Square resistance control method and system for composite aluminum current collector process

Abstract

The invention relates to a composite aluminum current collector process sheet resistance control method, which comprises the following steps of: (a) forming a first aluminum metal layer on a surface A of a base film in a vacuum evaporation device by adopting a vacuum evaporation method; (b) carrying out online sheet resistance detection on the first aluminum metal layer formed on the A surface of the base film by adopting first sheet resistance detection equipment; (c) forming a second aluminum metal layer on the B surface of the base film in the vacuum evaporation device by adopting a vacuum evaporation method; and (d) carrying out on-line sheet resistance detection on the second aluminum metal layer formed on the B surface of the base film by adopting second sheet resistance detection equipment. Therefore, by detecting the sheet resistance of the plating layers on the two sides of the composite aluminum current collector, the sheet resistance difference of the aluminum metal layers on the A surface and the B surface of the base film can be accurately controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a composite aluminum current collector process sheet resistance control method and system. BACKGROUND

[0002] The composite current collector, especially the composite aluminum current collector, usually adopts the method of vacuum evaporation to form the aluminum layer on the base film, but the sheet resistance of the aluminum layer on the upper and lower surfaces of the current collector generated at present is quite different. SUMMARY

[0003] In view of the above deficiencies of the prior art, the purpose of the present application is to provide a composite aluminum current collector process sheet resistance control method to solve the problem of the large difference in sheet resistance of the aluminum layer on the two surfaces of the existing composite current collector mentioned in the background art.

[0004] In order to achieve the above purpose, on the one hand, the present application adopts the following technical scheme: A composite aluminum current collector process sheet resistance control method, comprising the following steps: (a) using the method of vacuum evaporation, forming a first aluminum metal layer on the A surface of the base film in the vacuum evaporation device; (b) using a first sheet resistance detection device to detect the sheet resistance of the first aluminum metal layer formed on the A surface of the base film; (c) using a second sheet resistance detection device to detect the sheet resistance of the aluminum metal layer on the A surface of the base film in the vacuum evaporation device; (d) using the method of vacuum evaporation, forming a second aluminum metal layer on the B surface of the base film in the vacuum evaporation device.

[0005] Further, the composite aluminum current collector sheet resistance process control method further comprises a step (e), which is: when the sheet resistance detection device detects that the sheet resistance of the aluminum metal layer does not meet the predetermined value, adjusting the amount of aluminum metal formed on the base film by the vacuum evaporation device.

[0006] Further, the vacuum evaporation device comprises a first vacuum evaporation device and a second vacuum evaporation device.

[0007] Further, the first sheet resistance detection device is arranged in the first vacuum evaporation device.

[0008] Further, the second sheet resistance detection device is arranged in the second vacuum evaporation device.

[0009] Further, the first vacuum evaporation device is provided with a first cooling main drum and a second cooling main drum, and the first cooling main drum and the second cooling main drum cool the A surface of the base film respectively.

[0010] Further, the second vacuum evaporation device is provided with a third cooling main drum and a fourth cooling main drum, which respectively cool the B face of the base film.

[0011] Further, a first sheet resistance detection device is arranged between the first cooling main drum and the second cooling main drum, and a third sheet resistance detection device is arranged after the second cooling main drum.

[0012] Further, a second sheet resistance detection device is arranged between the unwinding device of the second vacuum evaporation device and the third cooling main drum, and a fourth sheet resistance detection device is arranged downstream of the fourth cooling main drum.

[0013] In another aspect, the present application also provides a system for process sheet resistance control of a composite aluminum current collector, which comprises a first vacuum evaporation device and a second vacuum evaporation device, the first vacuum evaporation device is provided with a first cooling main drum and a second cooling main drum, and a first sheet resistance detection device is arranged between the first cooling main drum and the second cooling main drum, the second vacuum evaporation device comprises a third cooling main drum and a fourth cooling main drum and an unwinding roller, and a second sheet resistance detection device is arranged between the third cooling main drum and the unwinding roller.

[0014] Compared with the prior art, the process sheet resistance control method of the composite aluminum current collector comprises the following steps: (a) forming a first aluminum metal layer on the A face of a base film by using a vacuum evaporation method in a vacuum evaporation device; (b) detecting the sheet resistance of the first aluminum metal layer formed on the A face of the base film by using a first sheet resistance detection device; (c) detecting the sheet resistance of the aluminum metal layer on the A face of the base film by using a second sheet resistance detection device in the vacuum evaporation device; and (d) forming a second aluminum metal layer on the B face of the base film by using a vacuum evaporation method in the vacuum evaporation device. In this way, the sheet resistance of the aluminum metal layers on the A face and the B face of the base film can be accurately controlled by detecting the sheet resistance of the plated layers on both sides of the composite aluminum current collector, and the difference is smaller. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A flowchart of the process sheet resistance control method of the composite aluminum current collector provided by the present application; Figure 2 An internal structure diagram of the first vacuum evaporation device provided by the present application; Figure 3 An internal structure diagram of the second vacuum evaporation device provided by the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and effect of the present application more clear and explicit, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0017] It should be noted that when a component is referred to as "mounted on", "fixed on" or "disposed on" another component, it can be directly on the other component or there can be a middle component. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there can be a middle component.

[0018] It should also be noted that the terms such as left, right, up, down and the like in the embodiments of the present application are only relative concepts or are referred to the normal use state of the product, and should not be considered as limiting.

[0019] The composite current collector is a sandwich structure, with an electrically non-conductive base film in the middle and conductive metal layers on both sides. Since the composite current collector needs to work in a battery, the difference in sheet resistance of the metal layers on both sides of the composite current collector needs to be controlled. To this end, as shown in Figure 1 the inventor proposes a composite aluminum current collector process sheet resistance control method, which includes step (a). In step (a), a vacuum evaporation method is used to form a first aluminum metal layer on the A surface of the base film in a vacuum evaporation device. In this step, the base film needs to be unwound first. At this time, the base film can be a pure PP film, a PET film or a PI film without an aluminum oxide surface, or a PP film, a PET film or a PI film with an aluminum oxide surface. In step (a), it is preferred to form a metal aluminum layer on the A surface of the base film using an evaporation boat. This is because if the first sheet resistance detection device detects that the sheet resistance of the metal aluminum layer formed on the A surface is different from the predetermined value, the wire feeding speed of the evaporation boat can be easily adjusted to adjust the metal aluminum layer formed on the A surface of the base film, thereby adjusting the sheet resistance of the metal aluminum layer formed on the A surface of the base film.

[0020] Further, the composite aluminum current collector process sheet resistance control method further includes step (b). In step (b), a first sheet resistance detection device is used to detect the sheet resistance of the first aluminum metal layer formed on the A surface of the base film. The purpose of using the first sheet resistance detection device is to detect the sheet resistance of the aluminum metal layer formed on the A surface of the base film for adjustment. Specifically, the first sheet resistance detection device is arranged behind the first sheet resistance detection device process. Specifically, the first sheet resistance detection device can be an eddy current method sheet resistance tester. The advantage of this eddy current method sheet resistance tester is that it can detect the sheet resistance of the aluminum layer on the composite current collector without contacting the sample.

[0021] Further, the composite aluminum current collector process sheet resistance control method further comprises step (c), which is: using a second sheet resistance detection device to detect the sheet resistance of the aluminum metal layer on the A surface of the base film in the vacuum evaporation device. By detecting the sheet resistance of the aluminum metal layer on the A surface of the base film, the sheet resistance value of the A surface of the base film can be known before the metal is evaporated on the B surface of the base film, preventing the sheet resistance from changing due to storage or other reasons. By detecting the sheet resistance of the A surface of the base film before the metal is evaporated on the B surface of the base film, the sheet resistance of the metal layer formed on the B surface of the base film can be easily controlled. In step (c), the purpose of using the second sheet resistance detection device is to detect the value of the sheet resistance of the A surface of the base film, so as to judge the deviation of the sheet resistance of the A surface of the base film, so as to control the difference in sheet resistance between the A surface and the B surface of the base film. Similarly, the second sheet resistance detection device can be an eddy current method sheet resistance tester. Here, the reason why it is written as "detecting the sheet resistance of the aluminum metal layer on the A surface of the base film" is that the aluminum metal layer on the A surface of the base film includes the first aluminum metal layer mentioned above.

[0022] Further, the composite aluminum current collector process sheet resistance control method further comprises step (d), which is: using a vacuum evaporation method to form a second aluminum metal layer on the B surface of the base film in the vacuum evaporation device. In step (d), the evaporation device of the vacuum evaporation device is an evaporation boat. Since the evaporation boat is used to transport aluminum wire into the evaporation boat by wire feeding, the speed of wire feeding can be controlled to adjust the sheet resistance of the aluminum metal formed on the B surface of the base film.

[0023] Further, the composite aluminum current collector process sheet resistance control method further comprises step (e), which is: adjusting the evaporation speed of the evaporation material of the vacuum evaporation device when the sheet resistance detection device detects the sheet resistance of the aluminum metal layer. The step (e) can be located after the step (b) or after the step (d). When the step (e) is located after the step (b), if the first sheet resistance detection device finds that the sheet resistance of the A surface of the base film deviates too much from the expected value after detecting the sheet resistance of the A surface of the base film, the first sheet resistance detection device will send a message to the control console, and then the control console will control the wire feeding speed of the wire feeding disc in the vacuum evaporation device, thereby controlling the sheet resistance of the aluminum metal layer on the A surface of the base film. When the step (e) is located after the step (d), the second sheet resistance detection device will detect the sheet resistance of the second aluminum metal layer formed on the B surface of the base film. After the second sheet resistance detection device detects the sheet resistance of the B surface of the base film, the data is sent to the control console, and the control console judges the sheet resistance of the A surface of the base film and the sheet resistance of the B surface of the base film. If the difference between the two is within an acceptable range, no action will be taken. If it is found that the difference between the two is not within an acceptable range, the wire feeding speed of the vacuum evaporation device will be controlled to adjust the sheet resistance of the aluminum layer formed on the B surface of the base film.

[0024] Further, the vacuum evaporation device comprises a first vacuum evaporation device and a second vacuum evaporation device. The vacuum evaporation device in step (a) is the first vacuum evaporation device, and the vacuum evaporation device in step (c) is the second vacuum evaporation device. Two vacuum evaporation devices can effectively and conveniently control the sheet resistance of the aluminum metal layer on the A surface and the B surface of the base film.

[0025] Preferably, as shown in Figure 2 , Figure 2 is a schematic view of the internal structure of the first vacuum evaporation device. In the first vacuum evaporation device, a first cooling main drum 2 and a second cooling main drum 3 are arranged. The first cooling main drum 2 and the second cooling main drum 3 are responsible for cooling the A surface of the base film to prevent the base film from being scalded when the aluminum metal layer is formed on the A surface of the base film. The first sheet resistance detection device 4 is arranged between the first cooling main drum 2 and the second cooling main drum 3. After the aluminum metal layer is formed on the A surface of the base film at the first cooling main drum, the first sheet resistance detection device 4 detects the sheet resistance of the aluminum metal layer formed at the first cooling main drum 2. If the detected sheet resistance is not within the predetermined range, the sheet resistance of the aluminum metal layer formed on the A surface of the base film can be controlled by adjusting the wire feeding speed of the evaporation boat below the first cooling main drum. In the first sheet resistance detection device, if the detected sheet resistance is not within the predetermined range, the sheet resistance of the aluminum metal layer formed on the A surface of the base film cannot be adjusted by adjusting the film running speed and the like, because if the film running speed before the first cooling main drum 2 is adjusted, the running speed of the second cooling main drum 3 will be affected, causing a domino effect. It can be seen that the first vacuum evaporation device further comprises a first unwinding device 1 and a first winding device 6, which are known components.

[0026] Preferably, a third sheet resistance detection device 5 is arranged downstream of the second cooling main drum 3. The third sheet resistance detection device 5 is used to control the sheet resistance of the aluminum metal layer formed on the A surface of the base film at the second cooling main drum 2. Preferably, an evaporation boat is used to evaporate the aluminum wire to form an aluminum metal layer on the A surface of the base film. The use of an evaporation boat can also improve the accuracy of control.

[0027] Preferably, as shown in Figure 3 , Figure 3This is an internal structural diagram of the second vacuum evaporation device. Within the second vacuum evaporation device, a third cooling drum 7 and a fourth cooling drum 8 are provided. These drums are used to cool the B-side of the base film. The second vacuum evaporation device also includes an unwinding device 11. Preferably, a second sheet resistance detection device 9 is installed between the unwinding device 11 and the third cooling drum 7. This arrangement utilizes the advantage of using dual drums to evaporate the base film on the same side within the vacuum evaporation device. It also avoids the impact of sheet resistance changes during storage of the base film with the aluminum metal layer on the performance of the composite current collector in the battery. This is because, after the base film on the A-side is deposited in the first vacuum evaporation device, before depositing the B-side in the second vacuum evaporation device, the sheet resistance of the coating on the A-side is detected. After determining the sheet resistance of the A-side, the control console adjusts the wire feeding speed of the evaporation boat according to the base film's running speed and path, ultimately achieving the effect of controlling the sheet resistance of the A-side and B-side of the base film.

[0028] On the other hand, the present invention also provides a sheet resistance control system for a composite aluminum current collector process. First, the composite aluminum current collector process sheet resistance control system includes a first vacuum evaporation device. In the first vacuum evaporation device, a first cooling main drum 2 and a second cooling main drum 3 are provided. The first cooling main drum 2 and the second cooling main drum 3 are used to cool the A side of the base film, so as to prevent the base film from being damaged during the coating process.

[0029] Furthermore, a first sheet resistance detection device 4 is installed between the first cooling drum 2 and the second cooling drum 3. This device detects the sheet resistance value of the aluminum metal layer on surface A of the base film after it has been deposited at the first cooling drum 2. Below the cooling drums (taking the first cooling drum 2 as an example, and similarly for the other cooling drums), there are multiple evaporation boats arranged below the first cooling drum. Each evaporation boat corresponds to a specific portion of surface A of the base film in the vertical direction. The first sheet resistance detection device continuously detects the portion of the evaporation boat corresponding to the base film in the vertical direction. When the sheet resistance at this location is detected, if it is outside the predetermined value range, the wire feeding speed of the corresponding evaporation boat is adjusted accordingly. This achieves sheet resistance adjustment on surface A of the base film.

[0030] Furthermore, a third sheet resistance detection device 5 can be installed downstream of the second cooling drum 3 in the first vacuum evaporation device, with the same function and principle as the first sheet resistance detection device 2.

[0031] Further, the system of the composite aluminum current collector process sheet resistance control method further comprises a second vacuum evaporation device responsible for forming an aluminum metal layer on the B surface of the base film, wherein the second vacuum evaporation device is provided with a third cooling main drum 7 and a fourth cooling main drum 8 for cooling the base film, and the second vacuum evaporation device further comprises an unwinding device 11, and a second sheet resistance detection device 9 is arranged between the unwinding device 11 and the third cooling main drum 7, so that on the one hand, since the first vacuum evaporation device adopts the first cooling main drum 2 and the second cooling main drum 3 to cool the A surface of the base film, the process of film plating can be more accurately controlled, and on the other hand, the sheet resistance change of the aluminum metal layer on the A surface of the base film can also prevent the sheet resistance uniformity of the two sides of the base film.

[0032] Preferably, a fourth sheet resistance detection device 10 is further arranged downstream of the fourth cooling main drum 8, and the fourth sheet resistance detection device 10 has the same function as the second sheet resistance detection device 9, and both are used for detecting the sheet resistance of the aluminum layer.

[0033] In summary, the composite aluminum current collector process sheet resistance control method comprises the following steps: (a) forming a first aluminum metal layer on the A surface of the base film in the vacuum evaporation device by using the vacuum evaporation method; (b) detecting the sheet resistance of the first aluminum metal layer formed on the A surface of the base film by using the first sheet resistance detection device; (c) detecting the sheet resistance of the aluminum metal layer on the A surface of the base film in the vacuum evaporation device by using the second sheet resistance detection device; and (d) forming a second aluminum metal layer on the B surface of the base film in the vacuum evaporation device by using the vacuum evaporation method. In this way, by detecting the sheet resistance of the plating layers on both sides of the composite aluminum current collector, the sheet resistance difference of the aluminum metal layers on the A surface and the B surface of the base film can be accurately controlled.

[0034] It can be understood that those skilled in the art can make equivalent replacements or changes according to the technical solutions and the inventive concept of the present application, and all these changes or replacements shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method for controlling the sheet resistance of a composite aluminum current collector process, characterized in that, Includes the following steps: (a) A first aluminum metal layer is formed on surface A of the base film using a vacuum evaporation method in a vacuum evaporation apparatus; (b) Using a first sheet resistance detection device, the sheet resistance of the first aluminum metal layer formed on the A side of the base film is detected online; (c) Using a second sheet resistance detection device, the sheet resistance of the aluminum metal layer on side A of the base film is detected online in a vacuum evaporation device; (d) A second aluminum metal layer is formed on the B side of the base film using a vacuum evaporation method in a vacuum evaporation apparatus.

2. The method for controlling the sheet resistance of the composite aluminum current collector process according to claim 1, characterized in that, It also includes step (e), which is: when the sheet resistance detection device detects that the sheet resistance of the aluminum metal layer does not meet the predetermined value, the amount of aluminum metal formed on the base film by the vacuum evaporation equipment is adjusted.

3. The method for controlling the sheet resistance of the composite aluminum current collector process according to claim 1, characterized in that, The vacuum evaporation apparatus includes a first vacuum evaporation apparatus and a second vacuum evaporation apparatus.

4. The method for controlling the sheet resistance of the composite aluminum current collector process according to claim 3, characterized in that, The first sheet resistance detection device is installed inside the first vacuum evaporation device.

5. The method for controlling the sheet resistance of the composite aluminum current collector process according to claim 4, characterized in that, The second sheet resistance detection device is installed inside the second vacuum evaporation device.

6. The method for controlling the sheet resistance of the composite aluminum current collector process according to claim 3, characterized in that, The first vacuum evaporation apparatus is provided with a first cooling drum and a second cooling drum, which respectively cool the A side of the base film.

7. The method for controlling the sheet resistance of a composite aluminum current collector according to claim 6, characterized in that, The second vacuum evaporation apparatus is equipped with a third cooling drum and a fourth cooling drum, which respectively cool the B side of the base film.

8. The method for controlling the sheet resistance of a composite aluminum current collector according to claim 7, characterized in that, A first sheet resistance detection device is provided between the first cooling main drum and the second cooling main drum, and a third sheet resistance detection device is provided after the second cooling main drum.

9. The method for controlling the sheet resistance of a composite aluminum current collector according to claim 8, characterized in that, A second sheet resistance detection device is provided between the unwinding device of the second vacuum evaporation apparatus and the third cooling main drum, and a fourth sheet resistance detection device is provided downstream of the fourth cooling main drum.

10. A system for implementing the sheet resistance control method for the composite aluminum current collector process according to claims 1-9, characterized in that, The device includes a first vacuum evaporation device and a second vacuum evaporation device. The first vacuum evaporation device is provided with a first cooling main drum and a second cooling main drum. A first sheet resistance detection device is provided between the first cooling main drum and the second cooling main drum. The second vacuum evaporation device includes a third cooling main drum, a fourth cooling main drum, and an unwinding roller. A second sheet resistance detection device is provided between the third cooling main drum and the unwinding roller.

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