Solar cell module packaged by silica gel

Abstract

The invention belongs to the technical field of solar cell modules, and particularly relates to a solar cell module and a preparation method thereof. The silica gel packaged solar cell module sequentially comprises a front plate, a silica gel packaging layer, a cell piece, a silica gel packaging layer and a back plate from top to bottom, the silica gel packaging layer is formed by coating a silica gel adhesive between the battery piece and the front plate as well as between the battery piece and the back plate, sequentially stacking, then laminating, defoaming, heating and curing, and the thickness of the silica gel packaging layer is 0.01-0.1 mm. According to the technical scheme provided by the invention, the problem of insufficient adhesive force of the silica gel is solved through grafting modification and selection of proper raw materials, the application of the silica gel to a packaging adhesive film is realized by adopting direct hot-pressing crosslinking after field preparation and spraying, and the production cost is effectively reduced due to excellent characteristics of the silica gel.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cell modules, and in particular relates to a solar cell module and a preparation method thereof. Background Art

[0002] Solar cell modules are generally composed of a front panel, an encapsulation film, a cell, an encapsulation film and a back panel. According to the materials of the front panel and the back panel, they are divided into ordinary solar cell modules made of glass panels and lightweight solar cell modules made of polymer materials. The encapsulation film protects the cell on the one hand, and has good adhesion with the front panel and the back panel, bonding the front panel, the cell and the back panel into a whole. The encapsulation film generally needs to have excellent light transmittance, bonding strength, thermal temperature resistance, air tightness, environmental stress cracking resistance, weather resistance, corrosion resistance and electrical properties.

[0003] In the prior art, the encapsulation film is generally made of EVA (polyethylene-vinyl acetate copolymer). The processing process is to process the front panel, encapsulation film, solar cell and back panel separately, and then stack the above layers, place the stacked components on the laminating table in the vacuum chamber, and then evacuate the vacuum chamber from the side, heat the stacked components in the vacuum chamber, and the EVA film undergoes a cross-linking reaction when heated. After the curing is completed and cooled, the encapsulation of the solar cell assembly is completed. The curing temperature of the EVA film needs to be 150°C and the curing time is about 30 minutes. The EVA film generally needs to be 0.3-0.5mm to meet the processing and use requirements. Summary of the invention

[0004] The invention provides a solar cell assembly encapsulated by silica gel, which is used to solve the problems of high curing temperature and high cost of the current EVA encapsulation.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: the silicone encapsulated solar cell assembly comprises, from top to bottom, a front panel, a silicone encapsulation layer, a battery cell, a silicone encapsulation layer and a back panel; the silicone encapsulation layer is formed by applying a silicone adhesive between the battery cell and the front panel, and between the battery cell and the back panel, stacking them in sequence, laminating, vacuuming, and heating and curing; the thickness of the silicone encapsulation layer is 0.01-0.1mm.

[0006] Optionally, the silicone adhesive comprises component A, component B and a silane coupling agent, the component A comprises polyether grafted polysiloxane, polyvinyl silicone oil and a platinum catalyst, and the component B comprises polyether grafted polysiloxane, polyvinyl silicone oil and hydrogen-containing silicone oil.

[0007] Optionally, the ratio of component A to component B is 1:1 by weight.

[0008] Optionally, the A component is distributed in the following proportions by weight:

[0009] Polyether grafted polysiloxane 10-20 parts

[0010] 80-90 parts of polyvinyl silicone oil

[0011] 0.1-0.2 parts of platinum catalyst.

[0012] Optionally, the B component is distributed in the following proportions by weight:

[0013] Polyether grafted polysiloxane 10-20 parts

[0014] 60-80 parts of polyvinyl silicone oil

[0015] Contains 10-20 parts of hydrogen silicone oil.

[0016] Optionally, the preparation method of the polyether-grafted polysiloxane comprises the following steps: mixing vinyl-terminated polysiloxane, 4-hydroxybutyl vinyl ether, hydrogen-containing silicone oil and a platinum catalyst, and stirring for 2 to 6 hours.

[0017] Optionally, the platinum catalyst is selected from chloroplatinic acid-isopropanol, chloroplatinic acid-divinyltetramethyldisiloxane or chloroplatinic acid-diethyl phthalate.

[0018] Optionally, the silane coupling agent is selected from KH550, KH560, KH570, KH580, KH590 or KH792.

[0019] Optionally, the silane coupling agent accounts for 0.5-3% of the total weight of the silicone adhesive by weight.

[0020] Optionally, the viscosity of the silicone adhesive is 500-30000 Cps.

[0021] The technical solution provided by the present invention has the following advantages over the prior art: due to the unique structure of organic silicon, it combines the properties of inorganic materials and organic materials, and is much better than EVA in terms of weather resistance, UV resistance, insulation and other properties. Therefore, its thickness can be thinner than EVA, which is undoubtedly an advantage for product cost. In addition, its thermal curing temperature is low, so the temperature of the final pressing molding can also be reduced, further reducing the production cost. The problem of insufficient adhesion of silicone is solved by grafting modification and selecting suitable raw materials. On-site preparation and spraying are used before direct hot pressing and cross-linking, so that its application in packaging film is realized. DETAILED DESCRIPTION

[0022] For ease of understanding, the silica gel encapsulated solar cell assembly is described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0023] Example 1 Preparation of polyether grafted polysiloxane

[0024] 90g of vinyl-terminated dimethylpolysiloxane (purchased from Hubei Xinsihai Chemical Co., Ltd.), 5g of 4-hydroxybutyl vinyl ether, and 18g of methyl hydrogen silicone oil (purchased from Hubei Xinsihai Chemical Co., Ltd.) were mechanically stirred at 300rpm for 10min until uniform; then 0.4g of chloroplatinic acid-diethyl phthalate was slowly added dropwise, and mechanically stirred at 300rpm for 2h until uniform to obtain colorless polyether grafted polysiloxane.

[0025] Example 2-4 Preparation of silica gel adhesive

[0026] The silicone adhesive comprises component A, component B and a silane coupling agent, wherein the component A comprises polyether grafted polysiloxane, polyvinyl silicone oil and a platinum catalyst, and the component B comprises polyether grafted polysiloxane, polyvinyl silicone oil and hydrogen-containing silicone oil. The polyether grafted polysiloxane is prepared in Example 1, the polyvinyl silicone oil is purchased from Shandong Dayi Chemical Co., Ltd., the hydrogen-containing silicone oil is purchased from Hubei Xinsihai Chemical Co., Ltd., the platinum catalysts are all chloroplatinic acid-diethyl phthalate, and the silane coupling agents are all KH560.

[0027] The preparation process is as follows:

[0028] 1) Preparation of component A: weigh according to the formula ratio and mix and stir evenly;

[0029] 2) Preparation of component B: weigh according to the formula ratio and mix and stir evenly;

[0030] 3) Preparation of binder: Weigh component A and component B in a ratio of 1:1 by weight and put them into a reaction kettle, then add the silane coupling agent, and stir for about 1 hour under nitrogen protection.

[0031] The proportions of the components in component A in Example 2-4 by weight are shown in Table 1, the proportions of the components in component B in Example 2-4 by weight are shown in Table 2, and the proportions of the components in the binder in Example 2-4 by weight are shown in Table 3.

[0032] Table 1

[0033] Polyether grafted polysiloxane Polyvinyl silicone oil Platinum catalysts Example 2 10 90 0.15 Example 3 20 80 0.2 Example 4 15 85 0.1

[0034] Table 2

[0035] Polyether grafted polysiloxane Polyvinyl silicone oil Hydrogen silicone oil Example 2 20 60 20 Example 3 10 80 10 Example 4 10 70 20

[0036] Table 3

[0037] Component A (parts) Component B (parts) KH560 (portion) Viscosity(Cps) Example 2 50 50 2 9800 Example 3 50 50 2.5 10500 Example 4 50 50 1 11250

[0038] Example 5-7 Preparation of solar cell module

[0039] The silicone adhesive prepared in Example 2-4 is first sprayed on the side of the backplane facing the battery cell, and scraped to make the surface uniform to form a first adhesive layer. The battery cell is then placed on the first adhesive layer and put into a laminator. After vacuuming for about 10 minutes, it is kept at 60-80°C and 1-2kg pressure for 20 minutes and taken out of the laminator; then the silicone adhesive prepared in Example 2-4 is sprayed on the upper surface of the arranged battery cell to form a second adhesive layer, which is also sprayed first and then scraped. Finally, the front plate is covered on the second adhesive layer for lamination. After the second vacuuming for about 10 minutes, it is kept at 60-80°C and 1-2kg pressure for 20 minutes, taken out of the laminator, and naturally cooled.

[0040] The difference between Examples 5-7 lies not only in the choice of silicone adhesive, but also in the change of the material of the front plate and the back plate. The front plate and the back plate of Example 5 are both traditional photovoltaic glass, with a glass thickness of about 3mm. The front plate material of Example 6 is ETFE (ethylene-tetrafluoroethylene copolymer) photovoltaic film, and the back plate material is PVF (polyvinyl fluoride film)-PET (polyester film)-PVF three-layer composite film. The front plate and the back plate material of Example 7 are both PVDF (polyvinylidene fluoride) film. The silicone encapsulation layer and the upper and lower adjacent layers are tightly bonded, meeting the various performance requirements of the composite solar cell module.

[0041] Performance Experiment

[0042] 1. Performance comparison between silicone adhesive and EVA film

[0043] The adhesive prepared in Example 2-4 was degassed under reduced pressure, coated on the surface of a glass plate, and heated and cured to form a 0.3 mm thick adhesive film, which was then tested for light transmittance and interlayer adhesion with a 0.3 mm thick EVA film.

[0044] Light transmittance: tested using the YP-CWF1 spectrophotometer produced by Shandong Youyunpu Optoelectronics Technology Co., Ltd., referring to the relevant IEC61215 standards

[0045] Interlayer adhesion: AGSJ manufactured by Shimadzu Corporation, measured in accordance with ASTM D1876.

[0046] High temperature and high humidity test: The test was carried out at 120°C, 2 kg atmospheric pressure, and 100% RH for 96 hours using C340 produced by Weiss-Voetsh Environmental Testing Instruments and in accordance with IEC61215-10.13.

[0047] 2. Solar cell module performance

[0048] Adhesion of MWT photovoltaic module cells: The adhesion of the silicone adhesive coatings prepared in Example 2 with dry thicknesses of 10 μm, 20 μm, 30 μm, and 50 μm, and the adhesion of the EVA coating with dry thickness of 400 μm were tested. It was found that the adhesion of the coating with dry thickness of 20 μm was close to that of the EVA coating with dry thickness of 400 μm.

[0049] Adhesion to the photovoltaic glass back panel: Dry thickness of the silicone adhesive coating prepared in Test Example 2

[0050] The adhesion of 20μm, 50μm, 80μm and 100μm, as well as the adhesion of EVA coating with a dry thickness of 400μm, was found to be close to that of EVA coating with a dry thickness of 50μm.

[0051] Table 4

[0052]

[0053] The above comparative experiments show that the silicone adhesive prepared by the technical solution of the present invention can completely replace

[0054] EVA film, and the usage can be less, and the lamination temperature can be reduced from 150℃ to 80℃, which greatly saves energy.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solar cell module encapsulated by silica gel, characterized in that: From top to bottom, it includes a front plate, a silicone encapsulation layer, a battery cell, a silicone encapsulation layer and a back plate; the silicone encapsulation layer is formed by applying silicone adhesive between the battery cell and the front plate, and between the battery cell and the back plate, stacking them in sequence, laminating, vacuuming, and heating to cure; the thickness of the silicone encapsulation layer is 0.01-0.1mm.

2. The solar cell assembly encapsulated with silica gel according to claim 1, characterized in that: The silicone adhesive comprises component A, component B and a silane coupling agent, wherein the component A comprises polyether grafted polysiloxane, polyvinyl silicone oil and a platinum catalyst, and the component B comprises polyether grafted polysiloxane, polyvinyl silicone oil and hydrogen-containing silicone oil.

3. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The ratio of component A to component B is 1:1 by weight.

4. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The distribution ratio of each group of the A component by weight is as follows: Polyether grafted polysiloxane 10-20 parts 80-90 parts of polyvinyl silicone oil 0.1-0.2 parts of platinum catalyst.

5. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The B component is distributed in the following proportions by weight: Polyether grafted polysiloxane 10-20 parts 60-80 parts of polyvinyl silicone oil Contains 10-20 parts of hydrogen silicone oil.

6. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The preparation method of the polyether grafted polysiloxane comprises the following steps: mixing vinyl-terminated polysiloxane, 4-hydroxybutyl vinyl ether, hydrogen-containing silicone oil and a platinum catalyst, and stirring for 2 to 6 hours.

7. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The platinum catalyst is selected from chloroplatinic acid-isopropanol, chloroplatinic acid-divinyltetramethyldisiloxane or chloroplatinic acid-diethyl phthalate.

8. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The silane coupling agent is selected from KH550, KH560, KH570, KH580, KH590 or KH792.

9. The solar cell assembly encapsulated with silica gel according to claim 2, characterized in that: The silane coupling agent accounts for 0.5-3% of the total weight of the silicone adhesive by weight.

10. The solar cell assembly encapsulated with silica gel according to claim 1, characterized in that: The viscosity of the silicone adhesive is 500-30000 Cps.

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