An encapsulating film and a solar cell

Abstract

This invention provides an encapsulating film and a solar cell, relating to the photovoltaic field. The encapsulating film includes a film body and a surface pattern disposed on the film body. The surface pattern includes at least one unit pattern, which includes columnar protrusions, rod-shaped protrusions, and grooves between the columnar and rod-shaped protrusions. The surface pattern reduces the contact area between the EVA film layer and the glass or solar cell, increasing the friction between the glass or solar cell and the EVA film layer, thus increasing the adhesion of the film. When the additives in the POE film layer migrate to the EVA film layer, the additives flow into and are stored in the grooves, reducing the amount of additives diffusing into the EVA film layer, thereby further increasing the friction between the glass or solar cell and the EVA film layer, and thus increasing the adhesion of the film. This invention also provides a solar cell including an encapsulating film.

Description

Technical Field

[0001] This utility model relates to the photovoltaic field, and more specifically, to an encapsulating film and a solar cell. Background Technology

[0002] Solar encapsulation films are used to encapsulate solar photovoltaic modules, providing mechanical protection and electrical insulation to ensure the long-term reliability of the photovoltaic modules.

[0003] Currently, a commonly used solar encapsulation film is EPE film. EPE film is a composite film made of three layers: EVA film, POE film, and EVA film stacked sequentially. The POE film layer contains small molecule additives such as antioxidants and lubricants. These small molecule additives will migrate under certain temperature and time conditions and gradually diffuse into the EVA film layer. The migration of additives will not only reduce the adhesion between the film and the glass or solar cell, but also cause the film surface to become slippery. This will make the photovoltaic module easy to shift during encapsulation, stacking, and transportation, affecting the stability and consistency of photovoltaic module production. Utility Model Content

[0004] This invention provides an encapsulating film and a solar cell that can solve a series of problems caused by the migration of additives.

[0005] The embodiments of this utility model can be implemented as follows:

[0006] An embodiment of this utility model provides an encapsulating film, comprising:

[0007] The adhesive film body and the surface pattern provided on the front and / or back of the adhesive film body;

[0008] The surface pattern includes at least one unit pattern, which includes columnar protrusions, rod-shaped protrusions, and grooves between the columnar protrusions and the rod-shaped protrusions.

[0009] Optionally, the columnar protrusion may be a cylindrical protrusion, an elliptical columnar protrusion, or a prismatic protrusion.

[0010] Optionally, the rod-shaped protrusion includes a uniform width middle section and tapering sections disposed at both ends of the uniform width middle section.

[0011] Optionally, the surface of the tapering section is a smooth arc surface, and the cross-sectional shape of the equal-width middle section is any one of the following: semi-circular, rounded rectangle, triangle, trapezoid, crescent, or pagoda.

[0012] Optionally, the thickness of the film body is 0.3-2.0 mm, the length of the rod-shaped protrusion is 2-7 mm, the maximum width of the rod-shaped protrusion is 3-4 mm, and the maximum height of the rod-shaped protrusion is 0.5-1.0 mm.

[0013] Optionally, the columnar protrusion is a cylindrical protrusion with a base diameter of 0.5-1.5 mm and a maximum height of 0.5-1.0 mm.

[0014] Optionally, the columnar protrusion is a cylindrical protrusion, and the center distance between the cylindrical protrusions of two adjacent unit patterns is 2-6 mm.

[0015] Optionally, the included angle between the two rod-shaped protrusions is 0-180°.

[0016] Optionally, the grooves of adjacent unit patterns are connected.

[0017] An embodiment of this utility model also provides a solar cell, including the encapsulating film described above.

[0018] The beneficial effects of this utility model embodiment:

[0019] The encapsulation film provided in the embodiments of this utility model includes a film body and surface patterns disposed on the front and / or back of the film body. The surface patterns include at least one unit pattern, and the unit pattern includes columnar protrusions, rod-shaped protrusions, and grooves between the columnar protrusions and rod-shaped protrusions. Because the surface of the film body is provided with columnar and rod-shaped protrusions, the contact area between the EVA film layer and the glass or battery cell is reduced, and the friction between the glass or battery cell and the EVA film layer is increased, thereby increasing the adhesion of the film. Furthermore, the surface patterns also include grooves. When the additives of the POE film layer migrate to the EVA film layer, the additives flow into and are stored in the grooves, indirectly reducing the amount of additives diffused into the EVA film layer, thereby further increasing the friction between the glass or battery cell and the EVA film layer, thus increasing the adhesion of the film.

[0020] The solar cell includes the aforementioned encapsulating film, which possesses all the functions of an encapsulating film. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a top view of the encapsulating film and its surface pattern provided in an embodiment of the present invention.

[0023] Figure 2 for Figure 1A cross-sectional schematic diagram of AA in the diagram;

[0024] Figure 3 This is a top view of the unit pattern provided in an embodiment of the present utility model;

[0025] Figure 4 for Figure 3 A cross-sectional view of BB in the diagram;

[0026] Figure 5 for Figure 3 A cross-sectional view of CC in the diagram;

[0027] Figure 6 This is a cross-sectional schematic diagram along the width direction of the equal-width middle section (which is a semi-circle) in an embodiment of this utility model;

[0028] Figure 7 This is a cross-sectional schematic diagram along the width direction of the equal-width middle section (the equal-width middle section is a rectangle with rounded corners) in an embodiment of this utility model;

[0029] Figure 8 This is a cross-sectional schematic diagram along the width direction of the equal-width middle section (the equal-width middle section is pagoda-shaped) in an embodiment of this utility model;

[0030] Figure 9 This is a cross-sectional schematic diagram along the width direction of the equal-width middle section (the equal-width middle section is trapezoidal) in an embodiment of this utility model;

[0031] Figure 10 This is a cross-sectional schematic diagram along the width direction of the equal-width middle section (the equal-width middle section is crescent-shaped) in an embodiment of this utility model;

[0032] Figure 11 This is a cross-sectional schematic diagram along the width direction of the equal-width middle section (the equal-width middle section is a triangle) in an embodiment of this utility model;

[0033] Figure 12 This is a schematic diagram of another unit pattern in an embodiment of the present invention;

[0034] Figure 13 This is a schematic diagram of another unit pattern in an embodiment of the present utility model;

[0035] Figure 14 This is a schematic diagram of another unit pattern in an embodiment of this utility model.

[0036] Icons: 1-Film body; 2-Surface pattern; 20-Unit pattern; 201-Columnar protrusion; 202-Rock-shaped protrusion; 2021-Equal width middle section; 2022-Gradual narrowing section; 203-Groove. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model 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 utility model.

[0041] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0042] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] Unless otherwise explicitly specified and limited, terms such as "setup" and "connection" should be interpreted broadly. For example, "connection" 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 a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0044] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0045] Solar encapsulation films play a crucial role in photovoltaic modules, protecting the solar cells, providing electrical insulation, and offering mechanical support. However, in traditional EPE films (EVA-POE-EVA composite structure), the POE layer additives migrate over time, gradually diffusing into the EVA layer. This causes the film surface to become slippery, reducing the adhesion between the film and the glass or solar cells. Consequently, photovoltaic modules are prone to displacement during encapsulation, stacking, and transportation, affecting the stability and consistency of photovoltaic module production and increasing the scrap rate.

[0046] In view of the above problems, the present invention provides an encapsulating film and a solar cell, which overcome the above defects and will be described in detail below.

[0047] Please refer to Figures 1 to 3 The encapsulation film includes a film body 1 and a surface pattern 2 disposed on the surface of the film body 1. The surface pattern 2 can be disposed on the front or back of the film body 1 or both. The surface pattern 2 on the film body 1 includes at least one unit pattern 20. Each unit pattern 20 includes a columnar protrusion 201, a rod-shaped protrusion 202, and a groove 203 between the columnar protrusion 201 and the rod-shaped protrusion 202. The surface of the adhesive film body 1 is provided with columnar protrusions 201, rod-shaped protrusions 202, and grooves 203, which reduces the contact area between the EVA adhesive film layer and the glass or battery cell, increases the friction between the glass or battery cell and the EVA adhesive film layer, thereby increasing the adhesion of the adhesive film and improving its anti-slip performance. Moreover, when the additives of the POE adhesive film layer migrate to the EVA adhesive film layer, the additives will flow into the grooves 203 and be stored, indirectly reducing the amount of additives diffused into the EVA adhesive film layer, thereby further increasing the friction between the glass or battery cell and the EVA adhesive film layer and increasing the adhesion of the adhesive film.

[0048] It should be noted that the surface pattern 2 can be set on the POE film layer or the EVA film layer alone, or it can be set on both the POE film layer and the EVA film layer at the same time.

[0049] The film body 1 is made of EVA film layer and POE film layer pressed together to meet the light transmittance, weather resistance and adhesion performance required for photovoltaic encapsulation. The surface pattern 2 can be processed on the surface of the film body 1 by hot pressing, molding or laser engraving process. The surface pattern 2 refers to the collection of all unit patterns 20 on a single film body 1.

[0050] The number of unit patterns 20 on the film body 1 is related to the area of ​​the film body 1 and the size of the unit patterns 20. Generally, the larger the area of ​​the film body 1, the more unit patterns 20 are provided. The pattern shape on the film body 1 is related not only to the shape and size of the unit patterns 20, but also to the arrangement of multiple unit patterns 20. For example, multiple unit patterns 20 can be arranged continuously, spaced apart, or arranged in partial areas. When multiple unit patterns 20 are arranged continuously, the grooves 203 of adjacent unit patterns 20 can also be connected, thereby avoiding the accumulation of a large amount of POE film additives in local areas and avoiding the formation of greasy or hazy pollution on the film surface.

[0051] Since each unit pattern 20 includes a columnar protrusion 201, a rod-shaped protrusion 202 and a groove 203, the arrangement of multiple unit patterns 20 can be a rotation around the columnar protrusion 201 within a range of 0-360°. That is, without distinguishing the two ends of the rod-shaped protrusion 202, the included angle between the two rod-shaped protrusions 202 is 0-180°.

[0052] refer to Figure 4 and Figure 5 The unit pattern 20 specifically includes columnar protrusions 201, rod-shaped protrusions 202, and grooves 203.

[0053] The columnar protrusion 201 can be a cylindrical protrusion, an elliptical cylindrical protrusion, a prismatic protrusion, or a protrusion of other shapes. On the single sheet adhesive film body 1, the columnar protrusion 201 can be any one or a combination of cylindrical protrusions, elliptical cylindrical protrusions, and prismatic protrusions. The columnar protrusion 201 shown in the accompanying drawings of this embodiment is a cylindrical protrusion, and the following description will also use a cylindrical protrusion as an example.

[0054] The rod-shaped protrusion 202 includes a uniform width middle section 2021 and tapered sections 2022 disposed at both ends of the uniform width middle section 2021. The tapered sections 2022 and the uniform width middle section 2021 are integrally formed. The height of the tapered sections 2022 gradually decreases in the height direction of the rod-shaped protrusion 202, and the surface of the tapered sections 2022 is a smooth arc surface. The highest part of the rod-shaped protrusion 202 is located in the middle of the uniform width middle section 2021. The height of the uniform width middle section 2021 gradually decreases from its middle to both sides of its length. Moreover, the height of the uniform width middle section 2021 in the width direction also decreases from its middle to both sides. This gradual change in height can effectively increase the friction of the adhesive film surface while reducing local stress concentration, avoiding damage or poor processing of the adhesive film surface caused by sharp edges, and extending the service life of the adhesive film.

[0055] refer to Figures 6 to 11 , Figures 6 to 11 The diagram shown is a cross-sectional view of the equal-width middle section 2021 of the rod-shaped protrusion 202 along the width direction. The cross-sectional shape of the equal-width middle section 2021 of the rod-shaped protrusion 202 can be any one of the following: semi-circular, rounded rectangle, triangle, trapezoid, crescent, or pagoda.

[0056] In one implementation, the thickness of the film body 1 is 0.3-2.0 mm (e.g., 0.5 mm, 0.8 mm, 1.0 mm, 1.5 mm), the length of the rod-shaped protrusion 202 is 2-7 mm, the maximum width of the rod-shaped protrusion 202 is 3-4 mm, and the maximum height of the rod-shaped protrusion 202 is 0.5-1.0 mm. The bottom diameter of the cylindrical protrusion is 0.5-1.5 mm, and the maximum height of the cylindrical protrusion is 0.5-1.0 mm.

[0057] Optionally, the columnar protrusion 201 is a cylindrical protrusion, and the center distance between the cylindrical protrusions of two adjacent unit patterns 20 is 2-6 mm.

[0058] It is worth mentioning that the positional relationship between the cylindrical protrusion and the rod-shaped protrusion 202 can be varied. For example, the cylindrical protrusion can be located outside the equal-width middle section 2021 of the rod-shaped protrusion 202, or it can be located on the side of the tapered section 2022 of the rod-shaped protrusion 202. In the accompanying drawings of this embodiment, the cylindrical protrusion is located on the side of the tapered section 2022, and the cylindrical protrusion and the rod-shaped protrusion 202 are approximately "L"-shaped.

[0059] The width of the groove 203 can be designed according to actual needs, and is not limited here.

[0060] In other embodiments, the form of the unit pattern 20 includes, but is not limited to, those described above, and may also be as follows: Figures 12 to 14 The form shown; Figure 12The unit pattern 20 shown is formed by three rod-shaped protrusions 202 arranged in an equilateral triangle and an inscribed columnar protrusion 201 set inside the equilateral triangle. Figure 13 The unit pattern 20 shown is composed of a columnar protrusion 201 and six rod-shaped protrusions 202 surrounding the columnar protrusion 201. Figure 14 The unit pattern 20 shown is composed of a columnar protrusion 201 and five rod-shaped protrusions 202 surrounding the columnar protrusion 201. Figure 13 and Figure 14 The rod-shaped protrusion 202 rotates in the opposite direction to the inner columnar protrusion 201.

[0061] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0062] Example 1: The encapsulating film includes a film body 1 and a surface pattern 2 disposed on the film body 1. The surface pattern 2 on the film body 1 includes at least one unit pattern 20. Each unit pattern 20 includes a columnar protrusion 201, a rod-shaped protrusion 202, and a groove 203 between the columnar protrusion 201 and the rod-shaped protrusion 202. The columnar protrusion 201 is a cylindrical protrusion, and the rod-shaped protrusion 202 includes a uniform width middle section 2021 and tapered sections 2022 disposed at both ends of the uniform width middle section 2021.

[0063] The thickness of the film body 1 is 1.5 mm. The bottom diameter of the cylindrical protrusion is 1.0 mm, and the height of the cylindrical protrusion is 0.8 mm. The cylindrical protrusion is tangent to the edge of the tapered section 2022 of the rod-shaped protrusion 202. The center distance between adjacent cylindrical protrusions is 3.0 mm. The length of the rod-shaped protrusion 202 is 5.0 mm. The cross-section of the equal-width middle section 2021 in the width direction is semi-circular. The width of the equal-width middle section 2021 is 3.0 mm, and the maximum height of the equal-width middle section 2021 is 0.9 mm. The lowest height of the edge of the tapered section 2022 is 0.5 mm. It gradually and smoothly transitions from the highest point of the equal-width middle section 2021 to the lowest height edge of the tapered section 2022. The radius of curvature of the arc surface of the tapered section 2022 is 0.5 mm. The included angle formed by adjacent rod-shaped protrusions 202 along their respective length directions is 90°.

[0064] Using the encapsulating film with surface pattern 2 set in Example 1 and the traditional unpatterned encapsulating film, a comparative test was conducted. After encapsulating photovoltaic modules, the sliding distance of the photovoltaic module stacking was reduced by 75% with the encapsulating film with surface pattern 2 set in Example 1. The amount of additives precipitated and the diffusion area on the surface of the film were reduced by 50% compared with the conventional unpatterned film. The encapsulating film with surface pattern 2 is cleaner. At the same time, due to the surface pattern 2, the separation time of the film was reduced by 60% during production, which greatly improved production efficiency and reduced the scrap rate of the product.

[0065] In other examples, different needs can be met by changing the shape and size of the columnar protrusions 201, changing the parameters of the rod-shaped protrusions 202, or changing the arrangement of the unit patterns 20. These will not be described in detail here.

[0066] The encapsulating film of this utility model embodiment has at least the following beneficial effects:

[0067] (1) By setting columnar protrusions 201, rod-shaped protrusions 202 and grooves 203, the friction of the film on the glass and cell surfaces is greatly improved, the risk of slippage is reduced, and the stability of the photovoltaic module stack is ensured.

[0068] (2) The columnar protrusion 201, the rod-shaped protrusion 202 and the groove 203 reduce the contact area of ​​the adhesive film surface, avoid the adhesion between adhesive film layers, and enable the adhesive film layers to be separated smoothly during the production process, thereby improving the loading and unloading efficiency.

[0069] (3) It reduces the possibility of additives accumulating on the surface of the film, and the migration path of additives is longer and the precipitation rate is significantly reduced, thereby effectively alleviating the problem of additives contaminating the film.

[0070] (4) The structure and height design of the surface pattern 2 are adapted to both adsorption and traction feeding methods, and have excellent process compatibility in new film casting extrusion equipment such as mesh belt machines, which improves the versatility and adaptability of the equipment.

[0071] An embodiment of this utility model also provides a solar cell, including the above-mentioned encapsulating film, which has all the functions of an encapsulating film.

[0072] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An encapsulation film, characterized by, Includes a film body (1) and surface patterns (2) disposed on the front and / or back of the film body (1). The surface pattern (2) includes at least one unit pattern (20), the unit pattern (20) includes a columnar protrusion (201), a rod-shaped protrusion (202) and a groove (203) between the columnar protrusion (201) and the rod-shaped protrusion (202). The rod-shaped protrusion (202) includes a uniform width middle section (2021) and tapered sections (2022) disposed at both ends of the uniform width middle section (2021). The height of the tapered sections (2022) gradually decreases in the height direction of the rod-shaped protrusion (202). The height of the uniform width middle section (2021) gradually decreases from its middle to both sides of its length. The height of the uniform width middle section (2021) in the width direction also decreases from its middle to both sides.

2. The encapsulation film according to claim 1, wherein, The columnar protrusion (201) is a cylindrical protrusion, an elliptical columnar protrusion, or a prismatic protrusion.

3. The encapsulation film according to claim 1, wherein, The surface of the tapered section (2022) is a smooth arc surface, and the cross-sectional shape of the equal-width middle section (2021) is any one of the following: semi-circular, rounded rectangle, triangle, trapezoid, crescent, or pagoda.

4. The encapsulation film of claim 1, wherein, The thickness of the adhesive film body (1) is 0.3-2.0 mm, the length of the rod-shaped protrusion (202) is 2-7 mm, the maximum width of the rod-shaped protrusion (202) is 3-4 mm, and the maximum height of the rod-shaped protrusion (202) is 0.5-1.0 mm.

5. The encapsulation film of claim 2, wherein, The columnar protrusion (201) is a cylindrical protrusion with a bottom diameter of 0.5-1.5 mm and a maximum height of 0.5-1.0 mm.

6. The encapsulation film of claim 2, wherein, The columnar protrusion (201) is a cylindrical protrusion, and the center distance between two adjacent cylindrical protrusions of the unit pattern (20) is 2-6mm.

7. The encapsulation film of claim 1, wherein, The included angle between the two rod-shaped protrusions (202) is 0-180°.

8. The encapsulation film according to any one of claims 1 to 7, wherein, The grooves (203) of adjacent unit patterns (20) are connected.

9. A solar cell, characterized by, Includes the encapsulating film as described in any one of claims 1 to 8.

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