Line for forming a microporous layer on a substrate layer

Abstract

The application provides a production line for forming a microporous layer on a substrate layer, which comprises a spray drying sub-production line, a hot pressing sub-production line and a sintering sub-production line. The spray drying sub-production line comprises a plurality of spray units and a plurality of drying units, each spray unit and each drying unit are arranged alternately from upstream to downstream. The spray units spray slurry on the substrate layer or the slurry layer which has been dried. The drying units dry the slurry layer. In this way, the slurry is sprayed and dried layer by layer, so that the thickness of the slurry layer formed by each spraying is very small, and thus, the slurry layer is not easy to crack during drying. After drying, the hot pressing sub-production line hot-presses the slurry layer and the substrate layer, so as to improve the flatness of the slurry layer and the bonding strength between the slurry layer and the substrate layer, and avoid separation of the microporous layer and the substrate layer formed finally. After hot pressing, the sintering sub-production line sinters the slurry layer and the substrate layer, so as to improve the hydrophobicity.

Description

Technical Field

[0001] This application relates to the field of gas diffusion layer production technology, and in particular to a production line for forming a microporous layer on a substrate. Background Technology

[0002] The core component of a proton exchange membrane fuel cell system is the membrane electrode assembly (MEA). As a key component of the MEA, the gas diffusion layer provides a conduction path for electrons between the bipolar plates and the catalyst layer and collects current; therefore, the gas diffusion layer must have low resistivity. The gas diffusion layer typically consists of a substrate layer and a microporous layer.

[0003] The substrate layer is composed of porous conductive materials. Currently, high-porosity porous carbon fiber materials (such as carbon paper and carbon cloth) are commonly used as substrate layers in the market. The main functions of the substrate layer are: to support the catalyst layer and prevent the catalyst from falling off; and to provide transport channels for gases and water, so that the reaction gases can reach the reaction area uniformly and stably.

[0004] The microporous layer is composed of carbon-based powder and hydrophobic agent. The main functions of the microporous layer are: to prevent the catalyst layer material from entering the substrate layer and improve the catalyst utilization rate; to reduce the contact resistance between the substrate layer and the catalyst layer; to provide a better pore structure and hydrophobicity, to help water drain out, to prevent the electrode from being flooded, and to ensure gas transport.

[0005] Currently, the process for forming a microporous layer on a substrate involves coating a slurry of carbon-based powder and a hydrophobic agent (such as PTFE) onto the substrate using a coating machine, followed by drying and sintering. However, coating machines require skilled operators, have high skill levels, and are expensive to build and maintain, making them unsuitable for pilot production. Cracking is common during drying after coating, especially severe under high-temperature, rapid drying conditions. Low-temperature, slow drying can alleviate the cracking problem to some extent, but it reduces production efficiency. Furthermore, the microporous layer formed after sintering does not bond well to the substrate. Increasing the proportion of hydrophobic agent in the slurry can alleviate this bonding problem, but it leads to increased resistivity, affecting the performance of the gas diffusion layer.

[0006] Therefore, how to avoid some or all of the above-mentioned drawbacks without affecting production efficiency and the performance of the gas diffusion layer is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0007] To address the aforementioned technical problems, this application provides a production line for forming a microporous layer on a substrate layer. The production line includes a spraying and drying sub-production line, which includes multiple spraying and drying devices arranged sequentially from upstream to downstream. Each spraying and drying device includes a spraying unit and a drying unit located downstream of the spraying unit. The spraying unit is used to spray slurry onto the substrate layer or a dried slurry layer to form a slurry layer, and the drying unit is used to dry the slurry layer.

[0008] An alternative embodiment of a production line for forming a microporous layer on a substrate layer includes a spraying unit comprising a slurry collection tank, a cover, a spray gun, and a support mesh plate. The cover is connected above the slurry collection tank, and the cover and the slurry collection tank enclose a spraying chamber. Gap is formed on the upstream and downstream sides of the spraying chamber, and the gap is formed between the lower end of the side wall of the cover and the upper end of the side wall of the slurry collection tank. A spray gun channel is provided at the upper end of the cover, and the spray gun extends through the spray gun channel into the interior of the spraying chamber. The support mesh plate is located in the spraying chamber, and the upper surface of the support mesh plate is used to support the substrate layer. The drying unit includes a circulating conveyor belt, and the upper surface of the support mesh plate is flush with the upper surface of the circulating conveyor belt.

[0009] In one alternative embodiment of a production line for forming a microporous layer on a substrate, the spraying unit includes a spray gun drive unit that is tractively connected to the spray gun and is capable of driving the spray gun to move up and down and to reciprocate in a direction perpendicular to the running direction of the substrate.

[0010] In one alternative embodiment of a production line for forming a microporous layer on a substrate, the nozzle of the spray gun is an ultrasonic nozzle, and the internal channel of the spray gun is connected to the ultrasonic nozzle, a high-pressure air pipe, and a feed pipe.

[0011] An alternative embodiment of a production line for forming a microporous layer on a substrate layer includes a hot pressing sub-line and a sintering sub-line. The hot pressing sub-line includes a hot pressing device for hot pressing the substrate layer and the slurry layer. The sintering sub-line includes a sintering device for sintering the hot-pressed substrate layer and the slurry layer.

[0012] An alternative embodiment of the production line for forming a microporous layer on a substrate layer, wherein the spraying and drying sub-production line, the hot pressing sub-production line, and the sintering sub-production line are independent of each other, and all three include an unwinding shaft and a rewinding shaft.

[0013] In one optional embodiment of a production line for forming a microporous layer on a substrate, the spraying and drying sub-production line, the hot pressing sub-production line, and the sintering sub-production line all include a deviation adjustment device. In the spraying and drying sub-production line, deviation adjustment devices are provided between the unwinding shaft and the upstream drying unit, and between the downstream drying unit and the rewinding shaft. In the hot pressing sub-production line, deviation adjustment devices are provided between the unwinding shaft and the hot pressing equipment, and between the hot pressing equipment and the rewinding shaft. In the sintering sub-production line, deviation adjustment devices are provided between the unwinding shaft and the sintering equipment, and between the sintering equipment and the rewinding shaft.

[0014] In one optional embodiment of a production line for forming a microporous layer on a substrate, the spraying and drying sub-production line, the hot pressing sub-production line, and the sintering sub-production line all include tension detection devices. In the spraying and drying sub-production line, a tension detection device is provided between the downstream drying unit and the winding shaft. In the hot pressing sub-production line, a tension detection device is provided between the hot pressing equipment and the winding shaft. In the sintering sub-production line, a tension detection device is provided between the sintering equipment and the winding shaft. The tension detection device in each sub-production line is communicatively connected to the drive motor of the winding shaft in the same sub-production line, enabling the drive motor of the winding shaft to automatically adjust its speed based on the detection data from the tension detection device.

[0015] An optional embodiment of a production line for forming a microporous layer on a substrate layer includes a hot pressing device comprising two circulating hot pressing belts arranged vertically. The lower surface of the top circulating hot pressing belt and the upper surface of the bottom circulating hot pressing belt cooperate to hot press the substrate layer and the slurry layer. Each circulating hot pressing belt has three temperature zones that can be individually controlled from upstream to downstream within its enclosed space: a first heating zone, a heat preservation zone, and a first cooling zone.

[0016] An optional embodiment of a production line for forming a microporous layer on a substrate layer includes a sintering device comprising a housing, wherein the housing has three temperature zones that can be individually controlled from upstream to downstream, namely a second heating zone, a sintering zone, and a second cooling zone, wherein the upper end of the housing is provided with an exhaust port and the lower end of the housing is provided with an air inlet.

[0017] The aforementioned production line forms a microporous layer through a layer-by-layer spraying and drying process. It can use a spray gun instead of a coating machine in traditional processes, and the configuration and operating costs of the spray gun are far lower than those of a coating machine, while also requiring less skilled operators. Furthermore, the layer-by-layer spraying and drying method results in a very thin slurry layer for each spray, thus reducing the likelihood of cracking during drying, even with high-temperature rapid drying. Moreover, the production line solves the problem of easy separation between the final microporous layer and the base layer by hot-pressing the slurry layer and the base layer. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an embodiment of a spray drying sub-production line for forming a microporous layer on a substrate layer provided in this application;

[0019] Figure 2 This is a schematic diagram of an embodiment of a hot press production line for forming a microporous layer on a substrate layer provided in this application;

[0020] Figure 3 This is a schematic diagram of an embodiment of a sintering sub-production line for forming a microporous layer on a substrate layer, as provided in this application.

[0021] The annotations in the attached figures are explained as follows:

[0022] 10 Spray coating and drying sub-production lines;

[0023] 11 Spraying and drying equipment, 111 Spraying unit, 111a Slurry collection tank, 111b Cover, 111c Spray gun, 111d Support mesh plate, 111e Drain hole, 111f Spray gun channel, 111g Gap, 111h Conveyor roller, 112 Drying unit, 112a Outer shell, 112b Hot air circulation device, 112c Circulating conveyor belt, 112d Conveyor belt roller, 112e Exhaust device;

[0024] 20 hot press production lines;

[0025] 21 Hot pressing equipment, 21a Circulating hot pressing belt, 21b Hot pressing belt roller, 21c First heating zone, 21d Insulation zone, 21e First cooling zone, 21f Chain blanket;

[0026] 30 sintering production lines;

[0027] 31 Sintering equipment, 31a Shell, 31b Second heating zone, 31c Sintering zone, 31d Second cooling zone, 31e Side port, 31f Nitrogen inlet, 31g Exhaust port, 31h Circulating conveyor belt, 31k Conveyor belt roller;

[0028] A. Unwinding shaft; B. Rewinding shaft; C. Alignment device; D. Tension detection device;

[0029] 01. Basal layer. Detailed Implementation

[0030] This application provides a production line for forming a microporous layer on a substrate. In order to enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1As shown, this application provides a production line for forming a microporous layer on a substrate, including a spraying and drying sub-production line 10. The spraying and drying sub-production line 10 includes multiple spraying and drying devices 11, where "multiple" refers to two or more; three spraying and drying devices 11 are shown in the figure. The spraying and drying devices 11 are arranged sequentially from upstream to downstream.

[0032] Each spray-drying apparatus 11 includes a spraying unit 111 and a drying unit 112, with the drying unit 112 located downstream of the spraying unit 111. The spraying unit 111 is used to spray slurry onto the substrate layer 01 or a dried slurry layer to form a slurry layer. The slurry contains carbon-based powder and a hydrophobic agent. The drying unit 112 is used to dry the slurry layer.

[0033] Taking the illustrated embodiment as an example, during the production process, the base layer 01 moves from upstream to downstream, passing through each spraying and drying device 11 in sequence. During this process, the spraying unit 111 of the upstream spraying and drying device 11 first sprays a first layer of slurry onto the base layer 01, and then the drying unit 112 of the same spraying and drying device 11 dries the first layer of slurry. After drying, the spraying unit 111 of the middle spraying and drying device 11 sprays a second layer of slurry onto the first layer of slurry, and then the drying unit 112 of the same spraying and drying device 11 dries the second layer of slurry. Then, the spraying unit 111 of the downstream spraying and drying device 11 sprays a third layer of slurry onto the second layer of slurry, and then the drying unit 112 of the same spraying and drying device 11 dries the third layer of slurry.

[0034] As can be seen, the above production line forms a microporous layer through a layer-by-layer spraying and drying process. Compared to forming a microporous layer by first applying the slurry with a coating machine and then drying it, a spray gun can replace the coating machine. The configuration and operating costs of a spray gun are far lower than those of a coating machine, and the requirements for operators are lower. In addition, by using a layer-by-layer spraying and drying method, the thickness of each slurry layer is very small, so cracks are less likely to occur during drying, even when using a high-temperature fast drying mode.

[0035] Specifically, such as Figure 1As shown, the spraying unit 111 includes a slurry collection tank 111a, a support mesh plate 111d, a spray gun 111c, and a cover 111b. The cover 111b is attached above the slurry collection tank 111a, and the cover 111b and the slurry collection tank 111a enclose a spraying chamber. The width of the cover 111b and the width of the slurry collection tank 111a are slightly larger than the width of the substrate layer 01. In the figure, the cross-section of the cover 111b is approximately conical, and the cross-section of the slurry collection tank 111a is approximately U-shaped. A spray gun channel 111f is provided at the top of the cover 111b, and the spray gun 111c extends through the spray gun channel 111f into the interior of the spraying chamber. The support mesh plate 111d is located inside the spraying chamber, and the upper surface of the support mesh plate 111d is used to support the substrate layer 01. A gap 111g is formed on the upstream and downstream sides of the spraying chamber. This gap 111g is formed between the lower end of the side wall of the cover 111b and the upper end of the side wall of the slurry collection tank 111a, allowing the substrate layer 01 to enter the spraying chamber through the upstream gap 111g, then be supported on the upper surface of the support mesh plate 111d and sprayed with slurry, before exiting the spraying chamber through the downstream gap 111g. The cover 111b acts as a shield to prevent slurry splashing. The slurry collection tank 111a collects dripping slurry, and a drain hole 111e can be provided at the bottom of the slurry collection tank 111a to facilitate slurry recovery. In the illustrated embodiment, a conveyor roller 111h is provided upstream and downstream of the slurry collection tank 111a of the spraying unit 111 to ensure the substrate layer 01 smoothly enters and exits the spraying chamber.

[0036] Specifically, such as Figure 1 As shown, the drying unit 112 includes a circulating conveyor belt 112c. After leaving the spraying chamber, the substrate layer 01 further travels onto the circulating conveyor belt 112c and is supported by the upper surface of the circulating conveyor belt 112c. Before that, it is supported by the upper surface of the support mesh plate 111d. To ensure the straight operation of the substrate layer 01, the upper surface of the support mesh plate 111d and the upper surface of the circulating conveyor belt 112c are flush. Moreover, the upper surfaces of the circulating conveyor belts 112c in each drying unit 112 are flush. The circulating conveyor belt 112c can be made of Teflon material, which is relatively heat-resistant. More specifically, the drying unit 112 also includes a conveyor belt roller 112d, with the upstream and downstream ends of the circulating conveyor belt 112c each wound around a conveyor belt roller 112d. The drying unit 112 also includes a housing 112a, inside which a hot air circulation device 112b is provided. The hot air circulation device 112b is located above the upper surface of the circulating conveyor belt 112c. The temperature of the hot air circulation device 112b can be set to be adjustable from 0 to 200°C. An exhaust device 112e is provided at the top of the housing 112a, through which the circulating exhaust gas can be discharged.

[0037] Specifically, in some embodiments, the spraying unit 111 may further include a spray gun drive unit, which is connected to the spray gun 111c and can drive the spray gun 111c to move up and down and reciprocate in a direction perpendicular to the running direction of the substrate layer 01 (the direction perpendicular to the paper in the figure). The structure of the spray gun drive unit is not limited; for example, it can be an electric structure, a pneumatic structure, etc., as long as it can achieve the above-mentioned driving function. During the production process, the spray gun 111c can be driven to move up and down according to the concentration of the slurry, process requirements, etc., to change the vertical distance between the nozzle of the spray gun 111c and the substrate layer or slurry layer. It can also be driven to reciprocate in a direction perpendicular to the running direction of the substrate layer 01 according to the width of the substrate layer, process requirements, etc., so as to ensure that all positions in the width direction of the substrate layer 01 can be sprayed. The spray width, spray flow rate, up and down movement speed, and reciprocating movement speed of the spray gun 111c are all adjustable.

[0038] Specifically, in some embodiments, the nozzle of the spray gun 111c is an ultrasonic nozzle, and the internal channel of the spray gun 111c is connected to the ultrasonic nozzle, the high-pressure air pipe, and the feed pipe. Thus, during production, under the power of the peristaltic pump, the slurry enters the internal channel of the spray gun 111c through the feed pipe. In the internal channel, the slurry is initially atomized due to the high-pressure gas. After initial atomization, it is sprayed out through the ultrasonic nozzle. During the spraying process, it is atomized again under the ultrasonic vibration of the ultrasonic nozzle. This double atomization ensures that the slurry is evenly and finely sprayed onto the substrate layer 01 or the already dried slurry layer, making the slurry thickness at each location basically consistent and avoiding localized excessive slurry thickness that could lead to cracking during drying.

[0039] Furthermore, such as Figure 2 and Figure 3 As shown, the production line also includes a hot pressing sub-line 20 and a sintering sub-line 30. The hot pressing sub-line 20 includes a hot pressing device 21, which is used to hot press the substrate layer 01 and the slurry layer. The sintering sub-line 30 includes a sintering device 31, which is used to sinter the hot-pressed substrate layer 01 and the slurry layer. By hot pressing the substrate layer 01 and the slurry layer, the smoothness of the slurry layer and the bonding strength between the slurry layer and the substrate layer 01 can be improved, solving the problem of easy separation between the final microporous layer and the substrate layer 01. Sintering the substrate layer 01 and the slurry layer can improve hydrophobicity.

[0040] Specifically, in the illustrated embodiment, the spraying and drying sub-production line 10, the hot pressing sub-production line 20, and the sintering sub-production line 30 are independent of each other, and each of them includes a take-up shaft B and an unwinding shaft A. Alternatively, any two of the spraying and drying sub-production lines 10, 20, and 30 can be connected in series, with the other one being independent. In the series structure, the unwinding shaft A is located upstream, and the take-up shaft B is located downstream. In the independent structure, the unwinding shaft A is located upstream, and the take-up shaft B is located downstream. Alternatively, the spraying and drying sub-production line 10, 20, and 30 can be connected in series sequentially, with the unwinding shaft A located upstream and the take-up shaft B located downstream.

[0041] The spraying and drying sub-production line 10, the hot pressing sub-production line 20, and the sintering sub-production line 30 are independent of each other, which can shorten the production line length. Moreover, if any one of them fails or is under maintenance, it will not affect the normal operation of the other two, thus making it easier to ensure production efficiency.

[0042] Specifically, in the illustrated embodiment, the spraying and drying sub-production line 10, the hot pressing sub-production line 20, and the sintering sub-production line 30 all include a deflection adjustment device C, which can adjust the base layer 01 in a timely manner to ensure the stable operation of the base layer 01.

[0043] More specifically, in the spraying and drying sub-production line 10, an alignment device C is provided between the unwinding shaft A and the upstream drying unit 112, and between the downstream drying unit 112 and the take-up shaft B. In the hot pressing sub-production line 20, an alignment device C is provided between the unwinding shaft A and the hot pressing equipment 21, and between the hot pressing equipment 21 and the take-up shaft B. In the sintering sub-production line 30, an alignment device C is provided between the unwinding shaft A and the sintering equipment 31, and between the sintering equipment 31 and the take-up shaft B.

[0044] Specifically, in the illustrated embodiment, the spraying and drying sub-production line 10, the hot pressing sub-production line 20, and the sintering sub-production line 30 all include a tension detection device D for detecting the tension of the substrate layer 01.

[0045] More specifically, in the spray coating and drying sub-production line 10, a tension detection device D is installed between the downstream drying unit 112 and the winding shaft B. In the hot pressing sub-production line 20, a tension detection device D is installed between the hot pressing equipment 21 and the winding shaft B. In the sintering sub-production line 30, a tension detection device D is installed between the sintering equipment 31 and the winding shaft B.

[0046] The tension detection device D in each sub-production line is communicatively connected to the drive motor of the take-up shaft B in the same sub-production line, enabling the drive motor of the take-up shaft B to automatically adjust its speed based on the detection data from the tension detection device D. When the tension detected by the tension detection device D exceeds the set range, the drive motor of the take-up shaft B will automatically decelerate to prevent the base layer 01 from breaking due to excessive tension. When the tension detected by the tension detection device D is less than the set range, the drive motor of the take-up shaft B will automatically accelerate to prevent the base layer 01 from loosening, deviating, or becoming unevenly wound.

[0047] Specifically, such as Figure 2 As shown in the illustrated embodiment, the hot pressing equipment 21 is a chain-carpet type double hot pressing belt hot press, including two stacked circulating hot pressing belts 21a. The lower surface of the top circulating hot pressing belt 21a and the upper surface of the bottom circulating hot pressing belt 21a cooperate to hot press the substrate layer 01 and the slurry layer. The upstream and downstream ends of each circulating hot pressing belt 21a are respectively wound around a hot pressing belt roller 21b. The circulating hot pressing belts 21a can be made of stainless steel. The lower surface of the top circulating hot pressing belt 21a and the upper surface of the bottom circulating hot pressing belt 21a can be coated with a non-stick coating (e.g., Teflon coating) to avoid adhesion to the substrate layer 01 and the slurry layer. The circulation speed and working pressure of the circulating hot pressing belts 21a are adjustable, and the adjustable range of the working pressure can be configured to 0-1 MPa. Each circulating hot press belt 21a has three temperature zones arranged sequentially from upstream to downstream within its enclosed space: a first heating zone 21c, a heat preservation zone 21d, and a first cooling zone 21e. The three temperature zones can be individually temperature controlled, and the temperature can be set to be adjustable from 0 to 200℃. Each temperature zone is equipped with a chain blanket 21f, which is used to apply pressure to the circulating hot press belt 21a.

[0048] Specifically, such as Figure 3As shown, the sintering equipment 31 includes a circulating conveyor belt 31h, the upper surface of which supports the base layer 01. The upstream and downstream ends of the circulating conveyor belt 31h are respectively wound around a conveyor roller 31k. The circulating conveyor belt 31h can be made of stainless steel mesh belt, and its operating speed is adjustable. The sintering equipment 31 also includes a shell 31a, inside which are three temperature zones from upstream to downstream: a second heating zone 31b, a sintering zone 31c, and a second cooling zone 31d. The three temperature zones can be individually temperature-controlled, and the temperature can be set to an adjustable range of 0-400℃. The shell 31a has two side openings 31e on its upstream and downstream sides respectively. The base layer enters the shell 31a through the upstream side opening 31e, passes through the second heating zone 31b, the sintering zone 31c, and the second cooling zone 31d in sequence, and exits the shell 31a through the downstream side opening 31e. The top of the housing 31a is provided with an exhaust port 31g, and multiple exhaust ports 31g can be evenly spaced along the running direction of the base layer 01. The bottom of the housing 31a is provided with an air inlet 31f to introduce an anti-oxidation gas (such as nitrogen) to prevent the base layer 01 from oxidizing at high temperature. Multiple air inlets 31f can be evenly spaced along the running direction of the base layer 01.

[0049] For example, the operation process of the above-mentioned spraying and drying sub-production line 10 can be as follows: ① A carbon rope is set along the sub-production line from the take-up shaft B to the unwind shaft A, with one end of the carbon rope connected to the base layer roll at the unwind shaft A; ② Each drying unit 112 is heated to the set temperature in advance, and the slurry is prepared in advance; ③ The sub-production line running speed, spray width of the spray gun 111c, spray flow rate, reciprocating speed and other parameters are set; ④ The sub-production line is started to begin the spraying and drying operation; ⑤ After the operation is completed, the slurry is recovered and the sub-production line is shut down.

[0050] For example, the operation process of the hot pressing sub-production line 20 can be as follows: ① A carbon rope is set along the sub-production line from the take-up shaft B to the unwinding shaft A, with one end of the carbon rope connected to the base layer roll at the unwinding shaft A; ② Each temperature zone of the hot pressing equipment 21 is preheated to the set temperature; ③ The sub-production line running speed, hot pressing pressure and other parameters are set; ④ The sub-production line is started to begin the hot pressing operation; ⑤ The sub-production line is shut down after the operation is completed.

[0051] For example, the operation process of the above-mentioned sintering sub-production line 30 can be as follows: ① A carbon rope is set along the sub-production line from the take-up shaft B to the unwinding shaft A, with one end of the carbon rope connected to the base layer roll at the unwinding shaft A; ② Nitrogen gas is introduced to preheat each temperature zone of the sintering equipment 31 to the set temperature; ③ The sub-production line operating speed is set; ④ The sub-production line is started to begin the sintering operation; ⑤ After the operation is completed, the temperature is cooled down and the sub-production line is shut down.

[0052] The above examples illustrate the principles and implementation methods of this application. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A production line for forming a microporous layer on a substrate, characterized in that, The production line includes a spraying and drying sub-production line (10), which includes multiple spraying and drying devices (11). The multiple spraying and drying devices (11) are arranged sequentially from upstream to downstream. Each spraying and drying device (11) includes a spraying unit (111) and a drying unit (112) located downstream of the spraying unit (111). The spraying unit (111) is used to spray slurry onto the substrate layer (01) or the dried slurry layer to form a slurry layer. The drying unit (112) is used to dry the slurry layer.

2. The production line for forming a microporous layer on a substrate layer according to claim 1, characterized in that, The spraying unit (111) includes a slurry collection tank (111a), a cover (111b), a spray gun (111c), and a support mesh plate (111d). The cover (111b) is connected above the slurry collection tank (111a). The cover (111b) and the slurry collection tank (111a) enclose a spraying chamber. Gap (111g) is formed on the upstream and downstream sides of the spraying chamber. The gap (111g) is formed at the lower end of the side wall of the cover (111b) and the slurry collection tank (111a). Between the upper ends of the side walls of the cover (111b), the upper end of the cover (111b) is provided with a spray gun channel (111f), the spray gun (111c) extends through the spray gun channel (111f) into the interior of the spraying chamber, the support mesh plate (111d) is located in the spraying chamber, the upper surface of the support mesh plate (111d) is used to support the base layer (01), the drying unit (112) includes a circulating conveyor belt (112c), the upper surface of the support mesh plate (111d) is flush with the upper surface of the circulating conveyor belt (112c).

3. The production line for forming a microporous layer on a substrate layer according to claim 2, characterized in that, The spraying unit (111) includes a spray gun drive unit, which is connected to the spray gun (111c) and can drive the spray gun (111c) to move up and down and to reciprocate in a direction perpendicular to the running direction of the substrate layer (01).

4. The production line for forming a microporous layer on a substrate layer according to claim 2, characterized in that, The nozzle of the spray gun (111c) is an ultrasonic nozzle, and the internal channel of the spray gun (111c) is connected to the ultrasonic nozzle, the high-pressure air pipe and the feed pipe.

5. The production line for forming a microporous layer on a substrate layer according to any one of claims 1-4, characterized in that, The production line includes a hot pressing sub-production line (20) and a sintering sub-production line (30). The hot pressing sub-production line (20) includes a hot pressing device (21) for hot pressing the substrate layer (01) and the slurry layer. The sintering sub-production line (30) includes a sintering device (31) for sintering the hot-pressed substrate layer (01) and the slurry layer.

6. The production line for forming a microporous layer on a substrate layer according to claim 5, characterized in that, The spraying and drying sub-production line (10), the hot pressing sub-production line (20), and the sintering sub-production line (30) are independent of each other, and all three include an unwinding shaft (A) and a rewinding shaft (B).

7. The production line for forming a microporous layer on a substrate layer according to claim 6, characterized in that, The spraying and drying sub-production line (10), the hot pressing sub-production line (20), and the sintering sub-production line (30) all include a deflection device (C). In the spraying and drying sub-production line (10), a deflection device (C) is provided between the unwinding shaft (A) and the upstream drying unit (112) and between the downstream drying unit (112) and the winding shaft (B). In the hot pressing sub-production line (20), a deflection device (C) is provided between the unwinding shaft (A) and the hot pressing equipment (21) and between the hot pressing equipment (21) and the winding shaft (B). In the sintering sub-production line (30), a deflection device (C) is provided between the unwinding shaft (A) and the sintering equipment (31) and between the sintering equipment (31) and the winding shaft (B).

8. The production line for forming a microporous layer on a substrate layer according to claim 6, characterized in that, The spraying and drying sub-production line (10), the hot pressing sub-production line (20), and the sintering sub-production line (30) all include a tension detection device (D). In the spraying and drying sub-production line (10), a tension detection device (D) is provided between the downstream drying unit (112) and the winding shaft (B). In the hot pressing sub-production line (20), a tension detection device (D) is provided between the hot pressing equipment (21) and the winding shaft (B). In the sintering sub-production line (30), a tension detection device (D) is provided between the sintering equipment (31) and the winding shaft (B). The tension detection device (D) in each sub-production line is communicatively connected to the drive motor of the winding shaft (B) in the same sub-production line, so that the drive motor of the winding shaft (B) can automatically adjust its speed according to the detection data of the tension detection device (D).

9. The production line for forming a microporous layer on a substrate layer according to claim 5, characterized in that, The hot pressing device (21) includes two circulating hot pressing belts (21a) arranged vertically. The lower surface of the top circulating hot pressing belt (21a) and the upper surface of the bottom circulating hot pressing belt (21a) cooperate to hot press the base layer (01) and the slurry layer. Each circulating hot pressing belt (21a) has three temperature zones that can be individually controlled from upstream to downstream in the enclosed space, namely the first heating zone (21c), the heat preservation zone (21d), and the first cooling zone (21e).

10. The production line for forming a microporous layer on a substrate layer according to claim 5, characterized in that, The sintering equipment (31) includes a shell (31a). The shell (31a) has three temperature zones that can be individually controlled from upstream to downstream, namely a second heating zone (31b), a sintering zone (31c), and a second cooling zone (31d). The upper end of the shell (31a) is provided with an exhaust port (31g), and the lower end of the shell (31a) is provided with an air inlet (31f).

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