Composite packaging adhesive film and photovoltaic module

Abstract

The embodiment of the utility model provides a composite packaging adhesive film and a photovoltaic module. The composite packaging adhesive film comprises a first end sealing part, a composite part and a second end sealing part which are sequentially arranged along a first direction, the composite part comprises a black film and a white film which are laminated along a second direction; the first end sealing part and the second end sealing part are used for absorbing light entering the gaps of the battery pieces; the black film is used for reflecting light penetrating through the gaps of the battery pieces; and the white film is used for reflecting the light which penetrates through the black film and has the wavelength of 760 nm to 1100 nm. The composite packaging adhesive film is used for achieving the effects of avoiding adhesive overflow at the edge and improving the water vapor barrier property.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic modules, and in particular to a composite encapsulation film and a photovoltaic module. Background Technology

[0002] In back-contact (BC) solar module technology, all electrodes and grid lines are moved to the back of the cell, leaving the front completely unobstructed by any metal grid lines, resulting in a pure black photovoltaic module with a flawless, line-free appearance. No-busbar (OBB) technology completely eliminates the large main grid, retaining only extremely fine grid lines, and combined with black solar cells, the resulting black photovoltaic module has virtually invisible grid lines on the front.

[0003] With the rapid development of back contact (BC) cell module technology and no-busbar (0BB) technology, as well as the aesthetics of black encapsulation solutions, black photovoltaic modules are gaining popularity in building integrated photovoltaic (BIPV) and distributed photovoltaic scenarios.

[0004] To achieve black photovoltaic (PV) modules, the demand for black encapsulant films in the PV module industry is increasing daily. Various encapsulant film manufacturers are employing multi-layer black and white designs to give the films high infrared reflectivity, while simultaneously optimizing the optical path, resulting in a 2%-3% increase in the power output of black PV modules. Current high-infrared-reflective black encapsulants have a reflectivity of over 80% for near-infrared light waves (760nm–1100nm), which can enhance the efficiency of the modules.

[0005] However, existing high-infrared-reflective black adhesive films also have obvious drawbacks: they are prone to adhesive overflow and color bleeding at the edges, and adhesion to the high-temperature fabric of the laminator. Although this problem can be solved by increasing the irradiation dose and reducing the particle melt index, this approach also introduces lamination bubbles and reduced adhesion, significantly impacting module production efficiency and yield. In addition, conventional black and white adhesive films also suffer from poor moisture barrier properties at the edges and the inability to recycle black and white edge materials during production.

[0006] Therefore, there is an urgent need to provide a composite encapsulation film to solve the problems of edge glue overflow during lamination, poor moisture barrier properties, and the inability to recycle black and white edge materials. Utility Model Content

[0007] This utility model provides a composite encapsulation film to achieve the effects of avoiding edge overflow, improving moisture barrier properties, and recycling edge scraps.

[0008] In a first aspect, the present invention provides a composite encapsulating film, comprising a first sealing end portion, a composite portion, and a second sealing end portion arranged sequentially along a first direction;

[0009] The composite part includes a black film and a white film stacked along the second direction;

[0010] The first and second sealing ends are used to absorb light incident on the gaps between the solar cells;

[0011] The black film is used to reflect light that passes through the gaps between the battery cells;

[0012] The white film is used to reflect light with wavelengths of 760nm-1100nm that passes through the black film.

[0013] In one possible implementation, the width of the first sealing end is 10mm-30mm;

[0014] And / or, the width of the second sealing end is 10mm-30mm.

[0015] In one possible implementation, the width of the first sealing end is 12mm-20mm;

[0016] And / or, the width of the second sealing end is 12mm-20mm.

[0017] In one possible implementation, the thickness of the black film is 80 μm-320 μm;

[0018] And / or, the thickness of the white film is 120μm-600μm.

[0019] In one possible implementation, the thickness of the black film is less than the thickness of the white film.

[0020] In one possible implementation, the thickness ratio of the black film to the white film is 1:(1.5-3.5).

[0021] In one possible implementation, the thickness of the black film is 120μm-180μm;

[0022] And / or, the thickness of the white film is 240μm-400μm.

[0023] In one possible implementation, the thickness of the first sealing end is 400μm-650μm;

[0024] And / or, the thickness of the second sealing end is 400μm-650μm.

[0025] In one possible implementation, the first end cap (101) contains a first polyolefin copolymer with a melt index of 3 g / 10 min to 15 g / 10 min;

[0026] And / or, the melt index of the second polyolefin copolymer contained in the second end cap (103) is 3 g / 10 min to 15 g / 10 min;

[0027] And / or, the black film (1021) contains a first EVA resin with a melt index of 5 g / 10 min to 25 g / 10 min;

[0028] And / or, the melt index of the second EVA resin contained in the white film (1022) is 5 g / 10 min to 25 g / 10 min.

[0029] Secondly, this utility model embodiment provides a photovoltaic module, including glass, a battery, a composite encapsulation film as described above, and a backsheet arranged sequentially from top to bottom.

[0030] The composite encapsulating film and photovoltaic module provided in this embodiment of the invention have the following advantages:

[0031] 1. By setting a vertically stacked structure, the black film can meet the appearance requirements of photovoltaic modules, and the white film can provide a high color reflectance, thereby increasing the power of photovoltaic modules;

[0032] 2. By designing the first and second sealing ends, the problem of glue overflow during the lamination process is avoided, thereby improving the module yield; at the same time, the water vapor barrier properties of the composite encapsulation film edge are also improved, so as to achieve the DH3000h resistance to humid heat aging of the photovoltaic module.

[0033] 3. The first and second sealing ends are designed in pure black, so that the edge material at both ends of the composite encapsulation film is uniformly black. The black film can be recycled online to the composite part, which greatly improves the utilization rate of raw materials and reduces product costs. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0035] Figure 1 This is a schematic diagram of the structure of the composite encapsulation film provided by this utility model.

[0036] Figure label:

[0037] 101-First sealing end; 102-Composite part; 1021-Black film; 1022-White film; 103-Second sealing end.

[0038] The accompanying drawings have illustrated specific embodiments of the present invention, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0039] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0041] Existing black and white double-layer adhesive films have technical problems such as edge glue overflow during lamination, poor aging resistance under humid heat during use, and the inability to recycle black and white edge materials online.

[0042] The composite encapsulation film provided by this utility model solves the problems of adhesive overflow, color contamination and humid heat aging at the edges of the black film by involving a single end-sealing layer at both ends of the longitudinally stacked structure (black film + white film).

[0043] The technical solution of this utility model and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this utility model will now be described with reference to the accompanying drawings.

[0044] Figure 1 This is a schematic diagram of the structure of the composite encapsulation film provided by this utility model, as shown below. Figure 1As shown, the composite encapsulation film includes: a first sealing end portion 101, a composite portion 102, and a second sealing end portion 103 arranged sequentially along a first direction; the composite portion 102 includes a black film 1021 and a white film 1022 stacked along a second direction; the first sealing end portion 101 and the second sealing end portion 103 are used to absorb light incident on the gap between the battery cells; the black film 1021 is used to reflect light transmitted through the gap between the battery cells; the white film 1022 is used to reflect light transmitted through the black film 1021; the width of the first sealing end portion 101 is 10mm-30mm; the width of the second sealing end portion 103 is 10mm-30mm.

[0045] It is understandable that, according to Fick's Law, the amount of water vapor permeating through a polymer is inversely proportional to the path length (material thickness). In this invention, by setting single-layer first sealing end 101 and second sealing end 103 at both ends of the composite part formed by stacking black film 1021 and white film 1022, and controlling their width to be 10nm-30nm, the diffusion path length required for water vapor to penetrate into the photovoltaic module from the edge is directly increased, delaying the time for water vapor to reach the cell, thereby improving the resistance to damp heat aging of the composite encapsulation film. At the same time, at this width, the first sealing end 101 and second sealing end 103 can be better matched with the lamination process parameters (temperature, pressure, time), ensuring uniform pressure on the entire film plane. This allows the melt in the composite part 102 to flow and fill fully, while also ensuring good interface adhesion at the edges while maintaining their shape, suppressing the problem of adhesive overflow and color bleeding.

[0046] For example, the width of the first end cap 101 can be a range of 10nm, 12nm, 14nm, 16nm, 18nm, 20nm, 22nm, 24nm, 26nm, 28nm, 30nm, or any two of these; the width of the second end cap 103 can be a range of 10nm, 12nm, 14nm, 16nm, 18nm, 20nm, 22nm, 24nm, 26nm, 28nm, 30nm, or any two of these.

[0047] In some embodiments, the width of the first end cap 101 is preferably 12nm-30nm.

[0048] In some embodiments, the width of the second end cap 103 is preferably 12nm-30nm.

[0049] It should be noted that the widths of the first sealing end 101 and the second sealing end 103 may be the same or different.

[0050] In some specific embodiments, the thickness of the black film 1021 is 80μm-320μm.

[0051] The black film 1021 is located on the front (top) of the solar cell, and its core functions are high light transmittance, cell protection, and adhesion. Any light passing through the black film 1021 experiences slight absorption and reflection losses. The thicker the film, the longer the light loss path, and the total transmittance (TT) usually decreases slightly. While ensuring encapsulation functions (such as adhesion strength and anti-PID), controlling the thickness of the black film 1021 to 80μm-320μm can relatively improve its light transmittance, allowing more sunlight to reach the solar cell surface, directly increasing the short-circuit current (Isc) and module power.

[0052] For example, the thickness of the black film 1021 can be a range of 80 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 320 μm or any combination thereof.

[0053] In some specific embodiments, the thickness of the white film 1022 is 120μm-600μm.

[0054] The white film 1022 is located on the back (lower layer) of the solar cell. Its core functions are efficient light reflection (reflecting light passing through the gaps between the solar cells back) and electrical insulation. The reflectivity of the white film 1022 increases with increasing thickness (until it reaches saturation). By controlling the thickness of the white film 1022 to 120μm-600μm, its reflectivity can be improved, thereby utilizing light entering from the back more effectively. At the same time, sufficient thickness can also better conceal the printed grid lines and other patterns on the back of the solar cell, avoiding color differences ("reddish back panel phenomenon").

[0055] In some specific embodiments, the thickness of the white film 1022 can be a range of 120μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, 550μm, 600μm or any combination thereof.

[0056] In some specific embodiments, the thickness of the black film 1021 is less than the thickness of the white film 1022.

[0057] Due to their different formulations (the white film contains a large amount of titanium dioxide), the black film 1021 and the white film 1022 exhibit differences in thermal properties, rheological properties, and curing (crosslinking) characteristics. Since heat is transferred from both the top and bottom surfaces during lamination heating, controlling the thickness of the black film 1021 to be less than that of the white film 1022 allows the black film 1021 to reach and stabilize at the set temperature more quickly, thus achieving better curing synchronization with the relatively thicker white film 1022, which may have different heat capacities. This helps reduce internal stress or poor adhesion caused by inconsistent curing rates between the upper and lower film layers. Because the white film 1022 is filled with a large amount of titanium dioxide, its flowability is generally worse than that of the black film 1021. Designing the white film 1022 to be thicker provides more "material margin" for flow and filling during the lamination process, ensuring it can fully fill the uneven structure on the back of the solar cell, forming good interfacial adhesion. In addition, the relatively thicker white film 1022 can provide stronger mechanical support for the solar cells and play a better role in buffering when the module is subjected to external stress (such as installation stress and wind load).

[0058] In some embodiments, the thickness ratio of the black film 1021 to the white film 1022 is 1:(1.5-3.5).

[0059] For example, the thickness ratio of the black film 1021 to the white film 1022 can be 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5 or any combination thereof.

[0060] In some embodiments, the thickness of the black film 1021 is preferably 120μm-180μm, specifically, it can be a range of 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm or any combination thereof.

[0061] In some embodiments, the thickness of the white film 1022 is preferably 240μm-400μm, specifically, it can be a range of 240μm, 260μm, 280μm, 300μm, 320μm, 340μm, 360μm, 380μm, 400μm or any combination thereof.

[0062] In some specific embodiments, the thickness of the first sealing end 101 is 400μm-650μm.

[0063] In some specific embodiments, the thickness of the second sealing end 103 is 400μm-650μm.

[0064] By controlling the thickness of the first sealing end 101 and / or the second sealing end 103 to be 400μm-650μm, they can achieve a higher section modulus, more effectively resisting creep (slow, permanent plastic deformation of the material) under long-term thermal stress, and reducing the risk of microcracks in the edge adhesive layer due to fatigue. Simultaneously, they can also serve as an effective stress buffer layer, absorbing and dispersing some mechanical stress, protecting the fragile battery cells and solder strips, and preventing failure modes such as edge delamination.

[0065] In some specific embodiments, the first sealing end 101 and the second sealing end 103 include a high melt flow rate polyolefin copolymer, a low melt flow rate polyolefin copolymer, and a black masterbatch material. The high melt flow rate polyolefin copolymer has a melt flow rate of 10 g / 10 min to 15 g / 10 min, the low melt flow rate polyolefin copolymer has a melt flow rate of 3 g / 10 min to 10 g / 10 min, and the mixed polyolefin compound material has a melt flow rate of 7 g / 10 min to 10 g / 10 min. The polyolefin copolymer includes at least one of ethylene-butene copolymer, ethylene-octene copolymer, and ultra-low density linear polyethylene. The black masterbatch material may include at least one of azo pigments, phthalocyanine pigments, perylene pigments, isoindolineone pigments, and quinacridone pigments, consistent with the black masterbatch material used in the black film 1021.

[0066] In some embodiments, the melt index of the high melt index ethylene-butene copolymer is 10 g / 10 min to 15 g / 10 min, and the melt index of the low melt index ethylene-butene copolymer is 3 g / 10 min to 10 g / 10 min; the melt index of the high melt index ethylene-octene copolymer is 10 g / 10 min to 15 g / 10 min, and the melt index of the low melt index ethylene-octene copolymer is 3 g / 10 min to 10 g / 10 min.

[0067] In this embodiment, a high melt flow index (MFI) polyolefin copolymer and a low melt flow index (LFI) polyolefin copolymer are used in combination. The high MFI polyolefin copolymer is characterized by short molecular chains, less entanglement, low viscosity, and insensitivity to shear rate (weak shear thinning effect). The low MFI polyolefin copolymer is characterized by long molecular chains, more entanglement, high initial viscosity, but is highly sensitive to shear rate (strong shear thinning effect). The MFI of the polyolefin copolymers contained in the first sealing end 101 and the second sealing end 103 is controlled to be 3 g / 10 min to 15 g / 10 min, resulting in high viscosity and high flow resistance under low shear force. During lamination, the high melt flow resistance of the first sealing end 101 and the second sealing end 103 prevents the melt of the black film 1021 and the white film 1022 in the composite section 102 from overflowing to the edges, thus avoiding color bleeding between the black film 1021 and the white film 1022 and adhesion to the high-temperature fabric of the laminator. In addition, due to its high viscosity and strong cohesion, the low melt index polyolefin material can more firmly "grab" the interface between the glass and the backing plate when heated and compressed, resisting the peeling force caused by material flow, ensuring the tight fit of the edge encapsulation interface (film / glass, film / backing plate), greatly reducing the generation of interface micro gaps, cutting off the main channel for water vapor to penetrate along the interface, and thus improving the water vapor barrier properties of the composite encapsulation film edge.

[0068] In some embodiments, the water vapor transmission rate of the first sealing end 101 and / or the second sealing end 103 is less than 5 g / (m²). 2 •day).

[0069] In some specific embodiments, the black film 1021 is a black encapsulation material obtained by adding black masterbatch to the first EVA resin. The black encapsulation material can reflect light that passes through the gaps between the battery cells.

[0070] In some embodiments, the first EVA resin may include at least one of propylene-ethylene copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, and ethylene-n-butyl acrylate-glycidyl ester terpolymer; the black masterbatch may include at least one of azo pigments, phthalocyanine pigments, perylene pigments, isoindolinone pigments, and quinacridone pigments.

[0071] Specifically, azo pigments consist of two aromatic compounds linked by an azo group (N=N), producing a wide range of colors from yellow to red. Azo pigments are often mixed with other pigments to provide deep black. Phthalocyanine pigments are composed of phthalocyanine molecules, a tetrapyrrole ring structure containing a metal center (such as copper or zinc). They typically provide blue to green hues, but specific phthalocyanine pigments can produce black by adjusting the metal center and molecular structure. Perylene pigments are composed of perylene derivatives and possess good thermal stability and solvent resistance. They can provide different hues from red to purple, but in some embodiments, black coatings can be produced through specific perylene derivatives and mixing techniques. Isoindolineone pigments are a class of high-performance organic pigments with excellent weather resistance and lightfastness. Quinacridone pigments are a class of organic pigments with excellent lightfastness and weather resistance, typically used to produce red and purple.

[0072] In some embodiments, the melt index of the first EVA resin in the black film 1021 is 5 g / 10 min to 25 g / 10 min.

[0073] For example, the melt index of the first EVA resin of the black film 1021 can be a range of 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min or any two of these.

[0074] White film 1022 is a white encapsulation material obtained by adding titanium dioxide to the second EVA resin, and has a high infrared reflectivity layer. White film 1022 is used to reflect light with wavelengths of 760nm-1100nm that has passed through black film 1021 back to the solar cell, further improving reflectivity without affecting light transmission and hue, so as to improve power generation efficiency and achieve a 1%-1.5% power increase.

[0075] In some embodiments, the second EVA resin may include at least one of ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, and ethylene-n-butyl acrylate-glycidyl ester terpolymer.

[0076] In some embodiments, the particle size of the titanium dioxide used is 10nm-60nm.

[0077] The white film 1022, encapsulated below the gaps between the solar cells (i.e., on the back side), can efficiently reflect sunlight passing through the gaps back to the solar cells, where it is absorbed again, directly increasing the module's short-circuit current and power output. By controlling the particle size of the titanium dioxide contained in the white film 1022 to 10nm-60nm, the reflectivity can be further improved. At the same time, it also helps to improve the volume resistivity of the composite encapsulation film and reduce the risk of potential-induced degradation.

[0078] For example, the particle size of titanium dioxide can be a range of 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, or any combination thereof.

[0079] In some embodiments, the melt index of the second EVA resin in the white film 1022 is 5 g / 10 min to 25 g / 10 min.

[0080] For example, the melt index of the second EVA resin in the white film 1022 can be a range of 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, or any combination thereof.

[0081] In this invention, the melt of the first sealing end 101, the melt of the black film 1021, the melt of the white film 1022, and the melt of the second sealing end 103 are driven by a common inlet pressure, and the pressure is released to atmospheric pressure at the end of the flow channel. For a given pressure gradient and flow channel size, the flow rate of high-viscosity fluid is slow, while the flow rate of low-viscosity fluid is fast. Therefore, by controlling the melt index of the polyolefin copolymer contained in the first sealing end 101 and the second sealing end 103 at both transverse ends of the composite encapsulation film to be 3 g / 10 min to 15 g / 10 min, and the melt index of the first EVA resin and the second EVA resin contained in the black film 1021 and the white film 1022 in the middle to be 5 g / 10 min to 25 g / 10 min, a structure of "high melt index in the middle + low melt index at both ends" is formed. The high melt index melt in the middle can spread quickly and fully on the surface of the battery cell and the solder ribbon, filling all microscopic voids, achieving better adhesion and lower battery cell stress. The melt at the first sealing end 101 and the second sealing end 103, which have lower melt flow rates and higher viscosity at both ends, acts like a "viscous soft wall" or a "flowing dam." It flows slowly on its own and, through viscous friction, drags and restricts the melts (high melt flow rate melts) of the adjacent black film 1021 and white film 1022, preventing them from flowing rapidly at will. On the one hand, this suppresses melt flow, preventing resin overflow from the black film 1021 and / or white film 1022 to both sides of the adhesive film during lamination, thus improving the yield of photovoltaic modules by 15%-20%. On the other hand, it prevents moisture from eroding the cells from the sides, improving the photovoltaic modules' resistance to damp heat aging.

[0082] The composite encapsulation film provided in this embodiment of the invention improves the optical performance of photovoltaic modules by setting a first sealing end and a second sealing end at both ends of the longitudinally stacked black and white films, while avoiding the phenomenon of glue overflow and color pollution at the edges of the black and white films, and improving the resistance of the composite encapsulation film to damp heat aging.

[0083] This invention also provides a photovoltaic module, comprising glass, solar cells, a composite encapsulating film as described above, and a backsheet. The composite encapsulating film is disposed on both the front and back sides of the solar cells via a white film 1022 facing the solar cells. By using the composite encapsulating film, reflectivity can be increased, thereby improving the power generation efficiency of the black photovoltaic module.

[0084] The photovoltaic module provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0085] Finally, it should be noted that other embodiments of the present invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A composite encapsulating film, characterized in that, It includes a first sealing end (101), a composite part (102), and a second sealing end (103) arranged sequentially along a first direction. The composite part (102) includes a black film (1021) and a white film (1022) stacked along the second direction. The first sealing end (101) and the second sealing end (103) are used to absorb light incident on the gap between the solar cells; The black film (1021) is used to reflect light that passes through the gaps between the solar cells; The white film (1022) is used to reflect light with wavelengths of 760nm-1100nm that passes through the black film (1021).

2. The composite encapsulating film according to claim 1, characterized in that, The width of the first sealing end (101) is 10mm-30mm; And / or, the width of the second sealing end (103) is 10mm-30mm.

3. The composite encapsulating film according to claim 2, characterized in that, The width of the first sealing end (101) is 12mm-20mm; And / or, the width of the second sealing end (103) is 12mm-20mm.

4. The composite encapsulating film according to claim 1, characterized in that, The thickness of the black film (1021) is 80μm-320μm; And / or, the thickness of the white film (1022) is 120μm-600μm.

5. The composite encapsulating film according to claim 1, characterized in that, The thickness of the black film (1021) is less than the thickness of the white film (1022).

6. The composite encapsulating film according to claim 5, characterized in that, The thickness ratio of the black film (1021) to the white film (1022) is 1:(1.5-3.5).

7. The composite encapsulating film according to claim 6, characterized in that, The thickness of the black film (1021) is 120μm-180μm; And / or, the thickness of the white film (1022) is 240μm-400μm.

8. The composite encapsulating film according to claim 1, characterized in that, The thickness of the first sealing end (101) is 400μm-650μm; And / or, the thickness of the second sealing end (103) is 400μm-650μm.

9. The composite encapsulating film according to claim 1, characterized in that, The melt index of the first polyolefin copolymer contained in the first end cap (101) is 3 g / 10 min to 15 g / 10 min; And / or, the melt index of the second polyolefin copolymer contained in the second end cap (103) is 3 g / 10 min to 15 g / 10 min; And / or, the black film (1021) contains a first EVA resin with a melt index of 5 g / 10 min to 25 g / 10 min; And / or, the melt index of the second EVA resin contained in the white film (1022) is 5 g / 10 min to 25 g / 10 min.

10. A photovoltaic module, characterized in that, It includes glass, battery, composite encapsulation film as described in any one of claims 1-9, and backplate arranged sequentially from top to bottom.

Images