Photovoltaic module

Abstract

The utility model relates to a photovoltaic module, which comprises a back plate, a cover plate, a plurality of battery pieces and a reflective film belt, and is characterized in that the cover plate is arranged on one side of the back plate along the thickness direction of the back plate; the plurality of battery pieces are arranged between the back plate and the cover plate, the plurality of battery pieces are arranged at intervals in the thickness direction perpendicular to the back plate, and a light-transmitting interval is formed between every two adjacent battery pieces. The reflective film belt is arranged on the back plate, is located between the back plate and the plurality of battery pieces and points to the direction of the plurality of battery pieces along the back plate, the reflective film belt comprises a bonding layer, a weather-proof layer, a base material layer and a reflective layer which are arranged in a laminated mode, and the orthographic projection of a part of the reflective layer on the back plate is located in the range of the orthographic projection of the light-transmitting interval on the back plate. The light irradiated to the light-transmitting interval is reflected to the battery piece through the reflective film belt, so that the light energy utilization rate is improved. And the weather-resistant layer of the reflective film tape can improve the weather resistance of the reflective film tape, reduce the risks of yellowing, pulverization, cracking and the like of the reflective film tape, and improve the durability of the photovoltaic module.

Description

Technical Field

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

[0002] As the efficiency of photovoltaic (PV) modules gradually improves, the power demand for individual PV modules has reached new heights. However, the power increase of PV modules themselves has reached a bottleneck, and improving the utilization rate of solar energy has become a new direction for development.

[0003] To address the gaps between adjacent solar cells in a photovoltaic module, reflective film strips can be placed at these gaps. The microstructure of the reflective film strips reflects light that has not yet reached the solar cells back onto them at a specific angle, thereby improving light energy utilization and increasing the module's power output.

[0004] However, the reflective film strips of photovoltaic modules in related technologies have poor durability and are prone to yellowing, powdering, and cracking. Utility Model Content

[0005] Therefore, it is necessary to provide a photovoltaic module that addresses the problem of poor durability of the reflective film strip in photovoltaic modules, which is prone to yellowing, powdering, and cracking.

[0006] According to one aspect of this application, a photovoltaic module is provided, the photovoltaic module comprising:

[0007] Back panel;

[0008] A cover plate is disposed on one side of the back plate along the thickness direction of the back plate;

[0009] Multiple solar cells are disposed between the back plate and the cover plate, and are spaced apart along a direction perpendicular to the thickness of the back plate, with a light-transmitting gap between adjacent solar cells; and

[0010] A reflective film strip is disposed on the back plate and located between the back plate and the plurality of battery cells; along the direction from the back plate to the plurality of battery cells, the reflective film strip includes an adhesive layer, a weather-resistant layer, a substrate layer and a reflective layer stacked together, and a portion of the reflective layer is projected onto the back plate within the range of the light-transmitting interval projected onto the back plate.

[0011] In one embodiment, the reflective film strip further includes a structural layer disposed between the substrate layer and the reflective layer.

[0012] In one embodiment, along the thickness direction of the back sheet, the size A of the structural layer satisfies: 7 micrometers ≤ A ≤ 29 micrometers, the thickness range B of the adhesive layer satisfies: 60 micrometers ≤ B ≤ 90 micrometers, and the thickness range C of the substrate layer satisfies: 5 micrometers ≤ C ≤ 42 micrometers.

[0013] In one embodiment, the weather-resistant layer is made of one of a mixture of polyethylene terephthalate, a mixture of fluorocarbon resin, and polyvinyl fluoride.

[0014] In one embodiment, the size H of the reflective film strip along the thickness direction of the backplate satisfies: 79 micrometers ≤ H ≤ 194 micrometers.

[0015] In one embodiment, along the thickness direction of the backing plate, the ratio of the size D of the weather-resistant layer to the size H of the reflective film strip satisfies: 5.2% ≤ D / H ≤ 37.5%.

[0016] In one embodiment, the size of the reflective film strip is larger than the size of the light-transmitting interval, in a direction pointing from one of the plurality of battery cells to another.

[0017] In one embodiment, the size D of the weather-resistant layer along the thickness direction of the backing plate satisfies: 7 micrometers ≤ D ≤ 33 micrometers.

[0018] In one embodiment, the reflective layer includes a plurality of microstructures connected sequentially along a first direction. The microstructures include a first reflective surface and a second reflective surface connected to each other along the first direction. Both the first reflective surface and the second reflective surface intersect the thickness direction of the back plate.

[0019] The first reflective surface and the second reflective surface of the same microstructure are arranged at a first preset angle to each other, and the first preset angle α satisfies: 110°≤α≤130°;

[0020] In two adjacent microstructures, the first reflective surface and the second reflective surface connected to each other are arranged at a second preset angle β, which satisfies: 110°≤β≤130°;

[0021] Wherein, the first direction intersects with the thickness direction of the back plate.

[0022] In one embodiment, the photovoltaic module further includes an adhesive film bonded between the solar cell and the reflective film strip.

[0023] The aforementioned photovoltaic module, by incorporating a reflective film strip, reflects light that shines onto the gaps between adjacent solar cells back onto the cells, improving light energy utilization. Furthermore, a weather-resistant layer is provided between the adhesive layer and the substrate layer of the reflective film strip. This weather-resistant layer enhances the reflective film strip's weather resistance and blocks at least part of the light from the back of the substrate layer, reducing the risk of yellowing, chalking, and cracking, thus improving the durability of the photovoltaic module. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a photovoltaic module in one embodiment of this application.

[0025] Figure 2 for Figure 1 A schematic diagram of the reflective film strip in the illustrated embodiment.

[0026] Explanation of icon numbers:

[0027] 10. Photovoltaic modules;

[0028] 100. Backplate; 200. Cover plate; 300. Battery cells;

[0029] 400. Reflective film strip; 410. Reflective layer; 420. Substrate layer; 430. Adhesive layer; 440. Weather-resistant layer; 450. Structural layer. Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are 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 of this application.

[0032] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] 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 based on the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0036] In the field of photovoltaic module encapsulation, reflective film strips are typically placed between adjacent solar cells. By applying reflective film strips to the gaps between the cells, sunlight hitting the gaps can be reflected back to the solar cells, thereby achieving secondary utilization of light energy and improving the power generation efficiency of the module.

[0037] Reflective film strips in related technologies often yellow, chalk, and crack after aging. This is usually mitigated by adding an additional metal layer, but metal is expensive and its effectiveness is unsatisfactory. Therefore, they still suffer from poor durability and are prone to yellowing, chalking, and cracking.

[0038] Based on this, this application provides a photovoltaic module whose reflective film has better durability, reducing the risk of problems such as yellowing, powdering and cracking of the photovoltaic module, and helping to improve the service life of the photovoltaic module.

[0039] See Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the structure of a photovoltaic module 10 in one embodiment of this application. Figure 2 for Figure 1 A schematic diagram of the structure of the reflective film strip 400 in the embodiment shown.

[0040] The photovoltaic module 10 provided in this application includes a backsheet 100, a cover plate 200, a plurality of solar cells 300, and a reflective film strip 400. The cover plate 200 is disposed on one side of the backsheet 100 along its thickness direction. The plurality of solar cells 300 are disposed between the backsheet 100 and the cover plate 200, and are spaced apart along a direction perpendicular to the thickness of the backsheet 100, with a light-transmitting gap between adjacent solar cells 300. Thus, light passes through the cover plate 200 and illuminates the solar cells 300 of the photovoltaic module 10, and is converted into electrical energy by the solar cells 300. The cover plate 200 and the backsheet 100 provide protection for the solar cells 300.

[0041] A reflective film strip 400 is disposed on the backsheet 100 and located between the backsheet 100 and the plurality of solar cells 300. Along the direction from the backsheet 100 to the plurality of solar cells 300, the reflective film strip 400 includes a laminated adhesive layer 430, a weather-resistant layer 440, a substrate layer 420, and a reflective layer 410. A portion of the reflective layer 410's orthogonal projection onto the backsheet 100 lies within the range of the orthogonal projection of the light-transmitting interval onto the backsheet 100. That is, the reflective film strip 400 is disposed between the layer containing the backsheet 100 and the layer containing the solar cells 300, and the reflective film strip 400 is located opposite the light-transmitting interval. It can be understood that, in addition to some of the light incident on the photovoltaic module 10 being directly utilized by the solar cells 300, some light also enters the light-transmitting interval. The light entering the light-transmitting interval is reflected back to the solar cells 300 by the reflective film strip 400, achieving secondary utilization of light energy.

[0042] The substrate layer 420 serves as a base to support the reflective layer 410, the weather-resistant layer 440, and the adhesive layer 430. The reflective layer 410 reflects light to the surface of the solar cell 300. The adhesive layer 430 is located on the side of the substrate layer 420 opposite to the reflective layer 410 and is used to bond the substrate layer 420 to the back sheet 100, thereby bonding the reflective film strip 400 to the back sheet 100.

[0043] A weather-resistant layer 440 is disposed between the substrate layer 420 and the reflective layer 410, capable of blocking at least part of the light entering the substrate layer 420 from the back side of the substrate layer 420, or from the side of the substrate layer 420 away from the reflective layer 410. Light entering from the front side of the substrate layer 420, or from the side of the substrate layer 420 closer to the reflective layer 410, is reflected by the reflective layer 410. This significantly reduces the amount of light hitting the substrate layer 420, lowering the risk of the substrate layer 420 aging easily due to prolonged exposure to light, leading to yellowing, powdering, and cracking. The light incident on the photovoltaic module 10 in this application can be sunlight containing ultraviolet light.

[0044] The photovoltaic module 10 of this application incorporates a reflective film strip 400, which reflects light that has reached the light-transmitting gap between adjacent solar cells 300 back onto the cells 300, thus achieving secondary utilization of light energy and improving light energy utilization efficiency. Furthermore, a weather-resistant layer 440 is provided between the adhesive layer 430 and the substrate layer 420 of the reflective film strip 400. This weather-resistant layer 440 enhances the weather resistance of the reflective film strip 400 and blocks at least part of the light from the back of the substrate layer 420, reducing the risk of yellowing, powdering, and cracking of the substrate layer 420, thereby improving the durability of the photovoltaic module 10. Therefore, the photovoltaic module 10 of this application solves the problems of yellowing, powdering, and cracking of the substrate layer 420 of the reflective film strip 400 without affecting the refractive index of the reflective film strip 400 and thus the luminous power of the photovoltaic module 10.

[0045] In some embodiments, such as Figure 1 and Figure 2As shown, the reflective film strip 400 also includes a structural layer 450, which is disposed between the substrate layer 420 and the reflective layer 410, and serves to support the reflective layer 410. The reflective layer 410 can be formed by depositing a metal film on the structural layer 450, which simplifies the fabrication process of the reflective layer 410. Alternatively, a metal layer can be deposited on the structural layer 450 to form the reflective layer 410, thereby supporting the reflective layer 410 through the structural layer 450, improving its structural strength, and consequently enhancing the stability and efficiency of light reflection, thus improving the reflectivity of the reflective film strip 400 and ultimately increasing the power generation efficiency of the photovoltaic module 10.

[0046] In some embodiments, see Figure 1 and Figure 2 The reflective layer 410 includes a plurality of microstructures sequentially connected along a first direction. Each microstructure includes a first reflective surface and a second reflective surface connected to each other along the first direction. Both the first and second reflective surfaces intersect the thickness direction of the backplate 100, wherein the first direction intersects the thickness direction of the backplate 100. For example... Figure 1 and Figure 2 As shown, the cross-section of the microstructure is triangular. The arrangement of multiple microstructures can disperse the reflected light, further expand the reflection range, further improve the reflection efficiency, and thus help increase the light received by the solar cell 300, thereby improving the power generation efficiency of the photovoltaic module 10.

[0047] In this embodiment, the first reflective surface and the second reflective surface of the same microstructure are arranged at a first preset angle to each other, where the first preset angle α satisfies: 110°≤α≤130°. Thus, the first reflective surface and the second reflective surface of the microstructure have a suitable angle, which is beneficial to improving the reflectivity of the reflective layer 410.

[0048] In this embodiment, in two adjacent microstructures, the first and second reflective surfaces connected to each other are arranged at a second preset angle β, which satisfies: 110°≤β≤130°. Alternatively, the first reflective surface of one of the two adjacent microstructures and the second reflective surface of the other adjacent microstructure form a second preset angle. Thus, the two adjacent microstructures have a better range of angles, which is beneficial for the structural design of the entire reflective layer 410, improves the reflectivity of the reflective layer 410, and consequently improves the power generation efficiency of the photovoltaic module 10.

[0049] In this embodiment, the cross-section of the microstructure can also be other shapes, such as arcs or trapezoids. The design can be tailored to specific needs, and no further restrictions are imposed here.

[0050] In some embodiments, see Figure 1 and Figure 2 As shown, along the thickness direction of the backplate 100, the dimension A of the structural layer 450 satisfies: 7 micrometers ≤ A ≤ 29 micrometers. Wherein, as... Figure 1 Because the microstructure of structural layer 450 varies in size along the thickness direction of backplate 100, it needs to be clarified that the size of structural layer 450 along the thickness direction of backplate 100 refers to the distance between the highest and lowest points of structural layer 450 along the thickness direction of backplate 100. The thickness range B of adhesive layer 430 satisfies: 60 micrometers ≤ B ≤ 90 micrometers, and the thickness range C of substrate layer 420 satisfies: 5 micrometers ≤ C ≤ 42 micrometers.

[0051] Thus, the structural layer 450, adhesive layer 430 and substrate layer 420 of the reflective film strip 400 of this application all have suitable thickness ranges. While the reflective film strip 400 achieves the effect of reflecting light, it is also conducive to saving costs, making the reflective film strip 400 thinner and lighter, and improving the miniaturization design of the photovoltaic module 10.

[0052] In some embodiments, such as Figure 1 As shown, along the thickness direction of the backing plate 100, the dimension D of the weathering layer 440 satisfies: 7 micrometers ≤ D ≤ 33 micrometers. Thus, the weathering layer 440 is within a suitable thickness range, which protects the substrate layer 420, significantly reducing the risk of yellowing and ensuring that the yellowing value of the substrate layer 420 is within a specified range (i.e., protecting it to a yellowing value less than 2). Furthermore, it significantly reduces the risk of powdering and cracking of the substrate layer 420.

[0053] In this embodiment, the weather-resistant layer 440 can be made of polyvinyl fluoride (T film), polyethylene terephthalate mixture (PET mixture), or fluorocarbon resin mixture. When the weather-resistant layer 440 is made of polyvinyl fluoride, the dimension D of the weather-resistant layer 440 along the thickness direction of the backing plate 100 satisfies: 15 micrometers ≤ D ≤ 25 micrometers. When the weather-resistant layer 440 is made of polyethylene terephthalate mixture, the dimension D of the weather-resistant layer 440 along the thickness direction of the backing plate 100 satisfies: 7 micrometers ≤ D ≤ 33 micrometers. When the weather-resistant layer 440 is made of fluorocarbon resin mixture, the dimension D of the weather-resistant layer 440 along the thickness direction of the backing plate 100 satisfies: 7 micrometers ≤ D ≤ 20 micrometers.

[0054] The dimension D of the weather-resistant layer 440 along the thickness direction of the back plate 100 can be flexibly adjusted according to the different materials of the weather-resistant layer 440, so that the weather-resistant layer 440 can have a suitable material and a suitable thickness while protecting the substrate layer 420, which is conducive to saving costs and improving the thinness of the reflective film strip 400.

[0055] In some embodiments, the weathering layer 440 is made of one of a polyethylene terephthalate mixture, a fluorocarbon resin mixture, and polyvinyl fluoride.

[0056] The polyethylene terephthalate mixture includes polyethylene terephthalate and a first auxiliary agent. The first auxiliary agent includes one or more of titanium dioxide, montmorillonite, zinc oxide, alumina, silica, organic ultraviolet filters, and processing aids, including dispersants, leveling agents, and defoamers.

[0057] The polyethylene terephthalate (PET) blend exhibits high crystallinity and a smooth surface, which is beneficial for improving the adhesive strength of the weather-resistant layer 440. Furthermore, the PET blend possesses excellent heat resistance, mechanical properties, dimensional stability, and electrical insulation, further enhancing the strength of the weather-resistant layer 440 and giving it superior structural stability, enabling it to withstand harsh environments such as high temperatures and high frequencies.

[0058] In this application, the weather-resistant layer 440 can be made of a white polyethylene terephthalate mixture. The white polyethylene terephthalate mixture is beneficial for improving the absorption capacity of ultraviolet rays, while also having a high reflectivity for visible light. This further reduces the amount of light shining into the substrate layer 420 from the side facing away from the reflective layer 410, and further reduces the risk of the substrate layer 420 of the reflective film strip 400 easily yellowing, chalking, and cracking, thereby improving the durability of the photovoltaic module 10.

[0059] The fluorocarbon resin mixture includes acrylic resin, fluorinated resin, and a second auxiliary agent. The second auxiliary agent includes one or more of the following: polyester resin, epoxy resin, silica, mica powder, wollastonite, calcium carbonate, diatomaceous earth, matting agent, and processing aids, including dispersants, leveling agents, and defoamers.

[0060] Fluorocarbon resin blends exhibit excellent weather resistance, chemical resistance, and solvent resistance, and their low surface energy provides good stain resistance and UV resistance. Using this material enhances the UV resistance of the weather-resistant layer 440, resulting in better weather resistance. This further reduces the amount of light irradiating the substrate layer 420 from the side facing away from the reflective layer 410, thereby reducing the risk of yellowing, chalking, and cracking of the substrate layer 420 of the reflective film strip 400.

[0061] In this embodiment, if the weather-resistant layer 440 is made of polyethylene terephthalate (PET) mixture, the weather-resistant layer 440 and the substrate layer 420 can be co-extruded in one step to simultaneously form the weather-resistant layer 440 and the substrate layer 420. If the weather-resistant layer 440 is made of fluorocarbon resin mixture, the weather-resistant layer 440 and the substrate layer 420 can be bonded together using a coating process, i.e., the substrate layer 420 is formed first, and then the weather-resistant layer 440 is coated onto the substrate layer 420. If the weather-resistant layer 440 is made of polyvinyl fluoride (PVC), the weather-resistant layer 440 and the substrate layer 420 can be bonded together using adhesive, and a composite process is used to bond the weather-resistant layer 440 and the substrate layer 420. Thus, depending on the materials of the weather-resistant layer 440 and the substrate layer 420, the forming and bonding methods of the substrate layer 420 and the weather-resistant layer 440 can be flexibly selected, meaning that the preparation method of the reflective film strip 400 of this application has excellent flexibility.

[0062] In this embodiment, the weather-resistant layer 440 may also include two or three of the following materials: a polyethylene terephthalate mixture, a fluorocarbon resin mixture, and polyvinyl fluoride. Specifically, the weather-resistant layer 440 can be designed to include a polyethylene terephthalate mixture and fluorocarbon resin, or it can be designed to include a polyethylene terephthalate mixture and polyvinyl fluoride, or it can be designed to include fluorocarbon resin and polyvinyl fluoride, or it can be designed to include a mixture of polyethylene terephthalate, fluorocarbon resin, and polyvinyl fluoride. Thus, a suitable weather-resistant layer 440 can be designed according to actual needs, so that the weather-resistant layer 440 can effectively block at least part of the light from the back of the substrate layer 420, reducing the risk of yellowing, chalking, and cracking of the substrate layer 420 of the reflective film strip 400, thereby improving the durability of the photovoltaic module 10.

[0063] In some embodiments, the substrate layer 420 may be made of a white polyethylene terephthalate mixture. The polyethylene terephthalate mixture includes polyethylene terephthalate and a first auxiliary agent. The first auxiliary agent includes one or more of titanium dioxide, montmorillonite, zinc oxide, alumina, silica, organic ultraviolet filters, and processing aids, including dispersants, leveling agents, and defoamers.

[0064] The white polyethylene terephthalate mixture has a high reflectivity to visible light, which helps to improve the reflection of light incident on the substrate layer 420 through the reflective layer 410. The reflected light can pass through the reflective layer 410 and be rerefracted onto the surface of the solar cell 300, where it can be used by the solar cell 300 to convert into electrical energy. Therefore, using white polyethylene terephthalate mixture material for the substrate layer 420 helps to improve the light utilization rate of the photovoltaic module 10 and increase the power of the photovoltaic module 10.

[0065] In some embodiments, along the thickness direction of the backplate 100, the dimension H of the reflective film strip 400 satisfies: 79 micrometers ≤ H ≤ 194 micrometers. For example... Figure 1 The dimension of the reflective film strip 400 along the thickness direction of the backsheet 100 refers to the distance from the highest point to the lowest point of the reflective film strip 400 along the thickness direction of the backsheet 100. The reflective film strip 400 has an optimal thickness range, enabling it to efficiently reflect light and improve the light utilization rate of the photovoltaic module 10.

[0066] In some embodiments, along the thickness direction of the back panel 100, the ratio of the dimension D of the weather-resistant layer 440 to the dimension H of the reflective film strip 400 satisfies: 5.2% ≤ D / H ≤ 37.5%. The weather-resistant layer 440 and the reflective film strip 400 meet the above requirements, thus improving the light reflection effect of the reflective film strip 400 while also satisfying the weather resistance requirements of the reflective film strip 400.

[0067] In some embodiments, the size of the reflective film strip 400 is larger than the size of the light-transmitting gap in a direction pointing from one of the plurality of solar cells 300 to another. Thus, light incident on the light-transmitting gap is difficult to pass between the reflective film strip 400 and the solar cell 300; that is, light incident on the light-transmitting gap can largely enter the reflective film strip 400, and is reflected by the reflective film strip 400 and propagated back to the solar cell 300, achieving secondary utilization of the light. Therefore, the above arrangement can significantly improve the light utilization rate of the photovoltaic module 10.

[0068] In some embodiments, the photovoltaic module 10 further includes an encapsulating film bonded between the solar cell 300 and the reflective film strip 400. This encapsulating film improves the connection stability between the solar cell 300 and the reflective film strip 400, thereby enhancing the structural stability of the photovoltaic module 10. Simultaneously, the encapsulating film isolates external moisture, protects the solar cell 300, and improves the light transmittance and mechanical stability of the photovoltaic module 10.

[0069] In this embodiment, the adhesive film can also be placed on the side of the solar cell 300 away from the reflective film strip 400, or the adhesive film can be placed on both sides of the solar cell 300. This allows the adhesive film position to be designed according to actual needs, improving the design flexibility of the photovoltaic module 10, and also helping to balance costs and improve the mechanical stability of the photovoltaic module 10.

[0070] The above embodiments do not limit the type of battery cell 300 and can be applied to various battery cell 300 designs. This application can select P-type or N-type batteries according to different needs, and apply the design of the reflective film strip 400 of the above embodiments to the selected different types of battery cells 300.

[0071] The types of solar cells 300 include, but are not limited to, tunnel oxide passivated contact (TOPCon), intrinsic thin-film heterojunction (HJT), back contact (BC), and perovskite solar cells.

[0072] 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.

[0073] 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.

[0074] For BC (Browser-Contact) cells, the absence of grid lines on the front side results in a more aesthetically pleasing appearance and advantages such as high conversion efficiency, low degradation, and a good temperature coefficient. Along the thickness direction of the BC cell, it sequentially comprises 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. Using ion implantation technology, BC cells can achieve uniform P- and N-regions with precise and controllable junction depth. The absence of grid lines on the front side eliminates light-shielding 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 the 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 allows for lower front surface recombination rates and surface reflection.

[0075] The reflective film strip 400 in the above embodiments of this application can be applied to TOPCon cells, HJT cells, and BC cells. When applied to TOPCon cells, it combines the advantages of TOPCon cells, such as high photoelectric conversion efficiency, low light-induced degradation, good temperature coefficient, and low degradation rate. When applied to HJT cells, it enables the cells to possess advantages such as high conversion efficiency, low temperature coefficient, excellent low-light response, and no light-induced degradation. When applied to BC cells, it facilitates an unobstructed design of the front side of the cell 300, improving the photoelectric conversion efficiency of the cell 300, while further enhancing the light utilization rate of the photovoltaic module 10 through the reflective film strip 400, thereby improving the efficiency of the photovoltaic module 10.

[0076] The photovoltaic module 10 of this application improves light energy utilization by providing a reflective film strip 400, which reflects light that shines on the gap between adjacent solar cells 300 and then propagates it onto the solar cells 300. Furthermore, a weather-resistant layer 440 is provided between the adhesive layer 430 and the substrate layer 420 of the reflective film strip 400. The weather-resistant layer 440 improves the weather resistance of the reflective film strip 400 and blocks at least part of the light from the back of the substrate layer 420, reducing the risk of yellowing, powdering, and cracking of the reflective film strip 400, thus improving the durability of the photovoltaic module 10.

[0077] 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.

[0078] 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 patent application. 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, The photovoltaic module includes: Back panel; A cover plate is disposed on one side of the back plate along the thickness direction of the back plate; Multiple solar cells are disposed between the back plate and the cover plate, and are spaced apart along a direction perpendicular to the thickness of the back plate, with a light-transmitting gap between adjacent solar cells; and A reflective film strip is disposed on the back plate and located between the back plate and the plurality of battery cells; along the direction from the back plate to the plurality of battery cells, the reflective film strip includes an adhesive layer, a weather-resistant layer, a substrate layer and a reflective layer stacked together, and a portion of the reflective layer is projected onto the back plate within the range of the light-transmitting interval projected onto the back plate.

2. The photovoltaic module according to claim 1, characterized in that, The reflective film strip also includes a structural layer, which is disposed between the substrate layer and the reflective layer.

3. The photovoltaic module according to claim 2, characterized in that, Along the thickness direction of the back sheet, the size A of the structural layer satisfies: 7 micrometers ≤ A ≤ 29 micrometers, the thickness range B of the adhesive layer satisfies: 60 micrometers ≤ B ≤ 90 micrometers, and the thickness range C of the substrate layer satisfies: 5 micrometers ≤ C ≤ 42 micrometers.

4. The photovoltaic module according to claim 1, characterized in that, The weather-resistant layer is made of one of the following materials: a mixture of polyethylene terephthalate, a mixture of fluorocarbon resin, and polyvinyl fluoride.

5. The photovoltaic module according to claim 1, characterized in that, Along the thickness direction of the backplate, the dimension H of the reflective film strip satisfies: 79 micrometers ≤ H ≤ 194 micrometers.

6. The photovoltaic module according to claim 1, characterized in that, Along the thickness direction of the backing plate, the ratio of the dimension D of the weather-resistant layer to the dimension H of the reflective film strip satisfies: 5.2% ≤ D / H ≤ 37.5%.

7. The photovoltaic module according to claim 1, characterized in that, The reflective film strip is larger than the light-transmitting interval in a direction pointing from one of the plurality of solar cells to another.

8. The photovoltaic module according to claim 1, characterized in that, Along the thickness direction of the backing plate, the dimension D of the weather-resistant layer satisfies: 7 micrometers ≤ D ≤ 33 micrometers.

9. The photovoltaic module according to claim 1, characterized in that, The reflective layer includes a plurality of microstructures connected in sequence along a first direction. Each microstructure includes a first reflective surface and a second reflective surface connected to each other along the first direction. Both the first reflective surface and the second reflective surface intersect the thickness direction of the back plate. The first reflective surface and the second reflective surface of the same microstructure are arranged at a first preset angle to each other, and the first preset angle α satisfies: 110°≤α≤130°; In two adjacent microstructures, the first reflective surface and the second reflective surface connected to each other are arranged at a second preset angle β, which satisfies: 110°≤β≤130°; Wherein, the first direction intersects with the thickness direction of the back plate.

10. The photovoltaic module according to claim 9, characterized in that, The photovoltaic module also includes an adhesive film, which is bonded between the solar cell and the reflective film strip.

Images