Welding structure and welding method of composite current collector tab

Abstract

The invention discloses a welding structure and method of a composite current collector tab, and the welding structure of the composite current collector tab comprises a plurality of composite current collectors, each composite current collector is provided with a welding hole; the composite current collectors are arranged in a stacked mode, the welding holes are aligned, and the metal structural parts are arranged between every two adjacent composite current collectors so as to be assembled to form a composite current collector structure; one end face of the composite current collector structure is provided with a first switching piece, the other opposite end face of the composite current collector structure is provided with a tab assembly, and the first switching piece, the composite current collector structure and the tab assembly are welded to form a welding printing area. According to the invention, the metal structural members are clamped between the two adjacent composite current collectors, so that the current can flow out from the multiple metal structural members, and then the overcurrent capability can be improved; meanwhile, the plurality of metal structural parts are welded with the first switching piece, so that the strength of the welding marks is improved.

Description

Technical Field

[0001] The invention relates to the technical field of lithium ion batteries, and in particular to a welding structure and a welding method for a composite current collector tab. Background Art

[0002] The composite current collector structure is a sandwich structure, with a polymer material layer in the middle and metal conductive layers on both sides. When the composite current collector is currently prepared into a battery, it is also necessary to transfer pure metal foil on the composite current collector through roll welding. The pure metal foil welded during the final assembly of the battery is used to conduct the current gathered by the composite current collector. However, when welding the current composite current collector tabs, the weld quality is low, and it is easy to have problems such as welding through, poor bonding strength and falling off. At the same time, the current capacity of the tab welds welded using the current welding method is low.

[0003] Therefore the prior art still needs to be improved and enhanced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a welding structure and a welding method for a composite current collector electrode tab, aiming to solve the problem of poor welding effect of the existing composite current collector electrode tab.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A welding structure of a composite current collector tab, comprising:

[0007] A plurality of composite current collectors, each of which is provided with a welding hole;

[0008] A plurality of metal structural members, wherein the composite current collectors are stacked and the welding holes are aligned, and the metal structural members are arranged between two adjacent composite current collectors to assemble and form a composite current collector structure;

[0009] A first adapter sheet is disposed on one end surface of the composite current collector structure, and a tab assembly is disposed on the other opposite end surface of the composite current collector structure. The first adapter sheet, the composite current collector structure and the tab assembly are welded to form a weld mark area.

[0010] The thickness of the first adapter sheet is 20 μm-1500 μm; the depth of the welding hole is 6 μm-600 μm, and the aperture of the welding hole is 1.5 mm-5 mm; the thickness of the metal structure is 4 μm-20 μm.

[0011] The thickness of the weld print area is 6 μm-50 μm, the length of the weld print area is 2 mm-100 mm, and the width of the weld print area is 10 mm-150 mm.

[0012] The first adapter is arranged on the upper end surface of the composite current collector structure, and the pole tab assembly includes a pole tab body arranged on the lower end surface of the composite current collector, the length of the pole tab body is greater than the length of the composite current collector, and one end of the pole tab body extends out of the edge of the composite current collector structure; the first adapter, the composite current collector structure and the pole tab body are welded through the welding hole to form a first welding mark area.

[0013] The length of the first adapter sheet is greater than that of the composite current collector, the same end of the first adapter sheet and the tab body extends out of the edge of the composite current collector, and the contact portion between the extended portion of the first adapter sheet and the extended portion of the tab body is welded to form a second weld mark area.

[0014] The tab assembly includes a second adapter plate arranged on the lower end surface of the composite current collector structure, the first adapter plate is arranged on the upper end surface of the composite current collector structure, and the first adapter plate, the composite current collector structure and the second adapter plate are welded through the welding hole to form a third welding print area.

[0015] The tab assembly also includes a tab body, the length of the two adapter plates is greater than the length of the composite current collector, and the same end of the two adapter plates extends out of the edge of the composite current collector structure, and the tab body contacts and welds with the extended parts of the two adapter plates to form a fourth weld print area.

[0016] The tab assembly also includes a tab body, the length of the metal structure and the two adapter plates is greater than the length of the composite current collector, and the same end of the metal structure and the two adapter plates extends out of the edge of the composite current collector, the extended portion of the metal structure and the extended portion of the two adapter plates are in contact and welded to form a fifth weld print area; one end of the tab body is in contact with the extended portion of the metal structure and welded to form a sixth weld print area.

[0017] The thickness of the second adapter sheet is 20 μm-1500 μm.

[0018] A welding method for the composite current collector welding structure described above comprises:

[0019] Drilling welding holes on a plurality of composite current collectors, wherein the welding holes penetrate the composite current collectors;

[0020] Stacking a plurality of the composite current collectors so that the welding holes are aligned, and arranging a metal structure between two adjacent composite current collectors to assemble a composite current collector structure;

[0021] The first adapter and the tab assembly are respectively placed on the upper and lower sides of the composite current collector structure, and connected to the upper and lower ends of the composite current collector structure;

[0022] The first adapter plate, the composite current collector structure and the tab assembly are welded together at the welding hole position by an ultrasonic welding process to form a welding mark area.

[0023] Compared with the prior art, the present invention provides a welding structure and method for a composite current collector pole tab, wherein the welding structure of the composite current collector pole tab includes: a plurality of composite current collectors, each of which is provided with a welding hole; a plurality of metal structural parts, wherein the composite current collectors are stacked and the welding holes are aligned, and the metal structural parts are provided between two adjacent composite current collectors to assemble and form a composite current collector structure; a first adapter plate is provided on one end face of the composite current collector structure, and a pole tab assembly is provided on the other opposite end face of the composite current collector structure, and the first adapter plate, the composite current collector structure and the pole tab assembly are welded to form a weld print area. In the present application, by sandwiching the metal structural parts between two adjacent composite current collectors, the current can flow out from a plurality of metal structural parts, thereby improving the current flow capacity; at the same time, the plurality of metal structural parts are welded to the first adapter plate, thereby improving the strength of the weld print. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of the first embodiment of the welding structure of the composite current collector electrode provided by the present invention.

[0025] Figure 2 It is a schematic structural diagram of the second embodiment of the welding structure of the composite current collector electrode provided by the present invention.

[0026] Figure 3 It is a schematic structural diagram of the third embodiment of the welding structure of the composite current collector electrode provided by the present invention.

[0027] Figure 4 It is a schematic structural diagram of a fourth embodiment of the welding structure of the composite current collector electrode tab provided by the present invention.

[0028] Figure 5 It is a schematic structural diagram of a pole tab on a part of the composite current collector structure in the welding structure of the composite current collector pole tab provided by the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] It should be noted that when a component is referred to as being "mounted on", "fixed on" or "disposed on" another component, it may be directly on the other component or there may be a central component at the same time. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time.

[0031] It should also be noted that the directional terms such as left, right, up, and down in the embodiments of the present invention are merely relative concepts or are based on the normal use status of the product and should not be considered as restrictive.

[0032] The composite current collector structure is a sandwich structure, with a polymer material layer in the middle and metal conductive layers on both sides. When the composite current collector is currently prepared into a battery, it is also necessary to transfer pure metal foil on the composite current collector through roll welding. The pure metal foil welded during the final assembly of the battery is used to conduct the current gathered by the composite current collector. However, when welding the current composite current collector tabs, the weld quality is low, and it is easy to have problems such as welding through, poor bonding strength and falling off. At the same time, the current capacity of the tab welds welded using the current welding method is low.

[0033] The present invention provides a welding structure of a composite current collector tab, see Figure 1-Figure 4 ,include:

[0034] A plurality of composite current collectors 1, each of which is provided with a welding hole 11;

[0035] A plurality of metal structural members 2, the composite current collectors 1 are stacked and the welding holes 11 are aligned, and the metal structural members 2 are arranged between two adjacent composite current collectors 1 to assemble and form a composite current collector structure;

[0036] A first adapter sheet 3 is provided on one end face of the composite current collector structure, and a tab assembly 4 is provided on the other opposite end face of the composite current collector structure. The first adapter sheet 3, the composite current collector structure and the tab assembly 4 are welded to form a weld print area. The material of the metal structural member 2 in the present application can be copper foil or aluminum foil. By sandwiching the metal structural member 2 between two adjacent composite current collectors 1, the current can flow out from multiple metal structural members 2, thereby improving the current flow capacity; at the same time, multiple metal structural members 2 are welded to the first adapter sheet 3, which improves the strength of the weld print. It should be noted that when the composite current collector 1 is used to prepare a battery, the weld print area will not be coated with active materials; the composite current collector structure in the present application is a structure formed by staggered stacking of a number of composite current collectors 1 and metal structural members 2.

[0037] The thickness of the first adapter sheet 3 and the second adapter sheet 42 is 20μm-1500μm, which can provide better conduction capability, which is beneficial to improving the stability of welding between the adapter sheet and the composite current collector 1 and preventing the adapter sheet from falling off the composite current collector structure; the depth of the welding hole 11 is 6μm-600μm, and the aperture of the welding hole 11 is 1.5mm-5mm; the thickness of the metal structure 2 is 4μm-20μm.

[0038] Generally speaking, the composite current collector 1 includes a thin film material layer located in the middle layer, and the thin film material layer can be a PP film, a PET film, a PI film, etc. The upper surface and the lower surface of the thin film material layer are covered with a conductive metal material layer, and the material of the conductive metal material can be metal copper, metal aluminum, etc.; when the composite current collector 1 is a composite copper current collector, the conductive metal material is metal copper. At this time, due to the potential difference between copper and other metals, and the potential difference will cause copper to be corroded, therefore, the first adapter sheet 3 used in the composite copper current collector in the present application is copper foil, and the metal structural member 2 is also copper foil.

[0039] When the composite current collector 1 in the present application is a composite aluminum current collector, the conductive metal material is aluminum, and the first adapter 3 and the metal structure 2 are also aluminum foil. In the present application, preferably, when the first adapter 3 is copper foil or aluminum foil, its thickness is 20μm-100μm; when the metal structure 2 is copper foil, the thickness of the metal structure 2 is 4.5μm-6μm; when the metal structure 2 is aluminum foil, the thickness of the metal structure 2 is 6μm-15μm; different thicknesses are selected according to different materials of the metal structure 2, which can reduce the thickness and weight of the entire weld print area after welding, and improve the peeling force and weld print strength of the product after welding.

[0040] The thickness of the weld print area is 6 μm-50 μm, the length of the weld print area is 2 mm-100 mm, and the width of the weld print area is 10 mm-150 mm, which is beneficial to improving the strength of the connection of the welding area.

[0041] In the first embodiment of the present application, the first adapter plate 3 is arranged on the upper end surface of the composite current collector structure, and the pole tab assembly 4 includes a pole tab body 41 arranged on the lower end surface of the composite current collector 1, the length of the pole tab body 41 is greater than the length of the composite current collector 1, and one end of the pole tab body 41 extends out of the edge of the composite current collector structure; the first adapter plate 3, the composite current collector structure and the pole tab body 41 are welded through the welding hole 11 to form a first welding mark area 51.

[0042] Specifically, in the first embodiment, a laser is first used to punch a welding hole 11 at the place where the pole ear body 41 is welded on the composite current collector 1, and the area irradiated by the laser is vaporized at high temperature to form a welding hole 11; a plurality of composite current collectors 1 with welding holes 11 are stacked so that their welding holes 11 are aligned, and a metal structure 2 is sandwiched between two adjacent composite current collectors 1 to form a composite current collector structure, and the outermost sides of the upper and lower end surfaces of the composite current collector structure are both composite current collectors 1; then a first adapter sheet 3 with a length equal to that of the composite current collector 1 and a adapter sheet longer than that of the composite current collector 1 are taken. The tab body 41, the first adapter 3 is placed on the upper surface of the composite current collector structure, the tab body 41 is placed on the lower surface of the composite current collector 1, the tab body 41 is aligned with the composite current collector structure at one end in the length direction, and the tab body 41 extends out of the edge of the composite current collector structure at the other end in the length direction, and the first adapter 3, the composite current collector structure and the tab body 41 form a sandwich structure; finally, an ultrasonic welding device is used to weld from both sides of the first adapter 3 and the tab body 41 toward the center of the sandwich structure along the position of the welding hole 11 to form a first weld print area 51. The welding structure of this embodiment can electrically connect the first adapter 3, the composite current collector structure and the tab body 41. When the composite current collector structure in this application is used in a battery, the current on one side of the first adapter 3 is directly guided to the tab body 41 through the welding hole 11 of the first weld print area 51, and then the tab body 41 outputs the current to the outside. In this embodiment, preferably, the sizes of the first adapter plate 3 and the metal structure 2 are the same as the sizes of the composite current collector 1, the width of the pole ear body 41 is the same as the width of the composite current collector 1, and the length of the pole ear body 41 is greater than the length of the composite current collector 1; of course, alternatively, in this embodiment, the metal structure 2 can also be the same size as the weld print area, but the size of the metal structure 2 needs to cover the weld hole 11.

[0043] An improvement is made on the basis of the first embodiment to form a second embodiment. In the second embodiment of the present application, the length of the first adapter sheet 3 is greater than the length of the composite current collector 1, and the same end of the first adapter sheet 3 and the pole tab body 41 extends out of the edge of the composite current collector 1, and the contact portion between the extended portion of the first adapter sheet 3 and the extended portion of the pole tab body 41 is welded to form a second weld mark area 52.

[0044] Specifically, in the second embodiment, first, a laser is used to punch a welding hole 11 at the place where the pole ear body 41 is welded on the composite current collector 1, and the area irradiated by the laser is vaporized at high temperature to form a welding hole 11; a plurality of composite current collectors 1 with welding holes 11 are stacked and arranged in layers to align the welding holes 11, and a metal structure 2 is sandwiched between two adjacent composite current collectors 1 to form a composite current collector structure, and the outermost sides of the upper and lower end surfaces of the composite current collector structure are both composite current collectors 1; then a first adapter sheet 3 and the pole ear body 41 with a length greater than the composite current collector 1 are taken, and the first adapter sheet 3 is placed on the composite current collector structure. The upper surface, the tab body 41 is placed on the lower surface of the composite current collector 1, the first adapter 3 and the tab body 41 are aligned with the composite current collector structure at one end in the length direction, the first adapter 3 and the other end of the tab extend out of the edge of the composite current collector structure, and the first adapter 3, the composite current collector structure and the tab body 41 form a sandwich structure; finally, the first adapter 3, the composite current collector structure and the tab body 41 are welded along the position of the welding hole 11 by an ultrasonic welding device to form a first weld print area 51, and the extended portion of the first adapter 3 and the extended portion of the tab body 41 are welded to form a second weld print area 52. In this embodiment, the current is gathered from the side of the composite current collector 1 where the first adapter 3 is welded through the welding hole 11 and the place where the first adapter 3 is welded to the tab body 41, and is output from the tab body 41, which has the advantage of accelerating the current output and improving the current capacity. It should be noted that, in actual situations, when the extension of the first adapter 3 and the extension of the tab body 41 are welded, because the composite current collector structure is flexible, the side contact portion of the composite current collector structure will be inclined after the first adapter 3 and the tab body 41 are welded. In this embodiment, preferably, the size of the metal structure 2 is the same as the size of the composite current collector 1, and the width of the first adapter 3 and the tab body 41 is the same as the width of the composite current collector 1; of course, alternatively, in this embodiment, the metal structure 2 can also be the same size as the weld print area, or the metal structure 2 is the same size as the first adapter 3, but the size of the metal structure 2 needs to cover the weld hole 11.

[0045] In the third embodiment of the present application, the tab assembly 4 includes a second adapter sheet 42 disposed on the lower end surface of the composite current collector structure, the first adapter sheet 3 is disposed on the upper end surface of the composite current collector structure, and the first adapter sheet 3, the composite current collector structure and the second adapter sheet 42 are welded through the welding hole 11 to form a third weld print area 53. The tab assembly 4 also includes a tab body 41, the length of the two adapter sheets is greater than the length of the composite current collector 1, and the same end of the two adapter sheets extends out of the edge of the composite current collector structure, and the tab body 41 contacts and welds with the extended portions of the two adapter sheets to form a fourth weld print area 54.

[0046] Specifically, in the third embodiment, first, a laser is used to punch a welding hole 11 on the composite current collector 1, and the area irradiated by the laser is vaporized at high temperature to form a welding hole 11; a plurality of composite current collectors 1 with welding holes 11 are stacked so that their welding holes 11 are aligned, and a metal structural member 2 is sandwiched between two adjacent composite current collectors 1 to form a composite current collector structure, and the outermost sides of the upper and lower end surfaces of the composite current collector structure are both composite current collectors 1, wherein one end of the metal structural member 2 is aligned with the composite current collector structure, and the other end of the metal structural member 2 extends out of the edge of the composite current collector structure; then, two adapter sheets with a length greater than that of the composite current collector 1 are taken, and the first adapter sheet 3 is placed on the upper surface of the composite current collector structure. The second adapter sheet 42 is placed on the lower surface of the composite current collector 1, one end of the two adapter sheets is aligned with one end of the composite current collector structure, and the other end of the two adapter sheets extends out of the edge of the composite current collector structure. At this time, the two adapter sheets and the composite current collector structure form a sandwich structure; then the extension of the two adapter sheets, the extension of the metal structure 2 and one end of the pole ear body 41 are at least partially overlapped; finally, the two adapter sheets and the composite current collector structure are welded along the position of the welding hole 11 by an ultrasonic welding device to form a third weld print area 53, and the extension of the two adapter sheets, the extension of the metal structure 2 and the area where the extension of the pole ear body 41 partially overlaps to form a fourth weld print area 54. In this embodiment, the width of the two adapter sheets, the width of the metal structure 2 and the width of the pole ear body 41 are all the same as the width of the composite current collector 1, the length of the two connecting sheets and the length of the metal structure 2 are greater than the length of the composite current collector 1, and the length of the pole ear body 41 is greater than the length of the extension of the two adapter sheets.

[0047] In the fourth embodiment of the present application, the tab assembly 4 includes a second adapter plate 42 arranged on the lower end surface of the composite current collector structure, the first adapter plate 3 is arranged on the upper end surface of the composite current collector structure, and the first adapter plate 3, the composite current collector structure and the second adapter plate 42 are welded through the welding hole 11 to form a third welding print area 53.

[0048] The tab assembly 4 also includes a tab body 41, the length of the metal structure 2 and the two adapter plates are greater than the length of the composite current collector 1, and the same end of the metal structure 2 and the two adapter plates extends out of the edge of the composite current collector 1, the extended portion of the metal structure 2 and the extended portions of the two adapter plates are in contact and welded to form a fifth weld print area 55; one end of the tab body 41 is in contact with the extended portion of the metal structure 2 and welded to form a sixth weld print area 56.

[0049] Specifically, in the fourth embodiment, first, a laser is used to punch a welding hole 11 on the composite current collector 1, and the area irradiated by the laser is vaporized at high temperature to form a welding hole 11; the composite current collectors 1 with multiple welding holes 11 are stacked so that their welding holes 11 are aligned, and a metal structural member 2 is sandwiched between two adjacent composite current collectors 1 to form a composite current collector structure, and the outermost sides of the upper and lower end surfaces of the composite current collector structure are both composite current collectors 1, wherein one end of the metal structural member 2 is aligned with the composite current collector structure, and the other end of the metal structural member 2 extends out of the edge of the composite current collector structure; then, two adapter sheets with a length greater than the composite current collector 1 are taken, the first adapter sheet 3 is placed on the upper surface of the composite current collector structure, and the second adapter sheet 42 is placed on the lower surface of the composite current collector 1. The surface of the composite current collector structure is aligned with one end of the two adapters, and the other ends of the two adapters extend out of the edge of the composite current collector structure. At this time, the two adapters and the composite current collector structure form a sandwich structure; then the extension of the two adapters is at least partially overlapped with the extension of the metal structure 2; then the extension of the metal structure 2 is partially overlapped with one end of the pole ear body 41; finally, the two adapters and the composite current collector structure are welded along the position of the welding hole 11 by an ultrasonic welding device to form a third weld print area 53, the extension of the two adapters and the extension of the metal structure 2 are welded to form a fifth weld print area 55, and the extension of the metal structure 2 and the end of the pole ear body 41 are partially overlapped to form a sixth weld print area 56. In this embodiment, the width of the two adapters, the width of the metal structure 2, and the width of the pole ear body 41 are the same as the width of the composite current collector 1, the length of the two connecting sheets and the length of the metal structure 2 are greater than the length of the composite current collector 1, and the length of the metal structure 2 is greater than the length of the two connecting sheets and partially overlaps with the pole ear body 41.

[0050] Please note that Figure 1-Figure 5In the present application, a lug region is provided on the composite current collector structure, that is, lug regions B are provided on the composite current collectors at both upper and lower end surfaces of the composite current collector structure. In the lug region, it is necessary to form a protruding lug A in the lug region through cutting or other methods so that the end surface of the composite current collector structure forms a protruding lug A in the lug region. At this time, it is called lug A on the composite current collector. Region C is the area for coating active materials, and the lug body in the lug assembly 4 refers to the lug of the battery cell. The present application is to weld the first adapter plate 3 and the external pole ear assembly 4 to the pole ear on the composite current collector structure, or to connect the first adapter plate 3 and the second adapter plate 42 to the pole ear on the composite current collector structure and to weld the external pole ear body 4 to the metal structure 2; in addition, when the pole ear body 4 and the first adapter plate 3 are welded to the pole ear on the composite current collector structure, the pole ear body 4 and the first adapter 3 are toward the inner side of the composite current collector structure but cannot extend into the interior of the composite current collector structure, that is, they need to be 0-1mm away from the edge of the composite current collector. The purpose of this is to prevent the pole ear body 4 or the first adapter 3 from extending into the composite current collector structure and causing a short circuit.

[0051] The present application also provides a corresponding welding method for the above-mentioned composite current collector 1 welding structure, including: drilling welding holes 11 on a plurality of composite current collectors 1, wherein the welding holes 11 penetrate the composite current collector 1; stacking a plurality of the composite current collectors 1 so that the welding holes 11 are aligned, and arranging a metal structure 2 between two adjacent composite current collectors 1 to assemble a composite current collector structure; placing a first adapter plate 3 and a tab assembly 4 on the upper and lower sides of the composite current collector structure, respectively, and connecting the first adapter plate 3, the composite current collector structure and the tab assembly 4 to the upper and lower ends of the composite current collector structure; welding the first adapter plate 3, the composite current collector structure and the tab assembly 4 together at the position of the welding hole 11 by an ultrasonic welding process to form a weld mark area. The welding methods corresponding to different welding structures have been described above, and will not be repeated here. In the aforementioned embodiment, the composite current collector 1 is firstly punched with welding holes 11, and then the composite current collector 1 and the metal structural member 2 are staggered and stacked to form a composite current collector structure; alternatively, the composite current collector 1 and the metal structural member 2 of the same size may be staggered and stacked to form a composite current collector structure, and then the welding holes 11 are uniformly punched on the composite current collector structure, that is, the welding holes 11 are punched on both the composite current collector 1 and the metal structural member 2. The welding equipment and welding raw materials used in this application are all related to the prior art and this application will not be repeated here.

[0052] Preferably, the thickness of the metal structural part 2 in the present application is 10μm-20μm. When the metal structural part 2 is thin, it is not only easy to cause welding penetration, but also may affect the welding effect due to high-frequency vibration during the welding process, resulting in an increase in the internal resistance of the battery, affecting the performance and safety of the battery.

[0053] In summary, the present invention provides a welding structure and method for a composite current collector pole tab, the welding structure of the composite current collector pole tab comprises: a plurality of composite current collectors, each of which is provided with a welding hole; a plurality of metal structural parts, the composite current collectors are stacked and the welding holes are aligned, the metal structural parts are provided between two adjacent composite current collectors to assemble and form a composite current collector structure; a first adapter plate is provided on one end face of the composite current collector structure, and a pole tab assembly is provided on the other opposite end face of the composite current collector structure, the first adapter plate, the composite current collector structure and the pole tab assembly are welded to form a weld print area. In the present application, by sandwiching the metal structural parts between two adjacent composite current collectors, the current can flow out from a plurality of metal structural parts, thereby improving the current flow capacity; at the same time, the plurality of metal structural parts are welded to the first adapter plate, thereby improving the strength of the weld print.

[0054] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A welding structure of a composite current collector tab, characterized in that: include: A plurality of composite current collectors, each of which is provided with a welding hole; A plurality of metal structural members, wherein the composite current collectors are stacked and the welding holes are aligned, and the metal structural members are arranged between two adjacent composite current collectors to assemble and form a composite current collector structure; A first adapter sheet is disposed on one end surface of the composite current collector structure, and a tab assembly is disposed on the other opposite end surface of the composite current collector structure. The first adapter sheet, the composite current collector structure and the tab assembly are welded to form a weld mark area.

2. The welding structure of the composite current collector tab according to claim 1, characterized in that: The thickness of the first adapter sheet is 20 μm-1500 μm; the depth of the welding hole is 6 μm-600 μm, and the aperture of the welding hole is 1.5 mm-5 mm; the thickness of the metal structure is 4 μm-20 μm.

3. The welding structure of the composite current collector tab according to claim 2, characterized in that: The thickness of the weld print area is 6 μm-50 μm, the length of the weld print area is 2 mm-100 mm, and the width of the weld print area is 10 mm-150 mm.

4. The welding structure of the composite current collector tab according to claim 3, characterized in that: The first adapter plate is arranged on the upper end surface of the composite current collector structure, and the pole tab assembly includes a pole tab body arranged on the lower end surface of the composite current collector, and one end of the pole tab body extends out of the edge of the composite current collector structure; the first adapter plate, the composite current collector structure and the pole tab body are welded through the welding hole to form a first welding mark area.

5. The welding structure of the composite current collector tab according to claim 4, characterized in that: The same end of the first adapter and the tab body extends out of the edge of the composite current collector, and the contact portion between the extended portion of the first adapter and the extended portion of the tab body is welded to form a second weld mark area.

6. The welding structure of the composite current collector tab according to claim 3, characterized in that: The tab assembly includes a second adapter plate arranged on the lower end surface of the composite current collector structure, the first adapter plate is arranged on the upper end surface of the composite current collector structure, and the first adapter plate, the composite current collector structure and the second adapter plate are welded through the welding hole to form a third welding print area.

7. The welding structure of the composite current collector tab according to claim 6, characterized in that: The tab assembly further includes a tab body, the same end of the two adapter sheets extends out of the edge of the composite current collector structure, and the tab body contacts and is welded with the extended portions of the two adapter sheets to form a fourth weld print area.

8. The welding structure of the composite current collector tab according to claim 6, characterized in that: The tab assembly also includes a tab body, the same end of the metal structure and the two adapter plates extend out of the edge of the composite current collector, the extended portion of the metal structure and the extended portions of the two adapter plates are in contact and welded to form a fifth weld print area; one end of the tab body is in contact with the extended portion of the metal structure and welded to form a sixth weld print area.

9. The welding structure of the composite current collector tab according to claim 7 or 8, characterized in that: The thickness of the second adapter sheet is 20 μm-1500 μm.

10. A welding method for the composite current collector welding structure according to any one of claims 1 to 9, characterized in that: include: Drilling welding holes on a plurality of composite current collectors, wherein the welding holes penetrate the composite current collectors; Stacking a plurality of the composite current collectors so that the welding holes are aligned, and arranging a metal structure between two adjacent composite current collectors to assemble a composite current collector structure; The first adapter and the tab assembly are respectively placed on the upper and lower sides of the composite current collector structure, and connected to the upper and lower ends of the composite current collector structure; The first adapter plate, the composite current collector structure and the tab assembly are welded together at the welding hole position by an ultrasonic welding process to form a welding mark area.

Images