Ultrasonic welding head, ultrasonic welding device, electrode assembly, battery cell, battery and electric device

Abstract

The invention discloses an ultrasonic welding head, a tab, an electrode assembly, a single battery, a battery and a power utilization device.The ultrasonic welding head comprises a welding head body and first welding teeth, the welding head body is provided with a welding face, the first welding teeth are arranged on the welding face in a protruding mode, and each first welding tooth comprises a plurality of tooth parts; the multiple tooth parts are the first tooth part and the mth tooth part which are sequentially arranged in the protruding direction of the first welding tooth, the nth tooth part is arranged on the end face of the end, away from the welding face, of the (n-1) th tooth part, the end face of the end, away from the welding face, of the (n-1) th tooth part exceeds the nth tooth part, and n is larger than or equal to 2 and smaller than or equal to m. The ultrasonic welding head can reliably weld corresponding parts of the battery monomer, and the service reliability of the battery monomer is improved.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and in particular to an ultrasonic welding head, an ultrasonic welding device, an electrode assembly, a battery cell, a battery and an electrical device. Background Art

[0002] In the field of electric vehicles, batteries, as the power source of electric vehicles, play an irreplaceable and important role. Among them, batteries, as core components of new energy vehicles, have high requirements in terms of energy density and reliability. Summary of the invention

[0003] The present application proposes an ultrasonic welding head, an ultrasonic welding device, an electrode assembly, a battery cell and an electrical device. The ultrasonic welding head can achieve reliable welding of corresponding components of the battery cell, thereby improving the service reliability of the battery cell.

[0004] In a first aspect, an embodiment of the present application provides an ultrasonic welding head, comprising: a welding head body, the welding head body having a welding surface; a first welding tooth, the first welding tooth being protruding on the welding surface, the first welding tooth comprising a plurality of tooth portions, the plurality of tooth portions being respectively a first tooth portion to an mth tooth portion arranged in sequence along a protruding direction of the first welding tooth, the nth tooth portion being arranged at an end face of the (n-1)th tooth portion away from the welding surface, and an end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, 2≤n≤m.

[0005] In the above technical scheme, a first welding tooth protruding from the welding surface is provided, including a first tooth portion to an mth tooth portion arranged in sequence along the protruding direction, the nth tooth portion is provided at an end face of the (n-1)th tooth portion away from the welding surface 1a, and an end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, so that a portion of the end face of the (n-1)th tooth portion away from the welding surface that exceeds the nth tooth portion can be formed as a welding pressing surface, so that when the ultrasonic welding head welds the welding material, each tooth portion can compact and press the multi-layer foil of the welding material, so as to realize multi-layer pressing and compacting of the welding material, effectively reduce the gap between the multi-layer foil materials, and thereby reduce the welding energy loss caused by the excessive interlayer gap of the multi-layer foil materials, and at the same time, the first welding tooth will not penetrate the welding material, thereby improving the welding quality and welding efficiency.

[0006] In some embodiments, a portion of an end surface of the (n-1)th tooth portion that is away from the welding surface (1a) and that exceeds the nth tooth portion is an annular surface.

[0007] In the above technical solution, by setting the portion of the end face of the (n-1)th tooth away from the welding surface that exceeds the nth tooth as an annular surface, it is convenient for the (n-1)th tooth to achieve a large area and balanced pressure on the corresponding local area of ​​the welding material, which is beneficial to improve the compaction effect of the (n-1)th tooth on the welding material, so as to further improve the problem of excessive gaps between multiple layers of foil.

[0008] In some embodiments, each of the first to m-th tooth portions is any one of a prism structure, a truncated cone structure, and a spherical structure.

[0009] In the above technical solution, by setting each of the first tooth portion and the mth tooth portion to be any one of a prism structure, a truncated cone structure and a spherical structure, it is convenient to simplify the structure of each tooth portion while taking into account the structural strength of each tooth portion, which is conducive to realizing the structural diversification design of the ultrasonic welding head so as to better meet the actual differentiated needs; at the same time, it is convenient to enable a part of the end face away from the welding face of each of the first tooth portion to the (n-1)th tooth portion to form a welding pier pressure surface, thereby improving the welding quality.

[0010] In some embodiments, there is at least one first welding tooth, there is one first tooth portion of the first welding tooth, and among the first to mth tooth portions, the number of the (n-1)th tooth portions is less than or equal to the number of the nth tooth portions.

[0011] In the above technical solution, by setting the first tooth portion of the first welding tooth to be one, the number of the (n-1)th tooth portions is less than or equal to the number of the nth tooth portions, so that in the area corresponding to the first welding tooth, multiple local positions of the above-mentioned area can be compacted by at least multiple mth tooth portions, which is beneficial to appropriately reduce the number of first welding teeth; and when there are multiple first welding teeth, multiple local positions of the welding area can be compacted by multiple first welding teeth, which is beneficial to appropriately reduce the number of mth tooth portions to simplify the structure of the first welding tooth.

[0012] In some embodiments, there are multiple first welding teeth, and any two first welding teeth are arranged at intervals.

[0013] In the above technical solution, multiple first welding teeth are set and any two first welding teeth are set at intervals, so that when welding the same area of ​​the area to be welded, the multiple first welding teeth can compact multiple local positions to achieve the compaction of the entire area to be welded. At the same time, the number of first welding teeth can be appropriately reduced, so as to achieve a balance between welding quality and the simplicity of the structure of the ultrasonic welding head.

[0014] In some embodiments, end surfaces of the (n-1)th tooth portion of the plurality of first welding teeth that are away from the welding surface are arranged flush.

[0015] In the above technical solution, by arranging the end faces of the (n-1)th teeth of the plurality of first welding teeth away from the welding surface to be flush, it is convenient for the same-level teeth of the plurality of first welding teeth to form a basically consistent compaction effect on the welding material, so as to help reduce the risk of poor compaction effect or easy penetration of the welding material by the first welding teeth due to large differences in compaction effect, thereby helping to improve the welding quality and welding qualification rate.

[0016] In some embodiments, the ultrasonic welding head further includes: at least one second welding tooth, the second welding tooth is protruding from the welding surface, and the second welding tooth is arranged between two adjacent first welding teeth.

[0017] In the above technical solution, by arranging a second welding tooth between two adjacent first welding teeth, the second welding tooth can compact and press the local area on the welding material corresponding to the interval between the two adjacent first welding teeth, so as to reasonably utilize the layout space provided by the welding head body to increase the compaction area of ​​the welding head on the welding material. Under the premise of basically not increasing the size of the ultrasonic welding head, it is beneficial to further reduce the gap between the multi-layer foil materials and improve the welding quality.

[0018] In some embodiments, the plurality of first welding teeth are arranged in a plurality of rows and columns, and a second welding tooth is respectively disposed between any two adjacent rows of first welding teeth.

[0019] In the above technical solution, second welding teeth are respectively arranged between two adjacent columns of first welding teeth in any two adjacent rows, so as to reasonably utilize the layout space on the welding surface and improve the compaction effect.

[0020] In some embodiments, in the protruding direction of the first welding tooth, the sum of the heights of the second tooth portion to the mth tooth portion is less than or equal to half the height of the first welding tooth.

[0021] In the above technical solution, by setting the sum of the heights from the second tooth portion to the mth tooth portion to be less than or equal to half the height of the first welding tooth, the height distribution of multiple teeth in the first welding tooth is more reasonable, so that the penetration force of the first welding tooth in its protruding direction is more appropriate, which is beneficial to further reduce the risk of the first welding tooth penetrating the weld material during the welding process, and at the same time reduce the probability of a cold weld occurring during ultrasonic welding due to the relatively large sum of the heights from the second tooth portion to the mth tooth portion, which results in the welding energy of the first welding tooth not being well transmitted to the weld material, resulting in the first welding tooth and the weld material not being in good contact with each other, which is beneficial to further improve the quality of the welding tooth.

[0022] In some embodiments, along the ultrasonic vibration direction, at least one of the two opposite sides of the welding head body has an avoidance surface, and the angle between the avoidance surface and the welding surface is an obtuse angle.

[0023] In the above technical solution, an avoidance surface is arranged on at least one side of the two sides of the welding head body along the ultrasonic vibration direction, and the angle between the avoidance surface and the welding surface is an obtuse angle, so that the avoidance surface can be used to avoid the warping of other areas of the welding material, such as the edge area of ​​the welding material, caused by the welding head body applying pressure to a local area of ​​the welding material during the welding process, so as to reduce the force between the welding head body and the above-mentioned warped part of the welding material, so that the welding head body is not easy to cut the welding material during the welding process, so as to improve the welding reliability; when the welding material is a plurality of pole tabs, the setting of the avoidance surface can effectively improve the cracking of the pole tabs.

[0024] In some embodiments, in the direction of ultrasonic vibration, the distance between one end of the avoidance surface away from the welding surface and the corresponding end of the welding surface 1a is D, 0.3mm≤D≤2mm; and / or, in the protruding direction of the first welding tooth, the distance between one end of the avoidance surface away from the welding surface and the welding surface is H4, 0.5mm≤H4≤2mm.

[0025] In the above technical solution, by setting the distance D between one end of the avoidance surface away from the welding surface and the corresponding end of the welding surface to satisfy 0.3mm≤D≤2mm, and / or setting the distance H4 between one end of the avoidance surface away from the welding surface and the welding surface to satisfy 0.5mm≤H4≤2mm, the position and size of the avoidance surface are more reasonable, so as to better adapt to practical applications while effectively avoiding the warped part of the welding material.

[0026] In some embodiments, 0.5 mm ≤ D ≤ 1 mm; and / or, H4 ≤ 1 mm.

[0027] In the above technical solution, by setting 0.5mm≤D≤1mm and / or H4≤1mm, the position and size of the avoidance surface can be further made more reasonable, which is beneficial to improving the adaptability of the welding head body to different welding area sizes while improving the cracking of the weld material.

[0028] In some embodiments, the avoidance surface and the welding surface are smoothly transitioned through an arc surface.

[0029] In the above technical solution, a smooth transition is provided between the avoidance surface and the welding surface through an arc surface, so that the part of the welding head body opposite to the welding material basically has no sharp corners. Even if the welding head body contacts the welding material, the risk of the welding head body cutting the welding material can be further reduced.

[0030] In some embodiments, each avoidance surface is formed as a plane and is tilted relative to the welding surface.

[0031] In the above technical solution, each avoidance surface is formed as a plane and is inclined relative to the welding surface, so that the outer surface shape of the welding head body is simplified while the avoidance surface can avoid the warped part of the welding material, thereby simplifying the structure of the welding head body and facilitating processing.

[0032] In some embodiments, the radius of the arc surface is R1, 0.3 mm ≤ R1 ≤ 1.5 mm.

[0033] In the above technical solution, the radius R1 of the arc surface is set to satisfy 0.3mm≤R1≤1.5mm, so as to simultaneously reduce the risk of the welding head body cutting the welding material and save the space occupied by the welding head body, without causing waste due to the large size of the welding head body and causing the welding head body to cut the welding material.

[0034] In some embodiments, R1 ≤ 1 mm.

[0035] In the above technical solution, by setting R1≤1mm, the size of the arc surface can be further reasonably set to better balance reducing the risk of the welding head body cutting the welding material and saving the space occupied by the welding head body.

[0036] In some embodiments, the welding surface has a first area and a second area, the first welding tooth is arranged in the first area, and the ultrasonic welding head further includes: a third welding tooth, the third welding tooth is convexly arranged in the second area and arranged at the periphery of the plurality of first welding teeth.

[0037] In the above technical solution, by arranging the first welding tooth in the first area and arranging the third welding tooth in the second area, it is beneficial to increase the area of ​​the compaction area of ​​the welding head body on the welding material, increase the number of local areas where the welding head body compacts the welding material, and help further improve the quality of ultrasonic welding; at the same time, the third welding tooth can perform a certain pre-pressure shaping on the outer part of the area of ​​the welding material corresponding to the first welding tooth, so as to realize the early pre-pressure shaping of the welding material, and the third welding tooth can optimize the friction area between the welding material and the welding head body from large surface friction to local surface friction, reduce the local stress concentration of the welding material, and further improve the cracking of the welding material.

[0038] In some embodiments, the second area is arranged around the first area and includes a plurality of first area segments connected end to end, each first area segment is respectively provided with a plurality of third welding teeth, and the plurality of third welding teeth of the plurality of first area segments are arranged around the first area.

[0039] In the above technical solution, each first area segment of the second area is provided with a plurality of third welding teeth so that the third welding teeth can perform relatively comprehensive pre-pressing and shaping of the welding material. Thus, no matter where the welding position corresponding to the welding head body is located on the welding material, the third welding teeth can play a role in improving the cracking of the welding material.

[0040] In some embodiments, a height of the third weld tooth protruding from the welding surface is less than a height of the first weld tooth protruding from the welding surface.

[0041] In the above technical solution, the height of the third weld tooth protruding from the welding surface is set to be smaller than the height of the first weld tooth protruding from the welding surface, and the height of the third weld tooth protruding from the welding surface is set to be smaller than the height of the first weld tooth protruding from the welding surface, so that the third weld tooth has a suitable pre-pressing and shaping effect on the welding material, and at the same time it is convenient to simplify the structure of the ultrasonic head welding head and reduce the amount of materials used.

[0042] In some embodiments, a height of the third welding tooth protruding from the welding surface is greater than a height of the first tooth protruding from the welding surface.

[0043] In the above technical solution, by setting the height of the third welding tooth protruding from the welding surface to be greater than the height of the first tooth protruding from the welding surface, it is convenient for the third welding tooth to contact the welding material before the first tooth, so that the third welding tooth can achieve a suitable pre-stressing and shaping effect on the welding material.

[0044] In some embodiments, the third welding tooth is a spherical structure, the radius of the third welding tooth is R3, the height of the first welding tooth protruding from the welding surface is H1, and 0.2≤R3 / H1≤0.8.

[0045] In the above technical solution, by setting the third welding tooth to a spherical structure, the outer surface of the third welding tooth has no sharp corners, thereby reducing the risk of the third welding tooth cutting the welding material. At the same time, 0.2≤R3 / H1≤0.8, the third welding tooth can contact the welding material before the welding surface 1a, so as to achieve a good pre-pressure shaping effect.

[0046] In some embodiments, 0.1 mm≤R3≤0.3 mm.

[0047] In some embodiments, at least one of the two opposite sides of the welding head body in the ultrasonic vibration direction has an avoidance surface, the angle between the avoidance surface and the welding surface is an obtuse angle, and the avoidance surface and the welding surface are smoothly transitioned through an arc surface, and a third welding tooth is provided at the connecting position of the second area and the arc surface.

[0048] In the above technical solution, by providing a third welding tooth at the connecting position of the second area and the arc surface, so that the third welding tooth can pre-press and shape the welding material, it is beneficial to rationally utilize the layout space provided by the welding surface in the direction of ultrasonic vibration, save the volume of the ultrasonic welding head in the direction of ultrasonic vibration, and reduce costs.

[0049] In a second aspect, an embodiment of the present application provides an ultrasonic welding device, comprising the above-mentioned ultrasonic welding head.

[0050] In the above technical solution, since the ultrasonic welding device adopts the above ultrasonic welding head, and the ultrasonic welding head can realize reliable welding of the pole tabs of the battery cell, thus laying a good foundation for welding the pole tabs with other components, the ultrasonic welding device can improve the service reliability of the battery cell.

[0051] In a third aspect, an embodiment of the present application provides an electrode assembly, the 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, and the pole ear portion comprising a plurality of pole ear sheets arranged in a stacked manner, the plurality of pole ear sheets being welded and fixed, at least two pole ear sheets having a weld print area on one side of the thickness thereof, the weld print area forming a first welding groove, the first welding groove comprising a plurality of groove portions, the plurality of groove portions being respectively arranged in sequence from a first groove portion to an mth groove portion along a concave direction of the first welding groove, the nth groove portion being arranged at the bottom wall of the (n-1)th groove portion, and the bottom wall of the (n-1)th groove portion being arranged beyond the nth groove portion, 2≤n≤m.

[0052] In the above technical solution, at least two pole lugs are provided with a weld mark area on one side of the thickness thereof, and a first welding groove is formed in the weld mark area. The first welding groove includes a first groove portion to an mth groove portion sequentially arranged along the concave direction of the first welding groove, and the nth groove portion is arranged at the bottom wall of the (n-1)th groove portion, and the bottom wall of the (n-1)th groove portion is arranged beyond the nth groove portion. Therefore, when the at least two pole lugs are welded and fixed, the welding device can perform multi-layer pressing on the at least two pole lugs to form a plurality of groove portions, effectively reducing the gap between the plurality of pole lugs. At the same time, the plurality of pole lugs will not be penetrated, thereby improving the welding quality, thereby facilitating the good welding of the pole lug portion and other components (such as pole posts, adapter sheets, etc.), which is beneficial to improving the service reliability of the battery cell.

[0053] In some embodiments, a portion of the bottom wall of the (n-1)th groove portion extending beyond the nth groove portion is an annular surface.

[0054] In the above technical solution, by setting the bottom wall of the (n-1)th groove portion extending beyond the nth groove portion as an annular surface, the welding device can achieve a large and balanced pressing of the local area, which is beneficial to improving the compaction effect of multiple pole tabs.

[0055] In some embodiments, the number of the first groove portion of the first welding groove is one, and among the first groove portion to the nth groove portion, the number of the (n-1)th groove portion is less than or equal to the number of the nth groove portion.

[0056] In the above technical solution, by setting the first groove portion of the first welding groove to one, the number of the (n-1)th groove portions is less than or equal to the number of the nth groove portions, so that in the area corresponding to the first welding groove, multiple local positions can be compacted, which is beneficial to simplify the structure of the welding device.

[0057] In some embodiments, there are multiple first welding grooves, and any two first welding grooves are arranged at intervals.

[0058] In the above technical solution, multiple first welding grooves are provided and any two first welding grooves are provided at intervals, so that when welding the same area of ​​the area to be welded, the welding device can compact multiple local positions to achieve compaction of the entire area to be welded.

[0059] In some embodiments, bottom walls of the (n-1)th groove portion of the plurality of first welding grooves are flush with each other.

[0060] In the above technical solution, by arranging the bottom walls of the (n-1)th groove portions of multiple first welding grooves to be flush, it is convenient for the welding device to form a basically consistent compaction effect on multiple pole tabs at the same level, so as to help reduce the risk of poor compaction effect or penetration of the pole tabs due to large differences in compaction effect, thereby helping to improve welding quality and welding pass rate.

[0061] In some embodiments, the weld printing area is further formed with at least one second welding groove, and the second welding groove is arranged between two adjacent first welding grooves.

[0062] In the above technical solution, by providing the second welding groove, it is helpful to increase the compaction area of ​​the welding device for multiple pole tabs, and the size of the welding device will not be increased substantially.

[0063] In some embodiments, the plurality of first welding grooves are arranged in a plurality of rows and columns, and a second welding groove is respectively provided between any two adjacent rows of the first welding grooves of any two adjacent columns.

[0064] In the above technical solution, second welding grooves are respectively provided between two adjacent columns of first welding grooves in any two adjacent rows, so as to further enable the welding device to reasonably utilize the occupied space and improve the compaction effect of multiple tab sheets.

[0065] In some embodiments, in a recessed direction of the first welding groove, a sum of depths from the second groove portion to the mth groove portion is less than or equal to half of a depth of the first welding groove.

[0066] In the above technical solution, by setting the sum of the depths of the second groove portion to the mth groove portion to be less than or equal to half of the depth of the first welding groove, the depth distribution of multiple groove portions in the first welding groove is more reasonable, thereby reducing the risk of the pole tab being penetrated. At the same time, it is beneficial to improve the contact effect between the welding device and the pole tab and reduce the probability of cold welding.

[0067] In some embodiments, the weld printing area includes a third area and a fourth area, the first welding groove is formed in the third area, and the weld printing area is further formed with a third welding groove, which is formed in the fourth area and is located outside the plurality of the first welding grooves.

[0068] In the above technical solution, by setting the third welding groove, the welding device can perform a certain pre-compression and shaping on multiple pole tabs at the position corresponding to the third welding groove, and at the same time, it is beneficial for the welding device to optimize the friction area between the pole tab and itself into local surface friction, reduce the local stress concentration of the pole tab, and improve the cracking of the pole tab.

[0069] In some embodiments, the fourth region is arranged around the third region and includes a plurality of second region segments connected end to end, each second region segment is respectively formed with a plurality of third welding grooves, and the plurality of third welding grooves of the plurality of second region segments are arranged around the third region.

[0070] In the above technical solution, by arranging a plurality of welding grooves around the third area, the position corresponding to the third welding groove on the welding device can pre-press and shape the pole piece in a relatively comprehensive manner.

[0071] In some embodiments, the depth of the third weld groove is less than the depth of the first weld groove.

[0072] In some embodiments, the depth of the third welding groove is greater than the depth of the first groove portion.

[0073] In a fourth 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 disposed in the shell, the active material coating portion is accommodated in the shell, and the pole ear portion is electrically connected to the pole.

[0074] In the above technical solution, since the battery cell adopts the above electrode assembly, and the electrode lug of the electrode assembly can be directly or indirectly welded to the electrode post, the service reliability of the battery cell can be improved.

[0075] In a fifth aspect, an embodiment of the present application provides a battery, comprising the above-mentioned battery cell.

[0076] In the above technical solution, since the battery adopts the above-mentioned battery monomer and the battery monomer has good service reliability, the service reliability of the battery can be improved.

[0077] In a sixth aspect, an embodiment of the present application provides an electrical device, comprising the above-mentioned battery, and the battery is used to provide electrical energy.

[0078] In the above technical solution, since the electrical device adopts the above battery and the battery has good reliability in use, the electrical device can be used reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0080] Figure 1 A schematic diagram of a vehicle provided for some embodiments of the present application;

[0081] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0082] Figure 3 A schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0083] Figure 4 for Figure 3 The enlarged view of the part A shown in the middle circle;

[0084] Figure 5 for Figure 3 The welding schematic diagram of the ultrasonic welding head shown in;

[0085] Figure 6 for Figure 5 An enlarged view of the circled section B;

[0086] Figure 7 for Figure 3 Another schematic diagram of the ultrasonic horn shown in ;

[0087] Figure 8 for Figure 7 The enlarged view of the C section circled in the middle;

[0088] Fig. 9 for Figure 7 Another schematic diagram of the ultrasonic horn shown in ;

[0089] Fig.10 for Fig. 9 A partial schematic diagram of the ultrasonic welding head shown in;

[0090] Fig.11 A schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0091] Fig.12 A schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0092] Fig.13 A schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0093] Fig.14 A schematic diagram of an ultrasonic welding head provided for some embodiments of the present application.

[0094] Reference numerals:

[0095] The electric device 1000, the controller 300, the motor 400, the battery 200, the battery cell 100, the battery case 101, the first case 101a, the second case 101b,

[0096] Ultrasonic welding head 10, electrode assembly 30, active material coating part 31, pole ear part 32,

[0097] The welding head body 1, the welding surface 1a, the avoidance surface 1b, the arc surface 1c, the first area 1d, the second area 1e, the first area segment 1f,

[0098] first welding tooth 2, tooth portion 20, welding pressure surface 20a, first tooth portion 21, second tooth portion 22,

[0099] The second welding tooth 3 and the third welding tooth 4. DETAILED DESCRIPTION

[0100] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0101] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0102] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0103] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0104] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application shown in the drawings are only exemplary and should not constitute any limitation to the present application.

[0105] The term "plurality" used in the present application refers to two or more (including two).

[0106] In the present 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 the present application do not limit this. Battery cells may be cylindrical, flat, rectangular, multi-prism or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0107] The battery mentioned in the embodiments of the present application refers to a single physical module including multiple battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may be a battery module or a battery pack. A battery module generally includes multiple battery cells. The battery generally includes a box for encapsulating multiple battery cells or multiple battery modules, and the box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells; of course, the battery may not include a box.

[0108] Exemplarily, a battery cell may generally include a shell, a battery cell assembly and an electrolyte, wherein the shell is used to contain the battery cell assembly and the electrolyte, and the shell is provided with at least one positive electrode column and at least one negative electrode column. The battery cell assembly includes one or more electrode assemblies, and the electrode assembly is formed by stacking or winding a positive electrode sheet, a negative electrode sheet and a separator.

[0109] Among them, the positive electrode sheet can generally include 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 sheet, and a plurality of positive electrode tab sheets are stacked together and electrically connected to the positive electrode column. Exemplarily, the plurality of stacked positive electrode tab sheets can be directly welded to the positive electrode column to form an electrical connection; or, the battery cell assembly can also include a positive electrode adapter sheet, the plurality of stacked positive electrode tab sheets are welded to one end of the positive electrode adapter sheet, and the other end of the positive electrode adapter sheet is welded to the positive electrode column, so that the positive electrode tab sheet is electrically connected to the positive electrode column.

[0110] 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 sheet, and a plurality of negative electrode tab sheets are stacked together and electrically connected to the negative electrode column. Exemplarily, a plurality of negative electrode tab sheets stacked together can be directly welded to the negative electrode column to form an electrical connection; or, the battery cell assembly can also include a negative electrode adapter sheet, a plurality of negative electrode tab sheets stacked together are welded to one end of the negative electrode adapter sheet, and the other end of the negative electrode adapter sheet is welded to the negative electrode column, so that the negative electrode tab sheet is electrically connected to the negative electrode column. The material of the separator is not limited, for example, it can be polypropylene or polyethylene.

[0111] In the field of electric vehicles, batteries, as the power source of electric vehicles, play an irreplaceable and important role. Among them, batteries, as core components of new energy vehicles, have high requirements in terms of energy density and reliability.

[0112] In the related art, as the battery requires high energy density and service reliability, the adapter structure is usually not provided in some battery cells. The multiple pole tabs of the battery cell are usually first ultrasonically welded to fix the multiple pole tabs into pole tabs, and then the pole tabs are laser welded with other components such as the pole column and top cover of the battery cell. Exemplarily, multiple pole tabs are ultrasonically welded to the adapter, and multiple pole tabs are stacked with the adapter to form a lap joint structure. The ultrasonic welding head is pressed on the stacked pole tabs and a certain pressure is applied by the ultrasonic welding head. Then, the ultrasonic device outputs ultrasonic waves to achieve atomic resonance on adjacent pole tabs under high-frequency vibration, thereby connecting the multiple layers of pole tabs to the adapter.

[0113] Ultrasonic welding uses high-frequency vibration waves to transmit to the surfaces of two objects to be welded. Under pressure, the two surfaces of the objects rub against each other to form a fusion between the molecular layers. It has the advantages of high efficiency, high quality, beautiful appearance, energy saving, and high welding strength. In the ultrasonic welding process, conventional square ultrasonic welding heads or spherical ultrasonic welding heads are usually used to weld multiple pole tabs. Due to the unreasonable structure of the ultrasonic welding head, there are large gaps between the multiple pole tabs. These gaps will cause welding pores, explosion points, cracking and other undesirable problems in the subsequent welding of the pole tabs and other parts of the battery cell, which greatly reduces the production qualification rate, increases production costs, and reduces the service reliability of the battery cell.

[0114] Based on the above considerations, in order to improve the reliability of battery cells, an embodiment of the present application proposes an ultrasonic welding head, a battery welding head body and a first welding tooth, the welding head body has a welding surface, the first welding tooth is protruding on the welding surface, the first welding tooth includes a plurality of tooth portions, and the plurality of tooth portions are respectively a first tooth portion to an mth tooth portion arranged in sequence along the protruding direction of the first welding tooth, the nth tooth portion is arranged at an end face of the (n-1)th tooth portion away from the welding surface, and an end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, 2≤n≤m.

[0115] In the above technical scheme, a first welding tooth protruding from the welding surface 1a is provided, including a first tooth portion to an mth tooth portion arranged in sequence along the protruding direction, and the nth tooth portion is provided at an end face of the (n-1)th tooth portion away from the welding surface, and an end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, so that a portion of the end face of the (n-1)th tooth portion away from the welding surface that exceeds the nth tooth portion can be formed as a welding pressing surface, so that when the ultrasonic welding head welds the welding material, each tooth portion can compact and press the multi-layer foil of the welding material, so as to realize multi-layer pressing and compacting of the welding material, effectively reduce the gap between the multi-layer foil materials, and thereby reduce the welding energy loss caused by the excessive interlayer gap of the multi-layer foil materials, and at the same time, the first welding tooth will not penetrate the welding material, thereby improving the welding quality and welding efficiency.

[0116] The embodiment of the present application provides an electric device using the battery disclosed in the present application as a power source, and 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 car, 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 may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric 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.

[0117] 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.

[0118] Please refer to Figure 1 , Figure 1The power consumption device 1000 provided for some embodiments of the present application is a structural schematic diagram of 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 be used not only 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.

[0119] Please refer to Figure 2 , Figure 2 The battery cell 100 provided in some embodiments of the present application is used for the structural explosion diagram of the battery 200. The battery 200 includes a battery case 101 and a plurality of battery cells 100, and the battery cells 100 are accommodated in the battery case 101. Among them, the battery case 101 is used to provide an assembly space for the battery cells, and the battery case 101 can adopt a variety of structures. In some embodiments, the battery case 101 may include a first case 101a and a second case 101b, the first case 101a and the second case 101b cover each other, and the first case 101a and the second case 101b jointly define a receiving cavity for accommodating the battery cells 100. The second box 101b may be a hollow structure with one end open, and the first box 101a may be a plate-like structure, and the first box 101a covers the open side of the second box 101b, so that the first box 101a and the second box 101b together define a receiving cavity; or the first box 101a and the second box 101b may both be hollow structures with one end open (for example, Figure 2 As shown in FIG. 1 , the open side of the first box body 101a covers the open side of the second box body 101b. Of course, the battery box body 101 formed by the first box body 101a and the second box body 101b can be in various shapes, such as a cylinder or a cuboid.

[0120] In the battery 200, multiple battery cells 100 can be connected in series, in parallel or in a mixed connection. A mixed connection means that multiple battery cells 100 are connected in series and in parallel. Multiple battery cells 100 can be directly connected in series, in parallel or in a mixed connection, and then the whole formed by multiple battery cells 100 is accommodated in the battery box 101; or, the battery 200 can also be a battery module formed by multiple battery cells 100 connected in series, in parallel or in a mixed connection, and then multiple battery modules are connected in series, in parallel or in a mixed connection to form a whole, and accommodated in the battery box 101. The battery 200 may also include other structures, for example, the battery 200 may also include a busbar for realizing electrical connection between multiple battery cells 100.

[0121] Please refer to Figure 3-Figure 4 The ultrasonic welding head 10 includes a welding head body 1 and a first welding tooth 2. The welding head body 1 has a welding surface 1a. The first welding tooth 2 is convexly arranged on the welding surface 1a. The first welding tooth 2 includes a plurality of tooth portions 20. The plurality of tooth portions 20 are respectively along the protruding direction of the first welding tooth 2 (for example Figure 3 The first tooth portion 21 to the mth tooth portion are arranged in sequence from the welding surface 1a along the direction Z toward the direction away from the welding head body 1, the nth tooth portion is arranged at an end surface of the (n-1)th tooth portion away from the welding surface 1a, and the end surface of the (n-1)th tooth portion away from the welding surface 1a exceeds the nth tooth portion, 2≤n≤m, that is, n can be any positive integer between 2 and m.

[0122] It can be seen that for multiple teeth 20, among any two adjacent teeth 20, the tooth 20 away from the welding surface 1a is arranged at the end of the tooth 20 close to the welding surface 1a that is away from the welding surface 1a, and the end surface of the tooth 20 close to the welding surface 1a that is away from the welding surface 1a exceeds the tooth 20 away from the welding surface 1a.

[0123] For example, m=2, then the multiple tooth portions 20 are respectively a first tooth portion 21 and a second tooth portion 22 which are arranged in sequence along the protruding direction of the first welding tooth 2, and the second tooth portion 22 is arranged at an end face of the first tooth portion 21 away from the welding surface 1a; the end face of the first tooth portion 21 away from the welding surface 1a exceeds the second tooth portion 22, then on the welding surface 1a, the orthographic projection of the second tooth portion 22 is located within the range of the orthographic projection outer contour of the end face of the first tooth portion 21 away from the welding surface 1a, so that a part of the orthographic projection of the end face of the first tooth portion 21 away from the welding surface 1a exceeds the orthographic projection outer contour of the second tooth portion 22.

[0124] For another example, m=3, then the plurality of teeth 20 are respectively the first tooth 21, the second tooth 22 and the third tooth 20 which are sequentially arranged along the protruding direction of the first welding tooth 2, the second tooth 22 is arranged at the end face of the first tooth 21 away from the welding surface 1a, and the end face of the first tooth 21 away from the welding surface 1a exceeds the second tooth 22, then on the welding surface 1a, the orthographic projection of the second tooth 22 is located within the orthographic projection outer contour range of the end face of the first tooth 21 away from the welding surface 1a, so that a part of the orthographic projection of the end face of the first tooth 21 away from the welding surface 1a exceeds The orthographic outer contour of the second tooth portion 22; the third tooth portion 20 is arranged at an end face of the second tooth portion 22 away from the welding surface 1a, that is, the third tooth portion 20 is arranged at an end of the second tooth portion 22 away from the first tooth portion 21, and the end face of the second tooth portion 22 away from the welding surface 1a exceeds the third tooth portion 20, then on the welding surface 1a, the orthographic projection of the third tooth portion 20 is located within the range of the orthographic projection outer contour of the end face of the second tooth portion 22 away from the welding surface 1a, so that a part of the orthographic projection of the end face of the second tooth portion 22 away from the welding surface 1a exceeds the orthographic projection outer contour of the third tooth portion 20.

[0125] For another example, m=4, then the multiple tooth portions 20 are respectively a first tooth portion 21, a second tooth portion 22, a third tooth portion 20 and a fourth tooth portion 20 which are sequentially arranged along the protruding direction of the first welding tooth 2, the second tooth portion 22 is arranged at an end face of the first tooth portion 21 away from the welding surface 1a, and the end face of the first tooth portion 21 away from the welding surface 1a exceeds the second tooth portion 22, then on the welding surface 1a, the orthographic projection of the second tooth portion 22 is located within the orthographic projection outer contour range of the end face of the first tooth portion 21 away from the welding surface 1a, so that a part of the orthographic projection of the end face of the first tooth portion 21 away from the welding surface 1a exceeds the orthographic projection outer contour of the second tooth portion 22; the third tooth portion 20 is arranged at an end face of the second tooth portion 22 away from the welding surface 1a, that is, the third tooth portion 20 is arranged at an end of the second tooth portion 22 away from the first tooth portion 21, and the end face of the second tooth portion 22 away from the welding surface 1a The end face exceeds the third tooth portion 20, then on the welding surface 1a, the orthographic projection of the third tooth portion 20 is located within the orthographic projection outer contour range of the end face of the second tooth portion 22 away from the welding surface 1a, so that a part of the orthographic projection of the end face of the second tooth portion 22 away from the welding surface 1a exceeds the orthographic projection outer contour of the third tooth portion 20; the fourth tooth portion 20 is arranged at the end face of the third tooth portion 20 away from the welding surface 1a, that is, the fourth tooth portion 20 is arranged at the end of the third tooth portion 20 away from the second tooth portion 22, and the end face of the third tooth portion 20 away from the welding surface 1a exceeds the fourth tooth portion 20, then on the welding surface 1a, the orthographic projection of the fourth tooth portion 20 is located within the orthographic projection outer contour range of the end face of the third tooth portion 20 away from the welding surface 1a, so that a part of the orthographic projection of the end face of the third tooth portion 20 away from the welding surface 1a exceeds the orthographic projection outer contour of the fourth tooth portion 20.

[0126] Of course, m can also be greater than or equal to 5.

[0127] It can be seen that for any two adjacent teeth 20, the end surface of the (n-1)th tooth away from the welding surface 1a exceeds the portion of the nth tooth, which can be formed as a welding pier pressing surface 20a; during the welding process, the mth tooth contacts the welding material before other teeth 20, so as to achieve pre-pressing and shaping of the local area of ​​the welding material, so as to reduce the gap between the multi-layer foil materials of the welding material, and the mth tooth can compact and pier the multi-layer foil materials; as the ultrasonic welding head 10 continues to apply pressure, the (m-1)th tooth until the first tooth 21 successively contacts the welding material, In order to achieve multiple pre-pressing and shaping of the welding material in the area to be welded, so as to further reduce the gap between the multiple layers of foil. At the same time, when the (n-1)th tooth portion to the first tooth portion 21 contacts the welding material, the welding piercing surface 20a from the (n-1)th tooth portion to the first tooth portion 21 can compact and pier the multiple layers of foil in turn, so that the ultrasonic welding head 10 can perform multi-layer piercing on the welding material through the first welding tooth 2 during the welding process, so as to effectively improve the problem of excessive gap between the multiple layers of foil during ultrasonic welding, so as to improve the ultrasonic welding quality and welding stability.

[0128] Obviously, the outer surface of the mth tooth portion can be formed as a welding pressing surface 20a; and, since the first weld tooth 2 can perform multi-layer pressing on the weld material during the welding process, so as to simultaneously take into account that the first weld tooth 2 will not penetrate the weld material during the welding process, thereby improving the penetration ability of the first weld tooth 2 in its protruding direction while not excessively increasing the penetration ability of the first weld tooth 2, so as to improve the welding reliability.

[0129] In the above technical solution, the first welding tooth 2 protruding from the welding surface 1a includes the first tooth portion 21 to the mth tooth portion sequentially arranged along the protruding direction, the nth tooth portion is arranged at the end face of the (n-1)th tooth portion away from the welding surface 1a, and the end face of the (n-1)th tooth portion away from the welding surface 1a exceeds the nth tooth portion, so that the end face of the (n-1)th tooth portion away from the welding surface 1a exceeds the nth tooth portion. The portion of the nth tooth portion can be formed as a welding pier surface 20a, so that when the ultrasonic welding head 10 welds the welding material, each tooth portion 20 can tamp and pier the multi-layer foil of the welding material, so as to achieve multi-layer piercing and tamping of the welding material, effectively reduce the gap between the multi-layer foil materials, and then reduce the welding energy loss caused by the excessive gap between the multi-layer foil materials. At the same time, the first welding tooth 2 will not penetrate the welding material, thereby improving the welding quality and welding efficiency. The ultrasonic welding head 10 has a simple structure, convenient welding processing and easy operation.

[0130] Exemplarily, the ultrasonic welding head 10 is used for ultrasonic welding of multiple pole lugs so that the multiple pole lugs are welded and fixed to form a pole lug portion 32. Since the ultrasonic welding head 10 of the embodiment of the present application can reduce the gap between the multiple pole lugs, it can reduce the welding energy loss caused by the excessive interlayer gap between the multiple pole lugs, improve the welding energy utilization rate, and thus improve the ultrasonic welding efficiency; at the same time, when the pole lug portion 32 is laser welded with other components, since the laser welding position overlaps with the ultrasonic welding position of the multiple pole lugs, the embodiment of the present application can improve the ultrasonic welding quality of the multiple pole lugs and reduce the gap between the multiple pole lugs. Therefore, when the pole lug portion 32 is laser welded with other components, the probability of welding pores, explosion points, cracking and other defects can be reduced, which is beneficial to improving the production qualification rate and reducing the production cost. That is, after the ultrasonic welding head 10 of the embodiment of the present application welds the pole lug portion 32, it can lay a good foundation for the subsequent laser welding of the pole lug portion 32 with other components, improve the welding reliability of the pole lug portion 32 with other components, and thus improve the reliability of the battery cell 100.

[0131] It can be understood that the horn body 1 of the ultrasonic horn 10 in the embodiment of the present application may have one welding surface 1a or multiple welding surfaces 1a; when the horn body 1 has multiple welding surfaces 1a, at least one of the multiple welding surfaces 1a is provided with a first welding tooth 2. For example, Figure 5 As shown, the welding head body 1 has two welding surfaces 1a arranged back to back, and each welding surface 1a is respectively provided with a first welding tooth 2. The two welding surfaces 1a can work simultaneously so as to weld two positions to be welded at the same time, and the two welding surfaces 1a can also form a redundant design, so that when one of the welding surfaces 1a cannot work, the other welding surface 1a can be used to perform the welding operation first; of course, the welding surface 1a of the welding head body 1 can also be three or more.

[0132] In addition, in the embodiment of the present application, the welding surface 1a of the welding head body 1 can be a plane or a curved surface (such as a spherical surface, etc.), and the present application does not make any specific restrictions.

[0133] Please refer to Figure 4 , Figure 7 and Figure 8 In some embodiments, the portion of the end surface of the (n-1)th tooth portion away from the welding surface 1a that exceeds the nth tooth portion is an annular surface, and the annular surface can be arranged around the nth tooth portion; for any tooth portion 20 except the mth tooth portion, the welding piercing surface 20a of each tooth portion 20 can be formed as an annular surface.

[0134] In the above technical solution, by setting the portion of the end face of the (n-1)th tooth away from the welding surface 1a that exceeds the nth tooth as an annular surface, it is convenient for the (n-1)th tooth to achieve a large area and balanced pressure on the corresponding local area of ​​the welding material, which is beneficial to improve the compaction effect of the (n-1)th tooth on the welding material, so as to further improve the problem of excessive gaps between multi-layer foils.

[0135] For example, Figure 7 As shown, the end face of the first tooth portion 21 away from the welding surface 1a is formed into a square, and the orthographic projection of the second tooth portion 22 on the welding surface 1a is a circle. Then, the part of the square area corresponding to the end face of the first tooth portion 21 away from the welding surface 1a that exceeds the above-mentioned circular area corresponding to the second tooth portion 22 is annular; Fig.12 As shown, the end face of the first tooth portion 21 away from the welding surface 1a is formed into a square, and the orthographic projection of the second tooth portion 22 on the welding surface 1a is a square. Then, the part of the square area corresponding to the end face of the first tooth portion 21 away from the welding surface 1a that exceeds the above-mentioned square area corresponding to the second tooth portion 22 is annular; Fig.13 As shown, the end face of the first tooth portion 21 away from the welding surface 1a is formed into a circle, and the orthographic projection of the second tooth portion 22 on the welding surface 1a is a square. Then, the part of the circular area corresponding to the end face of the first tooth portion 21 away from the welding surface 1a that exceeds the above-mentioned square area corresponding to the second tooth portion 22 is annular; Fig.14 As shown, the end face of the first tooth portion 21 away from the welding surface 1a is formed into a circle, and the positive projection of the second tooth portion 22 on the welding surface 1a is a circle. Then, the part of the circular area corresponding to the end face of the first tooth portion 21 away from the welding surface 1a that exceeds the above-mentioned circular area corresponding to the second tooth portion 22 is annular.

[0136] It should be noted that, in the embodiments of the present application, “ring” should be understood in a broad sense, including but not limited to a circular ring, a polygonal ring, and the like.

[0137] Of course, the shape of the portion of the end face of the (n-1)th tooth away from the welding surface 1a that exceeds the nth tooth is not limited to an annular surface. For example, the end face of the (n-1)th tooth away from the welding surface 1a is square, the outer contour of the nth tooth is also formed into a square, one of the corners of the nth tooth is aligned with one of the corners of the (n-1)th tooth, and the welding pier surface 20a of the (n-1)th tooth is roughly L-shaped, and two of the corners of the nth tooth are aligned with the two corners of the (n-1)th tooth, respectively, and the welding pier surface 20a of the (n-1)th tooth is roughly strip-shaped.

[0138] Please refer to Figure 4In some embodiments, each of the first tooth portion 21 to the mth tooth portion is any one of a prism structure, a truncated cone structure and a spherical structure; that is, the first tooth portion 21 is a prism structure, a truncated cone structure or a spherical structure, the second tooth portion 22 is a prism structure, a truncated cone structure or a spherical structure,…, the mth tooth portion is a prism structure, a truncated cone structure or a spherical structure.

[0139] It can be understood that the shapes of the plurality of tooth portions 20 may be the same, or the shapes of at least two of the plurality of tooth portions 20 may be different.

[0140] In the above technical scheme, by setting the first tooth portion 21 and each of the mth tooth portion to be any one of a prism structure, a truncated cone structure and a spherical structure, it is convenient to simplify the structure of each tooth portion 20 while taking into account the structural strength of each tooth portion 20, which is conducive to realizing the structural diversification design of the ultrasonic welding head 10 so as to better meet the actual differentiated needs; at the same time, it is convenient to enable a part of the end face of each of the first tooth portion 21 to the (n-1)th tooth portion away from the welding surface 1a to form a welding pier pressing surface 20a, thereby improving the welding quality.

[0141] Exemplarily, the plurality of teeth 20 are respectively a first tooth 21 and a second tooth 22; Figure 4 , Figure 7-Figure 11 As shown, the first tooth portion 21 is a prism structure, and the second tooth portion 22 is a spherical structure; Fig.12 As shown, the first tooth portion 21 and the second tooth portion 22 are respectively prism structures; Fig.13 As shown, the first tooth portion 21 is a truncated cone structure, and the second tooth portion 22 is a prism structure; Fig.14 As shown, the first tooth portion 21 is a truncated cone structure, and the second tooth portion 22 is a spherical structure.

[0142] It is understandable that in the embodiment of the present application, the prism structure includes but is not limited to a triangular prism, a square prism (the end faces of the square prism in the protruding direction of the first welding tooth 2 can be rectangular, square, diamond or other quadrilaterals), a pentagonal prism, etc. The tooth portion 20 adopts a square prism structure with a square end face, which is beneficial to improving the welding reliability and service life of the first welding tooth 2. For example, Fig.12 In the example, the first tooth portion 21 and the second tooth portion 22 are respectively square pyramid structures.

[0143] In some embodiments, as shown in the figure, the first tooth portion 21 is a square prism structure, and the end faces of the square prism structure at both ends in the protruding direction of the first welding tooth 2 are square, and the side length of the end face of the first tooth portion 21 corresponding to the second tooth portion 22 is W1, and the side length of the end face of the first tooth portion 21 corresponding to the welding surface 1a is W2, 0.2*W2≤W1<W2. For example, W1 can be 0.2*W2, 0.3*W2, 0.5*W2, 0.6*W2, 0.8*W2, or 0.9*W2, etc.

[0144] Please refer to Figure 4 and Figure 7 In some embodiments, there is at least one first welding tooth 2, there is one first tooth portion 21 of the first welding tooth 2, and the number of the (n-1)th tooth portions from the first tooth portion 21 to the mth tooth portion is less than or equal to the number of the nth tooth portion. Obviously, for a single first welding tooth 2, the number of its mth tooth portions is the largest, the number of the first tooth portions 21 is the smallest, or the number of the plurality of tooth portions 20 is equal, that is, in a single first welding tooth 2, the number of the first tooth portions 21 ≤ the number of the second tooth portions 22 ≤…≤ the number of the mth tooth portions.

[0145] It can be seen that in the above technical solution, for a single first welding tooth 2, the number of each tooth portion 20 is one, or the number of at least one tooth portion 20 from the nth tooth portion to the mth tooth portion is multiple. For example, for a single first welding tooth 2: m=2, the first tooth portion 21 is one, and the second tooth portion 22 is multiple; or, m=3, the first tooth portion 21 and the second tooth portion 22 are one, and the third tooth portion is multiple; or, m=3, the first tooth portion 21 is one, the second tooth portion 22 and the third tooth portion are multiple, and the number of the second tooth portion 22 is less than or equal to the number of the third tooth portion.

[0146] In the above technical solution, by setting the first tooth portion 21 of the first welding tooth 2 to be one, the number of the (n-1)th tooth portions is less than or equal to the number of the nth tooth portions, so that in the area corresponding to the first welding tooth 2, multiple local positions of the above-mentioned area can be compacted by at least multiple mth tooth portions, which is beneficial to appropriately reduce the number of first welding teeth 2; and when there are multiple first welding teeth 2, multiple local positions of the welding area can be compacted by multiple first welding teeth 2, which is beneficial to appropriately reduce the number of mth tooth portions to simplify the structure of the first welding tooth 2.

[0147] For example, Figure 4 , Figure 7 , Figure 11-Figure 14 As shown, there are multiple first welding teeth 2, each of which includes a first tooth portion 21 and a second tooth portion 22, and the central axis of the second tooth portion 22 and the central axis of the first tooth portion 21 can be arranged to coincide with or deviate from each other.

[0148] Please refer to Figure 4 and Figure 7 In some embodiments, there are multiple first welding teeth 2, and any two first welding teeth 2 are arranged at intervals.

[0149] In the above technical solution, multiple first welding teeth 2 are set and any two first welding teeth 2 are set at intervals, so that when welding the same area of ​​the area to be welded, multiple first welding teeth 2 can compact multiple local positions to achieve compaction of the entire area to be welded. At the same time, the number of first welding teeth 2 can be appropriately reduced, thereby facilitating the realization of a balance between welding quality and the simplicity of the structure of the ultrasonic welding head 10.

[0150] It can be understood that, when there are multiple first welding teeth 2, the interval between any two first welding teeth 2 can be specifically set according to actual needs.

[0151] Please refer to Fig. 9 and Fig.10 In some embodiments, the end surfaces of the (n-1)th teeth of the plurality of first welding teeth 2 away from the welding surface 1a are arranged flush, and the welding piercing surfaces 20a of the (n-1)th teeth of the plurality of first welding teeth 2 are arranged flush.

[0152] In the above technical solution, by arranging the end faces of the (n-1)th teeth of the plurality of first welding teeth 2 away from the welding surface 1a to be flush, it is convenient for the same-level teeth of the plurality of first welding teeth 2 to form a basically consistent compaction effect on the welding material, so as to help reduce the risk of poor compaction effect or easy penetration of the welding material by the first welding teeth 2 due to large differences in compaction effect, thereby helping to improve the welding quality and welding qualification rate.

[0153] It should be noted that the first tooth portion 21 of the multiple first welding teeth 2 can be a tooth portion at the same level, the second tooth portion 22 of the multiple first welding teeth 2 can be a tooth portion at the same level, the third tooth portion of the multiple first welding teeth 2 can be a tooth portion at the same level, and so on, the mth tooth portion of the multiple first welding teeth 2 is a tooth portion at the same level.

[0154] For example, Figure 4 , Figure 8 , Figure 11-Figure 14 As shown, the welding pressing surface 20a of the (n-1)th tooth portion is formed as a plane, and the welding pressing surfaces 20a of the (n-1)th tooth portions of multiple first welding teeth 2 are located on the same plane to simplify the structure of the tooth portion 20.

[0155] Please refer to Fig.11 In some embodiments, the ultrasonic welding head 10 further includes at least one second welding tooth 3 , the second welding tooth 3 is convexly disposed on the welding surface 1 a , and the second welding tooth 3 is disposed between two adjacent first welding teeth 2 .

[0156] In the above technical solution, by arranging the second welding tooth 3 between two adjacent first welding teeth 2, the second welding tooth 3 can compact and press the local area on the welding material corresponding to the interval between the two adjacent first welding teeth 2, so as to reasonably utilize the layout space provided by the welding head body 1 to increase the compaction area of ​​the welding material by the ultrasonic welding head 10, which is beneficial to further reduce the gap between the multi-layer foil materials and improve the welding quality without basically increasing the size of the ultrasonic welding head 10.

[0157] Optionally, a second welding tooth 3 is respectively provided between any two of the plurality of first welding teeth 2, and the second welding tooth 3 is spaced apart from two adjacent first welding teeth 2, so as to further compact the area of ​​the welding material with the ultrasonic welding head 10.

[0158] Please refer to Fig.11 In some embodiments, multiple first welding teeth 2 are arranged in multiple rows and columns, and second welding teeth 3 are respectively provided between any two adjacent columns of first welding teeth 2 in any two adjacent rows. Then, a single second welding tooth 3 corresponds to two adjacent first welding teeth 2 in two adjacent rows of first welding teeth 2, that is, a single second welding tooth 3 can correspond to four first welding teeth 2.

[0159] In the above technical solution, second welding teeth 3 are respectively provided between two adjacent columns of first welding teeth 2 in any two adjacent rows, so as to reasonably utilize the layout space on the welding surface 1a and improve the compaction effect.

[0160] For example, Fig.11 As shown, a plurality of first welding teeth 2 arranged at intervals along the first direction constitute a row of welding teeth, and a plurality of rows of welding teeth are arranged at intervals along the second direction, and the intersection area between two adjacent columns of first welding teeth 2 of any two adjacent rows is respectively provided with second welding teeth 3. Among them, one of the first direction and the second direction can be the length direction X of the welding surface 1a, and the other can be the width direction Y of the welding surface 1a. The first direction and the second direction are not limited thereto, and the shape of the welding surface 1a is not limited to a rectangle. Of course, the arrangement of the plurality of first welding teeth 2 is not limited thereto.

[0161] Please refer to Fig.10 In some embodiments, in the protruding direction of the first welding tooth 2, the sum of the heights from the second tooth portion 22 to the mth tooth portion is less than or equal to half the height of the first welding tooth 2, and the sum of the heights from the second tooth portion 22 to the mth tooth portion is less than or equal to the height of the first tooth portion 21.

[0162] In the above technical scheme, by setting the sum of the heights of the second tooth portion 22 to the mth tooth portion to be less than or equal to half the height of the first welding tooth 2, the height distribution of the multiple tooth portions 20 in the first welding tooth 2 is more reasonable, so that the penetration force of the first welding tooth 2 in its protruding direction is more appropriate, which is beneficial to further reduce the risk of the first welding tooth 2 penetrating the weld material during the welding process, and at the same time reduce the probability of a cold weld occurring during ultrasonic welding due to the relatively large sum of the heights of the second tooth portion 22 to the mth tooth portion, which causes the welding energy of the first welding tooth 2 to be unable to be well transmitted to the weld material, resulting in the first welding tooth 2 and the weld material being unable to have good contact, which is beneficial to further improve the quality of the weld tooth.

[0163] For example, Fig.10 As shown, m=2, in the protruding direction of the first welding tooth 2, the height of the first tooth portion 21 is H11, the height of the second tooth portion 22 is H12, the height of the first welding tooth 2 is H1, H12≤H1 / 2, H1=H11+H12. Of course, in some examples, m=3, the height H11 of the first tooth portion 21, the height H12 of the second tooth portion 22, and the height H13 of the third tooth portion satisfy, H12+H13≤H1 / 2, H1=H11+H12+H13.

[0164] In some embodiments, Fig.10 As shown, m=2, in the protruding direction of the first welding tooth 2, the height of the first tooth portion 21 is H11, the height of the second tooth portion 22 is H12, the second tooth portion 22 is a spherical structure and the radius of the second tooth portion 22 is R2, the height of the first welding tooth 2 is H1, 0.4*H1≤R2≤0.8*H1, 0.2*H1≤H12≤0.8*H1, which is conducive to improving the welding reliability and service life of the second tooth portion 22 to the welding material. It can be seen that R2 and H12 can be equal or unequal, for example, R2 can be 0.4*H1, 0.5*H1, 0.7*H1, or 0.8*H1, etc., and H12 can be 0.2*H1, 0.4*H1, 0.6*H1, 0.7*H1, or 0.8*H1, etc.

[0165] Please refer to Figure 5 , Figure 6 and Fig.10 In some embodiments, along the direction of ultrasonic vibration (e.g. Figure 5 At least one of the two opposite sides of the welding head body 1 has an avoidance surface 1b, and an angle α between the avoidance surface 1b and the welding surface 1a is an obtuse angle.

[0166] In the above technical scheme, a avoidance surface 1b is provided on at least one side of the two sides of the welding head body 1 along the ultrasonic vibration direction, and the angle α between the avoidance surface 1b and the welding surface 1a is an obtuse angle, so that the avoidance surface 1b can be used to avoid the warping of other areas of the welding material, such as the edge area of ​​the welding material, caused by the welding head body 1 applying pressure to a local area of ​​the welding material during the welding process, so as to reduce the force between the welding head body 1 and the above-mentioned warped part of the welding material, so that the welding head body 1 is not easy to cut the welding material during the welding process, so as to improve the welding reliability; when the welding material is a plurality of pole tabs, the setting of the avoidance surface 1b can effectively improve the cracking problem of ultrasonic welding of the pole tabs.

[0167] It can be understood that, in the above technical solution, the width of the portion of the welding head body 1 corresponding to the avoidance surface 1b in the ultrasonic vibration direction can be gradually reduced along the protruding direction of the first welding tooth 2. The avoidance surface 1b can be a plane or a curved surface. When the avoidance surface 1b is a curved surface, on a preset cross section, the angle between the tangent at any point on the avoidance surface 1b and the welding surface 1a is an obtuse angle, and the preset cross section is perpendicular to the avoidance surface 1b and parallel to the ultrasonic vibration direction.

[0168] Please refer to Fig.10 In some embodiments, in the ultrasonic vibration direction, the distance between the end of the avoidance surface 1b away from the welding surface 1 and the corresponding end of the welding surface 1a is D, 0.3mm≤D≤2mm; and / or, in the protruding direction of the first welding tooth 2, the distance between the end of the avoidance surface 1b away from the welding surface 1a and the welding surface 1a is H4, 0.5mm≤H4≤2mm. For example, D can be 0.3mm, 0.5mm, 1mm, 1.2mm, 1.5mm, 1.7mm, or 2mm, etc.; H4 can be 0.5mm, 1mm, 1.3mm, 1.5mm, 1.8mm, or 2mm, etc.

[0169] In the above technical solution, by setting the distance D between the end of the avoidance surface 1b away from the welding surface 1a and the corresponding end of the welding surface 1a to satisfy 0.3mm≤D≤2mm, and / or setting the distance H4 between the end of the avoidance surface 1b away from the welding surface 1a and the welding surface 1a to satisfy 0.5mm≤H4≤2mm, the position and size of the avoidance surface 1b are more reasonable, so as to better adapt to practical applications while effectively avoiding the warped part of the welding material.

[0170] Further, 0.5 mm ≤ D ≤ 1 mm; and / or, H4 ≤ 1 mm. For example, D may be 0.6 mm, 0.8 mm, 0.9 mm, etc.; H4 may be 0.6 mm, 0.7 mm, 0.8 mm, or 0.9 mm, etc.

[0171] In the above technical solution, by setting 0.5mm≤D≤1mm and / or H4≤1mm, the position and size of the avoidance surface 1b can be further made more reasonable, which is beneficial to improve the adaptability of the welding head body 1 to different welding area sizes while improving the cracking of the welding material.

[0172] Please refer to Fig. 9 and Fig.10 In some embodiments, the avoidance surface 1b and the welding surface 1a are smoothly transitioned through the arc surface 1c.

[0173] In the above technical solution, a smooth transition is provided between the avoidance surface 1b and the welding surface 1a through the arc surface 1c, so that the two ends of the arc surface 1c can be tangent to the avoidance surface 1b and the welding surface 1a respectively, so that the part of the welding head body 1 opposite to the welding material basically has no sharp corners, and even if the welding head body 1 contacts the welding material, the risk of the welding head body 1 causing cutting of the welding material can be further reduced.

[0174] Please refer to Fig. 9 and Fig.10 In some embodiments, each avoidance surface 1b is formed as a plane, and each avoidance surface 1b is inclined relative to the welding surface 1a. Then, each avoidance surface 1b can be gradually arranged close to the welding surface 1a along the protruding direction of the first welding tooth 2 in the direction of ultrasonic vibration.

[0175] In the above technical solution, each avoidance surface 1b is formed as a plane and is inclined relative to the welding surface 1a, so that the outer surface shape of the welding head body 1 is simplified while the avoidance surface 1b can avoid the warped part of the welding material, thereby simplifying the structure of the welding head body 1 and facilitating processing.

[0176] Please refer to Fig.10 In some embodiments, the radius of the arc surface 1c is R1, 0.3 mm ≤ R1 ≤ 1.5 mm. For example, R1 may be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, or 1.5 mm.

[0177] In the above technical solution, the radius R1 of the arc surface 1c is set to satisfy 0.3mm≤R1≤1.5mm, so as to simultaneously reduce the risk of the welding head body 1 cutting the welding material and save the space occupied by the welding head body 1, without causing the welding head body 1 to be too large and causing waste, and without causing the welding head body 1 to cut the welding material.

[0178] Furthermore, R1≤1mm. Thus, the size of the arc surface 1c can be further reasonably set to better balance the reduction of the risk of the welding head body 1 cutting the welding material and the saving of the space occupied by the welding head body 1. For example, R1 can be 0.4mm, 0.6mm, 0.7mm, or 0.9mm.

[0179] Please refer to Figure 7 In some embodiments, the welding surface 1a has a first area 1d and a second area 1e, the first welding tooth 2 is arranged in the first area 1d, and the ultrasonic welding head 10 also includes a third welding tooth 4, the third welding tooth 4 is protruding from the second area 1e and is arranged on the periphery of multiple first welding teeth 2, then the second area 1e is located on the periphery of the first area 1d.

[0180] In the above technical scheme, by arranging the first welding tooth 2 in the first area 1d and arranging the third welding tooth 4 in the second area 1e, it is beneficial to increase the area of ​​the compaction area of ​​the welding head body 1 on the welding material, increase the number of local areas where the welding head body 1 compacts the welding material, and help to further improve the quality of ultrasonic welding; at the same time, the third welding tooth 4 can perform a certain pre-stressing and shaping on the outer part of the area of ​​the welding material corresponding to the first welding tooth 2, so as to realize the early pre-stressing and shaping of the welding material, and the third welding tooth 4 can optimize the friction area between the welding material and the welding head body 1 from large surface friction to local surface friction, reduce the local stress concentration of the welding material, and further improve the cracking of the welding material.

[0181] It is understandable that when the ultrasonic welding head 10 welds the welding material, a part of the welding material will be lifted up and has a tendency to stick to the welding head body 1. If the welding material sticks to the welding head body 1, it is easy to cause the welding material to tear, and the gap between the multi-layer foils will be larger. The third welding tooth 4 of the embodiment of the present application can reduce the mechanical friction applied by the high-frequency vibrating welding head body 1 to the multi-layer foil during the welding process, thereby improving the stress concentration of the welding material and reducing the risk of cracking of the welding material.

[0182] For example, the structure of the third welding tooth 4 may be different from the structure of the first welding tooth 2 .

[0183] Please refer to Figure 7 In some embodiments, the second area 1e is arranged around the first area 1d, and the second area 1e includes a plurality of first area segments 1f connected end to end, each first area segment 1f is provided with a plurality of third welding teeth 4, and the plurality of third welding teeth 4 of the plurality of first area segments 1f are arranged around the first area 1d. The spacing between two adjacent third welding teeth 4 of each first area segment 1f is set according to requirements.

[0184] In the above technical solution, each first area segment 1f of the second area 1e is provided with a plurality of third welding teeth 4, so that the third welding teeth 4 can perform relatively comprehensive pre-pressing and shaping of the welding material, so that no matter where the welding position corresponding to the welding head body 1 is located on the welding material, the third welding teeth 4 can play a role in improving the cracking of the welding material.

[0185] For example, Figure 7As shown, the first area 1d is a rectangle, the second area 1e is a square ring and includes four first area segments 1f, each of which is formed into a long strip, and the plurality of third welding teeth 4 on each first area segment 1f can be arranged at intervals along the length direction of the corresponding first area segment 1f, so as to achieve a good pre-pressing shaping effect with a small number of third welding teeth 4. Of course, in some other examples, the first area 1d can also be circular, and the second area 1e can be annular, in which case the plurality of third welding teeth 4 can be arranged at intervals along the direction surrounding the first area 1d.

[0186] Please refer to Fig.10 In some embodiments, the height H3 of the third welding tooth 4 protruding from the welding surface 1a is less than the height H1 of the first welding tooth 2 protruding from the welding surface 1a. The height of the first welding tooth 2 protruding from the welding surface 1a can be understood as the sum of the heights of the first tooth portion 21 to the mth tooth portion in the protruding direction of the first welding tooth 2.

[0187] In the above technical solution, the height of the third welding tooth 4 protruding from the welding surface 1a is set to be smaller than the height of the first welding tooth 2 protruding from the welding surface 1a, so that the third welding tooth 4 has a suitable pre-pressing and shaping effect on the welding material, and at the same time it is convenient to simplify the structure of the ultrasonic head welding head 10 and reduce the amount of materials used.

[0188] Please refer to Fig.10 In some embodiments, a height H3 of the third welding tooth 4 protruding from the welding surface 1 a is greater than a height H11 of the first tooth portion 21 protruding from the welding surface 1 a .

[0189] In the above technical solution, by setting the height of the third welding tooth 4 protruding from the welding surface 1a to be greater than the height of the first tooth portion 21 protruding from the welding surface 1a, it is convenient for the third welding tooth 4 to contact the welding material before the first tooth portion 21, so that the third welding tooth 4 can achieve a suitable pre-stressing and shaping effect on the welding material.

[0190] Please refer to Fig.10 In some embodiments, the third welding tooth 4 is a spherical structure, the radius of the third welding tooth 4 is R3, the height of the first welding tooth 2 protruding from the welding surface 1a is H1, and 0.2≤R3 / H1≤0.8. For example, R3 / H1 can be 0.2, 0.4, 0.5, 0.7, or 0.8.

[0191] In the above technical solution, by setting the third welding tooth 4 to a spherical structure, the outer surface of the third welding tooth 4 has no sharp corners, thereby reducing the risk of the third welding tooth 4 cutting the welding material. At the same time, 0.2≤R3 / H1≤0.8, the third welding tooth 4 can contact the welding material before the welding surface 1a, so as to achieve a good pre-pressure shaping effect.

[0192] Of course, the structure of the third welding tooth 4 is not limited to this. For example, the third welding tooth 4 can also be a prism structure, a truncated cone structure, a combination of a spherical structure and a prism structure (such as a spherical structure and a square prism structure), or a combination of a spherical structure and a truncated cone structure.

[0193] Furthermore, 0.1 mm ≤ R3 ≤ 0.3 mm. For example, R3 may be 0.1 mm, 0.15 mm, 0.2 mm, 0.26 mm, or 0.3 mm.

[0194] Please refer to Fig.10 In some embodiments, the welding head body 1 has a avoidance surface 1b on at least one of the two opposite sides in the ultrasonic vibration direction, the angle between the avoidance surface 1b and the welding surface 1a is an obtuse angle, and the avoidance surface 1b and the welding surface 1a are smoothly transitioned through the arc surface 1c, and a third welding tooth 4 is provided at the connecting position of the second area 1e and the arc surface 1c, then a part of the third welding tooth 4 is provided in the second area 1e, and the other part of the third welding tooth 4 is provided on the arc surface 1c.

[0195] In the above technical solution, by providing a third welding tooth 4 at the connecting position of the second area 1e and the arc surface 1c, so that the third welding tooth 4 can pre-press and shape the welding material, it is beneficial to rationally utilize the layout space provided by the welding surface 1a in the ultrasonic vibration direction, save the volume of the ultrasonic welding head 10 in the ultrasonic vibration direction, and reduce costs.

[0196] In a second aspect, an embodiment of the present application provides an ultrasonic welding device, comprising the ultrasonic welding head 10 mentioned above.

[0197] In the above technical solution, since the ultrasonic welding device adopts the above-mentioned ultrasonic horn 10, and the ultrasonic horn 10 can perform multi-layer pressing on the welding material to compact the welding material without penetrating the welding material, the welding quality and welding efficiency can be improved.

[0198] In a third aspect, an embodiment of the present application provides an electrode assembly 30, which includes an active material coating portion 31 and a pole ear portion 32, and the pole ear portion 32 is connected to the active material coating portion 31. Exemplarily, the portion of the positive electrode sheet having the positive electrode active material layer, the separator, and the portion of the negative electrode sheet having the negative electrode active material layer are sequentially stacked, and the active material coating portion 31 is formed by winding or laminating. 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, and the positive electrode active material coating portion includes a portion of the positive electrode sheet coated with the positive electrode active material layer, and the negative electrode active material coating portion includes a portion of the negative electrode sheet coated with the negative electrode active material layer. The positive electrode ear portion is electrically connected to the positive electrode active material coating portion and the positive electrode column, and the negative electrode ear portion is electrically connected to the negative electrode active material coating portion and the negative electrode column. In the electrode assembly 40, at least one of the positive electrode ear portion and the negative electrode ear portion can be configured as the above-mentioned pole ear portion 32.

[0199] Among them, the pole ear part 32 includes a plurality of pole ear sheets arranged in a stacked manner, and the plurality of pole ear sheets are welded and fixed. A welding area is provided on one side of the thickness of at least two pole ear sheets, and a first welding groove is formed in the welding area. The first welding groove includes a plurality of groove portions, and the plurality of groove portions are sequentially arranged from the first groove portion to the mth groove portion along the concave direction of the first welding groove, and the nth groove portion is arranged at the bottom wall of the (n-1)th groove portion, and the bottom wall of the (n-1)th groove portion is arranged beyond the nth groove portion, 2≤n≤m.

[0200] It can be seen that for multiple groove portions, among any two adjacent groove portions, the nth groove portion is arranged on the side wall of the (n-1)th groove portion opposite to its groove opening (i.e., the bottom wall of the (n-1)th groove portion), and the (n-1)th groove portion occupies a part of the bottom wall of the (n-1)th groove portion, so that the bottom wall of the (n-1)th groove portion exceeds the (n-1)th groove portion.

[0201] For example, m=2, then the multiple groove portions are respectively the first groove portion and the second groove portion which are arranged in sequence along the recessed direction of the first welding groove, and the second groove portion is arranged on the bottom wall of the first groove portion; the bottom wall of the first groove portion is arranged beyond the second groove portion, then along the thickness direction of the electrode ear, the orthographic projection of the second groove portion is located within the range of the orthographic projection outer contour of the bottom wall of the first groove portion, so that a part of the orthographic projection of the bottom wall of the first groove portion exceeds the orthographic projection outer contour of the second groove portion.

[0202] For another example, m=3, then the multiple groove portions are respectively the first groove portion, the second groove portion and the third groove portion which are arranged in sequence along the recessed direction of the first welding groove, the second groove portion is arranged on the bottom wall of the first groove portion, and the bottom wall of the first groove portion is arranged beyond the second groove portion, then along the thickness direction of the pole ear, the orthographic projection of the second groove portion is located within the orthographic projection outer contour range of the bottom wall of the first groove portion, so that a part of the orthographic projection of the bottom wall of the first groove portion exceeds the orthographic projection outer contour of the second groove portion; the third groove portion is arranged on the bottom wall of the second groove portion, and the bottom wall of the second groove portion is arranged beyond the third groove portion, then along the thickness direction of the pole ear, the orthographic projection of the third groove portion is located within the orthographic projection outer contour range of the bottom wall of the second groove portion, so that a part of the orthographic projection of the bottom wall of the second groove portion exceeds the orthographic projection outer contour of the third groove portion.

[0203] For another example, m=4, then the multiple groove portions are respectively the first groove portion, the second groove portion, the third groove portion and the fourth groove portion which are arranged in sequence along the recessed direction of the first welding groove, the second groove portion is arranged at the bottom wall of the first groove portion, and the bottom wall of the first groove portion is arranged beyond the second groove portion, then along the thickness direction of the pole ear, the orthographic projection of the second groove portion is located within the orthographic projection outer contour range of the bottom wall of the first groove portion, so that a part of the orthographic projection of the bottom wall of the first groove portion exceeds the orthographic projection outer contour of the second groove portion; the third groove portion is arranged at the bottom wall of the second groove portion, and the bottom wall of the second groove portion is arranged beyond the third groove portion, then along the thickness direction of the pole ear, the orthographic projection of the third groove portion is located within the orthographic projection outer contour range of the bottom wall of the second groove portion, so that a part of the orthographic projection of the bottom wall of the second groove portion exceeds the orthographic projection outer contour of the third groove portion; the fourth groove portion is arranged at the bottom wall of the third groove portion, and the bottom wall of the third groove portion is arranged beyond the fourth groove portion, then along the thickness direction of the pole ear, the orthographic projection of the fourth groove portion is located within the orthographic projection outer contour range of the bottom wall of the third groove portion, so that a part of the orthographic projection of the bottom wall of the third groove portion exceeds the orthographic projection outer contour of the fourth groove portion.

[0204] Of course, for the tab, m can also be greater than or equal to 5.

[0205] It can be seen that for any two adjacent grooves, the multiple pole tabs corresponding to the portion where the bottom wall of the (n-1)th groove exceeds the (n-1)th groove can be pressed and compacted during welding; during the welding process, the structure corresponding to the mth groove on the welding device contacts the pole tab before other parts, so as to achieve pre-pressing and shaping of the local areas of the multiple pole tabs to reduce the gaps between the multiple pole tabs, and the above-mentioned structure corresponding to the mth groove on the welding device can compact and press the multiple pole tabs; as the welding device continues to apply pressure, the depth of the first welding groove increases, To form the (m-1)th groove portion to the first groove portion, during this process, the portion of the bottom wall of each groove portion from the (m-1)th groove portion to the first groove portion that exceeds the corresponding groove portion can be formed by multiple pre-pressing and shaping by the welding device to further reduce the gap between the multiple pole tabs, so that the multiple pole tabs are subjected to multi-layer pressing by the welding device during the welding process to form a weld mark area, and the multiple pole tabs are not penetrated, but a first welding groove is formed in the weld mark area, thereby effectively improving the problem of excessive intervals of the multi-layer foil parts during the welding process to improve the welding quality and welding stability.

[0206] It can be understood that in the embodiment of the present application, at least two of the multiple pole lug sheets of the pole lug portion 32 have a weld mark area on one side of the thickness, then a portion of the multiple pole lug sheets of the pole lug portion 32 are welded and fixed to form the weld mark area, or all the pole lug sheets of the pole lug portion 32 are welded and fixed to form the weld mark area.

[0207] In the above technical solution, a welding area is provided on one side of the thickness of at least two pole lugs, and a first welding groove is formed in the welding area. The first welding groove includes a first groove portion to an mth groove portion which are sequentially arranged along the concave direction of the first welding groove, and the nth groove portion is arranged at the bottom wall of the (n-1)th groove portion, and the bottom wall of the (n-1)th groove portion is arranged beyond the nth groove portion. Therefore, when the at least two pole lugs are welded and fixed, the welding device can perform multi-layer pressing on the at least two pole lugs to form multiple grooves, effectively reducing the gap between the multiple pole lugs. At the same time, the multiple pole lugs will not be penetrated, thereby improving the welding quality, thereby facilitating the good welding of the pole lug portion 32 with other components (such as poles, adapters, etc.), which is beneficial to improving the service reliability of the battery cell 100.

[0208] Optionally, the weld mark area of ​​the pole ear portion 32 of the embodiment of the present application can be formed by welding multiple pole ear sheets with the ultrasonic welding head 10 of the embodiment of the present application. At this time, the weld mark area can correspond to the welding surface 1a, and the first welding groove can correspond to the first welding tooth 2, that is, during the welding process, the first welding tooth 2 can form a first welding groove on the pole ear portion 32, then the multiple groove portions can correspond to the multiple tooth portions 20 respectively, the first groove portion corresponds to the first tooth portion 21, and the mth groove portion corresponds to the mth tooth portion.

[0209] In some embodiments, a portion of the bottom wall of the (n-1)th groove portion extending beyond the nth groove portion is an annular surface.

[0210] In the above technical solution, by setting the bottom wall of the (n-1)th groove portion extending beyond the nth groove portion as an annular surface, the welding device can achieve a large and balanced pressing of the local area, which is beneficial to improving the compaction effect of multiple pole tabs.

[0211] In some embodiments, there is at least one first welding groove, there is one first groove portion of the first welding groove, and among the first to nth groove portions, the number of the (n-1)th groove portions is less than or equal to the number of the nth groove portions.

[0212] In the above technical solution, by setting the first groove portion of the first welding groove to one, the number of the (n-1)th groove portions is less than or equal to the number of the nth groove portions, so that in the area corresponding to the first welding groove, multiple local positions can be compacted, which is beneficial to simplify the structure of the welding device.

[0213] In some embodiments, there are multiple first welding grooves, and any two first welding grooves are arranged at intervals. In the above technical solution, by providing multiple first welding grooves and any two first welding grooves are arranged at intervals, when welding the area to be welded of the same area, the welding device can compact multiple local positions to achieve compaction of the entire area to be welded.

[0214] In some embodiments, the bottom walls of the (n-1)th groove portions of the plurality of first welding grooves are flushly arranged. It can be seen that by setting the bottom walls of the (n-1)th groove portions of the plurality of first welding grooves to be flushly arranged, it is convenient for the welding device to form a substantially consistent tamping effect on the plurality of tabs at the same level, so as to reduce the risk of poor tamping effect or penetration of the tabs due to large differences in tamping effect, thereby facilitating the improvement of welding quality and welding pass rate.

[0215] In some embodiments, the weld printing area is further formed with at least one second welding groove, and the second welding groove is arranged between two adjacent first welding grooves.

[0216] In the above technical solution, by providing the second welding groove, it is helpful to increase the compaction area of ​​the welding device for multiple pole tabs, and the size of the welding device will not be increased substantially.

[0217] It can be seen that if the weld mark area of ​​the pole ear portion 32 is formed by welding multiple pole ear sheets through the ultrasonic welding head 10 of the embodiment of the present application, the second welding groove can correspond to the second welding tooth 3, that is, the second welding tooth 3 can form a second welding groove on the pole ear portion 32 during the welding process.

[0218] In some embodiments, the plurality of first welding grooves are arranged in multiple rows and columns, and a second welding groove is respectively provided between the first welding grooves of any two adjacent rows. In the above technical solution, by respectively providing a second welding groove between the first welding grooves of any two adjacent rows, the welding device can further reasonably utilize the occupied space and improve the compaction effect of the plurality of tabs.

[0219] In some embodiments, in the concave direction of the first welding groove, the sum of the depths from the second groove portion to the mth groove portion is less than or equal to half of the depth of the first welding groove. In the above technical solution, by setting the sum of the depths from the second groove portion to the mth groove portion to be less than or equal to half of the depth of the first welding groove, the depth distribution of the plurality of groove portions in the first welding groove is more reasonable, reducing the risk of the tab being penetrated, and at the same time, it is beneficial to improve the contact effect between the welding device and the tab, and reduce the probability of false welding.

[0220] In some embodiments, the weld print area includes a third area and a fourth area, the first weld groove is formed in the third area, the weld print area is further formed with a third weld groove, and the third weld groove is formed in the fourth area and is located outside the plurality of first weld grooves. In the above technical solution, by providing the third weld groove, the welding device can perform a certain pre-compression shaping on the plurality of pole tabs at the position corresponding to the third weld groove, and at the same time, it is beneficial for the welding device to optimize the friction area between the pole tab and the pole tab into local surface friction, reduce the local stress concentration of the pole tab, and improve the cracking of the pole tab.

[0221] It can be seen that if the weld mark area of ​​the pole ear portion 32 is formed by welding multiple pole ear sheets through the ultrasonic welding head 10 of the embodiment of the present application, the third welding groove can correspond to the third welding tooth 4, that is, the third welding tooth 4 can form a third welding groove on the pole ear portion 32 during the welding process.

[0222] In some embodiments, the fourth region is arranged around the third region and includes a plurality of second region segments connected end to end, each second region segment is respectively formed with a plurality of third welding grooves, and the plurality of third welding grooves of the plurality of second region segments are arranged around the third region. In the above technical solution, by arranging a plurality of welding grooves around the third region, it is convenient for the position corresponding to the third welding groove on the welding device to pre-press and shape the pole tab in a relatively comprehensive manner.

[0223] In some embodiments, the depth of the third welding groove is less than the depth of the first welding groove. Thus, the welding device can improve the cracking of the pole tab and achieve a suitable pre-compression shaping effect on the pole tab.

[0224] In some embodiments, the depth of the third welding groove is greater than the depth of the first groove portion. Thus, the welding device can improve the cracking of the pole tab and also achieve a suitable pre-compression shaping effect on the pole tab.

[0225] In a fourth aspect, an embodiment of the present application provides a battery cell 100, including a shell, a pole and the above-mentioned electrode assembly 30, the pole is arranged in the shell, the active material coating portion 31 is accommodated in the shell, and the pole ear portion 32 is electrically connected to the pole. Exemplarily, a accommodating cavity is formed inside the shell, the active material coating portion 31 is accommodated in the accommodating cavity, the pole is passed through the shell, and the pole ear portion 32 is directly welded to the pole or connected through an adapter sheet, so that the pole ear portion 32 is electrically connected between the active material coating portion 31 and the pole. In the above technical solution, since the battery cell 100 adopts the above-mentioned electrode assembly 30, and the pole ear portion 32 of the electrode assembly 30 can be directly or indirectly well welded to the pole, the service reliability of the battery cell 100 can be improved.

[0226] In a fifth aspect, the present application provides a battery 200, comprising the above-mentioned battery cell 100. In the above technical solution, since the battery 200 adopts the above-mentioned battery cell 100, and the battery cell 100 has good service reliability, the service reliability of the battery 200 can be improved.

[0227] In a sixth aspect, the present application embodiment provides an electric device 1000, comprising the above-mentioned battery 200, the battery 200 is used to provide electric energy. In the above technical solution, since the electric device 1000 adopts the above-mentioned battery 200, and the battery 200 has good reliability in use, the electric device 1000 can be used reliably.

[0228] Please refer again Figure 3-Figure 10 , describing the ultrasonic welding head 10 of a specific embodiment of the present application.

[0229] In the embodiment of the present application, the ultrasonic horn 10 includes a horn body 1 and a plurality of first welding teeth 2. The horn body 1 has a welding surface 1a. The plurality of first welding teeth 2 are arranged in multiple rows and columns, each of which is convexly arranged on the welding surface 1a. Each of the first welding teeth 2 includes a first tooth portion 21 and a second tooth portion 22 arranged in sequence along the protruding direction of the first welding tooth 2. The second tooth portion 22 is arranged on an end face of the first tooth portion 21 away from the welding surface 1a, and the end face of the first tooth portion 21 away from the welding surface 1a exceeds the second tooth portion 22, and the portion of the end face of the first tooth portion 21 away from the welding surface 1a that exceeds the second tooth portion 22 is an annular surface. Among them, the end faces of the first tooth portions 21 of the plurality of first welding teeth 2 away from the welding surface 1a are arranged flush, and the end faces of the second tooth portions 22 of the plurality of first welding teeth 22 away from the welding surface 1a are arranged flush; in the protruding direction of the first welding tooth 2, the height of the second tooth portion 22 is less than or equal to half of the height of the first welding tooth 2.

[0230] The welding surface 1a is rectangular. In the width direction of the welding surface 1a, the opposite sides of the welding head body 1 have avoidance surfaces 1b respectively. Each avoidance surface 1b is formed as a plane and the angle between it and the welding surface 1a is an obtuse angle. Each avoidance surface 1b and the welding surface 1a are smoothly transitioned through an arc surface 1c. The radius R1 of the arc surface 1c satisfies 0.3mm≤R1≤1mm, so as to further improve the problems of the welding head body 1 being too large to cause interference with the workpiece and the welding head body 1 being too small to cause welding cracks in the welding material in the actual process.

[0231] The ultrasonic welding head 10 further includes a plurality of third welding teeth 4, which are arranged at intervals in a direction surrounding all the first welding teeth 2, so that the plurality of third welding teeth 4 are arranged around all the first welding teeth 2 in a circle, so that all the first welding teeth 2 are respectively provided with a plurality of third welding teeth 4 on both sides in the X direction, and all the first welding teeth 2 are respectively provided with a plurality of third welding teeth 4 on both sides in the Y direction, and the height of the third welding teeth 4 protruding from the welding surface 1a is less than the height of the first welding teeth 2 protruding from the welding surface 1a, and the height of the third welding teeth 4 protruding from the welding surface 1a is greater than the height of the first tooth portion 21 protruding from the welding surface 1a. Among them, a part of the third welding teeth 4 among the plurality of third welding teeth 4 is arranged at the connection position between the arc surface 1c and the welding surface 1a.

[0232] The second tooth portion 22 is a spherical structure, the radius R2 of the second tooth portion 22 is within 0.1 mm to 0.3 mm, the height H12 of the second tooth portion 22 is within 0.1 mm to 0.4 mm, and the height H1 of the first welding tooth 2 is within 0.4 mm to 0.8 mm; the first tooth portion 21 is a square prism structure, the end face of the first tooth portion 21 corresponding to the welding surface 1a and the end face of the first tooth portion 21 corresponding to the second tooth portion 22 are both square, and the side length W1 of the end face of the first tooth portion 21 corresponding to the second tooth portion 22 is within The first welding tooth 21 has a spherical structure, and the radius R3 of the third welding tooth 4 is within 0.1mm~0.3mm. On the surface where the welding surface 1a is located, the width D of the orthographic projection of the avoidance surface 1b in the direction of ultrasonic vibration is within 0.5mm~1mm, and the distance H4 between the end of the avoidance surface 1b away from the welding surface 1a and the welding surface 1a is within 0.5mm~1mm. In the direction of ultrasonic vibration, the spacing between two adjacent first welding teeth 2 is x1, and in the direction perpendicular to the direction of ultrasonic vibration, the spacing between two adjacent first welding teeth 2 is x2, x1=x2 and both are within 0.2mm~0.4mm, which is conducive to improving the flow uniformity of multi-layer welding materials during ultrasonic welding.

[0233] In the above technical solution, when the ultrasonic welding head welds the welding material, each tooth portion can compact and press the multiple layers of foil of the welding material, so as to realize multi-layer pressing and compacting of the welding material, effectively reduce the gap between the multiple layers of foil, and thus reduce the welding energy loss caused by the excessive gap between the multiple layers of foil. At the same time, the first welding tooth will not penetrate the welding material, thereby improving the welding quality and welding efficiency.

[0234] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can 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 changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. An ultrasonic welding head, characterized in that: include: A welding head body, wherein the welding head body has a welding surface; A first welding tooth, wherein the first welding tooth is protruding from the welding surface, the first welding tooth comprises a plurality of tooth portions, the plurality of tooth portions are respectively a first tooth portion to an mth tooth portion which are sequentially arranged along a protruding direction of the first welding tooth, the nth tooth portion is arranged at an end face of the (n-1)th tooth portion away from the welding surface, and an end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, 2≤n≤m.

2. The ultrasonic horn according to claim 1, characterized in that: A portion of an end surface of the (n-1)th tooth portion that is away from the welding surface and that exceeds the nth tooth portion is an annular surface.

3. The ultrasonic horn according to claim 1, characterized in that: Each of the first to m-th tooth portions is any one of a prism structure, a truncated cone structure, and a spherical structure.

4. The ultrasonic horn according to claim 1, characterized in that: There is at least one first welding tooth, and the first tooth portion of the first welding tooth is one. Among the first tooth portion to the mth tooth portion, the number of the (n-1)th tooth portion is less than or equal to the number of the nth tooth portion.

5. The ultrasonic horn according to claim 1, characterized in that: There are a plurality of first welding teeth, and any two of the first welding teeth are arranged at an interval.

6. The ultrasonic horn according to claim 5, characterized in that: The end surfaces of the (n-1)th tooth portions of the plurality of first welding teeth away from the welding surface are arranged flush.

7. The ultrasonic horn according to claim 5, characterized in that: The ultrasonic horn also includes: At least one second welding tooth, wherein the second welding tooth is protruding from the welding surface, and the second welding tooth is arranged between two adjacent first welding teeth.

8. The ultrasonic horn according to claim 7, characterized in that: The plurality of first welding teeth are arranged in a plurality of rows and columns, and the second welding teeth are respectively arranged between the first welding teeth in any two adjacent rows and columns.

9. The ultrasonic horn according to claim 1, characterized in that: In the protruding direction of the first welding tooth, the sum of heights from the second tooth portion to the mth tooth portion is less than or equal to half of the height of the first welding tooth.

10. The ultrasonic horn according to claim 1, characterized in that: Along the ultrasonic vibration direction, at least one of the two opposite sides of the welding head body has an avoidance surface, and the angle between the avoidance surface and the welding surface is an obtuse angle.

11. The ultrasonic horn according to claim 10, characterized in that: On the surface where the welding surface is located, the width of the orthographic projection of the avoidance surface in the ultrasonic vibration direction is D, 0.3mm≤D≤2mm; and / or, The distance between the end of the avoidance surface away from the welding surface and the welding surface is H4, 0.5mm≤H4≤2mm.

12. The ultrasonic horn according to claim 11, characterized in that: 0.5mm≤D≤1mm; and / or, H4≤1mm.

13. The ultrasonic horn according to claim 10, characterized in that: The avoidance surface and the welding surface are smoothly transitioned through an arc surface.

14. The ultrasonic horn according to claim 13, characterized in that: Each of the avoidance surfaces is formed as a plane and is arranged to be inclined relative to the welding surface.

15. The ultrasonic horn according to claim 14, characterized in that: The radius of the arc surface is R1, 0.3mm≤R1≤1.5mm.

16. The ultrasonic horn according to claim 15, characterized in that: R1≤1mm.

17. The ultrasonic horn according to any one of claims 1 to 16, characterized in that: The welding surface has a first area and a second area, and the first welding tooth is arranged in the first area. The ultrasonic horn also includes: The third welding tooth is protrudingly disposed in the second area and disposed on the periphery of the plurality of first welding teeth.

18. The ultrasonic horn according to claim 17, characterized in that: The second area is arranged around the first area and includes a plurality of first area segments connected end to end in sequence, each of the first area segments is provided with a plurality of the third welding teeth, and the plurality of the third welding teeth of the plurality of the first area segments are arranged around the first area.

19. The ultrasonic horn according to claim 17, characterized in that: A height of the third welding tooth protruding from the welding surface is smaller than a height of the first welding tooth protruding from the welding surface.

20. The ultrasonic horn according to claim 17, characterized in that: A height of the third welding tooth protruding from the welding surface is greater than a height of the first tooth portion protruding from the welding surface.

21. The ultrasonic horn according to claim 17, characterized in that: The third welding tooth is a spherical structure, the radius of the third welding tooth is R3, the height of the first welding tooth protruding from the welding surface is H1, and 0.2≤R3 / H1≤0.

8.

22. The ultrasonic horn according to claim 21, characterized in that: 0.1mm≤R3≤0.3mm.

23. The ultrasonic horn according to claim 17, characterized in that: The welding head body has an avoidance surface on at least one of the two opposite sides in the ultrasonic vibration direction, the angle between the avoidance surface and the welding surface is an obtuse angle, and the avoidance surface and the welding surface are smoothly transitioned through an arc surface, and the third welding tooth is provided at the connecting position of the second area and the arc surface.

24. An ultrasonic welding device, characterized in that: Comprising an ultrasonic horn according to any one of claims 1-23.

25. An electrode assembly, characterized in that: The invention comprises an active material coating portion and a pole ear portion, wherein the pole ear portion is connected to the active material coating portion, and the pole ear portion comprises a plurality of pole ear sheets which are stacked and fixed by welding, and at least two of the pole ear sheets have a welded area on one side of the thickness thereof, and the welded area forms a first welding groove, and the first welding groove comprises a plurality of groove portions, and the plurality of groove portions are respectively a first groove portion to an mth groove portion which are sequentially arranged along the concave direction of the first welding groove, and the nth groove portion is arranged at the bottom wall of the (n-1)th groove portion, and the bottom wall of the (n-1)th groove portion is arranged beyond the nth groove portion, and 2≤n≤m.

26. The electrode assembly according to claim 25, characterized in that A portion of the bottom wall of the (n-1)th groove portion that exceeds the nth groove portion is an annular surface.

27. The electrode assembly according to claim 25, characterized in that There is at least one first welding groove, and the first groove portion of the first welding groove is one. Among the first groove portion to the nth groove portion, the number of the (n-1)th groove portions is less than or equal to the number of the nth groove portions.

28. The electrode assembly according to claim 25, characterized in that There are a plurality of first welding grooves, and any two of the first welding grooves are arranged at an interval.

29. The electrode assembly according to claim 28, characterized in that The bottom walls of the (n-1)th groove portions of the plurality of first welding grooves are flush with each other.

30. The electrode assembly according to claim 28, characterized in that The weld print area is further formed with at least one second weld groove, and the second weld groove is arranged between two adjacent first weld grooves.

31. The electrode assembly according to claim 30, characterized in that The plurality of first welding grooves are arranged in a plurality of rows and columns, and the second welding grooves are respectively arranged between the first welding grooves in any two adjacent rows and columns.

32. The electrode assembly according to claim 25, characterized in that In a recessed direction of the first welding groove, a sum of depths from the second groove portion to the mth groove portion is less than or equal to half of a depth of the first welding groove.

33. The electrode assembly according to any one of claims 25 to 32, characterized in that: The welding area includes a third area and a fourth area, and the first welding groove is formed in the third area. The weld printing area is further formed with a third welding groove, which is formed in the fourth area and is located at the periphery of the plurality of first welding grooves.

34. The electrode assembly according to claim 33, characterized in that The fourth region is arranged around the third region and includes a plurality of second region segments connected end to end, each of the second region segments is respectively formed with a plurality of the third welding grooves, and the plurality of the third welding grooves of the plurality of the second region segments are arranged around the third region.

35. The electrode assembly according to claim 33, characterized in that A depth of the third welding groove is smaller than a depth of the first welding groove.

36. The electrode assembly according to claim 33, characterized in that The depth of the third welding groove is greater than the depth of the first groove portion.

37. A battery cell, characterized in that: It comprises a shell, a pole and an electrode assembly according to any one of claims 25-36, wherein the pole is arranged in the shell, the active material coating part is accommodated in the shell, and the pole ear part is electrically connected to the pole.

38. A battery, characterized in that: Comprising a battery cell according to claim 37.

39. An electrical device, characterized in that: A battery according to claim 38, for providing electrical energy.

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