Composite adhesive film of photovoltaic module, preparation method and photovoltaic module

Abstract

The invention discloses a composite adhesive film of a photovoltaic module, a preparation method of the composite adhesive film and the photovoltaic module, and relates to the technical field of packaging adhesive films. The composite adhesive film of the photovoltaic module comprises an anti-PID core layer and an anti-PID function enhancement layer which are stacked along a first direction, and the first direction is perpendicular to a plane where the composite adhesive film is located. The anti-PID function enhancement layer comprises a one-dimensional carbon chain material. Based on the synergistic effect of the one-dimensional carbon chain materials in the anti-PID core layer and the anti-PID function enhancement layer, the composite adhesive film can more effectively improve the anti-PID performance of the photovoltaic module, prolong the service life of the photovoltaic module, and improve the overall reliability and power generation efficiency of a photovoltaic system.

Description

Technical Field

[0001] The present application relates to the technical field of encapsulation films, and in particular to a composite film for a photovoltaic module, a preparation method, and a photovoltaic module. Background Art

[0002] Over the long term, photovoltaic modules experience a phenomenon known as potential-induced degradation (PID), which severely impacts the efficiency and lifespan of the system. Specifically, when a photovoltaic module is subjected to a constant external voltage over a long period of time, its power output gradually decreases. This degradation is primarily due to the performance degradation of the semiconductor materials within the module caused by the combined effects of the electric field and the humid and hot environment.

[0003] Although the existing anti-PID packaging film can absorb and capture the Na generated by PID to a certain extent, + , will Na + Gathered inside the encapsulating film, thus preventing Na + However, as time goes by, these Na + It will gradually break through the constraints of the encapsulation film and run onto the battery cell again. + Accumulation on the cell can trigger a series of adverse chemical reactions, causing changes in the cell's internal structure, which in turn affects the module's power output, reducing its power generation efficiency and shortening its service life. Therefore, there is an urgent need to develop a new type of PID-resistant encapsulation film to address the limitations of existing technologies. Summary of the Invention

[0004] In view of the above problems, this application provides a composite film for photovoltaic modules, a preparation method, and a photovoltaic module to achieve the purpose of suppressing the PID effect. The specific solution is as follows:

[0005] In a first aspect, the present application provides a composite film for a photovoltaic module, comprising an anti-PID core layer and an anti-PID enhancement layer stacked along a first direction perpendicular to the plane of the composite film, and the anti-PID enhancement layer comprising a one-dimensional carbon chain material.

[0006] The composite adhesive film of the photovoltaic module provided in the present application includes an anti-PID core layer and an anti-PID function enhancement layer, and the anti-PID function enhancement layer includes a one-dimensional carbon chain material.

[0007] The core mechanism of PID generation is the Na + Under the action of bias, it migrates to the surface of the cell, or the charge on the cell surface accumulates and causes polarization, which eventually causes the power of the photovoltaic module to decay. One-dimensional carbon chain materials can efficiently adsorb and capture Na generated by PID.+ and can form a stable structure, completely preventing Na + diffusion onto the cell sheet, avoiding Na + accumulation on the surface of the cell sheet or the PN junction region, thereby preventing performance degradation caused by polarization. Thus, the anti-PID core layer and the anti-PID function-enhanced layer can more effectively reduce the risk of PID failure of the photovoltaic module and improve the stability and service life of the photovoltaic module. +

[0008] Therefore, through the synergistic effect of the anti-PID core layer and the anti-PID function-enhanced layer, the composite adhesive film can more effectively improve the anti-PID performance of the photovoltaic module, prolong the service life of the photovoltaic module, and improve the overall reliability and power generation efficiency of the photovoltaic system.

[0009] Optionally, the one-dimensional carbon chain material can be a material including a one-dimensional carbon chain molecule, such as a carbon nanotube, a graphene nanoribbon, or a functionalized carbon fiber. The carbon nanotube can adsorb Na + based on wall defects or its own cavity structure; the graphene nanoribbon can adsorb Na + based on edge points and hole defects; and the functionalized carbon fiber can adsorb Na + .

[0010] In some embodiments, the anti-PID core layer includes a first base material and a quaternary ammonium salt additive uniformly mixed in the first base material.

[0011] In some embodiments, the first base material includes an ethylene-vinyl acetate copolymer or a polyolefin elastomer or a mixed material of the ethylene-vinyl acetate copolymer and the polyolefin elastomer.

[0012] The anti-PID function-enhanced layer includes a second base material, and the one-dimensional carbon chain material is uniformly mixed in the second base material. The second base material includes a photosensitive resin. The anti-PID core layer and the anti-PID function-enhanced layer are fixed by heat pressing based on a carboxyl-modified silicone coupling agent bonding layer.

[0013] In some embodiments, along the first direction, the anti-PID function-enhanced layer includes at least two anti-PID function-enhanced sub-layers stacked in sequence. Each anti-PID function-enhanced sub-layer includes the one-dimensional carbon chain material. In adjacent two anti-PID function-enhanced sub-layers, the arrangement direction of the one-dimensional carbon chain molecules of the one-dimensional carbon chain material intersects.

[0014] In some embodiments, the thickness of the anti-PID core layer is greater than the thickness of the anti-PID function-enhanced layer.

[0015] ​The second aspect of the present application provides a photovoltaic module, which comprises a back plate, a solar cell and a cover plate arranged in sequence. The solar cell is fixed by an encapsulation adhesive film between the back plate and the cover plate. The encapsulation adhesive film on at least one side of the solar cell is the composite adhesive film in any of the above embodiments.

[0016] The composite adhesive film comprises an anti-PID core layer and an anti-PID functional enhancement layer arranged in sequence along a first direction. The first direction is perpendicular to the plane of the composite adhesive film. The anti-PID functional enhancement layer comprises one-dimensional carbon chain material.

[0017] The composite adhesive film provided by the present application is used for the solar cell in the photovoltaic module. The anti-PID core layer directly hinders ion migration, and the one-dimensional carbon chain material in the anti-PID functional enhancement layer quickly adsorbs charges, further reducing ion migration to the surface of the solar cell, effectively reducing the PID effect, and improving the stability and service life of the photovoltaic module.

[0018] In some embodiments, the anti-PID core layer is away from the solar cell in the same layer of the composite adhesive film.

[0019] In some embodiments, the preparation method of the composite adhesive film in the above embodiments comprises: preparing an anti-PID core layer and an anti-PID functional enhancement layer, the anti-PID functional enhancement layer comprising one-dimensional carbon chain material, and hot-pressing the anti-PID core layer and the anti-PID functional enhancement layer.

[0020] In some embodiments, the method for preparing the anti-PID core layer comprises: adding a first base material, a quaternary ammonium salt additive and a first coupling agent into an extruder, forming a first gum material with uniform components by high-temperature melt blending, and extruding the first gum material into a film by the extruder to form the anti-PID core layer.

[0021] The method for preparing the anti-PID functional enhancement layer comprises: uniformly mixing a second base material and one-dimensional carbon chain material to form a second gum material, forming a coating layer of the second gum material on a release film, and performing light curing on the coating layer.

[0022] In some embodiments, the hot-pressing of the anti-PID core layer and the anti-PID functional enhancement layer comprises hot-pressing and fixing based on a second coupling agent adhesive layer arranged between the anti-PID core layer and the anti-PID functional enhancement layer. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only are the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative effort based on the provided drawings.

[0024] The structures, proportions, sizes, etc. shown in the drawings of the present specification are merely used to cooperate with the disclosed content, to be understood and read by those skilled in the art, and are not used to limit the conditions that can be implemented by the present application, and therefore do not have technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that can be produced by the present application and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present application.

[0025] Figure 1 A structural schematic diagram of a composite adhesive film provided by the present application is shown in the following figure.

[0026] Figure 2 A structural schematic diagram of another composite adhesive film provided by the present application is shown in the following figure.

[0027] Figure 3 A structural schematic diagram of a photovoltaic module provided by the present application is shown in the following figure.

[0028] Figure 4 A flowchart of a method for preparing a composite adhesive film provided by the present application is shown in the following figure.

[0029] Reference signs:

[0030] 101-PID-resistant core layer; 102-PID-resistant functional enhancement layer; 1021-PID-resistant functional enhancement sub-layer; 105-back plate; 103-solar cell piece; 104-cover plate; 10-composite adhesive film; 100-photovoltaic module; Y-first direction. DETAILED DESCRIPTION

[0031] The embodiments in the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Those skilled in the art can know that the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems as the technology develops and new scenarios appear.

[0032] The photovoltaic module will produce potential-induced degradation, i.e. PID effect, in the long-term operation process, which seriously affects the efficiency and service life of the photovoltaic system. The existing PID-resistant packaging adhesive film can absorb and capture Na + , which is generated by PID to some extent, so as to prevent Na + from gathering inside the packaging adhesive film in the short term, thereby preventing the PID effect from occurring. +However, as time goes by, these Na + It will gradually break through the constraints of the encapsulation film and run onto the battery cell again. + The accumulation on the battery cells will trigger a series of adverse chemical reactions, causing changes in the internal structure of the battery cells, which in turn affects the power output of the components, reducing the power generation efficiency of the components and shortening their service life.

[0033] In order to solve the above problems, the embodiment of the present application provides a composite adhesive film for a photovoltaic module, comprising: an anti-PID core layer and an anti-PID function enhancement layer stacked along a first direction;

[0034] The first direction is perpendicular to the plane where the composite film is located; and the anti-PID function enhancement layer includes a one-dimensional carbon chain material.

[0035] The composite film provided in the embodiment of the present application includes a one-dimensional carbon chain material. Such a material has abundant surface defects, holes, edge sites or microporous structures. These sites can interact with positively charged Na by electrostatic attraction, chemical adsorption, etc. + Combine and fix it inside or on the surface of the material to reduce the migration of Na to the surface of the battery cell. + Quantity, weakening factor Na + The power attenuation caused by the accumulation on the surface of the battery cell. At the same time, the anti-PID core layer can absorb the Na generated by the cover plate or packaging film from the source. + , preventing it from migrating to the solar cells. Through the synergistic effect of the anti-PID core layer and the one-dimensional carbon chain material in the anti-PID functional enhancement layer, this composite film can more effectively enhance the anti-PID performance of photovoltaic modules, extend the service life of photovoltaic modules, and improve the overall reliability and power generation efficiency of the photovoltaic system.

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] The embodiment of the present application provides a composite adhesive film 10 for a photovoltaic module, such as Figure 1 As shown, Figure 1 This is a schematic structural diagram of a composite adhesive film 10 of a photovoltaic module 100 provided in this application.

[0038] like Figure 1 As shown, the composite film 10 of the photovoltaic module includes an anti-PID core layer 101 and an anti-PID functional enhancement layer 102 stacked along a first direction Y. The first direction Y is perpendicular to the plane of the composite film 10. The anti-PID functional enhancement layer 102 comprises a one-dimensional carbon chain material. The one-dimensional carbon chain material can be a material containing one-dimensional carbon chain molecules, such as carbon nanotubes, graphene nanoribbons, and functionalized carbon fibers.

[0039] The composite film 10 in the embodiment of the present application includes an anti-PID core layer 101 and an anti-PID function enhancement layer 102. The anti-PID core layer 101 is the key part to improve the anti-PID performance, and the one-dimensional carbon chain material in the anti-PID function enhancement layer 102 can efficiently absorb and capture Na generated by PID. + , and can form a stable structure, completely preventing Na + Diffusion to the battery cell to avoid Na + It accumulates on the surface of the battery cell or in the PN junction area, thereby preventing the performance degradation caused by polarization, and can play an auxiliary role, further improving the adsorption of Na + The role of Na + The dual adsorption and fixation effect can greatly improve the anti-PID performance of photovoltaic modules.

[0040] Optionally, one-dimensional carbon chain materials include carbon nanotubes, graphene nanoribbons, functionalized carbon fibers and other materials, which have special structures and excellent electrical properties.

[0041] The core mechanism of PID generation is the Na + Under the action of bias, the carbon nanotubes migrate to the surface of the cell, or the charge on the cell surface accumulates and causes polarization, which eventually causes the power of the photovoltaic module 100 to decay. Carbon nanotubes can adsorb Na based on the defects of the tube wall or the cavity structure of the carbon nanotubes. + Graphene nanoribbons can adsorb Na based on edge sites and hole defects + Functional groups on the surface of functionalized carbon fibers, such as carboxyl, amino, etc. + The cations undergo complexation reactions, trapping them in the anti-PID function enhancement layer 102 and preventing them from migrating further into the cell. This helps the anti-PID core layer 101 better enhance its anti-PID performance, effectively reducing the risk of PID failure in photovoltaic modules and increasing their stability and service life.

[0042] Therefore, through the synergistic effect of the one-dimensional carbon chain material in the anti-PID core layer 101 and the anti-PID function enhancement layer 102, the composite film 10 can more effectively improve the anti-PID performance of the photovoltaic module, extend the service life of the photovoltaic module, and improve the overall reliability and power generation efficiency of the photovoltaic system.

[0043] In some embodiments, the anti-PID core layer 101 includes a first matrix material and a quaternary ammonium salt additive uniformly mixed in the first matrix material.

[0044] Specifically, when the photovoltaic module is working, the interface between the glass and the film, and between the film and the cell will form an electric field gradient due to the bias voltage, and the electric field gradient will drive the Na+ migration, Na + migration to the surface of the cell sheet, destroy the PN junction and the anti-reflective layer, and form a leakage current channel.

[0045] R4N in the quaternary ammonium salt molecule + cations and Na in the glass + All are positively charged, but the quaternary ammonium cation is larger in size and more polar, and has a stronger binding force with polar groups such as ester groups and hydroxyl groups in the first matrix material of the anti-PID core layer 101, such as ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), and other resin materials. When Na + When attempting to migrate through the adhesive film, the quaternary ammonium cation will preferentially bind to the polar sites in the matrix material, occupying the migration channels and adsorption sites of Na + , reducing the diffusion rate of Na + in the adhesive film.

[0046] The positive charge in the quaternary ammonium salt can neutralize the negative charge at the interface, such as the silicon-oxygen negative ions on the surface of the glass, through electrostatic interaction, reducing the interface electric field strength. After the electric field gradient weakens, the migration driving force of Na + decreases, thereby reducing its migration to the cell sheet and inhibiting the occurrence of PID from the source.

[0047] The alkyl chain in the quaternary ammonium salt molecule can enhance the compatibility with the matrix material, such as EVA, reducing the hydrolytic aging of the adhesive film in a humid and hot environment, wherein hydrolysis can cause the adhesive film to produce micropores and accelerate ion migration. Its stable chemical structure can maintain the denseness of the adhesive film for a long time, ensuring the effectiveness of the anti-PID core layer 101 as a physical barrier.

[0048] In some embodiments, the first matrix material includes ethylene-vinyl acetate copolymer or polyolefin elastomer or a mixed material of ethylene-vinyl acetate and polyolefin elastomer. The anti-PID function enhancement layer 102 includes a second matrix material, and a one-dimensional carbon chain material is uniformly mixed in the second matrix material. The second matrix material includes a photosensitive resin, such as an ultraviolet curing resin. The anti-PID core layer 101 and the anti-PID function enhancement layer 102 are fixed by hot pressing based on a carboxyl-modified siloxane coupling agent bonding layer.

[0049] Currently, the industry mainly uses modified packaging adhesive film or glass modification to suppress the PID effect. The existing modified packaging adhesive film or glass modification requires an additional functional layer on its surface to achieve the anti-PID effect. However, the bonding force between the multi-layer structure is insufficient, and delamination phenomenon may occur during long-term use, further affecting the performance and stability of the module.

[0050] The carboxyl-modified siloxane coupling agent can cause the matrix materials of the anti-PID core layer 101 and the anti-PID function-enhanced layer 102 to chemically react, form stable chemical bonds, ensure a very high bonding strength between the layers, avoid separation or delamination between the two layers, and improve the overall structural stability of the composite adhesive film.

[0051] In some embodiments, as shown in FIG. 1B, Figure 2 Figure 2 FIG. 1C shows another structure of a composite adhesive film provided by the present application. In the first direction Y, the anti-PID function-enhanced layer 102 includes at least two anti-PID function-enhanced sub-layers 1021 stacked in sequence, and each of the anti-PID function-enhanced sub-layers 1021 includes one-dimensional carbon chain materials. In the two adjacent anti-PID function-enhanced sub-layers 1021, the arrangement directions of the one-dimensional carbon chain molecules of the one-dimensional carbon chain materials intersect. For example, the arrangement direction of the one-dimensional carbon chain molecules in the one-dimensional carbon chain materials in the anti-PID function-enhanced layer can be controlled by external magnetic field or electric field induction, template-induced growth, mechanical stretching orientation, or other processes.

[0052] The one-dimensional carbon chain molecules with different arrangement directions form a more complex and interwoven network structure, which can better block Na + Through the anti-PID function-enhanced layer 102, the anti-PID function-enhanced layer 102 can more effectively adsorb and fix Na + When ions or charges migrate in the adhesive film, this structure can provide more diverse adsorption sites. The ions can be adsorbed and blocked by the carbon chain molecules in different directions multiple times, increasing the migration resistance and reducing the number of ions migrating to the surface of the battery piece, thereby enhancing the anti-PID performance.

[0053] In some embodiments, the thickness of the anti-PID core layer 101 is greater than the thickness of the anti-PID function-enhanced layer 102. Specifically, the thickness of the anti-PID core layer 101 can be 200-400 μm, and the thickness of the anti-PID function-enhanced layer 102 can be 10-50 μm.

[0054] The thicker anti-PID core layer 101 can make the blocking effect stronger, and the Na + To reach the battery piece, the Na

[0055] ​Meanwhile, one-dimensional carbon chain materials such as carbon nanotubes and graphene nanoribbons have high costs and need to be uniformly dispersed to form a conductive network. A thinner thickness can reduce the amount of material used while ensuring coverage and reducing overall costs. The light transmittance of the anti-PID function enhancement layer 102 can be greater than 90%. The anti-PID function enhancement layer 102 applied to a photovoltaic module needs to ensure high light transmittance to reduce the impact on the light absorption of the cell. If the amount of one-dimensional carbon chain material is too large or the layer is too thick, the light transmittance may be reduced due to light absorption or scattering. A thickness of 10-50 μm can control the light loss within an acceptable range while exerting the function.

[0056] The embodiments of the present application also provide a photovoltaic module 100, as shown in Figure 3 Figure 3 The photovoltaic module structure provided by the present application is a schematic diagram of the photovoltaic module 100, which includes a back plate 105, a solar cell 103, and a cover plate 104 arranged in sequence. The solar cell 103 is fixed and bonded between the back plate 105 and the cover plate 104 based on an encapsulation adhesive film. The encapsulation adhesive film on at least one side of the solar cell is a composite adhesive film 10 as described in any of the above embodiments. The composite adhesive film includes an anti-PID core layer 101 and an anti-PID function enhancement layer 102 arranged in sequence along a first direction Y. The first direction Y is perpendicular to the plane on which the composite adhesive film is located. The anti-PID function enhancement layer 102 includes one-dimensional carbon chain material.

[0057] The encapsulation adhesive film on both sides of the solar cell can produce a PID effect. At least one side of the adhesive film can be selected to use the composite adhesive film 10. Since the cover plate 104 on the light entrance side of the photovoltaic module 100 is usually glass, the cover plate glass contains a large amount of Na + Under the action of the bias electric field during the operation of the module, Na + will migrate to the surface of the negatively charged cell through the encapsulation adhesive film, which is the main source of ions causing PID. Therefore, the composite adhesive film 10 is used in the encapsulation adhesive film on the light entrance side. Na + in the glass can be directly adsorbed by the anti-PID core layer 101. At the same time, the one-dimensional carbon chain material in the anti-PID function enhancement layer 102 can adsorb charges, reduce the amount of Na + migrated to the surface of the cell, and reduce the high PID effect on the light entrance side. Therefore, at least the adhesive film is the composite adhesive film 10 described above. Both sides of the adhesive film can also use the composite adhesive film 10 described above to further reduce the PID effect.

[0058] In the photovoltaic module 100 provided by the embodiments of the present application, the composite adhesive film 10 provided by the above embodiments is used as the encapsulation adhesive film. The composite adhesive film 10 can achieve double adsorption and fixation of Na + by the anti-PID core layer 101 and the anti-PID function enhancement layer 102, which can greatly improve the anti-PID performance of the photovoltaic module 100.​

[0059] In some embodiments, the anti-PID core layer 101 is away from the solar cell 103 in the same layer of the composite adhesive film 10. + The main source of Na+is the cover plate 104 glass of the light-in side of the photovoltaic module 100. When the anti-PID core layer 101 is away from the solar cell 103, it is closer to the source of Na+, and the positive charge of the quaternary ammonium salt additive in the anti-PID core layer 101 can adsorb Na+. + + The adsorption effect is generated in the early stage of Na+entering the composite adhesive film 10, which prevents the inward migration of Na+, and the thicker anti-PID core layer 101 can provide a longer barrier path, so that Na+is effectively intercepted before reaching the solar cell 103, reducing the Na+close to the solar cell 103 from the source. + + .

[0060] At the same time, the back plate 105 of the photovoltaic module 100 may be aged in a humid and hot environment, and the additives contained therein or the pollutants infiltrated from the outside may release ions. After the water vapor penetrates the back plate 105 into the interior of the photovoltaic module 100, it will dissolve these ions and form a conductive channel, migrating to the solar cell 103. When the anti-PID core layer 101 is away from the solar cell 103, the quaternary ammonium salt additive in the anti-PID core layer 101 can adsorb these ions by positive charge, and the thicker anti-PID core layer 101 can form a physical barrier to prevent the ions from moving through the composite adhesive film 10 to the solar cell 103, avoiding the ion migration on the side of the back plate 105 causing the PID effect.

[0061] The application also provides a preparation method of the composite adhesive film 10 as described in any one of the above embodiments. Figure 4 As shown in the figure, Figure 4 a flow chart of a method for preparing the composite adhesive film 10 provided by the application.

[0062] As shown in the figure, Figure 4 the preparation method comprises the following steps S10-S20:

[0063] Step S10: preparing the anti-PID core layer 101 and the anti-PID function enhancement layer 102, wherein the anti-PID function enhancement layer 102 comprises one-dimensional carbon chain material.

[0064] In some embodiments, the method for preparing the anti-PID core layer 101 comprises: adding the first base material, the quaternary ammonium salt additive, and the first coupling agent into an extruder, forming a first gum material with uniform components by high-temperature melt blending, and extruding the first gum material into a film by the extruder to form the anti-PID core layer 101. ​​

[0065] The first base material, such as EVA or POE, is a thermoplastic resin, which is melted at high temperature in the extruder. The quaternary ammonium salt additive can be uniformly dispersed in the molten matrix, avoiding the local agglomeration of the quaternary ammonium salt additive affecting the ion blocking effect. The first coupling agent, such as silane coupling agent, is added therein, which can be combined with the molecular chain of the first base material through melt blending, improving the interlayer compatibility with the anti-PID functional enhancement layer 102, laying a foundation for the fixation of the composite adhesive film 10. The screw shearing of the extruder and the mold forming can make the first rubber material form a continuous, bubble-free film. The relatively thick thickness can be achieved by one-time extrusion, without the need for multiple coatings, avoiding the influence of interfacial defects on the ion blocking effect.

[0066] In some embodiments, the method for preparing the anti-PID functional enhancement layer 102 includes uniformly mixing the second base material and the one-dimensional carbon chain material to form a second rubber material, forming a coating layer of the second rubber material on a release film, and performing light curing on the coating layer.

[0067] The second base material, such as photosensitive resin, is a liquid or low-viscosity melt before curing. The one-dimensional carbon chain material can be dispersed with the aid of a dispersing agent to form a uniformly distributed state in the photosensitive resin, avoiding agglomeration of the one-dimensional carbon chain material. If it is necessary to regulate the arrangement direction of the carbon chain molecules, the stretching, electric field induction, etc. can be used in the coating stage to achieve orientation, and then the structure is fixed by light curing. The photosensitive resin can be cured under ultraviolet light, at which time the photosensitive resin is in a semi-cured state, which is convenient for the subsequent formation of the composite adhesive film 10 of the anti-PID functional enhancement layer 102 and the anti-PID core layer 101. By controlling the coating amount of the coating layer, the thickness of the anti-PID functional enhancement layer 102 can be accurately controlled, taking into account the material utilization rate and light transmittance.

[0068] Step S20: hot pressing the anti-PID core layer 101 and the anti-PID functional enhancement layer 102.

[0069] In some embodiments, the thermal compression bonding is based on a second coupling agent adhesive layer arranged between the anti-PID core layer 101 and the anti-PID function enhancement layer 102. When the anti-PID function enhancement layer 102 is not completely cured, it is thermally compressed with the anti-PID core layer 101, and the curing of the anti-PID function enhancement layer 102 is carried out synchronously with the thermal compression, so as to realize the integrated molding of the anti-PID core layer 101 and the anti-PID function enhancement layer 102, shorten the production rhythm by 50%, improve the yield by 30%, and reduce the production cost. The second coupling agent can be a carboxyl-modified siloxane coupling agent. This coupling agent can chemically react with the matrix materials of the anti-PID core layer 101 and the anti-PID function enhancement layer 102 to form stable chemical bonds, ensuring that the interlayer has extremely high bonding strength and avoiding separation or delamination between the two layers. The anti-PID core layer 101 and the anti-PID function enhancement layer 102 are tightly integrated and combined, the interlayer bonding force is increased by more than 40%, and the overall structural stability of the composite adhesive film 10 is effectively improved, ensuring the long-term reliable operation of the photovoltaic module 100 in harsh environments.

[0070] Specifically, the temperature of the thermal compression can be controlled at 80-100℃, and the pressure is 0.5MPa. Under this condition, the two layers of materials can be better fused together to form a tight bond. After the compounding is completed, cool to room temperature, then peel off the PET release film, and the finished anti-PID composite adhesive film 10 can be obtained.

[0071] The composite adhesive film 10 containing one-dimensional carbon chain material adopted by the present application makes the PID attenuation rate of the photovoltaic module 100 as low as 3% or less, which is significantly lower than the PID attenuation rate of more than 5% of the traditional photovoltaic module 100. The present application significantly inhibits the damage of the PID effect to the performance of the photovoltaic module 100. At the same time, the composite adhesive film 10 has excellent light transmission uniformity and a haze of less than 2%, which can fully meet the high standard requirements of the double-sided power generation photovoltaic module 100 for light transmission and uniform distribution, and ensure the efficient power generation of the photovoltaic module 100.

[0072] Moreover, after 1000 hours of accelerated aging test under the harsh condition of 85℃ / 85%RH, the composite adhesive film 10 has no delamination phenomenon and maintains good structural integrity, and the long-term stability is much better than that of the traditional composite adhesive film 10, which can ensure the long-term stable operation of the photovoltaic module 100 in complex and harsh environments.

[0073] The various embodiments in the specification of the present application are described in a progressive, parallel, or progressive and parallel combination manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts of each embodiment can be referred to each other. The embodiments provided by the embodiments of the present application can be combined with each other without contradiction.

[0074] It is to be understood that the drawings and description are illustrative of exemplary embodiments and not restrictive. Like reference numerals in different drawings denote like elements. Additionally, for purposes of explanation and ease of understanding, the drawings can exaggerate the thickness of some layers, films, panels, regions, etc. It is to be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, "on" can mean that the element is positioned on or below another element, but not necessarily directly on the other element.

[0075] The terms "upper," "lower," "top," "bottom," "inner," "outer," and the like, refer to the orientation or position of the apparatus or element as shown in the drawings, and are used only to facilitate the description of the application and the claims, and are not intended to limit or confine the application to a particular orientation, construction or operation, and thus should not be construed as limiting the application. When one component is said to be "connected" to another component, it can be directly connected to the other component or intervening components can also be present.

[0076] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, to the extent that the terms "including", "includes", "having", "has", "a", "an", "one" or "said" are used in the detailed description and / or claims, such terms are intended to be inclusive (i.e., in a manner that says that one), unless otherwise indicated herein.

[0077] The above description of disclosed embodiments provides information sufficient to understand how to make and use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite film for a photovoltaic module, characterized in that: include: An anti-PID core layer and an anti-PID function enhancement layer stacked along a first direction; Wherein, the first direction is perpendicular to the plane where the composite film is located; and the anti-PID function enhancement layer includes a one-dimensional carbon chain material.

2. The composite adhesive film according to claim 1, characterized in that: The anti-PID core layer comprises: A first base material and a quaternary ammonium salt additive uniformly mixed in the first base material.

3. The composite adhesive film according to claim 2, characterized in that: The first matrix material comprises ethylene-vinyl acetate copolymer and / or polyolefin elastomer; The anti-PID function enhancement layer includes a second matrix material, the one-dimensional carbon chain material is uniformly mixed in the second matrix material, and the second matrix material includes a photosensitive resin; The anti-PID core layer and the anti-PID function enhancement layer are fixed by hot pressing based on a carboxyl-modified siloxane coupling agent adhesive layer.

4. The composite adhesive film according to claim 1, characterized in that: Along the first direction, the anti-PID function enhancing layer includes at least two anti-PID function enhancing sub-layers stacked sequentially; each of the anti-PID function enhancing sub-layers includes the one-dimensional carbon chain material; In two adjacent anti-PID function enhancing sub-layers, the arrangement directions of the one-dimensional carbon chain molecules of the one-dimensional carbon chain material intersect.

5. The composite adhesive film according to claim 1, characterized in that: The thickness of the anti-PID core layer is greater than the thickness of the anti-PID function enhancing layer.

6. A photovoltaic module, characterized in that: include: A back sheet, a solar cell sheet and a cover sheet stacked in sequence; The solar cell is fixed to the back plate and the cover plate by bonding with an encapsulating film, and the encapsulating film on at least one side of the solar cell is the composite film according to any one of claims 1 to 5. The composite film comprises an anti-PID core layer and an anti-PID function enhancement layer stacked along a first direction; the first direction is perpendicular to the plane of the composite film; the anti-PID function enhancement layer comprises a one-dimensional carbon chain material.

7. The photovoltaic module according to claim 6, characterized in that: In the same layer of the composite adhesive film, the anti-PID core layer is away from the solar cell sheet.

8. A method for preparing a composite adhesive film according to any one of claims 1 to 5, characterized in that: The preparation method comprises: An anti-PID core layer and an anti-PID function enhancement layer are prepared; the anti-PID function enhancement layer comprises a one-dimensional carbon chain material; The anti-PID core layer and the anti-PID function enhancement layer are composited by hot pressing.

9. The preparation method according to claim 8, characterized in that The method for preparing the anti-PID core layer includes: adding a first base material, a quaternary ammonium salt additive, and a first coupling agent into an extruder, forming a first colloid material in which the components are uniformly mixed by high-temperature melt blending, and extruding the first colloid material into a film through the extruder to form the anti-PID core layer; The method for preparing the anti-PID function enhancement layer includes: uniformly mixing a second base material and the one-dimensional carbon chain material to form a second colloid material, forming a coating of the second colloid material on a release film, and light-curing the coating.

10. The preparation method according to claim 8, characterized in that The anti-PID core layer and the anti-PID function enhancement layer are hot-pressed and laminated, comprising: Hot pressing composite fixing is performed based on a second coupling agent adhesive layer arranged between the anti-PID core layer and the anti-PID function enhancement layer.

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