Composite current collector roll press welding integrated machine

Abstract

The utility model discloses a composite current collector roll press welding integrated machine, including roll press machine still include: first heating device, first heating device is located the feed end of roll press machine for the heating of the intermediate polymer layer of composite current collector, to make the intermediate polymer layer lose the elastoplasticity of heat. The utility model discloses through the first heating device of adding before roll press machine feed roller to the heating of the intermediate polymer layer of composite current collector, makes it lose the elastoplasticity, easy to deform and has no rebound characteristic, cooperates roll press machine both sides tension control, lets the tab area can with material area synchronous extension, successfully realizes the extension of material area and tab area in the roll press process, effectively prevents the tab wrinkle, tearing and other problems caused by the extension difference of both, avoids the delamination of the metal layer on both sides of the surface of composite current collector, greatly improves the product quality and production yield of composite current collector.

Description

Technical Field

[0001] This utility model relates to the technical field of composite current collector processing, and in particular to a composite current collector roll forming and welding integrated machine. Background Technology

[0002] In the manufacturing of lithium-ion batteries and other battery cells, current collectors are key components that play a crucial role in cell performance. Currently, conventional current collectors commonly use aluminum foil as the positive electrode current collector and copper foil as the negative electrode current collector. However, as battery technology continues to demand higher energy density, cycle life, and safety performance, the limitations of conventional current collectors are becoming increasingly apparent.

[0003] The emergence of composite current collectors offers a new approach to solving these problems. Composite current collectors have a unique structure consisting of an intermediate polymer layer and metal layers deposited or sputtered on both sides of the polymer layer. This structure brings several advantages: firstly, the introduction of the intermediate polymer layer increases the energy density of the cell; secondly, because the intermediate polymer layer has better toughness than pure metal foil, it can effectively release stress and expansion during cell cycling, thus significantly improving the cell's cycle life. More importantly, regarding cell safety, when thermal runaway occurs inside the cell, the metal layer on the surface of the composite current collector shrinks due to heat, while the polymer layer expands thermally, forming an internal circuit break, thereby greatly improving the battery's safety performance.

[0004] Despite the numerous advantages of composite current collectors, a key technical challenge exists in practical production applications. Because the tensile strength of the intermediate polymer is much lower than that of the metal, the intermediate material area undergoes significant elongation during the rolling process. However, the tab areas on both sides, due to the elasto-plastic nature of the polymer, experience springback after stretching at room temperature. This difference in elongation characteristics between the material area and the tab area during rolling prevents conventional rolling equipment from successfully rolling coated composite current collectors. Specifically, during rolling, the tab area, due to springback, cannot maintain the same degree of elongation as the material area, leading to problems such as tab wrinkling and tearing. Ultimately, this causes the metal layers on both sides of the composite current collector surface to delaminate, severely affecting the quality of the composite current collector and limiting its large-scale application in battery cell manufacturing. Utility Model Content

[0005] In view of the above-mentioned problems in the production of existing composite current collectors, the aim is to provide a composite current collector roll forming and welding integrated machine.

[0006] The specific technical solution is as follows:

[0007] A composite current collector roller pressing and welding integrated machine includes a roller press and a first heating device located at the feed end of the roller press for heating the intermediate polymer layer of the composite current collector so that the intermediate polymer layer loses its elasticity and plasticity upon heating.

[0008] As a further improvement and optimization of this solution, an ultrasonic welding machine and a second heating device are also included. The second heating device is located between the feed end of the ultrasonic welding machine and the discharge end of the roller press, and is used to heat and melt the intermediate polymer layer.

[0009] As a further improvement and optimization of this solution, both the first heating device and the second heating device are infrared heaters.

[0010] As a further improvement and optimization of this solution, the heating temperature of the first heating device is 200-400℃.

[0011] As a further improvement and optimization of this solution, the heating temperature of the second heating device is 400-600℃.

[0012] As a further improvement and optimization of this solution, an unwinding mechanism for unwinding the composite current collector is provided upstream of the first heating device.

[0013] As a further improvement and optimization of this solution, a winding mechanism for winding up the conformal current collector is provided downstream of the ultrasonic roll welding machine.

[0014] As a further improvement and optimization of this solution, the first heating device, the roller press, the second heating device, and the ultrasonic welding machine are arranged sequentially in the horizontal direction.

[0015] As a further improvement and optimization of this solution, a first tension roller is provided between the unwinding mechanism and the first heating device, and the first tension roller is located above the unwinding mechanism.

[0016] As a further improvement and optimization of this solution, a second tension roller is provided between the ultrasonic welding machine and the winding mechanism, and the second tension roller is located above the winding mechanism.

[0017] The positive effects of the above technical solution compared with the existing technology are:

[0018] (1) This utility model heats the polymer layer in the middle of the composite current collector by adding a first heating device in front of the feed roller of the roller press, so that it loses its elasticity and plasticity, is easily deformed and has no rebound characteristics. Combined with the tension control on both sides of the roller press, the tab area can be extended synchronously with the material area, and the material area and the tab area are extended in the same way during the roller pressing process. This effectively eliminates the problems of tab wrinkles and tears caused by the difference in extension between the two, avoids the delamination and peeling of the metal layers on both sides of the surface of the composite current collector, and greatly improves the product quality and production yield of the composite current collector.

[0019] (2) The discharge end of the roller press of this utility model is equipped with a second heating device to heat and melt the middle polymer layer of the composite current collector, making it soft and easy to deform. Then, it is passed through an ultrasonic roller welding machine, which uses pressure and vibration to squeeze or push the middle polymer apart, so that the metal layers on both sides can be directly welded, thus achieving the connection between the metal layers on both sides of the composite current collector. This method does not require external copper foil or aluminum foil. First, it reduces the additional material procurement, cutting, positioning and other processes, simplifies the operation process, and saves labor and equipment investment costs. Second, the metal layers at the weld are tightly bonded, the resistance is reduced, and the conductivity is better, reducing the problems of heat generation and energy loss caused by poor contact, ensuring the stability and reliability of the internal circuit connection of the cell, reducing the defect rate of cell production, and finally reducing the thickness of the tabs, thereby reducing the limitation on the number and thickness of individual cell layers. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a composite current collector roller pressing and welding integrated machine according to the present invention;

[0021] In the attached diagram: 1. Roller press; 2. First heating device; 3. Second heating device; 4. Ultrasonic roll welding machine; 5. Unwinding mechanism; 6. Rewinding mechanism; 7. First tension roller; 8. Second tension roller. Detailed Implementation

[0022] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] Figure 1 This is a structural schematic diagram of a composite current collector roller pressing and welding integrated machine according to the present invention. Figure 1 As shown, a preferred embodiment of a composite current collector roll forming and welding machine is provided, including a roll forming machine 1 and a first heating device 2. The first heating device 2 is located at the feed end of the roll forming machine 1 and is used to heat the intermediate polymer layer of the composite current collector so that the intermediate polymer layer loses its elasticity and plasticity due to heat.

[0026] Specifically, by adding a first heating device 2 before the feed roller of the roller press 1 to heat the intermediate polymer layer of the composite current collector, the polymer layer loses its elasticity and plasticity, becomes easily deformable, and has no rebound characteristics. Combined with the tension control on both sides of the roller press 1, the tab area can extend synchronously with the material area. This successfully achieves consistent extension of the material area and the tab area during the roller pressing process, effectively preventing problems such as tab wrinkles and tears caused by the difference in extension between the two. It also avoids the delamination and peeling of the metal layers on both sides of the composite current collector surface, greatly improving the product quality and production yield of the composite current collector.

[0027] Furthermore, as a preferred embodiment, it also includes an ultrasonic welding machine 4 and a second heating device 3, which is located between the feed end of the ultrasonic welding machine 4 and the discharge end of the roller press 1, and is used to heat and melt the intermediate polymer layer.

[0028] Specifically, a second heating device 3 is added to the discharge end of the roller press 1 to heat and melt the intermediate polymer layer of the composite current collector, making it soft and easily deformable. Then, it is passed through an ultrasonic roller welding machine 4, which uses pressure and vibration to extrude or separate the intermediate polymer, allowing the metal layers on both sides to be directly welded, thus achieving the connection between the metal layers on both sides of the composite current collector. This method does not require external copper or aluminum foil, which firstly reduces the additional material procurement, cutting, positioning and other processes, simplifies the operation process, and saves labor and equipment investment costs. Secondly, the metal layers at the weld are tightly bonded, the resistance is reduced, and the conductivity is better, reducing problems such as heat generation and energy loss caused by poor contact, ensuring the stability and reliability of the internal circuit connection of the cell, reducing the defect rate of cell production, and finally reducing the thickness of the tabs, thereby reducing the restrictions on the number and thickness of individual cell layers.

[0029] Specifically, the roller press 1 and the ultrasonic welding machine 4 in this application are both existing mature equipment, and their working principles and specific structures will not be described in detail here.

[0030] Furthermore, as a preferred embodiment, both the first heating device 2 and the second heating device 3 are infrared heaters. In terms of heating efficiency, the infrared heater directly acts on the composite current collector through infrared radiation, resulting in rapid and precise energy transfer. It can quickly heat the intermediate polymer layer to the required temperature. Compared to traditional heating methods, the heating time is significantly shortened, and the efficiency of a single heating cycle is improved, effectively increasing the overall production cycle time. Regarding heating uniformity, the infrared heater can generate a uniform infrared radiation field, ensuring even heating of all parts of the composite current collector and avoiding localized overheating or underheating. This guarantees the consistency of changes in the physical properties of the intermediate polymer layer, thereby ensuring the stability and product quality of subsequent rolling, stretching, and welding processes.

[0031] Furthermore, as a preferred embodiment, the heating temperature of the first heating device 2 is 200–400°C, and the heating temperature of the second heating device 3 is 400–600°C. Within this range, the first heating device 2 can efficiently change the properties of the intermediate polymer layer, causing it to lose its elasticity and plasticity and not rebound, creating conditions for the synchronous extension of the material area and the tab area, effectively avoiding the risk of tab wrinkling and tearing. At the same time, precise temperature control avoids damage to the metal layers on both sides, ensuring the integrity of the composite current collector structure and improving the yield and production efficiency of the rolling process. The high-temperature range of the second heating device 3 can fully melt the polymer layer, making it soft and easily deformable, laying a solid foundation for the tight bonding and welding of the metal layers on both sides in the ultrasonic roll welding process, reducing welding gaps and incomplete welds, reducing resistance and improving conductivity. Moreover, the different temperature gradients of the two devices are smoothly connected, synergistically ensuring high-quality connection of the composite current collector from pretreatment to welding, comprehensively optimizing the quality and efficiency of cell production.

[0032] Furthermore, as a preferred embodiment, an unwinding mechanism 5 for unwinding the composite current collector is provided upstream of the first heating device 2, and a winding mechanism 6 for winding the composite current collector is provided downstream of the ultrasonic welding machine 4. In one embodiment, the unwinding mechanism 5 may be a rotatably mounted unwinding roller, and the winding mechanism 6 may be a rotatably mounted winding roller, both of which are driven by a motor to unwind and wind up the composite current collector.

[0033] Furthermore, as a preferred embodiment, the first heating device 2, the roller press 1, the second heating device 3, and the ultrasonic welding machine 4 are arranged sequentially in the horizontal direction to ensure a high degree of consistency of the composite current collector during the roller pressing and welding processes.

[0034] Furthermore, as a preferred embodiment, a first tension roller 7 is provided between the unwinding mechanism 5 and the first heating device 2, and the first tension roller 7 is located above the unwinding mechanism 5. A second tension roller 8 is provided between the ultrasonic welding machine 4 and the winding mechanism 6, and the second tension roller 8 is located above the winding mechanism 6. By providing the first tension roller 7 and the second tension roller 8, the flatness of the composite current collector during unwinding or winding can be guaranteed.

[0035] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A composite current collector roller pressing and welding integrated machine, comprising a roller press, characterized in that, Also includes: The first heating device is located at the feed end of the roller press and is used to heat the intermediate polymer layer of the composite current collector so that the intermediate polymer layer loses its elasticity and plasticity when heated.

2. The composite current collector roller pressing and welding integrated machine according to claim 1, characterized in that, It also includes an ultrasonic welding machine and a second heating device, which is located between the feed end of the ultrasonic welding machine and the discharge end of the roller press, and is used to heat and melt the intermediate polymer layer.

3. The composite current collector roller pressing and welding integrated machine according to claim 2, characterized in that, Both the first heating device and the second heating device are infrared heaters.

4. The composite current collector roll forming and welding integrated machine according to any one of claims 1-3, characterized in that, The heating temperature of the first heating device is 200-400℃.

5. The composite current collector roll forming and welding integrated machine according to any one of claims 2-3, characterized in that, The heating temperature of the second heating device is 400-600℃.

6. The composite current collector roller pressing and welding integrated machine according to claim 2, characterized in that, An unwinding mechanism for unwinding the composite current collector is provided upstream of the first heating device.

7. The composite current collector roll forming and welding integrated machine according to claim 6, characterized in that, Downstream of the ultrasonic roll welding machine is a winding mechanism for winding up the conformal current collector.

8. The composite current collector roll forming and welding integrated machine according to claim 7, characterized in that, The first heating device, the roller press, the second heating device, and the ultrasonic welding machine are arranged sequentially in the horizontal direction.

9. The composite current collector roll forming and welding integrated machine according to claim 8, characterized in that, A first tension roller is provided between the unwinding mechanism and the first heating device, and the first tension roller is located above the unwinding mechanism.

10. The composite current collector roll forming and welding integrated machine according to claim 8, characterized in that, A second tension roller is provided between the ultrasonic welding machine and the winding mechanism, and the second tension roller is located above the winding mechanism.

Images