Ultrasonic welding head and wear detection method, battery cell, battery device and power device

Abstract

The present invention discloses an ultrasonic welding head and a wear detection method, a battery cell, a battery device and an electrical device, belonging to the field of battery technology. The ultrasonic welding head includes: a welding head body, a first welding tooth structure and a second welding tooth structure. The welding head body has a welding surface, the first welding tooth structure is protruding from the welding surface, the second welding tooth structure is protruding from the side of the first welding tooth structure away from the welding surface, and the second welding tooth structure includes at least one second welding tooth, and the second welding tooth extends in a long strip shape in the extension direction of the welding surface. According to an embodiment of the present invention, the ultrasonic welding head can perform multi-stage pressing on multi-layer foils by adding a second welding tooth structure on the side of the first welding tooth structure of the ultrasonic welding head away from the welding surface, thereby enhancing the compaction effect of the first welding tooth structure and the second welding tooth structure on the welding of the multi-layer foils, reducing the gap between the multi-layer foils, and helping to improve the welding quality of subsequent welding processes.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to an ultrasonic welding head and a wear detection method, a battery cell, a battery device and an electrical device. Background Art

[0002] In related technologies, to further increase the energy density of battery cells, the adapter used to connect the tabs to the electrode terminals is eliminated. The tabs of the electrode assembly are directly connected to the electrode terminals on the battery cell housing without an adapter. The process for connecting the tabs and electrode terminals is as follows: The multiple layers of tab sheets are first ultrasonically pre-welded to form a single, integrated tab. The tabs are then laser-welded to the electrode terminals.

[0003] However, laser welding of the tabs to the electrode terminals in related technologies is prone to weld defects such as cracking and collapse. Furthermore, the tabs are prone to numerous cracks and other weld defects. This poor laser welding process affects the battery's service stability. Therefore, improving the quality of laser welding between the tabs and the electrode terminals, and thus enhancing the battery's service stability, is a pressing technical issue. Summary of the Invention

[0004] The present invention provides an ultrasonic welding head and a wear detection method, a battery cell, a battery device and an electrical device. When the ultrasonic welding head is used to weld a workpiece made of multi-layer foil such as a tab, the workpiece can be compacted and the gap between the multi-layer foils can be reduced, thereby helping to improve the welding quality of subsequent welding processes.

[0005] In a first aspect, the present invention provides an ultrasonic welding head, comprising: a welding head body, the welding head body having a welding surface; a first welding tooth structure, the first welding tooth structure being protruded from the welding surface; a second welding tooth structure, the second welding tooth structure being protruded from a side of the first welding tooth structure away from the welding surface, the second welding tooth structure comprising at least one second welding tooth, the second welding tooth extending in a long strip shape in the extension direction of the welding surface.

[0006] In the above technical solution, by adding a second welding tooth structure on the side of the first welding tooth structure of the ultrasonic welding head away from the welding surface, the multi-layer foil can be pressed at multiple levels, the compaction effect of the first welding tooth structure and the second welding tooth structure on the welding of the multi-layer foil can be enhanced, the gap between the multi-layer foil can be reduced, and it is helpful to improve the welding quality of the subsequent welding process. For example, when the subsequent welding process is a laser welding process, the welding defects such as explosion points and collapse generated during the laser welding process can be reduced, and the welding cracks can also be reduced. Moreover, since the gap between the multi-layer foils is reduced, it is beneficial to improve the heat dissipation uniformity of the laser welding joint, thereby helping to improve the problem of foil cracking caused by excessive local stress in the foil. In addition, by setting the second welding tooth to The welding surface extends in a long strip shape in the extension direction, which can increase the contact length between the second welding tooth structure and the surface of the multi-layer foil, further enhance the compaction effect between the multi-layer foil, thereby further reducing the gap between the multi-layer foil, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer foils at the welding mark position corresponding to the second welding tooth is tighter and the gap is smaller. In this way, laser welding can be performed at the welding mark position corresponding to the second welding tooth, which can better reduce laser welding defects and better improve laser welding quality. When the ultrasonic welding head is used to weld the multi-layer foil of the pole ear, it helps to improve the subsequent laser welding quality of the pole ear and the electrode terminal, which is beneficial to improving the service stability of the battery.

[0007] In some embodiments, both ends of the second welding tooth in the length direction extend to opposite ends of the welding surface respectively.

[0008] In the above technical solution, by extending the two ends of the second welding tooth in the length direction to the opposite ends of the welding surface, the length of the second welding tooth can be increased. When ultrasonic welding is performed, the contact length of the second welding tooth structure with the surface of the multi-layer foil is longer, further enhancing the compaction effect of the second welding tooth structure on the multi-layer foil; and, since the length of the second welding tooth is longer, the weld mark corresponding to the second welding tooth is longer. In this way, when laser welding is performed on the weld mark position corresponding to the second welding tooth in the subsequent welding process, the length of the laser welding can be made longer, which is beneficial to improving the reliability and stability of the subsequent welding connection; for example, after the ultrasonic welding head is used to weld the multi-layer foil of the pole tab, when the subsequent welding process is a laser welding process, the laser weld between the pole tab and the electrode terminal can be made longer, and the laser weld between the pole tab and the electrode terminal can be made longer, which helps to improve the stability and reliability of the welding connection between the pole tab and the electrode terminal.

[0009] In some embodiments, the second welding teeth extend along the length direction of the welding surface.

[0010] In the above technical solution, by extending the second welding tooth along the length direction of the welding surface, the space in the length direction of the welding surface can be utilized, and the length of the second welding tooth can be increased. When ultrasonic welding is performed, the contact length between the second welding tooth structure and the surface of the multi-layer foil is longer, thereby enhancing the compaction effect of the second welding tooth structure on the multi-layer foil.

[0011] In some embodiments, the second welding teeth extend along the width direction of the welding surface.

[0012] In the above technical solution, by extending the second welding teeth along the width direction of the welding surface, the space in the width direction of the welding surface can be utilized, and it is also beneficial to increase the number of arranged second welding teeth. When ultrasonic welding is performed, the contact area between the second welding tooth structure and the surface of the multi-layer foil is larger, thereby enhancing the compaction effect of the second welding tooth structure on the multi-layer foil.

[0013] In some embodiments, the second welding tooth extends along a straight line.

[0014] In the above technical solution, by providing a second welding tooth extending along a straight line, the result of the second welding tooth can be made simple and convenient for processing and forming; and the welding mark corresponding to the second welding tooth extending in a straight line also basically extends along a straight line, so that in the subsequent welding process, welding connection can be performed along a straight line, making the design of the subsequent welding process relatively simple.

[0015] In some embodiments, the second welding teeth are multiple and spaced apart.

[0016] In the above technical solution, by setting a plurality of second welding teeth arranged at intervals, the plurality of second welding teeth can compact a plurality of different positions of a plurality of multi-layer foils, thereby reducing the gaps between the plurality of different positions of the multi-layer foils, which helps to improve the quality of subsequent welding processes.

[0017] In some embodiments, a plurality of the second welding teeth are arranged side by side along the width direction of the second welding teeth.

[0018] In the above technical solution, by arranging multiple second welding teeth side by side along the width direction of the second welding teeth, the contact area between the second welding tooth structure and the surface of the multi-layer foil can be increased, and the compaction effect between the multi-layer foils can be enhanced, so that the gaps at different positions in the width direction of the second welding teeth of the multi-layer foil can be reduced, which helps to improve the quality of subsequent welding processes.

[0019] In some embodiments, the second welding teeth extend along the length direction of the welding surface, and a plurality of the second welding teeth are arranged along the width direction of the welding surface.

[0020] In the above technical solution, by extending the second welding tooth along the length direction of the welding surface, the space in the length direction of the welding surface can be fully utilized, so that the extension length of the second welding tooth is longer, and multiple second welding teeth are arranged along the width direction of the welding surface. The distribution of multiple second welding teeth is relatively uniform, which can increase the contact length and contact area between the second welding tooth structure and the workpiece surface, make the second welding tooth structure contact with the workpiece surface more uniform, make the heat inside the workpiece more evenly distributed, and enhance the compaction effect on the workpiece surface.

[0021] In some embodiments, in the arrangement direction of the plurality of second welding teeth, the distance between two adjacent second welding teeth is d1, the maximum width of the second welding teeth is W2, and W2<d1.

[0022] In the above technical solution, by making the maximum width W2 of the second welding tooth smaller than the spacing d1 between two adjacent second welding teeth, the width of the second welding tooth can be made smaller. Under a certain welding pressure, the second welding tooth can generate a greater pressure on the multi-layer foil, further enhancing the compaction effect of the second welding tooth on the multi-layer foil.

[0023] In some embodiments, the ratio of W2 to d1 ranges from 0.2 to 0.8.

[0024] In the above technical solution, by setting the ratio of the maximum width W2 of the second welding tooth to the spacing d1 between two adjacent second welding teeth within the range of 0.2 to 0.8, it is possible to generate a greater pressure on the multi-layer foil under a certain welding pressure while making the contact area between the second welding tooth structure and the surface of the multi-layer foil larger, thereby enhancing the compaction effect between the multi-layer foils.

[0025] In some embodiments, in the arrangement direction of the plurality of second welding teeth, the minimum distance between the second welding teeth and the edge of the welding surface is d2, the maximum width of the second welding teeth is W2, and d2>W2.

[0026] In the above technical solution, by making the minimum distance d2 between the second welding tooth and the edge of the welding surface greater than the maximum width W2 of the second welding tooth, the second welding tooth can be made to have a certain distance from the edge of the welding surface, so that the second welding tooth can better compact the multi-layer foil, thereby enhancing the compaction effect between the multi-layer foils.

[0027] In some embodiments, the cross-section of the second weld tooth is a second cross-section, and the second cross-section has a tapered portion, which extends to a side of the second weld tooth away from the welding surface, and the width of the tapered portion gradually decreases in the direction from the welding surface to the second weld tooth.

[0028] In the above technical solution, by gradually reducing the width of the tapered portion of the second welding tooth in the direction from the welding surface to the second welding tooth, the second welding tooth can exert a greater pressure on the multi-layer foil under a certain welding pressure, thereby enhancing the compaction effect of the second welding tooth on the multi-layer foil.

[0029] In some embodiments, in the extension direction of the second welding teeth, at least part of the cross-sectional areas of the second welding teeth are the same.

[0030] In the above technical solution, by making the cross-sectional area of ​​at least part of the second welding tooth in the extension direction the same, the second welding tooth can maintain a relatively uniform compaction of the multi-layer foil in the extension direction, thereby enhancing the compaction effect of the second welding tooth on the multi-layer foil, and the width dimension of the weld mark corresponding to the second welding tooth in its extension direction is relatively uniform, which facilitates the subsequent welding process at the weld mark corresponding to the second welding tooth.

[0031] In some embodiments, the cross-section of the second welding tooth is arcuate, circular, or elliptical.

[0032] In the above technical solution, by setting the cross section of the second welding tooth to an arcuate, circular or elliptical shape, the surface of the second welding tooth is less likely to scratch the multi-layer foil when in contact with the foil.

[0033] In some embodiments, the second welding tooth includes a tooth portion.

[0034] In the above technical solution, by making the second welding tooth include one tooth portion, the structure of the second welding tooth can be simplified and convenient for processing and forming.

[0035] In some embodiments, the second welding tooth includes a plurality of teeth, and the surface of the tooth away from the welding surface constitutes a tooth end face, and the plurality of teeth are respectively the first tooth to the mth tooth arranged in sequence along the protruding direction of the second welding tooth, the nth tooth is arranged on the tooth end face of the (n-1)th tooth, and the projection of the nth tooth on the tooth end face of the (n-1)th tooth is located within the tooth end face of the (n-1)th tooth, and 2≤n≤m.

[0036] In the above technical solution, the second welding tooth is provided to include 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 second welding tooth, the nth tooth portion is provided on the tooth portion end face of the (n-1)th tooth portion, and the projection of the tooth portion end face of the (n-1)th tooth portion is located within the tooth portion end face of the (n-1)th tooth portion, so that the portion of the tooth portion 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 multi-layer foil, each tooth portion can compact and press the multi-layer foil, so as to achieve multi-layer pressing and compacting of the welding material, further enhance the compaction effect between the multi-layer foils, and better reduce the gap between the multi-layer foils, thereby reducing the welding energy loss caused by the excessive gap between the layers of the multi-layer foils and the impact on the subsequent welding process, which helps to better improve the welding quality of the subsequent welding process.

[0037] In some embodiments, the first welding tooth structure includes a first welding tooth, a side surface of the first welding tooth away from the welding surface constitutes a welding tooth end face, the second welding tooth is arranged on the welding tooth end face, and the projection of the second welding tooth on the welding tooth end face is located within the welding tooth end face.

[0038] In the above technical solution, by arranging the second welding tooth inside the welding tooth end face of the first welding tooth, there can be a clear boundary between the second welding tooth and the first welding tooth, which is more conducive to the first welding tooth and the second welding tooth forming a multi-level welding tooth structure, and is more conducive to achieving multi-level pressing of multi-layer foil, and the compaction effect is better.

[0039] In some embodiments, in the protruding direction of the first welding tooth relative to the welding surface, the tooth height of the first welding tooth is h1, the tooth height of the second welding tooth is h2, and the ratio of h2 to h1 ranges from 0.3 to 0.8.

[0040] In the above technical solution, by making the ratio of the tooth height h2 of the second welding tooth to the tooth height h1 of the first welding tooth not less than 0.3, the second welding tooth can have a higher tooth height, so that the second welding tooth has a better compaction effect on the multi-layer foil; and, by making the ratio of the tooth height h2 of the second welding tooth to the tooth height h1 of the first welding tooth not greater than 0.8, the second welding tooth will not affect the welding effect of the first welding tooth due to the excessive tooth height. In this way, it can better avoid the contact between the first welding tooth and the multi-layer foil due to the excessive tooth height of the second welding tooth, so that when the ultrasonic welding head is used to weld the multi-layer foil, the first welding tooth and the second welding tooth can fully contact the multi-layer foil, so that the contact area between the first welding tooth and the second welding tooth and the multi-layer foil is larger, which can improve the compaction effect on the multi-layer foil.

[0041] In some embodiments, in the protruding direction of the first welding tooth relative to the welding surface, the tooth height of the first welding tooth is h1, and the value range of h1 is 0.2 mm to 0.6 mm.

[0042] In the above technical solution, by making the tooth height h2 of the second welding tooth not less than 0.2 mm, the second welding tooth can have a higher tooth height, so that the second welding tooth has a better compaction effect on the multi-layer foil; and, by making the tooth height h2 of the second welding tooth not greater than 0.6 mm, the second welding tooth will not affect the welding effect of the first welding tooth due to the excessive tooth height. In this way, it can better avoid the contact between the first welding tooth and the multi-layer foil due to the excessive tooth height of the second welding tooth, so that when the multi-layer foil is welded with the ultrasonic welding head, the first welding tooth and the second welding tooth can fully contact the multi-layer foil, so that the contact area between the first welding tooth and the second welding tooth and the multi-layer foil is larger, which can improve the compaction effect on the multi-layer foil.

[0043] In some embodiments, the end surface of the welding tooth is flat.

[0044] In the above technical solution, by setting the end face of the first welding tooth to a plane, the contact area between the first welding tooth and the multi-layer foil can be increased, and the compaction area of ​​the multi-layer foil can be increased, which is beneficial to improving the compaction effect of the multi-layer foil.

[0045] In some embodiments, the first welding tooth structure includes a third welding tooth, and the third welding tooth is arranged between adjacent first welding teeth.

[0046] In the above technical solution, by arranging the third welding teeth between adjacent first welding teeth, the portion of the multi-layer foil located between adjacent first welding teeth can be compacted by the third welding teeth, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of subsequent welding processes.

[0047] In some embodiments, the first welding tooth structure includes a fourth welding tooth, and the fourth welding tooth is arranged between the first welding tooth and the edge of the welding surface.

[0048] In the above technical solution, by arranging the fourth welding tooth at the edge of the first welding tooth and the welding surface, the portion of the multi-layer foil located at the edge of the first welding tooth and the welding surface can be compacted by the fourth welding tooth, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of the subsequent welding process; and the fourth welding tooth can also reduce the occurrence of scratches on the multi-layer foil by the edge of the first welding tooth.

[0049] In some embodiments, the first welding tooth includes a welding tooth body and a plurality of welding tooth branches, the welding tooth body extends in a long strip shape in the extension direction of the welding surface, and the plurality of welding tooth branches are connected to at least one side of the width direction of the welding tooth body, and the second welding tooth is arranged on the welding tooth body and is consistent with the extension direction of the welding tooth body.

[0050] In the above technical solution, by setting the first welding tooth to include a welding tooth main body and multiple welding tooth branches and the multiple welding tooth branches are connected to at least one side of the width direction of the welding tooth main body, the contact area between the first welding tooth and the multi-layer foil can be increased, which is beneficial to enhancing the compaction uniformity and compaction effect of the multi-layer foil. By setting the second welding tooth on the welding tooth main body and consistent with the extension direction of the welding tooth main body, the contact length between the second welding tooth structure and the surface of the multi-layer foil is increased, and the compaction effect of the second welding tooth on the multi-layer foil is enhanced.

[0051] In some embodiments, the width of the second welding tooth is W2, the width of the welding tooth body is W1, and W2≤W1.

[0052] In the above technical solution, by making the width W2 of the second welding tooth less than or equal to the width W1 of the welding tooth body, the width of the welding tooth body of the first welding tooth can be made larger, thereby providing sufficient support area for the second welding tooth, and making the contact area between the first welding tooth and the multi-layer foil larger, and further enhancing the compaction effect of the second welding tooth on the multi-layer foil.

[0053] In some embodiments, the ratio of W2 to W1 ranges from 0.5 to 0.9.

[0054] In the above technical solution, by making the ratio of the width W2 of the second welding tooth to the width W1 of the welding tooth body not less than 0.5, the contact area between the second welding tooth and the multi-layer foil can be larger, the compaction range is larger, and the compaction effect is better. In addition, by making the ratio of the width W2 of the second welding tooth to the width W1 of the welding tooth body not greater than 0.9, a multi-level welding tooth structure is better formed between the second welding tooth and the first welding tooth, which is more conducive to multi-level pressing of the multi-layer foil and better compaction effect.

[0055] In some embodiments, the first welding tooth structure includes a third welding tooth, and a plurality of accommodating grooves are defined between two adjacent first welding teeth. The plurality of accommodating grooves are arranged at intervals along the extension direction of the welding tooth body, the welding tooth branch is located between two adjacent accommodating grooves, and the third welding tooth is located in the accommodating groove.

[0056] In the above technical solution, by defining a plurality of accommodating grooves between two adjacent first welding teeth, the plurality of accommodating grooves are arranged at intervals along the extension direction of the welding tooth body, and a third welding tooth is arranged in the accommodating groove, the contact area between the first welding tooth structure and the multi-layer foil can be further increased, so that the portion of the multi-layer foil located between adjacent first welding teeth can obtain the compaction effect of the third welding tooth, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of subsequent welding processes.

[0057] In some embodiments, the third welding tooth is in a pyramidal shape.

[0058] In the above technical solution, by making the third welding tooth into a prism shape, the third welding tooth can have a larger contact area with the multi-layer foil and achieve a better compaction effect. The contact surface between the third welding tooth and the multi-layer foil can form a welding pressure surface, providing a larger heat transfer area, which is conducive to reducing welding cracks caused by local stress concentration in the multi-layer foil.

[0059] In some embodiments, the first welding tooth structure includes a fourth welding tooth, and the fourth welding tooth is arranged between the first welding tooth and the edge of the welding surface. There are multiple fourth welding teeth, and the multiple fourth welding teeth located on the same side of the first welding tooth are arranged at intervals along the extension direction of the welding tooth body.

[0060] In the above technical solution, by arranging the fourth welding tooth at the edge of the first welding tooth and the welding surface, the portion of the multi-layer foil located at the edge of the first welding tooth and the welding surface can be compacted by the fourth welding tooth, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of the subsequent welding process; and the fourth welding tooth can also reduce the situation where the edge of the first welding tooth scratches the multi-layer foil; and, by arranging the fourth welding teeth to be spaced apart along the extension direction of the welding tooth body, the fourth welding teeth can compact the multi-layer foil more evenly and the compaction effect is better.

[0061] In a second aspect, the present invention provides an ultrasonic welding device, comprising: an ultrasonic welding head according to an embodiment of the first aspect.

[0062] In the above technical solution, by setting the above-mentioned ultrasonic welding head, by adding a second welding tooth structure on the side of the first welding tooth structure of the ultrasonic welding head away from the welding surface, the multi-layer foil can be pressed at multiple levels, the compaction effect of the first welding tooth structure and the second welding tooth structure on the welding of the multi-layer foil can be enhanced, the gap between the multi-layer foil can be reduced, and it is helpful to improve the welding quality of the subsequent welding process. For example, when the subsequent welding process is a laser welding process, the welding defects such as explosion points and collapse generated during the laser welding process can be reduced, and welding cracks can also be reduced. Moreover, since the gap between the multi-layer foil is reduced, it is beneficial to improve the heat dissipation uniformity of the laser welding joint, thereby helping to improve the problem of foil cracking caused by excessive local stress in the foil; and, by The welding teeth are arranged to extend in a long strip shape in the extension direction of the welding surface, which can increase the contact length between the second welding tooth structure and the surface of the multi-layer foil, further enhance the compaction effect between the multi-layer foil, thereby further reducing the gap between the multi-layer foil, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer foils at the welding mark position corresponding to the second welding teeth is tighter and the gap is smaller. In this way, laser welding can be performed at the welding mark position corresponding to the second welding teeth, which can better reduce laser welding defects and better improve laser welding quality. When the ultrasonic welding head is used to weld the multi-layer foil of the pole ear, it helps to improve the subsequent laser welding quality of the pole ear and the electrode terminal, which is beneficial to improving the service stability of the battery.

[0063] In a third aspect, the present invention provides a method for detecting wear of an ultrasonic horn, wherein the ultrasonic horn is an ultrasonic horn according to an embodiment of the first aspect, and the method for detecting wear of the ultrasonic horn comprises:

[0064] Performing ultrasonic pre-welding on the workpiece sample using the ultrasonic welding head, wherein the weld mark on the workpiece sample corresponding to the second weld tooth is the second weld mark;

[0065] identifying the second weld mark formed on the workpiece sample;

[0066] Calculating a weld mark area of ​​a single second weld mark;

[0067] The wear condition of the ultrasonic welding head is judged according to the weld mark area of ​​a single second weld mark.

[0068] In the above technical solution, by calculating the single weld mark area of ​​the second weld mark corresponding to the second weld tooth formed on the workpiece sample, the wear condition of the second weld tooth in the ultrasonic welding head can be judged more intuitively and accurately, so that the ultrasonic welding head can be replaced or repaired in time, reducing the occurrence of poor welding and poor compaction effect of multi-layer foils caused by wear of the ultrasonic welding head, which affects the subsequent welding process, and helps to improve the compaction effect of the ultrasonic welding head on the multi-layer foil.

[0069] In some embodiments, identifying the second weld mark formed on the workpiece sample includes:

[0070] Collecting a weld mark image of the side of the workpiece sample where the weld mark is formed;

[0071] The second weld mark is identified in the weld mark image.

[0072] In the above technical solution, by collecting the weld mark image of the side of the workpiece sample on which the weld mark is formed and identifying the second weld mark in the weld mark image, the second weld mark can be easily identified and found.

[0073] In some embodiments, calculating the weld footprint area of ​​a single second weld footprint includes:

[0074] identifying an outer contour of a single second weld mark;

[0075] Calculate the graphic area enclosed by the outer contour of the second weld mark.

[0076] In the above technical solution, by first identifying the outer contour of a single second weld mark and then calculating the area of ​​the figure enclosed by the outer contour of the second weld mark, the weld mark area of ​​the second weld mark can be conveniently calculated. The calculation method of the weld mark area is simple and the calculation result is relatively accurate.

[0077] In some embodiments, judging the wear condition of the ultrasonic welding head according to the weld print area of ​​a single second weld print includes:

[0078] The wear condition of the ultrasonic welding head is judged according to the ratio of the weld mark area of ​​the single second weld mark to the designed area of ​​the single second weld mark.

[0079] In the above technical solution, the amount by which the weld mark area of ​​the current second weld mark is reduced relative to the design area of ​​the second weld mark can be obtained based on the size relationship between the ratio of the weld mark area of ​​a single second weld mark and the design area of ​​the single second weld mark. The amount by which the weld mark area of ​​the second weld mark is reduced relative to the design area of ​​the second weld mark can more intuitively reflect the wear condition of the second weld tooth, thereby reflecting the wear condition of the ultrasonic welding head, which helps to improve the accuracy of judging the wear condition of the ultrasonic welding head.

[0080] In some embodiments, judging the wear condition of the ultrasonic horn according to the ratio of the weld area of ​​a single second weld mark to the designed area of ​​the single second weld mark includes:

[0081] The weld mark area of ​​a single second weld mark is Sx, and the design area of ​​a single second weld mark is S0. When the ratio of Sx to S0 is less than 0.2, it is determined that the service life of the ultrasonic welding head has expired.

[0082] In the above technical solution, by judging whether the ratio of the weld print area Sx of a single second weld print to the design area S0 of the single second weld print is less than 0.2, it is judged whether the service life of the ultrasonic welding head has been reached, and it is possible to judge whether the ultrasonic welding head should be replaced or repaired more simply and accurately.

[0083] In a fourth aspect, the present invention provides a battery cell, comprising: a shell, the shell being provided with an electrode terminal; an electrode assembly, the electrode assembly being arranged in the shell and comprising a tab, the tab being connected to the electrode terminal, the tab comprising a plurality of tab sheets stacked and welded together, a weld mark area being formed on the tab, the weld mark area being formed by welding with the ultrasonic welding head according to the embodiment of the first aspect, the weld mark area comprising a first weld mark and a second weld mark, the first weld mark and the second weld mark both being formed into a groove structure, the second weld mark being formed on the bottom wall of the first weld mark and extending in a long strip shape.

[0084] In the above technical solution, by welding on the multi-layered tab sheet of the tab, a first weld mark and a second weld mark are formed, both of which are groove structures. In the process of welding the multi-layered tab sheet, the multi-layered tab sheet can be compacted, and the air between the multi-layered tab sheets can be discharged, thereby reducing the gap between the multi-layered tab sheets, and reducing the problems of explosion points, collapse, welding cracks, and tab sheet cracking caused by the presence of air between the multi-layered tab sheets in the subsequent welding process; the second weld mark is formed on the bottom wall of the first weld mark and extends in a long strip shape, so that the second weld mark and the first weld mark can form a multi-level weld mark structure and the length of the second weld mark is larger In the process of welding the multi-layer tab sheets, the compaction effect between the multi-layer tab sheets can be further enhanced, thereby further reducing the gap between the multi-layer tab sheets, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer tab sheets at the second weld mark position is tighter and the gap is smaller. In this way, laser welding can be performed at the second weld mark position, which can better reduce laser welding defects and improve laser welding quality, which is helpful to improve the subsequent laser welding quality of the tabs and electrode terminals, and is beneficial to improving the service stability of the battery.

[0085] In some embodiments, the first weld stamp includes a weld stamp body and a plurality of weld stamp branches, the weld stamp body is in the shape of an elongated strip, the plurality of weld stamp branches are connected to at least one side of the width direction of the weld stamp body, and the second weld stamp is formed on the bottom wall of the weld stamp body and is consistent with the extension direction of the weld stamp body.

[0086] In the above technical solution, by making the first weld mark on the tab include a weld mark main body and multiple weld mark branches, and making the weld mark main body in the shape of a long strip, the weld mark area and weld mark length of the first weld mark can be increased, which is beneficial to enhancing the compaction uniformity and compaction effect of the multi-layer tab sheets. By forming the second weld mark on the bottom wall of the weld mark main body and in the same direction as the extension of the weld mark main body, the weld mark length and weld mark area of ​​the second weld mark can be increased, which is beneficial to enhancing the compaction effect of the second weld mark on the multi-layer tab sheets.

[0087] In some embodiments, the weld print area includes a third weld print, and the third weld print is located between adjacent first weld prints.

[0088] In the above technical solution, by arranging a third weld mark between adjacent first weld marks, the weld mark area can be further increased, so that the portion of the multi-layer tab sheet located between adjacent first weld marks can obtain the compaction effect of the third weld mark, thereby making the multi-layer tab sheet compacted more evenly, which is beneficial to improving the welding quality of subsequent welding processes.

[0089] In some embodiments, the weld print area includes a fourth weld print, and the fourth weld print is located between the first weld print and the edge of the tab.

[0090] In the above technical solution, a fourth weld mark is printed in the weld mark area between the first weld mark and the edge of the tab, so that the portion of the multi-layer tab sheet located at the edge of the first weld mark and the tab can be compacted by the fourth weld mark, thereby making the multi-layer tab sheet compacted more evenly, which is beneficial to improving the welding quality of subsequent welding processes.

[0091] In some embodiments, the multiple layers of the tab sheets are connected by ultrasonic welding, the tab is connected to the electrode terminal by laser welding to form a laser weld, and the laser weld and the second weld mark are arranged opposite to each other in the stacking direction of the multiple layers of the tab sheets.

[0092] In the above technical solution, the multi-layer tab sheets of the tab are connected by ultrasonic welding, and the ultrasonic welding forms the above-mentioned weld mark area on the tab, and the weld mark area includes the above-mentioned first weld mark and second weld mark. During ultrasonic welding, the multi-layer tab sheets can be compacted, and the gap between the multi-layer tab sheets is reduced, which facilitates the laser welding connection between the tab and the electrode terminal, reduces the occurrence of explosion points, collapse, etc. of the tab sheets during laser welding, and can improve the laser welding quality between the tab and the electrode terminal, which is beneficial to improving the service stability of the battery.

[0093] In a fifth aspect, the present invention provides a battery device, comprising: a box; and a battery cell according to an embodiment of the fourth aspect, disposed in the box.

[0094] In the above technical solution, by setting the above-mentioned battery monomer, the first weld mark and the second weld mark, both of which are groove structures, are formed by welding on the multi-layered pole tab sheets of the pole tab. In the process of welding the multi-layered pole tab sheets, the multi-layered pole tab sheets can be compacted, and the air between the multi-layered pole tab sheets can be discharged, thereby reducing the gap between the multi-layered pole tab sheets, and reducing the problems of explosion points, collapse, welding cracks, and pole tab cracking caused by the presence of air between the multi-layered pole tab sheets in the subsequent welding process; the second weld mark is formed on the bottom wall of the first weld mark and extends in a long strip shape, so that the second weld mark and the first weld mark can form a multi-level weld mark structure and the second weld mark The length of the mark is relatively large, and in the process of welding the multi-layer pole tab sheets, the compaction effect between the multi-layer pole tab sheets can be further enhanced, thereby further reducing the gap between the multi-layer pole tab sheets, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer pole tab sheets at the second weld mark position is tighter and the gap is smaller, so that laser welding can be performed at the second weld mark position, which can better reduce laser welding defects, better improve laser welding quality, help to improve the subsequent laser welding quality of the pole tab and the electrode terminal, and help to improve the service stability of the battery.

[0095] In a sixth aspect, the present invention provides an electrical device comprising the battery device of the fifth aspect embodiment.

[0096] In the above technical solution, by setting the above-mentioned battery device, the battery cells arranged in the battery device are welded on the multi-layered pole tab sheets of the pole tab to form a first weld mark and a second weld mark, both of which are groove structures. In the process of welding the multi-layered pole tab sheets, the multi-layered pole tab sheets can be compacted, and the air between the multi-layered pole tab sheets can be discharged, thereby reducing the gap between the multi-layered pole tab sheets and reducing the problems of explosion points, collapse, welding cracks, and pole tab cracking caused by the presence of air between the multi-layered pole tab sheets in the subsequent welding process; the second weld mark is formed on the bottom wall of the first weld mark and extends in a long strip shape, so that the second weld mark and the first weld mark can form a multi-level weld mark The structure and the length of the second weld mark are relatively large. During the welding process of the multi-layer pole tab sheets, the compaction effect between the multi-layer pole tab sheets can be further enhanced, thereby further reducing the gap between the multi-layer pole tab sheets, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer pole tab sheets at the second weld mark position is tighter and the gap is smaller, so that laser welding can be performed at the second weld mark position, which can better reduce laser welding defects, better improve laser welding quality, help to improve the subsequent laser welding quality of the pole tab and the electrode terminal, and help to improve the service stability of the battery.

[0097] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] 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:

[0099] Figure 1 is a schematic diagram of an ultrasonic horn according to some embodiments of the present invention;

[0100] Figure 2 yes Figure 1 A partial schematic diagram of the ultrasonic welding head;

[0101] Figure 3 yes Figure 1 A schematic diagram of another angle of the ultrasonic welding head;

[0102] Figure 4 yes Figure 1 Side view of;

[0103] Figure 5 yes Figure 4 Enlarged view of point A in the middle;

[0104] Figure 6 is a schematic diagram of welding a tab of a battery cell using an ultrasonic welding head according to some embodiments of the present invention;

[0105] Figure 7 yes Figure 6 Enlarged view of point B in the middle;

[0106] Figure 8 is a schematic diagram of a first weld mark and a second weld mark on a workpiece sample according to some embodiments of the present invention;

[0107] Figure 9 is a schematic diagram of a battery cell according to some embodiments of the present invention;

[0108] Figure 10 is a schematic diagram of a battery device according to some embodiments of the present invention;

[0109] Figure 11 is a schematic diagram of an electrical device according to some embodiments of the present invention.

[0110] Reference numerals:

[0111] 100. Ultrasonic welding head;

[0112] 10. Welding head body; 11. Welding surface; 12. Tooth end surface; 13. Accommodation groove;

[0113] 20. First welding tooth structure; 21. First welding tooth; 211. Welding tooth body; 212. Welding tooth branch; 22. Welding tooth end face; 23. Third welding tooth; 24. Fourth welding tooth;

[0114] 30. Second welding tooth structure; 31. Second welding tooth;

[0115] 200, battery device; 201, box;

[0116] 40. Battery cells;

[0117] 41. Housing; 401. Electrode terminal; 42. Tab; 43. Welding area; 44. First welding area; 45. Second welding area; 46. Electrode assembly;

[0118] 50. Sample workpiece;

[0119] 300. Electrical device; 60. Vehicle body. DETAILED DESCRIPTION

[0120] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0121] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification and application of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having," as well as any variations thereof, in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," etc., in the specification and claims of the present invention and the accompanying drawings are used to distinguish between different objects, rather than to describe a specific order or a primary-secondary relationship.

[0122] Reference to an "embodiment" in the present invention means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. 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.

[0123] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0124] The term "and / or" in this disclosure 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, or B exists alone. Furthermore, the character " / " in this disclosure generally indicates that the related objects are in an "or" relationship.

[0125] In the embodiments of the present invention, identical reference numerals denote identical components, and for the sake of brevity, detailed descriptions of identical components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of the present invention, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings, are merely illustrative and do not constitute any limitation on the present invention.

[0126] The term “plurality” used in the present invention refers to two or more (including two).

[0127] In the embodiments of the present invention, unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form a new technical solution.

[0128] In the embodiments of the present invention, unless otherwise specified, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0129] In embodiments of the present invention, a battery apparatus may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or parallel via a busbar. For example, a battery cell assembly is typically formed by arranging multiple battery cells; a battery cell assembly may be a battery module, which is formed by arranging and securing multiple battery cells to form a single module. For example, a battery module may be formed by bundling multiple battery cells using cable ties.

[0130] The battery device may be a battery pack, which includes a housing and one or more battery cell assemblies housed within the housing. The battery cell assemblies may be battery modules, which may be housed within the housing by securing the battery module within the housing. Alternatively, the battery cell assembly may be housed within the housing by directly securing multiple battery cells to the housing.

[0131] In an embodiment of the present invention, the housing may include a first housing and a second housing. The first housing and the second housing engage to form an enclosed space within the housing to accommodate the battery cell assembly. Enclosed herein means covered or closed, and may be sealed or unsealed. The first housing may be a top cover or a bottom plate. For example, the housing may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame to form an enclosed space within the housing to accommodate the battery cell assembly.

[0132] In an embodiment of the present invention, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0133] In the embodiments of the present invention, the battery cells may be secondary batteries, which are defined as batteries that can be recharged after discharge to activate the active material and continue to be used. The battery cells may be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like, although the embodiments of the present invention do not limit this. The battery cells may be cylindrical, flat, rectangular, or in other shapes, although the embodiments of the present invention do not limit this. Battery cells are generally categorized into three types based on packaging: cylindrical, prismatic, and soft-pack. The embodiments of the present invention do not limit this either.

[0134] A battery cell is the smallest energy unit in a battery device. It includes a housing and an electrode assembly disposed within the housing. The electrode assembly is the component within the battery cell where the electrochemical reaction occurs. The housing may contain one or more electrode assemblies. The electrode assembly is primarily formed by winding or stacking positive and negative electrode sheets, and a separator is typically provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly, while the portions of the positive and negative electrode sheets without active material each constitute a tab.

[0135] The positive electrode sheet may include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.

[0136] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector.

[0137] As an example, the positive electrode current collector may be a metal foil or a composite current collector.

[0138] The negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.

[0139] As an example, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0140] As an example, the negative electrode current collector may be a metal foil, a foamed metal, or a composite current collector.

[0141] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. As the application of power batteries continues to expand, market demand is also growing.

[0142] In related technologies, to further increase the energy density of battery cells, the adapter used to connect the tabs to the electrode terminals is eliminated. The tabs of the electrode assembly are directly connected to the electrode terminals on the battery cell housing without an adapter. The process for connecting the tabs and electrode terminals is as follows: The multiple layers of tab sheets are first ultrasonically pre-welded to form a single, integrated tab. The tabs are then laser-welded to the electrode terminals.

[0143] However, laser welding of the tabs to the electrode terminals in related technologies is prone to weld defects such as cracking and collapse. Furthermore, the tabs are prone to numerous cracks and other weld defects. This poor laser welding process affects the battery's service stability. Therefore, improving the quality of laser welding between the tabs and the electrode terminals, and thus enhancing the battery's service stability, is a pressing technical issue.

[0144] Based on this, the present invention provides an ultrasonic horn, comprising: a horn body, a first welding tooth structure, and a second welding tooth structure. The horn body has a welding surface, the first welding tooth structure is protruding from the welding surface, and the second welding tooth structure is protruding from a side of the first welding tooth structure away from the welding surface. The second welding tooth structure includes at least one second welding tooth, and the second welding tooth extends in an elongated strip shape in the direction of the welding surface.

[0145] In the above-mentioned ultrasonic welding head, by adding a second welding tooth structure on the side of the first welding tooth structure of the ultrasonic welding head away from the welding surface, the multi-layer foil can be pressed at multiple levels, the compaction effect of the first welding tooth structure and the second welding tooth structure on the welding of the multi-layer foil can be enhanced, the gap between the multi-layer foil can be reduced, and it is helpful to improve the welding quality of the subsequent welding process. For example, when the subsequent welding process is a laser welding process, the welding defects such as explosion points and collapse generated during the laser welding process can be reduced, and welding cracks can also be reduced. Moreover, since the gap between the multi-layer foils is reduced, it is beneficial to improve the heat dissipation uniformity of the laser welding joint, thereby helping to improve the problem of foil cracking caused by excessive local stress in the foil; and, by setting the second welding tooth to It extends in a long strip shape in the extension direction of the welding surface, which can increase the contact length between the second welding tooth structure and the surface of the multi-layer foil, further enhance the compaction effect between the multi-layer foil, thereby further reducing the gap between the multi-layer foil, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer foils at the welding mark position corresponding to the second welding tooth is tighter and the gap is smaller. In this way, laser welding can be performed at the welding mark position corresponding to the second welding tooth, which can better reduce laser welding defects and better improve laser welding quality. When the ultrasonic welding head is used to weld the multi-layer foil of the pole ear, it helps to improve the subsequent laser welding quality of the pole ear and the electrode terminal, which is beneficial to improving the service stability of the battery.

[0146] The battery device disclosed in the embodiments of the present invention can be used in electrical equipment that uses the battery device as a power source or various energy storage systems that use the battery device as an energy storage element. In addition to being used in vehicles, the battery device can also be used in, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric cars, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0147] The power-consuming device disclosed in the embodiments of the present invention may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device is provided inside the vehicle, and the battery device may be provided at the bottom, head or tail of the vehicle. The battery device may be used to power the vehicle, for example, the battery device may serve as an operating power source for the vehicle. The vehicle may further include a controller and a motor, and the controller is used to control the battery device to power the motor, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present invention, the battery device may serve not only as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0148] Reference below Figures 1-9 An ultrasonic horn 100 according to an embodiment of the present invention is described.

[0149] refer to Figure 1-Figure 3 In a first aspect, the present invention provides an ultrasonic horn 100 comprising a horn body 10, a first welding tooth structure 20, and a second welding tooth structure 30. The horn body 10 has a welding surface 11, the first welding tooth structure 20 protruding from the welding surface 11, and the second welding tooth structure 30 protruding from a side of the first welding tooth structure 20 away from the welding surface 11. The second welding tooth structure 30 includes at least one second welding tooth 31, which extends in an elongated strip shape in the direction of extension of the welding surface 11.

[0150] The ultrasonic horn 100 is the part of the ultrasonic welding device that contacts the multi-layer foil during the welding process. The ultrasonic horn 100 typically receives high-frequency vibration energy generated by a transducer, which is then modulated in amplitude by a horn and ultimately transmitted to the ultrasonic horn 100. The ultrasonic horn 100 then concentrates the received vibration energy on the joining portion of the multi-layer foil. Under pressure, friction is converted into heat energy, welding the parts together.

[0151] The welding head body 10 has a welding surface 11, which can be a plane where the welding head body 10 contacts the multi-layer foil. For example, the welding head body 10 can be made of a material with good thermal conductivity and corrosion resistance, such as aluminum alloy, titanium alloy or stainless steel.

[0152] The first welding tooth structure 20 is protruding from the welding surface 11 , which means that the first welding tooth structure 20 is provided on the welding surface 11 and protrudes relative to the welding surface 11 .

[0153] The first welding tooth structure 20 is provided on the welding surface 11. The first welding tooth 21 can effectively transmit vibration energy to the welding part, and simultaneously transmit pressure and amplitude. Under pressure, friction is converted into heat energy to weld the welding parts together.

[0154] The second welding tooth structure 30 is positioned protruding from the first welding tooth structure on the side away from the welding surface 11. The second welding tooth structure 30 compacts the multi-layer foil during ultrasonic welding, reducing gaps between the layers and improving the quality of subsequent welding processes. If gaps remain between the layers after ultrasonic welding, uneven heat dissipation can occur during subsequent welding processes, leading to localized excessive pressure and cracking of the multi-layer foil.

[0155] For example, the direction in which the first welding tooth structure protrudes from the welding surface 11 can refer to the direction e3 in the figure.

[0156] The second welding tooth structure 30 includes at least one second welding tooth 31. The second welding tooth structure 30 may include one second welding tooth 31, or the second welding tooth structure 30 may include multiple second welding teeth 31. By having the second welding tooth structure 30 include at least one second welding tooth 31 and having the second welding teeth 31 extend in the direction of the welding surface 11 in an elongated strip shape, the contact length between the second welding tooth structure 30 and the surface of the multi-layer foil is increased, thereby enhancing the compaction effect of the second welding tooth structure 30 on the surface of the multi-layer foil.

[0157] In the above technical solution, by adding a second welding tooth structure 30 on the side of the first welding tooth structure 20 of the ultrasonic welding head 100 away from the welding surface 11, the multi-layer foil can be pressed at multiple levels, the compaction effect of the first welding tooth structure 20 and the second welding tooth structure 30 on the welding of the multi-layer foil can be enhanced, the gap between the multi-layer foil can be reduced, and the welding quality of the subsequent welding process can be improved. For example, when the subsequent welding process is a laser welding process, the welding defects such as explosion points and collapse generated during the laser welding process can be reduced, and the welding cracks can also be reduced. Moreover, since the gap between the multi-layer foils is reduced, it is beneficial to improve the heat dissipation uniformity of the laser welding joint, thereby improving the problem of foil cracking caused by excessive local stress in the foil; and, by setting the second welding tooth 31 to be at the welding The surface 11 extends in a long strip shape in the extension direction, which can increase the contact length between the second welding tooth structure 30 and the surface of the multi-layer foil, further enhance the compaction effect between the multi-layer foil, thereby further reducing the gap between the multi-layer foil, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer foils at the welding position corresponding to the second welding tooth 31 is tighter and the gap is smaller. In this way, laser welding can be performed at the welding position corresponding to the second welding tooth 31, which can better reduce laser welding defects and better improve laser welding quality. When the ultrasonic welding head 100 is used to weld the multi-layer foil of the pole ear 42, it helps to improve the subsequent laser welding quality of the pole ear 42 and the electrode terminal 401, which is beneficial to improving the service stability of the battery.

[0158] refer to Figure 1-Figure 5 In some embodiments, both ends of the second welding tooth 31 in the length direction extend to the opposite ends of the welding surface 11 respectively.

[0159] For example, both ends of the second welding tooth 31 in the length direction may extend to both ends of the welding surface 11 in the length direction, respectively.

[0160] In the above technical solution, by extending the two ends of the second welding tooth 31 in the length direction to the opposite ends of the welding surface 11, the length of the second welding tooth 31 can be increased. When ultrasonic welding is performed, the contact length of the second welding tooth structure 30 with the surface of the multi-layer foil is longer, further enhancing the compaction effect of the second welding tooth structure 30 on the multi-layer foil. Moreover, since the length of the second welding tooth 31 is longer, the weld mark corresponding to the second welding tooth 31 is longer. In this way, when laser welding is performed on the weld mark position corresponding to the second welding tooth 31 in the subsequent welding process, the length of the laser welding can be made longer, which is beneficial to improving the reliability and stability of the subsequent welding connection. For example, after the ultrasonic welding head 100 is used to weld the multi-layer foil of the pole tab 42, when the subsequent welding process is a laser welding process, the laser weld between the pole tab 42 and the electrode terminal 401 can be made longer, and the laser weld between the pole tab 42 and the electrode terminal 401 can be made longer, which helps to improve the stability and reliability of the welding connection between the pole tab 42 and the electrode terminal 401.

[0161] refer to Figure 2-Figure 3 In some embodiments, the second welding tooth 31 extends along the length direction of the welding surface 11 .

[0162] For example, the welding surface 11 may be rectangular.

[0163] For example, the length direction of the welding surface 11 can refer to the e1 direction in the drawings.

[0164] In the above technical solution, by extending the second welding tooth 31 along the length direction of the welding surface 11, the space in the length direction of the welding surface 11 can be utilized, and the length of the second welding tooth 31 can be increased. When ultrasonic welding is performed, the contact length between the second welding tooth structure 30 and the surface of the multi-layer foil is longer, thereby enhancing the compaction effect of the second welding tooth structure 30 on the multi-layer foil.

[0165] refer to Figure 2-Figure 3 In some embodiments, the second welding teeth 31 extend along the width direction of the welding surface 11 .

[0166] For example, the welding surface 11 may be rectangular.

[0167] For example, the width direction of the welding surface 11 can refer to the direction e2 in the drawings.

[0168] In the above technical solution, by extending the second welding teeth 31 along the width direction of the welding surface 11, the space in the width direction of the welding surface 11 can be utilized, and it is also beneficial to increase the number of arrangement of the second welding teeth 31. When ultrasonic welding is performed, the contact area between the second welding tooth structure 30 and the surface of the multi-layer foil is larger, thereby enhancing the compaction effect of the second welding tooth structure 30 on the multi-layer foil.

[0169] refer to Figure 2-Figure 3 In some embodiments, the second welding tooth 31 extends along a straight line.

[0170] In the above technical solution, by providing the second welding tooth 31 extending along a straight line, the second welding tooth 31 can be made simple and convenient to process and form; and the welding mark corresponding to the second welding tooth 31 extending in a straight line also basically extends along a straight line, so that in the subsequent welding process, the welding connection can be performed along a straight line, making the design of the subsequent welding process relatively simple.

[0171] refer to Figure 2-Figure 3 In some embodiments, a plurality of second welding teeth 31 are arranged at intervals.

[0172] For example, the second welding teeth 31 may be two, three, four, etc., arranged at intervals.

[0173] In the above technical solution, by setting a plurality of second welding teeth 31 arranged at intervals, the plurality of second welding teeth 31 can compact a plurality of different positions of a plurality of multi-layer foils, thereby reducing the gaps between the plurality of different positions of the multi-layer foils, which helps to improve the quality of subsequent welding processes.

[0174] refer to Figure 2-Figure 3 In some embodiments, a plurality of second welding teeth 31 are arranged side by side along the width direction of the second welding teeth 31 .

[0175] The width direction of the second welding tooth 31 is perpendicular to the extension direction of the second welding tooth 31 .

[0176] In the above technical solution, by arranging multiple second welding teeth 31 side by side along the width direction of the second welding teeth 31, the contact area between the second welding tooth structure 30 and the surface of the multi-layer foil can be increased, and the compaction effect between the multi-layer foils can be enhanced, so that the gaps at different positions in the width direction of the second welding teeth 31 of the multi-layer foil can be reduced, which helps to improve the quality of subsequent welding processes.

[0177] refer to Figure 2-Figure 3 In some embodiments, the second welding teeth 31 extend along the length direction of the welding surface 11 , and a plurality of second welding teeth 31 are arranged along the width direction of the welding surface 11 .

[0178] In the above technical solution, by extending the second welding tooth 31 along the length direction of the welding surface 11, the space in the length direction of the welding surface 11 can be fully utilized, so that the extension length of the second welding tooth 31 is longer, and multiple second welding teeth 31 are arranged along the width direction of the welding surface 11. The distribution of multiple second welding teeth 31 is relatively uniform, which can increase the contact length and contact area between the second welding tooth structure 30 and the surface of the multi-layer foil, so that the second welding tooth structure 30 contacts the surface of the multi-layer foil more evenly, and the heat between the multi-layer foil is more evenly distributed, which can enhance the compaction effect between the multi-layer foil.

[0179] refer to Figure 2 In some embodiments, in the arrangement direction of the plurality of second welding teeth 31 , the spacing between two adjacent second welding teeth 31 is d1 , the maximum width of the second welding teeth 31 is W2 , and W2 < d1 .

[0180] When the width of the second weld tooth 31 is uniform in the direction in which the second weld tooth 31 protrudes from the weld surface 11, the width of the second weld tooth 31 is the maximum width of the second weld tooth 31. When the width of the second weld tooth 31 varies in the direction in which the second weld tooth 31 protrudes from the weld surface 11, the width of the second weld tooth 31 at the point of maximum width is the maximum width of the second weld tooth 31.

[0181] In the above technical solution, by making the maximum width W2 of the second welding tooth 31 smaller than the spacing d1 between two adjacent second welding teeth 31, the width of the second welding tooth 31 can be made smaller. Under a certain welding pressure, the second welding tooth 31 can generate a greater pressure on the multi-layer foil, further enhancing the compaction effect of the second welding tooth 31 on the multi-layer foil.

[0182] refer to Figure 2 In some embodiments, the ratio of W2 to d1 ranges from 0.2 to 0.8.

[0183] For example, the ratio of the maximum width W2 of the second welding teeth 31 to the distance d1 between two adjacent second welding teeth 31 may be 0.2, 0.4, 0.6, 0.8, etc.

[0184] In the above technical solution, by setting the ratio of the maximum width W2 of the second welding tooth 31 to the distance d1 between two adjacent second welding teeth 31 in the range of 0.2 to 0.8, it is possible to generate a greater pressure on the multi-layer foil under a certain welding pressure while making the contact area between the second welding tooth structure 30 and the surface of the multi-layer foil larger, thereby enhancing the compaction effect between the multi-layer foils.

[0185] refer to Figure 2In some embodiments, in the arrangement direction of the plurality of second welding teeth 31 , the minimum distance between the second welding teeth 31 and the edge of the welding surface 11 is d2 , the width of the second welding teeth 31 is W2 , and d2 > W2 .

[0186] In the above technical solution, by making the minimum distance d2 between the second welding tooth 31 and the edge of the welding surface 11 greater than the maximum width W2 of the second welding tooth 31, the second welding tooth 31 can be made to have a certain distance from the edge of the welding surface 11, so that the second welding tooth 31 can better compact the multi-layer foil, thereby enhancing the compaction effect between the multi-layer foils.

[0187] refer to Figure 7 In some embodiments, the cross-section of the second weld tooth 31 is a second cross-section, and the second cross-section has a tapered portion, which extends to the side of the second weld tooth 31 away from the welding surface 11. In the direction from the welding surface 11 to the second weld tooth 31, the width of the tapered portion gradually decreases.

[0188] The cross section of the second welding tooth 31 is obtained by cutting the second welding tooth 31 along a plane perpendicular to the length direction of the second welding tooth 31 .

[0189] The width of the tapered portion refers to the dimension of the tapered portion in the width direction of the second welding tooth 31 .

[0190] The tapered portion may be formed by a portion of the second welding tooth 31 or the entire second welding tooth 31 .

[0191] In the above technical solution, by gradually reducing the width of the tapered portion of the second welding tooth 31 in the direction from the welding surface 11 to the second welding tooth 31, the second welding tooth 31 can exert a greater pressure on the multi-layer foil under a certain welding pressure, thereby enhancing the compaction effect of the second welding tooth 31 on the multi-layer foil.

[0192] refer to Figure 2-Figure 7 In some embodiments, in the extension direction of the second welding teeth 31 , at least part of the cross-sectional areas of the second welding teeth 31 are the same.

[0193] A cross section of the second welding tooth 31 obtained by cutting the second welding tooth 31 along a plane perpendicular to the length direction of the second welding tooth 31 is a cross section of the second welding tooth 31 .

[0194] For example, in the extending direction of the second welding tooth 31 , the cross-sectional areas of part of the second welding tooth 31 may be the same, or the cross-sectional areas of all the second welding teeth 31 may be the same.

[0195] In the above technical solution, by making the cross-sectional area of ​​at least part of the second welding tooth 31 in the extension direction the same, the second welding tooth 31 can maintain a relatively uniform compaction of the multi-layer foil in the extension direction, thereby enhancing the compaction effect of the second welding tooth 31 on the multi-layer foil, and the width dimension of the weld mark corresponding to the second welding tooth 31 in its extension direction is relatively uniform, which facilitates the subsequent welding process at the weld mark corresponding to the second welding tooth 31.

[0196] refer to Figure 7 In some embodiments, the cross section of the second welding tooth 31 is arcuate, circular or elliptical.

[0197] For example, the cross section of the second welding tooth 31 may be one of an arcuate shape, a circular shape, and an elliptical shape.

[0198] In the above technical solution, by setting the cross section of the second welding tooth 31 to an arcuate, circular or elliptical shape, the surface of the second welding tooth 31 is less likely to scratch the multi-layer foil when in contact with the foil.

[0199] refer to Figure 2 In some embodiments, the second welding tooth 31 includes a tooth portion.

[0200] For example, the second welding tooth 31 includes one tooth portion, which may be the second tooth portion formed by the second welding tooth 31 itself.

[0201] In the above technical solution, by making the second welding tooth 31 include one tooth portion, the structure of the second welding tooth 31 can be simplified and convenient for processing and forming.

[0202] refer to Figure 2-Figure 7 In some embodiments, the second welding tooth 31 includes a plurality of teeth, and the surface of the tooth away from the welding surface 11 constitutes a tooth end face 12. The plurality of teeth are respectively a first tooth portion to an mth tooth portion arranged in sequence along the protruding direction of the second welding tooth 31, the nth tooth portion is arranged on the tooth end face 12 of the (n-1)th tooth portion, and the projection of the nth tooth portion on the tooth end face 12 of the (n-1)th tooth portion is located within the tooth end face 12 of the (n-1)th tooth portion, and 2≤n≤m.

[0203] For example, the value of n can be 2, 3, 4, 5, etc., the value of m can be 2, 3, 4, 5, etc., and 2≤n≤m is satisfied.

[0204] In the above technical solution, the second welding tooth 31 is provided to include 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 second welding tooth 31, the nth tooth portion is provided on the tooth portion end face 12 of the (n-1)th tooth portion, and the projection of the tooth portion end face 12 of the (n-1)th tooth portion is located within the tooth portion end face 12 of the (n-1)th tooth portion, so that the portion of the tooth portion end face 12 of the (n-1)th tooth portion away from the welding surface 11 that exceeds the nth tooth portion can be formed as a welding pressing surface, so that when the ultrasonic welding head 100 welds the welding material, each tooth portion can compact and press the multi-layer foil material, so as to achieve multi-layer pressing and compacting of the welding material, further enhance the compaction effect between the multi-layer foil materials, and can better reduce the gap between the multi-layer foil materials, thereby reducing the welding energy loss caused by the excessive gap between the layers of the multi-layer foil materials and the impact on the subsequent welding process, which helps to better improve the welding quality of the subsequent welding process.

[0205] refer to Figure 2-Figure 3 In some embodiments, the first welding tooth structure 20 includes a first welding tooth 21, a side surface of the first welding tooth 21 away from the welding surface 11 constitutes a welding tooth end surface 22, a second welding tooth 31 is arranged on the welding tooth end surface 22, and a projection of the second welding tooth 31 on the welding tooth end surface 22 is located within the welding tooth end surface 22.

[0206] In the above technical solution, by arranging the second welding tooth 31 within the welding tooth end face 22 of the first welding tooth 21, a clear boundary can be formed between the second welding tooth 31 and the first welding tooth 21, which is more conducive to forming a multi-level welding tooth structure with the first welding tooth 21 and the second welding tooth 31, and is more conducive to achieving multi-level pressing of multi-layer foil, and the compaction effect is better.

[0207] refer to Figure 5 In some embodiments, in the protruding direction of the first welding tooth 21 relative to the welding surface 11, the tooth height of the first welding tooth 21 is h1, the tooth height of the second welding tooth 31 is h2, and the ratio of h2 to h1 ranges from 0.3 to 0.8.

[0208] The protruding direction of the first welding tooth 21 relative to the welding surface 11 can refer to the direction e3 in the accompanying drawings.

[0209] For example, the ratio of h2 to h1 can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

[0210] In the above technical solution, by making the ratio of the tooth height h2 of the second welding tooth 31 to the tooth height h1 of the first welding tooth 21 not less than 0.3, the second welding tooth 31 can have a higher tooth height, so that the second welding tooth 31 has a better compaction effect on the multi-layer foil; and, by making the ratio of the tooth height h2 of the second welding tooth 31 to the tooth height h1 of the first welding tooth 21 not greater than 0.8, the second welding tooth 31 will not affect the welding effect of the first welding tooth 21 due to excessive tooth height. In this way, it can be better avoided that the contact between the first welding tooth 21 and the multi-layer foil is affected by the excessive tooth height of the second welding tooth 31, so that when the ultrasonic welding head 100 welds the multi-layer foil, the first welding tooth 21 and the second welding tooth 31 can both fully contact the multi-layer foil, so that the contact area between the first welding tooth 21 and the second welding tooth 31 and the multi-layer foil is larger, which can improve the compaction effect of the multi-layer foil.

[0211] refer to Figure 5 In some embodiments, in the protruding direction of the first welding tooth 21 relative to the welding surface 11, the tooth height of the first welding tooth 21 is h1, and the value range of h1 is 0.2mm~0.6mm.

[0212] For example, the tooth height h1 of the first welding tooth 21 may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc.

[0213] In the above technical solution, by making the tooth height h2 of the second welding tooth 31 not less than 0.2 mm, the second welding tooth 31 can have a higher tooth height, so that the second welding tooth 31 has a better compaction effect on the multi-layer foil; and, by making the tooth height h2 of the second welding tooth 31 not greater than 0.6 mm, the second welding tooth 31 will not affect the welding effect of the first welding tooth 21 due to the excessive tooth height. In this way, it can be better avoided that the contact between the first welding tooth 21 and the multi-layer foil is affected by the excessive tooth height of the second welding tooth 31, so that when the ultrasonic welding head 100 welds the multi-layer foil, the first welding tooth 21 and the second welding tooth 31 can fully contact the multi-layer foil, so that the contact area between the first welding tooth 21 and the second welding tooth 31 and the multi-layer foil is larger, which can improve the compaction effect on the multi-layer foil.

[0214] refer to Figure 2 In some embodiments, the weld tooth end face 22 is a plane.

[0215] In the above technical solution, by setting the welding tooth end surface 22 of the first welding tooth 21 to be a plane, the contact area between the first welding tooth 21 and the multi-layer foil can be increased, and the compaction area of ​​the multi-layer foil can be increased, which is conducive to improving the compaction effect of the multi-layer foil.

[0216] refer to Figure 2-Figure 3In some embodiments, the first welding tooth structure 20 includes a third welding tooth 23 , and the third welding tooth 23 is disposed between adjacent first welding teeth 21 .

[0217] For example, the third welding tooth 23 is located between adjacent first welding teeth 21 , or the third welding tooth 23 is located between two adjacent first welding teeth 21 .

[0218] In the above technical solution, by arranging the third welding teeth 23 between adjacent first welding teeth 21, the portion of the multi-layer foil located between adjacent first welding teeth 21 can be compacted by the third welding teeth 23, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of subsequent welding processes.

[0219] refer to Figure 2-Figure 3 In some embodiments, the first welding tooth structure 20 includes a fourth welding tooth 24 , which is disposed between the first welding tooth 21 and an edge of the welding surface 11 .

[0220] For example, the fourth welding tooth 24 may be disposed between the first welding tooth 21 and an edge of the welding surface 11 extending along the length direction of the welding surface 11 .

[0221] In the above technical solution, by arranging the fourth welding tooth 24 at the edge of the first welding tooth 21 and the welding surface 11, the portion of the multi-layer foil located at the edge of the first welding tooth 21 and the welding surface 11 can be compacted by the fourth welding tooth 24, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of the subsequent welding process; and the fourth welding tooth 24 can also reduce the situation where the edge of the first welding tooth 21 scratches the multi-layer foil.

[0222] refer to Figure 2-Figure 3 In some embodiments, the first welding tooth 21 includes a welding tooth body 211 and a plurality of welding tooth branches 212. The welding tooth body 211 extends in a long strip shape in the extension direction of the welding surface 11. The plurality of welding tooth branches 212 are connected to at least one side of the width direction of the welding tooth body 211. The second welding tooth 31 is provided on the welding tooth body 211 and is consistent with the extension direction of the welding tooth body 211.

[0223] For example, the first welding tooth 21 may include two, three, four, five or other welding tooth branches 212 .

[0224] Multiple welding tooth branches 212 are connected to at least one side of the welding tooth body 211 in the width direction. Multiple welding tooth branches 212 can be connected to one side of the welding tooth body 211 in the width direction, or multiple welding tooth branches 212 can be connected to both sides of the welding tooth body 211 in the width direction.

[0225] In the above technical solution, by setting the first welding tooth 21 to include a welding tooth body 211 and multiple welding tooth branches 212 and the multiple welding tooth branches 212 are connected to at least one side of the width direction of the welding tooth body 211, the contact area between the first welding tooth 21 and the multi-layer foil can be increased, which is beneficial to enhancing the compaction uniformity and compaction effect of the multi-layer foil. By setting the second welding tooth 31 on the welding tooth body 211 and consistent with the extension direction of the welding tooth body 211, the contact length of the second welding tooth structure 30 with the surface of the multi-layer foil is increased, and the compaction effect of the second welding tooth 31 on the multi-layer foil is enhanced.

[0226] refer to Figure 2 In some embodiments, the width of the second welding tooth 31 is W2, the width of the welding tooth body 211 is W1, and W2≤W1.

[0227] For example, the width direction of the second welding tooth 31 and the width direction of the welding tooth body 211 can refer to the direction e2 in the drawings.

[0228] In the above technical solution, by making the width W2 of the second welding tooth 31 less than or equal to the width W1 of the welding tooth body 211, the width of the welding tooth body 211 of the first welding tooth 21 can be made larger, thereby providing a sufficient support area for the second welding tooth 31, and making the contact area between the first welding tooth 21 and the multi-layer foil larger, and further enhancing the compaction effect of the second welding tooth 31 on the multi-layer foil.

[0229] refer to Figure 2 In some embodiments, the ratio of W2 to W1 ranges from 0.5 to 0.9.

[0230] For example, the ratio of the width W2 of the second welding tooth 31 to the width W1 of the welding tooth body 211 may be 0.5, 0.7, 0.9, etc.

[0231] In the above technical solution, by making the ratio of the width W2 of the second welding tooth 31 to the width W1 of the welding tooth body 211 not less than 0.5, the contact area between the second welding tooth 31 and the multi-layer foil material can be larger, the compaction range can be larger, and the compaction effect can be better. In addition, by making the ratio of the width W2 of the second welding tooth 31 to the width W1 of the welding tooth body 211 not greater than 0.9, a multi-level welding tooth structure can be better formed between the second welding tooth 31 and the first welding tooth 21, which is more conducive to multi-level pressing of the multi-layer foil material and has a better compaction effect.

[0232] refer to Figure 2-Figure 3In some embodiments, the first welding tooth structure 20 includes a third welding tooth 23, and a plurality of accommodating grooves 13 are defined between two adjacent first welding teeth 21. The plurality of accommodating grooves 13 are arranged at intervals along the extension direction of the welding tooth body 211. The welding tooth branch 212 is located between two adjacent accommodating grooves 13, and the third welding tooth 23 is located in the accommodating groove 13.

[0233] For example, each receiving groove 13 may receive the third welding tooth 23 , or some of the receiving grooves 13 may receive the third welding tooth 23 .

[0234] In the above technical solution, a plurality of accommodating grooves 13 are defined between two adjacent first welding teeth 21, the plurality of accommodating grooves 13 are arranged at intervals along the extension direction of the welding tooth body 211, and a third welding tooth 23 is provided in the accommodating groove 13. This can further increase the contact area between the first welding tooth structure 20 and the multi-layer foil, so that the portion of the multi-layer foil located between adjacent first welding teeth 21 can obtain the compaction effect of the third welding tooth 23, thereby making the multi-layer foil more evenly compacted, which is beneficial to improving the welding quality of subsequent welding processes.

[0235] refer to Figure 2-Figure 3 In some embodiments, the third welding tooth 23 is in a prism shape.

[0236] In the above technical solution, by making the third welding tooth 23 into a prism shape, the contact area between the third welding tooth 23 and the multi-layer foil can be larger and the compaction effect is better. The contact surface between the third welding tooth 23 and the multi-layer foil can form a welding pressure surface, providing a larger heat transfer area, which is conducive to reducing welding cracks caused by local stress concentration in the multi-layer foil.

[0237] refer to Figure 2-Figure 3 In some embodiments, the first welding tooth structure 20 includes a fourth welding tooth 24, which is arranged between the first welding tooth 21 and the edge of the welding surface 11. There are multiple fourth welding teeth 24, and the multiple fourth welding teeth 24 located on the same side of the first welding tooth 21 are arranged at intervals along the extension direction of the welding tooth body 211.

[0238] In the above technical solution, by arranging the fourth welding tooth 24 at the edge of the first welding tooth 21 and the welding surface 11, the portion of the multi-layer foil located at the edge of the first welding tooth 21 and the welding surface 11 can be compacted by the fourth welding tooth 24, so that the multi-layer foil is compacted more evenly, which is beneficial to improving the welding quality of the subsequent welding process; and the fourth welding tooth 24 can also reduce the situation where the edge of the first welding tooth 21 scratches the multi-layer foil; and, by arranging the fourth welding teeth 24 to be spaced apart along the extension direction of the welding tooth body 211, the fourth welding teeth 24 can compact the multi-layer foil more evenly and the compaction effect is better.

[0239] refer to Figure 1-Figure 7 In a second aspect, the present invention provides an ultrasonic welding device, comprising: an ultrasonic welding head 100 according to an embodiment of the first aspect.

[0240] In the above technical solution, by setting the above-mentioned ultrasonic welding head 100, by adding the second welding tooth structure 30 on the side of the first welding tooth structure 20 of the ultrasonic welding head 100 away from the welding surface 11, the multi-layer foil can be pressed at multiple levels, the compaction effect of the first welding tooth structure 20 and the second welding tooth structure 30 on the welding of the multi-layer foil can be enhanced, the gap between the multi-layer foil can be reduced, and the welding quality of the subsequent welding process can be improved. For example, when the subsequent welding process is a laser welding process, the welding defects such as explosion points and collapse generated during the laser welding process can be reduced, and the welding cracks can also be reduced. Moreover, since the gap between the multi-layer foil is reduced, it is beneficial to improve the heat dissipation uniformity of the laser welding joint, thereby improving the problem of foil cracking caused by excessive local stress in the foil; and, by 31 is configured to extend in a long strip shape in the extension direction of the welding surface 11, which can increase the contact length between the second welding tooth structure 30 and the surface of the multi-layer foil, further enhance the compaction effect between the multi-layer foil, thereby further reducing the gap between the multi-layer foil, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, since the compaction between the multi-layer foils at the welding mark position corresponding to the second welding tooth 31 is tighter and the gap is smaller, laser welding can be performed at the welding mark position corresponding to the second welding tooth 31, which can better reduce laser welding defects and better improve laser welding quality. When the ultrasonic welding head 100 is used to weld the multi-layer foil of the pole ear 42, it helps to improve the subsequent laser welding quality of the pole ear 42 and the electrode terminal 401, which is beneficial to improving the service stability of the battery.

[0241] refer to Figure 8 In a third aspect, the present invention provides a wear detection method for an ultrasonic horn 100, wherein the ultrasonic horn 100 is the ultrasonic horn 100 according to the embodiment of the first aspect. The wear detection method for the ultrasonic horn 100 includes:

[0242] The ultrasonic welding head 100 is used to perform ultrasonic pre-welding on the workpiece sample. The weld mark corresponding to the second weld tooth 31 on the workpiece sample is the second weld mark 45.

[0243] Identifying a second weld mark 45 formed on the workpiece sample;

[0244] Calculating the weld area of ​​the single second weld mark 45;

[0245] The wear condition of the ultrasonic horn 100 is determined based on the weld mark area of ​​the single second weld mark 45 .

[0246] The workpiece sample may be a multi-layer foil.

[0247] The weld mark on the workpiece sample corresponding to the second weld tooth 31 is a second weld mark 45. The shape and area of ​​the second weld mark 45 depend on the shape and size of the second weld tooth 31. The weld area of ​​the second weld mark 45 can reflect the wear of the second weld tooth 31, and thus the wear of the ultrasonic horn 100.

[0248] For example, the second weld mark 45 formed on the workpiece sample can be identified manually or by a machine.

[0249] In the above technical solution, by calculating the single weld mark area of ​​the second weld mark 45 corresponding to the second weld tooth 31 formed on the workpiece sample, the wear of the second weld tooth 31 in the ultrasonic welding head 100 can be judged more intuitively and accurately, so that the ultrasonic welding head 100 can be replaced or repaired in time, reducing the occurrence of poor welding and poor compaction effects of multi-layer foils caused by the wear of the ultrasonic welding head 100, which affects the subsequent welding process, and helps to improve the compaction effect of the ultrasonic welding head 100 on the multi-layer foil.

[0250] In some embodiments, identifying the second weld mark 45 formed on the workpiece sample includes:

[0251] Collecting a weld mark image of the workpiece sample to form a weld mark side;

[0252] A second weld mark 45 is identified in the weld mark image.

[0253] For example, a camera may be used to capture a weld mark image of the side of the workpiece sample where the weld mark is formed. The camera may be a CCD camera.

[0254] For example, a calibration plate may be used to calibrate the camera to convert camera pixels into actual distances; and the second weld mark 45 in the weld mark image may be identified using a find_circle tool in the software.

[0255] In the above technical solution, by collecting the weld mark image of the side of the workpiece sample where the weld mark is formed and identifying the second weld mark 45 in the weld mark image, the second weld mark 45 can be easily identified and found.

[0256] In some embodiments, calculating the weld footprint area of ​​the single second weld footprint 45 includes:

[0257] Identifying the outer contour of a single second weld mark 45;

[0258] The area of ​​the pattern enclosed by the outer contour of the second weld mark 45 is calculated.

[0259] The area of ​​the pattern enclosed by the outer contour of the second weld mark 45 is the weld mark area of ​​the second weld mark 45 .

[0260] For example, the software uses the Distance_PP operator to calculate the area of ​​the graphic enclosed by the outer contour of the second weld mark 45 .

[0261] In the above technical solution, by first identifying the outer contour of a single second weld mark 45 and then calculating the area of ​​the figure enclosed by the outer contour of the second weld mark 45, the weld area of ​​the second weld mark 45 can be conveniently calculated. The calculation method of the weld area is simple and the calculation result is relatively accurate.

[0262] In some embodiments, judging the wear of the ultrasonic horn 100 based on the weld area of ​​a single second weld mark 45 includes:

[0263] The wear condition of the ultrasonic horn 100 is determined based on the ratio of the weld area of ​​the single second weld mark 45 to the designed area of ​​the single second weld mark 45 .

[0264] The design area of ​​a single second weld mark 45 refers to the weld mark area formed by the second weld teeth 31 on the foil when the ultrasonic welding head 100 is used for the first time. The weld mark area can be obtained by the above-mentioned calculation method.

[0265] During long-term use of the ultrasonic horn 100, the second welding teeth 31 will gradually wear out, and the weld area of ​​the second weld mark 45 corresponding to the second welding teeth 31 will gradually decrease. Based on the ratio of the weld area of ​​a single second weld mark 45 to the designed area of ​​the single second weld mark 45, the wear of the second welding teeth 31 can be more accurately determined, and the degree of wear of the ultrasonic horn 100 can also be determined.

[0266] In the above technical solution, by calculating the ratio of the weld mark area of ​​a single second weld mark 45 to the design area of ​​the single second weld mark 45, the amount by which the weld mark area of ​​the current second weld mark 45 is reduced relative to the design area of ​​the second weld mark 45 can be obtained. The amount by which the weld mark area of ​​the second weld mark 45 is reduced relative to the design area of ​​the second weld mark 45 can more intuitively reflect the wear condition of the second weld tooth 31, thereby reflecting the wear condition of the ultrasonic welding head 100, which helps to improve the accuracy of judging the wear condition of the ultrasonic welding head 100.

[0267] In some embodiments, judging the wear of the ultrasonic horn 100 based on the ratio of the weld area of ​​the single second weld mark 45 to the designed area of ​​the single second weld mark 45 includes:

[0268] The weld area of ​​a single second weld mark 45 is Sx, and the designed area of ​​the single second weld mark 45 is S0. When the ratio of Sx to S0 is less than 0.2, it is determined that the service life of the ultrasonic welding head 100 has expired.

[0269] For example, when the ratio of Sx to S0 is 0.3, it is determined that the life of the ultrasonic horn 100 has not been reached and it can continue to be used; when the ratio of Sx to S0 is 0.18, it is determined that the life of the ultrasonic horn 100 has been reached and it is stopped from being used.

[0270] In the above technical solution, by judging whether the ratio of the weld mark area Sx of the single second weld mark 45 to the design area S0 of the single second weld mark 45 is less than 0.2, it is judged whether the service life of the ultrasonic welding head 100 has been reached, and it can be simply and accurately judged whether the ultrasonic welding head 100 should be replaced or repaired.

[0271] refer to Figure 9 In a fourth aspect, the present invention provides a battery cell 40 comprising a housing 41 and an electrode assembly 46. Housing 41 is provided with an electrode terminal 401. Electrode assembly 46 is disposed within housing 41 and includes a tab 42 connected to electrode terminal 401. Tab 42 comprises a plurality of tab sheets stacked and welded together. A weld mark 43 is formed on tab 42. Weld mark 43 is formed by welding using the ultrasonic welding head 100 according to the embodiment of the first aspect. Weld mark 43 includes a first weld mark 44 and a second weld mark 45. Both first weld mark 44 and second weld mark 45 are formed as grooves. Second weld mark 45 is formed on the bottom wall of first weld mark 44 and extends in an elongated strip shape.

[0272] The housing 41 of the battery cell 40 is usually at least partially made of metal. For example, the housing 41 may be an aluminum shell or a steel shell.

[0273] For example, multiple tabs can be welded by ultrasonic welding.

[0274] The weld mark area 43 includes a first weld mark 44 and a second weld mark 45. The first weld mark 44 and the second weld mark 45 are both formed into a groove structure. The second weld mark 45 is formed on the bottom wall of the first weld mark 44 and extends in a long strip shape. By forming the first weld mark 44 and the second weld mark 45, the multi-layer electrode tab sheets can be compacted, the air between the multi-layer electrode tab sheets can be discharged, and the gap between the multi-layer electrode tab sheets can be reduced, which facilitates the subsequent connection between the electrode tab 42 and the electrode terminal 401.

[0275] For example, the weld mark area 43 of the tab sheet can be formed by welding multiple tab sheets using the ultrasonic welding head 100 of the first embodiment of the present application. At this time, the weld mark area 43 can correspond to the welding surface 11, the first weld mark 44 can correspond to the first weld tooth 21, and the second weld mark 45 can correspond to the second weld tooth 31, that is, during the welding process, the first weld tooth 21 of the ultrasonic welding head 100 can form a first weld mark 44 on the tab sheet, and the second weld tooth 31 of the ultrasonic welding head 100 can form a second weld mark 45 on the tab sheet.

[0276] In the above technical solution, a first weld mark 44 and a second weld mark 45, both of which are groove structures, are formed by welding on the multi-layered tab sheet of the tab 42. In the process of welding the multi-layered tab sheet, the multi-layered tab sheet can be compacted, the air between the multi-layered tab sheets can be discharged, the gap between the multi-layered tab sheets can be reduced, and the problems of explosion points, collapse, welding cracks, and tab sheet cracking caused by the presence of air between the multi-layered tab sheets in the subsequent welding process can be reduced; the second weld mark 45 is formed on the bottom wall of the first weld mark 44 and extends in a long strip shape, so that the second weld mark 45 and the first weld mark 44 can form a multi-level weld mark structure and the length of the second weld mark 45 is The degree is larger, and in the process of welding the multi-layer pole tabs, the compaction effect between the multi-layer pole tabs can be further enhanced, thereby further reducing the gap between the multi-layer pole tabs, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer pole tabs at the position of the second weld mark 45 is tighter and the gap is smaller, so that laser welding can be performed at the position of the second weld mark 45, which can better reduce laser welding defects, better improve laser welding quality, help to improve the subsequent laser welding quality of the pole tab 42 and the electrode terminal 401, and is beneficial to improving the service stability of the battery.

[0277] In some embodiments, the first weld stamp 44 includes a weld stamp body and multiple weld stamp branches. The weld stamp body is in the shape of an elongated strip, and the multiple weld stamp branches are connected to at least one side of the width direction of the weld stamp body. The second weld stamp 45 is formed on the bottom wall of the weld stamp body and is consistent with the extension direction of the weld stamp body.

[0278] For example, multiple welding branches are connected to at least one side of the width direction of the welding body. Multiple welding branches can be connected to one side of the width direction of the welding body, or multiple welding branches can be connected to both sides of the width direction of the welding body.

[0279] In the above technical solution, by making the first weld mark 44 on the tab sheet include a weld mark main body and multiple weld mark branches, and making the weld mark main body in a long strip shape, the weld mark area and weld mark length of the first weld mark 44 can be increased, which is beneficial to enhancing the compaction uniformity and compaction effect of the multi-layer tab sheet. By forming the second weld mark 45 on the bottom wall of the weld mark main body and in the same direction as the extension of the weld mark main body, the weld mark length and weld mark area of ​​the second weld mark 45 can be increased, which is beneficial to enhancing the compaction effect of the second weld mark 45 on the multi-layer tab sheet.

[0280] refer to Figure 7 In some embodiments, the weld print area 43 includes a third weld print, and the third weld print is located between adjacent first weld prints 44.

[0281] For example, the third weld mark is located between adjacent first weld marks 44 , or the third weld mark is located in the middle of two adjacent first weld marks 44 .

[0282] In the above technical solution, by arranging a third weld mark between adjacent first weld marks 44, the weld mark area can be further increased, so that the portion of the multi-layer tab sheet located between adjacent first weld marks 44 can obtain the compaction effect of the third weld mark, thereby making the multi-layer tab sheet compacted more evenly, which is beneficial to improving the welding quality of subsequent welding processes.

[0283] refer to Figure 7 In some embodiments, the weld mark area 43 includes a fourth weld mark, and the fourth weld mark is located between the first weld mark 44 and the edge of the tab 42 .

[0284] For example, the fourth weld mark may be disposed between the first weld mark 44 and the edges of the tab 42 .

[0285] In the above technical solution, a fourth weld mark is printed on the weld mark area 43 between the first weld mark 44 of the tab 42 and the edge of the tab 42, so that the portion of the multi-layer tab sheet located at the edge of the first weld mark 44 and the tab 42 can be compacted by the fourth weld mark, thereby making the multi-layer tab sheet more evenly compacted, which is beneficial to improving the welding quality of subsequent welding processes.

[0286] In some embodiments, the multi-layer tab sheets of the tab 42 are ultrasonically welded, the tab 42 is laser welded to the electrode terminal 401 to form a laser weld, and the laser weld and the second weld mark 45 are arranged opposite to each other in the stacking direction of the multi-layer tab sheets.

[0287] Among them, laser welding is an efficient and precise welding method that uses a high-energy-density laser beam as a heat source to melt materials and connect workpieces.

[0288] In the above technical solution, the multi-layered tab sheets of the tab 42 are ultrasonically welded to form the above-mentioned weld mark area 43 on the tab 42, and the weld mark area 43 includes the above-mentioned first weld mark 44 and second weld mark 45. During ultrasonic welding, the multi-layered tab sheets can be compacted, and the gap between the multi-layered tab sheets can be reduced, which facilitates the laser welding connection between the tab 42 and the electrode terminal 401, reduces the occurrence of explosion points, collapse, etc. of the tab sheets during laser welding, and can improve the laser welding quality between the tab 42 and the electrode terminal 401, which is beneficial to improving the service stability of the battery.

[0289] refer to Figure 10 In a fifth aspect, the present invention provides a battery device 200 , comprising: a box body 201 and a battery cell 40 according to an embodiment of the fourth aspect, wherein the battery cell 40 is disposed in the box body 201 .

[0290] In the above technical solution, by setting the above-mentioned battery cell 40, a first weld mark 44 and a second weld mark 45, both of which are groove structures, are formed by welding on the multi-layered tab sheet of the tab 42. In the process of welding the multi-layered tab sheet, the multi-layered tab sheet can be compacted, the air between the multi-layered tab sheet can be discharged, the gap between the multi-layered tab sheet can be reduced, and the problems of explosion point, collapse, welding cracks, and tab sheet cracking caused by the presence of air between the multi-layered tab sheet in the subsequent welding process can be reduced; the second weld mark 45 is formed on the bottom wall of the first weld mark 44 and extends in a long strip shape, so that the second weld mark 45 and the first weld mark 44 can form a multi-level weld mark structure and the first weld mark 45 can form a multi-level weld mark structure. The second weld mark 45 is relatively long, and during the welding process of the multi-layer pole tab sheets, it can further enhance the compaction effect between the multi-layer pole tab sheets, thereby further reducing the gap between the multi-layer pole tab sheets, and is more helpful to improve the welding quality of the subsequent welding process. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer pole tab sheets at the position of the second weld mark 45 is tighter and the gap is smaller, so that laser welding can be performed at the position of the second weld mark 45, which can better reduce laser welding defects and better improve laser welding quality, which is helpful to improve the subsequent laser welding quality of the pole tab 42 and the electrode terminal 401, and is beneficial to improving the service stability of the battery.

[0291] refer to Figure 11 In a sixth aspect, the present invention provides an electrical device 300, comprising the battery device 200 of the fifth aspect embodiment.

[0292] For example, the electric device 300 may be a vehicle, and the battery device 200 may be installed on the bottom of the vehicle body 60 .

[0293] In the above technical solution, by setting the above-mentioned battery device 200, the battery cell 40 set in the battery device 200 is formed by welding on the multi-layer pole tab sheet of the pole tab 42 to form a first weld mark 44 and a second weld mark 45, both of which are groove structures. In the process of welding the multi-layer pole tab sheet, the multi-layer pole tab sheet can be compacted, the air between the multi-layer pole tab sheets can be discharged, the gap between the multi-layer pole tab sheets can be reduced, and the problems of explosion point, collapse, welding cracks, and pole tab sheet cracking caused by the presence of air between the multi-layer pole tab sheets in the subsequent welding process can be reduced; the second weld mark 45 is formed on the bottom wall of the first weld mark 44 and extends in a long strip shape, so that the second weld mark 45 and the first weld mark 44 can be A multi-level weld mark structure is formed and the length of the second weld mark 45 is relatively large. During the welding process of the multi-layer pole tab sheets, the compaction effect between the multi-layer pole tab sheets can be further enhanced, thereby further reducing the gap between the multi-layer pole tab sheets, and helping to improve the welding quality of subsequent welding processes. For example, when the subsequent welding process is a laser welding process, the compaction between the multi-layer pole tab sheets at the position of the second weld mark 45 is tighter and the gap is smaller. In this way, laser welding can be performed at the position of the second weld mark 45, which can better reduce laser welding defects and better improve laser welding quality, thereby helping to improve the subsequent laser welding quality of the pole tab 42 and the electrode terminal 401, and is beneficial to improving the service stability of the battery.

[0294] Refer to the following Figure 1-Figure 7 An ultrasonic horn 100 according to some embodiments of the present invention is described.

[0295] In this embodiment, the ultrasonic horn 100 includes a horn body 10 , a first welding tooth structure 20 and a second welding tooth structure 30 .

[0296] The welding head body 10 has a welding surface 11, the first welding tooth structure 20 is protruded from the welding surface 11, and the second welding tooth structure 30 is protruded from the side of the first welding tooth structure away from the welding surface 11. The second welding tooth structure 30 includes two second welding teeth 31 arranged at intervals and extending in a long strip shape in the extension direction of the welding surface 11. The two second welding teeth 31 are arranged side by side along the width direction of the second welding teeth 31, and the two ends of the second welding teeth 31 in the length direction extend to the opposite ends of the welding surface 11 respectively.

[0297] The first welding tooth structure 20 includes a first welding tooth 21, a third welding tooth 23, and a fourth welding tooth 24. The first welding tooth 21 includes a welding tooth body 211 extending in an elongated strip in the direction of the welding surface 11 and welding tooth branches 212 formed on both sides of the welding tooth body 211 in the width direction. The third welding tooth 23 is arranged between adjacent first welding teeth 21, and the fourth welding tooth 24 is arranged between the first welding tooth 21 and the edge of the welding surface 11.

[0298] A plurality of receiving grooves 13 are defined between two adjacent first welding teeth 21 , and the plurality of receiving grooves 13 are arranged at intervals along the extension direction of the welding tooth body 211 . The welding tooth branch 212 is located between two adjacent receiving grooves 13 , and the third welding tooth 23 is located in the receiving groove 13 and is prism-shaped.

[0299] The fourth welding teeth 24 are disposed between the first welding teeth 21 and the edge of the welding surface 11 . A plurality of fourth welding teeth 24 are arranged at intervals along the extending direction of the welding tooth body 211 .

[0300] The surface of the first welding tooth 21 facing away from the welding surface 11 forms a planar welding tooth end surface 22. The second welding tooth 31 is disposed within the welding tooth end surface 22 and extends in the same direction as the welding tooth body 211. The projection of the second welding tooth 31 on the welding tooth end surface 22 is located within the welding tooth end surface 22. The second welding tooth 31 has a second cross-sectional area, which includes a tapered portion extending to the side of the second welding tooth 31 facing away from the welding surface 11. The width of the tapered portion gradually decreases in the direction from the welding surface 11 to the second welding tooth 31. The cross-sectional area of ​​the second welding tooth 31 remains constant along the extension direction of the second welding tooth 31, and the cross-sectional area of ​​the second welding tooth 31 is arcuate.

[0301] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0302] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An ultrasonic welding head, characterized in that: include: A welding head body, wherein the welding head body has a welding surface; a first welding tooth structure, the first welding tooth structure being protruding from the welding surface, the first welding tooth structure comprising a first welding tooth, a surface of the first welding tooth away from the welding surface constituting a welding tooth end face, the first welding tooth comprising a welding tooth body and a plurality of welding tooth branches, the welding tooth body extending in an elongated strip shape in the extending direction of the welding surface, the plurality of welding tooth branches being connected to at least one side of the welding tooth body in the width direction; A second welding tooth structure, the second welding tooth structure is protruding on the side of the first welding tooth structure away from the welding surface, the second welding tooth structure includes at least one second welding tooth, the second welding tooth is arranged on the end face of the welding tooth, the projection of the second welding tooth on the end face of the welding tooth is located within the end face of the welding tooth, the second welding tooth extends in a long strip shape in the extension direction of the welding surface, the second welding tooth is arranged on the welding tooth body and is consistent with the extension direction of the welding tooth body.

2. The ultrasonic horn according to claim 1, characterized in that: Both ends of the second welding tooth in the length direction extend to opposite ends of the welding surface respectively.

3. The ultrasonic horn according to claim 1, characterized in that: The second welding teeth extend along the length direction or the width direction of the welding surface.

4. The ultrasonic horn according to claim 1, characterized in that: The second welding tooth extends along a straight line.

5. The ultrasonic horn according to claim 1, characterized in that: There are a plurality of second welding teeth arranged at intervals.

6. The ultrasonic horn according to claim 5, characterized in that: A plurality of second welding teeth are arranged side by side along the width direction of the second welding teeth.

7. The ultrasonic horn according to claim 6, characterized in that: The second welding teeth extend along the length direction of the welding surface, and a plurality of second welding teeth are arranged along the width direction of the welding surface.

8. The ultrasonic horn according to claim 6, characterized in that: In the arrangement direction of the plurality of second welding teeth, the distance between two adjacent second welding teeth is d1, the maximum width of the second welding teeth is W2, and W2<d1.

9. The ultrasonic horn according to claim 8, characterized in that: The ratio of W2 to d1 ranges from 0.2 to 0.

8.

10. The ultrasonic horn according to claim 6, characterized in that: In the arrangement direction of the plurality of second welding teeth, the minimum distance between the second welding teeth and the edge of the welding surface is d2, the maximum width of the second welding teeth is W2, and d2>W2.

11. The ultrasonic horn according to claim 1, characterized in that: The cross section of the second welding tooth is a second cross section, and the second cross section has a tapered portion, which extends to a side of the second welding tooth away from the welding surface. In the direction from the welding surface to the second welding tooth, the width of the tapered portion gradually decreases.

12. The ultrasonic horn according to claim 1, characterized in that: In the extension direction of the second welding teeth, at least part of the cross-sectional areas of the second welding teeth are the same.

13. The ultrasonic horn according to claim 1, characterized in that: The cross section of the second welding tooth is arcuate, circular or elliptical.

14. The ultrasonic welding head according to any one of claims 1 to 13, characterized in that: The second welding tooth includes one tooth portion; or, the second welding tooth includes multiple tooth portions, the surface of the tooth portion away from the welding surface constitutes a tooth portion end face, the multiple tooth portions are respectively the first tooth portion to the mth tooth portion arranged in sequence along the protruding direction of the second welding tooth, the nth tooth portion is arranged on the tooth portion end face of the (n-1)th tooth portion, and the projection of the nth tooth portion on the tooth portion end face of the (n-1)th tooth portion is located within the tooth portion end face of the (n-1)th tooth portion, 2≤n≤m.

15. The ultrasonic horn according to claim 1, characterized in that: In the protruding direction of the first welding tooth relative to the welding surface, the tooth height of the first welding tooth is h1, the tooth height of the second welding tooth is h2, and the ratio of h2 to h1 ranges from 0.3 to 0.

8.

16. The ultrasonic horn according to claim 1, characterized in that: In the protruding direction of the first welding tooth relative to the welding surface, the tooth height of the first welding tooth is h1, and the value range of h1 is 0.2mm to 0.6mm.

17. The ultrasonic horn according to claim 1, characterized in that: The end face of the welding tooth is a plane.

18. The ultrasonic horn according to claim 1, characterized in that: The first welding tooth structure includes a third welding tooth, and the third welding tooth is arranged between adjacent first welding teeth; and / or the first welding tooth structure includes a fourth welding tooth, and the fourth welding tooth is arranged between the first welding tooth and the edge of the welding surface.

19. The ultrasonic horn according to claim 1, characterized in that: The width of the second welding tooth is W2, the width of the welding tooth body is W1, and W2≤W1.

20. The ultrasonic horn according to claim 1, characterized in that: The ratio of W2 to W1 ranges from 0.5 to 0.

9.

21. The ultrasonic horn according to claim 1, characterized in that: The first welding tooth structure includes a third welding tooth, and a plurality of accommodating grooves are defined between two adjacent first welding teeth. The plurality of accommodating grooves are arranged at intervals along the extension direction of the welding tooth body. The welding tooth branch is located between two adjacent accommodating grooves, and the third welding tooth is located in the accommodating groove.

22. The ultrasonic horn according to claim 21, characterized in that: The third welding tooth is in a prism shape.

23. The ultrasonic horn according to claim 1, characterized in that: The first welding tooth structure includes a fourth welding tooth, which is arranged between the first welding tooth and the edge of the welding surface. There are multiple fourth welding teeth, and the multiple fourth welding teeth located on the same side of the first welding tooth are arranged at intervals along the extension direction of the welding tooth body.

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

25. A battery cell, characterized in that: include: a housing, wherein the housing is provided with electrode terminals; An electrode assembly, wherein the electrode assembly is arranged in the shell and includes a tab, the tab is connected to the electrode terminal, the tab includes a plurality of tab sheets stacked and welded together, a weld mark area is formed on the tab, the weld mark area is formed by welding with an ultrasonic welding head according to any one of claims 1-23, the weld mark area includes a first weld mark and a second weld mark, the first weld mark and the second weld mark are both formed into a groove structure, and the second weld mark is formed on the bottom wall of the first weld mark and extends in a long strip shape.

26. The battery cell according to claim 25, characterized in that The first welding stamp includes a welding stamp body and multiple welding stamp branches. The welding stamp body is in the shape of an elongated strip. The multiple welding stamp branches are connected to at least one side of the width direction of the welding stamp body. The second welding stamp is formed on the bottom wall of the welding stamp body and is consistent with the extension direction of the welding stamp body.

27. The battery cell according to claim 25, characterized in that The weld mark area includes a third weld mark, and the third weld mark is located between adjacent first weld marks; and / or the weld mark area includes a fourth weld mark, and the fourth weld mark is located between the first weld mark and the edge of the tab.

28. The battery cell according to any one of claims 25 to 27, characterized in that: The multiple layers of the tab sheets are connected by ultrasonic welding, the tab is connected to the electrode terminal by laser welding to form a laser weld, and the laser weld and the second weld mark are arranged opposite to each other in the stacking direction of the multiple layers of the tab sheets.

29. A battery device, characterized in that: include: Box; The battery cell according to any one of claims 25 to 28, wherein the battery cell is arranged in the box.

30. An electrical device, characterized in that: A battery device comprising the battery device of claim 29.

Images