Connecting piece, battery and punch

Abstract

The utility model provides a connecting piece, a battery and a punch. The connecting piece is used for connecting a pole and a tab of a battery, the connecting piece comprises a tab connecting part and a pole connecting part, the pole connecting part is connected to one side of the tab connecting part, the pole connecting part is provided with a welding area, the welding area is used for being in contact with welding laser, a rough surface is arranged on the pole connecting part in the welding area, a plurality of grooves are formed in the rough surface, and the grooves are communicated with the tab connecting part. And the shapes and / or sizes of the plurality of grooves are different. The utility model aims to solve the technical problems that the connection sheet and the pole of the existing lithium battery are not firmly welded and are easy to fall off.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a connecting piece, a battery and a punch. Background Art

[0002] Lithium batteries have the advantages of small size, high energy density, long service life, and green environmental protection. They are widely used in industries such as automobiles, electronic products, and energy storage systems. In related technologies, the connecting piece of lithium batteries is used as a structure connecting the core pack and the pole. The main connection method is to weld the connecting piece to the surface of the pole by laser penetration welding. However, the connecting piece and the pole are made of different materials. Due to the different materials, the reflectivity and absorption rate of the laser are different during the laser welding process, resulting in the material being unable to be melted quickly, and it is easy to form high reflection, resulting in unstable connection between the connecting piece and the pole, and the risk of falling off. Utility Model Content

[0003] The embodiments of the utility model provide a connecting piece, a battery and a punch, aiming to solve the technical problem that the connecting piece and the pole of the existing lithium battery are not firmly welded and are easy to fall off.

[0004] In a first aspect, an embodiment of the present utility model provides a connecting piece for connecting a pole and a pole ear of a battery, the connecting piece comprising:

[0005] a tab connection portion; and

[0006] A pole connection portion is connected to one side of the pole ear connection portion, and the pole connection portion is provided with a welding area, and the welding area is used to contact with a welding laser. A rough surface is provided on the pole connection portion in the welding area, and the rough surface is formed with a plurality of grooves, and the shapes and / or sizes of the plurality of grooves are different.

[0007] In one embodiment, the surface of the pole connecting portion in the welding area has the rough surface formed by stamping.

[0008] In one embodiment, the surface area of ​​the welding region is S1, and the surface area of ​​the rough surface is S2, wherein S2=aS1, a is a first coefficient, 0.15≤a≤1.

[0009] In one embodiment, the groove has a first size L1, which is the distance between two parallel planes virtually abutting against groove walls on both sides of the groove, wherein L1≥0.1 mm.

[0010] In one embodiment, the depth of the groove is H1, wherein 5um≤H1≤100um; and / or,

[0011] The thickness of the pole connection portion is H2, wherein 0.4 mm≤H2≤2 mm.

[0012] In one embodiment, the surface roughness of the welding area is Sz, wherein 0.5um≤Sz≤50um; or

[0013] The surface roughness of the welding area is Rz, wherein 0.5um≤Rz≤50um.

[0014] In one embodiment, the shape of the groove includes at least two of a circle, an ellipse, an irregular circle, a polygon, and an irregular polygon.

[0015] In one embodiment, the depth of each of the grooves is different; and / or,

[0016] The groove has a first size L1, and the first size L1 of each groove is different; and / or,

[0017] The distances between two adjacent grooves are different.

[0018] In a second aspect, an embodiment of the utility model provides a battery, comprising the above-mentioned connecting piece, wherein the connecting piece comprises:

[0019] a tab connection portion; and

[0020] A pole connecting portion is connected to one side of the pole lug connecting portion, and the pole lug connecting portion is provided with a welding area, and the welding area is used to contact with a welding laser. A rough surface is provided on the pole connecting portion within the welding area, and the rough surface is formed with a plurality of grooves, and the shapes and / or sizes of the plurality of grooves are different.

[0021] In a third aspect, an embodiment of the utility model provides a punch for preparing the above-mentioned connecting sheet, the punch comprising:

[0022] a connecting portion for connecting to a machine tool; and

[0023] A stamping portion is arranged opposite to the connecting portion, and is used for stamping the welding area of ​​the connecting piece. A stamping boss is provided at one end of the stamping portion facing the welding area, and a plurality of the stamping bosses are used to correspond to the plurality of the grooves.

[0024] In one embodiment, the stamping portion has a stamping boss formed by electrical spark machining or chemical etching at one end thereof facing the welding region.

[0025] In one embodiment, the surface area of ​​the stamping portion is S3, and the sum of the surface areas of the plurality of stamping bosses is S4, wherein S4=bS3, b is a first coefficient, 0.3≤b≤1.

[0026] Beneficial effects of the embodiments of the utility model:

[0027] In the technical solution of the utility model, the pole lug connection part is used to connect with the pole lug, and the pole connection part is provided with a welding area, and the welding area is used to connect with the pole, and the connection is connected by welding, which can improve the connection strength between the pole connection part and the pole. At the same time, the welding area is arranged in a rough surface, and the rough surface can increase the surface refractive index of the welding area, improve the absorption rate of the welding area to the laser, so that the pole connection part in the welding area can be quickly melted and connected, thereby improving the machinability of the pole connection part and the pole, reducing the difficulty of welding the pole connection part and the pole, further improving the connection strength between the pole connection part and the pole, and reducing the probability of the pole connection part and the pole falling off. Furthermore, the purpose of setting a plurality of grooves with different shapes and / or sizes is to increase the roughness of the rough surface, thereby improving the machinability of the welding area. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a schematic diagram of the structure of the connecting piece provided in an embodiment of the utility model;

[0030] Figure 2 yes Figure 1 Microscopic image of the medium rough surface;

[0031] Figure 3 yes Figure 2 An enlarged schematic diagram of the middle groove;

[0032] Figure 4 It is a schematic diagram of the structure of the punch provided by the embodiment of the utility model;

[0033] Figure 5 yes Figure 4 Microscopic image of the middle stamping part;

[0034] Figure 6 It is a schematic diagram of the preparation process of the punch provided by the utility model.

[0035] Description of Figure Numbers

[0036]

[0037] DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0039] In the related art, the connecting piece of the lithium battery is used as a structure connecting the core pack and the pole, and the connection method is mainly to weld the connecting piece to the surface of the pole by laser penetration welding. However, the connecting piece and the pole are made of different materials. Due to the different materials, the reflectivity and absorption rate of the laser are different during the laser welding process, resulting in the material being unable to be melted quickly and easily forming high reflection, which leads to unstable connection between the connecting piece and the pole and the risk of falling off.

[0040] In view of this, the utility model proposes a connecting piece. Figures 1 to 3 This is a structural schematic diagram of an embodiment of a connecting piece provided by the utility model. The connecting piece provided by the utility model has a large refractive index for lasers, can absorb a large amount of energy generated by lasers, has reduced difficulty in welding with poles, increases connection strength, and reduces the risk of falling off. The connecting piece will be described in detail below in conjunction with the main drawings.

[0041] See also Figure 1 , Figure 2 and Figure 3 The utility model provides a connecting piece 100 for connecting a pole and a pole lug of a battery. The connecting piece 100 includes a pole lug connecting portion 101 and a pole connecting portion 102. The pole connecting portion 102 is connected to one side of the pole lug connecting portion 101. The pole lug connecting portion 101 is provided with a welding area 103. The welding area 103 is used to contact with a welding laser. A rough surface 104 is provided in the welding area 103 of the pole connecting portion 102. The rough surface 104 is formed with a plurality of grooves 105. The shapes and / or sizes of the plurality of grooves 105 are different.

[0042] In the technical solution of the utility model, the pole lug connection part 101 is used to connect with the pole lug, and the pole connection part 102 is provided with a welding area 103, and the welding area 103 is used to connect with the pole. The connection is connected by welding, which can improve the connection strength between the pole connection part 102 and the pole. At the same time, a rough surface 104 is provided in the welding area 103, and the rough surface 104 can increase the surface refractive index of the welding area 103, and improve the absorption rate of the welding area 103 to the laser, so that the pole connection part 102 in the welding area 103 can be quickly melted and connected, thereby improving the processability of the pole connection part 102 and the pole, reducing the difficulty of welding the pole connection part 102 and the pole, further improving the connection strength between the pole connection part 102 and the pole, and reducing the probability of the pole connection part 102 and the pole falling off. Furthermore, the purpose of providing a plurality of grooves 105 with different shapes and / or sizes is to increase the roughness of the rough surface 104, thereby improving the processability of the welding area 103.

[0043] It should be noted that, in this embodiment, the pole tab connection portion 101 and the pole connection portion 102 are integrally formed.

[0044] Specifically, in the present embodiment, the connecting piece 100 is made of aluminum, and the pole is made of copper. Since the surfaces of copper and aluminum are too smooth, during the welding process, large laser refraction is likely to occur on the surface, and the absorption rate is too low, so that the material cannot be melted quickly, resulting in high reflection, which leads to the risk of the pole connecting portion 102 and the pole falling off easily. A rough surface 104 is provided in the welding area 103. During the welding process, the absorption rate of the laser by the welding area 103 can be improved, so that the welding area 103 and the pole can be melted quickly, the machinability of the pole connecting portion 102 can be improved, the welding difficulty of the pole connecting portion 102 and the pole can be reduced, and the connection strength between the pole connecting portion 102 and the pole can be improved.

[0045] It should be noted that, in order to ensure the connection strength, the pole lug connection part 101 is welded to the pole lug, and the pole post connection part 102 is welded to the pole post. The pole lug connection part 101 includes a main body and two connection sub-parts, one side of the main body is connected to the pole post connection part 102, and the other side of the main body is connected to the two connection sub-parts, and the two connection sub-parts are arranged at intervals.

[0046] It should be noted that the formation process of the rough surface 104 is not limited and can be selected according to actual conditions. In this embodiment, the rough surface 104 is formed on the surface of the pole connection portion 102 in the welding area 103 by a stamping process. Specifically, the connecting piece 100 is placed on a punching machine, and the welding area 103 corresponds to the punch 200 on the punching machine. The punch 200 is provided with a plurality of stamping bosses 203. The punch 200 is stamped on the surface of the welding area 103, and the pattern on the punch 200 is printed on the welding area 103, thereby forming a plurality of grooves 105 in the welding area 103, so that the surface of the welding area 103 is no longer flat and smooth, and the plurality of grooves 105 increase the surface roughness of the welding area 103, thereby forming a rough surface 104.

[0047] See also Figure 2 and Figure 3 The shape of the groove 105 is not limited and the grooves 105 are arranged irregularly. The purpose of such a setting is to increase the roughness of the rough surface 104 so that the welding area 103 can better cope with laser high reflection. Specifically, in some embodiments, the shape of the groove 105 includes at least two of a circle, an ellipse, an irregular circle, a polygon, and an irregular polygon. More specifically, in one embodiment, the shape of the groove 105 includes a circle, an ellipse, a triangle, a square, and a rectangle; the circle, the ellipse, the triangle, the rectangle, and the square are arranged irregularly. It should be noted that please refer to Figure 2 , Figure 2 is a microscopic image of the welding area 103. Figure 2 It can be seen that in the actual production process, the shape of the groove 105 is more irregular. Since the shape of the stamping boss 203 on the punch 200 is irregular, the shape of the groove 105 is more irregular.

[0048] Specifically, in some embodiments, the surface area of ​​the welding area 103 is S1, and the surface area of ​​the rough surface 104 is S2, wherein S2=aS1, a is the first coefficient, and 0.15≤a≤1. It should be noted that when the ratio of the rough surface 104 to the welding area 103 is less than 0.15, the area of ​​the rough surface 104 is small, and there are fewer areas that can reflect the laser light less, resulting in a higher reflection of the laser light in the welding area 103, and the welding difficulty of the welding area 103 and the pole increases, resulting in a decrease in the connection strength between the connecting piece 100 and the pole, and a risk of falling off. When the ratio of the rough surface 104 to the welding area 103 is greater than 1, the rough surface 104 exceeds the welding area 103, resulting in an increase in the roughness of the pole connection part 102 where the welding area 103 is not set. It should be noted that when the roughness increases, the corresponding surface smoothness decreases. The decrease in smoothness will cause the pole connection part 102 to be easily corroded by water vapor in the air, resulting in a decrease in the service life of the connecting piece 100, which is not worth the loss. Specifically, the surface area of ​​the rough surface 104 is 0.15 to 1 times the surface area of ​​the welding area 103. Within the above range, the welding difficulty between the welding area 103 and the pole can be reduced, the connection strength between the connecting piece 100 and the pole can be increased, and the service life of the connecting piece 100 can be ensured to prevent the connecting piece 100 from being corroded.

[0049] In some embodiments, the groove 105 has a first size L1, which is the distance between two parallel planes of the groove walls on both sides of the groove 105 at virtual abutment (virtual abutment means that when measuring the size of the groove, the start and end lines of the dimension line coincide with the straight line where the groove wall of the groove is located), wherein L1≥0.1mm. It should be noted that due to the different sizes of the poles, the sizes of the welding area 103 are also different, and the areas of the rough surface 104 are also different, resulting in different numbers of grooves 105. Generally, the surface area of ​​the rough surface 104 is related to the size of the pole. As the size of the pole changes, when the size of the pole is larger, in order to ensure the connection strength, the area of ​​the welding area 103 is also increased accordingly, the area of ​​the rough surface 104 is increased accordingly, and the number and size of the grooves 105 are also increased accordingly. When the size of the pole is reduced, the area of ​​the welding area 103 is correspondingly reduced, the area of ​​the rough surface 104 is correspondingly reduced, and the number and size of the grooves 105 are correspondingly reduced. It should be noted that, through research conducted by the applicant, it is found that when the first size of the groove 105 is greater than or equal to 0.1 mm, the light reflection of the welding area 103 can be significantly improved. When the first size is less than 0.1 mm, although the roughness of the rough surface 104 can be improved, the improvement effect on the light reflection phenomenon of the welding area 103 is small, so the first size needs to be greater than or equal to 0.1 mm. As a preferred embodiment, the first size of the groove 105 is 0.1 mm, which can significantly improve the light reflection phenomenon of the welding area 103.

[0050] It should be noted that the groove 105 has an opening, the opening has a width, and the first dimension is the widest width of the opening.

[0051] In some embodiments, the depth of the groove 105 is H1, where 5um≤H1≤100um; it should be noted that when the depth of the groove 105 is less than 5um, the roughness of the rough surface 104 is small, the light reflection phenomenon of the welding area 103 is more obvious, the welding difficulty of the welding area 103 and the pole is increased, and the connection strength between the welding area 103 and the pole is also reduced. When the depth of the groove 105 is greater than 100um, the deformation of the pole connection part 102 is too large, resulting in serious overall deformation of the connecting piece 100, and the service life of the connecting piece 100 is reduced. Specifically, the depth of the groove 105 can be 5um, 6um, 7um, 8um, 9um, 10um, 11um, 12um, 13um, 14um, 15um, 16um, 17um, 18um, 19um, 20um, 25um, 30um, 35um, 40um, 45um, 50um, 55um, 60um, 65um, 70um, 75um, 80um, 85um, 90um, 91um, 92um, 93um, 94um, 95um, 96um, 97um, 98um, 99um, 100um.

[0052] In some embodiments, the thickness of the pole connection portion 102 is H2, wherein 0.4 mm ≤ H2 ≤ 2 mm. It should be noted that when the thickness of the pole connection portion 102 is less than 0.4 mm, the strength of the pole connection portion 102 is correspondingly reduced, and during the process of stamping the rough surface 104, the pole connection portion 102 may be broken due to insufficient strength. When the thickness of the pole connection portion 102 is greater than 2 mm, the welding difficulty increases when the pole connection portion 102 is welded to the pole. The thickness of the pole connection portion 102 can be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm.

[0053] It should be noted that Sz is the maximum height difference of the measurement plane, and Sz is usually the surface roughness measured by a depth of field test instrument. In specific operation, an area is selected on the rough surface 104, and the depth of field test instrument is aimed at this area for measurement to obtain the surface roughness of this area. Specifically, in this embodiment, the surface roughness of the welding area 103 is Sz, where 0.5um≤Sz≤50um. It should be noted that when the roughness of the welding area 103 is less than 0.5um, the light reflection phenomenon of the welding area 103 is more obvious, the welding difficulty of the welding area 103 and the pole increases, and the connection strength between the welding area 103 and the pole is also reduced. When the surface roughness of the welding area 103 is greater than 50um, the welding area 103 is easily corroded by moisture in the air, resulting in corrosion of the connecting piece 100, which affects the service life of the connecting piece 100.

[0054] Rz is the maximum height difference of the tested contour line. Rz is usually measured by a roughness tester. The roughness tester is placed at the position to be measured, so that the probe is aligned with the welding area 103. The roughness tester is started, and the probe will draw a line on the surface of the welding area 103. The surface roughness of the welding area 103 can be calculated through this line. Specifically, in the present embodiment, the surface roughness of the welding area 103 is Rz, where 0.5um≤Rz≤50um. It should be noted that when the surface roughness of the welding area 103 is less than 0.5um, the light reflection phenomenon of the welding area 103 is more obvious, the welding difficulty of the welding area 103 and the pole increases, and the connection strength of the welding area 103 and the pole is also reduced. When the surface roughness of the welding area 103 is greater than 50um, the welding area 103 is easily corroded by moisture in the air, resulting in corrosion of the connecting piece 100, which affects the service life of the connecting piece 100.

[0055] It should be noted that the above method can be selected according to the actual situation during the actual test process.

[0056] In some embodiments, the depth of each groove 105 is different. In other embodiments, the groove 105 has a first size L1, and the first size L1 of each groove 105 is different. In other embodiments, the distance between two adjacent grooves 105 is different. In this way, the depth of the groove 105, the width of the groove 105, and the distance between the grooves 105 and the grooves 105 are all different, which can achieve different depths of the structure, increase the roughness of the rough surface 104, improve the light reflection phenomenon of the welding area 103, reduce the difficulty of welding the pole connecting part 102 and the pole, and improve the connection strength between the pole connecting part 102 and the pole.

[0057] The utility model also provides a battery, which includes a pole, a pole ear and the above-mentioned connecting piece 100. The connecting piece 100 is connected between the pole and the pole ear. The specific structure of the connecting piece 100 refers to the above-mentioned embodiment. Since the battery adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0058] In addition, due to the different materials of the connecting piece and the pole, the reflectivity and absorption rate of the laser are different during the laser welding process, which makes the material unable to be melted quickly and easily forms high reflection, resulting in unstable connection between the connecting piece and the pole, and the risk of falling off. In the related art, the connecting piece is embossed by regular embossing to improve the surface roughness of the connecting piece and improve the light reflection phenomenon of the connecting piece, so as to achieve welding. However, regular embossing requires too high precision of the punch. During repeated stamping, the punch will wear. When the wear is large, it cannot meet the requirements. In view of this, the utility model also proposes a punch 200 for preparing the connecting piece 100 in the above-mentioned embodiment 1. The punch 200 provided by the utility model has a simple structure, can punch out irregular patterns on the connecting piece 100, and has a long service life. The connecting piece 100 will be described in detail below in conjunction with the main drawings.

[0059] See also Figure 4 and Figure 5 The punch 200 includes a connecting portion 202 and a stamping portion 201. The connecting portion 202 is used to connect to the machine tool; the stamping portion 201 is arranged opposite to the connecting portion 202, and the stamping portion 201 is used to stamp the welding area 103 of the connecting piece 100. A stamping boss 203 is provided at one end of the stamping portion 201 facing the welding area 103, and multiple stamping bosses 203 are used to correspond to multiple grooves 105.

[0060] In the technical solution of the present utility model, the stamping part 201 stamps the connecting piece 100 so that a plurality of grooves 105 are formed on the connecting piece 100, thereby increasing the surface roughness of the connecting piece 100, improving the light reflection phenomenon of the connecting piece 100 to the laser, reducing the difficulty of welding the connecting piece 100 and the pole, and increasing the connection strength between the connecting piece 100 and the pole.

[0061] It should be noted that the forming method of the stamping boss 203 is not limited, and the surface of the object can be processed by electric spark, sandblasting, sun graining, chemical etching, etc. to form surface grains (i.e., the stamping boss 203); specifically, in this embodiment, the stamping boss 203 is formed at one end of the stamping portion 201 facing the welding area 103 by electric spark machining or chemical etching. The surface roughness processed by electric spark machining or chemical etching can reach 1um to 100um.

[0062] It should be noted that the EDM process is relatively simple, and it is only necessary to ensure that the object to be processed can conduct electricity. Therefore, in this embodiment, please refer to Figure 6 , put the punch 200 to be processed into the processing groove 300 of the electric spark machine 400, fill the processing groove 300 with protective liquid, align the electric spark machine 400 with the punch 200 to be processed (i.e., the stamping part 201), and the electric spark machine 400 discharges, instantly concentrating a large amount of heat, leaving tiny irregular pit marks on the surface of the stamping part 201. Through repeated processing, the surface of the stamping part 201 can be covered with irregular pits, and the pit walls of two adjacent pits constitute a stamping boss 203.

[0063] More specifically, after the punch 200 is processed, the punching portion 201 is subjected to nitriding treatment to enhance the surface hardness of the punching portion 201 and increase the life of the punch 200 .

[0064] See also Figure 5 , the shape of the stamping boss 203 is not limited and the stamping boss 203 is arranged irregularly. With such a configuration, the precision requirement for the punch 200 is relatively low. Even if the punch 200 is slightly worn due to long-term use, it will not affect the stamping of the connecting piece 100, thereby increasing the service life of the punch 200. Specifically, in some embodiments, the shape of the stamping boss 203 includes at least two of a circle, an ellipse, an irregular circle, a polygon, and an irregular polygon. More specifically, in one embodiment, the shape of the stamping boss 203 includes a circle, an ellipse, a triangle, a square, and a rectangle; the circle, the ellipse, the triangle, the rectangle and the square are arranged irregularly. It should be noted that please refer to Figure 5 , Figure 5 is a microscopic image of the stamping boss 203. Figure 5 It can be seen that in the actual production process, the shape of the stamping boss 203 is more irregular, which can effectively increase the service life of the punch 200 and reduce costs.

[0065] Specifically, in some embodiments, the surface area of ​​the stamping portion 201 is S3, and the sum of the surface areas of the plurality of stamping bosses 203 is S4, wherein S4=bS3, b is the second coefficient, and 0.3≤b≤1. It should be noted that when the ratio of the sum of the surface areas of the plurality of stamping bosses 203 to the surface area of ​​the stamping portion 201 is less than 0.15, the number of stamping bosses 203 formed on the stamping portion 201 is small, resulting in a low roughness of the punched connecting piece 100, a high light reflection of the connecting piece 100 to the laser, and an increased difficulty in welding the connecting piece 100 to the pole, resulting in a reduced connection strength between the connecting piece 100 and the pole, and a risk of falling off. When the ratio of the sum of the surface areas of the plurality of stamping bosses 203 to the surface area of ​​the stamping portion 201 is greater than 1, the processing difficulty of the stamping portion 201 increases.

[0066] In some embodiments, the height of the stamping boss 203 is H2, where 5um≤H2≤100um; it should be noted that when the height of the stamping boss 203 is less than 5um, the roughness of the welding area 103 on the punched connecting piece 100 is small, the light reflection phenomenon of the welding area 103 is more obvious, the welding difficulty of the welding area 103 and the pole is increased, and the connection strength between the welding area 103 and the pole is also reduced. When the height of the stamping boss 203 is greater than 100um, during the stamping process, the deformation of the connecting piece 100 is too large, resulting in serious overall deformation of the connecting piece 100, and the service life of the connecting piece 100 is reduced. Specifically, the height of the stamping boss 203 can be 5um, 6um, 7um, 8um, 9um, 10um, 11um, 12um, 13um, 14um, 15um, 16um, 17um, 18um, 19um, 20um, 25um, 30um, 35um, 40um, 45um, 50um, 55um, 60um, 65um, 70um, 75um, 80um, 85um, 90um, 91um, 92um, 93um, 94um, 95um, 96um, 97um, 98um, 99um, and 100um.

[0067] Specifically, the stamping process of the connecting piece 100 is as follows: the raw material of the connecting piece 100 is unrolled, and shaped according to the shape of the connecting piece 100, and then the connecting piece 100 is placed on the mold, and the punch 200 is assembled on the mold so that the stamping part 201 is opposite to the welding area 103 of the connecting piece 100, and the stamping depth of the mold is adjusted. During the stamping process, rough punching is first performed to punch out the outer contour of the groove 105, and then fine punching is performed to punch out the depth and width of the groove 105. The material is blanked and cleaned to complete the manufacture of the connecting piece 100. The roughness of the connecting piece 100 is measured by a depth of field test instrument or a roughness test instrument. When the surface roughness Sz of the connecting piece 100 is between 0.5 and 50 um or the line roughness Rz is between 0.5 and 50 um, the product meets the requirements.

[0068] The embodiments of the present invention are described in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A connecting piece for connecting a pole and a lug of a battery, characterized in that: The connecting piece comprises: a tab connection portion; and A pole connection portion is connected to one side of the pole ear connection portion, and the pole connection portion is provided with a welding area, and the welding area is used to contact with a welding laser. A rough surface is provided on the pole connection portion in the welding area, and the rough surface is formed with a plurality of grooves, and the shapes and / or sizes of the plurality of grooves are different.

2. The connecting piece according to claim 1, characterized in that: The surface of the pole connecting portion in the welding region has the rough surface formed by stamping.

3. The connecting sheet according to claim 1, characterized in that: The surface area of ​​the welding region is S1, and the surface area of ​​the rough surface is S2, wherein S2=aS1, a is the first coefficient, 0.15≤a≤1.

4. The connecting sheet according to any one of claims 1 to 3, characterized in that: The groove has a first size L1, which is the distance between two parallel planes virtually abutting against groove walls on both sides of the groove, wherein L1≥0.1 mm.

5. The connecting sheet according to any one of claims 1 to 3, characterized in that: The depth of the groove is H1, wherein 5um≤H1≤100um; and / or, The thickness of the pole connection portion is H2, wherein 0.4 mm≤H2≤2 mm.

6. The connecting sheet according to any one of claims 1 to 3, characterized in that: The surface roughness of the welding area is Sz, wherein 0.5um≤Sz≤50um; or The surface roughness of the welding area is Rz, wherein 0.5um≤Rz≤50um.

7. The connecting sheet according to any one of claims 1 to 3, characterized in that: The shapes of the grooves include at least two of circular, elliptical and polygonal shapes.

8. The connecting sheet according to any one of claims 1 to 3, characterized in that: The depth of each of the grooves is different; and / or, The groove has a first size L1, and the first size L1 of each groove is different; and / or, The distances between two adjacent grooves are different.

9. A battery, characterized in that: Comprising the connecting piece as described in any one of claims 1 to 8.

10. A punch, characterized in that: For preparing the connecting piece according to any one of claims 1 to 8, the punch comprises: a connecting portion for connecting to a machine tool; and A stamping portion is arranged opposite to the connecting portion, and is used for stamping the welding area of ​​the connecting piece. A stamping boss is provided at one end of the stamping portion facing the welding area, and a plurality of the stamping bosses are used to correspond to the plurality of the grooves.

11. The punch according to claim 10, characterized in that One end of the stamping portion facing the welding area has the stamping boss formed by electrical spark machining or chemical etching.

12. The punch according to claim 10 or 11, characterized in that: The surface area of ​​the stamping portion is S3, and the sum of the surface areas of the plurality of stamping bosses is S4, wherein S4=bS3, b is the first coefficient, 0.3≤b≤1.

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