Gasket structure for electrode coating process and coating method

Abstract

The application provides a gasket structure and a coating method for an electrode coating process. The gasket structure comprises a gasket body having an outlet surface facing a material coating direction, and a first flow channel for conveying electrode slurry, a second flow channel for conveying insulating slurry and a third flow channel for conveying isolation medium are arranged in the gasket body. The outlets of the first flow channel, the second flow channel and the third flow channel are located on the outlet surface, and the outlet of the third flow channel is arranged between the outlets of the first flow channel and the second flow channel at intervals, so as to separate the electrode slurry flowing out of the outlet of the first flow channel from the insulating slurry flowing out of the outlet of the second flow channel. The application can avoid the migration of the insulating slurry to the interior of the electrode slurry, so as to ensure the accurate collection of coating film width data, and further improve the coating success rate and production efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic, in particular to a gasket structure for electrode coating process and a coating method. BACKGROUND

[0002] With the expansion of the power battery market and the energy storage battery market year by year, the demand for lithium iron phosphate battery is increasing rapidly, and the demand for improving the production efficiency of the battery is becoming more and more urgent. The coating process is the main process that affects the production efficiency of the battery, and improving the coating speed is the simplest and most effective means to improve the production capacity of the battery. However, with the increase of the coating speed, the temperature and air frequency in the oven need to be increased accordingly, which causes the electrode slurry and the insulating slurry on both sides to be more easily penetrated under the condition of high-speed coating. Generally, when the coating speed is greater than 50 m / min, the insulating slurry will migrate to the inside of the electrode slurry (such as lithium iron phosphate slurry) after being heated, resulting in white marks in the electrode coating film area of the material after drying. This appearance defect will cause the coating CCD (Charge Coupled Device) to fail to identify, and the coating film width data cannot be accurately collected, thereby affecting the coating yield and reducing the production efficiency. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a gasket structure for electrode coating process and a coating method, which can avoid the migration of the insulating slurry to the inside of the electrode slurry, thereby ensuring the accurate collection of the coating film width data, and further improving the coating yield and the production efficiency.

[0004] To achieve the purpose of the present application, a gasket structure for electrode coating process is provided, which comprises a gasket body having an outflow surface facing the material coating direction, and a first flow channel for conveying electrode slurry, a second flow channel for conveying insulating slurry and a third flow channel for conveying isolation medium are arranged in the gasket body. The outlets of the first flow channel, the second flow channel and the third flow channel are located on the outflow surface, and the outlet of the third flow channel is arranged between the outlet of the first flow channel and the outlet of the second flow channel to separate the electrode slurry flowing out of the outlet of the first flow channel from the insulating slurry flowing out of the outlet of the second flow channel.

[0005] Optionally, the isolation medium comprises at least one of deionized water, methanol, ethanol, ethyl cellulose and dimethyl carbonate.

[0006] Optionally, the gasket body comprises a main plate and two side plates located on both sides of the main plate; the main plate and the two side plates surround to form the first flow channel in a hollow shape.

[0007] The second flow guide channel and the third flow guide channel are hollowed in each of the two side plates, and the outlet of each third flow guide channel is arranged between the outlet of the first flow guide channel and the outlet of the second flow guide channel.

[0008] Optionally, the outflow direction of the outlet of the third flow guide channel forms an angle with the outflow direction of the outlet of the first flow guide channel.

[0009] Optionally, the angle is greater than or equal to 0° and less than or equal to 30°.

[0010] Optionally, the outflow direction of the outlet of the third flow guide channel is consistent with the outflow direction of the outlet of the second flow guide channel.

[0011] Optionally, the interval between the outlet of the third flow guide channel and the outlet of the first flow guide channel is greater than 0 mm and less than or equal to 8 mm, and the interval between the outlet of the third flow guide channel and the outlet of the second flow guide channel is greater than 0 mm and less than or equal to 4 mm.

[0012] As another technical solution, the application further provides a coating method, which uses a coating machine to perform a coating process on a material, wherein the coating machine comprises the coating structure provided by the application.

[0013] During the coating process, the electrode slurry is delivered to the material through the outlet of the first flow guide channel, the insulating slurry is delivered to the material through the outlet of the second flow guide channel, and the isolation medium is delivered to the material through the outlet of the third flow guide channel.

[0014] Optionally, the flow rate of the isolation medium is 5% to 15% of the flow rate of the insulating slurry.

[0015] Optionally, the coating temperature used in the coating process is greater than or equal to 15℃ and less than or equal to 60℃, and the coating speed used in the coating process is greater than 0 and less than or equal to 100 m / s.

[0016] The application has the following advantages:

[0017] The gasket structure for the coating process of the battery cell provided by the application can separate the electrode slurry flowing out of the outlet of the first flow guide channel from the insulating slurry flowing out of the outlet of the second flow guide channel by additionally arranging the third flow guide channel for delivering the isolation medium and arranging the outlet of the third flow guide channel between the outlet of the first flow guide channel and the outlet of the second flow guide channel, thereby avoiding the migration of the insulating slurry to the inside of the electrode slurry, and thus ensuring the accurate collection of the coating film width data, and further improving the coating success rate and production efficiency.

[0018] The coating method provided by the present invention, by employing a coating machine including the gasket structure provided by the present invention, can prevent the insulating slurry from migrating into the interior of the electrode slurry, thereby ensuring accurate acquisition of coating film width data, and thus improving coating yield and production efficiency. Attached Figure Description

[0019] Figure 1 This is a perspective view of a gasket structure for a battery cell coating process provided in an embodiment of the present invention;

[0020] Figure 2 This is a front view of a gasket structure for a battery cell coating process provided in an embodiment of the present invention;

[0021] Figure 3 for Figure 2 A magnified view of region I in the middle. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solution of the present invention, the gasket structure and coating method for battery cell coating process provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0023] This invention provides a gasket structure for a battery cell coating process, which is installed between the upper and lower dies of a coating machine (e.g., an extrusion coating machine) to coat the electrode slurry (e.g., positive or negative electrode slurry) and insulating slurry stored in the upper and lower dies onto the positive or negative electrode plate of the battery cell, such as a lithium-ion battery.

[0024] Please refer to the following: Figures 1 to 3 The aforementioned gasket structure includes a gasket body 1, which has a direction oriented toward the material coating direction (i.e., parallel to the direction of material coating). Figure 1 and Figure 2 The gasket body 1 has an outlet surface 121 (in the X direction), and a first guide channel 21 for conveying electrode slurry, a second guide channel 22 for conveying insulating slurry, and a third guide channel 23 for conveying insulating medium. The outlets 211 of the first guide channel 21, 221 of the second guide channel 22, and 231 of the third guide channel 23 are all located on the outlet surface 121. Moreover, the outlets 231 of the third guide channel 23 are spaced between the outlets 211 of the first guide channel 21 and 221 of the second guide channel 22, so as to separate the electrode slurry flowing out from the outlet 211 of the first guide channel 21 from the insulating slurry flowing out from the outlet 221 of the second guide channel 22.

[0025] During the coating process, the electrode slurry is delivered to the material through the outlet 211 of the first flow channel 21, the insulating slurry is delivered to the material through the outlet 221 of the second flow channel 22, and the isolation medium is delivered to the material through the outlet 231 of the third flow channel 23. The isolation medium not only has a physical blocking effect to prevent the internal migration of the insulating slurry to the electrode slurry, but also can contact the PVDF (polyvinylidene difluoride) in the insulating slurry to cause cross-linking of the PVDF, thereby causing the insulating slurry to lose fluidity and preventing the internal migration of the insulating slurry to the electrode slurry, and further ensuring accurate collection of the coating film width data and improving the coating success rate and production efficiency.

[0026] In some optional embodiments, the isolation medium can include at least one of deionized water, methanol, ethanol, ethyl cellulose (EC), and dimethyl carbonate (DMC). For the insulating slurry containing hydrated aluminum oxide, PVDF, and N-methylpyrrolidone (NMP), the isolation medium preferably uses deionized water, which can form cross-linking with the insulating slurry and the electrode slurry. Since the PVDF changes from a chain structure to a three-dimensional network structure after cross-linking, the molecular chain is larger, and the fluidity and solubility are poor, so the isolation medium can inhibit migration, thereby preventing the internal migration of the insulating slurry to the electrode slurry.

[0027] In some optional embodiments, the gasket body 1 includes a main plate 11 and two side plates 12 located on both sides of the main plate 11; the two side plates 12 are arranged on both sides of the main plate 11 in the X direction in the Figure 2 upward surface in the X direction in the Figure 1 and Figure 2 direction in the X direction in the

[0028] The two side plates 12 are each provided with a hollow second flow channel 22 and a hollow third flow channel 23, and the outlet 221 of each second flow channel 22 and the outlet 231 of each third flow channel 23 are located on the side plate 12 in the Figure 2The third flow channel 23 is arranged on the upper surface of the gasket body 1, and the outlet 231 of each third flow channel 23 is arranged between the outlet 211 of the first flow channel 21 and the outlet 221 of the second flow channel 22. The second flow channel 22 is used to guide the insulating paste introduced from the upper die or the lower die, and the outlet 221 of the second flow channel 22 is used to coat the insulating paste on both sides of the positive plate or the negative plate of the battery cell. The third flow channel 23 is used to guide the separation medium introduced from the upper die or the lower die, and the outlet 231 of the third flow channel 23 is used to spray the separation medium between the electrode paste and the insulating paste, so as to separate the electrode paste flowing out of the outlet 211 of the first flow channel 21 from the insulating paste flowing out of the outlet 221 of the second flow channel 22.

[0029] Specifically, as shown in Figure 1 and Figure 2 The gasket body 1 is in an inverted C shape, which includes a horizontal main plate 11 and two side plates 12 arranged on both sides of the main plate 11 and perpendicular to the main plate 11. The side plate 12 is similar to an L shape, and the two L-shaped side plates 12 and the main plate 11 form a hollow first flow channel 21, and the outlet 211 of the first flow channel 21 is arranged on the side of the first flow channel 21 away from the main plate 11. A plurality of mounting holes 111 are arranged on the main plate 11, which are used to connect the gasket body 1 with the upper die and the lower die. The upper die and the lower die are both provided with a plurality of mounting holes with the same diameter, and the mounting holes of the three components are aligned and mounted into fasteners to fix the gasket body 1 between the upper die and the lower die. Preferably, the mounting holes on the gasket body 1, the upper die and the lower die are all threaded holes, and the fasteners are bolts, which are used to connect the three components. The threaded bolt connection has good fastening effect and is convenient to connect.

[0030] The side plate 12 is used to form the first flow channel 21 with the main plate 11, and is also used for discharging the insulating paste and the separation medium. The second flow channel 22 and the third flow channel 23 are hollow and arranged on the side plate 12. The first flow channel 21, the second flow channel 22 and the third flow channel 23 are communicated with corresponding storage cavities in the upper die and the lower die, and the storage cavities form a circulation loop with a circulating pump and a buffer tank through a transmission pipeline, so that the electrode paste, the insulating paste and the separation medium can all circulate.

[0031] In some optional embodiments, in order to better separate the electrode paste flowing out of the outlet 211 of the first flow channel 21 from the insulating paste flowing out of the outlet 221 of the second flow channel 22, the outlet direction of the outlet 231 of the third flow channel 23 forms an angle with the outlet direction of the outlet 211 of the first flow channel 21. The angle is greater than or equal to 0° and less than or equal to 30°, for example. Figure 1 and Figure 2In some embodiments, the outlet 231 of the third flow channel 23 is spaced apart from the outlet 211 of the first flow channel 21 and the outlet 221 of the second flow channel 22.

[0032] In some alternative embodiments, in order to better separate the electrode slurry flowing out of the outlet 211 of the first flow channel 21 from the insulating slurry flowing out of the outlet 221 of the second flow channel 22, the outlet 231 of the third flow channel 23 is arranged to have the same flow direction as the outlet 221 of the second flow channel 22. The spacing between the outlet 231 of the third flow channel 23 and the outlet 211 of the first flow channel 21 is greater than 0 mm and less than or equal to 8 mm, for example. The spacing between the outlet 231 of the third flow channel 23 and the outlet 221 of the second flow channel 22 is greater than 0 mm and less than or equal to 4 mm, for example. Preferably, the spacing is greater than or equal to 0.5 mm and less than or equal to 4 mm, and more preferably, the spacing is greater than or equal to 2.5 mm and less than or equal to 4 mm.

[0033] In summary, the gasket structure for the electrode coating process provided by the embodiments of the present application can separate the electrode slurry flowing out of the outlet of the first flow channel from the insulating slurry flowing out of the outlet of the second flow channel by adding a third flow channel for conveying the isolation medium and spacing the outlet of the third flow channel between the outlet of the first flow channel and the outlet of the second flow channel. This can prevent the insulating slurry from migrating into the electrode slurry, thereby ensuring accurate collection of the coating film width data and improving the coating yield and production efficiency.

[0034] As another technical solution, the embodiments of the present application also provide a coating method for coating a material by using a coating machine. The coating machine includes the above-mentioned coating gasket provided by the embodiments of the present application. Optionally, the coating machine includes an upper die head, a lower die head, and the above-mentioned coating gasket. The coating gasket is compressed and sealed between the upper die head and the lower die head.

[0035] During the coating process, the electrode slurry is conveyed to the material through the outlet 211 of the first flow channel 21, the insulating slurry is conveyed to the material through the outlet 221 of the second flow channel 22, and the isolation medium is conveyed to the material through the outlet 231 of the third flow channel 23.

[0036] It should be noted that the embodiments of the present application do not have special limitations on the specific structure of the coating machine. The extrusion head for mounting the coating gasket can also use any other structure other than the upper die head and the lower die head.

[0037] Before the coating process is performed, the circulating pumps can be started to circulate the electrode slurry, the insulating slurry and the isolation medium in the respective circulating loops (formed by the corresponding storage cavities in the upper die head and the lower die head, the transmission pipelines, the circulating pumps and the buffer tanks) for a period of time, for example, 30 minutes. When the coating process is started, the control switches of the corresponding storage cavities in the upper die head and the lower die head are first turned on to supply the electrode slurry to the first flow channel 21 and to adjust the coating parameters so that the coating width of the electrode slurry reaches the set width; then the control switches of the corresponding storage cavities in the upper die head and the lower die head are turned on to supply the insulating slurry to the second flow channel 22 and to adjust the coating parameters so that the coating width of the insulating slurry reaches the set width; and then the control switches of the corresponding storage cavities in the upper die head and the lower die head are turned on to supply the isolation medium to the third flow channel 23 and to adjust the flow rate of the isolation medium so that the electrode slurry flowing out of the outlet of the first flow channel is separated from the insulating slurry flowing out of the outlet of the second flow channel, and the insulating slurry and the electrode slurry are respectively coated on the corresponding regions of the material, and the boundaries are just fused (i.e., the insulating slurry does not migrate to the inside of the electrode slurry). During the coating process, the oven parameters are adjusted to control the weight loss rate of the positive plate or the negative plate of the coated battery cell within a reasonable range.

[0038] In some optional embodiments, in order to better achieve the effect of separating the electrode slurry flowing out of the outlet 211 of the first flow channel 21 from the insulating slurry flowing out of the outlet 221 of the second flow channel 22, the flow rate of the isolation medium is 5% to 15% of the flow rate of the insulating slurry.

[0039] In some optional embodiments, the coating temperature used in the coating process is greater than or equal to 15°C and less than or equal to 60°C, and the coating speed used in the coating process is greater than 0 and less than or equal to 100 m / s. The coating method provided by the embodiments of the present application can use a higher coating speed on the premise that the insulating slurry does not migrate to the inside of the electrode slurry, thereby improving the production efficiency.

[0040] In summary, the coating method provided by the embodiments of the present application can avoid the migration of the insulating slurry to the inside of the electrode slurry by using the coating machine comprising the above-mentioned gasket structure provided by the embodiments of the present application, thereby ensuring accurate collection of the coating film width data, and further improving the coating success rate and the production efficiency.

[0041] It can be understood that the above embodiments are only exemplary embodiments adopted for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the protection scope of the present application.

Claims

1. A spacer structure for an electrode coating process, characterized by, The spacer body has an outflow surface facing a material coating direction, and a first flow guide channel for conveying electrode paste, a second flow guide channel for conveying insulating paste and a third flow guide channel for conveying isolation medium are arranged in the spacer body, the outlets of the first, second and third flow guide channels are located on the outflow surface, and the outlet of the third flow guide channel is arranged between the outlets of the first and second flow guide channels to separate the electrode paste flowing out of the outlet of the first flow guide channel from the insulating paste flowing out of the outlet of the second flow guide channel.

2. The gasket structure of claim 1, wherein The isolation medium includes at least one of deionized water, methanol, ethanol, ethyl cellulose, and dimethyl carbonate.

3. The gasket structure of claim 1, wherein The spacer body includes a main plate and two side plates located on both sides of the main plate; the main plate and the two side plates surround to form the first flow guide channel in a hollow shape. The second flow guide channel and the third flow guide channel are arranged in a hollow shape in each of the two side plates, and the outlet of each third flow guide channel is arranged between the outlets of the first and second flow guide channels.

4. The gasket structure according to any one of claims 1 to 3, characterized in that, The outflow direction of the outlet of the third flow guide channel forms an angle with the outflow direction of the outlet of the first flow guide channel.

5. The gasket structure of claim 4, wherein The angle is greater than or equal to 0° and less than or equal to 30°.

6. The gasket structure according to any one of claims 1 to 3, characterized by The outflow direction of the outlet of the third flow guide channel is consistent with the outflow direction of the outlet of the second flow guide channel.

7. The gasket structure according to any one of claims 1 to 3, wherein The interval between the outlet of the third flow guide channel and the outlet of the first flow guide channel is greater than 0 mm and less than or equal to 8 mm, and the interval between the outlet of the third flow guide channel and the outlet of the second flow guide channel is greater than 0 mm and less than or equal to 4 mm.

8. A coating method characterized by, A coating machine is used for a material coating process, and the coating machine includes the coating structure according to any one of claims 1-7. During the coating process, the electrode paste is conveyed to the material through the outlet of the first flow guide channel, the insulating paste is conveyed to the material through the outlet of the second flow guide channel, and the isolation medium is conveyed to the material through the outlet of the third flow guide channel.

9. The coating method according to claim 8, characterized in that, The flow rate of the isolation medium is 5% to 15% of the flow rate of the insulating paste.

10. The coating method according to claim 8, characterized in that, The coating temperature used in the coating process is greater than or equal to 15°C and less than or equal to 60°C, and the coating speed used in the coating process is greater than 0 and less than or equal to 100 m / s.

Images