Coating system

Abstract

The utility model is suitable for the technical field of batteries, and provides a coating system. The coating system comprises a conveying roller, a first coating device, a first drying device and one or more magnetic suction devices. The conveying roller is used for conveying a current collector, and the current collector is provided with a first face and a second face opposite to each other in the thickness direction. The first coating device is used for coating the first surface with slurry to form a coating; the first drying device is arranged at the downstream of the first coating device along the conveying direction of the current collector and is used for drying the coating coated on the first surface; the at least one magnetic attraction device is arranged between the first coating device and the first drying device in the conveying direction, is arranged on the side, where the second face is located, of the current collector and is used for generating magnetic attraction force on ferromagnetic substances in the coating coated on the first face. And the magnetic attraction device can generate a magnetic attraction effect on the ferromagnetic substances in the coating on the first surface, so that the ferromagnetic substances in the coating on the first surface move towards the direction close to the surface of the current collector.

Description

Technical Field

[0001] The present application relates to the technical field of battery production, and particularly to a coating system. Background Art

[0002] With the development of battery technology, batteries have been widely used in various fields such as electric vehicles, energy storage power systems, aerospace, etc., to provide electrical energy for electrical devices in these fields. A battery includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive and negative electrode sheets. The separator has functions of electronic insulation and ion transport.

[0003] When ferromagnetic foreign matters in the coating are too close to the surfaces of the positive and negative electrode coatings, during the hot pressing process, the positive and negative current collectors, the coatings, and the separator are compressed, causing the ferromagnetic foreign matters to pierce the separator, thereby causing a short circuit in the battery. Moreover, ferromagnetic substances will oxidize at the positive electrode and dissolve in an ionic state. When the dissolved metal ions migrate to the surface of the negative electrode under the action of an electric field, the metal ions of the ferromagnetic substances will be reduced to a metal state on the surface of the negative electrode and form dendrites. When the dendrites grow to pierce the separator, it will also cause a short circuit in the battery. Summary of the Utility Model

[0004] To solve the above technical problems, the present application provides a coating system to adjust the distribution of ferromagnetic substances in the coating and reduce the probability of the separator being pierced.

[0005] An embodiment of the present application provides a coating system, including:

[0006] A conveying roller for conveying a current collector, and the current collector has opposite first and second surfaces in the thickness direction;

[0007] A first coating device for coating a slurry onto the first surface to form a coating;

[0008] A first drying device disposed downstream of the first coating device along the conveying direction of the current collector for drying the coating coated on the first surface;

[0009] One or more magnetic attraction devices, at least one of the magnetic attraction devices being disposed between the first coating device and the first drying device along the conveying direction and on the side where the second surface of the current collector is located.

[0010] In the above technical solution, since the coating has not yet undergone the drying process, ferromagnetic substances have the condition to migrate in the coating. The magnetic attraction device disposed between the first coating device and the first drying device can exert a magnetic attraction on the ferromagnetic substances in the coating on the first surface, causing the ferromagnetic substances in the coating on the first surface to move towards the surface close to the current collector, that is, the ferromagnetic substances in the coating on the first surface will not accumulate on the surface layer of the coating. Therefore, after the drying process, the ferromagnetic substances are hardly on the surface of the coating, thereby reducing the probability that the ferromagnetic substances in the coating on the first surface pierce the separator film during the hot pressing process. Moreover, the ferromagnetic substances are far from the surface of the coating on the first surface, so that the ferromagnetic substances are far from the surface of the coating after the coating is dried, and thus far from the separator film. When metal ions are precipitated at a position farther from the separator film, the migration path of the metal ions is longer. Due to the blocking effect of the positive electrode coating, the dendritic area formed by the metal ions on the negative electrode surface is larger and the height along the thickness direction of the current collector is lower, ultimately reducing the probability of forming dendrites with a higher height, thereby reducing the probability that the separator film is pierced by dendrites.

[0011] In some embodiments, the coating system includes a second coating device and a second drying device. The second coating device is disposed downstream of the first drying device. The second coating device is used to coat the slurry on the second surface to form a coating. The second drying device is disposed downstream of the second coating device and is used to dry the coating coated on the second surface.

[0012] The number of the magnetic attraction devices is at least two. At least one of the magnetic attraction devices is disposed between the second coating device and the second drying device along the conveying direction and on the side where the first surface of the current collector is located.

[0013] In the above technical solution, the magnetic attraction device disposed between the second coating device and the second drying device is used to adjust the distribution of the ferromagnetic substances in the coating on the second surface, causing the ferromagnetic substances in the coating on the second surface to move towards the surface close to the current collector, reducing the probability that the ferromagnetic substances in the coating on the second surface pierce the separator film during the hot pressing process. At the same time, after the coating on the second surface is dried, the ferromagnetic substances are far from the surface of the coating, reducing the probability of forming dendrites with a higher height, thereby reducing the probability that the separator film is pierced by dendrites. Moreover, the magnetic attraction device disposed between the second coating device and the second drying device can also adsorb the ferromagnetic substances on the surface of the coating on the first surface after the coating on the first surface is dried to the first surface, further reducing the risk of the separator film being pierced.

[0014] In some embodiments, the number of the magnetic attraction devices is at least three, and at least one of the magnetic attraction devices is arranged downstream of the second drying device along the conveying direction of the current collector. And it is arranged on the side where the second surface of the current collector is located.

[0015] In the above technical solution, the magnetic attraction device can also adsorb ferromagnetic substances on the surface of the coating after drying the coating on the second surface to the magnetic attraction device.

[0016] In some embodiments, the conveying roller is arranged between the first drying device and the second coating device, and the conveying roller is arranged on the side where the first surface is located to change the conveying direction of the current collector.

[0017] In the above technical solution, the conveying direction of the current collector is changed by the conveying roller, which is convenient for the second coating device to coat the second surface.

[0018] In some embodiments, the magnetic attraction device includes a housing and a magnetic attraction structure arranged in the housing. The housing has a first surface facing the current collector, and the first surface is spaced from the surface of the current collector along the thickness direction of the current collector.

[0019] In the above technical solution, the housing can form a good protection effect on the magnetic attraction structure. The first surface of the housing is spaced from the surface of the current collector along the thickness direction, which can reduce the interference of the magnetic attraction device on the current collector.

[0020] In some embodiments, the magnetic attraction structure extends beyond the opposite sides of the current collector along the width direction of the current collector.

[0021] In the above technical solution, as much as possible, the ferromagnetic substances in the coating on the surface of the current collector along the width direction are subjected to the adsorption effect of the magnetic attraction structure.

[0022] In some embodiments, the magnetic attraction structure includes a plurality of magnetic cores and at least one magnetic conduction sheet. Each single magnetic core extends along the width direction of the current collector, and the plurality of magnetic cores are arranged along the conveying direction, and the magnetic conduction sheet is arranged between two adjacent magnetic cores.

[0023] In the above technical solution, the plurality of magnetic cores are arranged along the conveying direction so that the magnetic attraction structure can continuously generate magnetic attraction force on the ferromagnetic substances in the coating. The magnetic conduction sheet arranged between two adjacent magnetic cores can guide the magnetic flux to flow along the conveying direction so as to form a more uniform magnetic field distribution, thereby making the entire magnetic field intensity of the magnetic attraction structure more uniform.

[0024] In some embodiments, the magnetic core includes a plurality of magnetic core monomers, and the plurality of magnetic core monomers are arranged in sequence along the width direction of the current collector to form the magnetic core.

[0025] In the above technical solution, the size of the magnetic core along the width direction of the current collector can be adjusted by adjusting the number of magnetic core monomers.

[0026] The above description is only an overview of the technical solution of this application. In order to be able to understand the technical means of this application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically given below. Description of the Drawings

[0027] Figure 1 Schematic diagram of the coating system provided by the embodiment of this application;

[0028] Figure 2 is Figure 1 Schematic cross-sectional view of the magnetic attraction device along the A-A direction in

[0029] Figure 3 Schematic structural diagram of the magnetic attraction device provided on one side of the current collector;

[0030] Figure 4 is Figure 3 Schematic cross-sectional view of the structure shown along the B-B direction.

[0031] Description of the Reference Numerals

[0032] 10. Current collector; 11. First surface; 12. Second surface; 200. Coating system; 20. First coating device; 30. First drying device; 40. Magnetic attraction device; 41. Outer shell; 411. First surface; 42. Magnetic attraction structure; 421. Magnetic core; 4211. Magnetic core monomer; 422. Magnetic conduction sheet; 50. Second coating device; 60. Second drying device; 71. Conveyor roller; 72. Guide roller. Detailed Embodiments

[0033] In order to make the purpose, technical solution and advantages of this application clearer, the following further describes this application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0034] In the various specific technical features described in the specific embodiments, without contradiction, they can be combined in any suitable manner. For example, different embodiments and technical solutions can be formed by combining different specific technical features. In order to avoid unnecessary repetition, various possible combination methods of the various specific technical features in this application will not be described separately.

[0035] In the following description, the terms "first", "second", etc. are only used to distinguish different objects, and do not imply any identity or relationship between the objects. It should be understood that the orientation descriptions "above", "below", "outside", and "inside" refer to the orientations in the normal use state. The "left" and "right" directions represent the left and right directions shown in the specific corresponding schematic diagram, which may or may not be the left and right directions in the normal use state.

[0036] It should be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising that element. "At least two" means greater than or equal to two.

[0037] Currently, from the perspective of the development of the market situation, with the development of battery technology, the application of batteries has become more and more extensive. Batteries are not only applied to energy storage power systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric transportation such as electric bicycles, electric motorcycles, electric vehicles, and in fields such as aerospace. With the continuous expansion of the battery application field, the market demand is also continuously increasing, and its output is also continuously increasing.

[0038] Some problems have also emerged during the use of batteries, such as the thermal runaway problem of batteries. A battery includes a positive electrode plate, a negative electrode plate, and a separator disposed between the positive and negative electrode plates. The separator has the functions of electronic insulation and ion transport.

[0039] When ferromagnetic foreign objects in the coating are too close to the surface of the positive and negative electrode coatings, during the hot pressing process, the compression of the positive and negative current collectors, coatings, and separator causes the ferromagnetic foreign objects to pierce the separator, thus causing a battery short circuit. Moreover, ferromagnetic substances will oxidize at the positive electrode and dissolve in an ionic state. When the dissolved metal ions migrate to the surface of the negative electrode under the action of an electric field, the metal ions of the ferromagnetic substances will be reduced to a metal state on the surface of the negative electrode and form dendrites. The growth of the dendrites to pierce the separator will also cause a battery short circuit.

[0040] The metal ions are precipitated at a position closer to the separator, and the metal ions will reach the surface of the negative electrode faster, that is, the migration path of the metal ions is shorter, the area of the dendrites formed by reduction on the surface of the negative electrode is smaller, and the height in the thickness direction of the current collector is higher, so it is easier to pierce the separator. The battery short circuit will ultimately trigger the thermal runaway problem.

[0041] Based on the above considerations, in order to reduce the probability of the battery short - circuiting, the applicant has designed a coating system through in - depth research.

[0042] Please refer to Figures 1 to 4 , in the embodiment of the present application, a coating system is provided. The coating system includes a conveying roller, a first coating device, a first drying device, and one or more magnetic attraction devices. The conveying roller is used to convey the current collector. The current collector has opposite first and second surfaces in the thickness direction. The first coating device is used to coat the slurry on the first surface to form a coating. The first drying device is arranged downstream of the first coating device along the conveying direction of the current collector and is used to dry the coating coated on the first surface. At least one magnetic attraction device is arranged between the first coating device and the first drying device along the conveying direction and on the side where the second surface of the current collector is located.

[0043] Since the coating has not yet undergone the drying process, ferromagnetic substances have the conditions for migration in the coating. The magnetic attraction device arranged between the first coating device and the first drying device can exert a magnetic attraction on the ferromagnetic substances in the coating on the first surface, causing the ferromagnetic substances in the coating on the first surface to move towards the direction close to the surface of the current collector. That is, the ferromagnetic substances in the coating on the first surface do not accumulate on the surface layer of the coating. Therefore, after the drying process, the ferromagnetic substances are hardly on the surface of the coating, thereby reducing the probability of the ferromagnetic substances in the coating on the first surface piercing the separator film during the hot - pressing process.

[0044] Moreover, in the embodiment of the present application, the ferromagnetic substances are far from the surface of the coating coated on the first surface, so that after the coating is dried, the ferromagnetic substances are far from the surface of the coating and thus far from the separator film. When metal ions are precipitated at a position far from the separator film, the migration path of the metal ions is longer. Due to the blocking effect of the positive - electrode coating, the dendrite area formed by the metal ions on the negative - electrode surface is larger and the height along the thickness direction of the current collector is lower, ultimately reducing the probability of the formation of dendrites with a higher height, thereby reducing the probability of the separator film being pierced by dendrites.

[0045] It should be noted that in the embodiment of the present application, the ferromagnetic substances are not removed from the coating, but rather the magnetic force is cleverly used to change the distribution of the ferromagnetic substances in the coating, thereby improving the safety of the battery.

[0046] The battery mentioned in the embodiment of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. A battery generally includes a box body for encapsulating one or more battery cells. The box body can, to a certain extent, prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0047] In a battery, there can be multiple battery cells. The multiple battery cells are connected in series, parallel, or a combination of both. A combination connection means that there are both series and parallel connections among the multiple battery cells. A battery cell refers to the smallest independent unit that can be charged and discharged independently. The battery can also include other structures. For example, the battery can also include a busbar component for realizing the electrical connection between multiple battery cells.

[0048] The battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging so that the active material can be reused. The battery cell can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium-metal battery, a sodium-metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, etc. The embodiments of the present application are not limited thereto.

[0049] The embodiments of the present application provide an electrical device, including a battery produced by any coating system provided by the embodiments of the present application. The electrical device can be, but is not limited to, a vehicle, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, etc. Among them, the vehicle can be a fuel vehicle, a gas vehicle, a new energy vehicle, or a rail vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; the electric toy can include a stationary or mobile electric toy. For example, a game console, an electric car toy, an electric ship toy, and an electric plane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool. For example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact drill, a concrete vibrator, and a planer, etc.; the spacecraft can include an airplane, a rocket, a space shuttle, and a spaceship, etc.

[0050] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the above-described batteries, but also applicable to all electrical devices using batteries.

[0051] The embodiments of the present application provide a coating system 200. Please refer to Figure 1 , the coating system 200 includes a conveying roller 71, a first coating device 20, a first drying device 30, and one or more magnetic attraction devices 40. The conveying roller 71 is used to convey the current collector 10. The current collector 10 has opposite first surface 11 and second surface 12 in the thickness direction. The first coating device 20 is used to coat the slurry on the first surface 11 to form a coating. The first drying device 30 is arranged downstream of the first coating device 20 along the conveying direction of the current collector 10 for drying the coating coated on the first surface 11. At least one magnetic attraction device 40 is arranged between the first coating device 20 and the first drying device 30 along the conveying direction and on the side where the second surface 12 of the current collector 10 is located.

[0052] With such a setting, the magnetic attraction device 40 disposed between the first coating device 20 and the first drying device 30 can exert a magnetic attraction on the ferromagnetic substances in the coating on the first surface 11, causing the ferromagnetic substances in the coating on the first surface 11 to move towards the surface close to the current collector 10, that is, the ferromagnetic substances in the coating on the first surface 11 will not aggregate on the surface of the coating. Therefore, after the drying process, the ferromagnetic substances are hardly on the surface of the coating, thereby reducing the probability that the ferromagnetic substances in the coating on the first surface 11 pierce the separator film during the hot pressing process.

[0053] Moreover, in the embodiments of the present application, the ferromagnetic substances are far from the surface of the coating applied to the first surface 11, so that the ferromagnetic substances are far from the surface of the coating after the coating is dried, and thus far from the separator film. When metal ions are precipitated at a position farther from the separator film, the migration path of the metal ions is longer. Due to the blocking effect of the positive electrode coating, the dendritic area formed by the metal ions on the negative electrode surface is larger and the height in the thickness direction of the current collector 10 is lower. Finally, the probability of forming dendrites with a higher height is reduced, thereby reducing the probability that the separator film is pierced by dendrites.

[0054] It should be noted that the conveying direction of the current collector 10 is Figure 1 、 Figure 2 and Figure 3 the direction shown by the conveying direction in Figure 1 and Figure 4 and the thickness direction of the current collector 10 is the direction shown by the thickness direction in

[0055] In some embodiments, the coating system 200 includes a second coating device 50 and a second drying device 60. The second coating device 50 is disposed downstream of the first drying device 30. The second coating device 50 is used to coat a slurry on the second surface 12 to form a coating. The second drying device 60 is disposed downstream of the second coating device 50 and is used to dry the coating applied to the second surface 12. The number of the magnetic attraction devices 40 is at least two, and at least one magnetic attraction device 40 is disposed between the second coating device 50 and the second drying device 60 along the conveying direction and on the side where the first surface 11 of the current collector 10 is located.

[0056] In this embodiment, the magnetic attraction device 40 located between the second coating device 50 and the second drying device 60 is used to adjust the distribution of ferromagnetic substances in the coating on the second surface 12, so that the ferromagnetic substances in the coating on the second surface 12 move towards the direction close to the surface of the current collector 10, reducing the probability that the ferromagnetic substances in the coating on the second surface 12 pierce the separator film during the hot pressing process. At the same time, after the coating on the second surface 12 is dried, the ferromagnetic substances are away from the surface of the coating, reducing the probability of forming dendrites with higher height, thereby reducing the probability of the separator film being pierced by dendrites. Moreover, the magnetic attraction device 40 located between the second coating device 50 and the second drying device 60 can also adsorb the ferromagnetic substances on the surface of the dried coating on the first surface 11 to the magnetic attraction device 40, further reducing the risk of the separator film being pierced.

[0057] In some embodiments, please refer to Figure 1 , the number of the magnetic attraction devices 40 is at least three, and at least one magnetic attraction device 40 is arranged downstream of the second drying device 60 along the conveying direction of the current collector, and is arranged on the side where the second surface 12 of the current collector 10 is located. With such a setting, the magnetic attraction device 40 can also adsorb the ferromagnetic substances on the surface of the dried coating on the second surface 12 to the magnetic attraction device 40, further reducing the risk of the separator film being pierced.

[0058] In some embodiments, the conveying roller 71 is arranged between the first drying device 30 and the second coating device 50, and the conveying roller 71 is arranged on the side where the first surface 11 of the current collector 10 is located to change the conveying direction of the current collector 10, facilitating the second coating device 50 to coat the second surface 12.

[0059] In some embodiments, please refer to Figure 4 , the magnetic attraction device 40 includes a housing 41 and a magnetic attraction structure 42 arranged in the housing 41. The housing 41 has a first surface 411 facing the current collector 10, and the first surface 411 is spaced from the surface of the current collector 10 along the thickness direction of the current collector 10.

[0060] It can be understood that in the embodiment where the magnetic attraction device 40 adsorbs the ferromagnetic substances to the magnetic attraction device 40, the ferromagnetic substances are adsorbed on the first surface 411.

[0061] In this embodiment, the housing 41 can provide good protection for the magnetic attraction structure 42. It should be noted that the material of the housing 41 in the embodiments of the present application is not limited, as long as the housing 41 has magnetic conductivity, such as stainless steel, iron, etc. The first surface 411 of the housing 41 is spaced from the surface of the current collector 10 along the thickness direction, which can reduce the interference of the magnetic attraction device 40 on the current collector 10, such as generating friction and collision on the current collector 10.

[0062] In some embodiments, please refer toFigure 3 , the magnetic attraction structure 42 extends beyond the opposite two side edges of the current collector 10 in the width direction of the current collector 10. With such an arrangement, it is possible to ensure that ferromagnetic substances in the coating on the surface of the current collector 10 in the width direction are all subjected to the adsorption effect of the magnetic attraction structure 42.

[0063] It should be noted that the width direction of the current collector 10 is Figure 2 and Figure 3 the direction shown as the width direction in

[0064] In some embodiments, referring to Figure 2 , the magnetic attraction structure 42 includes a plurality of magnetic cores 421 and at least one magnetic conduction sheet 422. A single magnetic core 421 extends in the width direction of the current collector 10, and the plurality of magnetic cores 421 are arranged in the conveying direction, and a magnetic conduction sheet 422 is provided between two adjacent magnetic cores 421.

[0065] In this embodiment, a single magnetic core 421 extends in the width direction of the current collector 10, and the extension dimension depends on the width of the current collector 10. It only needs to ensure that both ends of a single magnetic core 421 in the width direction exceed the opposite two side edges of the current collector 10 in the width direction. The plurality of magnetic cores 421 are arranged in the conveying direction so that the magnetic attraction structure 42 can continuously generate a magnetic attraction force on ferromagnetic substances in the coating. The magnetic conduction sheet 422 provided between two adjacent magnetic cores 421 can guide the magnetic flux to flow along the conveying direction, so as to form a more uniform magnetic field distribution, thereby making the entire magnetic field intensity of the magnetic attraction structure 42 more uniform.

[0066] It should be noted that in this embodiment, the width direction of the magnetic core 421 is parallel to the conveying direction of the current collector 10, and the extending direction of the magnetic core 421 is parallel to the width direction of the current collector 10. When the magnetization direction of the magnetic core 421 is along the width direction of the magnetic core 421, the magnetic induction lines of the magnetic core 421 point from one side of the magnetic core 421 in its width direction to the other side in its width direction. There will be intersection points of the magnetic induction lines between two adjacent magnetic cores 421, and the magnetic field intensity at the intersection points will be superimposed, that is, the magnetic field intensity will increase. The straight line formed by the intersection points of several magnetic induction lines in the width direction of the current collector 10 is the highest magnetic field line. Since the magnetization direction is along the width direction of the magnetic core 421, the magnetic field intensity at each point of the magnetic core 421 in its extending direction is relatively close. Therefore, the highest magnetic field line is substantially parallel to the extending direction of the magnetic core 421, and the number of the highest magnetic field lines is the same as the number of the magnetic conduction sheets 422.

[0067] It should be noted that in the embodiments of the present application, no limitation is imposed on the interval between two adjacent magnetic cores 421. Therefore, the interval between the highest magnetic field lines depends on the interval between every two adjacent magnetic cores 421 among the plurality of magnetic cores 421.

[0068] In some embodiments, the magnetic core 421 includes a plurality of magnetic core monomers 4211, and the plurality of magnetic core monomers 4211 are arranged in sequence along the width direction of the current collector 10 to form the magnetic core 421. In this embodiment, the size of the magnetic core 421 along the width direction of the current collector 10 can be adjusted by adjusting the number of the magnetic core monomers 4211. The number of the magnetic core monomers 4211 can be set according to the size of a single magnetic core monomer 4211 along the width direction of the current collector 10 and the width of the current collector 10, as long as the size of the magnetic core 421 along the width direction of the current collector 10 is greater than the width of the current collector 10.

[0069] In some embodiments, the coating system 200 includes a plurality of guide rollers 72. The plurality of guide rollers 72 are spaced along the conveying direction of the current collector 10, and the guide rollers 72 are used to support the current collector 10. The supporting effect of the plurality of guide rollers 72 helps to make the current collector 10 transfer smoothly during long-distance transmission.

[0070] In the description of the present application, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 embodiments of the present application. In the present application, the schematic description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or at least two embodiments or examples in a suitable manner. In addition, without conflict, those skilled in the art can combine different embodiments or examples described in the present application and the features of different embodiments or examples.

[0071] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A coating system, characterized in that, Comprising: A conveying roller for conveying a current collector, the current collector having opposite first and second surfaces in the thickness direction; A first coating device for coating a slurry onto the first surface to form a coating; A first drying device disposed downstream of the first coating device along the conveying direction of the current collector for drying the coating applied to the first surface; One or more magnetic attraction devices, at least one of the magnetic attraction devices being disposed between the first coating device and the first drying device along the conveying direction of the current collector and on the side where the second surface of the current collector is located.

2. The coating system according to claim 1, wherein The coating system includes a second coating device and a second drying device. The second coating device is disposed downstream of the first drying device. The second coating device is used for coating a slurry onto the second surface to form a coating. The second drying device is disposed downstream of the second coating device for drying the coating applied to the second surface; The number of the magnetic attraction devices is at least two, and at least one of the magnetic attraction devices is disposed between the second coating device and the second drying device along the conveying direction and on the side where the first surface of the current collector is located.

3. The coating system according to claim 2, characterized in that, The number of the magnetic attraction devices is at least three, and at least one of the magnetic attraction devices is disposed downstream of the second drying device along the conveying direction of the current collector and on the side where the second surface of the current collector is located.

4. The coating system according to claim 2, characterized in that, The conveying roller is disposed between the first drying device and the second coating device, and the conveying roller is disposed on the side where the first surface is located to change the conveying direction of the current collector.

5. The coating system according to any one of claims 1-4, characterized in that, The magnetic attraction device includes a housing and a magnetic attraction structure disposed inside the housing. The housing has a first surface facing the current collector, and the first surface is spaced apart from the surface of the current collector in the thickness direction of the current collector.

6. The coating system according to claim 5, wherein The magnetic attraction structure extends beyond the opposite sides of the current collector in the width direction on the opposite sides thereof.

7. The coating system according to claim 5, characterized in that, The magnetic attraction structure includes a plurality of magnetic cores and at least one magnetic conductive sheet. Each single magnetic core extends in the width direction of the current collector, and the plurality of magnetic cores are arranged in the conveying direction. A magnetic conductive sheet is disposed between adjacent two magnetic cores.

8. The coating system according to claim 7, characterized in that, The magnetic core includes a plurality of magnetic core monomers, and the plurality of magnetic core monomers are arranged in sequence in the width direction of the current collector to form the magnetic core.

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