Double-layer turn-back type coating machine and coating system

Abstract

The invention provides a double-layer turn-back type coating machine and a coating system. The double-layer turn-back type coating machine comprises a drying mechanism, an integrated coating mechanism, an unwinding mechanism, a winding mechanism and a turn-over mechanism. And after the first surface of the pole piece is coated, the pole piece immediately enters a first drying oven for foldback drying, the wet surface of the pole piece faces upwards and faces an air nozzle for first drying, and the pole piece is dried for the second time at the tail end through rotation of the dry surface. And after the first surface of the pole piece is dried, the pole piece is overturned by 180 degrees in a suspended mode according to the original advancing direction through the overturning mechanism, after the second surface coating is completed, the pole piece immediately enters the second drying oven to be folded back and dried, and the belt conveying and drying mode of the pole piece after the second surface coating is the same as the situation of the pole piece after the first surface coating. And the coating machine realizes four times of drying through the E-shaped piece path, so that the length of the drying oven and the energy consumption are reduced and the drying efficiency is improved under the condition of ensuring the production quality of the pole piece. The coating machine is reasonable in overall layout, compact in structure, convenient to operate and monitor, capable of achieving centralized feeding and capable of being arranged in a clean workshop.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery production equipment, and in particular relates to a double-layer return coating machine and a coating system. Background Art

[0002] In the production process of lithium-ion batteries, a coating machine is required to evenly coat the first side (side A) and the second side (side B) of the electrode with slurry. After coating the first side, the slurry on the first side needs to be dried in a first oven, and then the slurry is coated on the second side on the other side, and then the slurry on the second coated side needs to be dried in a second oven.

[0003] Most of the existing coating machines are long double-layer distributed coating machines, and the electrode only travels once in each layer of the oven, resulting in a large overall footprint and high energy consumption. Moreover, the coating head on the first side and the coating head on the second side are respectively arranged on both sides of the whole machine, which not only leads to low work efficiency during debugging and maintenance, but also requires partitioned feeding and multi-person operation. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides a double-layer folding coater, which adopts a double-layer E-type folding sheet path layout. After each coating, the electrode to be dried is dried twice in each layer of the oven, and it is ensured that the wet side is facing up, facing the wind nozzle, and the back is against the roller during the drying process. Under this new layout, the length of the oven is reduced by 50%, and 30% of energy consumption is saved. In addition, in the double-layer folding coater of the present invention, the turning mechanism turns the electrode over without changing the direction of travel of the electrode; in this way, the first-side coating mechanism and the second-side coating mechanism can be set on the same side of the drying mechanism, which is convenient for operation, monitoring and centralized feeding, and requires fewer operators; this layout also prevents the situation of empty belts.

[0005] The technical effects to be achieved by the present invention are achieved through the following technical aspects: In a first aspect, the present invention provides a double-layer folding coater, which adopts a modular layout, including a drying mechanism, an integrated coating mechanism, a reeling mechanism, a reeling mechanism and a flipping mechanism; the integrated coating mechanism, the reeling mechanism and the reeling mechanism are all arranged on the same side of the drying mechanism, and the first side of the electrode is flipped by the flipping mechanism after coating and drying, and then the second side is coated and dried; The drying mechanism comprises a first oven and a second oven which are stacked, the first surface of the pole piece is turned back and traveled in the first oven and baked twice, and the second surface of the pole piece is turned back and traveled in the second oven and baked twice; The integrated coating mechanism comprises a first-side coating mechanism for coating the slurry on the first side of the pole piece, and a second-side coating mechanism for coating the slurry on the second side of the pole piece; The flipping mechanism flips the pole piece, and the direction in which the pole piece is output from the flipping mechanism is the same as the direction in which the pole piece enters the flipping mechanism.

[0006] In some embodiments, the pole piece is unwound by the unwinding mechanism, enters the first-side coating mechanism for slurry coating on the first side after the first side is corrected, and immediately enters the first oven for return drying after the coating is completed, and the direction of travel of the pole piece entering the first oven is opposite to the direction of travel of the pole piece output from the first oven; After the first side of the electrode is dried, the electrode is turned over 180 degrees by the turning mechanism in the original direction of travel, and after thickness measurement and second side deviation correction, it enters the second side coating mechanism for slurry coating on the second side, and immediately enters the second oven for return drying after coating. The direction of travel of the electrode entering the second oven is opposite to the direction of travel of the electrode output from the second oven; After the pole piece is dried on the second side, it is pulled and thickness measured, and then rolled up by a rolling mechanism.

[0007] In some embodiments, the drying mechanism includes a first drying area, a second drying area, a partition, an active roller, an air nozzle and a steering roller, the first drying area is arranged above the second drying area, and the partition separates the first drying area from the second drying area to form independent drying areas; The second drying oven comprises a third drying area, a fourth drying area, a partition, an active roller, an air nozzle and a transformation roller, the third drying area is arranged above the fourth drying area, and the partition separates the third drying area from the fourth drying area to form an independent drying area; Wherein, in the first oven and the second oven, the side of the pole piece coated with the wet slurry is always facing upward and is not in contact with the active roller and the steering roller.

[0008] In some embodiments, in the first drying area and the second drying area, the first surface of the pole piece faces the air nozzle, and the second surface of the pole piece contacts the active roller and is driven by the active roller; In the third drying area and the fourth drying area, the second surface of the pole piece faces the air nozzle, and the first surface of the pole piece contacts the active roller and is driven by the active roller.

[0009] In some embodiments, the steering roller is disposed on a side away from the pole piece feed port, and the steering roller may be one or more contact-type active rollers, or a non-contact air-floating roller or a magnetic-floating roller.

[0010] In some embodiments, the flipping mechanism includes a first suspended flipping roller and a second suspended flipping roller; The pole piece enters the first suspension flip roller along the first direction, with the first surface of the pole piece facing downward and the second surface facing upward; the pole piece is output from the second suspension flip roller along the first direction, with the first surface of the pole piece facing upward and the second surface facing downward.

[0011] In some embodiments, the flipping mechanism further comprises a base, wherein the base has a base surface; The first direction is the initial travel direction of the pole piece entering the flipping mechanism; along the first direction, the projection of the pole piece on the base surface has a pole piece center line; The projections of the first floating flipping roller and the second floating flipping roller on the base surface respectively have a first center line and a second center line, and an angle θ between the first center line and the second center line is 90°±10°.

[0012] In some embodiments, a first angle α is formed between the first center line and the pole piece center line, a second angle β is formed between the second center line and the pole piece center line, and the first angle α and the second angle β have a relationship: α+β+θ=180°.

[0013] In some embodiments, the first suspension flipping roller is an air floating roller; The first suspended flipping roller and the second suspended flipping roller both include a roller body and an air inlet and an exhaust hole opened on the roller body, wherein the number of the air inlets k≥1; the exhaust holes are evenly distributed axially on the roller body to form an m×n exhaust hole array; wherein m≥2, n≥2; and the diameter of the exhaust hole is 0.5mm-20mm.

[0014] In some embodiments, the roller body has a central axis, and in the same column of exhaust holes, a line connecting the exhaust holes in the first row and the central axis and a line connecting the exhaust holes in the mth row and the central axis have an arc angle γ, and the arc angle γ is 1°-30°; In the same row of exhaust holes, the spacing between adjacent exhaust holes is 1 mm to 80 mm.

[0015] In some embodiments, the first suspension flipping roller and the second suspension flipping roller are non-contact air floating rollers or magnetic floating rollers.

[0016] In some embodiments, the double-layer return coater further comprises a first-layer platform and a second-layer platform; The turning mechanism is arranged on the second-layer platform, or on the first-layer platform, or between the second-layer platform and the first-layer platform.

[0017] In a second aspect, the present invention provides a coating system, comprising a first thickness measuring device and a second thickness measuring device, and the above-mentioned double-layer return coater; The first-side coating mechanism comprises a first-side deviation correcting device, a first-side coating head and a first traction device; The second-side coating mechanism includes a second-side deviation correcting device, a second-side coating head and a second traction device; The integrated coating mechanism adopts a high-strength frame and integrates the first-side deviation correcting device, the first-side coating head, the first traction device, the second-side deviation correcting device, the second-side coating head and the second traction device.

[0018] In some embodiments, the reeling mechanism and the unreeling mechanism are disposed adjacent to each other with a gap greater than 1 m therebetween, and the unreeling mechanism is disposed outside the reeling mechanism.

[0019] In summary, the present invention has at least the following benefits: 1. The double-layer folding coater provided by the present invention adopts a double-layer E-type folding sheet layout. After each coating, the electrode to be dried is dried twice in each layer of the oven, and the drying process is ensured to be with the wet side facing up, facing the air nozzle, back against the roller, and the dry side rotating, which can prevent the wet slurry from scraping the air nozzle and efficiently and stably complete the drying of the slurry on the surface of the electrode. Under this new layout, the length of the oven is reduced by 50%, and 30% of energy consumption is saved.

[0020] 2. In the double-layer return coater provided by the present invention, the flipping mechanism flips the electrode sheet without changing the moving direction of the electrode sheet; in this way, the first-side coating mechanism and the second-side coating mechanism can be arranged on the same side of the drying mechanism, which is convenient for operation, monitoring and centralized feeding, and requires fewer operators; this layout also prevents the situation of empty belts.

[0021] 3. The coating system provided by the present invention realizes four-time drying in the E-type film path, which greatly reduces the length of the oven and energy consumption and improves the drying efficiency while ensuring the production quality of the electrode and reducing failures. In addition, the tape travel of the electrode is optimized. After the electrode completes the second-side drying process in the second oven on the first platform, the electrode is tape-guided in the winding direction, and there is no need to run the empty tape in the opposite direction, thus saving space and energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the layout of the double-layer return coater of Example 1 of the present invention.

[0023] Figure 2 for Figure 1 Enlarged schematic diagram of part A.

[0024] Figure 3 for Figure 1 Schematic diagram of the enlarged portion B.

[0025] Figure 4 This is a schematic structural diagram of the drying structure of Example 1 of the present invention.

[0026] Figure 5 Another schematic diagram of the layout of the double-layer return coater of Example 2 of the present invention.

[0027] Figure 6 It is a structural schematic diagram of the turning mechanism of Example 3 of the present invention.

[0028] Figure 7 It is a schematic diagram of the pole piece center line, the first center line and the second center line and the angles between them in the projection of the base surface of Example 3 of the present invention.

[0029] Figure 8 Schematic diagram of the distribution of the pole piece center line, the first center line and the second center line on the base surface projection of Example 3 of the present invention.

[0030] Fig. 9 This is a schematic structural diagram of the first suspended flipping roller according to Example 3 of the present invention.

[0031] Fig.10 This is a schematic diagram of the structure of the coating system of Example 4 of the present invention.

[0032] Markings in the figure: 100-Double layer return coater; 10-Integrated coating mechanism; 1-first side coating mechanism, 11-first side deviation correcting device, 12-first side coating head, 13-first traction device; 2-second side coating mechanism, 21-second side deviation correcting device, 22-second side coating head, 23-second traction device; 3- Turning mechanism; 30-base, 31-first suspended flipping roller, 32-second suspended flipping roller, 33-edge flattening roller, 34-tension adjustment roller, 301-base surface, 311-roller body, 312-air inlet, 313-exhaust hole; 4-Drying mechanism; 41-first oven, 42-second oven, 43-partition plate, 44-active roller, 45-air nozzle, 46-turning roller, 47-pole piece feeding port; 401-first drying area, 402-second drying area, 403-third drying area, 404-fourth drying area; 51-first floor platform, 52-second floor platform; 200-pole piece, 201-first surface, 202-second surface; L1-first direction, Z0-pole piece centerline, Z1-first centerline, Z2-second centerline, Z3-central axis; 300 - unwinding mechanism, 400 - rewinding mechanism, 500 - first thickness measuring device, 600 - second thickness measuring device. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively in conjunction with the accompanying drawings and specific embodiments. The preferred embodiments of the present invention are provided in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0034] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] Example 1 refer to Figure 1-Figure 8, this embodiment provides a double-layer folding coater 100, which is used to coat and dry the slurry on both sides of the pole piece 200. The double-layer folding coater 100 adopts a modular layout, which includes an integrated coating mechanism 10, a drying mechanism 4, a reeling mechanism 300, a reeling mechanism 400 and a flipping mechanism 3. The integrated coating mechanism 10, the reeling mechanism 300 and the reeling mechanism 400 are all arranged on the same side of the drying mechanism 4. After coating and drying, the first side 201 of the pole piece 200 is flipped over by the flipping mechanism 3, and then the second side 202 is coated and dried; The integrated coating mechanism 10 includes a first-side coating mechanism 1 and a second-side coating mechanism 2. The first-side coating mechanism 1 and the second-side coating mechanism 2 respectively coat the slurry on the first side 201 and the second side 202 of the pole piece 200. The integrated coating mechanism 10 of this embodiment adopts a high-strength frame and is independent of other mechanisms, which can prevent vibration interference from other mechanisms / modules and ensure the stability of slurry coating.

[0038] exist Figure 2 and Figure 3 In the figure, the first surface 201 is represented by a thicker line, and the second surface 202 is represented by a thinner line.

[0039] The drying mechanism 4 dries the electrode piece 200 coated with the slurry. The drying mechanism 4 includes a first oven 41 and a second oven 42, wherein the first oven 41 is stacked above the second oven 42. In the drying mechanism 4, the first surface 201 of the electrode piece 200 is turned back and baked twice in the first oven 41, and the second surface 202 of the electrode piece 200 is turned back and baked twice in the second oven 42.

[0040] Furthermore, the first oven 41 and the second oven 42 are an integrated stacked oven structure, and a support platform layer or a separator is used between the two to separate the internal drying chambers. The pole piece 200 coated with slurry by the first side coating mechanism 1 enters the first oven 41 for secondary drying, and the pole piece 200 coated with slurry by the second side coating mechanism 2 enters the second oven 42 for secondary drying.

[0041] Before the pole piece 200 enters the second-side coating mechanism 2, the flipping mechanism 3 flips the pole piece 200. The first side 201 and the second side 202 of the pole piece 200 are the opposite sides of the pole piece 200, respectively. The flipping mechanism 3 flips the pole piece 200 180° to achieve the exchange of the orientation of the second side 202 and the first side 201. It should be noted that after the flipping mechanism 3 completes the flipping of the pole piece 200, the traveling direction of the pole piece 200 output from the flipping mechanism 3 is the same as the traveling direction of the pole piece 200 entering the flipping mechanism 3. That is, the flipping mechanism 3 completes the flipping of the pole piece 200 without changing the traveling direction of the pole piece 200, which can effectively improve the belt running efficiency of the pole piece.

[0042] Further references Figure 1 and Figure 4 The electrode 200 is unwound by the unwinding mechanism 300, and after the first side is corrected, it enters the first side coating mechanism 1 to coat the first side 201 with slurry. After the coating is completed, it immediately enters the first oven 41 for return drying. The moving direction of the electrode 200 entering the first oven 41 is opposite to the moving direction of the electrode output from the first oven 41.

[0043] After the first side 201 of the electrode 200 is dried, it is suspended and turned over 180° in the original direction of travel by the turning mechanism 3. After thickness measurement and second side correction, it enters the second side coating mechanism 2 for slurry coating of the second side 202. After coating, it immediately enters the second oven 42 for return drying. The travel direction of the electrode entering the second oven 42 is opposite to the travel direction of the electrode output from the second oven 42. After the second side 202 of the electrode 200 is dried, it is pulled and thickness measured, and then rolled up by the rolling mechanism 400.

[0044] In the drying mechanism 4, the first oven 41 includes a first drying area 401, a second drying area 402, a partition 43, an active roller 44, a wind nozzle 45 and a turning roller 46. The first drying area 401 is arranged above the second drying area 402, and the partition 43 separates the first drying area 401 from the second drying area 402. After the first surface 201 of the pole piece 200 is coated with slurry, it enters the first drying area 401 of the first oven 41 from the pole piece feed port 47 on the left side. The first surface 201 coated with slurry faces the wind nozzle 45, and the second surface 202 not coated with slurry contacts the active roller 44 and is driven by the active roller 44. The airflow pressure above the pole piece 200 acts on the first surface 201, so that the second surface 202 is close to the active roller 44, which can reduce the fluctuation of the pole piece 200 and avoid the situation where the surface fluctuation of the pole piece is large, resulting in wrinkling and cracking.

[0045] After the first drying (baking) process is completed in the first drying area 401, the electrode 200 is transferred to the second drying area 402 by the turning roller 46 for secondary drying. The turning roller 46 changes the direction of travel of the electrode 200 in the first oven 41. Figure 4 As shown, the moving direction of the pole piece 200 in the second drying area 402 is opposite to the moving direction of the pole piece 200 in the first drying area 401. In the second drying area 402, the pole piece 200 moves from the right side to the left side; at this time, the first surface 201 of the pole piece 200 is also facing the air nozzle 45, and the second surface 202 is in contact with the active roller 44 and driven by the active roller 44.

[0046] It should be noted that, since the partition 43 separates the first drying area 401 from the second drying area 402 to form a relatively independent drying chamber, the disturbance of the airflow to the electrode can be reduced, and the drying temperature can be controlled in zones and sections.

[0047] The second oven 42 includes a third drying area 403, a fourth drying area 404, a partition 43, an active roller 44, a nozzle 45 and a turning roller 46. The second oven 42 is disposed below the first oven 41, and its overall structure is similar to that of the first oven 41.

[0048] In the second oven 42 , the third drying area 403 is disposed above the fourth drying area 404 , and the partition 43 separates the third drying area 403 from the fourth drying area 404 .

[0049] After the electrode piece 200 is turned over by the turning mechanism 3, the second side coating mechanism 2 coats the second side 202 of the electrode piece 200 with slurry, and then enters the third drying area 403 of the second oven 42 from the electrode piece feed port 47 on the left side, and the second side 202 coated with slurry faces the air nozzle 45, and the first side 201 where the slurry has been dried contacts with the active roller 44 and is driven by the active roller 44. It should be noted that the air nozzles in the first oven 41 and the second oven 42 are densely arranged.

[0050] After the first drying process is completed in the third drying area 403, the pole piece 200 is transferred by the turning roller 46 to the fourth drying area 404 for secondary drying. The moving direction of the pole piece 200 in the fourth drying area 404 is opposite to the moving direction of the pole piece 200 in the third drying area 403. That is, in the fourth drying area 404, the pole piece 200 moves from the right side to the left side. In the third drying area 403 and the fourth drying area 404, the second surface 202 of the pole piece 200 is facing the air nozzle 45, and the first surface 201 of the pole piece 200 is in contact with the active roller 44 and driven by the active roller 44.

[0051] In the coating machine of this embodiment, the first oven 41 and the second oven 42 of the drying mechanism 4 are both provided with two relatively independent drying areas, which are separated by a partition to achieve secondary drying. In other embodiments, three or more drying areas can be provided as needed to achieve multiple baking processes.

[0052] In the first oven 41, the steering roller 46 is disposed between the first drying area 401 and the second drying area 402, and the steering roller 46 is located on the side away from the electrode sheet feeding port 47; the second surface 202 of the electrode sheet 200 faces the steering roller 46. In the second oven 42, the steering roller 46 is disposed between the third drying area 403 and the fourth drying area 404, and the steering roller 46 is located on the side away from the electrode sheet feeding port 47, and the first surface 201 of the electrode sheet 200 faces the steering roller 46.

[0053] The steering roller 46 can be set as a contact type active roller, and the number of the active rollers can be one or more to increase the driving force; the steering roller 46 can also be set as a non-contact air floating roller or magnetic floating roller, which can avoid the wear of the pole piece facing the steering roller.

[0054] In the double-layer folding coating machine 100 of this embodiment, the first-side coating mechanism 1 and the second-side coating mechanism 2 are both arranged on the same side of the drying mechanism 4. Figure 1 and Figure 4 As shown, the first side coating mechanism 1 and the second side coating mechanism 2 are both located on the left side of the drying mechanism 4. In other embodiments, the first side coating mechanism 1 and the second side coating mechanism 2 may be disposed on the right side of the drying mechanism 4.

[0055] In the double-layer folding coater provided in this embodiment, a double-layer E-type folding sheet path layout is adopted. The pole pieces coated by the first-side coating mechanism and the second-side coating mechanism enter the first oven and the second oven respectively for secondary drying. After each coating, the pole pieces to be dried are dried twice in each layer of the oven, and it is ensured that the drying process is with the wet side facing up, facing the wind nozzle, and with the back against the roller, which can reduce the fluctuation of the pole pieces and efficiently and stably complete the drying of the slurry on the surface of the pole pieces. Under this new layout, the length of the oven is reduced by 50%, and 30% of energy consumption is saved.

[0056] Example 2 exist Figure 1-Figure 4 Based on the reference Figure 5 The position of the flipping mechanism 3 can be optimized as needed. In the double-layer folding coating machine 100, the flipping mechanism 3 performs a 180° floating flip on the pole piece 200.

[0057] The electrode 200 is transported out from the flipping mechanism 3 and passes through the second surface coating mechanism 2 to coat the second surface 202 with slurry. When entering the second oven 42, the second surface 202 coated with slurry faces upward, and the first surface 201 where the slurry has been dried faces downward.

[0058] Further references Figure 1 and Figure 5The double-layer folding coating machine 100 includes a first-layer platform 51 and a second-layer platform 52, and the second-layer platform 52 is arranged above the first-layer platform 51. In this embodiment, the first-layer coating mechanism 1 is installed on the second-layer platform 52, and the second-layer coating mechanism 2 is installed on the first-layer platform 51. In coordination with the first-layer coating mechanism 1, the first oven 41 is also arranged on the second-layer platform 52; in coordination with the second-layer coating mechanism 2, the second oven 42 is also arranged on the first-layer platform 51. In this way, the pole piece 200 is firstly coated with slurry on the first surface 201 by the first-layer coating mechanism 1 located on the second-layer platform 52, and then enters the first oven 41 and the turning mechanism 3, and then the second surface 202 is coated with slurry by the second-layer coating mechanism 2 located on the first-layer platform 51, and then enters the second oven 42 for drying.

[0059] The flipping mechanism 3 is independent of the first-side coating mechanism 1 and the second-side coating mechanism 2. According to the placement and connection method, the flipping mechanism 3 can be placed according to the layout requirements of the device. For example, the flipping mechanism 3 can be installed on the second-layer platform 52, adjacent to the first-side coating mechanism 1 ( Figure 1 The turning mechanism 3 can also be installed on the first platform 51, adjacent to the second coating mechanism 2.

[0060] The flipping mechanism 3 can also be installed between the second platform 52 and the first platform 51, for example, installed at the connection point between the pole piece belt of the second platform 52 and the first platform 51 ( Figure 5 ). When the flipping mechanism 3 is arranged between the second platform 52 and the first platform 51, a set of 180° turning rollers needs to be added at the discharge end of the flipping mechanism. At this time, the pole piece enters from the top of the flipping mechanism and is discharged from the bottom.

[0061] Example 3 exist Figure 1-Figure 4 Based on the reference Figure 6-Figure 9 This embodiment describes the situation where the turning mechanism is installed on the second-layer platform 52.

[0062] like Figure 6 As shown, the flipping mechanism 3 includes a base 30, a first suspended flipping roller 31 and a second suspended flipping roller 32. The base 30 is a base structure having a base surface 301. The first suspended flipping roller 31 and the second suspended flipping roller 32 are arranged above the base 30. It can be understood that the first suspended flipping roller 31 and the second suspended flipping roller 32 are located above the base surface 301, and the two form corresponding projections on the base surface 301.

[0063] After the first surface 201 of the pole piece 200 is coated with the slurry and dried, it enters the first suspension turning roller 31 along the first direction L1, at which time the first surface 201 faces the base surface 301, and the second surface 202 faces away from the base surface 301; that is, the first surface 201 faces downward, and the second surface 202 faces upward. After the pole piece 200 is subjected to a 180° suspension turning process by the first suspension turning roller 31 and the second suspension turning roller 32, the pole piece 200 is still transported out of the second suspension turning roller 32 along the first direction L1, at which time the second surface 202 faces the base surface 301, and the first surface 201 faces away from the base surface 301; that is, the second surface 202 faces downward, and the first surface 201 faces upward.

[0064] Furthermore, the first direction L1 is the initial moving direction of the pole piece 200 entering the flipping mechanism 3, and the first direction L1 is the same direction as the positive direction of the y-axis. Figure 6 and Figure 7 Along the first direction L1, the projection of the pole piece 200 on the base surface 301 has a pole piece center line Z0.

[0065] As described above, the first suspended flipping roller 31 and the second suspended flipping roller 32 form corresponding projections on the base surface 301, and the projections of the first and second suspended flipping rollers 31 and 32 on the base surface 301 respectively have a first center line Z1 and a second center line Z2. Since the first suspended flipping roller 31 and the second suspended flipping roller 32 are cross-distributed, the first center line Z1 and the second center line Z2 form an angle θ, and the range of the angle θ is 90°±10°. Preferably, the first suspended flipping roller 31 and the second suspended flipping roller 32 are vertically distributed in space, and at this time, the angle θ formed by the first center line Z1 and the second center line Z2 is 90°, that is, θ=90°.

[0066] A first angle α is formed between the first center line Z1 and the pole piece center line Z0, and a second angle β is formed between the second center line Z2 and the pole piece center line Z0. The first angle α and the second angle β have a relationship of: α+β+θ=180°.

[0067] Preferably, the first angle α and the second angle β are complementary angles, that is, α+β=90°.

[0068] exist Figure 6 and Figure 7 Based on the reference Figure 8 In some embodiments, as shown in FIG8A , the first angle α and the second angle β are both 45°, that is, α=β=45°.

[0069] In some embodiments, as shown in FIG8B , the first angle α is 30° and the second angle β is 60°, that is, α=30° and β=60°.

[0070] In some embodiments, as shown in FIG8C , the first angle α is 60° and the second angle β is 30°, that is, α=60° and β=30°.

[0071] In other embodiments, the crossing manner of the first floating turning roller 31 and the second floating turning roller 32 may be set according to the relationship of “α+β+θ=180°”.

[0072] The flipping mechanism 3 is also provided with an edge flattening roller 33 and a tension adjusting roller 34. The flipping mechanism 3 can perform 180° floating flipping of the pole piece without changing the initial moving direction of the pole piece by providing the first floating flipping roller 31 and the second floating flipping roller 32 and the combination of the two. The edge flattening roller 33 and the tension adjusting roller 34, as well as the edge measurement sensor, can realize automatic deviation correction and wrinkle removal during the flipping process of the pole piece.

[0073] The first suspension flipping roller 31 and the second suspension flipping roller 32 are non-contact air floating rollers or magnetic floating rollers. The first suspension flipping roller 31 and the second suspension flipping roller 32 can adopt the same or different structures. The first suspension flipping roller 31 and the second suspension flipping roller 32 can have different structures.

[0074] In this embodiment, the first suspension flipping roller 31 and the second suspension flipping roller 32 have the same structure, and the first suspension flipping roller 31 with an air floating roller structure is taken as an example for description. Fig. 9 As shown, the first floating flipping roller 31 includes a roller body 311, an air inlet 312 and an exhaust hole 313. The second floating flipping roller 32 also includes a roller body 311, an air inlet 312 and an exhaust hole 313. The air inlet 312 and the exhaust hole 313 are provided on the roller body 311, and the number of the air inlets 312 is k, k ≥ 1, that is, the number k of the air inlets can be set to 1 or more as required. The roller body 311 is a columnar structure, and the roller body 311 has a central axis Z3.

[0075] The exhaust holes 313 are evenly distributed on the roller body 311 in the axial direction, that is, the exhaust holes 313 are evenly distributed on the side wall of the roller body 311 in a manner parallel to the central axis Z3, forming an m×n exhaust hole array. Wherein, m≥2, n≥2. The diameter of the exhaust hole 313 is 0.5mm-20mm, In the same row of exhaust holes 313, the line connecting the exhaust holes in the first row and the central axis and the line connecting the exhaust holes in the mth row and the central axis have an arc angle γ, and the arc angle γ is 1°-30°. In the same row of exhaust holes 313, the spacing between adjacent exhaust holes is 1mm-80mm.

[0076] Further references Figure 6After the slurry is coated and dried, the first surface 201 of the pole piece 200 moves along the first direction L1, that is, the positive direction of the y-axis; at this time, the first surface 201 faces the negative direction of the z-axis, toward the base surface 301.

[0077] After entering the first suspended flipping roller 31 of the flipping mechanism 3, the second side 202 of the pole piece 200 faces the exhaust hole 313, and the pole piece is blown up and suspended by the airflow discharged from the exhaust holes 313 evenly distributed on the roller body 311, and the pole piece 200 completes the first flipping; at this time, the moving direction of the pole piece 200 is opposite to the x-axis.

[0078] The tension adjustment roller 34 is disposed between the first suspension turning roller 31 and the second suspension turning roller 32. After adjustment by the tension adjustment roller 34, the pole piece 200 moves in the positive direction of the x-axis, and the second surface 202 faces the positive direction of the z-axis.

[0079] Next, the pole piece 200 is transported to the second suspension turning roller 32 to complete the second turning; at this time, the moving direction of the pole piece 200 is the same as the first direction L1 (initial moving direction), and is still moving along the positive direction of the y-axis. The second surface 202 of the pole piece 200 faces the opposite direction of the z-axis, that is, toward the base surface 301; the first surface 201 faces the positive direction of the z-axis, that is, away from the base surface 301.

[0080] Before the pole piece 200 enters the first suspension turning roller 31 and the second suspension turning roller 32, and when it is conveyed out from the first suspension turning roller 31 and the second suspension turning roller 32, the edge flattening roller 33 is used to make the pole piece 200 flat as a whole, so that the belt can run smoothly.

[0081] The case where the flipping mechanism 3 is installed on the first-layer platform 51 is similar to the case where the flipping mechanism 3 is installed on the second-layer platform 52, and will not be described in detail here.

[0082] In the double-layer turn-back coating machine provided in this embodiment, the flipping mechanism flips the electrode sheet without changing the direction of the electrode sheet. In this way, the first-side coating mechanism and the second-side coating mechanism can be arranged on the same side of the drying mechanism, which is convenient for operation, monitoring and centralized feeding, and requires fewer operators. This layout also prevents the occurrence of empty belts. In addition, by optimizing the number and arrangement of the exhaust holes of the floating flipping roller, the electrode sheet can be stably suspended and flipped.

[0083] Example 4 exist Figure 1-Figure 9 Based on the reference Fig.10 This embodiment provides a coating system, including a first thickness measuring device 500 and a second thickness measuring device 600, and the double-layer return coater 100 of embodiment 1 or embodiment 2.

[0084] The double-layer reversing coater 100 is a double-layer reversing coater, in which the first-side coating mechanism 1 comprises a first-side deflection correction device 11, a first-side coating head 12 and a first traction device 13. The pole piece 200 passes through the unwinding mechanism 300, the first-side deflection correction device 11, the first-side coating head 12, the first oven 41 and the first traction device 13, and then enters the flipping mechanism.

[0085] The second side coating mechanism 2 includes a second side deflection correction device 21, a second side coating head 22 and a second traction device 23. After the electrode 200 is turned over 180° by the turning mechanism 3, it passes through the first thickness measuring device 500, the second side deflection correction device 21, the second side coating head 22, the second oven 42, the second traction device 23 and the second thickness measuring device 600, and then enters the winding mechanism 400 for winding.

[0086] The second thickness measuring device 600 is a winding thickness measuring device. In some embodiments, a second surface correction device 21 may be provided between the winding mechanism 400 and the second thickness measuring device 600 to correct the position of the pole piece when the winding mechanism 400 winds up the pole piece.

[0087] The unwinding mechanism 300 and the rewinding mechanism 400 are disposed adjacent to each other, with a gap greater than 1 m therebetween, and the unwinding mechanism 300 is disposed outside the rewinding mechanism 400 .

[0088] It should be noted that after the pole piece 200 is dried in the second oven 42, its moving direction is the same as the winding direction of the winding mechanism 400. In this way, the pole piece 200 does not need to run empty in the reverse direction, saving energy and space.

[0089] The above contents are merely examples and illustrations of the structure of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and these obvious replacement forms all belong to the protection scope of the present invention.

Claims

1. Double-layer folding coater, characterized in that: The double-layer folding coating machine adopts a modular layout, including a drying mechanism, an integrated coating mechanism, a reeling mechanism, a reeling mechanism and a turning mechanism; the integrated coating mechanism, the reeling mechanism and the turning mechanism are all arranged on the same side of the drying mechanism, and the first side of the electrode is turned over by the turning mechanism after coating and drying, and then the second side is coated and dried; The drying mechanism comprises a first oven and a second oven which are stacked, the first surface of the pole piece is turned back and traveled in the first oven and baked twice, and the second surface of the pole piece is turned back and traveled in the second oven and baked twice; The integrated coating mechanism comprises a first-side coating mechanism for coating the slurry on the first side of the pole piece, and a second-side coating mechanism for coating the slurry on the second side of the pole piece; The flipping mechanism flips the pole piece, and the direction in which the pole piece is output from the flipping mechanism is the same as the direction in which the pole piece enters the flipping mechanism.

2. The double-layer folding coating machine according to claim 1, characterized in that: The pole piece is unwound by the unwinding mechanism, enters the first surface coating mechanism for slurry coating on the first surface after the first surface is corrected, and immediately enters the first oven for return drying after the coating is completed. The direction of movement of the pole piece entering the first oven is opposite to the direction of movement of the pole piece output from the first oven; After the first side of the electrode is dried, the electrode is turned over 180 degrees by the turning mechanism in the original direction of travel, and after thickness measurement and second side deviation correction, it enters the second side coating mechanism for slurry coating on the second side, and immediately enters the second oven for return drying after coating. The direction of travel of the electrode entering the second oven is opposite to the direction of travel of the electrode output from the second oven; After the pole piece is dried on the second side, it is pulled and thickness measured, and then rolled up by a rolling mechanism.

3. The double-layer folding coating machine according to any one of claims 1 or 2, characterized in that: The drying mechanism comprises a first drying area, a second drying area, a partition, an active roller, an air nozzle and a turning roller, the first drying area is arranged above the second drying area, and the partition separates the first drying area from the second drying area to form independent drying areas; The second drying oven comprises a third drying area, a fourth drying area, a partition, an active roller, an air nozzle and a transformation roller, the third drying area is arranged above the fourth drying area, and the partition separates the third drying area from the fourth drying area to form an independent drying area; Wherein, in the first oven and the second oven, the side of the pole piece coated with the wet slurry is always facing upward and is not in contact with the active roller and the steering roller.

4. The double-layer folding coating machine according to claim 3, characterized in that: In the first drying area and the second drying area, the first surface of the pole piece faces the air nozzle, and the second surface of the pole piece contacts the active roller and is driven by the active roller; In the third drying area and the fourth drying area, the second surface of the pole piece faces the air nozzle, and the first surface of the pole piece contacts the active roller and is driven by the active roller.

5. The double-layer folding coating machine according to claim 3, characterized in that: The steering roller is arranged at a side away from the pole piece feeding port, and the steering roller is one or more contact-type active rollers, or a non-contact air-floating roller or a magnetic-floating roller.

6. The double-layer folding coating machine according to claim 1, characterized in that: The flipping mechanism comprises a first suspended flipping roller and a second suspended flipping roller; The pole piece enters the first suspension turning roller along a first direction, with the first surface of the pole piece facing downward and the second surface facing upward; The pole piece is output from the second suspension turning roller along a first direction, with a first surface of the pole piece facing upward and a second surface facing downward.

7. The double-layer folding coating machine according to claim 6, characterized in that: The flipping mechanism further comprises a base, wherein the base has a base surface; The first direction is the initial travel direction of the pole piece entering the flipping mechanism; along the first direction, the projection of the pole piece on the base surface has a pole piece center line; The projections of the first floating flipping roller and the second floating flipping roller on the base surface respectively have a first center line and a second center line, and an angle θ between the first center line and the second center line is 90°±10°.

8. The double-layer folding coating machine according to claim 7, characterized in that: A first angle α is formed between the first center line and the pole piece center line, and a second angle β is formed between the second center line and the pole piece center line. The first angle α and the second angle β have a relationship of: α+β+θ=180°.

9. The double-layer folding coating machine according to claim 6, characterized in that: The first suspended flipping roller is an air floating roller; The first suspended flipping roller and the second suspended flipping roller both include a roller body and an air inlet and an exhaust hole opened on the roller body, the number of the air inlets k≥1, and the exhaust holes are axially evenly distributed on the roller body to form an m×n exhaust hole array; wherein m≥2, n≥2; and the diameter of the exhaust hole is 0.5mm-20mm.

10. The double-layer folding coating machine according to claim 9, characterized in that: The roller body has a central axis, and in the exhaust holes in the same row, a line connecting the exhaust holes in the first row and the central axis and a line connecting the exhaust holes in the mth row and the central axis have an arc angle γ, and the arc angle γ is 1°-30°; In the same row of exhaust holes, the spacing between adjacent exhaust holes is 1 mm to 80 mm.

11. The double-layer folding coating machine according to claim 6, characterized in that: The first suspension flipping roller and the second suspension flipping roller are non-contact air floating rollers or magnetic floating rollers.

12. The double-layer folding coating machine according to claim 1, characterized in that: Also includes the first and second level platforms; The turning mechanism is arranged on the second-layer platform, or on the first-layer platform, or between the second-layer platform and the first-layer platform.

13. A coating system, characterized in that It comprises a first thickness measuring device and a second thickness measuring device, and a double-layer return coating machine as described in any one of claims 1 to 12; The first-side coating mechanism comprises a first-side deviation correcting device, a first-side coating head and a first traction device; The second-side coating mechanism includes a second-side deviation correcting device, a second-side coating head and a second traction device; The integrated coating mechanism adopts a high-strength frame and integrates the first-side deviation correcting device, the first-side coating head, the first traction device, the second-side deviation correcting device, the second-side coating head and the second traction device.

14. The coating system according to claim 13, characterized in that: The reeling mechanism and the unreeling mechanism are arranged adjacent to each other, with a gap greater than 1 m between them, and the unreeling mechanism is arranged outside the reeling mechanism.

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