Photovoltaic module

Abstract

The invention provides a photovoltaic module. The photovoltaic module at least comprises front glass (100), a front adhesive film (200), a battery string (300) and a back adhesive film (400) which are arranged in sequence, the back adhesive film (400) integrally or partially comprises an oxygen blocking adhesive film (410), and the oxygen blocking adhesive film (410) is used for blocking oxygen for the front adhesive film (200); the oxygen barrier adhesive film (410) comprises: an oxygen barrier material layer (411) comprising a first surface and a second surface arranged opposite to each other; and the packaging material layer (412) is adhered to the first surface and / or the second surface of the oxygen barrier material layer (411) and is used for adhering the oxygen barrier adhesive film (410) to the battery string (300). The whole or local back adhesive film adopts the oxygen-blocking adhesive film to block oxygen for the front adhesive film, so that functional failure and aging of the light conversion adhesive film caused by oxidation of the light conversion adhesive film on the front surface of the cell string by the oxygen invaded from the back surface are avoided, and then ultraviolet light-induced attenuation and aging of the cell string are avoided, thereby improving the conversion efficiency of the photovoltaic module and improving the service life of the photovoltaic module. And the service life of the photovoltaic module is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and particularly to a photovoltaic module. Background Art

[0002] A solar cell is a device that directly converts light energy into electrical energy through the photovoltaic effect or the photochemical effect. As long as it is irradiated by light, voltage and current can be output instantly. It is called solar photovoltaic (PV) in physics, abbreviated as PV.

[0003] Solar cells face many challenges in practical applications. One of the main difficulties is ultraviolet light-induced degradation. Taking heterojunction (HJT) cells and tunnel oxide passivated contact (TOPCon) cells as examples, ultraviolet light destroys the silicon-hydrogen bonds (Si-H) in the cells, resulting in the failure of passivation and the reduction of cell efficiency. Conventional solutions include using a cutoff film to filter ultraviolet light, or using a light conversion film to convert ultraviolet light into visible light. Among them, using a light conversion film can further improve the light utilization rate compared with using a cutoff film. However, during the use of the light conversion film, the efficiency of the solar cell still continues to decrease. Summary of the Invention

[0004] Based on this, in view of the problems in the above background art, it is necessary to provide a photovoltaic module that can at least avoid ultraviolet light-induced degradation, improve the conversion efficiency of the photovoltaic module, and extend the service life of the photovoltaic module.

[0005] To achieve the above object and other related objects, one aspect of the present application provides a photovoltaic module, which at least includes a front glass, a front film, a cell string, and a back film arranged in sequence; wherein, the back film wholly or partially includes an oxygen barrier film, and the oxygen barrier film is used to block oxygen for the front film;

[0006] The oxygen barrier film includes:

[0007] An oxygen barrier material layer, including a first surface and a second surface arranged oppositely;

[0008] An encapsulation material layer, bonded to the first surface and / or the second surface of the oxygen barrier material layer, and used to bond the oxygen barrier film to the cell string.

[0009] In one embodiment, the front film includes a light conversion film, and the light conversion film is used to convert the first wavelength light into the second wavelength light, and the wavelengths of the first wavelength light and the second wavelength light are different.

[0010] In one embodiment, the light conversion film is at least used to convert ultraviolet light into visible light.

[0011] In one embodiment, the battery string includes light-aging batteries, and the service life of the light-aging batteries in light of the first wavelength is less than that in light of the second wavelength; and / or, the battery string includes light-decaying batteries, and the conversion efficiency of the light-decaying batteries in light of the first wavelength is lower than that in light of the second wavelength.

[0012] In one embodiment, the light-aging batteries and / or the light-decaying batteries include at least one of heterojunction batteries and tunnel oxide passivated contact batteries.

[0013] In one embodiment, the light conversion adhesive film includes a packaging material layer and a light conversion agent dispersed in the packaging material layer, and the light conversion agent is used to convert light of the first wavelength into light of the second wavelength.

[0014] In one embodiment, the light conversion agent includes an organic fluorescent compound, and the oxygen barrier adhesive film is used to block oxygen for the light conversion agent.

[0015] In one embodiment, the oxygen barrier material layer includes at least one of ethylene-vinyl alcohol copolymer and polyvinyl alcohol.

[0016] In one embodiment, the packaging material layer includes a single-layer structure or a laminated structure, and the packaging material layer includes at least one of an ethylene-vinyl acetate copolymer layer and a polyolefin elastomer layer.

[0017] In one embodiment, the thickness range of the oxygen barrier material layer includes 0.01 mm to 0.1 mm, and the thickness range of the packaging material layer includes 0.2 mm to 0.8 mm.

[0018] In one embodiment, the packaging material layer further includes:

[0019] A water barrier material layer, and the water barrier material layer is at least used to block water for the front adhesive film.

[0020] In one embodiment, the photovoltaic module further includes: a back glass disposed on a side of the back adhesive film away from the battery string, and the back glass can be used to block oxygen; or, a backsheet disposed on a side of the back adhesive film away from the battery string, and the backsheet is oxygen-permeable.

[0021] In one embodiment, at least one opening area is provided on the back glass, and the oxygen barrier adhesive film is disposed at least inside the opening area.

[0022] In one embodiment, the size of the oxygen barrier adhesive film is larger than the size of the opening area, and the oxygen barrier adhesive film completely covers the opening area.

[0023] In one embodiment, the oxygen barrier adhesive film is disposed at least in an edge area of the back adhesive film.

[0024] In one embodiment, the back adhesive film includes: an encapsulation adhesive film, the encapsulation adhesive film at least includes an encapsulation material layer, and the encapsulation adhesive film covers the battery string; an oxygen barrier adhesive film, the oxygen barrier adhesive film is bonded to the encapsulation adhesive film, and the oxygen barrier adhesive film and the encapsulation adhesive film are laminated to form the back adhesive film.

[0025] In one embodiment, the width range of the oxygen barrier adhesive film disposed in the edge region of the back adhesive film includes 10 mm to 50 mm, the oxygen barrier adhesive film and the encapsulation adhesive film are overlapped, and the width range of the overlapping region between the oxygen barrier adhesive film and the encapsulation adhesive film includes 3 mm to 10 mm.

[0026] In one embodiment, the oxygen barrier adhesive film is disposed on the side of the encapsulation adhesive film away from the battery string.

[0027] In one embodiment, the oxygen barrier adhesive film completely covers the back plate.

[0028] According to the photovoltaic module provided by the present invention, by using the oxygen barrier adhesive film as the oxygen barrier for the front adhesive film as a whole or partially for the back adhesive film, it is avoided that the light conversion adhesive film located on the front of the battery string is oxidized by the oxygen invading from the back, resulting in the failure of the function and aging of the light conversion adhesive film, and further avoiding the ultraviolet light-induced attenuation and aging of the battery string, thereby improving the conversion efficiency of the photovoltaic module and extending the service life of the photovoltaic module. Description of the Drawings

[0029] In order to better describe and illustrate the embodiments and / or examples of those applications disclosed herein, one or more drawings may be referred to. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the presently described embodiments and / or examples, and the presently understood best mode of these applications.

[0030] Figure 1 It is a schematic structural diagram of a photovoltaic module provided in an embodiment;

[0031] Figure 2A It is a schematic structural diagram of an oxygen barrier adhesive film provided in an embodiment;

[0032] Figure 2B It is a schematic structural diagram of another oxygen barrier adhesive film provided in an embodiment;

[0033] Figure 2C It is a schematic structural diagram of yet another oxygen barrier adhesive film provided in an embodiment;

[0034] Figure 3 It is a schematic structural diagram of the back adhesive film in an embodiment;

[0035] Figure 4 It is a schematic structural diagram of a photovoltaic module provided in another embodiment;

[0036] Figure 5Schematic structural diagram of a photovoltaic module provided in another embodiment.

[0037] Description of reference numerals:

[0038] 100, front glass; 200, front encapsulant film; 300, cell string; 400, back encapsulant film; 410, oxygen barrier encapsulant film; 411, oxygen barrier material layer; 412, encapsulation material layer; 420, encapsulation adhesive film; 500, back glass; 501, opening area; 600, backsheet. Detailed implementation manners

[0039] For ease of understanding the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application is thorough and complete.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein in the description of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0041] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present application. When used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. When used herein, the term "and / or" includes any and all combinations of the related listed items.

[0042] It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present application. Although only the components related to the present application are shown in the illustrations and are not drawn according to the number, shape and size of the components in actual implementation, the types, quantities and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0043] Solar cells face numerous challenges in practical applications. One of the main difficulties is ultraviolet (UV) light-induced degradation. Taking heterojunction (HJT) cells and tunnel oxide passivated contact (TOPCon) cells as examples, UV light breaks the silicon-hydrogen bonds (Si-H) in the cells, resulting in the failure of passivation and a decrease in cell efficiency. Conventional solutions include using a cut-off film to filter UV light or using a light conversion film to convert UV light into visible light. Among them, using a light conversion film can further improve the light utilization rate compared to using a cut-off film. However, during the use of the light conversion film, the efficiency of the solar cell still continues to decrease.

[0044] Research and analysis on the problem that the efficiency of solar cells still continues to decrease during the use of the light conversion film found that oxidation is an important reason for the decrease in the efficiency of the light conversion film. Especially when oxygen in the air oxidizes the light conversion agent in the light conversion film, it will cause the light conversion film to fail, and then lead to UV light-induced degradation of the solar cell. Therefore, it is necessary to provide oxygen barrier protection for the light conversion film.

[0045] Further analysis of the photovoltaic module using the light conversion film found that the oxidation degree of different regions of the light conversion film is different. After research, the main reason for the oxidation of the light conversion film is the intrusion of oxygen from the back of the photovoltaic module, especially at the openings such as the wiring holes provided on the back of the photovoltaic module. The oxidation degree of the light conversion film at the corresponding positions is significantly higher than that of other regions. Therefore, it is necessary to provide oxygen barrier protection for the regions of the light conversion film that are easily oxidized.

[0046] Based on the above research and analysis, the present invention provides a photovoltaic module. Referring to Figure 1 、 Figure 4 、 Figure 5 and Figures 2A to 2C as shown, the photovoltaic module at least includes a front glass 100, a front film 200, a cell string 300, and a back film 400 arranged in sequence; wherein, the back film 400 wholly or partially includes an oxygen barrier film 410, and the oxygen barrier film 410 is used to provide oxygen barrier for the front film 200.

[0047] Among them, the oxygen barrier film 410 includes:

[0048] An oxygen barrier material layer 411, including a first surface and a second surface arranged opposite to each other;

[0049] An encapsulation material layer 412, bonded to the first surface and / or the second surface of the oxygen barrier material layer 411, and used to bond the oxygen barrier film 410 to the cell string 300.

[0050] According to the photovoltaic module provided by the present invention, by using an oxygen barrier film for the entire or partial back adhesive film to block oxygen for the front adhesive film, it is avoided that the photo-conversion adhesive film located on the front of the battery string is oxidized by the oxygen invading from the back, resulting in the failure of the function and aging of the photo-conversion adhesive film, and further avoiding the ultraviolet light-induced attenuation and aging of the battery string, thereby improving the conversion efficiency of the photovoltaic module and extending the service life of the photovoltaic module.

[0051] Embodiment 1

[0052] Refer to Figure 1 As shown, the photovoltaic module at least includes a front glass 100, a front adhesive film 200, a battery string 300, a back adhesive film 400, and a back glass 500 arranged in sequence; wherein, a part of the back adhesive film 400 includes an oxygen barrier film 410, and the oxygen barrier film 410 is used to block oxygen for the front adhesive film 200.

[0053] Refer to Figures 2A to 2C As shown, the oxygen barrier film 410 includes: an oxygen barrier material layer 411, including a first surface and a second surface arranged oppositely; an encapsulation material layer 412, bonded to the first surface and / or the second surface of the oxygen barrier material layer 411, and used to bond the oxygen barrier film 410 to the battery string 300 and the back glass 500.

[0054] Exemplarily, the battery string 300 includes a photo-aging battery, and the service life of the photo-aging battery in the first wavelength light is less than the service life of the photo-aging battery in the second wavelength light; and / or, the battery string includes a photo-decay battery, and the conversion efficiency of the photo-decay battery in the first wavelength light is lower than the conversion efficiency of the photo-decay battery in the second wavelength light. Among them, the wavelengths of the first wavelength light and the second wavelength light are different. Generally, the wavelength of the first wavelength light is less than the wavelength of the second wavelength light. Specifically, the wavelength range of the first wavelength light includes 280nm - 500nm, and the wavelength range of the second wavelength light includes 380nm - 800nm. For example, the first wavelength light includes ultraviolet light, and the second wavelength light includes visible light.

[0055] In one embodiment, the photo-aged battery and / or the light-decaying battery include, but are not limited to, at least one of a heterojunction (HJT) battery and a tunnel oxide passivated contact (TOPCon) battery. For a heterojunction (HJT) battery, there is an amorphous silicon layer (a-Si) on its surface. The amorphous silicon layer serving as a passivation layer contains a large number of silicon-hydrogen (Si-H) bonds, and the Si-H bonds are easily damaged by ultraviolet rays and broken, resulting in defects in the internal structure and built-in electric field of the heterojunction (HJT) battery cell, thereby causing power attenuation and shortened service life of the heterojunction (HJT) battery. For a tunnel oxide passivated contact (TOPCon) battery, ultraviolet rays damage the silicon-hydrogen (Si-H) bonds in the passivation layer, leading to passivation failure and reduced battery efficiency. This kind of damage mainly occurs in the tunnel oxide layer (SiOx) and the doped polysilicon layer. The front surface passivation is jointly effected by aluminum oxide (AlO x ), and silicon nitride (SiN). Ultraviolet irradiation damages the hydrogen bonds, increases the recombination of electron-hole pairs, and reduces the open-circuit voltage (VOC) and the fill factor (FF). The back surface passivation depends on the chemical passivation of the tunnel oxide layer and the field-effect passivation of the doped polysilicon layer. Ultraviolet rays trigger the overflow of hydrogen in the tunnel oxide layer, resulting in the failure of chemical passivation and aggravating the back surface degradation, thereby causing power attenuation and shortened service life of the tunnel oxide passivated contact (TOPCon) battery.

[0056] In one embodiment, in order to reduce the adverse effects of ultraviolet light on the photo-aged battery and the light-decaying battery and ensure the light utilization rate, the front adhesive film 200 of the photovoltaic module can be integrally set as a light-converting adhesive film, that is, the light-converting adhesive film entirely covers the battery string 300. The light-converting adhesive film is used to achieve the conversion between lights of different wavelengths. For example, it converts the first-wavelength light into the second-wavelength light. Specifically, in view of the fact that ultraviolet light damages the silicon-hydrogen (Si-H) bonds, the light-converting adhesive film can be used to convert ultraviolet light into visible light.

[0057] In one embodiment, the light-converting adhesive film includes a packaging material layer and a light converter dispersed in the packaging material layer. Among them, the light converter is used to convert the first-wavelength light into the second-wavelength light. The light-converting adhesive film has a high quantum efficiency, can convert ultraviolet light into visible light, avoid the efficiency attenuation of the photovoltaic module caused by ultraviolet light, and improve the ultraviolet aging resistance performance of the photovoltaic module.

[0058] In one embodiment, the encapsulation material layer includes but is not limited to at least one of EVA film, POE film, and EPE film. The EVA film for photovoltaic modules is a functional film processed from ethylene-vinyl acetate copolymer (EVA) resin as the main raw material by adding appropriate crosslinking agents, anti-aging additives, and other components. The EVA film has characteristics such as high light transmittance, resistance to ultraviolet heat and humidity yellowing, and good adhesion to glass and the backsheet, which can allow sunlight to pass through the film to the solar cells to the greatest extent. The POE (Polyolefin elastomer) film for photovoltaic modules is a metallocene polyethylene elastomer polymerized from ethylene and 1-hexene or 1-octene under the action of a metallocene catalyst system. Compared with the EVA film, the POE film has a more stable molecular structure, higher volume resistivity, better thermal stability, and stronger resistance to ultraviolet aging. In addition, the water vapor transmission rate of the POE film is only about 1 / 8 of that of the EVA film, which can effectively block water vapor. The EPE film, namely the "EVA-POE-EVA" three-layer composite structure film, is manufactured by compounding and modifying EVA materials and POE materials through a co-extrusion process. The EPE film combines the advantages of the EVA film and the POE film and provides more combinatorial options.

[0059] In one embodiment, the light conversion agent includes but is not limited to organic fluorescent compounds, whose molecular structure has a chromophore, mostly a large π-conjugated structure with a benzene ring or other aromatic rings. The light conversion film is prone to yellowing and attenuation under ultraviolet light irradiation because the light conversion agent is oxidized, resulting in yellowing and attenuation of the light conversion performance. To avoid oxidation of the light conversion agent, the back film 400 can be set as an oxygen barrier film 410 so that the oxygen barrier film 410 can block oxygen for the light conversion agent.

[0060] In one embodiment, the oxygen barrier film 410 includes at least an oxygen barrier material layer 411 and a packaging material layer 412. The oxygen barrier material layer 411 includes, but is not limited to, at least one of ethylene-vinyl alcohol copolymer (EVOH) and polyvinyl alcohol (PVA). The packaging material layer 412 includes, but is not limited to, at least one of EVA film, POE film, and EPE film, which will not be elaborated here. Optionally, the oxygen barrier film 410 further includes a water barrier material layer, and the water barrier material layer includes, but is not limited to, polyolefin elastomer (POE). When the water barrier material layer is provided in the oxygen barrier film 410, it can prevent water and moisture for the front film 200 and the battery string 300, so as to improve the performance of the photovoltaic module. In addition, it should be noted that in an environment with high humidity, it is usually necessary to use the oxygen barrier material layer 411 in combination with the water barrier material layer to ensure the oxygen barrier effect of the oxygen barrier material layer 411. For example, in a low-humidity environment, using EVOH or PVA as the oxygen barrier material layer, its oxygen transmission rate is extremely low. However, in an environment with high humidity, the EVOH or PVA material will absorb moisture, resulting in an increase in the oxygen transmission rate. Therefore, it is necessary to keep the oxygen barrier material layer 411 in an environment with relatively low humidity to ensure that the oxygen barrier material layer 411 has good oxygen barrier performance. In addition, since polyolefin elastomer (POE) is both a packaging material and a water barrier material, the POE layer can be used as either a packaging material layer or a water barrier material layer, or it can have both packaging function and water barrier function at the same time.

[0061] In one embodiment, the packaging material layer 412 is bonded to the first surface and / or the second surface of the oxygen barrier material layer 411 to form the oxygen barrier film 410. Refer to Figure 2A As shown, when the packaging material layer 412 is only bonded to one of the surfaces of the oxygen barrier material layer 411, a packaging material layer-oxygen barrier material layer structure can be formed, such as EVA-EVOH, POE-EVOH, EPE-EVOH, PVA-EVA, PVA-POE, PVA-EPE, etc. Refer to Figure 2B As shown, when the packaging material layer 412 is bonded to the two surfaces of the oxygen barrier material layer 411, a first packaging material layer-oxygen barrier material layer-second packaging material layer structure can be formed, where the first packaging material layer and the second packaging material layer can be the same or different, such as EVA-EVOH-EVA, POE-EVOH-POE, EVA-EVOH-POE, EVA-PVA-EVA, POE-PVA-POE, POE-PVA-EVA, etc. Refer to Figure 2CAs shown, the encapsulation material layer 412 can be not only a single-layer structure but also a laminated structure, and the number of layers of the encapsulation material layer 412 bonded to the first surface and the second surface of the oxygen barrier material layer 411 can be the same or different, such as POE-EVA-EVOH-POE-EVA, EPE-EVOH-EPE, EVA-EVOH-POE-EVA, POE-EVOH-EPE, EVA-POE-PVA-POE-EVA, EPE-PVA-EPE, EVA-POE-PVA-POE, EPE-PVA-EVA, etc.

[0062] In one embodiment, the oxygen barrier film can be formed by a co-extrusion molding process. For example, EVA film particles and EVOH particles are co-extruded to form a three-layer structure, namely an EVA-EVOH-EVA film. The thickness range of the formed EVA layer includes 0.2 mm to 0.8 mm, and the thickness range of the formed EVOH layer includes 0.01 mm to 0.1 mm. The interfacial adhesion force between the EVA layer and the EVOH layer is greater than a preset value, such as 0.5 N. Optionally, the oxygen barrier film can also be formed by a lamination process. For example, an EVOH single-layer film is first cast, and then EVA or POE is laminated on the surface of the EVOH layer film through the lamination process to form a final two-layer or three-layer structure film; afterwards, POE can be further laminated on the surface of the EVA layer film or EVA can be laminated on the surface of the POE layer film through the lamination process to generate a multi-layer film, thereby improving the interfacial adhesion force and anti-aging performance of the film.

[0063] In one embodiment, the photovoltaic module includes a double-glass photovoltaic module. The double-glass photovoltaic module includes a front glass 100, a front encapsulant film 200, a battery string 300, a back encapsulant film 400, and a back glass 500 arranged in sequence. Among them, the oxygen transmission rate of the back glass 500 is less than a preset value, and the back glass 500 can be used for oxygen barrier. Therefore, the back encapsulant film 400 of the double-glass photovoltaic module can partially adopt an oxygen barrier film 410, as shown in Figure 1 shown.

[0064] In one embodiment, as shown in Figure 3 When the back encapsulant film 400 partially adopts the oxygen barrier film 410, the back encapsulant film 400 is at least composed of an encapsulation film 420 and an oxygen barrier film 410. Among them, the encapsulation film 420 covers the entire battery string 300 and is used to bond the battery string 300 to the back glass 500. The encapsulation film 420 at least includes an encapsulation material layer, and the encapsulation material layer includes but is not limited to at least one of an EVA film, a POE film, and an EPE film, which will not be elaborated here.

[0065] In one embodiment, as shown in Figure 1As shown, at least one opening area 500 is provided on the back glass 500, and the oxygen barrier adhesive film 410 is disposed at least inside the opening area 501. The opening area 501 includes, but is not limited to, functional openings such as wire connection holes, mounting and fixing holes, ventilation and drainage holes, etc. When the back adhesive film 400 is disposed at the opening area 501, the oxygen barrier adhesive film 410 is usually disposed outside the encapsulation adhesive film 420, that is, on the side of the encapsulation adhesive film 420 facing away from the battery string 300. Further, the size of the oxygen barrier adhesive film 410 for covering the opening area 501 is usually larger than the size of the opening area 501, so that not only the oxygen barrier adhesive film 410 completely covers the opening area 501, but also covers a part of the back glass 500 around the opening area 501 to improve the oxygen barrier effect. Specifically, the overlapping size range of the oxygen barrier adhesive film 410 and the back glass 500 around the opening area 501 includes 5 mm to 15 mm, such as 5 mm, 10 mm or 15 mm. When the size of the opening area 501 is about 10 mm × 10 mm or the diameter is about 10 mm, the size of the oxygen barrier adhesive film 410 for covering the opening area 501 can be 25 mm × 30 mm or 30 mm × 40 mm.

[0066] In one embodiment, referring to Figure 3 As shown, since the oxidation degree of the edge area of the front adhesive film 200 is relatively serious, an oxygen barrier adhesive film 410 is disposed in the edge area of the back adhesive film 400. The width range of the oxygen barrier adhesive film 410 disposed in the edge area of the back adhesive film 400 includes 10 mm to 50 mm, wherein the width range of the overlapping area of the oxygen barrier adhesive film 410 and the encapsulation adhesive film 420 includes 3 mm to 10 mm.

[0067] In one embodiment, the back adhesive film 400 can be formed by a lamination process. For example, first, an encapsulation adhesive film 420 for covering the entire battery string 300 is provided. Referring to Figure 3 As shown, an oxygen barrier adhesive film 410 is disposed at a position corresponding to the opening area 501 of the back glass 500 on the encapsulation adhesive film 420, and an oxygen barrier adhesive film 410 is disposed in the edge area of the encapsulation adhesive film 420, and the edge of the oxygen barrier adhesive film 410 extends beyond the edge of the encapsulation adhesive film 420. The encapsulation adhesive film and the oxygen barrier adhesive film 410 are laminated to form the back adhesive film 400. When forming the photovoltaic module, the encapsulation adhesive film 420 is close to the battery string 300, and the oxygen barrier adhesive film 410 is close to the back glass 500 for encapsulation.

[0068] In one embodiment, the front encapsulant 200 may include a light conversion encapsulant and an oxygen barrier encapsulant 410. For example, the oxygen barrier encapsulant 410 completely covers the light conversion encapsulant, and the oxygen barrier encapsulant 410 is disposed on a side of the light conversion encapsulant facing away from the battery string 300. Optionally, the oxygen barrier encapsulant 410 may also only cover a part of the light conversion encapsulant. For example, the oxygen barrier encapsulant 410 is disposed in an edge region of the front encapsulant 200, and the width range of the oxygen barrier encapsulant 410 disposed in the edge region of the front encapsulant 200 includes 10 mm to 50 mm. Among them, the width range of the overlapping region between the oxygen barrier encapsulant 410 and the light conversion encapsulant includes 3 mm to 10 mm. The light oxidation encapsulant and the oxygen barrier encapsulant 410 can be laminated by a lamination process to form the front encapsulant 200, which will not be elaborated here.

[0069] According to the photovoltaic module provided by the present invention, by locally using an oxygen barrier encapsulant for the back encapsulant to prevent oxygen from entering the front encapsulant, it is avoided that the light conversion encapsulant located on the front of the battery string is oxidized by the oxygen invading from the back opening and the edge, resulting in the failure of the function and aging of the light conversion encapsulant, and further avoiding the ultraviolet light induced attenuation and aging of the battery string, thereby improving the conversion efficiency of the photovoltaic module and extending the service life of the photovoltaic module.

[0070] Embodiment 2

[0071] Referring to Figure 4 As shown, the photovoltaic module at least includes a front glass 100, a front encapsulant 200, a battery string 300, a back encapsulant 400, and a back glass 500 arranged in sequence; among them, the back encapsulant 400 as a whole includes an oxygen barrier encapsulant 410, and the oxygen barrier encapsulant 410 is used to prevent oxygen from entering the front encapsulant 200.

[0072] Referring to Figures 2A to 2C As shown, the oxygen barrier encapsulant 410 includes: an oxygen barrier material layer 411, including a first surface and a second surface arranged oppositely; an encapsulation material layer 412, bonded to the first surface and / or the second surface of the oxygen barrier material layer 411, for bonding the oxygen barrier encapsulant 410 to the battery string 300.

[0073] In one embodiment, the battery string 300 includes light-aged batteries, and the service life of the light-aged batteries in the first-wavelength light is less than that in the second-wavelength light; and / or, the battery string includes light-decay batteries, and the conversion efficiency of the light-decay batteries in the first-wavelength light is lower than that in the second-wavelength light. The light-aged batteries and / or the light-decay batteries include, but are not limited to, at least one of heterojunction (HJT) batteries and tunnel oxide passivated contact (TOPCon) batteries. Among them, the wavelengths of the first-wavelength light and the second-wavelength light are different. Generally, the wavelength of the first-wavelength light is less than that of the second-wavelength light. Specifically, the wavelength range of the first-wavelength light includes 280 nm to 500 nm, and the wavelength range of the second-wavelength light includes 380 nm to 800 nm. For example, the first-wavelength light includes ultraviolet light, and the second-wavelength light includes visible light.

[0074] In one embodiment, in order to reduce the adverse effects of ultraviolet light on the light-aged batteries and the light-decay batteries and ensure the light utilization rate, the front adhesive film 200 of the photovoltaic module can be integrally set as a light-converting adhesive film, that is, the light-converting adhesive film entirely covers the battery string 300. The light-converting adhesive film includes a packaging material layer and a light conversion agent dispersed in the packaging material layer. The packaging material layer includes, but is not limited to, at least one of EVA adhesive film, POE adhesive film, and EPE adhesive film. The light conversion agent includes, but is not limited to, organic fluorescent compounds, whose molecular structure has a chromophore, mostly a large π-conjugated structure with a benzene ring or other aromatic rings. In order to prevent the light conversion agent from being oxidized, the back adhesive film 400 can be set as an oxygen barrier adhesive film 410 to make the oxygen barrier adhesive film 410 block oxygen for the light conversion agent.

[0075] In one embodiment, the photovoltaic module includes a double-glass photovoltaic module, which includes a front glass 100, a front adhesive film 200, a battery string 300, a back adhesive film 400, and a back glass 500 arranged in sequence. Among them, the oxygen transmittance of the back glass 500 is less than a preset value, and the back glass 500 can be used to block oxygen. Therefore, the back adhesive film 400 of the double-glass photovoltaic module can be entirely made of the oxygen barrier adhesive film 410, as Figure 4 shown.

[0076] In one embodiment, the oxygen barrier adhesive film 410 at least includes an oxygen barrier material layer 411 and a packaging material layer 412. The oxygen barrier material layer 411 includes, but is not limited to, at least one of ethylene-vinyl alcohol copolymer (EVOH) and polyvinyl alcohol (PVA). The packaging material layer 412 includes, but is not limited to, at least one of EVA adhesive film, POE adhesive film, and EPE adhesive film. Optionally, the oxygen barrier adhesive film 410 further includes a water barrier material layer.

[0077] In one embodiment, the packaging material layer 412 is bonded to the first surface and / or the second surface of the oxygen barrier material layer 411 to form the oxygen barrier adhesive film 410. Refer to Figures 2A to 2CAs shown, the encapsulation material layer 412 can be bonded only to one of the surfaces of the oxygen barrier material layer 411, can be bonded to both surfaces of the oxygen barrier material layer 411, and the encapsulation material layer 412 can be not only a single-layer structure but also a laminated structure.

[0078] Embodiment 3

[0079] Referring to Figure 5 As shown, the photovoltaic module at least includes a front glass 100, a front encapsulant film 200, a battery string 300, a back encapsulant film 400, and a backsheet arranged in sequence; wherein, the back encapsulant film 400 integrally includes an oxygen barrier encapsulant film 410, and the oxygen barrier encapsulant film 410 is used to block oxygen for the front encapsulant film 200.

[0080] Referring to Figures 2A to 2C As shown, the oxygen barrier encapsulant film 410 includes: an oxygen barrier material layer 411 including a first surface and a second surface arranged opposite to each other; an encapsulation material layer 412 bonded to the first surface and / or the second surface of the oxygen barrier material layer 411 for bonding the oxygen barrier encapsulant film 410 to the battery string 300.

[0081] In one embodiment, the battery string 300 includes a photoaging battery, and the service life of the photoaging battery in the first wavelength light is less than the service life of the photoaging battery in the second wavelength light; and / or, the battery string includes a light attenuation battery, and the conversion efficiency of the light attenuation battery in the first wavelength light is lower than the conversion efficiency of the light attenuation battery in the second wavelength light. The photoaging battery and / or the light attenuation battery include but are not limited to at least one of a heterojunction (HJT) battery and a tunnel oxide passivated contact (TOPCon) battery. Among them, the wavelengths of the first wavelength light and the second wavelength light are different. Generally, the wavelength of the first wavelength light is less than the wavelength of the second wavelength light. Specifically, the wavelength range of the first wavelength light includes 280nm to 500nm, and the wavelength range of the second wavelength light includes 380nm to 800nm. For example, the first wavelength light includes ultraviolet light, and the second wavelength light includes visible light.

[0082] In one embodiment, in order to reduce the adverse effects of ultraviolet light on the photoaging battery and the light attenuation battery and ensure the light utilization rate, the entire front encapsulant film 200 of the photovoltaic module can be set as a light conversion encapsulant film, that is, the light conversion encapsulant film entirely covers the battery string 300. The light conversion encapsulant film includes an encapsulation material layer and a light conversion agent dispersed in the encapsulation material layer. The encapsulation material layer includes but is not limited to at least one of an EVA encapsulant film, a POE encapsulant film, and an EPE encapsulant film. The light conversion agent includes but is not limited to an organic fluorescent compound, and its molecular structure has a chromophore, mostly a large π-conjugated structure with a benzene ring or other aromatic rings. In order to avoid oxidation of the light conversion agent, the back encapsulant film 400 can be set as the oxygen barrier encapsulant film 410 so that the oxygen barrier encapsulant film 410 blocks oxygen for the light conversion agent.

[0083] In one embodiment, the photovoltaic module includes a single-glass photovoltaic module. The single-glass photovoltaic module includes a front glass 100, a front encapsulant film 200, a cell string 300, a back encapsulant film 400, and a backsheet 600 arranged in sequence. Among them, the oxygen transmission rate of the backsheet 600 is greater than a preset value, that is, the backsheet 600 is oxygen-permeable. Therefore, the entire back encapsulant film 400 of the single-glass photovoltaic module uses an oxygen-barrier encapsulant film 410, such as Figure 5 shown.

[0084] In one embodiment, the oxygen-barrier encapsulant film 410 includes at least an oxygen-barrier material layer 411 and an encapsulation material layer 412. The oxygen-barrier material layer 411 includes, but is not limited to, at least one of ethylene-vinyl alcohol copolymer (EVOH) and polyvinyl alcohol (PVA). The encapsulation material layer 412 includes, but is not limited to, at least one of EVA film, POE film, and EPE film. Optionally, the oxygen-barrier encapsulant film 410 further includes a water-barrier material layer.

[0085] In one embodiment, the encapsulation material layer 412 is bonded to the first surface and / or the second surface of the oxygen-barrier material layer 411 to form the oxygen-barrier encapsulant film 410. Referring to Figures 2A to 2C shown, the encapsulation material layer 412 can be bonded to only one of the surfaces of the oxygen-barrier material layer 411, or can be bonded to both surfaces of the oxygen-barrier material layer 411, and the encapsulation material layer 412 can be not only a single-layer structure but also a laminated structure.

[0086] According to the photovoltaic module provided by the present invention, by using an oxygen-barrier encapsulant film for the whole or part of the back encapsulant film to prevent oxygen from the back from invading the front, the photo-conversion encapsulant film located in front of the cell string is prevented from being oxidized by the oxygen invading from the back, resulting in the failure of the function and aging of the photo-conversion encapsulant film, and further preventing the cell string from occurring ultraviolet light-induced attenuation and aging, thereby improving the conversion efficiency of the photovoltaic module and extending the service life of the photovoltaic module.

[0087] Please note that the above embodiments are for illustrative purposes only and do not imply any limitation to the present application.

[0088] Each embodiment in this specification is described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other.

[0089] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0090] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application.

Claims

1. A photovoltaic module, characterized in that, It includes at least a front glass (100), a front encapsulant film (200), a battery string (300), and a back encapsulant film (400) arranged in sequence; wherein, the back encapsulant film (400) wholly or partially includes an oxygen barrier encapsulant film (410), and the oxygen barrier encapsulant film (410) is used to block oxygen for the front encapsulant film (200). The oxygen barrier encapsulant film (410) includes: An oxygen barrier material layer (411) including a first surface and a second surface arranged oppositely; An encapsulation material layer (412) bonded to the first surface and / or the second surface of the oxygen barrier material layer (411) for bonding the oxygen barrier encapsulant film (410) to the battery string (300).

2. The photovoltaic module according to claim 1, wherein The front encapsulant film (200) includes a light conversion encapsulant film, and the light conversion encapsulant film is used to convert first-wavelength light into second-wavelength light, and the wavelengths of the first-wavelength light and the second-wavelength light are different.

3. The photovoltaic module according to claim 2, wherein, The light conversion encapsulant film is at least used to convert ultraviolet light into visible light.

4. The photovoltaic module according to claim 2, wherein The battery string (300) includes a light-aging battery, and the service life of the light-aging battery in the first-wavelength light is less than the service life of the light-aging battery in the second-wavelength light; and / or, The battery string (300) includes a light-decay battery, and the conversion efficiency of the light-decay battery in the first-wavelength light is lower than the conversion efficiency of the light-decay battery in the second-wavelength light.

5. The photovoltaic module according to claim 4, characterized in that, The light-aging battery and / or the light-decay battery includes at least one of a heterojunction battery and a tunnel oxide passivated contact battery.

6. The photovoltaic module according to claim 2, characterized in that, The light conversion encapsulant film includes an encapsulation material layer and a light conversion agent dispersed in the encapsulation material layer, and the light conversion agent is used to convert the first-wavelength light into the second-wavelength light.

7. The photovoltaic module according to claim 6, wherein The light conversion agent includes an organic fluorescent compound, and the oxygen barrier encapsulant film (410) is used to block oxygen for the light conversion agent.

8. The photovoltaic module according to claim 1, wherein, The oxygen barrier material layer (411) includes at least one of ethylene-vinyl alcohol copolymer and polyvinyl alcohol.

9. The photovoltaic module according to claim 1, wherein The encapsulation material layer (412) includes a single-layer structure or a laminated structure, and the encapsulation material layer (412) includes at least one of an ethylene-vinyl acetate copolymer layer and a polyolefin elastomer layer.

10. The photovoltaic module according to claim 1, characterized in that, The thickness range of the oxygen barrier material layer (411) includes 0.01 mm to 0.1 mm, and the thickness range of the encapsulation material layer includes 0.2 mm to 0.8 mm.

11. The photovoltaic module according to claim 1, wherein, The encapsulation material layer (412) further includes: A water barrier material layer, and the water barrier material layer is at least used to block water for the front encapsulant film (200).

12. The photovoltaic module according to claim 1, characterized in that, It further includes: A back glass (500) arranged on the side of the back encapsulant film (400) away from the battery string (300), and the back glass (500) can be used to block oxygen; or, A backplane arranged on the side of the back encapsulant film (400) away from the battery string (300), and the backplane can permeate oxygen.

13. The photovoltaic module according to claim 12, wherein, At least one opening area (501) is arranged on the back glass (500), and the oxygen barrier encapsulant film (410) is at least arranged inside the opening area (501).

14. The photovoltaic module according to claim 13, wherein The size of the oxygen barrier adhesive film (410) is larger than the size of the opening area (501), and the oxygen barrier adhesive film (410) completely covers the opening area (501).

15. The photovoltaic module according to claim 12, wherein, The oxygen barrier adhesive film (410) is at least disposed in the edge area of the back adhesive film (400).

16. The photovoltaic module according to any one of claims 13 to 15, characterized in that, The back adhesive film (400) includes: An encapsulation adhesive film (420), the encapsulation adhesive film (420) at least includes an encapsulation material layer, and the encapsulation adhesive film covers the battery string (300); An oxygen barrier adhesive film (410), the oxygen barrier adhesive film (410) is bonded to the encapsulation adhesive film (420), and the oxygen barrier adhesive film (410) and the encapsulation adhesive film (420) are laminated to form the back adhesive film (400).

17. The photovoltaic module according to claim 16, wherein, The width range of the oxygen barrier adhesive film (410) disposed in the edge area of the back adhesive film (400) is 10 mm to 50 mm. The oxygen barrier adhesive film (410) and the encapsulation adhesive film (420) are overlapped, and the width range of the overlapping area between the oxygen barrier adhesive film (410) and the encapsulation adhesive film (420) is 3 mm to 10 mm.

18. The photovoltaic module according to claim 16, characterized in that, The oxygen barrier adhesive film (410) is disposed on the side of the encapsulation adhesive film (420) away from the battery string (300).

19. The photovoltaic module according to claim 12, characterized in that, The oxygen barrier adhesive film (410) completely covers the backplane.

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