Transparent film tape, photovoltaic module and photovoltaic module packaging method

Abstract

The invention relates to a transparent film tape, a photovoltaic module and a photovoltaic module packaging method.The transparent film tape comprises a first light-transmitting layer, a second light-transmitting layer and a light-reflecting microstructure layer, the second light-transmitting layer and the first light-transmitting layer are arranged at an interval in the thickness direction, the second light-transmitting layer is used for being connected with the back face of a cover plate of the photovoltaic module, and the light-reflecting microstructure layer is used for being connected with the back face of the cover plate. The reflective microstructure layer is stacked between the first light-transmitting layer and the second light-transmitting layer, a cavity is formed between the reflective microstructure layer and the first light-transmitting layer, and the reflective microstructure layer is configured to be capable of totally reflecting part of light penetrating through the second light-transmitting layer at an interface between the reflective microstructure layer and the cavity; according to the transparent film tape, the photovoltaic module and the photovoltaic module packaging method, the light utilization rate of the photovoltaic module can be improved.

Description

Technical Field

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

[0002] Photovoltaic modules are the core component of a solar power generation system, converting solar energy into electrical energy. To prevent leakage tracking or arcing caused by photovoltaic modules under operating voltage, safe creepage distances need to be designed around the photovoltaic modules. Creepage distance refers to the shortest insulation distance between conductive components (such as busbars or solar cells) on the edge of the module and the frame or external interface.

[0003] In related technologies, encapsulating adhesive is usually filled or applied around the photovoltaic module to meet the safety creepage distance requirements.

[0004] However, when photovoltaic modules are put into use, the area corresponding to the encapsulating adhesive occupies the area of ​​the photovoltaic module that receives sunlight, and the photovoltaic module cannot utilize the light incident on the encapsulating adhesive, resulting in a low light utilization rate of the photovoltaic module. Summary of the Invention

[0005] Based on this, this application provides a transparent film strip, a photovoltaic module, and a photovoltaic module encapsulation method to solve the technical problem of how to improve the light utilization rate of photovoltaic modules.

[0006] On one hand, this application provides a transparent film strip, comprising:

[0007] First light-transmitting layer;

[0008] The second light-transmitting layer and the first light-transmitting layer are spaced apart along the thickness direction. The second light-transmitting layer is used to connect with the back of the cover plate of the photovoltaic module.

[0009] A reflective microstructure layer is stacked between the first light-transmitting layer and the second light-transmitting layer, and a cavity is formed between the reflective microstructure layer and the first light-transmitting layer. The reflective microstructure layer is configured to cause total internal reflection of a portion of the light transmitted through the second light-transmitting layer at the interface between the reflective microstructure layer and the cavity.

[0010] In one embodiment, the reflective microstructure layer includes a plurality of serrated reflective elements, which are arranged along a first direction, and the length direction of each serrated reflective element is parallel to a second direction, the first direction intersecting the second direction; the tooth peaks of the serrated reflective elements abut against the first light-transmitting layer, such that a cavity is formed between any two adjacent serrated reflective elements, and the refractive index of the material of the serrated reflective elements is greater than the refractive index of the medium in the cavity; wherein, the plurality of serrated reflective elements are spaced apart from each other, or the plurality of serrated reflective elements abut against each other.

[0011] In one embodiment, the first direction and the second direction are perpendicular to each other, and the cross-section of the serrated reflector is triangular or trapezoidal.

[0012] In one embodiment, the serrated reflector has a bottom surface, a first inclined surface, and a second inclined surface. The bottom surface abuts against the second light-transmitting layer. The first inclined surface and the second inclined surface are both inclined relative to the bottom surface and are set at an acute angle. The edges of the first inclined surface and the second inclined surface away from the bottom surface are connected to form the tooth peaks. The first inclined surface is configured to totally reflect light perpendicularly incident on the bottom surface to the cover plate.

[0013] In one embodiment, the angle between the first inclined plane and the second inclined plane ranges from 5° to 60°.

[0014] In one embodiment, the transparent film strip further includes an anti-UV coating disposed on the side of the second light-transmitting layer opposite to the reflective microstructure layer.

[0015] In one embodiment, the transparent film strip further includes at least one of the following technical solutions:

[0016] At least one of the first light-transmitting layer and the second light-transmitting layer is a PET film; the thickness of at least one of the first light-transmitting layer and the second light-transmitting layer is 20um-30um; the material of the reflective microstructure layer is acrylic resin; the thickness of the reflective microstructure layer is 40um-60um.

[0017] On the other hand, this application provides a photovoltaic module including the transparent film strip as described above. The photovoltaic module also includes a cover plate, a back plate, and a plurality of solar cells arranged in an array between the cover plate and the back plate. The transparent film strip is provided around the cover plate. The transparent film strip is configured to reflect a portion of the light irradiated on the transparent film strip through the cover plate to the front of the solar cells.

[0018] In one embodiment, the transparent film strip further includes a transparent adhesive film layer disposed on the side of the second light-transmitting layer opposite to the first light-transmitting layer, and the transparent adhesive film layer is used to bond the second light-transmitting layer to the back of the cover plate.

[0019] In one embodiment, the edge of the cover plate has an embossed surface, and the transparent film strip on the cover plate is attached to the embossed surface.

[0020] In one embodiment, the photovoltaic module further includes busbars, with the transparent film strip disposed on a portion of the busbars.

[0021] Furthermore, this application provides a photovoltaic module encapsulation method, comprising the following steps:

[0022] Provide the transparent film strip as described above;

[0023] The transparent film strip is laid on the edge of the cover plate, such that the second light-transmitting layer of the transparent film strip is connected to the back of the cover plate;

[0024] One side of the solar cell is connected to the back of the cover plate, such that the edge of the transparent film strip is in contact with the edge of the solar cell, and the transparent film strip can reflect a portion of the light incident on the transparent film strip through the cover plate to the front of the solar cell of the photovoltaic module.

[0025] The aforementioned transparent film strip, photovoltaic module, and photovoltaic module encapsulation method include a reflective microstructure layer stacked between a first light-transmitting layer and a second light-transmitting layer. A cavity is formed between the reflective microstructure layer and the first light-transmitting layer. The reflective microstructure layer is configured to cause total internal reflection of some of the light transmitted through the second light-transmitting layer at the interface between the reflective microstructure layer and the cavity, and then reflect it through a cover plate to the front of the solar cells of the photovoltaic module, thereby improving the light utilization rate of the photovoltaic module. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a top view schematic diagram of a partial structure of a photovoltaic module according to one embodiment of this application.

[0028] Figure 2 A photovoltaic module according to one embodiment of this application Figure 2A schematic diagram of the cross-sectional structure of line II in the diagram.

[0029] Figure 3 This is a schematic diagram of the structure of the transparent film strip of a photovoltaic module according to an embodiment of this application. The diagram shows multiple serrated reflective elements abutting each other, and the cross-section of the serrated reflective elements is triangular.

[0030] Figure 4 This is a schematic diagram of the optical path of a photovoltaic module according to one embodiment of this application.

[0031] Figure 5 This is a schematic diagram of the structure of a transparent film strip of a photovoltaic module according to another embodiment of this application. The diagram shows multiple serrated reflective elements spaced apart from each other.

[0032] Figure 6 This is a schematic diagram of the structure of the transparent film strip of a photovoltaic module according to another embodiment of this application. The diagram shows that the cross-section of the serrated reflector is trapezoidal.

[0033] Explanation of reference numerals in the attached figures:

[0034] 10. Transparent film strip; 11. First light-transmitting layer; 12. Second light-transmitting layer; 13. Reflective microstructure layer; 131. Serrated reflector; 1311. Bottom surface; 1312. First inclined surface; 1313. Second inclined surface; 132. Cavity; 14. Anti-UV coating; 15. Transparent adhesive film layer; 20. Cover plate; 30. Back plate; 40. Battery cell; 50. Busbar; 60. First encapsulation film; 70. Second encapsulation film. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Combination Figure 1 and Figure 2 As shown, one embodiment of this application provides a photovoltaic module, including a transparent film strip 10, a cover plate 20, a back sheet 30, and a plurality of solar cells 40, which are connected between the cover plate 20 and the back sheet 30. The cover plate 20 and the back sheet 30 can be made of glass. For example, when the cover plate 20 is made of glass, it can also be called the "front glass," i.e., the glass located on the front side of the solar cell 40; when the back sheet 30 is made of glass, it can also be called the "back glass," i.e., the glass located on the back side of the solar cell 40. The front side of the solar cell 40 refers to the side facing away from the ground, and correspondingly, the back side of the solar cell 40 refers to the side facing the ground. It should be noted that, in addition to glass, the cover plate 20 and the back sheet 30 can also be made of materials such as silicone polyester resin or polycarbonate.

[0042] Combination Figure 3 and Figure 4 As shown, the transparent film strip 10 includes a first light-transmitting layer 11, a second light-transmitting layer 12, and a reflective microstructure layer 13.

[0043] The first light-transmitting layer 11 and the second light-transmitting layer 12 are spaced apart along the thickness direction. That is, the first light-transmitting layer 11 and the second light-transmitting layer 12 are opposite to each other and spaced apart in the thickness direction. This allows the first light-transmitting layer 11 and the second light-transmitting layer 12 to provide encapsulation space for the reflective microstructure layer 13, thus improving the stability of the reflective microstructure layer 13. The second light-transmitting layer 12 is used to connect to the back side of the cover plate 20 of the photovoltaic module. With this arrangement, when the solar cell 40 is covered on the back side of the cover plate 20, the light passing through the cover plate 20 will pass through the second light-transmitting layer 12 and enter the reflective microstructure layer 13.

[0044] A reflective microstructure layer 13 is stacked between the first light-transmitting layer 11 and the second light-transmitting layer 12. A cavity 132 is formed between the reflective microstructure layer 13 and the first light-transmitting layer 11. The reflective microstructure layer 13 is configured to cause total internal reflection of some of the light transmitted through the second light-transmitting layer 12 at the interface between the reflective microstructure layer 13 and the cavity 132. In this way, the light that would otherwise not be incident on the front side of the solar cell 40 can be reflected to the front side of the solar cell 40 via the cover plate 20 by utilizing the reflective effect of the transparent film strip 10. Furthermore, the light undergoes total internal reflection at the interface between the reflective microstructure layer 13 and the cavity 132, thereby improving the light utilization efficiency of the photovoltaic module and thus increasing the front power of the solar cell 40.

[0045] It should be noted that since the refractive index of the cover plate 20 is greater than that of air, the light reflected by the reflective microstructure layer 13 enters the cover plate 20 and then enters the air. The light follows the pattern of light moving from an optically denser medium to an optically less dense medium. Therefore, as long as the incident angle of the light at the interface between the front of the cover plate 20 and the air is greater than the total internal reflection angle, the light will undergo total internal reflection at the interface between the front of the cover plate 20 and the air. This increases the amount of light reflected by the cover plate 20 to the solar cell 40, thereby allowing the solar cell 40 to utilize the light illuminating the transparent film strip 10, thus improving the light utilization rate.

[0046] In this embodiment, a transparent film strip 10 is provided around the perimeter of the cover plate 20, thereby utilizing the insulating properties of the transparent film strip 10 to ensure a safe creepage distance around the photovoltaic module. Furthermore, with this structural arrangement, the transparent film strip 10 surrounds the photovoltaic module, resulting in no light leakage from the photovoltaic module's appearance. Therefore, this embodiment not only improves the front-side power of the solar cell 40 but also enhances the aesthetic appearance while ensuring a safe creepage distance.

[0047] Multiple solar cells 40 are arranged in an array. For example, in some embodiments, the array arrangement of the solar cells 40 includes, but is not limited to, 3 rows * 3 columns, 3 rows * 4 columns, 4 rows * 4 columns, 4 rows * 5 columns, 4 rows * 6 columns, or 5 rows * 10 columns.

[0048] Furthermore, the reflective microstructure layer 13 includes a plurality of serrated reflective elements 131, which are arranged along a first direction, and the length direction of each serrated reflective element 131 is parallel to the second direction.

[0049] The first direction intersects with the second direction, meaning that the arrangement direction of the multiple serrated reflectors 131 is different from their own length direction.

[0050] The serrated reflector 131 has its serrations abutting against the first light-transmitting layer 11, creating a cavity 132 between any two adjacent serrated reflectors 131. The refractive index of the material of the serrated reflector 131 is greater than the refractive index of the medium within the cavity 132. When light incident from the second light-transmitting layer 12 strikes the serrated reflector 131, the serrated reflector 131 totally reflects a portion of the light back to the cover plate 20, causing the cover plate 20 to reflect a portion of the light back to the front of the solar cell 40. This structural arrangement allows the front of the solar cell 40 to utilize the light illuminating the transparent film strip 10, thereby improving light utilization.

[0051] It should be noted that the first direction and the second direction are perpendicular to each other. With this structural arrangement, the light incident on the serrated reflector 131 can be emitted to the cover plate 20 as perpendicular as possible to the second direction (i.e., the length direction of the serrated reflector 131).

[0052] Combination Figure 3 As shown, multiple serrated reflectors 131 can offset each other, thereby increasing the arrangement density of the serrated reflectors 131 and increasing the utilization rate of light. Combined with... Figure 5 As shown, in some embodiments, the multiple sawtooth reflectors 131 can also be arranged at intervals, thus reducing the material consumption required for setting the sawtooth reflectors 131. Of course, in this embodiment, the sawtooth reflectors 131 can still improve the light utilization rate of the photovoltaic module by performing total internal reflection on part of the light irradiated at the interface between the reflective microstructure layer 13 and the cavity 132, so that the light is incident on the front side of the solar cell 40.

[0053] In some implementations, such as Figure 3 and Figure 5 As shown, the cross-section of the serrated reflector 131 is triangular. It should be noted that, in conjunction with... Figure 6 As shown, in some embodiments, the cross-section of the serrated reflector 131 may also be trapezoidal. The shape of the cross-section of the serrated reflector 131 is not limited here, as long as the serrated reflector 131 reflects part of the light to the positive glass 20, so that the positive glass 20 reflects part of the light to the front of the battery cell 40.

[0054] For photovoltaic modules, which are typically rectangular, the cover plate 20 is also rectangular. A transparent film strip 10 is arranged around the perimeter of the cover plate 20, such that the length direction of the transparent film strip 10 coincides with the extension direction of the corresponding edge of the cover plate 20. Thus, the serrated reflector 131 of the transparent film strip 10, located along the long side of the photovoltaic module, and the serrated reflector 131 of the transparent film strip 10, located along the short side of the photovoltaic module, are also arranged along the short side. Therefore, when the serrated reflector 131 emits light perpendicular to the second direction (i.e., the length direction of the serrated reflector 131) onto the cover plate 20, the light reflected by the cover plate 20 can be reflected onto the front of the solar cell 40 as much as possible, further improving the light utilization rate of the photovoltaic module.

[0055] See again Figure 3 As shown, in some embodiments, the serrated reflector 131 has a bottom surface 1311, a first inclined surface 1312, and a second inclined surface 1313. The bottom surface 1311 abuts against the second light-transmitting layer 12. The first inclined surface 1312 and the second inclined surface 1313 are both inclined relative to the bottom surface 1311, and the first inclined surface 1312 and the second inclined surface 1313 are set at an acute angle. The edges of the first inclined surface 1312 and the second inclined surface 1313 away from the bottom surface 1311 are connected to form tooth peaks.

[0056] Understandably, for a serrated reflector 131 with a triangular or trapezoidal cross-section, with the width at the corresponding tooth peak position remaining constant, the larger the included angle between the first inclined surface 1312 and the second inclined surface 1313 located on both sides of the tooth peak, the larger the width of the bottom surface 1311 of the serrated reflector 131 (i.e., the dimension of the bottom surface 1311 in the first direction) is. Therefore, in this embodiment, since the first inclined surface 1312 and the second inclined surface 1313 are set at an acute angle, it is beneficial to reduce the control of the width of the bottom surface 1311 of the serrated reflector 131. As a result, more serrated reflectors 131 can be set in the limited space between the first light-transmitting layer 11 and the second light-transmitting layer 12. In other words, this structural arrangement can increase the arrangement density of the serrated reflectors 131 in the first direction, thereby increasing the amount of light reflected from the incident light onto the transparent film strip 20 to the front of the battery cell 40, and further improving the light utilization rate.

[0057] In some embodiments, the included angle α between the first inclined plane 1312 and the second inclined plane 1313 ranges from 5° to 60°. For example, the value of α can be 5°, 10°, 15°, 20°, 35°, 45°, 50° or 60°.

[0058] In this embodiment, the included angle α between the first inclined surface 1312 and the second inclined surface 1313 is set to 5° to 60°, so that the included angle between the first inclined surface 1312 and the second inclined surface 1313 is not too small, which is not conducive to controlling the processing accuracy of the reflective structure, nor is the included angle too large, which is not conducive to improving the arrangement density of the serrated reflective element 131 in the first direction.

[0059] The first inclined surface 1312 is configured to totally reflect light rays that are perpendicularly incident on the bottom surface 1311 to the cover plate 20.

[0060] In some embodiments, the refractive index of the material of the reflective microstructure layer 13 is 1.3 to 1.6. For example, the refractive index of the material of the reflective microstructure layer 13 may be 1.3, 1.4, 1.5 or 1.6.

[0061] The included angle β between the first inclined plane 1312 and the bottom plane 1311 ranges from 45° to 55°. For example, the value of β can be 45°, 48°, 52° or 55°.

[0062] The refractive index of the material and the value of the included angle β of the reflective microstructure layer 13 are not limited here, as long as the light rays incident perpendicularly on the bottom surface 1311 can be totally reflected to the cover plate 20 by the first inclined surface 1312.

[0063] The reflective microstructure layer 13 may be made of materials including, but not limited to, acrylic resin. Acrylic resin, as an epoxy resin, is easy to mold into the reflective microstructure layer 13. For example, in some embodiments, the reflective microstructure layer 13 may be formed by roll forming of epoxy resin material using pressure rollers.

[0064] The thickness of the reflective microstructure layer 13 is 40um-60um. For example, the thickness of the reflective microstructure layer 13 can be 40um, 45um, 50um, 55um or 60um.

[0065] Since the reflective microstructure layer 13 is stacked between the first light-transmitting layer 11 and the second light-transmitting layer 12, when the reflective microstructure layer 13 abuts against the first light-transmitting layer 11 on one side and against the second light-transmitting layer 12 on the other side, the thickness of the reflective microstructure layer 13 can be understood as the distance between the first light-transmitting layer 11 and the second light-transmitting layer 12.

[0066] In this embodiment, since the thickness of the reflective microstructure layer 13 is 40um-60um, the reflective microstructure layer 13 has sufficient thickness to facilitate the forming of the reflective microstructure layer 13, while avoiding the reflective microstructure layer 13 being too thick, which would be detrimental to the thinning of the transparent film strip 10.

[0067] In some embodiments, the transparent film strip 10 further includes an anti-UV coating 14, which is disposed on the side of the second light-transmitting layer 12 opposite to the reflective microstructure layer 13. The anti-UV coating 14 has good UV resistance, thereby making the reflective microstructure layer 13 less susceptible to aging due to UV exposure, thus improving the aging resistance of the reflective microstructure layer 13, which in turn improves the reliability of light from the transparent film strip 10 being reflected from the cover plate 20 to the front of the battery cell 40.

[0068] The UV-resistant coating 14 includes, but is not limited to, a fluorocarbon coating. In this way, the fluorocarbon coating can effectively absorb and filter ultraviolet rays, so that after the light passes through the UV-resistant coating 14, less ultraviolet light enters the reflective microstructure layer 13, thereby reducing the probability of the reflective microstructure layer 13 aging due to ultraviolet radiation.

[0069] It should be noted that the first light-transmitting layer 11 and the second light-transmitting layer 12 can be made of a light-transmitting organic film. For example, in some embodiments, at least one of the first light-transmitting layer 11 and the second light-transmitting layer 12 is a PET (Polyethylene terephthalate) film. This PET film helps to maintain a tight adhesion between the transparent film strip 10 and the cover plate 20.

[0070] At least one of the first light-transmitting layer 11 and the second light-transmitting layer 12 has a thickness of 20um-30um. For example, the thickness of the first light-transmitting layer 11 is 20um, 22um, 25um, 27um, or 30um. As another example, the thickness of the second light-transmitting layer 12 is 20um, 22um, 25um, 27um, or 30um.

[0071] It should be noted that the thickness of the first light-transmitting layer 11 may be equal to or unequal to the thickness of the second light-transmitting layer 12; this is not limited here. In some embodiments, the thickness of the first light-transmitting layer 11 is equal to the thickness of the second light-transmitting layer 12, and the material of the first light-transmitting layer 11 is the same as that of the second light-transmitting layer 12. Thus, when manufacturing the transparent film strip 10, it is not necessary to distinguish the materials used for the first light-transmitting layer 11 and the second light-transmitting layer 12, thereby simplifying the processing technology.

[0072] In some embodiments, the transparent film strip 10 further includes a transparent adhesive film layer 15, which is disposed on the side of the second light-transmitting layer 12 facing away from the first light-transmitting layer 11. The transparent adhesive film layer 15 is used to bond the second light-transmitting layer 12 to the back side of the cover plate 20, so that the transparent film strip 10 is attached to the back side of the cover plate 20, and the transparent film strip 10 can be positioned relative to the battery cell 40 along with the cover plate 20 when the cover plate 20 covers the battery cell 40. It should be noted that the edge of the transparent film strip 10 and the edge of the battery cell 40 can be seamlessly joined, or there can be a small gap, as long as the transparent film strip 10 can reflect part of the light illuminating the reflective microstructure layer 13 to the front side of the battery cell 40 through the cover plate 20.

[0073] The transparent film layer 15 is made of materials including, but not limited to, EVA (Ethylene Vinyl Acetate Copolymer). EVA is a thermoplastic plastic copolymerized from ethylene and vinyl acetate, possessing properties such as elasticity, flexibility, and weather resistance. Therefore, the transparent film layer 15 is made of EVA, which allows the second light-transmitting layer 12 to be bonded to the back of the cover plate 20, thereby attaching the transparent film strip 10 to the back of the cover plate 20. This ensures that when the cover plate 20 covers the battery cell 40, the transparent film strip 10 can be positioned relative to the battery cell 40 along with the cover plate 20.

[0074] In some embodiments, the edge of the cover plate 20 has an embossed surface (not shown), and the transparent film strip 10 disposed on the cover plate 20 is attached to the embossed surface. In this embodiment, the embossed surface increases the surface roughness of the area of ​​the cover plate 20 where the transparent film strip 10 is attached, thereby enhancing the adhesion stability of the transparent film strip 10 on the cover plate 20 and making it less likely to peel off from the cover plate 20. It should be noted that the embossed surface can be formed during the processing of the cover plate 20.

[0075] See again Figure 2 As shown, the photovoltaic module also includes a first encapsulating film 60 and a second encapsulating film 70.

[0076] In some embodiments, the battery cell 40 and the cover plate 20 can be bonded together with a first encapsulating film 60 to improve the connection reliability between the battery cell 40 and the cover plate 20.

[0077] Furthermore, a portion of the structure of the first encapsulating film 60 covers the side of the transparent film strip 10 facing away from the cover plate 20. In this embodiment, since the transparent film strip 10 is connected to the back side of the cover plate 20, when the first encapsulating film 60 connects the battery cell 40 to the cover plate 20, as long as the coverage area of ​​the first encapsulating film 60 is reasonably arranged, the first encapsulating film 60 can cover the transparent film strip 10. In this way, the bonding force between the first encapsulating film 60 and the cover plate 20 can enhance the connection stability between the transparent film strip 10 and the cover plate 20, making it less likely for the transparent film strip 10 to fall off from the front, thereby improving the reliability of the transparent film strip 10 reflecting light through the cover plate 20 to the front side of the battery cell 40.

[0078] The battery cell 40 and the backsheet 30 can be bonded together using a second encapsulating film 70 to improve the connection reliability between the battery cell 40 and the backsheet 30.

[0079] The material of the first encapsulating film 60 includes, but is not limited to, EVA film or POE (polyolefin elastomer) film. The material of the second encapsulating film 70 includes, but is not limited to, EVA film or POE film.

[0080] In some embodiments, the photovoltaic module also includes a busbar 50, and a transparent film strip 10 is disposed on a portion of the busbar 50. In this way, the transparent film strip 10 disposed on the busbar 50 can reflect the light originally incident on the busbar 50 to the front of the solar cell 40, thereby further improving the light utilization rate of the solar cell 40.

[0081] The location of the busbar 50 is not limited here. For example, in some embodiments, the photovoltaic module is rectangular in shape, with two long sides and two short sides. The busbar 50 is arranged along the long side of the photovoltaic module and is located at the terminal of the solar cell 40 located on the corresponding long side of the photovoltaic module.

[0082] Furthermore, this application provides a photovoltaic module encapsulation method, comprising the following steps:

[0083] Step S102: Provide a transparent film strip 10.

[0084] It should be noted that the transparent film strip 10 is the transparent film strip 10 in any of the above embodiments.

[0085] Step S104: A transparent film strip 10 is laid on the edge of the cover plate 20, so that the second light-transmitting layer 12 of the transparent film strip 10 is connected to the back side of the cover plate 20.

[0086] In step S104, the transparent film strip 10 can be attached to the cover plate 20 by heat fusion, so that there is no need for other adhesive materials to connect the transparent film strip 10 and the cover plate 20.

[0087] To facilitate understanding, the process of attaching the transparent film strip 10 will be further explained below, taking the cover plate 20 as a rectangular plate as an example.

[0088] In some embodiments, a laminating machine can be used to apply the transparent film strip 10 to the cover plate 20. Specifically, the cover plate 20 is fed into the laminating machine, and the machine applies the transparent film strip 10 along the edge of the cover plate 20, so that the transparent film strip 10 is provided on both long and two short sides of the cover plate 20. It should be noted that during the application of the transparent film strip 10, the rollers in the laminating machine used to roll the transparent film strip 10 can be set to a constant speed and constant pressure, thereby stabilizing the application of the transparent film strip 10 and ensuring that the application effect of the transparent film strip 10 on the cover plate 20 is uniform.

[0089] The film applicator can also adjust the speed and pressure of the rollers according to production needs to adapt to applying transparent film tape 10 to cover plates 20 of different specifications and shapes.

[0090] The laminating machine can be equipped with an automatic control system to monitor the running status of the rollers and the application effect of the transparent film strip 10 in real time, so that the size and uniformity of the transparent film strip 10 meet the design requirements, thereby improving the application efficiency and application quality.

[0091] In step S106, one side of the solar cell 40 is connected to the back side of the cover plate 20, so that the edge of the transparent film strip 10 is attached to the edge of the solar cell 40, and the transparent film strip 10 can reflect part of the light incident on the transparent film strip 20 through the cover plate 20 to the front side of the solar cell 40 of the photovoltaic module.

[0092] In the above embodiments, the transparent film strip 20 can reflect a portion of the light incident on the transparent film strip 20 through the cover plate 20 to the front of the solar cell 40 of the photovoltaic module, thereby improving the utilization rate of light by the photovoltaic module.

[0093] It should be noted that the photovoltaic module encapsulation method may also include other steps. For example, the photovoltaic module encapsulation method may also include the step of connecting the solar cell 40 to the backsheet 30.

[0094] 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.

[0095] The above embodiments merely illustrate 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 this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive 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 transparent film strip (10), characterized in that, include: First light-transmitting layer (11); The second light-transmitting layer (12) and the first light-transmitting layer (11) are spaced apart along the thickness direction. The second light-transmitting layer (12) is used to connect with the back of the cover plate (20) of the photovoltaic module. A reflective microstructure layer (13) is stacked between the first light-transmitting layer (11) and the second light-transmitting layer (12). A cavity (132) is formed between the reflective microstructure layer (13) and the first light-transmitting layer (11). The reflective microstructure layer (13) is configured to cause total internal reflection of some of the light transmitted through the second light-transmitting layer (12) at the interface between the reflective microstructure layer (13) and the cavity (132).

2. The transparent film strip (10) according to claim 1, characterized in that, The reflective microstructure layer (13) includes a plurality of sawtooth reflective elements (131), which are arranged along a first direction, and the length direction of each sawtooth reflective element (131) is parallel to a second direction, and the first direction intersects the second direction; the tooth peaks of the sawtooth reflective elements (131) abut against the first light-transmitting layer (11), so that a cavity (132) is formed between any two adjacent sawtooth reflective elements (131); the refractive index of the material of the sawtooth reflective elements (131) is greater than the refractive index of the medium in the cavity (132); The plurality of the sawtooth reflectors (131) are spaced apart from each other, or the plurality of the sawtooth reflectors (131) abut against each other.

3. The transparent film strip (10) according to claim 2, characterized in that, The first direction and the second direction are perpendicular to each other, and the cross-section of the serrated reflector (131) is triangular or trapezoidal.

4. The transparent film strip (10) according to claim 2 or 3, characterized in that, The serrated reflector (131) has a bottom surface (1311), a first inclined surface (1312) and a second inclined surface (1313). The bottom surface (1311) abuts against the second light-transmitting layer (12). The first inclined surface (1312) and the second inclined surface (1313) are both inclined relative to the bottom surface (1311) and are set at an acute angle. The edges of the first inclined surface (1312) and the second inclined surface (1313) away from the bottom surface (1311) are connected to form the tooth peaks. The first inclined surface (1312) is configured to be able to completely reflect light perpendicularly incident on the bottom surface (1311) to the cover plate (20).

5. The transparent film strip (10) according to claim 4, characterized in that, The angle between the first inclined plane (1312) and the second inclined plane (1313) ranges from 5° to 60°.

6. The transparent film strip (10) according to claim 1, characterized in that, The transparent film strip (10) also includes an anti-ultraviolet coating (14), which is disposed on the side of the second light-transmitting layer (12) opposite to the reflective microstructure layer (13).

7. The transparent film strip (10) according to claim 1, characterized in that, The transparent film strip (10) also includes at least one of the following technical solutions: At least one of the first light-transmitting layer (11) and the second light-transmitting layer (12) is a PET film; The thickness of at least one of the first light-transmitting layer (11) and the second light-transmitting layer (12) is 20um-30um; The reflective microstructure layer (13) is made of acrylic resin; The thickness of the reflective microstructure layer (13) is 40um-60um.

8. A photovoltaic module, characterized in that, Including the transparent film strip (10) as described in any one of claims 1-7, the photovoltaic module further includes a cover plate (20), a back plate (30), and a plurality of arrayed solar cells (40) connected between the cover plate (20) and the back plate (30). The transparent film strip (10) is provided around the cover plate (20), and the transparent film strip (10) is configured to reflect a portion of the light irradiated on the transparent film strip (10) through the cover plate (20) to the front of the solar cells (40).

9. The photovoltaic module according to claim 8, characterized in that, The transparent film strip (10) further includes a transparent adhesive film layer (15), which is disposed on the side of the second light-transmitting layer (12) facing away from the first light-transmitting layer (11). The transparent adhesive film layer (15) is used to bond the second light-transmitting layer (12) to the back of the cover plate (20).

10. The photovoltaic module according to claim 8 or 9, characterized in that, The edge of the cover plate (20) is provided with an embossed surface, and the transparent film strip (10) provided on the cover plate (20) is attached to the embossed surface.

11. The photovoltaic module according to claim 8 or 9, characterized in that, The photovoltaic module also includes busbars (50), and some of the busbars (50) are provided with the transparent film strip (10).

12. A photovoltaic module encapsulation method, characterized in that, Includes the following steps: A transparent film strip (10) is provided, wherein the transparent film strip (10) is the transparent film strip (10) as described in any one of claims 1-7. The transparent film strip (10) is laid on the edge of the cover plate (20) so that the second light-transmitting layer (12) of the transparent film strip (10) is connected to the back of the cover plate (20); One side of the solar cell (40) is connected to the back of the cover plate (20), so that the edge of the transparent film strip (10) is in contact with the edge of the solar cell (40), and the transparent film strip (10) can reflect part of the light incident on the transparent film strip (10) through the cover plate (20) to the front of the solar cell (40) of the photovoltaic module.

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