CN217868706U - Packaging adhesive film and photovoltaic module - Google Patents

Abstract

The application belongs to the technical field of photovoltaic. The application discloses a packaging adhesive film which comprises a light transmitting layer, a reflection increasing layer and a white film layer; the thickness of the light transmitting layer is 60-300 μm, and the reflection increasing layer is a high-reflection PET layer. The application also discloses a photovoltaic module, includes front substrate, front encapsulation glued membrane, battery cluster, back layer encapsulation glued membrane and back layer base plate in proper order, and back layer encapsulation glued membrane is above-mentioned encapsulation glued membrane. The photovoltaic technology field is applied to this application, and encapsulation glued membrane in this application outstanding anti PID performance, have good adhesive property and excellent light reflectivity, can guarantee photovoltaic module's generating efficiency and life.

Description

Packaging adhesive film and photovoltaic module

Technical Field

The utility model belongs to the technical field of the photovoltaic, especially, relate to a packaging adhesive film and photovoltaic module.

Background

With the increasing severity of energy and environmental issues, photovoltaic power generation technology has been receiving attention. The packaging adhesive film is an important packaging material in photovoltaic packaging, the packaging adhesive film bonds the battery string, the photovoltaic glass and the back plate, and the battery string is protected from being packaged in parallel to form a photovoltaic module capable of outputting direct current.

Along with the popularization of the double-sided battery technology and the increasing maturity of the double-glass photovoltaic module packaging technology, the auxiliary material cost of the double-glass packaging can be even lower than that of the single-glass packaging scheme. The back layer packaging adhesive film of the double-glass packaging generally adopts an EVA adhesive film, a POE adhesive film or a co-extrusion POE adhesive film.

However, in the process of implementing the technical solution applied in the embodiment of the present application, the applicant finds that the above-mentioned technology has at least the following technical problems:

the EVA adhesive film packaging scheme is adopted for the double-glass assembly back layer adhesive film, and the photovoltaic potential induced power attenuation (PID) phenomenon is easy to occur. Although the scheme of using POE or co-extrusion POE packaging adhesive film can solve the PID problem, the pre-crosslinked colored pure POE adhesive film can cause the packaging adhesive film cost to be obviously increased. The adopted POE adhesive film has the problem of unstable bonding property with glass.

SUMMERY OF THE UTILITY MODEL

The embodiment of this application has solved the PID problem of two-sided battery dual glass assembly through providing a encapsulation glued membrane, guarantees photovoltaic module's generating efficiency, improves photoelectric conversion efficiency.

One aspect of the embodiments of the present application provides a packaging adhesive film, which includes a light-transmitting layer, a reflection-increasing layer and a white film layer; the thickness of the euphotic layer is 60-300 mu m, the reflection increasing layer is arranged on one side of the euphotic layer, the thickness of the reflection increasing layer is 50-300 mu m, and the white film layer is arranged on one side, far away from the euphotic layer, of the reflection increasing layer; the reflectivity of the reflection increasing layer in the wavelength range of 400-1100nm is greater than or equal to 85%, and the reflectivity of the white film layer in the wavelength range of 400-1100nm is greater than or equal to 85%; the reflectivity of the packaging adhesive film in the wavelength range of 760-1100nm is greater than or equal to 75%.

Furthermore, the reflectivity of the reflection increasing layer in the wavelength range of 400-1100nm is greater than or equal to 90%, and the reflectivity of the white film layer in the wavelength range of 400-1100nm is greater than or equal to 90%.

Further, the light-transmitting layer is colorless transparent EVA or colored EVA.

Further, the colored transparent EVA is black transparent EVA or white EVA.

Furthermore, the transmittance of black transparent EVA in the wavelength range of 700-1100nm is greater than or equal to 55%.

Furthermore, the reflection increasing layer is a PET layer.

Further, the light reflectivity of the reflection increasing layer is more than or equal to 92%.

Further, the reflection-increasing layer includes a cellular structure.

Furthermore, the white film layer is a thermoplastic film layer.

Further, the white film layer is at least one of ethylene-vinyl acetate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene butene copolymer, metallocene-catalyzed ethylene octene copolymer, metallocene-catalyzed ethylene pentene copolymer, ethylene propylene copolymer, ethylene methyl acrylate copolymer, ethylene methyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, saponified ethylene-vinyl acetate-acrylate copolymer, low-density polyethylene, linear low-density polyethylene, or linear ultra-low density polyethylene.

Furthermore, the anti-reflection coating further comprises an upper coating layer and a lower coating layer, wherein the upper coating layer is arranged between the light transmitting layer and the anti-reflection layer, and the lower coating layer is arranged between the white film layer and the anti-reflection layer.

Another aspect of the application provides a photovoltaic module, which includes a front substrate, a front encapsulation adhesive film, a battery string, a back encapsulation adhesive film and a back substrate, wherein the back encapsulation adhesive film includes a light-transmitting layer, a reflection-increasing layer and a white film layer; the thickness of the euphotic layer is 60-300 mu m, the reflection increasing layer is arranged on one side of the euphotic layer, the thickness of the reflection increasing layer is 50-300 mu m, and the white film layer is arranged on one side, far away from the euphotic layer, of the reflection increasing layer; the reflectivity of the reflection increasing layer in the wavelength range of 400-1100nm is greater than or equal to 85%, and the reflectivity of the white film layer in the wavelength range of 400-1100nm is greater than or equal to 85%; the reflectivity of the packaging adhesive film in the wavelength range of 760-1100nm is more than or equal to 75 percent; the euphotic layer is attached to the surface of the battery string.

The technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

1. according to the packaging adhesive film, the reflection increasing layer is additionally arranged and can block alkali metal ions of back glass, so that the alkali metal ions are difficult to migrate to the back of the double-sided battery, and the PID problem of the double-glass assembly is effectively solved;

2. the packaging adhesive film has high light reflection performance, particularly has high reflectivity in a visible light-infrared light area, has an obvious reflectivity improvement effect aiming at an infrared band of 700-1100nm, can reach over 75% in 760-1100nm, and has a good power gain effect;

3. the non-pre-crosslinking design of the white film layer of the packaging adhesive film effectively improves the bonding property with glass.

Drawings

FIG. 1 is a schematic cross-sectional view of one implementation of the packaging adhesive film of the present application;

FIG. 2 is a schematic cross-sectional view of another embodiment of the packaging film of the present application;

FIG. 3 is a schematic cross-sectional view of another embodiment of a packaging adhesive film of the present application;

FIG. 4 is a schematic cross-sectional view of a photovoltaic module according to the present application;

FIG. 5 is a schematic cross-sectional view showing the structure of the packaging adhesive film in comparative example 1 and comparative example 2;

fig. 6 is a schematic cross-sectional view of the packaging film of comparative example 3.

In the figure: the packaging film comprises a packaging adhesive film 100, a light-transmitting layer 11, a reflection-increasing layer 12, a white film layer 13, an upper coating layer 14, a lower coating layer 15, a black light-transmitting adhesive film 16 and a white high-reflection adhesive film 17; the photovoltaic module 200, a front substrate 21, a front packaging adhesive film 22, a battery string 23, a back packaging adhesive film 24 and a back substrate 25.

Detailed Description

In order to make the technical solution better understood by those skilled in the art, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiment of the present invention. It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments. It should be noted that, in the present application, the embodiments and features of the embodiments may be combined with each other without conflict. The present application will be described in detail with reference to examples.

The problem of two glass photovoltaic module induced power attenuation Phenomenon (PID) easily take place is solved to this application embodiment, and this application provides an intermediate layer type encapsulation glued membrane, constitutes through multilayer structure, makes photovoltaic module have excellent anti PID performance. The photovoltaic module generally needs to use the cell pieces in series, and the electromotive force on the surface of the cell string is increased along with the large-scale application of the photovoltaic system. Due to the requirement of lightning protection engineering, the frame of a general photovoltaic module is required to be grounded, so that higher voltage is formed between the battery string and the frame. The PID (Potential Induced Degradation) effect is also called Potential Induced attenuation, and refers to a phenomenon that when a higher bias voltage exists between an electrode and a frame of a photovoltaic module, cations in glass undergo ion migration and are attached to the surface of a cell string, so that the power of the photovoltaic module is reduced. The direct damage of PID is that a large amount of charges are accumulated on the surface of a battery string, so that the passivation effect of the surface of the battery is deteriorated, and the filling factor, the open-circuit voltage and the short-circuit current of the battery string are reduced, so that the integral output power of the photovoltaic module is attenuated. When the PID phenomenon is serious, it will cause the power attenuation of one block of component to be more than 50%, thereby affecting the power output of the whole string. The embodiment of the application adopts a packaging adhesive film in the three-layer structure design, solves the PID problem of the double-sided battery double-glass assembly, and improves the high reflectivity of infrared bands.

The embodiment of the application provides a packaging adhesive film 100 as shown in fig. 1, which is composed of a multi-layer structure, specifically including a light-transmitting layer 11, a reflection-increasing layer 12, and a white film layer 13. Wherein the thickness of the light-transmitting layer 11 is 60 to 300 μm. The reflection increasing layer 12 is provided on one side of the light transmitting layer 11, has a thickness of 50 to 300 μm, and has a light reflectance of 85% or more in a wavelength range of 400 to 1100nm, and further has a light reflectance of 90% or more in a wavelength range of 400 to 1100nm. The white film layer 13 is provided on the side of the reflection increasing layer away from the light transmitting layer 11, and has a light reflectance of 85% or more in a wavelength range of 400 to 1100nm, and further has a light reflectance of 90% or more in a wavelength range of 400 to 1100nm. The reflection increasing layer 12 and the white film layer 13 have high reflectivity, light penetrating through the cell is reflected by the reflection increasing layer 12 and the white film layer 13 after passing through the euphotic layer 11, and the reflected light reaches the back of the cell through the euphotic layer 11, so that the utilization rate of the cell to light is improved, and the power generation efficiency of the photovoltaic module is improved. The reflectivity of the packaging adhesive film 100 in the wavelength range of 760-1100nm is greater than or equal to 75%, the packaging adhesive film has a good reflection effect on near infrared light, and the energy borne by the packaging adhesive film 100 in the near infrared fluctuation can be reduced while the power gain of the assembly is promoted, so that the temperature of the packaging adhesive film 100 is reduced, and the output power of the assembly is improved; the white film layer 13 has high reflectance, low transmittance, and high barrier property, and a rear substrate having higher transparency can be used.

In one embodiment, light transmitting layer 11 is colorless transparent EVA or colored EVA. The colorless transparent EVA has high light transmittance, is formed by taking EVA resin as a main raw material and adding various auxiliaries through melting processing, has a transparent appearance and is used for bonding with a battery string. The whole colorless and transparent EVA adhesive film does not need pre-crosslinking treatment, so that the production procedures of the adhesive film can be reduced, and the production cost of the adhesive film can be reduced. Because the pre-crosslinking treatment is not carried out, the colorless and transparent EVA has better viscosity, the bonding property of the packaging adhesive film 100 and the battery string can be improved, and the problem of hidden cracking or splitting of the battery caused by the lamination of the dual-glass assembly can be solved. The color of the EVA is that the EVA shows different colors by adding color fillers and additives into the EVA resin. In order to prevent colored EVA from overflowing to the front side of the cell, the colored EVA needs pre-crosslinking treatment. Through crosslinking reaction, form new chemical bond between the EVA macromolecule for EVA changes three-dimensional network structure into from linear structure, can make the glued membrane surface structure who obtains compact, slows down the infiltration diffusion velocity of steam in the use. Meanwhile, the cross-linking reaction can reduce the fluidity of the whole colored adhesive film in the lamination process and inhibit the colored adhesive film from polluting the front surface of the battery, the welding strip or the front surface of the bus bar due to the up-and-down flow in the lamination process.

As an embodiment, the colored EVA comprises black clear EVA or white EVA. The white EVA is prepared by pretreating EVA adhesive film with white filler such as titanium dioxide. The white EVA adhesive film can change the reflection path of light, so that sunlight is secondarily reflected to the surface of the cell string, and the power generation efficiency of the solar module is improved. White transparent EVA can satisfy the high yield encapsulation processing requirement of single glass assembly, dual glass assembly, and film assembly, but the price is also higher relatively, and the separation nature is stronger, the luminousness is lower, has the high reflectivity, can improve the subassembly generated power. Meanwhile, the white EVA has strong damp-heat aging resistance and ultraviolet aging resistance, and inhibits the aging and cracking of the back plate. The black light-transmitting EVA comprises EVA resin and black filler. The monocrystalline silicon cell is usually dark and has a color similar to that of black light-transmitting EVA, and the use of the black light-transmitting EVA can make the photovoltaic module more beautiful. Meanwhile, in distributed roof power stations and other places, the black light-transmitting EVA can effectively avoid light pollution caused by strong light reflection of the white EVA.

In one embodiment, the black light-transmitting EVA has a light transmittance of 55% or more in a wavelength range of 400 to 1100nm. Although the black color is more beautiful and can effectively avoid light pollution, the black color can absorb almost all visible light and has strong absorption capacity to light in an infrared band, thereby reducing the utilization rate of the battery to sunlight. Meanwhile, the temperature of the photovoltaic module can be increased by the strong black light absorption capacity, and the power generation power is reduced. Therefore, ordinary black EVA is not suitable. Compared with common black EVA, the black light-transmitting EVA has higher light transmittance, and can effectively reduce the black light-transmitting absorption capacity, thereby improving the light-transmitting utilization rate of the cell and the power generation power of the photovoltaic module.

In one embodiment, the reflection increasing layer 12 is a high-reflectivity PET layer. PET is polyethylene terephthalate, has good mechanical property, impact strength 3-5 times that of other films, good folding resistance, high corrosion resistance, oil resistance, fat resistance, dilute acid, dilute alkali, most solvents and low price. The reflection increasing layer 12 has high reflectivity, one part of reflected light is directly reflected to the back surface of the cell for photoelectric conversion, and the other part of the reflected light passes through the cell and is reflected by the front layer glass to the front surface of the cell so as to be utilized by the cell, so that the conversion efficiency of the assembly can be increased. The reflection increasing layer 12 has the function of blocking radiation crosslinking, and radiation crosslinking of the white film layer 13 is avoided. Due to the barrier effect of the reflection increasing layer 12, alkali metal ions of the back glass are difficult to migrate to the back of the double-sided battery, and the sandwich type packaging adhesive film 100 has a good PID (proportion integration differentiation) resistance function.

As one embodiment, the reflection-increasing layer 12 includes a cellular structure, as shown in FIG. 2. The cellular structure is that countless interconnected or non-interconnected cells are distributed in the whole material by a foaming technology. The structure can lead the material to have higher toughness, higher specific strength, smaller density, lower thermal conductivity and good chemical stability, does not corrode the contents per se, and has stronger resistance to chemical medicines such as acid, alkali and the like. Contain innumerable bubble in the cell structure, light can carry out refraction and reflection many times in the bubble, and then the light reflectance who promotes to promote the holistic reflectivity of sandwich type encapsulation glued membrane. The more and finer the cells in the cell structure, the stronger the light reflectance of the reflection increasing layer 12. Meanwhile, the cellular structure can also improve the buffering and damping capacity of the packaging adhesive film 100, so that the impact on the photovoltaic module in the using process is reduced, and the service life of the photovoltaic module is prolonged.

As an embodiment, the white film layer 13 is a non-pre-crosslinked layer, and the white film layer 13 may be a thermoplastic film layer. The white film layer 13 is not subjected to pre-crosslinking treatment, so that the production procedures of the adhesive film can be reduced, and the production efficiency can be improved. The white film layer 13 is bonded on the rear substrate of the photovoltaic module, the fluidity and the viscosity of the white film layer 13 can be ensured without pre-crosslinking treatment, and the packaging adhesive film 100 and the rear substrate can be better bonded together, so that the mechanical strength and the service life of the photovoltaic module are ensured. Compared with a cross-linking layer, the thermoplastic adhesive film layer can avoid cross-linking in the extrusion process, and can improve the production efficiency of adhesive film extrusion.

As an embodiment, the white film layer 13 includes a matrix resin and a reflective filler. The matrix resin is at least one of ethylene-vinyl acetate copolymer, metallocene catalyzed polyethylene, metallocene catalyzed ethylene butene copolymer, metallocene catalyzed ethylene octene copolymer, metallocene catalyzed ethylene pentene copolymer, ethylene propylene copolymer, ethylene methyl acrylate copolymer, ethylene methyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, saponified ethylene-vinyl acetate-acrylic ester copolymer, low density polyethylene, linear low density polyethylene or linear ultra-low density polyethylene. The matrix resin is preferably ethylene-vinyl acetate copolymer, also called EVA, which belongs to polar materials and has high transparency. Excellent ultraviolet aging resistance, excellent damp-heat aging resistance, extremely low shrinkage rate and higher volume resistivity. The EVA has higher adhesive capacity, can be suitable for various interfaces including glass, metal and various plastics, and has mature EVA production technology.

As an embodiment, as shown in fig. 3, the adhesive packaging film 100 further includes an upper coating layer 14 and a lower coating layer 15, wherein the upper coating layer 14 is disposed between the light transmitting layer 11 and the reflection-increasing layer 12 and is used for bonding the light transmitting layer 11 and the reflection-increasing layer 12. The lower coating 15 is disposed between the white film layer 13 and the reflection-increasing layer 12, and is used for bonding the white film layer 13 and the reflection-increasing layer 12. The upper coating layer 14 and the lower coating layer 15 improve the bonding performance between adjacent layers, ensure that the euphotic layer 11 and the reflection-increasing layer 12 and the white film layer 13 and the reflection-increasing layer 12 cannot be peeled off after long-time use, and ensure the durability of the adhesive film. Specifically, the raw materials of the upper and lower coating layers 14 and 15 may be binding materials commonly used in the art.

As an embodiment, the present application further provides a photovoltaic module 200, as shown in fig. 4, which sequentially includes a front substrate 21, a front encapsulant film 22, a cell string 23, a back encapsulant film 24, and a back substrate 25. The rear-layer adhesive film 24 is the adhesive film 100 shown in fig. 1, and is located below the battery string 23 and above the rear-layer substrate 25, the light-transmitting layer 11 of the adhesive film 100 is attached to the surface of the battery string 23, and the white layer 13 is attached to the rear-layer substrate 25. The increased reflection layer 12 in the packaging adhesive film 100 can effectively solve the PID problem of the photovoltaic module 200. The white film layer 13 is not pre-crosslinked, has good fluidity and viscosity, and can enhance the bonding capability with the rear substrate 25, thereby improving the supporting and protecting effects of the rear substrate 25 on the photovoltaic module 200.

The present application is further described with reference to the following examples, but the scope of protection of the present application is not limited to the examples.

Example 1:

as shown in FIG. 1, a packaging adhesive film 100 comprises a transparent layer 11, a reflection layer 12, and a white film layer 13. Wherein, the transparent layer 11 is a black transparent EVA film layer with a thickness of 100 μm. The reflection increasing layer 12 is a high-reflectivity PET layer with the thickness of 100 μm and the reflectivity (400-1100 nm) of the high-reflectivity PET layer is 90%. The thickness of the white film layer 13 is 300 μm, and the reflectance (400-1100 nm) of the white film layer is 90%.

Example 2:

as shown in fig. 2, a packaging adhesive film 100 is composed of a transparent layer 11, a reflection increasing layer 12, and a white film layer 13 in sequence. Wherein, the transparent layer 11 is a black transparent EVA film layer with a thickness of 100 μm. The reflection increasing layer 12 is a high-reflectivity PET layer with a cellular structure, and the reflectivity (400-1100 nm) of the high-reflectivity PET layer is 92%. The thickness was 100. Mu.m. The thickness of the white film layer 13 is 300 μm, and the reflectance (400-1100 nm) of the white film layer is 90%.

Example 3:

as shown in fig. 3, a packaging adhesive film 100 is composed of a transparent layer 11, a reflection layer 12, a white film layer 13, an upper coating layer 14, and a lower coating layer 15 in sequence. Wherein, the transparent layer 11 is a black transparent EVA film layer with a thickness of 100 μm. The reflection increasing layer 12 is a high-reflectivity PET layer with the thickness of 100 μm and the reflectivity (400-1100 nm) of the high-reflectivity PET layer is 90%. The thickness of the white film layer 13 was 300 μm, and the reflectance (400-1100 nm) of the white film layer was 95%. The thickness of the white film layer 13 was 300. Mu.m. The thickness of the upper coat layer 14 was 10 μm. The thickness of the lower coating 15 was 1 μm.

Example 4:

as shown in fig. 3, a packaging adhesive film 100 is composed of a transparent layer 11, a reflection layer 12, a white film layer 13, an upper coating layer 14, and a lower coating layer 15 in sequence. Wherein, the transparent layer 11 is a white transparent EVA film layer with a thickness of 100 μm. The reflection increasing layer 12 is a high-reflectivity PET layer with the thickness of 100 mu m, and the reflectivity (400-1100 nm) of the high-reflectivity PET layer is 95%. The thickness of the white film layer 13 was 300 μm, and the reflectance (400-1100 nm) of the white film layer was 95%. The thickness of the white film layer 13 was 300. Mu.m. The thickness of the upper coat layer 14 was 10 μm. The thickness of the lower coating 15 was 1 μm.

Example 5:

as shown in fig. 3, a packaging adhesive film 100 is composed of a transparent layer 11, a reflection layer 12, a white film layer 13, an upper coating layer 14, and a lower coating layer 15 in sequence. Wherein, the transparent layer 11 is a colorless transparent EVA film layer with a thickness of 100 μm. The reflection increasing layer 12 is a high-reflectivity PET layer with the thickness of 100 μm and the reflectivity (400-1100 nm) of the high-reflectivity PET layer is 95%. The thickness of the white film layer 13 was 300 μm, and the reflectance (400-1100 nm) of the white film layer was 95%. The thickness of the white film layer 13 was 300. Mu.m. The thickness of the upper coat layer 14 was 10 μm. The lower coating 15 has a thickness of 1 μm.

Example 6:

as shown in fig. 3, a packaging adhesive film 100 is composed of a transparent layer 11, a reflection layer 12, a white film layer 13, an upper coating layer 14, and a lower coating layer 15 in sequence. Wherein, the transparent layer 11 is a white transparent EVA film layer with a thickness of 100 μm. The reflection increasing layer 12 is a high-reflectivity PET layer with the thickness of 300 μm. The white film layer 13 had a thickness of 300 μm, and the high-reflectance PET layer had a reflectance (400-1100 nm) of 95%. The thickness of the white film layer 13 was 300 μm, and the reflectance (400-1100 nm) of the white film layer was 95%. The thickness of the upper coat layer 14 was 10 μm. The thickness of the lower coating 15 was 1 μm.

Comparative example 1:

as shown in FIG. 5, a packaging adhesive film 100 is a single-layer EVA adhesive film with a thickness of 500 μm.

Comparative example 2:

as shown in FIG. 5, a packaging adhesive film 100 is a single-layer POE adhesive film with a thickness of 500 μm.

Comparative example 3:

as shown in fig. 6, a packaging adhesive film 100 is a conventional high-reflective black film with two layers, and sequentially comprises a black transparent adhesive film 16 and a white high-reflective adhesive film 17, wherein the thickness of the black transparent adhesive film 16 is 250 μm, and the thickness of the white high-reflective adhesive film 17 is 250 μm. In order to prevent the high anti-black film from overflowing to the front side of the battery, the welding strip or the bus bar, two layers of adhesive films of the high anti-black film are subjected to pre-crosslinking treatment.

And (3) performance testing:

the above-described adhesive films for encapsulation in examples 1 to 6 and the adhesive films for encapsulation in comparative examples 1 to 3 were subjected to performance tests. Meanwhile, the photovoltaic module 200 shown in fig. 4 is assembled by using the encapsulant films in the above embodiments and comparative examples as the rear encapsulant film, the photovoltaic module 200 sequentially includes a front substrate 21, a front encapsulant film 22, a cell string 23, a rear encapsulant film 24, and a rear substrate 25, the front substrate 21 is made of photovoltaic glass, the front encapsulant film 22 is made of F406PS (foster, hangzhou), the cell string 23 is made of P-PERC cell string, the rear encapsulant film 24 is made of the encapsulant films 100 in embodiments 1 to 6 and comparative examples 1 to 3, respectively, and the rear substrates 15 in embodiments 1 to 6 and comparative examples 1 to 3 are made of transparent photovoltaic glass.

1. Reflectance ratio:

the test method refers to a spectrophotometer method with an integrating sphere in standard GB/T29848 ethylene-vinyl acetate copolymer (EVA) adhesive film for packaging photovoltaic modules. Testing an instrument: an ultraviolet-visible spectrophotometer; and (3) testing conditions are as follows: 400nm-1100nm and 760nm-1100nm.

2. Volume resistivity:

the test method refers to the standard GB/T31034 insulating back plate for crystalline silicon solar cell modules. Sample size: 100mm; and (3) testing conditions: the test voltage is 1000V.

3. Interlayer peel strength:

the test method refers to a standard GB/T2790 method for testing 180-degree peel strength of an adhesive for flexible materials versus rigid materials. Sample size: 200mm 15mm; stretching speed: 100mm/min.

4. Peeling strength between the adhesive film and the glass:

the test method refers to a standard GB/T2790 method for testing 180-degree peel strength of adhesive for flexible materials versus rigid materials. Sample size: 300mm by 300mm; stretching speed: 100mm/min.

5. Maximum power:

the test method refers to the design identification and design of crystalline silicon photovoltaic modules for ground in IEC 61215. Sample size: a double-sided battery piece, a 60-piece assembly; the test conditions are as follows: AM 1.5, irradiance 1000W/m ² ， +25℃，50％RH。

And 6.PID test:

the test method is referred to the standard IEC TS 2804-1. The test conditions are as follows: +85 ℃ and relative humidity of 85%; -1500V constant dc voltage, 192h.

And (3) performance test results:

the results of the performance tests of the adhesive packaging films of examples 1 to 6 and comparative examples 1 to 3 are shown in the following table 1.

Table 1: examples results of Performance testing

As can be seen from the relevant data in table 1, the encapsulation adhesive film in embodiments 1 to 6 of the present application is provided with the reflection increasing layer having a higher infrared reflection performance, and has a higher reflectivity for light in an infrared band, and the reflectivity for light in a band of 760 to 1100nm is up to more than 75%, even up to more than 90%, so that the encapsulation adhesive film has a function of isolating infrared light, has a function of blocking radiation crosslinking, can prevent a white film layer and other parts of a component in the encapsulation adhesive film from generating crosslinking, ensures a good adhesive property, and has a good peel strength; meanwhile, due to the isolation effect of the reflection increasing layer, the packaging adhesive film has a good PID function, and the power attenuation of the photovoltaic module is reduced.

It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to fall within the scope of the appended claims.

Claims (10)

1. A packaging adhesive film, comprising:

the thickness of the euphotic layer is 60-300 mu m;

the reflection increasing layer is arranged on one side of the euphotic layer, and the thickness of the reflection increasing layer is 50-300 mu m;

the white film layer is arranged on one side, far away from the light transmitting layer, of the reflection increasing layer;

the reflectivity of the reflection increasing layer in the wavelength range of 400-1100nm is greater than or equal to 85%, and the reflectivity of the reflection increasing layer in the wavelength range of Bai Moceng in the wavelength range of 400-1100nm is greater than or equal to 85%; the reflectivity of the packaging adhesive film in the wavelength range of 760-1100nm is greater than or equal to 75%.

2. The packaging adhesive film of claim 1, wherein:

the reflectivity of the reflection increasing layer in the wavelength range of 400-1100nm is greater than or equal to 90%, and the reflectivity of the Bai Moceng in the wavelength range of 400-1100nm is greater than or equal to 90%.

3. The packaging adhesive film of claim 2, wherein:

the light transmitting layer is colorless transparent EVA or colored EVA;

preferably, the colored EVA is black clear EVA or white EVA.

4. The packaging adhesive film of claim 3, wherein:

the transmittance of the black light-transmitting EVA in light with the wavelength range of 700-1100nm is greater than or equal to 55%.

5. The packaging adhesive film of claim 1, wherein:

the reflection increasing layer is a PET layer;

preferably, the light reflectivity of the reflection increasing layer is greater than or equal to 92%.

6. The packaging adhesive film of claim 1, wherein:

the reflection-increasing layer comprises a cellular structure.

7. The packaging adhesive film of claim 1, wherein:

the white film layer is a thermoplastic adhesive film layer.

8. The packaging adhesive film of claim 1, wherein:

the white film layer is one of ethylene-vinyl acetate copolymer, metallocene catalyzed polyethylene, metallocene catalyzed ethylene butene copolymer, metallocene catalyzed ethylene octene copolymer, metallocene catalyzed ethylene pentene copolymer, ethylene propylene copolymer, ethylene methyl acrylate copolymer, ethylene methyl methacrylate copolymer, ethylene-glycidyl methacrylate-vinyl acetate copolymer, ethylene-glycidyl methacrylate-methyl acrylate copolymer, saponified ethylene-vinyl acetate-acrylic ester copolymer, low density polyethylene, linear low density polyethylene or linear ultra-low density polyethylene.

9. The packaging adhesive film of claim 1, wherein:

the light-transmitting layer and the reflection-increasing layer are arranged on the surface of the light-transmitting layer, the light-transmitting layer is arranged on the surface of the light-transmitting layer, the reflection-increasing layer is arranged on the surface of the light-transmitting layer, and the lower coating is arranged between the white film layer and the reflection-increasing layer.

10. A photovoltaic module comprises a front substrate, a front packaging adhesive film, a battery string, a rear packaging adhesive film and a rear substrate, and is characterized in that;

the back layer packaging adhesive film comprises:

the thickness of the euphotic layer is 60-300 mu m;

the reflection increasing layer is arranged on one side of the euphotic layer, and the thickness of the reflection increasing layer is 50-300 mu m;

the white film layer is arranged on one side, far away from the light transmitting layer, of the reflection increasing layer;

the reflectivity of the reflection increasing layer in the wavelength range of 400-1100nm is greater than or equal to 85%, and the reflectivity of the reflection increasing layer in the wavelength range of Bai Moceng in the wavelength range of 400-1100nm is greater than or equal to 85%; the reflectivity of the packaging adhesive film in the wavelength range of 760-1100nm is more than or equal to 75 percent;

the euphotic layer is attached to the surface of the battery string.

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