Leveling device and preparation system of composite current collector

Abstract

The utility model relates to a leveling device and a preparation system of a composite current collector, and belongs to the technical field of composite current collectors. The leveling device comprises a first leveling assembly and a second leveling assembly, wherein the first leveling assembly and the second leveling assembly are sequentially arranged in the conveying direction of the composite current collector; wherein the first leveling assembly comprises a first roller wheel and a second roller wheel, the first roller wheel and the second roller wheel are axially parallel, and a first space for the composite current collector to pass through is formed between the first roller wheel and the second roller wheel; the second leveling assembly comprises a third roller and a fourth roller, the third roller and the fourth roller are axially parallel, a second interval for the composite current collector to pass through is formed between the third roller and the fourth roller, and the second interval is smaller than the first interval. The leveling device provided by the utility model can effectively improve appearance defects such as bulges on the surface of the composite current collector, such as splashing points, so that the surface of the composite current collector is smoother, and the performance of the composite current collector is improved.

Description

Technical Field

[0001] This application relates to the technical field of composite current collectors, and in particular to a leveling device and a preparation system for composite current collectors. Background Art

[0002] Composite current collectors have the characteristics of being thin and light, and high safety, and have been widely studied in recent years. Composite current collectors are mainly in a multi-layer sheet structure, and are generally prepared by coating layers on the surface of a substrate layer by layer. Due to the limitations of the preparation process, situations such as plating solution splashing and uneven evaporation may occur during the coating process, resulting in appearance defects such as pinholes, bumps, and splashing points on the composite current collector. Using the composite current collector with the above appearance defects to prepare a battery may cause problems such as the appearance defects such as splashing points piercing the positive and negative electrodes and causing the positive and negative electrodes to conduct, which greatly affects the application of the composite current collector. Utility Model Content

[0003] This application provides a leveling device and a preparation system for composite current collectors to solve the technical problems that the existing composite current collectors have appearance defects and affect the performance and application of the composite current collectors.

[0004] According to one aspect of this application, a leveling device for a composite current collector is provided, including a first leveling component and a second leveling component. The first leveling component and the second leveling component are arranged in sequence along the conveying direction of the composite current collector and are used for roll-pressing and leveling the composite current collector; wherein, the first leveling component includes a first roller and a second roller, the axes of the first roller and the second roller are parallel, and there is a first spacing for the composite current collector to pass through between the first roller and the second roller; the second leveling component includes a third roller and a fourth roller, the axes of the third roller and the fourth roller are parallel, and there is a second spacing for the composite current collector to pass through between the third roller and the fourth roller, and the second spacing is smaller than the first spacing.

[0005] In a further preferred solution, the diameters of the first roller and the second roller are larger than the diameters of the third roller and the fourth roller.

[0006] In a further preferred solution, the linear velocities of the surfaces of the first roller, the second roller, the third roller, and the fourth roller are all the same as the conveying velocity of the composite current collector.

[0007] In a further preferred solution, the hardness of the first roller and the second roller is less than the hardness of the third roller and the fourth roller.

[0008] In a further preferred embodiment, the flattening device further includes a heating roller, which is arranged on the upstream side of the first flattening assembly and is used to heat the composite current collector to soften its surface.

[0009] In a further preferred embodiment, the flattening device further includes a third flattening assembly, which includes a fifth roller and a sixth roller. The axes of the fifth roller and the sixth roller are parallel, and there is a third spacing for the composite current collector to pass between the fifth roller and the sixth roller; the first flattening assembly, the second flattening assembly, and the third flattening assembly are arranged in sequence along the conveying direction of the composite current collector, and the third spacing is smaller than the second spacing.

[0010] In a further preferred embodiment, the diameters of the fifth roller and the sixth roller are smaller than the diameters of the third roller and the fourth roller.

[0011] In a further preferred embodiment, the flattening device further includes a fourth flattening assembly, which includes a seventh roller and an eighth roller. The axes of the seventh roller and the eighth roller are parallel, and there is a fourth spacing for the composite current collector to pass between the seventh roller and the eighth roller; the first flattening assembly, the second flattening assembly, the third flattening assembly, and the fourth flattening assembly are arranged in sequence along the conveying direction of the composite current collector, and the fourth spacing is smaller than the third spacing.

[0012] In a further preferred embodiment, the diameters of the seventh roller and the eighth roller are smaller than the diameters of the fifth roller and the sixth roller.

[0013] According to another aspect of the present application, a preparation system for a composite current collector is provided, which includes an evaporation device and the flattening device for a composite current collector according to any one of the above; the evaporation device is used to evaporate and coat a film on a substrate to prepare a composite current collector, and the flattening device is used to roll and flatten the composite current collector.

[0014] In summary, the flattening device and the preparation system for a composite current collector provided by the present application have at least the following beneficial effects:

[0015] The preparation system of the composite current collector provided by this application includes a flattening device, which includes a first flattening component and a second flattening component. When it is necessary to flatten a composite current collector with protrusions on its surface, by controlling the composite current collector to pass between the first roller and the second roller first, the protrusions on the surface of the composite current collector can be preliminarily flattened by the strong extrusion between the first roller and the second roller; then control the composite current collector to pass between the third roller and the fourth roller, and the protrusions on the surface of the composite current collector can be further flattened by the strong extrusion between the third roller and the fourth roller, which is beneficial to improving the flatness of the surface of the composite current collector. The flattening device in the embodiments of this application can effectively improve the appearance defects such as splashing points on the surface of the composite current collector, make the surface of the composite current collector flatter, and is beneficial to improving the performance of the composite current collector. When the composite current collector is used to prepare a battery, the risk that the protrusions on the surface of the composite current collector pierce the positive and negative electrodes and cause the positive and negative electrodes to conduct can be avoided, and it has a good application prospect. Description of the Drawings

[0016] In order to more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of the flattening device provided by the embodiment of this application;

[0018] Figure 2 It is a schematic structural diagram of the flattening device provided by another embodiment of this application;

[0019] Figure 3 It is a schematic structural diagram of the flattening device provided by still another embodiment of this application.

[0020] The reference numerals are as follows:

[0021] 100, flattening device;

[0022] 110, first flattening component; 111, first roller; 112, second roller;

[0023] 120, second flattening component; 121, third roller; 122, fourth roller;

[0024] 130, third flattening component; 131, fifth roller; 132, sixth roller;

[0025] 140, fourth flattening component; 141, seventh roller; 142, eighth roller;

[0026] 150. Heating roller

[0027] 200. Composite current collector; 210. Protrusion Detailed implementation manners

[0028] In the description of the present application, it should be understood that, when terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are used to indicate the orientation or positional relationship, without special explanation, it is understood as the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0029] In addition, features defined with "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Features defined with "first" and "second" may explicitly or implicitly include at least one of the defined features. When the description of "a plurality" appears, the general meaning is at least including two, such as two, three, etc., unless otherwise specifically defined.

[0030] In the present application, unless otherwise clearly specified and limited, when terms such as "installation", "connection", "connection", "fixation", etc. are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0031] In the description of this specification, when terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" appear, it means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples.

[0032] Figure 1 The structural schematic diagram of the leveling device provided by the embodiment of the present application; Figure 2 The structural schematic diagram of the leveling device provided by another embodiment of the present application; Figure 3 The structural schematic diagram of the leveling device provided by still another embodiment of the present application.

[0033] Please refer to Figures 1 to 3 , the leveling device 100 provided by the embodiment of the present application includes a first leveling assembly 110 and a second leveling assembly 120. The first leveling assembly 110 and the second leveling assembly 120 are arranged in sequence along the conveying direction of the composite current collector 200 and are used for roll leveling the composite current collector 200.

[0034] It should be noted that, in the embodiment of the present application, in order to clearly show the working state of the leveling device 100, the conveying direction of the composite current collector 200 is schematically shown in the X direction in the drawings, and this conveying direction is also the length direction of the composite current collector 200.

[0035] The first leveling assembly 110 includes a first roller 111 and a second roller 112. The axes of the first roller 111 and the second roller 112 are parallel. There is a first gap for the composite current collector 200 to pass through between the first roller 111 and the second roller 112, and the first gap refers to the closest distance between the first roller 111 and the second roller 112.

[0036] Specifically, both the first roller 111 and the second roller 112 are circular columnar members with a hard surface. For example, the first roller 111 and the second roller 112 can be steel rollers, rubber rollers, ceramic rollers, etc., and their materials can be determined based on the material of the composite current collector 200 to be leveled. The first roller 111 and the second roller 112 are arranged at intervals along the thickness direction of the composite current collector 200. When the composite current collector 200 passes between the first roller 111 and the second roller 112, the first roller 111 and the second roller 112 are respectively in contact with the upper surface and the lower surface of the composite current collector 200. Moreover, the first gap should be greater than the thickness of the composite current collector 200 to avoid damage to the composite current collector 200 caused by excessive extrusion when it passes between the first roller 111 and the second roller 112.

[0037] Exemplarily, the diameters of the first roller 111 and the second roller 112 are the same, so as to facilitate the control of the first roller 111 and the second roller 112 to keep the same rotation speed, so that the upper surface and the lower surface of the composite current collector 200 can be smoothly roll leveled by the first roller 111 and the second roller 112.

[0038] The second leveling assembly 120 includes a third roller 121 and a fourth roller 122. The axes of the third roller 121 and the fourth roller 122 are parallel. There is a second spacing for the composite current collector 200 to pass between the third roller 121 and the fourth roller 122. The second spacing is smaller than the first spacing, where the second spacing refers to the closest distance between the third roller 121 and the fourth roller 122.

[0039] Specifically, both the third roller 121 and the fourth roller 122 are circular columnar members with a hard surface. For example, the third roller 121 and the fourth roller 122 can be steel rollers, rubber rollers, ceramic rollers, etc. Their materials can be determined based on the material of the composite current collector 200 to be leveled. The third roller 121 and the fourth roller 122 are arranged at intervals in the thickness direction of the composite current collector 200. When the composite current collector 200 passes between the third roller 121 and the fourth roller 122, the third roller 121 and the fourth roller 122 are respectively in contact with the upper surface and the lower surface of the composite current collector 200. Moreover, the second spacing should be greater than the thickness of the composite current collector 200 to prevent the composite current collector 200 from being damaged due to excessive extrusion when passing between the third roller 121 and the fourth roller 122.

[0040] Exemplarily, the third roller 121 and the fourth roller 122 have the same diameter, which is convenient for controlling the third roller 121 and the fourth roller 122 to maintain the same rotation speed, so that the upper surface and the lower surface of the composite current collector 200 can be smoothly roll-pressed by the third roller 121 and the fourth roller 122.

[0041] Through the above structural design, when it is necessary to level the composite current collector 200 with protrusions 210 on its surface, by controlling the composite current collector 200 to pass between the first roller 111 and the second roller 112 first, the protrusions 210 on the surface of the composite current collector 200 can be preliminarily flattened by the strong extrusion between the first roller 111 and the second roller 112; then control the composite current collector 200 to pass between the third roller 121 and the fourth roller 122, and the protrusions 210 on the surface of the composite current collector 200 can be further flattened by the strong extrusion between the third roller 121 and the fourth roller 122, which is beneficial to improving the flatness of the surface of the composite current collector 200.

[0042] Moreover, since the second spacing between the third roller 121 and the fourth roller 122 is smaller than the first spacing between the first roller 111 and the second roller 112, when the composite current collector 200 first passes through the first spacing, the protrusion 210 with a higher protrusion height on the surface of the composite current collector 200 will first be squeezed by the first roller 111 and the second roller 112, causing the height of the protrusion 210 to be depressed. Then, the depressed protrusion 210 will be squeezed again by the third roller 121 and the fourth roller 122 when passing through the smaller second spacing, further depressing the height of the protrusion 210. This is beneficial to compress the final height of the protrusion 210 into an acceptable range to ensure the performance of the composite current collector 200.

[0043] Thus, the flattening device 100 of the embodiment of the present application can effectively improve the protrusions 210 (such as splash points) on the surface of the composite current collector 200, making the surface of the composite current collector 200 flatter, which is beneficial to improving the performance of the composite current collector 200. When the composite current collector 200 is used to prepare a battery, the risk that the protrusions 210 on the surface of the composite current collector 200 pierce the positive and negative electrodes and cause the positive and negative electrodes to conduct can be avoided, and it has a good application prospect.

[0044] As a further preferred implementation scheme, on the basis of the above scheme, in the specific embodiments of the present application, one or more of the following additions or combinations may also be included.

[0045] In some alternative embodiments, the diameters of the first roller 111 and the second roller 112 are larger than the diameters of the third roller 121 and the fourth roller 122.

[0046] Specifically, referring to Figure 1 , the first roller 111, the second roller 112, the third roller 121, and the fourth roller 122 are all cylindrical and arranged with parallel axes. Since the composite current collector 200 first passes through the first roller 111 and the second roller 112 and then passes through the third roller 121 and the fourth roller 122, when the diameters of the first roller 111 and the second roller 112 are set to be larger than the diameters of the third roller 121 and the fourth roller 122, the contact area between the first roller 111 and the second roller 112 and the surface of the composite current collector 200 is relatively larger than the contact area between the third roller 121 and the fourth roller 122 and the surface of the composite current collector 200 at this time. Thus, the larger protrusions 210 on the surface of the composite current collector 200 can be squeezed over a large area by the first roller 111 and the second roller 112 first, and then the smaller protrusions 210 on the surface of the composite current collector 200 can be finely squeezed by the third roller 121 and the fourth roller 122, which is beneficial to further improving the surface flatness of the composite current collector 200 and thus enhancing the performance of the composite current collector 200.

[0047] In some alternative embodiments, the linear velocities of the surfaces of the first roller 111, the second roller 112, the third roller 121, and the fourth roller 122 are all the same as the conveying speed of the composite current collector 200.

[0048] When the conveying speed of the composite current collector 200 is greater than or less than the linear velocities of the surfaces of the first roller 111, the second roller 112, the third roller 121, and the fourth roller 122, if the extrusion forces between the first roller 111 and the second roller 112 and between the third roller 121 and the fourth roller 122 are large enough, this may cause a frictional force in the conveying direction between the composite current collector 200 and the rollers, and it is easy to damage the composite current collector 200.

[0049] In this embodiment, by controlling the rotational speeds of the first roller 111, the second roller 112, the third roller 121, and the fourth roller 122 to be all adapted to the conveying speed of the composite current collector 200, the first roller 111, the second roller 112, the third roller 121, and the fourth roller 122 can move synchronously with the composite current collector 200, thereby effectively avoiding the problem of damage to the composite current collector 200.

[0050] In some alternative embodiments, the hardness of the first roller 111 and the second roller 112 is less than the hardness of the third roller 121 and the fourth roller 122. Herein, hardness represents the ease of deformation of the roller when it is subjected to force. Specifically, when subjected to the same magnitude of external force, the first roller 111 and the second roller 112 are more likely to deform, while the third roller 121 and the fourth roller 122 are less likely to deform, that is, the materials of the first roller 111 and the second roller 112 are softer than the materials of the third roller 121 and the fourth roller 122.

[0051] Exemplarily, in some embodiments, the first roller 111 and the second roller 112 can be rubber rollers with a smaller hardness, and the third roller 121 and the fourth roller 122 can be steel rollers with a larger hardness.

[0052] When the composite current collector passes between the first roller 111 and the second roller 112, since the materials of the first roller 111 and the second roller 112 are softer, the composite current collector 200 will not be subjected to excessive extrusion force at this time, which is conducive to avoiding damage to the composite current collector 200. When the composite current collector 200 passes between the third roller 121 and the fourth roller 122, since the composite current collector 200 has passed through the rolling of the first roller 111 and the second roller 112, the protruding height of the protrusion 210 on the surface of the composite current collector 200 has been depressed at this time. Then, the harder third roller 121 and fourth roller 122 can be used to roll the surface protrusion 210, which is conducive to further leveling the surface of the composite current collector 200. Thus, through the above design, the composite current collector 200 can be effectively flattened, and damage to the composite current collector 200 can be avoided, and the leveling effect is better.

[0053] In some alternative embodiments, the second spacing is greater than the thickness of the composite current collector 200.

[0054] In some cases where the structural requirements for the composite current collector 200 are relatively high, if the second spacing is less than or equal to the thickness of the composite current collector 200, the composite current collector 200 may be squeezed and damaged when passing between the third roller 121 and the fourth roller 122. Therefore, in this embodiment, the second spacing is controlled to be greater than the thickness of the composite current collector 200, so that there is a certain buffer gap between the composite current collector 200 and the third roller 121 and the fourth roller 122, which is conducive to avoiding the problem of deformation and damage of the composite current collector 200 caused by excessive extrusion.

[0055] Since the protrusion 210 on the surface of the composite current collector 200 may have a certain hardness, when the composite current collector 200 passes through the first spacing and the second spacing, the protrusion 210 may cause damage such as fracture to the structure of the composite current collector 200 itself after being squeezed by the roller. Based on this, the leveling device 100 can be optimized.

[0056] In some alternative embodiments, the leveling device 100 further includes a heating roller 150, and the heating roller 150 is disposed on the upstream side of the first leveling assembly 110 for heating the composite current collector 200 to soften its surface. Among them, the upstream side refers to the upstream along the conveying direction of the composite current collector 200.

[0057] Refer to Figure 2, the heating roller 150, the first flattening assembly 110, and the second flattening assembly 120 are arranged in sequence along the conveying direction of the composite current collector 200. For example, the heating roller 150 can be cylindrical. Before the composite current collector 200 passes through the first flattening assembly 110 and the second flattening assembly 120, the heating roller 150 heats the composite current collector 200, which can soften the protrusions 210 on the surface of the composite current collector 200, making it easier for the composite current collector 200 to be flattened by the rollers when passing through the first flattening assembly 110 and the second flattening assembly 120, thus effectively avoiding the problem that the composite current collector 200 is damaged after the protrusions 210 are squeezed by the rollers.

[0058] Exemplarily, the heating roller 150 can be arranged based on the principle of electromagnetic induction heating of metals, and heat is transferred through the rotation of the roller shaft. Exemplarily, the heating roller 150 can also be arranged to use electrical energy as the energy source, and by introducing electrical energy into the resistor body inside the heating roller, the resistor body generates heat energy to heat the entire roller barrel. The embodiments of the present application do not limit this.

[0059] In some optional embodiments, the flattening device 100 further includes a third flattening assembly 130. The third flattening assembly 130 includes a fifth roller 131 and a sixth roller 132. The axes of the fifth roller 131 and the sixth roller 132 are parallel, and there is a third spacing for the composite current collector 200 to pass through between the fifth roller 131 and the sixth roller 132; the first flattening assembly 110, the second flattening assembly 120, and the third flattening assembly 130 are arranged in sequence along the conveying direction of the composite current collector 200, and the third spacing is smaller than the second spacing.

[0060] Refer to Figure 3 , both the fifth roller 131 and the sixth roller 132 are circular columnar members with a hard surface. The fifth roller 131 and the sixth roller 132 are arranged at intervals along the thickness direction of the composite current collector 200. When the composite current collector 200 passes between the fifth roller 131 and the sixth roller 132, the fifth roller 131 and the sixth roller 132 are respectively in contact with the upper surface and the lower surface of the composite current collector 200. Moreover, the third spacing should be greater than the thickness of the composite current collector 200 to avoid damage to the composite current collector 200 caused by excessive squeezing when the composite current collector 200 passes between the fifth roller 131 and the sixth roller 132.

[0061] In this embodiment, since the third distance between the fifth roller 131 and the sixth roller 132 is smaller than the second distance between the third roller 121 and the fourth roller 122, the fifth roller 131 and the sixth roller 132 can further flatten the composite current collector 200 flattened by the third roller 121 and the fourth roller 122. Thus, the height of the protrusions 210 on the surface of the composite current collector 200 is gradually controlled within a controllable range by multiple sets of pressing rollers, which is beneficial to obtaining a composite current collector 200 with a flatter surface and better performance.

[0062] Exemplarily, in some embodiments, the fifth roller 131 and the sixth roller 132 have the same diameter, so as to facilitate controlling the fifth roller 131 and the sixth roller 132 to maintain the same rotation speed, and thus the upper surface and the lower surface of the composite current collector 200 can be stably roll-pressed by the fifth roller 131 and the sixth roller 132.

[0063] Optionally, in some embodiments, the first flattening assembly 110, the second flattening assembly 120, and the third flattening assembly 130 are arranged in the horizontal direction, that is, the composite current collector 200 is conveyed in a straight line, which is beneficial to reducing the deformation problem of the composite current collector 200 during the conveying process.

[0064] In some alternative embodiments, the diameters of the fifth roller 131 and the sixth roller 132 are smaller than the diameters of the third roller 121 and the fourth roller 122. At this time, the contact area between the third roller 121 and the fourth roller 122 and the surface of the composite current collector 200 is relatively larger than the contact area between the fifth roller 131 and the sixth roller 132 and the surface of the composite current collector 200. Thus, the larger protrusions 210 on the surface of the composite current collector 200 can be extruded over a large area by the third roller 121 and the fourth roller 122 first, and then the smaller protrusions 210 on the surface of the composite current collector 200 can be finely extruded by the fifth roller 131 and the sixth roller 132, which is beneficial to further improving the surface flatness of the composite current collector 200 and thus enhancing the performance of the composite current collector 200.

[0065] Optionally, in some embodiments, the fifth roller 131 and the sixth roller 132 have the same diameter, so as to facilitate controlling the fifth roller 131 and the sixth roller 132 to maintain the same rotation speed, and thus the upper surface and the lower surface of the composite current collector 200 can be stably roll-pressed by the fifth roller 131 and the sixth roller 132.

[0066] In some alternative embodiments, the hardness of the fifth roller 131 and the sixth roller 132 is greater than that of the third roller 121 and the fourth roller 122. At this time, through the mutual cooperation of the first leveling assembly 110, the second leveling assembly 120, and the third leveling assembly 130, the leveling effect on the composite current collector 200 can be further improved, and damage to the composite current collector 200 can be avoided.

[0067] In some alternative embodiments, the leveling device 100 further includes a fourth leveling assembly 140. The fourth leveling assembly 140 includes a seventh roller 141 and an eighth roller 142. The axes of the seventh roller 141 and the eighth roller 142 are parallel. There is a fourth spacing for the composite current collector 200 to pass through between the seventh roller 141 and the eighth roller 142. The first leveling assembly 110, the second leveling assembly 120, the third leveling assembly 130, and the fourth leveling assembly 140 are arranged in sequence along the conveying direction of the composite current collector 200, and the fourth spacing is smaller than the third spacing.

[0068] Referring again to Figure 3 , both the seventh roller 141 and the eighth roller 142 are circular columnar members with a hard surface. The seventh roller 141 and the eighth roller 142 are arranged at intervals in the thickness direction of the composite current collector 200. When the composite current collector 200 passes between the seventh roller 141 and the eighth roller 142, the seventh roller 141 and the eighth roller 142 are respectively in contact with the upper surface and the lower surface of the composite current collector 200. Moreover, the fourth spacing should be greater than the thickness of the composite current collector 200 to avoid damage to the composite current collector 200 caused by excessive extrusion when it passes between the seventh roller 141 and the eighth roller 142.

[0069] In this embodiment, since the fourth spacing between the seventh roller 141 and the eighth roller 142 is smaller than the third spacing between the fifth roller 131 and the sixth roller 132, the composite current collector 200 flattened by the fifth roller 131 and the sixth roller 132 can be further flattened by the seventh roller 141 and the eighth roller 142. Thus, the height of the protrusion 210 on the surface of the composite current collector 200 can be gradually controlled within a controllable range through more groups of rollers, so as to obtain a composite current collector 200 with a flatter surface and better performance.

[0070] Exemplarily, in some embodiments, the seventh roller 141 and the eighth roller 142 have the same diameter, so as to facilitate controlling the seventh roller 141 and the eighth roller 142 to maintain the same rotation speed, and thus the upper surface and the lower surface of the composite current collector 200 can be smoothly roll-pressed by the seventh roller 141 and the eighth roller 142.

[0071] Optionally, in some embodiments, the first leveling assembly 110, the second leveling assembly 120, the third leveling assembly 130, and the fourth leveling assembly 140 are arranged in the horizontal direction, that is, the composite current collector 200 is conveyed in a straight line, which is beneficial to reducing the deformation problem of the composite current collector 200 during the conveying process.

[0072] In some alternative embodiments, the diameters of the seventh roller 141 and the eighth roller 142 are smaller than the diameters of the fifth roller 131 and the sixth roller 132. At this time, it is beneficial to further improve the surface flatness of the composite current collector 200, thereby improving the performance of the composite current collector 200.

[0073] Optionally, in some embodiments, the seventh roller 141 and the eighth roller 142 have the same diameter, so as to facilitate the control of the seventh roller 141 and the eighth roller 142 to keep the seventh roller 141 and the eighth roller 142 rotating at the same speed, so that the upper surface and the lower surface of the composite current collector 200 can be smoothly rolled by the seventh roller 141 and the eighth roller 142.

[0074] In some alternative embodiments, the hardness of the seventh roller 141 and the eighth roller 142 is greater than the hardness of the fifth roller 131 and the sixth roller 132. At this time, it is beneficial to further improve the leveling effect on the composite current collector 200 and avoid damaging the composite current collector 200.

[0075] It can be understood that in other alternative embodiments, the number of leveling assemblies included in the leveling device is not limited to the examples in the above embodiments. For example, the leveling device may further include a fifth leveling assembly, a sixth leveling assembly, etc. Without departing from the design spirit of the present application, any form of leveling device should be within the protection scope of the present application.

[0076] According to another embodiment of the present application, a preparation system for a composite current collector is provided, including an evaporation device and the leveling device 100 of any of the above embodiments; the evaporation device is used to evaporate and coat a film on a substrate to prepare the composite current collector 200, and the leveling device 100 is used to roll and level the composite current collector 200. Exemplarily, the evaporation device can be used to deposit a metal conductive layer on the surface of the substrate through processes such as vacuum evaporation to prepare the composite current collector 200.

[0077] Since the preparation system of the embodiment of the present application adopts the leveling device 100 of the above embodiment, based on the structural design of the leveling device 100 itself, it can effectively improve the protrusions 210 on the surface of the composite current collector 200, such as splash points, making the surface of the composite current collector 200 flatter, which is beneficial to improving the performance of the composite current collector 200. When the composite current collector 200 is used to prepare a battery, the risk that the protrusions 210 on the surface of the composite current collector 200 pierce the positive and negative electrodes and cause the positive and negative electrodes to conduct can be avoided, and it has a good application prospect.

[0078] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A leveling device (100) for a composite current collector, characterized in that, It includes a first flattening component (110) and a second flattening component (120). The first flattening component (110) and the second flattening component (120) are arranged in sequence along the conveying direction of the composite current collector (200) and are used for roll flattening the composite current collector (200). Among them, the first flattening component (110) includes a first roller (111) and a second roller (112). The axes of the first roller (111) and the second roller (112) are parallel, and there is a first spacing for the composite current collector (200) to pass between the first roller (111) and the second roller (112). The second flattening component (120) includes a third roller (121) and a fourth roller (122). The axes of the third roller (121) and the fourth roller (122) are parallel, and there is a second spacing for the composite current collector (200) to pass between the third roller (121) and the fourth roller (122). The second spacing is smaller than the first spacing.

2. The leveling device (100) according to claim 1, characterized in that, The diameters of the first roller (111) and the second roller (112) are larger than the diameters of the third roller (121) and the fourth roller (122).

3. The leveling device (100) according to claim 1, wherein, The linear speeds of the surfaces of the first roller (111), the second roller (112), the third roller (121), and the fourth roller (122) are all the same as the conveying speed of the composite current collector (200).

4. The leveling device (100) according to claim 1, characterized in that, The hardness of the first roller (111) and the second roller (112) is less than the hardness of the third roller (121) and the fourth roller (122).

5. The leveling device (100) according to claim 1, characterized in that, The flattening device (100) further includes a heating roller (150). The heating roller (150) is arranged on the upstream side of the first flattening component (110) and is used for heating the composite current collector (200) to soften its surface.

6. The leveling device (100) according to any one of claims 1-5, characterized in that, The flattening device (100) further includes a third flattening component (130). The third flattening component (130) includes a fifth roller (131) and a sixth roller (132). The axes of the fifth roller (131) and the sixth roller (132) are parallel, and there is a third spacing for the composite current collector (200) to pass between the fifth roller (131) and the sixth roller (132). The first flattening component (110), the second flattening component (120), and the third flattening component (130) are arranged in sequence along the conveying direction of the composite current collector (200), and the third spacing is smaller than the second spacing.

7. The leveling device (100) according to claim 6, characterized in that, The diameters of the fifth roller (131) and the sixth roller (132) are smaller than the diameters of the third roller (121) and the fourth roller (122).

8. The leveling device (100) according to claim 6, characterized in that, The flattening device (100) further includes a fourth flattening assembly (140). The fourth flattening assembly (140) includes a seventh roller (141) and an eighth roller (142). The axial directions of the seventh roller (141) and the eighth roller (142) are parallel, and there is a fourth spacing for the composite current collector (200) to pass between the seventh roller (141) and the eighth roller (142). The first flattening assembly (110), the second flattening assembly (120), the third flattening assembly (130), and the fourth flattening assembly (140) are arranged in sequence along the conveying direction of the composite current collector (200), and the fourth spacing is smaller than the third spacing.

9. The leveling device (100) according to claim 8, characterized in that, The diameters of the seventh roller (141) and the eighth roller (142) are smaller than the diameters of the fifth roller (131) and the sixth roller (132).

10. A preparation system for a composite current collector, characterized in that, It includes an evaporation device and a flattening device (100) for the composite current collector according to any one of claims 1 to 9; The evaporation device is used to evaporate and coat a film on a substrate to prepare a composite current collector (200), and the flattening device (100) is used to roll and flatten the composite current collector (200).

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