Electrode assembly, processing method therefor, battery cell, battery, electrical apparatus and cutter assembly

Abstract

An electrode assembly, a processing method therefor, a battery cell, a battery, an electrical apparatus and a cutter assembly. The electrode assembly comprises an active substance-coated part and a tab part. The tab part comprises a plurality of tab pieces, overlapping parts of the plurality of tab pieces forming an overlapping region, and misaligned parts of the plurality of tab pieces forming a misalignment region connected to the overlapping region. The misalignment region comprises a first connection part and a second connection part, the side of the first connection part in a first direction being connected to the active substance-coated part, and the second connection part being connected to the other side of the first connection part in the first direction. In a second direction, the end of the second connection part away from the overlapping region is closer to the overlapping region than the end of the first connection part away from the overlapping region.

Description

Electrode assembly and processing method thereof, battery cell, battery, electrical device, and cutting knife assembly

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202311439490.0 and application date October 31, 2023, and claims the priority of the above-mentioned Chinese patent application. The entire content of the above-mentioned Chinese patent application is hereby introduced into this application as a reference. Technical Field

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

[0004] In recent years, new energy vehicles have experienced rapid development. Batteries, as the power source of electric vehicles, play an irreplaceable and important role. As core components of new energy vehicles, batteries have high requirements for both energy density and reliability, with reliability in particular requiring further improvement.

[0005] Summary of the Invention

[0006] The present application proposes an electrode assembly and a processing method thereof, a battery cell, a battery, an electrical device, and a cutting knife assembly. The electrode assembly has good reliability and can improve the reliability of the battery cell.

[0007] In a first aspect, an embodiment of the present application provides an electrode assembly, comprising an active material coating portion and a pole ear portion, the pole ear portion being connected to the active material coating portion, the pole ear portion comprising a plurality of pole ear sheets stacked and connected, the overlapping portions of the plurality of pole ear sheets forming an overlapping area, and the staggered portions of the plurality of pole ear sheets forming a staggered area connected to the overlapping area; wherein the staggered area comprises a first connecting portion and a second connecting portion, the first connecting portion being connected to the active material coating portion on one side along a first direction, and the second connecting portion being connected to the first connecting portion on the other side along the first direction; in the second direction, an end of the second connecting portion away from the overlapping area is closer to the overlapping area than an end of the first connecting portion away from the overlapping area, and the second direction intersects with the first direction.

[0008] In the above technical solution, by providing the offset regions of the multiple tabs including a first connection portion and a second connection portion, in the second direction, the end of the second connection portion away from the overlapping region is closer to the overlapping region than the end of the first connection portion away from the overlapping region, so that the width of the tab portion corresponding to the position of the second connection portion in the second direction is smaller than the width of the tab portion corresponding to the position of the first connection portion in the second direction, so as to fully utilize the offset regions of the multiple tabs, increase the connection length between the tab portion and the active material coating portion, improve the electrical connection area and connection reliability between the tab portion and the active material coating portion, and thus improve the reliability and current carrying capacity of the electrode assembly, thereby improving the reliability of the battery cell. At the same time, the width of the offset region at the end of the tab portion can be reduced. If the tab portion needs to pass through the avoidance portion of other components (for example, the tab portion passes through the through-hole on the pole column described later), the interference between the tab portion and other components, such as the pole column, is reduced, which is conducive to further improving the reliability of the battery cell and saving the space required for the tab portion to be passed through during the passing operation, thereby improving the convenience of passing through the tab portion, thereby improving the assembly convenience and efficiency of the battery cell.

[0009] In some embodiments, an edge of the second connecting portion away from the overlapping region has a serrated structure; and / or an edge of the first connecting portion away from the active material coating portion has a serrated structure.

[0010] In the above technical solution, the edge of one end of the second connecting part away from the overlapping area is set to have a serrated structure, or the edge of one end of the first connecting part away from the active material coating part is set to have a serrated structure, so as to control the length of the wire drawing at the edge of the pole ear by controlling the width of the serrated structure, thereby improving to a certain extent the problem of short circuit caused by the long wire drawing at the edge of the pole ear falling into or extending into other positions, thereby improving the safety of the electrode assembly.

[0011] In some embodiments, the sawtooth structure includes a plurality of protrusions sequentially arranged along the first direction, wherein the height h1 of the protrusions is ≤2 mm; and / or the diameter d1 of the circumscribed circle of the projection of the protrusions along the thickness direction of the pole ear is ≤2 mm.

[0012] In the above technical solution, by setting the height h1 of the protrusion to ≤ 2 mm, and / or the circumscribed circle diameter d1 of the projection of the protrusion along the thickness direction of the pole ear to ≤ 2 mm, effective control of the drawing length of the edge of the pole ear can be achieved. Even if the entire serrated structure is folded, the risk of short circuit caused by the protrusion can be reduced.

[0013] In some embodiments, the sawtooth structure includes a plurality of protrusions sequentially arranged along the first direction, and the protrusions are square or trapezoidal.

[0014] In the above technical solution, the convex portion is set to be square or trapezoidal, so as to simplify the shape of the convex portion and facilitate processing. At the same time, it is convenient to reasonably control the height, width and other dimensions of the convex portion, which is conducive to further facilitating the control of the drawing length.

[0015] In some embodiments, when the edge of the second connecting portion forms a serrated structure, a first groove is formed at a position where the edge of the first connecting portion is connected to the edge of one end of the second connecting portion away from the overlapping area; or, when the edge of the first connecting portion forms a serrated structure, a second groove is formed at a position where the second connecting portion is connected to the edge of one end of the first connecting portion away from the active material coating portion.

[0016] In the above technical solution, when the second connecting portion forms a serrated structure, a first groove is formed on the edge of the side of the first connecting portion away from the active material coating portion, or when the first connecting portion forms a serrated structure, a second groove is formed on the edge of the side of the second connecting portion away from the overlapping area. The first groove or the second groove can be formed by cutting, which is beneficial to reducing the position requirements of the cutting knife in the first direction during the process of cutting to form the first groove or the second groove, and at the same time can play a certain obstructive role on the cutting knife, which is beneficial to improving the cutting balance and accuracy.

[0017] In some embodiments, at least one of an edge of the first connecting portion away from the active material coating portion and an edge of the second connecting portion away from the overlapping region is obtained by cutting.

[0018] In the above technical solution, by setting at least one of the edge of one end of the first connecting part away from the active material coating part and the edge of one end of the second connecting part away from the overlapping area to be obtained by cutting, the length of the wire drawing at the edge of the pole ear after the electrode assembly is cut can be effectively shortened, and the problem of long wire drawing being easily generated after the pole ear is cut can be effectively improved, so as to improve the problem of short circuit caused by long wire drawing falling into or extending into other positions to a certain extent.

[0019] In some embodiments, a misalignment region is respectively provided on two opposite sides of the overlapping region in the second direction.

[0020] In the above technical solution, by setting the overlapping area on both sides of the relative sides in the second direction, respectively, the offset areas are provided, which is conducive to further increasing the connection length between the pole ear and the active material coating part, further improving the electrical connection area and connection reliability between the pole ear and the active material coating part, thereby further improving the use reliability and overcurrent capacity of the electrode assembly.

[0021] In some embodiments, the active material coating portion includes a positive electrode sheet body, a negative electrode sheet body and a separator, a plurality of electrode tabs are respectively connected to the positive electrode sheet body and the negative electrode sheet body, and the separator is arranged between the positive electrode sheet body and the negative electrode sheet body and exceeds the positive electrode sheet body and the negative electrode sheet body; wherein, at least part of the first connection portion is blocked by the separator.

[0022] In the above technical solution, by setting an isolation membrane beyond the positive electrode plate body and the negative electrode plate body to cover at least part of the first connection part, at least part of the first connection part covered by the isolation membrane can be insulated, so as to shorten the length of the first connection part that can bypass the isolation membrane and extend into other positions to cause a short circuit, thereby further improving the safety of the electrode assembly.

[0023] In a second aspect, an embodiment of the present application provides a battery cell, comprising a shell, a pole and the above-mentioned electrode assembly, wherein the pole is provided in the shell, the active material coating portion is accommodated in the shell, and the pole ear portion is electrically connected to the pole.

[0024] In the above technical solution, since the battery cell adopts the above electrode assembly, and the electrode assembly has good reliability and overcurrent capability, it is beneficial to improve the charge and discharge capability and reliability of the battery cell.

[0025] In some embodiments, a receiving groove is formed on the pole, and a portion of the pole ear portion is accommodated in the receiving groove. The side of the receiving groove facing away from the active material coating portion is open, and the groove wall on the side facing the active material coating portion is formed with a through hole connected to the interior of the shell, and the pole ear portion is inserted into the through hole.

[0026] In the above technical solution, by accommodating a portion of the tab within the receiving groove, the energy density of the battery cell can be increased, or the size of the battery cell can be reduced while maintaining the same energy density, and the structural complexity and processing difficulty of the housing can be reduced. Furthermore, the perforation can also serve to limit the tab portion.

[0027] In some embodiments, the battery cell further includes a pole cover plate, which is disposed on the pole and closes a notch of the receiving slot.

[0028] In the above technical solution, a pole cover is provided to close the notch of the receiving tank so as to improve the problem of leakage of electrolyte in the shell from the notch of the receiving tank. Moreover, since the pole cover closes the notch of the receiving tank and is electrically connected to the pole, it is convenient to use the pole cover to realize the electrical connection between the pole and the busbar component, which is beneficial to increase the connection area at the electrical connection position and improve the current carrying capacity.

[0029] In a third aspect, an embodiment of the present application provides a battery comprising the above-mentioned battery cell.

[0030] In the above technical solution, since the battery adopts the above-mentioned battery monomer, and the battery monomer has good charge and discharge capabilities and reliability, it is beneficial to improve the performance and reliability of the battery.

[0031] In a fourth aspect, an embodiment of the present application provides an electrical device comprising the above-mentioned battery, which is used to provide electrical energy.

[0032] In the above technical solution, since the electrical device adopts the above battery and the battery has good performance and reliability, it is beneficial to improve the performance and reliability of the electrical device.

[0033] In the fifth aspect, an embodiment of the present application provides a processing method for an electrode assembly, which is characterized in that it includes: stacking and partially staggering multiple connecting sheets connected to the active material coating part, and the multiple connecting sheets have overlapping parts and staggered parts; dividing the staggered parts into cutting areas and non-cutting areas, and the non-cutting areas include a first connecting part and a second connecting part that are connected to each other and respectively connected to the overlapping parts, the first connecting part is respectively connected to the active material coating part and the cutting area on both sides in the first direction, and the second connecting part is respectively connected to the overlapping part and the cutting area on both sides in the second direction, and the second direction intersects with the first direction; cutting off the cutting area so that the remaining parts of the multiple connecting sheets are formed into the pole ear part of the electrode assembly.

[0034] In the above technical solution, the staggered parts of multiple connecting sheets are divided into cutting areas and non-cutting areas, and the cutting areas are connected to the side of the first connecting part away from the active material coating part, and the cutting areas are connected to the side of the second connecting part away from the overlapping part, so that after the cutting areas are cut off, the remaining parts of the multiple connecting sheets are formed into the pole ear part of the electrode assembly, so that the width of the end of the pole ear part away from the active material coating part in the second direction is smaller than the width of the end of the pole ear part connected to the active material coating part in the second direction, thereby improving the penetration and arrangement capacity of the pole ear part and facilitating the assembly of the battery cell while taking into account the current flow capacity and reliability of the electrode assembly.

[0035] In some embodiments, the staggered portion has a first cutting reference extending along the first direction and a second cutting reference extending along the second direction, the cutting area includes a plurality of first long strip areas and a plurality of second long strip areas, the plurality of first long strip areas and the plurality of second long strip areas are alternately arranged one by one along the first direction or the second direction, the first long strip areas and the second long strip areas extend along the second direction or the first direction, and the cutting area is cut off, including: cutting off the plurality of first long strip areas based on the first cutting reference and the second cutting reference; cutting off the plurality of second long strip areas based on the first cutting reference and the second cutting reference.

[0036] In the above technical solution, for the cutting area, multiple first long strip areas are first cut out based on the first cutting reference and the second cutting reference, and then multiple second long strip areas are cut out based on the first cutting reference and the second cutting reference, so as to realize the cutting of the cutting area. At the same time, the cutting position of the cutting knife assembly during the cutting process is set based on the first cutting reference and the second cutting reference, which is convenient for realizing effective control of the wire drawing length at the first cutting reference and the second cutting reference after the multiple connecting pieces are cut, so as to improve the problem of long wire drawing that is easy to generate after the multiple connecting pieces are cut, thereby improving the problem of short circuit caused by long wire drawing falling into or extending into other positions to a certain extent.

[0037] In some embodiments, multiple first long strip areas are cut out based on the first cutting reference and the second cutting reference, including: the adjacent two sides of the cutting knife assembly are aligned with the first cutting reference and the second cutting reference, respectively; based on the first cutting reference and the second cutting reference, multiple second long strip areas are cut out, including: the adjacent two side edges of the cutting knife assembly are aligned with the first reference line and the second reference line, respectively, the first reference line corresponds to the inside of the cutting area and is at a first predetermined value a away from the first cutting reference, and the second reference line corresponds to the outside of the cutting area and is at a second predetermined value b away from the second cutting reference.

[0038] In the above technical solution, during the process of the cutting knife assembly cutting multiple second long strip areas, the position of the cutting knife assembly is set so that the first side edge of the cutting knife assembly is aligned between the first reference line and the second reference line, or aligned with the first reference line, and the second side edge of the cutting knife assembly is aligned with the third reference line, so as to achieve effective control of the wire drawing length at the first cutting reference and the second cutting reference.

[0039] In some embodiments, each second elongated region includes a first sub-region and a second sub-region arranged in sequence along its length direction, the second sub-region is located between the first cutting reference and the first reference line, the circumscribed circle diameter d2 of the projection of the second sub-region along the stacking direction is ≤2mm, and the stacking direction is perpendicular to the first direction and the second direction respectively; and / or, a≤2mm; and / or, b≤2mm.

[0040] In the above technical solution, by setting the circumscribed circle diameter d2≤2mm, and / or a≤2mm, and / or b≤2mm of the projection of the second sub-area along the third direction, effective control of the size of the portion of the second sub-area retained on the workpiece to be cut is achieved, that is, effective control of the wire drawing length after cutting is achieved. Even if the entire second sub-area remains on the workpiece to be cut, the risk of short-circuiting of the portion corresponding to the second sub-area due to folding can be reduced.

[0041] In a sixth aspect, an embodiment of the present application provides a cutting knife assembly, which is used to cut a piece to be cut to obtain an electrode assembly. The piece to be cut includes an active material coating portion and a piece to be cut, and the piece to be cut is connected to the active material coating portion; the piece to be cut includes a plurality of connecting sheets that are stacked and connected, and the overlapping parts of the plurality of connecting sheets form an overlapping area. The staggered parts of the plurality of connecting sheets include a cutting area and a non-cutting area. The non-cutting area includes a first connecting portion and a second connecting portion that are connected to each other and respectively connected to the overlapping parts. The first connecting portion is respectively connected to the active material coating portion and the cutting area on both sides in a first direction, and the second direction intersects with the first direction; the cutting knife assembly includes: a first cutter, the first cutter includes a plurality of first blades spaced apart along the first direction, and each first blade extends along the second direction; the first cutter is used to cut off at least part of the cutting area so that the remaining parts of the plurality of connecting sheets form an ear portion, so that the ear portion and the active material coating portion form an electrode assembly.

[0042] In the above technical solution, a first cutter is provided including a plurality of first blades arranged at intervals, and the first cutter is used to cut off at least part of the cutting area, and the cutting knife assembly is used to cut off the cutting area, so that in the second direction, the end of the second connection part away from the overlapping area is closer to the overlapping area than the end of the first connection part away from the overlapping area, so as to improve the convenience of passing the pole ear part and increase the connection area between the pole ear part and the active material coating part, thereby facilitating the realization of both the improvement of the battery cell assembly efficiency and the improvement of the current capacity.

[0043] In some embodiments, the cutting area includes a plurality of first elongated regions and a plurality of second elongated regions, the plurality of first elongated regions and the plurality of second elongated regions are alternately arranged one by one along the first direction, the first elongated regions and the second elongated regions extend along the second direction, and the first blade is used to cut off the first elongated regions and the second elongated regions in sequence to form the pole ear portion; wherein the first blade includes a first cutting portion and a first cutting tooth portion arranged in sequence along the second direction, and the first cutting tooth portions of the plurality of first blades are located at the same end of the plurality of first blades in the second direction.

[0044] In the above technical solution, the first blade is provided with a first cutting portion and a first cutting tooth portion, and multiple first cutting tooth portions are located at the same end of multiple first blades, and the ends of multiple first cutting portions away from the first cutting tooth portion are fixedly connected, so as to realize the synchronous cutting of multiple first long strip areas by multiple first blades, and facilitate the synchronous cutting of multiple second long strip areas by at least one first blade, thereby facilitating the removal of the entire cutting area by the first cutter, and facilitating the simplification of the structure of the cutting knife assembly.

[0045] In some embodiments, the length y1 of the first cutting tooth portion in the second direction is ≤2 mm; and / or the interval x3 between two adjacent first cutting tooth portions is ≤2 mm.

[0046] In the above technical solution, by setting the spacing x3 between two adjacent first cutting tooth portions to ≤2mm, and / or the length y1 of the first cutting tooth portion in the second direction to ≤2mm, when the cutting knife assembly cuts multiple second long strip areas, a suitable cutting position can be selected based on the previous cutting position of the first cutting tooth portion, and the spacing x3 between two adjacent first cutting tooth portions and the length y1 of the first cutting tooth portion in the second direction will affect the size of the portion of the second long strip area retained on the workpiece to be cut, so as to achieve effective control of the size of the portion of the second long strip area retained on the workpiece to be cut, thereby achieving effective control of the length of the wire drawing generated after the cutting knife assembly cuts the cutting area, so as to control the length of the wire drawing within a reasonable range, so as to further improve the reliability and safety of the product.

[0047] In some embodiments, the first cutting tooth portion is triangular, and the maximum thickness of the first blade t1≤1mm; or, the first cutting tooth portion is square, and the maximum thickness of the first blade t2≤0.71mm; or, the first cutting tooth portion is trapezoidal, and the maximum thickness of the first blade t3≤1mm.

[0048] In the above technical solution, by setting the maximum thickness of the first blade when the first cutting tooth portion has different shape structures, the thickness of the first blade is well matched with the shape of the first cutting tooth portion, so that the first blade has appropriate cutting ability, thereby improving the cutting reliability of the first blade and the accuracy of controlling the cutting size.

[0049] In some embodiments, the cutting area includes a plurality of first long strip areas and a plurality of second long strip areas, the plurality of first long strip areas and the plurality of second long strip areas are alternately arranged one by one along the first direction, the first long strip areas and the second long strip areas extend along the second direction, the first cutter is used to cut the plurality of first long strip areas, and the cutting knife assembly also includes: a second cutter, the second cutter includes at least one second blade extending along the first direction, and the second cutter is used to cut the plurality of second long strip areas.

[0050] In the above technical solution, by setting the cutting knife assembly to also include a second cutter, the first cutter and the second cutter cut different areas of the cutting area respectively, which can simplify the cutting control of the first cutter and the second cutter, and facilitate the first cutter to maintain the same posture for cutting and the second cutter to maintain the same posture for cutting. The first blade is extended along a fixed direction, and the second blade is extended along a fixed direction, and the extension direction of the first blade and the extension direction of the second blade intersect. There is no need to frequently adjust the placement posture of the first cutter and the second cutter during cutting. It is only necessary to replace the corresponding cutter, which facilitates simplifying the cutting process.

[0051] In some embodiments, the second cutter includes two sets of blade groups, each set of blade groups includes at least one second blade, and multiple second blades are arranged at intervals along the second direction, and the two sets of blade groups are respectively used to cut the second long strip areas on both sides of the overlapping area in the second direction.

[0052] In the above technical solution, the second cutter is provided with two sets of blade groups, and the two sets of blade groups are respectively used to cut the second long strip area located on both sides of the overlapping area in the second direction. The two sets of blade groups are respectively used to cut the cutting areas located on both sides of the overlapping area in the second direction, so as to perform synchronous cutting on the cutting areas on both sides of the overlapping area, thereby improving the processing efficiency of the electrode assembly.

[0053] In some embodiments, the distance between the two blade sets is adjustable.

[0054] In the above technical solution, by setting the spacing between the two sets of blade groups to be adjustable, it is convenient for the second cutter to cut two cutting areas at the same time. Regardless of whether the pieces to be cut are the same or different, the second cutter can adapt to the different spacings between multiple cutting areas, that is, adapt to the different sizes of pole ears, so as to improve the operability and applicability of the second cutter for cutting two cutting areas at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0056] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0057] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0058] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0059] FIG4 is a cross-sectional view of the battery cell shown in FIG3 ;

[0060] FIG5 is a schematic diagram of an electrode assembly provided in some embodiments of the present application;

[0061] FIG6 is a partial schematic diagram of the electrode assembly shown in FIG5 ;

[0062] FIG7 is a schematic diagram of a plurality of tabs of the tab portion shown in FIG6 ;

[0063] FIG8 is a schematic diagram of a structure before cutting provided by some embodiments of the present application (a schematic diagram of stacking multiple connecting sheets);

[0064] FIG9 is a schematic diagram of the plurality of connecting pieces shown in FIG8 being cut by a first cutter;

[0065] FIG10 is a schematic diagram of the plurality of connecting pieces shown in FIG9 after being cut by a first cutter;

[0066] FIG11 is a schematic diagram of the plurality of connecting pieces shown in FIG10 being cut by a second cutter. After being cut by the second cutter, the structure shown in FIG6 is obtained;

[0067] FIG12 is a schematic diagram of cutting a tab provided in some embodiments of the present application;

[0068] FIG13 is a schematic diagram of a processing method provided in some embodiments of the present application;

[0069] FIG14 is a schematic diagram of a processing method provided in some embodiments of the present application;

[0070] FIG15 is a schematic diagram of a processing method provided in some embodiments of the present application;

[0071] FIG16 is a schematic diagram of a cutting knife assembly provided in some embodiments of the present application;

[0072] FIG17 is a partial schematic diagram of the first blade shown in FIG16;

[0073] FIG18 is a schematic diagram of a cutting knife assembly provided in some embodiments of the present application;

[0074] FIG19 is a schematic diagram of a cutting knife assembly provided in some embodiments of the present application;

[0075] FIG20 is a schematic diagram of various implementations of a cutting knife assembly provided in some embodiments of the present application;

[0076] FIG. 21 is a partial schematic diagram of the second blade shown in FIG. 20( c ).

[0077] Reference numerals: Power-consuming device 1000, controller 300, motor 400, battery 200, battery cell 100, housing 101, first housing 1011, second housing 1012, cutting device 500, cutting knife assembly 10, first reference line L1, second reference line L2, third reference line L3, first cutter 11, first blade 111, first cutting portion 1111, first cutting tooth portion 1112, second cutter 12, second blade 121, second cutting portion 1211, second cutting tooth portion 1212, pole 20, receiving groove 20a, through-hole 20b, electrode assembly 30, active material coating portion 31, pole ear portion 32, protrusion 32a, serrated structure 3 2b, pole tab 320, overlapping area 321, offset area 322, first groove 3220, first connecting portion 3221, second connecting portion 3222, connecting piece 33, overlapping portion 331, offset portion 332, cutting area 3321, non-cutting area 3322, shell 40, first cutting reference 5a, second cutting reference 5b, first elongated area 51, second elongated area 52, first sub-area 521, second sub-area 522, pole cover 60. DETAILED DESCRIPTION

[0078] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0079] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only 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 drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0080] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the 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.

[0081] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0082] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0083] The term "plurality" used in this application refers to two or more (including two).

[0084] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0085] The battery referred to in the embodiments of this application refers to a single physical module that includes multiple battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or battery pack. A battery module generally includes multiple battery cells. A battery generally includes a casing for enclosing multiple battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells. Of course, the battery may also not include a casing.

[0086] For example, a battery cell typically includes a housing, a cell assembly, and an electrolyte. The housing is used to house the cell assembly and electrolyte, and is provided with at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding positive and negative electrode sheets and separators.

[0087] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the stacked multiple positive electrode tabs can be directly welded to the positive electrode column to form an electrical connection. Alternatively, the battery cell assembly may further include a positive electrode adapter. The stacked multiple positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode column to form an electrical connection between the positive electrode tab and the positive electrode column.

[0088] The negative electrode sheet can generally include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tabs can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter. The multiple stacked negative electrode tabs are welded to one end of the negative electrode adapter, and the other end of the negative electrode adapter is welded to the negative electrode column to form an electrical connection between the negative electrode tab and the negative electrode column. The material of the separator is not limited, and can be, for example, polypropylene or polyethylene.

[0089] The pressure relief structure on the battery cell mentioned in this application is used to release gas from the battery cell when the internal pressure of the battery cell is excessive (for example, due to overcharging), thereby reducing the internal pressure of the battery cell and preventing the battery cell from exploding due to excessive internal pressure. For example, the pressure relief structure can be an explosion-proof valve, explosion-proof disk, etc.

[0090] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, batteries, as the power source of electric vehicles, play an irreplaceable and important role. As core components of new energy vehicles, batteries have high requirements in terms of both energy density and reliability.

[0091] In the related art, a battery includes multiple battery cells. In some cases, in order to facilitate the connection between the pole ear portion and the pole post of the battery cell, the pole ear portion often needs to pass through the avoidance portion (such as a through hole) of other components (pole post); however, the pole ear portion is formed by stacking pole ear sheets, and the stacking position of the pole ear sheets can form a weld mark. The staggered position of the pole ear sheets is relatively fluffy, which makes the fluffy pole ear portion easy to interfere with other components when passing through the avoidance portion of other components, affecting the reliability of the battery cell.

[0092] Based on the above considerations, in order to improve the reliability of battery cells, an electrode assembly is proposed, which includes an active material coating portion and a pole ear portion, which is connected to the active material coating portion; the pole ear portion includes a plurality of pole ear sheets that are stacked and connected, the overlapping portions of the plurality of pole ear sheets form an overlapping area, and the staggered portions of the plurality of pole ear sheets form a staggered area connected to the overlapping area; wherein the staggered area includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the active material coating portion on one side along a first direction, and the second connecting portion is connected to the first connecting portion on the other side along the first direction; in the second direction, the end of the second connecting portion away from the overlapping area is closer to the overlapping area than the end of the first connecting portion away from the overlapping area, and the second direction intersects with the first direction.

[0093] In the above technical solution, by providing the offset regions of the multiple tabs including the first connecting portion and the second connecting portion, in the second direction, the end of the second connecting portion away from the overlapping region is closer to the overlapping region than the end of the first connecting portion away from the overlapping region, so that the width of the tab portion corresponding to the position of the second connecting portion in the second direction is smaller than the width of the tab portion corresponding to the position of the first connecting portion in the second direction, so as to fully utilize the offset regions of the multiple tabs, increase the connection length between the tab portion and the active material coating portion, improve the electrical connection area and connection reliability between the tab portion and the active material coating portion, and facilitate improving the reliability and current carrying capacity of the electrode assembly, thereby improving the reliability of the battery cell. At the same time, the width of the offset region at the end of the tab portion can be reduced. If the tab portion needs to pass through the avoidance portion of other components (for example, the tab portion passes through the through-hole on the pole column described later), the interference between the tab portion and other components, such as the pole column, is reduced, which is conducive to further improving the reliability of the battery cell and saving the space required for the tab portion to be passed through during the passing operation, thereby improving the convenience of passing through the tab portion, thereby improving the assembly convenience and efficiency of the battery cell.

[0094] The embodiments of the present application provide an electric device using the battery disclosed herein as a power source. The electric 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 a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric tool includes a metal cutting power tool, a grinding power tool, an assembly power tool, and a railway power tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc.

[0095] For the convenience of description, the following embodiments take the electric device 1000 as a vehicle as an example, and describe in detail the structures of the electric device 1000, the battery 200 and the battery cell 100 of the present application.

[0096] Please refer to Figure 1, which is a schematic structural diagram of a vehicle in which the power-consuming device 1000 provided in some embodiments of the present application is a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The vehicle is provided with a battery 200, and the battery 200 can be arranged at the bottom, head or tail of the vehicle. The battery 200 can be used to power the vehicle, for example, the battery 200 can be used as an operating power source for the vehicle. The vehicle may also include a controller 300 and a motor 400, and the controller 300 is used to control the battery 200 to power the motor 400, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present application, the battery 200 can not only serve as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0097] Please refer to Figure 2, which is an exploded view of the structure of the battery cell 100 provided in some embodiments of the present application for the battery 200. The battery 200 includes a housing 101 and a plurality of battery cells 100, and the battery cells 100 are accommodated in the housing 101. Among them, the housing 101 is used to provide an assembly space for the battery cells 100, and the housing 101 can adopt a variety of structures. In some embodiments, the housing 101 may include a first housing 1011 and a second housing 1012, and the first housing 1011 and the second housing 1012 cover each other, and the first housing 1011 and the second housing 1012 jointly define a housing cavity for accommodating the battery cells 100. The second box body 1012 can be a hollow structure with one end open, and the first box body 1011 can be a plate-like structure, with the first box body 1011 covering the open side of the second box body 1012, so that the first box body 1011 and the second box body 1012 jointly define a receiving cavity; alternatively, the first box body 1011 and the second box body 1012 can both be hollow structures with one end open (for example, as shown in FIG. 2 ), with the open side of the first box body 1011 covering the open side of the second box body 1012. Of course, the box body 101 formed by the first box body 1011 and the second box body 1012 can have various shapes, such as a cylinder or a rectangular parallelepiped.

[0098] In the battery 200, multiple battery cells 100 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 100. Multiple battery cells 100 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 100 can be housed within the housing 101. Alternatively, the battery 200 can be constructed by first connecting multiple battery cells 100 in series, in parallel, or in a hybrid connection to form a battery module. The multiple battery modules are then connected in series, in parallel, or in a hybrid connection to form a single unit, which is then housed within the housing 101. The battery 200 may also include other structures. For example, the battery 200 may also include a busbar to electrically connect the multiple battery cells 100.

[0099] Referring to Figures 3 and 4, in an embodiment of the present application, a battery cell 100 includes a housing 40, an electrode post 20, and an electrode assembly 30. The electrode post 20 is disposed in the housing 40. The electrode assembly 30 includes an active material coating portion 31 disposed within the housing 40, and a tab portion 32 connected to the active material coating portion 31. The tab portion 32 is electrically connected to the electrode post 20. Exemplarily, a housing 40 is formed within the housing 40, and the active material coating portion 31 is accommodated in the compartment. The electrode post 20 is disposed within the housing 40. The tab portion 32 is directly welded to the electrode post 20 or connected via an adapter, such that the tab portion 32 is electrically connected between the active material coating portion 31 and the electrode post 20. Exemplarily, the portion of the positive electrode sheet having the positive active material layer (referred to as the positive electrode sheet body), the separator, and the portion of the negative electrode sheet having the negative active material layer (referred to as the negative electrode sheet body) are stacked in sequence, and the active material coating portion 31 is formed by winding or laminating.

[0100] The active material coating portion 31 can be divided into a positive electrode active material coating portion and a negative electrode active material coating portion. The positive electrode active material coating portion includes the portion of the positive electrode current collector coated with a positive electrode active material layer, while the negative electrode active material coating portion includes the portion of the negative electrode current collector coated with a negative electrode active material layer. The positive electrode tab electrically connects the positive electrode active material coating portion to the positive electrode post, while the negative electrode tab electrically connects the negative electrode active material coating portion to the negative electrode post.

[0101] Please refer to Figures 5 to 7. According to the electrode assembly 30 in some embodiments of the present application, the pole ear portion 32 includes a plurality of pole ear sheets 320. The plurality of pole ear sheets 320 are stacked and connected. The overlapping portions of the plurality of pole ear sheets 320 form an overlapping area 321. The misaligned portions of the plurality of pole ear sheets 320 form a misaligned area 322. The misaligned area 322 is connected to the overlapping area 321.

[0102] It is understood that after the multiple tabs 320 are stacked, the multiple tabs 320 have misaligned regions 322. The misaligned regions 322 can be understood as regions where the number of stacked tabs 320 is less than the total number of tabs 320 in the tab portion 32. The overlapped regions 321 can be understood as regions where the number of stacked tabs 320 is equal to the total number of tabs 320 in the tab portion 32. In other words, along the thickness direction of the tab portion 32, the portion where the projections of the multiple tabs 320 completely overlap corresponds to the overlapped region 321, while the portion where the projections of the multiple tabs 320 do not completely overlap corresponds to the misaligned regions 322. For example, the diagonal hatched region shown in FIG6 represents the overlapped region 321, and the diagonal hatched region represents the misaligned region 322.

[0103] Among them, the dislocation area 322 includes a first connecting part 3221 and a second connecting part 3222, the first connecting part 3221 is connected to the active material coating part 31 on one side along the first direction, and the second connecting part 3222 is connected to the first connecting part 3221 on the other side along the first direction, then the second connecting part 3222 is connected to the side of the first connecting part 3221 away from the active material coating part 31 in the first direction; in the second direction, the end of the second connecting part 3222 away from the overlapping area 321 is closer to the overlapping area 321 than the end of the first connecting part 3221 away from the overlapping area 321, and the second direction intersects with the first direction.

[0104] It can be seen that in the above technical solution, the misaligned area 322 can be located on one side of the overlapping area 321 in the second direction, and the first connection part 3221 and the second connection part 3222 are arranged in sequence along the first direction. In the second direction, the distance between the end of the second connection part 3222 away from the overlapping area 321 and the overlapping area 321 is x2, and the distance between the end of the first connection part 3221 away from the overlapping area 321 and the overlapping area 321 is x1, x2<x1, so that the width of the pole ear part 32 corresponding to the position of the second connection part 3222 in the second direction is smaller than the width of the pole ear part 32 corresponding to the position of the first connection part 3221 in the second direction. Then the pole ear part 32 may include a first part and a second part connected along the first direction, the first part may include a part of the overlapping area 321 and the first connection part 3221, and the second part may include another part of the overlapping area 321 and the second connection part 3222. In the second direction, the width of the second part is smaller than the width of the first part.

[0105] Since the second portion is connected to the active material coating portion 31, the staggered areas 322 of the multiple pole tabs 320 can be fully utilized to increase the connection length between the pole tab portion 32 and the active material coating portion 31, improve the electrical connection area and connection reliability between the pole tab portion 32 and the active material coating portion 31, and help improve the reliability and current capacity of the electrode assembly 30, thereby improving the reliability of the battery cell 100; when the electrode assembly 30 is used in the battery cell 100, if the pole tab portion 32 needs to pass through the avoidance portion of other components (for example, the pole tab portion 32 passes through the through-hole 20b on the pole column 20 described later), then the width of the second portion is relatively small, which is beneficial to saving the space required for the pole tab portion 32 during the passing operation, thereby improving the convenience of passing the pole tab portion 32, reducing the interference between the pole tab portion 32 and the pole column 20, and improving the reliability of the battery cell 100. At the same time, it can also improve the assembly convenience and assembly efficiency of the battery cell 100.

[0106] Exemplarily, the second direction is perpendicular to the first direction. For example, with the first direction being the front-to-back direction and the second direction being the left-to-right direction, an offset region 322 is provided on the left side of the overlapping region 321. The offset region 322 includes a first connection portion 3221 and a second connection portion 3222 sequentially connected along the front-to-back direction. The front side of the first connection portion 3221 is connected to the active material coating portion 31, the rear side of the first connection portion 3221 is connected to the second connection portion 3222, and the right side of the first connection portion 3221 and the right side of the second connection portion 3222 are both connected to the overlapping region 321. In the left-to-right direction, the distance between the left end of the second connection portion 3222 and the overlapping region 321 is less than the distance between the left end of the first connection portion 3221 and the overlapping region 321. It should be noted that the front-to-back and left-to-right directions corresponding to the first and second directions described above are merely for simplification of description and are not the corresponding directions used by the electrode assembly 30 or the battery cell 100 during manufacture or use. Of course, in other examples, the second direction may form any angle with the first direction other than a right angle.

[0107] 5 and 6 , in some embodiments, an edge of the second connection portion 3222 away from the overlapping region 321 has a serrated structure 32 b ; and / or an edge of the first connection portion 3221 away from the active material coating portion 31 has a serrated structure 32 b .

[0108] In the above technical solution, the edge of one end of the second connecting part 3222 away from the overlapping area 321 is provided with a serrated structure 32b, and / or the edge of one end of the first connecting part 3221 away from the active material coating part 31 is provided with a serrated structure 32b, so as to control the length of the wire drawing at the edge of the pole ear part 32 by controlling the width of the serrated structure 32b, so as to improve to a certain extent the problem of short circuit caused by the long wire drawing at the edge of the pole ear part 32 falling into or extending into other positions, thereby improving the safety of the electrode assembly 30.

[0109] Referring to FIG6 , in some embodiments, the sawtooth structure 32 b includes a plurality of protrusions 32 a sequentially arranged along a first direction, wherein the height h1 of the protrusions 32 a is ≤ 2 mm; and / or the diameter d1 of the circumscribed circle of the projection of the protrusions 32 a along the thickness direction of the tab portion 32 is ≤ 2 mm.

[0110] For example, h1 is 1 mm, 1.2 mm, 1.5 mm, or 2 mm, and d1 is 1 mm, 1.4 mm, 1.73 mm, or 2 mm, etc.

[0111] In the above technical solution, by setting the height h1 of the protrusion 32a to ≤ 2 mm and / or the circumscribed diameter d1 of the projection of the protrusion 32a along the thickness direction of the tab 32 to ≤ 2 mm, the length of the wire drawing at the edge of the tab 32 can be effectively controlled. Even if the entire serrated structure 32b is folded, the risk of short circuit caused by the protrusion 32a can be reduced. The height of the protrusion 32a can be understood as the height of the protrusion 32a in the second direction.

[0112] Exemplarily, when d1≤2mm, this can be achieved by reasonably setting the height and / or width of the protrusion 32a, for example, the protrusion 32a is trapezoidal, the width of the protrusion 32a is less than or equal to 1.73mm, and the height is less than or equal to 2mm.

[0113] It can be understood that in the embodiment of the present application, the multiple protrusions 32a of the sawtooth structure 32b can be arranged at intervals (as shown in FIG. 12 ), or the multiple protrusions 32a can be arranged without intervals (as shown in FIG. 6 ).

[0114] Referring to the figures, in some embodiments, the sawtooth structure 32b includes a plurality of protrusions 32a sequentially arranged along the first direction, and the protrusions 32a are square or trapezoidal.

[0115] In the above technical solution, by setting the protrusion 32a to be square or trapezoidal, the shape of the protrusion 32a is simplified, which is convenient for processing. At the same time, it is convenient to reasonably control the height, width and other dimensions of the protrusion 32a, which is conducive to further facilitating the control of the drawing length.

[0116] Please refer to Figure 6. In some embodiments, when a serrated structure 32b is formed on the edge of the second connecting portion 3222, a first groove 3220 is formed at a position where the first connecting portion 3221 is connected to an edge of one end of the second connecting portion 3222 away from the overlapping area 321. The first groove 3220 can be located at a side edge of the first connecting portion 3221 away from the active material coating portion 31, and the first groove 3220 is arranged adjacent to the second connecting portion 3222.

[0117] In the above technical solution, when a serrated structure 32b is formed in the second connecting portion 3222, a first groove 3220 is formed by setting an edge of the first connecting portion 3221 away from the active material coating portion 31. The first groove 3220 can be formed by cutting, which is beneficial to reducing the position requirements of the cutting knife in the first direction during the process of cutting to form the first groove 3220. At the same time, it can play a certain obstructive role on the cutting knife, which is beneficial to improving the cutting balance and accuracy.

[0118] It is understood that in the second direction, the first groove 3220 can be spaced apart from the second connecting portion 3222, or the first groove 3220 and the second connecting portion 3222 can be arranged without spacing (as shown in FIG6 ). For example, the radius of the circumscribed circle of the projection of the edge of the first groove 3220 in the thickness direction of the pole ear portion 32 can be less than or equal to 2 mm, so as to further achieve effective control of the drawing length of the edge of the pole ear portion 32, and even if the portion at the first groove 3220 is completely folded, the risk of short circuit can be reduced.

[0119] For example, the first groove 3220 may be a triangular groove (as shown in FIG. 6 ), a square groove (as shown in FIG. 12 ), or a trapezoidal groove (as shown in FIG. 12 ).

[0120] For example, when the cutting blade assembly 10 is used for cutting to form the tab portion 32, when the first cutting blade 11 is used for cutting the plurality of second elongated regions 52, the first groove 3220 can be formed by cutting the free end of the first blade 111 (e.g., at least a portion of the first cutting tooth portion 1112); when the second cutting blade 12 is used for cutting the plurality of second elongated regions 52, the first groove 3220 can be formed by cutting the free end of the second blade 121 (e.g., at least a portion of the second cutting tooth portion 1212). The depth of the first groove 3220 can also correspond to the distance between the second reference line L2 and the second cutting reference 5b described below, i.e., the second predetermined value b.

[0121] In other embodiments, when a serrated structure 32b is formed on the edge of the first connection portion 3221, a second groove is formed at a position of the second connection portion 3222 connected to an edge of one end of the first connection portion 3221 away from the active material coating portion 31, and the second groove can be located at a side edge of the second connection portion 3222 away from the overlapping area 321, and the second groove is arranged adjacent to the first connection portion 3221.

[0122] In the above technical solution, when a serrated structure 32b is formed on the first connecting portion 3221, a second groove is formed by setting the edge of the second connecting portion 3222 on one side away from the overlapping area 321. The second groove can be formed by cutting, which is beneficial to reducing the position requirements of the cutting knife in the second direction during the process of cutting to form the second groove. At the same time, it can play a certain obstructive role on the cutting knife, which is beneficial to improving the cutting balance and accuracy.

[0123] It is understood that, in the first direction, the second groove can be spaced apart from the first connecting portion 3221, or the second groove can be spaced apart from the first connecting portion 3221. For example, the radius of the circumscribed circle of the projection of the edge of the second groove in the thickness direction of the pole ear portion 32 can be less than or equal to 2 mm, so as to further effectively control the drawing length of the edge of the pole ear portion 32, and reduce the risk of short circuit even if the portion at the second groove is completely folded.

[0124] Illustratively, the second groove may be a triangular groove, a square groove, a trapezoidal groove, or the like.

[0125] In some other embodiments, the first connection portion 3221 does not have the first groove 3220 formed thereon, and the second connection portion 3222 does not have the second groove formed thereon.

[0126] Please refer to Figure 6, and in combination with Figures 8 to 11, in some embodiments, at least one of the edge of the end of the first connection part 3221 away from the active material coating part 31 and the edge of the end of the second connection part 3222 away from the overlapping area 321 is obtained by cutting, then at least one of the edge of the end of the first connection part 3221 away from the active material coating part 31 and the edge of the end of the second connection part 3222 away from the overlapping area 321 is configured as a cutting edge, that is, after cutting, the edge of the end of the first connection part 3221 away from the active material coating part 31 and / or the edge of the end of the second connection part 3222 away from the overlapping area 321 are formed.

[0127] It can be seen that if the edge of one end of the first connection portion 3221 away from the active material coating portion 31 is obtained by cutting, then before cutting, the edge of one end of the first connection portion 3221 away from the active material coating portion 31 is connected to the cut-off area (for example, the cut-off area 3321 described later); if the edge of one end of the second connection portion 3222 away from the overlapping area 321 is obtained by cutting, then before cutting, the edge of one end of the second connection portion 3222 away from the overlapping area 321 is connected to the cut-off area (for example, the cut-off area 3321 described later).

[0128] It is understandable that the edge of the first connection portion 3221 away from the active material coating portion 31 and the edge of the second connection portion 3222 away from the overlapping region 321 may be obtained through the same cutting or through different cutting.

[0129] In the above technical solution, by setting the edge of one end of the first connecting part 3221 away from the active material coating part 31 and / or the edge of one end of the second connecting part 3222 away from the overlapping area 321 to be obtained by cutting, the length of the wire drawing at the edge of the pole ear part 32 of the electrode assembly 30 after cutting can be effectively shortened, and the problem of long wire drawing being easily generated after the pole ear part 32 is cut can be effectively improved, so as to improve the problem of short circuit caused by long wire drawing falling into or extending into other positions to a certain extent.

[0130] For example, the edge of one end of the second connection part 3222 away from the overlapping area 321 is a serrated structure 32b, and the serrated structure 32b is configured as a cutting edge. The edge of one side of the first connection part 3221 away from the active material coating part 31 is also configured as a cutting edge; if at this time a first groove 3220 is formed at the position where the first connection part 3221 is connected to the edge of one end of the second connection part 3222 away from the overlapping area 321, the edge corresponding to the second groove is also configured as a cutting edge.

[0131] Please refer to Figure 6. In some embodiments, an offset region 322 is respectively provided on two opposite sides of the overlapping region 321 in the second direction, and each offset region 322 respectively includes a first connecting portion 3221 and a second connecting portion 3222, and for each offset region 322, the first connecting portion 3221 is connected to the active material coating portion 31, and the distance between the end of the second connecting portion 3222 away from the overlapping region 321 and the overlapping region 321 is smaller than the distance between the end of the corresponding first connecting portion 3221 away from the overlapping region 321 and the overlapping region 321, so that the width of the pole ear portion 32 corresponding to the position of the second connecting portion 3222 in the second direction is smaller than the width of the pole ear portion 32 corresponding to the position of the first connecting portion 3221 in the second direction.

[0132] For example, the misaligned regions 322 on both sides of the overlapping region 321 in the second direction can be arranged opposite each other along the second direction, and the first connection portions 3221 of the two misaligned regions 322 can be arranged opposite each other along the second direction; for example, the misaligned regions 322 on both sides of the overlapping region 321 can be arranged symmetrically, and of course the misaligned regions 322 on both sides of the overlapping region 321 can also be arranged asymmetrically.

[0133] In the above technical solution, by setting the overlapping area 321 and providing the offset areas 322 on the opposite sides in the second direction, it is beneficial to further increase the connection length between the pole ear portion 32 and the active material coating portion 31, further improve the electrical connection area and connection reliability between the pole ear portion 32 and the active material coating portion 31, thereby further improving the use reliability and overcurrent capacity of the electrode assembly 30.

[0134] For example, an offset region 322 is provided on opposite sides of the overlapping region 321 in the second direction, each offset region 322 includes a first connecting portion 3221 and a second connecting portion 3222, and an edge of one end of each second connecting portion 3222 away from the overlapping region 321 is a serrated structure 32b, and an edge of one side of each first connecting portion 3221 away from the active material coating portion 31 is formed with a first groove 3220; or, an edge of one end of each first connecting portion 3221 away from the active material coating portion 31 is a serrated structure 32b, and each second connecting portion 32 22 is formed with a second groove on one side edge away from the overlapping area 321; or, in one of the dislocated areas 322, the edge of one end of the first connecting part 3221 away from the active material coating part 31 is a serrated structure 32b, and the edge of one side of the second connecting part 3222 away from the overlapping area 321 is formed with a second groove; in the other dislocated area 322, the edge of one end of the second connecting part 3222 away from the overlapping area 321 is a serrated structure 32b, and the edge of one side of the first connecting part 3221 away from the active material coating part 31 is formed with a first groove 3220.

[0135] Please refer to Figure 6. In some embodiments, the active material coating portion 31 includes a positive electrode sheet body, a negative electrode sheet body and a separator. A plurality of electrode tabs 320 are respectively connected to the positive electrode sheet body and the negative electrode sheet body. The separator is arranged between the positive electrode sheet body and the negative electrode sheet body, and the separator exceeds the positive electrode sheet body and the negative electrode sheet body. Wherein, at least a portion of the first connection portion 3221 is blocked by the separator, and the portion of the separator exceeding the positive electrode sheet body and the negative electrode sheet body blocks at least a portion of the first connection portion 3221.

[0136] It can be seen that in the above technical solution, the pole tab 320 connected to the positive pole sheet body can be formed as a positive pole tab, and the pole tab 320 connected to the negative pole sheet body can be formed as a negative pole tab. In the first direction, the portion of the isolation membrane that exceeds the positive pole sheet body can block at least a portion of the first connection portion 3221 of the positive pole tab, and the portion of the isolation membrane that exceeds the negative pole sheet body can block at least a portion of the first connection portion 3221 of the negative pole tab.

[0137] In the above technical solution, by setting an isolation membrane beyond the positive electrode plate body and the negative electrode plate body to block at least part of the first connection part 3221, at least part of the first connection part 3221 blocked by the isolation membrane can be insulated, so as to shorten the length of the first connection part 3221 that can bypass the isolation membrane and extend into other positions to cause a short circuit, thereby further improving the safety of the electrode assembly 30.

[0138] For example, the isolation film blocks the entire first connection part 3221 to improve the insulation setting of the first connection part 3221, and even if a part of the first connection part 3221 is folded, the short circuit problem can be improved; for another example, the isolation film blocks a part of the first connection part 3221, and at this time the width of the part of the first connection part 3221 exposed outside the isolation film in the first direction can be less than or equal to 2 mm, but is not limited to this.

[0139] In some embodiments, the width h2 of the first connection portion 3221 in the first direction is greater than 1 mm. For example, h2 is 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, etc. Furthermore, h2 is greater than 2 mm.

[0140] In the above technical solution, by setting the width h2 of the first connecting portion 3221 to be greater than 1 mm, so that when the pole ear portion 32 is cut, the interval between the cutting area 3321 and the current collector is greater than 1 mm, the problem of other components of the electrode assembly, such as the isolation membrane, etc., that extend beyond the positive electrode sheet body and the negative electrode sheet body being punched out together during the cutting process can be improved.

[0141] Secondly, an embodiment of the present application provides a battery cell 100 including a shell 40 , a pole 20 and the above-mentioned electrode assembly 30 , wherein the pole 20 is disposed in the shell 40 , the active material coating portion 31 is accommodated in the shell 40 , and the pole ear portion 32 is electrically connected to the pole 20 .

[0142] In the above technical solution, since the battery cell 100 adopts the above electrode assembly 30 and the electrode assembly 30 has good reliability and overcurrent capability, it is beneficial to improve the charge and discharge capability and reliability of the battery cell 100 .

[0143] For example, the pole ear portion 32 is directly electrically connected to the pole 20 , or the pole ear portion 32 is indirectly electrically connected to the pole 20 via an adapter.

[0144] Please refer to Figure 4. In some embodiments, a receiving groove 20a is formed on the pole 20, and a portion of the pole ear portion 32 is received in the receiving groove 20a, so that a portion of the pole ear portion 32 can occupy the space in the receiving groove 20a, thereby reducing the space occupied by the pole ear portion 32 in the shell 40, saving space in the shell 40 to accommodate a larger volume of active material coating portion 31, which is beneficial to improving the energy density of the battery cell 100, or when the energy density of the battery cell 100 remains unchanged, it is beneficial to reduce the size of the battery cell 100.

[0145] Among them, the side of the accommodating groove 20a facing away from the active material coating portion 31 is open, and the groove wall of the accommodating groove 20a facing the active material coating portion 31 is formed with a through-hole 20b connected to the interior of the shell 40. The through-hole 20b can pass through the groove wall of the accommodating groove 20a close to the active material coating portion 31, and the through-hole 20b connects the accommodating groove 20a and the internal space of the shell 40, and the pole ear portion 32 is passed through the through-hole 20b.

[0146] Thus, when the electrolyte is injected into the battery cell 100, the electrolyte can be injected into the receiving groove 20a, and then flow toward the inside of the shell 40 through the perforation 20b. The receiving groove 20a can serve as a buffer for the electrolyte to improve problems such as splashing and overflow of the electrolyte. Moreover, the side wall of the receiving groove 20a (that is, the groove wall extending from the notch of the receiving groove 20a toward the active material coating portion 31) can block the electrolyte from splashing to a certain extent, reduce the pollution caused by the electrolyte to the outside, and facilitate rapid injection. Moreover, since there is no need to open a separate injection channel on the shell 40, there is no need to perform special processing on the shell 40, which is beneficial to reducing the structural complexity and processing difficulty of the shell 40. In addition, the perforation 20b can also play a certain limiting role on the pole ear portion 32.

[0147] It can be seen that when the battery cell 100 is assembled, in the process of inserting the pole ear portion 32 into the through-hole 20b, the end of the second connection portion 3222 away from the first connection portion 3221 and the end of the overlapping area 321 away from the active material coating portion 31 first extend into the through-hole 20b. Since the width of the second connection portion 3222 in the second direction is relatively smaller than that of the first connection portion 3221, the width of the end of the pole ear portion 32 away from the active material coating portion 31 in the second direction is smaller than the width of the end of the pole ear portion 32 close to the active material coating portion 31 in the second direction, thereby improving the convenience of inserting the pole ear portion 32.

[0148] It is understood that there may be one or more through-holes 20b, and the electrode ear portion 32 may be provided through at least one of the through-holes 20b. For example, at least one through-hole 20b may allow electrolyte to pass through, and at least one through-hole 20b may be left vacant (i.e., not provided with the electrode ear portion 32), thereby allowing electrolyte to pass through without being obstructed by the electrode ear portion 32. For another example, at least one through-hole 20b may still allow electrolyte to pass through after the electrode ear portion 32 is provided.

[0149] For example, the portion of the pole ear 32 accommodated in the receiving groove 20a is welded to the pole 20 to form an electrical connection, thereby realizing the electrode output of the electrode assembly 30 from the pole 20. If the side of the receiving groove 20a facing away from the active material coating portion 31 is open, the pole ear 32 is welded to the side of the groove wall of the receiving groove 20a close to the active material coating portion 31, thereby improving the compactness of the fit and facilitating the welding operation of the two. Of course, the electrical connection position of the pole ear 32 and the pole 20 is not limited to this. For example, the portion of the pole ear 32 passing through the through-hole 20b is welded to the pole 20 to form an electrical connection. In other examples, the pole ear 32 can also be set to be welded to the pole cover plate 60 described later to form an electrical connection, which is not limited here.

[0150] Referring to FIG. 4 , in some embodiments, the battery cell 100 further includes a pole cover 60 . The pole cover 60 is disposed on the pole 20 and closes the opening of the receiving groove 20 a.

[0151] In the above technical solution, the pole cover 60 is provided to close the notch of the receiving tank 20a so as to improve the problem of leakage of the electrolyte in the shell 40 from the notch of the receiving tank 20a. Moreover, since the pole cover 60 closes the notch of the receiving tank 20a and is electrically connected to the pole 20, it is convenient to use the pole cover 60 to realize the electrical connection between the pole 20 and the busbar component, which is beneficial to increase the connection area at the electrical connection position and improve the current carrying capacity.

[0152] For example, a liquid injection hole that can communicate with the accommodating groove 20a is formed on the pole cover 60, and the battery cell 100 also includes a sealing structure for sealing the liquid injection hole; or, a sealing member is provided at the perforation 20b to improve the problem of electrolyte leakage from the perforation.

[0153] In a third aspect, an embodiment of the present application provides a battery 200 including the above-mentioned battery cell 100 .

[0154] In the above technical solution, since the battery adopts the above-mentioned battery cell 100 and the battery cell 100 has good charge and discharge capabilities and reliability, it is beneficial to improve the performance and reliability of the battery 200.

[0155] In a fourth aspect, an embodiment of the present application provides an electrical device 1000 , comprising the above-mentioned battery 200 , and the battery 200 is used to provide electrical energy.

[0156] In the above technical solution, since the power-consuming device 1000 adopts the above-mentioned battery 200 and the battery 200 has good performance and reliability, it is beneficial to improve the performance and reliability of the power-consuming device 1000.

[0157] In a fifth aspect, embodiments of the present application provide a method for processing an electrode assembly 30, as shown in Figures 13-15. The method includes: stacking and partially staggering a plurality of connecting sheets 33 connected to an active material coating portion 31, wherein the plurality of connecting sheets 33 have overlapping portions 331 and staggered portions 332; dividing the staggered portions 332 into a cutting region 3321 and a non-cutting region 3322, wherein the non-cutting region 3322 includes a first connecting portion 3221 and a second connecting portion 3222 connected to each other and to the overlapping portions, the first connecting portion 3221 connecting the active material coating portion 31 and the cutting region 3321 on either side in a first direction, and the second connecting portion 3222 connecting the overlapping portion 331 and the cutting region 3321 on either side in a second direction, the second direction intersecting the first direction; and removing the cutting region 3321, so that the remaining portions of the plurality of connecting sheets 33 form the electrode tabs 32 of the electrode assembly 30.

[0158] Obviously, after the plurality of connecting sheets 33 are cut as described above, the remaining portion of each connecting sheet 33 forms a tab sheet 320 , and the offset portion 332 corresponds to the offset region 322 described above, and the overlapping portion 331 corresponds to the overlapping region 321 described above.

[0159] It can be seen that in the above technical solution, in the first direction, the first connecting portion 3221 is located between the cutting area 3321 and the active material coating portion 31, and in the second direction, the second connecting portion 3222 is located between the cutting area 3321 and the overlapping portion 331, and in the second direction, the end of the second connecting portion 3222 away from the overlapping area 321 is closer to the overlapping area 321 than the end of the first connecting portion 3221 away from the overlapping area 321.

[0160] It can be understood that after multiple connecting plates 33 are stacked, there are misaligned parts 332 in the multiple connecting plates 33. The misaligned parts 332 can be understood as the number of stacked connecting plates 33 in this part is less than the number of all connecting plates 33, and the overlapping parts 331 can be understood as the number of stacked connecting plates 33 in this part is equal to the number of all connecting plates 33; in other words, along the stacking direction, the part where the projections of the multiple layers of connecting plates 33 completely overlap corresponds to the overlapping part 331, and the part where the projections of the multiple layers of connecting plates 33 do not completely overlap corresponds to the misaligned parts 332.

[0161] In the above technical solution, the staggered parts of the multiple connecting sheets 33 are divided into cutting areas 3321 and non-cutting areas 3322, and the cutting areas 3321 are connected to the side of the first connecting portion 3221 away from the active material coating portion 31, and the cutting areas 3321 are connected to the side of the second connecting portion 3222 away from the overlapping portion, so that after the cutting areas 3321 are cut off, the remaining parts of the multiple connecting sheets 33 are formed into the pole ear portion 32 of the electrode assembly 30, so that the width of the end of the pole ear portion 32 away from the active material coating portion 31 in the second direction is smaller than the width of the end of the pole ear portion 32 connected to the active material coating portion 31 in the second direction, thereby improving the penetration and arrangement capability of the pole ear portion 32 while taking into account the current-carrying capacity and reliability of the electrode assembly 30, and facilitating the assembly of the battery cell 100.

[0162] Referring to Figures 5, 8, and 11, in some embodiments, the offset portion 332 has a first cutting reference 5a extending along the first direction and a second cutting reference 5b extending along the second direction. The cutting area 3321 includes a plurality of first elongated regions 51 and a plurality of second elongated regions 52. The plurality of first elongated regions 51 and the plurality of second elongated regions 52 are alternately arranged along the first direction or the second direction, and the first elongated regions 51 and the second elongated regions 52 extend along the second direction or the first direction. It can be seen that there are two different arrangements for the cutting area 3321: 1. The plurality of first elongated regions 51 and the plurality of second elongated regions 52 are alternately arranged along the first direction, and the first elongated regions 51 and the second elongated regions 52 extend along the second direction; 2. The plurality of first elongated regions 51 and the plurality of second elongated regions 52 are alternately arranged along the second direction, and the first elongated regions 51 and the second elongated regions 52 extend along the first direction.

[0163] Cutting off the cutting area 3321 includes: cutting off the plurality of first long strip areas 51 based on the first cutting reference 5 a and the second cutting reference 5 b ; and cutting off the plurality of second long strip areas 52 based on the first cutting reference 5 a and the second cutting reference 5 b .

[0164] It can be seen that in the above cutting process, no matter whether the first long strip area 51 or the second long strip area 52 is cut, the cutting positions are based on the first cutting reference 5 a and the second cutting reference 5 b.

[0165] In the above technical solution, for the cutting area 3321, multiple first long strip areas 51 are first cut off based on the first cutting reference 5a and the second cutting reference 5b, and then multiple second long strip areas 52 are cut off based on the first cutting reference 5a and the second cutting reference 5b, so as to achieve the cutting of the cutting area 3321. At the same time, the cutting position of the cutting knife assembly 10 during the cutting process is set based on the first cutting reference 5a and the second cutting reference 5b, which is convenient for achieving effective control of the wire drawing length at the first cutting reference 5a and the second cutting reference 5b after the multiple connecting pieces 33 are cut, so as to improve the problem of long wire drawing that is easy to generate after the multiple connecting pieces 33 are cut, thereby improving the problem of short circuit caused by long wire drawing falling into or extending into other positions to a certain extent.

[0166] For example, the cutter used to cut the plurality of first elongated regions 51 and the cutter used to cut the plurality of second elongated regions 52 may be the same cutter or different cutters.

[0167] In some embodiments, the cutting knife assembly 10 includes a first cutter 11, and the first cutter 11 includes a plurality of first blades 111 arranged at intervals; the cutting method includes: the plurality of first blades 111 cut the plurality of first long strip areas 51 respectively, and at least one first blade 111 located at the edge of the first cutter 11 cuts the plurality of second long strip areas 52.

[0168] For example, each first long strip area 51 is cut by a corresponding first blade 111. During the cutting process, the width side of the outermost one of the multiple first blades 111 in the first direction can be aligned with the second cutting reference 5b, and the ends of the multiple first blades 111 in the second direction can be aligned with the first cutting reference 5a. After the multiple first long strip areas 51 are cut, the width side of the outermost one of the multiple first blades 111 can be cut with the first cutting reference 5a as the reference, so as to cut the multiple second long strip areas 52 at the same time. Obviously, the arrangement posture of the first cutter 11 changes during the above two cutting processes. When cutting the multiple first long strip areas 51, the length end of the first blade 111 can be aligned with the first cutting reference 5a. When cutting the multiple second long strip areas 52, the above-mentioned length end of the first blade 111 can be aligned with the second cutting reference 5b as the reference.

[0169] In the above technical solution, the first cutter 11 can be used to cut multiple first long strip areas 51 and multiple second long strip areas 52, which is convenient for simplifying the structure of the cutting knife assembly 10 while shortening the drawing length at the cutting reference of the cutting area 3321.

[0170] Please refer to Figures 8 to 11. In some embodiments, the cutting knife assembly 10 includes a first cutter 11 and a second cutter 12. The first cutter 11 includes a plurality of first blades 111 arranged at intervals, and the second cutter 12 includes at least one second blade 121. The cutting method includes: the plurality of first blades 111 cut the plurality of first long strip areas 51 respectively, and the at least one second blade 121 cuts the plurality of second long strip areas 52.

[0171] For example, each first long strip area 51 is cut by a corresponding first blade 111. During the cutting process, the width side of the outermost one of the multiple first blades 111 in the first direction can be aligned with the second cutting reference 5b, and the ends of the multiple first blades 111 in the second direction can be aligned with the first cutting reference 5a. After the multiple first long strip areas 51 are cut, the width side of the second blade 121 on the outermost side of the second cutter 12 can be cut with the first cutting reference 5a as the reference reference, so as to cut the multiple second long strip areas 52 at the same time. Obviously, when cutting the multiple first long strip areas 51, the length end of the first blade 111 can be aligned with the first cutting reference 5a, and when cutting the multiple second long strip areas 52, the above-mentioned length end of the second blade 121 can be aligned with the second cutting reference 5b as the reference reference.

[0172] In the above technical solution, the first cutter 11 is used to cut multiple first long strip areas 51, and the second cutter 12 is used to cut multiple second long strip areas 52. The cutting arrangement posture of the first cutter 11 and the cutting arrangement posture of the second cutter 12 do not need to be adjusted frequently, which is conducive to simplifying the cutting process.

[0173] It can be understood that when the second cutter 12 includes a second blade 121, the second blade 121 can be aligned with the first cutting reference 5a for cutting; when the second cutter 12 includes multiple second blades 121, the multiple second blades 121 can be arranged at intervals along the second direction, and the outermost first blade 111 among the multiple second blades 121 can be aligned with the first cutting reference 5a for cutting.

[0174] Please refer to Figures 8 to 11. In some embodiments, multiple first long strip areas 51 are cut based on the first cutting reference 5a and the second cutting reference 5b, including: adjacent two sides of the cutting knife assembly 10 are aligned with the first cutting reference 5a and the second cutting reference 5b respectively.

[0175] Based on the first cutting reference 5a and the second cutting reference 5b, multiple second long strip areas 52 are cut, including: the adjacent two sides of the cutting knife assembly 10 are aligned with the first reference line L1 and the second reference line L2 respectively, the first reference line L1 corresponds to the inner side of the cutting area 3321 and is at a first predetermined value a away from the first cutting reference 5a, and the second reference line L2 corresponds to the outer side of the cutting area 3321 and is at a second predetermined value b away from the second cutting reference 5b.

[0176] It can be seen that the cutting knife assembly 10 can cut off a part of each second long strip area 52, and the remaining part of each second long strip area 52 corresponds to the drawing at the first cutting reference 5a; moreover, after cutting off multiple first long strip areas 51, the cutting knife assembly 10 can cut off a part of the second cutting reference 5b to change the edge shape of the position, or it can not change the interference with the second cutting reference 5b during the cutting process so that the edge shape of the position does not change.

[0177] In the above technical solution, during the process of the cutting knife assembly 10 cutting the multiple second long strip areas 52, by setting the position of the cutting knife assembly 10, the first side edge of the cutting knife assembly 10 is aligned between the first reference line L1 and the second reference line L2, or aligned with the first reference line L1, and the second side edge of the cutting knife assembly 10 is aligned with the third reference line L3, so as to achieve effective control of the drawing length at the first cutting reference 5a and the second cutting reference 5b.

[0178] It is understandable that the first predetermined value a and the second predetermined value b can be specifically set according to the drawing length requirement; for example, if the drawing length does not exceed 2 mm, the first predetermined value a and the second predetermined value b can both be less than or equal to 2 mm.

[0179] The following is an example of the first cutter 11 cutting multiple first long strip areas 51 and the second cutter 12 cutting multiple second long strip areas 52. After reading the following description, those skilled in the art will easily understand the implementation plan of cutting multiple first long strip areas 51 and multiple second long strip areas 52 with the first cutter 11.

[0180] As shown in Figures 8 to 11, the cutting area 3321 is roughly a square area, the first cutting reference 5a and the second cutting reference 5b are perpendicular, and the edge opposite to the first cutting reference 5a and the edge opposite to the second cutting reference 5b in the cutting area 3321 are free end edges respectively; the first cutting reference 5a extends in the left-right direction, and the second cutting reference 5b extends in the front-back direction.

[0181] When the first cutter 11 cuts the plurality of first long strip regions 51, the front edge of the most forward first blade 111 among the plurality of first blades 111 is aligned with the second cutting reference 5b, and the free ends of the lengthwise direction of the plurality of first blades 111 are aligned with the first cutting reference 5a in the left-right direction to cut the plurality of first long strip regions 51. After the plurality of first long strip regions 51 are cut, the width side of the corresponding second blade 121 of the second cutter 12 can be aligned with the first reference line L1, and the free end of the lengthwise direction of the second blade 121 can be aligned with the second reference line L2 to cut the plurality of second long strip regions 52 simultaneously. Obviously, after cutting the cutting area 3321, the first predetermined value and the second predetermined value are related to the product drawing length.

[0182] Referring to Figures 10 and 11 , in some embodiments, each second elongated region 52 includes a first sub-region 521 and a second sub-region 522 sequentially arranged along its length. The second sub-region 522 is located between the first cutting datum 5a and the first reference line L1, i.e., the opposite edges of the second sub-region 522 are located on the first cutting datum 5a and the first reference line L1, respectively. The circumscribed circle diameter d2 of the projection of the second sub-region 522 along the stacking direction is ≤ 2 mm, with the stacking direction being perpendicular to the first and second directions, respectively; and / or a is ≤ 2 mm; and / or b is ≤ 2 mm.

[0183] In the above technical solution, by setting the circumscribed circle diameter d2≤2mm, and / or a≤2mm, and / or b≤2mm of the projection of the second sub-area 522 along the third direction, effective control of the size of the portion of the second sub-area 522 retained on the workpiece to be cut is achieved, that is, effective control of the wire drawing length after cutting is achieved. Even if the entire second sub-area 522 remains on the workpiece to be cut, the risk of short-circuiting of the portion corresponding to the second sub-area 522 due to folding can be reduced.

[0184] For example, d2 is 2 mm, 1.73 mm, 1.5 mm, 1.2 mm, 1 mm, or 0.9 mm, a is 2 mm, 1.8 mm, 1.5 mm, 1.3 mm, 1 mm, or 0.8 mm, and b is 2 mm, 1.9 mm, 1.5 mm, 1.2 mm, 1 mm, or 0.9 mm. In addition, a and b may also be 0.

[0185] It can be understood that the electrode assembly 30 in the embodiment of the present application can be processed using the processing method in the embodiment of the present application; the processing method in the embodiment of the present application can be implemented by adopting the cutting knife assembly 10 in the embodiment of the present application.

[0186] It can be seen that in the embodiment of the present application, multiple connecting pieces 33 are cut to form the pole ear portion 32, so as to reduce the area of ​​the misalignment region of the multiple pole ear pieces 320. At the same time, the misalignment region remaining after cutting can be used to improve the connection reliability and flow capacity between the pole ear portion 32 and the active material coating portion 31, and reduce the adverse effects of excessive misalignment of the pole ear piece 320 on subsequent processes.

[0187] It can be understood that when the pole ear portion 32 is cut using the above-mentioned processing method, if the second connecting portion 3222 is formed with a serrated structure 32b, the first cutting reference 5a is set corresponding to the second connecting portion 3222, and the second cutting reference 5b is set corresponding to the first connecting portion 3221. At this time, the first cutting reference 5a can be the edge of the second connecting portion 3222 away from the overlapping area 321, or the first cutting reference 5a can be set at a distance from the above-mentioned edge of the second connecting portion 3222 (as shown in Figure 6); for example, the interval between the first cutting reference 5a and the edge of the second connecting portion 3222 is less than or equal to 1 mm, for example, the interval can be 0.9 mm, 0.94 mm, or 0.98 mm, etc. If the first connection portion 3221 is formed with a serrated structure 32b, the first cutting reference 5a is set corresponding to the first connection portion 3221, and the second cutting reference 5b is set corresponding to the second connection portion 3222. At this time, the first cutting reference 5a can be the edge of the first connection portion 3221 away from the active material coating portion 31, or the first cutting reference 5a can be set at intervals from the above-mentioned edge of the first connection portion 3221.

[0188] In a sixth aspect, an embodiment of the present application provides a cutting knife assembly. Please refer to Figures 16 to 20. The cutting knife assembly 10 is used to cut the cutting area 3321 of the workpiece to be cut to obtain the electrode assembly 30.

[0189] The part to be cut includes an active material coating portion 31 and a part to be cut, the part to be cut is connected to the active material coating portion 31, and the part to be cut includes a plurality of connecting pieces 33 that are stacked and connected, and the plurality of connecting pieces 33 are partially staggered so that the plurality of connecting pieces 33 have overlapping parts 331 and staggered parts 332; the overlapping parts 331 of the plurality of connecting pieces 33 form an overlapping area 321, and the staggered parts 332 of the plurality of connecting pieces 33 include a cutting area 3321 and a non-cutting area 3322, and the non-cutting area 3322 includes a first connecting part 3221 and a second connecting part 3222 that are connected to each other and respectively connected to the overlapping part 331, the first connecting part 3221 is respectively connected to the active material coating portion 31 and the cutting area 3321 on both sides in the first direction, and the second connecting part 3222 is respectively connected to the overlapping part 331 and the cutting area 3321 on both sides in the second direction, and the second direction intersects with the first direction.

[0190] The cutter assembly 10 includes a first cutter 11, which includes a plurality of first blades 111 spaced apart along a first direction, each of which extends along a second direction. The first cutter 11 is configured to remove at least a portion of a cutting region 3321, thereby forming the electrode lugs 32 from the remaining portions of the plurality of connecting tabs 33. The electrode lugs 32 and the active material coating 31 form the electrode assembly 30.

[0191] It can be seen that in the process of the cutting knife assembly 10 cutting the workpiece to obtain the electrode assembly 30, the first cutting knife 11 can be used to cut the entire cutting area 3321, or the first cutting knife 11 can be used to cut a part of the cutting area 3321, and other parts of the cutting knife assembly 10 (such as the second cutting knife 12 described later) can be used to cut another part of the cutting area 3321.

[0192] In the above technical solution, a first cutter 11 is provided including a plurality of first blades 111 arranged at intervals, and the first cutter 11 is used to cut off at least a portion of the cutting area 3321, and the cutter assembly 10 is used to cut off the cutting area 3321, so that in the second direction, the end of the second connection portion 3222 away from the overlapping area 321 is closer to the overlapping area 321 than the end of the first connection portion 3221 away from the overlapping area 321, so as to improve the convenience of passing the pole ear portion 32 and increase the connection area between the pole ear portion 32 and the active material coating portion 31, thereby facilitating the improvement of the assembly efficiency of the battery cell 100 and the improvement of the current carrying capacity.

[0193] In addition, whether the first cutter 11 is used to cut the entire cutting area 3321 or the first cutter 11 is used to cut a part of the cutting area 3321, the entire cutting area 3321 needs to be cut multiple times to be cut. Since the first cutter 11 includes multiple first blades 111 arranged at intervals, it is helpful to improve the problem of long wire drawing at the cutting edge.

[0194] For example, when the first cutter 11 is used to cut the cutting area 3321, the first cutter 11 can punch the cutting area 3321 in a direction perpendicular to the cutting area 3321. For example, the first cutter 11 punches along the thickness direction of the workpiece to be cut. Then, the portion of the cutting area 3321 aligned with each first blade 111 is punched by the first cutter 11, while the portion of the cutting area 3321 aligned with the gap between two adjacent first blades 111 is not punched by the first cutter 11, so that the first cutter 11 can cut off a portion of the cutting area 3321 after punching the cutting area 3321 once. At this time, The cut portion may include a plurality of first elongated regions 51 spaced apart along a first direction, and the remaining portion of the cutting region 3321 may include a plurality of second elongated regions 52 spaced apart along the first direction. The remaining portion of the cutting region 3321 may then be cut using the cutting blade assembly 10 to cut away at least a portion of each second elongated region 52, thereby effectively shortening the length of the wires after the cut piece is cut, thereby effectively alleviating the problem of long wires being easily generated after the cut piece is cut, and to a certain extent alleviating the problem of the cut piece being unable to be used normally due to the long wires falling into or extending into other locations. The direction perpendicular to the cutting region 3321 may be perpendicular to the first direction and the second direction, respectively.

[0195] For example, if the workpiece to be cut is a tab, some technologies use a flat knife to cut the tab. Due to the gap between the blades of the flat knife, long wires are easily produced during cutting, which makes it easy for the subsequent long wires to extend into the electrode assembly of the battery cell, which can easily cause the risk of electrode short circuit. In addition, during the use of the flat knife, the gap between the blades will gradually increase, making it more likely for long wires to be produced during cutting. In the embodiment of the present application, a cutting knife assembly 10 is provided, which includes a first cutter 11. The first cutter 11 includes a plurality of first blades 111 spaced apart along a first direction, each of which extends along a second direction. The first blades 111 can cut the plurality of first long strip regions 51 and the plurality of second long strip regions 52 of the cutting area 3321 in sequence, thereby effectively shortening the length of the plurality of second long strip regions 52 remaining on the workpiece to be cut, thereby shortening the length of the wires when cutting the tab portion 32, effectively reducing the risk of the wires extending into the electrode assembly due to their long length, causing electrode short circuit, and improving the reliability and safety of the electrode assembly.

[0196] Exemplarily, the first direction is perpendicular to the second direction, and the first cutter 11 punches the cutting area 3321 along a direction perpendicular to the cutting area 3321 to cut off a portion of the cutting area 3321. At this time, the cut portion may include a plurality of first long strip areas 51 set at intervals, and the remaining portion of the cutting area 3321 is a plurality of second long strip areas 52 set at intervals; then, the first cutter 11 can be used again to cut the remaining portion of the cutting area 3321 so as to cut off the plurality of second long strip areas 52. Obviously, during the above-mentioned second cutting, the placement posture of the first cutter 11 needs to be adjusted. For example, the two adjacent cutting references of the cutting area 3321 are the first cutting reference 5a and the second cutting reference 5b, and the two are perpendicular to each other. When the first cutter 11 performs the first cutting, the ends of the multiple first blades 111 can correspond to the first cutting reference 5a, and the multiple first blades 111 can be arranged at intervals in the front-to-back direction, and each first blade 111 extends in the left-to-right direction. When the first cutter 11 performs the second cutting, the ends of the multiple first blades 111 can correspond to the second cutting reference 5b, and the multiple first blades 111 can be arranged at intervals in the left-to-right direction, and each first blade 111 extends in the front-to-back direction, that is, the first cutter 11 can be rotated 90° around the vertical direction; it can be seen that the above-mentioned setting can at least effectively control the wire drawing length at the first cutting reference 5a.

[0197] Of course, two adjacent cutting references of the cutting area 3321 may also form an acute angle or an obtuse angle, and the first cutter 11 may rotate around the vertical direction by a corresponding angle during the two cutting operations.

[0198] Of course, in other examples, after the first cutter 11 sequentially cuts the cutting area 3321, other components of the cutter assembly 10 other than the first cutter 11, such as the second cutter 12 described below, can be used to further cut the cutting area 3321, rather than always using the first cutter 11. That is, throughout the entire process of cutting the cutting area 3321, the first cutter 11 can be used to cut the cutting area 3321, or the first cutter 11 can be used in conjunction with other cutting components of the cutter assembly 10 to cut the cutting area 3321. Furthermore, the angle between the first direction and the second direction can be any non-zero angle other than 90°.

[0199] It is understood that when the first cutter 11 cuts the cutting area 3321, at least a portion of all first blades 111 in the first cutter 11 is used to perform the cutting. In the embodiment of the present application, the cutter assembly 10 cuts the cutting area 3321 at least twice. For simplicity, the following description of the present application uses the cutter assembly 10 cutting the cutting area 3321 twice as an example. After reading the following scheme, those skilled in the art will readily understand implementations in which the cutter assembly 10 cuts the cutting area 3321 more than twice.

[0200] In the above technical solution, the cutting knife assembly 10 includes a first cutting knife 11, and the first cutting knife 11 includes a plurality of first blades 111 spaced apart along a first direction, and each first blade 111 extends along a second direction, so that the cutting area 3321 can be cut multiple times using the cutting knife assembly 10. During two adjacent cutting processes, the second cutting can shorten the length of the long strip portion that is not cut off after the first cutting and remains on the workpiece to be cut, thereby effectively shortening the length of the wire drawing of the workpiece to be cut after being cut, and effectively improving the problem of long wire drawing that is easy to generate after the workpiece to be cut is cut, so as to improve to a certain extent the problem that the workpiece to be cut cannot be used normally due to the long wire drawing falling into or extending into other positions, thereby improving the reliability of the product.

[0201] Please refer to Figures 16 to 19. In some embodiments, the cutting area 3321 includes a plurality of first elongated areas 51 and a plurality of second elongated areas 52, and the plurality of first elongated areas 51 and the plurality of second elongated areas 52 are alternately arranged along the first direction, and the first elongated areas 51 and the second elongated areas 52 extend along the second direction; the first blade 111 is used to cut off the first elongated areas 51 and the second elongated areas 52 in sequence to form the pole ear portion 32; wherein, the first blade 111 includes a first cutting portion 1111 and a first cutting tooth portion 1112 arranged in sequence along the second direction, and the first cutting tooth portions 1112 of the plurality of first blades 111 are located at the same end of the plurality of first blades 111 in the second direction, and the ends of the plurality of first cutting portions 1111 away from the first cutting tooth portion 1112 are fixedly connected.

[0202] For example, the first direction is perpendicular to the second direction, and the first cutter 11 first punches the plurality of first elongated regions 51 along a direction perpendicular to the cutting area 3321 to cut off the plurality of first elongated regions 51; then, the first cutter 11 is used again to punch out the plurality of second elongated regions 52, thereby achieving the removal of the entire cutting area 3321. Obviously, during the second cutting mentioned above, the placement of the first cutter 11 needs to be adjusted. For example, when the first cutter 11 performs the first cutting, the plurality of first blades 111 are extended along the second direction. When the first cutter 11 performs the second cutting, the plurality of first blades 111 are adjusted to extend along the first direction, that is, the first cutter 11 can be rotated 90 degrees around the vertical direction. In particular, during the second cutting, the outermost first blade 111 can be arranged to correspond to the end of the plurality of second elongated regions 52 connected to the overlapping region 321, so that the plurality of second elongated regions 52 can be removed simultaneously by at least one first blade 111.

[0203] As can be seen, the first cutting tooth portion 1112 is located at the free end of the first blade 111; when the first blade 111 is used for cutting, the first cutting portion 1111 and the first cutting tooth portion 1112 can cut different parts. For example, the second direction is the left-right direction. For each first blade 111, the first cutting tooth portion 1112 is located at the right end of the first blade 111. In this case, by fixing the left ends of multiple first blades 111 together, the multiple first blades 111 are connected into a whole, so that the multiple first blades 111 can cut synchronously; of course, the first cutting tooth portion 1112 can also be located at the left end of the first blade 111.

[0204] In the above technical solution, the first blade 111 is provided with a first cutting portion 1111 and a first cutting tooth portion 1112, and multiple first cutting tooth portions 1112 are located at the same end of multiple first blades 111, and the ends of multiple first cutting portions 1111 away from the first cutting tooth portion 1112 are fixedly connected, so as to realize the synchronous cutting of multiple first long strip areas 51 by multiple first blades 111, and facilitate the synchronous cutting of multiple second long strip areas 52 by at least one first blade 111, thereby facilitating the cutting of the entire cutting area 3321 by the first cutter 11, and simplifying the structure of the cutting knife assembly 10.

[0205] For example, the plurality of first cutting teeth 1112 may be located on the same straight line extending along the first direction, so that the first cutter 11 can better adapt to the cutting area 3321 whose cutting reference is a straight line. In this case, when the first cutter 11 cuts the cutting area 3321, the first cutting teeth 1112 are adapted to be aligned with one of the cutting references of the cutting area 3321. Of course, in other examples, the plurality of first cutting teeth 1112 may also be located on the same curve.

[0206] For example, the position of at least one of all the first blades 111 of the first cutter 11 in the second direction is adjustable so as to achieve the adjustment of the relative positions of multiple first cutting teeth 1112 in the second direction, so that the first cutter 11 can better adapt to cutting areas 3321 of different shapes, thereby improving the applicability of the first cutter 11.

[0207] Please refer to Figures 16 and 17. In some embodiments, the spacing x3 between two adjacent first cutting teeth 1112 is ≤2mm, where x3 is also the spacing between two adjacent first blades 111; and / or the length y1 of the first cutting teeth 1112 in the second direction is ≤2mm.

[0208] For example, x3 may be 0.9 mm, 1 mm, 1.2 mm, 1.5 mm, or 2 mm, etc.; y1 may be 2 mm, 1.8 mm, 1.6 mm, 1.3 mm, 1 mm, or 0.9 mm, etc.

[0209] In the above technical solution, by setting the spacing x3 between two adjacent first cutting tooth portions 1112 to ≤2mm, and / or the length y1 of the first cutting tooth portion 1112 in the second direction to ≤2mm, when the cutting knife assembly 10 cuts multiple second long strip areas 52, a suitable cutting position can be selected based on the previous cutting position of the first cutting tooth portion 1112, and the spacing x3 between two adjacent first cutting tooth portions 1112 and the length y1 of the first cutting tooth portion 1112 in the second direction will affect the size of the portion of the second long strip area 52 retained on the workpiece to be cut, so as to achieve effective control of the size of the portion of the second long strip area 52 retained on the workpiece to be cut, thereby achieving effective control of the length of the wire drawing generated after the cutting knife assembly 10 cuts the cutting area 3321, so as to control the length of the wire drawing within a reasonable range, so as to further improve the reliability and safety of the product.

[0210] It can be understood that in the embodiment of the present application, when the first cutter 11 cuts the cutting area 3321, the spacing between two adjacent first cutting tooth portions 1112 corresponds to the width of the root position of the second elongated area 52 in the first direction; when the size of the cutting area 3321 is fixed, the width of the root position of the second elongated area 52 in the first direction and the length of the second elongated area 52 in the second direction will affect the size of the portion of the second elongated area 52 retained on the piece to be cut, that is, affect the wire drawing length.

[0211] For example, when the cutting knife assembly 10 cuts multiple second long strip areas 52 of the cutting area 3321, the cutting position can be based on the cutting position of the first cutting tooth part 1112 in the previous cutting process as a reference. For example, the cutting position can be selected from the first extreme cutting position corresponding to the end of the first cutting tooth part 1112 connected to the first cutting part 1111, or the cutting position can be selected from the second extreme cutting position corresponding to the end of the first cutting tooth part 1112 away from the first cutting part 1111, or the cutting position can be selected from any position between the above-mentioned first extreme cutting position and the above-mentioned second extreme cutting position, and the length of the part of the second long strip area 52 retained on the workpiece to be cut is related to the cutting position; for this reason, the above-mentioned technical solution realizes effective control of the drawing length by reasonably setting the size and arrangement spacing of the first cutting tooth part 1112.

[0212] In addition, when the first cutter 11 is used to cut the second elongated area 52, the first cutting tooth portion 1112 can correspond to the second cutting reference 5b. At this time, at least a portion of the first cutting tooth portion 1112 can extend out of the second cutting reference 5b to cut out the first groove 3220. In the above technical solution of the present application, the size of the first groove 3220 can be controlled by setting the length of the first cutting tooth portion 1112 to no more than 2mm, thereby controlling the length of the wire drawing at the second cutting reference 5b, that is, achieving the length of the wire drawing retained on the workpiece to be cut at the second cutting reference 5b. Similarly, the cutting and forming process of the second groove is similar to that of the first groove, and will not be repeated herein.

[0213] Referring to Figures 16-19, in some embodiments, the first cutting tooth portion 1112 is triangular, and the maximum thickness t1 of the first blade 111 is ≤ 1 mm, for example, t1 can be 1 mm, 0.9 mm, or 0.8 mm; or, the first cutting tooth portion 1112 is square, and the maximum thickness t2 of the first blade 111 is ≤ 0.71 mm, for example, t2 can be 0.71 mm, 0.6 mm, or 0.55 mm; or, the first cutting tooth portion 1112 is trapezoidal, and the maximum thickness t3 of the first blade 111 is ≤ 1 mm, for example, t3 can be 1 mm, 0.95 mm, or 0.8 mm. Therefore, for the above embodiments, the maximum thickness of the first cutting tooth portion 1112 is the maximum thickness of the first blade 111.

[0214] It can be understood that in the embodiment of the present application, when the first cutter 11 cuts the cutting area 3321, the thickness of the first blade 111 corresponds to the width of the first long strip area 51 in the first direction, or corresponds to the distance between two adjacent second long strip areas 52 in the first direction.

[0215] In the above technical solution, by setting the maximum thickness of the first blade 111 when the first cutting tooth portion 1112 has different shapes and structures, the thickness of the first blade 111 is well matched with the shape of the first cutting tooth portion 1112, so that the first blade 111 has appropriate cutting ability, improving the cutting reliability of the first blade 111 and the accuracy of the control of the cutting size. Obviously, the first cutting tooth portion 1112 can form a concave portion between two adjacent convex portions 2a on the sawtooth structure 2b at the cutting position.

[0216] For example, if the first cutting portion 1111 is of a constant thickness structure and the thickness of the first cutting tooth portion 1112 decreases or remains constant in a direction away from the first cutting portion 1111, then the maximum thickness of the first cutting tooth portion 1112 is equal to the thickness of the first cutting portion 1111. It can be seen that when the first cutting tooth portion 1112 and the first cutting portion 1111 are both of constant thickness structure, their thicknesses are equal, and the thickness of the first cutting tooth portion 1112 and the thickness of the first cutting portion 1111 can both be the maximum thickness of the first blade 111; when the first cutting portion 1111 is of a constant thickness structure and the thickness of the first cutting tooth portion 1112 decreases in the direction of the first cutting portion 1111, the maximum thickness of the first cutting tooth portion 1112 and the thickness of the first cutting portion 1111 are both the maximum thickness of the first blade 111.

[0217] Please refer to Figure 8-11 and Figure 20. In some embodiments, the cutting area 3321 includes a plurality of first elongated areas 51 and a plurality of second elongated areas 52. The plurality of first elongated areas 51 and the plurality of second elongated areas 52 are alternately arranged one by one along the first direction. The first elongated areas 51 and the second elongated areas 52 extend along the second direction. The first cutter 11 is used to cut the plurality of first elongated areas 51. The cutting knife assembly 10 also includes a second cutter 12. The second cutter 12 includes at least one second blade 121 extending along the first direction. The second blade 121 can be extended into a strip shape. The second cutter 12 is used to cut the plurality of second elongated areas 52.

[0218] In the above technical solution, by setting the cutting knife assembly 10 to also include a second cutter 12, the first cutter 11 and the second cutter 12 respectively cut different areas of the cutting area 3321, which can simplify the cutting control of the first cutter 11 and the second cutter 12, so that the first cutter 11 and the second cutter 12 can maintain the same posture for cutting and the second cutter 12 can maintain the same posture for cutting. The first blade 111 is extended along a fixed direction, and the second blade 121 is extended along a fixed direction, and the extension direction of the first blade 111 and the extension direction of the second blade 121 intersect. There is no need to frequently adjust the placement posture of the first cutter 11 and the second cutter 12 during cutting. It is only necessary to replace the corresponding cutter, which facilitates simplifying the cutting process.

[0219] For example, the first cutter 11 maintains a certain posture to punch the first elongated area 51, thereby cutting off the corresponding portions of the first elongated area 51; then, the second cutter 12 maintains a certain posture to cut the remaining plurality of second elongated areas 52, thereby cutting off the plurality of second elongated areas 52. It can be seen that the cutting area 3321 is cut twice, and the cutting paths and cutting positions of the two sides are different. The embodiment of the present application uses different cutters to achieve the above-mentioned cutting on both sides, thereby eliminating the need to frequently adjust the cutting posture of the cutter assembly 10, simplifying the cutting operation.

[0220] For example, when the second cutter 12 is cutting the second area, the cutting position of the second cutter 12 can be based on the cutting position of the first cutting tooth portion 1112 during the last cutting process of the first cutter 11 as a reference. For example, the cutting position of the second cutter 12 can be selected from the first extreme cutting position corresponding to the end of the first cutting tooth portion 1112 connected to the first cutting portion 1111, or the cutting position of the second cutter 12 can be selected from the second extreme cutting position corresponding to the end of the first cutting tooth portion 1112 away from the first cutting portion 1111, or the cutting position of the second cutter 12 can be selected from any position between the first extreme cutting position and the second extreme cutting position. Taking the cutting position of the second cutter 12 as an example, the thickness side surface of the second cutter 12 away from the free end of the second long strip portion can be aligned with the first extreme cutting positions of the multiple first cutting tooth portions 1112, and cutting is performed in a direction perpendicular to the cutting area 3321.

[0221] Please refer to Figure 20. In some embodiments, the second cutter 12 includes two groups of blade groups spaced apart along the second direction, each group of blade groups includes at least one second blade 121, and the two groups of blade groups are respectively used to cut the second long strip area 52 located on both sides of the overlapping area 321 in the second direction.

[0222] It can be understood that when the second cutter 12 includes multiple second blades 121, during a cutting process, the second cutter 12 can be used to simultaneously cut the cutting areas on opposite sides of the overlapping area 321, that is, one group of blade groups cuts off the cutting area on one side of the overlapping area 321, and the other group of blade groups cuts off the cutting area on the other side of the overlapping area 321.

[0223] For example, as shown in Figures 8-11 and 20, the second cutter 12 includes two blade groups, each blade group includes a second blade 121, and the workpiece to be cut has a cutting area on opposite sides of the second direction. After the first cutter 11 cuts the two cutting areas in sequence, one of the second blades 121 can be aligned with the cutting position required for one of the cutting areas, and the other second blade 121 can be aligned with the cutting position required for the other cutting area, so that the second cutter 12 simultaneously performs a secondary cut on the two cutting areas. In other examples, the second cutter 12 includes two second blades 121, and the two second blades 121 are used to cut a cutting area. In this case, one of the first blades 121 can be used to correspond to the cutting reference for cutting. For example, the second cutter 12 on the left side of Figure 17 is used to cut multiple second long strip areas 52 in the leftmost cutting area. The second cutter 12 can be moved to the left until the second blade 121 on the right side is aligned with the required cutting position of the multiple second long strip areas 52. Of course, the second cutter 12 can also be used for cutting more than two cutting areas.

[0224] In the above technical solution, the second cutter 12 is provided with two sets of blade groups, and the two sets of blade groups are respectively used to cut the second long strip area 52 located on both sides of the overlapping area 321 in the second direction. The two sets of blade groups are respectively used to cut the cutting areas 3321 located on both sides of the overlapping area 321 in the second direction, so as to perform synchronous cutting on the cutting areas 3321 on both sides of the overlapping area 321, thereby improving the processing efficiency of the electrode assembly 30.

[0225] Of course, in other examples, the second cutter 12 may further include a second blade 121 .

[0226] In some embodiments, the distance between the two blade sets is adjustable.

[0227] In the above technical solution, by setting the spacing between the two sets of blade groups to be adjustable, it is convenient for the second cutter 12 to simultaneously cut the two cutting areas 3321. Regardless of whether the pieces to be cut are the same or different, the second cutter 12 can adapt to the different spacings between the two cutting areas 3321, that is, adapt to the different sizes of the ear portions 32, so as to improve the operability and applicability of the second cutter 12 for simultaneously cutting the two cutting areas 3321.

[0228] Exemplarily, the second cutter 12 includes two sets of blade groups, each having a cutting area 3321 on opposite sides of the workpiece to be cut. For workpieces to be cut of different specifications, the spacing between the cutting areas 3321 on opposite sides is different, and the spacing between the two sets of blade groups is adjustable to adapt to the changes in the spacing between the two cutting areas 3321, thereby improving the applicability of the second cutter 12.

[0229] 20 and 21 , in some embodiments, each second blade 121 includes a second cutting portion 1211 and a second cutting tooth portion 1212 sequentially arranged along the first direction, and a length y2 of the second cutting tooth portion 1212 in the first direction is ≤2 mm.

[0230] In the above technical solution, the second blade 121 is provided with a second cutting portion 1211 and a second cutting tooth portion 1212, and the length y2 of the second cutting tooth portion 1212 in the first direction is ≤2mm, so that when the second cutter 12 cuts the plurality of second long strip areas 52, the cutting position of the second cutter 12 in the second direction can be selected based on the previous cutting position of the first cutting tooth portion 1112, and the cutting position of the second cutter 12 in the first direction can be selected based on the relative position of the second cutting tooth portion 1212 and the second cutting reference 5b. If at least part of the second cutting tooth portion 1212 extends out of the second cutting reference 5b to cut out the first groove 3220 on the second cutting reference 5b, then the size of the first groove 3220 can be controlled to achieve control of the wire drawing length at the second cutting reference 5b.

[0231] It can be understood that when there are multiple second blades 121, the second cutting tooth portions 1212 of the multiple second blades 121 are located at the same end of the multiple second blades 121 in the first direction, so that the multiple second blades 121 are connected into a whole by fixing the ends of the multiple second cutting portions 1211 away from the second cutting tooth portions 1212, so as to achieve synchronous cutting of the multiple second blades 121.

[0232] For example, when the second cutter 12 includes a plurality of second blades 121 spaced apart along the second direction, the plurality of second cutting teeth 1212 may be located on the same straight line extending along the second direction, so that the second cutter 12 can better adapt to the cutting area 3321 whose cutting reference is a straight line. In this case, when the second cutter 12 cuts the cutting area 3321, the second cutting teeth 1212 are adapted to be aligned with one of the cutting references of the cutting area 3321. Of course, in other examples, the plurality of second cutting teeth 1212 may also be located on the same curve.

[0233] For example, the position of at least one of all the second blades 121 of the first cutter 11 in the first direction is adjustable so as to achieve the adjustment of the relative positions of the multiple second cutting teeth 1212 in the first direction, so that the second cutter 12 can better adapt to cutting areas 3321 of different shapes, thereby improving the applicability of the second cutter 12.

[0234] For example, when the first blade 111 includes a first cutting portion 1111 and a first cutting tooth portion 1112, and the second blade 121 includes a second cutting portion 1211 and a second cutting tooth portion 1212, the shape of the second cutting tooth portion 1212 can be the same as or different from the shape of the first cutting tooth portion 1112. Exemplarily, the second cutting tooth portion 1212 and the first cutting tooth portion 1112 are both formed in a triangle, a square, or a trapezoid; of course, in some other examples, the first cutting tooth portion 1112 is formed in a triangle, and the second cutting tooth portion 1212 is formed in a square or a trapezoid.

[0235] Please refer to Figures 20 and 21. In some embodiments, the second cutting portion 1211 is a uniform thickness structure, and the thickness of the second cutting portion 1211 decreases or remains unchanged in a direction away from the second cutting portion 1211. Then the maximum thickness of the second cutting tooth portion 1212 is equal to the thickness of the second cutting portion 1211.

[0236] It can be seen that when the second cutting tooth portion 1212 and the second cutting portion 1211 are both of equal thickness structures, the thicknesses of the two are equal, and the thickness of the second cutting tooth portion 1212 and the thickness of the second cutting portion 1211 can both be the maximum thickness of the second blade 121; when the second cutting portion 1211 is of equal thickness structure and the thickness of the second cutting tooth portion 1212 decreases along the direction of the second cutting portion 1211, the maximum thickness of the second cutting tooth portion 1212 and the thickness of the second cutting portion 1211 are both the maximum thickness of the second blade 121.

[0237] Wherein, the second cutting tooth portion 1212 is triangular, and the maximum thickness t4 of the second blade 121 is ≤ 1 mm; alternatively, the second cutting tooth portion 1212 is square, and the maximum thickness t5 of the second blade 121 is ≤ 0.71 mm; alternatively, the second cutting tooth portion 1212 is trapezoidal, and the maximum thickness t6 of the second blade 121 is ≤ 1 mm. Therefore, for the above embodiments, the maximum thickness of the second cutting tooth portion 1212 is the maximum thickness of the second blade 121.

[0238] In the above technical solution, by setting the maximum thickness of the second blade 121 when the second cutting tooth portion 1212 has different shape structures, the thickness of the second blade 121 is well matched with the shape of the second cutting tooth portion 1212, so that the second blade 121 has appropriate cutting ability, thereby improving the cutting reliability of the second blade 121 and the accuracy of controlling the cutting size.

[0239] For example, the pole tab 320 has a square structure, and the pole tab 320 has two first edges and two second edges that are oppositely arranged, wherein one of the first edges is electrically connected to the current collector 311, and at least one of the two second edges is formed with a plurality of first protrusions, and the plurality of protrusions 32a located on the same edge are formed into a sawtooth structure 32b; for another example, the pole tab 320 has a trapezoidal structure, and the bottom edge of the pole tab 320 is electrically connected to the current collector 311, and at least one of the edges corresponding to the two waists of the pole tab 320 is formed with a plurality of protrusions 32a, and the plurality of protrusions 32a located on the same edge are formed into a sawtooth structure 32b.

[0240] In the above technical solution, a plurality of protrusions 32 a are formed on at least one edge of the tab 320 , and the plurality of protrusions 32 a located at the same end are formed into a sawtooth structure 32 b.

[0241] It is understandable that the shape of the protrusion 32 a is not specifically limited in the embodiment of the present application. For example, the protrusion 32 a can be formed in a square or trapezoidal shape.

[0242] It can be understood that the convex portion 32a corresponds to the second sub-region 522 in the above-mentioned cutting method of the present application, and d2=d1.

[0243] Please refer to Figures 9 and 14-18 again to describe the electrode assembly 30, the cutting knife assembly 10 and the cutting method of the specific embodiment of the present application.

[0244] The electrode assembly 30 includes an active material coating portion 31 and a pole ear portion 32. The pole ear portion 32 includes a plurality of pole ear sheets 320 that are stacked and connected. The overlapping portions of the plurality of pole ear sheets 320 form an overlapping region 321, and the staggered portions of the plurality of pole ear sheets 320 form a staggered region 322 connected to the overlapping region 321. There are two staggered regions 322, and the two staggered regions 322 are respectively located on both sides of the overlapping region 321 in the second direction. Each staggered region 322 includes a first connecting portion 3221 and a second connecting portion 3222. The first connecting portion 3221 is connected to the active material coating portion 31 on one side along the first direction, and the second connecting portion 3222 is connected to the other side of the first connecting portion 3221 along the first direction. In the second direction, the end of the second connecting portion 3222 away from the overlapping region 321 is closer to the overlapping region 321 than the end of the first connecting portion 3221 away from the overlapping region 321. The second direction is perpendicular to the first direction. Among them, the edge of one end of the second connecting part 3222 away from the overlapping area 321 is a serrated structure 32b, and a first groove 3220 is formed at the position where the first connecting part 3221 is connected to the edge of one end of the second connecting part 3222 away from the overlapping area 321. The serrated structure 32b of the end of the first connecting part 3221 away from the active material coating part 31 and the edge of one end of the second connecting part 3222 away from the overlapping area 321 are both obtained by cutting.

[0245] In an embodiment of the present application, the cutter assembly 10 includes a first cutter 11 and a second cutter 12. The first cutter 11 includes a plurality of first blades 111 spaced apart along a first direction, each first blade 111 extending along a second direction, the first and second directions intersecting. The second cutter 12 includes two second blades 121 spaced apart along the second direction. Each first blade 111 includes a first cutting portion 1111 and a first cutting tooth portion 1112 sequentially arranged along the second direction. The first cutting tooth portions 1112 of the plurality of first blades 111 are located at the same end of the plurality of first blades 111 in the second direction, and the ends of the plurality of first cutting portions 1111 away from the first cutting tooth portion 1112 are fixedly connected. Each second blade 121 includes a second cutting portion 1211 and a second cutting tooth portion 1212 sequentially arranged along the first direction. The second cutting tooth portions 1212 of the plurality of second blades 121 are located at the same end of the plurality of second blades 121 in the second direction, and the ends of the plurality of second cutting portions 1211 away from the second cutting tooth portion 1212 are fixedly connected.

[0246] The cutting area 3321 has a first cutting reference 5a and a second cutting reference 5b adjacent to each other. The first cutting reference 5a extends along the first direction. The cutting area 3321 includes a plurality of first long strip areas 51 and a plurality of second long strip areas 52. The plurality of first long strip areas 51 and the plurality of second long strip areas 52 are alternately arranged along the first direction. The first long strip areas 51 and the second long strip areas 52 extend along the second direction. The cutting method includes:

[0247] S1. Stacking a plurality of connecting pieces 33 connected to the active material coating portion 31 and partially staggering the plurality of connecting pieces 33, wherein the plurality of connecting pieces 33 have overlapping portions 331 and staggered portions 332;

[0248] S2. Divide the dislocated portion 332 into a cutting area 3321 and a non-cutting area 3322, wherein the non-cutting area 3322 includes a first connecting portion 3221 and a second connecting portion 3222 connected to each other and respectively connected to the overlapping portion, the first connecting portion 3221 connecting the active material coating portion 31 and the cutting area 3321 on both sides in the first direction, and the second connecting portion 3222 connecting the overlapping portion 331 and the cutting area 3321 on both sides in the second direction; the dislocated portion 332 has a first cutting reference 5a extending along the first direction and a second cutting reference 5b extending along the second direction, the cutting area 3321 includes a plurality of first elongated areas 51 and a plurality of second elongated areas 52, the plurality of first elongated areas 51 and the plurality of second elongated areas 52 being alternately arranged one by one along the first direction, and the first elongated areas 51 and the second elongated areas 52 extending along the second direction;

[0249] S3, cutting off the cutting area 3321 so that the remaining parts of the plurality of connecting pieces 33 form the pole ear portion 32 of the electrode assembly 30, including: S31, cutting off the plurality of first elongated areas 51 based on the first cutting reference 5a and the second cutting reference 5b, including: aligning the adjacent two sides of the cutting knife assembly 10 with the first cutting reference 5a and the second cutting reference 5b, respectively, so that the width side of the first blade 111 on the edge of the first cutter 11 away from the other first blades 111 is aligned with the second cutting reference 5b, and the ends of the plurality of first cutting teeth 1112 are aligned with the first cutting reference 5a; S32, based on the first cutting reference 5a and The second cutting reference 5b cuts off the multiple second long strip areas 52, including: the adjacent two side edges of the cutting knife assembly 10 are aligned with the first reference line L1 and the second reference line L2 respectively, the first reference line L1 corresponds to the inner side of the cutting area and is separated from the first cutting reference 5a by a first predetermined value a, the second reference line L2 corresponds to the outer side of the cutting area and is separated from the second cutting reference 5b by a second predetermined value b, then the opposite side of each second blade 112 is aligned with the corresponding first cutting reference 5a, and the end of the second cutting tooth portion 1212 is aligned with the second cutting reference 5b, so that the second cutting tooth portion 1212 cuts out the first groove 3220.

[0250] In the above technical solution, the size of the upper part of the pole ear 32, namely the convex portion 32a, retained at the first cutting reference 5a and the second cutting reference 5b can be effectively shortened, thereby shortening the wire drawing length when cutting the pole ear 32, effectively reducing the risk of the wire drawing extending into the electrode assembly due to its long length and causing pole piece short circuit, improving the reliability and safety of the electrode assembly, and improving the first yield rate (i.e., FTY) of the product; moreover, since the edge of the pole ear 32 has a convex portion 32a, it is convenient to have a certain tolerance for the cutting gap during the cutting process, which is beneficial to reduce the requirements for the cutting knife assembly 10 and facilitate to improve the service life of the cutting knife assembly 10.

[0251] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application may be combined with each other. The above are only preferred embodiments of this application and are not intended to limit this application. For those skilled in the art, this application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the scope of protection of this application.

Claims

1. An electrode assembly, wherein: include: Active material coating unit; a pole ear portion connected to the active material coating portion; the pole ear portion comprises a plurality of pole ear sheets stacked and connected, the overlapping portions of the plurality of pole ear sheets form an overlapping region, and the staggered portions of the plurality of pole ear sheets form a staggered region connected to the overlapping region; Wherein, the misaligned region includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the active material coating portion on one side along the first direction, and the second connecting portion is connected to the first connecting portion on the other side along the first direction; in the second direction, an end of the second connecting portion away from the overlapping region is closer to the overlapping region than an end of the first connecting portion away from the overlapping region, and the second direction intersects with the first direction.

2. The electrode assembly according to claim 1, wherein: The edge of one end of the second connecting portion away from the overlapping area is in a serrated structure; and / or, An edge of one end of the first connection portion away from the active material coating portion has a sawtooth structure.

3. The electrode assembly according to claim 2, wherein: The sawtooth structure includes a plurality of convex portions arranged in sequence along the first direction, The height h1 of the convex portion is ≤2 mm; and / or, A diameter d1 of a circumscribed circle of a projection of the protrusion along a thickness direction of the pole lug portion is ≤2 mm.

4. The electrode assembly according to claim 2 or 3, wherein: The sawtooth structure includes a plurality of convex portions sequentially arranged along the first direction, and the convex portions are square or trapezoidal.

5. The electrode assembly according to any one of claims 2 to 4, wherein: When the edge of the second connection portion is formed with the sawtooth structure, a first groove is formed at a position of the first connection portion connected to an edge of the second connection portion away from the overlapping area; or When the edge of the first connection portion is formed with the sawtooth structure, a second groove is formed at a position of the second connection portion connected to an edge of the first connection portion away from the active material coating portion.

6. The electrode assembly according to any one of claims 2 to 5, wherein: At least one of an edge of the first connection portion away from the active material coating portion and an edge of the second connection portion away from the overlapping region is obtained by cutting.

7. The electrode assembly according to any one of claims 1 to 6, wherein: One of the offset regions is provided on opposite sides of the overlapping region in the second direction.

8. The electrode assembly according to any one of claims 1 to 7, wherein: The active material coating portion includes a positive electrode sheet body, a negative electrode sheet body and a separator, the plurality of tabs are respectively connected to the positive electrode sheet body and the negative electrode sheet body, and the separator is disposed between the positive electrode sheet body and the negative electrode sheet body and exceeds the positive electrode sheet body and the negative electrode sheet body; Wherein, at least a portion of the first connecting portion is blocked by the isolation film.

9. A battery cell, wherein: The invention comprises a shell, a pole and an electrode assembly according to any one of claims 1 to 8, wherein the pole is arranged in the shell, the active material coating portion is accommodated in the shell, and the pole ear portion is electrically connected to the pole.

10. The battery cell according to claim 9, wherein: A receiving groove is formed on the pole, a part of the pole ear portion is accommodated in the receiving groove, the side of the receiving groove facing away from the active material coating portion is open, and a groove wall on the side of the receiving groove facing the active material coating portion is formed with a through hole connected to the interior of the shell, and the pole ear portion is inserted through the through hole.

11. The battery cell according to claim 10, wherein: The battery cell further includes a pole cover plate, which is disposed on the pole and closes a notch of the receiving groove.

12. A battery, wherein: The invention comprises a battery cell according to any one of claims 9 to 11.

13. An electrical device, wherein: A battery according to claim 12, for providing electrical energy.

14. A method for processing an electrode assembly, wherein: include: A plurality of connection sheets connected to the active material coating portion are stacked and partially staggered, wherein the plurality of connection sheets have overlapping portions and staggered portions; Dividing the dislocated portion into a cutting area and a non-cutting area, the non-cutting area includes a first connecting portion and a second connecting portion connected to each other and respectively connected to the overlapping portion, the first connecting portion is connected to the active material coating portion and the cutting area on both sides in a first direction, and the second connecting portion is connected to the overlapping portion and the cutting area on both sides in a second direction, and the second direction intersects with the first direction; The cutting area is cut off so that the remaining parts of the plurality of connecting sheets are formed into the electrode lugs of the electrode assembly.

15. The method for processing an electrode assembly according to claim 14, wherein: The offset portion has a first cutting reference extending along the first direction and a second cutting reference extending along the second direction, the cutting area includes a plurality of first long strip areas and a plurality of second long strip areas, the plurality of first long strip areas and the plurality of second long strip areas are alternately arranged one by one along the first direction or the second direction, the first long strip areas and the second long strip areas extend along the second direction or the first direction, Cutting off the cropping area includes: Cutting off the plurality of first long strip regions based on the first cutting reference and the second cutting reference; The plurality of second long strip regions are cut off based on the first cutting reference and the second cutting reference.

16. The method for processing an electrode assembly according to claim 15, wherein: Cutting off the plurality of first long strip regions based on the first cutting reference and the second cutting reference comprises: aligning adjacent two sides of the cutting knife assembly to the first cutting reference and the second cutting reference respectively; The plurality of second long strip areas are cut out based on the first cutting reference and the second cutting reference, including: adjacent side edges of the cutting knife assembly are aligned with a first reference line and a second reference line, respectively, the first reference line corresponds to the inner side of the cutting area and is at a first predetermined value a away from the first cutting reference, and the second reference line corresponds to the outer side of the cutting area and is at a second predetermined value b away from the second cutting reference.

17. The method for processing an electrode assembly according to claim 16, wherein: Each of the second long strip regions includes a first sub-region and a second sub-region sequentially arranged along the length direction thereof, wherein the second sub-region is located between the first cutting reference and the first reference line. The diameter d2 of the circumscribed circle of the projection of the second sub-region along the stacking direction is ≤2 mm, and the stacking direction is perpendicular to the first direction and the second direction respectively; and / or, a≤2mm; and / or, b≤2mm.

18. A cutting knife assembly, wherein: Used to cut a workpiece to be cut to obtain an electrode assembly, the workpiece to be cut includes an active material coating portion and a part to be cut, the part to be cut is connected to the active material coating portion; the part to be cut includes a plurality of connecting sheets stacked and connected, the overlapping parts of the plurality of connecting sheets form an overlapping area, the staggered parts of the plurality of connecting sheets include a cutting area and a non-cutting area, the non-cutting area includes a first connecting portion and a second connecting portion connected to each other and respectively connected to the overlapping portion, the first connecting portion is connected to the active material coating portion and the cutting area on both sides in a first direction, the second connecting portion is connected to the overlapping portion and the cutting area on both sides in a second direction, and the second direction intersects with the first direction; The cutting knife assembly comprises: A first cutter, the first cutter comprising a plurality of first blades spaced apart along a first direction, each of the first blades extending along a second direction; The first cutter is used to cut off at least a portion of the cutting area so that the remaining portions of the plurality of connecting sheets form a pole ear portion, so that the pole ear portion and the active material coating portion form the electrode assembly.

19. The cutting knife assembly according to claim 18, wherein: The cutting area includes a plurality of first long strip areas and a plurality of second long strip areas, the plurality of first long strip areas and the plurality of second long strip areas are alternately arranged one by one along the first direction, and the first long strip areas and the second long strip areas extend along the second direction; The first blade is used to cut off the first long strip area and the second long strip area in sequence to form the pole ear portion; Wherein, the first blade includes a first cutting portion and a first cutting tooth portion arranged in sequence along the second direction, the first cutting tooth portions of multiple first blades are located at the same end of multiple first blades in the second direction, and one end of multiple first cutting portions away from the first cutting tooth portion is fixedly connected.

20. The cutter assembly according to claim 19, wherein: The length y1 of the first cutting tooth portion in the second direction is ≤2 mm; and / or, The distance x3 between two adjacent first cutting tooth parts is ≤2 mm.

21. The cutting knife assembly according to claim 19 or 20, wherein: The first cutting tooth portion is triangular, and the maximum thickness of the first blade is t1≤1mm; or The first cutting tooth portion is square, and the maximum thickness t2 of the first blade is ≤0.71 mm; or The first cutting tooth portion is trapezoidal, and the maximum thickness t3 of the first blade is ≤1 mm.

22. The cutter assembly according to claim 18, wherein: The cutting area includes a plurality of first long strip areas and a plurality of second long strip areas, the plurality of first long strip areas and the plurality of second long strip areas are alternately arranged one by one along the first direction, the first long strip areas and the second long strip areas extend along the second direction, the first cutter is used to cut the plurality of first long strip areas, and the cutter assembly further includes: The second cutter includes at least one second blade extending along the first direction, and the second cutter is used for cutting a plurality of the second elongated strip areas.

23. The cutting knife assembly according to claim 22, wherein: The second cutter includes two groups of blade sets spaced apart in the second direction, each group of the blade sets includes at least one second blade, and the two groups of the blade sets are respectively used to cut the second long strip areas located on both sides of the overlapping area in the second direction.

24. The cutter assembly according to claim 23, wherein: The distance between the two blade groups is adjustable.

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