Gap film and photovoltaic module

Abstract

The application belongs to the field of solar cells. A gap film and a photovoltaic module are provided. The gap film comprises a reflective layer, a base film and a weather-resistant layer which are arranged in a stack, wherein the base film comprises a first base film, a reinforcing layer and a second base film which are arranged in a stack. The gap film of the application has good reflection effect and good wrinkle resistance.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to a gap film and a photovoltaic module. Background Technology

[0002] Solar photovoltaic (PV) power generation directly converts light energy into electrical energy using the photovoltaic effect at semiconductor interfaces. As the demands for sustainable economic and social development increase, so do the requirements for energy and environmental protection, making this power generation method increasingly important. A photovoltaic module, composed of solar cells, typically consists of a front panel (photovoltaic glass), a front transparent encapsulating film, solar cells, a back transparent encapsulating film, and a back panel (or glass). To improve the output power of PV modules, more and more emerging technologies have been applied to their design and manufacturing in recent years. For example, by setting several parallel reflective films in the gaps corresponding to the solar cell strings on the back panel, sunlight can be reflected multiple times back to the solar cells for reuse, thereby increasing the output power and power generation of the PV module.

[0003] However, existing reflective gap films are prone to wrinkling during the application and lamination process due to mechanical external forces and the melting and flow of EVA during lamination, which in turn affects the appearance and photoelectric performance of photovoltaic modules.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Utility Model Content

[0005] This application provides a gap film and a photovoltaic module to solve or alleviate the technical problem mentioned above, where existing reflective gap films are prone to wrinkles due to mechanical external force and EVA melting and flow during lamination, which in turn affects the appearance and photoelectric performance of photovoltaic modules.

[0006] The first aspect of this application provides a gap membrane, comprising: a reflective layer, a base film, and a weather-resistant layer stacked together, wherein the base film comprises a first base film, a reinforcing layer, and a second base film stacked together.

[0007] The reflective layer in the gap film of this application embodiment can effectively increase light utilization, thereby significantly improving the power of both the front and back sides of the module and increasing the bifaciality. Adding a reinforcing layer in the middle of the base film gives it a certain elastic deformation modulus, resulting in strong anti-wrinkle capability. This reduces the risk of poor appearance of the laminated module and also ensures that the reflective layer in the gap film reflects light at a good angle, reducing ineffective reflection caused by incident light escaping back into the air after reflection. The weather-resistant layer enhances the gap film's resistance to ultraviolet radiation and damp heat aging. In summary, the gap film of this application has both good reflective properties and good anti-wrinkle capability.

[0008] According to an embodiment of this application, the reflective layer has a plurality of first protrusion structures arranged in a specific orientation, and the angle between the arrangement direction of the first protrusion structures and the length direction of the base film is an acute angle.

[0009] According to an embodiment of this application, the first protrusion structure is a serrated structure, the apex angle of the serrated structure is 100°~150°, and the height is 5μm~30μm.

[0010] According to an embodiment of this application, the weather-resistant layer has a plurality of oriented second protrusion structures, and the angle between the arrangement direction of the second protrusion structures and the length direction of the base film is an acute angle.

[0011] According to an embodiment of this application, the gap membrane further includes: a first adhesive layer, the first adhesive layer being located on the side of the reflective layer away from the base membrane.

[0012] According to an embodiment of this application, the gap membrane further includes a second adhesive layer, the second adhesive layer being located on the side of the weather-resistant layer away from the base membrane.

[0013] According to an embodiment of this application, the thickness of the first base film of the gap membrane is 20 μm to 100 μm.

[0014] According to an embodiment of this application, the thickness of the second base film is 20 μm to 100 μm.

[0015] According to an embodiment of this application, the thickness of the reinforcing layer is 5 μm to 15 μm.

[0016] According to an embodiment of this application, the reinforcing layer includes composite fibers selected from glass fibers, carbon fibers, basalt fibers, or nylon fibers.

[0017] According to embodiments of this application, the diameter of the composite fiber is 2μm to 13μm; and / or, the length of the composite fiber is 50mm to 1500mm.

[0018] A second aspect of the embodiments of this application provides a photovoltaic module comprising a front panel, a front encapsulant film, a battery layer, a back encapsulant film, and a rear panel stacked sequentially. The battery layer includes multiple battery cells. A gap film as described in the first aspect is provided between the battery layer and the back adhesive film, or a gap film as described in the first aspect is provided between the back adhesive film and the back panel, and the gap film corresponds to the gap between adjacent battery cells. The photovoltaic module of this application exhibits superior photoelectric efficiency and better reliability. Attached Figure Description

[0019] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0020] Figure 1 These are schematic diagrams of the gap membrane structure in some embodiments; Figure 2 These are schematic diagrams of the reflective layer structure in some embodiments; Figure 3 These are schematic diagrams of the reflective layer in other embodiments; Figure 4 These are schematic diagrams of the weather-resistant layer in some embodiments; Figure 5 These are schematic diagrams of the weather-resistant layer in other embodiments; Figure 6 These are schematic diagrams of the structure of a gap membrane with a first adhesive layer in some embodiments; Figure 7 This is a schematic diagram of the structure of a gap membrane with a first adhesive layer in some embodiments; Figure 8 These are schematic diagrams of the structure of a gap membrane with a second adhesive layer in some embodiments; Figure 9 This is a schematic diagram of the structure of a gap membrane with a second adhesive layer in some embodiments; Figure 10 These are schematic diagrams of the structure of photovoltaic modules according to some embodiments.

[0021] Explanation of reference numerals in the attached figures: 1: Reflective layer; 2: Base film; 21: First base film; 22: Reinforcing layer; 23: Second base film; 3: Weather-resistant layer; 4: First black layer; 5: Second adhesive layer; 6: Front panel; 7: Front adhesive film; 8: Back adhesive film; 9: Rear panel; 10: Battery layer; 100: Battery cell; 11: Gap film. Detailed Implementation

[0022] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0023] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this application.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0027] The fill factor (FF) used in this article refers to the ratio of the actual maximum obtainable power (Pm or Vmp*Jmp) to the theoretical (not actually obtainable) power (Jsc*Voc). Therefore, FF can be determined by the following formula: FF = (Vmp*Jmp) / (Jsc*Voc), where Jmp and Vmp represent the current density and voltage at the maximum power point (Pm), respectively, which is obtained by changing the resistance in the circuit until J*V reaches its maximum value; Jsc and Voc represent the short-circuit current and open-circuit voltage, respectively. The fill factor is a key parameter for evaluating solar cells. Commercial solar cells typically have a fill factor of approximately 60% or higher.

[0028] The open-circuit voltage (Voc) used in this paper is the potential difference between the anode and cathode of the device under conditions of no external load connection.

[0029] The power conversion efficiency (PCE) of solar cells used in this article refers to the percentage of power converted from absorbed light into electrical energy. The PCE of a solar cell can be measured under standard test conditions (STC) based on incident light irradiance (E: W / m²). 2 ) and the surface area of ​​solar cells (Ac:m 2 STC is calculated by dividing the maximum power point (Pm). STC usually refers to the spectrum at a temperature of 25°C, irradiance of 100 W / m2, and air quality of 1.5 (AM1.5).

[0030] Currently, most reflective films used for photovoltaic module gaps are aluminum-plated reflective layers. However, aluminum-plated reflective layers have the following drawbacks: First, they are easily corroded by carboxylic acids (the hydrolysis products of encapsulation materials such as EVA) and moisture, causing a decrease in reflectivity. Second, the blocking reflective layer is conductive, and contact with conductors such as solder ribbons during use can cause poor creepage. A common solution is to add a transparent insulating layer on the aluminum-plated film for isolation and protection, but this reduces reflectivity and does not solve the leakage risk caused by solder ribbons piercing the insulating layer. Since reflective films with a metal layer at the module edge reduce the creepage distance, creating an edge leakage risk, traditional reflective gap films cannot be fully applied to the module, resulting in some wasted sunlight.

[0031] Existing insulating reflective film solutions involve adding a transparent insulating layer to the metal reflective layer to reduce overall reflectivity, or applying an insulating reflective coating to the reflective microstructure, or using thermosetting resin to form the reflective coating. Both of these solutions still present challenges in precisely designing the shape of the reflective layer. Furthermore, these technologies suffer from ineffective reflection, meaning that some incident light escapes back into the air after reflection. Secondly, existing reflective gap films are prone to wrinkling during application and lamination due to mechanical forces and the melting and flow of EVA during lamination, thus affecting the appearance of the photovoltaic module and the reflective performance of the thin film.

[0032] Accordingly, embodiments of this application provide a spacer membrane. (See reference...) Figure 1 The gap membrane includes a reflective layer 1, a base film 2, and a weather-resistant layer 3 stacked together, wherein the base film includes a first base film 21, a reinforcing layer 22, and a second base film 23 stacked together.

[0033] The reflective layer in the gap film of this application embodiment can effectively increase light utilization, thereby significantly improving the power of both the front and back sides of the module and increasing the bifaciality. Adding a reinforcing layer in the middle of the base film gives it a certain elastic deformation modulus, resulting in strong anti-wrinkle capability. This reduces the risk of poor appearance of the laminated module and also ensures that the reflective layer in the gap film reflects light at a good angle, reducing ineffective reflection caused by incident light escaping back into the air after reflection. The weather-resistant layer enhances the gap film's resistance to ultraviolet radiation and damp heat aging. In summary, the gap film of this application has both good reflective properties and good anti-wrinkle capability.

[0034] In some embodiments, the reflective layer has a plurality of first protrusions arranged in an oriented manner, the angle between the arrangement direction of the first protrusions and the length direction of the base film being an acute angle.

[0035] According to the embodiments of this application, refer to Figure 2 The reflective layer has multiple oriented first protrusions, and the angle α between the arrangement direction A of the first protrusions and the length direction B of the base film is an acute angle.

[0036] Furthermore, the included angle α is 0° < α < 90°, for example, 1°, 20°, 30°, 45°, 50°, 60°, 80°, 89°, etc. Therefore, the arrangement direction of the first protrusion structure can be directionally controlled according to the structural design and light reception requirements of the photovoltaic module, so that the light incident on the gap film is directionally reflected onto the solar cell. Simultaneously, since the included angle α between the direction A of the first protrusion structure's directional arrangement and the length direction B of the base film is an acute angle, the ineffective reflection phenomenon caused by the incident light escaping back into the air after reflection from the first protrusion structure can be reduced, thereby increasing the power generation capacity of the solar cell.

[0037] Furthermore, the included angle α is 30°~60°.

[0038] It is understandable that the orientation can be determined according to the actual processing, and its direction can also be set according to the shape of the first protrusion structure. The purpose is that the first protrusion structure and the length direction of the base film have an angle, and the angle is an acute angle, which is beneficial to reflect the incident light.

[0039] In some embodiments, reference Figure 3 The first protrusion structure is a sawtooth structure, with an apex angle β of 100°~150° and a height L1 of 5μm~30μm. This sawtooth structure has two inclined reflective surfaces. By controlling the apex angle and height of the sawtooth structure, it achieves better reflectivity, thereby increasing the probability of light incident on the gap membrane being reflected back to the solar cell, and ultimately improving the utilization rate of light illuminating the gap membrane.

[0040] Furthermore, the apex angle β of the sawtooth structure of the first protrusion is 110°~138°. This allows the incident light to be reflected by the reflective layer to form total internal reflection, thereby improving the utilization rate of the light illuminating the gap film.

[0041] Furthermore, the reflective effect of the sawtooth structure can be improved by adjusting the size and number of the sawtooths.

[0042] In some embodiments, the reflective layer comprises a matrix resin (55wt%~85wt%), filler (25wt%~35wt%), dispersant (0.5wt%~1wt%), antioxidant (1wt%~3wt%), ultraviolet absorber (0.5wt%~1wt%), and adhesion promoter (3wt%~5wt%).

[0043] The matrix resin is selected from one or more of acrylic resin, epoxy resin, and polyester resin. The filler is selected from titanium dioxide and / or perylene black; the dispersant is selected from cationic or anionic dispersants; the antioxidant is selected from hindered amine antioxidants (BSF1010); the ultraviolet absorber is selected from benzotriazine or benzotriazole (BSF479); and the adhesion promoter is selected from maleic acid modified polyester resin.

[0044] In some embodiments, reference Figure 4 and 5 The weather-resistant layer has multiple oriented second protrusions, and the angle θ between the orientation C of the second protrusions and the length direction B of the base film is an acute angle.

[0045] Furthermore, the included angle θ is 0° < θ < 90°, for example, 1°, 20°, 30°, 45°, 50°, 60°, 80°, 89°, etc. Therefore, the arrangement direction of the second protrusion structure can be directionally controlled according to the structural design of the photovoltaic module and its light-receiving requirements, so that the light incident on the gap film is directionally reflected onto the solar cell. Simultaneously, since the included angle θ between the direction C of the second protrusion structure's directional arrangement and the length direction B of the base film is an acute angle, the phenomenon that the reflective surface of the protrusion structure is perpendicular to the edge of the gap film, preventing reflected light from failing to reach the solar cell, is avoided, thus increasing the power generation of the solar cell.

[0046] Furthermore, the included angle θ is 30~60°.

[0047] In some embodiments, reference Figure 5 The second protrusion structure is a sawtooth structure, with an apex angle L1 of 100°~150° and a height L2 of 5μm~15μm. This sawtooth structure has two inclined reflective surfaces. By controlling the apex angle and height of the sawtooth structure, it achieves better reflectivity, thereby increasing the probability of light incident on the gap film being reflected back to the solar cell, and ultimately improving the utilization rate of the light illuminating the gap film.

[0048] In some embodiments, the weather-resistant layer comprises a matrix resin (55wt%~85wt%), fillers (25wt%~35wt%), and additives (5wt%~10wt%). The matrix resin is selected from acrylic resin, fluororesin, epoxy resin, or polyester resin. The filler is selected from titanium dioxide or silica. The additives include antioxidants, UV absorbers, dispersants, etc., wherein the dispersant is selected from cationic or anionic dispersants; the antioxidant is selected from hindered amine antioxidants (BSF1010); and the UV absorber is selected from benzotriazine or benzotriazole derivatives (BSF479).

[0049] In other embodiments, the weather-resistant layer has a flat surface and a thickness of 5 μm to 15 μm.

[0050] In some embodiments, reference Figure 6 and 7 The gap membrane further includes a first adhesive layer 4, which is located on the side of the reflective layer 1 away from the base film. This gap membrane can be directly bonded to the solar cell, meaning the first adhesive layer contacts the back of the solar cell, thereby improving the photoelectric performance of the photovoltaic module.

[0051] In other embodiments, reference is made to Figure 8 and 9 The gap membrane further includes a second adhesive layer 5, which is located on the side of the weather-resistant layer 3 away from the base film. Such a gap membrane can be used for bonding to a back panel, i.e., the second adhesive layer is in contact with the back panel.

[0052] In some other embodiments, the gap membrane includes a first adhesive layer and a second adhesive layer, the first adhesive layer being located on the side of the reflective layer away from the base film, and the second adhesive layer being located on the side of the weather-resistant layer away from the base film.

[0053] Optionally, the first adhesive layer and the second adhesive layer comprise a hot melt adhesive or a pressure-sensitive adhesive. The hot melt adhesive is selected from EVA and / or POE. The pressure-sensitive adhesive is selected from acrylic adhesives.

[0054] In some embodiments, the thicknesses of the first adhesive layer and the second adhesive layer are independently 7μm to 50μm, such as 7μm, 20μm, 30μm, 40μm, 50μm, etc.

[0055] In this application, the base film includes a first base film, a reinforcing layer, and a second base film. Adding a reinforcing layer in the middle of the base film gives it a certain elastic deformation modulus, thus providing strong anti-wrinkle capability. This reduces the risk of poor appearance of the film assembly and also ensures that the reflective layer in the gap film reflects light at a good angle, reducing ineffective reflection caused by incident light escaping back into the air after reflection.

[0056] In some embodiments, the thickness of the first base film is 20μm to 100μm, such as 20μm, 30μm, 60μm, 80μm, 90μm, 100μm, etc.

[0057] In some embodiments, the thickness of the second base film is 20μm to 100μm, such as 20μm, 30μm, 60μm, 80μm, 90μm, 100μm, etc.

[0058] In some embodiments, the thickness of the reinforcing layer is 5 μm to 15 μm. If the thickness of the reinforcing layer is too thick, the risk of battery fragmentation will increase; if the thickness of the reinforcing layer is too thin, it will not be able to provide an anti-wrinkle effect. Therefore, when the thickness of the reinforcing layer is within the aforementioned range, it helps to improve the anti-wrinkle ability of the gap membrane.

[0059] Optionally, the first base film and the second base film are independently selected from PET, PO or PI.

[0060] In some embodiments, the reinforcing layer includes composite fibers selected from glass fibers, carbon fibers, basalt fibers, or nylon fibers.

[0061] Furthermore, the diameter of the composite fiber is 2μm~13μm.

[0062] In some embodiments, the length of the composite fiber is not specifically limited and can be set according to actual production needs. Optionally, the length of the composite fiber is 500mm to 1500mm.

[0063] In some embodiments, during the formation of the reinforcing layer using composite fibers, the composite fibers are arranged transversely and / or longitudinally, and an adhesive is applied to the contact points of adjacent composite fibers and cured to form the reinforcing layer. The adhesive includes epoxy resin, phenolic resin, vinyl resin, etc.

[0064] In some embodiments, a method for preparing the gap membrane of this application is provided: S1. Provide a base film, which includes a first base film, a reinforcing layer and a second base film stacked together.

[0065] S2. Apply the weather-resistant layer material to the side of the first base film away from the reinforcing layer by coating, and form a weather-resistant layer after curing.

[0066] S3. The reflective layer material is applied to the side of the first base film away from the reinforcing layer by coating. The uncured adhesive layer is mechanically molded to give the adhesive layer a first protrusion structure. Then, after being bombarded by an electron beam, the free radicals in the adhesive layer are polymerized and quickly cured to obtain the reflective layer.

[0067] S4: A first adhesive layer is formed on the side of the reflective layer away from the base film by coating.

[0068] In other embodiments, a method for preparing the gap membrane of this application is provided: S1. Provide a base film, which includes a first base film, a reinforcing layer and a second base film stacked together.

[0069] S2. The weather-resistant layer material is applied to the side of the first base film away from the reinforcing layer by coating. The uncured adhesive layer is mechanically molded to give the adhesive layer a second raised structure. After curing, the weather-resistant layer is formed.

[0070] S3. The reflective layer material is applied to the side of the first base film away from the reinforcing layer by coating. The uncured adhesive layer is mechanically molded to give the adhesive layer a first protrusion structure. Then, after being bombarded by an electron beam, the free radicals in the adhesive layer are polymerized and quickly cured to obtain the reflective layer.

[0071] S4: A second adhesive layer is formed on the side of the weather-resistant layer away from the base film by coating.

[0072] A second aspect of the embodiments of this application provides a photovoltaic module comprising a front panel, a front encapsulant film, a battery layer, a back encapsulant film, and a rear panel stacked sequentially. The battery layer includes multiple battery cells. A gap film as described in the first aspect is provided between the battery layer and the back adhesive film, or a gap film as described in the first aspect is provided between the back adhesive film and the back panel, and the gap film corresponds to the gap between adjacent battery cells. The photovoltaic module of this application exhibits superior photoelectric performance and better reliability.

[0073] In some embodiments, reference Figure 10 The photovoltaic module includes a front panel 6, a front encapsulating film 7, a cell layer 10, a back encapsulating film 8, and a rear panel 9, stacked sequentially. The cell layer includes multiple solar cells 100. A gap film 11, as described in the first aspect, is disposed between the cell layer 10 and the back encapsulating film 8, and the gap film 11 corresponds to the gap between adjacent solar cells 100. The gap film is placed between adjacent solar cells in the cell layer, wherein a first adhesive layer of the gap film contacts the solar cells. The first adhesive layer, which has buffering and bonding functions, can improve the yield of the solar cell stacking.

[0074] In other embodiments, a gap film is provided between the back adhesive film and the back plate, and the second adhesive layer in the gap film can be attached to the back plate, thereby effectively preventing the back plate from shifting or misaligning during the lamination process.

[0075] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. It should be understood that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0076]

Example 1

[0077] The gap membrane is configured as follows: a first adhesive layer, a reflective layer, a first base film, a reinforcing layer, a second base film, and a weather-resistant layer are stacked in sequence, with the first adhesive layer in contact with the solar cell.

[0078] The first adhesive layer has a thickness of 50 μm. The first protrusion of the reflective layer is a serrated structure with a 120° apex angle and a height of 20 μm. The angle between the serrated structure's arrangement direction and the length direction of the base film is acute. Both the first and second base films have a thickness of 30 μm. The reinforcing layer has a thickness of 10 μm, and the composite fibers in the reinforcing layer are glass fibers with a diameter of 5 μm, arranged along the length direction of the first base film. The weather-resistant layer has a thickness of 10 μm.

[0079]

Examples 2 and 3

[0080]

Examples 4 and 5

[0081]

Example 6

[0082] The performance of the photovoltaic modules described above was tested, and the test results are shown in Table 1. The specific test methods and standards are as follows: (1) Optical Density (OD): Characterizes the light-blocking ability of a material. Optical density has no dimensionless unit and is a logarithmic value. Typically, the optical density value of aluminized film is 1~3 (i.e., the light transmittance is 10%~0.1%), and the higher the value, the thicker the aluminized layer. Optical density can be calculated using the following formula: OD=log(1 / trans), where trans represents the light transmittance, which can be measured with reference to ASTM D1003 "Test Method for Light Transmittance and Haze of Transparent Plastics".

[0083] (2) Reflectivity: Refer to CQC 3308-2013 "Technical Specification for Certification of Backsheet for Photovoltaic Module Encapsulation".

[0084] (3) Lamination reliability: The photovoltaic backsheet, multiple solar cells, encapsulating film and photovoltaic cover are assembled, and then... The photovoltaic module is obtained by lamination under a pressure of 0.1MPa~0.15MPa. The probability of microcracks in the solar cell is calculated based on the number of cells with microcracks in the photovoltaic module.

[0085] (4) The test method for bifaciality is as follows: test the power of the front side and the power of the back side of the module at the same time. Bifaciality = power of the back side of the module / power of the front side of the module * 100%, wherein the power of the front side and the power of the back side are tested using a Panson power tester.

[0086] Table 1

[0087] As shown in Table 1 above, the photovoltaic modules of Examples 1-6 have better performance than the photovoltaic module of Comparative Example 1, indicating that setting a reinforcement layer helps to improve the photoelectric performance of photovoltaic modules.

[0088] Comparing Example 1 with Examples 2-3, it can be seen that the angle setting of the reflective structure can effectively improve the photoelectric efficiency of photovoltaic modules.

[0089] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. The directional terms "inner" and "outer" refer to the inside or outside relative to the outline of the component itself. For example, if a device in the drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0090] It should also be noted that the terms "some embodiments," "other embodiments," and "embodiments" used in this application refer to specific features, structures, or characteristics described in connection with those embodiments, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0091] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0092] It should also be noted that the above are merely preferred embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A gap film, characterized in that, It includes a reflective layer, a base film, and a weather-resistant layer stacked together, wherein the base film includes a first base film, a reinforcing layer, and a second base film stacked together; The reflective layer has a plurality of oriented first protrusions, and the angle between the orientation of the first protrusions and the length direction of the base film is an acute angle. The weather-resistant layer has multiple oriented second protrusions, and the angle between the orientation of the second protrusions and the length direction of the base film is an acute angle.

2. The gap membrane according to claim 1, characterized in that, The first protrusion structure is a sawtooth structure, with an apex angle of 100°~150° and a height of 5μm~30μm.

3. The gap membrane according to claim 1, characterized in that, Also includes: A first adhesive layer is located on the side of the reflective layer away from the base film.

4. The gap membrane according to claim 3, characterized in that, Also includes: A second adhesive layer is located on the side of the weather-resistant layer away from the base film.

5. The gap membrane according to claim 1, characterized in that, The thickness of the first base film is 20μm~100μm; The thickness of the second base film is 20μm~100μm; The thickness of the reinforcing layer is 5μm to 15μm.

6. The gap membrane according to claim 1, characterized in that, The reinforcing layer includes composite fibers, which are selected from glass fibers, carbon fibers, basalt fibers or nylon fibers.

7. The gap membrane according to claim 6, characterized in that, The diameter of the composite fiber is 2μm~13μm; And / or, the length of the composite fiber is 50mm to 1500mm.

8. A photovoltaic module, characterized in that, It includes a front panel, a front adhesive film, a battery layer, a back adhesive film, and a rear panel, which are stacked in sequence. The battery layer includes multiple battery cells. A gap membrane as described in any one of claims 1-7 is provided between the battery layer and the back adhesive film, or a gap membrane as described in any one of claims 1-7 is provided between the back adhesive film and the back plate, and the gap membrane corresponds to the gap between adjacent battery cells.

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