Photovoltaic encapsulant film and photovoltaic module

Abstract

The application discloses a kind of photovoltaic encapsulation adhesive films, which comprises a substrate layer, a barrier layer and an adhesive layer. The barrier layer is attached to at least one side of the substrate layer, and the barrier layer is in a hollow grid shape. The adhesive layer is attached to the side of the barrier layer away from the substrate layer. The application also discloses a photovoltaic module. When the photovoltaic encapsulation adhesive film in the application is arranged in the back layer of the photovoltaic module, the barrier layer in the hollow grid shape can effectively reduce the migration rate of functional additives from the front layer to the back layer, and also reduce the manufacturing cost of the adhesive film.

Description

Technical Field

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

[0002] With the accelerating pace of technological iteration and innovation in the photovoltaic industry, the continuous expansion of application scenarios has spurred diversified market demands, driving photovoltaic module products towards greater customization and differentiation. Current industry competition has moved beyond simple structural and aesthetic optimization. Beyond the differences in visual appearance and structural design of module products, photoelectric conversion efficiency, as a core performance indicator, remains the focus of industry competition, with technological breakthroughs and optimizations directly determining the power generation efficiency and commercial value of photovoltaic systems.

[0003] To further improve the photoelectric conversion efficiency of photovoltaic modules, related technologies include adding light conversion functional additives to the front encapsulation film of photovoltaic modules. Through the conversion effect, light energy in non-effective response bands of the solar spectrum (such as ultraviolet light) is converted into blue light bands that can be used by the battery. Alternatively, high-transmittance nanofillers and other materials are added to the front encapsulation film to optimize the refractive index and reduce light loss caused by interface reflection, thereby reducing light loss and improving the photoelectric conversion efficiency of photovoltaic modules.

[0004] However, the addition of the aforementioned functional additives creates a significant concentration gradient between the front and rear encapsulation films. The functional additives migrate from the front to the rear encapsulation film through diffusion, leading to a continuous decrease in the concentration of the effective components in the front encapsulation film. Ultimately, this results in a significant reduction in the optical gain effect of the front encapsulation film. Adding functional additives to both the front and rear encapsulation films would greatly increase manufacturing costs. Utility Model Content

[0005] To address the aforementioned issues, this application provides a photovoltaic encapsulation film that can effectively reduce the migration rate of functional additives while maintaining low manufacturing costs.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0007] This application provides a photovoltaic encapsulation film, which includes a substrate layer, a barrier layer, and an adhesive layer; the barrier layer is attached to at least one side of the substrate layer and is in the form of a perforated grid; the adhesive layer is attached to the side of the barrier layer away from the substrate layer.

[0008] Furthermore, the plane containing the base layer is defined as the preset plane, the orthographic projection of the base layer on the preset plane is the base projection, the orthographic projection of the barrier layer on the preset plane is the barrier projection, and the area ratio between the barrier projection and the base projection ranges from 0.03 to 0.13.

[0009] Furthermore, the thickness of the adhesive layer ranges from 3.5 μm to 6.5 μm;

[0010] Furthermore, the adhesive layer is one of a POE film layer, an EVA film layer, or a multilayer structure film formed by a POE film layer and an EVA film layer.

[0011] Furthermore, the thickness of the barrier layer ranges from 5 μm to 100 μm;

[0012] Furthermore, the barrier layer is made of at least one of PE or PP.

[0013] Furthermore, the thickness of the substrate ranges from 100 μm to 5000 μm;

[0014] Furthermore, the substrate layer is one of a POE film layer, an EVA film layer, or a multilayer structure film formed by a POE film layer and an EVA film layer.

[0015] Furthermore, the pre-crosslinking degree of the adhesive layer is greater than or equal to 60%.

[0016] Furthermore, the barrier layer includes grid lines and a perforated grid formed by the grid lines, wherein the shape of the grid lines is straight, curved, or a shape composed of at least one straight line and at least one curve.

[0017] Furthermore, the width of the grid lines ranges from 0.5mm to 10mm.

[0018] Furthermore, the shape of the hollowed-out grid is one of the following: triangular, quadrilateral, pentagonal...n-sided, where n is an integer greater than 3; or the shape of the hollowed-out grid is a shape formed by at least one curve; or the shape of the hollowed-out grid is a shape formed by at least one curve and at least one straight line.

[0019] Another aspect of this application provides a photovoltaic module, which sequentially includes a front substrate, a front encapsulant film, a battery string, a back encapsulant film, and a back substrate, wherein the back encapsulant film is selected from the aforementioned photovoltaic encapsulant films.

[0020] Therefore, this application has at least the following beneficial effects:

[0021] 1. In this application, by setting a perforated grid-like barrier layer, the migration rate of functional additives to the back layer can be effectively reduced, and the manufacturing cost of the film can also be reduced.

[0022] 2. The adhesive layer with a specific degree of pre-crosslinking in this application can provide good support for the barrier layer during the lamination process of photovoltaic modules, and avoid the deformation of the barrier layer from affecting the performance.

[0023] 3. When the photovoltaic encapsulating film of this application is placed on the back layer of the photovoltaic module, the influence of the barrier layer on the light transmittance of the photovoltaic module can be completely avoided. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a photovoltaic encapsulation film provided in an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of another photovoltaic encapsulation film provided in an embodiment of this application;

[0026] Figures 3 to 7 A schematic diagram of the structure of the barrier layer with different perforated meshes provided in the embodiments of this application;

[0027] Figure 8 This is a schematic diagram showing the dimensions of the photovoltaic encapsulation film provided in the embodiments of this application;

[0028] Figure 9 This is a schematic diagram of the structure of a photovoltaic module provided in an embodiment of this application.

[0029] In the figure: photovoltaic encapsulation film 100, substrate layer 11, barrier layer 12, grid line 121, hollow grid 122, adhesive layer 13, photovoltaic module 200, front substrate 21, front encapsulation film 22, cell string 23, back encapsulation film 24, back substrate 25. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0031] This application provides a photovoltaic encapsulating film 100, such as... Figure 1 As shown, the photovoltaic encapsulation film 100 includes a base layer 11, a barrier layer 12, and an adhesive layer 13. The base layer 11 constitutes the main body of the photovoltaic encapsulation film 100, and also provides support for the entire photovoltaic encapsulation film 100. The barrier layer 12 is attached to at least one side of the base layer 11. Specifically, the photovoltaic encapsulation film 100 can be configured as follows: Figure 1 The barrier layer 12 shown is provided only on one side of the base layer 11, or it can be as follows: Figure 2 As shown, barrier layers 12 are provided on both sides of the base layer 11. The barrier layers 12 are shaped as follows: Figure 3The barrier layer 12, as shown, is a perforated mesh structure. It serves to prevent the migration of functional additives within the photovoltaic encapsulation film 100 or the photovoltaic module 200. The barrier layer 12 is a perforated mesh structure rather than a complete layer, which, while ensuring the prevention of functional additive migration, also reduces material costs. The adhesive layer 13 is disposed on the side of the barrier layer 12 away from the substrate layer 11, on the outer side of the barrier layer 12. The adhesive layer 13 provides excellent adhesion, ensuring superior bonding performance between the photovoltaic encapsulation film 100 and the battery string and photovoltaic substrate, improving the reliability and lifespan of the photovoltaic module 200. Furthermore, the adhesive layer with a certain degree of pre-crosslinking provides good support to the barrier layer during the lamination process of the photovoltaic module 200, preventing deformation of the barrier layer from affecting its performance. The functional additives mentioned in this application include not only light conversion agents, but also other functional additives added to photovoltaic encapsulation films such as ultraviolet blocking agents, anti-reflective agents, and light diffusing agents. In this application, the photovoltaic encapsulation film 100, especially the barrier layer 12 therein, has a good barrier effect on the above-mentioned additives and can prevent the above-mentioned functional additives from migrating inside the photovoltaic encapsulation film 100 or the photovoltaic module 200.

[0032] In one specific application scenario, the photovoltaic encapsulating film 100 is used as a rear encapsulating film for the photovoltaic module 200 and is disposed on the back surface of the photovoltaic cell string 23. In this photovoltaic encapsulating film 100 disposed on the rear layer of the photovoltaic module, the barrier layer 12 can prevent functional additives from migrating from the front photovoltaic film to the rear photovoltaic film.

[0033] As an optional implementation, the plane containing the substrate layer 11 is defined as a preset plane, the orthographic projection of the substrate layer 11 on the preset plane is called the substrate projection, and the orthographic projection of the barrier layer 12 on the preset plane is called the barrier projection. The area ratio between the barrier projection and the substrate projection ranges from 0.03 to 0.13. This area ratio range essentially represents the proportion of the barrier layer 12 covering the substrate layer 11. Within this range, the amount of raw material used in the barrier layer 12 can be reduced while still meeting the requirements for preventing the migration of functional additives, thereby reducing the overall manufacturing cost of the encapsulating film. Furthermore, the impact of the barrier layer 12 on the light transmittance can be reduced, ensuring that the photovoltaic encapsulating film 100 has superior light transmittance. Especially for bifacial photovoltaic cells, a high light transmittance in the encapsulating film disposed on the back layer of the photovoltaic module 200 can also improve the overall photoelectric conversion efficiency of the photovoltaic module 200. Further, the area ratio between the barrier projection and the substrate projection ranges from 0.05 to 0.11. Furthermore, the area ratio between the blocking projection and the base projection ranges from 0.06 to 0.10.

[0034] As an optional implementation method, such as Figure 3As shown, the barrier layer 12 includes grid lines 121 and a perforated grid 122 formed by the grid lines 121. The grid lines 121 can be straight, curved, or composed of at least one straight line and at least one curve. The perforated grid 122 is formed by at least one straight line or curve surrounding the grid. The grid lines 121 can be composed of straight lines, forming the network shape of the barrier layer 12, such as a common latitude and longitude network. The grid lines 121 can also be composed of curves, forming the network shape of the barrier layer 12. The grid lines 121 can also be composed of at least one straight line and at least one curve, forming the network shape of the barrier layer 12 with a slightly more complex shape. Furthermore, the grid lines 121 in the barrier layer 12 can be of uniform width or have varying widths. Depending on the actual needs and shape, the grid lines 121 in some areas of the barrier layer 12 may be slightly wider, while the grid lines 121 in other areas may be slightly narrower. Alternatively, on a continuous grid line 121, some areas are slightly wider and others are slightly narrower.

[0035] As an optional implementation, the width W of the grid lines 121 ranges from 0.5 mm to 10 mm. The width of the grid lines 121 affects the coverage area of ​​the barrier layer 12 on the substrate layer 11 and the barrier effect of the barrier layer 12 on the functional additives. When the width of the grid lines 121 is within the above range, it can satisfy the barrier effect of the barrier layer 12 on the functional additives, preventing the functional additives in the front encapsulant film 22 from migrating to the back encapsulant film 24, and also minimize the amount of the barrier layer 12 covering the substrate layer 11, avoiding a significant reduction in the light transmittance of the photovoltaic encapsulant film 100, reducing the amount of raw materials used in the barrier layer 12, and reducing production costs. Further, the width W of the grid lines 121 ranges from 1 mm to 7 mm. Even further, the width W of the grid lines 121 ranges from 1.5 mm to 5 mm. Most preferably, the width W of the grid lines 121 is 2 mm.

[0036] As an optional implementation, the shape of the perforated mesh 122 is one of a triangle, quadrilateral, pentagon...n-sided polygon, where n is an integer greater than 3; or the shape of the perforated mesh 122 is a shape formed by at least one curve, or a shape formed by at least one curve and at least one straight line. The shape of the perforated mesh 122 can be any shape. The perforated mesh 122 can be a polygon composed only of multiple straight lines, a graphic composed of at least one curve, or a graphic composed of at least one straight line and at least one curve. However, relatively speaking, the perforated mesh 122 with a regular shape has advantages in terms of uniform distribution and ease of manufacturing. Therefore, choosing a perforated mesh 122 with a regular shape can improve the barrier effect of the barrier layer 12 on functional additives, and at the same time reduce the production cost of the barrier layer 12. Specifically, the shape of the perforated mesh 122 can include, for example, Figures 3 to 7 The shape shown.

[0037] Furthermore, the shape of the perforated grid 122 formed by the grid lines 121 can be the same as the shape of the solar cells in the battery string 23, and the size of the perforated grid 122 can be the same as the size of the solar cells, meaning that the solar cells can be perfectly embedded in the perforated grid 122. In this case, the barrier layer 12, in cooperation with the solar cells, can effectively prevent the migration of functional additives, while also reducing the area of ​​the barrier layer 12 and the amount of raw materials used to form the barrier layer 12. This achieves the goal of preventing the migration of functional additives between the front and rear encapsulants in the most economical way. Of course, it is understandable that if the shape of the perforated grid 122 is not exactly the same as the solar cells, or if the size of the perforated grid 122 is smaller than the size of the solar cells, and the barrier layer 12 containing the perforated grid 122 can still cover the gaps between the solar cells in the photovoltaic module, although it may not be possible to achieve the goal of preventing the migration of functional additives between the front and rear encapsulants in the most economical way, it can still achieve the goal of preventing the migration of functional additives between the front and rear encapsulants.

[0038] As an optional implementation, the barrier layer 12 is made of at least one of PE or PP. The barrier layer 12 needs to be able to prevent functional additives from migrating from the front photovoltaic film to the back photovoltaic film. Both PE and PP materials have good barrier effects on functional additives.

[0039] As an optional implementation, the pre-crosslinking degree of the adhesive layer 13 is greater than or equal to 60%. The adhesive layer 13 with the above pre-crosslinking degree has certain mechanical strength and high adhesion, which can provide a certain support for the barrier layer 12 during the lamination process of the photovoltaic module 200, so as to avoid the barrier layer 12 from deforming and thus affecting the performance. At the same time, it can also improve the bonding performance between the components after the photovoltaic module 200 is laminated.

[0040] As an optional implementation method, such as Figure 8 As shown, the thickness H1 of the adhesive layer 13 ranges from 3.5 μm to 6.5 μm. Within this range, the thickness of the adhesive layer 13 ensures excellent adhesion between components after the photovoltaic module 200 is encapsulated, while also preventing defects such as adhesive overflow caused by excessive thickness of the adhesive layer 13. Further, the thickness H1 of the adhesive layer 13 ranges from 4 μm to 6 μm. Even further, the thickness H1 of the adhesive layer 13 ranges from 4.5 μm to 5.5 μm. Most preferably, the thickness H1 of the adhesive layer 13 is 5 μm.

[0041] As an optional implementation method, such as Figure 8 As shown, the thickness H2 of the barrier layer 12 ranges from 5 μm to 100 μm. The thickness of the barrier layer 12 has a significant impact on the barrier effect, and also affects the light transmittance and manufacturing cost. Within the above-mentioned range, the thickness of the barrier layer 12 satisfies both the barrier effect for functional additives and the light transmittance and manufacturing cost requirements of the photovoltaic encapsulation film 100. Further, the thickness H2 of the barrier layer 12 ranges from 5 μm to 70 μm. Even further, the thickness H2 of the barrier layer 12 ranges from 5 μm to 40 μm. Most preferably, the thickness H2 of the barrier layer 12 is 10 μm.

[0042] As an optional implementation method, such as Figure 8 As shown, the thickness H3 of the substrate layer 13 ranges from 100 μm to 5000 μm. The substrate layer 13 constitutes the base portion of the photovoltaic encapsulating film 100. The thickness of the substrate layer 13 within the aforementioned range satisfies the basic encapsulation performance of the photovoltaic encapsulating film 100 while avoiding the impact on performance such as light transmittance due to excessive thickness. Further, the thickness H3 of the substrate layer 13 ranges from 500 μm to 4500 μm. Even further, the thickness H3 of the substrate layer 13 ranges from 1000 μm to 4000 μm.

[0043] As an optional implementation, the substrate layer 11 is one of a POE film layer, an EVA film layer, or a multilayer film layer composed of POE film layers and EVA film layers. The adhesive layer 13 is one of a POE film layer, an EVA film layer, or a multilayer film layer composed of POE film layers and EVA film layers. In the photovoltaic encapsulation film 100 of this application, both the substrate layer 11 and the adhesive layer 13 can be made of materials commonly used in conventional encapsulation films in the prior art, and even encapsulation films of corresponding thickness and material can be used as the substrate layer 11 and the adhesive layer 13. Specifically, the substrate layer 11 can be a POE film layer, an EVA film layer, or a stacked film layer composed of POE film layers and EVA film layers, such as the more common EPE film layer. Similarly, the adhesive layer 13 can also be a film layer of the above-mentioned materials. In addition, the substrate layer 11 and the adhesive layer 13 can be film layers of the same material or film layers of different materials. In addition, the base layer 11 and the adhesive layer 13 can be made of materials other than those used in conventional encapsulation films. In particular, the base layer 11, which mainly plays a supporting role, can be made of other materials with slightly worse adhesive properties but better supporting capabilities.

[0044] The photovoltaic encapsulation film 100 in this application can be prepared using conventional multilayer encapsulation film preparation methods. For example, the substrate layer 11, barrier layer 12, and adhesive layer 13 can be prepared separately first, and then the substrate layer 11, barrier layer 12, and adhesive layer 13 can be bonded together under heating to finally obtain the photovoltaic encapsulation film 100 in this application.

[0045] This application embodiment also provides a method such as Figure 9 The photovoltaic module 200 shown includes, in sequence, a front substrate 21, a front encapsulant film 22, a cell string 23, a back encapsulant film 24, and a back substrate 25. The back encapsulant film 24 is selected from the aforementioned photovoltaic encapsulant film 100. Specifically, the front encapsulant film 22 in this photovoltaic module 200 is a light conversion encapsulant film with added light conversion factor.

[0046] In this application, a perforated mesh is formed in the photovoltaic encapsulating film 100 to achieve the purpose of blocking functional additives. At the same time, the perforated mesh can ensure high light transmittance and low manufacturing cost. In addition, when the photovoltaic encapsulating film 100 is placed on the back layer of the photovoltaic module 200, the influence of the barrier layer 12 on the light transmittance of the photovoltaic module 200 can be completely avoided, and the functional additives can also be prevented from migrating from the front encapsulating film to the back encapsulating film.

[0047] Finally, it should be noted that the above are only some preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photovoltaic encapsulating film, characterized in that, include: basal layer; A barrier layer is attached to at least one side of the substrate layer, and the barrier layer is in the form of a perforated mesh. An adhesive layer is attached to the side of the barrier layer away from the substrate layer.

2. The photovoltaic encapsulating film according to claim 1, characterized in that: The plane containing the base layer is defined as a preset plane, the orthographic projection of the base layer on the preset plane is the base projection, the orthographic projection of the barrier layer on the preset plane is the barrier projection, and the area ratio between the barrier projection and the base projection ranges from 0.03 to 0.

13.

3. The photovoltaic encapsulating film according to claim 1, characterized in that: The thickness of the adhesive layer ranges from 3.5 μm to 6.5 μm; And / or, the adhesive layer is one of a POE film layer, an EVA film layer, or a multilayer structure film formed by a POE film layer and an EVA film layer.

4. The photovoltaic encapsulating film according to claim 1, characterized in that: The thickness of the barrier layer ranges from 5 μm to 100 μm; And / or, the barrier layer is made of either PE or PP.

5. The photovoltaic encapsulating film according to claim 1, characterized in that: The thickness of the substrate layer ranges from 100 μm to 5000 μm; And / or, the substrate layer is one of a POE film layer, an EVA film layer, or a multilayer structure film formed by a POE film layer and an EVA film layer.

6. The photovoltaic encapsulating film according to claim 1, characterized in that: The pre-crosslinking degree of the adhesive layer is greater than or equal to 60%.

7. The photovoltaic encapsulating film according to claim 1, characterized in that: The barrier layer includes grid lines and a hollow grid formed by the grid lines. The grid lines are straight, curved, or composed of at least one straight line and at least one curve.

8. The photovoltaic encapsulating film according to claim 7, characterized in that: The width of the grid lines ranges from 0.5 mm to 10 mm.

9. The photovoltaic encapsulating film according to claim 7, characterized in that: The shape of the hollowed-out grid is one of the following: triangular, quadrilateral, pentagonal...n-sided polygon, where n is an integer greater than 3; Alternatively, the shape of the hollowed-out mesh may be a shape formed by at least one curve surrounding it; Alternatively, the shape of the hollowed-out mesh may be a shape formed by at least one curve and at least one straight line.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises, in sequence, a front substrate, a front encapsulant film, a battery string, a rear encapsulant film, and a back substrate, wherein the rear encapsulant film is selected from the photovoltaic encapsulant films as described in any one of claims 1 to 9.

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