A kind of reinforced black photovoltaic back sheet film and preparation method thereof

Abstract

The present application discloses a reinforced black photovoltaic backplane film and a preparation method thereof, wherein the photovoltaic backplane film includes a black reflective layer, a white support layer and a black weather-resistant layer from top to bottom, wherein the raw materials for preparing the black reflective layer include Ce-BiFeO3 high-reflective material, the raw materials for preparing the white support layer include Mg(OH)2 / MMT-TiO2 high-reflective material, and the raw materials for preparing the black weather-resistant layer include Ce-BiFeO3 / CoAl2O4 light-absorbing composite material. The reinforced black photovoltaic backplane film of the present application adds different raw materials between different layers, which can improve the reflectivity of the photovoltaic backplane to ultraviolet light, ensure that the photovoltaic backplane has high weather resistance, and extend its service life.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic cells, and in particular to a reinforced black photovoltaic backplane film and a preparation method thereof. Background Art

[0002] With the growth of the world's population and economic development, the demand for energy supply is increasing. Solar energy, which has significant advantages such as safety, cleanliness, pollution-free, inexhaustible and inexhaustible, has attracted the most attention and the fastest development speed among many renewable energy sources.

[0003] In recent years, with the development of the solar photovoltaic industry, the safety of photovoltaic systems has received more attention. The aging problem in photovoltaic power generation systems poses a certain threat to the safe operation of the system. During operation, the photovoltaic backplane needs to resist environmental erosion such as ultraviolet radiation, acid and alkali, thermal shock and other environmental erosions. In addition, the poor reflective performance of the photovoltaic backplane and the generation of partial discharge will also accelerate the aging of the photovoltaic backplane, greatly reducing the service life of the photovoltaic module. Therefore, this problem has received widespread attention and attention from researchers. Summary of the invention

[0004] The purpose of this application is to improve the ultraviolet light reflectivity of photovoltaic backplane film and extend its service life.

[0005] To achieve the above objectives, the technical solution adopted in this application is: a reinforced black photovoltaic backplane film, comprising a black reflective layer, a white supporting layer and a black weather-resistant layer from top to bottom, wherein the raw materials for preparing the black reflective layer include Ce-BiFeO3 highly reflective material, the raw materials for preparing the white supporting layer include Mg(OH)2 / MMT-TiO2 highly reflective material, and the raw materials for preparing the black weather-resistant layer include Ce-BiFeO3 / CoAl2O4 light-absorbing composite material.

[0006] As a preferred method, the preparation method of the Ce-BiFeO3 high reflective material is: using iron salt and bismuth salt as raw materials, adding Ce powder, chitosan and solvent, reacting in a reactor, centrifuging, washing and drying the product to obtain the Ce-BiFeO3 high reflective material.

[0007] As another preferred embodiment, the preparation method of the Mg(OH)2 / MMT-TiO2 high reflective material is: using montmorillonite as a carrier, introducing nano-TiO2 into the MMT interlayer by titanium tetrachloride hydrolysis method, and obtaining MMT-TiO2 white powder after calcination, reacting Mg(OH)2, MMT-TiO2 powder and solvent in a reactor, and obtaining the Mg(OH)2 / MMT-TiO2 high reflective material after centrifugation, washing and drying the product.

[0008] As another preferred embodiment, the preparation method of the Ce-BiFeO3 / CoAl2O4 light absorbing composite material is: cobalt salt and aluminum salt are dispersed in a solvent as raw materials to form a CoAl2O4 precursor solution, iron salt and bismuth salt are dispersed in the solution to form a BiFeO3 precursor solution, the CoAl2O4 precursor solution, the BiFeO3 precursor solution, Ce powder and chitosan solution are reacted, the product is centrifuged, washed and dried to obtain a Ce-BiFeO3 / CoAl2O4 precursor, and the Ce-BiFeO3 / CoAl2O4 precursor is calcined to obtain the Ce-BiFeO3 / CoAl2O4 light absorbing composite material.

[0009] As another preferred embodiment, the raw materials for preparing the black reflective layer include: black pigment, the Ce-BiFeO3 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET.

[0010] As another preferred embodiment, the raw materials for preparing the white support layer include: the Mg(OH)2 / MMT-TiO2 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET.

[0011] As another preferred embodiment, the raw materials for preparing the black weather-resistant layer include: a black raw material, the Ce-BiFeO3 / CoAl2O4 light-absorbing composite material, a SEBS polymer elastomer, an antioxidant, an anti-hydrolysis agent, a light stabilizer, other additives and PET.

[0012] As another preferred embodiment, the anti-hydrolysis agent is any one or more combinations of oxazoline compounds, epoxy compounds, aromatic carbodiimides, aliphatic carbodiimides, and polycarbodiimides.

[0013] As another preferred embodiment, the light stabilizer is any one or more of bis(2,2,6,6-tetramethyl-1-octyloxy-4-piperidinyl) sebacate, 2-hydroxy-4-octyloxybenzophenone, 2-(2ˊ-hydroxy-5ˊ-methylphenyl)benzotriazole, 2-(2ˊ-hydroxy-3ˊ5ˊ-di-tert-butylphenyl)-5-chloro-benzotriazole, 2,2'-methylene-(6-(2H-benzotriazole)-4-tert-octyl)phenol, 2-cyano-3,3ˊ-diphenylacrylate, bis(2,2,6,6-tetramethylpiperidinol sebacate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and tris(2,4-di-tert-butylphenol)phosphite.

[0014] A method for preparing a reinforced black photovoltaic backplane film comprises the following steps:

[0015] S1: using iron salt and bismuth salt as raw materials, adding Ce powder, chitosan and solvent, reacting in a reactor, centrifuging, washing and drying the product to obtain Ce-BiFeO3 high reflective material; S2: using cobalt salt and aluminum salt as raw materials, dispersing them in a solvent to form a CoAl2O4 precursor solution, dispersing iron salt and bismuth salt in the solution to form a BiFeO3 precursor solution, reacting the CoAl2O4 precursor solution, the BiFeO3 precursor solution, Ce powder and chitosan solution, and centrifuging, washing and drying the product; After drying, a Ce-BiFeO3 / CoAl2O4 precursor is obtained, and the Ce-BiFeO3 / CoAl2O4 precursor is calcined to obtain a Ce-BiFeO3 / CoAl2O4 light absorption composite material; S3: Using MMT as a carrier, nano-TiO2 is introduced into the MMT interlayer by titanium tetrachloride hydrolysis method, and MMT-TiO2 white powder is obtained after calcination, Mg(OH)2, the MMT-TiO2 powder and a solvent are reacted in a reactor, and the product is centrifuged, washed and dried to obtain M S4: mixing the black pigment, the Ce-BiFeO3 high reflective material, the SEBS polymer elastomer, the antioxidant, the anti-hydrolysis agent, the light stabilizer, other additives and the PET masterbatch, and adding them into a screw extruder, extruding and plasticizing to obtain a black reflective layer; mixing the Mg(OH)2 / MMT-TiO2 high reflective material, the SEBS polymer elastomer, the antioxidant, the anti-hydrolysis agent, the light stabilizer, other additives and the PET masterbatch After mixing, add the mixture into a screw extruder, extrude and plasticize to obtain a white support layer; mix the black pigment, the Ce-BiFeO3 / CoAl2O4 light absorbing composite material, the SEBS polymer elastomer, the antioxidant, the anti-hydrolysis agent, the light stabilizer, the other additives and the PET masterbatch, add the mixture into a screw extruder, extrude and plasticize to obtain a black weather-resistant layer; the black reflective layer, the white support layer and the black weather-resistant layer are formed by a three-layer co-extrusion casting machine to obtain the reinforced black photovoltaic backplane film.

[0016] Compared with the prior art, the beneficial effects of this application are:

[0017] (1) The present application adds Ce-BiFeO3 to the black reflective layer to give full play to its high reflectivity and enhance the anti-aging and weather resistance of the photovoltaic backplane film;

[0018] (2) The present application adds Ce-BiFeO3 / CoAl2O4 light-absorbing composite material to the raw materials for preparing the black weather-resistant layer, thereby enhancing the light absorption and reflection efficiency and high-temperature aging resistance of the photovoltaic backplane film;

[0019] (3) This application prepares Mg(OH)2 / MMT-TiO2 high-reflection material and Ce-BiFeO3 / CoAl2O4 light-absorbing composite material, and the two are coordinated and applied in photovoltaic backplane materials to prepare a low-cost, green and environmentally friendly new type of reinforced black photovoltaic backplane composite film. DETAILED DESCRIPTION

[0020] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0021] The terms "including" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0022] The present application provides a reinforced black photovoltaic backplane film, which includes a black reflective layer, a white supporting layer and a black weather-resistant layer from top to bottom, wherein the raw materials for preparing the black reflective layer include Ce-BiFeO3 highly reflective material, the raw materials for preparing the white supporting layer include Mg(OH)2 / MMT-TiO2 highly reflective material, and the raw materials for preparing the black weather-resistant layer include Ce-BiFeO3 / CoAl2O4 light-absorbing composite material.

[0023] The reinforced black photovoltaic backplane film of the present application adds different raw materials between different layers, which can improve the reflectivity of the photovoltaic backplane to ultraviolet light, ensure that the photovoltaic backplane has high weather resistance, and extend its service life.

[0024] First, the present application adds Ce-BiFeO3 high reflective material to the black reflective layer. BiFeO3 is a new type of perovskite material with unique physical and mechanical properties. The lanthanide element cerium (Ce) is doped into the BiFeO3 material. The introduction of Ce ions inhibits the formation of oxygen vacancies and improves the structural stability and mechanical strength of the material. In addition, the addition of Ce can effectively control the band gap width, and exhibits excellent photocatalytic performance and high reflectivity under light irradiation. Therefore, Ce-BiFeO3 is added to the black reflective layer to exert its high reflectivity and enhance the anti-aging and weather resistance of the photovoltaic backplane film.

[0025] Secondly, the white support layer of the present application is added with Mg(OH)2 / MMT-TiO2 high reflective material. Mg(OH)2 has a high reflectivity and can effectively reflect sunlight, thereby reducing heat absorption. TiO2 has the advantages of stable chemical properties, high toughness, oxidation resistance, high temperature resistance, antibacterial properties and high reflectivity. MMT (montmorillonite) is combined with TiO2 to improve the dispersibility and stability of TiO2 materials. It has good barrier properties and is not easy to thermally decompose. In addition, the excellent photocatalytic properties of MMT-TiO2, synergistically with the high reflectivity of Mg(OH)2, enhance the resistance of the white support layer to UV aging.

[0026] Finally, Ce-BiFeO3 / CoAl2O4 light absorption composite material is added to the raw materials for preparing the black weather-resistant layer. CoAl2O4 is a material with high thermal stability and chemical stability, and has good optical properties and infrared reflection functions. This application utilizes the coordinated effect of the ultraviolet light absorption properties of CoAl2O4 and the high reflective properties of Ce-BiFeO3 material for the preparation of the black weather-resistant layer in contact with the air, thereby enhancing the light absorption and reflection efficiency and high temperature aging resistance of the photovoltaic backplane film.

[0027] The present application provides a method for preparing a Ce-BiFeO3 high reflective material, which uses iron salt and bismuth salt as raw materials, adds Ce powder, chitosan and solvent, reacts in a reactor, and obtains the Ce-BiFeO3 high reflective material after centrifugation, washing and drying the product.

[0028] The present application also provides a method for preparing a Mg(OH)2 / MMT-TiO2 high reflective material, which uses montmorillonite (MMT) as a carrier, introduces nano-TiO2 into the MMT interlayer by titanium tetrachloride hydrolysis, and obtains MMT-TiO2 white powder after calcination. Mg(OH)2, MMT-TiO2 powder and solvent are reacted in a reactor, and the product is centrifuged, washed and dried to obtain the Mg(OH)2 / MMT-TiO2 high reflective material.

[0029] The present application also provides a method for preparing a Ce-BiFeO3 / CoAl2O4 light-absorbing composite material, wherein cobalt salt and aluminum salt are dispersed in a solvent as raw materials to form a CoAl2O4 precursor solution, iron salt and bismuth salt are dispersed in the solution to form a BiFeO3 precursor solution, the CoAl2O4 precursor solution, the BiFeO3 precursor solution, Ce powder and chitosan solution are reacted, the product is centrifuged, washed and dried to obtain a Ce-BiFeO3 / CoAl2O4 precursor, and the Ce-BiFeO3 / CoAl2O4 precursor is calcined to obtain a Ce-BiFeO3 / CoAl2O4 light-absorbing composite material.

[0030] In some embodiments, the raw materials for preparing the black reflective layer of the present application include: black pigment, Ce-BiFeO3 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET.

[0031] In some embodiments, the raw materials for preparing the white support layer of the present application include: Mg(OH)2 / MMT-TiO2 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET.

[0032] In some embodiments, the raw materials for preparing the black weather-resistant layer of the present application include: black raw materials, Ce-BiFeO3 / CoAl2O4 light-absorbing composite materials, SEBS polymer elastomers, antioxidants, anti-hydrolysis agents, light stabilizers, other additives and PET.

[0033] The reinforced black photovoltaic backplane film of the present application uses PET resin as the main base material for all three layers of material, has good light transmittance and mechanical properties, and has low gas and water vapor permeability, which can block water vapor and most substances such as acids, alkalis, and salts, and has a good protective effect on photovoltaic modules.

[0034] In some embodiments, the anti-hydrolysis agent is any one or more combinations of oxazoline compounds, epoxy compounds, aromatic carbodiimide, aliphatic carbodiimide, and polycarbodiimide.

[0035] In a more preferred embodiment, the anti-hydrolysis agent is an aromatic carbodiimide. Aromatic carbodiimide anti-hydrolysis stabilizers react chemically with hydrolysis products such as carboxylic acid or water to inhibit catalytic hydrolysis degradation and extend service life. In addition, aromatic carbodiimide also has excellent antioxidant, heat resistance and flame resistance, greatly improving the weather resistance and aging resistance of the backsheet film, thereby ensuring a higher reflectivity of the photovoltaic backsheet to sunlight.

[0036] In some embodiments, the light stabilizer is any one or more of bis(2,2,6,6-tetramethyl-1-octyloxy-4-piperidinyl) sebacate, 2-hydroxy-4-octyloxybenzophenone, 2-(2ˊ-hydroxy-5ˊ-methylphenyl)benzotriazole, 2-(2ˊ-hydroxy-3ˊ5ˊ-di-tert-butylphenyl)-5-chloro-benzotriazole, 2,2'-methylene-(6-(2H-benzotriazole)-4-tert-octyl)phenol, 2-cyano-3,3ˊ-diphenylacrylate, sebacate bis-2,2,6,6-tetramethylpiperidinol, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, and tris(2,4-di-tert-butylphenol)phosphite.

[0037] In a more preferred embodiment, the light stabilizer is bis-2,2,6,6-tetramethylpiperidinol sebacate and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole. The two can significantly improve the performance of the photovoltaic backsheet layer and prevent it from losing light, cracking, bubbling, shedding and discoloration.

[0038] In some embodiments, the antioxidant is an antioxidant that is any one or more of an amine antioxidant, a quinoline derivative antioxidant, a hindered phenol antioxidant, a phosphite antioxidant, a thioester antioxidant, a hydroperoxide decomposer, and a heavy metal ion passivator.

[0039] In a more preferred embodiment, the antioxidant is a hindered phenol and a phosphite antioxidant, and the combination of the two produces a synergistic effect to improve the weather resistance and discoloration resistance of the backsheet film.

[0040] In some embodiments, the other auxiliary agent may be any one of a curing agent, a stabilizer, a dispersant or a plasticizer.

[0041] The reinforced black photovoltaic backplane film of the present application is prepared by adding polystyrene-ethylene-butylene-polystyrene (SEBS) polymer elastomer to the raw materials. It is a linear triblock copolymer and a high-performance thermoplastic elastomer with good transparency. SEBS has many excellent physical and chemical properties, including good aging resistance, high elasticity and plasticity. In addition, SEBS also has good thermal stability, resistance to ultraviolet radiation and chemical stability. Due to its saturated molecular structure, SEBS is more resistant to aging, yellowing, temperature and corrosion than SBS. The present invention uses SEBS in the photovoltaic backplane film layer, fully utilizes its characteristics to enhance the weather resistance of the photovoltaic backplane film, and solves the problem of poor compatibility between the materials in each layer and between the PET inner layer and the backplane substrate EVA, effectively improving the interfacial bonding strength between the film and EVA.

[0042] The present application prepares Mg(OH)2 / MMT-TiO2 high-reflection material and Ce-BiFeO3 / CoAl2O4 light-absorbing composite material, and coordinates the two for use in photovoltaic backplane materials to prepare a low-cost, green and environmentally friendly new reinforced black photovoltaic backplane composite film. The preparation process is simple, and the prepared black photovoltaic backplane film has high reflective performance, as well as good adhesion, mechanical properties, anti-oxidation, anti-hydrolysis and anti-aging and weathering stability, which significantly improves the service life of the photovoltaic backplane.

[0043] The present application provides a method for preparing a reinforced black photovoltaic backplane film, comprising the following steps:

[0044] S1: using iron salt and bismuth salt as raw materials, adding Ce powder, chitosan and solvent, reacting in a reactor, centrifuging, washing and drying the product to obtain Ce-BiFeO3 high reflective material;

[0045] S2: Cobalt salt and aluminum salt are dispersed in a solvent as raw materials to form a CoAl2O4 precursor solution, iron salt and bismuth salt are dispersed in the solution to form a BiFeO3 precursor solution, the CoAl2O4 precursor solution, the BiFeO3 precursor solution, Ce powder and chitosan solution are reacted, the product is centrifuged, washed and dried to obtain a Ce-BiFeO3 / CoAl2O4 precursor, and the Ce-BiFeO3 / CoAl2O4 precursor is calcined to obtain a Ce-BiFeO3 / CoAl2O4 light absorbing composite material;

[0046] S3: Using montmorillonite (MMT) as a carrier, nano-TiO2 is introduced into the MMT interlayer by titanium tetrachloride hydrolysis method, and MMT-TiO2 white powder is obtained after calcination. Mg(OH)2, MMT-TiO2 powder and solvent are reacted in a reactor, and the product is centrifuged, washed and dried to obtain Mg(OH)2 / MMT-TiO2 high reflective material;

[0047] S4: black pigment, Ce-BiFeO3 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET masterbatch are mixed and added into a screw extruder, and extruded and plasticized to obtain a black reflective layer;

[0048] Mg(OH)2 / MMT-TiO2 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET masterbatch are mixed and added into a screw extruder, and extruded and plasticized to obtain a white support layer;

[0049] The black pigment, Ce-BiFeO3 / CoAl2O4 light absorbing composite material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET masterbatch are mixed and added into a screw extruder, and extruded and plasticized to obtain a black weather-resistant layer;

[0050] The black reflective layer, the white support layer and the black weather-resistant layer are formed by a three-layer co-extrusion casting machine to obtain a reinforced black photovoltaic backplane film of the present application.

[0051] Example 1

[0052] S1: Preparation of Ce-BiFeO3 high reflective material: Fe(NO3)3·9H2O and Bi(NO3)3·5H2O raw materials with a mass ratio of 1:1 were weighed, added to 80% deionized water, 3% KOH and 10% polyethylene glycol, and magnetically stirred for 30 min, then 5% Ce powder and 2% chitosan were added. After stirring for 30 min, the mixture was transferred to a polytetrafluoroethylene-lined reactor and reacted in a water bath in a 120 ℃ oven for 16 h. After cooling to room temperature, the mixture was centrifuged, washed repeatedly, and vacuum dried at 65 ℃ for 6 h to obtain Ce-BiFeO3 high reflective material.

[0053] S2: Preparation of Ce-BiFeO3 / CoAl2O4 light-absorbing composite materials: Co(NO3)2·6H2O and Al(NO3)3·9H2O were weighed in a molar ratio of 2:1, added to 80% deionized water, and appropriate amounts of urea and ammonium fluoride were added, and a CoAl2O4 precursor solution was formed after magnetic stirring; Fe(NO3)3·9H2O and Bi(NO3)3·5H2O raw materials with a mass ratio of 1:1 were weighed, added to 80% deionized water, 5% KOH and 10% polyethylene glycol were added, and a BiFeO3 precursor solution was formed after magnetic stirring for 30 minutes; the above CoAl2O4 precursor solution and BiFeO3 precursor solution were mixed and transferred to a polytetrafluoroethylene-lined reactor, 8% Ce powder and 2% chitosan solution were added, and the mixed solution was placed in a 160 ℃ oven for water bath reaction for 18 h, cooled to room temperature and centrifuged, washed repeatedly and dried under vacuum at 60 °C for 6 h to obtain Ce-BiFeO3 / CoAl2O4 precursor, which was then calcined in a muffle furnace at 750 °C for 2 h to obtain Ce-BiFeO3 / CoAl2O4 light-absorbing composite material;

[0054] S3: Preparation of Mg(OH)2 / MMT-TiO2 high reflective material: Using montmorillonite as a carrier, nano-TiO2 was introduced into the interlayer of montmorillonite by titanium tetrachloride hydrolysis method, and a stable structure of MMT-TiO2 white powder was obtained after calcination at 550°C. Then 10% Mg(OH)2, 5% MMT-TiO2, 1.2% dilute hydrochloric acid and 85% purified water were ultrasonically stirred for 40 min, transferred to a closed reactor, reacted in a water bath in an oven at 180°C for 16h, cooled to room temperature and centrifuged, repeatedly washed with anhydrous ethanol and purified water, and finally vacuum dried at 65°C for 6h to obtain Mg(OH)2 / MMT-TiO2 material;

[0055] S4: 5% perylene black, 8% Ce-BiFeO3 high reflective material, 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the remaining PET masterbatch are mixed uniformly in a high-speed mixer, and the mixed raw materials are added to a screw extruder, and extruded at a temperature of 220 ° C and a speed of 15 r / min to melt and plasticize to obtain a black reflective layer;

[0056] 10% Mg(OH)2 / MMT-TiO2 high reflective material, 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the remaining PET masterbatch were mixed evenly in a high-speed mixer, and the mixed raw materials were added into a screw extruder, and extruded and melted at a temperature of 220 ° C and a rotation speed of 15 r / min to obtain a white support layer;

[0057] 5% perylene black, 10% Ce-BiFeO3 / CoAl2O4 light absorbing composite material, 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the balance PET masterbatch were mixed uniformly in a high-speed mixer, and the mixed raw materials were added into a screw extruder, and extruded and melted at a temperature of 220 ° C and a rotation speed of 15 r / min to obtain a black weather-resistant layer;

[0058] The black reflective layer, the white support layer and the black weather-resistant layer are formed by a three-layer co-extrusion casting machine to obtain a reinforced black photovoltaic backplane film of the present application.

[0059] Example 2

[0060] The addition amount of Ce-BiFeO3 high reflective material in step S4 is adjusted to 6%, and the other preparation steps are consistent with the preparation steps in Example 1.

[0061] Example 3

[0062] The addition amount of Mg(OH)2 / MMT-TiO2 high reflective material in step S4 is adjusted to 15%, and the other preparation steps are consistent with the preparation steps in Example 1.

[0063] Example 4

[0064] The addition amount of the Ce-BiFeO3 / CoAl2O4 light absorbing composite material in step S4 was adjusted to 15%, and the other preparation steps were consistent with the preparation steps in Example 1.

[0065] Comparative Example 1

[0066] According to steps S1 and S2 in Example 1, a Ce-BiFeO3 high reflective material and a Mg(OH)2 / MMT-TiO2 high reflective material are prepared, and according to step S4 in Example 1, a black reflective layer and a white support layer are prepared;

[0067] Preparation of a black weather-resistant layer: 5% perylene black, 10% Ce-BiFeO3 high reflective material, 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the remainder of PET masterbatch were mixed evenly in a high-speed mixer, and the mixed raw materials were added into a screw extruder, and extruded and melted at a temperature of 220°C and a rotation speed of 15 r / min to obtain the black weather-resistant layer of Comparative Example 1, and the three-layer co-extrusion casting machine was formed to obtain the photovoltaic backplane film of Comparative Example 1.

[0068] Comparative Example 2

[0069] According to steps S1 and S3 in Example 1, a Ce-BiFeO3 high reflective material and a Ce-BiFeO3 / CoAl2O4 light absorbing composite material are prepared, and according to step S4 in Example 1, a black reflective layer and a black weather-resistant layer are prepared;

[0070] Intermediate supporting layer: 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the remaining PET masterbatch are mixed evenly in a high-speed mixer, and the mixed raw materials are added into a screw extruder, and extruded and melted at a temperature of 220°C and a rotation speed of 15 r / min to obtain the intermediate supporting layer of Comparative Example 2; the three-layer co-extrusion casting machine is formed to obtain the photovoltaic backplane film of Comparative Example 2.

[0071] Comparative Example 3

[0072] According to steps S2 and S3 in Example 1, a Ce-BiFeO3 / CoAl2O4 light absorbing composite material and a Mg(OH)2 / MMT-TiO2 high reflective material were prepared, and according to step S4 in Example 1, a white support layer and a black weather-resistant layer were prepared;

[0073] Black reflective layer: 5% perylene black, 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the remainder of PET masterbatch were mixed evenly in a high-speed mixer, and the mixed raw materials were added into a screw extruder, and extruded and melted at a temperature of 220°C and a rotation speed of 15 r / min to obtain the black reflective layer of Comparative Example 3; the three-layer co-extrusion casting machine was formed to obtain the photovoltaic backplane film of Comparative Example 3.

[0074] Comparative Example 4

[0075] According to steps S1 and S3 in Example 1, a Ce-BiFeO3 high reflective material and a Mg(OH)2 / MMT-TiO2 high reflective material are prepared, and according to step S4 in Example 1, a black reflective layer and a white support layer are prepared;

[0076] Black weather-resistant layer: 5% perylene black, 5% SEBS polymer elastomer, 0.5% antioxidant, 0.5% anti-hydrolysis agent, 0.5% light stabilizer, 1.2% other additives and the remainder PET masterbatch are mixed evenly in a high-speed mixer, and the mixed raw materials are added into a screw extruder, and extruded and melted at a temperature of 220°C and a rotation speed of 15 r / min to obtain the black weather-resistant layer of Comparative Example 4; the three-layer co-extrusion casting machine is formed to obtain the photovoltaic backplane film of Comparative Example 4.

[0077] Performance Testing

[0078] The photovoltaic backplane films prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were respectively subjected to performance tests. The thermal deformation temperature of the photovoltaic backplane films was tested by a thermal Vicat thermal deformation instrument according to ASTM D648-2000 standard. The reflectivity was tested by ultraviolet spectrophotovoltaic method with reference to GB / T29848 standard, and the test results are recorded in Table 1 below.

[0079] Table 1 Performance test results of various embodiments and comparative examples

[0080]

[0081] From the analysis of the performance test results in Table 1, it can be seen that the reinforced black photovoltaic backplane film of the present application is prepared by adding Ce-BiFeO3 high-reflection material to the black reflective layer, adding Mg(OH)2 / MMT-TiO2 high-reflection material to the white support layer, and adding Ce-BiFeO3 / CoAl2O4 light-absorbing composite material to the black weather-resistant layer. The photovoltaic backplane film has good ultraviolet reflectivity and can maintain a high thermal deformation temperature. It is not easy to deform and crack in harsh environments such as outdoor environments, and can better protect photovoltaic modules and obtain a longer service life.

[0082] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A reinforced black photovoltaic backplane film, characterized in that: From top to bottom, it includes a black reflective layer, a white support layer and a black weather-resistant layer, wherein the raw material for preparing the black reflective layer includes a Ce-BiFeO3 high-reflective material, the raw material for preparing the white support layer includes a Mg(OH)2 / MMT-TiO2 high-reflective material, and the raw material for preparing the black weather-resistant layer includes a Ce-BiFeO3 / CoAl2O4 light-absorbing composite material; The preparation method of the Ce-BiFeO3 high reflective material is as follows: using iron salt and bismuth salt as raw materials, adding Ce powder, chitosan and solvent, reacting in a reactor, centrifuging, washing and drying the product to obtain the Ce-BiFeO3 high reflective material; The preparation method of the Mg(OH)2 / MMT-TiO2 high reflective material is as follows: using montmorillonite as a carrier, introducing nano-TiO2 into the MMT interlayer by titanium tetrachloride hydrolysis method, calcining to obtain MMT-TiO2 white powder, reacting Mg(OH)2, MMT-TiO2 powder and solvent in a reactor, centrifuging, washing and drying the product to obtain the Mg(OH)2 / MMT-TiO2 high reflective material; The preparation method of the Ce-BiFeO3 / CoAl2O4 light-absorbing composite material is as follows: cobalt salt and aluminum salt are dispersed in a solvent as raw materials to form a CoAl2O4 precursor solution, iron salt and bismuth salt are dispersed in a solution to form a BiFeO3 precursor solution, the CoAl2O4 precursor solution, the BiFeO3 precursor solution, Ce powder and chitosan solution are reacted, the product is centrifuged, washed and dried to obtain a Ce-BiFeO3 / CoAl2O4 precursor, and the Ce-BiFeO3 / CoAl2O4 precursor is calcined to obtain the Ce-BiFeO3 / CoAl2O4 light-absorbing composite material.

2. The reinforced black photovoltaic backplane film according to claim 1, characterized in that: The raw materials for preparing the black reflective layer include: black pigment, the Ce-BiFeO3 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET, and the other additives are any one of a curing agent, a stabilizer, a dispersant or a plasticizer.

3. The reinforced black photovoltaic backplane film according to claim 1, characterized in that: The raw materials for preparing the white support layer include: the Mg(OH)2 / MMT-TiO2 high-reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET, and the other additives are any one of a curing agent, a stabilizer, a dispersant or a plasticizer.

4. The reinforced black photovoltaic backplane film according to claim 1, characterized in that: The raw materials for preparing the black weather-resistant layer include: black raw material, the Ce-BiFeO3 / CoAl2O4 light-absorbing composite material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET, wherein the other additives are any one of a curing agent, a stabilizer, a dispersant or a plasticizer.

5. The reinforced black photovoltaic backplane film according to any one of claims 2 to 4, characterized in that: The anti-hydrolysis agent is any one or more combinations of oxazoline compounds, epoxy compounds, aromatic carbodiimides, and aliphatic carbodiimides.

6. The reinforced black photovoltaic backplane film according to claim 5, characterized in that: The light stabilizer is any one or more of bis(2,2,6,6-tetramethyl-1-octyloxy-4-piperidinyl) sebacate, 2-hydroxy-4-octyloxybenzophenone, 2-(2ˊ-hydroxy-5ˊ-methylphenyl)benzotriazole, 2-(2ˊ-hydroxy-3ˊ5ˊ-di-tert-butylphenyl)-5-chloro-benzotriazole, 2,2'-methylene-(6-(2H-benzotriazole)-4-tert-octyl)phenol, 2-cyano-3,3ˊ-diphenylacrylate, bis(2,2,6,6-tetramethylpiperidinol sebacate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol, and tris(2,4-di-tert-butylphenol)phosphite.

7. A method for preparing a reinforced black photovoltaic backplane film, characterized in that: The following steps are involved: S1: using iron salt and bismuth salt as raw materials, adding Ce powder, chitosan and solvent, reacting in a reactor, centrifuging, washing and drying the product to obtain Ce-BiFeO3 high reflective material; S2: using cobalt salt and aluminum salt as raw materials and dispersing them in a solvent to form a CoAl2O4 precursor solution, and dispersing iron salt and bismuth salt in the solution to form a BiFeO3 precursor solution, reacting the CoAl2O4 precursor solution, the BiFeO3 precursor solution, Ce powder and chitosan solution, and obtaining a Ce-BiFeO3 / CoAl2O4 precursor after centrifugation, washing and drying, and calcining the Ce-BiFeO3 / CoAl2O4 precursor to obtain a Ce-BiFeO3 / CoAl2O4 light absorption composite material; S3: Using montmorillonite MMT as a carrier, introducing nano-TiO2 into the MMT interlayer by titanium tetrachloride hydrolysis method, and obtaining MMT-TiO2 white powder after calcination, reacting Mg(OH)2, the MMT-TiO2 powder and a solvent in a reactor, and obtaining Mg(OH)2 / MMT-TiO2 high reflective material after centrifugation, washing and drying the product; S4: mixing the black pigment, the Ce-BiFeO3 high reflective material, the SEBS polymer elastomer, the antioxidant, the anti-hydrolysis agent, the light stabilizer, other additives and the PET masterbatch, and adding them into a screw extruder, extruding and plasticizing to obtain a black reflective layer, wherein the other additives are any one of a curing agent, a stabilizer, a dispersant or a plasticizer; The Mg(OH)2 / MMT-TiO2 high reflective material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET masterbatch are mixed and added into a screw extruder, and extruded and plasticized to obtain a white support layer, wherein the other additives are any one of a curing agent, a stabilizer, a dispersant or a plasticizer; The black pigment, the Ce-BiFeO3 / CoAl2O4 light absorbing composite material, SEBS polymer elastomer, antioxidant, anti-hydrolysis agent, light stabilizer, other additives and PET masterbatch are mixed and added into a screw extruder, and extruded and plasticized to obtain a black weather-resistant layer, wherein the other additives are any one of a curing agent, a stabilizer, a dispersant or a plasticizer; The black reflective layer, the white support layer and the black weather-resistant layer are formed by a three-layer co-extrusion casting machine to obtain the reinforced black photovoltaic backplane film.

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