Filtering and degassing system and coating system

Abstract

The utility model provides a filtering and degassing system and a coating system. The filtering and degassing system comprises a filtering device used for filtering impurities in a film coating liquid, and a degassing device used for degassing the film coating liquid, the liquid inlet end of the degassing equipment is connected with the liquid outlet end of the filtering equipment, and the degassing equipment is used for removing gas in the coating liquid. The filtering and degassing system disclosed by the utility model is applied to the coating of coating liquid, in particular to the coating of perovskite solution, so that the perovskite solution conveyed inside the coating machine can be further filtered and exhausted, the perovskite solution discharged from a coating head can be ensured to be high in quality and free of impurities, the problem that foreign matters are wrapped on the film surface in the coating process is reduced, and the coating quality of the coating machine is improved. And meanwhile, tiny bubbles mixed into the solution in the perovskite solution conveying process can be eliminated, so that the film layer quality is improved.

Description

Technical Field

[0001] The utility model relates to the field of solution coating, and particularly relates to a filtering and degassing system and a coating system. Background Art

[0002] Perovskite is a very promising new photovoltaic material with high-efficiency optoelectronic conversion characteristics. In order to improve the performance of perovskite photovoltaic cells and extend their service life, the coating process of perovskite is particularly important.

[0003] Currently, the actual operation process of coating perovskite solution by a coater is as follows: after filtering the prepared perovskite solution, the filtered perovskite solution is transferred to the coater, and then through the perovskite solution transmission system inside the coater, the perovskite solution is conveyed to the coating head for coating operation. Among them, the specific transmission process of the perovskite solution inside the coater is: the filtered perovskite solution is stored in a liquid medicine tank. During coating, the perovskite solution in the liquid medicine tank is conveyed to a buffer tank, and the perovskite solution is injected into the coating head by an injection pump, and then coating is realized through the coating head.

[0004] In the prior art, in order to avoid the reduction of the performance of the perovskite coating caused by foreign matters wrapped in the perovskite film layer, the perovskite solution before being transferred to the coater is usually filtered. However, through actual verification, even under this filtering method, there are still problems such as foreign matters being wrapped in the perovskite film layer after coating, ultimately resulting in film layer defects. Summary of the Utility Model

[0005] Therefore, the technical problem to be solved by the utility model is that the perovskite film layer formed by the coating design disclosed in the prior art still has film layer defects, and thus a filtering and degassing system and a coating system for improving the above problems are provided.

[0006] A filtering and degassing system includes:

[0007] A filtering device for filtering impurities in the coating solution;

[0008] A degassing device, whose liquid inlet end is connected to the liquid outlet end of the filtering device, for removing gas in the coating solution.

[0009] The above-mentioned filtering and degassing system is used for filtering and degassing the coating solution during coating, and is particularly suitable for filtering and degassing the perovskite solution during the coating process. Specifically, by installing it on the solution transfer pipeline before the coating head of the coating system, the filtering and degassing of the perovskite solution during the coating process can be achieved. Among them, the perovskite solution may refer to a coating solution containing raw materials for preparing perovskite. For example, it may be a perovskite precursor solution, or a liquid directly containing perovskite components. The perovskite solution is not necessarily a solution, but may also be a colloid. During the research process, it was found that the filtering equipment itself may increase the bubbles in the coating solution during the filtering process, which may lead to film layer defects. In the present utility model, by first setting the filtering equipment and then setting the degassing equipment, the degassing equipment can be used to remove both the originally existing bubbles in the coating solution and the bubbles introduced by the filtering equipment.

[0010] The filtering equipment includes filters with decreasing filter hole diameters in at least two stages.

[0011] The filtering equipment is a three-stage filter. Specifically, the filtering equipment includes a primary filter, a secondary filter, and a tertiary filter; the filter hole diameter of the primary filter is larger than that of the secondary filter, the filter hole diameter of the secondary filter is larger than that of the tertiary filter, the liquid outlet end of the primary filter is connected to the liquid inlet end of the secondary filter, and the liquid outlet end of the secondary filter is connected to the liquid inlet end of the tertiary filter.

[0012] Preferably, the filter hole diameter of the primary filter is 2 - 5 μm, the filter hole diameter of the secondary filter is 1 - 2 μm, and the filter hole diameter of the tertiary filter is 0.2 - 0.45 μm. The filter hole diameter of the primary filter can be any value within 2 - 5 μm, such as: 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc. The filter hole diameter of the secondary filter can be any value within 1 - 2 μm, such as: 1.0 μm, 1.2 μm, 1.4 μm, 1.6 μm, 1.8 μm, 2.0 μm, etc. The filter hole diameter of the tertiary filter can be any value within 0.2 - 0.45 μm, such as: 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, etc.

[0013] Furthermore, the filtering equipment further includes a bubble discharger for discharging the bubbles in the coating solution, and the bubble discharger is arranged at the liquid inlet end and / or the liquid outlet end of the filter.

[0014] The material of the filter is a chemically corrosion-resistant material, preferably polytetrafluoroethylene;

[0015] And / or, the bubble discharger includes a liquid discharge port.

[0016] The degassing device includes a waterproof breathable membrane and a vacuum pump. The waterproof breathable membrane refers to a thin film that can permeate gas and prevent liquid from permeating. For example, it can be a thin film composed of microporous hollow fibers. The micropores on the thin film can permeate gas and prevent liquid from permeating.

[0017] A coating system includes the above-mentioned filtration and degassing system.

[0018] The coating system further includes:

[0019] A buffer tank, the liquid outlet end of the buffer tank is connected to the liquid inlet end of the filtration and degassing system;

[0020] A liquid medicine barrel, the liquid outlet end of the liquid medicine barrel is connected to the liquid inlet end of the buffer tank;

[0021] A liquid injection pump, the liquid inlet end of the liquid injection pump is connected to the liquid outlet end of the filtration and degassing system;

[0022] A coating head, the liquid inlet end of the coating head is connected to the liquid outlet end of the liquid injection pump.

[0023] There are two liquid medicine barrels.

[0024] The technical solution of the present invention has the following advantages:

[0025] A filtration and degassing system provided by the present invention includes a filtration device for filtering impurities in the coating solution; a degassing device, its liquid inlet end is connected to the liquid outlet end of the filtration device, for removing gas in the coating solution; the filtration and degassing system of the present invention is applicable to the filtration and degassing of the coating solution, especially applicable to the filtration and degassing of the perovskite solution; specifically, it is installed on the solution transmission pipeline before the coating head of the coating system, and can realize the filtration and degassing of the perovskite solution in the coating system. The filtration and degassing system of the present invention can filter and exhaust the perovskite solution conveyed inside the coater, reduce the impurity content of the perovskite solution coming out of the coating head, and at the same time can remove the bubbles contained in the perovskite solution itself and the bubbles mixed into the solution during the conveying process, so as to reduce the problem of foreign objects wrapped in the film generated during the coating process, and further improve the film layer quality. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of Embodiment 1 in the present invention.

[0028] Figure 2 This is a schematic structural diagram of Comparative Example 1 in the present utility model.

[0029] Explanation of reference numerals:

[0030] 1 - liquid medicine barrel, 2 - buffer tank, 3 - liquid injection pump, 4 - coating head, 5 - filter, 6 - degassing device, 7 - bubble discharge port. Specific embodiments

[0031] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0032] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0033] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0034] In addition, the technical features involved in different embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0035] Embodiment 1

[0036] A coating system for coating perovskite solution, as Figure 1 shown, includes a solution transmission system located inside the coater and communicating with the coating head 4, and a filtration and degassing system provided in the solution transmission system; wherein, the filtration and degassing system includes a filtration device and a degassing device 6, the liquid inlet end of the degassing device is connected to the liquid outlet end of the filtration device, the filtration device is used to filter impurities in the coating solution, and the degassing device is used to remove gas in the coating solution.

[0037] In this embodiment, by adding a filtration and degassing system to the solution transmission system, the perovskite solution transported inside the coater can be filtered and degassed, which can reduce the impurity content of the perovskite solution coming out of the coating head, reduce the problem of film wrapping foreign matters generated during the coating process, and at the same time can remove the bubbles contained in the perovskite solution itself and the bubbles mixed into the solution during the transportation process, thereby improving the film layer quality.

[0038] Among them, the filtering device is a filter 5 with at least two stages of filter hole diameters decreasing gradually. Through this setting, large particulate matters mixed in the perovskite solution can be removed stage by stage, better improving the quality of the perovskite solution and achieving a better coating effect. The structure of the filter 5 includes a housing and at least two stages of filter elements sequentially arranged inside the housing along the flowing direction of the perovskite solution, and the filter hole diameters of the sequentially arranged filter elements decrease along the flowing direction of the perovskite solution. Preferably, the filtering device is a three-stage filter, namely a primary filter, a secondary filter, and a tertiary filter arranged in sequence; that is, three filter elements are arranged in the housing and are sequentially arranged along the flowing direction of the perovskite solution; among them, the primary filter includes a first-stage filter element with a filter hole diameter of 2 - 5 μm; the secondary filter includes a second-stage filter element with a filter hole diameter of 1 - 2 μm; the tertiary filter includes a third-stage filter element with a filter hole diameter of 0.2 - 0.45 μm. In this embodiment, the filter hole diameter of the first-stage filter element is 5 μm, the filter hole diameter of the second-stage filter element is 2 μm, and the filter hole diameter of the third-stage filter element is 0.45 μm. The material of the filter can be selected as any chemically corrosion-resistant material, and in this embodiment, PTFE (polytetrafluoroethylene) is preferably used.

[0039] Furthermore, a bubble eliminator for discharging the bubbles in the coating solution is also arranged in the filtering device. The bubble eliminator can be arranged at the liquid inlet end and / or the liquid outlet end of each stage of the filter 5, and a bubble discharge port 7 is arranged on the bubble eliminator. This setting can discharge the bubbles through the bubble discharge port when there are bubbles in the perovskite solution in the filter, achieving a certain degassing effect. For example, when the system pipeline is used for the first time, or when the pipeline is reused after being cleaned, after the coating solution enters the system pipeline, the coating solution entering the pipeline first may contain more bubbles. At this time, the bubbles can be discharged only through the bubble eliminator, or the coating solution entering the pipeline first and the bubbles can be discharged together through the bubble eliminator. Preferably, in this embodiment, the bubble eliminator is arranged at the liquid inlet end of each stage of the filter 5, and a bubble discharge port 7 is arranged on the bubble eliminator arranged at the liquid inlet end of each stage of the filter 5, as Figure 1As shown. The bubble discharge port is arranged at the front end of the filter element of the filter 5 at each stage, effectively ensuring the continuity and stability of the subsequent operation of the filter; and the setting method of arranging the bubble discharger before the filter element can first discharge the bubbles originally contained in the coating solution, avoiding or reducing the generation of smaller and more difficult-to-remove bubbles after these bubbles pass through the filter element, and improving the final film quality.

[0040] Furthermore, the degassing device adopted in this embodiment includes a waterproof breathable membrane and a vacuum pump, wherein the waterproof breathable membrane is a degassing membrane equipped with hollow fibers. The degassing membrane equipped with hollow fibers can achieve the purpose of separating liquid and gas; specifically, a large number of hollow fibers are installed inside the degassing membrane, and there are tiny holes on the walls of the fibers. Liquid cannot pass through these small holes, while gas can pass through. During operation, the coating solution passes through the inside of the hollow fibers under a certain pressure, and the gas outside the hollow fibers is continuously pumped away under the action of the vacuum pump, forming a certain negative pressure. In this way, the gas in the coating solution continuously overflows from the coating solution through the hollow fibers to the outside, so as to achieve the purpose of removing the gas in the coating solution. Installing a large number of hollow fibers in the degassing membrane can expand the area of the gas-liquid interface, thereby accelerating the degassing speed. The structure of the degassing membrane equipped with hollow fibers is a prior art and will not be elaborated in this utility model. By pumping out the gas discharged through the micropores on the side wall of the degassing membrane equipped with hollow fibers by the vacuum pump, a better exhaust effect can be achieved.

[0041] The solution transmission system located inside the coater in this embodiment includes: a medicine liquid barrel 1, a buffer tank 2, and an injection pump 3 that are connected in sequence. The liquid outlet end of the injection pump 3 is connected to the liquid inlet end of the coating head 4.

[0042] The filtration and degassing system in this utility model can be set at any position after the medicine liquid barrel 1 of the solution transmission system, for example: between the medicine liquid barrel 1 and the buffer tank 2, between the buffer tank 2 and the injection pump 3, or between the injection pump 3 and the coating head 4.

[0043] As a preferred setting method, the liquid outlet end of the medicine liquid barrel is connected to the liquid inlet end of the buffer tank, the liquid outlet end of the buffer tank is connected to the liquid inlet end of the filtration and degassing system, the liquid outlet end of the filtration and degassing system is connected to the liquid inlet end of the injection pump, and the liquid outlet end of the injection pump is connected to the liquid inlet end of the coating head. The connections between the above-mentioned various components can all be connected through pipelines and valves.

[0044] The medicine liquid barrel in this embodiment can preferably be set to two, one of which is the currently used medicine liquid barrel, and the other is the standby medicine liquid barrel. Both medicine liquid barrels are respectively connected to the buffer tank through valves.

[0045] The process of coating the perovskite solution using the coating system of this embodiment is as follows:

[0046] During the production process, the stirred perovskite solution is filtered once outside the equipment, with the filter aperture controlled at 0.45 μm or less. The filtered perovskite solution is stored in the liquid medicine barrel of the coating system. The liquid medicine barrel pressurizes the solution in the liquid medicine barrel 1 through CDA (clean and dry air), and the solution in the liquid medicine barrel 1 is pressed into the buffer tank 2 through valves and relevant pipelines. The solution in the buffer tank 2 is then pressed into the filtering equipment and the degassing equipment 6 through relevant pipelines and valves for filtering and degassing in sequence. The perovskite solution after filtering and degassing is pushed into the coating head 4 through the injection pump 3 through relevant pipelines and valves to achieve uniform liquid discharge, and thus coating is completed.

[0047] Example 2

[0048] A coating system, which is different from that in Example 1 in that the filtering equipment is differently arranged, and the others are exactly the same as those in Example 1; specifically, the filtering equipment is a three-stage filter, wherein the pore diameter of the first stage is 3 μm, the pore diameter of the second stage is 1.5 μm, and the pore diameter of the third stage is 0.3 μm.

[0049] Example 3

[0050] A coating system, which is different from that in Example 1 in that the filtering equipment is differently arranged, and the others are exactly the same as those in Example 1; specifically, the filtering equipment is a three-stage filter, wherein the pore diameter of the first stage is 2 μm, the pore diameter of the second stage is 1 μm, and the pore diameter of the third stage is 0.2 μm.

[0051] Example 4

[0052] A coating system, which is different from that in Example 1 in that the filtering equipment and the degassing equipment are added between the injection pump and the coating head, and the others are exactly the same as those in Example 1.

[0053] Comparative Example 1

[0054] A coating system, as Figure 2 shown, includes: a liquid medicine barrel 1, a buffer tank 2 communicated with the liquid medicine barrel 1 through connecting pipelines and valves, an injection pump 3 communicated with the buffer tank 2 through connecting pipelines and valves, and the coating head 4 is communicated with the injection pump through connecting pipelines and valves.

[0055] The process of coating using the coating system in this comparative example is as follows: During the production process, the stirred perovskite solution is filtered once outside the equipment, with the filter aperture controlled at 0.45 μm or less. The filtered perovskite solution is stored in the liquid medicine barrel of the coating system. The liquid medicine barrel pressurizes the solution in the liquid medicine barrel through CDA (clean and dry air), and the solution in the liquid medicine barrel is pressed into the buffer tank through valves and relevant pipelines. The solution in the buffer tank is then pressed into the injection pump through relevant pipeline valves, and the injection pump pushes it through pipelines and valves into the coating head to achieve uniform liquid discharge, and thus coating is completed.

[0056] Comparative Example 2

[0057] A coating system, which is different from that of Example 1 in that only a filtering device is added between the buffer tank 2 and the liquid injection pump 3, and there is no degassing device, and the others are exactly the same as those of Example 1.

[0058] The process of coating using the coating system in this comparative example is as follows: During the production process, the stirred perovskite solution is filtered once outside the equipment, and the filter diameter is controlled at 0.45 μm or less. The filtered perovskite solution is stored in the liquid medicine barrel of the coating system. The solution in the liquid medicine barrel is pressurized by CDA (clean dry air) and is pressed into the buffer tank through the valve and related pipelines. The solution in the buffer tank is then pressed into the filtering device through the related pipeline valves for filtering. The filtered perovskite solution is pushed into the coating head through the pipeline and valve by the liquid injection pump to complete uniform liquid output, and thus complete the coating.

[0059] It is found by comparing the examples and comparative examples that: Compared with the perovskite coatings prepared in Comparative Examples 1 and 2, the perovskite coating prepared in the example has less impurities and fewer microbubbles, reduces the foreign objects wrapped in the film during the coating process, and achieves the effect of significantly improving the film layer defects.

[0060] Obviously, the above examples are only for clearly illustrating the examples and are not intended to limit the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A filtration and degassing system, characterized in that, Comprising: A filtering device for filtering impurities in the coating solution; A degassing device, whose liquid inlet end is connected to the liquid outlet end of the filtering device, for removing gas in the coating solution.

2. The filtering and degassing system according to claim 1, characterized in that The filtering device includes at least two filters with decreasing pore diameters in stages.

3. The filtering and degassing system according to claim 2, characterized in that, The filtering device includes a primary filter, a secondary filter and a tertiary filter. The pore diameter of the primary filter is larger than that of the secondary filter, the pore diameter of the secondary filter is larger than that of the tertiary filter. The liquid outlet end of the primary filter is connected to the liquid inlet end of the secondary filter, and the liquid outlet end of the secondary filter is connected to the liquid inlet end of the tertiary filter.

4. The filtration and degassing system according to claim 3, wherein The pore diameter of the primary filter is 2 - 5 μm, the pore diameter of the secondary filter is 1 - 2 μm, and the pore diameter of the tertiary filter is 0.2 - 0.45 μm.

5. The filtration and degassing system according to claim 2, characterized in that, The filtering device further includes a defoamer for discharging air bubbles in the coating solution, and the defoamer is arranged at the liquid inlet end and / or the liquid outlet end of the filter.

6. The filtering and degassing system according to claim 5, characterized in that, The material of the filter is polytetrafluoroethylene; And / or, the defoamer includes a liquid discharge port.

7. The filtration and degassing system according to any one of claims 1-6, characterized in that, The degassing device includes a waterproof breathable membrane and a vacuum pump.

8. A coating system, characterized in that, Comprising the filtering and degassing system according to any one of claims 1 - 7.

9. The coating system according to claim 8, characterized in that, Further comprising: A buffer tank, whose liquid outlet end is connected to the liquid inlet end of the filtering and degassing system; A liquid medicine barrel, whose liquid outlet end is connected to the liquid inlet end of the buffer tank; A liquid injection pump, whose liquid inlet end is connected to the liquid outlet end of the filtering and degassing system; A coating head, whose liquid inlet end is connected to the liquid outlet end of the liquid injection pump.

10. The coating system according to claim 9, wherein There are two liquid medicine barrels.

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