Photovoltaic module

Abstract

This application relates to the field of photovoltaic technology, and particularly to a photovoltaic module. The photovoltaic module includes a front cover plate, multiple solar cells, a film strip, and an organic light-transmitting backsheet. The multiple solar cells are spaced apart between the front cover plate and the organic light-transmitting backsheet. The film strip is located on the side of the organic light-transmitting backsheet closest to the solar cells. The film strip includes a modified EVA layer with a VA content of 28wt%~33wt%, and the modified EVA layer is in contact with the organic light-transmitting backsheet. The surface roughness of the side of the organic light-transmitting backsheet in contact with the modified EVA layer is 1.1μm±0.1μm. This application can effectively reduce bubbles generated between the film strip and the organic light-transmitting backsheet, improving the delamination problem.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic module. Background Technology

[0002] Photovoltaic modules can be categorized into bifacial and single-sided modules based on whether the back of the cell is translucent. Bifacial modules have translucent panels on both the front and back of the solar cells, allowing the back to absorb reflected sunlight and convert it into electricity. Single-sided modules, on the other hand, have opaque panels on the back of the solar cells, only collecting sunlight from the front for conversion into electricity. Compared to single-sided modules, bifacial modules offer higher power generation per watt.

[0003] Depending on the back-side encapsulation of the solar cells, bifacial photovoltaic modules can be further divided into bifacial double-glass photovoltaic modules and bifacial single-glass photovoltaic modules. Bifacial double-glass photovoltaic modules refer to solar cells with glass panels on both the front and back sides, while bifacial single-glass photovoltaic modules refer to solar cells with glass panels on the front side and organic light-transmitting backsheets on the back side.

[0004] Photovoltaic module gap film technology refers to adding specific film materials between photovoltaic cells to improve the photoelectric conversion efficiency of solar cells. The gap film can improve the utilization rate of sunlight by reflecting and absorbing light in the gap without affecting the normal operation of the cells, thereby enhancing the overall performance of the photovoltaic module. Currently, the gap film of bifacial double-glass photovoltaic modules is mainly formed by applying a film tape to the glass or screen printing a glaze containing titanium dioxide (TiO2) onto the glass. However, the gap film of bifacial single-glass photovoltaic modules can only be formed by screen printing a glaze containing titanium dioxide (TiO2) onto an organic light-transmitting backsheet. This is because if the film tape is attached to the glass and then to the organic light-transmitting backsheet, there is a problem with its aging resistance. During the aging process, bubbles are easily formed between the film tape and the organic light-transmitting backsheet, leading to delamination. Summary of the Invention

[0005] Based on this, the first aspect of this application provides a photovoltaic module, the technical solution of which is as follows:

[0006] A photovoltaic module includes a front cover plate, a plurality of solar cells, a film strip, and an organic light-transmitting back sheet. The plurality of solar cells are spaced apart between the front cover plate and the organic light-transmitting back sheet, and the film strip is located on the side of the organic light-transmitting back sheet closer to the solar cells.

[0007] The membrane strip includes a modified EVA layer, the organic light-transmitting backsheet includes a modified coating, the modified EVA layer is in contact with the modified coating, the degree of crosslinking of the modified EVA layer is 65%~85%, the VA content is 28wt%~33wt%, and the surface roughness of the modified coating is 1.1μm±0.1μm.

[0008] Compared with traditional solutions, this application has the following advantages:

[0009] This application involves attaching a film strip to an organic light-transmitting backsheet. Compared to screen printing a titanium dioxide (TiO2)-containing glaze onto glass, this method is beneficial for improving the power and reflectivity of photovoltaic modules. To ensure the feasibility of backsheet film attachment, both the film strip and the organic light-transmitting backsheet are modified. The film strip includes a modified EVA layer, and the organic light-transmitting backsheet includes a modified coating. The modified EVA layer has a crosslinking degree of 65%–85%, a VA content of 28 wt%–33 wt%, and a surface roughness of 1.1 μm ± 0.1 μm. Through these modifications, the cohesive strength and surface polarity of the film strip are improved, and the surface roughness is increased, enhancing the adhesion at the contact surface. During aging, this effectively reduces air bubbles generated between the film strip and the organic light-transmitting backsheet, improving delamination issues. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of a traditional bifacial single-wave photovoltaic module;

[0012] Figure 2 A schematic diagram showing air bubbles appearing between the membrane strip and the organic light-transmitting backsheet;

[0013] Figure 3 A schematic diagram of the structure of a bifacial single-wave photovoltaic module according to one embodiment;

[0014] Figure 4 This is a schematic diagram of the structure of a membrane strip according to one embodiment;

[0015] Figure 5 This is a schematic diagram of the membrane strip structure according to another embodiment;

[0016] Figure 6 This is a schematic diagram of the structure of an organic light-transmitting back panel according to one embodiment. Detailed Implementation

[0017] The present application will be further described in detail below with reference to specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0019] the term

[0020] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0021] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more or more.

[0022] In this application, "several" means at least one, such as one, two, etc., unless otherwise expressly and specifically defined.

[0023] In this application, the terms "optionally," "optionally," and "optional" refer to options that are optional, meaning they can be selected from either "with" or "without." If multiple "optional" options appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" option is independent.

[0024] In this application, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only a non-exhaustive enumeration purpose and should be understood not to constitute a closed limitation on quantity.

[0025] In this application, numerical intervals (i.e. numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the above-mentioned numerical intervals are considered continuous, and include the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical range, as well as every value between the two numerical endpoints.

[0026] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0027] In this application, %(w / w) and wt% both represent weight percentage, %(v / v) refers to volume percentage, and %(w / v) refers to mass-volume percentage.

[0028] Currently, the gap film in bifacial double-glass photovoltaic modules is mainly formed by applying a film tape to the glass or by screen printing a glaze containing titanium dioxide (TiO2) onto the glass. However, the gap film in bifacial single-glass photovoltaic modules can only be formed by screen printing a glaze containing titanium dioxide (TiO2) onto an organic light-transmitting backsheet. Please refer to [link to relevant documentation]. Figure 1 This is a schematic diagram of a traditional bifacial single-wave photovoltaic module 100, including a front cover plate 11, multiple solar cells 12, an enamel layer 13, and an organic light-transmitting backsheet 14. The solar cells 12 are spaced apart between the front cover plate 11 and the organic light-transmitting backsheet 14. The enamel layer 13 is located on the side of the organic light-transmitting backsheet 14 closest to the solar cells 12. The front cover plate 11, multiple solar cells 12, enamel layer 13, and organic light-transmitting backsheet 14 are bonded together with a transparent adhesive film. The enamel layer 13 is formed by printing an enamel containing titanium dioxide (TiO2). It has a light-reflecting effect, which can improve the utilization rate of sunlight by reflecting and absorbing light between the solar cells without affecting the normal operation of the solar cells, thereby improving the overall performance of the photovoltaic module. However, the surface of the enamel layer is rough and uneven, resulting in diffuse reflection of incident light. Compared with the total internal reflection of incident light by the film tape, the utilization rate of light through diffuse reflection is insufficient. However, it is currently impossible to form a gap film by attaching the film tape to the organic light-transmitting backsheet because if the film tape, which is bonded to the glass, is attached to the organic light-transmitting backsheet, there is a problem with its aging resistance. During the aging process, bubbles are prone to appear between the film tape 15 and the organic light-transmitting backsheet 14. Please refer to [link / reference needed]. Figure 2 This leads to the problem of delamination.

[0029] This application provides a photovoltaic module; please refer to [link / reference]. Figure 3 In one embodiment, the photovoltaic module 200 includes a front cover plate 21, a plurality of solar cells 22, a film strip 23, and an organic light-transmitting backsheet 24. The plurality of solar cells 22 are spaced apart between the front cover plate 21 and the organic light-transmitting backsheet 24. The film strip 23 is located on the side of the organic light-transmitting backsheet 24 closer to the solar cells 22. The front cover plate 21, the plurality of solar cells 22, the film strip 23, and the organic light-transmitting backsheet 24 can be bonded together with a transparent adhesive film. In this embodiment, the film strip 23 is attached to the organic light-transmitting backsheet 24. Compared with printing a glaze containing titanium dioxide (TiO2) onto the organic light-transmitting backsheet 24 to form a glaze layer, the film strip 23 can perform total internal reflection of incident light, improving light utilization and thus improving the power and reflectivity of the photovoltaic module.

[0030] To address the issue of air bubbles easily forming between the film strip 23 and the organic light-transmitting backsheet 24, the film strip is modified. After modification, the film strip 23 includes a modified EVA layer, wherein the degree of crosslinking of the modified EVA layer is 65%~85%, and the VA (vinyl acetate) content is 28wt%~33wt%. The degree of crosslinking of the modified EVA layer includes, but is not limited to, 65%, 70%, 75%, 80%, and 85%. The VA content includes, but is not limited to, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, and 33wt%. The degree of crosslinking and the VA content of the modified EVA layer can be adjusted to fall within the above ranges. Controlling the degree of crosslinking within the range of 65%~85% is beneficial for improving the cohesive strength of the film strip itself, thereby improving the adhesion. Controlling the VA content within the range of 28wt%~33wt% is beneficial for increasing the surface polarity of the film strip, thereby improving the adhesion between the surface of the film strip and the surface of the organic light-transmitting backsheet 24.

[0031] Modified EVA layers can be obtained by modifying traditional EVA layer formulations by adding additives or increasing the content of vinyl acetate monomer. Optionally, the raw materials for the modified EVA layer include a main resin and additives. The main resin includes ethylene monomer and vinyl acetate monomer, and the additives include one or more of coupling agents and crosslinking agents. By controlling the amount of additives and polar materials (VA), the degree of crosslinking and VA content of the modified EVA layer can be controlled.

[0032] Optionally, the thickness of the modified EVA layer is 1 μm to 100 μm. For example, the thickness of the modified EVA layer is 1 μm, 20 μm, 50 μm, 80 μm, or 100 μm.

[0033] Please see Figure 4 In this embodiment, the film strip 23 includes a modified EVA layer 231, a PET support layer 232, an uneven structure 233, an insulating layer 234, and an aluminum reflective layer 235, wherein the modified EVA layer 231 is as described above. The PET support layer 232 is located on the side of the modified EVA layer 231 away from the organic light-transmitting backsheet 14, the uneven structure 233 is located on the side of the PET support layer 232 away from the modified EVA layer 231, the insulating layer 234 is located on the side of the uneven structure 233 away from the PET support layer 232, and the aluminum reflective layer 235 is located on the side of the insulating layer 234 away from the uneven structure 233.

[0034] In this embodiment, the reflective layer is an aluminum reflective layer. The reflectivity of metallic aluminum (≥85%) is higher than that of the glaze layer (≥75%), resulting in higher light utilization.

[0035] Optionally, the position of the membrane strip corresponds to the gap between two adjacent solar cells, or multiple solar cells are connected in series to form multiple solar cell strings, and the position of the membrane strip corresponds to the gap between two adjacent solar cell strings. Optionally, the width of the membrane strip is 2mm to 6mm.

[0036] This embodiment does not limit the structure of the battery cell. The types of battery cells include, but are not limited to, passivated emitter rear cell (PERC), tunnel oxide passivated contact (TOPCon), intrinsic thin-film heterojunction (HJT), interdigitated back contact (IBC), perovskite battery, etc.

[0037] For PERC cells, along their thickness direction, the PERC cell sequentially includes a front-surface silver electrode, a front-surface silicon nitride passivation layer, a phosphorus emitter layer, a P-type substrate silicon layer, a localized aluminum back field, a metallic aluminum back electrode, and a back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back side, replacing the all-aluminum back field, enhancing light reflection within the silicon substrate, reducing the recombination rate on the back side, and improving the cell efficiency by 0.5%-1%.

[0038] For TOPCon cells, along their thickness direction, the TOPCon cell sequentially includes a silver electrode, a front-surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate silicon layer, a diffused doped layer, an ultrathin silicon oxide layer, doped polycrystalline silicon, silicon nitride, and the silver electrode. The back of the cell consists of an ultrathin silicon oxide layer (1nm~2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure can block minority carrier recombination, increasing the cell's open-circuit voltage and short-circuit current. The ultrathin oxide layer allows majority carrier electrons to tunnel into the polycrystalline silicon layer while blocking minority carrier recombination. The excellent passivation effect of the ultrathin silicon oxide and heavily doped silicon film causes band bending on the silicon wafer surface, resulting in a field passivation effect. This significantly increases the probability of electron tunneling, reduces contact resistance, and improves the cell's open-circuit voltage and short-circuit current, thereby increasing the cell's conversion efficiency.

[0039] For an HJT cell, along its thickness direction, the HJT cell sequentially includes a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type substrate silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0040] For an IBC cell, along its thickness direction, it sequentially includes a silicon nitride anti-reflection layer, an N+ front surface field, an N-type substrate silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride anti-reflection layer, and a silver electrode. IBC cells utilize ion implantation technology to obtain P- and N-regions with good uniformity and precisely controllable junction depth. The absence of grid lines on the front side eliminates light-blocking current loss from the metal electrodes, maximizing the utilization of incident photons and improving short-circuit current by approximately 7% compared to conventional solar cells. Due to its back-contact structure, grid line shading is not a concern, allowing for a wider grid line ratio, thus reducing series resistance and achieving a high fill factor. Optimized design of surface passivation and light-trapping structures can be achieved, resulting in lower front-surface recombination rates and surface reflection.

[0041] For a perovskite solar cell, along its thickness direction, it sequentially comprises a substrate material, a conductive thin film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials possess a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrodes with minimal loss, thus generating high photogenerated voltage and current, resulting in high photoelectric conversion efficiency.

[0042] To ensure no light leakage, the width of the enamel layer formed on the organic transparent backsheet is generally greater than the gap between two adjacent solar cells, thus blocking more incident light from the back. In this embodiment, the position and size of the film strip correspond to the gap between two adjacent solar cells. The width of the film strip can be set according to the gap between two adjacent solar cells (0~2mm). Compared to a traditional enamel layer, the width of the film strip can be narrowed, thereby improving the bifaciality. In other embodiments, multiple solar cells are connected in series to form multiple solar cell strings, and the position and size of the film strip correspond to the gap between two adjacent solar cell strings.

[0043] In another embodiment, please refer to Figure 5The film strip 33 includes a modified EVA layer 331, an EVA layer 336, a PET support layer 332, an uneven structure 333, an insulating layer 334, and an aluminum reflective layer 335. The modified EVA layer 331 has a crosslinking degree of 65%~85% and a VA content of 28wt%~33wt%. The PET support layer 332 is located on the side of the modified EVA layer 331 away from the organic light-transmitting backsheet 14, and the EVA layer 336 is located between the modified EVA layer 331 and the PET support layer 332. The uneven structure 333 is located on the side of the PET support layer 332 away from the modified EVA layer 331, the insulating layer 334 is located on the side of the uneven structure 333 away from the PET support layer 332, and the aluminum reflective layer 335 is located on the side of the insulating layer 334 away from the uneven structure 333. In this embodiment, a portion of the EVA layer is modified.

[0044] Optionally, the thickness of the membrane strip is 50 μm to 150 μm. This includes, but is not limited to, 50 μm, 75 μm, 100 μm, and 150 μm.

[0045] To address the issue of air bubbles easily forming between the film strip 23 and the organic light-transmitting backsheet 24, this application not only modifies the film strip 23 but also modifies the organic light-transmitting backsheet 24 in conjunction with the modification of the film strip 23. After modification, the organic light-transmitting backsheet 24 includes a modified coating with a surface roughness of 1.1 μm ± 0.1 μm. At this point, the modified coating of the organic light-transmitting backsheet 24 contacts the modified EVA layer of the film strip 23. The surface roughness of the modified coating (1.1 μm ± 0.1 μm) helps increase the adhesion between the contact surfaces of the organic light-transmitting backsheet 24 and the film strip 23. By simultaneously improving both the film strip 23 and the organic light-transmitting backsheet 24, not only is the adhesion between the two improved under normal conditions, but more importantly, the adhesion is maintained during aging, effectively reducing air bubbles generated between the film strip and the organic light-transmitting backsheet and improving the delamination problem between them.

[0046] Optionally, the modified coating contains SiO2 particles. By adding SiO2 particles to the coating of a conventional coating, the roughness of the modified coating can be improved without affecting the reliability and light transmittance of the organic transparent backsheet. Before and after adding SiO2 particles, the roughness of the modified coating can be increased from the initial 0.55μm±0.1μm to 1.1μm±0.1μm.

[0047] Optionally, the average particle size of the SiO2 particles is 5 μm ± 1 μm.

[0048] Optionally, the SiO2 particles account for 5% ± 1% by mass in the modified coating.

[0049] Optionally, the modified coating comprises a base resin, functional additives, and the SiO2 particles. The base resin comprises fluorocarbon resin and acrylic resin, and the functional additives comprise one or more of ultraviolet absorbers, light stabilizers, anti-hydrolysis agents, leveling agents, and dispersants.

[0050] Optionally, the thickness of the modified coating is 50 μm to 180 μm. This includes, but is not limited to, 50 μm, 75 μm, 100 μm, 150 μm, and 180 μm.

[0051] Please see Figure 6 In this embodiment, the organic light-transmitting backsheet 24 includes a modified coating 241, an organic substrate 242, and a protective coating 243, as described above. The organic substrate 242 is located on the side of the modified coating 241 away from the film strip 23, and the protective coating 243 is located on the side of the organic substrate 242 away from the modified coating 241.

[0052] Alternatively, the organic matrix material can be PET.

[0053] Optionally, the protective coating comprises a base resin and functional additives, wherein the base resin comprises fluorocarbon resin and acrylic resin, and the functional additives comprise one or more of ultraviolet absorbers, light stabilizers, anti-hydrolysis agents, leveling agents, and dispersants.

[0054] This embodiment involves attaching a film strip to an organic light-transmitting backsheet. Compared to screen printing a glaze containing titanium dioxide (TiO2) onto glass, this method is beneficial for improving the power and reflectivity of photovoltaic modules. To ensure the feasibility of backsheet film attachment, both the film strip and the organic light-transmitting backsheet are modified. The film strip includes a modified EVA layer, and the organic light-transmitting backsheet includes a modified coating. The crosslinking degree of the modified EVA layer is 65%~85%, the VA content is 28wt%~33wt%, and the surface roughness of the modified coating is 1.1μm±0.1μm. Through the above modifications, the cohesive strength and surface polarity of the film strip are improved, and the surface roughness is increased, enhancing the adhesion at the contact surface. During the aging process, this effectively reduces the bubbles generated between the film strip and the organic light-transmitting backsheet, improving the delamination problem.

[0055] The following description is further illustrated with specific embodiments and comparative examples. Unless otherwise specified, the raw materials involved in the following specific embodiments and comparative examples are all commercially available. Unless otherwise specified, the instruments used are all commercially available. Unless otherwise specified, the processes involved are conventionally selected by those skilled in the art.

[0056] Example 1

[0057] This embodiment provides a photovoltaic module, the structure of which is described in [reference needed]. Figure 3The device includes a front cover plate 21, multiple battery cells 22, a film strip 23, and an organic light-transmitting back panel 24. The multiple battery cells 12 are spaced apart between the front cover plate 21 and the organic light-transmitting back panel 24. The film strip 23 is located on the side of the organic light-transmitting back panel 24 closer to the battery cells 22. The front cover plate 21, multiple battery cells 22, film strip 23, and organic light-transmitting back panel 24 are bonded together by a transparent adhesive film. The film strip 23 includes a modified EVA layer 231, a PET support layer 232, a textured structure 233, an insulating layer 234, and an aluminum reflective layer 235. The PET support layer 232 is located on the side of the modified EVA layer 231 away from the organic light-transmitting back panel 14. The textured structure 233 is located on the side of the PET support layer 232 away from the modified EVA layer 231. The insulating layer 234 is located on the side of the textured structure 233 away from the PET support layer 232. The aluminum reflective layer 235 is located on the side of the insulating layer 234 away from the textured structure 233. The organic light-transmitting backsheet 24 includes a modified coating 241, an organic substrate 242, and a protective coating 243. The organic substrate 242 is located on the side of the modified coating 241 away from the membrane strip 23, and the protective coating 243 is located on the side of the organic substrate 242 away from the modified coating 241. The modified coating 241 of the organic light-transmitting backsheet 24 is in contact with the modified EVA layer 231 of the membrane strip 23. The modified EVA layer has a crosslinking degree of 70%, a VA content of 30 wt%, and a thickness of 75 μm. The position and size of the membrane strip correspond to the gap between two adjacent solar cells, and the width of the membrane strip is 2 mm. The modified coating contains SiO2 particles, has a surface roughness of 1.1 μm, and a thickness of 80 μm.

[0058] Comparative Example 1

[0059] This comparative example provides a photovoltaic module, the structure of which is shown below. Figure 1 The system includes a front cover plate 11, multiple solar cells 12, a glaze layer 13, and an organic light-transmitting back panel 14. The solar cells 12 are spaced apart between the front cover plate 11 and the organic light-transmitting back panel 14. The glaze layer 13 is located on the side of the organic light-transmitting back panel 14 closest to the solar cells 12. The front cover plate 11, multiple solar cells 12, glaze layer 13, and organic light-transmitting back panel 14 are bonded together with a transparent adhesive film. The glaze layer 13 is formed by printing a glaze containing titanium dioxide (TiO2). The glaze formulation includes titanium dioxide, glass powder, and organic binder. The glaze layer thickness is 75 μm. The glaze position corresponds to the gap between two adjacent solar cells, and its width is greater than the gap between two adjacent solar cells, with a glaze width of 6 mm. The organic light-transmitting backplate 14 consists of an organic substrate, a first protective coating on one side of the organic substrate, and a second protective coating on the other side of the organic substrate. The first protective coating is in contact with the glaze layer and its coating material is consistent with the modified coating in Example 1 without the addition of SiO2 particles, with a surface roughness of 0.55 μm and a thickness of 80 μm. The front cover plate 11, multiple battery cells 12, transparent film, organic substrate, and second protective coating are consistent with those in Example 1.

[0060] The photovoltaic modules of the above embodiments and comparative examples were tested using the following methods:

[0061] Project 1: Power testing. Following the IEC 61215 MQT06 test method, the photovoltaic modules were placed under STC standard illumination (1000W / m²). 2 (The solar spectral distribution at 25℃ and according to IEC 60904-3) uses the corresponding standard plate as a standard sheet to test the current, voltage, and power of the photovoltaic module under test.

[0062] Project 2: Bifaciality test. Using the same power test method, flip the photovoltaic module to test the back side. The bifaciality calculation formula is: Power on the back of the module / Power on the front of the module * 100%.

[0063] Project 3, Aging Resistance Test: Refer to IEC61215 MQT13 Damp Heat Test, Test conditions (85±2)℃, (85±5)% humidity, (1000+48)h, no pretreatment required; During the test, the photovoltaic module needs to be short-circuited (except for specific components that need to be energized) and open-circuited, (23±5)℃, less than 75% humidity, and recover for 2~4h.

[0064] The test results are shown in Table 1.

[0065] Table 1

[0066]

[0067] As can be seen, compared with Comparative Example 1, the photovoltaic module of Example 1 has a power increase of 0.54% and a bifaciality increase of 2.8%. Moreover, the photovoltaic module of Example 1 has excellent aging resistance, and no delamination problem was found after the aging test.

[0068] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0069] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A photovoltaic module, characterized in that, It includes a front cover plate, multiple battery cells, a film strip, and an organic light-transmitting back panel. The multiple battery cells are spaced apart between the front cover plate and the organic light-transmitting back panel, and the film strip is located on the side of the organic light-transmitting back panel closer to the battery cells. The membrane strip includes a modified EVA layer, the organic light-transmitting backsheet includes a modified coating, the modified EVA layer is in contact with the modified coating, the degree of crosslinking of the modified EVA layer is 65%~85%, the VA content is 28wt%~33wt%, and the surface roughness of the modified coating is 1.1μm±0.1μm.

2. The photovoltaic module according to claim 1, characterized in that, The raw materials for the modified EVA layer include a main resin and additives. The main resin includes ethylene monomer and vinyl acetate monomer, and the additives include one or more of coupling agents and crosslinking agents.

3. The photovoltaic module according to claim 1, characterized in that, The film strip also includes a PET support layer, an uneven structure, an insulating layer, and an aluminum reflective layer; the PET support layer is located on the side of the modified EVA layer away from the organic light-transmitting backsheet, the uneven structure is located on the side of the PET support layer away from the modified EVA layer, the insulating layer is located on the side of the uneven structure away from the PET support layer, and the aluminum reflective layer is located on the side of the insulating layer away from the uneven structure.

4. The photovoltaic module according to claim 3, characterized in that, The film strip also includes an EVA layer, which is located between the modified EVA layer and the PET support layer.

5. The photovoltaic module according to claim 1, characterized in that, Includes at least one of the following features: (1) The thickness of the modified EVA layer is 1μm~100μm; (2) The thickness of the membrane strip is 50μm~150μm.

6. The photovoltaic module according to claim 1, characterized in that, The position and size of the membrane strip correspond to the gap between two adjacent battery cells, or multiple battery cells are connected in series to form multiple battery strings, and the position and size of the membrane strip correspond to the gap between two adjacent battery strings.

7. The photovoltaic module according to any one of claims 1 to 6, characterized in that, The modified coating contains SiO2 particles.

8. The photovoltaic module according to claim 7, characterized in that, The SiO2 particles satisfy at least one of the following conditions: (1) The average particle size of the SiO2 particles is 5 μm ± 1 μm; (2) The mass percentage of the SiO2 particles in the modified coating is 5% ± 1%.

9. The photovoltaic module according to claim 8, characterized in that, The modified coating comprises a base resin, functional additives, and SiO2 particles. The base resin comprises fluorocarbon resin and acrylic resin, and the functional additives comprise one or more of ultraviolet absorbers, light stabilizers, anti-hydrolysis agents, leveling agents, and dispersants.

10. The photovoltaic module according to any one of claims 1 to 6, 8 to 9, characterized in that, The organic light-transmitting backsheet also includes an organic substrate and a protective coating. The organic substrate is located on the side of the modified coating away from the film strip, and the protective coating is located on the side of the organic substrate away from the modified coating.

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