Packaging adhesive film for packaging photovoltaic module and double-glass photovoltaic module

Abstract

The invention belongs to the technical field of photovoltaics, particularly provides a packaging adhesive film for packaging a photovoltaic module and a double-glass photovoltaic module, and aims to solve the problem that an existing photovoltaic module is poor in hail impact resistance due to the fact that the existing photovoltaic module can only meet the impact of hail with the size of 35 mm or below. Therefore, the packaging adhesive film for packaging the photovoltaic module comprises the following components in percentage by weight: 85%-98.8% of a resin system, 0.2%-10% of inorganic filler and 1%-5% of a toughening agent. According to the packaging adhesive film, 0.2%-10% of inorganic filler and 1%-5% of flexibilizer are added into the packaging adhesive film, so that the toughness and impact resistance of the adhesive film can be improved, and the service life of a photovoltaic module is further prolonged.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and specifically provides an encapsulation film for encapsulating photovoltaic modules and a double-glass photovoltaic module. Background Art

[0002] Photovoltaic modules are a crucial component of solar power generation systems, primarily consisting of solar cell layers, encapsulation materials, and connectors. The encapsulation materials protect and secure the solar cell layers while also ensuring efficient light transmission. A photovoltaic module's ability to withstand hail impact is a crucial performance indicator, directly impacting its safety and lifespan. Direct impacts from hail can cause cracks, scratches, or breakage on the module's physical surface. This not only reduces the module's effective light-receiving area but can also cause short circuits or disconnections in internal circuits, further reducing power generation efficiency. Severe hail damage can also significantly increase the operational and maintenance costs of a photovoltaic power station, including costs for module replacement and repair, reduced electricity sales revenue due to reduced power generation, and downtime losses.

[0003] Currently, there are more and more extreme climates around the world, which poses a huge challenge to the quality assurance and lifespan of photovoltaic modules. According to the IEC61215 standard, the minimum diameter required in the hail test is 25mm. This means that most photovoltaic modules should be able to withstand the impact of hail of this size during the design and certification stages. Conventional and common module designs can generally pass the 35mm hail test. However, in actual outdoor situations, the size of hail often exceeds this size. For example, in June 2020, the photovoltaic power station in Qianxinan Prefecture, Guizhou Province encountered hail the size of eggs (about 50mm in diameter), resulting in heavy losses of hundreds of megawatts of photovoltaic modules and obvious damage to a large number of modules. Therefore, existing photovoltaic modules cannot cope with hail larger than 35mm.

[0004] Accordingly, this field requires a new technical solution to solve the above technical problems. Summary of the Invention

[0005] The present application aims to solve the above technical problem, that is, to solve the problem that existing photovoltaic modules can only withstand the impact of hail of 35 mm and below and have poor anti-hail impact effect.

[0006] In a first aspect, the present application provides an encapsulation film for encapsulating photovoltaic modules, wherein the encapsulation film comprises the following components by weight: 85% to 98.8% resin system, 0.2% to 10% inorganic filler, and 1% to 5% toughening agent.

[0007] In the above-mentioned preferred technical solution of the encapsulation film for encapsulating photovoltaic modules, the inorganic filler includes one or more of silica, alumina, and calcium carbonate; and / or the particle size of the inorganic filler is 1 nm to 10 μm; and / or the toughening agent includes one or more of transparent thermoplastic elastomer particles, ABS, polymethyl methacrylate, polyurethane, polyester, bisphenol A epoxy resin, polycarbonate, polyethylene terephthalate, and polyvinylidene fluoride.

[0008] In a second aspect, the present application provides a double-glass photovoltaic module, which includes a front glass, a front packaging film, a battery layer, a back packaging film and a back glass stacked in sequence, and the front packaging film and the back packaging film are the above-mentioned packaging films used to encapsulate photovoltaic modules.

[0009] In the preferred technical solution of the above double-glass photovoltaic module, the front encapsulation film comprises the following components by weight: 90% to 98.8% resin system, 0.2% to 5% inorganic filler, and 1% to 5% toughening agent.

[0010] In the preferred technical solution of the above-mentioned double-glass photovoltaic module, in the front packaging film, the ratio of the mass content of the inorganic filler to the mass content of the toughening agent is 1:(2~5); and / or, in the back packaging film, the ratio of the mass content of the inorganic filler to the mass content of the toughening agent is 1:(1~3).

[0011] In the preferred technical solution of the above double-glass photovoltaic module, the ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is (1-3):1.

[0012] In the preferred technical solution of the above-mentioned double-glass photovoltaic module, the ratio of the mass content of the inorganic filler in the back packaging film to the mass content of the inorganic filler in the front packaging film is (1.2~2.5):1; preferably, the ratio of the mass content of the inorganic filler in the back packaging film to the mass content of the inorganic filler in the front packaging film is 1.5:1.

[0013] In the preferred technical solution of the above double-glass photovoltaic module, the inorganic filler in the front encapsulation film is a nanometer-scale inorganic filler, and the inorganic filler in the back encapsulation film is a micrometer-scale inorganic filler.

[0014] In the preferred technical solution of the above-mentioned double-glass photovoltaic module, the particle size of the nanoscale inorganic filler is 1nm~100nm, preferably the particle size of the nanoscale inorganic filler is 20nm~40nm; and / or, the nanoscale inorganic filler includes one or more of nano-silicon dioxide and nano-alumina.

[0015] In the preferred technical solution of the above-mentioned double-glass photovoltaic module, the particle size of the micron-sized inorganic filler is 0.01μm to 10μm, preferably the particle size of the micron-sized inorganic filler is 0.1μm to 5μm; and / or, the micron-sized inorganic filler includes one or more of silica, alumina, and calcium carbonate.

[0016] Compared with the existing technology, the technical solution of this application has the following beneficial effects:

[0017] (1) The present application can improve the toughness and impact resistance of the encapsulating film by adding 0.2% to 10% of inorganic fillers and 1% to 5% of toughening agents to the encapsulating film. Therefore, after being applied to photovoltaic modules, the photovoltaic modules can effectively improve their resistance to hail impacts, enabling the photovoltaic modules to withstand the impact of hailstones larger than 35 mm, thereby increasing the service life of the photovoltaic modules.

[0018] (2) The double-glass photovoltaic module of the present application can improve the light transmittance and the toughness of the front packaging film by adding nano-scale inorganic fillers and toughening agents to the front packaging film, thereby effectively improving the hail impact resistance of the photovoltaic module. At the same time, adding micron-scale inorganic fillers and toughening agents to the back packaging film can improve the reflectivity of the back packaging film, so that the light passing through the battery layer and the light between the battery layers can also be reflected back to the battery layer, thereby improving the utilization rate of light and effectively improving the impact resistance of the back packaging film. By simultaneously regulating the materials of the front packaging film and the back packaging film, the front packaging film and the back packaging film provide effective stress buffering, effectively disperse and absorb hail impact energy, reduce impact stress concentration, thereby significantly improving the hail impact resistance of the photovoltaic module, and the hail impact resistance of the prepared double-glass photovoltaic module can be increased to 40-45 mm; effectively improving the hail impact resistance of the photovoltaic module.

[0019] (3) The mass content of the inorganic filler in the back encapsulation film is not lower than the mass content of the inorganic filler in the front encapsulation film, which can better improve the hail impact resistance of the photovoltaic module to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The preferred embodiments of the present application are described below with reference to the accompanying drawings, in which:

[0021] Figure 1 It is a structural diagram of the double-glass photovoltaic module of this application.

[0022] List of reference numerals:

[0023] 1. Front glass; 2. Front encapsulation film; 3. Battery layer; 4. Back encapsulation film; 5. Back glass. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application.

[0025] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0026] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0027] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0028] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0029] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0030] The terms "first" and "second" are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features being referred to. For example, without departing from the scope of the embodiments of this application, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0031] Unless otherwise specified, the experimental methods in the following examples are conventional methods. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0032] It should be noted that, in the description of this application, unless otherwise specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through other components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0033] As pointed out in the background art, the existing photovoltaic modules can only withstand the impact of hailstones of 35 mm or less in size and have a poor hail impact resistance effect.

[0034] In a first aspect, the present application provides an encapsulation film for encapsulating photovoltaic modules. The encapsulation film can improve the toughness and impact resistance of the film by adding 0.2% to 10% inorganic filler and 1% to 5% toughening agent to the encapsulation film. Therefore, after being applied to the photovoltaic module, the film can effectively improve the photovoltaic module's resistance to hail impact, enabling the photovoltaic module to withstand the impact of hail larger than 35 mm, thereby increasing the service life of the photovoltaic module.

[0035] Specifically, the encapsulation film for encapsulating photovoltaic modules of the present application comprises the following components by weight: 85% to 98.8% of a resin system, 0.2% to 10% of an inorganic filler, and 1% to 5% of a toughening agent.

[0036] Specifically, the resin system includes, by weight percentage, 95% to 98% resin, 0.5% to 1.5% cross-linking agent, 1% to 3% auxiliary cross-linking agent, 0.1% to 0.5% coupling agent, 0% to 0.5% ultraviolet absorber, and 0.02% to 0.2% antioxidant.

[0037] Among them, the resin includes one or more of EVA, EPE, and POE; the cross-linking agent includes one or more of diphenyl carbonate, benzoyl peroxide, triallyl cyanurate, and peroxy acetal cross-linking agents; the auxiliary cross-linking agent includes one or more of zinc oxide, magnesium oxide, triallyl cyanurate, triallyl triisocyanate, and trimethylolpropane trimethacrylate; the coupling agent includes one or more of vinyl triethoxysilane, vinyl trimethoxysilane, or vinyl tris(β-methoxyethoxy) silane; the ultraviolet absorber includes one or more of benzotriazole organic matter, benzophenone organic matter, and cyanoacrylate organic matter; the antioxidant includes one or more of 2,6-di-tert-butyl-4-methylphenol, trisnonylphenyl phosphite, triphenyl phosphate, or didodecyl-3,3'-thiodipropionate.

[0038] Preferably, the resin includes one or more of EVA, EPE, and POE.

[0039] Preferably, the inorganic filler includes one or more of silicon dioxide, aluminum oxide, and calcium carbonate.

[0040] Preferably, the particle size of the inorganic filler is 1 nm to 10 μm.

[0041] Preferably, the toughening agent includes one or more of transparent thermoplastic elastomer (TPE) particles, ABS, polymethyl methacrylate, polyurethane, polyester, bisphenol A epoxy resin, polycarbonate, polyethylene terephthalate, and polyvinylidene fluoride.

[0042] The present application can improve the toughness and impact resistance of the encapsulation film by adding 0.2% to 10% inorganic filler and 1% to 5% toughening agent to the encapsulation film. Therefore, after being applied to the photovoltaic module, the photovoltaic module can effectively improve the hail impact resistance, so that the photovoltaic module can withstand the impact of hail larger than 35mm, thereby increasing the service life of the photovoltaic module.

[0043] In the second aspect, the present application provides a double-glass photovoltaic module, which has good hail impact resistance, can withstand the impact of 40-45mm hail, can effectively adapt to various harsh environments, and improve the service life of the double-glass photovoltaic module.

[0044] Specifically, see Figure 1 The double-glass photovoltaic module of the present application includes a front glass 1, a front packaging film 2, a battery layer 3, a back packaging film 4 and a back glass 5 stacked in sequence. The front packaging film 2 and the back packaging film 4 are both packaging films for encapsulating photovoltaic modules provided in the first aspect of the present application.

[0045] The inorganic filler in the front encapsulation film 2 is a nanometer-scale inorganic filler, and the inorganic filler in the back encapsulation film 4 is a micrometer-scale inorganic filler.

[0046] The double-glass photovoltaic module of the present application can improve the light transmittance and the toughness of the front encapsulation film 2 by adding nano-scale inorganic fillers and toughening agents to the front encapsulation film 2, thereby effectively improving the hail impact resistance of the photovoltaic module. At the same time, adding micron-scale inorganic fillers and toughening agents to the back encapsulation film 4 can improve the reflectivity of the back encapsulation film 4, so that the light passing through the battery layer 3 and the light between the battery layers 3 can also be reflected back to the battery layer 3, thereby improving the utilization rate of light and effectively improving the impact resistance of the back encapsulation film 4. Therefore, the double-glass photovoltaic module of the present application simultaneously regulates the materials of the front encapsulation film 2 and the back encapsulation film 4, so that the front encapsulation film 2 and the back encapsulation film 4 provide effective stress buffering, effectively disperse and absorb hail impact energy, and reduce impact stress concentration, thereby significantly improving the hail impact resistance of the photovoltaic module, so that the hail impact resistance of the prepared double-glass photovoltaic module is increased from 35mm to 40-45mm; effectively improving the hail impact resistance of the photovoltaic module.

[0047] The cells in the cell layer 3 may be crystalline silicon cells, perovskite cells or other solar cells of any type and model.

[0048] Preferably, the particle size of the nanoscale inorganic filler is 1 nm to 100 nm.

[0049] Specifically, the particle size of the nanoscale inorganic filler can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm and a value between any two of the above numerical ranges.

[0050] More preferably, the particle size of the nanoscale inorganic filler is 20 nm to 40 nm.

[0051] Specifically, the particle size of the nanoscale inorganic filler can be 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 33 nm, 35 nm, 38 nm, 40 nm, and a value between any two of the above numerical ranges.

[0052] Preferably, the nano-scale inorganic filler includes one or more of nano-silicon dioxide and nano-aluminum oxide.

[0053] Preferably, the particle size of the micron-sized inorganic filler is 0.01 μm to 10 μm.

[0054] Specifically, the particle size of the micron-sized inorganic filler can be 0.01 μm, 0.02 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 8 μm, 10 μm and a value between any two of the above numerical ranges.

[0055] More preferably, the particle size of the micron-sized inorganic filler is 0.1 μm to 5 μm.

[0056] Specifically, the particle size of the micron-sized inorganic filler can be 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.2μm, 1.5μm, 1.8μm, 2μm, 2.2μm, 2.5μm, 2.8μm, 3μm, 3.2μm, 3.5μm, 3.8μm, 4μm, 4.2μm, 4.5μm, 4.8μm, 5μm and a value between any two of the above numerical ranges.

[0057] Preferably, the micron-sized inorganic filler includes one or more of silicon dioxide, aluminum oxide, and calcium carbonate.

[0058] More preferably, the micron-sized inorganic filler includes silicon dioxide and calcium carbonate.

[0059] Preferably, the front encapsulation film 2 comprises the following components by weight: 90% to 98.8% of a resin system, 0.2% to 5% of a nano-scale inorganic filler, and 1% to 5% of a toughening agent.

[0060] In some preferred embodiments, the front encapsulation film 2 comprises the following components by weight: 94% resin system, 2% nano-scale inorganic filler, and 4% toughening agent.

[0061] Preferably, the backside encapsulation film 4 comprises the following components by weight: 85% to 98.8% of a resin system, 0.2% to 10% of a micron-sized inorganic filler, and 1% to 5% of a toughening agent.

[0062] In some preferred embodiments, the backside encapsulation film 4 comprises the following components by weight: 92.5% resin system, 3% micron-sized inorganic filler, and 4.5% toughening agent.

[0063] Preferably, the ratio of the mass content of the inorganic filler in the back encapsulation film 4 to the mass content of the inorganic filler in the front encapsulation film 2 is (1-3):1.

[0064] The ratio of the mass content of the inorganic filler in the back packaging film 4 to the mass content of the inorganic filler in the front packaging film 2 is controlled to be (1-3):1. By regulating the mass content of the inorganic filler in different packaging films, the overall hail impact resistance of the final double-glass photovoltaic module can be effectively guaranteed.

[0065] More preferably, the ratio of the mass content of the inorganic filler in the back encapsulation film 4 to the mass content of the inorganic filler in the front encapsulation film 2 is (1.2-2.5):1.

[0066] More preferably, the ratio of the mass content of the inorganic filler in the back encapsulation film 4 to the mass content of the inorganic filler in the front encapsulation film 2 is 1.5:1.

[0067] Specifically, the ratio of the mass content of the inorganic filler in the back packaging film 4 to the mass content of the inorganic filler in the front packaging film 2 can be 1:1, 1.2:1, 1.5:1, 1.7:1, 2:1, 2.5:1, 3:1 and a ratio between any two of the above ratio ranges. The preferred ratio is (1.2~2.5):1, and the most preferred ratio is 1.5:1.

[0068] Preferably, in the front encapsulation film 2 , the ratio of the mass content of the inorganic filler to the mass content of the toughening agent is 1:(2-5).

[0069] Specifically, in the front packaging film 2, the ratio of the mass content of the inorganic filler to the mass content of the toughening agent can be 1:1, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.2, 1:4.5, 4:4.8, 1:5 and the ratio between any two of the above ratio ranges, and the preferred ratio is 1:2.

[0070] Preferably, in the backside encapsulation film 4 , the ratio of the mass content of the inorganic filler to the mass content of the toughening agent is 1:(1-3).

[0071] Specifically, in the back packaging film 4, the ratio of the mass content of the inorganic filler to the mass content of the toughening agent can be 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.5, 1:2.8, 1:3 and the ratio between any two of the above ratio ranges, and the preferred ratio is 1:1.5.

[0072] Preferably, the ratio of the thickness of the front encapsulation film 2 to the thickness of the back encapsulation film 4 is 1:(1-1.2).

[0073] Specifically, the ratio of the thickness of the front encapsulation film 2 to the thickness of the back encapsulation film 4 can be 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, or a ratio between any two of the above ratio ranges, preferably 1:1.

[0074] Preferably, the thickness of the front packaging film 2 is 0.25 mm to 0.65 mm.

[0075] More preferably, the thickness of the front packaging film 2 is 0.3 mm to 0.5 mm.

[0076] Preferably, the thickness of the back packaging film 4 is 0.25 mm to 0.65 mm.

[0077] More preferably, the thickness of the backside packaging film 4 is 0.3 mm to 0.5 mm.

[0078] In a preferred embodiment, the thickness of the front packaging film 2 and the back packaging film 4 are both 0.4 mm.

[0079] By controlling the thickness of the front encapsulation film 2 and the back encapsulation film 4 in the double-glass photovoltaic module, the light transmittance and hail impact resistance of the double-glass photovoltaic module can be effectively improved, thereby enabling the double-glass photovoltaic module to adapt to various extreme weather conditions and extend its service life.

[0080] The double-glass photovoltaic module of the present application is described in detail below through several specific embodiments.

[0081] Example 1

[0082] The double-glass photovoltaic module in this embodiment is prepared by the following steps:

[0083] (1) Extrusion of front encapsulation film: 94% of the resin system, 2% of the nano-scale inorganic filler (silicon dioxide with a particle size of 30 nm), and 4% of the toughening agent (thermoplastic elastomer (TPE) particles) were uniformly blended and extruded to obtain a 0.4 mm thick front encapsulation film.

[0084] (2) Extrusion of back-side encapsulation film: 92.5% of the resin system, 3% of a micron-sized inorganic filler (silicon dioxide with a particle size of 3 μm), and 4.5% of a toughening agent (polycarbonate) were uniformly blended and extruded to obtain a 0.4 mm thick back-side encapsulation film.

[0085] (3) The front encapsulation film and the back encapsulation film were applied to the front and back of the photovoltaic double-glass 2.0mm+2.0mm module respectively, and cured at 200°C for 30 minutes to obtain a double-glass photovoltaic module.

[0086] Among them, the resin system of this embodiment is composed of the following components: 95% EVA resin, 1.5% cross-linking agent (diphenyl carbonate), 2.7% auxiliary cross-linking agent (triallyl tricyanate), 0.5% coupling agent (vinyl triethoxysilane), 0.2% UV absorber (benzotriazole), and 0.1% antioxidant (2,6-di-tert-butyl-4-methylphenol).

[0087] Example 2

[0088] The preparation process of the double-glass photovoltaic module of this comparative example is as follows:

[0089] (1) Extrusion of front encapsulation film: 94% of the resin system, 2% of the nano-scale inorganic filler (silicon dioxide with a particle size of 30 nm), and 4% of the toughening agent (thermoplastic elastomer (TPE) particles) were uniformly blended and extruded to obtain a 0.4 mm thick front encapsulation film.

[0090] (2) Extrusion of back-side encapsulation film: The resin system is uniformly blended and extruded to obtain a 0.4 mm thick back-side encapsulation film.

[0091] (3) The front encapsulation film and the back encapsulation film were applied to the front and back of the photovoltaic double-glass 2.0mm+2.0mm module respectively, and cured at 200°C for 30 minutes to obtain a double-glass photovoltaic module.

[0092] The composition and proportion of the resin system in this embodiment are the same as those in Example 1.

[0093] Example 3

[0094] The preparation process of the double-glass photovoltaic module of this comparative example is as follows:

[0095] (1) Extrusion of front encapsulation film: The resin system is uniformly blended and extruded to obtain a 0.4 mm thick front encapsulation film.

[0096] (2) Extrusion of back-side encapsulation film: 92.5% of the resin system, 3% of a micron-sized inorganic filler (silicon dioxide with a particle size of 3 μm), and 4.5% of a toughening agent (polycarbonate) were uniformly blended and extruded to obtain a 0.4 mm thick back-side encapsulation film.

[0097] (3) The front encapsulation film and the back encapsulation film are applied to the front and back of the photovoltaic double-glass 2.0mm+2.0mm module respectively, and cured at 130-200°C for 10-30 minutes to obtain a double-glass photovoltaic module.

[0098] The composition and proportion of the resin system in this embodiment are the same as those in Example 1.

[0099] Example 4

[0100] The preparation process of the double-glass photovoltaic module of this embodiment is the same as that of Example 1. The only difference from Example 1 is that the addition ratio of the nano-scale inorganic filler and the toughening agent in the composition of the front encapsulation film is different.

[0101] Specifically, in this embodiment, the components of the front packaging film are: 94% resin system, 1.5% nano-scale inorganic filler (silicon dioxide with a particle size of 30nm), and 4.5% toughening agent (thermoplastic elastomer (TPE) particles), and the composition and ratio of the resin system of this embodiment are the same as those of Example 1.

[0102] Example 5

[0103] The preparation process of the double-glass photovoltaic module of this embodiment is the same as that of Example 1. The only difference from Example 1 is that the addition ratio of the nano-scale inorganic filler and the toughening agent in the composition of the front encapsulation film is different.

[0104] Specifically, in this embodiment, the components of the front packaging film are: 94% resin system, 1% nano-scale inorganic filler (silicon dioxide with a particle size of 30nm), and 5% toughening agent (thermoplastic elastomer (TPE) particles), and the composition and ratio of the resin system of this embodiment are the same as those of Example 1.

[0105] Example 6

[0106] The preparation process of the double-glass photovoltaic module of this embodiment is the same as that of Example 1. The only difference from Example 1 is that the addition ratio of the micron-sized inorganic filler and the toughening agent in the composition of the back encapsulation film is different.

[0107] Specifically, in this embodiment, the components of the back packaging film are: 92.5% resin system, 3.75% micron-sized inorganic filler (silicon dioxide with a particle size of 3 μm), and 3.75% toughening agent (polycarbonate), and the composition and ratio of the resin system of this embodiment are the same as those of Example 1.

[0108] Example 7

[0109] The preparation process of the double-glass photovoltaic module of this embodiment is the same as that of Example 1. The only difference from Example 1 is that the addition ratios of the resin system, micron-sized inorganic filler and toughening agent in the composition of the back encapsulation film are different.

[0110] Specifically, in this embodiment, the components of the back packaging film are: 94% resin system, 1.5% micron-sized inorganic filler (silicon dioxide with a particle size of 3 μm), and 4.5% toughening agent (polycarbonate), and the composition and ratio of the resin system of this embodiment are the same as those of Example 1.

[0111] Example 8

[0112] The preparation process of the double-glass photovoltaic module of this embodiment is the same as that of Example 1. The only difference from Example 1 is that the ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is different.

[0113] Specifically, in this embodiment, the components of the front encapsulation film are: 97% resin system, 1% nano-scale inorganic filler (silicon dioxide with a particle size of 30 nm), and 2% toughening agent (thermoplastic elastomer (TPE) particles); the components of the back encapsulation film are: 97% resin, 1.2% micron-scale inorganic filler (silicon dioxide with a particle size of 3 μm), and 1.8% toughening agent (polycarbonate). The ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is 1.2:1, and the composition and ratio of the resin system of this embodiment are the same as those in Example 1.

[0114] Example 9

[0115] The preparation process of the double-glass photovoltaic module of this embodiment is the same as that of Example 1. The only difference from Example 1 is that the ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is different.

[0116] Specifically, in this embodiment, the components of the front encapsulation film are: 97% resin system, 1% nano-scale inorganic filler (silicon dioxide with a particle size of 30 nm), and 2% toughening agent (thermoplastic elastomer (TPE) particles); the components of the back encapsulation film are: 93.75% resin, 2.5% micron-scale inorganic filler (silicon dioxide with a particle size of 3 μm), and 3.75% toughening agent (polycarbonate). The ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is 1.2:1, and the composition and ratio of the resin system of this embodiment are the same as those in Example 1.

[0117] Comparative Example 1

[0118] The preparation process of the double-glass photovoltaic module of this comparative example is as follows:

[0119] (1) Extrusion of front encapsulation film: The resin system is uniformly blended and extruded to obtain a 0.4 mm thick front encapsulation film.

[0120] (2) Extrusion of back-side encapsulation film: The resin system is uniformly blended and extruded to obtain a 0.4 mm thick back-side encapsulation film.

[0121] (3) The front encapsulation film and the back encapsulation film were applied to the front and back of the photovoltaic double-glass 2.0mm+2.0mm module respectively, and cured at 200°C for 30 minutes to obtain a double-glass photovoltaic module.

[0122] The composition and proportion of the resin system in this comparative example are the same as those in Example 1.

[0123] Comparative Example 2

[0124] The preparation process of the double-glass photovoltaic module of this comparative example is as follows:

[0125] (1) Extrusion of front encapsulation film: 98% of the resin system and 2% of the nano-scale inorganic filler (silicon dioxide with a particle size of 30 nm) were uniformly blended and extruded to obtain a 0.4 mm thick front encapsulation film.

[0126] (2) Extrusion of a back-side encapsulation film: 97% of a resin system and 3% of a micron-sized inorganic filler (silicon dioxide with a particle size of 3 μm) were uniformly blended and extruded to obtain a 0.4 mm thick back-side encapsulation film.

[0127] (3) The front encapsulation film and the back encapsulation film are applied to the front and back of the photovoltaic double-glass 2.0mm+2.0mm module respectively, and cured at 130-200°C for 10-30 minutes to obtain a double-glass photovoltaic module.

[0128] The composition and proportion of the resin system in this comparative example are the same as those in Example 1.

[0129] Comparative Example 3

[0130] The preparation process of the double-glass photovoltaic module of this comparative example is as follows:

[0131] (1) Extrusion of front encapsulation film: 96% of the resin system and 4% of the toughening agent (thermoplastic elastomer (TPE) particles) were uniformly blended and extruded to obtain a 0.4 mm thick front encapsulation film.

[0132] (2) Extrusion of a back-side encapsulation film: 95.5% of the resin system and 4.5% of the toughening agent (polycarbonate) were uniformly blended and extruded to obtain a 0.4 mm thick back-side encapsulation film.

[0133] (3) The front encapsulation film and the back encapsulation film are applied to the front and back of the photovoltaic double-glass 2.0mm+2.0mm module respectively, and cured at 130-200°C for 10-30 minutes to obtain a double-glass photovoltaic module.

[0134] The composition and proportion of the resin system in this comparative example are the same as those in Example 1.

[0135] Test Example 1

[0136] The double-glass photovoltaic modules of Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to hail impact resistance tests and module power tests, and the test results are shown in Table 2.

[0137] Among them, the test method for hail impact resistance test is as follows:

[0138] During the hail test, a standard ice ball is removed from its storage container, placed in a launcher, and fired at the designated impact location. The test results must meet the requirements of no severe cosmetic defects or wet leakage as defined in IEC 61215-1. The ball is struck at various locations on the component at the diameter and velocity specified in Table 1.

[0139] Table 1 Ice ball diameter and test speed data Ice ball diameter (mm) Test speed (m / s) 25mm 23.0 30mm 25.2 35mm 27.2 38mm 28.3 40mm 29.0 43mm 30.0 45mm 30.7 50mm 32.3 55mm 33.9

[0140] Table 2 Test data of embodiment and comparative example

[0141] From the test data in Table 2, we can see that:

[0142] 1. Comparing Example 1 with Comparative Examples 1 to 3, it can be seen that the double-glass photovoltaic module of Example 1 can resist a maximum hail particle size far exceeding that of the double-glass photovoltaic modules of Comparative Examples 1 to 3. Therefore, when inorganic fillers and toughening agents are added to the encapsulation film at the same time, the hail impact resistance of the prepared photovoltaic module can be effectively improved, thereby effectively extending the service life of the photovoltaic module; in addition, the module power of Example 1 is not reduced compared with Comparative Example 1, so the addition of inorganic fillers and toughening agents will not have an adverse effect on the performance of the photovoltaic module.

[0143] 2. Comparing Examples 1 to 3 with Comparative Examples 1 to 3, the module power of the photovoltaic modules of Comparative Examples 2 and 3 is improved relative to that of Comparative Example 1, but is lower than that of Examples 2 and 3 and much lower than that of Example 1. This shows that although the addition of inorganic fillers or toughening agents to the encapsulation film alone can improve the hail impact resistance of the photovoltaic module to a certain extent, the degree of improvement is very limited. Therefore, only when inorganic fillers and toughening agents are added to the encapsulation film at the same time, the hail impact resistance of the photovoltaic module obtained is the best.

[0144] In addition, the hail impact resistance of Example 1 is much better than that of Example 2 and Example 3. It can be seen that in the double-glass photovoltaic module, when nano-scale inorganic fillers and toughening agents are added to the front packaging film and micron-scale inorganic fillers and toughening agents are added to the back packaging film, the hail impact resistance of the double-glass photovoltaic module is the best.

[0145] 3. Comparing Example 1 with Example 4 and Example 5, the hail impact resistance of Example 1 is slightly better than that of Example 4 and Example 5. It can be seen that in practical applications, in the front packaging film, the preferred ratio of the mass content of the nanoscale inorganic filler to the mass content of the toughening agent is 1:(2-5), and the most preferred ratio of the mass content of the nanoscale inorganic filler to the mass content of the toughening agent is 1:2.

[0146] 4. Comparing Example 1 with Example 6 and Example 7, Example 1 has slightly better hail impact resistance than Example 6 and Example 7. Therefore, in practical applications, in the back-side encapsulation film, the ratio of the mass content of the micron-sized inorganic filler to the mass content of the toughening agent is preferably 1:(1-3), and the most preferred ratio of the mass content of the micron-sized inorganic filler to the mass content of the toughening agent is 1:1.5.

[0147] 5. Comparing Example 1 with Example 8 and Example 9, Example 1 has much better hail impact resistance than Example 8 and Example 9. Therefore, in practical applications, the ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is (1.2-2.5):1, and the most preferred ratio of the mass content of the inorganic filler in the back encapsulation film to the mass content of the inorganic filler in the front encapsulation film is 1.5:1.

[0148] Thus far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A packaging film for packaging photovoltaic modules, characterized in that: Calculated by weight percentage, the packaging film includes the following components: 85% to 98.8% of a resin system, 0.2% to 10% of an inorganic filler, and 1% to 5% of a toughening agent.

2. The encapsulation film for encapsulating photovoltaic modules according to claim 1, characterized in that: The inorganic filler includes one or more of silicon dioxide, aluminum oxide, and calcium carbonate; and / or, the particle size of the inorganic filler is 1 nm to 10 μm; And / or, the toughening agent includes one or more of transparent thermoplastic elastomer particles, ABS, polymethyl methacrylate, polyurethane, polyester, bisphenol A epoxy resin, polycarbonate, polyethylene terephthalate, and polyvinylidene fluoride.

3. A double-glass photovoltaic module, characterized in that: The double-glass photovoltaic module comprises a front glass (1), a front encapsulation film (2), a battery layer (3), a back encapsulation film (4) and a back glass (5) stacked in sequence, wherein the front encapsulation film (2) and the back encapsulation film (4) are the encapsulation films for encapsulating photovoltaic modules according to claim 1 or 2.

4. The double-glass photovoltaic module according to claim 3, characterized in that: The front packaging adhesive film (2) comprises the following components by weight percentage: 90% to 98.8% of a resin system, 0.2% to 5% of an inorganic filler, and 1% to 5% of a toughening agent.

5. The double-glass photovoltaic module according to claim 3, characterized in that: In the front packaging film (2), the ratio of the mass content of the inorganic filler to the mass content of the toughening agent is 1:(2-5); And / or, in the backside packaging film (4), the ratio of the mass content of the inorganic filler to the mass content of the toughening agent is 1:(1-3).

6. The double-glass photovoltaic module according to claim 3, characterized in that: The ratio of the mass content of the inorganic filler in the back packaging film (4) to the mass content of the inorganic filler in the front packaging film (2) is (1-3):

1.

7. The double-glass photovoltaic module according to claim 6, characterized in that: The ratio of the mass content of the inorganic filler in the back packaging film (4) to the mass content of the inorganic filler in the front packaging film (2) is (1.2-2.5):1; Preferably, the ratio of the mass content of the inorganic filler in the back packaging film (4) to the mass content of the inorganic filler in the front packaging film (2) is 1.5:

1.

8. The double-glass photovoltaic module according to any one of claims 3 to 7, characterized in that: The inorganic filler in the front packaging film (2) is a nanometer-level inorganic filler, and the inorganic filler in the back packaging film (4) is a micrometer-level inorganic filler.

9. The double-glass photovoltaic module according to claim 8, characterized in that: The particle size of the nanoscale inorganic filler is 1 nm to 100 nm, preferably the particle size of the nanoscale inorganic filler is 20 nm to 40 nm; And / or, the nano-scale inorganic filler includes one or more of nano-silicon dioxide and nano-aluminum oxide.

10. The double-glass photovoltaic module according to claim 8, characterized in that: The particle size of the micron-sized inorganic filler is 0.01 μm to 10 μm, preferably the particle size of the micron-sized inorganic filler is 0.1 μm to 5 μm; And / or, the micron-sized inorganic filler includes one or more of silicon dioxide, aluminum oxide, and calcium carbonate.

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