Photovoltaic module and photovoltaic system

Abstract

The utility model provides a photovoltaic assembly and a photovoltaic system, and relates to the field of photovoltaic technology. The photovoltaic module includes: a photovoltaic laminate; the photovoltaic laminate includes: an array of cell strings; the glass back plate is positioned on the first side of the battery string array; the glass cover plate is positioned on the second side of the battery string array; the back anti-reflection layer is arranged on the first surface, far away from the cell string array, of the glass back plate; the reflective film is arranged on the second surface, close to the battery string array, of the glass back plate; the thickness of the back anti-reflection layer is a, and a is larger than or equal to 100 nm and smaller than or equal to 150 nm; the refractive index of the back anti-reflection layer is b, and b is larger than or equal to 1.1 and smaller than or equal to 1.5 The front power generation power and the back power generation power of the photovoltaic module are both gained, so that the power generation power of the photovoltaic module can be improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a photovoltaic module and a photovoltaic system. Background Technology

[0002] Solar cells can convert solar energy into electrical energy, utilizing clean energy sources and therefore have broad application prospects. Because a single solar cell outputs a relatively low voltage, and unencapsulated solar cells are easily affected by the environment, a certain number of solar cells are usually connected in series or parallel to form photovoltaic modules to expand their application scenarios.

[0003] Photovoltaic modules typically include solar cells. However, existing photovoltaic modules suffer from problems such as poor power generation. Utility Model Content

[0004] This invention provides a photovoltaic module and a photovoltaic system, aiming to solve the problem of poor power generation of existing photovoltaic modules.

[0005] A first aspect of this utility model provides a photovoltaic module, comprising:

[0006] Photovoltaic laminates;

[0007] Photovoltaic laminates include:

[0008] Battery string array; battery string array includes: several battery strings arranged in an array; battery strings include: several electrically connected battery cells;

[0009] A glass backplate is located on the first side of the battery string array;

[0010] A glass cover is located on the second side of the battery string array, with the first and second sides opposite each other;

[0011] A back anti-reflective layer is disposed on the first surface of the glass backplate away from the battery string array;

[0012] A reflective film is applied to the second surface of the glass backplate near the battery string array.

[0013] The thickness of the back antireflection layer is 'a', which satisfies: 100nm ≤ a ≤ 150nm;

[0014] The refractive index of the back antireflection layer is b, which satisfies: 1.1≤b≤1.5.

[0015] In this invention, the anti-reflective layer on the first surface of the glass backplate away from the cell array has a gain effect on the back-side power generation of the photovoltaic module. A reflective film is disposed on the second surface of the glass backplate near the cell array. On one hand, the reflective film reflects light that shines from the light-facing side of the photovoltaic laminate and passes through the gaps between the cells to the back-side of the cells, thus gaining the back-side power generation of the photovoltaic module. On the other hand, the reflective film reflects light that shines from the light-facing side of the photovoltaic laminate and passes through the gaps between the cells to the glass cover, and then reflects it to the light-facing side of the cells, thus gaining the front-side power generation of the photovoltaic module. Therefore, the reflective film gains power on both the front and back sides of the photovoltaic module. Thus, this application gains power on both the front and back sides of the photovoltaic module, thereby improving the overall power generation of the photovoltaic module. Meanwhile, through the interaction of the thickness and refractive index of the back anti-reflective layer, during the operation of the photovoltaic module, the back anti-reflective layer can transmit as much light reflected from the ground as possible to the glass backsheet, which then transmits this light to the solar cells, thereby increasing the amount of light illuminating the back surface of the solar cells and thus enhancing the power generation of the back side of the photovoltaic module. Furthermore, the back anti-reflective layer with this thickness and refractive index is readily available and relatively inexpensive, representing an optimized balance between light transmission, cost, and other factors. Therefore, this application enhances both the front and back power generation of the photovoltaic module, thereby improving its overall power output. In addition, the photovoltaic module provided in this application has a back anti-reflective layer on the first surface of the glass backsheet and a reflective film on the second surface. Compared to a structure with a back anti-reflective layer on the first surface and an enamel layer on the second surface, this application uses both back anti-reflective layers and reflective films on both sides of the glass backsheet. This allows for compatibility with existing processes, which are easy to implement, and also has minimal adverse impact on subsequent tempering processes.

[0016] Optionally, the thickness of the back antireflection layer is 'a', satisfying: 120nm≤a≤140nm;

[0017] The refractive index of the back antireflection layer is b, satisfying 1.2 ≤ b ≤ 1.4. The thickness a of the back antireflection layer mainly determines which wavelengths of light can enter the back antireflection layer, while the refractive index b mainly determines the percentage of incident light. If b > 1.4 or b < 1.2, the percentage of light entering the back antireflection layer is small, resulting in more light failing to penetrate. Therefore, 1.2 ≤ b ≤ 1.4 ensures that more light can enter the back antireflection layer. The light received by the back antireflection layer is mainly reflected light from the ground, which typically has a large wavelength. If a < 120 nm, and the back antireflection layer is too thin, these larger wavelengths of light may... Light of larger wavelengths cannot penetrate the back anti-reflection layer, and it is difficult to process and manufacture, resulting in high manufacturing costs. While a > 140 nm ensures that light of these wavelengths can penetrate the back anti-reflection layer, its excessive thickness leads to material waste and increases the overall thickness of the photovoltaic module. Therefore, 120 nm ≤ a ≤ 140 nm considers factors such as allowing larger wavelengths of light to penetrate the back anti-reflection layer, ease of processing, and avoiding material waste. In summary, 120 nm ≤ a ≤ 140 nm, and 1.2 ≤ b ≤ 1.4, ensures that as much of the larger wavelengths of light as possible penetrate the back anti-reflection layer while avoiding material waste. Therefore, through optimized coordination of the back anti-reflection layer's thickness and refractive index, during photovoltaic module operation, the back anti-reflection layer can further maximize the transmission of light reflected from the ground to the glass backsheet, which then transmits this light to the solar cells, thereby increasing the amount of light illuminating the back surface of the solar cells and resulting in a greater gain in the back-side power generation of the photovoltaic module.

[0018] Optionally, the reflective film includes: a support layer; the support layer includes opposite sides along the direction of the thickness of the photovoltaic laminate;

[0019] A reflective layer may be disposed on either side of the support layer, or two reflective layers may be disposed on opposite sides of the support layer. The reflective layer includes a directional reflective structure layer and a metallic reflective layer attached to the directional reflective structure layer. The directional reflective structure layer is adjacent to the support layer. Both single and double reflective layers significantly increase the power generation of the photovoltaic module.

[0020] Optionally, the reflective film includes two reflective layers, respectively disposed on both sides of the support layer; the distance between the reflective film and the back anti-reflection layer along the thickness direction of the photovoltaic laminate is c, 0.8mm≤c≤2.5mm; the directional reflection structure layer includes two side plates extending from the support layer and intersecting; at the intersection, the included angle between the two side plates is d, 110°≤d≤130°. If the distance c between the reflective film 5 and the back anti-reflection layer 4 is less than 0.8mm or greater than 2.5mm, light illuminating the reflective film 5 from the glass backplate 2 side, after being reflected back to the glass backplate 2, is likely to fall at the edge of the solar cell. Furthermore, after being reflected back to the glass backplate 2, the light is likely to be directly transmitted through the back anti-reflection layer 4 instead of being reflected again by the back anti-reflection layer 4 and re-entering the solar cell, reducing the solar cell's light utilization rate. A distance of 0.8mm≤c≤2.5mm ensures that light from the back anti-reflection layer... Light entering the photovoltaic module through the anti-reflective layer and glass backsheet is reflected by the reflective film to the glass backsheet, and then reflected again by the glass backsheet to the back surface of the solar cells. The light is distributed as much as possible in a larger central area of ​​the back surface of the solar cells to maximize absorption. However, if d > 130°, the angle of incidence of light entering the photovoltaic module from the back anti-reflective layer and glass backsheet, reflected by the reflective film to the glass backsheet, is too large. This results in a more dispersed distribution of light reflected from the glass backsheet to the back surface of the solar cells, which tends to fall at the edges of the solar cells. Furthermore, the light reflected from the solar cells to the back surface... After the glass backsheet 2, light can easily pass directly through the anti-reflection layer 4 on the back, instead of being reflected by the anti-reflection layer 4 and then entering the solar cell again, reducing the solar cell's light utilization rate. Since d < 110°, the incident angle of light entering the photovoltaic module from the anti-reflection layer and glass backsheet, after being reflected by the reflective film, is too small. The light reflected from the glass backsheet to the back surface of the solar cell is relatively densely distributed, or only distributed within a small area of ​​the back surface. This small area of ​​the back surface may not be able to fully absorb the relatively dense light. This leads to wasted light. Therefore, an angle of 0.8mm ≤ c ≤ 2.5mm and 110° ≤ d ≤ 130° ensures that light entering the photovoltaic module from the back anti-reflective layer and glass backsheet is reflected by the reflective film to the glass backsheet, and then reflected by the glass backsheet to the back surface of the solar cell. This ensures that the light is distributed as much as possible within a larger central area of ​​the back surface of the solar cell, maximizing absorption. This optimizes the light path from the back surface of the photovoltaic module to the back of the solar cell, improving the cell's light utilization rate and further increasing the power generation from the back of the photovoltaic module. Simultaneously, the included angle d provides excellent directional reflection, resulting in a more significant increase in front-side power generation.

[0021] Optionally, the back anti-reflection layer is rectangular in shape; the back anti-reflection layer includes: an intersecting first side and a second side, the length of the first side is x, the length of the second side is y, and x is greater than or equal to y;

[0022] Along the extension direction of the first side, the size of the orthogonal projection of the reflective film on the back antireflection layer is e in proportion to x, where 92% ≤ e ≤ 98%. Within the above proportion range, the reflective film has high coverage between cells and between cell strings, resulting in a significant reflection effect and enhancing the light utilization rate of the photovoltaic module. At the same time, it can ensure that air bubbles in the laminate can be effectively eliminated during the photovoltaic module manufacturing process, thereby improving the manufacturing yield and the reliability of the photovoltaic module.

[0023] Along the extension direction of the second side, the size of the orthogonal projection of the reflective film on the back antireflection layer is y in proportion to f, where 95% ≤ f ≤ 98%. Within the above proportion range, the reflective film has high coverage between cells and between cell strings, resulting in a significant reflection effect and enhancing the light utilization rate of the photovoltaic module. At the same time, it can ensure that air bubbles in the laminate can be effectively eliminated during the photovoltaic module manufacturing process, thereby improving the manufacturing yield and the reliability of the photovoltaic module.

[0024] Optionally, the photovoltaic module also includes: a front anti-reflection layer located on the side of the glass cover away from the cell string array. This front anti-reflection layer can transmit as much light from the light-facing side of the photovoltaic module to the cells as possible, thereby increasing the front power generation of the photovoltaic module and thus improving the efficiency of the photovoltaic module.

[0025] The thickness of the front antireflection layer is g, where g ≤ a. When g = a, both layers have the same thickness and can be fabricated using the same or similar processes, resulting in high process compatibility, reduced process complexity, and lower costs. Generally, the thickness of the antireflection layer primarily determines which wavelengths of light can enter it. A thicker antireflection layer allows for longer wavelengths of light to enter, while a thinner layer allows for shorter wavelengths. The back antireflection layer typically receives longer wavelengths of light. Therefore, the thickness 'a' of the back antireflection layer needs to be greater than the thickness 'g' of the front antireflection layer (g < a) to accommodate different wavelengths of incident light. A thicker back antireflection layer helps ensure that longer wavelengths of light can enter, thus further improving light transmittance.

[0026] The refractive index of the front antireflective layer is h, 1.1≤h≤1.5, which allows as much light received from the light-facing side of the photovoltaic laminate as possible to be transmitted to the glass cover plate so that it can enter the solar cells, further increasing the power generation of the photovoltaic module.

[0027] Optionally, in the reflective film, two reflective layers are symmetrically arranged on both sides of the support layer. On the one hand, this increases the light received from the light-facing side of the photovoltaic module as well as the light received from the back side of the photovoltaic module, resulting in a more significant and balanced increase in the power generation of the front and back sides of the photovoltaic module. On the other hand, it reduces the difficulty of manufacturing the reflective film.

[0028] Optionally, the back antireflective layer is rectangular in shape; the back antireflective layer includes: an intersecting first side and a second side; the cell adjacent to the first side is the first cell, and the side of the first cell perpendicular to the first side is the third side of the first cell; along the extension direction of the third side of the first cell, the proportion by which the orthographic projection of the reflective film on the back antireflective layer covers the orthographic projection of the third side of the first cell is i, 1 / 3≤i≤2 / 3; and / or the cell adjacent to the second side is the second cell, and the side of the second cell perpendicular to the second side is the fourth side of the second cell; along the extension direction of the fourth side of the second cell, the proportion by which the orthographic projection of the reflective film on the back antireflective layer covers the orthographic projection of the fourth side of the second cell is k, 1 / 3≤k≤2 / 3. When i and k are within the above ranges, a good balance is achieved between reflective efficiency, bubble removal, and offset compatibility processes, which not only improves reflective efficiency but also facilitates the removal of bubbles during the lamination process, while also resulting in a high yield.

[0029] Optionally, the back antireflective layer is rectangular in shape; the back antireflective layer includes: an intersecting first side and a second side; the length of the first side is x, and the length of the second side is y, where x is greater than or equal to y; the shortest distance between the orthographic projection of the reflective film on the back antireflective layer and the adjacent first side is m, and the shortest distance between the orthographic projection of the reflective film on the back antireflective layer and the adjacent second side is n, where n is greater than or equal to m. In the direction parallel to the first side, the distance from bubbles generated during the lamination process to the edge of the photovoltaic module is relatively large, making bubble removal difficult; therefore, a larger gap n is reserved. In the direction parallel to the second side, the distance from bubbles generated during the lamination process to the edge of the photovoltaic module is relatively small, making bubble removal easier; therefore, a smaller gap m is reserved.

[0030] Optionally, the photovoltaic module further includes: a plurality of busbars located at the first end, the second end, and the middle, respectively; the first end and the second end are at opposite ends of the photovoltaic module, and the middle is located between the first end and the second end;

[0031] The positive projection of the reflective film onto the anti-reflective layer on the back does not cover the positive projection of the busbar onto the anti-reflective layer on the back, thus reducing the risk of short circuit of the busbar.

[0032] Optionally, the reflective film includes: an adhesive layer immediately adjacent to the glass back panel; and / or,

[0033] The reflective film includes an insulating layer located on the side of the reflective film furthest from the glass backing.

[0034] Optionally, the thickness of the reflective film is r, 100μm≤r≤160μm; and / or,

[0035] The reflective film includes: a support layer; the thickness of the support layer is t, 20μm≤t≤45μm; and / or,

[0036] The thickness of the reflective layer is w, where 5μm≤w≤15μm.

[0037] Optionally, the thickness of the adhesive layer is z, 60μm≤z≤90μm; and / or,

[0038] The thickness of the insulating layer is u, where 5μm≤u≤15μm.

[0039] Optionally, the metal reflective layer includes an aluminum layer, which has good reflective properties and is relatively inexpensive.

[0040] Optionally, the support layer includes a PET layer; the directional reflective structural layer includes a UV adhesive layer.

[0041] A second aspect of this invention provides a photovoltaic system comprising: a plurality of photovoltaic modules arranged in an array as described above.

[0042] The photovoltaic modules and photovoltaic systems mentioned above have the same or similar beneficial effects, and will not be repeated here to avoid repetition. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram of the structure of a photovoltaic laminate according to an embodiment of the present invention is shown;

[0045] Figure 2 This diagram illustrates the optical path of light in a photovoltaic laminate according to an embodiment of the present invention.

[0046] Figure 3 A schematic diagram of the structure of a reflective film according to an embodiment of the present invention is shown;

[0047] Figure 4 This diagram illustrates the optical path of light in another photovoltaic laminate according to an embodiment of the present invention.

[0048] Figure 5 A schematic diagram showing the distribution of reflective film in a photovoltaic laminate according to an embodiment of the present invention is shown;

[0049] Figure 6 A partial schematic diagram of the photovoltaic laminate in an embodiment of the present invention is shown.

[0050] Explanation of reference numerals in the attached figures:

[0051] 1-Battery cell, 11-First battery cell, 12-Second battery cell, 2-Glass backplate, 3-Glass cover, 4-Back antireflective layer, 5-Reflective film, 6-Front antireflective layer, 7-Encapsulating film, 8-Through hole, 51-Adhesive layer, 52-Supporting layer, 53-Reflective layer, 54-Insulating layer, 41-First side length, 42-Second side length, 111-Third side length, 121-Fourth side length. Detailed Implementation

[0052] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0053] This utility model provides a photovoltaic module, with reference to... Figure 1 , Figure 2 and Figure 4 The photovoltaic module includes: a photovoltaic laminate, which includes: a cell string array. The cell string array includes: a plurality of cell strings arranged in an array. The number and arrangement of the cell strings in the cell string array are not specifically limited. The cell string includes: a plurality of electrically connected solar cells 1. The number and arrangement of the solar cells in the cell string are not specifically limited, nor are the type and size of the solar cells specifically limited.

[0054] The photovoltaic laminate may further include a glass backplate 2 and a glass cover plate 3. The glass backplate 2 is located on the first side of the cell string array, and the glass cover plate 3 is located on the second side of the cell string array. The first side and the second side are opposite to each other in the direction of the thickness of the photovoltaic laminate. Here, the first side refers to the backlight side of the cell string array, and the second side refers to the light-facing side of the cell string array. During normal operation of the photovoltaic laminate, the side that mainly receives light is the light-facing side, and the backlight side is opposite to the light-facing side.

[0055] Reference Figure 1 , Figure 2 and Figure 4The photovoltaic laminate may further include: a back antireflection layer 4, disposed on the first surface of the glass backplate 2 away from the cell string array. (See reference...) Figure 1 A back-side antireflective layer 4 is disposed on the first surface of the glass backplate away from the battery string array, and the thickness of the back-side antireflective layer 4 is denoted by 'a', where 100nm ≤ a ≤ 150nm. The method for determining the thickness 'a' of the back-side antireflective layer 4 is not limited. For example, it can be the average thickness of multiple locations in the back-side antireflective layer 4. Alternatively, the thickness 'a' of the back-side antireflective layer 4 can be determined using the national standard (GB / T33826-2017). It should be noted that in this application, unless otherwise specified, the method for determining the thickness of the film layer can be the same as or similar to the method for determining the thickness 'a' here; to avoid repetition, it will not be elaborated further.

[0056] The refractive index of the back antireflection layer 4 is b, where 1.1 ≤ b ≤ 1.5. The refractive index of the back antireflection layer 4 can be measured using an ellipsometer. For example, when the back antireflection layer 4 is located on a glass backplate, its refractive index can be measured using an ellipsometer. The thickness 'a' of the back antireflection layer mainly determines which wavelengths of light can enter it, while the refractive index 'b' mainly determines the percentage of incident light. If b > 1.5 or b < 1.1, the percentage of light entering the back antireflection layer is small, resulting in more light failing to penetrate. Therefore, 1.1 ≤ b ≤ 1.5 ensures that more light can enter the back antireflection layer. The light received by the back antireflection layer is mainly reflected light from the ground, which typically has a large wavelength, a < 100 nm. If the back antireflection layer is too thin, these larger wavelengths of light may not be able to penetrate it. The back antireflection layer is difficult to process and has a high manufacturing cost. While a > 150 nm can ensure that the larger wavelength light can enter the back antireflection layer, the back antireflection layer is too thick for the wavelength light, which will lead to material waste and increase the thickness of the photovoltaic module. Therefore, 100 nm ≤ a ≤ 150 nm is a consideration of multiple factors such as ensuring that the larger wavelength light can enter the back antireflection layer, being easy to process, and avoiding material waste. In summary, 100 nm ≤ a ≤ 150 nm and 1.1 ≤ b ≤ 1.5 can ensure that as much of the larger wavelength light as possible enters the back antireflection layer and avoid material waste. Therefore, through the interaction of the thickness and refractive index of the back anti-reflection layer 4, during the operation of the photovoltaic module, the back anti-reflection layer 4 can transmit as much light reflected from the ground as possible to the glass backsheet, which then transmits this light to the solar cells, thereby increasing the amount of light illuminating the back surface of the solar cells and thus enhancing the power generation of the back side of the photovoltaic module. Furthermore, the thickness and refractive index of the back anti-reflection layer 4 are readily available and relatively inexpensive, representing an optimized balance between light transmission, cost, and other factors. The photovoltaic laminate may also include: a reflective film 5, disposed on the second surface of the glass backsheet 2 near the cell string array, and disposed on the glass backsheet near... The reflective film on the second surface of the battery string array has two functions: firstly, it reflects light that shines from the light-facing side of the photovoltaic laminate and passes through the gaps between the cells to the back surface of the cells, thus increasing the power generation of the back side of the photovoltaic module; secondly, it reflects light that shines from the light-facing side of the photovoltaic laminate and passes through the gaps between the cells to the glass cover, and then reflects it back to the light-facing side of the cells, thus increasing the power generation of the front side of the photovoltaic module. Therefore, this application increases both the front and back power generation of the photovoltaic module, thereby improving the overall power generation of the photovoltaic module.

[0057] Meanwhile, with a back anti-reflection layer on the first surface of the glass backsheet and a glaze layer on the second surface, existing processes require significant improvements to achieve this. Furthermore, the presence of a back anti-reflection layer on the first surface and a glaze layer on the second surface negatively impacts the tempering process of the glass backsheet, reducing its yield. To address these technical issues, the photovoltaic module provided in this application features a back anti-reflection layer 4 on the first surface of the glass backsheet 2 and a reflective film 5 on the second surface. This design is compatible with existing processes, which are easily implemented. Moreover, the structure on both sides of the glass backsheet in this application has minimal negative impact on the subsequent tempering process of the glass backsheet 2, resulting in a high yield for the glass backsheet 2.

[0058] For example, the thickness of the back antireflection layer 4 is a, which can be 100nm, 103nm, 105nm, 110nm, 115nm, 120nm, 125nm, 130nm, 135nm, 140nm, 145nm, or 150nm.

[0059] For example, the refractive index b of the back antireflection layer 4 can be 1.1, 1.2, 1.3, 1.4, 1.22, 1.29, 1.48, or 1.5.

[0060] Optionally, the thickness of the back antireflection layer 4 is a, 120nm≤a≤140nm, and the refractive index of the back antireflection layer 4 is b, 1.2≤b≤1.4. Through further optimization of the thickness and refractive index of the back antireflection layer 4, during the operation of the photovoltaic module, the back antireflection layer 4 can further transmit as much light reflected from the ground as possible to the glass backsheet, and the glass backsheet then transmits this light to the solar cells, thereby increasing the amount of light illuminating the back surface of the solar cells, which has a greater gain effect on the power generation of the back side of the photovoltaic module.

[0061] For example, the thickness of the back antireflection layer is 'a', which can be 120nm, 123nm, 136nm, 128nm, 129nm, 132nm, 136nm, 138nm, 136nm, or 140nm.

[0062] For example, the refractive index b of the back antireflection layer 4 can be 1.2, 1.25, 1.28, 1.33, 1.35, 1.22, 1.29, 1.37, or 1.49.

[0063] Optional, refer to Figure 3The reflective film 5 includes an adhesive layer 51 adjacent to the glass backing plate 2. The adhesive layer 51 is mainly used to bond other structures of the reflective film 5 to the glass backing plate 2 to improve the bonding strength between the reflective film 5 and the glass backing plate 2. Optionally, the adhesive layer 51 includes an EVA (ethylene-vinyl acetate copolymer) layer. The EVA layer not only has good adhesive properties but is also readily available.

[0064] Optionally, in the direction L1 where the thickness of the photovoltaic laminate is located, the reflective film 5 includes: a support layer 52, which includes opposite sides along the direction L1 where the thickness of the photovoltaic laminate is located; Figure 3 In this context, the support layer 52 includes its upper and lower sides, which are opposite to each other. (See reference...) Figure 1 and Figure 2 The reflective film 5 also includes a reflective layer disposed on either of the aforementioned two sides of the support layer 52. That is, the reflective film 5 includes only one reflective layer, which is disposed on only one of the aforementioned two sides of the support layer 52. This reflective layer can be disposed on the backlight side or the light-facing side of the support layer 52. The reflective layer includes: a directional reflective structure layer and a metal reflective layer attached to the directional reflective structure layer. The support layer 52 provides mechanical support for the directional reflective structure layer, and the directional reflective structure layer provides a surface for the metal reflective layer. The metal reflective layer provides good reflectivity. In the reflective layer, the directional reflective structure layer is adjacent to the support layer 52, and the metal reflective layer is further away from the support layer 52.

[0065] Reference Figure 2 Regarding the reflective film 5, which has its reflective layer disposed on only one side of the aforementioned two sides of the support layer 52, on the one hand, the reflective film 5 can reflect light that shines from the light-facing side of the photovoltaic laminate and passes through the gaps between the cells to the back surface of the cells, thus increasing the power generation of the back side of the photovoltaic module; on the other hand, the reflective film 5 can reflect light that shines from the light-facing side of the photovoltaic laminate and passes through the gaps between the cells to the glass cover, and then reflect it from the glass cover to the light-facing side of the cells, thus increasing the power generation of the front side of the photovoltaic module. Therefore, this application increases both the power generation of the front and back sides of the photovoltaic module, thereby improving the power generation of the photovoltaic module.

[0066] Or, refer to Figure 3 Based on the reflective film 5 including a support layer 52, the reflective film 5 also includes two aforementioned reflective layers 53, which are respectively disposed on both sides of the support layer 52. Based on the aforementioned light gain of the reflective film 5 where only one reflective layer is disposed on one side of the aforementioned two sides of the support layer 52, referring to... Figure 4Regarding the reflective film 5, which includes the two aforementioned reflective layers 53, the reflective film 5 reflects light transmitted from the back anti-reflection layer 4 onto its surface, onto the glass backsheet 2, and then onto the back surface of the solar cells, increasing the back-side power generation of the photovoltaic module. In other words, the back anti-reflection layer 4 enhances the incident light on the back of the photovoltaic module and also enhances the light reflection within the photovoltaic module. Furthermore, regarding the reflective film 5, which includes the two aforementioned reflective layers 53, the reflective film 5 reflects light transmitted from the gaps between the solar cells. Light transmitted through the reflective film 5 and incident on it is reflected on its surface. On one hand, it can be reflected from the gaps between the solar cells to the glass cover 3, and then from the glass cover 3 to the light-facing side of the solar cells, increasing the front-side power generation of the photovoltaic module. On the other hand, the reflective film 5 also reflects light transmitted through the gaps between the solar cells directly to the back-side of the solar cells, increasing the back-side power generation of the photovoltaic module. In other words, compared to a reflective film 5 that only includes a single reflective layer 53, this method offers significant advantages. Figure 3 and Figure 4 The reflective film 5, which includes two reflective layers 53, has a greater effect on the power generation of photovoltaic modules.

[0067] It should be noted that the size of the orthographic projection of the reflective layer on the plane perpendicular to the thickness of the photovoltaic laminate is not specifically limited and can be set according to actual needs.

[0068] Optional, refer to Figure 3 The reflective film 5 includes two reflective layers 53. The two reflective layers 53 are symmetrically arranged on opposite sides of the support layer 52. On the one hand, it has an increase in the light received from the light-facing side of the photovoltaic module and the light received from the back-facing side of the photovoltaic module, and the increase effect on the power generation of the front and back of the photovoltaic module is more obvious and balanced. On the other hand, it reduces the difficulty of manufacturing the reflective film.

[0069] Optional, refer to Figures 1 to 4 The directional reflection structure layer includes two side plates extending from the support layer 52 and intersecting each other; at the intersection, the included angle between the two side plates is d, which is between 110° and 130°. The included angle d can achieve a good directional reflection effect and has a more obvious effect on the gain of the front power generation.

[0070] For example, the included angle d can be 110°, 112°, 115°, 118°, 120°, 123°, 125°, 127°, or 130°.

[0071] Optional, refer to Figure 4Along the direction L1 where the thickness of the photovoltaic laminate is located, the distance c between the reflective film 5 and the back anti-reflection layer 4 is 0.8mm≤c≤2.5mm. If the distance c between the reflective film 5 and the back anti-reflection layer 4 is less than 0.8mm or greater than 2.5mm, the light that shines on the reflective film 5 from the glass backsheet 2 side, after being reflected back to the glass backsheet 2, is likely to fall at the edge of the solar cell. After being reflected back to the glass backsheet 2, the light is likely to be directly transmitted through the back anti-reflection layer 4 instead of being reflected back into the solar cell by the back anti-reflection layer 4, which reduces the utilization rate of light by the solar cell. Therefore, in this application, the distance c between the reflective film 5 and the back anti-reflection layer 4 is within the above range, which can improve the utilization rate of light by the solar cell and further improve the front power generation and back power generation of the photovoltaic module. More specifically, if the distance c between the reflective film 5 and the back anti-reflective layer 4 is less than 0.8 mm or greater than 2.5 mm, light shining onto the reflective film 5 from the glass backplate 2 side, after being reflected back to the glass backplate 2, is more likely to fall at the edge of the solar cell. Furthermore, after being reflected back to the glass backplate 2, the light is more likely to pass directly through the back anti-reflective layer 4 instead of being reflected again by the back anti-reflective layer 4 and then re-entering the solar cell, thus reducing the solar cell's light utilization rate. (0.8 mm) A resolution of mm ≤ c ≤ 2.5mm ensures that light entering the photovoltaic module from the anti-reflective layer and glass backsheet is reflected by the reflective film to the glass backsheet, and then reflected by the glass backsheet to the back surface of the solar cells. This ensures that the light is distributed as much as possible within a larger central area of ​​the back surface of the solar cells, maximizing light absorption. Simultaneously, a resolution of d > 130° prevents excessive incident angles of light entering the photovoltaic module from the anti-reflective layer and glass backsheet, reflected by the reflective film to the glass backsheet, and then reflected by the glass backsheet to the back surface of the solar cells. The light distribution is relatively scattered, easily falling at the edges of the solar cells. Furthermore, after reflection from the solar cells to the glass backsheet 2, the light tends to directly transmit through the anti-reflection layer 4 instead of re-entering the solar cells after reflection from the anti-reflection layer 4, reducing the solar cells' light utilization rate. With d < 110°, the incident angle of light entering the photovoltaic module from the anti-reflection layer and glass backsheet, after reflection by the reflective film to the glass backsheet, is too small. The distribution of light reflected from the glass backsheet to the back surface of the solar cells is relatively dense, or rather, only... Distributed within a small area of ​​the back surface of the solar cell, the relatively dense light may not be fully absorbed, resulting in light waste. Therefore, 0.8mm≤c≤2.5mm and 110°≤d≤130° can ensure that the light entering the photovoltaic module from the back anti-reflective layer and glass backsheet is reflected by the reflective film to the glass backsheet, and then reflected by the glass backsheet to the back surface of the solar cell. The light is distributed as much as possible in the larger central area of ​​the back surface of the solar cell to fully absorb the light.In summary, by controlling the distance c between the reflective film and the back anti-reflective layer and the included angle d between the two side panels within the above range, the light path incident from the back surface of the photovoltaic module to the back of the cell is optimized, which can improve the utilization rate of light by the cell and further improve the power generation of the back of the photovoltaic module.

[0072] For example, c can be 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.1mm, 2.2mm, 2.4mm, or 2.5mm.

[0073] Optional, refer to Figure 3 The reflective film 5 also includes an insulating layer 54, located on the side of the reflective film 5 furthest from the glass backplate 2. Because the directional reflective structure layer has sharp edges, the insulating layer 54 prevents the directional reflective structure layer and the metal reflective layer from puncturing the encapsulating film 7, thus preventing a short circuit in the battery cells. The insulating layer 54 has good insulation properties and a certain buffering effect, and can also prevent the directional reflective structure layer from breaking.

[0074] Optionally, the aforementioned metal reflective layer may include an aluminum layer, which has good reflective properties and is relatively inexpensive. The aluminum layer may be deposited on the directional reflective structure layer.

[0075] Optionally, the reflectivity of the surface of the reflective film 5 facing away from the glass backplate 2 is greater than or equal to 60%. A higher reflectivity of this surface results in stronger light reflection and a more significant increase in power generation. A reflectivity meter can be used to measure the reflectivity at any location on the surface of the reflective film 5 facing away from the glass backplate 2, which can then be taken as the reflectivity of that surface. Alternatively, the reflectivity can be measured at multiple locations on the surface, and the average value can be taken as the reflectivity of the surface. The specific method for measuring the reflectivity of this surface is not limited.

[0076] For example, the reflectivity of the surface of the reflective film 5 facing away from the glass backplate 2 is greater than or equal to 60%, 63%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 90%, 93%, 95%, and 98%.

[0077] Optionally, there is a string spacing between adjacent battery strings, and a cell spacing between adjacent cells within a battery string; the orthographic projection of the aforementioned reflective film 5 on the back anti-reflection layer 4 covers the orthographic projections of the string spacing and cell spacing on the back anti-reflection layer 4. Specifically, no cells are placed at the locations of the cell spacing and string spacing, and light will shine on the aforementioned reflective film 5, and then be reflected to the light-facing side of the cells to improve the front power generation of the photovoltaic module.

[0078] It should be noted that the orthogonal projection of the reflective film 5 onto the back antireflection layer 4 mentioned in this application refers to the projection of the reflective film 5 onto the back antireflection layer 4 near the glass back plate 2 when the reflective film 5 is illuminated by light perpendicular to the surface of the back antireflection layer 4 near the glass back plate 2. The orthogonal projection of other structures mentioned in this application onto the back antireflection layer 4 is similar.

[0079] Optionally, in the reflective film 5, the width of the portion located on the string spacing is greater than the width of the portion located on the cell spacing. Specifically, the width of the string spacing is usually greater than or equal to the width of the cell spacing. The reflective film 5 covers both the string spacing and the cell spacing, so the width of the portion located on the string spacing in the reflective film 5 is greater than the width of the portion located on the cell spacing, making full use of the space where no cells are installed, thereby maximizing the front-side power generation of the photovoltaic module.

[0080] For example, if the string spacing width is 1.66 mm, the width of the portion of the reflective film 5 located on the string spacing can be 5 mm; if the cell spacing width is 1.1 mm, the width of the portion of the reflective film 5 located on the cell spacing can be 4 mm. It should be noted that the photovoltaic module is rectangular in shape, with its longer side being greater than or equal to the shorter side. Therefore, the direction of the string spacing width can be parallel to the extension direction of the shorter side, and the direction of the cell spacing width can be parallel to the extension direction of the longer side.

[0081] Optional, refer to Figure 5 and Figure 6 The orthogonal projection of the reflective film 5 onto the back antireflective layer 4 does not cover the edge of the back antireflective layer 4. That is, the reflective film 5 is not placed at the edge of the photovoltaic laminate. During the lamination process, air bubbles may be generated. The absence of the reflective film 5 at the edge of the photovoltaic laminate facilitates the removal of these air bubbles during lamination. Optionally, refer to... Figure 5 The shape of the back anti-reflection layer 4 is rectangular; the back anti-reflection layer 4 includes: an intersecting first side 41 and a second side 42, the side length of the first side 41 is x, the side length of the second side 42 is y, x is greater than or equal to y, that is, the first side 41 is the long side and the second side 42 is the short side. Figure 6 for Figure 5 A partial schematic diagram showing the upper left corner of the photovoltaic laminate. (Refer to...) Figure 6In the photovoltaic laminate, the cell immediately adjacent to the first side 41 is the first cell 11, the cell immediately adjacent to the second side 42 is the second cell 12, and the side of the first cell 11 perpendicular to the first side 41 is the third side 111 of the first cell 11. Along the extension direction of the third side 111 of the first cell 11, the orthographic projection of the reflective film 5 on the back antireflection layer 4 covers the orthographic projection of the third side 111 of the first cell 11 by a ratio of i, where 1 / 3 ≤ i ≤ 2 / 3; the side of the second cell 12 perpendicular to the second side 42 is the fourth side 121 of the second cell 12. Along the extension direction of the fourth side 121 of the second solar cell 12, the proportion of the orthogonal projection of the reflective film 5 on the back antireflective layer 4 covering the orthogonal projection of the fourth side 121 of the second solar cell 12 is k, where 1 / 3 ≤ k ≤ 2 / 3. The fourth side 121 is perpendicular to the second side 42. If both i and k are less than 1 / 3, the reserved space for the reflective film 5 at the edge of the photovoltaic laminate is too large, reducing the area where the reflective film 5 can be installed and affecting its gain on power generation, which is detrimental to improving reflectivity. If both i and k are greater than 2 / 3, the reserved space for the reflective film 5 at the edge of the photovoltaic laminate is too small, hindering the removal of air bubbles generated during the lamination process. Furthermore, the reflective film 5 may shift during bonding. Therefore, when i and k are within the above range, a good balance is achieved between reflectivity, air bubble removal, and process compatibility. This not only improves reflectivity but also facilitates the removal of air bubbles during the lamination process, while maintaining a high yield. Whether i and k are equal is not specifically limited here. It should be noted that the first and second solar cells here can be the same solar cell, for example, both being solar cells. Figure 6 The battery cell in the upper left corner.

[0082] For example, i can be 1 / 3, 6 / 15, 7 / 15, 8 / 15, 1 / 2, 2 / 3, 17 / 30, 3 / 5, 19 / 30, or 39 / 60. Similarly, k can be 1 / 3, 6 / 15, 7 / 15, 8 / 15, 1 / 2, 2 / 3, 17 / 30, 3 / 5, 19 / 30, or 37 / 60.

[0083] It should be noted that in the photovoltaic laminate, the number of first solar cells may be greater than or equal to 1. For the first solar cell located at the corner of the photovoltaic module, it has only one third side, which is the side of the first solar cell that is more closely inside the photovoltaic module than the two sides perpendicular to the first side 41. For solar cells located in other positions, each first solar cell has two third sides. Here, i can be the proportion i corresponding to any position of any third side of any first solar cell in the photovoltaic laminate, or i can be the average of multiple proportions i corresponding to multiple positions of any third side of any first solar cell, or i can be the average of multiple proportions i corresponding to multiple positions of two third sides of any first solar cell, or i can be the average of multiple proportions i corresponding to multiple positions of multiple third sides of multiple first solar cells. The method of determining i is not limited to the methods listed above. The method of determining k is similar, and will not be elaborated here to avoid repetition.

[0084] Optional, refer to Figure 5 The anti-reflective layer 4 on the back is rectangular in shape. It includes an intersecting first side 41 and a second side 42. The length of the first side 41 is x, and the length of the second side 42 is y, where x is greater than or equal to y (meaning the first side 41 is the longer side and the second side 42 is the shorter side). The shortest distance between the orthographic projection of the reflective film 5 onto the back anti-reflective layer 4 and its adjacent first side 41 is m. The shortest distance between the orthographic projection of the reflective film 5 onto the back anti-reflective layer 4 and its adjacent second side is n, where n is greater than or equal to m. Specifically, in the direction parallel to the first side 41, the distance from bubbles generated during the lamination process to the edge of the photovoltaic module is relatively large, making bubble removal difficult; therefore, a larger gap n is reserved. In the direction parallel to the second side 42, the distance from bubbles generated during the lamination process to the edge of the photovoltaic module is relatively small, making bubble removal easier; therefore, a smaller gap m is reserved.

[0085] Optional, refer to Figure 5 x is 1000mm to 2500mm, y is 900mm to 1200mm, m is 11.5mm to 20.5mm, and n is 18mm to 62mm. For photovoltaic modules of this size, the above m and n are within the corresponding range. On the one hand, the space reserved for the reflective film 5 at the edge of the photovoltaic laminate is not too large. The larger placement of the reflective film 5 has a more obvious effect on the gain of the front power generation of the photovoltaic module.

[0086] For example, x here can be 1000mm, 2375mm, 2375.5mm, 2375.8mm, 2375.9mm, 2376mm, 2376.2mm, 2376.5mm, 2376.7mm, 2376.8mm, 2377mm, 2500mm; y here can be 900mm, 1127mm, 1127.69mm, 1127.2mm, 1127.4mm, 1127.5mm, 1127.7mm, 1128mm, 1 128.2mm, 1128.5mm, 1128.7mm, 1129mm, 1134mm, 1200mm; m can be 11.5mm, 12mm, 13.5mm, 14mm, 15mm, 16.5mm, 17mm, 19mm, 18.5mm, 20mm, 20.5mm; n can be 18mm, 19mm, 20mm, 19.8mm, 22mm, 30mm, 40mm, 50mm, 60mm, 59mm, 61mm, 62mm.

[0087] Optional, refer to Figure 5 Along the extension direction of the first side 41 (long side), the size of the orthogonal projection of the reflective film 5 onto the back antireflection layer 4 is e, accounting for 92% ≤ e ≤ 98% of x; along the extension direction of the second side 42 (short side), the size of the orthogonal projection of the reflective film 5 onto the back antireflection layer 4 is f, accounting for 95% ≤ f ≤ 98%. Specifically, if the reserved space of the reflective film 5 at the edge of the photovoltaic laminate is too small, it may be difficult to remove air bubbles that may be generated during the lamination process. If the reserved space of the reflective film 5 at the edge of the photovoltaic laminate is too large, the placement area of ​​the reflective film 5 will be reduced, affecting the gain effect of the reflective film 5 on power generation. In this application, e and f are within the above-mentioned ratio range. The reflective film has a high coverage rate between cells and between cell strings, and the reflection effect is obvious, enhancing the light utilization rate of the photovoltaic module. At the same time, it can ensure that air bubbles in the laminate can be effectively removed during the photovoltaic module manufacturing process, improving the manufacturing yield and the reliability of the photovoltaic module.

[0088] For example, given that x is 2382 mm and y is 1134 mm, along the extension direction of the short side (i.e., the second side) of the photovoltaic laminate, the ratio of the length of the reflective film 5 to the length y of the second side can range from (1134 - 13.5 × 2) / 1134 = 97.6% to (1134 - 18.5 × 2) / 1134 = 96.7%. Here, 13.5 mm and 18.5 mm refer to the shortest distance m between the orthogonal projection of the reflective film 5 onto the antireflective layer 4 on the back side of the photovoltaic laminate and the first side 41. Along the direction of the second side 42, there are two m values, therefore this... The value needs to be multiplied by 2; along the long side (i.e., the first side 41) of the photovoltaic laminate, the ratio of the length of the reflective film 5 to the length x of the first side can be in the range of (2382-60×2-16) / 2382=94.3% to (2380-20×2-16) / 2380=97.5%; here, 60mm and 20mm are on one side of the photovoltaic laminate: the shortest distance between the orthographic projection of the reflective film 5 on the back antireflection layer 4 and the second side 42 is n. Along the direction of the first side 41, there are two n, so it needs to be multiplied by 2 here. Here, 16mm is Figure 5 The diameter of the through hole 8 is such that a busbar is installed at the location of the through hole. The through hole 8 is mainly used for installing junction boxes, etc.

[0089] For example, along the extension direction of the first side 41, the size of the orthogonal projection of the reflective film on the back antireflection layer 4, as a percentage of x, can be 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, or 98%; along the extension direction of the second side 42, the size of the orthogonal projection of the reflective film 5 on the back antireflection layer 4, as a percentage of y, can be 95%, 95.4%, 95.5%, 96%, 96.2%, 96.5%, 97%, 97.5%, 97.8%, or 98%.

[0090] Optional, refer to Figure 5 The photovoltaic module also includes: several busbars located at the first end, the second end, and the middle respectively; the first end and the second end are opposite each other in the extension direction of the cell string, and the middle is located between the first end and the second end; the orthographic projection of the reflective film 5 on the back anti-reflection layer 4 does not cover the orthographic projection of the busbars on the back anti-reflection layer 4. On the one hand, the setting method of the reflective film 5 is more compatible with the existing film setting process. On the other hand, the glass back panel 2 usually has a through hole 8 at the middle position corresponding to the busbar. The absence of the reflective film 5 at this position will not affect the setting of the through hole 8, and reduces the risk of short circuit of the busbar.

[0091] Optionally, the second surface of the glass backplate 2, which is closer to the battery string array, is rougher than the first surface of the glass backplate 2, which is farther away from the battery string array. The rougher second surface is conducive to the adhesion of the reflective film 5, while the first surface is relatively flat, making it easier to form a back anti-reflective layer 4 with better film quality.

[0092] Optionally, the glass backing includes at least one of patterned glass and float glass, wherein one surface of the glass is rough and the other is flat, meeting the aforementioned requirements, and the glass is readily available and inexpensive.

[0093] For example, patterned glass includes a textured surface and a rolled surface, with the textured surface being relatively smooth and the rolled surface being rougher. A reflective film 5 is provided on the rolled surface, and a back anti-reflective layer 4 is provided on the textured surface. As another example, float glass includes a tin surface and a non-tin surface, with the tin surface being relatively smooth and the non-tin surface being rougher. A reflective film 5 is provided on the non-tin surface, and a back anti-reflective layer 4 is provided on the tin surface.

[0094] Optional, refer to Figure 3 The thickness of the reflective film 5 is r, 100μm≤r≤160μm. The direction of this thickness r is parallel to the direction L1 of the thickness of the photovoltaic laminate. The reflective film 5 with this thickness range has a good reflection effect and relatively low cost, which means that the reflection effect and cost are well balanced. Moreover, the thickness is not too large, so it will not have a negative impact on the lamination process.

[0095] For example, without an insulating layer, the thickness r of the reflective film 5 can be 125 μm, with a processing error of ±25 μm; as another example, with an insulating layer 54, the thickness r of the reflective film 5 can be 130 μm, with a processing error of ±25 μm. Furthermore, the thickness r of the reflective film 5 can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, or 160 μm.

[0096] Optional, refer to Figure 3 The thickness of the support layer 52 is t, with a value of 20μm ≤ t ≤ 45μm. This thickness is suitable for providing good support to the directional reflection structure layer without wasting material. For example, the thickness of the support layer 52 can be 25μm or 38μm, with a processing error of ±5μm; alternatively, the thickness of the support layer 52 can be 20μm, 22μm, 25μm, 30μm, 35μm, 40μm, or 45μm. The direction of the thickness t of the support layer 52 is parallel to the direction L1 of the photovoltaic laminate thickness.

[0097] Optionally, the thickness of the reflective layer 53, which is the sum of the thicknesses of the metal reflective layer and the directional reflective structure layer on one side of the support layer 52, is w, where 5μm ≤ w ≤ 15μm. This thickness range is suitable, providing good reflection and low cost. For example, the metal reflective layer can be an aluminum layer on the directional reflective structure layer, with a total thickness of 10μm for the aluminum-plated layer and the directional reflective structure layer on one side of the support layer 52, and a processing error of ±5μm. Alternatively, the total thickness of the metal reflective layer and the directional reflective structure layer on one side of the support layer 52 can be 5μm, 6μm, 10μm, 9μm, 11μm, 13μm, or 15μm. The direction of the thickness w of the reflective layer 53 is parallel to the direction L1 of the thickness of the photovoltaic laminate.

[0098] Optionally, the thickness of the adhesive layer 51 is z, where 60μm ≤ z ≤ 90μm. Adhesive layers 51 with the above-mentioned thickness have good adhesive performance and are not excessively thick, thus avoiding adverse effects on the lamination process. For example, adhesive layer 51 may be an EVA (ethylene-vinyl acetate copolymer) layer with a thickness z of 75μm and a processing error of ±5μm. Alternatively, the thickness of adhesive layer 51 can be 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, or 90μm.

[0099] Optionally, the tear strength (i.e., post-lamination peel strength) between the reflective film and the glass backing plate 2 is greater than or equal to 12 N / cm, indicating a higher bonding strength and more reliable installation. This tear strength refers to the force required to tear the reflective film from the glass backing plate 2 after lamination. For example, this tear strength can be: 12 N / cm, 13 N / cm, 14 N / cm, 15 N / cm, 16 N / cm, 17 N / cm, 18 N / cm, 19 N / cm, or 20 N / cm. A tear strength tester can be used to measure the tear strength between the reflective film and the glass backing plate 2.

[0100] Optionally, after removing the adhesive layer 51, the tensile strength of the remaining reflective film should be greater than or equal to 50 MPa. This is because the adhesive layer 51 is usually quite flexible, and removing it makes the tensile strength measurement more accurate. A higher tensile strength also reduces the likelihood of damage during lamination. For example, after removing the adhesive layer 51, the tensile strength of the remaining reflective film could be 50 MPa, 55 MPa, 60 MPa, 65 MPa, 70 MPa, 75 MPa, 80 MPa, 85 MPa, or 90 MPa.

[0101] Optionally, after removing the adhesive layer 51, the remaining reflective film has an elongation at break greater than or equal to 30%, making it less prone to damage during lamination. Because the adhesive layer 51 is typically quite flexible, removing it allows for more accurate measurement of the elongation at break. For example, after removing the adhesive layer 51, the remaining reflective film can have an elongation at break of 30%, 35%, 40%, 45%, 50%, 55%, or 60%.

[0102] Optionally, the melting point of the adhesive layer is between 60°C and 90°C, which is a suitable melting point and has little impact on the lamination process. For example, the melting point of the adhesive layer can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 73°C, 90°C, or 84°C.

[0103] It should be noted that the tear strength, tensile strength, elongation at break, and melting point here can be measured using the relevant national standards for the photovoltaic industry.

[0104] Optionally, the thickness of the insulating layer 54 is u, where 5μm ≤ u ≤ 15μm. A suitable thickness for the insulating layer 54 provides good insulation and blocking effect against the directional reflective structure layer and the metal reflective layer. For example, the thickness of the insulating layer 54 can be 10μm with a processing error of ±5μm; further examples include thicknesses of 5μm, 6μm, 10μm, 9μm, 11μm, 13μm, and 15μm.

[0105] Optionally, the support layer 52 includes a PET (polyethylene terephthalate) layer; the directional reflective structure layer includes a UV (photocurable) adhesive layer; and the adhesive layer 51 includes an EVA layer. All of the above layers have good desired functions and are readily available.

[0106] Optional, refer to Figure 1 , Figure 2 and Figure 4 The photovoltaic module also includes a front anti-reflection layer 6, located on the side of the glass cover plate 3 away from the cell string array. This front anti-reflection layer 6 can transmit as much light from the light-facing side of the photovoltaic module to the cells as possible, thereby improving the front power generation of the photovoltaic module and thus improving the efficiency of the photovoltaic module.

[0107] Optional, refer to Figure 1The thickness of the front antireflection layer 6 is g, and the thickness of the back antireflection layer 4 is a, where g ≤ a. When g = a and both layers are the same thickness, they can be prepared using the same or similar processes, resulting in high process compatibility, reduced process complexity, and lower costs. For example, both the front antireflection layer 6 and the back antireflection layer 4 can be deposited using an AR (antireflection) film solution, and their thicknesses can be within the range of 120 ± 15 nm. Alternatively, specifically, the wavelength of light received by the back antireflection layer 4 is usually longer; therefore, g < a, a thicker back antireflection layer 4 is beneficial for further improving light transmittance.

[0108] Optionally, the refractive index h of the front antireflective layer 6 is 1.1 ≤ h ≤ 1.5. When the refractive index h of the front antireflective layer 6 is within this range, it allows as much light received from the light-facing side of the photovoltaic laminate as possible to be transmitted to the glass cover plate and enter the solar cells, further increasing the power generation of the photovoltaic module. For example, the refractive index h of the front antireflective layer 6 can be 1.1, 1.2, 1.25, 1.3, 1.4, or 1.5. As another example, a refractive index h of approximately 1.3 makes mass production easier. In this case, the light transmittance of the front antireflective layer 6 is >93.8%, higher than that of uncoated glass (approximately 91.6%), thereby increasing the back-side power (≥10W) and improving the bifaciality.

[0109] Optionally, the light transmittance of the front antireflection layer 6 is greater than or equal to 93.8%, which provides good light transmission and helps to improve the power generation of photovoltaic modules.

[0110] The present application will be further explained below with reference to specific embodiments.

[0111] Example

[0112] The photovoltaic module in the embodiment is as follows Figure 1 , Figure 2 and Figure 4 As shown, the photovoltaic laminate includes: a battery string array; the battery string array includes: a plurality of battery strings arranged in an array; the battery string includes: a plurality of electrically connected battery cells 1; a glass backplate 2 located on the first side of the battery string array; a glass cover plate 3 located on the second side of the battery string array, the first side and the second side being opposite to each other; a back antireflective layer 4 disposed on the first surface of the glass backplate away from the battery string array; a reflective film 5 disposed on the second surface of the glass backplate 2 close to the battery string array; and a front antireflective layer 6 disposed on the side of the glass cover plate 3 away from the battery string array.

[0113] The structure of reflective film 5 is as follows Figure 3In the direction of the thickness of the photovoltaic laminate, the reflective film 5 includes: a support layer 52, along the thickness direction L1 of the photovoltaic laminate, the support layer 52 including opposite sides; the reflective film 5 also includes two reflective layers 53, respectively disposed on the aforementioned two sides of the support layer 52. The reflective layer 53 includes: a directional reflective structure layer and a metal reflective layer attached to the directional reflective structure layer; the two directional reflective structure layers are symmetrically disposed on both sides of the support layer 52. Here, the included angle d is 120°, the support layer 52 is a PET layer; the directional reflective structure layer is a UV adhesive layer; the adhesive layer is an EVA layer, and the metal reflective layer is an aluminum layer. The thickness t of the support layer 52 is 30 μm, the thickness r of the reflective film is 135 μm, the thickness u of the insulating layer is 10 μm, the thickness of the reflective layer 52 is 10 μm, and the thickness of the EVA layer is 75 μm. (Refer to...) Figure 5 x is 2376m, y is 1128mm, m is 13.5mm, and n is 40mm. (Refer to...) Figure 6 The aforementioned ratios i and k are both 1 / 2. The thickness a of the back antireflection layer 4 is 130 nm, and the refractive index b of the back antireflection layer 4 is 1.3. Along the direction L1 where the thickness of the photovoltaic laminate is located, the distance c between the reflective film 5 and the back antireflection layer 4 is 2 mm, the thickness g of the front antireflection layer is 1.9 mm, and the refractive index h of the front antireflection layer is 1.3.

[0114] Comparative Example

[0115] The only difference between the comparative example and the embodiment is that the glass backplate of the comparative example has an enamel layer on the side closest to the battery string array, while the glass backplate of the comparative example does not have a back anti-reflective layer on the side away from the battery string array. The enamel layer covers the entire second surface of the glass backplate closest to the battery string array. The other parts of the comparative example are the same as those of the embodiment.

[0116] Table 1: Comparison of Results between Examples and Comparative Examples

[0117] Frontal power generation / W Rear power generation / W Double-sidedness / % Comparative Example 611.32 485.2 79.4％ Example 612.43 497.7 81.2％ Gain 1.1 12.5 1.8％

[0118] As can be seen from Table 1, compared with the comparative example, the front power generation and back power generation of this embodiment are both increased. The main reason is that the back anti-reflection layer disposed on the first surface of the glass backplate away from the battery string array has an increasing effect on the back power generation of the photovoltaic module, and the reflective film disposed on the second surface of the glass backplate close to the battery string array has an increasing effect on both the front power generation and back power generation of the photovoltaic module. Therefore, this application has an increasing effect on both the front power generation and back power generation of the photovoltaic module, thereby improving the power generation of the photovoltaic module.

[0119] This application also provides a photovoltaic system comprising: a plurality of photovoltaic modules arranged in an array as described in any of the aforementioned examples. No specific limitations are made on the arrangement method or location of the photovoltaic system. This photovoltaic system has the same or similar beneficial effects as any of the aforementioned photovoltaic modules, and related aspects can be referred to each other. To avoid repetition, further details are omitted here.

[0120] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0121] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A photovoltaic module, characterized in that, include: Photovoltaic laminates; The photovoltaic laminate includes: A battery string array; the battery string array includes: a plurality of battery strings arranged in an array; the battery string includes: a plurality of electrically connected battery cells; A glass backplate is located on the first side of the battery string array; A glass cover is located on the second side of the battery string array, with the first side and the second side opposite to each other; A back anti-reflective layer is disposed on the first surface of the glass backplate away from the battery string array; A reflective film is applied to the second surface of the glass backplate near the battery string array; The thickness of the back antireflection layer is a, which satisfies: 100nm≤a≤150nm; The refractive index of the back antireflection layer is b, which satisfies: 1.1≤b≤1.

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2. The photovoltaic module according to claim 1, characterized in that, The thickness of the back antireflection layer is a, which satisfies: 120nm≤a≤140nm; The refractive index of the back antireflection layer is b, which satisfies: 1.2≤b≤1.

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3. The photovoltaic module according to claim 1, characterized in that, The reflective film includes: a support layer; along the direction of the thickness of the photovoltaic laminate, the support layer includes opposite sides; A reflective layer is disposed on either side of the support layer, or two reflective layers are disposed on the opposite sides of the support layer; the reflective layer includes a directional reflective structure layer and a metal reflective layer attached to the directional reflective structure layer; in the reflective layer, the directional reflective structure layer is adjacent to the support layer.

4. The photovoltaic module according to claim 3, characterized in that, The reflective film includes two reflective layers, which are respectively disposed on both sides of the support layer; Along the direction of the thickness of the photovoltaic laminate, the distance between the reflective film and the back antireflective layer is c, where 0.8mm ≤ c ≤ 2.5mm; The directional reflective structure layer includes two side plates extending from the support layer and intersecting each other; at the intersection, the included angle of the two side plates is d, where 110°≤d≤130°.

5. The photovoltaic module according to claim 1, characterized in that, The back anti-reflection layer is rectangular in shape; the back anti-reflection layer includes: an intersecting first side and a second side, the length of the first side is x, the length of the second side is y, and x is greater than or equal to y; Along the extension direction of the first side, the size of the orthographic projection of the reflective film onto the back antireflective layer, as a percentage of x, is e, where 92% ≤ e ≤ 98%. Along the extension direction of the second side, the size of the orthographic projection of the reflective film onto the back antireflective layer, in proportion to y, is f, where 95% ≤ f ≤ 98%.

6. The photovoltaic module according to claim 1, characterized in that, Also includes: The front anti-reflective layer is located on the side of the glass cover that faces away from the battery string array; The thickness of the front antireflection layer is g, where g ≤ a; The refractive index of the front antireflection layer is h, where 1.1 ≤ h ≤ 1.

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7. The photovoltaic module according to claim 3, characterized in that, In the reflective film, the two reflective layers are symmetrically arranged on both sides of the support layer.

8. The photovoltaic module according to claim 1, characterized in that, The back anti-reflective layer is rectangular in shape; the back anti-reflective layer includes: an intersecting first side and a second side; The battery cell adjacent to the first side is the first battery cell, and the side of the first battery cell perpendicular to the first side is the third side of the first battery cell. Along the extension direction of the third side of the first battery cell, the proportion by which the orthographic projection of the reflective film on the back anti-reflection layer covers the orthographic projection of the third side of the first battery cell is i, where 1 / 3 ≤ i ≤ 2 / 3; and / or the battery cell adjacent to the second side is the second battery cell, and the side of the second battery cell perpendicular to the second side is the fourth side of the second battery cell. Along the extension direction of the fourth side of the second battery cell, the proportion by which the orthographic projection of the reflective film on the back anti-reflection layer covers the orthographic projection of the fourth side of the second battery cell is k, where 1 / 3 ≤ k ≤ 2 / 3.

9. The photovoltaic module according to claim 1, characterized in that, The back antireflective layer is rectangular in shape; the back antireflective layer includes: an intersecting first side and a second side; the length of the first side is x, the length of the second side is y, and x is greater than or equal to y; the shortest distance between the orthographic projection of the reflective film on the back antireflective layer and the adjacent first side is m, and the shortest distance between the orthographic projection of the reflective film on the back antireflective layer and the adjacent second side is n, and n is greater than or equal to m.

10. The photovoltaic module according to any one of claims 1 to 9, characterized in that, It also includes a plurality of busbars located at the first end, the second end, and the middle of the photovoltaic module; the first end and the second end are at opposite ends of the photovoltaic module, and the middle is located between the first end and the second end; The orthographic projection of the reflective film onto the back antireflective layer does not cover the orthographic projection of the busbar onto the back antireflective layer.

11. The photovoltaic module according to any one of claims 1 to 9, characterized in that, The reflective film includes: an adhesive layer immediately adjacent to the glass back panel; and / or, The reflective film includes an insulating layer located on the side of the reflective film furthest from the glass backplate.

12. The photovoltaic module according to claim 11, characterized in that, The thickness of the reflective film is r, 100μm≤r≤160μm; and / or, The reflective film includes: a support layer; the thickness of the support layer is t, 20μm≤t≤45μm; and / or, The thickness of the reflective layer is w, 5μm≤w≤15μm; and / or, The thickness of the adhesive layer is z, 60μm≤z≤90μm; and / or, The thickness of the insulating layer is u, where 5μm≤u≤15μm.

13. The photovoltaic module according to claim 3, characterized in that, The metal reflective layer includes an aluminum layer.

14. The photovoltaic module according to claim 3, characterized in that, The support layer includes a PET layer; the directional reflective structure layer includes a UV adhesive layer.

15. A photovoltaic system, characterized in that, include: A plurality of photovoltaic modules arranged in an array as described in any one of claims 1 to 14.

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