Light reflective film and photovoltaic modules

Abstract

The present invention provides a light-reflecting film, which includes a first adhesive layer, a substrate layer, a reflective layer, and a protective layer arranged in sequence, and also includes a second adhesive layer arranged on one side of the protective layer. A microstructure layer is arranged on one side of the substrate layer, and the microstructure layer includes a plurality of strip microstructures arranged in sequence, the extension direction of the microstructure along the length is the long axis direction, the short axis direction of the microstructure is perpendicular to the long axis direction, and the cross section of each microstructure along the short axis direction is an arc. The reflective layer is arranged on the microstructure layer, which expands the reflection range of light to enhance the reflective effect. The first adhesive layer and the second adhesive layer enable both sides of the light-reflecting film to have bonding ability, which is easy for workers to install. The present invention provides a photovoltaic module, which enhances the stability of the internal structure of the photovoltaic module through the light-reflecting film, and solves the problem of slipping and displacement of the light-reflecting film in the photovoltaic module.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic industry, and in particular to a light reflecting film and a photovoltaic module. Background Art

[0002] Solar photovoltaic is one of the important forms of solar energy utilization. Solar photovoltaic power generation can reduce dependence on and consumption of non-renewable fossil fuels and reduce environmental pollution. In recent years, researchers have developed solar cells based on the photovoltaic effect, realizing the conversion of solar energy into electrical energy. People have conducted detailed analysis and research on the non-cell area in photovoltaic modules and found that the welding ribbon in the photovoltaic module can realize the re-reflection of incident light. Solar cells are connected in series through the welding ribbon to achieve current conduction, but the high-intensity light incident on the welding ribbon is mostly positive reflection, which is reflected to the outside of the photovoltaic module, resulting in a waste of light energy. In order to reduce the impact of the welding ribbon on the conversion efficiency of solar cells and reduce the light energy loss of photovoltaic modules, a light reflective film is usually set on the welding ribbon to improve the conversion efficiency. At present, the hot melt adhesive layer of the light reflective film generally has poor adhesion, and it is very easy to slip, skew, and shift during the thermal bonding and lamination steps. Summary of the invention

[0003] In view of this, it is necessary to provide a light reflecting film and a photovoltaic module, which have the advantages of good reflective effect and easy installation.

[0004] The present invention provides a light reflection film, comprising a first bonding layer, a substrate layer, a reflective layer, and a protective layer which are arranged in sequence. The light reflection film also comprises a second bonding layer which is arranged on one side of the protective layer. A microstructure layer is arranged on the side of the substrate layer which is away from the first bonding layer. The microstructure layer comprises a plurality of strip microstructures which are arranged in sequence. The extension direction of the microstructure along the length is the long axis direction. The short axis direction of the microstructure is perpendicular to the long axis direction. The cross section of each microstructure along the short axis direction is an arc.

[0005] Furthermore, the side of the first adhesive layer facing away from the substrate layer is a planar structure, the side of the second adhesive layer facing away from the protective layer is a planar structure, and the thickness of the first adhesive layer and the second adhesive layer are both in the range of 20 μm to 200 μm.

[0006] Furthermore, the thickness of the substrate layer ranges from 30 μm to 400 μm, and the width of the substrate layer ranges from 1 mm to 10 mm.

[0007] Furthermore, the extending direction of the light reflective film along the length is a main axis direction, and the angle between the main axis direction and the long axis direction is in the range of -90° to 90°.

[0008] Furthermore, the chord length of the arc is in the range of 5 μm to 500 μm, the radius of the circle where the arc is located is in the range of 1 μm to 500 μm, and the central angle corresponding to each arc is in the range of 0° to 180°.

[0009] Furthermore, the reflective layer is disposed on the microstructure layer, the reflective layer has a thickness ranging from 10 nm to 500 nm, and the protective layer has a thickness ranging from 10 nm to 500 nm.

[0010] The present invention provides a photovoltaic module, comprising the light reflective film, the photovoltaic module also comprising a backplane, a first packaging film, a plurality of battery cells, a welding strip, a second packaging film and a packaging board installed in sequence, the battery cells are connected into a battery board through the welding strip, part of the light reflective film is bonded to the welding strip, and another part of the light reflective film is bonded to the gap between the battery cells.

[0011] Furthermore, one side of a portion of the light reflective film is bonded to the soldering tape, and the other side of the light reflective film is bonded to a side of the second packaging film close to the battery cell.

[0012] Furthermore, one side of the other part of the light reflective film is adhered to the first packaging film and is located in the gap between the battery cells, and the other side of the light reflective film is adhered to one side of the second packaging film close to the first packaging film.

[0013] Furthermore, one side of the other part of the light reflective film is bonded to the back plate and faces the gap between the battery cells, and the other side of the light reflective film is bonded to one side of the first packaging film close to the back plate.

[0014] The light reflective film provided by the present invention comprises a first adhesive layer, a substrate layer, a reflective layer, and a protective layer which are arranged in sequence. The light reflective film also comprises a second adhesive layer arranged on one side of the protective layer. A microstructure layer is arranged on the side of the substrate layer away from the first adhesive layer. The microstructure layer comprises a plurality of strip microstructures arranged in sequence. The extension direction of the microstructure along the length is the long axis direction. The short axis direction of the microstructure is perpendicular to the long axis direction. The cross section of each microstructure along the short axis direction is an arc. The reflective layer is arranged on the microstructure layer to expand the reflection range of light so as to enhance the reflective effect. The first adhesive layer and the second adhesive layer enable both sides of the light reflective film to have bonding ability, which is easy for workers to install. The photovoltaic module provided by the present invention improves the utilization rate of light through the light reflective film, enhances the stability of the internal structure of the photovoltaic module, and solves the problem of slipping and displacement of the light reflective film in the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1FIG. 4 is a schematic diagram of the structure of a light reflective film in one embodiment of the present invention.

[0016] Figure 2 FIG. 4 is a schematic cross-sectional view of a microstructure in an embodiment of the present invention.

[0017] Figure 3 It is a schematic structural diagram of a photovoltaic assembly in the first embodiment of the present invention.

[0018] Figure 4 Schematic diagram of the structure of a photovoltaic module in the second embodiment of the present invention.

[0019] Main component symbols

[0020]

[0021]

[0022] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0023] In order to more clearly understand the above-mentioned purposes, features and advantages of the embodiments of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the technical field of the embodiments of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific implementation methods and are not intended to limit the embodiments of the present invention.

[0026] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of a light reflective film 100 in one embodiment of the present invention. The light reflective film 100 includes a first adhesive layer 10, a substrate layer 20, a reflective layer 30, a protective layer 40 and a second adhesive layer 50 arranged in sequence. The reflective layer 30 has a reflective property. The protective layer 40 protects the reflective layer 30 from being corroded by acid gas and water vapor. The first adhesive layer 10 and the second adhesive layer 50 enable both sides of the light reflective film 100 to have bonding ability, which facilitates the installation of the light reflective film 100.

[0027] The light reflective film 100 is generally a long thin film structure, the first adhesive layer 10 is arranged on one side of the substrate layer 20, and the side of the first adhesive layer 10 away from the substrate layer 20 is a planar structure. Specifically, the first adhesive layer 10 is arranged on one side of the substrate layer 20 by lamination. The first adhesive layer 10 is made of one or more of EVA, EAA, POE or other hot melt adhesive materials. In this embodiment, the first adhesive layer 10 is made of EVA or EEA material. The thickness of the first adhesive layer 10 is 20μm to 200μm, preferably, the thickness of the first adhesive layer 10 is 20μm to 60μm.

[0028] Please also read Figure 1 and Figure 2 , Figure 2 The cross-sectional schematic diagram of the microstructure 2011 in one embodiment of the present invention. The thickness of the substrate layer 20 ranges from 30 μm to 400 μm, and the width of the substrate layer 20 ranges from 1 mm to 10 mm. Preferably, the thickness of the substrate layer is 30 μm to 80 μm. The first bonding layer 10 is arranged on one side of the substrate layer 20, and the microstructure layer 201 is arranged on the side of the substrate layer 20 away from the first bonding layer 10. The microstructure layer 201 includes a plurality of strip-shaped microstructures 2011 arranged in sequence. The microstructure layer 201 is formed by hot stamping on one side of the substrate layer 20. The extension direction of the light reflective film 100 along the length is the main axis direction, and the extension direction of each of the microstructures 2011 along the length is the long axis direction. The angle between the main axis direction and the long axis direction ranges from -90° to 90°. Preferably, the angle between the main axis direction and the long axis direction ranges from -45° to 45°. The short axis direction of the microstructure 2011 is perpendicular to the long axis direction, and the cross section of each microstructure 2011 along the short axis direction is an arc. The chord length L of the arc is 5μm to 500μm, preferably, the chord length L of the arc ranges from 5μm to 70μm. The radius R of the circle where the arc is located is 1μm to 500μm, preferably, the radius R of the circle where the arc is located ranges from 3μm to 40μm. The center angle α corresponding to each arc is 0° to 180°, preferably, the center angle α corresponding to the arc ranges from 25° to 180°. The cross section of each microstructure 2011 along the short axis direction is an arc, which prevents the risk of being damaged during processing, packaging and use. The substrate layer 20 is made of one or more polymer materials such as PET, PP, PVC, etc. In this embodiment, the substrate layer 20 is made of PET material.

[0029] The reflective layer 30 is disposed on the microstructure layer 201, and the protective layer 40 is disposed on the side of the reflective layer 30 away from the microstructure layer 201. Specifically, the reflective layer 30 is made of a reflective material and laid on the microstructure layer 201 by vacuum evaporation, chemical plating or magnetron sputtering. The material of the reflective layer 30 is one or more reflective materials such as aluminum, silver, stainless steel, etc. In this embodiment, the material of the reflective layer 30 is aluminum. The thickness of the reflective layer 30 is 10nm to 500nm. Preferably, the thickness of the reflective layer 30 ranges from 10nm to 150nm. The reflective layer 30 is attached to the microstructure layer 201 to expand the reflection range of light, so as to enhance the reflective effect.

[0030] The side of the protective layer 40 away from the reflective layer 30 is a planar structure or an arc-shaped structure consistent with the reflective layer 30. In this embodiment, the side of the protective layer 40 away from the reflective layer 30 is an arc-shaped structure consistent with the reflective layer 30. Specifically, the protective layer 40 is made of metal oxide or fluoride and laid on the reflective layer 30 by vacuum evaporation or magnetron sputtering. The thickness of the protective layer 40 is 10nm to 500nm, preferably, the thickness of the protective layer 40 ranges from 20nm to 100nm. The material of the protective layer 40 is SiO2, SiO X , MgF2, ZrO2, TiO2 and other metal oxides or fluorides. In this embodiment, the material of the protective layer 40 is SiO2 and SiO X The protective layer 40 is disposed on the reflective layer 30 to protect the reflective layer 30 from being corroded by acid gas and water vapor.

[0031] The second adhesive layer 50 is disposed on the protective layer 40, and the side of the second adhesive layer 50 away from the protective layer 40 is a planar structure. Specifically, the second adhesive layer 50 is disposed on the side of the protective layer 40 away from the microstructure layer 201 by lamination. The second adhesive layer 50 is one or more of EVA, EAA, POE or other hot melt adhesive materials. In this embodiment, the material of the second adhesive layer 50 is EVA or EAA. The thickness of the second adhesive layer 50 is 20μm to 200μm, and preferably, the thickness of the second adhesive layer 50 is 20μm to 60μm.

[0032] The first adhesive layer 10 and the second adhesive layer 50 are respectively provided on both sides of the light reflective film 100, which solves the problems of the light reflective film 100 being difficult to position, easy to fall off, and easy to move during installation, and is easy for workers to install.

[0033] See also Figure 3 , Figure 3Schematic diagram of the structure of the photovoltaic module 200 in the first embodiment of the present invention. The photovoltaic module 200 also includes a backplane 210, a first packaging film 220, a plurality of battery cells 230, a welding strip 240, a second packaging film 250 and a packaging board 260 which are installed in sequence. The battery cells 230 are connected to form a battery board through the welding strip 240. Part of the light reflective film 100 is bonded to the welding strip 240. Specifically, the first adhesive layer 10 is bonded to the welding strip 240, and the second adhesive layer 50 is bonded to the side of the second packaging film 250 close to the battery cells 230. The first adhesive layer 10 of another part of the light reflective film 100 is bonded to the first packaging film 220 and is located in the gap between the battery cells 230, and the second adhesive layer 50 is bonded to the side of the second packaging film 250 close to the first packaging film 220, so as to enhance the stability of the internal structure of the photovoltaic module and solve the problem of slipping and displacement of the light reflective film in the photovoltaic module 200. When the photovoltaic module 200 is in use, light irradiated by the light reflecting film 100 at the gap between the welding strips 240 or the battery cells 230 is reflected to the junction of the packaging board 260 and the air, and then the light is reflected to the battery cells 230 through the packaging board 260 to improve the light utilization rate of the photovoltaic module 200.

[0034] See also Figure 4 , Figure 4 Schematic diagram of the structure of the photovoltaic module 200 in the second embodiment of the present invention. The second embodiment of the present invention is different from the first embodiment in that the light reflective film 100 bonded to the gaps between the cells 230 is arranged between the back plate 210 and the first packaging adhesive film 220. Specifically, the first adhesive layer 10 is bonded to the back plate 210 and faces the gaps between the cells 230, and the second adhesive layer 50 is bonded to the side of the first packaging adhesive film 220 close to the back plate 210. When the photovoltaic module 200 is in use, the light irradiated on the back plate 210 and the light reflective film 100 in the gaps between the cells 230 is reflected to the side of the cells 230 away from the packaging board 260, so as to improve the light utilization rate of the photovoltaic module 200.

[0035] The light reflective film 100 and the photovoltaic module 200 have the advantages of good light reflection effect and easy installation.

[0036] The above implementation modes are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit the present invention. Although the embodiments of the present invention are described in detail with reference to the above preferred implementation modes, those skilled in the art should understand that the technical solutions of the embodiments of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photovoltaic module, comprising a light reflecting film, wherein the light reflecting film comprises a first adhesive layer, a substrate layer, a reflective layer, and a protective layer arranged in sequence, characterized in that: The light reflective film further comprises a second adhesive layer disposed on one side of the protective layer, a microstructure layer is disposed on the side of the substrate layer away from the first adhesive layer, the microstructure layer comprises a plurality of strip microstructures arranged in sequence, the microstructure extending in the length direction is the long axis direction, the short axis direction of the microstructure is perpendicular to the long axis direction, and the cross section of each microstructure along the short axis direction is an arc; The photovoltaic module also includes a backplane, a first packaging film, a plurality of battery cells, a welding strip, a second packaging film and a packaging board installed in sequence, wherein the battery cells are connected to form a battery board through the welding strip, wherein a portion of the light reflecting film is bonded to the welding strip through the first adhesive layer, and another portion of the light reflecting film is bonded to the gap between the battery cells and bonded to a side of the second packaging film close to the battery cell through the second adhesive layer.

2. The photovoltaic module according to claim 1, characterized in that: One side of the other part of the light reflective film is adhered to the first packaging film and is located in the gap between the battery cells, and the other side of the light reflective film is adhered to one side of the second packaging film close to the first packaging film.

3. The photovoltaic module according to claim 1, characterized in that: One side of the other part of the light reflective film is bonded to the back plate and faces the gap between the battery cells, and the other side of the light reflective film is bonded to one side of the first packaging film close to the back plate.

4. The photovoltaic module according to claim 1, characterized in that: The side of the first adhesive layer facing away from the substrate layer is a planar structure, and the side of the second adhesive layer facing away from the protective layer is a planar structure. The thickness of the first adhesive layer and the second adhesive layer are both in the range of 20 μm to 200 μm.

5. The photovoltaic module according to claim 1, characterized in that: The thickness of the substrate layer ranges from 30 μm to 400 μm, and the width of the substrate layer ranges from 1 mm to 10 mm.

6. The photovoltaic module according to claim 1, characterized in that: The extending direction of the light reflective film along the length is a main axis direction, and the angle between the main axis direction and the long axis direction is in the range of -90° to 90°.

7. The photovoltaic module according to claim 1, characterized in that: The chord length of the arc is in the range of 5 μm to 500 μm, the radius of the circle where the arc is located is in the range of 1 μm to 500 μm, and the central angle corresponding to each arc is in the range of 0° to 180°.

8. The photovoltaic module according to claim 1, characterized in that: The reflective layer is disposed on the microstructure layer, the reflective layer has a thickness ranging from 10 nm to 500 nm, and the protective layer has a thickness ranging from 10 nm to 500 nm.

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