Composite current collector welding structure

Abstract

The utility model provides a kind of composite current collector welding structure, belong to composite current collector welding technical field, including composite current collector, the composite current collector includes two metal layers, and the insulating layer between two the metal layer, including electrode lead, the electrode lead is welded in one of the metal layer surface, the conductive connecting portion of metal material composition is equipped with below the electrode lead;Above the metal layer and insulating layer form the recess that penetrates above metal layer and insulating layer in welding process, the conductive connecting portion is embedded in the recess, and the conductive connecting portion is respectively welded with two the metal layer and fixed, to make two the metal layer with the electrode lead be conductive connection;The utility model can not need to rely on adapter piece as conductive intermediary, so that at least one pure copper foil adapter piece can be reduced in overall welding structure, to reduce welding frequency to improve welding efficiency, effectively reduce the overall manufacturing cost of tab welding structure.

Description

Technical Field

[0001] This utility model relates to the field of composite current collector welding technology, and specifically to a composite current collector welding structure. Background Technology

[0002] In the field of electrode assembly manufacturing for energy storage devices such as lithium batteries, composite current collectors are widely used for conductive connections between electrodes and external circuits due to their advantages such as lightweight and high safety. These composite current collectors typically employ a three-layer composite structure, consisting of two metal layers and an insulating layer sandwiched between them. The core requirement is to achieve mutual conductivity between the two metal layers and simultaneously establish a stable conductive connection between the two metal layers and the electrode leads. This allows the electrode leads to act as a dielectric to conductively connect the tabs and terminals, ensuring efficient current transmission.

[0003] The existing conductive connection structure between the composite current collector and the electrode lead generally adopts a four-layer superimposed welding structure of "electrode lead-adapter piece-composite current collector-adapter piece". Specifically, two pure copper foil adapter pieces need to be welded to the upper and lower metal layers of the current collector respectively, and then the two adapter pieces are welded together so that the two metal layers of the current collector can conduct electricity through the adapter pieces. Finally, the electrode lead is welded to the adapter piece, thereby realizing the overall conductivity between the current collector, the adapter piece and the electrode lead.

[0004] However, this welding structure requires at least three welding operations, and the conductive connection of a single current collector requires at least two pure copper foil adapters. Pure copper foil material itself is expensive, and the adapters only serve as transitional conductive components, which directly leads to an increase in the overall manufacturing cost of the composite current collector welding structure. Utility Model Content

[0005] In view of this, the present invention provides a composite current collector welding structure that can eliminate the need for an adapter plate as a conductive medium, thereby reducing the number of pure copper foil adapter plates in the overall welding structure, thus reducing the number of welding operations and improving welding efficiency, and effectively reducing the overall manufacturing cost of the composite current collector welding structure.

[0006] To solve the above-mentioned technical problems, this utility model provides a composite current collector welding structure, including a current collector consisting of two metal layers and an insulating layer between the two metal layers, and an electrode lead welded to the surface of one of the metal layers; it also includes a conductive connection part made of metal material, which is disposed on the wall surface where the electrode lead and the metal layer are attached, and the conductive connection part and the electrode lead are integrally formed. During the welding process, the upper metal layer and the insulating layer form a groove penetrating the upper metal layer and the insulating layer, and the conductive connection part is embedded in the groove, and the conductive connection part is respectively connected to the two metal layers. Welding fixation: Since the conductive connection part is made of metal, when the conductive connection part is welded to the two metal layers, the two metal layers will conduct electricity through the conductive connection part as a medium. Furthermore, since one end of the electrode lead is welded to one of the metal layers, the electrode lead can achieve a conductive connection with the two metal layers. Finally, the other end of the electrode lead is welded to the pole, thus achieving a conductive connection between the tab and the pole. This allows the two metal layers of the composite current collector to be directly electrically connected through the conductive connection part, thereby reducing the number of welding operations and improving welding efficiency, effectively reducing the overall manufacturing cost of the composite current collector welding structure.

[0007] The conductive connection is a solder joint. When the electrode lead is bonded to one of the metal layers and welded, the welded part of the electrode lead will be heated and deformed under the action of ultrasonic welding, thereby producing microscopic plastic deformation. This causes the welded part of the electrode lead to form a downward protrusion, which is the solder joint. There is at least one solder joint. The protrusion can pass through the bonded metal layers and the middle insulating layer in sequence under the action of ultrasonic waves, and the solder joint is welded to the lower metal layer. Thus, the solder joint is welded to the upper and lower metal layers, realizing the conductive connection between the two metal layers.

[0008] The electrode lead is soldered to one of the metal layers, while the surface of the other metal layer is provided with a conductive reinforcement layer. The conductive reinforcement layer is attached to the side of the metal layer facing away from the insulating layer. When the solder joint passes through the two metal layers, it is soldered together with the conductive reinforcement layer, thereby fixing the electrode lead, the composite current collector, and the conductive reinforcement layer together through the solder joint. Thus, the conductive reinforcement layer design enhances the conductivity between the electrode lead and the current collector.

[0009] The conductive reinforcement layer is an adapter piece, which is made of pure copper foil. The adapter piece improves the conductivity.

[0010] The conductive reinforcement layer is another electrode lead. The electrode post and the electrode tab are fixed by welding with an electrode lead. At this time, the electrode lead is welded to the metal layer to form a solder joint. The solder joint passes through the metal layer below and is fixed by welding with another electrode lead. Thus, two electrode leads are used. Since the electrode leads are made of stainless steel, the cost is lower, and the connection strength can be strengthened.

[0011] There are multiple solder joints. When the electrode leads are soldered to the metal layer, the multiple solder joints are distributed in an array at the soldering location, which makes the contact between the electrode leads and the metal layer more uniform and avoids single-point overload.

[0012] Multiple solder joints are arranged in parallel rows along the length of the electrode lead, and the solder joints in each adjacent row are staggered in the width direction of the electrode lead. The multiple rows of parallel and staggered solder joints can better adapt to the width direction of the electrode lead, making the current transmission path between the electrode lead and the metal layer more dispersed and uniform.

[0013] In summary, compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0014] 1. When this utility model is used, the two metal layers of the composite current collector can be directly electrically connected through the conductive connection part without relying on the adapter piece as a conductive medium. This reduces at least one pure copper foil adapter piece in the overall welding structure, thereby reducing the number of welding operations and improving welding efficiency, effectively reducing the overall manufacturing cost of the electrode welding structure.

[0015] 2. When this utility model is used, the conductive connection part is directly welded to the two metal layers to form a conductive path, which reduces the multi-interface contact resistance caused by traditional adapter pieces and improves the overall conductive stability.

[0016] 3. When using this utility model, by setting a conductive reinforcing layer (adapter piece or another electrode lead), different reinforcement schemes can be flexibly selected according to actual needs: the pure copper foil adapter piece can enhance conductivity, while the other electrode lead can improve connection strength while controlling costs, adapting to the performance and cost requirements of different scenarios, and the multi-point welding design reduces structural stress concentration and improves overall mechanical reliability.

[0017] 4. When this utility model is used, the multiple rows of parallel and staggered solder joints can better adapt to the width direction of the electrode leads, making the current transmission path between the electrode leads and the metal layer more dispersed and uniform. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the welded structure in the prior art of this utility model;

[0019] Figure 2 This is a cross-sectional view of the welded structure in Embodiment 1 of this utility model;

[0020] Figure 3 This is a cross-sectional view of the welded structure in Embodiment 2 of this utility model;

[0021] Figure 4 This is a cross-sectional view of the welded structure in Embodiment 3 of this utility model;

[0022] Figure 5 This is a top view of the welding structure in Embodiment 1 of this utility model.

[0023] Explanation of reference numerals in the attached figures:

[0024] 100, Metal layer; 101, Insulating layer; 200, Adapter piece; 300, Electrode lead; 400, Solder joint. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the following will be described in conjunction with the accompanying drawings of the embodiments of this utility model. Figure 1-5 The technical solutions of the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model are within the protection scope of this utility model.

[0026] A composite current collector welding structure, such as Figure 1 and Figure 2 As shown: It includes a composite current collector, which consists of two metal layers 100 and an insulating layer 101 located between the two metal layers 100.

[0027] Includes electrode leads 300, which are soldered to the surface of one of the metal layers 100;

[0028] It also includes a conductive connection part made of metal material. The conductive connection part is disposed on the wall surface where the electrode lead 300 and the metal layer 100 are attached, and the conductive connection part and the electrode lead 300 are integrally formed. During the welding process, the upper metal layer 100 and the insulating layer 101 form a groove that penetrates the upper metal layer and the insulating layer. The conductive connection part is embedded in the groove and is welded and fixed to the two metal layers 100 respectively. Since the conductive connection part is made of metal material, when the conductive connection part is welded and fixed to the two metal layers 100, the two metal layers 100 will achieve [connection / relation] through the conductive connection part as a medium. The electrode lead 300 is conductive, and since one end of the electrode lead 300 is welded and fixed to one of the metal layers 100, the electrode lead 300 and the two metal layers 100 can achieve a conductive connection. Finally, the other end of the electrode lead 300 is welded to the pole, thus achieving a conductive connection between the tab and the pole. This allows the two metal layers 100 of the composite current collector to be directly electrically connected through the conductive connection part, without relying on the adapter piece 200 as a conductive medium. This reduces at least one pure copper foil adapter piece 200 in the overall welding structure, thereby reducing the number of welding operations and improving welding efficiency, effectively reducing the overall manufacturing cost of the tab welding structure.

[0029] Specifically, the conductive connection is a solder joint 400. When the electrode lead 300 is bonded to one of the metal layers 100 and welded, the welded part of the electrode lead 300 will be heated and deformed under the action of ultrasonic welding, thereby producing microscopic plastic deformation, so that the welded part of the electrode lead 300 forms a downward protrusion. This protrusion is the solder joint 400, and there is at least one solder joint 400. The protrusion can penetrate the bonded metal layers 100 and the middle insulating layer 101 in sequence under the action of ultrasonic waves, and the solder joint 400 is welded to the lower metal layer 100, thereby welding the upper and lower metal layers 100 together to achieve the conductive connection between the two metal layers 100.

[0030] like Figure 5 As shown, there are multiple solder joints 400. When the electrode lead 300 is soldered to the metal layer 100, the multiple solder joints 400 are arranged in an array at the soldering location, so that the contact between the electrode lead 300 and the metal layer 100 is more uniform. Each solder joint 400 undertakes part of the current transmission task, avoiding single-point overload.

[0031] Furthermore, multiple solder joints 400 are arranged in parallel rows along the length of the electrode lead 300, and the solder joints 400 in each adjacent row are staggered in the width direction of the electrode lead 300. The multiple rows of parallel and staggered solder joints 400 can better adapt to the width direction of the electrode lead 300, making the current transmission path between the electrode lead 300 and the metal layer 100 more dispersed and uniform. The staggered layout avoids the solder joints 400 from clustering on the same vertical line, reducing local damage to the metal layer 100 and the electrode lead 300.

[0032] Example 2:

[0033] The difference from Example 1 is as follows:

[0034] according to Figure 3 As shown, the electrode lead 300 is welded to one of the metal layers 100, while the surface of the other metal layer 100 is provided with a conductive reinforcement layer. The conductive reinforcement layer is attached to the side of the metal layer 100 facing away from the insulating layer 101. When the solder joint 400 passes through the two metal layers 100, it is welded together with the conductive reinforcement layer, thereby fixing the electrode lead 300, the composite current collector, and the conductive reinforcement layer together through the solder joint 400. Thus, the design of the conductive reinforcement layer strengthens the connection strength and conductivity between the electrode lead 300 and the composite current collector.

[0035] Specifically, the conductive reinforcement layer is an adapter piece 200, which is made of pure copper foil. The electrode lead 300 deforms under the action of ultrasound and forms a solder joint 400 downward. The solder joint 400 passes through the metal layer 100, the insulating layer 101 and the metal layer 100 below in sequence, and is welded to the adapter piece 200 by the action of ultrasonic welding. The conductivity is improved by the adapter piece 200.

[0036] Example 3:

[0037] The difference from Example 2 is as follows:

[0038] according to Figure 4 As shown, the conductive reinforcement layer is another electrode lead 300. The electrode post and the electrode tab are welded and fixed together by an electrode lead 300. At this time, the electrode lead 300 is welded to the metal layer 100 to form a solder joint 400. The solder joint 400 passes through the lower metal layer 100 and is welded and fixed together with another electrode lead 300. Thus, two electrode leads 300 are used. The stainless steel electrode lead 300 is cheaper than the pure copper foil adapter piece 200 in Embodiment 2, which reduces costs.

[0039] Preferably, considering lower costs, the structure in Embodiment 1 can be used without a conductive reinforcement layer. If, while ensuring connection strength, costs are minimized, a different stainless steel electrode lead 300 can be used as the conductive reinforcement layer in Embodiment 3. If, while ensuring connection strength, conductivity also needs to be improved, a pure copper foil adapter piece 200 can be used as the conductive reinforcement layer in Embodiment 2.

[0040] First, it should be clarified that this welding structure is only applicable to single-layer composite current collectors and not to stacked composite current collectors. The composite current collector can be directly connected to the electrode post through the electrode lead 300. It should be noted here that the composite current collector and the electrode lead 300 are existing structures in the prior art. No model is specified here, nor is the structure described in detail. Only the usage method and position of the conductive connection part are explained in detail.

[0041] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A composite current collector welding structure, comprising a composite current collector, the composite current collector comprising two metal layers (100) and an insulating layer (101) located between the two metal layers (100), characterized in that: Includes an electrode lead (300), the electrode lead (300) being soldered to the surface of one of the metal layers (100), and a conductive connection portion made of metal material being provided below the electrode lead (300); During the welding process, the metal layer (100) and the insulating layer (101) above can form a groove that penetrates the metal layer (100) and the insulating layer (101). The conductive connection part is embedded in the groove, and the conductive connection part is welded and fixed to the two metal layers (100) respectively, so that the two metal layers (100) are conductively connected to the electrode lead (300).

2. A composite current collector weld structure as in claim 1, wherein: The conductive connection part is a solder joint (400), and the number of solder joints (400) is at least one.

3. A composite current collector weld structure as in claim 2, wherein: It also includes a conductive reinforcement layer, which is attached to the side of another metal layer (100) facing away from the insulating layer (101); The solder joint (400), the other metal layer (100), and the conductive reinforcing layer are welded together.

4. A composite current collector weld structure as in claim 3, wherein: The conductive reinforcement layer is an adapter piece (200).

5. A composite current collector weld structure as in claim 3, wherein: The conductive reinforcement layer is another electrode lead (300).

6. A composite current collector weld structure as in claim 2, wherein: The number of solder joints (400) is multiple, and the multiple solder joints (400) are distributed in an array at the welding position of the metal layer (100).

7. A composite current collector weld structure as in claim 6, wherein: The multiple solder joints (400) are arranged in multiple parallel rows along the length direction of the electrode lead (300), and the solder joints (400) in each adjacent two rows are staggered in the width direction of the electrode lead (300).

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