Packaging adhesive film, preparation method thereof and solar cell module

Abstract

The invention provides a packaging adhesive film, a preparation method thereof and a solar cell module. The packaging adhesive film comprises the following components in percentage by weight: 85 to 95 weight percent of matrix resin, 3 to 8 weight percent of sulfonic ion exchange resin, 0.5 to 2 weight percent of lead ion detection agent and the balance of auxiliary agent, the lead ion detection agent comprises a carrier and a rhodamine compound loaded on the surface of the carrier. According to the packaging adhesive film provided by the invention, a sulfonic acid group in the sulfonic acid ion exchange resin can be coordinated with divalent lead ions (Pb < 2 + >), so that the purpose of capturing the lead ions is achieved, and the lead ions are prevented from seeping out; and meanwhile, the lead ion detection agent is introduced into the packaging adhesive film, so that leakage of lead ions can be prompted through a closed-loop structure in the rhodamine compound and a color development reaction of Pb < 2 + >, and operation and maintenance personnel of a power station are helped to quickly identify the leaked solar cell module, so that the solar cell module is quickly repaired or replaced, and pollution to the environment and harm to a human body are reduced.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more specifically, to an encapsulating film, its preparation method, and a solar cell module. Background Technology

[0002] Perovskite solar cell technology has attracted widespread attention in the photovoltaic field in recent years due to its high photoelectric conversion efficiency and relatively low production cost. The core structure of this type of cell is based on perovskite materials, and Pb (lead) ions play a crucial role in the perovskite structure, making Pb an indispensable component of perovskite solar cells. However, lead is a harmful heavy metal that poses a potential threat to the environment and human health, especially when solar modules are exposed to outdoor conditions for extended periods, where lead ions may leak due to aging of encapsulation materials or physical damage to the modules.

[0003] Currently, the encapsulation technology for perovskite modules mainly borrows from traditional crystalline silicon solar cell encapsulation methods, such as using polymer-based encapsulating films like POE (ethylene octene copolymer). However, traditional encapsulating films have significant shortcomings in preventing lead leakage. The design of crystalline silicon cell encapsulating films does not take into account the need for heavy metal capture and detection, as such issues do not exist in crystalline silicon cells. Therefore, when applied to perovskite modules, these encapsulating films cannot effectively prevent lead ion leakage, nor do they provide a simple and intuitive detection method to quickly identify lead leakage after module damage.

[0004] Furthermore, physical damage that perovskite modules may encounter during actual use (such as cracks caused by severe weather or external impacts) can further exacerbate the risk of lead ion leakage. Once lead ions leach out, they not only pollute the environment but may also affect the performance and lifespan of other electrical equipment around the modules, and even cause long-term harm to human health and the ecosystem.

[0005] Therefore, it is necessary to research and develop an encapsulation film that can prevent and detect lead leakage. This is of great significance in helping maintenance personnel quickly locate problematic components, perform timely maintenance or replacement, and reduce environmental pollution and health risks. Summary of the Invention

[0006] The main objective of this invention is to provide an encapsulating film, its preparation method, and a solar cell module, in order to solve the problem that existing encapsulating films are difficult to simultaneously prevent lead leakage and detect lead leakage, thus causing environmental pollution.

[0007] To achieve the above objectives, the present invention provides an encapsulating film comprising, by weight percentage: 85-95 wt% matrix resin, 3-8 wt% sulfonic acid-based ion exchange resin, 0.5-2 wt% lead ion detection agent, and the balance being additives; the lead ion detection agent comprises a carrier and a rhodamine-like compound loaded on its surface.

[0008] Further, the sulfonic acid-based ion exchange resin is selected from one or more of poly(1-vinylimidazolium co-2-acrylamido-2-methyl-1-propanesulfonic acid), polystyrene sulfonic acid, and perfluorosulfonic acid resins; and / or, the weight-average molecular weight of the sulfonic acid-based ion exchange resin is 5 × 10⁻⁶. 4 ~5×10 5 The porosity is 30-70%.

[0009] Furthermore, in the lead ion detection reagent, the carrier is selected from silicon dioxide; and / or, the rhodamine compound is selected from one or more of rhodamine 6G, rhodamine B, and rhodamine 101.

[0010] Furthermore, in the lead ion detection reagent, the weight ratio of rhodamine compounds to the carrier is (0.01–0.2):(1–10).

[0011] Furthermore, the matrix resin is selected from ethylene octene copolymers; and / or, the weight-average molecular weight of the matrix resin is 1 × 10⁻⁶. 5 ~5×10 5 .

[0012] Furthermore, the additives include compatibilizers, light stabilizers, and antioxidants.

[0013] Furthermore, based on the weight percentage of the encapsulating film, the encapsulating film includes: 0.5–2 wt% compatibilizer, 0.1–0.5 wt% light stabilizer, and 0.1–0.5 wt% antioxidant.

[0014] Furthermore, the compatibilizer is selected from maleic anhydride-grafted ethylene-octene copolymer.

[0015] Furthermore, the light stabilizer is selected from one or more of bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidine)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidine)imino}], and bis(2,2,6,6-tetramethyl-4-piperidine) sebacate.

[0016] Furthermore, the antioxidant is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0017] Furthermore, the thickness of the encapsulating film is 0.1–1 mm.

[0018] To achieve the above objectives, another aspect of the present invention provides a method for preparing the encapsulating film provided in this application. The method includes: step S1, mixing a matrix resin, a sulfonic acid-based ion exchange resin, a lead ion detector, and additives to obtain a mixture; step S2, kneading the mixture to obtain a kneaded product; step S3, extruding and pelletizing the kneaded product sequentially to obtain granules; and step S4, casting and shaping the granules sequentially to obtain an encapsulating film. The mixture comprises, by weight percentage, 85–95 wt% matrix resin, 3–8 wt% sulfonic acid-based ion exchange resin, 0.5–2 wt% lead ion detector, and the balance being additives.

[0019] Further, in step S1, the mixing speed is 700-900 rpm and the time is 3-5 min; and / or, in step S2, the mixing temperature is 85-95℃ and the time is 5-15 min; and / or, in step S3, the extrusion temperature is 85-110℃ and the time is 1-3 min; and / or, extrusion is performed using a twin-screw extruder with a screw speed of 150-180 rpm; and / or, the average particle size of the granules is 2-4 mm; and / or, in step S4, the casting temperature is 90-105℃ and the setting temperature is 20-25℃.

[0020] Furthermore, the additives include compatibilizers, light stabilizers, and antioxidants.

[0021] Furthermore, based on the weight percentage of the mixture, the encapsulating film includes: 0.5–2 wt% compatibilizer, 0.1–0.5 wt% light stabilizer, and 0.1–0.5 wt% antioxidant.

[0022] Another aspect of the present invention provides a solar cell module, including a single-cell perovskite solar cell or a tandem solar cell, and an encapsulating film disposed on its surface, wherein the encapsulating film is selected from the encapsulating films provided in this application.

[0023] Applying the technical solution of this invention, the sulfonic acid groups in the sulfonic acid ion exchange resin of the encapsulating film provided in this application can react with divalent lead ions (Pb). 2+The lead ion is coordinated to capture lead ions and prevent them from leaking out. At the same time, the introduction of lead ion detection agent into the encapsulation film can indicate the leakage of lead ions through a color reaction, helping power plant operation and maintenance personnel to quickly identify leaking solar cell modules, thereby quickly carrying out repairs or replacements to reduce environmental pollution and harm to human health.

[0024] Compared to other ranges, limiting the content of each component in the encapsulating film to the above range is beneficial for the encapsulating film to maintain good physical protection, electrical insulation and optical transparency, while improving lead capture and detection effects, thus meeting the environmental protection and safety requirements of the commercial application of encapsulating films. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 A cross-sectional structural schematic diagram of a perovskite solar cell module in an embodiment and comparative example of this application is shown.

[0027] The above figures include the following reference numerals:

[0028] 100, First transparent substrate layer; 200, Edge sealant; 300, Encapsulating film; 400, Single-cell perovskite solar cell; 500, Second transparent substrate layer. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0030] As described in the background section, existing encapsulating films have the problem of being unable to simultaneously prevent and detect lead leakage, thus causing environmental pollution. To address this technical problem, the first aspect of this application provides an encapsulating film comprising, by weight percentage: 85–95 wt% matrix resin, 3–8 wt% sulfonic acid-based ion exchange resin, 0.5–2 wt% lead ion detection agent, and the balance being additives; the lead ion detection agent comprises a carrier and a rhodamine-like compound loaded on its surface.

[0031] The sulfonic acid groups in the sulfonic acid ion exchange resin of the encapsulating film provided in this application can react with divalent lead ions (Pb). 2+ This allows for coordination with Pb, thereby capturing lead ions and preventing their leakage. Simultaneously, the introduction of the lead ion detection agent into the encapsulation film enables it to interact with Pb through the closed-ring structure of the rhodamine-like compound. 2+The colorimetric reaction indicates lead ion leakage, helping power plant maintenance personnel quickly identify leaking solar cell modules, enabling rapid repair or replacement to reduce environmental pollution and harm to human health.

[0032] Compared to other ranges, limiting the content of each component in the encapsulating film to the above range is beneficial for the encapsulating film to maintain good physical protection, electrical insulation and optical transparency, while improving lead capture and detection effects, thus meeting the environmental protection and safety requirements of the commercial application of encapsulating films.

[0033] In a preferred embodiment, the sulfonic acid-based ion exchange resin includes, but is not limited to, one or more of poly(1-vinylimidazolium co-2-acrylamido-2-methyl-1-propanesulfonic acid) (P(VIm-co-APSA)), polystyrene sulfonic acid, and perfluorosulfonic acid resins. Using the above-mentioned types of sulfonic acid-based ion exchange resins is beneficial for further improving the lead ion capture capacity of the encapsulation film, further enhancing the lead ion capture effect, thereby helping to further reduce or avoid lead ion leakage, reducing environmental pollution and harm to human health.

[0034] To improve the processability of the encapsulating film and to better utilize the lead ion capture capability of the sulfonic acid-based ion exchange resin, preferably, the weight-average molecular weight of the sulfonic acid-based ion exchange resin is 5 × 10⁻⁶. 4 ~5×10 5 The porosity is 30-70%.

[0035] In a preferred embodiment, the carrier in the lead ion detection agent includes, but is not limited to, silicon dioxide. The carrier in the lead ion detection agent of this application can be a commonly used carrier.

[0036] When Pb in solar cell modules 2+ During leakage, the closed-ring structure of the rhodamine-like compound in the encapsulating film interacts with Pb. 2 + During coordination, ring opening occurs, resulting in a strong color change. In a preferred embodiment, the lead ion detection reagent contains rhodamine compounds, including but not limited to one or more of rhodamine 6G, rhodamine B, and rhodamine 101. Compared to other types, the above-mentioned rhodamine compounds are more effective against Pb. 2+ It has higher sensitivity and the color change is more obvious after the color reaction, which helps power plant operation and maintenance personnel to quickly identify leaking components and then quickly carry out repairs or replacements.

[0037] It should be noted that the chemical structural formula of Rhodamine 6G is as follows:

[0038] .

[0039] The chemical structural formula of Rhodamine B is as follows:

[0040] .

[0041] The chemical structural formula of Rhodamine 101 is as follows:

[0042] .

[0043] To further improve the sensitivity of the lead ion detection reagent and enhance the lead ion detection capability of the encapsulation film, preferably, the weight ratio of rhodamine-like compounds to the carrier in the lead ion detection reagent is (0.01-0.2):(1-10).

[0044] In a preferred embodiment, the matrix resin includes, but is not limited to, ethylene octene copolymer (POE). Using the above-mentioned types of matrix resins is beneficial for improving the mechanical properties and thermal stability of the encapsulating film.

[0045] In a preferred embodiment, the weight-average molecular weight of the matrix resin is 1 × 10⁻⁶. 5 ~5×10 5 The weight-average molecular weight of the base resin includes, but is not limited to, the ranges mentioned above. Limiting it to these ranges is beneficial for further improving the mechanical properties, thermal stability, and transparency of the encapsulating film.

[0046] In a preferred embodiment, the additives include a compatibilizer, a light stabilizer, and an antioxidant. The introduction of a compatibilizer improves the interfacial bonding between the matrix resin and other functional components, thereby enhancing the overall uniformity and chemical stability of the encapsulating film. The introduction of a light stabilizer enhances the encapsulating film's resistance to ultraviolet radiation, thus extending the lifespan of the solar cell module. The introduction of an antioxidant improves the antioxidant properties of the encapsulating film, enhancing the weather resistance and long-term stability of the solar cell module. Introducing these additives into the encapsulating film allows for synergistic effects among the components, improving the physical and chemical properties and long-term stability of the encapsulating film.

[0047] To further improve the physical and chemical properties and long-term stability of the encapsulating film, preferably, the encapsulating film comprises, by weight percentage, 0.5–2 wt% compatibilizer, 0.1–0.5 wt% light stabilizer and 0.1–0.5 wt% antioxidant.

[0048] To further improve the interfacial bonding between the matrix resin and other functional components, preferably, the compatibilizer includes, but is not limited to, maleic anhydride-grafted ethylene-octene copolymer (MAH-g-POE compatibilizer).

[0049] To further enhance the encapsulating film's resistance to ultraviolet radiation and extend the lifespan of solar cell modules, preferably, the light stabilizer includes, but is not limited to, one or more of the following: bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidine)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidine)imino}], and bis(2,2,6,6-tetramethyl-4-piperidine) sebacate.

[0050] To further improve the antioxidant properties of the encapsulating film and enhance the weather resistance and long-term stability of solar cell modules, preferably, the antioxidant includes, but is not limited to, one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

[0051] In a preferred embodiment, the thickness of the encapsulating film is 0.1–1 mm. The thickness of the encapsulating film includes, but is not limited to, the above range. Limiting it to this range helps to ensure sufficient strength and stability to adapt to the actual application scenarios of solar cell modules, and also provides more suitable permeation channels and reaction space, allowing the sulfonic acid-based ion exchange resin and rhodamine compounds to respond rapidly upon contact with lead ions.

[0052] The second aspect of this application also provides a method for preparing the above-mentioned encapsulating film provided in this application. The preparation method includes: step S1, mixing a matrix resin, a sulfonic acid-based ion exchange resin, a lead ion detector, and additives to obtain a mixture; step S2, internally mixing the mixture to obtain an internally mixed product; step S3, sequentially extruding and pelletizing the internally mixed product to obtain granules; and step S4, sequentially casting and shaping the granules to obtain an encapsulating film; wherein, based on the weight percentage of the mixture, the mixture includes 85-95 wt% matrix resin, 3-8 wt% sulfonic acid-based ion exchange resin, 0.5-2 wt% lead ion detector, and the balance being additives.

[0053] In the above preparation method, the matrix resin, sulfonic acid ion exchange resin, lead ion detection agent and additives are first mixed to obtain a mixture, and then the mixture is kneaded to obtain a kneaded product; then the kneaded product is extruded and granulated to obtain granules; finally, the granules are cast and molded to obtain an encapsulation film containing the above specific components.

[0054] The sulfonic acid groups in the sulfonic acid ion exchange resin of the encapsulating film provided in this application can react with divalent lead ions (Pb). 2+The lead ion is coordinated to capture lead ions and prevent them from leaking out. At the same time, the introduction of lead ion detection agent into the encapsulation film can indicate the leakage of lead ions through a color reaction, helping power plant operation and maintenance personnel to quickly identify leaking solar cell modules, thereby quickly carrying out repairs or replacements to reduce environmental pollution and harm to human health.

[0055] Compared to other ranges, limiting the content of each component in the mixture to the above range can produce encapsulating films with specific compositions. This allows the encapsulating films to maintain good physical protection, electrical insulation, and optical transparency while improving lead capture and detection effects, thus meeting the environmental and safety requirements for the commercial application of encapsulating films.

[0056] In a preferred embodiment, in step S1, the mixing speed is 700–900 rpm and the mixing time is 3–5 min. The mixing speed and time include, but are not limited to, the above range. Limiting them to the above range is beneficial to improving the dispersibility of the matrix resin and other raw materials, resulting in a more thoroughly mixed mixture, which is convenient for subsequent processing.

[0057] In a preferred embodiment, in step S2, the mixing temperature is 85–95°C, and the time is 5–15 minutes. The mixing temperature and time include, but are not limited to, the above ranges. Limiting them to the above ranges is beneficial for uniformly coating the sulfonic acid ion exchange resin and lead ion detector on the surface of the matrix resin melt, thereby obtaining a mixed product with a more uniform distribution of each part.

[0058] In a preferred embodiment, in step S3, the extrusion temperature is 85–110°C, and the time is 1–3 minutes. The extrusion temperature and time include, but are not limited to, the above ranges. Limiting them to these ranges is beneficial for uniformly coating the sulfonic acid-based ion exchange resin and lead ion detector on the surface of the matrix resin melt, thereby improving the overall performance of the granules.

[0059] In a preferred embodiment, extrusion is performed using a twin-screw extruder with a screw speed of 150–180 rpm. The screw speed includes, but is not limited to, the above range. Limiting it within this range facilitates the uniform coating of the sulfonic acid-based ion exchange resin and lead ion detector onto the surface of the matrix resin melt, thereby improving the overall performance of the granules.

[0060] To facilitate subsequent casting and obtain a smoother and more uniform encapsulating film, the average particle size of the granules is preferably 2-4 mm.

[0061] In a preferred embodiment, in step S4, the casting temperature is 90–105°C, and the setting temperature is 20–25°C. The casting and setting temperatures include, but are not limited to, the above ranges. Limiting them within these ranges facilitates rapid setting and improved surface finish of the encapsulating film, helps avoid thermal degradation during the casting process, and facilitates obtaining an encapsulating film with more uniform thickness, thereby improving the mechanical properties and dimensional stability of the encapsulating film.

[0062] In a preferred embodiment, the additives include a compatibilizer, a light stabilizer, and an antioxidant. The introduction of a light stabilizer enhances the encapsulating film's resistance to ultraviolet radiation, thereby extending the lifespan of the solar cell module. The introduction of an antioxidant improves the antioxidant properties of the encapsulating film, enhancing the weather resistance and long-term stability of the solar cell module. Incorporating these additives into the encapsulating film allows for synergistic effects among the components, improving the physical and chemical properties and long-term stability of the encapsulating film.

[0063] To further improve the physical and chemical properties and long-term stability of the encapsulating film, preferably, the encapsulating film comprises, by weight percentage of the mixture, 0.5–2 wt% compatibilizer, 0.1–0.5 wt% light stabilizer and 0.1–0.5 wt% antioxidant.

[0064] In a preferred embodiment, the preparation method of the lead ion detection agent includes: step SA1, mixing and reacting a carrier, a silane coupling agent, and a first solvent to obtain an aminated carrier; step SA2, mixing and immobilizing the aminated carrier, a rhodamine-like compound, and a second solvent, followed by separation and drying to obtain the lead ion detection agent.

[0065] In step SA1, the amino groups in the silane coupling agent are grafted onto the support, forming an aminated support. In step SA2, the carbonyl groups in the rhodamine-like compound react with the amino groups in the aminated support to form amide bonds, which are then fixed on the surface of the aminated support. Simultaneously, hydrogen bonds also form between the two groups, completing the loading process. Then, separation and drying are performed sequentially to obtain the lead ion detection reagent. This preparation method has a high loading rate and a simple preparation process.

[0066] To improve the formation rate of the amination support, preferably, the weight ratio of the support to the silane coupling agent is (1-10):(0.05-0.3).

[0067] To enhance the reactivity of the silane coupling agent and increase the formation rate of the aminated support, the silane coupling agent is preferably selected from one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-β(aminoethyl)-γ-aminopropyltriethoxysilane.

[0068] To improve the formation rate of the amination support, preferably, in step SA1, the reaction temperature is 60–100°C and the time is 1–3 h.

[0069] In a preferred embodiment, the first solvent is selected from one or more of toluene, xylene, and benzene. Compared to other types, using the first solvent of the above types is beneficial for improving the dispersibility of the support and the silane coupling agent, facilitating their reaction.

[0070] To improve the loading rate of rhodamine compounds in lead ion detection reagents and enhance the sensitivity of lead ion detection reagents, preferably, the weight ratio of the aminated carrier to the rhodamine compounds is (1-10):(0.01-0.2).

[0071] To improve the loading effect, increase the loading rate of rhodamine compounds in the lead ion detection reagent, and improve the sensitivity of the lead ion detection reagent, preferably, in step SA2, the immobilization is carried out under stirring conditions, and the immobilization time is 1 to 24 hours.

[0072] In a preferred embodiment, the second solvent is selected from one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP). Compared to other types, using the above-mentioned second solvents is beneficial for improving the dispersibility of the aminated support and rhodamine compounds, thereby facilitating immobilization.

[0073] A third aspect of this application also provides a solar cell module, comprising a single-cell perovskite solar cell or a tandem solar cell, and an encapsulating film disposed on its surface, wherein the encapsulating film is selected from the encapsulating films provided in this application. The sulfonic acid-based ion exchange resin in the encapsulating film provided in this application can capture divalent lead ions, preventing lead ion leakage. Simultaneously, the introduction of a lead ion detection agent in the encapsulating film can indicate the leakage of divalent lead ions through a color reaction, helping power plant maintenance personnel to quickly identify leaking solar cell modules, thereby enabling rapid repair or replacement and reducing environmental pollution and harm to human health. Applying the encapsulating film provided in this application to solar cell modules can prevent lead ion leakage, and even if lead ion leakage occurs, it can be indicated by a color change, helping power plant maintenance personnel to quickly identify leaking solar cell modules and thus enabling rapid repair or replacement, thereby reducing environmental pollution and harm to human health.

[0074] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0075] (a) Preparation of encapsulating film

[0076] Example 1

[0077] A method for preparing a lead ion detection reagent, comprising:

[0078] 1.00 g of SiO2 with an average particle size of 200 nm was dispersed in 40 g of anhydrous toluene, and 0.10 g of 3-aminopropyltriethoxysilane was added for surface amination. The mixture was stirred at 80 °C for 2 h. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain the amination-treated SiO2 support.

[0079] 1.00 g of aminated SiO2 support was dispersed in 20 g of DMF, and 0.02 g of Rhodamine 6G (CAS No.: 989-38-8) was added. The mixture was immobilized and reacted under magnetic stirring at room temperature for 12 h. After the reaction was completed, the mixture was filtered, washed with ethanol, and dried under vacuum in the dark to obtain a colorless lead ion detection reagent.

[0080] A method for preparing an encapsulating film, comprising:

[0081] (1) Weigh out 92g of each weight-average molecular weight of 3×10 5 POE matrix resin, 5g of P(VIm-co-APSA) (weight average molecular weight of 2×10 5 1g of lead ion detection reagent (with a porosity of 50%), 1.5g of MAH-g-POE compatibilizer, 0.3g of light stabilizer bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, and 0.2g of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester were added to a high-speed mixer and stirred at 800 rpm for 4 minutes to obtain a mixture.

[0082] (2) Add the mixture from step (1) into the internal mixer, set the temperature of the internal mixer to 90°C, and mix for 10 minutes to obtain the internally mixed product;

[0083] (3) The intensive product obtained in step (2) is fed into a twin-screw extruder, the temperature is set to 100℃, the screw speed is kept at 160rpm, the extruded material is cooled by a water-cooled strip system, and then pelletized by a pelletizer into pellets with an average particle size of 3mm.

[0084] (4) Add the granules obtained in step (3) to a single screw casting machine, set its front temperature to 95°C, and the extruded product is shaped by a cooling and calendering roller (20°C) to obtain a 0.5mm thick encapsulation film.

[0085] Example 2

[0086] The preparation method of the encapsulating film is the same as that in Example 1, except that the rhodamine-like compound in the lead ion detection agent is rhodamine B.

[0087] A method for preparing a lead ion detection reagent, comprising:

[0088] 1.00 g of SiO2 with an average particle size of 200 nm was dispersed in 40 g of anhydrous toluene, and 0.10 g of 3-aminopropyltriethoxysilane was added for surface amination. The mixture was stirred at 80 °C for 2 h. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain the amination-treated SiO2 support.

[0089] 1.00 g of aminated SiO2 support was dispersed in 20 g of DMF, and 0.02 g of Rhodamine B (CAS No.: 81-88-9) was added. The mixture was immobilized and reacted under magnetic stirring at room temperature for 12 h. After the reaction was completed, the mixture was filtered, washed with ethanol, and dried under vacuum in the dark to obtain a colorless lead ion detection reagent.

[0090] Example 3

[0091] The preparation method of the encapsulating film is the same as that in Example 1, except that the rhodamine compound in the lead ion detection reagent is rhodamine 101.

[0092] A method for preparing a lead ion detection reagent, comprising:

[0093] 1.00 g of SiO2 with an average particle size of 200 nm was dispersed in 40 g of anhydrous toluene, and 0.10 g of 3-aminopropyltriethoxysilane was added for surface amination. The mixture was stirred at 80 °C for 2 h. After the reaction was completed, the mixture was filtered, washed, and vacuum dried to obtain the amination-treated SiO2 support.

[0094] 1.00 g of aminated SiO2 support was dispersed in 20 g of DMF, and 0.02 g of Rhodamine 101 (CAS No.: 64339-18-0) was added. The mixture was immobilized and reacted under magnetic stirring at room temperature for 12 h. After the reaction was completed, the mixture was filtered, washed with ethanol, and dried under vacuum in the dark to obtain a colorless lead ion detection reagent.

[0095] Example 4

[0096] The difference from Example 1 is that in step (1), 85g of POE matrix resin, 8g of P(VIm-co-APSA), 2g of lead ion detection agent, 3g of MAH-g-POE compatibilizer, 1g of light stabilizer bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, and 1g of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester are weighed out respectively. The remaining steps are the same as in Example 1.

[0097] Example 5

[0098] The difference from Example 1 is that in step (1), 95g of POE matrix resin, 3g of P(VIm-co-APSA), 0.5g of lead ion detection agent, 0.5g of MAH-g-POE compatibilizer, 0.5g of light stabilizer bis(2,2,6,6-tetramethyl-4-piperidine) sebacate and 0.5g of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester are weighed. The remaining steps are the same as in Example 1.

[0099] Comparative Example 1

[0100] The difference from Example 1 is that no lead ion detection agent was prepared, and no lead ion detection agent was added in the preparation method of the encapsulating film.

[0101] Comparative Example 2

[0102] The difference from Example 1 is that P(VIm-co-APSA) was not added in the preparation method of the encapsulating film.

[0103] Comparative Example 3

[0104] The difference from Example 1 is that in step (1), 80g of POE matrix resin, 10g of P(VIm-co-APSA), 3g of lead ion detection agent, 4g of MAH-g-POE compatibilizer, 1.5g of light stabilizer bis(2,2,6,6-tetramethyl-4-piperidine) sebacate and 1.5g of antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester are weighed. The remaining steps are the same as in Example 1.

[0105] (II) Assembly of perovskite solar cell modules:

[0106] The first transparent substrate 100, edge sealant 200, the encapsulating film 300 prepared in the embodiments and comparative examples of this application, the single-junction perovskite solar cell 400, and the second transparent substrate 500 are arranged in accordance with... Figure 1 The setup is as shown, where edge sealant 200 is sandwiched between the first transparent substrate layer 100 and the second transparent substrate layer 500, surrounding the periphery of the single-cell perovskite solar cell 400 and the encapsulating film 300; then it is placed in a laminator and laminated at 115°C for 20 minutes to obtain the perovskite solar cell module. A 2cm wide slit is made in the central region of the first transparent substrate layer, and deionized water is dripped into the slit to simulate rain conditions.

[0107] The color development time and color change of the perovskite solar cell modules in all the embodiments and comparative examples of this application were tested. The Pb content in the liquid seeping from cracks under simulated rainwater conditions was measured by graphite furnace atomic absorption spectrometry according to GB / T 5750.6-2023 "Standard Examination Methods for Drinking Water - Metallic Indicators". 2+ The concentrations and test results are shown in Table 1.

[0108] It should be noted that the first transparent substrate 100 and the second transparent substrate 500 used in the above embodiments and comparative examples of this application are transparent glass substrates; the stacked structure of the single-junction perovskite solar cell 400 used is ITO / NiO. x / MAPbI3 / C60 / SnO2 / ITO / Ag; The edge sealant 200 used in the above embodiments and comparative examples of this application is butyl rubber (Foster, PIB-401).

[0109] Table 1

[0110]

[0111] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0112] The sulfonic acid groups in the sulfonic acid ion exchange resin of the encapsulating film provided in this application can react with divalent lead ions (Pb). 2+ This allows for coordination with Pb, thereby capturing lead ions and preventing their leakage. Simultaneously, the introduction of the lead ion detection agent into the encapsulation film enables it to interact with Pb through the closed-ring structure of the rhodamine-like compound. 2+ The colorimetric reaction indicates lead ion leakage, helping power plant maintenance personnel quickly identify leaking solar cell modules, enabling rapid repair or replacement to reduce environmental pollution and harm to human health.

[0113] Compared to other ranges, limiting the content of each component in the encapsulating film to the above range is beneficial for the encapsulating film to maintain good physical protection, electrical insulation and optical transparency, while improving lead capture and detection effects, thus meeting the environmental protection and safety requirements of the commercial application of encapsulating films.

[0114] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0115] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An encapsulating film, characterized in that, The encapsulating film comprises, by weight percentage, 85-95 wt% matrix resin, 3-8 wt% sulfonic acid-based ion exchange resin, 0.5-2 wt% lead ion detection agent, and the balance being additives; the lead ion detection agent comprises a carrier and a rhodamine-like compound loaded on its surface.

2. The encapsulating film according to claim 1, characterized in that, The sulfonic acid-based ion exchange resin is selected from one or more of poly(1-vinylimidazolium co-2-acrylamido-2-methyl-1-propanesulfonic acid), polystyrene sulfonic acid, and perfluorosulfonic acid resins; and / or, the weight-average molecular weight of the sulfonic acid-based ion exchange resin is 5 × 10⁻⁶. 4 ~5×10 5 The porosity is 30-70%.

3. The encapsulating film according to claim 1, characterized in that, In the lead ion detection reagent, the carrier is selected from silicon dioxide; and / or, the rhodamine compound is selected from one or more of rhodamine 6G, rhodamine B, and rhodamine 101. Preferably, in the lead ion detection reagent, the weight ratio of the rhodamine compound to the carrier is (0.01-0.2):(1-10).

4. The encapsulating film according to any one of claims 1 to 3, characterized in that, The matrix resin is selected from ethylene octene copolymer; and / or, the weight-average molecular weight of the matrix resin is 1 × 10⁻⁶. 5 ~5×10 5 .

5. The encapsulating film according to any one of claims 1 to 4, characterized in that, The additives include compatibilizers, light stabilizers, and antioxidants; Preferably, the encapsulating film comprises, by weight percentage, 0.5–2 wt% of the compatibilizer, 0.1–0.5 wt% of the light stabilizer, and 0.1–0.5 wt% of the antioxidant; Preferably, the compatibilizer is selected from maleic anhydride-grafted ethylene-octene copolymer; Preferably, the light stabilizer is selected from one or more of bis(2,2,6,6-tetramethyl-4-piperidine) sebacate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidine)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidine)imino}], and bis(2,2,6,6-tetramethyl-4-piperidine) sebacate; Preferably, the antioxidant is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl)phosphite, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].

6. The encapsulating film according to claim 1, characterized in that, The thickness of the encapsulating film is 0.1 to 1 mm.

7. A method for preparing the encapsulating film according to claim 1, characterized in that, The preparation method includes: Step S1: Mix the matrix resin, sulfonic acid-based ion exchange resin, lead ion detection reagent, and additives to obtain a mixture; Step S2: The mixture is subjected to intensive kneading to obtain the intensively kneaded product; Step S3: The intensively mixed product is extruded and pelletized sequentially to obtain granules; Step S4: The granules are sequentially cast and shaped to obtain the encapsulating film; The mixture comprises, by weight percentage, 85-95 wt% of the matrix resin, 3-8 wt% of the sulfonic acid-based ion exchange resin, 0.5-2 wt% of the lead ion detection agent, and the balance being the additives.

8. The method for preparing the encapsulating film according to claim 7, characterized in that, In step S1, the mixing speed is 700–900 rpm, and the time is 3–5 min; and / or, In step S2, the mixing temperature is 85–95°C, and the time is 5–15 minutes; and / or, In step S3, the extrusion temperature is 85–110°C, and the time is 1–3 minutes; and / or, The extrusion is performed using a twin-screw extruder with a screw speed of 150–180 rpm; and / or; The average particle size of the granules is 2–4 mm; and / or, In step S4, the casting temperature is 90-105°C, and the setting temperature is 20-25°C.

9. The method for preparing the encapsulating film according to claim 7, characterized in that, The additives include compatibilizers, light stabilizers, and antioxidants; Preferably, the encapsulating film comprises, by weight percentage of the mixture, 0.5–2 wt% of the compatibilizer, 0.1–0.5 wt% of the light stabilizer, and 0.1–0.5 wt% of the antioxidant.

10. A solar cell module, comprising a single-cell perovskite solar cell or a tandem solar cell, and an encapsulating film disposed on its surface, characterized in that, The encapsulating film is selected from the encapsulating film according to any one of claims 1 to 6.

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