Adhesive film and photovoltaic module

Abstract

This application relates to the photovoltaic field, providing a photovoltaic film and a photovoltaic module. The film is used to encapsulate a string of cells in a photovoltaic module. Adjacent strings of cells have a first gap, and the cells forming the strings of cells have a second gap. The film includes: a photovoltaic film having a first side facing the string of cells and a second side opposite to the first side; the photovoltaic film having at least one groove recessed from the first side towards the second side, the groove being opposite at least one of the first gap or the second gap; and a plurality of waterproof films located within the groove, the plurality of waterproof films being arranged at intervals. The film and photovoltaic module provided by this application can at least improve the waterproof performance of the film.

Description

[0001] This application is a divisional application of patent application No. 202210917220.5, filed on August 1, 2022, entitled "Coating Film and Photovoltaic Module". Technical Field

[0002] This application relates to the photovoltaic field, and particularly to an encapsulant film and a photovoltaic module. Background Technology

[0003] A solar cell is a device that directly converts light energy into electrical energy through the photoelectric effect or photochemical effect. A single solar cell cannot be used directly as a power source. To use it as a power source, several individual cells must be connected in series or parallel and tightly packaged into a module. A solar cell module (also called a solar panel) is the core and most important part of a solar power generation system. The function of a solar cell module is to convert solar energy into electrical energy, either for storage in batteries or to power loads.

[0004] Solar cells are very fragile, and generally require an encapsulant film and a cover plate on the top and bottom surfaces of the solar module to protect them. The cover plate is usually made of photovoltaic glass, which cannot be directly attached to the solar cells; an encapsulant film is needed in the middle to act as an adhesive. While the encapsulant film generally has excellent light transmittance, it yellows and ages upon exposure to air, leading to a series of problems that affect power generation efficiency, such as waterproofing issues. Summary of the Invention

[0005] This application provides an adhesive film and a photovoltaic module, which at least helps to improve the waterproof performance of the adhesive film.

[0006] According to some embodiments of this application, one aspect of this application provides an encapsulating film for encapsulating battery strings in a photovoltaic module, wherein adjacent battery strings have a first gap and the battery cells constituting the battery strings have a second gap, comprising: a photovoltaic encapsulating film having a first side facing the battery strings and a second side opposite to the first side, the photovoltaic encapsulating film having at least one groove recessed from the first side toward the second side, the groove being opposite to at least one of the first gap or the second gap; and a plurality of waterproof encapsulating films located within the groove, the plurality of waterproof encapsulating films being arranged at intervals.

[0007] In addition, the groove includes a first groove and a second groove, the first groove being opposite to a first gap, the second groove being opposite to a second gap, and at least one of the first groove or the second groove having a waterproof adhesive membrane; each first groove is connected to at least one second groove.

[0008] In addition, along the first direction, the second grooves corresponding to different battery strings are connected, and the second grooves corresponding to different battery strings are connected to the same first groove; wherein, the first direction is parallel to the first surface and perpendicular to the arrangement direction of the battery cells of the battery string.

[0009] In addition, part of the waterproof membrane is located in the first groove, and / or part of the waterproof membrane is located in the second groove.

[0010] In addition, along the first direction, a plurality of waterproof membranes located in the second groove are arranged at intervals; the ratio of the first spacing of the plurality of waterproof membranes to the second spacing of the adjacent first groove is 4 / 5 to 1.

[0011] In addition, along the arrangement direction of the battery cells in the battery string, multiple waterproof membranes located in the first groove are arranged at intervals; the ratio of the third spacing of the multiple waterproof membranes to the fourth spacing of the adjacent second groove is 4 / 5 to 1.

[0012] In addition, the waterproof membranes located in different first grooves are staggered along the first direction; or, the waterproof membranes located in different second grooves are staggered along the arrangement direction of the battery cells of the battery string.

[0013] In addition, the width of the first groove is less than or equal to the string spacing between adjacent battery strings; and / or, the width of the second groove is less than or equal to the cell spacing between adjacent battery cells.

[0014] In addition, the depth of at least one of the first groove or the second groove is less than or equal to 0.05 mm.

[0015] In addition, the width of the waterproof membrane gradually decreases along the direction from the second surface to the first surface.

[0016] In addition, along the direction from the second surface to the first surface, the top surface of the waterproof film is higher than the first surface of the photovoltaic film.

[0017] In addition, the height difference between the top surface of the waterproof membrane and the first surface of the photovoltaic membrane is less than or equal to the thickness of the solar cell.

[0018] In addition, the materials of waterproof adhesive film are different from those of photovoltaic adhesive film. The melting point of waterproof adhesive film is less than or equal to that of photovoltaic adhesive film.

[0019] In addition, the waterproof membrane is made of the same material as the photovoltaic membrane; the membrane is a one-piece molded structure.

[0020] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: a first cover plate, a first encapsulant film, a battery string, a second encapsulant film, and a second cover plate, wherein at least one of the first encapsulant film or the second encapsulant film is an encapsulant film as described in any of the above embodiments.

[0021] In addition, along the direction parallel to the first surface of the photovoltaic film, the cross-sectional shape of the waterproof adhesive film is mesh-like or honeycomb-like.

[0022] The technical solution provided in this application has at least the following advantages:

[0023] In the technical solution provided in this application embodiment, the first surface of the photovoltaic encapsulant film has grooves. These grooves are opposite to the first gap between the battery strings or the second gap between the battery cells. The grooves serve as guide grooves for the waterproof encapsulant film. During lamination, the waterproof encapsulant film is in a molten state and extends along the direction of the grooves. Adjacent waterproof encapsulants connect to each other, ultimately forming a mesh structure or a striped structure. The shapes of the striped and mesh structures are opposite to the first and second gaps. The overall waterproof performance of the assembled encapsulant film combined with the photovoltaic encapsulant film is good, preventing water vapor from entering and corroding the battery cells. The grooves in the photovoltaic encapsulant film and the gaps in the waterproof encapsulant film facilitate gas venting, preventing air bubbles from forming in the final photovoltaic module and affecting its performance. Attached Figure Description

[0024] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of an adhesive film provided in an embodiment of this application;

[0026] Figure 2 This is a schematic cross-sectional view of the adhesive film provided in one embodiment of this application;

[0027] Figure 3 This is a schematic diagram of a solar cell provided in an embodiment of this application;

[0028] Figure 4 This is a schematic diagram of a battery assembly provided in an embodiment of this application;

[0029] Figure 5 This is a schematic diagram of a photovoltaic module provided in an embodiment of this application. Detailed Implementation

[0030] As can be seen from the background technology, the waterproof performance of existing adhesive films is not good.

[0031] This application provides an encapsulating film for encapsulating battery strings in a photovoltaic module. Adjacent battery strings have a first gap, and the battery cells forming the battery strings have a second gap. The film includes: a photovoltaic encapsulating film having a first side facing the battery strings and a second side opposite to the first side; the photovoltaic encapsulating film has at least one groove recessed from the first side towards the second side, the groove being opposite at least one of the first or second gap; and multiple waterproof encapsulating films located within the groove, spaced apart. The groove serves as a guide groove for the waterproof encapsulating film. During lamination, the waterproof encapsulating film is in a molten state, extending along the extension direction of the groove. Adjacent waterproof encapsulating films connect to form a mesh structure or a striped structure. The shape of the striped structure and mesh structure is opposite to the first and second gaps. The overall waterproof performance of the assembled film combining the waterproof encapsulating film and the photovoltaic encapsulating film is good, preventing moisture from entering and corroding the battery cells. The grooves in the photovoltaic encapsulating film and the gaps in the waterproof encapsulating film facilitate gas venting, preventing air bubbles from forming in the final photovoltaic module and affecting its performance.

[0032] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0033] Figure 1 This is a schematic diagram of the structure of an adhesive film provided in an embodiment of this application; Figure 2 This is a schematic cross-sectional view of the adhesive film provided in one embodiment of this application; Figure 3 This is a schematic diagram of a solar cell provided in an embodiment of this application; Figure 4 This is a schematic diagram of a battery assembly provided in an embodiment of this application.

[0034] According to some embodiments of this application, reference is made to Figures 1-5 One embodiment of this application provides an encapsulating film for encapsulating battery strings in a photovoltaic module. Adjacent battery strings have a first interval 11, and the battery cells 10 constituting the battery strings have a second interval 12. The film includes: a photovoltaic encapsulating film 111, which has a first surface 113 facing the battery strings and a second surface 114 opposite to the first surface 113. The photovoltaic encapsulating film 111 has at least one groove 120 recessed from the first surface 113 toward the second surface 114, and the groove 120 is opposite to at least one of the first interval 11 or the second interval 12; and a plurality of waterproof encapsulating films 112, which are located within the groove 120 and are spaced apart.

[0035] In some embodiments, reference Figure 3 The solar cell 10 includes, but is not limited to, any one of the following: PERC cell (Passivated Emitter and Rear Cell), PERT cell (Passivated Emitter and Rear Totally-diffused cell), TOPCon cell (Tunnel Oxide Passivated Contact), and HIT / HJT cell (Heterojunction Technology).

[0036] In some embodiments, the grid lines are used to collect the photocurrent generated within the solar cell and lead it to the outside of the cell 10. The grid lines include main grid lines 102 and auxiliary grid lines (sub-grid lines), where the auxiliary grid lines are also referred to as sub-grid lines. The auxiliary grid lines are used to guide the current, and the main grid lines 102 are used to collect and summarize the current from the auxiliary grid lines. In other embodiments, the grid lines only include auxiliary grid lines, thereby shortening the carrier transport path and reducing the series resistance, thereby increasing the front-side light-receiving area, improving the module power, increasing the short-circuit current, and reducing the amount of silver paste used for grid line printing to reduce production costs.

[0037] In some embodiments, the number of main grid lines 102 can be any value, generally 8 to 30; preferably, the number of main grid lines 102 is 14 to 22, specifically 8, 10, 12, 14, 16, 18, or 20. The number of solder joints 101 on the same main grid line 102 can be any value, preferably 8 to 20. Each solder joint 101 has the same area; in other embodiments, the solder joint areas may be different, for example, the area of ​​the solder joints located at both ends of the main grid line 102 is larger than the area of ​​the solder joints on the main grid line 102 excluding the ends. It is understood that the solder joint 101 is the contact point where the main grid line 102 contacts the solder strip 103. This application embodiment uses a battery cell 10 having 10 main grid lines and 10 solder joints 102 on the same main grid line 102 as an example for illustration.

[0038] In some embodiments, the battery cell 10 can be a whole battery or a sliced ​​battery. Sliced ​​batteries can be half-cell, three-cell, four-cell, or eight-cell batteries, etc. A half-cell can also be understood as a battery cut in half or a battery divided into two segments. The battery string group is sequentially divided into a first battery string and a second battery string in the first direction X. Multiple first and second battery strings are arranged parallel to each other and spaced apart in the first direction X. The positive and negative poles of the first and second battery strings are opposite, or the current transmission directions are opposite. A battery string group with an overall rectangular shape is formed by connecting the positive pole of the first battery string to the negative pole of the second battery string, and the positive pole of the second battery string to the negative pole of another adjacent first battery string. The positive and negative poles of adjacent battery cells 10 are connected by solder strips 103.

[0039] In some embodiments, the material of the waterproof adhesive film 112 is different from that of the photovoltaic adhesive film 111, and the melting point of the waterproof adhesive film 112 is less than or equal to the melting point of the photovoltaic adhesive film 111. Thus, during the lamination process, when the material of the waterproof adhesive film 112 is in a molten state, the grooves 120 of the photovoltaic adhesive film 111 still exist, serving as guide grooves for the molten waterproof adhesive film 112, allowing multiple molten waterproof adhesive films 112 to come into contact, thereby forming a continuous film layer and creating a relatively dense waterproof film layer, preventing moisture from entering the surface of the solar cell 10 and causing corrosion or even failure of the solar cell 10 surface. The photovoltaic encapsulant film 111 can be made of EVA. Films made from EVA have lower manufacturing costs and are easier to mass-produce. The waterproof encapsulant film 112 can be made of POE, liquid silicone, or PVB (polyvinyl butyral resin). POE is a non-polar material with excellent water vapor and ion barrier capabilities; its water vapor transmission rate is only about 1 / 8 that of EVA film. Due to its stable molecular chain structure, it does not decompose to produce acidic substances during aging, exhibiting excellent anti-aging properties. PVB has good water resistance, oil resistance, and water resistance. Furthermore, PVB resin has excellent optical clarity; its refractive index is similar to that of glass, and images viewed through laminated glass do not exhibit optical distortion or double phases, reducing the loss of incident light on the photovoltaic module surface. PVB remains unchanged over a wide temperature range, possessing both flexibility and rigidity, as well as excellent impact resistance; it also has excellent adhesion efficiency to various glass surfaces. Liquid silicone possesses excellent tear resistance, resilience, anti-yellowing properties, thermal stability, and heat aging resistance, while also exhibiting moderate viscosity, ease of handling, and high product transparency. However, the manufacturing costs of POE, liquid silicone, and PVB are all relatively high, which is detrimental to reducing the cost of photovoltaic modules. In other embodiments, the waterproof adhesive film is made of the same material as the photovoltaic adhesive film; the adhesive film is a one-piece molded structure. For example, the waterproof adhesive film and the photovoltaic adhesive film are composite films, and the materials of the waterproof adhesive film and the photovoltaic adhesive film include any two or more of EVA, POE, liquid silicone, or PVB.

[0040] In some embodiments, the groove 120 includes a first groove 121 and a second groove 122, the first groove 122 being opposite to a first spacer 11 and the second groove 122 being opposite to a second spacer 12, and at least one of the first groove 121 or the second groove 122 having a waterproof membrane 112; each first groove 121 is connected to at least one second groove 122. Thus, the groove 120 can form a comb-shaped groove, and after the lamination process, the cross-sectional shape of the waterproof membrane 112 is a comb-shaped structure, improving the waterproof performance of the membrane.

[0041] In some embodiments, second grooves 122 corresponding to different battery strings are connected along the first direction Y, and the second grooves 122 corresponding to different battery strings are connected to the same first groove 121; wherein, the first direction Y is parallel to the first surface 113, and the first direction Y is perpendicular to the arrangement direction X of the battery cells 10 of the battery string. In this way, the grooves can form mesh grooves or honeycomb grooves. After the lamination process, the cross-sectional shape of the waterproof membrane 112 is a mesh structure or a honeycomb structure, which improves the waterproof performance of the membrane.

[0042] In some embodiments, a portion of the waterproof membrane 112 is located in the first groove 121 and a portion of the waterproof membrane 112 is located in the second groove 122. After lamination, the waterproof membrane 112 may have a mesh or honeycomb cross-sectional shape to improve its waterproof performance. Furthermore, the grooves 120 of the photovoltaic membrane 111 and the gaps in the waterproof membrane 112 facilitate gas venting, preventing air bubbles from forming in the final photovoltaic module and affecting its performance. In other embodiments, a portion of the waterproof membrane 112 is located in the first groove 121 or a portion of the waterproof membrane 112 is located in the second groove 122.

[0043] In some embodiments, a plurality of waterproof adhesive films 112 are arranged at intervals along the first direction Y in the second groove 122; the ratio of the first spacing of the plurality of waterproof adhesive films 112 to the second spacing of adjacent first grooves 112 is 4 / 5 to 1. Specifically, the spacing between adjacent waterproof adhesive films 112 is greater than 9 times the spacing L1 between adjacent solder joints 101, or the end of the waterproof adhesive film 112 near the battery cell 10 does not exceed the end of the first solder joint 101 or the last solder joint 101 on the main grid line 102. Since the top surface of the solder ribbon is higher than the top surface of the battery cell, and the waterproof adhesive film 112 is located above the solder joint 101, the adhesive film strength at the location of the solder ribbon may be poor, and the part of the adhesive film in contact with the solder ribbon is prone to puncture, thereby affecting the waterproof performance of the adhesive film.

[0044] In some embodiments, a plurality of waterproof adhesive films 112 are spaced apart along the arrangement direction X of the battery cells 10 in the battery string. The ratio of the third spacing of the plurality of waterproof adhesive films 112 to the fourth spacing of the adjacent second groove 122 is 4 / 5 to 1. Specifically, the spacing between adjacent waterproof adhesive films 112 is greater than 9 times the spacing L2 between adjacent main grid lines 102, or the end of the waterproof adhesive film 112 near the battery cell 10 does not exceed the end of the outermost main grid line 102. Since the top surface of the solder ribbon 103 is higher than the top surface of the battery cell 10, and the waterproof adhesive film 112 is located above the main grid line 102, the adhesive film strength at the location of the solder ribbon 103 may be poor, and the part of the adhesive film in contact with the solder ribbon is prone to puncture, thereby affecting the waterproof performance of the adhesive film.

[0045] In some embodiments, waterproof membranes 112 located in different first grooves 121 are arranged at equal intervals along the first direction Y; or, waterproof membranes 112 located in different second grooves 122 are arranged at equal intervals along the arrangement direction X of the battery cells 10 of the battery string. In other embodiments, waterproof membranes 112 located in different first grooves 121 are arranged in a staggered manner; or, waterproof membranes 112 located in different second grooves 122 are arranged in a staggered manner along the arrangement direction X of the battery cells 10 of the battery string.

[0046] In some embodiments, the width of the first groove 121 is less than or equal to the string spacing between adjacent battery strings; and / or, the width of the second groove 122 is less than or equal to the sheet spacing between adjacent battery cells, to prevent the waterproof adhesive film 112 after lamination from being located on the surface of the battery cell 10, thus avoiding damage to the battery cell 10. Furthermore, the area where the solder ribbon 103 is located is a thick adhesive film area, effectively preventing the solder ribbon 103 from puncturing the adhesive film during processing and use, thereby improving the reliability of the low-basis-weight adhesive film.

[0047] In some embodiments, the depth of at least one of the first groove 121 or the second groove 122 is less than or equal to 0.05 mm. Since the thickness of the low-basis-weight film is approximately 0.05 mm, the overall thickness of the adhesive film can also be considered approximately 0.05 mm, thereby reducing the overall basis weight of the adhesive film and saving material costs. The adhesive film at the location of the solder ribbon 103 is a thickened area, which effectively prevents the solder ribbon 103 from puncturing the adhesive film during processing and use, thereby improving the reliability of the low-basis-weight adhesive film.

[0048] In some embodiments, the width of the waterproof adhesive film 112 gradually decreases along the direction from the second surface 114 to the first surface 113, which is more conducive to the extension of the molten waterproof adhesive film 112 along the extension direction of the groove 120 during the lamination process, forming an interconnected mesh structure and a honeycomb structure. Along the direction from the second surface 114 to the first surface 113, the top surface of the waterproof adhesive film 112 is higher than the first surface of the photovoltaic film 111. A large content of waterproof adhesive film 112 can avoid the influence of the ends of the waterproof adhesive film 112 on the main grid line 102 and the solder joint 101, and also ensures that enough waterproof adhesive films 112 can be interconnected to ultimately form an interconnected mesh film. The height difference between the top surface of the waterproof adhesive film 112 and the first surface of the photovoltaic film 111 is less than or equal to the thickness of the solar cell 10, avoiding the influence of the waterproof adhesive film 112 on the structure of the other surface of the solar cell 10.

[0049] In the technical solution provided in this application embodiment, the first surface 113 of the photovoltaic encapsulant film 111 has a groove 120. The groove 120 is opposite to the first interval 11 between the battery strings or the second interval 12 between the battery cells 10. The groove 120 serves as a guide groove for the waterproof encapsulant film 112. During the lamination process, the waterproof encapsulant film 112 is in a molten state and extends along the extension direction of the groove 120. Adjacent waterproof encapsulant films 112 are connected to each other, ultimately forming a mesh structure or a striped structure. The shape of the striped structure and the mesh structure is opposite to the first interval 11 and the second interval 12. The overall waterproof performance of the assembled encapsulant film formed by the waterproof encapsulant film 112 and the photovoltaic encapsulant film 111 is good, preventing water vapor from entering and corroding the battery cells 10. The groove 120 of the photovoltaic encapsulant film 111 and the intervals of the waterproof encapsulant film 112 facilitate gas venting, preventing air bubbles from appearing in the final photovoltaic module and affecting the performance of the photovoltaic module.

[0050] Figure 5 This is a schematic diagram of a photovoltaic module provided in an embodiment of this application.

[0051] According to some embodiments of this application, reference is made to Figure 5 Another aspect of this application embodiment also provides a photovoltaic module, including: a first cover plate 23, a first encapsulant film 21, a battery string, a second encapsulant film 22 and a second cover plate 24, wherein at least one of the first encapsulant film 21 or the second encapsulant film 22 is an encapsulant film as described in any of the above embodiments.

[0052] In some embodiments, the first adhesive film 21 and the second adhesive film 22 are used to cover the surface of the battery string to seal and protect it. A first cover plate 23 is used to cover the surface of the first adhesive film 21 facing away from the battery string; a second cover plate 24 is used to cover the surface of the second adhesive film 22 facing away from the battery string. At least one of the first cover plate 23 or the second cover plate 24 can be a glass cover or a plastic cover, etc., used to protect the battery string. At least one of the first cover plate 23 or the second cover plate 24 is provided with a light-trapping structure to increase the utilization rate of incident light. Photovoltaic modules have high current collection capacity and low carrier recombination rate, enabling high photoelectric conversion efficiency.

[0053] In some embodiments, along a direction parallel to the first surface 113 of the photovoltaic film 111, the cross-sectional shape of the waterproof adhesive film 112 is mesh-like or honeycomb-like, resulting in good overall waterproof performance and preventing moisture from entering and corroding the solar cell 10. Both the first adhesive film 21 and the second adhesive film 22 are provided with grooves 120 and waterproof adhesive films, and the grooves 120 are opposite to at least one of the first spacing 11 or the second spacing 12.

[0054] According to some embodiments of this application, another aspect of this application provides a method for manufacturing a photovoltaic module, comprising: sequentially stacking a first cover plate 23, a first encapsulant film 21, a battery string, a second encapsulant film 22, and a second cover plate 24, wherein at least one of the first encapsulant film 21 or the second encapsulant film 22 is an encapsulant film as described in any of the above embodiments, a first interval 11 is provided between adjacent battery strings, a second interval 12 is provided between the battery cells 10 constituting the battery string, and a groove 120 is opposite to at least one of the first interval 11 or the second interval 12; and laminating to form a laminated photovoltaic module.

[0055] Those skilled in the art will understand that the above-described embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this application. Any person skilled in the art can make their own modifications and alterations without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A film for encapsulating a battery string in a photovoltaic module, wherein adjacent battery strings have a first spacing and the battery cells constituting the battery string have a second spacing, characterized in that, include: A photovoltaic encapsulant film having a first side facing the battery string and a second side opposite to the first side, the photovoltaic encapsulant film having at least one groove recessed from the first side toward the second side, the groove being opposite at least one of the first spacer or the second spacer; Multiple waterproof membranes are located within the groove and are arranged at intervals. In the direction from the second surface to the first surface, the top surface of the waterproof adhesive film is higher than the first surface of the photovoltaic adhesive film; The groove includes a first groove and a second groove, the first groove being opposite to the first interval, the second groove being opposite to the second interval, and at least one of the first groove or the second groove having the waterproof adhesive film; each of the first grooves is connected to at least one of the second grooves; The height difference between the top surface of the waterproof membrane and the first surface of the photovoltaic membrane is less than or equal to the thickness of the solar cell.

2. The adhesive film according to claim 1, characterized in that, Along a first direction, second grooves corresponding to different battery strings are connected, and second grooves corresponding to different battery strings are connected to the same first groove; wherein, the first direction is parallel to the first surface and perpendicular to the arrangement direction of the battery cells of the battery string.

3. The adhesive film according to claim 1, characterized in that, Part of the waterproof membrane is located in the first groove, and / or part of the waterproof membrane is located in the second groove.

4. The adhesive film according to claim 1, characterized in that, Along the first direction, multiple waterproof membranes located in the second groove are arranged at intervals; the ratio of the first spacing of the multiple waterproof membranes to the second spacing of the adjacent first groove is 4 / 5 to 1.

5. The adhesive film according to claim 3, characterized in that, Along the arrangement direction of the battery cells in the battery string, multiple waterproof membranes located in the first groove are arranged at intervals; the ratio of the third spacing of the multiple waterproof membranes to the fourth spacing of the adjacent second groove is 4 / 5 to 1.

6. The adhesive film according to claim 1, characterized in that, Along the first direction, the waterproof membranes located in different first grooves are staggered; or, along the arrangement direction of the battery cells of the battery string, the waterproof membranes located in different second grooves are staggered.

7. The adhesive film according to claim 1, characterized in that, The width of the first groove is less than or equal to the string spacing between adjacent battery strings; and / or, the width of the second groove is less than or equal to the cell spacing between adjacent battery cells.

8. The adhesive film according to claim 1, characterized in that, The depth of at least one of the first groove or the second groove is less than or equal to 0.05 mm.

9. The adhesive film according to claim 1, characterized in that, The width of the waterproof membrane gradually decreases along the direction from the second surface to the first surface.

10. The adhesive film according to claim 1 or 9, characterized in that, In the direction from the second surface to the first surface, the top surface of the waterproof adhesive film is higher than the first surface of the photovoltaic adhesive film.

11. The adhesive film according to claim 1, characterized in that, The waterproof adhesive film is made of a different material than the photovoltaic adhesive film, and the melting point of the waterproof adhesive film is less than or equal to the melting point of the photovoltaic adhesive film.

12. The adhesive film according to claim 1, characterized in that, The waterproof adhesive film is made of the same material as the photovoltaic adhesive film; the adhesive film is a one-piece molded structure.

13. A photovoltaic module, characterized in that, include: The first cover plate, the first adhesive film, the battery string, the second adhesive film, and the second cover plate, wherein at least one of the first adhesive film or the second adhesive film is the adhesive film as described in any one of claims 1 to 12.

14. The photovoltaic module according to claim 13, characterized in that, Along a direction parallel to the first surface of the photovoltaic film, the cross-sectional shape of the waterproof adhesive film is mesh-like or honeycomb-like.

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