Battery pole piece removal device and battery pole piece removal method

Abstract

A battery pole piece removal device, wherein the battery pole piece includes a current collector and a coating material attached to the surface of the current collector, and the battery pole piece removal device is used to remove the coating material in a predetermined area of ​​the battery pole piece, and includes: a positioning member, the positioning member includes a side plate and a hollow space surrounded by the side plate, the side plate is used to contact the current collector to isolate the coating material in the predetermined area in the hollow space; a spray port, the spray port is located in the hollow space, the spray port is used to communicate with a liquid source to spray liquid on the coating material in the predetermined area, and the liquid increases the fluidity of the coating material in the predetermined area; a suction port, the suction port is located in the hollow space, and is used to communicate with a vacuum generating device to suck the coating material in the predetermined area away from the current collector. Using the battery pole piece removal device for material removal can efficiently and effectively remove the coating material at the position where the electrode ear needs to be welded on the battery pole piece, greatly reducing the degree of damage to the current collector after material removal and the residual coating material on the current collector.

Description

Technical Field

[0001] The present application relates to the preparation of battery pole pieces, and in particular to a battery pole piece removal device and a battery pole piece removal method. Background Art

[0002] With the widespread application of lithium-ion batteries, research on the optimization of lithium-ion battery performance has also attracted much attention. Among them, the improvement of lithium-ion battery energy density has always been the focus of people's attention. The improvement of lithium-ion battery energy density can be considered not only from the inherent properties of the battery material itself, but also from the perspective of lithium-ion battery structure. In order to improve the energy density of lithium-ion batteries and reduce the internal impedance of the battery caused by the battery structure, the position of the pole ear on the battery pole piece in the lithium-ion battery has begun to change from the early position of the pole piece to the middle position of the pole piece, that is, the coating area of ​​the battery pole piece. The change in the position of the pole ear also means a change in the preparation method of the battery pole piece. The pole ear is located in the coating area of ​​the battery pole piece. In the presence of electrode coating, the pole ear cannot be welded with the electrode collector, so it is necessary to first remove the coating corresponding to the coating area and the pole ear. At present, the commonly used methods for removing coating materials include mechanical scraping and cleaning, chemical cleaning and laser cleaning. However, regarding the mechanical scraping and cleaning method, it uses a metal scraper to directly contact the surface of the current collector, which has certain production risks. In addition, when the gap between the scraper and the battery pole is too large, paint residue will be generated, and the cleaning will not be clean. When the gap between the scraper and the battery pole is too small, the battery collector will be scratched or even broken, and the powder produced during the scraping will stick to the battery pole, which will also increase the defective rate of the battery pole. Regarding the chemical cleaning method, it will cause certain pollution to the environment, and there are problems such as poor working environment and low production efficiency. Regarding the laser cleaning method, due to the uneven distribution of laser energy, the battery pole will be easily damaged, and the surface of the pole will be easily oxidized and the strength will be reduced. Therefore, a better way is needed to remove the coating material in specific areas on the battery pole. Summary of the invention

[0003] In order to solve the technical problems of various drawbacks in the prior art methods for removing battery pole piece coverings, the present application provides a battery pole piece removal device and a battery pole piece removal method. By using the battery pole piece removal device for material removal, the covering material at the position where the electrode ear needs to be welded on the battery pole piece can be efficiently and effectively removed, which greatly reduces the degree of damage to the current collector after material removal and the residual covering material on the current collector.

[0004] To achieve the above-mentioned purpose, in a first aspect, the present application provides a battery pole piece removal device, wherein the battery pole piece includes a current collector and a coating material attached to the surface of the current collector, characterized in that the battery pole piece removal device is used to remove the coating material of a predetermined area of ​​the battery pole piece, and comprises:

[0005] A positioning member, the positioning member includes a side plate and a hollow space surrounded by the side plate, the side plate is used to contact the current collector to isolate the coating material of the predetermined area in the hollow space,

[0006] a spraying port, the spraying port being located in the hollow space, the spraying port being used to communicate with a liquid source to spray liquid on the coating material in the predetermined area, the liquid increasing the fluidity of the coating material in the predetermined area,

[0007] A suction port is located in the hollow space and is used to communicate with a vacuum generating device to suck the coating material in the predetermined area away from the current collector.

[0008] In one embodiment of the present application, the positioning member further includes a top plate, the side plate is arranged on the periphery of the top plate to form the hollow space, and the side plate is in contact with the current collector to seal the hollow space.

[0009] In one embodiment of the present application, the side plate includes an inner plate close to the hollow space and an outer plate away from the hollow space, and the inner plate and the outer plate are arranged at a distance to form a suction pipe, and the suction pipe is connected to the suction port to suck the coating material of the predetermined area from the side plate to the collector.

[0010] In one embodiment of the present application, the side plate includes an inner plate close to the hollow space and an outer plate away from the hollow space, the top plate includes an inner top plate close to the hollow space and an outer top plate away from the hollow space, the inner plate is connected to the inner top plate to form an inner wall of the suction pipe, the outer plate is connected to the outer top plate to form an outer wall of the suction pipe, the inner wall of the suction pipe and the outer wall of the suction pipe form a suction pipe, and the suction pipe is connected to the suction port to suck the coating of the predetermined area away from the top plate from the collector.

[0011] In one embodiment of the present application, one end of the inner plate close to the battery electrode and one end of the outer plate close to the battery electrode jointly form the material suction port, one end of the outer plate close to the battery electrode is used to contact the current collector to isolate the coating material of the predetermined area in the hollow space, and one end of the inner plate close to the battery electrode is used to contact the coating material of the predetermined area.

[0012] In one embodiment of the present application, a spray pipe is provided inside the top plate, and the spray pipe forms the spray port on a side of the top plate close to the battery electrode. The spray port is connected to a liquid source through the spray pipe to spray liquid on the coating material in the predetermined area.

[0013] In one embodiment of the present application, the battery electrode sheet removal device also includes a spray plate, which is arranged in the hollow space. A spray pipe is provided inside the spray plate, and the spray pipe forms a spray port on the surface of the spray plate. The spray pipe is connected to a liquid source to spray liquid on the coating material in the predetermined area.

[0014] In one embodiment of the present application, the spray plate is opposite to the battery pole piece, and the spray port is located on a side of the spray plate close to the battery pole piece.

[0015] In one embodiment of the present application, the suction port is located in the covering material, and the distance between the suction port away from the side plate and the current collector is greater than the distance between the suction port close to the side plate and the current collector.

[0016] Through the above technical solution, the battery pole piece removal device of the present application can accurately remove the coating of the predetermined area on the battery pole piece for welding the pole ear. The positioning member contained therein can lock the predetermined area where the coating needs to be removed. The side plate in the positioning member contacts the current collector to separate the predetermined area where the coating needs to be removed from the non-predetermined area where the coating does not need to be removed, so that when the coating is removed from the predetermined area, the coating of the non-predetermined area will not be affected, thereby improving the removal accuracy. In addition, the battery pole piece removal device also includes a spray port, which is connected to a liquid source. Liquid can be sprayed on the predetermined area isolated by the positioning member to reduce the viscosity of the coating material in the predetermined area, which is conducive to the absorption of the coating material in this area; furthermore, the battery pole piece removal device also includes a suction port, which can absorb the coating material in the predetermined area with low viscosity from the current collector. Since the coating material is absorbed, the absorption method can greatly reduce the damage to the battery pole piece and reduce the residual coating material on the current collector compared to the mechanical scraping cleaning method, chemical cleaning method and laser cleaning method in the prior art, thereby improving the welding yield of the pole ear on the current collector. Not only that, the battery pole piece removal device provided by the present application integrates the positioning member with positioning and isolation functions, the spraying port with the function of spraying liquid, and the suction port with the function of absorbing coating material, so that the coating material in the predetermined area of ​​the battery pole piece can be removed conveniently, quickly and efficiently, thereby improving the production efficiency of the battery pole piece.

[0017] In a second aspect, the present application provides a battery pole piece removal method, which uses the battery pole piece removal device described above to remove the covering material in a predetermined area of ​​the battery pole piece, comprising the following steps:

[0018] (1) Positioning the removal area: placing the positioning member on the battery electrode so that the side plate contacts the current collector, so that the coating material in the predetermined area is isolated in the hollow space;

[0019] (2) Spraying liquid: the spraying port in the hollow space sprays liquid to wet the coating material in the predetermined area;

[0020] (3) Absorbing the coating material: The coating material in the predetermined area soaked in step (2) is absorbed from the current collector through the suction port.

[0021] In one embodiment of the present application, the method further includes step (4) cleaning: spraying liquid on the current collector after the coating material is sucked off in step (3), and sucking the liquid off the current collector through the suction port.

[0022] By using the above-mentioned battery pole piece removal method, the covering material at the position where the pole ear needs to be set can be conveniently, quickly and effectively removed, which is beneficial to the welding of the pole ear on the current collector and improves the welding yield of the pole ear.

[0023] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a battery pole piece with a pole ear located at the end;

[0025] Figure 2 Schematic diagram of a battery pole piece with a pole ear located on the covering layer;

[0026] Figure 3 This is a schematic diagram of a battery pole piece removal device according to an embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of a battery pole piece removal device according to another embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of a battery pole piece removal method according to an embodiment of the present application;

[0029] Reference numerals:

[0030] Battery pole piece 1, current collector 11, coating material 12, pole ear 13, predetermined area 14, battery pole piece removal device 100, positioning member 2, side plate 21, inner plate 211, outer plate 212, hollow space 22, top plate 23, inner top plate 231, outer top plate 232, spray port 3, suction port 4, suction pipe 5, spray pipe 6, spray plate 7. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] The lithium-ion battery comprises a battery pole piece, wherein the battery pole piece 1 comprises a current collector 11, a coating material 12 layer attached to the surface of the current collector 11, and a pole ear 13 welded to the current collector 11. Figure 1 As shown, the end of the current collector 11 is a blank current collector, which is used for welding the pole ear 13, and the other part is used for coating the coating material 12. When the lithium-ion battery is discharged, taking the negative electrode as an example, since the electrons are transmitted to the external circuit through the current collector 11 and the pole ear 13, and for the coating material far away from the end of the pole ear 13, the path for the electrons to be transmitted to the external circuit is longer, so that some heat will be generated during the electron transmission process, resulting in a loss of battery capacity, which is not conducive to the improvement of battery energy density. Therefore, to solve this problem, the position of the pole ear 13 on the battery pole sheet 1 can be changed, such as Figure 2 As shown, the position of the pole tab 13 is transferred from the end of the current collector to the middle of the coating material 12 layer or a position close to the middle of the coating material 12 layer, which can shorten the path of electron transmission between the battery pole piece 1 and the external circuit, reduce the loss of battery energy density caused by electron transmission, and help improve the battery energy density. Since the pole tab 13 cannot be directly welded to the coating material 12 layer, it is necessary to remove the coating material 12 at the welding pole tab position to expose the current collector 11, so that the current collector 11 and the pole tab 13 can be welded together.

[0033] Based on this, Figure 3-4 As shown, the present application provides a battery pole piece removal device 100, which can be used to remove the covering material 12 of a predetermined area 14 of a battery pole piece, and the predetermined area 14 is the area used for welding the pole lug 13. The battery pole piece removal device 100 includes a positioning member 2, a spray port 3 and a suction port 4, wherein the positioning member 2 includes a side plate 21 and a hollow space 22 surrounded by the side plate. When the battery pole piece removal device is used to remove the coating material in the predetermined area 14 of the battery pole piece, the positioning member 2 needs to be in contact with the battery pole piece 1, wherein the side plate 21 is used to contact the current collector 11 to isolate the coating material in the predetermined area 14 in the hollow space 22, wherein the contact between the side plate 21 and the current collector 11 is that the side plate 11 passes through the coating material 12 layer and contacts the current collector 11, the spray port 3 is arranged in the hollow space 22, the spray port 3 is used to connect with a liquid source to spray liquid on the coating material in the predetermined area 14, and the liquid increases the fluidity of the coating material in the predetermined area 14, and the suction port 4 is arranged in the hollow space 22, and the suction port 4 is used to connect with a vacuum generating device to suck the coating material in the predetermined area 14 away from the current collector 11.

[0034] It can be seen that since the battery electrode removal device contains a positioning member 2, the side plate 21 contacts the current collector 11 to separate the coating that needs to be removed from the coating that does not need to be removed. On this basis, the spray port connected to the liquid source can spray liquid on the coating that needs to be removed. After the coating is soaked in the liquid, the viscosity will decrease and the fluidity will increase, which is conducive to suction. Since the spray port 3 is arranged in the hollow space 22, and the side plate 21 isolates the coating that needs to be removed from the coating that does not need to be removed, the sprayed liquid will not contact the area where the coating does not need to be removed, that is, the coating that does not need to be removed will not be affected by the liquid. In this way, the coating in the predetermined area 14 can be accurately removed without affecting the coating that does not need to be removed, thereby improving the accuracy of material removal. Furthermore, the suction port 4 arranged in the hollow space 22 will only absorb the coating material isolated in the predetermined area 14 of the hollow space 22 from the collector 11, and will not affect the coating material outside the hollow space 22 that does not need to be removed, thereby not affecting the subsequent use effect of the battery electrode 1.

[0035] In one embodiment of the present application, the suction port 4 is located in the covering material 12 , and the distance between the suction port 4 away from the side plate 21 and the current collector 11 is greater than the distance between the suction port 4 close to the side plate 21 and the current collector 11 .

[0036] That is to say, the plane where the feed point of the suction port 4 is located is not parallel to the current collector 11, but is at a certain angle. Compared with the feed point of the suction port being parallel to the current collector 11, such a setting can increase the feed amount at the feed point, that is, it is more conducive to the coating material entering the suction port.

[0037] like Figure 3-4 As shown, in one embodiment of the present application, the positioning member 2 further includes a top plate 23 , and the side plate 21 is arranged on the periphery of the top plate 21 to form a hollow space 22 , and the side plate 21 is in contact with the current collector 11 to seal the hollow space 22 .

[0038] That is, the top plate 23 and the side plate 21 surround and form a hollow space 22 with an open end. When the side plate 21 contacts the current collector 11, the current collector 11 can seal the opening, and the coating material of the predetermined area 14 is also isolated at the opening.

[0039] In one embodiment of the present application, a suction pipe 5 is provided inside the side panel 21, and the suction pipe 5 forms a first discharge port on the side of the side panel 21 close to the hollow space 22, and forms a second discharge port on the side of the side panel away from the hollow space 22. The first discharge port is used to be connected with the suction port, and the second discharge port is used to be connected with the vacuum generating device. Under the action of the vacuum generating device, the coating material in the predetermined area 14 is sucked away from the collector 11 through the suction port 4 and the suction pipe 5.

[0040] like Figure 4As shown, in one embodiment of the present application, a suction pipe 5 is provided inside the side plate 21, and the side plate 21 includes an inner plate 211 close to the hollow space 22 and an outer plate 212 away from the hollow space 22, and the inner plate 211 and the outer plate 212 are arranged at a distance to form the suction pipe 5, that is, the inner plate 211 and the outer plate 212 are arranged at a certain distance, and the outer plate 212 surrounds the hollow space 22, and the inner plate 211 is arranged in the hollow space 22 around the outer plate 212, and a crossbeam is provided at one end of the inner plate 211 and the outer plate 212 away from the battery pole piece 1, and the crossbeam is used to connect the inner plate 211 and the outer plate 212, and the space with one end open surrounded by the inner plate 211, the outer plate 212 and the crossbeam is the suction pipe 5. Among them, the arrow in the suction pipe 5 in the figure indicates the direction in which the coating material is sucked away.

[0041] Furthermore, the suction pipe 5 forms a second discharge port on the cross beam for communicating with the vacuum generating device, and the suction pipe 5 forms a first discharge port at a position where the inner plate 211 can contact the covering material, and the first discharge port is the suction port 4.

[0042] Furthermore, one end of the inner plate 211 close to the battery electrode 1 and one end of the outer plate 212 close to the battery electrode 1 together form a suction port 4, that is, the opening of the suction pipe 5 surrounded by the inner plate 211, the outer plate 212 and the crossbeam is the suction port 4, and one end of the outer plate 212 close to the battery electrode 1 is used to contact the collector 11 to isolate the coating of the predetermined area 14 in the hollow space 22, and one end of the inner plate 211 close to the battery electrode 1 is used to contact the coating of the predetermined area 14.

[0043] That is to say, at one end of the side plate 21 close to the battery electrode 1, the outer plate 212 is not flush with the inner plate 211, but the outer plate 212 protrudes from the inner plate 211. When the positioning member 2 is used to position the coating of the predetermined area 14, the outer plate 212 is in contact with the current collector 11 for positioning. The inner plate 211 is shorter and cannot contact the current collector 11, but can contact the coating 12. It can contact the surface of the coating layer or be inserted into the coating layer to contact the coating, as long as it does not contact the current collector 11. Preferably, the inner plate 211 is in contact with the surface of the coating layer.

[0044] By making the inner plate 211 and the outer plate 212 have a certain height difference at one end of the side plate 21 close to the battery pole piece 1 to form the suction port 4, it is possible to avoid setting a separate suction port 4 in the hollow space 22, reduce the components, and simplify the device structure. In addition, the inner plate 211 does not contact the current collector 11, but only contacts the coating material 12 layer, so that the coating material can be effectively sucked away from the current collector surface; the inner plate 211 contacts the surface of the coating material 12 layer, so that the area of ​​the suction port 4 is large enough to efficiently and quickly suck away the coating material 12.

[0045] like Figure 3 As shown, in one embodiment of the present application, a suction pipe 5 is provided in both the top plate 23 and the side plate 21, and the suction pipe 5 consists of an inner wall and an outer wall. The side plate 21 includes an inner plate 211 close to the hollow space 22 and an outer plate 212 away from the hollow space 22. The top plate 23 includes an inner top plate 231 close to the hollow space 22 and an outer top plate 232 away from the hollow space 22. The inner plate 211 is connected to the inner top plate 231 to form the inner wall of the suction pipe 5, and the outer plate 212 is connected to the outer top plate 232 to form the outer wall of the suction pipe 5. The suction pipe 5 is connected to the suction port 4 through the suction pipe 5 and the vacuum generating device to suck the coating material in the predetermined area 14 away from the collector 11.

[0046] like Figure 3 As shown, in one embodiment of the present application, the battery electrode sheet removal device also includes a spray plate 7, which is arranged in the hollow space 22. A spray pipe 6 is provided inside the spray plate 7. The spray pipe 6 forms a spray port 3 on the surface of the spray plate 7. The spray port 3 is connected to a liquid source through the spray pipe 6 to spray liquid on the coating material in the predetermined area 14.

[0047] Furthermore, the spray plate 7 is opposite to the battery pole piece 1 , and the spray port 3 is located on a side of the spray plate 7 close to the battery pole piece 1 .

[0048] Furthermore, a plurality of spray ports 3 are provided on the spray plate 7 .

[0049] That is to say, in this embodiment, the spray plate 7 is similar to a shower head in life, and has multiple spray ports 3, so that the spray efficiency can be improved. In addition, the spray plate 7 is preferably arranged in parallel with the battery electrode 1, so that the liquid sprayed from the spray plate 7 can be directly sprayed onto the coating material in the predetermined area 14, so that the coating material in the predetermined area 14 can quickly contact the sprayed liquid, thereby improving the efficiency of the coating material infiltration in the predetermined area 14.

[0050] In such Figure 4 As shown, in one embodiment of the present application, a spraying pipe 6 is provided inside the top plate 23 , and the spraying pipe 6 forms a spraying port 3 on one side of the top plate 23 close to the battery electrode 1 , and the spraying port 3 is connected to a liquid source through the spraying pipe 6 to spray liquid on the coating material in the predetermined area 14 .

[0051] In the present application, the shape and size of the area enclosed by the side plate 21 and the battery electrode current collector 11 on the battery electrode 1 are determined according to the shape and size of the pre-designed battery electrode that needs to remove the coating material. In the prior art, the tab 13 welded on the current collector 11 is composed of a tab body and a tab glue, a part of the tab body is welded to the current collector 11, and another part of the tab body exceeds the current collector 11. The part of the tab body welded to the current collector 11 is usually rectangular, so the area enclosed by the side plate 21 on the battery electrode 1 is rectangular, and the area of ​​the enclosed area is larger than the area of ​​the part of the tab body welded to the current collector.

[0052] On the other hand, Figure 5 As shown, the present application also provides a battery pole piece removal method, which uses the above-mentioned battery pole piece removal device to remove the coating material of the predetermined area of ​​the battery pole piece. The method comprises the following steps:

[0053] (1) Locate the cutout area: Figure 5 As shown in (a), the positioning member 2 is placed in the predetermined area 14 of the battery electrode 1, that is, the area where the coating needs to be removed, so that the side plate 21 passes through the coating layer 12 and contacts the current collector 11, so that the coating in the predetermined area 14 can be isolated in the hollow space 22, that is, the side plate 21 surrounds the coating in the predetermined area 14 in the hollow space 22.

[0054] The side plate 21 can be set up to isolate the predetermined area 14 separately, so that the coating material that needs to be removed can be separated from the coating material that does not need to be removed, so as to avoid affecting the coating material that does not need to be removed when the coating material that needs to be removed is removed, so that the coating material that does not need to be removed is also removed, which will cause the failure of the electrode manufacturing. Therefore, the ingenious design and application of the side plate 21 improves the removal accuracy of the coating material in the predetermined area of ​​the battery electrode and improves the yield rate of the battery electrode manufacturing.

[0055] (2) Spraying liquid: Figure 5 As shown in (b), after the coating material of the predetermined area 14 is positioned and isolated, the spraying program needs to be started. The spray port 3 located in the hollow space 22 is used to connect with the liquid source. The liquid can be sprayed from the spray port 3 into the hollow space 22, and then fully contact with the coating material of the predetermined area 14; wherein the arrow in the figure indicates the direction of liquid spraying.

[0056] Since the side plate 21 has isolated the coating material in the predetermined area 14 in step (1), the liquid sprayed from the spray port 3 will not contact the coating material outside the predetermined area. Only the coating material in the predetermined area 14 can contact the liquid. The liquid will infiltrate the coating material in the predetermined area 14, thereby reducing the viscosity of the coating material and increasing the fluidity of the coating material in the predetermined area 14, making it easier to absorb and remove.

[0057] (3) Remove the coating material: Figure 5 As shown in (c), after the liquid sprayed in step (2) soaks the coating material in the predetermined area 14, the suction procedure can be started. The suction port 4 located in the hollow space 22 is connected to a vacuum generating device. Under negative pressure, the coating material in the predetermined area 14 can be sucked away from the suction port 4; wherein the arrow in the figure indicates the direction in which the coating material is sucked away.

[0058] Due to the existence of the side plate 21 and the fact that only the coating material in the predetermined area 14 is soaked in liquid, the fluidity is enhanced. Therefore, when the suction port 4 sucks the material, it only sucks away the coating material in the predetermined area 14, while the coating material outside the predetermined area is not affected.

[0059] In order to ensure that the coating material in the predetermined area can be cleaned by suction, further, such as Figure 5 As shown in (d), after the coating material of the predetermined area is sucked away in step (3), step (4) can be performed to clean the predetermined area 14, that is, after step (3) is completed, the spraying program is started again to distribute the liquid sprayed from the spray port 3 on the collector of the predetermined area 14, and the suction program is started at the same time to suck away the liquid on the collector 11 of the predetermined area 14, thereby cleaning the predetermined area 14; wherein the arrows indicate the direction in which the liquid is sprayed and the direction in which the liquid is sucked away.

[0060] After cleaning in step (4), it can be ensured that the coating material in the predetermined area 14 is completely removed, so that the surface of the current collector in the predetermined area can be clean enough to facilitate welding of the electrode lug.

[0061] Furthermore, in step (2), the standard for spraying the liquid is 1-3 g of liquid per square centimeter of the predetermined area.

[0062] Furthermore, in step (3), the vacuum degree of the vacuum generating device is 50-300 kPa.

[0063] Furthermore, in step (4), the standard for spraying the liquid is 1-3 g of liquid per square centimeter of the predetermined area, and the vacuum degree of the vacuum generating device is 50-300 kPa.

[0064] Furthermore, in step (1), the battery pole piece 1 is a battery pole piece whose surface coating material has not been dried. The coating material that has not been dried is more easily soaked in the liquid sprayed from the spray port and is easy to absorb.

[0065] Furthermore, after the above operations, the battery pole pieces may be dried.

[0066] Furthermore, the liquid is an organic solvent, and the organic solvent is selected from at least one of an ester solvent and an ether solvent. The ester solvent is selected from at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethyl acetate, methyl acetate, ethyl propionate, methyl propionate, propyl propionate, and butyrolactone. The ether solvent is selected from at least one of ether, tetrahydrofuran, and furan.

[0067] Example 1

[0068] Prepare positive electrode active slurry: add lithium cobalt oxide, conductive carbon and PVDF into NMP (N-methyl-2-pyrrolidone) in a mass ratio of 97:1.5:1.5, mix, and evenly prepare slurry by mechanical stirring. The prepared positive electrode active slurry has a viscosity of 5000cp and a solid content of 80%.

[0069] Preparation of positive electrode sheet: The above positive electrode active slurry was coated on aluminum foil, and the obtained surface density was 14 mg / cm 2 .

[0070] Removing the coating material in the predetermined area: The battery pole piece removal device of the present application is used to remove the coating material in the predetermined area of ​​the positive pole piece. Start the positioning piece so that the side plate passes through the coating layer and contacts the current collector, start the spraying program, spray 1.5g of NMP on the coating material in the predetermined area per square centimeter, wait for 1 second, start the vacuum generating device, set the vacuum degree to 90kPa, and maintain the pressure for 3 seconds to absorb the coating material in the predetermined area; start the spraying program again, spray 1.5g of NMP on the predetermined area per square centimeter, and start the vacuum generating device at the same time, maintain the pressure for 1 second to complete the cleaning of the current collector in the predetermined area.

[0071] The tabs are welded to the predetermined area of ​​the prepared positive electrode sheet and assembled into a lithium-ion battery.

[0072] Example 2

[0073] Prepare positive electrode active slurry: add lithium cobalt oxide, conductive carbon and PVDF into NMP (N-methyl-2-pyrrolidone) at a mass ratio of 90:5:5, mix, and evenly prepare slurry by mechanical stirring. The prepared positive electrode active slurry has a viscosity of 3000cp and a solid content of 60%.

[0074] Preparation of positive electrode sheet: The above positive electrode active slurry was coated on aluminum foil, and the obtained surface density was 11 mg / cm 2 .

[0075] Removing the coating material in the predetermined area: The battery pole piece removal device of the present application is used to remove the coating material in the predetermined area of ​​the positive pole piece. Start the positioning piece so that the side plate passes through the coating layer and contacts the current collector, start the spraying program, spray 1g of NMP on the coating material in the predetermined area per square centimeter, wait for 0.5s, start the vacuum generating device, set the vacuum degree to 200kPa, maintain the pressure for 0.5s to absorb the coating material in the predetermined area; start the spraying program again, spray 1.5g of NMP on the predetermined area per square centimeter, and start the vacuum generating device at the same time, maintain the pressure for 1s, and complete the cleaning of the current collector in the predetermined area.

[0076] The tabs are welded to the predetermined area of ​​the prepared positive electrode sheet and assembled into a lithium-ion battery.

[0077] Example 3

[0078] Prepare positive electrode active slurry: add lithium cobalt oxide, conductive carbon and PVDF into NMP (N-methyl-2-pyrrolidone) in a mass ratio of 99:0.5:0.5, mix, and evenly prepare slurry by mechanical stirring. The prepared positive electrode active slurry has a viscosity of 7000cp and a solid content of 85%.

[0079] Preparation of positive electrode sheet: The above positive electrode active slurry was coated on aluminum foil, and the obtained surface density was 17 mg / cm 2 .

[0080] Removing the coating material in the predetermined area: The battery pole piece removal device of the present application is used to remove the coating material in the predetermined area of ​​the positive pole piece. Start the positioning piece so that the side plate passes through the coating layer and contacts the current collector, start the spraying program, spray 3g of NMP on the coating material in the predetermined area per square centimeter, wait for 3 seconds, start the vacuum generating device, set the vacuum degree to 90kPa, and maintain the pressure for 3 seconds to absorb the coating material in the predetermined area; start the spraying program again, spray 1.5g of NMP on the predetermined area per square centimeter, and start the vacuum generating device at the same time, maintain the pressure for 1 second, and complete the cleaning of the current collector in the predetermined area.

[0081] The tabs are welded to the predetermined area of ​​the prepared positive electrode sheet and assembled into a lithium-ion battery.

[0082] Example 4

[0083] Preparation of negative electrode active slurry: Add graphite, conductive carbon, styrene-butadiene rubber and sodium carboxymethyl cellulose into deionized water in a mass ratio of 96:1.5:1.5:1.0, and prepare slurry by mechanical stirring. The prepared negative electrode active slurry has a viscosity of 3500cp and a solid content of 80%.

[0084] Preparation of negative electrode sheet: The above positive electrode active slurry was coated on copper foil, and the obtained surface density was 8 mg / cm 2 .

[0085] Removing the coating material in the predetermined area: The battery pole piece removal device of the present application is used to remove the coating material in the predetermined area of ​​the negative pole piece. Start the positioning piece so that the side plate passes through the coating layer and contacts the current collector, start the spraying program, spray 1g of NMP on the coating material in the predetermined area per square centimeter, wait for 3 seconds, start the vacuum generating device, set the vacuum degree to 100kPa, maintain the pressure for 1 second to absorb the coating material in the predetermined area; start the spraying program again, spray 1g of NMP on the predetermined area per square centimeter, and start the vacuum generating device at the same time, maintain the pressure for 1 second, and complete the cleaning of the current collector in the predetermined area.

[0086] The tabs are welded to the predetermined area of ​​the prepared negative electrode sheet and assembled into a lithium-ion battery.

[0087] Example 5

[0088] Preparation of negative electrode active slurry: graphite, conductive carbon, styrene-butadiene rubber and sodium carboxymethyl cellulose were added into deionized water at a mass ratio of 90:3.5:3.5:3.0, and the mixture was uniformly stirred by mechanical stirring to form a slurry. The prepared negative electrode active slurry had a viscosity of 2000cp and a solid content of 60%.

[0089] Preparation of negative electrode sheet: The above positive electrode active slurry was coated on copper foil, and the obtained surface density was 6 mg / cm 2 .

[0090] Removing the coating material in the predetermined area: The battery pole piece removal device of the present application is used to remove the coating material in the predetermined area of ​​the negative pole piece. Start the positioning piece so that the side plate passes through the coating layer and contacts the current collector, start the spraying program, spray 0.2g of NMP on the coating material in the predetermined area per square centimeter, wait for 0.2s, start the vacuum generating device, set the vacuum degree to 300kPa, maintain the pressure for 0.3s to absorb the coating material in the predetermined area; start the spraying program again, spray 1g of NMP on the predetermined area per square centimeter, and start the vacuum generating device at the same time, maintain the pressure for 1s, and complete the cleaning of the current collector in the predetermined area.

[0091] The tabs are welded to the predetermined area of ​​the prepared negative electrode sheet and assembled into a lithium-ion battery.

[0092] Example 6

[0093] Preparation of negative electrode active slurry: adding graphite, conductive carbon, styrene-butadiene rubber and sodium carboxymethyl cellulose into deionized water in a mass ratio of 98:0.7:0.7:0.6, and uniformly stirring the mixture through mechanical stirring to form a slurry. The prepared negative electrode active slurry has a viscosity of 6000cp and a solid content of 80%.

[0094] Preparation of negative electrode sheet: The above positive electrode active slurry was coated on copper foil, and the obtained surface density was 10 mg / cm2 .

[0095] Removing the coating material in the predetermined area: The battery pole piece removal device of the present application is used to remove the coating material in the predetermined area of ​​the above-mentioned negative pole piece. Start the positioning piece so that the side plate passes through the coating layer and contacts the current collector, start the spraying program, spray 2g of NMP on the coating material of each square centimeter of the predetermined area, wait for 3 seconds, start the vacuum generating device, set the vacuum degree to 100kPa, maintain the pressure for 1 second to absorb the coating material in the predetermined area; start the spraying program again, spray 1g of NMP on each square centimeter of the predetermined area, and start the vacuum generating device at the same time, maintain the pressure for 1 second, and complete the cleaning of the current collector in the predetermined area.

[0096] The tabs are welded to the predetermined area of ​​the prepared negative electrode sheet and assembled into a lithium-ion battery.

[0097] Comparative Example 1

[0098] For the positive electrode sheet prepared in Example 3, a laser cleaning device is used to remove the coating material in a predetermined area, and the other steps remain unchanged.

[0099] Comparative Example 2

[0100] For the negative electrode sheet prepared in Example 6, a laser cleaning device is used to remove the coating material in a predetermined area, and the other steps remain unchanged.

[0101] Experimental testing

[0102] (1) Test of residual coating material in the predetermined area of ​​the battery pole piece and test of surface damage of the current collector in the predetermined area:

[0103] For the positive and negative electrode sheets prepared in Examples 1-6 and Comparative Examples 1-2, the coating material residues in the predetermined areas and the current collector damage in the predetermined areas were observed with a 30x magnifying glass. The test results are shown in Table 1.

[0104] (2) Lithium-ion battery capacity test:

[0105] The lithium ion batteries prepared in Examples 1-6 and Comparative Examples 1-2 were subjected to battery capacity tests. The lithium ion batteries were first allowed to stand for 3 minutes, then charged to 4.3V at a constant current of 0.5C, and then charged to 0.05C at a constant voltage to obtain an initial charge capacity of AGC0, allowed to stand for 3 minutes, and then discharged to 3.0V at a constant current of 0.5C to obtain an initial discharge capacity of D0, allowed to stand for 3 minutes, and the lithium ion battery capacity test was completed. The test results are shown in Table 1.

[0106] Table 1

[0107] AGC0 / mAh D0 / mAh Current collector damage Residue of coating Example 1 4090 4081 none none Example 2 4087 4072 none none Example 3 4091 4085 none none Example 4 4095 4091 none none Example 5 4075 4063 none none Example 6 4079 4076 none none Comparative Example 1 2656 2521 obvious Small amount Comparative Example 2 3089 3048 slight Small amount

[0108] It can be seen from the test results in Table 1 that, compared with the existing battery pole piece coating removal method, when the battery pole piece removal device and the battery pole piece removal method provided in the present application are used to remove the positive pole piece and the negative pole piece, there is less residual coating material on the surface of the current collector in the predetermined area, and the damage to the current collector after removal is also very small, so that when the battery pole piece is used to assemble a battery, the battery performance is better.

[0109] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery pole piece removal device, wherein the battery pole piece comprises a current collector and a coating material attached to the surface of the current collector, characterized in that: The battery pole piece removal device is used to remove the covering material of a predetermined area of ​​the battery pole piece, and comprises: A positioning member, the positioning member comprising a side plate and a hollow space surrounded by the side plate, the side plate being used to pass through the coating material and contact the current collector to isolate the coating material of the predetermined area in the hollow space, wherein the side plate separates the predetermined area where the coating material needs to be removed from the non-predetermined area where the coating material does not need to be removed, so that when the coating material is removed from the predetermined area, the coating material of the non-predetermined area will not be affected; a spraying port, the spraying port being located in the hollow space and being used to communicate with a liquid source to spray liquid on the coating material in the predetermined area, wherein the liquid reduces the viscosity and increases the fluidity of the coating material in the predetermined area; A suction port, the suction port is located in the hollow space and is used to communicate with a vacuum generating device to suck the coating material in the predetermined area away from the current collector; The side plate comprises an inner plate close to the hollow space and an outer plate away from the hollow space, the inner plate and the outer plate are arranged at a distance to form a suction pipe, and the suction pipe is connected with the suction port to suck the coating material in the predetermined area from the side plate to the current collector; The suction port is located in the covering material, and a portion of the suction port away from the side plate is at a greater distance from the current collector than a portion of the suction port close to the side plate is at a greater distance from the current collector.

2. The battery pole piece removal device according to claim 1, characterized in that: The positioning member further includes a top plate, the side plate is disposed at a periphery of the top plate to form the hollow space, and the side plate is in contact with the current collector to seal the hollow space.

3. The battery pole piece removal device according to claim 2, characterized in that: The top plate includes an inner top plate close to the hollow space and an outer top plate away from the hollow space, the inner plate is connected to the inner top plate to form an inner wall of a suction pipe, the outer plate is connected to the outer top plate to form an outer wall of a suction pipe, the inner wall of the suction pipe and the outer wall of the suction pipe form a suction pipe, and the suction pipe is connected to the suction port to suck the coating of the predetermined area away from the top plate and the current collector.

4. The battery pole piece removal device according to claim 3, characterized in that: One end of the inner plate close to the battery electrode and one end of the outer plate close to the battery electrode jointly form the material suction port, one end of the outer plate close to the battery electrode is used to contact the current collector to isolate the coating material of the predetermined area in the hollow space, and one end of the inner plate close to the battery electrode is used to contact the coating material of the predetermined area.

5. The battery pole piece removal device according to claim 2, characterized in that: A spraying pipe is provided inside the top plate, and the spraying pipe forms the spraying port on a side of the top plate close to the battery pole piece. The spraying port is connected to a liquid source through the spraying pipe to spray liquid on the coating material in the predetermined area.

6. The battery pole piece removal device according to claim 1 or 2, characterized in that: The battery pole piece removal device also includes a spray plate, which is arranged in the hollow space. A spray pipe is provided inside the spray plate, and the spray pipe forms a spray port on the surface of the spray plate. The spray pipe is connected to a liquid source to spray liquid on the coating material in the predetermined area.

7. The battery pole piece removal device according to claim 6, characterized in that: The spray plate is opposite to the battery pole piece, and the spray port is located on a side of the spray plate close to the battery pole piece.

8. A battery pole piece removal method, characterized in that: The battery pole piece removal device according to any one of claims 1 to 7 is used to remove the coating material in the predetermined area of ​​the battery pole piece, comprising the following steps: (1) Positioning the material removal area: placing the positioning member on the battery electrode so that the side plate is in contact with the current collector, so that the coating material of the predetermined area is isolated in the hollow space; (2) spraying liquid: the spraying port in the hollow space sprays liquid to wet the coating material in the predetermined area; (3) Absorption of coating Material: The coating material of the predetermined area soaked in step (2) is sucked away from the current collector from the suction port.

9. The battery pole piece removal method according to claim 8, characterized in that: The method further comprises the step (4) of cleaning: spraying liquid on the current collector after the coating material is sucked off in the step (3), and sucking the liquid off the current collector through the suction port.

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