Connecting structure of tab and connecting piece, battery and power device

Abstract

The invention relates to the technical field of batteries, and particularly discloses a connecting structure of a tab and a connecting piece, a battery and a power device. In the connecting structure of the tabs and the connecting pieces, the tabs and the connecting pieces are stacked in the first direction, the connecting pieces and the tabs are welded to form a welding area, M welding marks are formed in the welding area, and the welding marks penetrate through the tabs and part of the connecting pieces, so that the connecting pieces and the tabs are connected into an integrated structure through welding. The M welding marks are arranged in the welding area in an array mode. The sum of the total areas of the M welding marks is S1. Pulling forces F in opposite directions are applied to the tabs and the connecting sheets, the N welding marks are peeled off, and the total area of all the residual welding marks after the N welding marks are peeled off is S2. S2 / S1 is greater than or equal to 0.6 and less than or equal to 1.0. Therefore, reliable connection between the tabs and the connecting pieces is ensured in a vibration working condition of the battery, and the safety risk is small. The invention provides a battery and a power device. The battery and the power device comprise the connecting structure of the tab and the connecting piece.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a connection structure between a tab and a connecting piece, a battery, and a power device. Background Art

[0002] Battery tabs are typically constructed from multiple layers of foil, which are then ultrasonically welded to a connecting tab. This allows current to flow between the battery pack and the external circuit. However, in actual manufacturing, the welding between the tab and the tab can be problematic, with poor weld quality and a high rate of defective welding between the tab and the tab, leading to scrapped batteries and increased production costs. Summary of the Invention

[0003] The object of the present invention is to provide a connection structure between a tab and a connecting piece, a battery and a power device, which improves the welding quality and welding yield between the tab and the connecting piece by rationally arranging the positions of the welding marks on the tab and the connecting piece, thereby increasing the reliability of the battery.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a connection structure between a tab and a connecting piece, comprising:

[0006] The tab comprises a plurality of foils stacked along a first direction;

[0007] a connecting sheet, stacked with the tab along a first direction, the connecting sheet and the tab being welded to form a welding area on the tab and the connecting sheet, the welding area including M weld marks, the M weld marks being arranged in a plurality of columns along a second direction and in a plurality of rows along a third direction, with the first direction, the second direction, and the third direction being perpendicular to each other;

[0008] The total area of the M weld marks is S1; a pulling force F is applied to the tab and the connecting sheet in opposite directions along the third direction, and N weld marks are peeled off. The total area of all the remaining weld marks after peeling off is S2; N is an integer greater than or equal to zero;

[0009] S1 and S2 satisfy the following conditions: 0.6≤S2 / S1≤1.0;

[0010] The value range of F is: 30N≤F≤200N.

[0011] Optionally, the welding area includes two first edges arranged opposite to each other along the second direction, and the distance between the welding mark close to the first edge and the first edge is e;

[0012] The value range of e is: 1.5mm≤e≤8.0mm;

[0013] And / or, the welding area includes two second edges arranged opposite to each other along a third direction, and the distance between the welding mark close to the second edge and the second edge is f;

[0014] The value range of f is: 1.5mm≤f≤8.0mm.

[0015] Optionally, the distance between two adjacent rows of weld marks along the second direction is a;

[0016] The value range of a is: 0.5mm≤a≤5.0mm;

[0017] The distance between two adjacent rows of weld marks arranged along the third direction is b;

[0018] The value range of b is: 0.5mm≤b≤5.0mm.

[0019] Optionally, the connecting piece and the tab form an overlapping area along the first direction; along the second direction, a distance between the first edge and an adjacent side of the overlapping area is C;

[0020] The value range of C is: 2mm≤C≤20mm.

[0021] Optionally, along the third direction, a distance between the second edge and an adjacent side edge of the overlapping area is D, and a value range of D is: 2 mm ≤ D ≤ 20 mm.

[0022] Optionally, the length of the welding area along the second direction is A, the width of the welding area along the third direction is B, the value range of A is: 6mm≤A≤80mm, and the value range of B is: 4mm≤B≤30mm.

[0023] Optionally, the shape of the weld mark is circular or polygonal.

[0024] In a second aspect, the present invention provides a battery comprising a pole group and a pole column, wherein the pole group comprises a pole tab, one end of the connecting plate is connected to the pole tab using the connection structure between the pole tab and the connecting plate described in any of the above schemes, and the other end of the connecting plate is electrically connected to the pole column.

[0025] Optionally, the electrode groups include two, each of which includes a positive electrode tab and a negative electrode tab, the electrode posts include a positive electrode post and a negative electrode post, and the connecting piece includes a first connecting portion and two second connecting portions, the two second connecting portions are both connected to the first connecting portion, the first connecting portion is connected to the positive electrode post, and the two second connecting portions are respectively connected to the positive electrode tabs of the two electrode groups;

[0026] Alternatively, the first connecting portion is connected to the negative electrode column, and the two second connecting portions are respectively connected to the negative electrode tabs of two electrode groups.

[0027] In a third aspect, the present invention provides a power device comprising the battery in any of the above solutions.

[0028] The beneficial effects of the present invention are:

[0029] The present invention provides a connection structure between a tab and a connecting piece, wherein the tab comprises a plurality of foils stacked along a first direction, the connecting piece is stacked with the tab along the first direction, the connecting piece and the tab are welded to form a welding area, M weld marks are formed in the welding area, the weld marks penetrate the tab and part of the connecting piece, so that the connecting piece and the tab are connected to form an integral structure by welding. The M weld marks are arranged in multiple columns at intervals along the second direction, and in multiple rows at intervals along the third direction. The sum of the total areas of the M weld marks is S1. A pulling force F in the opposite direction along the third direction is applied to the tab and the connecting piece, and N weld marks are peeled off. The total area of all the weld marks remaining after peeling is S2. The relationship between S1 and S2 satisfies: 0.6≤S2 / S1≤1.0. Thus, it is ensured that the connection between the tab and the connecting piece is reliable and will not be disconnected when the battery is in a vibration condition, and the safety risk is small.

[0030] The present invention provides a battery comprising the above-mentioned connection structure between the tab and the connecting piece, wherein the tab and the connecting piece have good electrical conductivity, and the connection between the tab and the connecting piece has high reliability, and the battery has high safety.

[0031] The present invention also provides a power device comprising the above-mentioned battery, which has high reliability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A top view of the connection structure between the tab and the connecting piece provided in the first embodiment of the present invention;

[0033] Figure 2 for Figure 1 A partial enlarged view of point Ⅰ in the middle;

[0034] Figure 3 A side view of the connection structure between the tab and the connecting piece provided in the first embodiment of the present invention;

[0035] Figure 4 A top view of the assembled electrode group and connecting piece provided in the first embodiment of the present invention;

[0036] Figure 5 A top view of the welding head provided in the first embodiment of the present invention;

[0037] Figure 6 A side view of the welding head provided in the first embodiment of the present invention;

[0038] Figure 7 A top view of the connection structure between the tab and the connecting piece provided in the second embodiment of the present invention;

[0039] Figure 8 for Figure 7 A partial enlarged view of the middle II;

[0040] Figure 9 A top view of the welding head provided in the second embodiment of the present invention;

[0041] Figure 10 This is a side view of the welding head provided in the second embodiment of the present invention.

[0042] In the picture:

[0043] 10. Tab; 10a. Positive tab; 10b. Negative tab; 11. Foil; 101. Overlapping area; 20. Connecting piece; 21. First connecting portion; 22. Second connecting portion; 30. Welding area; 301. First edge; 302. Second edge; 31. Weld mark; 40. Pole group; 50. Welding head; 51. Base; 52. Welding teeth. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0047] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0048] In the description of the present invention, it should be noted that, unless otherwise specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0049] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0050] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0051] Example 1

[0052] like Figure 1-Figure 3As shown, this embodiment provides a connection structure between a tab and a connecting piece, including a tab 10 and a connecting piece 20. The tab 10 includes a plurality of foils 11 stacked along a first direction. The connecting piece 20 is stacked with the tab 10 along the first direction. The connecting piece 20 and the tab 10 are connected to form an integral structure by welding. For example, the connecting piece 20 and the tab 10 can be ultrasonically welded. The connecting piece 20 and the tab 10 are placed on a welding seat, and the welding head 50 is used to press down to weld the connecting piece 20 and the tab 10 into one piece, forming a welding area 30 on the tab 10 and the connecting piece 20.

[0053] See also Figure 1 、 Figure 5 and Figure 6 The welding head 50 includes a base 51 and a plurality of welding teeth 52, and the plurality of welding teeth 52 are arranged in an array on one end surface of the base 51. In this embodiment, the welding teeth 52 are circular teeth as an example for explanation. When the welding head 50 is pressed down, the welding teeth 52 face the tab 10 and the connecting piece 20. After the welding head 50 is pressed down to weld the connecting piece 20 and the tab 10 into one, the outer contour of the welding area 30 formed on the tab 10 and the connecting piece 20 is consistent with the outer contour of the end surface of the base 51 on which the welding teeth 52 are provided, that is, the base 51 corresponds to the welding area 30, and the projection of the base 51 on the tab 10 along the first direction coincides with the welding area 30, and the outer contour of the base 51 is the same as the outer contour of the welding area 30. Each welding tooth 52 on the welding head 50 corresponds to a weld mark 31 within the welding area 30 on the tab 10 and the connecting tab 20. The welding teeth 52 are arranged in an array along the second and third directions, and the weld marks 31 are also arranged in an array along the second and third directions within the welding area 30. Because the welding teeth 52 are round, the weld marks 31 formed on the tab 10 and the connecting tab 20 are also circular in shape. It is important to note that when the welding head 50 is pressed downward, the end surface of the base 51 facing the tab 10 does not contact the tab 10, thereby ensuring that adjacent weld marks 31 are spaced apart.

[0054] Optionally, in this embodiment, M weld marks 31 are formed in the welding area 30 as an example, each weld mark 31 penetrates the tab 10 and part of the connecting piece 20, and the M weld marks 31 are arranged in multiple columns along the second direction and in multiple rows along the third direction, and the first direction, the second direction and the third direction are perpendicular to each other. Figure 3 The Z-axis direction shown in the figure, the second direction is Figure 1 The X-axis direction shown in the figure, the third direction is Figure 1 The Y-axis direction shown in .

[0055] The total area of the M weld marks 31 is S1. A pulling force F is applied to the tab 10 and the connecting piece 20 in opposite directions along the third direction, and the N weld marks 31 are peeled off. The total area of all the remaining weld marks 31 after peeling off is S2; N is an integer greater than or equal to zero. S1 and S2 satisfy: 0.6≤S2 / S1≤1.0. For example, the value of S2 / S1 can be 0.6, 0.7, 0.8, 0.9 or 1.0. The value range of F is: 30N≤F≤200N. That is to say, when the value of F is the largest (F=200N), the value of S2 / S1 should also be greater than or equal to 0.6, so as to ensure that the connection between the tab 10 and the connecting piece 20 is reliable and will not be disconnected when the battery is in vibration conditions, and the safety risk is small. If F=200N, the value of S2 / S1 is less than 0.6. After part of the weld marks 31 are peeled off, the total area S2 of all the remaining weld marks 31 is small, the connection strength between the connecting piece 20 and the tab 10 is low, and it cannot withstand a large tensile force. It is easy to separate under vibration conditions, does not meet the use requirements, and has low reliability.

[0056] Optionally, in this embodiment, the shape of the welding mark 31 is circular. The number of welding marks 31 is M, and the area of each welding mark 31 is S11, where S11 = S1 / M1.

[0057] Continue to see Figure 2 In this embodiment, the welding area 30 includes two first edges 301 arranged opposite to each other along the second direction. The distance between the welding mark 31 near the first edge 301 and the first edge 301 is e, and the value range of e is: 1.5mm≤e≤8.0mm. For example, the value of e can be 1.5mm, 2.0mm, 4.0mm, 6.0mm, or 8.0mm. The welding area 30 includes two second edges 302 arranged opposite to each other along the third direction. The distance between the welding mark 31 near the second edge 302 and the second edge 302 is f, and the value range of f is: 1.5mm≤f≤8.0mm. For example, the value of f can be 1.5mm, 2.0mm, 4.0mm, 6.0mm, or 8.0mm. In some embodiments, the value of e is equal to the value of f. By limiting the values of e and f to meet the above-mentioned size restrictions, it is ensured that after the tab 10 and the connecting piece 20 are ultrasonically welded, the tab 10 located at the edge of the welding area 30 will not be damaged, ensuring good welding quality between the tab 10 and the connecting piece 20 and a high processing yield.

[0058] Furthermore, the distance between two adjacent rows of weld marks 31 arranged along the second direction is a, and the value range of a is: 0.5mm≤a≤5.0mm. For example, the value of a can be 0.5mm, 1.5mm, 2.5mm, 3.5mm, 4.5mm or 5.0mm. The distance between two adjacent rows of weld marks 31 arranged along the third direction is b, and the value range of b is: 0.5mm≤b≤5.0mm. For example, the value of b can be 0.5mm, 1.5mm, 2.5mm, 3.5mm, 4.5mm or 5.0mm. In some embodiments, the value of a is equal to the value of b. By limiting the values of a and b to meet the above-mentioned size restrictions, it is ensured that after the tab 10 and the connecting piece 20 are ultrasonically welded, the tab 10 inside the welding area 30 will not be damaged, ensuring good welding quality between the tab 10 and the connecting piece 20 and a high processing yield. Otherwise, if the values of a and b are too small, the distance between two adjacent weld marks 31 along the second direction is too close, and the distance between two adjacent weld marks 31 along the third direction is too close, the tab 10 between the weld marks 31 may be damaged, affecting the performance of the tab 10, the welding quality between the tab 10 and the connecting piece 20 is poor, and the processing yield is low.

[0059] Continue to see Figure 1 , the connecting piece 20 and the tab 10 form an overlapping area 101 along the first direction, and the center of the welding area 30 and the center of the overlapping area 101 are located at the same point. Along the second direction, the distance between the first edge 301 and the adjacent side of the overlapping area 101 is C, and the value range of C is: 2mm≤C≤20mm. For example, the value of C can be 2.0mm, 5.0mm, 10.0mm, 15.0mm or 20.0mm. Along the third direction, the distance between the second edge 302 and the adjacent side of the overlapping area 101 is D, and the value range of D is: 2mm≤D≤20mm. For example, the value of D can be 2.0mm, 5.0mm, 10.0mm, 15.0mm or 20.0mm. By limiting the values of C and D within the above range, when welding with the welding head 50, the boundary between the welding head 50 and the overlapping area 101 is farther away, which is beneficial to protecting the welding head 50 from damage and also ensures better welding quality between the tab 10 and the connecting piece 20.

[0060] Furthermore, the length of the welding area 30 along the second direction is A, and the width of the welding area 30 along the third direction is B. The value range of A is: 6mm≤A≤80mm. For example, the value of A can be 6.0mm, 10.0mm, 25.0mm, 50.0mm, 65mm or 80.0mm, etc. The value range of B is: 4mm≤B≤30mm. For example, the value of B can be 4.0mm, 6.0mm, 10.0mm, 20.0mm or 30.0mm, etc. By limiting the values of A and B to the above range, the area of the welding area 30 is ensured to be large enough to arrange enough weld marks 31 to connect the tab 10 and the connecting piece 20, and the connection between the tab 10 and the connecting piece 20 is reliable and not easy to separate.

[0061] See also Figure 4 This embodiment provides a battery comprising an electrode assembly 40 and an electrode column. The electrode assembly 40 includes a tab 10. One end of a connecting piece 20 is connected to the tab 10 using the aforementioned tab-to-tab connection structure, and the other end of the connecting piece 20 is electrically connected to the electrode column. Thus, current from the electrode assembly 40 can be drawn out of the battery via the tab 10 and the connecting piece 20 and connected to an external circuit via the electrode column. By employing the aforementioned tab-to-tab connection structure, the battery has high reliability, and the tab 10 and the connecting piece 20 are less likely to separate and fail.

[0062] Optionally, the battery in this embodiment can be a square-shell battery, in which two electrode groups 40 are provided, each electrode group 40 includes a positive electrode tab 10a and a negative electrode tab 10b (only the positive electrode tab 10a or the negative electrode tab 10b is shown in the figure), the electrode column includes a positive electrode column and a negative electrode column, and the connecting piece 20 includes a first connecting portion 21 and two second connecting portions 22, and the two second connecting portions 22 are connected to the first connecting portion 21. The first connecting portion 21 is electrically connected to the positive electrode column, and the two second connecting portions 22 are respectively connected to the positive electrode tabs 10a of the two electrode groups 40. Alternatively, the first connecting portion 21 is electrically connected to the negative electrode column, and the two second connecting portions 22 are respectively connected to the negative electrode tabs 10b of the two electrode groups 40.

[0063] This embodiment also provides a power device, comprising the above-mentioned battery, which has high reliability and safety.

[0064] Next, a peel test was performed on batteries having the above-described connection structure between the tab and the connecting piece using samples of different design sizes to determine whether the connection strength between the tab 10 and the connecting piece 20 is qualified and whether it can meet the requirements of safety and reliability. The results are shown in Table 1.

[0065] Table 1

[0066]

[0067] From the above results, it can be concluded that in Samples 1 and 2, after the peel test with an F value of 200N, the value of S2 / S1 is less than the minimum value of 0.6≤S2 / S1≤1.0, and the value of S2 of the total area of all the weld marks 31 remaining after peeling is small, which is not enough to reliably connect the tab 10 and the connecting piece 20. Under vibration conditions, there is a risk of separation between the tab 10 and the connecting piece 20, poor reliability, and a defective battery.

[0068] In samples 3 to 11, after the peeling test with an F value of 200N, the value of S2 / S1 meets the size limit of 0.6≤S2 / S1≤1.0. The value of S2 of the total area of all the weld marks 31 remaining after peeling is large enough to ensure that the tab 10 and the connecting piece 20 are reliably connected. Under vibration conditions, the tab 10 and the connecting piece 20 are not easy to separate, with high reliability and safety, excellent current transmission performance between the pole column and the pole group 40, and good battery performance.

[0069] The following samples with different design sizes are used to verify the relevant parameters of the connection structure between the tab and the connecting piece to determine whether the connection strength between the tab 10 and the connecting piece 20 is qualified and whether it can meet the requirements of safety and reliability. The results are shown in Table 2.

[0070] Table 2

[0071]

[0072] From the above results, it can be concluded that in sample 1, the value of a is less than the minimum value of 0.5mm≤a≤5.0mm, and the value of b is less than the minimum value of 0.5mm≤b≤5.0mm. At this time, when the welding head 50 and the welding seat cooperate to weld the tab 10 and the connecting piece 20, the surface of the tab 10 between the two adjacent weld marks 31 is damaged, and the welding quality between the tab 10 and the connecting piece 20 is unqualified. At the same time, the conductive performance of the tab 10 is also reduced, and the product is defective.

[0073] In sample 2, the value of e is less than the minimum value of 1.5mm≤e≤8.0mm, and the value of f is less than the minimum value of 1.5mm≤f≤8.0mm. At this time, when the welding head 50 and the welding seat cooperate to weld the tab 10 and the connecting piece 20, the surface of the tab 10 at the edges around the welding area 30 is damaged, and the welding quality between the tab 10 and the connecting piece 20 is unqualified. At the same time, the conductive performance of the tab 10 is also reduced, and the product is defective.

[0074] In sample 3, the value of C is less than the minimum value of 2mm≤C≤20mm, and the value of D is less than the minimum value of 2mm≤D≤20mm. At this time, after the welding head 50 and the welding seat cooperate to weld the tab 10 and the connecting piece 20, the welding head 50 is slightly damaged, which affects the service life of the welding head 50 and is not recommended for use.

[0075] In samples 4 to 13, the values of a, b, e, f, C, and D all meet their corresponding size limits. After the welding head 50 and the welding seat cooperate to weld the tab 10 and the connecting piece 20, there is no damage on the surface of the tab 10, the welding quality between the tab 10 and the connecting piece 20 is qualified, the conductive performance of the tab 10 is good, and the welding head 50 is not damaged. The welding head 50 has a long service life and the product is good.

[0076] In sample 14, the values of a, b, e, f, C, and D are all greater than the maximum value of their size limits. At this time, the intervals between adjacent weld marks 31 in the welding area 30 are large, resulting in a reduction in the number of weld marks 31 arranged in the welding area 30 of the same area, and a reduction in the connection strength between the tab 10 and the connecting piece 20. Under vibration conditions, the tab 10 and the connecting piece 20 are easily separated, resulting in poor reliability and safety, and a defective product.

[0077] In summary, it can be seen that the layout of the welding area 30 and the layout design of the weld mark 31 in the welding area 30 have a great influence on the connection strength between the tab 10 and the connecting piece 20. When the values of S2 / S1, a, b, e, f, C, and D all meet the design requirements, it can ensure that the connection strength between the tab 10 and the connecting piece 20 is high, and the reliability and safety of the battery are high.

[0078] Example 2

[0079] See also Figure 7 and Figure 8 This embodiment provides a connection structure between a tab and a connecting piece, which differs from the connection structure between a tab and a connecting piece in the first embodiment in that the shape of the weld mark 31 is polygonal.

[0080] like Figure 9 and Figure 10 As shown, the welding head 50 used to weld the connecting tab 20 and the tab 10 together includes a base 51 and a plurality of welding teeth 52 arranged in an array on one end face of the base 51. The welding teeth 52 are sharp teeth, with their bottom walls connected to one end face of the base 51. The bottom wall of the sharp teeth includes multiple bottom edges, with the intersection of two adjacent bottom edges corresponding to an edge. The other ends of the multiple edges converge to a point, and the point where the multiple edges converge faces away from the base 51 of the welding head 50. The number of bottom edges of the sharp teeth is the same as the number of edges of the weld marks 31 on the tab 10 and the connecting tab 20. In this embodiment, the bottom wall of the sharp teeth includes four bottom edges, and the bottom wall of the sharp teeth is square.

[0081] After the connecting piece 20 and the tab 10 are welded together using the welding head 50, the outer contour of the welding area 30 formed on the tab 10 and the connecting piece 20 is the same as the outer contour of the base 51, and the shape of the welding mark 31 is the same as the shape of the bottom wall of the tine. Figure 7 and Figure 8In this embodiment, the shape of the weld mark 31 is a square. Of course, in other embodiments, when the shape of the weld teeth 52 on the welding head 50 is different, the weld mark 31 formed on the tab 10 and the connecting piece 20 can also be of other shapes.

[0082] The remaining size design and layout scheme are the same as those in implementation one and will not be repeated here.

[0083] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A connection structure between a tab and a connecting piece, characterized in that: include: The tab comprises a plurality of foils stacked along a first direction; a connecting sheet, stacked with the tab along a first direction, the connecting sheet and the tab being welded to form a welding area on the tab and the connecting sheet, the welding area including M weld marks, the M weld marks being arranged in a plurality of columns along a second direction and in a plurality of rows along a third direction, with the first direction, the second direction, and the third direction being perpendicular to each other; The total area of the M weld marks is S1; a pulling force F is applied to the tab and the connecting sheet in opposite directions along the third direction, and N weld marks are peeled off. The total area of all the remaining weld marks after peeling off is S2; N is an integer greater than or equal to zero; S1 and S2 satisfy the following conditions: 0.6≤S2 / S1≤1.0; The value range of F is: 30N≤F≤200N.

2. The connection structure between the tab and the connecting piece according to claim 1, characterized in that: The welding area includes two first edges arranged opposite to each other along the second direction, and the distance between the welding mark close to the first edge and the first edge is e, and the value range of e is: 1.5 mm ≤ e ≤ 8.0 mm; And / or, the welding area includes two second edges arranged opposite to each other along a third direction, and the distance between the welding mark close to the second edge and the second edge is f; The value range of f is: 1.5mm≤f≤8.0mm.

3. The connection structure between the tab and the connecting piece according to claim 2, characterized in that: The distance between two adjacent rows of weld marks along the second direction is a; The value range of a is: 0.5mm≤a≤5.0mm; The distance between two adjacent rows of weld marks arranged along the third direction is b; The value range of b is: 0.5mm≤b≤5.0mm.

4. The connection structure between the tab and the connecting piece according to claim 2, characterized in that: The connecting piece and the tab form an overlapping area along the first direction; along the second direction, the distance between the first edge and the adjacent side of the overlapping area is C, and the value range of C is: 2mm≤C≤20mm.

5. The connection structure between the tab and the connecting piece according to claim 4, characterized in that: Along the third direction, a distance D is between the second edge and an adjacent side edge of the overlapping area; The value range of D is: 2mm≤D≤20mm.

6. The connection structure between the tab and the connecting piece according to claim 1, characterized in that: The length of the welding area along the second direction is A, and the width of the welding area along the third direction is B; The value range of A is: 6mm≤A≤80mm; The value range of B is: 4mm≤B≤30mm.

7. The connection structure between the tab and the connecting piece according to claim 1, characterized in that: The shape of the weld mark is circular or polygonal.

8. A battery, characterized in that: The invention comprises a pole group and a pole column, wherein the pole group comprises a pole lug, one end of the connecting piece is connected to the pole lug by adopting the connection structure of the pole lug and the connecting piece according to any one of claims 1 to 7, and the other end of the connecting piece is electrically connected to the pole column.

9. The battery according to claim 8, characterized in that The electrode groups include two, each of which includes a positive electrode tab and a negative electrode tab. The electrode posts include a positive electrode post and a negative electrode post. The connecting piece includes a first connecting portion and two second connecting portions. The two second connecting portions are both connected to the first connecting portion. The first connecting portion is connected to the positive electrode post. The two second connecting portions are respectively connected to the positive electrode tabs of the two electrode groups. Alternatively, the first connecting portion is connected to the negative electrode column, and the two second connecting portions are respectively connected to the negative electrode tabs of two electrode groups.

10. A power device, characterized in that: A battery comprising the battery according to claim 8 or 9.

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