A battery pole piece double-layer coating system and method

Abstract

The application discloses a battery pole piece double-layer coating system and method, which comprises a back roller, a coating nozzle, a first feeding module, a second feeding module and a third feeding module. The back roller is used for bearing a battery current collector. The coating nozzle comprises isolated first, second and third spraying channels. The first feeding module is located on one side of the coating nozzle and is used for providing spraying slurry to the first spraying channel. The second feeding module is arranged in parallel with the first feeding module and is used for providing spraying slurry to the second spraying channel. The third feeding module is arranged in parallel with the first and second feeding modules and is used for providing ceramic slurry to the third spraying channel. The battery pole piece double-layer coating system can realize double-layer coating and special ceramic edge coating of the positive pole piece, has high coating efficiency, high coating consistency and good coating stability.

Description

TECHNICAL FIELD

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

[0002] With the continuous improvement of the breadth and depth of the application of lithium batteries, the requirements for lithium batteries are also getting higher and higher. Under the premise of ensuring good safety, cycle life and rate performance, the demand for developing lithium batteries with high energy density and low production cost is becoming more and more urgent. At present, one of the effective solutions is to use multi-layer coating in lithium battery production, which not only improves the energy density of the battery but also enhances the safety of the battery. The existing mature multi-layer coating method and system can only complete single-layer coating of a single side, and multi-layer coating is realized by reciprocating multiple times. This way has low production efficiency and it is difficult to improve product yield, which further leads to high production cost. In the actual production process, the coating process of the positive pole piece needs to coat a circle of ceramic edge. The existing multi-layer coating method and system cannot coat the ceramic edge at the same time as coating the film layer, and the ceramic edge needs to be coated again after the coating is completed, which makes the coating process more complex and reduces the production efficiency. SUMMARY

[0003] The first object of the present application is to provide a battery pole piece double-layer coating system, which can realize double-layer coating and special ceramic edge coating of the positive pole piece at the same time, has high coating efficiency, high coating consistency and good coating stability.

[0004] The second object of the present application is to provide a battery pole piece double-layer coating method, which has high coating efficiency, high coating consistency and good coating stability.

[0005] To achieve the above technical effects, the technical solutions of the present application are as follows:

[0006] The present application discloses a battery pole piece double-layer coating system, comprising: a back roller, which is used to carry the battery pole piece; a coating nozzle, which comprises isolated first, second and third spraying channels; a first feeding module, which is located on one side of the coating nozzle and is used to provide spraying slurry to the first spraying channel; a second feeding module, which is arranged parallel to the first feeding module and is used to provide the spraying slurry to the second spraying channel; and a third feeding module, which is arranged parallel to the first and second feeding modules and is used to provide ceramic slurry to the third spraying channel.

[0007] In some embodiments, the first supply module comprises a first transfer tank, a first diaphragm pump, a first buffer tank, a first delivery pump and a first capsule filter connected in sequence, wherein: the first buffer tank and the first delivery pump are located on a first moving platform; the first transfer tank is a plurality of parallelly arranged.

[0008] In some more specific embodiments, a first iron remover and a first dynamic filter are arranged between the first buffer tank and the first diaphragm pump.

[0009] In some embodiments, the second supply module comprises a second transfer tank, a second diaphragm pump, a second buffer tank, a second delivery pump and a second capsule filter connected in sequence, wherein: the second buffer tank and the second delivery pump are located on a second moving platform; the second transfer tank is a plurality of parallelly arranged.

[0010] In some more specific embodiments, a second iron remover and a second dynamic filter are arranged between the second buffer tank and the second diaphragm pump.

[0011] In some embodiments, the third supply module comprises a third buffer tank, a third delivery pump and a third capsule filter connected in sequence, wherein: the third buffer tank and the third delivery pump are located on a third moving platform.

[0012] In some embodiments, the battery pole piece double-layer coating system further comprises: a wet film detection module located downstream of the back roller, the wet film detection module being used for detecting the quality of the wet film coating on the battery current collector; a drying module located downstream of the wet film detection module, the drying module being used for drying the coating; a dry film detection module located downstream of the drying module, the dry film detection module being used for detecting the quality of the dried coating; and a control module electrically connected with the wet film detection module, the dry film detection module, the first supply module, the second supply module, the third supply module and the coating nozzle.

[0013] The application further discloses a battery pole piece double-layer coating method, which is performed by using the battery pole piece double-layer coating system.

[0014] The second supply module is started, and the first supply module and the third supply module are closed for coating to form a primary coating.

[0015] The first supply module and the second supply module are started for coating to form a double-layer coating; or:

[0016] start the second supply module and the third supply module, and close the first supply module to perform coating and ceramic edge coating to form a primary coating and a ceramic edge;

[0017] start the first supply module and the second supply module to perform coating to form a double-layer coating.

[0018] In some embodiments, the battery pole piece double-layer coating method further comprises: detecting a primary wet film parameter and a primary dry film parameter of the primary coating, and adjusting a supply speed of the second supply module, a lip gap of the second spraying channel of the coating nozzle, and a gap between the coating nozzle and the back roller according to the primary wet film parameter and the primary dry film parameter; detecting a double-layer dry film parameter and a double-layer dry film parameter of the double-layer coating, and adjusting a supply speed of the first supply module, a lip gap of the first spraying channel of the coating nozzle, and a gap between the coating nozzle and the back roller according to the double-layer dry film parameter and the double-layer dry film parameter.

[0019] In some embodiments, a coating quality ratio of the primary coating and the double-layer coating is 1:9-9:1.

[0020] The battery pole piece double-layer coating system has the following advantages: due to the first supply module, the second supply module, and the third supply module, the battery pole piece double-layer coating system can realize synchronous and efficient continuous spraying of the double-layer coating in the production process, has high coating consistency and stability, is easy to control in the production process, has low manufacturing cost, and when the double-layer coating is formed in the process of processing the positive pole piece, the ceramic edge is simultaneously sprayed to form, so that the positive pole piece does not need to be additionally processed in actual work, and the production and manufacturing process of the positive pole piece is simplified.

[0021] The battery pole piece double-layer coating method has the following advantages: due to the synchronous and efficient continuous spraying of the double-layer coating in the coating process, and the ceramic edge can be simultaneously generated in the process of forming the coating, the coating process of the battery pole piece double-layer coating method is simple, the coating efficiency is high, the coating consistency is high, and the coating stability is good.

[0022] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic diagram of a battery pole piece double-layer coating system of an embodiment of the application;

[0024] Figure 2 is a control architecture diagram of a control module of a battery pole piece double-layer coating system of an embodiment of the application;

[0025] Figure 3 is a flow chart of coating a positive electrode sheet by a battery electrode sheet double-layer coating system according to an embodiment of the present application;

[0026] Figure 4 is a flow chart of coating a negative electrode sheet by a battery electrode sheet double-layer coating system according to an embodiment of the present application.

[0027] Reference signs:

[0028] 1, back roller;

[0029] 2, coating nozzle;

[0030] 3, first supply module; 31, first transfer tank; 32, first diaphragm pump; 33, first iron remover; 34, first dynamic filter; 35, first buffer tank; 36, first delivery pump; 37, first capsule filter; 38, first motion platform;

[0031] 4, second supply module; 41, second transfer tank; 42, second diaphragm pump; 43, second iron remover; 44, second dynamic filter; 45, second buffer tank; 46, second delivery pump; 47, second capsule filter; 48, second motion platform;

[0032] 5, third supply module; 51, third buffer tank; 52, third delivery pump; 53, third capsule filter; 54, third motion platform. DETAILED DESCRIPTION

[0033] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the present application will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0034] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0035] In addition, the features defined as "first", "second" can explicitly or implicitly include one or more of the features, for distinguishing the description of the features, without order, without light and heavy. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] The specific structure of the battery pole piece double-layer coating system according to the embodiments of the present application will be described below with reference to the accompanying drawings. Figures 1-2 The specific structure of the battery pole piece double-layer coating system according to the embodiments of the present application will be described below with reference to the accompanying drawings.

[0038] The present application discloses a kind of battery pole piece double-layer coating system, as Figure 1 As shown in the drawings, the battery pole piece double-layer coating system of the present embodiment includes back roll 1, coating spray head 2, first supply module 3, second supply module 4 and third supply module 5, back roll 1 is used to carry battery current collector, and coating spray head 2 includes isolated first spraying channel, second spraying channel and third spraying channel. First supply module 3 is located upstream of coating spray head 2, and is used to provide spraying slurry to the first spraying channel. Second supply module 4 and first supply module 3 are arranged side by side, and second supply module 4 is used to provide spraying slurry to the second spraying channel. Third supply module 5 is arranged side by side with first supply module 3 and second supply module 4, and is used to provide ceramic slurry to the third spraying channel.

[0039] It can be understood that when spraying negative pole piece, first start second supply module 4, close first supply module 3 and third supply module 5, and second supply module 4 provides spraying raw material into one spraying channel of coating spray head 2 to realize one spraying of negative pole piece, and when one spraying is carried out for a distance and is detected to be qualified, first supply module 3 is started again to provide spraying slurry into one spraying channel of coating spray head 2 to realize double-layer simultaneous spraying of negative pole piece.

[0040] And when spraying positive pole piece, first start second supply module 4 and third supply module 5, close first supply module 3, and second supply module 4 and third supply module 5 provide spraying slurry into second and third spraying channels of coating spray head 2 respectively to realize one spraying of positive pole piece and ceramic edge spraying, and when one spraying is carried out for a distance and is detected to be qualified, first supply module 3 is started again to provide spraying slurry into first spraying channel of coating spray head 2 to realize double-layer simultaneous spraying of positive pole piece.

[0041] In summary, the battery pole piece double-layer coating system of the embodiment can realize synchronous and efficient continuous spraying of double-layer coating in the production process, has high coating consistency and stability, is easy to control in the production process, and has low manufacturing cost. In the process of processing the positive pole piece, the ceramic edge is formed at the same time when the double-layer coating is formed, so that the positive pole piece does not need to be additionally processed in actual work, and the production and manufacturing process of the positive pole piece is simplified.

[0042] In some embodiments, as shown in Figure 1 The first supply module 3 includes a first transfer tank 31, a first diaphragm pump 32, a first buffer tank 35, a first delivery pump 36 and a first capsule filter 37 connected in sequence. The first buffer tank 35 and the first delivery pump 36 are located on a first moving platform 38, and the first transfer tank 31 is in parallel. It can be understood that the first transfer tank 31 is used to store the spraying raw material, and the first transfer tank 31 is in parallel, so that when the spraying raw material in one first transfer tank 31 is about to run out, another first transfer tank 31 can be directly switched to output the spraying raw material, realizing non-stop output of the first supply module 3 and ensuring uniformity of the supply. The first capsule filter 37 can improve the cleanliness and uniformity of the spraying raw material, thereby indirectly improving the coating quality.

[0043] It should be noted that if the first diaphragm pump 32 is directly used to send the spraying raw material into the coating nozzle 2, due to the poor accuracy and long transportation route of the first diaphragm pump 32, the supply consistency is poor, the spraying raw material speed is slow, and the supply is uneven. In the embodiment, the first buffer tank 35 is added to temporarily store the spraying slurry, and the first buffer tank 35 stably supplies the first delivery pump 36 through liquid level control. The first delivery pump 36 delivers the slurry in the first buffer tank 35 to the coating nozzle 2, which not only improves the supply speed of the spraying raw material, but also significantly improves the uniformity of the spraying raw material, thereby ensuring the pole piece coating quality. In addition, the first buffer tank 35 and the first delivery pump 36 are located on the first moving platform 38, which can conveniently move the first buffer tank 35 and the first delivery pump 36, thereby facilitating the splicing and adjustment of the entire system.

[0044] In some more specific embodiments, as shown in Figure 1 A first de-ironer 33 and a first dynamic filter 34 are arranged between the first buffer tank 35 and the first diaphragm pump 32. Thus, the first de-ironer 33 and the first dynamic filter 34 can further filter and remove ferromagnetic substances and agglomerated particles in the spraying slurry, ensuring the cleanliness and uniformity of the spraying slurry delivered to the coating nozzle 2, thereby improving the pole piece coating quality. Of course, it should be additionally noted that in other embodiments of the present application, other types of filtering devices can be added between the first buffer tank 35 and the first diaphragm pump 32 according to actual needs, and are not limited to the above description.

[0045] In some embodiments, as shown in Figure 1 Fig. 2, the second supply module 4 comprises a second transfer tank 41, a second diaphragm pump 42, a second buffer tank 45, a second delivery pump 46 and a second capsule filter 47 connected in sequence, wherein: the second buffer tank 45 and the second delivery pump 46 are located on a second moving platform 48; and the second transfer tank 41 is in parallel. It can be understood that the second transfer tank 41 is used to store the spraying raw material, and the second transfer tank 41 is in parallel, so that when the spraying raw material in one second transfer tank 41 is about to run out, another second transfer tank 41 can be directly switched to output the spraying raw material, realizing non-stop output of the second supply module 4 and ensuring the uniformity of the supply. The second capsule filter 47 can improve the cleanliness and uniformity of the spraying raw material, thereby indirectly improving the coating quality.

[0046] It should be noted that if the second diaphragm pump 42 is directly used to send the spraying raw material into the coating nozzle 2, due to the poor precision and long transportation route of the second diaphragm pump 42, the supply consistency is poor, the spraying raw material speed is slow, and the supply is uneven. In the present embodiment, the second buffer tank 45 is additionally provided to temporarily store the spraying slurry, and the second buffer tank 45 is used to stably supply the second delivery pump 46 through liquid level control. The use of the second delivery pump 46 to deliver the slurry in the second buffer tank 45 to the coating nozzle 2 not only improves the supply speed of the spraying raw material, but also significantly improves the uniformity of the spraying raw material, thereby ensuring the quality of the pole piece coating. In addition, the first buffer tank 35 and the second delivery pump 46 are located on the second moving platform 48, which can facilitate the movement of the second buffer tank 45 and the second delivery pump 46, thereby facilitating the connection and adjustment of the entire system.

[0047] In some more specific embodiments, as shown in Figure 1 Fig. 3, a second iron remover 43 and a second dynamic filter 44 are provided between the second buffer tank 45 and the second diaphragm pump 42. Thus, the second iron remover 43 and the second dynamic filter 44 are additionally provided to further filter and remove ferromagnetic substances and agglomerated particles in the spraying slurry, ensuring the cleanliness and uniformity of the spraying slurry delivered to the coating nozzle 2, thereby improving the quality of the pole piece coating. Of course, it should be additionally noted that in other embodiments of the present application, other types of filtering devices can be added between the second buffer tank 45 and the second diaphragm pump 42 according to actual needs, and are not limited to the above description.

[0048] In some embodiments, as shown in Figure 1As shown, the third supply module 5 includes a third buffer tank 51, a third delivery pump 52 and a third capsule filter 53 connected in sequence, and the third buffer tank 51 and the third delivery pump 52 are located on the third moving platform 54. It can be understood that the added third buffer tank 51 can temporarily store the spraying slurry, the liquid level control of the third buffer tank 51 can stably supply the third delivery pump 52, and the use of the third delivery pump 52 to deliver the slurry in the third buffer tank 51 to the coating nozzle 2 can not only improve the supply speed of the spraying raw material, but also significantly improve the uniformity of the spraying raw material, thereby ensuring the quality of the pole piece coating. In addition, locating the third buffer tank 51 and the third delivery pump 52 on the third moving platform 54 can facilitate moving the third buffer tank 51 and the third delivery pump 52, thereby facilitating the splicing and adjustment of the entire system.

[0049] In some embodiments, as Figure 2 As shown, the battery pole piece double-layer coating system further includes a wet film detection module, a drying module, a dry film detection module and a control module. The wet film detection module is located downstream of the back roller 1 and is used to detect the quality of the wet film coating. The drying module is located downstream of the wet film detection module and is used to dry the coating. The dry film detection module is located downstream of the drying module and is used to detect the quality of the dried coating. The control module is electrically connected with the wet film detection module, the drying module, the dry film detection module, the first supply module 3, the second supply module 4, the third supply module 5 and the coating nozzle 2. It can be understood that during the actual coating process, the wet film detection module and the dry film detection module can detect the coating quality before and after drying, and the control module can adjust and control the first supply module 3, the second supply module 4, the third supply module 5 and the coating nozzle 2 according to the detection results of the wet film detection module and the dry film detection module, adjust the feeding speed of the above-mentioned three sets of supply systems, the lip gap of the coating nozzle 2 and the gap between the coating nozzle 2 and the coating back roller 1, realize closed-loop control during the coating process, and improve the consistency and stability of the coating quality.

[0050] It should be noted that the drying module can be selected according to the existing technology, the type of sensor of the wet film detection module and the dry film detection module can be selected according to the actual parameters for measuring the spraying quality, and the wet film detection module and the dry film detection module can be any one or more of a beta-ray area density detector, an X-ray area density detector and a laser thickness gauge.

[0051] It should be noted that in other embodiments of the present application, the control module can also be electrically connected with the drying module to control the drying parameters of the drying module.

[0052] Furthermore, the control module can be a microcontroller, either a single microcontroller or a system composed of multiple microcontrollers, or it can be a PLC control chip. In other words, the control module can select the actual required chip type and control logic based on the existing electrical control technology, without limiting the specific type of control module.

[0053] The following is for reference. Figures 1-2 This invention describes a specific embodiment of a battery electrode double-layer coating system.

[0054] like Figure 1 As shown, the battery electrode double-layer coating system of this embodiment includes a back roller 1, a coating nozzle 2, a first feeding module 3, a second feeding module 4, a third feeding module 5, a wet film detection module, a drying module, a dry film detection module, and a control module. The back roller 1 is used to carry the battery current collector. The coating nozzle 2 includes a first spraying channel, a second spraying channel, and a third spraying channel that are isolated from each other. The first spraying channel is located above the second spraying channel. The first feeding module 3 is located on one side of the coating nozzle 2 and is used to supply the coating slurry to the first spraying channel. The first feeding module 3 includes a first transfer tank 31, a first diaphragm pump 32, a first iron remover 33, a first dynamic filter 34, a first buffer tank 35, a first delivery pump 36, and a first capsule filter 37 connected in sequence. The first buffer tank 35 and the first delivery pump 36 are located on a first motion platform 38. There are two first transfer tanks 31 arranged in parallel. The second feeding module 4 is arranged in parallel with the first feeding module 3 and is used to supply the coating slurry to the second spraying channel. The second feeding module 4 includes a second transfer tank 41, a second diaphragm pump 42, a second iron remover 43, a second dynamic filter 44, a second buffer tank 45, a second delivery pump 46, and a second capsule filter 47, all connected in sequence. The second buffer tank 45 and the second delivery pump 46 are located on the second motion platform 48. Two second transfer tanks 41 are connected in parallel. The third feeding module is arranged in parallel with the second feeding module 4 and the first feeding module 3, and is used to supply ceramic raw materials to the third spraying channel. The third feeding module 5 includes a third buffer tank 51, a third delivery pump 52, and a third capsule filter 53, all connected in sequence. The third buffer tank 51 and the third delivery pump 52 are located on the third motion platform 54. The wet film detection module is located downstream of the back roller 1 and is used to detect the quality of the wet film coating. The drying module is located downstream of the wet film detection module and is used to dry the coating. The dry film detection module is located downstream of the drying module and is used to detect the quality of the dried coating. The control module is electrically connected to the wet film detection module, the drying module, the dry film detection module, the first feeding module 3, the second feeding module 4, the third feeding module 5, and the coating nozzle 2.

[0055] The beneficial effects of the battery electrode double-layer coating system in this embodiment are as follows:

[0056] Firstly, the double-layer coating can be synchronously and efficiently sprayed in the production process, the coating consistency is high and stable, the production process is easy to control, the manufacturing cost is low, and the ceramic edge is formed when the double-layer coating is formed in the process of processing the positive plate, so that the positive plate does not need to be additionally processed in actual work, and the production and manufacturing process of the positive plate is simplified.

[0057] Secondly, the first transfer tank 31 and the second transfer tank 41 are two, which realizes non-stop feeding of the first feeding module 3 and the second feeding module 4, indirectly improves the spraying efficiency and uniformity.

[0058] Thirdly, the first de-ironer 33, the first dynamic filter 34, the second de-ironer 43 and the second dynamic filter 44 can improve the cleanliness and uniformity of the coating raw material output by the first feeding module 3 and the second feeding module 4, and ensure the quality of the coating.

[0059] Fourthly, the first moving platform 38, the second moving platform 48 and the third moving platform 54 are added, which facilitates the movement of the first buffer tank 35, the second buffer tank 45 and the third buffer tank 51, and facilitates the lapping and adjustment of the whole system.

[0060] Fifthly, the control module can adjust and control the first feeding module 3, the second feeding module 4, the third feeding module 5 and the coating nozzle 2 according to the detection results of the wet film detection module and the dry film detection module, adjust the feeding speed of the above three feeding systems, the lip gap of the coating nozzle 2 and the gap between the coating nozzle 2 and the coating back roller 1, realize closed-loop control in the coating process, and improve the consistency and stability of the coating quality.

[0061] The specific process of the battery pole piece double-layer coating method of the embodiment of the application will be described below with reference to Figure 3 and Figure 4 The specific process of the battery pole piece double-layer coating method of the embodiment of the application will be described below with reference to

[0062] The application also discloses a battery pole piece double-layer coating method, which is carried out by using the battery pole piece double-layer coating system.

[0063] In the process of processing the negative pole piece, as shown in Figure 3 , the specific process is as follows:

[0064] The second feeding module 4 is started, while the first feeding module 4 and the third feeding module 5 are turned off to coat the coating and form a primary coating layer. The primary wet film parameters and primary dry film parameters of the primary coating layer are detected. Based on the primary wet film parameters and primary dry film parameters, the feeding speed of the second feeding module 4 (in actual adjustment, the second conveying pump 46) is adjusted, as are the lip gap of the second spraying channel of the coating nozzle 2 and the gap between the coating nozzle 2 and the back roller 1. After the primary coating has been completed for a certain distance and the test is qualified, the first feeding module 3 is started again to coat the coating layer simultaneously to form a double coating layer. The double dry film parameters and double dry film parameters of the double coating layer are detected. Based on the double dry film parameters and double dry film parameters, the feeding speed of the first feeding module 3 (in actual adjustment, the first conveying pump 36) is adjusted, as are the lip gap of the first spraying channel of the coating nozzle 2 and the gap between the coating nozzle 2 and the back roller 1.

[0065] In other words, when spraying the negative electrode sheet, the second feeding module 4 is started first, and the first feeding module 3 and the third feeding module 5 are turned off. The second feeding module 4 provides the spraying material into one spraying channel of the coating nozzle 2 to achieve one spraying of the negative electrode sheet. After the first spraying has gone a certain distance and passed the test, the first feeding module 3 is started again to provide the spraying slurry into one spraying channel of the coating nozzle 2 to achieve two-layer simultaneous spraying of the negative electrode sheet.

[0066] In the process of processing positive electrode sheets, such as Figure 4 As shown, specifically:

[0067] The second feeding module 4 and the third feeding module 5 are started, and the first feeding module 3 is turned off to perform coating and ceramic edge coating to form a primary coating and ceramic edge. The primary wet film parameters and primary dry film parameters of the primary coating and ceramic edge are detected. Based on the primary wet film parameters and primary dry film parameters, the feeding speed of the second feeding module 4 (in actual adjustment, the second conveying pump 46) is adjusted, as are the lip gap of the second spraying channel of the coating nozzle 2 and the gap between the second feeding module 3 and the back roller 1. After the primary spraying has been completed for a certain distance and the test is qualified, the first feeding module 3 is started again to perform coating to form a double-layer coating. The double-layer dry film parameters and double-layer dry film parameters of the double coating are detected. Based on the double-layer dry film parameters and double-layer dry film parameters, the feeding speed of the first feeding module 3 (in actual adjustment, the first conveying pump 36) is adjusted, as are the lip gap of the first spraying channel of the coating nozzle 2 and the gap between the coating nozzle 2 and the back roller 1.

[0068] That is to say, when spraying the positive electrode sheet, the second feeding module 4 and the third feeding module 5 are first started, the first feeding module 3 is closed, the second feeding module 4 and the third feeding module 5 respectively provide the spraying slurry into the second and third spraying channels of the coating spray head 2 to realize the first spraying of the positive electrode sheet and the spraying of the ceramic edge, and when the first spraying is detected to be qualified for a distance, the first feeding module 3 is started to provide the spraying slurry into the first spraying channel of the coating spray head 2 to realize the double-layer simultaneous spraying of the positive electrode sheet.

[0069] It should be noted that, in the process of processing the positive electrode sheet or the negative electrode sheet, the feedback data of the longitudinal and transverse surface densities of the first coating and the double-layer coating can be obtained through the first wet film parameter, the first dry film parameter, the double-layer dry film parameter, and the double-layer dry film parameter, so that the feeding speed of the first feeding module 3, the lip gap of the first spraying channel of the coating spray head 2, the gap between the first feeding module 3 and the back roller 1, the feeding speed of the second feeding module 4, the lip gap of the second spraying channel of the coating spray head 2, and the gap between the second feeding module 4 and the back roller 1 can be automatically adjusted online according to the feedback data to realize the closed-loop control of the longitudinal and transverse surface densities of the coating.

[0070] In some embodiments, the coating quality ratio of the first coating and the double-layer coating is 1:9-9:1. In the actual spraying process, the coating quality of the first coating and the double-layer coating can be selected according to actual needs, and is not limited by the embodiments.

[0071] In the description of the present specification, the description of the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials or characteristics described in combination with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0072] The above is only the preferred embodiment of the present application, and for those skilled in the art, the specific implementation and application range can be changed according to the idea of the present application, and the content of the specification should not be understood as a limitation of the present application.

Claims

1. A double-layer coating system for battery electrodes, characterized in that, include: Back roller (1), the back roller (1) is used to carry the battery current collector; The coating nozzle (2) includes a first coating channel, a second coating channel and a third coating channel that are isolated from each other; The first feeding module (3) is located on one side of the coating nozzle (2) and is used to supply the coating slurry to the first spraying channel; The second feeding module (4) and the first feeding module (3) are arranged side by side. The second feeding module (4) is used to supply the spraying slurry to the second spraying channel. The third feeding module (5) is arranged in parallel with the first feeding module (3) and the second feeding module (4), and is used to supply ceramic slurry to the third spraying channel; When spraying the positive electrode sheet, the second feeding module (4) and the third feeding module (5) are started, and the first feeding module (3) is turned off. The second feeding module (4) and the third feeding module (5) respectively provide spraying slurry and ceramic slurry to the second spraying channel and the third spraying channel of the coating nozzle (2) to achieve one-time spraying of the positive electrode sheet and spraying of the ceramic edge. After the first spraying has been carried out for a certain distance and the test is qualified, the first feeding module (3) is started again to provide spraying slurry to the first spraying channel of the coating nozzle (2) to achieve simultaneous double-layer spraying of the positive electrode sheet. The ceramic edge is formed while the double-layer coating is being formed.

2. The battery electrode double-layer coating system according to claim 1, characterized in that, The first feeding module (3) includes a first transfer tank (31), a first diaphragm pump (32), a first buffer tank (35), a first delivery pump (36), and a first capsule filter (37) connected in sequence, wherein: The first buffer tank (35) and the first delivery pump (36) are located on the first motion platform (38); The first transfer tank (31) consists of multiple units connected in parallel.

3. The battery electrode double-layer coating system according to claim 2, characterized in that, A first iron remover (33) and a first dynamic filter (34) are provided between the first buffer tank (35) and the first diaphragm pump (32).

4. The battery electrode double-layer coating system according to claim 1, characterized in that, The second feeding module (4) includes a second transfer tank (41), a second diaphragm pump (42), a second buffer tank (45), a second delivery pump (46), and a second capsule filter (47) connected in sequence, wherein: The second buffer tank (45) and the second delivery pump (46) are located on the second motion platform (48); The second transfer tank (41) consists of multiple units connected in parallel.

5. The battery electrode double-layer coating system according to claim 4, characterized in that, A second iron remover (43) and a second dynamic filter (44) are provided between the second buffer tank (45) and the second diaphragm pump (42).

6. The battery electrode double-layer coating system according to claim 1, characterized in that, The third feeding module (5) includes a third buffer tank (51), a third delivery pump (52) and a third capsule filter (53) connected in sequence. The third buffer tank (51) and the third delivery pump (52) are located on the third motion platform (54).

7. The battery electrode double-layer coating system according to claim 1, characterized in that, The battery electrode double-layer coating system also includes: A wet film detection module is located downstream of the back roller (1) and is used to detect the quality of the wet film coating. A drying module is located downstream of the wet film detection module, and the drying module is used to dry the coating. A dry film detection module is located downstream of the drying module and is used to detect the quality of the coating after drying. The control module is electrically connected to the wet film detection module, the dry film detection module, the first feeding module (3), the second feeding module (4), the third feeding module (5), and the coating nozzle (2).

8. A method for double-layer coating of battery electrodes, characterized in that, The battery electrode double-layer coating method is performed using the battery electrode double-layer coating system as described in any one of claims 1-7, and the battery electrode double-layer coating method includes: When spraying the negative electrode sheet, the second feeding module (4) is started, and the first feeding module (3) and the third feeding module (5) are turned off to form a primary coating. After a certain distance has been covered by a single spraying and the inspection is passed, the first material supply module (3) and the second material supply module (4) are started to apply the coating to form a double-layer coating. When spraying the positive electrode sheet, the second feeding module (4) and the third feeding module (5) are started, and the first feeding module (3) is turned off to carry out coating and ceramic edge coating to form a primary coating and ceramic edge; After a certain distance has been covered by a single spraying and the test is passed, the first material supply module (3) and the second material supply module (4) are activated to apply the coating to form a double-layer coating.

9. The method for double-layer coating of battery electrodes according to claim 8, characterized in that, Also includes: The wet film parameters and dry film parameters of the first coating are detected, and the feeding speed of the second feeding module (4), the lip gap of the second spraying channel of the coating nozzle (2), and the gap between the coating nozzle (2) and the back roller (1) are adjusted according to the wet film parameters and the dry film parameters. The double-layer dry film parameters and double-layer dry film parameters of the double-layer coating are detected, and the feeding speed of the first feeding module (3), the lip gap of the first spraying channel of the coating nozzle (2), and the gap between the coating nozzle (2) and the back roller (1) are adjusted according to the double-layer dry film parameters and double-layer dry film parameters.

10. The method for double-layer coating of battery electrodes according to claim 9, characterized in that, The coating mass ratio of the primary coating to the double coating is 1:9 to 9:1.

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