Photovoltaic module and preparation method thereof

Abstract

The invention provides a photovoltaic module and a preparation method thereof. The photovoltaic module comprises a front plate, a first adhesive film layer, a pre-packaged battery, a fourth adhesive film layer and a rear plate which are sequentially stacked; the pre-packaged battery comprises a second adhesive film layer, a battery piece layer and a third adhesive film layer; wherein ML values of the second adhesive film layer and the third adhesive film layer at 130 DEG C are respectively and independently greater than or equal to 0.35 dN.m; the ML value of the second adhesive film layer is larger than that of the first adhesive film layer, and the ML value of the third adhesive film layer is larger than that of the fourth adhesive film layer. According to the invention, the adhesive film layers with relatively low fluidity are arranged on the two sides of the battery, so that the battery piece can be protected before the photovoltaic module is laminated, the safe bending angle of the battery is improved, and the risk of breaking and cracking of the battery is reduced; and therefore, the photovoltaic module can be better applied to the fields of building outer walls, vehicles and the like with high requirements on the bending degree and the fitting degree of the photovoltaic module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic modules, in particular to a photovoltaic module and a preparation method thereof. BACKGROUND

[0002] The photovoltaic module used in the conventional photovoltaic power station is mostly of a planar structure, which generally comprises a front plate (generally planar glass), a front layer of encapsulating adhesive film, a cell, a rear layer of encapsulating adhesive film and a rear plate (planar glass or back plate). However, the surface of a building outer wall and a car is mostly curved, and the planar module has poor adhesion, thereby affecting the appearance and safety. Therefore, there is an increasing demand for a curved photovoltaic module which meets the curved surface of a building outer wall, a car and has higher adhesion.

[0003] During the lamination process of the planar photovoltaic module, the adhesive film is first melted under heat and then is subjected to pressure. Therefore, the cell sheet is flat and uniformly stressed, and even if the cell sheet is thin and brittle, the risk of breakage and hidden cracks is low. However, in the curved photovoltaic module, the cell sheet is bent. If the structure of front plate / front layer of encapsulating adhesive film / cell / rear layer of encapsulating adhesive film / rear plate is still adopted, the cell sheet is difficult to be well protected during the lamination process, and the risk of breakage and hidden cracks is high. SUMMARY

[0004] The main purpose of the present application is to provide a photovoltaic module and a preparation method thereof, so as to solve the problem of breakage and hidden cracks of the cell of the curved photovoltaic module in the prior art during the lamination process.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a photovoltaic module is provided, which comprises a front plate, a first adhesive film layer, a pre-encapsulated cell, a fourth adhesive film layer and a rear plate which are sequentially stacked; the pre-encapsulated cell comprises a second adhesive film layer, a cell sheet layer and a third adhesive film layer; wherein the ML value of the second adhesive film layer and the third adhesive film layer at 130℃ is independently ≥ 0.35 dN·m; the ML value of the second adhesive film layer is greater than that of the first adhesive film layer, and the ML value of the third adhesive film layer is greater than that of the fourth adhesive film layer.

[0006] Further, the ML value of the second adhesive film layer and the third adhesive film layer at 130℃ is independently 0.35-2.35 dN·m; and / or, the ML value of the second adhesive film layer is greater than that of the first adhesive film layer by at least 0.3 dN·m; and / or, the ML value of the third adhesive film layer is greater than that of the fourth adhesive film layer by at least 0.3 dN·m.

[0007] Further, the radius of curvature of the photovoltaic module is 0.5-5 m, preferably 0.5-4 m.

[0008] Further, the adhesive force between the first adhesive film layer and the second adhesive film layer is > 30 N / cm; and / or, the adhesive force between the third adhesive film layer and the fourth adhesive film layer is > 30 N / cm.

[0009] Further, the thickness of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer is independently 0.2-1.0 mm, and the total thickness of the first adhesive film layer and the second adhesive film layer is ≥ 0.5 mm, and the total thickness of the third adhesive film layer and the fourth adhesive film layer is ≥ 0.5 mm.

[0010] Further, at least one of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer contains a pigment; preferably, the pigment is selected from any one or more of carbon black, copper-chromium black, iron oxide black, iron-chromium black, titanium white, barium sulfate, zinc white, zinc oxide, antimony white, calcium carbonate, indigo, cyan blue, cobalt blue, phthalocyanine blue, indanthrene blue, chromium red, iron red, cinnabar red, rose madder red, lemon yellow, barium chromate, cadmium yellow, cobalt yellow, Naples yellow, chromium oxide green, cobalt green, emerald green, earth green, phenophthalocyanine green, naphthol green, and cadmium green.

[0011] Further, the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer further comprise a base resin and an auxiliary agent; preferably, the base resin is independently selected from any one or more of ethylene-vinyl acetate copolymer, polyolefin elastomer and ethylene-propylene elastomer; preferably, the auxiliary agent is independently selected from any one or more of crosslinking agent, crosslinking aid, antioxidant and light stabilizer.

[0012] Further, the front plate and the back plate each independently comprise a substrate selected from any one or more of glass, glass fiber composite, modified or unmodified polypropylene, modified or unmodified polycarbonate, and modified or unmodified polyethylene terephthalate.

[0013] Further, the modification comprises surface coating treatment and / or mixing treatment; preferably, the surface coating treatment comprises coating an acrylic coating on the surface of the substrate; and / or, the mixing treatment comprises mixing the substrate and inorganic filler, preferably, the inorganic filler is selected from any one or more of titanium white, calcium carbonate, white carbon black, talc powder and carbon black.

[0014] According to another aspect of the present application, there is provided a method for preparing the photovoltaic module as described above, which comprises: step S1, sequentially stacking and laying the second adhesive film layer, the cell unit and the third adhesive film layer to perform first lamination to obtain a pre-packaged cell; step S2, sequentially performing online stacking and laying of the front plate, the first adhesive film layer, the pre-packaged cell, the fourth adhesive film layer and the back plate to obtain a laminated assembly; and step S3, performing second lamination on the laminated assembly to obtain the photovoltaic module; wherein the temperature of the first lamination is 110-160°C, and the temperature of the second lamination is 110-160°C.

[0015] By applying the technical solution of the present application, the battery piece can be protected before lamination of the photovoltaic module by arranging the low-flowability adhesive film layers on both sides of the battery, thereby improving the safe bending angle of the battery, reducing the risk of battery breakage and cracking, and better applying to the fields of building outer walls and vehicles with high requirements for the bending degree and fit degree of the photovoltaic module. Specifically, the first adhesive film layer can ensure good adhesion between the second adhesive film layer and the front plate, thereby improving the reliability of the photovoltaic module, the second adhesive film layer and the third adhesive film layer can ensure that the battery does not break or crack in the curved module, thereby improving the yield of the module; the fourth adhesive film layer can ensure good adhesion between the third adhesive film layer and the back plate, thereby improving the reliability of the photovoltaic module, and the above-mentioned adhesive film layers can improve the yield of the curved module (including the first adhesive film layer, the second adhesive film layer, the battery layer, the third adhesive film layer, and the fourth adhesive film layer arranged in sequence) and ensure the reliability of the curved module, thereby realizing the mass production of the curved module. The ML value is the minimum torque, which is used to represent the flowability of the adhesive film. BRIEF DESCRIPTION OF DRAWINGS

[0016] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the exemplary embodiments of the present application and its description, and do not constitute improper limitations on the present application. In the drawings:

[0017] Figure 1 The structure of the photovoltaic module in Embodiment 1 of the present application is shown.

[0018] Among them, the above drawings include the following reference signs:

[0019] 1, front plate; 2, first adhesive film layer; 3, second adhesive film layer; 4, battery layer; 5, third adhesive film layer; 6, fourth adhesive film layer; 7, back plate. DETAILED DESCRIPTION

[0020] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0021] As analyzed in the background art of the present application, the battery of the curved photovoltaic module in the prior art has the problems of breakage and hidden cracking during lamination. In order to solve the above problems, the present application provides a photovoltaic module and a preparation method thereof.

[0022] In an exemplary embodiment of the present application, a photovoltaic module is provided, which comprises a front plate, a first adhesive film layer, a pre-packaged cell, a fourth adhesive film layer and a back plate which are sequentially stacked; the pre-packaged cell comprises a second adhesive film layer, a cell layer and a third adhesive film layer; wherein the ML value of the second adhesive film layer and the third adhesive film layer at 130℃ is independently ≥ 0.35 dN·m; the ML value of the second adhesive film layer is greater than that of the first adhesive film layer, and the ML value of the third adhesive film layer is greater than that of the fourth adhesive film layer.

[0023] The present application can protect the cell before laminating the photovoltaic module by setting the adhesive film layer with low flowability on both sides of the cell, thereby improving the safe bending angle of the cell, reducing the risk of cell breakage and cracking, and better applying to the fields of building exterior walls and vehicles which have high requirements for the bending degree and fit degree of photovoltaic modules. Specifically, the first adhesive film layer can ensure good adhesion between the second adhesive film layer and the front plate, thereby improving the reliability of the photovoltaic module, the second adhesive film layer and the third adhesive film layer can ensure that the cell does not break or crack in the curved module, thereby improving the yield of the module; the fourth adhesive film layer can ensure good adhesion between the third adhesive film layer and the back plate, thereby improving the reliability of the photovoltaic module, and the above-mentioned adhesive film layers can improve the yield of the curved module (including the first adhesive film layer, the second adhesive film layer, the cell layer, the third adhesive film layer, the fourth adhesive film layer which are sequentially stacked) and ensure the reliability of the curved module, thereby realizing the mass production of the curved module. The ML value is the minimum torque, which is used to represent the flowability of the adhesive film.

[0024] Preferably, the pre-packaged cell comprises a second adhesive film layer, a cell layer and a third adhesive film layer which are sequentially stacked, and further preferably, the photovoltaic module comprises a front plate, a first adhesive film layer, a second adhesive film layer, a cell layer, a third adhesive film layer, a fourth adhesive film layer and a back plate which are sequentially stacked.

[0025] In an embodiment of the present application, the ML value of the second adhesive film layer and the third adhesive film layer at 130℃ is independently 0.35-2.35 dN·m; and / or, the ML value of the second adhesive film layer is at least 0.3 dN·m greater than that of the first adhesive film layer, preferably 0.5-2.0 dN·m; and / or, the ML value of the third adhesive film layer is at least 0.3 dN·m greater than that of the fourth adhesive film layer, preferably 0.5-2.0 dN·m.

[0026] Preferably, the ML value of the second adhesive film layer is greater than that of the first adhesive film layer, and the difference is within the above range, and the ML value of the fourth adhesive film layer is greater than that of the third adhesive film layer, and the difference is within the above range, which helps the second adhesive film layer and the third adhesive film layer with relatively high ML values to provide stronger support and protection during lamination, especially when the battery piece is in a curved state, which helps to reduce the deformation of the battery piece under high temperature and high pressure, thereby reducing the risk of breaking and cracking. At the same time, the first adhesive film layer and the fourth adhesive film layer with relatively low ML values are more likely to melt and fully fill the gap between the front plate or the back plate and the battery during lamination, thereby improving the structural stability of the photovoltaic module.

[0027] In an embodiment of the present application, the radius of curvature of the photovoltaic module is 0.5-5 m, preferably 0.5-4 m.

[0028] Preferably, controlling the radius of curvature of the photovoltaic module within the above range helps the curved photovoltaic module to closely fit various non-planar surfaces, such as the curved wall surface of a building, the roof of a vehicle, etc. If the radius of curvature is too small, the degree of bending of the module will be too large, which will increase the risk of breaking and cracking of the battery piece. If the radius of curvature is too large, the bending is not obvious, which cannot meet the application requirements of the curved module.

[0029] In an embodiment of the present application, the adhesive force between the first adhesive film layer and the second adhesive film layer is >30 N / cm, preferably 60-180 N / cm; and / or, the adhesive force between the third adhesive film layer and the fourth adhesive film layer is >30 N / cm, preferably 60-180 N / cm.

[0030] Preferably, controlling the adhesive force between the first adhesive film layer and the second adhesive film layer and the adhesive force between the third adhesive film layer and the fourth adhesive film layer within the above range helps to closely combine the layers in the photovoltaic module, reduces the sliding and separation between the layers, especially for the curved module, which helps to improve the structural stability and anti-deformation ability of the photovoltaic module when subjected to external pressure, and also helps to improve the reliability of the module.

[0031] In an embodiment of the present application, the thickness of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer is independently 0.2-1.0 mm, and the total thickness of the first adhesive film layer and the second adhesive film layer is ≥0.5 mm, preferably 0.5-0.8 mm, and the total thickness of the third adhesive film layer and the fourth adhesive film layer is ≥0.5 mm, preferably 0.5-0.8 mm.

[0032] Preferably, controlling the thickness of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer within the above range, and controlling the total thickness of the first adhesive film layer and the second adhesive film layer and the total thickness of the third adhesive film layer and the fourth adhesive film layer within the above range, helps to balance the structural strength and curved adaptability of the photovoltaic module.

[0033] The melt index of the first adhesive film layer and the fourth adhesive film layer is independently 6-30 g / 10 min, and preferably the melt index of the second adhesive film layer and the third adhesive film layer is independently 2.5-6 g / 10 min, which helps to adjust the ML value of each adhesive film layer.

[0034] In an embodiment of the present application, at least one of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer contains a pigment, and preferably the pigment is selected from any one or more of carbon black, copper chromium black, iron oxide black, iron chromium black, titanium white, barium sulfate, zinc white, zinc oxide, antimony white, calcium carbonate, indigo, ultramarine blue, cobalt blue, phthalocyanine blue, indanthrene blue, chromium red, iron red, cinnabar red, rose madder red, lemon yellow, barium chromate, cadmium yellow, cobalt yellow, Naples yellow, chromium oxide green, cobalt green, emerald green, earth green, phenophthalocyanine green, naphthol green, and cadmium green.

[0035] The type of pigment is preferably within the above range, which helps to regulate the appearance and light transmission efficiency of the photovoltaic module.

[0036] In an embodiment of the present application, the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer further comprise a base resin and an additive, and preferably the first resin and the second resin are independently selected from any one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE) and ethylene-propylene elastomer (EPE); and preferably the additive is independently selected from any one or more of a crosslinking agent, a co-crosslinking agent, an antioxidant and a light stabilizer.

[0037] The type of resin is preferably within the above range, which helps to provide the basic physical properties of the above adhesive film layers, such as flexibility, weather resistance and adhesion.

[0038] In order to better form the above adhesive film layers, in an embodiment of the present application, the second adhesive film layer and the third adhesive film layer each independently comprise, in parts by weight: 100 parts of the first resin, 0-15 parts of the first pigment, 0.2-2 parts of the first crosslinking agent, 0.2-2 parts of the first co-crosslinking agent, and 0.2-2 parts of the first silane coupling agent; and / or the first adhesive film layer and the fourth adhesive film layer each independently comprise, in parts by weight: 100 parts of the second resin, 0-15 parts of the second pigment, 0.2-2 parts of the second crosslinking agent, 0.2-2 parts of the second co-crosslinking agent, and 0.2-2 parts of the second silane coupling agent.

[0039] The composition and content of the second adhesive film layer and the third adhesive film layer and the first adhesive film layer and the fourth adhesive film layer are preferably controlled within the above range, which helps to regulate the flowability and adhesion of each adhesive film layer, so that the ML value thereof is within the above range, thereby better protecting the battery.

[0040] wherein the first crosslinking agent and the second crosslinking agent are each independently selected from any one or more of t-butyl peroxy isopropyl carbonate, 2,5-dimethyl-2,5-(bis-t-butylperoxy)hexane, t-butyl peroxy-2-ethylhexyl carbonate, 1,1 -bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1 -bis(t-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1 -bis(t-amylperoxy)cyclohexane, 1,1 -bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane, t-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl 2,5-dimethyl 2,5-bis(benzoylperoxy)-hexane, t-amyl peroxy carbonate, t-butyl peroxy-3,3,5-trimethylhexanoate; and / or the first co-crosslinking agent and the second co-crosslinking agent are each independently selected from any one or more of allyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glyceryl triacrylate, propoxylated glyceryl triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ditrimethylolpropane tetraacrylate, ditrimethylolpropane tetramethacrylate, propoxylated pentaerythritol tetraacrylate, 2,4,6-tris(2-propenyloxy)-1,3,5-triazine, tricyclodecane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate. The first silane coupling agent and the second silane coupling agent are each independently selected from any one or more of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris(tert-butylperoxy)silane, vinyltriacetoxysilane, vinyltris(β-methoxyethoxy)silane, γ-aminopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethylsilane.

[0041] To better accommodate different radii of curvature of the photovoltaic module, in one embodiment of the present application, the front sheet and the back sheet each independently comprise a substrate selected from any one or more of glass, fiberglass composite, modified or unmodified polypropylene (PP), modified or unmodified polycarbonate (PC), modified or unmodified polyethylene terephthalate (PET).

[0042] In an embodiment of the present application, the modification comprises a surface coating treatment and / or a mixing treatment; preferably, the surface coating treatment comprises coating an acrylic coating on the surface of the substrate; and / or, the mixing treatment comprises mixing the substrate and the inorganic filler, preferably, the inorganic filler is selected from any one or more of titanium dioxide, calcium carbonate, white carbon black, talc powder and carbon black.

[0043] The surface coating treatment helps to improve the adhesion between the front plate, the back plate and the adhesive film layer and the reliability of the curved component. The mixing treatment helps to improve the strength of the front plate and the back plate and the stability of the curved component after forming.

[0044] In another typical embodiment of the present application, a preparation method of the above-mentioned photovoltaic component is provided, which comprises: step S1, sequentially stacking and laying a second adhesive film layer, a cell unit, a third adhesive film layer to obtain a pre-packaged cell after first laminating; step S2, sequentially stacking and laying a front plate, a first adhesive film layer, the pre-packaged cell, a fourth adhesive film layer and a back plate to obtain a laminated component; and step S3, second laminating the laminated component to obtain the photovoltaic component; wherein the temperature of the first laminating is 110-160℃, and the temperature of the second laminating is 110-160℃.

[0045] The present application uses an adhesive film with low flowability to pre-package the cell unit, which can protect the cell sheet before laminating the photovoltaic component, thereby improving the safe bending angle of the cell and reducing the risk of cell breakage and cracking. Controlling the temperature of the first laminating in the above range can help the second adhesive film layer and the third adhesive film layer to better package the cell unit. Controlling the temperature of the second laminating in the above range can make the first adhesive film layer and the fourth adhesive film layer melt better, thereby realizing the close bonding between the adhesive film and the pre-packaged cell, the front plate and the back plate, and further improving the packaging quality of the photovoltaic component. Controlling the ML value of each adhesive film layer in the above range can better protect the cell, thereby reducing the breakage and cracking of the cell sheet and improving the yield of the curved component.

[0046] The beneficial effects of the present application will be further illustrated in the following examples.

[0047] Example 1

[0048] The front plate is a curved glass, the cell layer is a Perc double-sided cell, and the back plate is a curved glass.

[0049] The raw materials of the first adhesive film layer are 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25g / 10min, 0.5 parts of tert-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate and 0.5 parts of vinyl triethoxysilane, by weight.

[0050] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 0.6 parts of 2,5-dimethyl-2,5-(bis-tert-butyl peroxy) hexane, 0.9 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyl trimethoxysilane.

[0051] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 1.0 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 1.2 parts of trimethylolpropane trimethylacrylate, and 0.45 parts of vinyl tri-tert-butylperoxy silane.

[0052] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri(beta-methoxyethoxy)silane.

[0053] Preparation of the photovoltaic module: the second adhesive film layer, the cell layer, and the third adhesive film layer are stacked in sequence, and then first lamination is performed at 125°C for 20 min to obtain a pre-packaged cell. Subsequently, the front curved glass, the first adhesive film layer, the pre-packaged cell, the fourth adhesive film layer, and the rear curved glass are stacked in sequence, and then lamination is performed at 140°C for 25 min to obtain the photovoltaic module with the structure as shown in Figure 1 .

[0054] Example 2

[0055] The difference from Example 1 is that the raw material of the first adhesive film layer is 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 30 g / 10 min, 0.5 parts of tert-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxysilane in terms of parts by weight.

[0056] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 0.6 parts of 2,5-dimethyl-2,5-(bis-tert-butyl peroxy) hexane, 0.9 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyl trimethoxysilane.

[0057] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 1.0 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 1.2 parts of trimethylolpropane trimethylacrylate, and 0.45 parts of vinyl tri-tert-butylperoxy silane.

[0058] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 30 g / 10 min, 0.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri(beta-methoxyethoxy)silane.

[0059] Preparation of photovoltaic module: the second adhesive film layer, the cell layer, the third adhesive film layer are stacked in sequence, then the first lamination is carried out at 110°C for 20 minutes to obtain a pre-packaged cell, and then the front curved glass, the first adhesive film layer, the pre-packaged cell, the fourth adhesive film layer, and the rear curved glass are stacked in sequence, and the lamination is carried out at 140°C for 25 minutes to obtain the photovoltaic module.

[0060] Example 3

[0061] The difference from Example 1 is that the raw materials of the first adhesive film layer are 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25g / 10min, 0.5 parts of t-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxy silane.

[0062] The raw materials of the second adhesive film layer are 100 parts of EVA with a melt index of 6g / 10min, 0.6 parts of 2,5-dimethyl-2,5-(bis-t-butyl peroxy) hexane, 0.9 parts of trimethylolpropane trimethacrylate, and 0.3 parts of vinyl trimethoxy silane.

[0063] The raw materials of the third adhesive film layer are 100 parts of EVA with a melt index of 6g / 10min, 1.0 parts of 1,1-bis(t-amyl peroxy)cyclohexane, 1.2 parts of trimethylolpropane trimethacrylate, and 0.45 parts of vinyl triperoxy-t-butyl silane.

[0064] The raw materials of the fourth adhesive film layer are 100 parts of EVA with a melt index of 6g / 10min, 0.8 parts of 1,1-bis(t-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri(β-methoxyethoxy)silane, and finally a photovoltaic module is obtained.

[0065] Example 4

[0066] The difference from Example 1 is that the raw materials of the first adhesive film layer are 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25g / 10min, 0.5 parts of t-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxy silane.

[0067] The raw materials of the second adhesive film layer are 100 parts of EVA with a melt index of 2.5g / 10min, 2.0 parts of 2,5-dimethyl-2,5-(bis-t-butyl peroxy) hexane, 2.0 parts of trimethylolpropane trimethacrylate, and 0.3 parts of vinyl trimethoxy silane.

[0068] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 2.5 g / 10 min, 2.0 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 2.0 parts of trimethylolpropane trimethacrylate, and 0.45 parts of vinyltris(tert-butylperoxy)silane.

[0069] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyltris(beta-methoxyethoxy)silane, to obtain a photovoltaic module finally.

[0070] Example 5

[0071] The difference from Example 1 is that the raw material of the first adhesive film layer is 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 21 g / 10 min, 0.5 parts of tert-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyltriethoxysilane, in parts by weight.

[0072] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 4.5 g / 10 min, 1.5 parts of 2,5-dimethyl-2,5-(bis tert-butyl peroxy)hexane, 1.5 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyltrimethoxysilane.

[0073] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 3.1 g / 10 min, 1.5 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 1.5 parts of trimethylolpropane trimethacrylate, and 0.45 parts of vinyltris(tert-butylperoxy)silane.

[0074] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 21 g / 10 min, 0.6 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.8 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyltris(beta-methoxyethoxy)silane, to obtain a photovoltaic module finally.

[0075] Example 6

[0076] The difference from Example 1 is that the raw material of the first adhesive film layer is 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25 g / 10 min, 0.5 parts of tert-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyltriethoxysilane, in parts by weight.

[0077] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 2.5 parts of 2,5-dimethyl-2,5-(bis-tert-butyl peroxy) hexane, 2.5 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyl trimethoxysilane.

[0078] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 2.5 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 2.5 parts of trimethylolpropane trimethylacrylate, and 0.45 parts of vinyl tri-tert-butylperoxy silane.

[0079] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri(beta-methoxyethoxy)silane. A photovoltaic module is finally obtained.

[0080] Example 7

[0081] The difference from Example 1 is that the raw material of the first adhesive film layer is 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25 g / 10 min, 0.5 parts of tert-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.2 parts of vinyl triethoxysilane in parts by weight.

[0082] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 2.5 g / 10 min, 2.0 parts of 2,5-dimethyl-2,5-(bis-tert-butyl peroxy) hexane, 2.0 parts of trimethylolpropane triacrylate, and 0.1 parts of vinyl trimethoxysilane.

[0083] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 2.5 g / 10 min, 2.0 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 2.0 parts of trimethylolpropane trimethylacrylate, and 0.15 parts of vinyl tri-tert-butylperoxy silane.

[0084] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.1 parts of vinyl tri(beta-methoxyethoxy)silane, and a photovoltaic module is finally obtained.

[0085] Example 8

[0086] The difference from Example 1 is that the raw material of the first adhesive film layer is 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25 g / 10 min, 0.5 parts of t-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxy silane, by weight.

[0087] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 2.5 g / 10 min, 2.0 parts of 2,5-dimethyl-2,5-(bis-t-butyl peroxy) hexane, 2.0 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyl trimethoxy silane.

[0088] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 1.0 parts of 1,1-bis-(t-amyl peroxy)cyclohexane, 1.2 parts of trimethylolpropane trimethylacrylate, and 0.45 parts of vinyl tri-t-butylperoxy silane.

[0089] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis-(t-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri-(β-methoxyethoxy) silane, to obtain a photovoltaic module finally.

[0090] Example 9

[0091] The difference from Example 1 is that the raw material of the first adhesive film layer is 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25 g / 10 min, 0.5 parts of t-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxy silane, by weight.

[0092] The raw material of the second adhesive film layer is 100 parts of EVA with a melt index of 6 g / 10 min, 0.6 parts of 2,5-dimethyl-2,5-(bis-t-butyl peroxy) hexane, 0.9 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyl trimethoxy silane.

[0093] The raw material of the third adhesive film layer is 100 parts of EVA with a melt index of 2.5 g / 10 min, 2.0 parts of 1,1-bis-(t-amyl peroxy)cyclohexane, 2.0 parts of trimethylolpropane trimethylacrylate, and 0.45 parts of vinyl tri-t-butylperoxy silane.

[0094] The raw material of the fourth adhesive film layer is 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis-(t-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri-(β-methoxyethoxy) silane, to obtain a photovoltaic module finally.

[0095] Example 10

[0096] The difference from Example 1 is that the temperature of the first lamination is 140°C and the temperature of the second lamination is 160°C, and finally a photovoltaic module is obtained.

[0097] Comparative Example 1

[0098] The difference from Example 1 is that the raw materials of the first adhesive film layer are 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 25 g / 10 min, 0.5 parts of tert-butyl peroxy isopropyl carbonate, 0.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxy silane.

[0099] The raw materials of the second adhesive film layer are 100 parts of EVA with a melt index of 6 g / 10 min, 0.6 parts of 2,5-dimethyl-2,5-(bis-tert-butyl peroxy) hexane, 0.9 parts of trimethylolpropane trimethacrylate, and 0.3 parts of vinyl trimethoxy silane.

[0100] The raw materials of the third adhesive film layer are 100 parts of EVA with a melt index of 6 g / 10 min, 1.0 parts of 1,1-bis(tert-amyl peroxy) cyclohexane, 1.2 parts of trimethylolpropane trimethacrylate, and 0.45 parts of vinyl triperoxy tert-butyl silane.

[0101] The raw materials of the fourth adhesive film layer are 100 parts of EVA with a melt index of 25 g / 10 min, 0.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 0.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri(β-methoxyethoxy) silane.

[0102] Preparation of the photovoltaic module: the second adhesive film layer, the cell layer, and the third adhesive film layer are stacked in order, and then first lamination is performed at 100°C for 20 min to obtain a pre-packaged cell, and then a front curved glass, a first adhesive film layer, the pre-packaged cell, a fourth adhesive film layer, and a rear curved glass are stacked in order, and then lamination is performed at 100°C for 15 min to obtain a photovoltaic module.

[0103] Comparative Example 2

[0104] The difference from Example 1 is that the raw materials of the first adhesive film layer are 100 parts of ethylene-vinyl acetate copolymer EVA with a melt index of 1.5 g / 10 min, 1.5 parts of tert-butyl peroxy isopropyl carbonate, 1.7 parts of triallyl cyanurate, and 0.5 parts of vinyl triethoxy silane.

[0105] The raw materials of the second adhesive film layer are 100 parts of EVA with a melt index of 6 g / 10 min, 0.6 parts of 2,5-dimethyl-2,5-(bis-tert-butyl peroxy) hexane, 0.9 parts of trimethylolpropane triacrylate, and 0.3 parts of vinyl trimethoxysilane.

[0106] The raw materials of the third adhesive film layer are 100 parts of EVA with a melt index of 6 g / 10 min, 1.0 parts of 1,1-bis(tert-amyl peroxy)cyclohexane, 1.2 parts of trimethylolpropane trimethylacrylate, and 0.45 parts of vinyl triperoxy-tert-butyl silane.

[0107] The raw materials of the fourth adhesive film layer are 100 parts of EVA with a melt index of 1.5 g / 10 min, 1.8 parts of 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, 1.6 parts of propoxylated glyceryl triacrylate, and 0.6 parts of vinyl tri(beta-methoxyethoxy)silane.

[0108] Preparation of the photovoltaic module: the second adhesive film layer, the cell layer, and the third adhesive film layer are stacked in sequence, and then pre-packaged cells are obtained after first lamination at 110°C for 20 min. Subsequently, the photovoltaic module is obtained by lamination at 140°C for 25 min in the order of front curved glass, first adhesive film layer, pre-packaged cells, fourth adhesive film layer, and back curved glass.

[0109] Test method:

[0110] Test of the ML value: 3.0-3.5 g of the adhesive film is cut into a square piece with a size of about 3 cm*3 cm, and then the square piece is clamped between two pieces of release PET with a thickness of 25 μm, and then the test is performed in a rotorless vulcanization instrument. The temperature of the vulcanization instrument is 130°C, the test time is 60 min, and the swing angle is 0.5°.

[0111] Test of the bonding force: the test method refers to the standard GB / T 29848 “Ethylene-vinyl acetate copolymer (EVA) adhesive film for encapsulating photovoltaic modules”.

[0112] Anti-cracking effect: the components are prepared in the order of curved glass (front plate), first adhesive film layer, pre-packaged cells, fourth adhesive film layer, and curved glass (back plate), wherein the pre-packaged cells contain a total of 64 cells, and 10 components are prepared for each combination. The number of cracked or broken cells is counted by testing EL of each component.

[0113] The photovoltaic modules of the above examples and comparative examples are subjected to performance tests, and the test results are shown in Tables 1 and 2.

[0114] Table 1

[0115]

[0116] Table 2

[0117]

[0118]

[0119] In the second adhesive film layer and the third adhesive film layer of Comparative Example 1, the ML values are less than 0.35, which leads to a reduced effect of protecting the battery sheet, and causes the battery sheet to have hidden cracks or breakage. In Comparative Example 2, the ML value of the second adhesive film layer is less than the ML value of the first adhesive film layer, and the ML value of the third adhesive film layer is less than the ML value of the fourth adhesive film layer, which leads to a reduced effect of protecting the battery sheet, and causes the battery sheet to have hidden cracks or breakage.

[0120] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0121] The present application can protect the battery sheet before laminating the photovoltaic module by setting the adhesive film layer with low flowability on both sides of the battery, thereby improving the safe bending angle of the battery, reducing the risk of battery breakage and cracking, and better applying to the fields of building outer walls and vehicles with high requirements for the bending degree and fit degree of the photovoltaic module. Specifically, the first adhesive film layer can ensure good adhesion between the second adhesive film layer and the front plate, thereby improving the reliability of the photovoltaic module, the second adhesive film layer and the third adhesive film layer can ensure that the battery does not break or have hidden cracks in the curved module, thereby improving the yield of the module; the fourth adhesive film layer can ensure good adhesion between the third adhesive film layer and the back plate, thereby improving the reliability of the photovoltaic module, and the above-mentioned synergistic effect of the adhesive film layers can improve the yield of the curved module (including the first adhesive film layer, the second adhesive film layer, the battery layer, the third adhesive film layer, and the fourth adhesive film layer arranged in sequence), and ensure the reliability of the curved module, thereby realizing the mass production of the curved module. The ML value is the minimum torque, which is used to represent the flowability of the adhesive film.

[0122] The above is only an embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A photovoltaic module, characterized in that, The photovoltaic module includes a front panel, a first encapsulating film layer, a pre-encapsulated cell, a fourth encapsulating film layer, and a rear panel stacked in sequence; the pre-encapsulated cell includes a second encapsulating film layer, a cell layer, and a third encapsulating film layer. The ML values ​​of the second and third adhesive layers at 130°C are each ≥0.35 dN·m; the ML value of the second adhesive layer is greater than that of the first adhesive layer, and the ML value of the third adhesive layer is greater than that of the fourth adhesive layer.

2. The photovoltaic module according to claim 1, characterized in that, The ML values ​​of the second and third adhesive layers at 130°C are each independently 0.35 to 2.35 dN·m; and / or, the ML value of the second adhesive layer is at least 0.3 dN·m greater than the ML value of the first adhesive layer; and / or, the ML value of the third adhesive layer is at least 0.3 dN·m greater than the ML value of the fourth adhesive layer.

3. The photovoltaic module according to claim 1 or 2, characterized in that, The radius of curvature of the photovoltaic module is 0.5 to 5 m, preferably 0.5 to 4 m.

4. The photovoltaic module according to any one of claims 1 to 3, characterized in that, The adhesive force between the first adhesive layer and the second adhesive layer is >30 N / cm; and / or, the adhesive force between the third adhesive layer and the fourth adhesive layer is >30 N / cm.

5. The photovoltaic module according to any one of claims 1 to 4, characterized in that, The thickness of each of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer, and the fourth adhesive film layer is independently 0.2 to 1.0 mm, and the total thickness of the first adhesive film layer and the second adhesive film layer is ≥0.5 mm, and the total thickness of the third adhesive film layer and the fourth adhesive film layer is ≥0.5 mm.

6. The photovoltaic module according to any one of claims 1 to 5, characterized in that, At least one of the first adhesive film layer, the second adhesive film layer, the third adhesive film layer, and the fourth adhesive film layer contains pigment; Preferably, the pigment is selected from any one or more of the following: carbon black, copper chromium black, iron oxide black, iron chromium black, titanium dioxide, barium sulfate, zinc barium white, zinc oxide, antimony white, calcium carbonate, indigo, ultramarine, cobalt blue, phthalocyanine blue, indanthrelin blue, chrome red, iron oxide red, vermilion, rose crimson, lemon yellow, barium chromate, cadmium yellow, cobalt yellow, Neapolitan yellow, chromium oxide green, cobalt green, emerald green, earth green, phenolic green, naphthol green, and cadmium green.

7. The photovoltaic module according to any one of claims 1 to 6, characterized in that, The first adhesive film layer, the second adhesive film layer, the third adhesive film layer, and the fourth adhesive film layer further include a base resin and additives. Preferably, each of the base resins is independently selected from any one or more of ethylene-vinyl acetate copolymer, polyolefin elastomer, and ethylene-propylene elastomer. Preferably, each of the additives is independently selected from any one or more of crosslinking agent, co-crosslinking agent, antioxidant, and light stabilizer.

8. The photovoltaic module according to any one of claims 1 to 7, characterized in that, The front panel and the rear panel each independently include a substrate, the substrate being selected from any one or more of glass, glass fiber composite, modified or unmodified polypropylene, modified or unmodified polycarbonate, and modified or unmodified polyethylene terephthalate.

9. The photovoltaic module according to claim 8, characterized in that, The modification includes surface coating treatment and / or mixing treatment; preferably, the surface coating treatment includes applying an acrylic coating to the surface of the substrate; and / or, the mixing treatment includes mixing the substrate and an inorganic filler, preferably, the inorganic filler is selected from any one or more of titanium dioxide, calcium carbonate, silica, talc and carbon black.

10. A method for preparing a photovoltaic module according to any one of claims 1 to 9, characterized in that, The preparation method includes: Step S1: After sequentially stacking and laying the second adhesive film layer, the battery cell, and the third adhesive film layer, a first lamination is performed to obtain a pre-encapsulated battery. Step S2 involves sequentially laminating the front panel, the first adhesive film layer, the pre-encapsulated battery, the fourth adhesive film layer, and the rear panel online to obtain a stacked assembly; and Step S3: Perform a second lamination on the stacked assembly to obtain the photovoltaic module; The temperature for the first lamination is 110–160℃, and the temperature for the second lamination is 110–160℃.

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