Photovoltaic module

Abstract

The utility model aims at disclosing a novel photovoltaic module. A casting co-extrusion layer is formed by a pre-crosslinking adhesive film layer and a non-crosslinking adhesive film layer; the pre-crosslinking adhesive film layer is an ultraviolet light catalytic crosslinking layer, and the thickness of the pre-crosslinking adhesive film layer is 0.05 mm to 0.20 mm; and the thickness of the pre-crosslinking adhesive film layer is 0.3 mm-0. 60mm. Compared with the prior art, the composite adhesive film for packaging has the beneficial effects that the composite adhesive film for packaging consists of the pre-crosslinking adhesive film layer and the non-crosslinking adhesive film layer, and is integrally formed by casting and co-extruding, the pre-crosslinking adhesive film layer is in contact with the surface of a battery, and compared with the non-crosslinking adhesive film layer, the pre-crosslinking adhesive film layer can reduce the thermal flowability of the pre-crosslinking adhesive film layer, so that the heat conductivity of the battery is improved, and the service life of the battery is prolonged. The purpose of controlling the fluidity of the pre-crosslinking adhesive film layer is achieved by controlling the crosslinking degree of the pre-crosslinking adhesive film layer, so that the pre-crosslinking adhesive film layer is prevented from flowing to a small gap between a low-temperature welding strip and a battery piece during hot pressing, the technical problem of insufficient soldering is solved, the performance and stability of a main-grid-free TOPCon and HJT battery piece assembly are guaranteed, and the power generation efficiency of the battery piece is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, in particular to a photovoltaic component. Background Art

[0002] Busbar-less TOPCon and HJT cells have become one of the important innovations in the field of photovoltaic technology. These cells are known for their excellent energy conversion efficiency and stability, making them an ideal choice for solar power generation. However, in the preparation and packaging process of busbar-less cells, especially in the low-temperature solder tape dispensing and laying step, the traditional film packaging technology has some problems.

[0003] In the process of low-temperature solder tape dispensing and laying, traditional film packaging often has problems such as EL blackening and cold solder joints due to the high fluidity of the film packaging: due to the high fluidity of traditional film, the film may flow into the tiny gap between the solder tape and the battery cell during lamination or aging, resulting in cold solder joints. Cold solder joints will seriously affect the performance and stability of the battery cell and reduce the efficiency of the battery cell.

[0004] In order to solve these problems, it is necessary to propose a new type of photovoltaic module. Summary of the invention

[0005] The utility model aims to disclose a novel composite adhesive film for photovoltaic module encapsulation and a photovoltaic module, which is particularly suitable for low-temperature solder tape dispensing and laying of main grid-free solar cells to improve the performance of the solar cells, reduce manufacturing costs, and ensure stable encapsulation quality.

[0006] The first invention objective of the utility model is to provide a composite adhesive film for photovoltaic module encapsulation.

[0007] The second invention objective of the utility model is to provide a photovoltaic module.

[0008] In order to achieve the above first invention purpose, the utility model provides a composite adhesive film for photovoltaic module encapsulation, which is composed of a pre-crosslinked adhesive film layer and an uncrosslinked adhesive film layer to form a cast co-extruded layer;

[0009] The pre-crosslinked adhesive film layer is an ultraviolet catalytic crosslinked layer, and the thickness of the pre-crosslinked adhesive film layer is 0.05mm-0.20mm;

[0010] The thickness of the uncrosslinked adhesive film layer is 0.3 mm-0.60 mm.

[0011] Preferably, the pre-crosslinked adhesive film layer is a first EVA adhesive film layer, and the uncrosslinked adhesive film layer is a second EVA adhesive film layer.

[0012] Preferably, the first EVA adhesive film layer is a thermosetting adhesive film, and the second EVA adhesive film layer is a thermosetting adhesive film.

[0013] Preferably, the first EVA film layer and the second EVA film layer are integrally formed by cast co-extrusion.

[0014] Preferably, the pre-crosslinking degree of the first EVA film layer is 20%-60%.

[0015] Preferably, the uncross-linked adhesive film layer is a buffer layer.

[0016] Based on the same inventive principle, in order to achieve the above second invention purpose, the utility model provides a photovoltaic module, including a stacked front transparent encapsulation layer, the composite adhesive film for encapsulation of the photovoltaic module described in the first invention, a busbar-free cell array, the composite adhesive film for encapsulation of the photovoltaic module described in the first invention, and a back encapsulation layer;

[0017] The pre-crosslinked film layer of the composite film for photovoltaic module encapsulation described in the first invention contacts the busbar-free solar cell array, and the uncrosslinked film layer of the composite film for photovoltaic module encapsulation described in the first invention contacts the front transparent encapsulation layer or the back encapsulation layer.

[0018] Preferably, the heat curing crosslinking degree of the pre-crosslinked adhesive film layer is 75%-95%, and the heat curing crosslinking degree of the uncrosslinked adhesive film layer is 75%-95%.

[0019] Preferably, the front transparent encapsulation layer is glass, and the peeling force between the pre-cross-linked adhesive film layer and the glass is 80N / cm-180N / cm.

[0020] Compared with the prior art, the beneficial effects of this embodiment are: the composite film for encapsulation of the utility model is composed of a pre-cross-linked film layer and a non-cross-linked film layer, which is formed by cast co-extrusion in one piece, and the pre-cross-linked film layer contacts the battery surface. Compared with the non-cross-linked film layer, the pre-cross-linked film layer can reduce its thermal fluidity. By controlling the cross-linking degree of the pre-cross-linked film layer, the purpose of controlling its fluidity is achieved, thereby preventing the pre-cross-linked film layer from flowing to the tiny gap between the low-temperature welding strip and the battery cell during hot pressing, solving the technical problem of cold soldering, ensuring the performance and stability of the main grid-free TOPCon and HJT battery cell components, and improving the power generation efficiency of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of the composite adhesive film for encapsulating photovoltaic modules of the utility model.

[0022] Figure 2 It is a cross-sectional view of the photovoltaic module of the present utility model.

[0023] Among them, 1. pre-cross-linked film layer; 2. non-cross-linked film layer; 3. front transparent encapsulation layer; 4. main grid-free solar cell array; 5. back encapsulation layer. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0025] 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" and the like indicating directions or positional relationships are based on the directions 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 device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0026] Embodiment 1

[0027] See also Figure 1 As shown, the utility model provides a composite adhesive film for photovoltaic module encapsulation, which is composed of a pre-crosslinked adhesive film layer 1 and an uncrosslinked adhesive film layer 2 to form a cast co-extruded layer; the pre-crosslinked adhesive film layer 1 is an ultraviolet light catalytic crosslinking layer, and the pre-crosslinked adhesive film layer 1 has a thickness of 0.05mm-0.20mm; the uncrosslinked adhesive film layer 2 has a thickness of 0.3mm-0.60mm.

[0028] Specifically, see Figure 1 The pre-crosslinked film layer 1 is a first EVA film layer, the uncrosslinked film layer 2 is a second EVA film layer, the first EVA film layer and the second EVA film layer are integrally formed by cast co-extrusion, and the first EVA film layer and the second EVA film layer substantially become a whole after cast extrusion, wherein a photocatalyst and a thermal crosslinking agent are added to the first EVA film layer, the first EVA film layer has both ultraviolet light catalytic crosslinking function and thermal crosslinking function, the first EVA film layer is both an ultraviolet light catalytic crosslinking layer and a thermosetting film; and a thermal crosslinking agent is added to the second EVA film layer, and the second EVA film layer is a thermosetting film.

[0029] After the composite film for photovoltaic module encapsulation is co-extruded by cast film, the composite film is irradiated with 400W ultraviolet light for 1min-3min, and the pre-crosslinking degree of the first EVA film layer is 20%-60%, while there is no ultraviolet catalyst in the second EVA film layer, and the second EVA film layer is not cross-linked. When the composite film is subsequently encapsulated into a main grid-free battery cell array, the uncross-linked film layer is a buffer layer.

[0030] See Table 1, which is a performance comparison table of the composite film and the traditional film.

[0031] Table 1 Performance comparison between composite film and traditional film

[0032]

[0033] The photovoltaic module in Table 1 includes a stacked front transparent encapsulation layer 3, a composite adhesive film for photovoltaic module encapsulation described in Example 1, a busbarless cell array 4, a composite adhesive film for photovoltaic module encapsulation described in Example 1, and a back encapsulation layer 5; the pre-crosslinked adhesive film layer 1 of the composite adhesive film for photovoltaic module encapsulation contacts the busbarless cell array 4, the busbarless cell array 4 can be a busbarless TOPCon or HJT cell, the uncrosslinked adhesive film layer 2 of the composite adhesive film for photovoltaic module encapsulation contacts the front transparent encapsulation layer 3 or the back encapsulation layer 5, and the front transparent encapsulation layer 3 is glass. During encapsulation, the photovoltaic modules of Examples 1 to 6 are vacuumed at 145°C for 5 minutes and then laminated for 10 minutes, and the appearance of the cell modules obtained after lamination is observed; during the lamination process, the lamination temperature is 145°, the pre-crosslinked adhesive film layer 1 undergoes thermal crosslinking and increases its crosslinking degree to 75%-95%, and the uncrosslinked adhesive film layer 2 reaches a thermal curing crosslinking degree of 75%-95%. The photovoltaic modules of Comparative Examples 1 to 4 are assembled and laminated in the same manner.

[0034] The performance of the encapsulation films provided in Examples 1 to 6 and Comparative Examples 1 to 4 were tested. The test method was as follows: the peeling force was tested in accordance with GB / T 29848-2018. The peeling force between the pre-crosslinked film layer and the glass in Examples 1 to 6 was 80N / cm-180N / cm, which met the requirements; and the EL (electroluminescence) test after lamination was performed in accordance with IEC

[0035] The EL after TC200 is also tested according to IEC 61215&61730. The appearance of component lamination (whether there are cracks or wrinkles on the battery cell) is obtained by observation.

[0036] Through comparative tests, it was found that although comparative example 1 also used a pre-cross-linked adhesive film layer and a non-cross-linked adhesive film layer, comparative example 1 was formed by independently forming two layers and then compounding them, which was prone to bubbles and stratification; comparative example 2 had EL cold soldering after lamination, and the EL turned black after TC200; comparative example 3 had EL blackening after TC200 and the battery cell was cracked; comparative example 4 had EL cold soldering after lamination, and the EL turned black after TC200. Through comparison, it was found that after the composite adhesive films of embodiments 1 to 6 were applied to photovoltaic modules, the EL did not have cold soldering after lamination, and the EL did not turn black after TC200, and there were no cracks or wrinkles on the battery cell. At the same time, the peeling strength between the composite adhesive film and the glass met the requirements.

Claims

1. A photovoltaic module, characterized in that It includes a stacked front transparent encapsulation layer, a composite adhesive film for encapsulating photovoltaic modules, a main grid-free cell array, a composite adhesive film for encapsulating photovoltaic modules, and a back encapsulation layer; The pre-crosslinked film layer of the composite film for photovoltaic module encapsulation contacts the busbar-free solar cell array, and the uncrosslinked film layer of the composite film for photovoltaic module encapsulation contacts the front transparent encapsulation layer or the back encapsulation layer; The composite adhesive film for photovoltaic module encapsulation comprises a cast co-extruded layer composed of a pre-cross-linked adhesive film layer and a non-cross-linked adhesive film layer; The pre-crosslinked adhesive film layer is an ultraviolet catalytic crosslinked layer, and the thickness of the pre-crosslinked adhesive film layer is 0.05mm-0.20mm; The thickness of the uncrosslinked adhesive film layer is 0.3 mm to 0.60 mm; The busbar-free cell array is a busbar-free TOPCon or HJT cell array.

2. The photovoltaic module according to claim 1, characterized in that: The heat curing crosslinking degree of the pre-crosslinked adhesive film layer is 75%-95%, and the heat curing crosslinking degree of the uncrosslinked adhesive film layer is 75%-95%.

3. The photovoltaic module according to claim 1, characterized in that: The front transparent encapsulation layer is glass, and the peeling force between the pre-crosslinked adhesive film layer and the glass is 80N / cm-180N / cm.

4. The photovoltaic module according to claim 1, characterized in that: The pre-crosslinked adhesive film layer is a first EVA adhesive film layer, and the uncrosslinked adhesive film layer is a second EVA adhesive film layer.

5. The photovoltaic module according to claim 4, characterized in that: The first EVA adhesive film layer is a thermosetting adhesive film, and the second EVA adhesive film layer is a thermosetting adhesive film.

6. The photovoltaic module according to claim 5, characterized in that: The first EVA film layer and the second EVA film layer are integrally formed by cast co-extrusion.

7. The photovoltaic module according to claim 6, characterized in that: The pre-crosslinking degree of the first EVA film layer is 20%-60%.

8. The photovoltaic module according to any one of claims 1 to 7, characterized in that: The uncrosslinked adhesive film layer is a buffer layer.

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