Pole piece drying method and drying equipment

Abstract

The embodiment of the invention provides a pole piece drying method and drying equipment. The method comprises the following steps: placing a pole piece coated with slurry in the drying equipment; wherein the pole piece comprises a first area and a second area, the first area is coated with first slurry and second slurry, and the second area is coated with second slurry; the drying speed of the second slurry is different from that of the first slurry under the same drying condition; drying equipment is used for drying, and the drying temperature of the first area is controlled to be lower than that of the second area. Due to the fact that the drying speed of the slurry which volatilizes fast is greatly influenced by reduction of the drying temperature, in the first area, the drying speed of the slurry which volatilizes fast is slowed down, the difference between the drying speed of the first slurry and the drying speed of the second slurry is reduced, and unexpected flowing of the slurry to the film area is restrained. Meanwhile, the drying speed of the second area is not influenced, and the second slurry in the second area is still quickly dried, so that the overall drying efficiency of the pole piece is ensured.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a pole piece drying method and drying equipment. Background Art

[0002] The manufacturing process of lithium batteries includes multiple steps such as pole piece production, battery cell production, and battery assembly. Among them, slurry coating is an important part of the pre-production process of lithium batteries. The main purpose of this process is to evenly coat the slurry with good stability, good viscosity, and good fluidity on the positive and negative electrode collectors. Pole piece coating is of great significance to the capacity, consistency, and safety of lithium-ion batteries.

[0003] Currently, more than one slurry may be coated on the electrode. The difference in drying speed between multiple slurries may cause unexpected flow of the slurry, resulting in a decrease in electrode performance, which in turn affects the capacity consistency of the battery.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0005] In view of the above problems, the embodiments of the present application provide a pole piece drying method and drying equipment, which can solve the problem of pole piece performance degradation caused by the difference in drying speed between slurries.

[0006] In a first aspect, an embodiment of the present application provides a method for drying an electrode, the method comprising:

[0007] Placing the electrode coated with the slurry in a drying device;

[0008] The pole piece includes a first region and a second region, the first region is coated with a first slurry and a second slurry, and the second region is coated with the second slurry; under the same drying conditions, the drying speed of the second slurry is different from the drying speed of the first slurry;

[0009] Drying is performed using a drying device, and the drying temperature of the first area is controlled to be lower than the drying temperature of the second area.

[0010] In the technical solution of the embodiment of the present application, since the drying temperature decreases and has a greater impact on the drying speed of the slurry that evaporates faster, the drying speed of the slurry that evaporates faster is slowed down in the first region, thereby reducing the difference in drying speed between the first slurry and the second slurry, and inhibiting the unintended flow of the slurry to the membrane region. At the same time, the drying speed of the second region is not affected, and the second slurry in the second region is still dried faster, thereby ensuring the overall drying efficiency of the electrode.

[0011] In some embodiments, the drying device includes a heating device, the heating device includes a first heating element, the first heating element includes a first heating portion and a second heating portion; the first distance between the first heating portion and the first region is greater than the second distance between the second heating portion and the second region, and / or the first heating temperature of the first heating portion is lower than the second heating temperature of the second heating portion; the use of the drying device for drying includes: placing the pole piece under the first heating element for drying, so that the drying temperature of the first region is lower than the drying temperature of the second region. In this embodiment, by placing the pole piece under a first heating element including two heating portions for drying, the distance between the two heating portions and the first region and the second region, respectively, and / or the heating temperature of the two heating portions are controlled, so that the first region and the second region can be in different drying environments, thereby achieving a drying temperature of the first region lower than the drying temperature of the second region.

[0012] In some embodiments, the heating device further comprises a second heating element, the second heating element comprises a third heating part, the third distance between the third heating part and the first region is less than the first distance, and / or the third heating temperature of the third heating part is higher than the first heating temperature; the drying using the drying device comprises: placing the pole piece under the first heating element for drying at a first time, so that at the first time, the drying temperature of the first region is less than the drying temperature of the second region; placing the pole piece under the second heating element for drying at a second time, so that at the second time, the drying temperature of the first region is greater than the drying temperature of the first region at the first time. In this embodiment, by setting a second heating element comprising a third heating part and controlling the distance and heating temperature between the third heating part and the first region, the pole piece is successively placed under the first heating element and the second heating element for drying from the first time to the second time, so that the drying speed of the slurry in the first region is increased from the first time to the second time. After the two slurries in the first region reduce their fluidity at the first time, the drying speed is increased at the second time, which not only suppresses the unexpected flow of the slurry to the membrane area, but also improves the drying efficiency of the pole piece.

[0013] In some embodiments, the heating device further comprises a third heating element disposed between the first heating element and the second heating element, the third heating element comprises a fifth heating portion, the fifth distance between the fifth heating portion and the first region is less than the first distance and greater than the third distance; and / or the fifth heating temperature of the fifth heating portion is higher than the first heating temperature and lower than the third heating temperature; the use of a drying device for drying comprises: from the first time to the second time, placing the pole piece under the first heating element, the third heating element and the second heating element in sequence for drying, so that the drying temperature of the first region increases from the first time to the second time. In this embodiment, by disposing a third heating element between the first heating element and the second heating element, and controlling the distance and heating temperature between the fifth heating portion of the third heating element and the first region, the drying temperature of the first region gradually increases from the first time to the second time. The gradual change of the drying temperature can prevent the drying temperature of the first region from suddenly increasing, resulting in uneven heating of the slurry and cracking.

[0014] In some embodiments, the second heating element further includes a fourth heating portion, a fourth distance between the fourth heating portion and the second region is greater than the second distance, and / or a fourth heating temperature of the fourth heating portion is lower than the second heating temperature, so that the drying temperature of the second region at the second time is lower than the drying temperature of the second region at the first time. In this embodiment, by providing a second heating element including a fourth heating portion, and controlling the distance and heating temperature between the fourth heating portion and the second region, the pole piece is placed successively under the first heating element and the second heating element for drying from the first time to the second time, so that the drying temperature of the second region decreases from the first time to the second time, thereby preventing the second slurry in the second region from cracking due to excessive heating.

[0015] In some embodiments, the heating device further comprises a third heating element disposed between the first heating element and the second heating element, the third heating element comprises a sixth heating portion, the sixth distance between the sixth heating portion and the second region is less than the fourth distance and greater than the second distance, and / or the sixth heating temperature of the sixth heating portion is higher than the fourth heating temperature and lower than the second heating temperature; the use of a drying device for drying comprises: from the first time to the second time, placing the pole piece under the first heating element, the third heating element and the second heating element in sequence for drying, so that the drying temperature of the second region decreases from the first time to the second time. In this embodiment, by disposing a third heating element between the first heating element and the second heating element, and controlling the distance and heating temperature between the sixth heating portion of the third heating element and the second region, the drying temperature of the second region gradually decreases from the first time to the second time. The gradual change in drying temperature can prevent the drying temperature of the second region from suddenly decreasing, resulting in uneven heating of the slurry and cracking.

[0016] In some embodiments, the drying device further includes a transmission device; from the first time to the second time, placing the electrode piece under the first heating element, the third heating element, and the second heating element in sequence for drying includes: from the first time to the second time, using the transmission device to sequentially transmit the electrode piece to the first heating element, the third heating element, and the second heating element for drying. This embodiment uses the transmission device to change the drying position of the electrode piece, so that the electrode piece can be automatically transmitted to each heating element for drying through the transmission device from the first time to the second time, thereby realizing full automation of electrode piece drying.

[0017] In some embodiments, the heating device further includes a fourth heating element, and the fourth heating element is used to control the ambient temperature inside the drying device; the method further includes: setting the heating temperatures of the first heating element, the second heating element, and the third heating element to be higher than the heating temperature of the fourth heating element. In this embodiment, the heating temperatures of the first heating element, the second heating element, and the third heating element are set to be higher than the heating temperature of the fourth heating element, so that the drying efficiency of the electrode can be improved by the first heating element, the second heating element, and the third heating element.

[0018] In some embodiments, the heating temperatures of the first heating element, the second heating element, and the third heating element meet 80-150° C. This improves the drying efficiency of the electrode sheet.

[0019] In some embodiments, the heating temperature of the fourth heating element satisfies 25-100° C. Thus, the pole piece can be dried in a wider range of ambient temperatures without sacrificing production capacity.

[0020] In some embodiments, the distance between the first heating element, the second heating element, and the third heating element and the pole piece meets 5-40 cm, thereby improving the drying efficiency of the pole piece.

[0021] In a second aspect, an embodiment of the present application provides a drying device, the device comprising:

[0022] A box body, forming a cavity, wherein the cavity is used to accommodate the pole piece;

[0023] A heating device is accommodated in the cavity; the heating device is used to dry the pole piece so that the drying temperature of the first area of ​​the pole piece is lower than the drying temperature of the second area;

[0024] The first area is coated with a first slurry and a second slurry, and the second area is coated with the second slurry; under the same drying conditions, the drying speed of the second slurry is different from the drying speed of the first slurry.

[0025] In some embodiments, the heating device includes a first heating element, which includes a first heating part and a second heating part; wherein a first distance between the first heating part and the first region is greater than a second distance between the second heating part and the second region, and / or a first heating temperature of the first heating part is lower than a second heating temperature of the second heating part.

[0026] In some embodiments, the heating device includes a first heating element and a second heating element arranged in sequence along a first direction; the first heating element includes a first heating portion and a second heating portion arranged along a second direction; the second heating element includes a third heating portion and a fourth heating portion arranged along the second direction; the first direction intersects with the second direction.

[0027] In some embodiments, the apparatus further includes: a conveying device for conveying the pole piece into the cavity; the first direction is parallel to a conveying direction of the conveying device; and the second direction is perpendicular to the first direction in the plane where the pole piece is located.

[0028] In some embodiments, a third distance between the third heating portion and the first region is smaller than the first distance, and / or a third heating temperature of the third heating portion is higher than the first heating temperature.

[0029] In some embodiments, a fourth distance between the fourth heating portion and the second region is greater than the second distance, and / or a fourth heating temperature of the fourth heating portion is lower than the second heating temperature.

[0030] In some embodiments, the heating device further includes a third heating element disposed between the first heating element and the second heating element along the first direction, and the third heating element includes a fifth heating portion and a sixth heating portion disposed along the second direction.

[0031] In some embodiments, the fifth distance between the fifth heating portion and the first region is less than the first distance and greater than the third distance between the third heating portion and the first region; and / or the fifth heating temperature of the fifth heating portion is higher than the first heating temperature and lower than the third heating temperature of the third heating portion.

[0032] In some embodiments, the sixth distance between the sixth heating portion and the second region is smaller than the fourth distance between the fourth heating portion and the second region and greater than the second distance, and / or the sixth heating temperature of the sixth heating portion is higher than the fourth heating temperature of the fourth heating portion and lower than the second heating temperature.

[0033] In some embodiments, the third heating element includes multiple third heating elements; the multiple third heating elements satisfy one or more of the following conditions: the fifth distance between the fifth heating part and the first region of at least part of the third heating elements decreases along the first direction; the fifth heating temperature of the fifth heating part of at least part of the third heating elements increases along the first direction; the sixth distance between the sixth heating part and the second region of at least part of the third heating elements increases along the first direction; the sixth heating temperature of the sixth heating part of at least part of the third heating elements decreases along the first direction.

[0034] In some embodiments, the first heating part includes two, which are respectively disposed on both sides of the second heating part; the third heating part includes two, which are respectively disposed on both sides of the fourth heating part; and the fifth heating part includes two, which are respectively disposed on both sides of the sixth heating part.

[0035] In some embodiments, the heating device further comprises a fourth heating element for controlling the ambient temperature in the cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1A schematic flow chart of a pole piece drying method provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the area division in the pole piece provided in an embodiment of the present application;

[0039] Figure 3 A schematic flow chart of a pole piece drying process in a pole piece drying method provided in an embodiment of the present application;

[0040] Figure 4 A schematic diagram of the structure of a drying device provided in an embodiment of the present application;

[0041] Figure 5 (a)- Figure 5 (e) is a schematic cross-sectional view of each heating element in a drying device provided in an embodiment of the present application;

[0042] Figure 6 A schematic cross-sectional structure diagram of another heating element in a drying device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0045] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0046] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0048] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0049] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0050] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] The purpose of slurry coating of battery pole pieces is to evenly coat the slurry with good stability, good viscosity and good fluidity on the pole pieces. As the solvent in the slurry dries and evaporates, the fluidity of the slurry will gradually decrease, and eventually a film will be formed in the coating area.

[0052] Among them, the pole piece may be coated with multiple slurries. Different slurries have different drying speeds due to different solid content, different solvent volatilization speeds and other factors, so that different slurries are formed into films one after another. When one slurry is dried and the other slurry is not yet dried and has a certain fluidity, the undried slurry will flow to the film area of ​​the dried slurry, that is, unexpected flow occurs, thereby covering part of the dried slurry.

[0053] For example, in order to prevent the substrate from cracking during welding, in addition to coating the cathode active slurry on the cathode pole piece, an anti-cracking insulating ceramic slurry AT11 can also be coated on the edge of the pole piece. However, due to the inconsistency between the solid content of AT11 and the cathode active slurry, AT11 dries more slowly than the cathode active slurry. Then during the drying process, AT11 will flow to the membrane area of ​​the dried cathode active slurry and cover part of the membrane area. The covered area appears white, so the edge of the cathode pole piece visually appears as a white virtual edge. Since part of the membrane area coated with the cathode active slurry is covered, the effective area of ​​the membrane area, or the effective area of ​​the cathode active slurry, is reduced. The covered cathode active slurry will not be utilized, so the effective cathode material is reduced. It can be seen that the difference in drying speeds of various slurries may cause the slurry to flow unexpectedly to the membrane area, resulting in a decrease in the performance of the pole piece and affecting the consistency of the battery capacity.

[0054] To this end, an embodiment of the present application proposes placing an electrode plate coated with a first slurry and a second slurry in a drying device. The first area of ​​the electrode plate is coated with the first slurry and the second slurry, and the second area of ​​the electrode plate is coated with the second slurry. Under the same drying conditions, since the drying speed of the second slurry is different from the drying speed of the first slurry, the above-mentioned slurry will flow to the membrane area in the first area. This embodiment uses a drying device to dry the electrode plate, and controls the drying temperature of the first area to be lower than the drying temperature of the second area. Since the reduction in drying temperature has a greater impact on the drying speed of the slurry that evaporates faster, when the drying temperature in the second area is lower than the drying temperature in the first area, the drying speed of the slurry that evaporates faster can be slowed down, thereby reducing the difference in drying speed between the first slurry and the second slurry, and suppressing the unexpected flow of the slurry.

[0055] In addition, since the drying temperature of the second area is higher than that of the first area, the second slurry coated on the second area dries faster and dries before the first area. Compared with the related art method of reducing the overall belt speed of the pole piece in the oven and sacrificing production capacity to suppress the flow of slurry to the membrane area, the embodiment of the present application only reduces the drying temperature of the local area of ​​the pole piece, so that the drying speed of the local area is lower, and the overall drying efficiency of the pole piece is not affected. Therefore, while suppressing the flow of slurry to the membrane area, the production capacity and efficiency are maintained.

[0056] The pole piece drying disclosed in the embodiment of the present application is one of the processes in battery manufacturing. The battery including the pole piece can be used in, but is not limited to, electrical devices such as vehicles, ships or aircraft. Electrical devices using batteries as power sources may include, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys, electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles, spacecraft, etc.

[0057] According to some embodiments of the present application, Figure 1 As shown, a first aspect provides a pole piece drying method, including steps 110 to 120.

[0058] Step 110: placing the electrode coated with the slurry in a drying device;

[0059] The pole piece includes a first region and a second region, the first region is coated with a first slurry and a second slurry, and the second region is coated with the second slurry; under the same drying conditions, the drying speed of the second slurry is different from the drying speed of the first slurry;

[0060] Step 120: Use a drying device to perform drying, and control the drying temperature of the first area to be lower than the drying temperature of the second area.

[0061] The pole piece is the core of the battery, including the anode pole piece and the cathode pole piece. According to the use requirements, some pole pieces can be coated with only one slurry; some pole pieces can be coated with multiple slurries, for example, at least coated with the first slurry and the second slurry.

[0062] Exemplarily, the coating areas of the first slurry and the second slurry on the pole piece are adjacent, for example, the distance between the two coating areas is less than a preset threshold.

[0063] Exemplarily, the coating area of ​​the first slurry on the pole piece may include one or more areas; similarly, the coating area of ​​the second slurry on the pole piece may include one or more areas.

[0064] The drying speed of the slurry is related to the drying conditions. The drying conditions may include, but are not limited to, the drying temperature, the distance from the heating source, the gas flow rate, etc. Under the same drying conditions, the drying speed of the first slurry and the second slurry are different. For example, the drying speed of the first slurry is greater than or less than the drying speed of the second slurry.

[0065] According to the coating areas of the first slurry and the second slurry, the pole piece can be divided into the first area and the second area. The first area is coated with the first slurry and the second slurry. The second area is coated with the second slurry. That is, the coating area of ​​the second slurry on the pole piece, the part close to the first slurry coating area and the first slurry coating area are divided into the first area, and the rest is divided into the second area.

[0066] For example, the first area and the second area may be two areas divided artificially, and are not distinguished by marking or the like on the pole piece.

[0067] Exemplarily, the number of the first regions may be one or more, and the number of the second regions may be one or more.

[0068] Take two slurries as an example, Figure 2 As shown, the first slurry is coated on both sides of the pole piece, namely, the coating area eadh (the area surrounded by point e, point a, point d, point h, and so on) and the coating area bfgc. The second slurry is coated on the remaining area of ​​the pole piece, namely, the area abcd. It can be seen that the first slurry has two coating areas on the pole piece, and the second slurry has one coating area on the pole piece.

[0069] According to the coating areas of the first slurry and the second slurry, the pole piece can be divided into a first area and a second area. The first area includes two, namely the first area ea'd'h and the first area b'fgc'. The second area includes one, namely the second area a'b'c'd'.

[0070] It can be seen that the first area ea'd'h and the first area b'fgc' include the coating area of ​​the second slurry and the partial coating area of ​​the first slurry. The second area a'b'c'd' includes the remaining coating area of ​​the first slurry.

[0071] Of course, the pole piece can be coated with more than two slurries, and each slurry can be coated at any position of the pole piece. Any two slurries can be divided into a first area and a second area according to their coating areas on the pole piece, and this embodiment does not limit this.

[0072] The drying equipment, such as an oven, has a drying function. The above-mentioned electrode is placed in the drying equipment for drying. By controlling the drying temperature of the first area to be lower than the drying temperature of the second area, the two areas have different drying conditions. In this way, the drying speed of the slurry in the two areas is also different. That is, the drying speed of the two slurries coated in the first area will be lower than the drying speed of the second slurry coated in the second area. Exemplarily, if the second slurry is continuously coated in the first area and the second area, then under different drying conditions in the two areas, the second slurry coated in the second area will be dried before the second slurry coated in the first area.

[0073] Since the drying temperature decrease has a greater impact on the drying speed of the slurry that evaporates faster, the drying speed of the slurry that evaporates faster is slowed down in the first area, thereby reducing the difference in drying speed between the first slurry and the second slurry, and inhibiting the unexpected flow of the slurry to the membrane area. At the same time, the drying speed of the second area is not affected, and the second slurry in the second area is still dried faster, thereby ensuring the overall drying efficiency of the electrode.

[0074] Based on the above embodiment, the drying device may include a heating device. The heating device includes a first heating element. The first heating element includes a first heating portion and a second heating portion. The first distance between the first heating portion and the first region is greater than the second distance between the second heating portion and the second region, and / or the first heating temperature of the first heating portion is lower than the second heating temperature of the second heating portion.

[0075] Thus, the drying process using a drying device in step 120 may include the following steps:

[0076] The pole piece is placed under the first heating element for drying, so that the drying temperature of the first area is lower than the drying temperature of the second area.

[0077] Regarding the first heating part and the second heating part, the first heating part may be disposed corresponding to the first region, and the second heating part may be disposed corresponding to the second region.

[0078] The number of the first heating parts can be set according to the number and / or area of ​​the first regions. For example, the number of the first heating parts is consistent with the number of the first regions. For another example, the number of the first heating parts is positively correlated with the area of ​​the first region.

[0079] Similarly, the number of second heating parts can be set according to the number and / or area of ​​the second regions, for example, the number of second heating parts is consistent with the number of second regions, or the number of second heating parts is positively correlated with the area of ​​the second region.

[0080] Optionally, the first heating part and the second heating part can be integrally formed. In this way, the first heating element is an independent heating unit. The heating unit may refer to the smallest unit for temperature control.

[0081] Optionally, the first heating part and the second heating part can be independently provided. In this way, the first heating part and the second heating part are two independent heating units, that is, the first heating temperature of the first heating part and the second heating temperature of the second heating part can be controlled separately. The first heating element includes at least two heating units.

[0082] When the pole piece is placed under the first heating element for drying, optionally, if the first distance between the first heating part and the first region is set to be greater than the second distance between the second heating part and the second region, then the first region is farther from the first heating part, and the second region is closer to the second heating part. Therefore, the drying temperature of the first region will be lower than the drying temperature of the second region. That is, this embodiment achieves differentiated drying conditions for the first region and the second region by controlling the heating distance. Among them, the first heating part and the second heating part can be set to the same or different heating temperatures.

[0083] Optionally, if the first heating temperature of the first heating part is set to be lower than the second heating temperature of the second heating part, the drying temperature of the first area will be lower than the drying temperature of the second area. That is, this embodiment achieves differentiated drying conditions of the first area and the second area by controlling the heating temperature. The first distance between the first heating part and the first area and the second distance between the second heating part and the second area can be set to be the same or different.

[0084] Optionally, the first distance may be set to be greater than the second distance, and the first heating temperature may be set to be lower than the second heating temperature, that is, differentiated drying conditions of the first area and the second area may be achieved by controlling the heating temperature and the heating distance.

[0085] In this embodiment, by placing the electrode under a first heating element including two heating parts for drying, the distances between the two heating parts and the first area and the second area respectively, and / or the heating temperatures of the two heating parts are controlled, so that the first area and the second area can be in different drying environments, thereby achieving the drying temperature of the first area being lower than the drying temperature of the second area.

[0086] Based on the above embodiment, the heating device may include a second heating element in addition to the first heating element. The second heating element includes a third heating portion. The third distance between the third heating portion and the first region is less than the first distance, and / or the third heating temperature of the third heating portion is higher than the first heating temperature.

[0087] Thus, step 120 uses a drying device for drying, which may include: Figure 3 Steps 121-122 are shown.

[0088] Step 121: placing the electrode under the first heating element for drying at a first time, so that at the first time, the drying temperature of the first area is lower than the drying temperature of the second area;

[0089] Step 122: at a second time, placing the electrode under the second heating element for drying, so that the drying temperature of the first area at the second time is greater than the drying temperature of the first area at the first time.

[0090] Exemplarily, the third heating portion of the second heating element can be arranged corresponding to the first region. The number of the third heating portions can be arranged according to the number and / or area of ​​the first region, for example, the number of the third heating portions is consistent with the number of the first region, and for example, the number of the third heating portions is positively correlated with the area of ​​the first region.

[0091] At the first time, the pole piece is placed under the first heating element for drying. From the above-described embodiments, it can be seen that at the first time, the drying temperature of the first area of ​​the pole piece is lower than the drying temperature of the second area to suppress the unintended flow of the slurry to the membrane area.

[0092] Exemplarily, the first time can be set according to the fluidity change law of the first slurry and / or the second slurry. For example, from the moment of starting drying to when the fluidity of the first slurry and the second slurry decreases to the fluidity threshold so that no unexpected flow occurs, the first time is taken. In this way, after the first time, the fluidity of the first slurry and the second slurry in the first region decreases, and no unexpected flow occurs between the slurries due to the sequential film formation, and the first slurry and the second slurry have been initially fixed.

[0093] However, after the first time, the slurry in the first region has not been completely dried. Therefore, at the second time, the pole piece is placed under the second heating element for drying. Since the third distance between the third heating part of the second heating element and the first region is set to be less than the first distance between the first heating part and the first region, and / or the third heating temperature of the third heating part is set to be higher than the first heating temperature of the first heating part, for the first region, its drying temperature at the second time is higher than that at the first time. That is, from the first time to the second time, the drying temperature of the first region increases. Accordingly, the drying speed of the slurry in the first region at the second time is greater than the drying speed at the first time, that is, from the first time to the second time, the drying speed of the first slurry and the second slurry in the first region is increased. In this way, after the slurry in the first region has been initially fixed and the unexpected flow of the slurry to the membrane area has been suppressed, the drying speed of the slurry in the first region is increased by shortening the heating distance and / or increasing the heating temperature, thereby improving the drying efficiency of the pole piece.

[0094] In this embodiment, by providing a second heating element including a third heating portion, and controlling the distance and heating temperature between the third heating portion and the first region, the pole piece is placed under the first heating element and the second heating element for drying from the first time to the second time, so that the drying speed of the slurry in the first region is increased from the first time to the second time. After the two slurries in the first region reduce their fluidity at the first time, the drying speed is increased at the second time, which not only suppresses the unexpected flow of the slurry to the membrane area, but also improves the drying efficiency of the pole piece.

[0095] Based on the above embodiment, the heating device may include a third heating element in addition to the first heating element and the second heating element. The third heating element is disposed between the first heating element and the second heating element. The third heating element includes a fifth heating portion. The fifth distance between the fifth heating portion and the first region is less than the first distance and greater than the third distance; and / or the fifth heating temperature of the fifth heating portion is higher than the first heating temperature and lower than the third heating temperature;

[0096] Thus, the drying process using a drying device in step 120 may include the following steps:

[0097] From the first time to the second time, the pole piece is placed under the first heating element, the third heating element and the second heating element in sequence for drying, so that the drying temperature of the first area increases from the first time to the second time.

[0098] Exemplarily, the fifth heating portion of the third heating element may be arranged corresponding to the first region. The number of the fifth heating portions may be arranged according to the number and / or area of ​​the first region, for example, the number of the fifth heating portions is consistent with the number of the first region, or the number of the fifth heating portions is positively correlated with the area of ​​the first region.

[0099] The first distance between the first heating part of the first heating element and the first region is greater than the fifth distance between the fifth heating part of the third heating element and the first region, and greater than the third distance between the third heating part of the second heating element and the first region. And / or, the first heating temperature of the first heating part is lower than the fifth heating temperature of the fifth heating part, and lower than the third heating temperature of the third heating part.

[0100] Thus, from the first time to the second time, when the electrode is placed under the first heating element, the third heating element and the second heating element for drying, the drying temperature of the first region gradually increases from the first time to the second time. Accordingly, the drying speed of the first slurry and the second slurry in the first region gradually increases from the first time to the second time.

[0101] Optionally, the number of the third heating elements may be one or more. The distance between the fifth heating portion of the plurality of third heating elements and the first region gradually decreases, and / or the heating temperature of the fifth heating portion of the plurality of third heating elements gradually increases.

[0102] Exemplarily, the number of third heating elements can be determined according to the setting distance between the first heating element and the second heating element, so that when the electrode piece is placed under each heating element for drying from the first time to the second time, the drying temperature of the first area gradually increases.

[0103] In this embodiment, a third heating element is arranged between the first heating element and the second heating element, and the distance and heating temperature between the fifth heating part of the third heating element and the first area are controlled, so that the drying temperature of the first area gradually increases from the first time to the second time. The gradual change of the drying temperature can prevent the drying temperature of the first area from suddenly increasing, resulting in uneven heating of the slurry and cracking.

[0104] Based on any of the above embodiments, the second heating element may include a fourth heating element in addition to the third heating portion. As an example, the fourth distance between the fourth heating portion and the second region may be consistent with the second distance between the second heating portion and the second region in the first heating element. And / or the fourth heating temperature of the fourth heating portion is consistent with the second heating temperature of the second heating portion. In this way, the drying temperature of the second region of the pole piece at the first time is consistent with that at the second time.

[0105] As another example, the fourth distance between the fourth heating portion and the second region is greater than the second distance, and / or the fourth heating temperature of the fourth heating portion is lower than the second heating temperature, so that the drying temperature of the second region at the second time is lower than the drying temperature of the second region at the first time.

[0106] Exemplarily, the fourth heating portion of the second heating element may be arranged corresponding to the second region. The number of the fourth heating portions may be arranged according to the number and / or area of ​​the second region, for example, the number of the fourth heating portions is consistent with the number of the second region, or the number of the fourth heating portions is positively correlated with the area of ​​the second region.

[0107] Optionally, the third heating portion and the fourth heating portion of the second heating element may be formed in one piece, that is, the second heating element is an independent heating unit.

[0108] Optionally, the third heating part and the fourth heating part can be independently provided, that is, they are independent heating units respectively. The second heating element includes at least two heating units.

[0109] At the first time, the electrode piece is placed under the first heating element for drying. From the above-described embodiments, it can be seen that the drying temperature of the second area of ​​the electrode piece at the first time is greater than the drying temperature of the first area, so the second slurry in the second area dries faster.

[0110] In particular, when the fluidity of the two slurries in the first region decreases after the first time and the films are basically formed, the drying degree of the second slurry in the second region is higher because the drying temperature of the second region at the first time is higher.

[0111] In this way, the fourth distance between the fourth heating part of the second heating element and the second region is set to be greater than the second distance between the first heating part and the second region, and / or the fourth heating temperature of the fourth heating part is set to be lower than the second heating temperature of the second heating part, and when the pole piece is placed under the first heating element and the second heating element for drying from the first time to the second time, for the second region, its drying temperature decreases from the first time to the second time. Accordingly, the drying speed of the second slurry in the second region decreases from the first time to the second time, avoiding the second slurry in the second region from cracking due to overheating.

[0112] In this embodiment, by providing a second heating element including a fourth heating part, and controlling the distance and heating temperature between the fourth heating part and the second region, the electrode piece is placed successively under the first heating element and the second heating element for drying from the first time to the second time, so that the drying temperature of the second region decreases from the first time to the second time, thereby preventing the second slurry in the second region from cracking due to excessive heating.

[0113] Based on the above embodiment, the third heating element disposed between the first heating element and the second heating element may include a sixth heating element in addition to the fifth heating portion. A sixth distance between the sixth heating portion and the second region is less than the fourth distance and greater than the second distance, and / or a sixth heating temperature of the sixth heating portion is higher than the fourth heating temperature and lower than the second heating temperature.

[0114] Thus, the drying process using a drying device in step 120 may include the following steps:

[0115] From the first time to the second time, the pole piece is placed under the first heating element, the third heating element and the second heating element in sequence for drying, so that the drying temperature of the second area decreases from the first time to the second time.

[0116] Exemplarily, the sixth heating portion of the third heating element may be arranged corresponding to the second region. The number of the sixth heating portions may be arranged according to the number and / or area of ​​the second region, for example, the number of the sixth heating portions is consistent with the number of the second region, or the number of the sixth heating portions is positively correlated with the area of ​​the second region.

[0117] Optionally, the fifth heating portion and the sixth heating portion of the third heating element may be formed in one piece, that is, the third heating element is an independent heating unit.

[0118] Optionally, the fifth heating portion and the sixth heating portion can be independently provided, that is, they are independent heating units respectively. The third heating element includes at least two heating units.

[0119] The second distance between the second heating portion of the first heating element and the second region is smaller than the sixth distance between the sixth heating portion of the third heating element and the second region, and smaller than the fourth distance between the fourth heating portion of the second heating element and the second region. And / or, the second heating temperature of the second heating portion is higher than the sixth heating temperature of the sixth heating portion, and higher than the fourth heating temperature of the fourth heating portion.

[0120] Thus, from the first time to the second time, when the electrode is placed under the first heating element, the third heating element and the second heating element for drying, the drying temperature of the second region gradually decreases from the first time to the second time. Accordingly, the drying speed of the second slurry in the second region gradually decreases from the first time to the second time.

[0121] Optionally, the number of the third heating elements may be one or more. The distance between the sixth heating portion of the plurality of third heating elements and the second region gradually increases, and / or the heating temperature of the sixth heating portion of the plurality of third heating elements gradually decreases.

[0122] Exemplarily, the number of third heating elements can be determined according to the setting distance between the first heating element and the second heating element, so that when the electrode piece is placed under each heating element for drying from the first time to the second time, the drying temperature of the second area gradually decreases.

[0123] In this embodiment, a third heating element is arranged between the first heating element and the second heating element, and the distance and heating temperature between the sixth heating part of the third heating element and the second area are controlled, so that the drying temperature of the second area gradually decreases from the first time to the second time. The gradual change of the drying temperature can prevent the drying temperature of the second area from suddenly decreasing, resulting in uneven heating of the slurry and cracking.

[0124] Based on any of the above embodiments, the drying device may further include a transmission device.

[0125] The transmission device can be used to transmit the electrode coated with slurry to the inside of the drying device for drying, can control the position of the electrode inside the drying device, and can transmit the electrode from the inside of the drying device out of the drying device. The specific structure of the transmission device can refer to the relevant technology, and this embodiment is not limited here.

[0126] As an example, a conveying device may be used to convey the pole piece to under the first heating element for drying.

[0127] As an example, at a first time, the electrode piece may be transferred to a first heating element for drying by a transfer device; at a second time, the electrode piece may be transferred to a second heating element for drying by a transfer device.

[0128] As an example, from the first time to the second time, the electrode piece can be sequentially transferred to the first heating element, the third heating element and the second heating element by a transfer device for drying.

[0129] Of course, in addition to changing the drying position of the pole piece by means of a transmission device so that the pole piece is dried under different heating elements, the drying position of the pole piece can also be changed by other mechanical structures or manually, and the present application does not limit this.

[0130] In this embodiment, the transmission device is used to change the drying position of the electrode, so that the electrode can be automatically transmitted to each heating element for drying from the first time to the second time through the transmission device, thereby realizing full automation of electrode drying.

[0131] Based on any of the above embodiments, the heating device may further include a fourth heating element. The fourth heating element is used to control the ambient temperature inside the drying device. In this way, the above method may further include the steps of:

[0132] The heating temperatures of the first heating element, the second heating element, and the third heating element are all set to be higher than the heating temperature of the fourth heating element.

[0133] The ambient temperature inside the drying device may refer to the basic temperature in the drying device. For example, when the drying device is in operation, the fourth heating element is in operation for heating. When the drying device is in operation, the first heating element, the second heating element, and the third heating element may be turned on or off. When the first heating element, the second heating element, and the third heating element are not in operation, the ambient temperature of the drying device when the fourth heating element is in operation is the basic temperature.

[0134] The heating temperatures of the first heating element, the second heating element, and the third heating element are higher than the heating temperature of the fourth heating element, including the heating temperatures of the heating parts of the first heating element, the second heating element, and the third heating element are higher than the heating temperature of the fourth heating element.

[0135] In this embodiment, the heating temperatures of the first heating element, the second heating element and the third heating element are set to be higher than the heating temperature of the fourth heating element, so that the drying efficiency of the electrode can be improved by the first heating element, the second heating element and the third heating element.

[0136] Based on the above embodiment, the heating temperatures of the first heating element, the second heating element, and the third heating element meet 80-150°C.

[0137] That is, under the condition that the heating temperatures of the first heating element, the second heating element and the third heating element are higher than the heating temperature of the fourth heating element, the heating temperatures of the heating parts of the first heating element, the second heating element and the third heating element meet 80-150°C.

[0138] In this embodiment, the heating temperatures of the first heating element, the second heating element and the third heating element are set in the range of 80-150° C., which can improve the drying efficiency of the electrode piece.

[0139] Based on the above embodiment, the heating temperature of the fourth heating element meets 25-100°C.

[0140] That is, under the condition that the heating temperatures of the first heating element, the second heating element, and the third heating element are higher than the heating temperature of the fourth heating element, the heating temperature of the fourth heating element meets 25-100°C.

[0141] In this embodiment, the heating temperature of the fourth heating element is set in the range of 25-100° C., and the electrode can be dried in a wider range of ambient temperature without sacrificing production capacity.

[0142] Based on the above embodiment, the distance between the first heating element, the second heating element, and the third heating element and the pole piece meets the requirement of 5-40 cm.

[0143] The invention includes that the distance between each heating part and the pole piece of the first heating element, the second heating element and the third heating element is 5-40 cm.

[0144] In this embodiment, the distances between the first heating element, the second heating element, the third heating element and the pole piece are set in the range of 5-40 cm, which can improve the drying efficiency of the pole piece.

[0145] According to some embodiments of the present application, a second aspect provides a drying device. Figure 4-Figure 6 As shown, the drying device 400 includes:

[0146] The box body 410 forms a cavity 411, and the cavity 411 is used to accommodate the pole piece;

[0147] A heating device 420 is accommodated in the cavity 411; the heating device 420 is used to dry the electrode piece so that the drying temperature of the first area of ​​the electrode piece is lower than the drying temperature of the second area;

[0148] The first area is coated with a first slurry and a second slurry, and the second area is coated with the second slurry; under the same drying conditions, the drying speed of the second slurry is different from the drying speed of the first slurry.

[0149] The drying device 400 , such as an oven, includes a box body 410 , and a cavity 411 is formed inside the box body 410 .

[0150] Optionally, the housing 410 further comprises at least one opening, through which the pole piece can enter and / or leave the cavity.

[0151] The cavity 411 contains a heating device 420. When working, it also contains a pole piece. The pole piece includes a first area and a second area. The description of the first area and the second area can be found in the above embodiment, and this embodiment will not be repeated here. When the pole piece is dried by the heating device 420, the drying temperature of the first area in the pole piece is lower than the drying temperature of the second area, so that the two areas have different drying conditions. Accordingly, the drying speed of the two slurries in the first area is lower than the drying speed of the second slurry in the second area.

[0152] Since the reduction in drying temperature has a greater impact on the drying speed of the slurry that evaporates faster, the drying speed of the slurry that evaporates faster is slowed down in the first region, thereby reducing the difference in drying speed between the first slurry and the second slurry, and suppressing the unexpected flow of the slurry to the membrane region. At the same time, the drying speed of the second region is not affected, and the second slurry in the second region still dries faster. Therefore, in this embodiment, by placing the electrode in the above-mentioned drying equipment for drying, the drying efficiency of the electrode is guaranteed while suppressing the unexpected flow of the slurry to the membrane region.

[0153] Based on the above embodiment, the heating device 420 includes a first heating element 421. The first heating element 421 includes a first heating portion 4211 and a second heating portion 4212. The first distance between the first heating portion 4211 and the first region is greater than the second distance between the second heating portion 4212 and the second region, and / or the first heating temperature of the first heating portion 4211 is lower than the second heating temperature of the second heating portion 4212.

[0154] Exemplarily, the first heating portion 4211 may be disposed corresponding to the first region, and the second heating portion 4212 may be disposed corresponding to the second region.

[0155] The number of first heating parts 4211 can be set according to the number and / or area of ​​the first regions. For example, the number of first heating parts 4211 is consistent with the number of first regions. For another example, the number of first heating parts 4211 is positively correlated with the area of ​​the first region.

[0156] Similarly, the number of second heating parts 4212 can be set according to the number and / or area of ​​the second regions, for example, the number of second heating parts 4212 is consistent with the number of second regions, or the number of second heating parts 4212 is positively correlated with the area of ​​the second region.

[0157] Optionally, the first heating portion 4211 and the second heating portion 4212 may be integrally formed.

[0158] Optionally, the first heating portion 4211 and the second heating portion 4212 may be independently provided.

[0159] As an example, in Figure 2 The pole piece shown is based on Figure 5 (a) shows one possible example of the first heating element 421. Figure 5 (a) Yes Figure 4 The first heating element 421 in the drying device 400 is a cross-sectional structural diagram along AA. The first heating element 421 includes a first heating portion 4211 and a second heating portion 4212. Figure 2 The pole piece shown includes two first regions, and accordingly, the first heating portion 4211 includes two. Each first heating portion 4211 is arranged corresponding to each first region; and the second heating portion 4212 is arranged corresponding to the second region.

[0160] Of course, if the coating area of ​​the first slurry and the second slurry on the electrode is different Figure 2 The shape of each heating element 421 is not limited to the coating area shown. Figure 5 (a) shows an embodiment.

[0161] Optionally, the first heating portion 4211 and the second heating portion 4212 may be integrally formed, and the first heating element 421 presents a V-shaped cross section. In this way, the first heating portion 4211 and the second heating portion 4212 are set to the same heating temperature.

[0162] Optionally, the first heating part 4211 and the second heating part 4212 can also be independently provided, and a plurality of independent heating units are combined to form a Figure 5(a) shows the shape of the first heating element 421. Thus, the first heating portion 4211 includes one or more heating units, and the second heating portion 4212 includes one or more heating units. Thus, the first heating portion 4211 and the second heating portion 4212 can be set to the same or different heating temperatures.

[0163] It can be seen that the first distance between the first heating portion 4211 and the first region is greater than the second distance between the second heating portion 4212 and the second region, thereby achieving differentiated drying conditions between the first region and the second region.

[0164] In this embodiment, the first heating element is designed to include a first heating part and a second heating part, and the distance and / or heating temperature between the two heating parts and the first area and the second area of ​​the electrode are designed respectively, so that the drying temperature of the first area is lower than the drying temperature of the second area, thereby suppressing the unexpected flow of slurry to the membrane area without affecting the overall drying efficiency of the electrode.

[0165] On the basis of the above embodiment, the heating device 420 includes a first heating element 421 and a second heating element 422 arranged in sequence along the first direction. The first heating element 421 includes a first heating portion 4211 and a second heating portion 4212 arranged along the second direction. The second heating element 422 includes a third heating portion 4221 and a fourth heating portion 4222 arranged along the second direction. The first direction intersects with the second direction.

[0166] Optionally, the first direction and the second direction are two directions intersecting on the plane where the pole piece is located.

[0167] Optionally, the coating area of ​​the first slurry and the coating area of ​​the second slurry on the pole piece are distributed along the second direction, so that the first area and the second area of ​​the pole piece are also distributed along the second direction.

[0168] In this embodiment, the heating device is provided with a first heating element and a second heating element along the first direction, so that different positions in the first direction have different drying conditions under different heating elements. Each heating element is provided with a plurality of heating parts in the second direction, so that different positions in the second direction have different drying conditions under different heating parts. In this way, the pole piece is dried under different heating elements at different times, and different areas on the pole piece are dried under different heating parts at the same time, and the drying conditions can be flexibly adjusted as needed, thereby improving the drying flexibility.

[0169] Based on the above embodiment, the drying device 400 further includes: a conveying device for conveying the electrode piece into the cavity, wherein the first direction is parallel to the conveying direction of the conveying device; and the second direction is perpendicular to the first direction in the plane where the electrode piece is located.

[0170] Optionally, the first direction and the second direction are two directions perpendicular to the plane where the pole piece is located.

[0171] Optionally, the first direction is the MD (Machine Direction) direction, and the second direction is the TD (Transverse Direction) direction. The conveying direction of the conveying device is parallel to the MD direction, so the first direction is parallel to the conveying direction.

[0172] Optionally, the coating area of ​​the first slurry and the coating area of ​​the second slurry on the pole piece are distributed along the TD direction, so that the first area and the second area of ​​the pole piece are also distributed along the TD direction.

[0173] Thus, in this embodiment, the electrode piece enters the cavity 411 of the drying device 400 along the first direction under the conveying device, and moves in the cavity 411 along the first direction. At different times, the electrode piece is conveyed to different heating elements for drying, so that the electrode piece is in different drying conditions at different times, and the differentiated drying conditions in the conveying direction are realized. In addition, at the same time, the first area and the second area of ​​the electrode piece are dried under different heating parts of the same heating element and are in different drying conditions, and the differentiated drying conditions in the direction perpendicular to the conveying direction are realized.

[0174] Based on the above embodiment, the third distance between the third heating portion 4221 of the second heating element 422 and the first region is smaller than the first distance, and / or the third heating temperature of the third heating portion 4221 is higher than the first heating temperature.

[0175] Exemplarily, the third heating portion can be arranged corresponding to the first region. The number of the third heating portions can be arranged according to the number and / or area of ​​the first region, for example, the number of the third heating portions is consistent with the number of the first region, or the number of the third heating portions is positively correlated with the area of ​​the first region.

[0176] In this embodiment, since the third distance between the third heating portion 4221 and the first region is set to be smaller than the first distance between the first heating portion 4211 and the first region, and / or the third heating temperature of the third heating portion 4221 is set to be higher than the first heating temperature of the first heating portion 4211, the drying temperature of the first region increases when the first region of the pole piece moves from the first heating portion 4211 of the first heating element 421 to the third heating portion 4221 of the second heating element 422. Accordingly, the drying speed of the two slurries in the first region is also increased. After the first region reduces the fluidity under the drying of the first heating element 421, the drying speed is increased under the second heating element 422, which not only suppresses the unexpected flow of the slurry to the membrane area, but also improves the drying efficiency of the pole piece.

[0177] As described above, the second heating member 422 includes the fourth heating portion 4222 in addition to the third heating portion 4221 .

[0178] Based on the above embodiment, as an example, the fourth distance between the fourth heating portion 4222 and the second region can be consistent with the second distance between the second heating portion 4222 and the second region in the first heating element 421. And / or the fourth heating temperature of the fourth heating portion 4222 is consistent with the second heating temperature of the second heating portion 4222. That is, the drying temperature of the second region of the electrode under the first heating element 421 is consistent with the drying temperature under the second heating element 422.

[0179] Based on the above embodiment, as another example, the fourth distance between the fourth heating portion 4222 and the second region is greater than the second distance, and / or the fourth heating temperature of the fourth heating portion 4222 is lower than the second heating temperature.

[0180] Exemplarily, the fourth heating portion 4222 may be provided corresponding to the second region. The number of the fourth heating portions 4222 may be provided according to the number and / or area of ​​the second region, for example, the number of the fourth heating portions 4222 is consistent with the number of the second region, or the number of the fourth heating portions 4222 is positively correlated with the area of ​​the second region.

[0181] Optionally, the third heating portion 4221 and the fourth heating portion 4222 of the second heating element 422 may be integrally formed.

[0182] Optionally, the third heating portion 4221 and the fourth heating portion 4222 may be independently provided.

[0183] As an example, in Figure 2 The pole piece shown is based on Figure 5 (e) shows one possible example of the second heating element 422. Figure 5 (e) Yes Figure 4 The second heating element 422 in the drying device 400 is a cross-sectional view along EE. The second heating element 422 includes a third heating portion 4221 and a fourth heating portion 4222. Figure 2 The pole piece shown includes two first regions, and accordingly, the third heating portion 4221 includes two. Each third heating portion 4221 is arranged corresponding to each first region; and the fourth heating portion 4222 is arranged corresponding to the second region.

[0184] Of course, the shape of the second heating element 422 is not limited to Figure 5 (e) The illustrated embodiment.

[0185] Optionally, the third heating portion 4221 and the fourth heating portion 4222 may be integrally formed, and the second heating element 422 presents a V-shaped cross section. In this way, the third heating portion 4221 and the fourth heating portion 4222 are set to the same heating temperature.

[0186] Optionally, the third heating part 4221 and the fourth heating part 4222 can also be independently provided, and a plurality of independent heating units are combined to form a Figure 5 (e) shows the shape of the second heating element 422. Thus, the third heating portion 4221 includes one or more heating units, and the fourth heating portion 4222 includes one or more heating units. Thus, the third heating portion 4221 and the fourth heating portion 4222 can be set to the same or different heating temperatures.

[0187] In this embodiment, by comparing Figure 5 (a) with Figure 5 (e) It can be seen that the third distance between the third heating part 4221 and the first region is smaller than the first distance between the first heating part 4211 and the first region, and the fourth distance between the fourth heating part 4222 and the second region is larger than the second distance between the second heating part 4212 and the second region. Therefore, from the first heating part 4211 to the third heating part 4221 in the first region, the drying temperature increases, and the drying speed of the slurry increases; from the second heating part 4212 to the fourth heating part 4222 in the second region, the drying temperature decreases, and the drying speed of the slurry decreases. This suppresses the unexpected flow of the slurry to the membrane area without affecting the overall drying efficiency of the pole piece, and also avoids the second slurry in the second region from cracking due to excessive heating.

[0188] Based on the above embodiment, the heating device 420 further includes a third heating element 423 disposed along the first direction between the first heating element 421 and the second heating element 422. The third heating element 423 includes a fifth heating portion 4231 and a sixth heating portion 4232 disposed along the second direction.

[0189] That is, the heating device 420 sequentially arranges a first heating element 421 , a third heating element 423 and a second heating element 422 in the first direction.

[0190] Exemplarily, the fifth heating portion 4231 may be arranged corresponding to the first region. The number of the fifth heating portions 4231 may be arranged according to the number and / or area of ​​the first region, for example, the number of the fifth heating portions 4231 is consistent with the number of the first region, or the number of the fifth heating portions 4231 is positively correlated with the area of ​​the first region.

[0191] Similarly, the sixth heating portion 4232 can be set corresponding to the second region. The number of the sixth heating portions 4232 can be set according to the number and / or area of ​​the second region, for example, the number of the sixth heating portions 4232 is consistent with the number of the second region, or the number of the sixth heating portions 4232 is positively correlated with the area of ​​the second region.

[0192] Optionally, the fifth heating portion 4231 and the sixth heating portion 4232 may be integrally formed.

[0193] Optionally, the fifth heating portion 4231 and the sixth heating portion 4232 may be independently provided.

[0194] When the pole piece moves along the first direction, it is dried in sequence under the first heating element 421, the third heating element 423, and the second heating element 422. The first area on the pole piece is dried in sequence under the first heating portion 4211, the fifth heating portion 4231, and the third heating portion 4221. The second area on the pole piece is dried in sequence under the second heating portion 4212, the sixth heating portion 4232, and the fourth heating portion 4222.

[0195] It can be seen that in this embodiment, by setting multiple heating elements in the first direction, each area in the drying device in the first direction achieves differentiated drying conditions. Each heating element includes multiple heating parts in the second direction, so that each area in the drying device in the second direction achieves differentiated drying conditions.

[0196] Based on the above embodiments, the fifth distance between the fifth heating portion 4231 and the first region is smaller than the first distance and greater than the third distance between the third heating portion 4221 and the first region; and / or the fifth heating temperature of the fifth heating portion 4231 is higher than the first heating temperature and lower than the third heating temperature of the third heating portion 4221.

[0197] That is, the first distance is greater than the fifth distance and greater than the third distance, and / or the first heating temperature is lower than the fifth heating temperature and lower than the third heating temperature.

[0198] Thus, when the first region on the electrode is dried in the first heating portion 4211, the fifth heating portion 4231, and the third heating portion 4221 in sequence, the drying temperature of the first region gradually increases. Accordingly, the drying speed of the first slurry and the second slurry in the first region gradually increases.

[0199] In this embodiment, a third heating element is arranged between the first heating element and the second heating element, so that the drying temperature of the first area gradually increases. The gradual change of the drying temperature can prevent the drying temperature of the first area from suddenly increasing, causing uneven heating of the slurry and cracking.

[0200] Based on the above embodiments, the sixth distance between the sixth heating portion 4232 and the second region is smaller than the fourth distance between the fourth heating portion 4222 and the second region and greater than the second distance, and / or the sixth heating temperature of the sixth heating portion 4232 is higher than the fourth heating temperature of the fourth heating portion 4222 and lower than the second heating temperature.

[0201] That is, the second distance is smaller than the sixth distance and smaller than the fourth distance, and / or the second heating temperature is higher than the sixth heating temperature and higher than the fourth heating temperature.

[0202] Thus, when the second region on the electrode is dried in the second heating portion 4212, the sixth heating portion 4232, and the fourth heating portion 4222 in sequence, the drying temperature of the second region gradually decreases. Accordingly, the drying speed of the second slurry in the second region gradually decreases.

[0203] In this embodiment, a third heating element is arranged between the first heating element and the second heating element, so that the drying temperature of the second area is gradually reduced. The gradual change of the drying temperature can prevent the slurry from cracking due to uneven heating caused by a sudden drop in the drying temperature of the second area.

[0204] In addition, the number of the third heating element 423 may be one or more. Figure 2 The pole piece shown is based on Figure 5 (b)- Figure 5 (d) shows various possible examples of the third heating element 423. The third heating element 423 may be Figure 5 (b)- Figure 5 (d) Any one or more of the examples shown.

[0205] In some embodiments, the third heating element 423 includes a plurality of third heating elements 423. The plurality of third heating elements 423 satisfy one or more of the following conditions:

[0206] Condition 1: a fifth distance between the fifth heating portion 4231 of at least part of the third heating member 423 and the first region decreases along the first direction.

[0207] Condition 2: the fifth heating temperature of the fifth heating portion 4231 of at least part of the third heating member 423 increases along the first direction.

[0208] Condition 3: a sixth distance between the sixth heating portion 4232 of at least part of the third heating element 423 and the second region increases along the first direction;

[0209] Condition 4: the sixth heating temperature of the sixth heating portion 4232 in at least part of the third heating member 423 decreases along the first direction.

[0210] by Figure 5As an example, an embodiment in which the heating device 420 includes three third heating elements 423 is shown. Figure 5 (b) Yes Figure 4 A schematic cross-sectional structural diagram of the first third heating element along line BB in the middle drying device 400 along the first direction. Figure 5 (c) Yes Figure 4 A schematic cross-sectional structural diagram of the second to third heating elements along CC in the first direction in the drying device 400. Figure 5 (d) Yes Figure 4 A schematic cross-sectional structural diagram of the third heating element along the first direction along DD in the drying device 400.

[0211] That is, the heating device 420 is sequentially arranged in the first direction from Figure 5 (b)- Figure 5 (d) shows three third heating elements 423.

[0212] It can be seen that due to Figure 2 The pole piece shown includes two first regions, and accordingly, the fifth heating portion 4231 includes two. Each fifth heating portion 4231 is arranged corresponding to each first region; and the sixth heating portion 4232 is arranged corresponding to the second region.

[0213] Optionally, the fifth heating portion 4231 and the sixth heating portion 4232 may be integrally formed. In this way, the fifth heating portion 4231 and the sixth heating portion 4232 are set to the same heating temperature.

[0214] Optionally, the fifth heating portion 4231 and the sixth heating portion 4232 may also be independently provided, and a plurality of independent heating units may be combined to form a Figure 5 (b)- Figure 5 (d) shows the shape of the third heating element 423. Thus, the fifth heating portion 4231 includes one or more heating units, and the sixth heating portion 4232 includes one or more heating units. Thus, the fifth heating portion 4231 and the sixth heating portion 4232 can be set to the same or different heating temperatures.

[0215] It can be seen that Figure 5 (c)- Figure 5 In the third heating element 423 shown in (d), the fifth distance between the fifth heating portion 4231 and the first region decreases along the first direction, which meets the above-mentioned condition 1.

[0216] like Figure 5 (b)- Figure 5 In the third heating element 423 shown in (c), the sixth distance between the sixth heating portion 4232 and the second region increases along the first direction, which meets the above-mentioned condition 3.

[0217] When the fifth heating part 4231 and the sixth heating part 4232 are independently set, the fifth heating temperature of the fifth heating part 4231 of at least part of the third heating element 423 can also be increased along the first direction to meet the above condition 2; and the sixth heating temperature of the sixth heating part 4232 of at least part of the third heating element 423 can be lowered along the first direction to meet the above condition 4.

[0218] certainly, Figure 5 The illustrated embodiment is merely an exemplary embodiment, and the shape of the third heating member 423 is not limited thereto.

[0219] Optionally, Figure 5 The first heating element 421, the second heating element 422 and the third heating element 423 shown in (a) to (e) can be integrally formed. In this way, each heating element is set to the same heating temperature.

[0220] Optionally, Figure 5 The first heating element 421, the second heating element 422 and the third heating element 423 shown in (a)-(e) can also be independent heating elements. In this way, the heating elements can be set to the same or different heating temperatures.

[0221] Exemplarily, the distance between each heating part in each heating element and the bearing assembly is 5-40 cm. The bearing assembly is used to bear the pole piece. Thus, the distance between each heating part and the pole piece satisfies 5-40 cm.

[0222] In this embodiment, a third heating element is arranged between the first heating element and the second heating element, so that the drying temperature of the first area gradually increases and the drying temperature of the second area gradually decreases. The gradual change of the drying temperature can prevent the slurry from cracking due to uneven heating caused by sudden changes in the drying temperature of each area.

[0223] Based on any of the above embodiments, Figure 5 (a)- Figure 5 As shown in (e), in the first heating element 421, the first heating portion 4211 includes two, which are respectively arranged on both sides of the second heating portion 4212. In the first heating element 422, the third heating portion 4221 includes two, which are respectively arranged on both sides of the fourth heating portion 4222. In the third heating element 423, the fifth heating portion 4231 includes two, which are respectively arranged on both sides of the sixth heating portion 4232.

[0224] In this embodiment, by setting the arrangement of the heating parts in each heating element, the heating element can meet the drying conditions required when different slurries are coated on the edge and center areas of the electrode.

[0225] Apart from Figure 5In addition to the embodiments of the first heating element 421, the second heating element 422 and the third heating element 423 shown, Figure 6 A feasible example of the first heating element 421 , the second heating element 422 and the third heating element 423 is also shown.

[0226] like Figure 6 As shown, one or more of the first heating element 421, the second heating element 422 and the third heating element 423 can be configured as follows: Figure 6 The heating element 600 shown, that is, one or more of the first heating element 421, the second heating element 422 and the third heating element 423 have the same shape.

[0227] The heating element 600 includes a heating portion 610 and a heating portion 620. The heating portion 610 and the heating portion 620 are independently provided, and the heating temperature of each heating portion can be set separately. The distance between the heating portion 610 and the first area and the distance between the heating portion 620 and the second area are consistent.

[0228] If the first heating element 421 is set as the heating element 600, the heating portion 610 corresponds to the first heating portion 4211, and the heating portion 620 corresponds to the second heating portion 4212. At this time, the heating temperature of the heating portion 610 is lower than the heating temperature of the heating portion 620.

[0229] If the second heating element 422 is set as the heating element 600, the heating portion 610 corresponds to the third heating portion 4221; the heating portion 620 corresponds to the fourth heating portion 4222. At this time, the heating temperature of the heating portion 610 can be set according to the magnitude relationship between the third heating temperature and the first heating temperature described in the above embodiment, and the heating temperature of the heating portion 620 can be set according to the magnitude relationship between the fourth heating temperature and the second heating temperature.

[0230] If the third heating element 423 is set as the heating element 600, the heating portion 610 corresponds to the fifth heating portion 4231; the heating portion 620 corresponds to the sixth heating portion 4232. At this time, the heating temperature of the heating portion 610 can be set according to the magnitude relationship between the fifth heating temperature and the first heating temperature and the third heating temperature described in the above embodiment, and the heating temperature of the heating portion 620 can be set according to the magnitude relationship between the sixth heating temperature and the second heating temperature and the fourth heating temperature.

[0231] Based on any of the above embodiments, the heating device 420 further includes a fourth heating element for controlling the ambient temperature in the cavity 411. When the first heating element 421, the second heating element 422 and the third heating element 423 are not in operation, the cavity 411 has a certain ambient temperature when the fourth heating element is in operation.

[0232] According to some embodiments of the present application, Figure 2 As shown, both sides of the pole piece, namely the coating area eadh and the coating area bfgc, are coated with AT11 to prevent the substrate from cracking during welding. The coating area abcd on the pole piece is coated with cathode active material. The above three coating areas are arranged along the TD direction. According to the three coating areas, the pole piece can be divided into a first area ea'd'h, a first area b'fgc', and a second area a'b'c'd'. The first area ea'd'h and the first area b'fgc' are arranged on both sides of the second area a'b'c'd' along the TD direction.

[0233] like Figure 5 (a)- Figure 5 As shown in (e), for the drying device 400, for example, an oven, a heating device 420 is arranged inside the drying device 400. The heating device 420 includes one or more heating elements. The heating element is, for example, an infrared lamp. By setting the shape of the heating element, the drying temperature at different positions in the TD direction and the MD direction in the cavity 411 is adjusted to achieve the effect of differentiating the drying speed of the electrode in different regions in the TD direction and the MD direction.

[0234] like Figure 5 (a)- Figure 5 As shown in (e), the drying equipment is sequentially arranged along the first direction Figure 5 (a) shows the first heating element 421, Figure 5 (b)- Figure 5 (d) The third heating element 431 shown in Figure 5 (e) shows the second heating element 432. Figure 5 (a)- Figure 5 (e) The opening angle of the heating element shape transitions from an acute angle to an obtuse angle, thereby changing the distance between each heating part of each heating element and the pole piece. By controlling the opening angle of the heating element shape, the heating effect on different areas of the pole piece is adjusted, thereby inhibiting the flow of AT11 to the film area of ​​the cathode active material, while not reducing the drying speed of the intermediate film area.

[0235] Among them, the heating temperature of the fourth heating element of the drying equipment is set to 80°C. That is, when the first heating element 421, the second heating element 422 and the third heating element 423 are not in operation, the ambient temperature of the cavity 411 is 80°C when the fourth heating element is in operation. The heating temperatures of the first heating element 421, the second heating element 432 and the third heating element 423 are all set to 105°C. As shown in Table 1, the drying temperatures of the same area of ​​the pole piece at different positions along the MD direction are different, and the drying temperatures of different areas along the TD direction are different.

[0236] Table 1

[0237]

[0238] As shown in Table 1, the drying equipment is divided into 11 sections along the first direction. After entering the drying equipment, the electrode piece is conveyed from the first section to the eleventh section by the conveying device, and then leaves the drying equipment. The electrode piece is dried in the first section to the eleventh section.

[0239] Among them, from the 1st section to the 11th section along the first direction are arranged as follows Figure 5 (a)- Figure 5 (e) The heating element shown. Among them, those skilled in the art can set which section each heating element is respectively set in and the number of each heating element according to actual conditions.

[0240] It can be seen that the drying temperature of the first area gradually increases from section 1 to section 11, which means that the drying temperature of the first area gradually increases from the first heating part of the first heating element, the fifth heating part of the third heating element, to the third heating part of the second heating element. Correspondingly, the drying speed of the AT11 and the cathode active material coated in the first area also gradually increases.

[0241] In the initial stage of drying, the drying temperature of the first area is relatively low. The reduction of drying temperature has a greater impact on the drying speed of the cathode active material, thereby reducing the difference in drying speed between the cathode active material and AT11, thereby inhibiting the flow of AT11 to the membrane area. As the electrode is conveyed in the drying equipment, the drying temperature of the first area gradually increases, accelerating the drying speed of the first area, thereby improving the overall drying efficiency of the electrode.

[0242] The drying temperature of the second region gradually decreases from section 1 to section 11, which means that the drying temperature of the second region gradually decreases from the second heating part of the first heating element, the sixth heating part of the third heating element, to the fourth heating part of the second heating element. Accordingly, the drying speed of the cathode active material coated in the second region also gradually decreases.

[0243] In the initial stage of drying, the drying temperature of the second area is relatively high, so that the cathode active slurry in the second area can be dried quickly to form a film. As the electrode sheet is conveyed in the drying equipment, the drying temperature of the second area is gradually reduced to prevent the cathode active slurry in the second area from cracking due to overheating.

[0244] It can be seen that after the electrode is dried by the drying equipment, while the flow of AT11 to the membrane area is suppressed, the drying efficiency of the electrode is not reduced.

[0245] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0246] In several embodiments of the present application, it should be understood that the disclosed device and method can also be implemented in other ways. The device embodiments described above are only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0247] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0248] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0249] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0250] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0251] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for drying an electrode, characterized in that: The method comprises: Placing the electrode coated with the slurry in a drying device; The pole piece includes a first region and a second region, the first region is coated with a first slurry and a second slurry, and the second region is coated with the second slurry; under the same drying conditions, the drying speed of the second slurry is different from the drying speed of the first slurry; The drying is performed using a drying device such that a drying temperature in the first zone is lower than a drying temperature in the second zone.

2. The method according to claim 1, characterized in that The drying device comprises a heating device, the heating device comprises a first heating element, the first heating element comprises a first heating portion and a second heating portion; a first distance between the first heating portion and the first region is greater than a second distance between the second heating portion and the second region, and / or a first heating temperature of the first heating portion is set to be lower than a second heating temperature of the second heating portion; The drying process using a drying device comprises: The pole piece is placed under the first heating element for drying, so that the drying temperature of the first area is lower than the drying temperature of the second area.

3. The method according to claim 2, characterized in that The heating device further comprises a second heating element, the second heating element comprises a third heating portion, a third distance between the third heating portion and the first region is smaller than the first distance, and / or a third heating temperature of the third heating portion is set higher than the first heating temperature; The drying process using a drying device comprises: At a first time, placing the electrode under the first heating element for drying, so that at the first time, the drying temperature of the first area is lower than the drying temperature of the second area; At a second time, the pole piece is placed under the second heating element for drying, so that the drying temperature of the first area at the second time is greater than the drying temperature of the first area at the first time.

4. The method according to claim 3, characterized in that The heating device further comprises a third heating element disposed between the first heating element and the second heating element, the third heating element comprising a fifth heating portion, a fifth distance between the fifth heating portion and the first region being smaller than the first distance and larger than the third distance; and / or a fifth heating temperature of the fifth heating portion being set to be higher than the first heating temperature and lower than the third heating temperature; The drying process using a drying device comprises: From the first time to the second time, the pole piece is placed under the first heating element, the third heating element and the second heating element in sequence for drying, so that the drying temperature of the first area increases from the first time to the second time.

5. The method according to claim 3, characterized in that: The second heating element also includes a fourth heating part, a fourth distance between the fourth heating part and the second region is greater than the second distance, and / or a fourth heating temperature of the fourth heating part is set to be lower than the second heating temperature, so that the drying temperature of the second region at the second time is lower than the drying temperature of the second region at the first time.

6. The method according to claim 5, characterized in that The heating device further comprises a third heating element disposed between the first heating element and the second heating element, the third heating element comprising a sixth heating portion, a sixth distance between the sixth heating portion and the second region being smaller than the fourth distance and larger than the second distance, and / or a sixth heating temperature of the sixth heating portion being set higher than the fourth heating temperature and lower than the second heating temperature; Placing the electrode coated with the slurry in a drying device for drying comprises: From the first time to the second time, the pole piece is placed under the first heating element, the third heating element and the second heating element in sequence for drying, so that the drying temperature of the second area decreases from the first time to the second time.

7. The method according to claim 4 or 6, characterized in that: The drying device further includes a transmission device; from the first time to the second time, the electrode piece is placed under the first heating element, the third heating element and the second heating element in sequence for drying, including: From the first time to the second time, the electrode piece is sequentially transferred to the first heating element, the third heating element and the second heating element by the transfer device for drying.

8. The method according to claim 4 or 6, characterized in that: The heating device further comprises a fourth heating element, and the fourth heating element is used to control the ambient temperature in the drying device; the method further comprises: The heating temperatures of the first heating element, the second heating element, and the third heating element are all set to be higher than the heating temperature of the fourth heating element.

9. The method according to claim 8, characterized in that The heating temperatures of the first heating element, the second heating element, and the third heating element meet 80-150°C.

10. The method according to any one of claims 8-9, characterized in that: The heating temperature of the fourth heating element meets 25-100°C.

11. The method according to any one of claims 8 to 10, characterized in that: The distances between the first heating element, the second heating element, and the third heating element and the pole piece are 5-40 cm.

12. A drying device, characterized in that: The device comprises: A box body, forming a cavity, wherein the cavity is used to accommodate the pole piece; A heating device is accommodated in the cavity; the heating device is used to dry the pole piece so that the drying temperature of the first area of ​​the pole piece is lower than the drying temperature of the second area; The first area is coated with a first slurry and a second slurry, and the second area is coated with the second slurry; under the same drying conditions, the drying speed of the second slurry is different from the drying speed of the first slurry.

13. The device according to claim 12, characterized in that The heating device comprises a first heating element, wherein the first heating element comprises a first heating portion and a second heating portion; wherein a first distance between the first heating portion and the first region is greater than a second distance between the second heating portion and the second region, and / or The first heating temperature of the first heating part is set to be lower than the second heating temperature of the second heating part.

14. The device according to claim 13, characterized in that The heating device comprises a first heating element and a second heating element arranged in sequence along a first direction; The first heating element includes a first heating portion and a second heating portion arranged along a second direction; The second heating element includes a third heating portion and a fourth heating portion arranged along the second direction; The first direction intersects the second direction.

15. The device according to claim 14, characterized in that The device also includes: A conveying device, used for conveying the pole piece into the cavity; The first direction is parallel to the conveying direction of the conveying device; The second direction is perpendicular to the first direction in the plane where the pole piece is located.

16. The device according to any one of claims 14-15, characterized in that: A third distance between the third heating portion and the first region is smaller than the first distance, and / or The third heating temperature of the third heating portion is set higher than the first heating temperature.

17. The device according to any one of claims 14 to 16, characterized in that: A fourth distance between the fourth heating portion and the second region is greater than the second distance, and / or The fourth heating temperature of the fourth heating portion is set to be lower than the second heating temperature.

18. The device according to any one of claims 14 to 17, characterized in that: The heating device further includes a third heating element disposed between the first heating element and the second heating element along the first direction, and the third heating element includes a fifth heating portion and a sixth heating portion disposed along the second direction.

19. The device according to claim 18, characterized in that A fifth distance between the fifth heating portion and the first region is smaller than the first distance and larger than a third distance between the third heating portion and the first region; and / or The fifth heating temperature of the fifth heating portion is set to be higher than the first heating temperature and lower than the third heating temperature of the third heating portion.

20. The device according to any one of claims 18-19, characterized in that: A sixth distance between the sixth heating portion and the second region is smaller than a fourth distance between the fourth heating portion and the second region and larger than the second distance, and / or The sixth heating temperature of the sixth heating portion is set to be higher than the fourth heating temperature of the fourth heating portion and lower than the second heating temperature.

21. The device according to any one of claims 18 to 20, characterized in that: The third heating element includes a plurality of third heating elements; the plurality of third heating elements satisfy one or more of the following conditions: A fifth distance between the fifth heating portion of the plurality of third heating elements and the second region decreases along the first direction; The fifth heating temperature of the fifth heating parts of the plurality of the third heating elements increases along the first direction; A sixth distance between the sixth heating portion of the plurality of third heating elements and the second region increases along the first direction; The sixth heating temperature of the sixth heating portion of the plurality of third heating members decreases along the first direction.

22. The device according to any one of claims 18 to 21, characterized in that: The first heating part includes two parts, which are respectively arranged on both sides of the second heating part; The third heating part includes two parts, which are respectively arranged on both sides of the fourth heating part; The fifth heating part includes two parts, which are respectively arranged on both sides of the sixth heating part.

23. The device according to any one of claims 18 to 22, characterized in that: The device also includes a fourth heating element for controlling the ambient temperature within the cavity.

Images