Electrolytic crude foil engine conductive structure and method for reducing warping of copper foil

Abstract

The invention relates to the technical field of electrolytic lithium battery copper foil manufacturing, and discloses an electrolytic crude foil engine conductive structure and a method for reducing warping of copper foils, the electrolytic crude foil engine conductive structure comprises a power supply, a rectifier, a plurality of copper plates, a plurality of anode plates electrically connected with the plurality of copper plates one by one, an electrolyte and a cathode roller; the current flow direction of the conductive structure of the electrolytic crude foil engine is as follows: the power supply anode, the rectifier, the copper plate, the anode plate, the electrolyte, the cathode roller and the power supply cathode. In the electrolytic deposition process, the current of each anode plate is independently controlled, and the deposition rate and grain growth of the copper foil at different positions of the roller surface are differently regulated and controlled, so that the warping direction of the copper foil is accurately guided, or the warping degree of the copper foil is inhibited within an extremely low range.

Description

Technical Field

[0001] This invention relates to the field of electrolytic lithium battery copper foil manufacturing technology, and in particular to a conductive structure for an electrolytic foil production machine and a method for reducing copper foil warping. Background Technology

[0002] Currently, the warpage of copper foil in lithium batteries is generally quite large, around 15-20mm. During the battery stacking process, this poses a risk of the tabs collapsing and failing to be detected. In copper foil factories, controlling warpage requires numerous ovens to bake the copper foil, resulting in significant time and electricity costs.

[0003] There is an urgent need to improve the existing equipment to reduce the warping of the copper foil. Summary of the Invention

[0004] The main objective of this invention is to solve the technical problem of excessive warping of copper foil in lithium-ion batteries in existing technologies. This invention provides a conductive structure for an electrolytic foil-making machine, comprising a power supply, a rectifier, multiple copper plates, multiple anode plates electrically connected to the copper plates, an electrolyte, and a cathode roller; the current flow direction of the conductive structure of the electrolytic foil-making machine is: positive terminal of the power supply, rectifier, copper plates, anode plates, electrolyte, cathode roller, and negative terminal of the power supply.

[0005] A second aspect of the present invention provides an electrolytic foil-making machine, which includes the aforementioned conductive structure for electrolytic foil-making.

[0006] A third aspect of the present invention provides a method for reducing copper foil warpage, comprising: A conductive circuit is established so that the current flows from the positive terminal of the power supply through the rectifier, multiple parallel and independent copper plates, an anode plate electrically connected to each of the multiple copper plates, and the electrolyte to the cathode roller, and then returns to the negative terminal of the power supply. The anode plate is electrically insulated from the anode tank containing the electrolyte. The magnitude of the current applied to each anode plate can be independently controlled through the multiple parallel and independent conductive paths. By adjusting the current applied to different anode plates, the copper foil layers deposited at different positions along the axial direction of the cathode roller can have differentiated crystal size distributions, thereby controlling the overall warpage direction and degree of the finished copper foil.

[0007] The present invention has the following beneficial effects: This invention directly controls the current of each anode plate during the electrolytic deposition process, thereby differentially regulating the deposition rate and grain growth of copper foil at different positions on the roller surface, thus precisely guiding its warpage direction or suppressing its warpage to an extremely low range. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of warping in Embodiment 1 of the present invention.

[0009] Figure 2 This is a schematic diagram of warping in Embodiment 2 of the present invention.

[0010] Figure 3 This is a schematic diagram of warping in Embodiment 3 of the present invention.

[0011] Figure 4 This is a schematic diagram of warping in Embodiment 4 of the present invention.

[0012] Figure 5 This is a schematic diagram of warping in Embodiment 5 of the present invention.

[0013] Figure 6 This is a schematic diagram of the electrical conduction method in a traditional foil production machine.

[0014] Figure 7 This is a schematic diagram of the conductive method of the foil-making machine according to the present invention. Detailed Implementation

[0015] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” or “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] Traditional foil-making machines use the following conductive method: current flows in a closed loop: positive power supply → rectifier → copper plate → anode tank → anode plate → electrolyte → cathode roller → negative power supply. Figure 6 .

[0017] For ease of understanding, the specific process of the embodiments of the present invention is described below. Please refer to [link / reference]. Figure 7 One embodiment of the conductive structure of the electrolytic foil machine in this invention includes: It includes a power supply, a rectifier, multiple copper plates, multiple anode plates electrically connected to the multiple copper plates, an electrolyte, and a cathode roller; The current flow direction of the conductive structure of the electrolytic foil machine is as follows: positive terminal of power supply, rectifier, copper plate, anode plate, electrolyte, cathode roller, and negative terminal of power supply.

[0018] In one implementation, each of the multiple anode plates is electrically connected to the rectifier via an independent copper plate, and the electrical connection between each anode plate and its corresponding copper plate is in parallel, so that the current applied to each anode plate can be independently controlled.

[0019] In one implementation, an insulating layer is provided between the anode plate and the anode tank containing the electrolyte. Three positions need to be completely insulated: position 1 is the back of the anode plate; position 2 is the entire screw of the anode plate; and position 3 is that the sealing cap must not come into contact with the anode tank. All three positions are indispensable.

[0020] In one implementation, the anode plate is electrically connected to its corresponding copper plate via studs, and the current is directly conducted to the anode plate via the studs without flowing through the anode tank.

[0021] In one implementation, the plurality of anode plates are divided into at least two different current application groups along the axial direction of the cathode roller, and the current values ​​applied by the different current application groups are different from each other.

[0022] In one implementation, multiple anode plates are divided into three groups of current application groups, namely the first group, the second group, and the third group; along the axial direction of the cathode roller, the first group and the third group are located at both ends, and the second group is located between the first group and the third group; wherein, the current value applied to the second group of anode plates is greater than the current value applied to the first group and the third group of anode plates.

[0023] In one implementation, the current applied to the second set of anode plates is 3 to 4 times the current applied to the first or third set of anode plates.

[0024] In one implementation, there are 18 anode plates. Along the axial direction of the cathode roller, the first to sixth anode plates are the first group of anode plates, the seventh to fourteenth anode plates are the second group of anode plates, and the fifteenth to eighteenth anode plates are the third group of anode plates. The first group of anode plates and the third group of anode plates are subjected to the same current.

[0025] The present invention also relates to an electrolytic foil-making machine, wherein the electrolytic foil-making machine includes the aforementioned conductive structure for electrolytic foil-making machines.

[0026] The present invention also relates to a method for reducing copper foil warpage, comprising the following steps: A conductive circuit is established so that the current flows from the positive terminal of the power supply through the rectifier, multiple parallel and independent copper plates, an anode plate electrically connected to each of the multiple copper plates, and the electrolyte to the cathode roller, and then returns to the negative terminal of the power supply. The anode plate is electrically insulated from the anode tank containing the electrolyte. The magnitude of the current applied to each anode plate can be independently controlled through the multiple parallel and independent conductive paths. By adjusting the current applied to different anode plates, the copper foil layers deposited at different positions along the axial direction of the cathode roller can have differentiated crystal size distributions, thereby controlling the overall warpage direction and degree of the finished copper foil.

[0027] The present invention is further described below with reference to embodiments. It should be noted that the present invention is not limited to the embodiments described below.

[0028] Example 1 Using the aforementioned scheme, the applied current, total current, and warping of the produced copper foil on copper plates 1-18 are shown in Table 1. A schematic diagram of the warping is shown below. Figure 1 .

[0029] Table 1 Example 2 Using the aforementioned scheme, the applied current, total current, and warping of the produced copper foil on copper plates 1-18 are shown in Table 2. A schematic diagram of the warping is shown below. Figure 2 .

[0030] Table 2 Example 3 Using the aforementioned scheme, the applied current, total current, and warping of the produced copper foil on copper plates 1-18 are shown in Table 3. A schematic diagram of the warping is shown below. Figure 3 .

[0031] Table 3 Example 4 Using the aforementioned scheme, the applied current, total current, and warping of the produced copper foil on copper plates 1-18 are shown in Table 4. A schematic diagram of the warping is shown below. Figure 4 .

[0032] Table 4 Example 5 Using the aforementioned scheme, the applied current, total current, and warping of the produced copper foil on copper plates 1-18 are shown in Table 5. A schematic diagram of the warping is shown below. Figure 5 .

[0033] Table 5 For a copper foil forming machine with 18 anode plates, the copper foil can be considered to consist of 18 layers. This is because the copper foil crystals are larger under low current and smaller under high current. Based on this phenomenon, a small current can be applied to the copper foil near the rough surface, and a large current can be applied near the smooth surface. It can be seen that the solution of this invention can control the warping of the copper foil.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A conductive structure for an electrolytic foil-making machine, characterized in that, The conductive structure of the electrolytic foil making machine includes a power supply, a rectifier, multiple copper plates, multiple anode plates electrically connected to the multiple copper plates, an electrolyte, and a cathode roller. The current flow direction of the conductive structure of the electrolytic foil machine is as follows: positive terminal of power supply, rectifier, copper plate, anode plate, electrolyte, cathode roller, and negative terminal of power supply.

2. The conductive structure of an electrolytic foil-making machine according to claim 1, characterized in that, Each of the plurality of anode plates is electrically connected to the rectifier via an independent copper plate, and the electrical connection between each anode plate and its corresponding copper plate is in parallel, so that the current applied to each anode plate can be independently controlled.

3. The conductive structure of an electrolytic foil-making machine according to claim 1, characterized in that, An insulating layer is provided between the anode plate and the anode tank containing the electrolyte.

4. The conductive structure of an electrolytic foil-making machine according to claim 1, characterized in that, The anode plate is electrically connected to its corresponding copper plate via studs, and the current is directly conducted to the anode plate via the studs without flowing through the anode tank.

5. The conductive structure of an electrolytic foil-making machine according to claim 1, characterized in that, Along the axial direction of the cathode roller, the plurality of anode plates are divided into at least two different current application groups, and the current values ​​applied by the different current application groups are different from each other.

6. The conductive structure of an electrolytic foil-making machine according to claim 5, characterized in that, The plurality of anode plates are divided into three groups of current application groups, namely the first group, the second group and the third group; along the axial direction of the cathode roller, the first group and the third group are located at the two ends, and the second group is located between the first group and the third group; wherein, the current value applied to the second group of anode plates is greater than the current value applied to the first group and the third group of anode plates.

7. The conductive structure of an electrolytic foil-making machine according to claim 6, characterized in that, The current applied to the second set of anode plates is 3 to 4 times the current applied to the first or third set of anode plates.

8. The conductive structure of an electrolytic foil-making machine according to claim 7, characterized in that, There are 18 anode plates. Along the axial direction of the cathode roller, the first to sixth anode plates are the first group of anode plates, the seventh to fourteenth anode plates are the second group of anode plates, and the fifteenth to eighteenth anode plates are the third group of anode plates. The first group of anode plates and the third group of anode plates are subjected to the same current.

9. An electrolytic foil-making machine, characterized in that, The electrolytic foil-making machine includes the conductive structure of the electrolytic foil-making machine as described in any one of claims 1-8.

10. A method for reducing copper foil warpage, characterized in that, Includes the following steps: A conductive circuit is established so that the current flows from the positive terminal of the power supply through the rectifier, multiple parallel and independent copper plates, an anode plate electrically connected to each of the multiple copper plates, and the electrolyte to the cathode roller, and then returns to the negative terminal of the power supply. The anode plate is electrically insulated from the anode tank containing the electrolyte. The magnitude of the current applied to each anode plate can be independently controlled through the multiple parallel and independent conductive paths. By adjusting the current applied to different anode plates, the copper foil layers deposited at different positions along the axial direction of the cathode roller can have differentiated crystal size distributions, thereby controlling the overall warpage direction and degree of the finished copper foil.

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