Adhesive film and photovoltaic module

Abstract

The embodiment of the application provides a kind of adhesive film and photovoltaic module, belong to photovoltaic cell technical field.The adhesive film is used to cover the multiple battery pieces in photovoltaic module, and the adhesive film includes: adhesive film body, the area of adhesive film body is adapted to the packaging requirement of photovoltaic module, adhesive film body includes multiple target areas and the flush area different from target area, the thickness of target area is higher than the thickness of flush area.The embodiment of the application sets thicker adhesive film in the area prone to grid breakage, to improve the adhesion of adhesive film in target area to battery piece, so that the adhesive film in target area has stronger pressure on the grid line of the area, is not easily affected by external force, and then is not prone to grid breakage.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module manufacturing technology, and more particularly to an encapsulant film and a photovoltaic module. Background Technology

[0002] In the manufacturing process of photovoltaic cells, both product quality stability and cost savings must be considered. The cost of precious metal pastes such as silver in the cells is relatively high. Therefore, during processes such as grid line deposition, efforts are made to minimize silver consumption while ensuring grid line quality, in order to save costs. However, in some localized areas, grid breakage can easily occur. Utility Model Content

[0003] This application provides an encapsulant film and a photovoltaic module to solve or alleviate one or more technical problems in the prior art.

[0004] As one aspect of the embodiments of this application, this application provides an adhesive film for covering multiple solar cells in a photovoltaic module. The adhesive film includes an adhesive film body, the area of ​​which is adapted to the encapsulation requirements of the photovoltaic module. The adhesive film body includes multiple target areas and a flush area that is different from the target areas. The thickness of the target areas is greater than the thickness of the flush area.

[0005] In one embodiment, in the film body, the target area protrudes towards the side closer to the battery cell relative to the flush area.

[0006] In one embodiment, the plurality of battery cells includes a target battery cell, which is a battery cell located at the edge of the plurality of battery cells; the target region includes a region corresponding to the target battery cell.

[0007] In one embodiment, the plurality of solar cells includes an intermediate solar cell that is distinct from the target solar cell, and the target region also includes a region corresponding to the edge position of the intermediate solar cell.

[0008] In one implementation, the thickness difference between the target area and the flush area is 5-30 μm.

[0009] In one embodiment, a conductive adhesive is also included, which is applied to the side of the target area facing the battery cell.

[0010] In one embodiment, the coating thickness of the conductive adhesive is 20-30 μm.

[0011] In one embodiment, conductive adhesive is applied to the target area corresponding to the grid line area of ​​the battery cell.

[0012] In one embodiment, the width of the conductive adhesive coating is 100%-200% of the grid line width of the battery cell.

[0013] As another aspect of the present application, the present application also provides a photovoltaic module, including a plurality of solar cells and an encapsulating film, wherein the encapsulating film covers opposite sides of the solar cells, and the thickness of the target area in the encapsulating film is higher than the thickness of the flush area.

[0014] In one embodiment, the encapsulating film is the film of any of the embodiments described above.

[0015] This application embodiment improves the adhesion of the adhesive film to the battery cell by setting a thicker film in the area where the grid is prone to breakage. As a result, the adhesive film in the target area exerts stronger pressure on the grid lines in that area, making it less susceptible to external forces and thus less prone to grid breakage.

[0016] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0017] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0018] Figure 1 This shows an image obtained from an EL test of an existing photovoltaic module.

[0019] Figure 2 A schematic diagram of the surface structure of an adhesive film provided according to an embodiment of this application is shown. Detailed Implementation

[0020] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0021] Figure 1 This shows an image obtained from an EL test of an existing photovoltaic module. Figure 2 A schematic diagram of the surface structure of an adhesive film provided according to an embodiment of this application is shown. Figure 1As can be seen from the provided images, grid breakage is prone to occur in the outer edge region surrounding the photovoltaic module 200. Furthermore, grid breakage also occurs at the edge region of each individual cell. Grid breakage leads to a reduction in the power generation of the photovoltaic module 200, resulting in a loss of power generation efficiency. Therefore, the embodiments of this application aim to solve the above-mentioned problems in existing photovoltaic modules 200, avoiding grid breakage at the edges of the photovoltaic module 200 and / or avoiding grid breakage at the edges of the individual cells.

[0022] like Figure 1 and Figure 2 As shown, this application embodiment provides an encapsulating film 100 for covering multiple solar cells in a photovoltaic module 200. This encapsulating film 100 is a sealing film required when encapsulating the solar cells. After covering the solar cells with the encapsulating film 100 and then covering them with encapsulating glass, lamination is performed to obtain a laminate, and then an aluminum frame is added to the laminate to obtain the photovoltaic module 200.

[0023] This application embodiment improves the encapsulating film 100 to address the problem of grid breakage that easily occurs in existing photovoltaic modules 200, thereby avoiding power generation efficiency loss and improving the power generation efficiency of the photovoltaic module 200.

[0024] The encapsulant film 100 provided in this application embodiment includes: an encapsulant film 100 body, the area of ​​which is adapted to the encapsulation requirements of the photovoltaic module 200, the encapsulant film 100 body including multiple target areas 110 and a flush area 120 different from the target areas 110, the thickness of the target areas 110 being greater than the thickness of the flush area 120.

[0025] The film 100 body can be any film 100 material that can be used to encapsulate battery cells, such as EVA film 100 or POE film 100.

[0026] It is understandable that in order to properly encapsulate the multiple cells of the photovoltaic module 200, the area of ​​its encapsulant film 100 needs to completely cover the multiple cells to avoid areas not covered by the encapsulant film 100, which could lead to the infiltration of air, moisture, etc.

[0027] The area of ​​the film 100 body can be determined using either existing or future encapsulation methods.

[0028] The target area 110 can be an area where grid breakage needs to be prevented, or an area in the existing or unmodified photovoltaic module 200 that is prone to grid breakage.

[0029] This embodiment of the application improves the adhesion of the adhesive film 100 to the battery cell by providing a thicker film 100 in areas prone to grid breakage. This results in the adhesive film 100 in the target area 110 exerting stronger pressure on the grid lines in that area, making it less susceptible to external forces and thus less prone to grid breakage. It is understood that the adhesive film 100 in the target area 110 can also exert stronger pressure on the solder ribbon, reducing the risk of the solder ribbon detaching from the grid lines, i.e., reducing the risk of desoldering.

[0030] The encapsulant film 100 provided in this application embodiment is used to encapsulate battery cells, which can reduce grid breakage and reduce the risk of desoldering.

[0031] In one embodiment, in the body of the film 100, the target region 110 protrudes toward the side closer to the battery cell relative to the flush region 120.

[0032] It is understandable that the film 100 is sheet-like, with one side facing the battery cell and the other side facing the encapsulation glass.

[0033] In some other examples, the adhesive film 100 of the target region 110 may also protrude toward the side opposite to the solar cell relative to the flush region 120. That is, as long as the adhesive film 100 of the target region 110 is relatively thicker, and the adhesive film 100 is flowable during the lamination process, the adhesive film 100 at that location can have a stronger adhesion to the solar cell.

[0034] In this embodiment of the application, preferably, the target area 110 protrudes towards the side closer to the battery cell relative to the flush area 120. During the lamination process, the adhesive film 100 at this protruding position can adhere to the battery cell more quickly, which can better ensure the adhesion force of the adhesive film 100 to the battery cell during the lamination process.

[0035] In one embodiment, the plurality of battery cells includes a target battery cell 210, which is a battery cell located at the edge of the plurality of battery cells; the target region 110 includes a region corresponding to the target battery cell 210.

[0036] In response to the issue that grid breakage is prone to occur in the edge area of ​​existing photovoltaic modules 200, the thickness of the encapsulant film 100 is specifically increased on the target cell 210 at the edge to exert a stronger adhesion force on the cell in the edge area, thereby ensuring that grid breakage does not occur on the target cell 210 in the edge area.

[0037] In some examples, when the film 100 of the target cell 210 in the edge area is thicker, it can be ensured that no grid breakage will occur on the target cell 210. For local grid breakage on other cells in the middle area, additional measures can be taken to prevent grid breakage.

[0038] In this embodiment, the adhesive film 100 is thicker at the edges and thinner in the middle. When preparing the adhesive film 100, it can be extruded and molded using a mold.

[0039] In one embodiment, the plurality of battery cells includes an intermediate battery cell 220 that is distinct from the target battery cell 210, and the target region 110 also includes a region corresponding to the edge position in the intermediate battery cell 220.

[0040] In the intermediate cell 220, the grid lines located at the edge of the cell are also prone to grid breakage. To address this, the thickness of the adhesive film 100 at the corresponding location is increased to enhance the adhesion of the cell at that location.

[0041] In one embodiment, the thickness difference between the target region 110 and the flush region 120 is 5-30 μm. The thickness of the target region 110 needs to ensure its adhesion to the solar cell, so that the corresponding target region 110 in the module is less prone to grid breakage.

[0042] In one example, a thicker adhesive film 100 can be set at the first target location where grid breakage is more likely to occur, and a thinner adhesive film 100 can be set at the second target location where grid breakage is relatively likely to occur, and the adhesive film 100 is thicker than the adhesive film 100 at the first target location, and is also thicker than the thickness of the flush area 120.

[0043] For example, the first target location can be the target area 110 at the target cell 210, and the second target location can be the target area 110 at the intermediate cell 220.

[0044] By setting the thickness of the encapsulant film 100 in a gradient manner, it is possible to reduce the amount of encapsulant film 100 used while achieving the effect of preventing grid breakage, thus avoiding increasing the weight of the photovoltaic module 200.

[0045] The thickness difference between the target region 110 and the flush region 120 is 5-30 μm. This thickness difference enhances the adhesion to the solar cell, preventing grid breakage. This thickness difference can be obtained from multiple experimental tests. Based on this difference, the film 100 of the target region 110 at the target solar cell 210 can be 30 μm thicker or close to 30 μm thicker than the film 120, and the film 100 of the target region 110 at the intermediate solar cell 220 can be 5 μm thicker or other values ​​thicker than the film 120.

[0046] In one example, experimental testing can determine how thick the encapsulant film 100 needs to be added in this type of photovoltaic module 200 to prevent grid breakage, and determine the maximum value of the thickness difference. In the actual manufacturing process, this maximum value can be used to determine the thickness of the encapsulant film 100 in the target area 110 of the target cell 210. Then, based on the thickness of the encapsulant film 100 in the flush area 120, the thickness of the encapsulant film 100 in the target area 110 at the intermediate cell 220 can be adaptively and appropriately determined.

[0047] In one embodiment, a conductive adhesive 130 is also included, which is applied to the side of the target area 110 facing the battery cell.

[0048] The conductive adhesive 130 has adhesive properties, which can enhance the adhesion to the solar cell at the application site and prevent grid breakage. The conductive adhesive 130 also has conductive properties, and when applied to the grid lines, it can also make the areas where grid breakage may occur conductive.

[0049] In some other examples, conductive adhesive 130 can also be applied to the battery cell, which allows for better identification of the areas where it needs to be applied.

[0050] In one example, grid breakage can be prevented in the target area 110 of the target cell 210 by increasing the thickness of the adhesive film 100, and in the target area of ​​the intermediate cell 220 by coating the conductive adhesive 130.

[0051] In one example, grid breakage can be prevented in the target area 110 of the target cell 210 by increasing the thickness of the adhesive film 100 and applying conductive adhesive 130. In the target area of ​​the intermediate cell 220, grid breakage can be prevented by applying conductive adhesive 130.

[0052] In one example, grid breakage can be prevented in the target region 110 of the target cell 210 by increasing the thickness of the adhesive film 100 and applying conductive adhesive 130. Similarly, grid breakage can be prevented in the target region 110 of the intermediate cell 220 by increasing the thickness of the adhesive film 100. The increased thickness of the adhesive film 100 can be the same in both regions, or the thickness of the adhesive film 100 in the target region 110 of the target cell 210 can be greater than that in the target region 110 of the intermediate cell 220.

[0053] In one example, conductive adhesive 130 can be applied to the grid line locations in multiple batteries to enhance the strength of the grid line soldering and prevent grid breakage.

[0054] In one embodiment, the coating thickness of the conductive adhesive 130 is 20-30 μm, for example, it can be 20 μm, 22 μm, 25 μm, 27 μm, or 30 μm. The coating thickness of the conductive adhesive 130 is determined according to its viscosity; the stronger the viscosity, the less conductive adhesive 130 can be applied. The coating thickness of the conductive adhesive 130 should not be too thick. If the conductive adhesive 130 is coated too thickly, it will flow during the lamination process, causing conduction between gate lines of different polarities and resulting in a short circuit.

[0055] In one embodiment, conductive adhesive 130 is applied to the target area 110 corresponding to the grid line area of ​​the battery cell. The conductive adhesive 130 is applied to the battery cell or to the adhesive film 100 by coating, and the coating can be controlled with high precision. Applying it to the grid line area can avoid short circuits, etc.

[0056] In one embodiment, the coating width of the conductive adhesive 130 is 100%-200% of the grid line width of the solar cell. The coating width of the conductive adhesive 130 is greater than or equal to the grid line width to ensure its effectiveness in preventing grid breakage. This avoids situations where localized areas lack the conductive adhesive 130, failing to prevent grid breakage and resulting in locally thinned grid lines, which would also affect the power generation efficiency of the photovoltaic module 200. However, the coating width of the conductive adhesive 130 cannot be too wide. If the conductive adhesive 130 is coated too wide, it will flow during lamination, easily becoming conductive with grid lines of different polarities, causing a short circuit.

[0057] Therefore, in this application embodiment, the coating width of the conductive adhesive 130 is limited to 100%-200% of the grid line width of the battery cell, for example, 100%, 120%, 150%, 170% or 200%.

[0058] This application also provides a photovoltaic module, including multiple solar cells and an encapsulating film. The encapsulating film covers opposite sides of the solar cells, and the thickness of the target area in the encapsulating film is higher than the thickness of the flush area.

[0059] For example, the encapsulating film can be applied to multiple battery cells in a stacked manner, and the film can be selectively added to the target area in a stacked manner, so that the thickness of the film in the target area is higher than that in the flush area.

[0060] In one embodiment, the encapsulating film is the film of any of the embodiments described above.

[0061] The encapsulant film described above can be stacked as a whole on multiple solar cells. Furthermore, the thickened areas of the encapsulant film are pre-set according to the arrangement of the solar cells. In similar photovoltaic modules, this pre-set encapsulant film can be used in batches as a finished product, eliminating the need for further adjustment or determination of the thickness in different areas. This improves the production efficiency of photovoltaic modules and ensures the prevention of grid breakage.

[0062] Other components of the photovoltaic modules in the above embodiments can be derived from various technical solutions that are now and will be known to those skilled in the art, and will not be described in detail here.

[0063] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Therefore, they should not be construed as limitations on this application.

[0064] Furthermore, the terms "first" and "second" are used 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 as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0065] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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, an electrical connection, or a communication 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0066] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0067] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0068] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A film, characterized in that, The encapsulant film is used to cover multiple solar cells in a photovoltaic module. The encapsulant film body has an area adapted to the encapsulation requirements of the photovoltaic module. The encapsulant film body includes multiple target areas and a flush area that is different from the target areas. The thickness of the target areas is greater than the thickness of the flush area.

2. The adhesive film according to claim 1, characterized in that, In the film body, the target area protrudes towards the side closer to the battery cell relative to the flush area.

3. The adhesive film according to claim 1, characterized in that, The plurality of battery cells includes a target battery cell, which is a battery cell located at the edge of the plurality of battery cells; the target region includes a region corresponding to the target battery cell.

4. The adhesive film according to claim 3, characterized in that, The plurality of battery cells includes an intermediate battery cell that is distinct from the target battery cell, and the target region also includes a region corresponding to the edge position of the intermediate battery cell.

5. The adhesive film according to any one of claims 1 to 4, characterized in that, The thickness difference between the target region and the flush region is 5-30 μm.

6. The adhesive film according to any one of claims 1 to 4, characterized in that, It also includes a conductive adhesive, which is applied to the side of the target area facing the battery cell.

7. The adhesive film according to claim 6, characterized in that, The coating thickness of the conductive adhesive is 20-30 μm.

8. The adhesive film according to claim 6, characterized in that, The conductive adhesive is applied to the target area corresponding to the grid line area of ​​the battery cell.

9. The adhesive film according to claim 8, characterized in that, The coating width of the conductive adhesive is 100%-200% of the grid line width of the battery cell.

10. A photovoltaic module, characterized in that, It includes multiple battery cells and an encapsulating film, the encapsulating film covering opposite sides of the battery cells, and the thickness of the target area in the encapsulating film being higher than the thickness of the flush area.

11. The photovoltaic module according to claim 10, characterized in that, The encapsulating film is the film described in any one of claims 1 to 9.

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