Coatings for photovoltaic modules, photovoltaic coatings, photovoltaic modules

Abstract

This application relates to the photovoltaic field, providing a coating for photovoltaic modules, a photovoltaic coating, and a photovoltaic module. The coating for photovoltaic modules of this application comprises: a hydrophilic polymer, a hydrophobic monomer, and a solvent. The hydrophilic polymer includes at least one selected from polyhydroxy polymers, polyvinyl alcohol, polyacrylic acid, polyacrylamide, or polyvinylpyrrolidone. The hydrophobic monomer includes at least one selected from methacrylates, acrylates, styrene, fluorinated acrylates, or vinyl silanes. The molar ratio of the hydrophilic polymer to the hydrophobic monomer is 1:10 to 10:1. After the coating for photovoltaic modules of this application is cured to form a photovoltaic coating, it can at least ensure good self-cleaning performance on the surface of the photovoltaic module in both high-humidity and low-humidity environments.

Description

Technical Field

[0001] This application relates to the photovoltaic field, and in particular to a coating for photovoltaic modules, a photovoltaic coating, and a photovoltaic module. Background Technology

[0002] As a core component of solar power generation systems, the surface cleanliness of photovoltaic (PV) modules directly affects their photoelectric conversion efficiency. Studies have shown that contaminants such as dust and salt spray adhering to the surface of PV glass can reduce power generation efficiency by 5%-20%. Therefore, a self-cleaning coating can be applied to the surface of the PV module cells to improve the performance of the PV module.

[0003] In existing photovoltaic modules, self-cleaning coatings are mainly divided into two categories: superhydrophobic coatings and superhydrophilic coatings. However, both have limitations in scene adaptability: in high-humidity environments such as coastal areas and rainy seasons, superhydrophobic coatings tend to form numerous and dense water droplets on the surface without a rolling bead effect, which instead accelerates dust adsorption; in low-humidity environments such as deserts and arid regions, superhydrophilic coatings have limited dust removal effects due to the lack of rainwater rinsing. Summary of the Invention

[0004] This application provides a coating, a photovoltaic coating, and a photovoltaic module that can at least ensure that the surface of the photovoltaic module has good self-cleaning performance in both high-humidity and low-humidity environments.

[0005] The first aspect of this application provides a coating for photovoltaic modules, comprising: a hydrophilic polymer, a hydrophobic monomer, and a solvent. The hydrophilic polymer includes at least one of a polyhydroxy polymer, polyvinyl alcohol, polyacrylic acid, polyacrylamide, or polyvinylpyrrolidone. The hydrophobic monomer includes at least one of a methacrylate, acrylate, styrene, fluorinated acrylate, or vinylsilane. The molar ratio of the hydrophilic polymer to the hydrophobic monomer is 1:0.1 to 1:10.

[0006] In one possible implementation, the polyhydroxy polymer includes polyethylene glycol monomethyl ether methacrylate.

[0007] In one possible implementation, the coating for photovoltaic modules further includes a water vapor diffusing agent, which includes at least one of hydroxylated graphene quantum dots, graphene oxide, hydroxylated carbon nanotubes, hydrophilic nano-silica, or mesoporous alumina.

[0008] A second aspect of this application provides a photovoltaic coating, including a humidity-responsive functional layer, which is obtained by curing the aforementioned photovoltaic module coating.

[0009] In one possible implementation, the thickness of the humidity-responsive functional layer is 50nm~60nm.

[0010] In one possible implementation, the photovoltaic coating further includes an antireflection layer located on one surface of the humidity-responsive functional layer, the antireflection layer having a refractive index of 1.46 to 1.48.

[0011] In one possible implementation, the antireflective layer comprises a silane coupling agent.

[0012] In one possible implementation, the thickness of the antireflection layer is 20nm~30nm.

[0013] In one possible implementation, the photovoltaic coating further includes a protective layer located on one surface of the humidity-responsive functional layer, the protective layer having pores with a diameter of 2nm to 5nm.

[0014] In one possible implementation, the protective layer includes anatase TiO2 with a particle size of 5 nm to 10 nm.

[0015] In one possible implementation, the thickness of the protective layer is 15nm~20nm.

[0016] A third aspect of this application provides a photovoltaic module, comprising: solar cells; a pair of photovoltaic glass panes, with the solar cells located between the pairs of photovoltaic glass panes; the aforementioned photovoltaic coating, or the aforementioned photovoltaic module coating after curing with a coating; the photovoltaic coating being located on the surface of the photovoltaic glass away from the solar cells.

[0017] The technical solution provided in this application has at least the following advantages: The coating for photovoltaic modules in this application contains hydrophilic polymers and hydrophobic monomers. When the coating for photovoltaic modules is cured to form a photovoltaic coating, the hydrophilic polymer swells to form a hydrophilic layer when the external environment is high humidity, making it difficult for many dense water droplets to form on the surface of the photovoltaic module. When the external environment is low humidity, the hydrophobic monomers can aggregate to form a hydrophobic surface. When the photovoltaic module is washed with water in the future, water is not easy to remain on the surface of the photovoltaic module, but will remove the dust on the surface of the photovoltaic module. Detailed Implementation

[0018] As can be seen from the background technology, the self-cleaning coating in existing photovoltaic modules has a defect in scene adaptability.

[0019] Based on this, this application provides a coating for photovoltaic modules, a photovoltaic coating layer, and a photovoltaic module. The coating for photovoltaic modules of this application contains a hydrophilic polymer and a hydrophobic monomer. After the coating for photovoltaic modules of this application cures to form a photovoltaic coating layer, it can absorb moisture in high humidity environments and ensure that liquid can better wash the surface of the photovoltaic module and remove dust from the surface of the solar cells in low humidity environments. Therefore, the coating for photovoltaic modules of this application can at least guarantee good self-cleaning performance on the surface of the photovoltaic module within a RH range of 30%~80%RH.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0023] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this application. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein can be interpreted accordingly.

[0024] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0025] In the description of embodiments of this application, the terms "about," "approximately," "roughly," or "about" for referring to a specific parameter include numerical values, and those skilled in the art will understand that the deviation from the numerical value is within the acceptable tolerance of the specific parameter. For example, "about" or "about" for a numerical value may include additional numerical values ​​that are in the range of 90.0% to 110.0% of the numerical value, such as in the range of 95.0% to 105.0%, 97.5% to 102.5%, 99.0% to 101.0%, 99.5% to 100.5%, or 99.9% to 100.1%.

[0026] In the description of embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be an intermediate component between the two components. Conversely, when describing a component on the surface of another component, or a component "directly" on another component, or a component surface on which another component is formed or disposed, it indicates that there is no intermediate component between the two components.

[0027] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0028] The “components” mentioned above can refer to layers, membranes, regions, parts, plates, or structures, etc.

[0029] The embodiments of this application will now be described in detail. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0030] This application provides a coating for photovoltaic modules and a photovoltaic coating layer, wherein the photovoltaic coating layer includes a humidity-responsive functional layer, which is formed by curing the coating for photovoltaic modules described in this application. Therefore, this application provides a unified description of the humidity-responsive functional layer and the coating for photovoltaic modules.

[0031] In this embodiment, the coating for photovoltaic modules includes a hydrophilic polymer, a hydrophobic monomer, and a solvent. The hydrophilic polymer includes at least one of a polyhydroxy polymer, polyvinyl alcohol, polyacrylic acid, polyacrylamide, and polyvinylpyrrolidone. The hydrophobic monomer includes at least one of methacrylate, acrylate, styrene, fluorinated acrylate, and vinylsilane. The molar ratio of the hydrophilic polymer to the hydrophobic monomer is 1:10 to 10:1, specifically 1:1 to 4:1.

[0032] In the embodiments of this application, the solvent serves to disperse the hydrophilic polymer and hydrophobic monomer, ensuring a relatively uniform composition of the coating for photovoltaic modules, and consequently, a relatively uniform humidity-responsive functional layer formed after curing. This application does not have specific requirements regarding the type and amount of solvent, as long as it meets the purpose of this application. Specifically, in some embodiments of this application, the solvent includes, but is not limited to, at least one of tetrahydrofuran (THF), ethanol, isopropanol, ethylene glycol monobutyl ether, and anhydrous methanol. Typically, the amount of solvent is generally used to ensure that the solid content of the coating for photovoltaic modules is between 10% and 20%, which makes the composition of the coating for photovoltaic modules more uniform, and the composition of the layer structure formed after curing is also more uniform.

[0033] After the coating on the photovoltaic module has cured, in a high-humidity environment, the hydrophilic polymer can accumulate on the surface of the layer structure. At this point, the surface contact angle of the humidity-responsive functional layer is less than 15°, meaning the layer exhibits good hydrophilicity in high-humidity environments. This prevents water from easily forming droplets and creating a beading effect on the photovoltaic module surface; instead, it forms a water film that spreads across the surface. This reduces dust adhesion to the photovoltaic coating. Furthermore, when humidity decreases, the absorbed moisture from the hydrophilic polymer overflows, ensuring the humidity-responsive functional layer maintains good water absorption even when humidity rises again. In a low-humidity environment, the hydrophobic monomers accumulate on the surface of the layer structure, resulting in a surface contact angle of 100°~110° for the humidity-responsive functional layer. This means the layer exhibits good hydrophobicity in low-humidity environments, further inhibiting dust adhesion. In addition, since the molar ratio of hydrophilic polymer to hydrophobic monomer is 1:10 to 10:1, it can provide sufficient intelligent humidity-responsive chain segment synergy while ensuring that the cured layer structure maintains a dense hydrophobic and dustproof surface under low humidity, while under high humidity, the hydrophilic chain segments can quickly flip to the surface to form a uniform water film, avoiding the decrease in crosslinking density or response failure due to excessive amount of any component; the preferred range is 1:1 to 4:1.

[0034] This application does not have specific requirements regarding the molecular weight of the hydrophilic polymer. Specifically, in some embodiments of this application, hydrophilic polymers with a number average molecular weight of 500-1000 are typically selected. Due to their low molecular weight, they can also be referred to as hydrophilic oligomers (the molecular weight of oligomers is generally 500-10000). This ensures a more uniform composition of the coating for photovoltaic modules and is more conducive to improving the hydrophilicity of the humidity-responsive functional layer under high humidity conditions. As an example, in subsequent embodiments of this application, hydrophilic polymers with a number average molecular weight of 800 are used. In addition, in some embodiments of this application, the polyhydroxy polymers in the hydrophilic polymers include, but are not limited to, polyethylene glycol monomethyl ether methacrylate (PEGMA). It should be noted that because PEGMA has a relatively well-defined structural formula and molecular weight, and can still undergo polymerization (similar to monomers), but its molecular weight is significantly larger, PEGMA can generally be considered an oligomer. Therefore, the polyhydroxy polymers in this application also include PEGMA.

[0035] In some embodiments of this application, the hydrophobic monomers include, but are not limited to, at least one of isooctyl methacrylate (EHMA), hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), and hydroxypropyl methacrylate (HPMA).

[0036] In some embodiments of this application, to ensure better diffusion of water vapor, a water vapor diffusing agent can be added to the coating for photovoltaic modules. The water vapor diffusing agent includes, but is not limited to, at least one of hydroxylated graphene quantum dots (G-GQDs), graphene oxide, hydroxylated carbon nanotubes, hydrophilic nano-silica, or mesoporous alumina. If a water vapor diffusing agent is added to the coating for photovoltaic modules, the humidity-responsive functional layer formed after subsequent curing will also contain the water vapor diffusing agent. Furthermore, this application does not have specific requirements regarding the content of the water vapor diffusing agent, as long as it meets the purpose of this application. For example, based on the total mass of the coating for photovoltaic modules, the mass content of the water vapor diffusing agent is generally in the range of 0.5% to 1%, specifically 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or within a range consisting of any two of the above values. In addition, the particle size of the water vapor diffuser can usually be 5nm~8nm, which can build a nanoscale efficient anisotropic water vapor diffusion channel in the humidity response functional layer. This not only does not affect the visible light transmittance of the 50nm~60nm thick functional layer, but also accelerates the adsorption and overflow response speed of water molecules.

[0037] This application does not impose any particular restrictions on the specific process of curing the coating for photovoltaic modules to form a humidity-responsive functional layer. Generally, a scraping method can be used, followed by drying at 60°C for 1 hour to obtain the humidity-responsive functional layer. Of course, adjustments can be made according to actual needs, and the above conditions should not be construed as limiting this application.

[0038] In some embodiments of this application, in order to balance the light absorption rate and self-cleaning function of the photovoltaic module, the thickness of the humidity response functional layer can usually be controlled within the range of 50nm~60nm. If the thickness is too small, the self-cleaning performance will be reduced; if the thickness is too large, the light absorption rate will be reduced. Therefore, the performance is more balanced within the range of 50nm~60nm.

[0039] In some embodiments of this application, in addition to the humidity-responsive functional layer, the photovoltaic coating may also include other layer structures, such as an anti-reflective layer and / or a protective layer, located on one surface of the humidity-responsive functional layer. Specifically, the humidity-responsive functional layer is divided into a first surface and a second surface along its thickness direction. The first surface will subsequently be close to the photovoltaic glass, and the second surface will subsequently be away from the photovoltaic glass. The anti-reflective layer is located on the first surface, and the protective layer is located on the second surface. The anti-reflective layer can improve light transmittance; the protective layer can protect the humidity-responsive functional layer.

[0040] It should be noted that the anti-reflective layer and the protective layer in the photovoltaic coating can coexist, or only one can be present, or neither can be present. This application does not impose any particular restrictions in this regard. When the photovoltaic coating does not contain an anti-reflective layer, the light transmittance of the entire photovoltaic coating will be reduced; when the photovoltaic coating does not contain a protective layer, the lifespan of the entire photovoltaic module will be reduced.

[0041] In addition, similar to the humidity-responsive functional layer, the antireflective layer and the protective layer are generally formed by curing slurry. The antireflective layer, the protective layer and their corresponding slurry will be explained in detail below.

[0042] In this embodiment, the refractive index of the antireflective layer is generally 1.46~1.48, which matches the refractive index of the photovoltaic glass and helps to improve the light transmittance of the photovoltaic coating. The thickness of the antireflective layer is generally 20nm~30nm, specifically 20nm, 22nm, 25nm, 28nm, 30nm, etc., or within a range of any two of the above values.

[0043] To achieve a refractive index of 1.46–1.48 for the antireflection layer, in some embodiments of this application, the antireflection slurry (i.e., the slurry corresponding to the antireflection layer) comprises, by mass fraction, 20% tetraethyl orthosilicate (TEOS), 10% monodisperse SiO2 dispersion, and 67.5% ethanol, wherein the concentration of the monodisperse SiO2 dispersion is typically 20%. Ethanol in the antireflection slurry acts as a solvent, dispersing the solute and ensuring relatively uniform composition. Other solvents can be used instead, and their content can be adjusted according to actual needs. Subsequently, after the antireflection slurry cures, the solvents such as ethanol, as well as the liquid dispersant in the monodisperse SiO2 dispersion, will evaporate. In the antireflection slurry, TEOS can act as a sol-gel precursor, synergistically interacting with SiO2 to promote the formation of an antireflection layer with a refractive index of 1.46–1.48.

[0044] In addition, in some embodiments of this application, the antireflective slurry may also contain 2.5% silane coupling agent. This allows the silane coupling agent to form stable chemical bonds with the hydroxyl groups on the photovoltaic glass surface, while also providing a good adhesion base for the humidity-responsive functional layer, thus enhancing the adhesion strength between the photovoltaic coating and the photovoltaic glass. The silane coupling agent includes, but is not limited to, at least one of γ-aminopropyltriethoxysilane (KH550), γ-methacryloyloxypropyltrimethoxysilane (KH570), and γ-glycidoxypropyltrimethoxysilane (KH560).

[0045] The steps for preparing an antireflective layer using antireflective slurry are generally as follows: After preparing the antireflective slurry, adjust the pH to 3.5-4.0 with 0.1 mol / L hydrochloric acid, keep it at 30℃ and stir for 2 hours to obtain a viscosity of 5-8 mPa. A transparent sol was prepared; then coated using a scraper and dried at 80°C for 30 minutes. The pH adjustment, heat preservation step, coating method, and drying step can be adjusted according to actual needs, and the above conditions should not be construed as limiting this application.

[0046] In some embodiments of this application, the protective layer contains pores with a diameter of 2nm to 5nm. This allows water vapor to permeate, ensuring the proper functioning of the humidity-responsive layer. Furthermore, the 2nm to 5nm pore size also blocks windblown sand and ultraviolet radiation, thus protecting the photovoltaic coating. Additionally, in some embodiments of this application, the protective layer may also contain anatase TiO2 with a particle size of 5nm to 10nm. Anatase TiO2 can photocatalytically degrade oil stains and improve wear resistance, further protecting the photovoltaic coating. Furthermore, in some embodiments of this application, the thickness of the protective layer is 15nm to 20nm, for example, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, or within any two of the above values.

[0047] Typically, the components of the protective slurry used to form the protective layer, by mass fraction, generally include 16.7% perfluorooctyltriethoxysilane (POTS), 3.3% anatase TiO2 dispersion (30% concentration, 3.3%), and 80% isopropanol. Isopropanol acts as a solvent, serving to disperse the slurry uniformly.

[0048] When using protective slurry to form a protective layer, it can generally be applied by spraying and then cured at 120°C. The coating method and curing process can be adjusted according to actual needs, and the above conditions should not be construed as limiting this application.

[0049] This application also provides a photovoltaic module, including the aforementioned photovoltaic coating and a pair of photovoltaic glass panels, with a solar cell disposed between the pair of photovoltaic glass panels, and the photovoltaic coating located on the surface of the photovoltaic glass panels away from the solar cell panels.

[0050] When a photovoltaic module contains the aforementioned photovoltaic coating, the surface of the photovoltaic module exhibits excellent self-cleaning properties, regardless of whether the environment is high or low humidity.

[0051] The technical solution of this application will be described in detail below with reference to specific embodiments.

[0052] Example 1 This embodiment provides a coating for photovoltaic modules with a solid content of 15%. Its components include hydrophilic polymer PEGMA, hydrophobic monomer EHMA, and 60g of THF, wherein the molar ratio of PEGMA to EHMA is 3:2.

[0053] Example 2 This embodiment provides a coating for photovoltaic modules. The main difference between this coating and that of Embodiment 1 is that it also contains 0.125g of H-GQDs.

[0054] Example 3 This embodiment provides a coating for photovoltaic modules. The main difference between this coating and that of Example 1 is that the same amount of hydrophilic polymer hydroxyethyl methacrylate (HEMA) is used instead of PEGMA.

[0055] Example 4 This embodiment provides a coating for photovoltaic modules. The main difference between this coating and that of Example 1 is that the same amount of hydrophobic monomer methyl methacrylate (MMA) is used instead of EHMA.

[0056] Example 5 This embodiment provides a coating for photovoltaic modules. The main difference between this coating and that of Embodiment 1 is that the molar ratio of PEGMA and EHMA is 1:1.

[0057] Example 6 This embodiment provides a coating for photovoltaic modules. The main difference between this coating and that of Embodiment 1 is that the molar ratio of PEGMA to EHMA is 4:1.

[0058] Example 7 This embodiment provides a photovoltaic module, including a pair of photovoltaic glass, solar cells, and a photovoltaic coating, wherein the solar cells are located between the pairs of photovoltaic glass and the photovoltaic coating is located on the surface of the photovoltaic glass away from the solar cells.

[0059] The photovoltaic coating contains a humidity-responsive functional layer with a thickness of 55 nm, which is obtained by curing the coating for photovoltaic modules in Example 1.

[0060] Example 8 This embodiment provides a photovoltaic module, which differs from Embodiment 7 mainly in that: The photovoltaic coating also includes an anti-reflective layer and a protective layer, and the anti-reflective layer, humidity-responsive functional layer, and protective layer are stacked in sequence, with the anti-reflective layer located on the surface of the photovoltaic glass.

[0061] The antireflective layer has a refractive index of 1.47 and a thickness of 25 nm, and also includes KH550.

[0062] The protective layer is 18 nm thick and contains pores with diameters between 2 nm and 5 nm. The protective layer also contains anatase TiO2 with an average particle size of 7 nm.

[0063] Comparative Example 1 This comparative example provides a coating for photovoltaic modules. The main difference between this coating and that of Example 1 is that this coating does not contain the hydrophilic polymer PEGMA, but instead uses the same amount of EHMA instead of PEGMA.

[0064] Comparative Example 2 This comparative example provides a coating for photovoltaic modules. The main difference between this coating and that of Example 1 is that it does not contain the hydrophobic monomer EHMA, but instead uses the same amount of PEGMA instead of EHMA.

[0065] Test methods and equipment Contact angle test The photovoltaic modules from Examples 1-5 and Comparative Examples 1-2 were cured with coatings to form layer structures with a thickness of 55 nm. After placing the layer structures in different humidity environments for 2 hours, the surface of the layer structures was observed. The surface of the layer structures was then cleaned, and the contact angle of each layer structure under different humidity environments was measured using an optical contact angle meter (using the seated drop method). Two humidity environments were used: one with 30% RH and the other with 80% RH.

[0066] transmittance test The transmittance of the photovoltaic coatings in the photovoltaic modules of Examples 7 and 8 was tested using a UV-Vis-NIR spectrophotometer (according to GB / T 2410-2008 standard).

[0067] Life test The service life of the photovoltaic coatings in the photovoltaic modules of Examples 7 and 8 was tested using a photovoltaic damp heat aging test chamber (1000h of double 85 damp heat aging test at 85℃ and 85%RH, according to IEC 61215 standard).

[0068] The test results are shown in Table 1.

[0069] Table 1

[0070] Furthermore, based on the transmittance and lifespan test results, it was found that the photovoltaic module of Example 8 had a high transmittance of 94.5% for its photovoltaic coating and a long lifespan of 1200 hours under the dual 85°C, 85%RH damp heat aging test. In contrast, the photovoltaic module of Example 7 had a low transmittance of 91.2% for its photovoltaic coating and a short lifespan of only 450 hours under the dual 85°C damp heat aging test.

[0071] Therefore, in this embodiment, because the coating for photovoltaic modules contains both hydrophilic polymers and hydrophobic monomers, the resulting layer structure has a smaller contact angle in low-humidity environments and a larger contact angle in high-humidity environments. Consequently, dust does not easily adhere to the surface of the layer structure in low-humidity environments; in high-humidity environments, a water film forms on the surface of the layer structure, also making dust adhesion difficult. Thus, the photovoltaic coating exhibits good self-cleaning performance in both low-humidity and high-humidity environments. In contrast, the contact angle in the comparative model is fixed, therefore it only possesses self-cleaning performance under a single humidity level; once external humidity conditions change, self-cleaning becomes difficult.

[0072] In particular, the test results of Examples 7 and 8 show that when the photovoltaic coating contains an anti-reflection layer, the light transmittance of the photovoltaic coating can be greatly improved; when a protective layer is provided on the surface of the humidity-responsive functional layer, the service life of the photovoltaic coating can be greatly improved.

[0073] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A coating for photovoltaic modules, characterized in that, include: The mixture comprises a hydrophilic polymer, a hydrophobic monomer, and a solvent, wherein the hydrophilic polymer includes at least one of a polyhydroxy polymer, polyvinyl alcohol, polyacrylic acid, polyacrylamide, or polyvinylpyrrolidone, and the hydrophobic monomer includes at least one of a methacrylate, acrylate, styrene, fluorinated acrylate, or vinylsilane. The molar ratio of the hydrophilic polymer to the hydrophobic monomer is 1:10 to 10:

1.

2. The coating for photovoltaic modules according to claim 1, characterized in that, The molar ratio of the hydrophilic polymer to the hydrophobic monomer is 1:1 to 4:

1.

3. The coating for photovoltaic modules according to claim 1, characterized in that, It also includes a water vapor diffuser, which includes at least one of hydroxylated graphene quantum dots, graphene oxide, hydroxylated carbon nanotubes, hydrophilic nano-silica, or mesoporous alumina.

4. A photovoltaic coating, characterized in that, include: A humidity-responsive functional layer, wherein the humidity-responsive functional layer is obtained by curing the coating for photovoltaic modules as described in any one of claims 1 to 3.

5. The photovoltaic coating according to claim 4, characterized in that, The thickness of the humidity-responsive functional layer is 50nm~60nm.

6. The photovoltaic coating according to claim 4, characterized in that, It also includes an antireflective layer, which is located on one surface of the humidity-responsive functional layer, and the refractive index of the antireflective layer is 1.46~1.48; and / or, The thickness of the antireflective layer is 20nm~30nm.

7. The photovoltaic coating according to claim 6, characterized in that, The antireflective layer includes a silane coupling agent.

8. The photovoltaic coating according to claim 4 or 6, characterized in that, It also includes a protective layer located on one surface of the humidity-responsive functional layer, wherein the protective layer has pores with a diameter of 2 nm to 5 nm; and / or, the thickness of the protective layer is 15 nm to 20 nm.

9. The photovoltaic coating according to claim 8, characterized in that, The protective layer includes anatase TiO2, and the particle size of the anatase TiO2 is 5nm~10nm.

10. A photovoltaic module, characterized in that, include: Battery cells; A pair of photovoltaic glass panes, with the solar cell located between the pairs of photovoltaic glass panes; The photovoltaic coating as described in any one of claims 4 to 9, or the photovoltaic coating after curing of the coating for photovoltaic modules as described in any one of claims 1 to 3; The photovoltaic coating is located on the surface of the photovoltaic glass away from the solar cell.

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