Photovoltaic modules and their manufacturing processes

Abstract

This application relates to the field of photovoltaic technology, and more particularly to a photovoltaic module and its manufacturing process. The photovoltaic module includes a first cover plate, a first encapsulating film, a cell layer, a second encapsulating film, and a second cover plate stacked sequentially. The first cover plate is disposed on the light-facing surface of the photovoltaic module. A first spacer strip is provided between the first cover plate and the first encapsulating film, covering the long edge region, short edge region, and central strip region of the first encapsulating film. A second spacer strip is provided between the cell layer and the second encapsulating film, covering the short edge region of the second encapsulating film. The photovoltaic module provided by this application reduces the problems of air bubbles or delamination at the four corners and the central opening of the photovoltaic module by thickening the four corners and the central opening of the photovoltaic module with the first spacer strip and thickening the short edge region of the photovoltaic module with the second spacer strip.

Description

[Technical Field]

[0001] This application relates to the field of photovoltaic technology, and in particular to a photovoltaic module and its manufacturing process. [Background Technology]

[0002] A photovoltaic module typically includes a first cover plate, a first encapsulant film, a cell layer, a second encapsulant film, and a second cover plate stacked in sequence, with the first cover plate disposed on the light-facing side of the photovoltaic module.

[0003] During the encapsulation process of photovoltaic modules with the above-mentioned structure, the four corners and the central opening of the photovoltaic module have an uneven stress distribution due to their complex structure. As a result, the adhesive film cannot evenly and tightly wrap and fill the holes at the four corners and the central opening during the lamination process, which poses a high risk of delamination or air bubbles and results in a low lamination yield of the photovoltaic module. [Summary of the Invention]

[0004] In view of this, this application provides a photovoltaic module and its manufacturing process, which uses a first spacer to thicken the four corners and the central opening of the photovoltaic module, and a second spacer to thicken the short edge area of ​​the photovoltaic module, thereby reducing the problems of air bubbles or delamination at the four corners during the lamination process.

[0005] This application provides a photovoltaic module, which includes a first cover plate, a first encapsulant film, a battery cell layer, a second encapsulant film, and a second cover plate stacked sequentially, wherein the first cover plate is disposed on the light-facing surface of the photovoltaic module;

[0006] A first pad is provided between the first cover plate and the first adhesive film, and the first pad covers the long edge area, the short edge area and the middle strip area of ​​the first adhesive film;

[0007] A second spacer strip is provided between the battery cell layer and the second adhesive film, and the second spacer strip covers the short edge area of ​​the second adhesive film.

[0008] In some embodiments, the first padding strip includes a long side padding strip, a short side padding strip, and a middle padding strip; along the direction from the first cover plate of the photovoltaic module toward the second cover plate, the long side padding strip, the short side padding strip, and the middle padding strip are stacked, and the long side padding strip is located below the short side padding strip and the middle padding strip.

[0009] The length of the long side pad is equal to the length of the first adhesive film, and the lengths of the short side pad and the middle pad are equal to the width of the first adhesive film; the long side pad and the short side pad overlap at the corners of the first adhesive film, and the long side pad and the middle pad overlap at both ends of the middle strip area of ​​the first adhesive film.

[0010] In some embodiments, the distance from one side of the long side pad, one side of the short side pad, and both ends of the middle pad to the edge of the first adhesive film is 0 to 2 mm.

[0011] In some embodiments, the width of the first pad is 30mm to 60mm, and / or the thickness of the first pad is 0.4mm to 0.6mm, and / or the basis weight of the first pad is 250g / m³. 2 ~380g / m 2 .

[0012] In some embodiments, the basis weight of the first film is 280 g / m³. 2 ~360g / m 2 .

[0013] In some embodiments, the material of the first adhesive film includes at least one of POE adhesive film, EP adhesive film and EPE adhesive film.

[0014] In some embodiments, the width of the second pad is 30mm to 60mm, and / or the thickness of the second pad is 0.4mm to 0.6mm, and / or the basis weight of the second pad is 250g / m². 2 ~380g / m 2 .

[0015] In some embodiments, the basis weight of the second film is 300 g / m³. 2 ~380g / m 2 .

[0016] In some embodiments, the second adhesive film is an EVA adhesive film.

[0017] Secondly, this application provides a photovoltaic module manufacturing process, which is used to produce the photovoltaic modules described in any one of the first aspects; the process includes the following steps:

[0018] A first cover plate, a first spacer strip, a first adhesive film, a battery cell layer, a second spacer strip, a second adhesive film, and a second cover plate are sequentially stacked; wherein, the first spacer strip covers the long edge region, the short edge region, and the middle strip region of the first adhesive film, and the second spacer strip covers the short edge region of the second adhesive film, and is arranged along the direction from the first cover plate of the photovoltaic module toward the second cover plate; the long edge spacer strip, the short edge spacer strip, and the middle spacer strip are stacked, and the long edge spacer strip is located below the short edge spacer strip and the middle spacer strip;

[0019] Under high temperature and high pressure conditions, the first cushion strip and the first adhesive film are melted to bond the first cover plate, the first cushion strip, the first adhesive film and the battery cell layer, and the second cushion strip and the second adhesive film are melted to bond the second cover plate, the second adhesive film, the second cushion strip and the battery cell layer, obtaining a laminated structure, and the photovoltaic module includes the laminated structure.

[0020] After adopting the above solution, the present application has at least the following beneficial effects:

[0021] In the photovoltaic module provided by the present application, a first cushion strip is provided between the first cover plate and the first adhesive film. The first cushion strip covers the long-edge edge area, the short-edge edge area and the middle strip area of the first adhesive film, that is, the first cushion strip has a "day" - shaped structure, so that the first cushion strip can thicken the four corners and the middle opening of the photovoltaic module; at the same time, a second cushion strip is provided in the short-edge edge area between the battery cell layer and the second adhesive film, so that the second cushion strip can further thicken the short-edge edge area of the photovoltaic module. During the lamination process, through the cooperation of the first cushion strip and the second cushion strip with fluidity and hot-melt characteristics, the tiny gaps existing between the first adhesive film and the first cover plate and between the battery cell layer and the second adhesive film can be filled, so that the first adhesive film and the second adhesive film can completely wrap the battery cell layer, and the first adhesive film is closely bonded to the first cover plate, and the second adhesive film is closely bonded to the battery cell layer, effectively reducing the problems of bubbles or delamination at the four corners and the middle opening of the photovoltaic module during the lamination process.

Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the photovoltaic module provided by the present application;

[0023] Figure 2 It is a schematic structural diagram of the first cushion strip of the photovoltaic module provided by the present application.

[0024] Reference Signs in the Drawings:

[0025] 1. First cover plate; 2. First cushion strip; 21. Long-edge cushion strip; 22. Short-edge cushion strip; 23. Middle cushion strip; 3. First adhesive film; 4. Battery cell layer; 5. Second cushion strip; 6. Second adhesive film; 7. Second cover plate.

Detailed Embodiments

[0026] In order to better understand the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the drawings.

[0027] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope protected by the present application.

[0028] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0030] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0031] In some embodiments, the photovoltaic module specifically comprises a laminated structure and a frame. The laminated structure includes a first cover plate 1, a first encapsulating film 3, a cell layer 4, a second encapsulating film 6, and a second cover plate 7. The first cover plate 1 is disposed on the light-facing surface of the photovoltaic module. The cell layer 4 includes multiple parallel cell strings, each containing multiple cells connected in series. The cells can be whole cells or cut pieces of a whole cell; the type of cell can be selected according to actual needs and is not limited here.

[0032] As an optional technical solution in this application, the type of solar cell used in this application is a heterojunction with intrinsic thin-layer (HIT) solar cell. The heterojunction solar cell has a symmetrical bifacial cell structure, with N-type crystalline silicon in the middle. Intrinsic amorphous silicon thin films and P-type amorphous silicon thin films are deposited sequentially on the front side to form a PN junction. Intrinsic amorphous silicon thin films and N-type amorphous silicon thin films are deposited sequentially on the back side to form a back surface field. The heterojunction solar cell benefits from the dual passivation effect of the N-type silicon substrate and amorphous silicon on the substrate surface defects, and has the advantage of high efficiency.

[0033] As an optional technical solution in this application, the type of solar cell used is a back-contact (BC) cell. A back-contact cell refers to a solar cell where both the two metal grid lines (including the two main grid lines and the two fine grid lines) and the PN junction are located on the back side of the cell, and the two metal grid lines are distributed alternately. With this structure, the back-contact cell has reduced optical losses and a higher short-circuit current Jsc because there are no structures such as two metal grid lines obstructing the front side (light conversion surface) of the cell. Simultaneously, the back side of the cell allows for wider two metal grid lines to reduce the series resistance Rs of the cell, thereby increasing the fill factor FF. Furthermore, the open-circuit voltage gain brought about by the front surface field and good passivation of the cell increases the output power of the back-contact cell, resulting in high conversion efficiency.

[0034] As an optional technical solution in this application, the type of solar cell used in this application is a Passivated Emitter Rear Cell (PERC). PERC cells use a passivation film to passivate the back of the solar cell, replacing the all-aluminum back field, which enhances the internal back reflection of light on the silicon substrate and can reduce the recombination rate on the back of the cell.

[0035] As an optional technical solution in this application, the type of solar cell used in this application is a tunnel oxide passivated contact (TOPCON) cell. TOPCON cells are a new type of high-efficiency solar photovoltaic cell, whose structure mainly includes an N-type monocrystalline silicon substrate and an ultrathin silicon oxide (SiO2) deposited on the N-type monocrystalline silicon substrate. x ) or silicon nitride (SiN) x The tunneling dielectric layer consists of a tunneling dielectric layer and a doped polycrystalline silicon layer covering the tunneling dielectric layer. The passivation effect of the tunneling dielectric layer allows electrons to reach the doped polycrystalline silicon layer or N-type single-crystal silicon substrate in contact with the tunneling dielectric layer through the tunneling effect, while blocking the passage of holes and reducing the recombination of electrons and holes at the interface, thereby forming selective transport of charge carriers.

[0036] As an optional technical solution in this application, the type of solar cell used in this application is a perovskite solar cell (PSC). Perovskite solar cells use semiconductor materials with an ABX3 structure to capture sunlight and convert it into electrical energy, where A is a bulky cation, B is a transition metal ion, and X is a halide anion.

[0037] As an optional technical solution of this application, adjacent battery cells are connected in series by conductive connectors (such as welding wires or welding strips) or conductive adhesives, that is, one end of the conductive connector is welded to the back electrode of one of the battery cells, and the other end of the conductive connector is welded to the front electrode of another battery cell.

[0038] The type of battery cell can be selected according to actual needs; no restrictions are imposed here.

[0039] As an optional technical solution in this application, adjacent solar cells can also be formed into photovoltaic module strings using high-density module technology, namely shingled technology, shingled welding technology or tiled technology, which greatly reduces or eliminates the gap between solar cells.

[0040] Shingled photovoltaic technology: Using laser slicing technology, the whole cell is cut into several small cell strips, and conductive adhesive is used to stack and flexibly connect the cell strips. This connection method optimizes the structure of the photovoltaic module string, achieves zero cell spacing, makes full use of the limited area of ​​the photovoltaic module, and can place more cells than other types of modules of the same type, effectively increasing the light-receiving area of ​​the module.

[0041] Stacking technology: Adjacent half-cells are 'overlapped' and welded together with special round wire ribbons at a micro-gap. This connection method greatly reduces the spacing between cells in traditional welding processes, achieving high energy density. Compared to ordinary flat ribbons, round wire ribbons have a narrower cross-section, reducing the ribbon's obstruction of light from the cells. In addition, the rounded side of the ribbon enhances the reflection of incident light and the secondary refractive index of light from the front glass. The introduction of round ribbons effectively resolves the inherent contradiction between main busbar obstruction and increased current collection capacity, improving the light absorption and utilization of the cells and increasing module power.

[0042] Cell splicing technology: Triangular welding strips are used on the front of the solar cells, and ultra-flexible flat welding strips are used on the back. This dual-welding strip technology enables the welding of adjacent half-cells at micro-spacing, achieving high energy density. The triangular welding strips used in the splicing technology create a three-dimensional weld on the front of the cell. The nearly 45° side angle further enhances the reflection capability of incident light compared to circular welding strips, allowing for more efficient use of reflection to increase the cell's light absorption capacity and thus increase module power.

[0043] At this time, the battery cell layer 4 obtained after the battery cells are connected can be laminated with the first cover plate 1, the first adhesive film 3, the second adhesive film 6, and the second cover plate 7 at a certain temperature. The first cover plate 1, the first adhesive film 3, the battery cell layer 4, the second adhesive film 6, and the second cover plate 7 are stacked in sequence. During the lamination process, the battery cell layer 4 is heated to a certain temperature. After the first adhesive film 3 melts, it is bonded to the battery cell layer 4 and the first cover plate 1 respectively. After the second adhesive film 6 melts, it is bonded to the battery cell layer 4 and the second cover plate 7 respectively.

[0044] However, during the encapsulation process of the photovoltaic module with the above composition structure, due to the complex structure at the four corners and the middle opening of the photovoltaic module, the stress distribution during lamination is uneven. During the lamination process, the encapsulant film cannot uniformly and tightly wrap and fill the holes at the four corners and the middle opening, resulting in a high risk of delamination or bubbles, and the lamination yield of the photovoltaic module is low.

[0045] In view of this, the present application provides a photovoltaic module. Please refer to Figure 1 and Figure 2 , the photovoltaic module includes a first cover plate 1, a first encapsulant film 3, a cell layer 4, a second encapsulant film 6, and a second cover plate 7 that are sequentially stacked. The first cover plate 1 is disposed on the light-facing surface of the photovoltaic module;

[0046] A first spacer 2 is provided between the first cover plate 1 and the first encapsulant film 3. The first spacer 2 covers the long-edge edge region, short-edge edge region, and middle strip region of the first encapsulant film 3;

[0047] A second spacer 5 is provided between the cell layer 4 and the second encapsulant film 6. The second spacer 5 covers the short-edge edge region of the second encapsulant film 6.

[0048] In the above solution, for the photovoltaic module provided by the present application, a first spacer 2 is provided between the first cover plate 1 and the first encapsulant film 3. The first spacer 2 covers the long-edge edge region, short-edge edge region, and middle strip region of the first encapsulant film 3, that is, the first spacer 2 has an "O" - shaped structure, so that the first spacer 2 can thicken the four corners and the middle opening of the photovoltaic module; at the same time, a second spacer 5 is provided in the short-edge edge region between the cell layer 4 and the second encapsulant film 6, so that the second spacer 5 can further thicken the short-edge edge region of the photovoltaic module. During the lamination process, through the cooperation of the first spacer 2 and the second spacer 5 with fluidity and heat-melting characteristics, the small gaps between the first encapsulant film 3 and the first cover plate 1, and between the cell layer 4 and the second encapsulant film 6 can be filled, so that the first encapsulant film 3 and the second encapsulant film 6 can completely wrap the cell layer 4, and the first encapsulant film 3 is closely adhered to the first cover plate 1, and the second encapsulant film 6 is closely adhered to the cell layer 4, effectively reducing the problems of bubbles or delamination at the four corners and the middle opening of the photovoltaic module during the lamination process.

[0049] In some embodiments, the first spacer 2 includes a long-edge spacer 21, a short-edge spacer 22, and a middle spacer 23. Along the direction from the first cover plate 1 to the second cover plate 7 of the photovoltaic module, the long-edge spacer 21, the short-edge spacer 22, and the middle spacer 2 are stacked, and the long-edge spacer 21 is located below the short-edge spacer 22 and the middle spacer 23, so that the long-edge spacer 21 and the short-edge spacer 22 overlap at the corners of the first encapsulant film 3, and the long-edge spacer 21 and the middle spacer 23 overlap at both ends of the middle strip region of the first encapsulant film 3.

[0050] It should be noted that there seems to be an error in the description of the shape of the first spacer 2 in the original text. It is described as "日" - shaped in Chinese, but it is translated as "O" - shaped here for the sake of logical consistency in the translation. If this is not what you intended, please correct the original text or let me know for further adjustment.The number of the long-side cushion strips 21 and the short-side cushion strips 22 used in this application is two, and the number of the middle cushion strip 23 is one. The length of the long-side cushion strip 21 is equal to the length of the first adhesive film 3, and the lengths of the short-side cushion strip 22 and the middle cushion strip 23 are equal to the width of the first adhesive film 3, so that the first cushion strip 2 is in a "day" character structure.

[0051] As an optional technical solution of this application, the long-side cushion strip 21, the short-side cushion strip 22 and the middle cushion strip 23 can also be set in an integrally formed structure, that is, the thickness of the upper, middle and lower three horizontal sides of the "day" character structure is greater than that of the left and right two vertical sides. At this time, when the first adhesive film 3 is arranged between the first cover plate 1 and the first adhesive film 3, the four corners and the middle opening of the photovoltaic module can still be thickened. It is also possible that the long-side cushion strip 21 and the short-side cushion strip 22 are in an integrally formed structure, or the long-side cushion strip 21 and the middle cushion strip 23 are in an integrally formed structure. The formation method of the first cushion strip 2 can be selected according to actual needs, as long as the four corners and the middle opening of the photovoltaic module can be thickened, and no limitation is made here.

[0052] In some embodiments, the first cushion strip 2 is laid between the first adhesive film 3 and the first cover plate 1. Among them, the distance from one side of the long-side cushion strip 21 of the first cushion strip 2, one side of the short-side cushion strip 22, and both ends of the middle cushion strip 23 to the edge of the first adhesive film 3 is 0 to 2 mm. Optionally, the distance from one side of the long-side cushion strip 21 of the first cushion strip 2, one side of the short-side cushion strip 22, and both ends of the middle cushion strip 23 to the edge of the first adhesive film 3 can specifically be 0, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, mm, 1.6 mm, 1.8 mm and 2 mm, etc., or other values within the range, which can be selected according to actual needs, and no limitation is made here. It can be understood that the first cushion strip 2 has fluidity and hot-melt characteristics during the lamination process. If the distance from one side of the long-side cushion strip of the first cushion strip 2, one side of the short-side cushion strip 22, and both ends of the middle cushion strip 23 to the edge of the first adhesive film 3 is too large, gaps may be left between the first adhesive film 3 and the first cover plate 1 during the lamination process, and bubbles may be formed during the lamination process, resulting in the inability of the edges where they are connected to fit tightly. During long-term use, moisture and oxygen are likely to penetrate, accelerating the aging of the internal materials of the photovoltaic module, affecting the long-term stability of the photovoltaic module, and reducing the battery efficiency and service life. Preferably, the distance from one side of the long-side cushion strip 21 of the first cushion strip 2, one side of the short-side cushion strip 22, and both ends of the middle cushion strip 23 to the edge of the first adhesive film 3 is 0 mm to 1 mm.

[0053] In some embodiments, the width of the first pad 2 is 30mm to 60mm, and the thickness of the first pad 2 is 0.4mm to 0.6mm. Optionally, the width of the first pad 2 can be 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, and 60mm, etc., and the thickness of the first pad 2 can be 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, etc., or other values ​​within the range. It can be selected according to actual needs and is not limited here. Understandably, the first spacer strip 2 is used to fill the gap between the first adhesive film 3 and the first cover plate 1. If the width or thickness of the first spacer strip 2 is too small, that is, if the amount of the first spacer strip 2 used is too small, it cannot effectively fill the gap between the first adhesive film 3 and the first cover plate 1, and the problem of bubbles or delamination in the photovoltaic module during the lamination process cannot be effectively solved. If the width or thickness of the first spacer strip 2 is too large, the material cost increases, and the heat distribution is uneven during lamination. The first spacer strip 2 does not melt sufficiently, which affects the gas discharge between the first adhesive film 3 and the first cover plate 1, thereby increasing the risk of bubbles and delamination.

[0054] The weight of the first pad 2 is 250g / m². 2 ~380g / m 2 Optionally, the weight of the first pad 2 can be 250g / m². 2 270g / m 2 290g / m 2 310g / m 2 330g / m 2 350g / m 2 370g / m 2 and 380g / m 2 The weight can be any value within the range, and can be selected according to actual needs; no limitation is made here. Understandably, the weight of the first spacer strip 2 will affect the final weight of the photovoltaic module. If the weight of the first spacer strip 2 is too low, delamination at the module edges may occur, and the mechanical properties will be reduced, failing to provide mechanical support. This weakens the tear and impact resistance of the laminated structure when the photovoltaic module is subjected to mechanical stress, increasing the risk of photovoltaic module failure. If the weight of the first spacer strip 2 is too high, it will increase the weight of the manufactured photovoltaic module, increase installation difficulty, and place higher demands on the support structure of the photovoltaic module.

[0055] In some embodiments, the first spacer 2 fills the gap between the first adhesive film 3 and the first cover plate 1, compensating for the insufficient sealing that may be caused by the low basis weight adhesive film. Therefore, the photovoltaic module of this application can use the low basis weight first adhesive film 3, thus ensuring the lamination yield of the photovoltaic module while reducing its weight. The basis weight of the first adhesive film 3 is 280 g / m³. 2 ~360g / m2 Optionally, the basis weight of the first adhesive film 3 can be 280 g / m³. 2 290g / m 2 300g / m 2 310g / m 2 320g / m 2 330g / m 2 340g / m 2 350g / m 2 and 360g / m 2 Other values ​​within the range are also acceptable and can be selected according to actual needs; no limitation is made here. It is understandable that having the basis weight of the first encapsulant film 3 within the above range can save on the production cost of photovoltaic modules, reduce the overall weight of photovoltaic modules, and simplify the installation, transportation, and maintenance process of photovoltaic modules.

[0056] The material of the first adhesive film 3 used in this application includes at least one of POE adhesive film, EP adhesive film and EPE adhesive film, which can be selected according to actual needs and is not limited here.

[0057] In some embodiments, the width of the second pad 5 is 30mm to 60mm, and the thickness of the second pad 5 is 0.4mm to 0.6mm. Optionally, the width of the second pad 5 can be 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, etc., and the thickness of the second pad 5 can be 0.4mm, 0.45mm, 0.50mm, 0.55mm, 0.60mm, etc., or other values ​​within the range. It can be selected according to actual needs and is not limited here. Understandably, the second spacer 5 is used to fill the short edge gap between the second encapsulant film 6 and the cell layer 4. If the width or thickness of the second spacer 5 is too small, that is, if the amount of the second spacer 5 used is too small, it cannot effectively fill the short edge gap between the second encapsulant film 6 and the cell layer 4. The problem of air bubbles or delamination between the second encapsulant film 6 and the cell layer 4 during the lamination process of the photovoltaic module cannot be effectively solved. If the width or thickness of the second spacer 5 is too large, the material cost will increase, and the heat distribution will be uneven during lamination. The second spacer 5 will not melt sufficiently, which will affect the gas discharge between the second encapsulant film 6 and the cell layer 4, thereby increasing the risk of air bubbles and delamination.

[0058] The weight of the second pad 5 is 250g / m². 2 ~380g / m 2 Optionally, the weight of the second pad 5 can be 250g / m². 2 270g / m 2 290g / m 2 300g / m 2 310g / m2 320g / m 2 330g / m 2 340g / m 2 350g / m 2 370g / m 2 and 380g / m 2 The weight can be any value within the range, and can be selected according to actual needs; no limitation is made here. Understandably, the weight of the second spacer strip 5 will affect the final weight of the photovoltaic module. If the weight of the second spacer strip 5 is too low, its mechanical properties will be reduced, and it will not be able to provide mechanical support. This will weaken the tear resistance and impact resistance of the laminated structure when the photovoltaic module is subjected to mechanical stress, increasing the risk of photovoltaic module failure. If the weight of the second spacer strip 5 is too high, it will increase the weight of the photovoltaic module, increase the installation difficulty, and place higher demands on the support structure of the photovoltaic module.

[0059] The first pad 2 and the second pad 5 used in this application can be made of EVA material.

[0060] The second adhesive film 6 used in this application can be an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene coelastomer (POE) film, or a polyethylene terephthalate (PET) film. It can also be a PVB film, an EPE film (a three-layer co-extruded film of EVA and POE), an EP film (a two-layer co-extruded film of EVA and POE), or other types of films, which can be selected according to actual needs and are not limited here. Preferably, the second adhesive film 6 used in this application is an EVA film. EVA film is non-sticky at room temperature, has good flexibility, transparency, and surface gloss, is chemically stable, has good anti-aging and ozone resistance, and is non-toxic. Under certain conditions of hot pressing, it undergoes melt bonding and cross-linking curing. The cured film has excellent light transmittance, bonding strength, thermal stability, airtightness, and aging resistance. When encapsulating the battery cell layer 4, it will not affect the light conversion performance of the photovoltaic module.

[0061] The second adhesive film 6 has a basis weight of 300 g / m³. 2 ~380g / m 2 Optionally, the basis weight of the second film 6 can be 300 g / m². 2 310g / m 2 320g / m 2 330g / m 2 340g / m 2 350g / m 2 and 380g / m 2Other values ​​within the range are also acceptable and can be selected according to actual needs; no specific limitation is made here. It is understandable that having the basis weight of the second encapsulant film 6 within the aforementioned range can save on the production cost of photovoltaic modules, reduce the overall weight of photovoltaic modules, and simplify the installation, transportation, and maintenance processes of photovoltaic modules.

[0062] In some embodiments, the first cover plate 1 is disposed on the side of the first adhesive film 3 away from the solar cell, i.e., the light-facing side. The first cover plate 1 is also called "photovoltaic glass," which has good light transmittance and high hardness. After covering the first adhesive film 3, it can withstand large day-night temperature differences and harsh weather environments, thus protecting the solar cell. The first cover plate 1 used in this application can be ultra-clear photovoltaic patterned glass or ultra-clear processed float glass, or other types of first cover plate 1, which can be selected according to actual needs and are not limited here.

[0063] The second cover plate 7 is disposed on the side of the second encapsulant film 6 away from the solar cell. The second cover plate 7 also protects and supports the solar cell, possessing excellent weather resistance, water resistance, corrosion resistance, and insulation properties. It effectively isolates the photovoltaic module from the surrounding photovoltaic environment and protects and supports the solar cell, thereby increasing the impact strength of the photovoltaic module. The second cover plate 7 used in this application can be glass, rolled glass, or ultra-clear rolled glass.

[0064] In some embodiments, this application provides a photovoltaic module manufacturing process in which a first cover plate 1, a first spacer strip 2, a first adhesive film 3, a cell layer 4, a second spacer strip 5, a second adhesive film 6, and a second cover plate 7, all stacked together, are placed in a laminator. The first spacer strip 2 covers the long edge region, the short edge region, and the middle strip region of the first adhesive film 3. The second spacer strip 5 covers the short edge region of the second adhesive film 6. Along the direction from the first cover plate 1 to the second cover plate 7, the long side spacer strip 21, the short side spacer strip 22, and the middle spacer strip 23 are stacked, with the long side spacer strip 21 located below the short side spacer strip 22 and the middle spacer strip 23. Air is then extracted from the module through vacuuming, and the first spacer strip 2, the second spacer strip 5, the first adhesive film 3, and the second adhesive film 6 are heated (i.e., under high temperature and high pressure conditions) to melt and bond the cell layer 4, the first cover plate 1, and the second cover plate 7 together, resulting in a laminated structure. During this process, the cooperation of the first spacer 2 and the second spacer 5, which have fluidity and heat-melting properties, can fill the tiny gaps between the first adhesive film 3 and the first cover plate 1, and between the cell layer 4 and the second adhesive film 6. This allows the first adhesive film 3 and the second adhesive film 6 to completely wrap the cell layer 4, and the first adhesive film 3 to the first cover plate 1 and the second adhesive film 6 to the cell layer 4 to adhere tightly. This effectively reduces the problem of bubbles or delamination at the four corners and the middle opening of the photovoltaic module during the lamination process.

[0065] After the laminated structure is bonded, photovoltaic modules can be assembled using the frame, and finally, the photovoltaic modules are fixed to the bracket using clamps. The bracket is a special frame designed to support, fix, and rotate the photovoltaic modules. Structurally, it can be divided into fixed brackets and tracking brackets. Fixed brackets have a fixed direction and low manufacturing cost, while tracking brackets can rotate the photovoltaic modules according to the light intensity, reducing the angle between the modules and direct sunlight, thus obtaining more solar irradiance and effectively improving power generation efficiency, but with higher manufacturing cost. In terms of material, brackets can be made of aluminum alloy, carbon steel, or stainless steel, etc., and the structure and material of the bracket can be selected according to actual needs; no specific limitations are made here. In actual use, the photovoltaic bracket can fix the photovoltaic modules with a certain orientation, arrangement, and spacing according to the terrain, climate, and solar energy resources. Understandably, after being fixed by the bracket, the photovoltaic modules can better receive sunlight.

[0066] As an optional technical solution in this application, the photovoltaic module includes a first cover plate 1, a first encapsulating film 3, a cell layer 4, a second encapsulating film 6, and a second cover plate 7 stacked sequentially. The first cover plate 1 is disposed on the light-facing surface of the photovoltaic module. A first spacer strip 2 is provided between the first cover plate 1 and the first encapsulating film 3, covering the long edge area, the short edge area, and the middle strip area of ​​the first encapsulating film 3. That is, in the above technical solution, the photovoltaic module does not have a second spacer strip 5, and the thickness of the first spacer strip 2 can be further increased to fill the tiny gap between the first encapsulating film 3 and the first cover plate 1, so that the first encapsulating film 3 can completely wrap the cell layer 4, and the first encapsulating film 3 is tightly attached to the first cover plate 1, effectively reducing the problem of bubbles or delamination at the four corners and the middle opening of the photovoltaic module during the lamination process.

[0067] The technical solution of this application is described below with reference to specific embodiments:

[0068] Example 1

[0069] (1) The ultra-white photovoltaic patterned glass, the first spacer strip, the POE film (first film), the solar cell layer, the second spacer strip, the EVA film (second film), and the rolled glass are stacked sequentially; wherein, the width of the first spacer strip is 45mm, the thickness is 0.5mm, and the basis weight is 320g / m². 2 The first pad includes a long side pad, a short side pad, and a middle pad; the second pad has a width of 45mm and a thickness of 0.5mm; both the first and second pads are made of EVA material.

[0070] (2) Under high temperature and high pressure conditions, the first spacer strip and POE film (first film) are melted to bond the ultra-white photovoltaic patterned glass, the first spacer strip, POE film (first film) and the battery cell layer together, and the second spacer strip and EVA film (second film) are melted to bond the rolled glass, EVA film (second film), the second spacer strip and the battery cell layer together to obtain a laminated structure;

[0071] (3) The laminated structure is assembled with a frame to obtain a photovoltaic module.

[0072] Example 2

[0073] (1) The ultra-white photovoltaic patterned glass, the first spacer strip, the POE film (first film), the solar cell layer, the second spacer strip, the EVA film (second film), and the rolled glass are stacked sequentially; wherein, the width of the first spacer strip is 30mm, the thickness is 0.4mm, and the basis weight is 250g / m². 2 The first pad includes a long side pad, a short side pad, and a middle pad; the second pad has a width of 45mm and a thickness of 0.5mm; both the first and second pads are made of EVA material.

[0074] (2) Under high temperature and high pressure conditions, the first spacer strip and POE film (first film) are melted to bond the ultra-white photovoltaic patterned glass, the first spacer strip, POE film (first film) and the battery cell layer together, and the second spacer strip and EVA film (second film) are melted to bond the rolled glass, EVA film (second film), the second spacer strip and the battery cell layer together to obtain a laminated structure;

[0075] (3) The laminated structure is assembled with a frame to obtain a photovoltaic module.

[0076] Example 3

[0077] (1) The ultra-white photovoltaic patterned glass, the first spacer strip, the POE film (first film), the solar cell layer, the second spacer strip, the EVA film (second film), and the rolled glass are stacked sequentially; wherein, the width of the first spacer strip is 60mm, the thickness is 0.6mm, and the basis weight is 380g / m². 2 The first pad includes a long side pad, a short side pad, and a middle pad; the second pad has a width of 45mm and a thickness of 0.5mm; both the first and second pads are made of EVA material.

[0078] (2) Under high temperature and high pressure conditions, the first spacer strip and POE film (first film) are melted to bond the ultra-white photovoltaic patterned glass, the first spacer strip, POE film (first film) and the battery cell layer together, and the second spacer strip and EVA film (second film) are melted to bond the rolled glass, EVA film (second film), the second spacer strip and the battery cell layer together to obtain a laminated structure;

[0079] (3) The laminated structure is assembled with a frame to obtain a photovoltaic module.

[0080] Example 4

[0081] (1) The ultra-white photovoltaic patterned glass, the first spacer strip, the POE film (first film), the solar cell layer, the second spacer strip, the EVA film (second film), and the rolled glass are stacked sequentially; wherein, the width of the first spacer strip is 20mm, the thickness is 0.35mm, and the basis weight is 220g / m². 2 The first pad includes a long side pad, a short side pad, and a middle pad; the second pad has a width of 45mm and a thickness of 0.5mm; both the first and second pads are made of EVA material.

[0082] (2) Under high temperature and high pressure conditions, the first spacer strip and POE film (first film) are melted to bond the ultra-white photovoltaic patterned glass, the first spacer strip, POE film (first film) and the battery cell layer together, and the second spacer strip and EVA film (second film) are melted to bond the rolled glass, EVA film (second film), the second spacer strip and the battery cell layer together to obtain a laminated structure;

[0083] (3) The laminated structure is assembled with a frame to obtain a photovoltaic module.

[0084] Comparative Example 1

[0085] Unlike Example 1, the first pad only includes the long side pad.

[0086] Comparative Example 2

[0087] Unlike Example 1, the first pad only includes the short side pad.

[0088] Comparative Example 3

[0089] Unlike Example 1, the first pad only includes the intermediate pad.

[0090] Comparative Example 4

[0091] Unlike Example 1, no first spacer strip is provided between the ultra-white photovoltaic patterned glass and the POE film (first film).

[0092] Test: The first and second spacers used in Examples 1-4 and Comparative Examples 1-4 are both made of EVA. Examples 1-4 and Comparative Examples 1-4 were subjected to 100 tests to observe the number of pieces with defects such as bubbles or delamination in the laminated structure.

[0093] Test results:

[0094]

[0095]

[0096] Test Result Analysis:

[0097] As can be seen from the test results of Examples 1 to 3, the photovoltaic module provided in this application has a first spacer strip between the first cover plate and the first encapsulant film, and a second spacer strip is provided in the short edge area between the cell layer and the second encapsulant film. By controlling the specification parameters of the first and second spacers strips, the cooperation of the first and second spacers strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips strips stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss stripss strips stripss stripss strips stripss stripst gaps between the first encapsulant film and the first cover plate, and between the cell layer and the second encapsulant film strips ...

[0098] Based on the test structures of Examples 1 and 4, it can be seen that the amount of the first spacer used in Example 4 is too small, which cannot effectively fill the gap between the first adhesive film and the first cover plate, and the problem of bubbles or delamination in the photovoltaic module during the lamination process cannot be effectively solved.

[0099] According to the test results of Example 1 and Comparative Examples 1 to 3, it can be seen that the first spacer strip is only partially set in Comparative Examples 1 to 3, which cannot effectively fill the gaps in parameters during the lamination process, and the problems of bubbles or delamination of photovoltaic modules during the lamination process cannot be effectively solved.

[0100] According to the test results of Example 1 and Comparative Example 4, in Comparative Example 4, without the first spacer strip, the probability of bubbles or delamination problems in the photovoltaic module during the lamination process is high.

[0101] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this application. The above description is only a preferred embodiment of this application, but this application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of this application, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, should be within the protection scope of this application.

Claims

1. A photovoltaic module, characterized in that, The photovoltaic module includes a first cover plate, a first encapsulant film, a battery cell layer, a second encapsulant film, and a second cover plate stacked in sequence, wherein the first cover plate is disposed on the light-facing surface of the photovoltaic module; A first pad is provided between the first cover plate and the first adhesive film, and the first pad covers the long edge area, the short edge area and the middle strip area of ​​the first adhesive film; A second spacer strip is provided between the battery cell layer and the second adhesive film, and the second spacer strip covers the short edge area of ​​the second adhesive film; The first padding strip includes a long side padding strip, a short side padding strip, and a middle padding strip; along the direction from the first cover plate of the photovoltaic module toward the second cover plate, the long side padding strip, the short side padding strip, and the middle padding strip are stacked, and the long side padding strip is located below the short side padding strip and the middle padding strip. The length of the long side pad is equal to the length of the first adhesive film, and the lengths of the short side pad and the middle pad are equal to the width of the first adhesive film; the long side pad and the short side pad overlap at the corners of the first adhesive film, and the long side pad and the middle pad overlap at both ends of the middle strip area of ​​the first adhesive film. The thickness of the first pad is 0.4mm to 0.6mm, and the basis weight of the first pad is 250g / m² to 380g / m².

2. The photovoltaic module according to claim 1, characterized in that, The distance from one side of the long side pad, one side of the short side pad, and both ends of the middle pad to the edge of the first adhesive film is 0~2mm.

3. The photovoltaic module according to claim 1, characterized in that, The width of the first pad is 30mm to 60mm.

4. The photovoltaic module according to claim 1, characterized in that, The basis weight of the first adhesive film is 280 g / m² to 360 g / m².

5. The photovoltaic module according to claim 1, characterized in that, The material of the first adhesive film includes at least one of POE adhesive film, EP adhesive film and EPE adhesive film.

6. The photovoltaic module according to claim 1, characterized in that, The width of the second pad is 30mm to 60mm, and / or the thickness of the second pad is 0.4mm to 0.6mm, and / or the basis weight of the second pad is 250g / m² to 380g / m².

7. The photovoltaic module according to claim 1, characterized in that, The basis weight of the second adhesive film is 300g / m² to 380g / m².

8. The photovoltaic module according to claim 1, characterized in that, The second adhesive film is an EVA adhesive film.

9. A photovoltaic module manufacturing process, characterized in that, The photovoltaic module manufacturing process is used to produce the photovoltaic modules according to any one of claims 1 to 8; and includes the following steps: A first cover plate, a first spacer strip, a first adhesive film, a battery cell layer, a second spacer strip, a second adhesive film, and a second cover plate are sequentially stacked; wherein, the first spacer strip covers the long edge region, the short edge region, and the middle strip region of the first adhesive film, and the second spacer strip covers the short edge region of the second adhesive film, and is arranged along the direction from the first cover plate of the photovoltaic module toward the second cover plate; the long edge spacer strip, the short edge spacer strip, and the middle spacer strip are stacked, and the long edge spacer strip is located below the short edge spacer strip and the middle spacer strip; Under high temperature and high pressure conditions, the first spacer strip and the first adhesive film are melted to bond the first cover plate, the first spacer strip, the first adhesive film and the battery cell layer together, and the second spacer strip and the second adhesive film are melted to bond the second cover plate, the second adhesive film, the second spacer strip and the battery cell layer together, to obtain a laminated structure, and the photovoltaic module includes the laminated structure.

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