Packaging adhesive film and photovoltaic module

Abstract

The utility model discloses a packaging adhesive film and a photovoltaic module. The packaging adhesive film comprises a first EVA adhesive film layer, a POE adhesive film layer and a second EVA adhesive film layer which are sequentially connected in a stacked mode, and the thickness of the edge position of the POE adhesive film layer is larger than that of the center position of the POE adhesive film layer. According to the packaging adhesive film, the thickness of the edge position of the POE adhesive film layer of the middle layer is set to be larger than that of the center position of the POE adhesive film layer, the water blocking capacity of the packaging adhesive film is improved, the water blocking capacity of the side face of the packaged photovoltaic module is improved, meanwhile, the material cost of the POE adhesive film layer can be effectively controlled, and the production cost of the photovoltaic module is effectively controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a packaging adhesive film and a photovoltaic component. Background Art

[0002] At present, the warranty life of photovoltaic modules is generally 25 to 30 years. Therefore, photovoltaic modules have high requirements for water vapor penetration resistance when used outdoors for a long time. When water vapor penetrates through the edge of the photovoltaic module and penetrates into the interior of the photovoltaic module, it will cause the film to hydrolyze. The acidic substances such as acetate ions produced by the hydrolysis of the film will corrode the battery cells and affect the life of the photovoltaic module. There are many factors that cause water vapor to penetrate into the photovoltaic module, among which the encapsulation film is one of the main factors. At present, one of the commonly used encapsulation films in the photovoltaic industry is EPE film. EPE film is co-extruded by three layers of EVA, POE and EVA. The EVA film on both sides and the POE film in the middle form a "sandwich" structure. EVA film has the characteristics of low cost, poor water barrier performance, and high acid value, while POE film has the characteristics of high cost, excellent water barrier performance, and low acid value. Therefore, EPE film has the characteristics of both EVA film and POE film, and related characteristics such as water barrier properties and light transmittance are also between EVA film and POE film.

[0003] Taking HJT cells as an example, the cells are more sensitive to water vapor, so it is necessary to improve the overall water vapor barrier of the photovoltaic module after encapsulation. If EPE film is used for encapsulation, the thickness of the middle POE layer must be increased. At present, the cost of POE film is about 50% higher than that of EVA film. When the overall POE film thickness is increased, the cost of film materials will increase significantly. Utility Model Content

[0004] Based on this, it is necessary to provide a packaging film. The packaging film of the utility model can improve its water barrier without causing a substantial increase in material costs, thereby achieving the purpose of effectively controlling production costs and improving light transmittance and output power of photovoltaic modules.

[0005] An embodiment of the present application provides a packaging film.

[0006] A packaging film comprises a first EVA film layer, a POE film layer and a second EVA film layer which are sequentially stacked and connected, wherein the thickness of the edge of the POE film layer is greater than the thickness of the center of the POE film layer.

[0007] In some embodiments, the thickness of a first region close to an edge position of the POE film layer is greater than the thickness of a second region close to a center position, and the first region surrounds the second region.

[0008] In some embodiments, the thickness of the first region gradually decreases along a direction from an edge position to a center position.

[0009] In some embodiments, the thickness of the second region gradually decreases along a direction from an edge position to a center position.

[0010] In some of the embodiments, the thickness of the POE film layer gradually decreases along the direction from the edge position to the center position.

[0011] In some embodiments, the surface of the POE film layer facing the first EVA film layer is in a concave curved surface, and correspondingly, the surface of the first EVA film layer facing the POE film layer is in a convex curved surface.

[0012] In some embodiments, the surface of the POE film layer facing the second EVA film layer is in a concave curved surface, and correspondingly, the surface of the second EVA film layer facing the POE film layer is in a convex curved surface.

[0013] In some of the embodiments, the thickness W1 at the center of the POE film layer and the thickness W2 at the edge of the POE film layer satisfy the following relationship: W1:W2=1:(4-6).

[0014] In some embodiments, the thickness W1 of the POE film layer at the center, the thickness W3 of the first EVA film layer at the center, and the thickness W4 of the second EVA film layer at the center satisfy the following relationship: W1:W3:W4=(0.2~0.6):1:1.

[0015] In some embodiments, the thickness W2 of the POE film layer at the edge, the thickness W5 of the first EVA film layer at the edge, and the thickness W6 of the second EVA film layer at the edge satisfy the following relationship: W2:W5:W6=(2-3):1:1.

[0016] In some embodiments, the thickness of each region of the encapsulation film composed of the first EVA film layer, the POE film layer and the second EVA film layer is the same.

[0017] In some embodiments, the thickness of each area of ​​the packaging film composed of the first EVA film layer, the POE film layer and the second EVA film layer is 10 mm to 100 mm.

[0018] Another object of the present application is to provide a photovoltaic module.

[0019] A photovoltaic module, characterized by comprising the packaging film.

[0020] In some embodiments, the photovoltaic module includes a front panel, a front film, a battery body, a back film and a back panel which are sequentially stacked and connected, and at least one of the front film and the back film uses the packaging film.

[0021] In some of these embodiments, the front panel is a photovoltaic glass panel.

[0022] In some embodiments, the back panel is a photovoltaic glass panel or a composite material panel.

[0023] The above-mentioned encapsulation film, by setting the thickness of the edge position of the middle layer POE film layer to be greater than the thickness at the center position of the POE film layer, can ensure that the water-blocking ability of the encapsulation film is stronger around it, thereby improving the water-blocking ability of the side of the photovoltaic module after encapsulation, and can also effectively control the material cost of the POE film layer and the production cost of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0025] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0026] FIG. 1 is a schematic diagram of a packaging film according to an embodiment of the present invention.

[0027] Description of Reference Numerals

[0028] 10. Encapsulation film; 100. First EVA film layer; 200. POE film layer; 300. Second EVA film layer. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] In the present disclosure, the terms "light-receiving surface or front surface" and "backlight surface or back surface" are only used to distinguish the locations of two opposite surfaces of the battery substrate. In actual working conditions, the "light-receiving surface or front surface" is the surface of the battery substrate that mainly receives light, but the "backlight surface or back surface" does not necessarily not receive light. On the contrary, due to the existence of diffusely reflected light, the "backlight surface or back surface" can also receive light in actual working conditions.

[0035] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for a broad range of quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0036] The present application provides a packaging film 10 to solve the problems of poor water barrier performance and high film material cost of EPE films used in photovoltaic module packaging in the prior art. The packaging film 10 will be described below in conjunction with the accompanying drawings.

[0037] The encapsulation film 10 provided in the embodiment of the present application is exemplified in Figure 1, which is a schematic diagram of the structure of the encapsulation film 10 provided in the embodiment of the present application. The encapsulation film 10 of the present application can be used for solar cell encapsulation and photovoltaic module production.

[0038] In order to more clearly illustrate the structure of the packaging film 10 , the packaging film 10 will be introduced below with reference to the accompanying drawings.

[0039] For example, referring to Fig. 1, a packaging film 10 includes a first EVA film layer 100, a POE film layer 200 and a second EVA film layer 300 which are sequentially stacked and connected. The thickness of the edge of the POE film layer 200 is greater than the thickness of the center of the POE film layer 200.

[0040] Since the current solar cell packaging uses photovoltaic glass panels or composite panels, for example, HJT cells are packaged based on a double-glass method, and the glass and composite panels have excellent water-blocking capabilities, there is almost no water vapor permeation through the front and back of the photovoltaic module, but the sides of the photovoltaic module are easily penetrated by water vapor. Therefore, the technical solution of the present application is to improve the water-blocking capability of the film at the side of the photovoltaic module. Specifically, in the present application, the packaging film 10 is formed by co-extrusion of a first EVA film layer 100, a POE film layer 200, and a second EVA film layer 300 to form a "sandwich" structure, and the thickness of the edge of the POE film layer 200 is increased to improve its water-blocking capability, while the thickness of the center of the POE film layer 200 is reduced to control the material cost of the POE film layer 200, and there is no need to increase the thickness of the overall POE film layer 200, which effectively controls the production cost of photovoltaic modules. Furthermore, in the present application, since the thickness of the central position of the POE film layer 200 is reduced, the light transmittance of the POE film layer 200 and the entire packaging film 10 will be improved, and the output power of the photovoltaic module can also be improved.

[0041] It should be noted that the structure, materials, etc. of the first EVA film layer 100 and the second EVA film layer 300 in the present application are basically the same, and the descriptions of the first and the second are only used to distinguish the positions. On the same concentric ring, the thickness of the first EVA film layer 100 and the thickness of the second EVA film layer 300 can be the same or different. As shown in Figure 1, based on the position after the encapsulation connection, the first EVA film layer 100 and the second EVA film layer 300 are symmetrical up and down, and on the same concentric ring, the thickness of the first EVA film layer 100 and the thickness of the second EVA film layer 300 are the same.

[0042] In some embodiments, the thickness of the first area of ​​the POE film layer 200 close to the edge position is greater than the thickness of the second area of ​​the POE film layer 200 close to the center position, and the first area surrounds the second area. It should be noted that the above-mentioned first area refers to a local position close to the edge position of the POE film layer 200 and having a certain width, and the above-mentioned second area refers to a local position close to the center position of the POE film layer 200 and having a certain width. In addition, other areas may be provided between the first area and the second area on the POE film layer 200, or there may be no other areas between the first area and the second area to achieve direct contact; preferably, the POE film layer 200 includes a first area and a second area that are in direct contact.

[0043] In some embodiments, the thickness of the first region may be the same thickness or may include multiple different thicknesses. When the first region includes multiple different thicknesses, it means that the thicknesses at different distances from the center of the first region are different. Similarly, the thickness of the second region may be the same thickness or may include multiple different thicknesses. When the second region includes multiple different thicknesses, it means that the thicknesses at different distances from the center of the second region are different.

[0044] Preferably, in a specific example, the first region includes a plurality of different thicknesses, and the second region includes a plurality of different thicknesses.

[0045] In some embodiments, the thickness of the first region gradually decreases from the edge to the center. It should be noted that the thickness of the first region gradually decreases, which means that the thickness of the first region can decrease continuously or discontinuously.

[0046] In some embodiments, the thickness of the second region gradually decreases from the edge position to the center position. It should be noted that the thickness of the second region gradually decreases, which means that the thickness of the second region can be continuously reduced or discontinuously reduced.

[0047] Preferably, the thickness of the first region gradually decreases along the direction from the edge position to the center position, and the thickness of the second region gradually decreases along the direction from the edge position to the center position. Referring to FIG. 1 , the thickness of the POE film layer 200 composed of the first region and the second region gradually decreases along the direction from the edge position to the center position. The above arrangement can reduce the material cost of the POE film layer 200 on the one hand, and can also improve the light transmittance of the POE film layer 200 on the other hand.

[0048] In some of the embodiments, the thickness W1 at the center of the POE film layer 200 and the thickness W2 at the edge of the POE film layer 200 satisfy the following relationship: W1:W2=1:(4-6).

[0049] In some embodiments, as shown in FIG. 1 , the surface of the POE film layer 200 facing the first EVA film layer 100 is a concave curved surface, and correspondingly, the surface of the first EVA film layer 100 facing the POE film layer 200 is a convex curved surface.

[0050] In some embodiments, as shown in FIG. 1 , the surface of the POE film layer 200 facing the second EVA film layer 300 is a concave curved surface, and correspondingly, the surface of the second EVA film layer 300 facing the POE film layer 200 is a convex curved surface.

[0051] Preferably, as shown in FIG. 1 , the surface of the POE film layer 200 facing the first EVA film layer 100 and the surface facing the second EVA film layer 300 are respectively in the shape of concave curved surfaces, and correspondingly, the surface of the first EVA film layer 100 facing the POE film layer 200 is in the shape of convex curved surfaces, and the surface of the second EVA film layer 300 facing the POE film layer 200 is in the shape of convex curved surfaces. The thickness distribution of the POE film layer 200 is thick at the edge and thin in the middle, so that the POE film layer 200 is similar to a dumbbell shape from a side angle, so that the thickness of the second area of ​​the POE film layer 200 close to the center position can be greatly reduced, and the thickness of the first area of ​​the POE film layer 200 close to the edge position can be relatively increased, which ensures the water-blocking ability of the edge area of ​​the POE film layer 200, while also reducing the material consumption of the POE film layer 200, and effectively controlling the cost.

[0052] In some embodiments, the thickness W1 at the center of the POE film layer 200, the thickness W3 at the center of the first EVA film layer 100, and the thickness W4 at the center of the second EVA film layer 300 satisfy the following relationship: W1:W3:W4=(0.2-0.6):1:1. The ratios among W1, W3, and W4 can be set according to actual needs.

[0053] In some embodiments, the thickness W2 at the edge of the POE film layer 200, the thickness W5 at the edge of the first EVA film layer 100, and the thickness W6 at the edge of the second EVA film layer 300 satisfy the following relationship: W2:W5:W6=(2~3):1:1. The ratio between W2, W5, and W6 can be set according to actual needs. For example, the thickness W2 at the edge of the POE film layer 200, the thickness W5 at the edge of the first EVA film layer 100, and the thickness W6 at the edge of the second EVA film layer 300 satisfy the following relationship: W2:W5:W6=2:1:1. For another example, the thickness W2 at the edge of the POE film layer 200, the thickness W5 at the edge of the first EVA film layer 100, and the thickness W6 at the edge of the second EVA film layer 300 satisfy the following relationship: W2:W5:W6=3:1:1. It is not difficult to understand that the ratio of the thickness W2 at the edge of the POE film layer 200, the thickness W5 at the edge of the first EVA film layer 100, and the thickness W6 at the edge of the second EVA film layer 300 is not limited to 2:1:1 or 3:1:1, and can be adaptively adjusted according to the requirements of the photovoltaic module for water-blocking performance. Similarly, the thickness ratio of the POE film layer 200 at different positions can be adjusted according to the requirements of the photovoltaic module for water-blocking performance and light transmittance.

[0054] In some embodiments, the overall thickness of each region of the packaging film 10 composed of the first EVA film layer 100 , the POE film layer 200 and the second EVA film layer 300 is the same.

[0055] In some of the embodiments, the thickness of each region of the packaging film 10 composed of the first EVA film layer 100 , the POE film layer 200 and the second EVA film layer 300 is 10 mm to 100 mm.

[0056] Another object of the present application is to provide a photovoltaic module.

[0057] A photovoltaic module includes the above-mentioned packaging film 10.

[0058] In some of the embodiments, the photovoltaic module includes a front panel, a front film, a battery body, a back film and a back panel which are sequentially stacked and connected, and at least one of the front film and the back film uses a packaging film 10.

[0059] In some embodiments, both the front adhesive film and the back adhesive film use the packaging adhesive film 10 .

[0060] In some of these embodiments, the front panel is a photovoltaic glass panel.

[0061] In some embodiments, the back panel is a photovoltaic glass panel or a composite material panel.

[0062] To sum up, the packaging film 10 of the present application can improve the water-blocking ability of the packaging film 10 around the edges or the areas close to the edges by setting the thickness of the middle layer POE film layer 200 greater than the thickness of the POE film layer 200 at the center or the areas close to the center, thereby improving the water-blocking ability of the sides of the photovoltaic module after packaging, and can also effectively control the material cost of the POE film layer 200, and effectively control the production cost of the photovoltaic module.

[0063] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0065] The above-mentioned embodiments only express several implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A packaging film (10), characterized in that: It comprises a first EVA film layer (100), a POE film layer (200) and a second EVA film layer (300) which are sequentially stacked and connected, wherein the thickness at the edge of the POE film layer (200) is greater than the thickness at the center of the POE film layer (200).

2. The packaging adhesive film (10) according to claim 1, characterized in that: The thickness of a first region close to an edge position on the POE adhesive film layer (200) is greater than the thickness of a second region close to a center position, and the first region surrounds the second region.

3. The packaging adhesive film (10) according to claim 2, characterized in that: The thickness of the first region gradually decreases along a direction from an edge position to a center position.

4. The packaging adhesive film (10) according to claim 2, characterized in that: The thickness of the second region gradually decreases along a direction from an edge position to a center position.

5. The packaging adhesive film (10) according to claim 1, characterized in that: The thickness of the POE adhesive film layer (200) gradually decreases in a direction from an edge position to a center position.

6. The packaging adhesive film (10) according to claim 1, characterized in that: The surface of the POE adhesive film layer (200) facing the first EVA adhesive film layer (100) is in the shape of an inwardly concave curved surface, and correspondingly, the surface of the first EVA adhesive film layer (100) facing the POE adhesive film layer (200) is in the shape of a convex curved surface; And / or, the surface of the POE adhesive film layer (200) facing the second EVA adhesive film layer (300) is in the shape of a concave curved surface, and correspondingly, the surface of the second EVA adhesive film layer (300) facing the POE adhesive film layer (200) is in the shape of a convex curved surface.

7. The packaging adhesive film (10) according to any one of claims 1 to 6, characterized in that: The thickness W1 at the center of the POE adhesive film layer (200) and the thickness W2 at the edge of the POE adhesive film layer (200) satisfy the following relationship: W1:W2=1:(4-6).

8. The packaging adhesive film (10) according to any one of claims 1 to 6, characterized in that: The thickness W1 at the center of the POE film layer (200), the thickness W3 at the center of the first EVA film layer (100), and the thickness W4 at the center of the second EVA film layer (300) satisfy the following relationship: W1:W3:W4=(0.2-0.6):1:1; And / or, the thickness W2 at the edge of the POE film layer (200), the thickness W5 at the edge of the first EVA film layer (100), and the thickness W6 at the edge of the second EVA film layer (300) satisfy the following relationship: W2:W5:W6=(2-3):1:

1.

9. The packaging adhesive film (10) according to any one of claims 1 to 6, characterized in that: The thickness of each region of the packaging film (10) composed of the first EVA film layer (100), the POE film layer (200) and the second EVA film layer (300) is the same.

10. A photovoltaic module, characterized in that: It comprises a front panel, a front adhesive film, a battery body, a back adhesive film and a back panel which are sequentially stacked and connected, and at least one of the front adhesive film and the back adhesive film uses the packaging adhesive film (10) according to any one of claims 1 to 9.

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