Packaging adhesive film, photovoltaic module and photovoltaic system

Abstract

The invention provides a packaging adhesive film, a photovoltaic module and a photovoltaic system, and relates to the technical field of photovoltaics. The packaging adhesive film comprises a base film; the base film comprises a first side and a second side which are opposite; a colored high reflective film on the first side of the base film; the colored high-reflective film comprises a first colored high-reflective film with the crosslinking degree smaller than or equal to 5%. The light utilization rate of the photovoltaic module can be improved. The first colored high-reflection film can be fused under lamination to cover the base film, appearance defects are avoided, meanwhile, the first colored high-reflection film can be fused under lamination to cover the conductive part between the battery pieces, colored appearance adhesive tape does not need to be arranged on the conductive part, the process is simplified, and the yield is improved. The color of the photovoltaic module formed by the packaging adhesive film is more uniform and consistent, and the photovoltaic module is more beautiful.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a packaging film, a photovoltaic module and a photovoltaic system. Background Art

[0002] Colored photovoltaic modules can better integrate with colored roofs and improve the overall aesthetics, so they have certain application prospects.

[0003] Currently, photovoltaic modules mainly use transparent encapsulation films combined with colored backsheets to improve the appearance and color of photovoltaic modules.

[0004] However, in these photovoltaic modules, a transparent film is placed between the cells and the colored backsheet, reducing light utilization. Furthermore, the cells are typically electrically connected via interconnects, which are typically silvery white. During the photovoltaic module manufacturing process, colored adhesive tape is typically placed in the gaps between the cells before the interconnects are placed and heated to achieve a preliminary bond between the colored adhesive tape and the cells. This involves using the colored adhesive tape to conceal the interconnects, resulting in a complex process. Summary of the Invention

[0005] The present invention provides an encapsulation film, a photovoltaic module and a photovoltaic system, aiming to solve the problems of low light utilization rate of existing photovoltaic modules and complex process for forming photovoltaic modules.

[0006] A first aspect of the present invention provides a packaging film, comprising:

[0007] a basement membrane; the basement membrane comprising a first side and a second side opposite to each other;

[0008] A colored high-reflective film is located on the first side of the base film; the colored high-reflective film comprises: a first colored high-reflective film with a cross-linking degree less than or equal to 5%.

[0009] In an embodiment of the present invention, a packaging film containing a colored highly reflective film replaces a transparent film, which can improve the light utilization rate of photovoltaic modules. Moreover, by adding a colored highly reflective film to the packaging film, and through the synergistic effect of the colored highly reflective film and the base film, the packaging film has a higher reflectivity, which can further improve the performance of the photovoltaic module. The cross-linking degree of the first colored highly reflective film in the colored highly reflective film is less than or equal to 5%, and the first colored highly reflective film has a certain ductility or fluidity, and can be melted under lamination to cover the base film, thereby avoiding appearance defects. At the same time, the first colored highly reflective film has a certain ductility or fluidity, and can be melted under lamination to cover the interconnection parts located between the battery cells. There is no need to set a colored appearance tape on the interconnection parts, and there is no need to perform a preliminary bonding heat treatment on the battery cells and the colored appearance tape, which simplifies the process and improves the yield. Moreover, the first colored highly reflective film has a certain degree of ductility or fluidity, and can be melted under lamination to cover the color of the cell cross-section, and can be melted under lamination to cover the color of conductive parts such as busbars. Therefore, the color of the photovoltaic module formed by the encapsulation film of the present application is more uniform and more beautiful. In summary, the power of the photovoltaic module using the encapsulation film of the present application can be increased by about 0.5% to 2%, and the cost is low. The process is simplified and the yield is improved, which has good prospects for mass production. In addition, the color of the photovoltaic module formed by the encapsulation film of the present application is more uniform and more beautiful.

[0010] Optionally, the melt index of the first colored high-reflective film is 5 to 30 grams per ten minutes; and / or, the first colored high-reflective film is a lamination film; and / or, the color of the first colored high-reflective film is black.

[0011] Optionally, the colored high-reflective film only includes the first colored high-reflective film; or

[0012] The colored high-reflective film further includes: a second colored high-reflective film with a cross-linking degree greater than 5%; the second colored high-reflective film is located between the base film and the first colored high-reflective film, and the first colored high-reflective film and the second colored high-reflective film have the same color.

[0013] Optionally, the colored high-reflective film includes: the first colored high-reflective film and the second colored high-reflective film, and the cross-linking degree of the second colored high-reflective film is greater than or equal to 15%; and / or,

[0014] The second colored high-reflective film and the base film are cross-linked structures; and / or,

[0015] The gram weight ratio of the first colored high-reflective film to the second colored high-reflective film is 8:1 to 1:8; and / or,

[0016] The melt index of the second colored high reflective film is 1.5 to 30 grams per ten minutes. Optionally, the packaging film further includes: a transparent film located on the second side of the base film;

[0017] And / or, the basement membrane includes: tunica albuginea.

[0018] Optionally, the weight of the colored high-reflective film accounts for 5% to 35% of the weight of the packaging film; and / or,

[0019] The ratio of the base film's gram weight to the packaging film's gram weight is greater than or equal to 50%; and / or the packaging film has a thickness of 300 micrometers to 800 micrometers.

[0020] A second aspect of the present invention provides a photovoltaic module, comprising:

[0021] A battery string group, the battery string group comprising a plurality of battery cells electrically connected by a conductive member;

[0022] and a rear packaging film, the rear packaging film being arranged on the backlight side of the battery string group;

[0023] The rear encapsulation film comprises: a base film; the base film comprises a first side and a second side opposite to each other; a colored high reflective film located on the first side of the base film;

[0024] The colored high-reflective film of the rear packaging film is arranged adjacent to the battery string, and the colored high-reflective film at least partially covers the surface of the conductive component adjacent to the rear packaging film.

[0025] In the present application, the colored high-reflective film of the rear encapsulation film has a certain degree of ductility or fluidity, and can be melted under lamination to cover the base film, thereby avoiding appearance defects. At the same time, the colored high-reflective film has a certain degree of ductility or fluidity, and can be melted under lamination to cover the conductive parts. There is no need or less need to set a colored appearance tape on the conductive parts, and there is no need or less need to perform a heat treatment for the initial bonding of the battery cells and the colored appearance tape, etc., which simplifies the process and improves the yield. Moreover, the colored high-reflective film has a certain degree of ductility or fluidity, and can be melted under lamination to cover the color of the battery cross-section. Therefore, the color of the photovoltaic module formed by the rear encapsulation film of the present application is more uniform and more beautiful. In summary, the power of the photovoltaic module using the rear encapsulation film of the present application can be increased by about 0.5% to 2%, and the cost is low. The process is simplified and the yield is improved, which has good prospects for mass production. In addition, the color of the photovoltaic module formed by the rear encapsulation film of the present application is more uniform and more beautiful.

[0026] Optionally, the conductive member includes: a bus bar; the colored high reflective film covers at least a portion of the surface of the bus bar;

[0027] And / or, the conductive member includes an interconnection member, and the colored high-reflective film covers at least a portion of the surface of the interconnection member.

[0028] Optionally, the colored high-reflective film includes: a first colored high-reflective film and a second colored high-reflective film of the same color, the second colored high-reflective film is located between the base film and the first colored high-reflective film; there is a dividing line between the first colored high-reflective film and the second colored high-reflective film, and there is a dividing line between the colored high-reflective film and the base film.

[0029] Optionally, the rear packaging film adopts any of the packaging films mentioned above; and / or,

[0030] The cross-linking degree of the colored high-reflective film is 75% to 95%, and the cross-linking degree of the basement membrane is 75% to 95%; and / or,

[0031] The weight of the rear packaging film is 200 g / m2 to 600 g / m2.

[0032] Optionally, the photovoltaic module further comprises: a front encapsulation film, the front encapsulation film being arranged on the light-facing side of the battery string group;

[0033] A curved dividing line is formed between the front packaging film and the rear packaging film.

[0034] Optionally, on the side of the battery cell, the coverage area of the rear encapsulation film is larger than the coverage area of the front encapsulation film.

[0035] Optionally, the reflectivity of the surface of the rear packaging film facing the battery string group is greater than or equal to 70%.

[0036] Optionally, the photovoltaic module further comprises: a back sheet, the back sheet being arranged on a side of the rear packaging film away from the battery string group;

[0037] The surface of the back plate close to the battery string is white; and / or the battery cell is a back contact battery cell.

[0038] A third aspect of the present invention further provides a photovoltaic system comprising any one of the photovoltaic modules described above.

[0039] The above-mentioned encapsulation films, photovoltaic modules and photovoltaic systems have the same or similar beneficial effects, and will not be described in detail here to avoid repetition. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0041] Figure 1 A schematic structural diagram of a packaging film according to an embodiment of the present invention is shown;

[0042] Figure 2 A schematic diagram of the partial structure of a photovoltaic module in an embodiment of the present invention is shown.

[0043] Description of the accompanying figures:

[0044] 1-base film, 2-first colored high-reflective film, 3-second colored high-reflective film, 4-interconnection part. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0046] The present invention provides a packaging film, which may include: a base film 1, wherein the base film 1 includes a first side and a second side opposite to each other. For example, Figure 1 、 Figure 2 In the embodiment, the upper side of the base film 1 is the first side, and the lower side of the base film 1 is the second side. The packaging film may further include: at least one layer of colored high reflective film located on the first side of the base film 1, such as Figure 1 、 Figure 2 In the figure, the upper side of the basement membrane 1 is a colored high-reflective membrane.

[0047] Optionally, the base film 1 may include a white film, which has a better reflective effect, making the encapsulation film have a higher reflectivity, which can further improve the performance of the photovoltaic module. The base film 1 can also be other colored films, such as gray film, red film, etc.

[0048] Optionally, the weight of the colored highly reflective film in the encapsulating film accounts for 5% to 35% of the weight of the encapsulating film. The colored highly reflective film in the encapsulating film is thinner, which reduces costs and prevents the colored highly reflective film from flowing to the front of the solar cell and blocking it. For example, the weight of all colored highly reflective films can account for 5%, 7.3%, 8.5%, 10%, 11.5%, 13.5%, 15%, 18.5%, 20%, 23%, 25%, 26.5%, 28%, 29.5%, 30%, 33.5%, or 35% of the weight of the encapsulating film.

[0049] Reference Figure 1 、 Figure 2 , the colored highly reflective film includes: a first colored highly reflective film 2 with a cross-linking degree less than or equal to 5%. The cross-linking degree of the first colored highly reflective film 2 can be 5%, 4.9%, 4%, 3%, 2.5%, 2%, 1.6%, 1.3%, 1%, 0.7%, 0.9%, 0.5%, 0.2%, or 0. In the embodiment of the present invention, the encapsulating film containing the colored highly reflective film replaces the transparent film in the related art, which can improve the light utilization efficiency of the photovoltaic module. Moreover, by adding the colored highly reflective film to the encapsulating film, and through the synergistic effect of the colored highly reflective film and the base film 1, the encapsulating film has a higher reflectivity, which can further improve the performance of the photovoltaic module. In addition, the crosslinking degree of the first colored highly reflective film 2 in the colored highly reflective film is less than or equal to 5%. The first colored highly reflective film 2 has a certain degree of ductility or fluidity, and can be melted under lamination to cover the base film 1, avoiding appearance defects. At the same time, the first colored highly reflective film 2 has a certain degree of ductility or fluidity, and can be melted under lamination to cover the conductive member 4 located between the cells. There is no need to set a colored appearance tape on the conductive member 4, and there is no need to perform a preliminary heat treatment for bonding the cell and the colored appearance tape, etc., which simplifies the process and improves the yield. Moreover, the first colored highly reflective film 2 has a certain degree of ductility or fluidity, and can be melted under lamination to cover the color of the cell cross section. Therefore, the color of the photovoltaic module formed by the encapsulation film of the present application is more uniform and more beautiful. In summary, the power of the photovoltaic module using the encapsulation film of the present application can be increased by about 0.5% to 2%, and the process is simplified and the yield is improved, which has good prospects for mass production. In addition, the color of the photovoltaic module formed by the encapsulation film of the present application is more uniform and more beautiful.

[0050] More specifically, in the process of forming a photovoltaic module using the encapsulation film provided by this application, the main steps include: placing the battery cells, placing the interconnecting parts (such as welding ribbons), welding, forming the battery array, and stacking the battery array, encapsulation film, and backplane. In the related art, the main steps of forming a photovoltaic module include: placing the battery cells, placing the colored appearance tape, placing the interconnecting parts (such as welding ribbons), welding, forming the battery array, and stacking the battery array, transparent encapsulation film, and colored high-reflective backplane. Compared with the related art, this application at least reduces the step of placing the colored appearance tape, resulting in fewer steps, higher production efficiency, and higher yield.

[0051] Optionally, the first colored high-reflective film 2 here can be a colored high-reflective spray film, which can be set on the base film 1 by spraying or the like, and the formation method is simpler.

[0052] Optionally, the color of the first colored high-reflective film 2 is black. The packaging film can be used in photovoltaic modules to form darker photovoltaic modules, which can better blend with dark roofs and improve the overall aesthetics.

[0053] It should be noted that the color of the first colored high-reflective film 2 can also be red, gray, etc.

[0054] Optionally, the base film 1 and the colored high-reflection film in the present application both include: a base and additives. The base here includes: EVA (ethylene-vinyl acetate copolymer) and / or POE (polyvinyl enol copolymer). Whether the material of the base of the base film 1 and the base of the colored high-reflection film is the same is not specifically limited. In the case where the base film 1 is a white film, the additives in the white film include: at least one of titanium dioxide, silicon dioxide, hollow glass microspheres, zinc oxide, aluminum-doped zinc oxide, indium tin oxide, antimony tin oxide, antimony trioxide, aluminum trioxide, calcium carbonate, barium sulfate, montmorillonite, kaolin, talc powder, and feldspar powder. The above-mentioned base film 1 is easy to obtain and has low cost. The additives in the black high-reflection film include: at least one of cobalt black, chrome green black, copper chrome black, manganese iron black, manganese chromium nickel black, titanium iron black, aniline black and perylene black. The reflectivity of the black high-reflection film is high and easy to obtain.

[0055] Optionally, the melt index of the first colored high-reflective film 2 is 5 to 30 grams per ten minutes (g / 10min). The melt index of the first colored high-reflective film 2 refers to the mass of the molten first colored high-reflective film 2 passing through a standard die capillary within ten minutes. The melt index of the first colored high-reflective film 2 is 5 to 30 grams per ten minutes. The melt index of the first colored high-reflective film 2 is relatively appropriate. During the lamination process, the first colored high-reflective film 2 can be melted to cover the base film 1, avoiding appearance defects. At the same time, under lamination, the first colored high-reflective film 2 can be melted to cover the conductive member 4 located between the battery cells without overflowing to the front of the battery. There is no need to set an appearance tape on the conductive member 4, and there is no need to perform preliminary bonding heat treatment on the battery cells and the colored appearance tape. Moreover, under lamination, the first colored high-reflective film 2 can melt to cover the color of the battery cross-section, so that the appearance of the photovoltaic module formed by the encapsulation film of the present application appears to be extremely uniform.

[0056] For example, the melt index of the first colored high-reflective film 2 can be 5g / 10min, 6g / 10min, 8g / 10min, 10g / 10min, 12g / 10min, 15g / 10min, 18g / 10min, 20g / 10min, 21.5g / 10min, 25g / 10min, 28g / 10min, or 30g / 10min.

[0057] Optional, see Figure 1 The colored highly reflective film comprises only the aforementioned first colored highly reflective film 2. Specifically, the encapsulating film comprises only the first colored highly reflective film 2 having a crosslinking degree of less than or equal to 5% and the base film 1. The first colored highly reflective film 2 accounts for 5% to 35% of the total weight of the encapsulating film. The encapsulating film has a simple structure and is easy to process. For example, the encapsulating film can be obtained by spraying a colored highly reflective liquid onto the base film 1.

[0058] Optional, see Figure 2In addition to the aforementioned first colored high-reflective film 2, the colored high-reflective film also includes a second colored high-reflective film 3 having a cross-linking degree greater than 5%. The second colored high-reflective film 3 is located between the base film 1 and the first colored high-reflective film 2. The second colored high-reflective film 3 and the first colored high-reflective film 2 have the same color. For example, the second colored high-reflective film 3 and the first colored high-reflective film 2 are both black, or both are red, gray, or the like. Furthermore, the second colored high-reflective film 3 and the base film 1 both have a cross-linked structure, wherein the cross-linking degree of the second colored high-reflective film 3 is greater than that of the first colored high-reflective film 2. The second colored high-reflective film 3 and the first colored high-reflective film 2 are disposed on the base film 1. That is, at least two layers of colored high-reflective film are disposed on the base film 1, further covering the base film 1 and avoiding appearance defects. This further ensures that the photovoltaic module formed by the encapsulation film of the present application has a pure appearance without white spots or blemishes. Furthermore, the encapsulation film has a flexible and diverse structure. In this case, the sum of the gram weights of the first colored highly reflective film 2 and the second colored highly reflective film 3 in the packaging film accounts for 5% to 35% of the gram weight of the packaging film.

[0059] For example, the cross-linking degree of the second colored highly reflective film 3 can be 5.1%, 7.7%, 8.5%, 10%, 11.5%, 13.5%, 15%, 18.5%, 20%, 23%, 25%, 27.5%, 28%, 29.5%, 30%, 34.9%, 35%, 40%, 42.8%, 45%, 47.2%, 50%, or 48.9%.

[0060] For example, the second colored highly reflective film 3 and the base film 1 can be co-extruded first, and then the co-extruded structure is irradiated. During the irradiation process, the second colored highly reflective film 3 and the base film 1 are pre-crosslinked, so that the second colored highly reflective film 3 and the base film 1 form a cross-linked structure. During the cooling process, holes may be generated in the second colored highly reflective film 3, so that the base film 1 is partially exposed. The cross-linking degree of the second colored highly reflective film 3 is greater than 5%. Then, a first colored highly reflective film 2 with the same color is sprayed on the second colored highly reflective film 3 in the co-extruded structure. The first colored highly reflective film 2 covers the exposed part of the base film 1 to form the encapsulating film. Moreover, the cross-linking degree of the first colored highly reflective film 2 is very low and has good ductility or fluidity. During the lamination process of forming the photovoltaic module, the exposed part of the base film 1 can be covered, so that the formed photovoltaic module achieves an extremely uniform effect.

[0061] Optionally, the melt index of the second colored highly reflective film 3 is 1.5 to 30 grams per ten minutes. The melt index of the second colored highly reflective film 3 refers to the mass of the molten second colored highly reflective film 3 passing through a standard die capillary within ten minutes. The melt index of the second colored highly reflective film 3 is 1.5 to 30 grams per ten minutes. The melt index of the second colored highly reflective film 3 is relatively appropriate. During the lamination process, the second colored highly reflective film 2 basically does not overflow onto the battery surface, and through the re-covering of the second colored highly reflective film 3, there is no need to set an appearance tape on the interconnect 4, and there is no need to perform preliminary bonding heat treatment on the battery cell and the colored appearance tape, etc., so that the appearance of the photovoltaic module formed by the encapsulation film of the present application appears to be extremely uniform.

[0062] For example, the melt index of the second colored high-reflective film 3 can be 1.5g / 10min, 2g / 10min, 3g / 10min, 4g / 10min, 5g / 10min, 6g / 10min, 8g / 10min, 10g / 10min, 12g / 10min, 15g / 10min, 17g / 10min, 20g / 10min, 21.5g / 10min, 25g / 10min, 26g / 10min, and 30g / 10min.

[0063] Optionally, the encapsulation film also includes: a first colored high-reflective film 2 and a second colored high-reflective film 3. The gram weight ratio of the first colored high-reflective film 2 to the second colored high-reflective film 3 is 8:1 to 1:8, and the gram weight ratio of the two is relatively appropriate. During the lamination process, the first colored high-reflective film 2 can be melted to cover the base film 1, avoiding appearance defects. At the same time, during lamination, the first colored high-reflective film 2 can be melted to cover the conductive parts located between the battery cells, but the first colored high-reflective film 2 and the second colored high-reflective film 3 do not overflow to the front of the battery.

[0064] For example, the gram weight ratio of the first colored highly reflective film 2 to the second colored highly reflective film 3 can be 8:1, 7:1, 7.5:1, 6:1, 5:1, 3:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, or 1:8.

[0065] Optionally, the encapsulation film also includes: a first colored highly reflective film 2 and a second colored highly reflective film 3, the cross-linking degree of the second colored highly reflective film 3 is greater than or equal to 15%, the cross-linking degree of the second colored highly reflective film 3 is relatively appropriate, and the second colored highly reflective film 3 basically does not overflow to the front of the battery during lamination.

[0066] For example, the cross-linking degree of the second colored highly reflective film 3 can be 15%, 20%, 30%, 25%, 35%, 45%, 40%, 50%, 55%, 60%, 65%, or 70%.

[0067] It should be noted that, when the encapsulating film includes: a first colored high-reflective film 2 and a second colored high-reflective film 3, there is no specific limitation on whether the base materials of the first colored high-reflective film 2 and the second colored high-reflective film 3 are the same, and there is no specific limitation on whether the additives of the first colored high-reflective film 2 and the second colored high-reflective film 3 are the same.

[0068] Optionally, the packaging film may further include: a transparent film located on the second side of the base film 1, such as Figure 1 、 Figure 2 , the transparent film can be located on the underside of the base film 1. The transparent film and base film 1 are co-extruded. Optionally, the weight of the transparent film accounts for less than or equal to 25% of the weight of the encapsulating film. By adding a transparent film of appropriate weight to the encapsulating film, the bonding strength or peel strength between the encapsulating film and the backsheet or backglass can be improved, thereby improving the mechanical properties of the photovoltaic module. In the encapsulating film, the weight of the colored highly reflective film still accounts for 5% to 35% of the weight of the encapsulating film.

[0069] For example, the ratio of the weight of the transparent film to the weight of the packaging film can be 25%, 22.5%, 20%, 18%, 17%, 15%, 13.5%, 12%, 10%, 7%, 8.5%, 6%, 5%, 2.5%, 0.5%, or 1%.

[0070] For example, the second colored highly reflective film 3, the base film 1, and the transparent film can be co-extruded first, and then the co-extruded structure can be irradiated. During the irradiation process, the second colored highly reflective film 3, the base film 1, and the transparent film are pre-crosslinked, forming a cross-linked structure. During the cooling process, holes may be generated in the second colored highly reflective film 3, leaving the base film 1 partially exposed. The cross-linking degree of the second colored highly reflective film 3 is greater than 5%. Then, the first colored highly reflective film 2 is sprayed onto the second colored highly reflective film 3 in the co-extruded structure. The first colored highly reflective film 2 covers the exposed portion of the base film 1, thereby forming the encapsulating film. Moreover, the first colored highly reflective film 2 has a very low cross-linking degree and good ductility or fluidity. During the lamination process of forming the photovoltaic module, it can cover the exposed portion of the base film 1, so that the formed photovoltaic module achieves an extremely uniform effect. It should be noted that the transparent film here can include: EVA and / or POE, which are easily available and relatively low in cost. It should be noted that the above-mentioned weight ratio is limited here, so that the formed packaging film is not prone to the risk of glue overflow during the lamination process, and the first colored high-reflective film 2 can fully cover the exposed base film 1 and the first colored high-reflective film 2 can fully cover the conductive parts.

[0071] Optionally, the gram weight of the base film 1 accounts for greater than or equal to 50% of the gram weight of the packaging film. Compared with the colored high-reflective film, the base film 1 is relatively cheap. The gram weight of the base film 1 accounts for a larger proportion in the packaging film, which can reduce costs without affecting other properties of the packaging film.

[0072] For example, the base film 1 may have a gram weight of 50% to 95% of the gram weight of the encapsulating film. For another example, the base film 1 may have a gram weight of 50%, 52.3%, 55%, 57%, 60%, 63.7%, 70%, 72.5%, 75%, 80%, 83.4%, 87%, 90%, 93%, or 95% of the gram weight of the encapsulating film.

[0073] Optionally, the encapsulation film has a thickness of 300 to 800 microns, which is a suitable thickness for use in common photovoltaic modules. For example, the encapsulation film may have a thickness of 300, 310, 320, 350, 400, 460, 500, 520, 570, 600, 700, or 800 microns.

[0074] For example, the thickness of the packaging film is 400 microns to 600 microns, and the packaging film includes: a base film 1, a second colored high-reflective film 3 and a first colored high-reflective film 2, the thickness of the second colored high-reflective film 3 is 50 microns to 150 microns, the thickness of the first colored high-reflective film 2 is 50 microns to 150 microns, and the sum of the gram weights of the second colored high-reflective film 3 and the first colored high-reflective film 2 accounts for 5% to 35% of the gram weight of the packaging film.

[0075] It should be noted that, in the encapsulating film, the number of layers of the base film 1 and the first colored highly reflective film 2 is not specifically limited. The number of layers of the base film 1, the second colored highly reflective film 3, and the first colored highly reflective film 2 is not specifically limited. The number of layers of the base film 1, the second colored highly reflective film 3, the first colored highly reflective film 2, and the transparent film is also not specifically limited.

[0076] The present invention further provides a photovoltaic module, comprising: a cell string, wherein the cell string comprises a plurality of cells electrically connected by a conductive member. The conductive member may be located on only one side of the cell string or on opposite sides of the cell string, without specific limitation. The number of cell strings in the photovoltaic module is not specifically limited.

[0077] The photovoltaic module may further include a rear encapsulation film. The rear encapsulation film is disposed on the backlight side of the cell string and includes a base film 1 having a first side and a second side opposite to each other, and a colored highly reflective film located on the first side of the base film 1.

[0078] The colored high reflective film is placed adjacent to the battery string group, that is, the base film 1 of the rear encapsulation film is placed adjacent to the back plate or back glass. During the normal operation of the photovoltaic module, the side of the battery string that mainly absorbs light is its light-facing side, and the backlight side is opposite to the light-facing side. Figure 2 In this photovoltaic module, a colored high-reflective film covers the surface of the conductive part adjacent to the rear encapsulation film. Specifically, the colored high-reflective film of the rear encapsulation film has a certain ductility or fluidity, and can be melted under lamination to cover the base film 1, thereby avoiding appearance defects. At the same time, the colored high-reflective film has a certain ductility or fluidity, and can be melted under lamination to cover the conductive part located between the cells. Optionally, the conductive part includes: an interconnection part 4, and the colored high-reflective film covers at least part of the surface of the interconnection part 4, thereby eliminating the need to provide a colored appearance tape on the interconnection part 4, and eliminating the need to perform a preliminary bonding heat treatment on the cell and the colored appearance tape, thereby simplifying the process and improving the yield. Moreover, the colored high-reflective film has a certain ductility or fluidity, and can be melted under lamination to cover the color of the cell cross-section, so the color of the photovoltaic module formed by the rear encapsulation film of this application is more uniform and more beautiful. To sum up, the power of photovoltaic modules using the post-encapsulation film of the present application can be increased by about 0.5% to 2%, and the cost is low. The process is simplified and the yield is improved, which has good prospects for mass production. In addition, the color of the photovoltaic modules formed by the post-encapsulation film of the present application is more uniform and more beautiful.

[0079] Optionally, the conductive part includes: a bus bar. In a photovoltaic module, the bus bar is usually located at both ends of a battery string, between battery strings, etc. The colored high-reflective film covers at least part of the surface of the bus bar. Specifically, the colored high-reflective film of the rear packaging film has a certain ductility or fluidity, and can be melted under lamination to cover or coat at least part of the surface of the bus bar, so that the photovoltaic module can further achieve a consistent color effect.

[0080] Optionally, if the colored high-reflective film does not completely cover the busbar surface, a colored material (sprayed or filmed) can be used to cover the uncovered busbar surface at the location on the front glass corresponding to the busbar, thereby further achieving a uniform color effect for the photovoltaic module. Alternatively, the uncovered busbar surface can be left untreated, and this is not specifically limited.

[0081] Optionally, the photovoltaic module further includes a backsheet disposed on a side of the rear encapsulation film facing away from the cell strings. The backsheet's surface adjacent to the cell strings is white, further enhancing reflectivity and reducing costs. Other components of the backsheet are not specifically limited.

[0082] Optionally, the cells in the photovoltaic module are back-contact cells. For the back-contact cells, there are no metal grid lines on the light-facing side. Not only is the front power much higher than other types of cells, but the appearance advantage is particularly obvious on the photovoltaic module, making the appearance of the photovoltaic module extremely uniform.

[0083] Optionally, the colored high-reflective film includes: a first colored high-reflective film 2 and a second colored high-reflective film 3, wherein the second colored high-reflective film 3 is located between the base film 1 and the first colored high-reflective film 2, and the colors of the first colored high-reflective film 1 and the second colored high-reflective film 2 are consistent, that is, the first colored high-reflective film 2 and the second colored high-reflective film 3 are simultaneously included in the post-encapsulation film, and in the laminate or photovoltaic module formed after the lamination process, there is a relatively obvious dividing line between the first colored high-reflective film 2 and the second colored high-reflective film 3, and the cross-linking degrees of the first colored high-reflective film 2 and the second colored high-reflective film 3 are roughly equal, and the difference in cross-linking degrees between the two is less than or equal to 10%. The photovoltaic module provided in this application can be a single-glass module or a double-glass module, which is not specifically limited. Optionally, in the photovoltaic module, there is a dividing line between the colored high-reflective film and the base film 1, and the dividing line can appropriately increase the light absorption of the battery cell, thereby improving the efficiency of the photovoltaic module.

[0084] Optionally, the cross-linking degree of the colored high-reflective film is 75% to 95%, and the cross-linking degree of the base film is 75% to 95%. The cross-linking degrees of the two are relatively appropriate, and the protection performance of the battery string or battery cell is better.

[0085] For example, in this photovoltaic module, the crosslinking degree of the colored highly reflective film can be 75%, 77%, 80%, 85%, 89%, 90%, 92%, 93%, or 95%. For example, in this photovoltaic module, the crosslinking degree of the base film can be 75%, 77%, 80%, 85%, 89%, 90%, 92%, 93%, or 95%.

[0086] Optionally, in this photovoltaic module, the weight of the rear encapsulation film is 300g / ㎡ to 600g / ㎡. The weight of the rear encapsulation film is relatively appropriate and provides good protection for the battery string or battery cell. For example, in this photovoltaic module, the weight of the rear encapsulation film is 300g / ㎡, 350g / ㎡, 350g / ㎡, 400g / ㎡, 450g / ㎡, 500g / ㎡, 550g / ㎡, 370g / ㎡, 480g / ㎡, and 600g / ㎡.

[0087] Optionally, the photovoltaic module further includes: a front packaging film, which is arranged on the light-facing side of the battery string group, and forms a curved dividing line between the front packaging film and the rear packaging film. The dividing line can appropriately increase the light absorption of the battery cell and improve the efficiency of the photovoltaic module.

[0088] Optionally, on the side of the cell, the coverage area of the rear encapsulation film is larger than the coverage area of the front encapsulation film, which can better block light leakage from the gaps between the cells, making the appearance of the photovoltaic module more uniform.

[0089] Optionally, the reflectivity of the surface of the rear encapsulation film facing the battery string group is greater than or equal to 70%, that is, the reflectivity of the surface of the colored high-reflective film of the rear encapsulation film facing away from the base film 1 and the surface of the rear encapsulation film facing the battery string group is higher, which can ensure that more light is reflected to the light-facing surface of the battery cell, thereby improving the performance of the photovoltaic module.

[0090] For example, the reflectivity of the surface of the rear encapsulation film facing the battery string group may be 70%, 72%, 75%, 77.6%, 79%, 80%, 82%, 85%, 87%, or 90%.

[0091] The photovoltaic module provided by the present application is lower in cost compared to the photovoltaic modules of the related art by eliminating the colored appearance tape and having a relatively small gram weight of the colored high-reflective film. Moreover, the reflectivity of the surface of the colored high-reflective film facing away from the base film is 70% to 90%, which exceeds the reflectivity of the colored high-reflective backsheet (60% to 80%), and because the surface of the backsheet on the back of the colored high-reflective film close to the battery string is white, the reflectivity can be further improved. Secondly, because the rear encapsulation film is flush with the battery cell, the reflection path of the light is reduced, which can ensure that more light is reflected to the front of the battery cell. In addition, because the colored appearance tape is replaced (the reflectivity of the colored surface is almost 0), the reflection area is increased. In summary, compared to the photovoltaic modules of the related art, the power gain of the photovoltaic module provided by the present application is 0.5% to 2%. At the same time, the colored appearance tape used in the photovoltaic modules of the related art is carbon black (reflectivity <10%), which cannot be consistent with the color of the colored high-reflective backsheet, resulting in the overall color not being perfectly consistent. The photovoltaic module provided in this application eliminates the colored appearance tape, so the overall color is seamless and more beautiful.

[0092] Optionally, the rear encapsulation film in the photovoltaic module can be an encapsulation film laminated with any of the aforementioned encapsulation films. The relevant parts of the photovoltaic module and the encapsulation film can be referenced to each other, and will not be described again here to avoid repetition.

[0093] The present application also provides a photovoltaic system, which may include any of the aforementioned photovoltaic assemblies. The photovoltaic system may also include, for example, photovoltaic brackets, etc., without specific limitation. The photovoltaic system may refer to any of the aforementioned photovoltaic assemblies and may achieve the same or similar beneficial effects. To avoid repetition, the details are not repeated here.

[0094] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0095] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A packaging film, characterized in that: include: basement membrane; The basement membrane includes opposing first and second sides; a colored highly reflective film located on the first side of the base film; The colored high-reflective film includes: a first colored high-reflective film with a cross-linking degree less than or equal to 5%.

2. The packaging film according to claim 1, wherein The melt index of the first colored high-reflective film is 5 to 30 grams per ten minutes; and / or the first colored high-reflective film is a lamination film; and / or the color of the first colored high-reflective film is black.

3. The packaging film according to claim 1, wherein: The colored high-reflective film only includes the first colored high-reflective film; Alternatively, the colored highly reflective film further comprises: a second colored highly reflective film having a cross-linking degree greater than 5%; The second colored high-reflection film is located between the base film and the first colored high-reflection film, and the first colored high-reflection film and the second colored high-reflection film have the same color.

4. The packaging film according to claim 3, characterized in that The colored high-reflective film comprises: the first colored high-reflective film and the second colored high-reflective film, wherein the cross-linking degree of the second colored high-reflective film is greater than or equal to 15%; and / or, The second colored high-reflective film and the base film are cross-linked structures; and / or, The gram weight ratio of the first colored high-reflective film to the second colored high-reflective film is 8:1 to 1:8; and / or, The second colored high reflective film has a melt index of 1.5 to 30 grams per ten minutes.

5. The packaging film according to any one of claims 1 to 4, characterized in that: Also includes: a transparent film located on the second side of the base film; And / or, the basement membrane includes: tunica albuginea.

6. The packaging film according to any one of claims 1 to 4, characterized in that: The weight of the colored high-reflective film accounts for 5% to 35% of the weight of the packaging film; and / or, The ratio of the base film's gram weight to the packaging film's gram weight is greater than or equal to 50%; and / or, The thickness of the packaging film is 300 microns to 800 microns.

7. A photovoltaic module, characterized in that: include: A battery string group, the battery string group including a plurality of battery cells electrically connected by a conductive member; and a rear packaging film, the rear packaging film being arranged on the backlight side of the battery string group; The rear encapsulation film comprises: a base film; the base film comprises a first side and a second side opposite to each other; and a colored high reflective film located on the first side of the base film; The colored high-reflective film of the rear packaging film is arranged adjacent to the battery string, and the colored high-reflective film at least partially covers the surface of the conductive member adjacent to the rear packaging film.

8. The photovoltaic module according to claim 7, characterized in that: The conductive member includes a bus bar, and the colored high-reflective film covers at least a portion of the surface of the bus bar; And / or, the conductive element includes an interconnection element, and the colored high-reflective film covers at least a portion of the surface of the interconnection element.

9. The photovoltaic module according to claim 8, characterized in that: The colored high-reflective film includes: a first colored high-reflective film and a second colored high-reflective film of the same color, the second colored high-reflective film is located between the base film and the first colored high-reflective film; there is a dividing line between the first colored high-reflective film and the second colored high-reflective film, and there is a dividing line between the colored high-reflective film and the base film.

10. The photovoltaic module according to claim 7, characterized in that: The rear encapsulation film is the encapsulation film according to any one of claims 1 to 6; and / or, The cross-linking degree of the colored high-reflective film is 75% to 95%, and the cross-linking degree of the basement membrane is 75% to 95%; and / or, The weight of the rear packaging film is 200 g / m2 to 600 g / m2.

11. The photovoltaic module according to claim 7, characterized in that: Also includes: A front packaging film, the front packaging film being arranged on the light-facing side of the battery string group; A curved dividing line is formed between the front packaging film and the rear packaging film.

12. The photovoltaic module according to claim 11, characterized in that: On the side of the battery cell, the coverage area of the rear packaging film is larger than the coverage area of the front packaging film.

13. The photovoltaic module according to any one of claims 7 to 12, characterized in that: The reflectivity of the surface of the rear packaging film facing the battery string group is greater than or equal to 70%.

14. The photovoltaic module according to any one of claims 7 to 12, characterized in that: Also includes: a backplane, the backplane being arranged on a side of the rear packaging film away from the battery string group; the surface of the backplane close to the battery string being white; and / or, The battery cell is a back contact battery cell.

15. A photovoltaic system, characterized in that: A photovoltaic module comprising the photovoltaic module according to any one of claims 7 to 14.

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