obvious structural boundaries in the actual structure. Of course, relevant boundaries can also be set on the first pole piece 121 for distinction, and no specific limitation is made here. It can be understood that the feeding end of the main body 1211 is the beginning of the first coil segment Q1 of the main body 1211, and the receiving end of the main body 1211 is the end of the last coil end of the main body 1211.

[0142] Please continue to refer to Figure 5 , and combined with reference Figure 7 , Figure 7 FIG2 is a schematic diagram of a top view of the electrode assembly 120 in another embodiment of the present application, in which it can be seen that the first circle segment Q1 and the last circle segment Q2 of the main body 1211 are both provided with a convex portion 1213. Figure 5 and Figure 7 The first tab 1212 and the convex portion 1213 are shown in different schematic forms. Of course, the middle ring segment Q3 of the main body 1211 may also be provided with the convex portion 1213 or may not be provided with the convex portion 1213, and no specific limitation is made here. Figure 4 、 Figure 5 and Figure 7 In the illustrated embodiment, the middle segment Q3 of the main body 1211 is also provided with a convex portion 1213. Figure 4 The relative positions of the first tab 1212, the second tab 1221 and the protrusion 1213 are shown in FIG. Figure 5 、 Figure 7 The relative positions of the first electrode tab 1212, the second electrode tab 1221 and the protrusion 1213 shown in FIG are different. It can be understood that this is just a different structural form, but the present invention is not limited to this.

[0143] Stiffness is a component's ability to resist bending and deformation. It is a performance parameter that measures a component's ability to maintain its shape (e.g., resist bending) when subjected to external forces. Stiffness can be used to characterize a component's mechanical properties for resisting deformation. The stiffness of protrusion 1213 is greater than the stiffness of first tab 1212, meaning that the ability of protrusion 1213 to resist deformation is stronger than the ability of first tab 1212 to resist deformation. For example, the stiffness of protrusion 1213 can be adjusted by controlling its shape, structure, and size, without specific limitation herein.

[0144] It should be noted that component stiffness can be measured by simulating bending forces and quantifying the force or deformation during bending. For example, testing can be performed using the cantilever beam method or the four-point bending method. In the cantilever beam method, for example, one end of the component is fixed, and a vertical force is applied to the free end. The force required to bend the free end to a specific angle (such as 15°, 30°, or other angles) is measured. A higher force value corresponds to a higher stiffness. This is not a specific limitation.

[0145] Combined with reference Figure 8 and Figure 9 , Figure 8 This is a schematic structural diagram of the first pole piece 121' in an unfolded state in some comparative examples of this application. Figure 9 This is a schematic diagram of a top view of a comparative electrode assembly 120' in some comparative examples of the present application. In some comparative examples of the present application, the comparative first electrode piece 121' in the comparative electrode assembly 120' is only provided with a first electrode ear 1212, and no protrusion 1213 is provided. Figure 10 and Figure 11 , Figure 10 Schematic diagram of a comparative electrode assembly 120' in some comparative embodiments of the present application in a state during the manufacturing process, Figure 11 This is a schematic diagram of a comparative electrode assembly 120' in another state during the manufacturing process in some comparative embodiments of the present application, illustrating the situation of the comparative first electrode piece 121' before and after the material is charged. When the image acquisition device 2000 is used to capture the image of the first electrode tab 1212 of the comparative first electrode piece 121' before the material is charged, the image of the comparative first electrode piece 121' is captured. Figure 10 and Figure 11 It can be seen that due to the image acquisition blind spot W, the image acquisition device 2000 is unable to capture a more accurate image. Furthermore, before the first comparative electrode piece 121' is fed, the feeding end of the first comparative electrode piece 121' is a free end. After the first comparative electrode piece 121' is fed, the feeding end of the first comparative electrode piece 121' is wound around the winding member 1000. During the feeding process, the tension of the first comparative electrode piece 121' changes, causing the position of the first electrode tab 1212 of the first comparative electrode piece 121' to easily change, further making it difficult to capture a more accurate image. Similarly, during the reeling process of the first comparative electrode piece 121', the first comparative electrode piece 121' is cut off by the cutting device 3000, thereby also causing the tension of the reeling end of the first comparative electrode piece 121' to change, and the image acquisition blind spot W also exists, making it impossible to capture a more accurate image.

[0146] In the embodiment of the present application, because the stiffness of the protrusion 1213 is greater than the stiffness of the first electrode tab 1212, when the tension changes due to feeding and rewinding, image capture can be performed based on the more stable protrusion 1213, thereby capturing more accurate images, which is conducive to determining more accurate feed and rewind alignment. Even if there is an image capture blind spot W, because the protrusion 1213 can be in a more stable state, more accurate images can be captured before and after feeding the first electrode piece 121 and before and after rewinding the first electrode piece 121.

[0147] It should be noted that the “winding alignment” refers to the alignment of the first electrode plate 121 and the second electrode plate 122 at the first turn section of the electrode assembly 120 , and the “winding alignment” refers to the alignment of the first electrode plate 121 and the second electrode plate 122 at the last turn section of the electrode assembly 120 .

[0148] Therefore, by providing the protrusions 1213 on the first coil segment Q1 and the last coil segment Q2 of the main body 1211 of the first electrode piece 121, and making the stiffness of the protrusions 1213 greater than the stiffness of the first electrode tab 1212, the bending resistance of the protrusions 1213 is made greater than the bending resistance of the first electrode tab 1212. Since the head and tail of the first electrode piece 121 are not tension-bound when cut, the actual relative position of the first electrode piece 121 and the second electrode piece 122 may change during winding, resulting in inaccurate results of the electrode piece alignment test. In an embodiment of the present application, when manufacturing the electrode assembly 120, since the bending resistance of the protrusion 1213 is greater than the bending resistance of the first pole ear 1212, when the tension changes, the protrusion 1213 can be in a more stable state relative to the first pole ear 1212, so that the protrusion 1213 that is less likely to bend can be used to determine the winding alignment and rewinding alignment of the electrode assembly 120, thereby improving the detection accuracy of the winding alignment and rewinding alignment, and thereby improving the detection accuracy of the alignment of the electrode assembly 120.

[0149] According to some embodiments of this application, please continue to refer to Figure 6 The first electrode piece 121 further includes an insulating layer, which includes a first insulating portion 12141 and a second insulating portion 12142 connected to the first insulating portion 12141. The edge region of the main body 1211, where the plurality of first electrode tabs 1212 and the protrusion 1213 are located, is defined as the first region Z1. The root region of the first electrode tab 1212, adjacent to the main body 1211, is defined as the second region Z2. The first insulating portion 12141 is located in the first region Z1, while the second insulating portion 12142 is located in the second region Z2 and covers at least a portion of the protrusion 1213.

[0150] Among them, Figure 6 The dotted lines in the figure roughly indicate the positions of the first zone Z1 and the second zone Z2.

[0151] The insulating layer is a layer used to provide insulation and protection. Exemplarily, the insulating layer includes an inorganic filler and a binder. The inorganic filler includes one or more of boehmite, aluminum oxide, magnesium oxide, titanium dioxide, zirconium oxide, silicon dioxide, silicon carbide, boron carbide, calcium carbonate, aluminum silicate, calcium silicate, potassium titanate, and barium sulfate. The binder includes one or more of polyvinylidene fluoride, polyacrylonitrile, polyacrylic acid, polyacrylate, polyacrylic acid-acrylate, polyacrylonitrile-acrylic acid, and polyacrylonitrile-acrylate.

[0152] Exemplarily, the thickness of the insulating layer may be 80 μm to 200 μm. For example, the thickness of the insulating layer may be 80 μm, 90 μm, 100 μm, 110 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, or 200 μm. The thickness of the insulating layer may be any value within the range of 80 μm to 200 μm, and is not specifically limited herein.

[0153] The second insulating portion 12142 may cover part or all of the convex portion 1213, which is not specifically limited here. Figure 6 As an example, the second insulating portion 12142 covers part of the protrusion 1213. Figure 12 For example, Figure 12 This is a schematic structural diagram of the first pole piece 121 in another embodiment of the present application in an unfolded state from one viewing angle, illustrating a situation where the second insulating portion 12142 completely covers the protrusion 1213. It can be understood that because the second insulating portion 12142 covers at least a portion of the protrusion 1213 and the insulating layer has a certain thickness, the stiffness of the protrusion 1213 is improved.

[0154] For example, Figure 12 and Figure 13 For example, Figure 13 This is a structural schematic diagram of the first pole piece 121 in some other embodiments of the present application in an unfolded state from another viewing angle. The first pole piece 121 is provided with an insulating layer on both sides in the thickness direction thereof.

[0155] The provision of an insulating layer provides insulation protection. Even if the first pole piece 1212 is inserted between the first pole piece 121 and the second pole piece 122, the insulating layer can separate the first pole piece 1212 from the second pole piece 122, thereby reducing the risk of short circuits and improving safety performance. Because the insulating layer has a certain thickness, the thickness of the area of ​​the first pole piece 121 covered with the insulating layer can be increased, which can increase the moment of inertia of the section, thereby increasing the stiffness of the area of ​​the first pole piece 121 covered with the insulating layer, which is conducive to further improving the stiffness of the protrusion 1213, thereby further improving the detection accuracy of the winding alignment and the winding alignment.

[0156] It should be noted that the stiffness of the protrusion 1213 can be adjusted by controlling the material, thickness and covered area of ​​the insulating layer, and no specific limitation is given here.

[0157] According to some embodiments of this application, please continue to refer to Figure 6 、 Figure 12 and Figure 13 The protrusion 1213 includes a first surface m1 and a second surface m2 that are oppositely disposed along the thickness direction of the protrusion 1213. The thickness direction of the protrusion 1213 is perpendicular to the winding axis direction J1 of the electrode assembly 120. The ratio of the area of ​​the first surface m1 covered by the second insulating portion 12142 to the area of ​​the first surface m1 is 0.8 to 1; and / or the ratio of the area of ​​the second surface m2 covered by the second insulating portion 12142 to the area of ​​the second surface m2 is 0.8 to 1.

[0158] For example, the ratio of the area of ​​the first surface m1 covered by the second insulating portion 12142 to the area of ​​the first surface m1 can be 0.8, 0.81, 0.83, 0.86, 0.9, 0.92, 0.94, 0.97, or 1. Of course, the ratio of the area of ​​the first surface m1 covered by the second insulating portion 12142 to the area of ​​the first surface m1 can be any value in the range of 0.8 to 1, and is not specifically limited here. The ratio of the area of ​​the second surface m2 covered by the second insulating portion 12142 to the area of ​​the second surface m2 can be 0.8, 0.81, 0.83, 0.86, 0.9, 0.92, 0.94, 0.97, or 1. Of course, the ratio of the area of ​​the second surface m2 covered by the second insulating portion 12142 to the area of ​​the second surface m2 can be any value in the range of 0.8 to 1, and is not specifically limited here. It can be understood that the more area on the protrusion 1213 that is covered by the insulating layer, the more conducive it is to improving the stiffness of the protrusion 1213.

[0159] By controlling the area ratio covered by the second insulating portion 12142 on the first surface m1 and / or the second surface m2 of the protrusion 1213 , the stiffness of the protrusion 1213 can be further improved, thereby further improving the detection accuracy of the winding alignment and the rewinding alignment.

[0160] According to some embodiments of this application, please continue to refer to Figure 6 、 Figure 12 and Figure 13 The ratio of the surface area of ​​the region where the protrusion 1213 is covered by the second insulating portion 12142 to the surface area of ​​the protrusion 1213 is 0.8 to 1.

[0161] For example, the ratio of the surface area of ​​the area of ​​the protrusion 1213 covered by the second insulating portion 12142 to the surface area of ​​the protrusion 1213 can be 0.8, 0.81, 0.83, 0.86, 0.9, 0.92, 0.94, 0.97, or 1. Of course, the ratio of the surface area of ​​the area of ​​the protrusion 1213 covered by the second insulating portion 12142 to the surface area of ​​the protrusion 1213 can be any value within the range of 0.8 to 1, and is not specifically limited herein. It will be appreciated that the more area of ​​the protrusion 1213 covered by the insulating layer, the more conducive it is to improving the stiffness of the protrusion 1213.

[0162] The size of the area covered by the insulating layer on the first surface m1 of the protrusion 1213 and the size of the area covered by the insulating layer on the second surface m2 of the protrusion 1213 can be the same or different, and there is no specific limitation here. In the embodiment of the present application, the size of the area covered by the insulating layer on the first surface m1 of the protrusion 1213 and the size of the area covered by the insulating layer on the second surface m2 of the protrusion 1213 are the same. This facilitates the fabrication of the insulating layer and the protrusion 1213.

[0163] By controlling the area ratio of the protrusion 1213 covered by the second insulating portion 12142 , the stiffness of the protrusion 1213 can be further improved, thereby further improving the detection accuracy of the winding alignment and the rewinding alignment.

[0164] According to some embodiments of this application, please continue to refer to Figure 6 、 Figure 12 and Figure 13 , along the winding axis direction J1 of the electrode assembly 120 , the size of the protrusion 1213 is smaller than the size of the first electrode tab 1212 ; and / or, along the winding direction J2 of the electrode assembly 120 , the size of the protrusion 1213 is smaller than the size of the first electrode tab 1212 .

[0165] Along the winding axis J1 of the electrode assembly 120, the dimension of the protrusion 1213 is a first dimension d1. Along the winding axis J1 of the electrode assembly 120, the dimension of the first electrode tab 1212 is a second dimension d2. That is, the first dimension d1 is smaller than the second dimension d2. Along the winding direction J2 of the electrode assembly 120, the dimension of the protrusion 1213 is a third dimension d3. Along the winding direction J2 of the electrode assembly 120, the dimension of the first electrode tab 1212 is a fourth dimension d4. That is, the third dimension d3 is smaller than the fourth dimension d4.

[0166] In this way, by controlling the size of the protrusion 1213 along the winding axis direction J1 of the electrode assembly 120 and / or along the winding direction J2 of the electrode assembly 120, the protrusion 1213 is roughly smaller than the first electrode tab 1212, which is beneficial to adjusting the stiffness of the protrusion 1213.

[0167] According to some embodiments of this application, please continue to refer to Figure 6 The ratio of the size of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 to the size of the protrusion 1213 along the winding axis direction J1 of the electrode assembly 120 is greater than or equal to 7.

[0168] That is, the ratio of the third dimension d3 to the first dimension d1 is greater than or equal to 7. For example, the ratio of the third dimension d3 to the first dimension d1 can be 7, 8, 9, 10, or 15. The upper limit of the ratio of the third dimension d3 to the first dimension d1 can be determined based on the first dimension d1. As shown in some of the aforementioned embodiments, the first dimension d1 is smaller than the second dimension d2. That is, the ratio of the third dimension d3 to the second dimension d2 is less than 7. This is not a specific limitation.

[0169] By controlling the ratio of the size of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 to the size along the winding axis direction J1 of the electrode assembly 120 , the stiffness of the protrusion 1213 can be further adjusted.

[0170] It should be noted that when "along the winding axis direction J1 of the electrode assembly 120, the size of the protrusion 1213 is smaller than the size of the first pole tab 1212", "along the winding direction J2 of the electrode assembly 120, the size of the protrusion 1213 is smaller than the size of the first pole tab 1212", and "the ratio of the size of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 to the size of the protrusion 1213 along the winding axis direction J1 of the electrode assembly 120 is greater than or equal to 7", the protrusion 1213 can have a smaller height and a larger lateral size. In this way, the protrusion 1213 is roughly arranged in a short and thick shape, which is beneficial to improving the stiffness of the protrusion 1213.

[0171] According to some embodiments of this application, please continue to refer to Figure 4 、 Figure 5 and Figure 7 The electrode assembly 120 has a reference plane E, and the winding axis L of the electrode assembly 120 is located on the reference plane E. The reference plane E has a first side and a second side opposite to each other. The plurality of first tabs 1212 are located on the first side, and all the protrusions 1213 are located on the second side.

[0172] exist Figure 5 and Figure 7 From the perspective of , the reference surface E is set in a linear shape and the winding axis L is set in a point shape.

[0173] By arranging the first electrode tabs 1212 and the protrusions 1213 on different sides, all the first electrode tabs 1212 can be arranged in the same area, which not only facilitates the connection of all the first electrode tabs 1212 with the electrode terminals 1121 of the battery cells 100 , but also helps to improve space utilization.

[0174] Of course, in some other embodiments, a portion of the first tab 1212 and a portion of the protrusion 1213 may be located on the first side, and another portion of the first tab 1212 and another portion of the protrusion 1213 may be located on the second side. This is not specifically limited here.

[0175] According to some embodiments of this application, please continue to refer to Figure 4 、 Figure 5 and Figure 7 The orthographic projections of all the protrusions 1213 on the reference plane E have overlapping portions with the orthographic projections of the plurality of first tabs 1212 on the reference plane E.

[0176] That is, in Figure 4 、 Figure 5 and Figure 7 In the third direction F3 shown, the protrusions 1213 and the first tabs 1212 have overlapping portions. The orthographic projections of all protrusions 1213 on the reference plane E may partially or completely overlap with the orthographic projections of the first tabs 1212 on the reference plane E, without specific limitation.

[0177] In this way, the protrusion 1213 can provide supporting force for the first pole ear 1212, thereby reducing the risk of the first pole ear 1212 being inserted into the first pole piece 121 and the second pole piece 122 causing a short circuit during the process of installing the electrode assembly 120 in the outer shell 110 of the battery cell 100 after the first pole ear 1212 is connected to the electrode terminal 1121 of the battery cell 100, thereby reducing the risk of pole ear redundancy and improving safety performance.

[0178] It should be noted that when multiple electrode assemblies 120 are combined and assembled within the housing 110 of a battery cell 100, redundant tabs often occur due to factors such as manufacturing processes and fixture interference. However, in the present embodiment, a protrusion 1213 is provided on the opposite side of the first tab 1212 to provide support for the first tab 1212.

[0179] According to some embodiments of this application, please continue to refer to Figure 4 、 Figure 5 and Figure 7 , the orthographic projection of any convex portion 1213 among all the convex portions 1213 on the reference plane E has an overlapping portion with the orthographic projection of any first pole ear 1212 among the plurality of first pole ears 1212 on the reference plane E; and / or, the number of loop segments of the main body 1211 is M, and the number of loop segments with convex portions 1213 is N; wherein 0.5≤N / M≤1, and both N and M are positive integers.

[0180] “The orthographic projection of any convex portion 1213 among all convex portions 1213 on the reference plane E has an overlapping portion with the orthographic projection of any first tab 1212 among the plurality of first tabs 1212 on the reference plane E”, that is, Figure 4 、 Figure 5 and Figure 7 In the third direction F3 shown, all first tabs 1212 and all protrusions 1213 can be considered as stacked. It is understood that the more protrusions 1213 stacked with the first tabs 1212, the more conducive to improving the support effect for the first tabs 1212.

[0181] "0.5≤N / M≤1", that is, most of the ring segments are provided with convex portions 1213. For example, the ratio of N / M can be 0.5, 0.8 or 1, which is not specifically limited here. Figure 5 and Figure 7 For example, the electrode assembly 120 is shown as having three segments, each of which is provided with a protrusion 1213. That is, the first segment Q1, the middle segment Q3, and the last segment Q2 of the main body 1211 are all provided with a protrusion 1213. It will be appreciated that the more segments provided with protrusions 1213, the more conducive it is to providing the aforementioned stacked protrusions 1213, thereby further improving the support effect on the first electrode tab 1212.

[0182] In this way, each protrusion 1213 can provide a supporting force acting on the first tab 1212, thereby further improving the support effect on the first tab 1212 and further reducing the risk of tab redundancy. By controlling the number of loop segments of the protrusion 1213, the protrusion 1213 can provide a certain supporting effect on the first tab 1212.

[0183] Of course, in some other embodiments, the protrusion 1213 may not overlap with the first electrode tab 1212 in the third direction F3, and no specific limitation is made here.

[0184] According to some embodiments of this application, please continue to refer to Figures 4 to 7 The middle circle segment Q3 of the main body 1211 is set to at least one circle, and a convex portion 1213 is provided on at least one middle circle segment Q3.

[0185] In this manner, since at least one intermediate segment Q3 is provided with a protrusion 1213, the alignment of the intermediate segment Q3 can be verified using the protrusion 1213 provided on the intermediate segment Q3, thereby further improving the accuracy of detecting the alignment of the electrode assembly 120. When the orthographic projection of the protrusion 1213 on the intermediate segment Q3 on the reference plane E overlaps with the orthographic projection of the first electrode tab 1212 on the reference plane E, the support provided by the protrusion 1213 to the first electrode tab 1212 is improved.

[0186] According to some embodiments of this application, please continue to refer to Figures 4 to 7 The middle circle segment Q3 is set to multiple circles, and each middle circle segment Q3 is provided with a convex portion 1213.

[0187] In this way, the protrusion 1213 of each intermediate segment Q3 can be used to verify the alignment of the intermediate segment Q3, thereby further improving the accuracy of detecting the alignment of the electrode assembly 120. Of course, when the orthographic projection of the protrusion 1213 on each intermediate segment Q3 on the reference plane E overlaps with the orthographic projection of the first electrode tab 1212 on the reference plane E, the support performance of the protrusion 1213 on the first electrode tab 1212 is further improved.

[0188] It should be noted that, in conjunction with the reference Figure 14 and Figure 15 , Figure 14 Schematic diagram of a cross-sectional structure of a portion of a battery cell 100 in some embodiments of the present application. Figure 15 This is a schematic diagram of a partial structure of a battery cell 100 in some embodiments of the present application. The first tab 1212 is connected to the electrode terminal 1121. Since the protrusion 1213 can support the first tab 1212, after the two electrode assemblies 120 are installed in the housing 110, the first tab 1212 can be kept in a retracted state. Figure 8 、 Figure 9 、 Figure 16 and Figure 17 Because the protrusion 1213 is not provided, after the two comparative electrode assemblies 120' are installed in the housing 110, the first electrode tab 1212 becomes redundant. Referring to the redundant area A in the diagram, there is a risk of short circuit between the first electrode sheet 121 and the second electrode sheet 122. Therefore, in the embodiment of the present application, the protrusion 1213 is used to support the first electrode tab 1212, which can reduce the risk of redundant tabs and improve the safety performance of the battery.

[0189] According to some embodiments of this application, please continue to refer to Figures 5 to 7 、 Figure 12 and Figure 13 Along the winding direction J2 of the electrode assembly 120 , the same number of first electrode tabs 1212 are arranged between every two adjacent protrusions 1213 .

[0190] exist Figures 5 to 7 、 Figure 12 and Figure 13 In the illustrated embodiment, one first tab 1212 is disposed between every two adjacent protrusions 1213. Of course, two first tabs 1212, three first tabs 1212, or another number of first tabs 1212 may also be disposed between every two adjacent protrusions 1213, without specific limitation.

[0191] Since the distribution of the protrusion 1213 and the first electrode tab 1212 is periodic, not only can the tension of the electrode assembly 120 formed by winding be more balanced along the circumference of the winding 1000, thereby improving the stability of the winding molding, but also it is convenient to automatically produce the first electrode tab 1212 and the protrusion 1213.

[0192] Of course, in some other embodiments, different numbers of first electrode tabs 1212 may be arranged between every two adjacent protrusions 1213 along the winding direction J2 of the electrode assembly 120 , without being specifically limited herein.

[0193] According to some embodiments of this application, please continue to refer to Figure 6 、 Figure 12 and Figure 13 The orthographic projection of the protrusion 1213 on a plane perpendicular to the thickness direction of the protrusion 1213 is a first projection, and the thickness direction of the protrusion 1213 is perpendicular to the winding axis direction J1 of the electrode assembly 120. All first projections have at least one of a rectangle, a square, a diamond, and a trapezoid.

[0194] The shapes of all the protrusions 1213 may be the same or different. Figure 6 、 Figure 12 and Figure 13 As an example, the shape of all protrusions 1213 is the same. Figure 6 、 Figure 12 and Figure 13 In the illustrated embodiment, the protrusion 1213 is substantially in the shape of a rectangular body.

[0195] In this way, by controlling the shape of the protrusion 1213 , the manufacturing convenience is improved while the protrusion 1213 has certain mechanical properties.

[0196] According to some embodiments of the present application, along the winding direction J2 of the electrode assembly 120, the size of the protrusion 1213 along the winding axis direction J1 of the electrode assembly 120 changes according to a first rule. The first rule includes one of unchanged, first decreasing and then increasing, first increasing and then decreasing, first decreasing and then increasing and then decreasing, and first increasing and then decreasing and then increasing.

[0197] For example, Figure 6 、 Figure 12 and Figure 13 For example, it is illustrated that along the winding direction J2 of the electrode assembly 120 , the size of the protrusion 1213 along the winding axis direction J1 of the electrode assembly 120 remains unchanged.

[0198] When the first rule is constant, it is advantageous to ensure that the protrusion 1213 has certain mechanical properties while facilitating the manufacture of the protrusion 1213. When the first rule includes one of decreasing first and then increasing, increasing first and then decreasing, decreasing first and then increasing, and decreasing first, or increasing first and then decreasing and then increasing, it is advantageous to control mechanical stress by changing the shape of the protrusion 1213, thereby improving the reliability of the protrusion 1213.

[0199] According to some embodiments of the present application, along the winding axis direction J1 of the electrode assembly 120, the size of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 changes according to a second rule. The second rule includes one of unchanged, decreasing, increasing, first decreasing then increasing, first increasing then decreasing, first decreasing then increasing then decreasing, and first increasing then decreasing then increasing.

[0200] For example, Figure 6 、 Figure 12 and Figure 13 For example, the situation in which the size of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 remains unchanged along the winding axis direction J1 of the electrode assembly 120 is illustrated.

[0201] When the second rule is constant, it is advantageous to ensure that the protrusion 1213 has certain mechanical properties while facilitating the manufacture of the protrusion 1213. When the second rule includes one of decreasing, increasing, decreasing first then increasing, increasing first then decreasing, decreasing first then increasing then decreasing, or increasing first then decreasing then increasing, it is advantageous to control mechanical stress by changing the shape of the protrusion 1213, thereby improving the reliability of the protrusion 1213.

[0202] According to some embodiments of this application, please continue to refer to Figure 6 , a dimension of the protrusion 1213 along the winding axis direction J1 of the electrode assembly 120 is 2 mm to 6 mm; and / or a dimension of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 is 5 mm to 9 mm.

[0203] For example, the dimension of the protrusion 1213 along the winding axis J1 of the electrode assembly 120 is a first dimension d1, which can be 2 mm, 3 mm, 4 mm, 5 mm, or 6 mm. The first dimension d1 can be any value within the range of 2 mm to 6 mm and is not specifically limited here.

[0204] For example, the dimension of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 is a third dimension d3, which may be 5 mm, 6 mm, 7 mm, 8 mm, or 9 mm. The third dimension d3 may be any value within the range of 5 mm to 9 mm.

[0205] The dimension of the protrusion 1213 along the winding axis J1 of the electrode assembly 120 can be considered the height dimension of the protrusion 1213, and the dimension of the protrusion 1213 along the winding direction J2 of the electrode assembly 120 can be considered the width dimension of the protrusion 1213. It should be understood that the height and width dimensions of the protrusion 1213 mentioned above do not restrict the placement of the electrode assembly 120, but are simply used to distinguish the two dimensions of the protrusion 1213. By controlling the height and / or width of the protrusion 1213, not only is the production of the protrusion 1213 facilitated, but the protrusion 1213 can also have a certain degree of mechanical reliability and adapt to the space constraints during the winding process.

[0206] According to some embodiments of the present application, the first electrode 121 is a positive electrode, and the second electrode 122 is a negative electrode.

[0207] In this way, the positive electrode sheet can include a first electrode tab 1212 and a protrusion 1213. Since the overall rigidity of the positive electrode sheet is greater than that of the negative electrode sheet, this helps improve the stability of the protrusion 1213, thereby improving the accuracy of alignment detection. At the same time, since the negative electrode sheet is generally slightly larger than the positive electrode sheet, using the protrusion 1213 on the positive electrode sheet as the detection reference can more directly determine whether the negative electrode sheet effectively covers the positive electrode sheet.

[0208] Of course, in some other embodiments, the first electrode 121 may be a negative electrode, and the second electrode 122 may be a negative electrode.

[0209] According to some embodiments of this application, please refer to Figure 18 , Figure 18 This is a flow chart of a method for manufacturing a battery cell in some embodiments of the present application. The present application provides a method for manufacturing a battery cell, comprising the following steps:

[0210] S110, providing a first pole piece, a second pole piece, and a separator; the first pole piece includes a main body, a plurality of first pole tabs, and protrusions respectively provided on a first loop section and an end loop section of the main body; along the width direction of the first pole piece, the plurality of first pole tabs and all the protrusions are provided on the same side of the main body, and the stiffness of the protrusions is greater than the stiffness of the first pole tabs;

[0211] S120, stacking and winding the separator, the first electrode sheet, and the second electrode sheet to form an electrode assembly;

[0212] S130. When both the winding alignment and the rewinding alignment of the first electrode sheet and the second electrode sheet meet the qualified alignment conditions, the electrode assembly is installed in the accommodating cavity of the shell to form a battery cell; wherein the winding alignment is determined based on the convex part of the first circle segment of the main body, and the rewinding alignment is determined based on the convex part of the last circle segment of the main body.

[0213] In step S110, the first electrode piece provided by the first electrode piece tape roll may include the first electrode ear and the protrusion, or the first electrode ear and the protrusion may be formed by, for example, a die-cutting process during the process of conveying the first electrode piece from the first electrode piece tape roll, without specific limitation herein. The second electrode piece and the separator may also be provided by corresponding tape rolls. Regarding the relevant implementation methods of the first electrode piece, the second electrode piece and the separator, as well as the understanding of the stiffness of the protrusion and the stiffness of the first electrode ear, reference may be made to the contents illustrated in some of the aforementioned embodiments, which will not be repeated here.

[0214] In step S120, illustratively, referring to Figure 19 and Figure 20 , Figure 19 This is a schematic diagram of an electrode assembly in some embodiments of the present application in a state during the manufacturing process. Figure 20 This is a schematic diagram of the electrode assembly in some embodiments of the present application in another state during the manufacturing process. The first electrode sheet 121 is the positive electrode sheet, and the second electrode sheet 122 is the negative electrode sheet. They can be stacked and rolled in the order of "first electrode sheet 121 → separator 123 → second electrode sheet 122 → separator 123" to form a stacked body. The rotation of the winding member 1000 drives the stacked body to be wound to form a wound body. In the winding stage, the wound body can be cut by the cutting device 3000 to form the electrode assembly 120. During the formation of the electrode assembly 120, the first electrode sheet 121, the separator 123 and the second electrode sheet 122 are transported by the conveying device 4000. Among them, the winding member 1000 can be a winding needle, and the conveying device 4000 can be a roller assembly.

[0215] In step S130, the winding alignment and the rewinding alignment can be understood with reference to the situations illustrated in some of the aforementioned embodiments, and will not be repeated here. The alignment qualification condition is a condition set based on the required alignment of the electrode assembly. The alignment qualification condition can be an alignment range. When the winding alignment and the rewinding alignment are within the alignment range, it means that the winding alignment and the rewinding alignment are qualified. When both the winding alignment and the rewinding alignment meet the alignment qualification condition, it means that the alignment of the first pole piece and the second pole piece at the first turn section of the electrode assembly, and the alignment of the first pole piece and the second pole piece at the last turn section of the electrode assembly meet the alignment qualification condition, and the electrode assembly is qualified. When either the winding alignment or the rewinding alignment does not meet the alignment qualification condition, it means that the electrode assembly is unqualified.

[0216] After the qualified electrode assembly is installed in the accommodating cavity of the shell, a battery cell can be formed through steps such as liquid injection and shell encapsulation, which will not be described in detail here.

[0217] In the technical solution of the embodiment of the present application, a convex portion is provided on the first and last loop sections of the main body of the first pole piece, and the stiffness of the convex portion is made greater than the stiffness of the first pole piece, so that the bending resistance of the convex portion is greater than the bending resistance of the first pole piece. Since there is no tension constraint when the head and tail of the first pole piece are cut off, the actual relative position of the first pole piece and the second pole piece may change during winding, resulting in inaccurate results of the pole piece alignment detection. In the embodiment of the present application, when manufacturing the electrode assembly, since the bending resistance of the convex portion is greater than the bending resistance of the first pole piece, when the tension changes, the convex portion can be in a more stable state relative to the first pole piece, so that the convex portion that is less likely to bend can be used to determine the winding alignment and winding alignment of the electrode assembly, thereby improving the detection accuracy of the winding alignment and winding alignment, and further improving the detection accuracy of the electrode assembly alignment.

[0218] According to some embodiments of this application, please refer to Figure 21 , Figure 21 This is a flow chart of steps S1, SJ, and SK in a method for manufacturing a battery cell in some embodiments of the present application. The method for manufacturing a battery cell further includes the following steps:

[0219] S1. Acquire a first image of the convex portion of the first winding section of the main body and the main body before the first pole piece is wound; determine a first distance between the convex portion of the first winding section of the main body and the main body in a width direction of the first pole piece based on the first image;

[0220] SJ, obtaining a second image of the convex portion of the first winding section of the main body after the first pole piece is wound and the main body wound onto the winding member; determining a second distance between the convex portion of the first winding section of the main body and the second pole piece in the width direction of the first pole piece based on the second image;

[0221] SK: Based on the difference between the first distance and the second distance, determine whether the incoming roll alignment meets the alignment qualification condition.

[0222] The above steps SI, SJ and SK are performed in the process of forming the electrode assembly.

[0223] In step S1, for example, please continue to refer to Figure 19 and Figure 20 The image acquisition device 2000 includes a first image acquisition component 2100, which is used to acquire a first image. For example, the first image acquisition component 2100 can be a camera. Figure 22 and Figure 23 , Figure 22 This is a schematic diagram of a first image in some embodiments of the present application. Figure 23This is a schematic diagram of the portion of the first electrode 121 corresponding to the first image in some embodiments of the present application. The first distance h1 can be the distance between the edge of the protrusion 1213 facing away from the main body 1211 and the edge of the insulating layer on the main body 1211 facing away from the protrusion 1213. A processor (not shown) electrically connected to the first image acquisition component 2100 can be provided to determine the first distance h1 based on the first image. It should be noted that Figure 22 The first image captured is shown to be only Figure 23 A portion of the structure is shown.

[0224] In step SJ, for example, please continue to refer to Figure 19 and Figure 20 The image acquisition device 2000 further includes a second image acquisition component 2200, which is used to acquire a second image. For example, the second image acquisition component 2200 may be a camera. Figure 24 and Figure 25 , Figure 24 This is a schematic diagram of the second image in some embodiments of the present application. Figure 25 This is a schematic diagram of a portion of the wound electrode assembly 120 corresponding to the second image in some embodiments of the present application. The second distance h2 can be the distance between the edge of the protrusion 1213 facing away from the main body 1211 and the edge of the second electrode 122 facing the protrusion 1213. The aforementioned processor can be electrically connected to the second image acquisition component 2200, and the processor is used to determine the second distance h2 based on the second image. It should be noted that Figure 24 The first image captured is shown to be only Figure 25 A portion of the structure is shown.

[0225] In step SK, combined with reference Figure 23 and Figure 25 Because the first distance h1 and the second distance h2 are determined based on the same convex portion 1213 located on the first loop segment Q1 of the main body 1211, the difference between the first distance h1 and the second distance h2 can be used to represent the winding alignment of the first pole piece 121 and the second pole piece 122. The processor can also be configured to determine whether the winding alignment meets the alignment qualification condition based on the first distance h1 and the second distance h2.

[0226] During the winding process of the first pole piece, the tension of the first pole piece will change. Since the convex portion of the first winding section of the main body can be in a more stable state, the first distance between the convex portion of the first winding section of the main body and the main body can be determined more accurately, which is conducive to improving the accuracy of the winding alignment detection.

[0227] According to some embodiments of this application, please refer to Figure 26 , Figure 26 This is a flow chart of steps SF, SG, and SH in a method for manufacturing a battery cell in some embodiments of the present application. The method for manufacturing a battery cell further includes the following steps:

[0228] SF, obtaining a third image of the convex portion of the last coil segment of the main body and the main body before the last coil segment of the main body is wound; determining a third distance between the convex portion of the last coil segment of the main body and the main body in the width direction of the first pole piece based on the third image;

[0229] SG. Obtain a fourth image of the convex portion of the last coil segment of the main body after the last coil segment of the main body is wound onto the winding member; determine, based on the fourth image, a fourth distance between the convex portion of the first coil segment of the main body and the second pole piece in the width direction of the first pole piece;

[0230] SH. Based on the difference between the third distance and the fourth distance, determine whether the winding alignment meets the alignment qualification condition.

[0231] In step SF, the first image acquisition component 2100 illustrated above may be used to acquire a third image, and the processor is configured to determine a third distance h3 based on the third image. Figure 27 , Figure 27 This is a schematic diagram of the portion of the first pole piece 121 corresponding to the third image in some embodiments of the present application. The third distance h3 can be the distance between the side edge of the protrusion 1213 facing away from the main body 1211 and the side edge of the insulating layer on the main body 1211 facing away from the protrusion 1213.

[0232] In step SG, the second image acquisition component 2200 illustrated above may be used to acquire a fourth image, and the processor is configured to determine a fourth distance h4 based on the fourth image. Figure 28 , Figure 28 This is a schematic diagram of the portion of the wound electrode assembly 120 corresponding to the fourth image in some embodiments of the present application. The fourth distance h4 can be the distance between the edge of the side of the protrusion 1213 away from the main body 1211 and the edge of the side of the second electrode 122 arranged toward the protrusion 1213.

[0233] In step SH, in conjunction with reference Figure 27 and Figure 28Because the third distance h3 and the fourth distance h4 are determined based on the same protrusion 1213 located on the last coil segment Q2 of the main body 1211, the difference between the third distance h3 and the fourth distance h4 can be used to represent the winding alignment of the first pole piece 121 and the second pole piece 122. The processor can also be configured to determine whether the winding alignment meets the qualified alignment condition based on the third distance h3 and the fourth distance h4.

[0234] During the winding process of the first pole piece, the tension of the first pole piece changes. Since the convex portion of the last coil segment of the main body is in a more stable state, the third distance between the convex portion of the last coil segment of the main body and the main body is more accurately determined, which helps to improve the accuracy of the winding alignment detection.

[0235] According to some embodiments of the present application, a convex portion is provided on the middle ring section of the main body. Figure 29 , Figure 29 Schematic diagram of the process of steps SO, SP, and SQ in the method for manufacturing a battery cell in some embodiments of the present application. The method for manufacturing a battery cell further includes the following steps:

[0236] SO, based on the verification alignment of the middle loop segments of the first and second pole pieces, verify the reference alignment of the middle loop segments of the first and second pole pieces; wherein the reference alignment is determined based on the first tab of the middle loop segment located at the main body, and the verification alignment is determined based on the convex portion of the middle loop segment located at the main body;

[0237] SP. When both the winding alignment and the rewinding alignment meet the alignment qualification conditions and the reference alignment meets the verification qualification conditions, the electrode assembly is installed in the accommodating cavity of the shell to form a battery cell.

[0238] In step SO, the verification alignment of the middle ring segment determined by the convex portion of the middle ring segment located on the main body can be performed with reference to the determination of the winding alignment and the rewinding alignment illustrated in some of the aforementioned embodiments, without specific limitation here.

[0239] In step SP, for the electrode assembly that meets the alignment qualification conditions and the verification qualification conditions, that is, the winding alignment, winding alignment and alignment of the middle ring segment of the electrode assembly are all determined to meet the corresponding conditions, so that the alignment of each part of the electrode assembly meets the requirements.

[0240] In this way, by verifying the alignment through the convex portion provided on the middle ring segment, the accuracy of the alignment of the middle ring segment can be further improved.

[0241] It should be noted that the first image acquisition component 2100 and the second image acquisition component 2200 illustrated above may include a line array camera and an area array camera. Furthermore, edge capture processing may be performed based on the acquired images to obtain corresponding edge lines. The processor can then determine the corresponding distance and whether the corresponding conditions are met based on the obtained edge lines. The technical logic for edge capture processing may include gradient calculation, image convolution using specific operators, and other techniques, which are not specifically limited here.

[0242] Of course, in other embodiments, if either the incoming or rewinding alignment fails to meet the qualified alignment criteria, a warning message can be output to facilitate the operator's operation. Furthermore, unqualified electrode assemblies can be placed in a failed area to facilitate subsequent destruction or repair of unqualified electrode assemblies. If the qualified verification criteria are not met, the aforementioned scenarios can also be used for implementation, and no specific limitations are imposed here.

[0243] According to some embodiments of this application, please refer to Figure 30 , Figure 30 This is a flow chart of steps S111 and S112 in some embodiments of the present application, providing a first pole piece, a second pole piece, and a separator, including the following steps:

[0244] S111, providing a first pole piece strip;

[0245] S112 , die-cutting the first pole piece strip to form a plurality of first pole tabs and all protrusions to obtain a first pole piece.

[0246] In this way, the first electrode tab and the protrusion can be manufactured through the same process, which not only can utilize the structure of the first electrode piece to manufacture the protrusion, thereby improving the convenience of manufacturing the protrusion, but also helps to improve production efficiency.

[0247] According to some embodiments of the present application, the method for manufacturing a battery cell further includes:

[0248] When the feeding end of the first pole piece is wound, a force is provided on the side of the feeding end of the first pole piece away from the winding piece, so that the feeding end of the first pole piece can be close to the winding piece.

[0249] For example, an air blowing mechanism may be provided to provide air flow force.

[0250] In this way, by providing a force acting on the feeding end of the first electrode piece, the feeding end of the first electrode piece can be fed more stably and reliably, reducing the risk of wrinkles, bending, etc. at the feeding end of the first electrode piece, thereby helping to improve the performance of the electrode assembly.

[0251] According to some embodiments of the present application, an embodiment of the present application provides a battery device, including the battery cell in any of the above embodiments; or, including a battery cell manufactured by the manufacturing method of the battery cell in any of the above embodiments.

[0252] The advantages possessed by the battery cell in any of the above embodiments and the battery cell manufactured by the manufacturing method of the battery cell in any of the above embodiments are also possessed by the battery device, which will not be described in detail here.

[0253] According to some embodiments of the present application, an electrical device is provided, comprising the battery device in any of the above embodiments.

[0254] The advantages possessed by the battery device in any of the above embodiments are also possessed by the electrical equipment, which will not be described in detail here.

[0255] 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. A battery cell, characterized in that: The electrode assembly comprises an electrode assembly having a wound structure, the electrode assembly comprising a first electrode sheet, a second electrode sheet and a separator, the separator separating the first electrode sheet from the second electrode sheet; The first pole piece includes a main body, multiple first pole tabs, and protrusions respectively arranged on the first and last loop segments of the main body; along the winding axis direction of the electrode assembly, the multiple first pole tabs and all the protrusions are arranged on the same side of the main body, and the stiffness of the protrusions is greater than the stiffness of the first pole tabs.

2. The battery cell according to claim 1, wherein: The first pole piece further includes an insulating layer, wherein the insulating layer includes a first insulating portion and a second insulating portion connected to the first insulating portion; The edge area of ​​the main body on one side of which the plurality of first tabs and the protrusion are provided is a first area, and the root area of ​​the first tab adjacent to the main body is a second area; The first insulating portion is provided in the first region, and the second insulating portion is provided in the second region and covers at least a portion of the protrusion.

3. The battery cell according to claim 2, characterized in that: The convex portion includes a first surface and a second surface arranged opposite to each other along a thickness direction of the convex portion; the thickness direction of the convex portion is perpendicular to the winding axis direction of the electrode assembly; wherein the ratio of the area of ​​the first surface covered by the second insulating portion to the area of ​​the first surface is 0.8 to 1; and / or A ratio of an area of ​​the second surface covered by the second insulating portion to an area of ​​the second surface is 0.8 to 1.

4. The battery cell according to claim 2, characterized in that: A ratio of a surface area of ​​a region of the protrusion covered by the second insulating portion to a surface area of ​​the protrusion is 0.8 to 1.

5. The battery cell according to any one of claims 1 to 4, characterized in that: Along the winding axis direction of the electrode assembly, the size of the protrusion is smaller than the size of the first electrode tab; and / or Along the winding direction of the electrode assembly, the size of the protrusion is smaller than the size of the first electrode tab.

6. The battery cell according to claim 5, characterized in that A ratio of a dimension of the protrusion along the winding direction of the electrode assembly to a dimension of the protrusion along the winding axis direction of the electrode assembly is greater than or equal to 7.

7. The battery cell according to any one of claims 1 to 4, characterized in that: The electrode assembly has a reference surface, and the winding axis of the electrode assembly is located on the reference surface; The reference surface has a first side and a second side that are opposite to each other, the plurality of first tabs are located on the first side, and all the protrusions are located on the second side.

8. The battery cell according to claim 7, characterized in that The orthographic projections of all the protrusions on the reference surface have overlapping portions with the orthographic projections of the plurality of first tabs on the reference surface.

9. The battery cell according to claim 8, characterized in that An orthographic projection of any one of all the protrusions on the reference surface has an overlapping portion with an orthographic projection of any one of the plurality of first tabs on the reference surface; and / or The number of the ring segments of the main body is M, and the number of the ring segments provided with the convex parts is N; wherein 0.5≤N / M≤1, and both N and M are positive integers.

10. The battery cell according to any one of claims 1 to 4, characterized in that: The middle circle section of the main body is provided with at least one circle, and the convex portion is provided on at least one middle circle section.

11. The battery cell according to claim 10, characterized in that The middle circle segment is provided with a plurality of circles, and each of the middle circle segments is provided with the convex portion.

12. The battery cell according to claim 10, characterized in that Along the winding direction of the electrode assembly, the same number of the first electrode tabs are arranged between every two adjacent protrusions.

13. The battery cell according to any one of claims 1 to 4, characterized in that: The orthographic projection of the convex portion on a plane perpendicular to the thickness direction of the convex portion is a first projection, and the thickness direction of the convex portion is perpendicular to the winding axis direction of the electrode assembly; The shapes of all the first projections include at least one of a rectangle, a square, a rhombus, and a trapezoid.

14. The battery cell according to any one of claims 1 to 4, characterized in that: Along the winding direction of the electrode assembly, the size of the protrusion along the winding axis direction of the electrode assembly changes according to a first rule; The first rule includes one of unchanged, first decreasing and then increasing, first increasing and then decreasing, first decreasing and then increasing and then decreasing, and first increasing and then decreasing and then increasing.

15. The battery cell according to any one of claims 1 to 4, characterized in that: Along the winding axis direction of the electrode assembly, the size of the protrusion along the winding direction of the electrode assembly changes according to a second rule; The second rule includes one of unchanged, decreasing, increasing, first decreasing and then increasing, first increasing and then decreasing, first decreasing and then increasing and then decreasing, and first increasing and then decreasing and then increasing.

16. The battery cell according to any one of claims 1 to 4, characterized in that: The dimension of the protrusion along the winding axis direction of the electrode assembly is 2 mm to 6 mm; and / or A dimension of the protrusion along the winding direction of the electrode assembly is 5 mm to 9 mm.

17. The battery cell according to any one of claims 1 to 4, characterized in that: The first pole piece is a positive pole piece, and the second pole piece is a negative pole piece.

18. A method for manufacturing a battery cell, characterized in that: include: A first pole piece, a second pole piece, and a separator are provided; the first pole piece includes a main body, a plurality of first pole tabs, and protrusions respectively provided on a first loop section and an end loop section of the main body; along the width direction of the first pole piece, the plurality of first pole tabs and all the protrusions are provided on the same side of the main body, and the stiffness of the protrusions is greater than the stiffness of the first pole tabs; stacking and winding the separator, the first pole piece, and the second pole piece to form an electrode assembly; When the winding alignment and the rewinding alignment of the first electrode sheet and the second electrode sheet both meet the qualified alignment conditions, the electrode assembly is loaded into the accommodating cavity of the shell to form a battery cell; wherein the winding alignment is determined based on the convex part of the first circle segment of the main body, and the rewinding alignment is determined based on the convex part of the last circle segment of the main body.

19. The method for manufacturing a battery cell according to claim 18, wherein: The manufacturing method of the battery cell further includes: obtaining a first image of the convex portion of the first winding section of the main body and the main body before the first pole piece is wound; and determining a first distance between the convex portion of the first winding section of the main body and the main body in a width direction of the first pole piece based on the first image; obtaining a second image of the convex portion of the first winding section of the main body portion and the main body portion wound onto the winding member after the first pole piece is wound; and determining, based on the second image, a second distance between the convex portion of the first winding section of the main body portion and the second pole piece in a width direction of the first pole piece; Based on the difference between the first distance and the second distance, it is determined whether the roll-in alignment satisfies an alignment qualification condition.

20. The method for manufacturing a battery cell according to claim 18, wherein: The manufacturing method of the battery cell further includes: obtaining a third image of the convex portion of the last coil segment of the main body and the main body before the last coil segment of the main body is wound; and determining, based on the third image, a third distance between the convex portion of the last coil segment of the main body and the main body in a width direction of the first pole piece; obtaining a fourth image of the convex portion of the last coil segment of the main body portion and the main body portion wound onto the winding member after the last coil segment of the main body portion is wound; and determining, based on the fourth image, a fourth distance between the convex portion of the first coil segment of the main body portion and the second pole piece in a width direction of the first pole piece; Based on the difference between the third distance and the fourth distance, it is determined whether the winding alignment satisfies an alignment qualification condition.

21. The method for manufacturing a battery cell according to any one of claims 18 to 20, characterized in that: The convex portion is provided on the middle ring section of the main body; The manufacturing method of the battery cell further includes: Verifying a reference alignment of the middle loop segments of the first and second pole pieces based on the verification alignment of the middle loop segments of the first and second pole pieces; wherein the reference alignment is determined based on a first tab of the middle loop segment of the main body, and the verification alignment is determined based on a convex portion of the middle loop segment of the main body; When both the winding alignment and the rewinding alignment meet the alignment qualification conditions, and the reference alignment meets the verification qualification conditions, the electrode assembly is installed in the accommodating cavity of the shell to form a battery cell.

22. The method for manufacturing a battery cell according to any one of claims 18 to 20, characterized in that: The method of providing a first pole piece, a second pole piece and a separator comprises: Providing the first pole piece strip; The first pole piece strip is die-cut to form the plurality of first pole tabs and all the protrusions to obtain the first pole piece.

23. The method for manufacturing a battery cell according to any one of claims 18 to 20, characterized in that: The manufacturing method of the battery cell further includes: When the feeding end of the first pole piece is wound, a force is provided on the side of the feeding end of the first pole piece away from the winding member, so that the feeding end of the first pole piece can be close to the winding member.

24. A battery device, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 17; or a battery cell manufactured by the method for manufacturing a battery cell according to any one of claims 18 to 23.

25. An electrical device, characterized in that: Comprising the battery device of claim 24.

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