A photovoltaic cell gap reflective film and photovoltaic module

Abstract

This utility model relates to the field of photovoltaic technology and discloses a photovoltaic cell gap reflective film and a photovoltaic module. The photovoltaic cell gap reflective film includes a base film; the base film includes a substrate layer, a transition adhesive layer, and an ionomer adhesive layer; the substrate layer and the ionomer adhesive layer are respectively disposed on the upper and lower surfaces of the transition adhesive layer; a light-reflecting layer is also provided on the upper surface of the base film. While ensuring high solar reflectivity, the cooperation between the transition adhesive layer and the ionomer adhesive layer also improves the adhesion between the layers within the gap reflective film, avoiding delamination problems and enhancing the adhesion between the gap reflective film and the photovoltaic backsheet (such as photovoltaic glass) of the photovoltaic module. This prevents delamination, degradation, and yellowing of the gap reflective film during long-term outdoor use of the photovoltaic module, thus helping to improve its service life and reflectivity. Furthermore, the gap reflective film is low in cost.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, specifically to a reflective film for the gaps between photovoltaic cells and a photovoltaic module. Background Technology

[0002] Traditional double-glass photovoltaic modules have white-glazed glass on the back, which is made by adding an glaze before tempering. However, double-glass photovoltaic modules using gap reflective films can have their back glass tempered directly without glazing, maintaining the uniformity of stress in the glass. This not only improves the load-bearing capacity of the back glass of the photovoltaic module, but also reduces the risk of glass cracking (through a four-point bending test comparison, the strength of the unglazed back glass is significantly improved compared to the glazed back glass).

[0003] Gap reflective films typically use PET (polyethylene terephthalate) as the base material. Its front side is a reflective layer, and its back side is an adhesive layer. The adhesive layer's function is to firmly bond the gap reflective film to the back glass of the photovoltaic module. In this way, the gap reflective film can replace traditional white glaze and be precisely positioned at the gaps between the photovoltaic cells. Simultaneously, with the reflective layer facing the front of the photovoltaic module, it can reflect light from the gaps between the cells back into the cells, increasing light absorption and light utilization efficiency.

[0004] To enhance reflectivity, fully utilize solar energy resources, and improve the power generation efficiency of photovoltaic cells, researchers have developed reflective films for photovoltaic modules, as shown in publication numbers CN117410365A, CN108598184B, CN109273548A, and CN116751527A. However, these reflective film products encounter various problems during production and long-term use: for example, production involves complex processes such as coating, rolling, lamination, and vacuum sputtering, resulting in expensive equipment and high production costs; furthermore, the reflective aluminum layer is highly susceptible to acid corrosion during outdoor use, leading to a sharp decrease in reflectivity; and the encapsulation adhesive layer and microstructure layer are often made of organic materials with poor weather resistance, such as EVA (ethylene-vinyl acetate copolymer) and acrylic resin, which are prone to delamination, degradation, and yellowing during outdoor use, reducing the lifespan and reflectivity of the reflective film. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a photovoltaic cell gap reflective film and a photovoltaic module.

[0006] Based on this, the present invention discloses a photovoltaic cell gap reflective film, including a base film; the base film includes a substrate layer, a transition adhesive layer and an ion polymer adhesive layer; the substrate layer and the ion polymer adhesive layer are respectively disposed on the upper surface and the lower surface of the transition adhesive layer; the upper surface of the base film is also provided with a light reflective layer.

[0007] Preferably, the light-reflecting layer is a barium sulfate reflective layer with a thickness of 5-15 μm (preferably 8-12 μm).

[0008] Preferably, the transition bonding layer is an adhesive resin layer with a thickness of 5-15 μm.

[0009] More preferably, the adhesive resin layer is made of modified polyethylene, modified polypropylene, modified ethylene vinyl acetate copolymer, or modified ethylene acrylate resin.

[0010] The adhesive resin layer is made of a material selected from the brand name ADMER. TM AT2717, BYNEL TM 21E533, BYNEL TM 22E757, NUCREL TM 925, Plexar PX3080 PX2250, ADMER TM NF410E, BYNEL TM 21E787 or NUCREL TM The adhesive resin of AE; the thickness of the adhesive resin layer is 8-12 μm.

[0011] Preferably, the thickness of the ionomer adhesive layer is 20-60 μm.

[0012] More preferably, the material of the ionomer adhesive layer is selected from grades Surlyn 9320, Surlyn 8920, and Himilan. TM 1557, AMPLIFY TM IO 1100, NUCREL TM 0910, AMPLIFY TM An ionomer of IO 3801 or Aclyn295; the thickness of the ionomer adhesive layer is 30-50 μm.

[0013] Preferably, the substrate layer is a polyester film with a thickness of 30-60 μm.

[0014] More preferably, the polyester film is a polyethylene terephthalate film with a thickness of 40-60 μm.

[0015] Preferably, the base film is a three-layer co-extruded structure formed by a substrate layer, a transition adhesive layer and an ionomer adhesive layer, and the thickness of the base film is 80-110 μm.

[0016] This utility model also discloses a photovoltaic module, including a photovoltaic front panel, a photovoltaic cell layer and a photovoltaic back panel arranged sequentially from top to bottom; the photovoltaic cell layer includes a plurality of cells arranged at intervals, and a gap reflective film is provided at the intervals of the cells, the gap reflective film being the photovoltaic cell gap reflective film described above in this utility model.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] This invention discloses a photovoltaic cell gap reflective film. A light-reflecting layer is formed on the upper surface of the substrate layer as its reflective functional layer, ensuring high solar reflectivity to reflect sunlight from the gaps between the cells back to the cells, thereby increasing the light absorption and utilization rate of the cells. Furthermore, a transition adhesive layer and an ionomer adhesive layer work synergistically to act as the adhesive layer of the gap reflective film. This effectively enhances the adhesion between the layers within the gap reflective film, preventing delamination between the reflective functional layer and the adhesive layer. It also effectively enhances the adhesion between the gap reflective film and the photovoltaic backsheet (such as photovoltaic glass) of the photovoltaic module, preventing delamination, degradation, and yellowing of the gap reflective film during long-term outdoor use. This helps to extend the service life and reflective effect of the gap reflective film in the photovoltaic module. In addition, the manufacturing process of this gap reflective film is simple and low-cost. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of a photovoltaic cell gap reflective film according to the present invention.

[0020] Reference numerals: 1. Light reflective layer; 2. Base film; 21. Substrate layer; 22. Transition adhesive layer; 23. Ion polymer adhesive layer. Detailed Implementation

[0021] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example

[0023] This embodiment provides a photovoltaic cell gap reflective film, see [link to relevant documentation]. Figure 1 The substrate film 2 includes a base film 2; the base film 2 includes a substrate layer 21, a transition adhesive layer 22, and an ionomer adhesive layer 23; the substrate layer 21 and the ionomer adhesive layer 23 are respectively disposed on the upper and lower surfaces of the transition adhesive layer 22; a light-reflecting layer 1 is also provided on the upper surface of the substrate layer 21. The substrate layer 21 is a polyester film with a thickness of 30-60 μm.

[0024] Specifically, the polyester film is a polyethylene terephthalate film (PET film), and the thickness of the substrate layer 21 is preferably 40-60 μm (more preferably 50 μm).

[0025] The light-reflecting layer 1 is a barium sulfate reflective layer; the thickness of the light-reflecting layer 1 is 5-15 μm, preferably 8-12 μm, and more preferably 10 μm.

[0026] In this embodiment, a light-reflecting layer 1 (barium sulfate reflective layer) is provided on the upper surface of the substrate layer 21 as the reflective functional layer of the photovoltaic cell gap reflective film. This ensures that it has high solar reflectivity, so as to reflect sunlight from the gap between the cells back to the cells, thereby increasing the light absorption and light utilization of the cells and improving the photoelectric conversion efficiency of the photovoltaic module. Moreover, the photovoltaic cell gap reflective film uses a barium sulfate reflective layer instead of a reflective aluminum layer, which effectively avoids the problem that existing reflective aluminum layers are easily corroded by acid, causing a sharp decrease in reflectivity.

[0027] The transition adhesive layer 22 is an adhesive resin layer with a thickness of 5-15 μm. Specifically, the adhesive resin layer is made of modified polyethylene, modified polypropylene, modified ethylene vinyl acetate copolymer, or modified ethylene acrylate resin.

[0028] In practice, the material of the adhesive resin layer is selected from the brand name ADMER. TM AT2717, BYNEL TM 21E533, BYNEL TM 22E757, NUCREL TM 925, Plexar PX3080 PX2250, ADMER TM NF410E, BYNEL TM 21E787 or NUCREL TM The adhesive resin of AE; the thickness of the transition adhesive layer 22 is preferably 8-12 μm (more preferably 10 μm). By providing the transition adhesive layer 22, the adhesion between the reflective functional layer and the ionomer adhesive layer 23 is improved, thereby improving the adhesion between the layers in the gap reflective film, so as to prevent the delamination problem of the layers in the gap reflective film.

[0029] The thickness of the ionomer adhesive layer 23 is 20-60 μm. Specifically, the material of the ionomer adhesive layer 23 is selected from grades Surlyn 9320, Surlyn 8920, and Himilan. TM 1557, AMPLIFY TM IO 1100, NUCREL TM 0910, AMPLIFYTM The ionomer is IO 3801 or Aclyn 295; the thickness of the ionomer adhesive layer 23 is preferably 30-50 μm (more preferably 40 μm).

[0030] In this embodiment, the transition adhesive layer 22 and the ionomer adhesive layer 23 work together to act as the adhesive layer of the gap reflective film. This can effectively improve the adhesion between the layers in the gap reflective film, prevent the reflective functional layer from delaminating from the adhesive layer, and effectively improve the adhesion between the gap reflective film and the photovoltaic backsheet (such as photovoltaic glass) of the photovoltaic module. This can prevent the gap reflective film from delaminating, degrading, yellowing and other phenomena during long-term outdoor use of the photovoltaic module, and help to improve the service life and reflection effect of the gap reflective film in the photovoltaic module.

[0031] The base film 2 is a three-layer co-extruded structure formed by a substrate layer 21, a transition adhesive layer 22, and an ionomer adhesive layer 23. The thickness of the base film 2 is 80-110 μm (preferably 100 μm). This base film 2 is formed by three-layer co-extrusion, eliminating the steps of structural adhesive coating, EVA lamination, sputtered aluminum film, and subsequent photocuring in the existing reflective film production process. This simplifies the process and reduces equipment, energy, and raw material costs, resulting in higher efficiency and lower cost.

[0032] Tests revealed that the photovoltaic cell gap reflective film of this embodiment exhibits an adhesion force of over 155 N / cm between the adhesive layer of the transition adhesive layer 22 + ion polymer adhesive layer 23 and the photovoltaic glass, an adhesion force of over 60 N / cm between the adhesive layer of the transition adhesive layer 22 + ion polymer adhesive layer 23 and the PET layer, and an adhesion force of barium sulfate reflective layer on the upper surface of the PET layer of grade 0. The light reflectivity of this photovoltaic cell gap reflective film in the 400-1100nm wavelength band can reach over 90%.

[0033] A photovoltaic module according to this embodiment includes a photovoltaic front panel, a photovoltaic cell layer and a photovoltaic back panel (such as photovoltaic glass) arranged sequentially from top to bottom; the photovoltaic cell layer includes a plurality of cells arranged at intervals, and a gap reflective film is provided at the intervals of the cells, the gap reflective film being a photovoltaic cell gap reflective film as described above in this embodiment.

[0034] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0035] The technical solution provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A reflective film for the gaps between photovoltaic cells, characterized in that, It includes a base film; the base film includes a substrate layer, a transition adhesive layer and an ionomer adhesive layer; the substrate layer and the ionomer adhesive layer are respectively disposed on the upper surface and the lower surface of the transition adhesive layer; the upper surface of the substrate layer is also provided with a light-reflecting layer.

2. The photovoltaic cell gap reflective film according to claim 1, characterized in that, The light-reflecting layer is a barium sulfate reflective layer with a thickness of 5-15 μm.

3. The photovoltaic cell gap reflective film according to claim 1, characterized in that, The transition bonding layer is an adhesive resin layer with a thickness of 5-15 μm.

4. The photovoltaic cell gap reflective film according to claim 3, characterized in that, The adhesive resin layer is made of modified polyethylene, modified polypropylene, modified ethylene vinyl acetate copolymer, or modified ethylene acrylate resin. The adhesive resin layer is made of a material selected from the brand name ADMER. TM AT2717, BYNEL TM 21E533, BYNEL TM 22E757, NUCREL TM 925, Plexar PX3080 PX2250, ADMER TM NF410E, BYNEL TM 21E787 or NUCREL TM The adhesive resin of AE; the thickness of the adhesive resin layer is 8-12 μm.

5. The photovoltaic cell gap reflective film according to claim 1, characterized in that, The thickness of the ionomer adhesive layer is 20-60 μm.

6. The photovoltaic cell gap reflective film according to claim 5, characterized in that, The ionomer adhesive layer is made of materials selected from Surlyn 9320, Surlyn 8920, and Himilan. TM 1557, AMPLIFY TM IO 1100, NUCREL TM 0910, AMPLIFY TM An ionomer of IO 3801 or Aclyn 295; the thickness of the ionomer adhesive layer is 30-50 μm.

7. The photovoltaic cell gap reflective film according to claim 1, characterized in that, The substrate layer is a polyester film with a thickness of 30-60 μm.

8. The photovoltaic cell gap reflective film according to claim 7, characterized in that, The polyester film is a polyethylene terephthalate film with a thickness of 40-60 μm.

9. A photovoltaic cell gap reflective film according to claim 1, characterized in that, The base film is a three-layer co-extruded structure formed by a substrate layer, a transition adhesive layer and an ionomer adhesive layer, and the thickness of the base film is 80-110 μm.

10. A photovoltaic module, characterized in that, It includes a photovoltaic front panel, a photovoltaic cell layer and a photovoltaic back panel arranged sequentially from top to bottom; the photovoltaic cell layer includes a plurality of cells arranged at intervals, and a gap reflective film is provided at the intervals between the cells, wherein the gap reflective film is a photovoltaic cell gap reflective film as described in any one of claims 1-9.

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