WO2020133283A1 - Light reflecting film and photovoltaic assembly thereof - Google Patents

Abstract

Provided by the present invention is a light reflecting film, comprising a substrate layer, a micro-structure layer, a light reflection layer, and a bonding layer that are sequentially provided, wherein the micro-structure layer is several micro-structures that are arranged in order and that protrude from a surface of the substrate, the light reflection layer and the bonding layer are provided with the same central axis, the substrate layer, micro-structure layer, and reflective layer have the same width, and the width of the bonding layer is greater than the width of the reflective layer. The light reflecting film provided by the present invention has a simple structure, provides the bonding layer on the light reflection layer to effectively prevent the light reflection layer from falling off, and has excellent insulation performance; in addition, the width of the bonding layer is greater than the width of other parts of the light reflecting film, which facilitates the fixation of the light reflecting film; the light reflection layer is prevented from sliding to contact a cell, thus causing a short circuit; and the contact area with a cell is increased during installation, which reduces the local force on the cell and effectively avoids the risk of damage to the cell.

Description

Light reflective film and its photovoltaic module Technical field

The invention relates to the field of photovoltaics, in particular to a light reflecting film and its photovoltaic components.

Background technique

Solar photovoltaic is one of the important forms of solar energy utilization. Solar photovoltaic power generation can reduce the dependence and consumption of non-renewable fossil fuels and can reduce environmental pollution. In recent years, researchers have developed solar cells based on the photovoltaic effect and realized the conversion of solar energy into electrical energy. People have made detailed analysis and research on the non-cell area of the photovoltaic module, and found that the solder strip in the photovoltaic module can realize the reflection of incident light again. The solar cells are connected in series through the welding tape, but the high-intensity light incident on the welding tape is mostly regular reflection, which is reflected to the outside of the photovoltaic module, causing a waste of light energy. In order to reduce the influence of the welding tape on the conversion efficiency of the solar cell and the light energy loss of the photovoltaic module, a reflective film is usually provided on the welding tape to improve the conversion efficiency. At present, the structure of the reflective film is likely to crack the battery sheet and damage the battery sheet due to the high hardness of the substrate layer during packaging, and the reflective layer is prone to fall off, resulting in the risk of short circuit of the battery sheet.

Summary of the invention

In view of this, it is necessary to provide a light reflective film that has good insulation properties and can effectively avoid the risk of cell cracking during the packaging process.

The invention provides a light reflecting film, which comprises a base layer, a microstructure layer, a light reflecting layer and an adhesive layer which are arranged in sequence. The microstructure layer is a number of ordered microstructures protruding from the surface of the base layer. The base layer, the microstructure layer and the reflective layer have the same width, and the width of the adhesive layer is greater than the width of the reflective layer.

Further, each of the microstructures is set to the same shape and size, the microstructures are closely connected in sequence, and the distance between the center points of each of the adjacent microstructures is set between 5 μm and 500 μm.

Further, the cross-section of the microstructure is an isosceles triangle, and the base angle of the cross-section triangle of the microstructure is 15°-90°.

Further, the extension direction of the light reflection film is taken as a main axis, the extension direction of the microstructure on the base layer 10 is taken as a longitudinal axis, at least one of the longitudinal axis and the main axis are inclined, and the main axis The angle of inclination to the longitudinal axis is 0° to 90°.

Further, the difference between the width of the adhesive layer and the width of the reflective layer is 0.1 mm to 20 mm.

Further, the thickness of the base layer is 30 μm to 400 μm, the thickness of the microstructure layer is 1 μm to 500 μm, the thickness of the reflective layer is 1 nm to 500 nm, and the thickness of the adhesive layer is 10 μm to 500 μm.

Further, the thickness of the adhesive layer is greater than the thickness of the microstructure.

Further, the reflective layer and the adhesive layer are provided with the same central axis,

A photovoltaic module adopting the light reflection film includes a packaging board, a packaging adhesive film, a plurality of battery sheets, the light reflecting film, a packaging adhesive film and a back plate arranged in sequence, the light reflecting film is disposed on the battery The back of the sheet is located in the gap between the two battery sheets.

Further, the adhesive layers are respectively pasted on the back surfaces of adjacent battery sheets and are located in the gaps between adjacent battery sheets, and the thickness of the adhesive layer is greater than between adjacent battery sheets Gap.

The light reflection film provided by the invention has a simple structure, and the adhesive layer is provided on the reflective layer, which effectively prevents the reflective layer from falling off, and has good insulation performance; in addition, the width of the adhesive layer is larger than the width of other parts of the light reflective film. When the battery is packaged, increasing the contact surface with the battery sheet is beneficial to fix the light reflecting film, reduce the stress, and effectively avoid the risk of damage to the battery sheet.

BRIEF DESCRIPTION

FIG. 1 is a schematic structural diagram of a light reflection film according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a photovoltaic module using the light reflective film shown in FIG.

Symbol description of main components

Light reflecting film	100
Basal layer	10
Microstructure layer	20
Reflective layer	30
Bonding layer	40

Photovoltaic module	101
Package board	102
Packaging film	103, 105
Cell	104
Backplane	106

The following specific embodiments will further illustrate the present invention with reference to the above drawings.

detailed description

The technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that when a component is said to be "installed on" another component, it can be directly on another component or there can be a centered component. When a component is considered to be "set on" another component, it may be set directly on another component or there may be a centered component at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terminology used in the description of the present invention herein is for the purpose of describing specific embodiments, and is not intended to limit the present invention. The term "or/and" as used herein includes any and all combinations of one or more related listed items.

Please refer to FIG. 1. FIG. 1 is a schematic structural diagram of a light reflective film 100 according to an embodiment of the present invention. The light reflective film 100 is disposed on the back of a photovoltaic module encapsulation board or on the back of an adjacent cell sheet for The sunlight shining on the gap of the solar cells is reflected on the solar cells, increasing the total amount of light received by the solar cells in the photovoltaic modules and increasing the power of the photovoltaic modules. The light reflective film 100 includes a base layer 10, a microstructure layer 20, a reflective layer 30, and an adhesive layer 40 disposed in this order.

The material used for the base layer 10 is polyethylene, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, phenolic resin, epoxy resin, polyurethane, polycarbonate, polyphenylene ether, thermoplastic resin, polyimide One or more mixed materials in polymer materials such as amines and polysulfone plastics. The thickness of the base layer 10 is 30 μm to 400 μm, preferably 30 μm to 350 μm.

The microstructure layer 20 is composed of several ordered microstructures protruding from the base layer 10, and the microstructures extend continuously on the base layer 10. Each of the microstructures is set to the same shape and size. The microstructures are closely connected in sequence and the distance between the center points of each adjacent microstructure is set between 5 μm and 500 μm, preferably 10 μm. 400μm. In this embodiment, the microstructure is prepared by pressure-sensitive adhesive or ultraviolet curing adhesive. The microstructure mainly includes rubber type, thermoplastic elastomers, polyacrylates, silicones, and polyurethane adhesives. One or more mixed materials. The microstructure is in the shape of a triangular prism, the height of the triangular prism is 1 μm to 500 μm, preferably 1 μm to 400 μm, the cross section of the triangular prism is an isosceles triangle, and the base angle of the isosceles triangle is 15° to 90°, preferably 30° to 90°. In other embodiments, the microstructure is in the shape of a triangular prism, and the top of the triangular prism is an arc-shaped structure. The extension direction of the light reflection film is taken as the main axis, and the extension direction of the microstructure on the base layer 10 is taken as the longitudinal axis. At least one of the longitudinal axis and the main axis are arranged obliquely. In this embodiment, The included angle between the main axis and the longitudinal axis is 0° to 90°.

The reflective layer 30 is a film layer made of metal by vacuum evaporation, magnetron sputtering, vacuum sputtering or electroplating method. In this embodiment, the metal is aluminum, silver, chromium, nickel, etc. One or more mixed materials, the thickness of the reflective layer 30 is 1 nm to 500 nm.

The adhesive layer 40 includes an adhesive, and the adhesive layer 40 is used to fix the light reflective film 100 on the gap between the back of the packaging board of the photovoltaic module or the back of the cell sheet. The thickness of the adhesive layer 40 is set to be 10 μm to 500 μm, preferably 20 μm to 400 μm, and the thickness of the adhesive layer 40 is greater than the thickness of the microstructure. The direction perpendicular to the extending direction of the light reflecting film is the width direction, the base layer 10, the microstructure layer 20 and the light reflecting layer 30 are provided with the same width, and the width of the adhesive layer 40 is larger than that of the light reflecting layer 30 The width is specifically 0.1 mm to 20 mm, preferably 0.5 mm to 18 mm. The width of the adhesive layer 40 is set to be larger than the width of the reflective layer 30, which is mainly used to increase the adhesive area, which is convenient for fixing the light reflective film, and prevents the reflective layer 30 from sliding and contacting the battery sheet to cause a short circuit The phenomenon occurs, and the contact area with the battery slice is increased during installation, the local force of the battery slice is reduced, and the risk of damage to the battery slice is effectively avoided. The adhesive layer 40 and the microstructure layer 20 have the same central axis. Specifically, the adhesive layer 40 is symmetrically disposed on the microstructure layer 20, and both sides of the adhesive layer 40 exceed the light reflection. The width of the layer 30 is equal. The material used for the adhesive layer 40 includes one or more mixed materials of ethylene vinyl acetate copolymer (EVA), ethylene ethyl acrylate (EEA), and ethylene octene copolymer (POE). The adhesive layer 40 has good insulation and light transmittance. After sunlight passes through the adhesive layer 40 and is reflected by the reflective layer 30, it is irradiated onto the battery sheet to increase the conversion efficiency of the battery sheet.

Referring to FIG. 2, the present invention also provides a photovoltaic module 101 using the above-mentioned light reflection film 100. The photovoltaic module 101 includes an encapsulation board 102, an encapsulation adhesive film 103, a plurality of battery sheets 104, and the light reflection film arranged in this order. 100. An encapsulation film 105 and a backplane 106. In this embodiment, the light reflecting film 100 is disposed on the back of the battery sheet 104 and is located in the gap between the two battery sheets 104, and the width of the light reflecting film is greater than that of the two batteries The width between the pieces 104. Sunlight is reflected by the light reflecting film 100 onto the battery sheet 104, increasing the light receiving area of the battery sheet 104, thereby improving the conversion efficiency of the photovoltaic module 101.

The light reflection film provided by the invention has a simple structure, and the adhesive layer is provided on the reflective layer, which effectively prevents the reflective layer from falling off, and has good insulation performance; in addition, the width of the adhesive layer is larger than the width of other parts of the light reflective film. When the battery is packaged, increasing the contact surface with the battery sheet is beneficial to fix the light reflecting film, reduce the stress, and effectively avoid the risk of damage to the battery sheet.

Persons of ordinary skill in the art should realize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention, as long as the above embodiments are appropriately changed within the spirit and scope of the present invention And changes fall within the scope of the claimed invention.

Claims (10)

1. A light reflecting film, characterized by comprising a base layer, a microstructure layer, a light reflecting layer and an adhesive layer arranged in sequence, the microstructure layer is an ordered array of microstructures protruding from the surface of the base layer. The base layer, the microstructure layer and the reflective layer have the same width, and the width of the adhesive layer is greater than the width of the reflective layer.
2. The light reflecting film according to claim 1, wherein each of the microstructures is set to the same shape and size, and the distance between the center points of each of the adjacent microstructures is set at 5 μm to 500 μm between.
3. The light reflecting film according to claim 1, wherein the cross-section of the microstructure is an isosceles triangle, and the base angle of the cross-section triangle of the microstructure is 15°-90°.
4. The light reflecting film according to claim 1, wherein the extending direction of the light reflecting film is taken as a main axis, and the extending direction of the microstructure on the base layer is taken as a longitudinal axis, at least one of the longitudinal axes The main shaft is inclined, and the angle between the main shaft and the longitudinal axis is 0° to 90°.
5. The light reflecting film according to claim 1, wherein the difference between the width of the adhesive layer and the width of the reflective layer is 0.1 mm to 20 mm.
6. The light reflecting film according to claim 1, wherein the thickness of the base layer is 30 μm to 400 μm, the thickness of the microstructure layer is 1 μm to 500 μm, and the thickness of the reflective layer is 1 nm to 500 nm. The thickness of the adhesive layer is 10 μm to 500 μm.
7. The light reflective film of claim 1, wherein the thickness of the adhesive layer is greater than the thickness of the microstructure.
8. The light reflecting film according to claim 1, wherein the reflective layer and the adhesive layer are provided with the same central axis.
9. A photovoltaic module adopting the light reflecting film according to any one of claims 1-8, characterized in that it comprises an encapsulating board, an encapsulating adhesive film, a plurality of battery plates, the light reflecting film, an encapsulating adhesive film, and A back plate, the light reflecting film is disposed on the back of the battery sheet, and is located in the gap between adjacent battery sheets.
10. The photovoltaic module according to claim 9, characterized in that: the adhesive layer is respectively pasted on the back of the adjacent cell sheet, and is located in the gap between the adjacent cell sheets, the adhesive layer The thickness of is larger than the gap between adjacent battery slices.

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