Pole piece processing method

Abstract

The application relates to the technical field of battery processing, and provides a pole piece processing method, which comprises the following steps: fixing a covering layer on a non-coating area of a base material; uniformly coating slurry on at least a coating area of the base material to form an initial pole piece; sequentially performing drying treatment and rolling treatment on the initial pole piece to form an intermediate pole piece, wherein the heat-resistant temperature of the covering layer is higher than the temperature required by the drying treatment; and tearing off the covering layer on the intermediate pole piece to form a finished pole piece. When the slurry is coated, whether the slurry is coated on the covering layer is not limited, that is, even if the slurry is coated on the covering layer, the slurry on the covering layer will also leave the base material together with the covering layer when the covering layer is torn off. Therefore, when the slurry is coated, the two ends of a coating roller can correspond to the covering layer, the thinning area of a coating edge is located on the covering layer, the coating area of the base material is prevented from being affected by the coating edge, and thus the problem that the edge of the coating area has a thinning area in the prior art can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery processing, and in particular to a pole piece processing method. BACKGROUND

[0002] A transfer coater is a common coating device, mainly used for uniformly coating slurry on the surface of an object. The working principle is to use a doctor blade to coat the slurry on a roller, and then transfer the slurry from the roller to the substrate. Due to the flow characteristics of the slurry itself, after coating on the substrate, the edge of the coating area will have a thickness lower than that of the coating area. These areas with thinner thickness are called "thinning areas". The existence of the thinning area is a major factor leading to the phenomenon of lithium metal precipitation.

[0003] Therefore, how to solve the problem of the existence of the thinning area at the edge of the coating area in the prior art has become an important technical problem to be solved by those skilled in the art. SUMMARY

[0004] The present application provides a pole piece processing method to solve the defect that the edge of the coating area exists a thinning area in the prior art.

[0005] The present application provides a pole piece processing method, comprising:

[0006] Fixing a cover layer on the non-coating area of the substrate;

[0007] Uniformly coating slurry on the coating area of the substrate to form an initial pole piece;

[0008] Sequentially performing drying treatment and roller pressing treatment on the initial pole piece to form an intermediate pole piece, and the heat-resistant temperature of the cover layer is higher than the temperature required by the drying treatment;

[0009] Tearing off the cover layer on the intermediate pole piece to form a finished pole piece.

[0010] According to the pole piece processing method provided by the present application, the cover layer is a silica gel tape or a PET tape.

[0011] According to the pole piece processing method provided by the present application, the roller pressing treatment is a hot roller pressing treatment, and the temperature of the roller pressing treatment is 45-75 degrees Celsius.

[0012] According to the pole piece processing method provided by the present application, before tearing off the cover layer on the intermediate pole piece, the method further comprises:

[0013] Sequentially performing rapid heating treatment and rapid cooling treatment on the intermediate pole piece.

[0014] According to the pole piece processing method, the heating rate of the rapid heating treatment is 5-20 degrees Celsius per minute, and the target temperature of the rapid heating treatment is 70-80 degrees Celsius.

[0015] The cooling rate of the rapid cooling treatment is 20-40 degrees Celsius per minute, and the target temperature of the rapid cooling treatment is 5-10 degrees Celsius.

[0016] According to the pole piece processing method, the tearing off of the cover layer on the intermediate pole piece comprises:

[0017] The initial end of the cover layer is separated from the base material, the initial end of the cover layer is one end of the cover layer along the length direction of the cover layer, and the length direction of the cover layer is perpendicular to the distribution direction of the coating area of the cover layer and the base material;

[0018] The initial end of the cover layer is separated from the base material, the initial end of the cover layer is one end of the cover layer along the length direction of the cover layer, and the length direction of the cover layer is perpendicular to the distribution direction of the coating area of the cover layer and the base material;

[0019] According to the pole piece processing method, the angle between the direction of the tearing force and the length direction of the cover layer is 20-80 degrees.

[0020] According to the pole piece processing method, the cover layer extends 1-50 mm away from the coating area of the base material.

[0021] According to the pole piece processing method, the thickness of the cover layer is 5-100 microns.

[0022] According to the pole piece processing method, the at least uniform coating of the slurry on the coating area of the base material comprises:

[0023] The slurry is transferred to the coating area of the base material and the cover layer by using a coating roller, the axial direction of the coating roller is parallel to the distribution direction of the cover layer and the coating area of the base material, and the length of the coating roller along its own axial direction is greater than the length of the coating area of the base material along the axial direction of the coating roller.

[0024] The present application provides a pole piece processing method, first fix a cover layer on the non-coating area of the substrate, then coat the slurry, and at least uniformly coat the slurry on the coating area of the substrate. The coating area of the substrate is coated with the slurry to form an initial pole piece. Then the initial pole piece is sequentially subjected to drying treatment and rolling treatment. The heat-resistant temperature of the cover layer is higher than the temperature required for drying treatment, and the state of the cover layer can be ensured to be stable during drying treatment, without deformation and peeling from the substrate. The cover layer and the slurry on the substrate participate in the rolling treatment together, and the intermediate pole piece is formed after the rolling treatment. Finally, the cover layer on the intermediate pole piece is torn off to form a finished pole piece. During the coating of the slurry, whether the cover layer is coated with the slurry is not limited. Even if the cover layer is coated with the slurry, the slurry on the cover layer will also leave the substrate together with the cover layer when the cover layer is torn off. Therefore, in order to ensure the uniformity of the slurry on the coating area of the substrate during the coating of the slurry, when the coating roller is used to coat the slurry on the coating area of the substrate, the two ends of the coating roller can correspond to the cover layer, and the thinning area of the coating edge can be located on the cover layer, so as to avoid the influence of the coating edge on the coating area of the substrate, thereby avoiding the formation of a thinning area on the coating area of the substrate, and solving the problem of the existing technology that the edge of the coating area exists a thinning area.

[0025] In addition, the cover layer participates in the rolling treatment, and the cover layer and the slurry on the cover layer can limit the slurry on the edge of the coating area of the substrate from being crushed, and can ensure the flatness of the substrate and the slurry on the coating area of the substrate, avoiding wrinkles on the intermediate pole piece. The rolling treatment increases the bonding strength of the slurry on the coating area of the substrate and the coating area of the substrate, and after the rolling treatment, the cover layer is torn off from the substrate, which can reduce the influence of the cover layer on the slurry on the edge of the coating area of the substrate, ensure the flatness of the slurry on the edge of the coating area of the substrate, and is beneficial to improve the quality of the finished pole piece. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 is a flow chart of the pole piece processing method provided by the present application;

[0028] Figure 2 is a schematic diagram of the distribution of the coating area and the non-coating area of the substrate provided by the present application;

[0029] Figure 3 is a schematic diagram of the structure of the intermediate pole piece processed by the pole piece processing method provided by the present application;

[0030] Figure 4 is a schematic diagram of the direction of the tearing force when the covering layer is torn off.

[0031] Reference signs:

[0032] 1, substrate; 2, non-coated area; 3, covering layer; 4, coated area; 5, slurry; 6, coating roller. DETAILED DESCRIPTION

[0033] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described below in connection with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0034] In the description of the embodiments of the present application, it should be noted that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0035] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0036] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0037] The application will be described below in conjunction with Figures 1 to 4 The application provides a pole piece processing method.

[0038] As Figures 1 to 4 shown, the pole piece processing method provided by the embodiment of the application comprises the following steps:

[0039] Step 110, fixing a cover layer on the non-coating area of the base material;

[0040] Step 120, uniformly coating the slurry on at least the coating area of the base material to form an initial pole piece.

[0041] Step 130, sequentially performing drying treatment and rolling treatment on the initial pole piece to form an intermediate pole piece, and the heat-resistant temperature of the cover layer is higher than the temperature required by the drying treatment.

[0042] Step 140, tearing off the cover layer on the intermediate pole piece to form a finished pole piece.

[0043] Specifically, according to the design requirements of the pole piece, the slurry 5 needs to be coated in some areas of the base material 1, which is the coating area 4, and some areas do not need to be coated with the slurry 5, which is the non-coating area 2. The position of the coating area 4 close to the non-coating area 2 is the edge of the coating area 4, which is easy to form a thinning area.

[0044] Before starting coating, the base material 1 needs to be arranged between the unwinding mechanism and the winding mechanism of the coating machine, so that the tension of each part of the base material 1 is uniformly distributed, without wrinkles, folding, deviation and other adverse conditions.

[0045] In the embodiment of the application, the cover layer 3 is first fixed on the non-coating area 2 of the base material 1. Specifically, an adhesive can be uniformly coated on the cover layer 3 or the non-coating area 2 of the base material 1, and the cover layer 3 is fixed on the non-coating area 2 of the base material 1 by pasting.

[0046] Then the slurry 5 is applied to the coating area 4 of the substrate 1, and the slurry 5 is uniformly applied to at least the coating area 4 of the substrate 1. After the coating area 4 of the substrate 1 is coated with the slurry 5, an initial electrode plate is formed.

[0047] It should be noted that when the slurry 5 is applied, the cover layer 3 and the substrate 1 move synchronously between the unwinding mechanism and the winding mechanism, and the coating speed is controlled to be 3-30 meters per minute (m / min). A small coating speed is conducive to reducing the thinning area, thereby reducing the requirement for the width dimension of the cover layer 3.

[0048] For the convenience of description, it is defined that the length direction of the cover layer 3 is the direction perpendicular to the distribution direction of the coating area 4 of the substrate 1 and the cover layer 3, and the width direction of the cover layer 3 is the direction parallel to the distribution direction of the coating area 4 of the substrate 1 and the cover layer 3. The width dimension of the cover layer 3 is the dimension of the cover layer 3 along the width direction thereof.

[0049] Specifically, the coating speed can be controlled to be 10-15 m / min, and in some preferred embodiments, the coating speed is controlled to be 13 m / min.

[0050] The initial electrode plate is then sequentially subjected to a drying treatment and a rolling treatment. The drying treatment can remove the solvent in the slurry 5, so that the slurry 5 is solidified.

[0051] The temperature of the drying treatment is 60-120 degrees Celsius.

[0052] When processing a positive electrode plate, the slurry used contains an organic solvent, and the temperature of the drying treatment is generally controlled to be 90-110 degrees Celsius. In some preferred embodiments, when processing a positive electrode plate, the temperature of the drying treatment can be controlled to be 100 degrees Celsius.

[0053] When processing a negative electrode plate, the slurry used contains water as the solvent, and the temperature of the drying treatment is generally controlled to be 65-85 degrees Celsius. In some preferred embodiments, when processing a negative electrode plate, the temperature of the drying treatment can be controlled to be 75 degrees Celsius.

[0054] The heat-resistant temperature of the cover layer 3 described above is higher than the temperature required for the drying treatment, and during the drying treatment, the state of the cover layer 3 can be ensured to be stable, without deformation and peeling from the substrate 1.

[0055] The rolling treatment can increase the bonding strength between the slurry 5 of the coating area 4 of the substrate 1 and the coating area 4 of the substrate 1, and the slurry 5 is compacted, so that the stability is improved. The cover layer 3 and the slurry 5 on the substrate 1 participate in the rolling treatment together, and after the rolling treatment, an intermediate electrode plate is formed.

[0056] Finally, the cover layer 3 on the intermediate electrode plate is removed, thereby forming a finished electrode plate.

[0057] It should be noted that the finished pole piece in the embodiment refers to the pole piece on which the slurry processing is completed.

[0058] When the slurry 5 is coated, whether the covering layer 3 is coated with the slurry 5 is not limited, even if the covering layer 3 is coated with the slurry 5, when the covering layer 3 is removed, the slurry 5 on the covering layer 3 will leave the substrate 1 together with the covering layer 3, and the thinning area is removed from the substrate 1.

[0059] Therefore, in order to ensure the uniformity of the slurry 5 of the coating area 4 of the substrate 1 when the slurry 5 is coated, when the slurry 5 is coated on the coating area 4 of the substrate 1 by using the coating roller 6, the two ends of the coating roller 6 can correspond to the covering layer 3, and the thinning area of the coating edge is located on the covering layer 3, so that the coating area 4 of the substrate 1 is not affected by the coating edge, thereby avoiding the formation of the thinning area on the coating area 4 of the substrate 1, and solving the problem that the edge of the coating area 4 in the prior art exists the thinning area.

[0060] In addition, the covering layer 3 participates in the rolling process, and the covering layer 3 and the slurry 5 on the covering layer 3 can limit the slurry 5 at the edge of the coating area 4 of the substrate 1 from being crushed, prevent the edge of the slurry 5 of the coating area 4 of the substrate 1 from being wrinkled, ensure the flatness of the substrate 1 and the slurry 5 on the coating area 4 of the substrate 1, and avoid the intermediate pole piece from being wrinkled. The rolling process increases the adhesion strength of the slurry 5 of the coating area 4 of the substrate 1 and the coating area 4 of the substrate 1, and after the rolling process, the covering layer 3 is removed from the substrate 1, which can reduce the influence of the slurry 5 at the edge of the coating area 4 of the substrate 1 being dragged by the covering layer 3, ensure the flatness of the slurry 5 at the edge of the coating area 4 of the substrate 1, and be beneficial to improving the quality of the finished pole piece.

[0061] In the embodiment of the application, at least when the slurry 5 is uniformly coated on the coating area 4 of the substrate 1, the slurry 5 is transferred to the coating area 4 of the substrate 1 and the covering layer 3 by using the coating roller 6, the axial direction of the coating roller 6 is parallel to the distribution direction of the covering layer 3 and the coating area 4 of the substrate 1, and the length of the coating roller 6 along its own axial direction is greater than the length of the coating area 4 of the substrate 1 along the axial direction of the coating roller 6.

[0062] The coating roller 6 can simultaneously transfer the slurry 5 to the coating area 4 of the substrate 1 and the covering layer 3, and the thinning area of the coating edge is located on the covering layer 3, which can effectively avoid the influence of the coating edge on the coating area 4 of the substrate 1.

[0063] The end of the axial direction of the coating roller 6 can correspond to the middle position of the width direction of the covering layer 3, and when the slurry 5 is coated, only part of the positions of the covering layer 3 is coated with the slurry 5.

[0064] The end of the axial direction of the coating roller 6 can correspond to the edge position of the covering layer 3 away from the coating area 4 of the substrate 1, and when the slurry 5 is coated, the slurry 5 is coated on all positions of the covering layer 3.

[0065] In the embodiment of the present application, the adhesive tape is directly selected as the covering layer 3, one side of the adhesive tape is provided with a glue layer, and the adhesive tape can be directly attached to the base material 1, thereby avoiding the process of applying adhesive on the non-coating area 2 of the covering layer 3 or the base material 1, reducing the operation steps, and being beneficial to improving the processing efficiency.

[0066] Specifically, the adhesive tape can be but is not limited to a silica gel adhesive tape or a PET adhesive tape. The adhesive tape is a non-thermal stripping adhesive tape, the silica gel adhesive tape and the PET adhesive tape have strong stability in the temperature range of 20-120 degrees Celsius, and still have good adhesive force and anti-aging performance in the temperature range, so that the adhesive tape can stably participate in the drying treatment step. In addition, the adhesive tape will not leave glue stains on the non-coating area 2 of the base material 1 after being torn off.

[0067] The PET adhesive tape can be specifically a PET adhesive tape made of a polyester film material.

[0068] The selection of the non-thermal stripping adhesive tape can allow the temperature of the roller pressing treatment to be controlled in the range of 45-75 degrees Celsius, that is, the hot roller pressing treatment is performed after the drying treatment.

[0069] The temperature of the roller pressing treatment is preferably 50-70 degrees Celsius, and can be specifically 60 degrees Celsius.

[0070] The hot roller pressing treatment can reduce the rebound of the pole piece, reduce the requirement for the roller pressing force, and enhance the adhesive strength between the slurry 5 and the base material 1, thereby reducing the occurrence of the powder falling of the battery in the charge and discharge cycle process and improving the service life of the battery.

[0071] In the embodiment of the present application, before the adhesive tape is torn off from the non-coating area 2 of the base material 1, the intermediate pole piece can be subjected to rapid heating treatment and then rapid cooling treatment. After the adhesive tape is subjected to the rapid heating treatment and the rapid cooling treatment, the adhesive strength between the adhesive tape and the base material 1 is reduced, and the adhesive tape is more easily torn off from the base material 1.

[0072] Specifically, the heating rate of the rapid heating treatment is 5-20 degrees Celsius per minute (℃ / min), and the target temperature of the rapid heating treatment is 70-80 degrees Celsius. The cooling rate of the rapid cooling treatment is 20-40 degrees Celsius per minute (℃ / min), and the target temperature of the rapid cooling treatment is 5-10 degrees Celsius.

[0073] It should be noted that the greater the temperature difference of the adhesive tape during the rapid heating treatment and the rapid cooling treatment, the easier the adhesive tape is torn off. However, it should be noted that the greater the temperature difference of the adhesive tape, the greater the energy required for the rapid heating treatment and the rapid cooling treatment, and the energy consumption increases.

[0074] In the embodiment, when the cover layer 3 on the intermediate pole piece is torn off, the initial end of the cover layer 3 is first separated from the base material 1, and then a tearing force is applied to the initial end of the cover layer 3 to tear off the cover layer 3 from the base material 1.

[0075] The initial end of the cover layer 3 is one end of the cover layer 3 along the length direction of the cover layer 3, which can be the end close to the unwinding mechanism or the end close to the winding mechanism.

[0076] The direction of the tearing force refers to the direction indicated by n in Figure 4 The angle between the direction of the tearing force and the length direction of the cover layer 3 is α, so that the tearing force has a component in the direction away from the coating area 4 of the base material 1. Understandably, when the cover layer 3 is torn off, the cover layer 3 is pulled obliquely, so that the cover layer 3 at a position away from the initial end of the cover layer 3 and close to the coating area 4 of the base material 1 is first separated from the base material 1, that is, the cover layer 3 is first disconnected from the slurry 5 of the coating area 4 of the base material 1, and then the cover layer 3 at a position away from the coating area 4 of the base material 1 is separated from the base material 1, which can reduce the pulling of the slurry 5 at the edge position of the coating area 4 of the base material 1 caused by tearing inertia, and is beneficial to improve the flatness of the slurry 5 at the edge position of the coating area 4 of the base material 1.

[0077] The above-mentioned tearing force can be manually applied by artificial or automatically applied by a robot or the like. When the tearing force is applied, it is necessary to ensure the uniformity and stability of the tearing force, and the size of the tearing force is controlled to be 5-25 N / mm, specifically, the size of the tearing force can be controlled to be 15 N / mm.

[0078] In the embodiment, the angle between the direction of the tearing force and the length direction of the cover layer 3 is controlled to be in the range of 20-80°, which can quickly tear off the cover layer 3 and ensure the flatness of the edge position of the coating area 4 of the base material 1.

[0079] Specifically, the angle between the direction of the tearing force and the length direction of the cover layer 3 can be controlled to be 50°.

[0080] In the embodiment, the cover layer 3 extends 1-50 mm in the direction away from the coating area 4 of the base material 1, that is, the width dimension of the cover layer 3 is set to be 1-50 mm. The cover layer 3 can cover the entire area of the non-coating area 2 of the base material 1, or the cover layer 3 can only cover part of the area of the non-coating area 2 of the base material 1 close to the coating area 4.

[0081] In the case that the covering layer 3 only covers the part of the non-coating area 2 of the base material 1 close to the coating area 4, the width dimension of the covering layer 3 required can be determined according to the distance between the end of the coating roller 6 and the edge of the coating area 4 of the base material 1, and the width dimension of the covering layer 3 should be no less than the distance between the end of the coating roller 6 and the edge of the coating area 4 of the base material 1.

[0082] The thickness of the covering layer 3 is selected to be 5-100 microns. The greater the thickness of the covering layer 3, the higher the strength of the covering layer 3, so that the covering layer 3 can be prevented from being cracked during the roller pressing process.

[0083] The following content will specifically describe the pole piece processing method provided by the embodiments of the present application in combination with the above-mentioned various embodiments. In the present embodiment, the middle position of the width direction of the pole piece to be processed has the slurry 5, and the two ends of the width direction thereof do not have the slurry 5. Referring to Figure 2 , accordingly, when the slurry 5 is coated on the base material 1, the slurry 5 only needs to be coated on the middle position of the width direction of the base material 1, which is the coating area 4, and the slurry 5 does not need to be coated on the two ends of the width direction of the base material 1, which are the non-coating areas 2. The width direction of the base material 1 is indicated by m in Figure 2 .

[0084] The axial length of the coating roller 6 is determined according to the width dimension of the thinning area and the width dimension of the coating area 4 of the base material 1. The coating area 4 of the base material 1 is located as much as possible at the middle position of the axial direction of the coating roller 6. The width of the covering layer 3 is determined according to the distance between the end of the coating roller 6 and the coating area 4 of the base material 1.

[0085] The base material 1 is arranged between the unwinding mechanism and the winding mechanism of the coating machine, so that the tension applied to each part of the base material 1 is uniformly distributed, and there is no undesirable situation such as wrinkling, folding, deviation, etc.

[0086] Silicone adhesive tape is selected as the covering layer 3, and the silicone adhesive tape with a corresponding width is pasted on each of the two non-coating areas 2 of the base material 1, so that the silicone adhesive tape extends along the boundary line between the coating area 4 and the non-coating area 2, and the edge of the silicone adhesive tape close to the coating area 4 is aligned with the edge of the coating area 4. The silicone adhesive tape can cover the entire non-coating area 2, or the silicone adhesive tape can only cover the part of the non-coating area 2 close to the coating area 4.

[0087] The operation of the coating roller 6 is controlled to coat the slurry 5 on the coating area 4 of the base material 1 and the silicone adhesive tape, and to perform drying treatment and hot roller pressing treatment.

[0088] After the hot roller pressing treatment is completed, a tearing force is applied to the silicone adhesive tape, the tearing force has a component in the direction away from the coating area 4 of the base material 1, so that the position of the silicone adhesive tape close to the coating area 4 of the base material 1 is first separated from the base material 1.

[0089] After the silica gel tapes on both sides of the coating area 4 of the substrate 1 are removed, the finished electrode plate is obtained.

[0090] In this way, the uniformity of the slurry of the coating area 4 of the substrate 1 can be ensured, the non-coating area 2 of the substrate 1 is free of slurry, and the flatness of the slurry at the edge position of the coating area 4 of the substrate 1 can be ensured.

[0091] The electrode plate processing method provided by the embodiments of the present application is suitable for processing positive electrode plates and negative electrode plates. The electrode plate processed by the electrode plate processing method provided by the embodiments of the present application has consistent slurry 5 thickness at each position, which can effectively avoid the problem of edge lithium precipitation and make the design ratio adjustment more accurate.

[0092] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for processing electrode sheets, characterized in that, include: A cover layer is fixed in the uncoated area of ​​the substrate; A slurry is uniformly applied to at least the coating area of ​​the substrate to form an initial electrode sheet; The initial electrode is sequentially dried and rolled to form an intermediate electrode, and the heat resistance temperature of the covering layer is higher than the temperature required for the drying process. The intermediate electrode is subjected to rapid heating and rapid cooling treatments in sequence. The covering layer on the intermediate electrode is removed to form the finished electrode. The step of removing the covering layer on the intermediate electrode includes: The initial end of the cover layer is separated from the substrate. The initial end of the cover layer is one end of the cover layer along its own length direction, and the length direction of the cover layer is perpendicular to the distribution direction of the coating area of ​​the cover layer and the substrate. A tearing force is applied to the initial end of the cover layer, the direction of which forms an angle with the length direction of the cover layer, the angle being 20° to 80°. The tearing force has a component in the direction away from the coating area of ​​the substrate, so that the cover layer at a position close to the coating area of ​​the substrate at the same distance from the initial end of the cover layer first detaches from the substrate, first breaking the connection between the cover layer and the slurry in the coating area of ​​the substrate, and then detaching the cover layer at a position relatively far from the coating area of ​​the substrate from the substrate.

2. The electrode processing method according to claim 1, characterized in that, The covering layer is silicone tape or PET tape.

3. The electrode processing method according to claim 2, characterized in that, The rolling process is a hot rolling process, and the rolling temperature is 45 to 75 degrees Celsius.

4. The electrode processing method according to claim 2, characterized in that, The rapid heating process has a heating rate of 5 to 20 degrees Celsius per minute, and the target temperature of the rapid heating process is 70 to 80 degrees Celsius. The rapid cooling process has a cooling rate of 20–40 degrees Celsius per minute, and the target temperature of the rapid cooling process is 5–10 degrees Celsius.

5. The electrode processing method according to claim 1, characterized in that, The cover layer extends 1 to 50 mm away from the coating area of ​​the substrate.

6. The electrode processing method according to claim 1, characterized in that, The thickness of the covering layer is 5 to 100 micrometers.

7. The electrode processing method according to claim 1, characterized in that, The uniform application of the slurry at least in the coating area of ​​the substrate includes: A coating roller is used to transfer slurry to the coating area of ​​the substrate and the cover layer. The axial direction of the coating roller is parallel to the distribution direction of the coating area of ​​the cover layer and the substrate. The length of the coating roller along its own axial direction is greater than the length of the coating area of ​​the substrate along the axial direction of the coating roller.

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