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

Abstract

An ultrasonic welding head (10). The ultrasonic welding head comprises a welding head main body (1) and first welding teeth (2); the welding head main body is provided with a welding surface (1a), the first welding teeth protruding from the welding surface; the first welding teeth comprise a plurality of tooth parts (20), the plurality of tooth parts respectively being a first tooth part (21) to an m-th tooth part which are successively arranged in the protruding direction of the first welding teeth; the n-th tooth part is arranged on the end surface of the end of the (n-1)th tooth part away from the welding surface, the end surface of the end of the (n-1)th tooth part away from the welding surface exceeding the n-th tooth part, and 2≤n≤m. The present application further relates to an ultrasonic welding device, an electrode assembly (30), a battery cell (100), a battery (200), and an electrical device (1000).

Description

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202311465441.4 and application date of November 6, 2023, and claims the priority of the above-mentioned Chinese patent application. The entire content of the above-mentioned Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present 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

[0004] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, batteries, as the power source of electric vehicles, play an irreplaceable and important role. As core components of new energy vehicles, batteries have high requirements in terms of both energy density and reliability.

[0005] Summary of the Invention

[0006] 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.

[0007] 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 protruded 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 the 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 the end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, 2≤n≤m.

[0008] In the above technical solution, 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, and 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 the 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 gap between 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.

[0009] 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 extends beyond the nth tooth portion is an annular surface.

[0010] 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 pressing of the corresponding local area of ​​the welding material, which is beneficial to improving the compacting 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.

[0011] In some embodiments, each of the first to m-th tooth portions is any one of a truncated pyramid structure, a truncated cone structure, and a spherical structure.

[0012] 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 of each of the first tooth portion to the (n-1)th tooth portion away from the welding surface to form a welding pier pressure surface, thereby improving the welding quality.

[0013] 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 (n-1)th tooth portions is less than or equal to the number of nth tooth portions.

[0014] In the above technical solution, by setting the first tooth portion of the first welding tooth to be one, the number of (n-1)th tooth portions is less than or equal to the number of 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 conducive to appropriately reducing 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 conducive to appropriately reducing the number of mth tooth portions to simplify the structure of the first welding tooth.

[0015] In some embodiments, there are multiple first welding teeth, and any two first welding teeth are arranged at intervals.

[0016] 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, multiple first welding teeth 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 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.

[0017] In some embodiments, end surfaces of the (n-1)th tooth portion of the plurality of first welding teeth away from the welding surface are arranged flush.

[0018] In the above technical solution, by arranging the end faces of the (n-1)th teeth of the multiple first welding teeth away from the welding surface to be flush, it is convenient for the same-level teeth of the multiple first welding teeth to form a basically consistent compacting effect on the welding material, which is conducive to reducing the risk of poor compacting effect or easy penetration of the welding material by the first welding teeth due to large differences in compacting effect, thereby helping to improve welding quality and welding qualification rate.

[0019] In some embodiments, the ultrasonic welding head further includes: at least one second welding tooth, the second welding tooth is protruded from the welding surface, and the second welding tooth is arranged between two adjacent first welding teeth.

[0020] 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 ultrasonic 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.

[0021] In some embodiments, the plurality of first welding teeth are arranged in multiple rows and columns, and a second welding tooth is provided between any two adjacent rows of first welding teeth.

[0022] In the above technical solution, second welding teeth are respectively provided 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.

[0023] 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.

[0024] In the above technical solution, by setting the sum of the heights of 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 cold welding during ultrasonic welding due to the relatively large sum of the heights of the second tooth portion to the mth tooth portion resulting in the welding energy of the first welding tooth not being well transferred to the weld material, resulting in the first welding tooth and the weld material not being able to make good contact, which is beneficial to further improve the quality of the welding teeth.

[0025] In some embodiments, along the ultrasonic vibration direction, at least one of the two opposite sides of the horn body has an avoidance surface, and the angle between the avoidance surface and the welding surface is an obtuse angle.

[0026] In the above technical solution, a avoidance surface is provided on at least one 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 the 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, thereby improving 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.

[0027] 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.

[0028] In the above technical solution, by setting the distance D between the 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 the 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.

[0029] In some embodiments, 0.5 mm ≤ D ≤ 1 mm; and / or, H4 ≤ 1 mm.

[0030] 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.

[0031] In some embodiments, the avoidance surface and the welding surface are smoothly transitioned through an arc surface.

[0032] 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 causing cutting of the welding material can be further reduced.

[0033] In some embodiments, each avoidance surface is formed as a plane and is tilted relative to the welding surface.

[0034] 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.

[0035] In some embodiments, the radius of the arc surface is R1, 0.3 mm ≤ R1 ≤ 1.5 mm.

[0036] In the above technical solution, the radius R1 of the arc surface is set to meet 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. It will not cause the welding head body to be too large and cause waste, nor will it cause the welding head body to cut the welding material.

[0037] In some embodiments, R1 ≤ 1 mm.

[0038] 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.

[0039] In some embodiments, the welding surface has a first area and a second area, the first welding teeth are arranged in the first area, and the ultrasonic welding head further includes: a third welding tooth, the third welding tooth is protruded in the second area and is arranged around the plurality of first welding teeth.

[0040] 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 area where the welding head body compacts 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-stressing and shaping on the outer part of the area corresponding to the first welding tooth of the welding material, so as to realize the early pre-stressing and 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.

[0041] In some embodiments, the second area is arranged around the first area and includes multiple first area segments connected end to end, each first area segment is respectively provided with multiple third welding teeth, and the multiple third welding teeth of the multiple first area segments are arranged around the first area.

[0042] 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 a more comprehensive pre-pressing and shaping of the welding material. Therefore, 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.

[0043] In some embodiments, a height of the third welding tooth protruding from the welding surface is less than a height of the first welding tooth protruding from the welding surface.

[0044] 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 material used.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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, 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-stressing and shaping effect.

[0049] In some embodiments, 0.1 mm ≤ R3 ≤ 0.3 mm.

[0050] In some embodiments, 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 a circular arc surface, and a third welding tooth is provided at the connection position between the second area and the circular arc surface.

[0051] In the above technical solution, a third welding tooth is provided at the connection position between the second area and the arc surface, so that the third welding tooth can pre-press and shape the welding material, which is conducive to the rational use of the layout space provided by the welding surface in the direction of ultrasonic vibration, saving the volume of the ultrasonic welding head in the direction of ultrasonic vibration and reducing costs.

[0052] In a second aspect, an embodiment of the present application provides an ultrasonic welding device, comprising the above-mentioned ultrasonic welding head.

[0053] 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 tabs of the battery cell, laying a good foundation for welding the tabs with other components, the ultrasonic welding device can improve the service reliability of the battery cell.

[0054] In a third aspect, an embodiment of the present application provides an electrode assembly, which includes an active material coating portion and a pole ear portion, the pole ear portion is connected to the active material coating portion, and the pole ear portion includes a plurality of stacked pole ear sheets, the plurality of pole ear sheets are welded and fixed, and at least two pole ear sheets have a weld print area on one side of the thickness, and the weld print area forms a first welding groove, the first welding groove includes a plurality of groove portions, and the plurality of groove portions are respectively arranged in sequence along the concave direction of the first welding groove, 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.

[0055] In the above technical solution, a weld mark area is provided on one side of the thickness of at least two pole tabs, 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 tabs are welded and fixed, the welding device can perform multi-layer pressing on the at least two pole tabs to form multiple groove portions, effectively reducing the gap between the multiple pole tabs. At the same time, the multiple pole tabs will not be penetrated, thereby improving the welding quality, thereby facilitating good welding of the pole tab portion and other components (such as pole posts, adapters, etc.), which is beneficial to improving the service reliability of the battery cell.

[0056] 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.

[0057] In the above technical solution, by setting the bottom wall of the (n-1)th groove portion extending beyond the nth groove portion to 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 tabs.

[0058] In some embodiments, the number of the first groove portion of the first welding groove is one, 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 portion.

[0059] 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 conducive to simplifying the structure of the welding device.

[0060] In some embodiments, there are multiple first welding grooves, and any two first welding grooves are arranged at intervals.

[0061] In the above technical solution, multiple first welding grooves are provided and any two first welding grooves are provided separately, so that 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.

[0062] In some embodiments, bottom walls of the (n-1)th groove portion of the plurality of first welding grooves are flush with each other.

[0063] 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 tabs at the same level, so as to help reduce the risk of poor compaction effect or penetration of the tabs due to large differences in compaction effect, thereby helping to improve welding quality and welding qualification rate.

[0064] In some embodiments, the weld imprint area is further formed with at least one second weld groove, and the second weld groove is disposed between two adjacent first weld grooves.

[0065] In the above technical solution, by providing the second welding groove, it is beneficial to increase the compaction area of ​​the welding device for multiple tabs, and the size of the welding device will not be increased.

[0066] In some embodiments, the plurality of first welding grooves are arranged in multiple rows and columns, and a second welding groove is provided between any two adjacent rows of first welding grooves.

[0067] In the above technical solution, second welding grooves are respectively provided between any two adjacent rows of first welding grooves, so as to further enable the welding device to reasonably utilize the occupied space and improve the compaction effect of multiple tabs.

[0068] 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 a depth of the first welding groove.

[0069] 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 the depth of the first welding groove, the depth distribution of multiple groove portions in the first welding groove is more reasonable, reducing the risk of the pole tab being penetrated, and at the same time being beneficial to improving the contact effect between the welding device and the pole tab, and reducing the probability of cold welding.

[0070] 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, and the weld print area further includes a third weld groove, which is formed in the fourth area and is located outside the plurality of first weld grooves.

[0071] 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. At the same time, it is beneficial for the welding device to optimize the friction area between the pole tab and the pole tab to local surface friction, reduce the local stress concentration of the pole tab, and improve the cracking of the pole tab.

[0072] In some embodiments, the fourth region is arranged around the third region and includes multiple second region segments connected end to end, each second region segment is formed with multiple third welding grooves, and the multiple third welding grooves of the multiple second region segments are arranged around the third region.

[0073] 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 tab in a relatively comprehensive manner.

[0074] In some embodiments, the depth of the third weld groove is less than the depth of the first weld groove.

[0075] In some embodiments, the depth of the third welding groove is greater than the depth of the first groove portion.

[0076] 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.

[0077] In the above technical solution, since the battery cell adopts the above electrode assembly, and the tabs of the electrode assembly can be directly or indirectly welded to the poles, the service reliability of the battery cell can be improved.

[0078] In a fifth aspect, an embodiment of the present application provides a battery comprising the above-mentioned battery cell.

[0079] In the above technical solution, since the battery adopts the above-mentioned battery cell and the battery cell has good service reliability, the service reliability of the battery can be improved.

[0080] In a sixth aspect, an embodiment of the present application provides an electrical device comprising the above-mentioned battery, which is used to provide electrical energy.

[0081] In the above technical solution, since the electric device adopts the above battery and the battery has good reliability, the electric device can be used reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0083] FIG1 is a schematic diagram of a vehicle provided in some embodiments of the present application;

[0084] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0085] FIG3 is a schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0086] FIG4 is an enlarged view of the circled portion A in FIG3 ;

[0087] FIG5 is a schematic diagram of welding of the ultrasonic welding head shown in FIG3 ;

[0088] FIG6 is an enlarged view of the circled portion B in FIG5 ;

[0089] FIG7 is another schematic diagram of the ultrasonic horn shown in FIG3 ;

[0090] FIG8 is an enlarged view of the circled portion C in FIG7 ;

[0091] FIG9 is another schematic diagram of the ultrasonic welding head shown in FIG7;

[0092] FIG10 is a partial schematic diagram of the ultrasonic welding head shown in FIG9;

[0093] FIG11 is a schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0094] FIG12 is a schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0095] FIG13 is a schematic diagram of an ultrasonic welding head provided in some embodiments of the present application;

[0096] FIG14 is a schematic diagram of an ultrasonic welding head provided in some embodiments of the present application.

[0097] Figure markings: electrical device 1000, controller 300, motor 400, battery 200, battery cell 100, battery case 101, first case 101a, second case 101b, ultrasonic welding head 10, electrode assembly 30, active material coating portion 31, pole ear portion 32, welding head body 1, welding surface 1a, avoidance surface 1b, arc surface 1c, first area 1d, second area 1e, first area segment 1f, first welding tooth 2, tooth portion 20, welding piercing surface 20a, first tooth portion 21, second tooth portion 22, second welding tooth 3, third welding tooth 4. DETAILED DESCRIPTION

[0098] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0099] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0100] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0101] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0102] 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 in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of the present application shown in the drawings are for illustrative purposes only and should not constitute any limitation on the present application.

[0103] The term "plurality" used in this application refers to two or more (including two).

[0104] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, polygonal, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0105] The battery referred to in the embodiments of this application refers to a single physical module that includes multiple battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or battery pack. A battery module generally includes multiple battery cells. A battery generally includes a casing for enclosing multiple battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells. Of course, the battery may also not include a casing.

[0106] For example, a battery cell typically includes a housing, a cell assembly, and an electrolyte. The housing is used to house the cell assembly and electrolyte, and is provided with at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding positive and negative electrode sheets and separators.

[0107] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the stacked multiple positive electrode tabs can be directly welded to the positive electrode column to form an electrical connection. Alternatively, the battery cell assembly may further include a positive electrode adapter. The stacked multiple positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode column to form an electrical connection between the positive electrode tab and the positive electrode column.

[0108] The negative electrode sheet can generally include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tabs can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter. The multiple stacked negative electrode tabs are welded to one end of the negative electrode adapter, and the other end of the negative electrode adapter is welded to the negative electrode column to form an electrical connection between the negative electrode tab and the negative electrode column. The material of the separator is not limited, and can be, for example, polypropylene or polyethylene.

[0109] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, batteries, as the power source of electric vehicles, play an irreplaceable and important role. As core components of new energy vehicles, batteries have high requirements in terms of both energy density and reliability.

[0110] In the related art, as batteries require high energy density and service reliability, some battery cells are usually not provided with an adapter structure. The multiple tabs of the battery cell are usually first ultrasonically welded to fix the multiple tabs into tabs, and then the tabs are laser welded to other components such as the poles and top covers of the battery cell. For example, multiple tabs are ultrasonically welded to the adapter, and the multiple tabs are stacked with the adapter to form a lap joint structure. The ultrasonic welding head is pressed on the stacked 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 tabs under high-frequency vibration, thereby connecting the multiple layers of tabs to the adapter.

[0111] Ultrasonic welding utilizes high-frequency vibration waves transmitted to the surfaces of two objects to be welded. Under pressure, the two surfaces rub against each other, forming a fusion between the molecular layers. It offers advantages such as high efficiency, high quality, aesthetics, energy saving, and high welding strength. During ultrasonic welding, conventional square or spherical ultrasonic welding heads are typically used to weld multiple tabs. Due to the irrational structure of the ultrasonic welding head, large gaps exist between the multiple tabs. These gaps can cause weld porosity, cracking, and other undesirable issues during the subsequent welding of the tabs to other battery cell components. This significantly reduces production qualification rates, increases production costs, and reduces the service reliability of the battery cells.

[0112] 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 the first tooth portion to the 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 the end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, 2≤n≤m.

[0113] In the above technical solution, 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 the end face of the (n-1)th tooth portion away from the welding surface, and the end face of the (n-1)th tooth portion away from the welding surface exceeds the nth tooth portion, so that the 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 pier pressing surface, so that when the ultrasonic welding head welds the welding material, each tooth portion can compact and pier the multi-layer foil of the welding material, so as to realize multi-layer pier 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 gap between 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.

[0114] The embodiments of the present application provide an electric device using the battery disclosed herein as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric tool includes a metal cutting power tool, a grinding power tool, an assembly power tool, and a railway power tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, etc.

[0115] 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.

[0116] Please refer to Figure 1, which is a schematic structural diagram of a vehicle in which the power-consuming device 1000 provided in some embodiments of the present application is a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The vehicle is provided with a battery 200, and the battery 200 can be arranged at the bottom, head or tail of the vehicle. The battery 200 can be used to power the vehicle, for example, the battery 200 can be used as an operating power source for the vehicle. The vehicle may also include a controller 300 and a motor 400, and the controller 300 is used to control the battery 200 to power the motor 400, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present application, the battery 200 can not only serve as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0117] Please refer to Figure 2, which is an exploded view of the structure of the battery cell 100 provided in some embodiments of the present application for the battery 200. The battery 200 includes a 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, and 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 accommodating cavity for accommodating the battery cells 100. The second housing 101b can be a hollow structure with one end open, and the first housing 101a can be a plate-like structure. The first housing 101a covers the open side of the second housing 101b, so that the first housing 101a and the second housing 101b together define a storage cavity. Alternatively, the first housing 101a and the second housing 101b can both be hollow structures with one end open (for example, as shown in FIG. 2 ), with the open side of the first housing 101a covering the open side of the second housing 101b. Of course, the battery housing 101 formed by the first housing 101a and the second housing 101b can be of various shapes, such as a cylinder or a rectangular parallelepiped.

[0118] In the battery 200, multiple battery cells 100 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among multiple battery cells 100. Multiple battery cells 100 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 100 can be housed in the battery case 101. Alternatively, the battery 200 can be formed by first connecting multiple battery cells 100 in series, in parallel, or in a hybrid connection to form a battery module. The multiple battery modules are then connected in series, in parallel, or in a hybrid connection to form an entire battery module, which is then housed in the battery case 101. The battery 200 may also include other structures. For example, the battery 200 may also include a busbar for electrically connecting the multiple battery cells 100.

[0119] Please refer to Figures 3-4. 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 protruded from the welding surface 1a. The first welding tooth 2 includes a plurality of tooth portions 20. The plurality of tooth portions 20 are respectively a first tooth portion 21 to an mth tooth portion arranged in sequence along the protruding direction of the first welding tooth 2 (for example, from the welding surface 1a along the direction Z toward the direction away from the welding head body 1 in Figure 3). 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 1a exceeds the nth tooth portion. 2≤n≤m, that is, n can be any positive integer between 2 and m.

[0120] 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 faces away from the welding surface 1a, and the end face of the tooth 20 close to the welding surface 1a that faces away from the welding surface 1a exceeds the tooth 20 away from the welding surface 1a.

[0121] For example, m=2, then the multiple tooth portions 20 are respectively a first tooth portion 21 and a second tooth portion 22 arranged in sequence along the protruding direction of the first welding tooth 2, and the second tooth portion 22 is arranged at the 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 outer contour range of the orthographic projection 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 outer contour of the orthographic projection of the second tooth portion 22.

[0122] For another example, m=3, then the plurality of teeth 20 are respectively a first tooth 21, a second tooth 22 and a third tooth 20 arranged in sequence along the protruding direction of the first welding tooth 2, the second tooth 22 is provided 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 outer contour range of the orthographic projection 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 the end face of the second tooth portion 22 away from the welding surface 1a, that is, the third tooth portion 20 is arranged at the 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 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 outer contour of the third tooth portion 20.

[0123] For another example, m=4, then the multiple tooth portions 20 are respectively the first tooth portion 21, the second tooth portion 22, the third tooth portion 20 and the fourth tooth portion 20 which are arranged in sequence along the protruding direction of the first welding tooth 2, the second tooth portion 22 is arranged at the 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 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 outer contour of the second tooth portion 22; the third tooth portion 20 is provided at the end face of the second tooth portion 22 away from the welding surface 1a, that is, the third tooth portion 20 is provided at the 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.

[0124] Of course, m can also be greater than or equal to 5.

[0125] 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 into a welding pier pressing surface 20a; during the welding process, the mth tooth contacts the welding material before the 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 tamp 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 pier surface 20a from the (n-1)th tooth portion to the first tooth portion 21 can tamp and pier the multiple layers of foil in turn, so that the ultrasonic welding head 10 can perform multi-layer pier pressing 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.

[0126] Obviously, the outer surface of the mth tooth portion can be formed as a welding piercing surface 20a; moreover, since the first welding tooth 2 can perform multi-layer piercing on the welding material during the welding process, it can simultaneously take into account that the first welding tooth 2 will not penetrate the welding material during the welding process, thereby improving the penetration ability of the first welding tooth 2 in its protruding direction while not excessively increasing the penetration ability of the first welding tooth 2, so as to improve the welding reliability.

[0127] In the above technical solution, a first welding tooth 2 protruding from the welding surface 1a includes a first tooth portion 21 to an mth tooth portion sequentially arranged along the protruding direction, and 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 portion of the end face of the (n-1)th tooth portion away from the welding surface 1a that exceeds the nth tooth portion can be formed into a welding pier pressing surface 20a. When the ultrasonic welding head 10 welds the welding material, each tooth portion 20 can compact and pier the multi-layer foil of the welding material, thereby achieving multi-layer piercing and compacting of the welding material, effectively reducing the gap between the multi-layer foil materials, and thereby reducing the welding energy loss easily 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.

[0128] Exemplarily, the ultrasonic welding head 10 is used for ultrasonic welding of multiple pole tabs so that the multiple pole tabs are welded and fixed to form the pole tab portion 32. Since the ultrasonic welding head 10 of the embodiment of the present application can reduce the gap between the multiple pole tabs, it can reduce the welding energy loss caused by the excessive interlayer gap between the multiple pole tabs, improve the welding energy utilization rate, and thus improve the ultrasonic welding efficiency; at the same time, when the pole tab portion 32 is laser welded with other components, since the laser welding position overlaps with the ultrasonic welding position of the multiple pole tabs, the embodiment of the present application can improve the ultrasonic welding quality of the multiple pole tabs and reduce the gap between the multiple pole tabs. Therefore, when the pole tab portion 32 is laser welded with other components, the probability of welding pores, explosion points, cracking and other defects can be reduced, which is conducive 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 tab portion 32, it can lay a good foundation for the subsequent laser welding of the pole tab portion 32 with other components, improve the welding reliability of the pole tab portion 32 with other components, and thus improve the reliability of the battery cell 100.

[0129] It is understandable 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, as shown in FIG5 , the horn body 1 has two back-to-back welding surfaces 1a, each welding surface 1a is respectively provided with a first welding tooth 2, and 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 horn body 1 can also have three or more welding surfaces 1a.

[0130] 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 impose any specific restrictions.

[0131] Please refer to Figures 4, 7 and 8. In some embodiments, the portion of the end surface of the (n-1)th tooth portion away from the welding surface 1a that extends beyond 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 pier surface 20a of each tooth portion 20 can be formed as an annular surface.

[0132] 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 portion as an annular surface, it is convenient for the (n-1)th tooth portion to achieve a large area and balanced pressing of the corresponding local area of ​​the welding material, which is beneficial to improving the compacting effect of the (n-1)th tooth portion on the welding material, so as to further improve the problem of excessive gaps between multiple layers of foil.

[0133] For example, as shown in FIG7 , 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 portion 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; as shown in FIG12 , 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 portion 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 shape; as shown in Figure 13, 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 circular area corresponding to the end face of the first tooth portion 21 away from the welding surface 1a exceeds the above-mentioned square area corresponding to the second tooth portion 22 to form a ring; as shown in Figure 14, 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 circle, then the circular area corresponding to the end face of the first tooth portion 21 away from the welding surface 1a exceeds the above-mentioned circular area corresponding to the second tooth portion 22 to form a ring.

[0134] 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, etc.

[0135] Of course, the shape of the portion of the end face of the (n-1)th tooth portion that extends beyond the nth tooth portion and that is away from the welding surface 1a is not limited to an annular surface. For example, the end face of the (n-1)th tooth portion that is away from the welding surface 1a is square, the outer contour of the nth tooth portion is also formed into a square, one of the corners of the nth tooth portion is aligned with one of the corners of the (n-1)th tooth portion, and in this case, the welding pier pressing surface 20a of the (n-1)th tooth portion is roughly L-shaped, and two of the corners of the nth tooth portion are aligned with two corners of the (n-1)th tooth portion, respectively, and in this case, the welding pier pressing surface 20a of the (n-1)th tooth portion is roughly strip-shaped.

[0136] Please refer to Figure 4. In 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.

[0137] 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 tooth portions 20 among the plurality of tooth portions 20 may be different.

[0138] In the above technical solution, 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 make 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 pressure surface 20a, thereby improving the welding quality.

[0139] Exemplarily, the plurality of tooth portions 20 are respectively a first tooth portion 21 and a second tooth portion 22; as shown in Figures 4 and 7 to 11, the first tooth portion 21 is a prism structure, and the second tooth portion 22 is a spherical structure; as shown in Figure 12, the first tooth portion 21 and the second tooth portion 22 are respectively prism structures; as shown in Figure 13, the first tooth portion 21 is a truncated cone structure, and the second tooth portion 22 is a prism structure; as shown in Figure 14, the first tooth portion 21 is a truncated cone structure, and the second tooth portion 22 is a spherical structure.

[0140] It is understood that in the embodiments of the present application, the pyramidal structure includes, but is not limited to, triangular pyramids, square pyramids (the end faces of the square pyramid in the direction of projection of the first welding tooth 2 may be rectangular, square, diamond-shaped, or other quadrilaterals), pentagonal pyramids, etc. The tooth portion 20 adopts a square pyramidal structure with square end faces, which is beneficial for improving the welding reliability and service life of the first welding tooth 2. For example, in the example of Figure 12, the first tooth portion 21 and the second tooth portion 22 are both square pyramidal structures.

[0141] In some embodiments, as shown in the figure, the first tooth portion 21 is a square pyramid structure, with both end faces of the square pyramid structure in the direction of the first welding tooth 2 protruding. 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, and 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.

[0142] Referring to Figures 4 and 7 , in some embodiments, there is at least one first welding tooth 2, and the first welding tooth 2 has one first tooth portion 21. Among the first tooth portions 21 through the mth tooth portion, the number of (n-1)th tooth portions is less than or equal to the number of nth tooth portions. Obviously, for a single first welding tooth 2, the number of mth tooth portions is the largest, and the number of first tooth portions 21 is the smallest, or the number of the plurality of tooth portions 20 is equal. In other words, for a single first welding tooth 2, the number of first tooth portions 21 ≤ the number of second tooth portions 22 ≤ ... ≤ the number of mth tooth portions.

[0143] It can be seen that in the above technical solution, the number of each tooth portion 20 of a single first welding tooth 2 is one, or the number of at least one tooth portion 20 in the nth to mth tooth portions is multiple. For example, for a single first welding tooth 2: m = 2, there is one first tooth portion 21 and multiple second tooth portions 22; or, m = 3, there are one first tooth portion 21 and one second tooth portion 22 respectively, and multiple third tooth portions; or, m = 3, there is one first tooth portion 21, there are multiple second tooth portions 22 and multiple third tooth portions respectively, and the number of second tooth portions 22 is less than or equal to the number of third tooth portions.

[0144] In the above technical solution, by setting the first tooth portion 21 of the first welding tooth 2 to be one, the number of (n-1)th tooth portions is less than or equal to the number of 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 conducive to appropriately reducing 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 conducive to appropriately reducing the number of mth tooth portions to simplify the structure of the first welding tooth 2.

[0145] For example, as shown in Figures 4, 7, and 11-14, 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.

[0146] Please refer to FIG. 4 and FIG. 7 . In some embodiments, there are multiple first welding teeth 2 , and any two first welding teeth 2 are spaced apart.

[0147] 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 balance between welding quality and the simplicity of the structure of the ultrasonic welding head 10.

[0148] 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.

[0149] Please refer to Figures 9 and 10. In some embodiments, the end surfaces of the (n-1)th tooth portions of the multiple first welding teeth 2 away from the welding surface 1a are arranged flush, and the welding pier pressing surfaces 20a of the (n-1)th tooth portions of the multiple first welding teeth 2 are arranged flush.

[0150] In the above technical solution, by arranging the end faces of the (n-1)th teeth of the multiple first welding teeth 2 away from the welding surface 1a to be flush, it is convenient for the same-level teeth of the multiple first welding teeth 2 to form a basically consistent tamping effect on the welding material, which is conducive to reducing the risk of poor tamping effect or easy penetration of the welding material by the first welding teeth 2 due to large differences in tamping effect, thereby helping to improve the welding quality and welding qualification rate.

[0151] 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.

[0152] For example, as shown in Figures 4, 8, and 11-14, the welding pier pressing surface 20a of the (n-1)th tooth portion is formed as a plane, and the welding pier pressing surfaces 20a of the (n-1)th tooth portions of multiple first welding teeth 2 are located on the same plane so as to simplify the structure of the tooth portion 20.

[0153] Referring 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 protruded from the welding surface 1 a and is disposed between two adjacent first welding teeth 2 .

[0154] In the above technical solution, by arranging the second welding tooth 3 between the 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. Under the premise of basically not increasing the size of the ultrasonic welding head 10, it is beneficial to further reduce the gap between the multi-layer foil materials and improve the welding quality.

[0155] For example, a second welding tooth 3 is 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 .

[0156] Please refer to Figure 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 the two adjacent rows of first welding teeth 2, that is, a single second welding tooth 3 can correspond to four first welding teeth 2.

[0157] 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 arrangement space on the welding surface 1a and improve the compaction effect.

[0158] For example, as shown in Figure 11, a plurality of first welding teeth 2 spaced apart along a first direction form a single row of welding teeth. Multiple rows of welding teeth are spaced apart along a second direction, and second welding teeth 3 are provided in the intersections between any two adjacent rows of first welding teeth 2. One of the first and second directions 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 and second directions are not limited to these, 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 to this.

[0159] Please refer to Figure 10. In some embodiments, in the protruding direction of the first welding tooth 2, the sum of the heights of 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 of the second tooth portion 22 to the mth tooth portion is less than or equal to the height of the first tooth portion 21.

[0160] In the above technical solution, 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 resulting in the welding energy of the first welding tooth 2 not being well transferred to the weld material, resulting in the first welding tooth 2 and the weld material not being in good contact, which is beneficial to further improve the quality of the welding tooth.

[0161] For example, as shown in FIG10 , 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, and H1 = H11 + H12. Of course, in some other 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, and H1 = H11 + H12 + H13.

[0162] In some embodiments, as shown in FIG10 , m=2, and 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, and 0.2*H1≤H12≤0.8*H1, which is beneficial for 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 different, for example, R2 can be 0.4*H1, 0.5*H1, 0.7*H1, or 0.8*H1, and H12 can be 0.2*H1, 0.4*H1, 0.6*H1, 0.7*H1, or 0.8*H1, etc.

[0163] Please refer to Figures 5, 6 and 10. In some embodiments, along the direction of ultrasonic vibration (for example, the Y direction in Figure 5), at least one of the two opposite sides of the welding head body 1 has an avoidance surface 1b, and the angle α between the avoidance surface 1b and the welding surface 1a is an obtuse angle.

[0164] In the above technical solution, a avoidance surface 1b is provided on at least one 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 the 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, thereby improving the welding reliability; when the welding material is a plurality of tabs, the setting of the avoidance surface 1b can effectively improve the cracking problem of the tabs in ultrasonic welding.

[0165] It is 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 direction of ultrasonic vibration can gradually decrease along the protruding direction of the first welding tooth 2. The avoidance surface 1b can be a flat surface or a curved surface. When the avoidance surface 1b is a curved surface, the angle between the tangent line at any point on the avoidance surface 1b and the welding surface 1a on a predetermined cross section is an obtuse angle, and the predetermined cross section is perpendicular to the avoidance surface 1b and parallel to the direction of ultrasonic vibration.

[0166] Referring to FIG. 10 , in some embodiments, in the direction of ultrasonic vibration, the distance D between the end of the avoidance surface 1b away from the welding surface 1 and the corresponding end of the welding surface 1a is 0.3 mm ≤ D ≤ 2 mm; and / or, in the protruding direction of the first welding tooth 2, the distance H4 between the end of the avoidance surface 1b away from the welding surface 1a and the welding surface 1a is 0.5 mm ≤ H4 ≤ 2 mm. For example, D can be 0.3 mm, 0.5 mm, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, or 2 mm, and H4 can be 0.5 mm, 1 mm, 1.3 mm, 1.5 mm, 1.8 mm, or 2 mm, etc.

[0167] 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.

[0168] Furthermore, 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.

[0169] 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 improving the adaptability of the welding head body 1 to different welding area sizes while improving the cracking of the welding material.

[0170] Please refer to FIG. 9 and FIG. 10 . In some embodiments, the avoidance surface 1 b and the welding surface 1 a are smoothly transitioned through an arc surface 1 c .

[0171] In the above technical solution, by setting a smooth transition between the avoidance surface 1b and the welding surface 1a through the arc surface 1c, 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. 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.

[0172] Please refer to Figures 9 and 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 approached to the welding surface 1a along the protruding direction of the first welding tooth 2 in the direction of ultrasonic vibration.

[0173] In the above technical solution, each avoidance surface 1b is formed into 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.

[0174] 10 , in some embodiments, the radius of the arc surface 1 c is R1, 0.3 mm ≤ R1 ≤ 1.5 mm. For example, R1 can be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, or 1.5 mm.

[0175] 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. It will not cause the welding head body 1 to be too large and cause waste, nor will it cause the welding head body 1 to cut the welding material.

[0176] Furthermore, R1 ≤ 1 mm. Thus, the size of the arc surface 1 c can be further rationally set to better balance reducing the risk of the welding head body 1 cutting the welding material and saving the space occupied by the welding head body 1. For example, R1 can be 0.4 mm, 0.6 mm, 0.7 mm, or 0.9 mm.

[0177] 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 protruded 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.

[0178] In the above technical solution, 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 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 advance 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.

[0179] 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 foil 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.

[0180] For example, the structure of the third welding tooth 4 may be different from that of the first welding tooth 2 .

[0181] Referring to FIG. 7 , in some embodiments, the second region 1e is disposed around the first region 1d. The second region 1e includes multiple first segments 1f connected end to end. Each first segment 1f is provided with multiple third welding teeth 4. The multiple third welding teeth 4 of the multiple first segments 1f are disposed around the first region 1d. The spacing between adjacent third welding teeth 4 in each first segment 1f is set as required.

[0182] 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 a relatively comprehensive pre-pressing and shaping of the welding material. Therefore, 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.

[0183] For example, as shown in FIG7 , the first region 1d is rectangular, the second region 1e is square and annular, and includes four first segments 1f. Each first segment 1f is formed into an elongated strip. The multiple third welding teeth 4 on each first segment 1f can be spaced apart along the length of the corresponding first segment 1f, thereby achieving a good pre-compression shaping effect with a smaller number of third welding teeth 4. Of course, in other examples, the first region 1d can also be circular, and the second region 1e can be annular. In this case, the multiple third welding teeth 4 can be spaced apart in a direction surrounding the first region 1d.

[0184] Referring 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.

[0185] 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, while facilitating the simplification of the structure of the ultrasonic head welding head 10 and the reduction of material consumption.

[0186] Referring 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 .

[0187] 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.

[0188] Referring to FIG. 10 , in some embodiments, the third welding tooth 4 is spherical, has a radius R3, and the height of the first welding tooth 2 protruding from the welding surface 1a is H1, where 0.2 ≤ R3 / H1 ≤ 0.8. For example, R3 / H1 can be 0.2, 0.4, 0.5, 0.7, or 0.8.

[0189] 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, 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-stressing and shaping effect.

[0190] 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.

[0191] 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.

[0192] Please refer to Figure 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. The third welding tooth 4 is provided at the connecting position of the second area 1e and the arc surface 1c, and 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.

[0193] In the above technical solution, a third welding tooth 4 is provided at the connection position between the second area 1e and the arc surface 1c, so that the third welding tooth 4 can pre-press and shape the welding material, which is conducive to the rational use of the layout space provided by the welding surface 1a in the direction of ultrasonic vibration, saving the volume of the ultrasonic welding head 10 in the direction of ultrasonic vibration and reducing costs.

[0194] In a second aspect, an embodiment of the present application provides an ultrasonic welding device, comprising the ultrasonic welding head 10 described above.

[0195] In the above technical solution, since the ultrasonic welding device adopts the above-mentioned ultrasonic welding head 10, and the ultrasonic welding head 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.

[0196] Thirdly, embodiments of the present application provide an electrode assembly 30, comprising an active material coating portion 31 and a tab portion 32, with the tab portion 32 connected to the active material coating portion 31. For example, the portion of a positive electrode sheet comprising a positive active material layer, a separator, and the portion of a negative electrode sheet comprising a negative active material layer are sequentially stacked, winding or laminating, to form the active material coating portion 31. The active material coating portion 31 can be divided into a positive active material coating portion and a negative active material coating portion. The positive active material coating portion includes the portion of the positive electrode sheet coated with the positive active material layer, while the negative active material coating portion includes the portion of the negative electrode sheet coated with the negative active material layer. The positive tab portion electrically connects the positive active material coating portion to the positive electrode post, while the negative tab portion electrically connects the negative active material coating portion to the negative electrode post. In the electrode assembly 40, at least one of the positive and negative tab portions can be configured as the tab portion 32.

[0197] Among them, the pole ear portion 32 includes a plurality of pole ear sheets arranged in a stacked manner, and the plurality of pole ear sheets are welded and fixed. At least two pole ear sheets have a weld mark area on one side of the thickness, and the weld mark area forms a first welding groove. 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. 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.

[0198] 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 (that is, 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.

[0199] For example, m=2, then the multiple groove portions are respectively the first groove portion and the second groove portion arranged in sequence along the concave 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 tab, 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.

[0200] 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 electrode 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 located 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 electrode 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.

[0201] 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 tab, 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 located 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 tab, 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 located 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 tab, 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.

[0202] Of course, for the tab, m can also be greater than or equal to 5.

[0203] 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 pre-pressed and shaped multiple times 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 intermittent intervals of the multi-layer foil parts during the welding process, so as to improve the welding quality and welding stability.

[0204] It can be understood that in the embodiment of the present application, at least two of the multiple pole tabs of the pole tab portion 32 have a weld mark area on one side of the thickness, then a portion of the multiple pole tabs of the pole tab portion 32 are welded and fixed to form the weld mark area, or all the pole tabs of the pole tab portion 32 are welded and fixed to form the weld mark area.

[0205] In the above technical solution, a weld mark area is provided on one side of the thickness of at least two pole tabs, 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 arranged in sequence 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 tabs are welded and fixed, the welding device can perform multi-layer pressing on the at least two pole tabs to form multiple groove portions, effectively reducing the gap between the multiple pole tabs. At the same time, the multiple pole tabs will not be penetrated, thereby improving the welding quality, thereby facilitating good welding of the pole tab portion 32 with other components (such as pole posts, adapters, etc.), which is beneficial to improving the service reliability of the battery cell 100.

[0206] For example, 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 using 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.

[0207] 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.

[0208] In the above technical solution, by setting the bottom wall of the (n-1)th groove portion extending beyond the nth groove portion to 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 tabs.

[0209] In some embodiments, there is at least one first welding groove, the first welding groove has one first groove portion, 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.

[0210] 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 conducive to simplifying the structure of the welding device.

[0211] In some embodiments, there are multiple first welding grooves, with any two first welding grooves spaced apart. In the above technical solution, by providing multiple first welding grooves and spacing any two first welding grooves apart, when welding a region to be welded of the same area, the welding device can compact multiple local locations to achieve compaction of the entire region to be welded.

[0212] In some embodiments, the bottom walls of the (n-1)th groove portions of the plurality of first welding grooves are flush. Thus, by arranging the bottom walls of the (n-1)th groove portions of the plurality of first welding grooves flush, the welding device can achieve a substantially uniform compaction effect on the plurality of tabs at the same level, thereby reducing the risk of poor compaction or tab penetration due to large differences in compaction effect, thereby improving welding quality and weld pass rate.

[0213] In some embodiments, the weld imprint area is further formed with at least one second weld groove, and the second weld groove is disposed between two adjacent first weld grooves.

[0214] In the above technical solution, by providing the second welding groove, it is beneficial to increase the compaction area of ​​the welding device for multiple tabs, and the size of the welding device will not be increased.

[0215] 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.

[0216] In some embodiments, the plurality of first welding grooves are arranged in multiple rows and columns, and a second welding groove is provided between any two adjacent rows of first welding grooves. In the above technical solution, by providing a second welding groove between any two adjacent rows of first welding grooves, the welding device can further rationally utilize the occupied space and improve the compaction effect of the multiple tabs.

[0217] In some embodiments, in the concave direction of the first welding groove, the sum of the depths of the second groove portion to the mth groove portion is less than or equal to half the depth of the first welding groove. 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 the depth of the first welding groove, the depth distribution of the multiple groove portions in the first welding groove is more reasonable, reducing the risk of the tab being penetrated, and at the same time facilitating improved contact between the welding device and the tab, reducing the probability of cold welding.

[0218] In some embodiments, the weld imprint region includes a third region and a fourth region, with the first weld groove formed in the third region. The weld imprint region also includes a third weld groove formed in the fourth region and located peripherally to the plurality of first weld grooves. In the above technical solution, the provision of the third weld groove allows the welding device to pre-press and shape the plurality of tabs at positions corresponding to the third weld grooves. This also facilitates the welding device to optimize the friction area between the tab and the electrode to localized surface friction, thereby reducing local stress concentration on the tab and improving tab cracking.

[0219] 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.

[0220] In some embodiments, the fourth region is disposed around the third region and includes a plurality of second region segments connected end to end. Each second region segment is formed with a plurality of third welding grooves, and the plurality of third welding grooves of the plurality of second region segments are disposed around the third region. In the above technical solution, by disposing the plurality of welding grooves around the third region, the positions on the welding device corresponding to the third welding grooves can be used to pre-press and shape the tab in a relatively comprehensive manner.

[0221] In some embodiments, the depth of the third welding groove is less than that of the first welding groove. Thus, the welding device can improve the cracking of the tab and achieve a suitable pre-stressing and shaping effect on the tab.

[0222] In some embodiments, the depth of the third welding groove is greater than the depth of the first groove portion. Thus, while the welding device can improve the cracking of the tab, it can also achieve a suitable pre-stressing and shaping effect on the tab.

[0223] Fourthly, an embodiment of the present application provides a battery cell 100, comprising a shell, a pole and the above-mentioned electrode assembly 30, wherein 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. For example, 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 well welded to the pole directly or indirectly, the service reliability of the battery cell 100 can be improved.

[0224] In a fifth aspect, the present invention provides a battery 200 including the aforementioned battery cell 100. In the above technical solution, since the battery 200 uses the aforementioned battery cell 100 and the battery cell 100 has good service reliability, the service reliability of the battery 200 can be improved.

[0225] In a sixth aspect, an embodiment of the present application provides an electrical device 1000, comprising the aforementioned battery 200, for providing electrical energy. In the above technical solution, since the electrical device 1000 employs the aforementioned battery 200 and the battery 200 has good reliability, the electrical device 1000 can be reliably used.

[0226] Please refer to Figures 3 to 10 again to describe the ultrasonic welding head 10 according to a specific embodiment of the present application.

[0227] In an embodiment of the present application, an 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 protruding from the welding surface 1a. Each first welding tooth 2a 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 provided at an end surface of the first tooth portion 21 away from the welding surface 1a, and the end surface of the first tooth portion 21 away from the welding surface 1a extends beyond the second tooth portion 22. The portion of the end surface of the first tooth portion 21 away from the welding surface 1a that extends beyond the second tooth portion 22 is an annular surface. The end surfaces of the first tooth portions 21 of the plurality of first welding teeth 2 away from the welding surface 1a are flush with each other, and the end surfaces of the second tooth portions 22 of the plurality of first welding teeth 22 away from the welding surface 1a are flush with each other. 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 the height of the first welding tooth 2.

[0228] 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 a circular arc surface 1c. The radius R1 of the circular arc surface 1c satisfies 0.3mm≤R1≤1mm, so as to further improve the problems in the actual process 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.

[0229] The ultrasonic horn 10 also includes a plurality of third welding teeth 4, which are spaced apart in a direction surrounding all the first welding teeth 2, such that the plurality of third welding teeth 4 surround all the first welding teeth 2 in a circle. This ensures that all the first welding teeth 2 are provided with a plurality of third welding teeth 4 on both sides in the X direction, and all the first welding teeth 2 are provided with a plurality of third welding teeth 4 on both sides in the Y direction. 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. Part of the plurality of third welding teeth 4 is provided at the junction of the arc surface 1c and the welding surface 1a.

[0230] Among them, the second tooth portion 22 is a spherical structure, the radius R2 of the second tooth portion 22 is within 0.1mm~0.3mm, the height H12 of the second tooth portion 22 is within 0.1mm~0.4mm, and the height H1 of the first welding tooth 2 is within 0.4mm~0.8mm; 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 side length W2 of the end face of the first tooth portion 21 corresponding to the welding surface 1a is within 0.1mm to 0.6mm. The third welding tooth 4 is a spherical structure, and the radius R3 of the third welding tooth 4 is within 0.1mm to 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 to 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 to 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 to 0.4mm, which is conducive to improving the flow uniformity of multi-layer welding materials during ultrasonic welding.

[0231] In the above technical solution, when the ultrasonic welding head welds the welding material, each tooth 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.

[0232] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application may be combined with each other. The above are only preferred embodiments of this application and are not intended to limit this application. For those skilled in the art, this application may have various modifications and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the scope of protection of this application.

Claims

1. An ultrasonic welding head, wherein: 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, wherein: 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 or 2, wherein: 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 any one of claims 1 to 3, wherein: 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 any one of claims 1 to 4, wherein: 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, wherein: 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 or 6, wherein: 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, wherein: 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 any one of claims 1 to 8, wherein: 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 any one of claims 1 to 9, wherein: 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, wherein: 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, wherein: 0.5mm≤D≤1mm; and / or, H4≤1mm.

13. The ultrasonic horn according to any one of claims 10 to 12, wherein: The avoidance surface and the welding surface are smoothly transitioned through an arc surface.

14. The ultrasonic horn according to claim 13, wherein: 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, wherein: The radius of the arc surface is R1, 0.3mm≤R1≤1.5mm.

16. The ultrasonic horn according to claim 15, wherein: R1≤1mm.

17. The ultrasonic horn according to any one of claims 1 to 16, wherein: 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, wherein: 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 or 18, wherein: 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 any one of claims 17 to 19, wherein: 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 any one of claims 17 to 20, wherein: 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, wherein: 0.1mm≤R3≤0.3mm.

23. The ultrasonic horn according to any one of claims 17 to 22, wherein: 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, wherein: Comprising an ultrasonic horn according to any one of claims 1-23.

25. An electrode assembly, wherein: It includes 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 includes a plurality of pole ear sheets stacked and welded and fixed, at least two of the pole ear sheets have a weld area on one side of the thickness, and the weld area forms a first welding groove, the first welding groove includes a plurality of groove portions, and the plurality of groove portions are respectively a first groove portion to an mth groove portion sequentially arranged along the concave direction of the first welding groove, 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.

26. The electrode assembly according to claim 25, wherein: 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 or 26, wherein: 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 any one of claims 25 to 27, wherein: 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, wherein: 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 or 29, wherein: 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, wherein: 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 any one of claims 25 to 31, wherein: 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, wherein: 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, wherein: 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 or 34, wherein: A depth of the third welding groove is smaller than a depth of the first welding groove.

36. The electrode assembly according to any one of claims 33 to 35, wherein: The depth of the third welding groove is greater than the depth of the first groove portion.

37. A battery cell, wherein: 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, wherein: Comprising a battery cell according to claim 37.

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

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