Photovoltaic module

Abstract

The utility model provides at least one photovoltaic assembly, which comprises a battery piece layer and a first reflective film, the battery piece layer comprises at least two battery strings, and each battery string comprises at least two battery pieces and an interconnection strip used for connecting the two adjacent battery pieces in series; the first light reflecting film is arranged at a first gap between two adjacent battery strings, the light reflecting surface of the first light reflecting layer faces the first gap, and the width of the first light reflecting film is larger than that of the first gap and smaller than the distance between two interconnecting strips located at the opposite edges of the two battery strings in the two adjacent battery strings; the first light reflecting film comprises a first light reflecting layer, a first microstructure layer and a first base material layer which are stacked in sequence; wherein the battery piece is a back contact battery.

Description

Technical Field

[0001] At least one embodiment of the present utility model relates to the field of photovoltaic technology, and particularly to a photovoltaic module. Background Art

[0002] The cells in a photovoltaic module are mostly arranged in the form of cell strings. The gaps between adjacent cell strings and cells form non-cell regions where photovoltaic conversion cannot be performed, thus limiting the light-receiving area of the photovoltaic module.

[0003] Glass is a commonly used encapsulation material in photovoltaic modules. For a photovoltaic module encapsulated with glass, a reflective film can be provided in the above non-cell region, so that part of the light irradiated on this region is reflected by the glass provided on the light-receiving surface to the cells again, thereby utilizing the light irradiated on the non-cell region.

[0004] Currently, the structures of the reflective films provided between cell strings and cells are generally the same, mainly including a light reflection layer made of a metal material and an insulating layer provided on the light reflection layer. It does not take into account the differences between the non-cell regions between cell strings and the non-cell regions between cells, resulting in poor reflective effects of the reflective films located between cell strings. Summary of the Utility Model

[0005] To solve the above and at least one other technical problem in the prior art, the present utility model provides a photovoltaic module, and provides a first reflective film for the characteristics of the first gap between cell strings, so as to have a better reflective effect.

[0006] An embodiment of the present utility model provides a photovoltaic module, including a cell layer and a first reflective film. The cell layer includes at least two cell strings, each cell string includes at least two cells and an interconnecting strip for connecting two adjacent cells in series. The cell includes a first surface and a second surface opposite to the first surface, and the interconnecting strips are all provided on the second surface of the cell; the first reflective film includes a first light reflection layer, a first microstructure layer and a first substrate layer stacked in sequence; the first reflective film is provided at the first gap between two adjacent cell strings, the reflective surface of the first light reflection layer faces the first gap, the width of the first reflective film is greater than the width of the first gap and less than the distance between two interconnecting strips located at the opposite edges of two adjacent cell strings in the two cell strings.

[0007] According to an embodiment of the present utility model, the width of the first reflective film is 5 to 8 millimeters.

[0008] According to an embodiment of the utility model, the photovoltaic module further comprises a first glass layer which is stacked on the backlight surface of the battery cell layer, and a first adhesive film layer is further arranged between the first glass layer and the battery cell.

[0009] According to an embodiment of the present invention, the thickness of the first reflective film is smaller than the thickness of the first adhesive film layer.

[0010] According to an embodiment of the present invention, the first reflective film further comprises a first adhesive layer disposed on a surface of the first substrate layer that is opposite to the first microstructure layer, and the first reflective film passes through the first adhesive layer.

[0011] According to an embodiment of the utility model, the photovoltaic module also includes a second reflective film, which is arranged at the second gap between two adjacent battery cells of the same battery string; the second reflective film includes an insulating layer, a second light reflecting layer, a second microstructure layer and a second substrate layer stacked in sequence; wherein the reflective surface of the second light reflecting layer is arranged facing the second gap.

[0012] According to an embodiment of the utility model, the second reflective film further comprises a second adhesive layer disposed on a surface of the second substrate layer opposite to the second microstructure layer, and the second reflective film is bonded to a surface of the first glass layer facing the cell through the second adhesive layer.

[0013] According to an embodiment of the present invention, the width of the second reflective film is greater than the width of the second gap.

[0014] According to an embodiment of the utility model, the first light reflecting layer includes a plurality of first light reflecting portions arranged side by side in the width direction, and the angle formed by the adjacent first light reflecting portions is 100-125°; and / or, the second light reflecting layer includes a plurality of second light reflecting portions arranged side by side in the width direction, and the angle formed by the adjacent second light reflecting portions is 100-125°. According to an embodiment of the utility model, in the orthographic projection of the first surface, the projection portions of the first reflective film and the second reflective film overlap, and in the overlapped portion, the second adhesive layer of the second reflective film is arranged on the first light reflecting layer of the first reflective film.

[0015] According to the photovoltaic module provided by the present utility model, for a photovoltaic module using back-contact cells as the cell pieces, the layer structure and width of the first reflective film located between the cell strings are designed. In this photovoltaic module, the cell pieces adjacent to the first gap are encapsulated by the glue film. And because the first gap is misaligned with the interconnection bars of the photovoltaic module, it is not easy for the interconnection bars to pierce the glue film. On this basis, the first reflective film located at the first gap does not need to consider insulation too much. Therefore, there is no need to set an insulating layer on the surface of the first light reflection layer. In this way, since the first light reflection layer is not covered by the insulating layer, it can have a better light reflection effect and also saves the materials required for setting the insulating layer. And setting the width of the first reflective film to be greater than the width of the first gap and less than the distance between the two interconnection bars on the opposite edges of the two cell strings can prevent light leakage and can compensate for the accuracy deviation during the welding of the interconnection bars to the cell pieces to prevent the occurrence of a short circuit caused by the connection of the first light reflection layer to the interconnection bars. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of a photovoltaic module according to a schematic embodiment of the present utility model;

[0017] Figure 2 is Figure 1 a cross-sectional schematic diagram of the first reflective film of the schematic embodiment shown;

[0018] Figure 3 is Figure 1 a partial cross-sectional view of the first gap part of the schematic embodiment shown;

[0019] Figure 4 is Figure 1 a cross-sectional schematic diagram of the second reflective film of the schematic embodiment shown;

[0020] Figure 5 is Figure 1 a partial cross-sectional view of the second gap part of the schematic embodiment shown.

[0021] In the said drawings, the meanings of the reference numerals are specifically as follows:

[0022] 1. Cell string;

[0023] 2. Cell piece;

[0024] 3. First reflective film;

[0025] 31. First light reflection layer;

[0026] 32. First micro-structure layer;

[0027] 33. First base material layer;

[0028] 34. First adhesive layer;

[0029] 4. Second reflective film;

[0030] 41. Insulating layer;

[0031] 42. Second light reflection layer;

[0032] 43. Second substrate layer;

[0033] 44. Second adhesive layer;

[0034] 45. Second microstructure layer;

[0035] 5. Second glass layer;

[0036] 6. Second adhesive film layer;

[0037] 7. First adhesive film layer;

[0038] 8. First glass layer. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the following further elaborates on the present utility model in detail with reference to specific embodiments and the accompanying drawings.

[0040] The terms used herein are merely for describing specific embodiments and are not intended to limit the present utility model. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0041] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0042] In cases where expressions similar to "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning commonly understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C. In cases where expressions similar to "at least one of A, B, or C, etc." are used, generally, it should be interpreted according to the meaning commonly understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0043] Glass is a commonly used encapsulation material in photovoltaic modules. Photovoltaic modules encapsulated with glass mainly include a back glass, a UV cutoff film, a cell layer, such as a transparent film and a front glass, which are stacked in sequence. Among them, the cell layer includes cell strings formed by cells arranged in a row form and cell strings arranged in a column form. Non-cell regions where no photoelectric conversion can occur are formed between adjacent cells and / or adjacent cell strings. To utilize the light irradiated on this non-cell region, a reflective film can be set to reflect a part of the light back to the light-receiving surface of the cells through the front glass again, so as to improve the photoelectric conversion efficiency of the photovoltaic module.

[0044] Currently, the reflective films arranged between cells and cell strings all include a light reflection layer made of a metal material (such as aluminum) and an insulating layer arranged on the reflective surface of the light reflection layer. To maintain the electrical isolation between the reflective film and other parts of the photovoltaic module (such as interconnection bars, main grids, and sub-grids, etc.), especially considering that the part of the interconnection bar located between cell strings is prone to form an arched deformation during the lamination process, which may pierce the insulating layer of the reflective film and cause a short-circuit situation, the insulating layer is often set relatively thick. However, it does not consider the structural differences between adjacent cells in the same cell string and adjacent cells in different cell strings.

[0045] The gap formed between adjacent cells in different cell strings is misaligned with the interconnection bar connecting the cells. Therefore, during the lamination process of the photovoltaic module, there is basically no situation where the arched deformation of the interconnection bar pierces the film layer covering the surface and side of the cells in this gap. For this reason, the requirement for the insulation performance of the reflective film arranged in this gap is relatively low, and its reflective effect should be improved accordingly. However, the insulating layer arranged on the light reflection layer reduces its reflective effect and causes waste of the material for setting the insulating layer.

[0046] Figure 1 It is a schematic diagram of a photovoltaic module according to a schematic embodiment of the present invention. Figure 2 is Figure 1 A cross-sectional schematic diagram of the first reflective film of the schematic embodiment shown. Figure 3 is Figure 1 A partial cross-sectional view of the first gap part of the schematic embodiment shown.

[0047] The photovoltaic module provided according to the present invention, as Figures 1 to 3 shown, includes a cell layer and a first reflective film 3. The cell layer includes at least two cell strings 1, each cell string 1 includes at least two cells 2 and an interconnection bar 9 for connecting two adjacent cells 2 in series. The cell 2 includes a first surface (such as Figure 1The surface in the facing perspective shown can be used as the light-receiving surface of the photovoltaic module), and the second surface opposite to the first surface (which is blocked in Figure 1 and not shown, can be used as the backlight surface of the photovoltaic module), and the interconnection bars 9 are all arranged on the second surface of the cell 2 (that is, a cell structure of the back-contact cell is formed). The first reflective film 3 includes a first light-reflection layer 31, a first microstructure layer 32, and a first substrate layer 33 that are sequentially stacked. The first reflective film 3 is arranged at the first gap between two adjacent cell strings 1, the reflective surface of the first light-reflection layer 31 faces the first gap, the width of the first reflective film 3 is greater than the width of the first gap, and less than the distance between two interconnection bars at the edges facing each other of two adjacent cell strings 1 among the two adjacent cell strings 1.

[0048] In a schematic embodiment, as Figure 3 shown, the interconnection bar 9 (which can also be called an electrical connector or a solder strip, etc.) of the photovoltaic module is configured to be connected to two adjacent cells 2 of the same cell string 3 ( Figure 3 not shown in the figure, and for details, reference can be made to the following Figure 4 ). Specifically, the interconnection bar 3 connects the positive electrode of one cell 2 to the negative electrode of another cell 2 to form a cell string 1 by connecting multiple cells 2 in series. In a preferred embodiment, the interconnection bar 3 can be welded to the joint (which can also be called a pad or a PAD point, etc.) formed by the main grid of the cell 2 through solder (such as solder) to form an effective and reliable connection and electrical connection between the cells 2.

[0049] In a schematic embodiment, as Figure 3 shown, the width of the first reflective film 3 (including the first light-reflection layer 31) (i.e., w1 as shown in Figure 3 ) is configured to be greater than the width of the first gap (i.e., d1 as shown in Figure 3 ), that is, w1 > d1. Further, the width of the first reflective film 3 (including the first light-reflection layer 31) (i.e., w1 as shown in Figure 3 ) is also configured to be less than the distance between two interconnection bars 9 that are closest to each other and located at the edges of two adjacent cells 2 among the two cell strings 1 (such as Figure 3 shown as d2). In a preferred embodiment, the width of the first reflective film 3 (i.e., w1 as shown in Figure 3 ) is preferably configured to be less than the distance between two interconnection bars 9 (such as Figure 3 shown as d2) - 0.4 mm, that is, d1 < w1 < d2 - 0.4 mm.

[0050] According to an embodiment of the present invention, as Figure 3As shown, the photovoltaic module further includes a first glass layer 8 which is stacked on the backlight surface of the battery cell layer, and a first adhesive film layer 7 is further arranged between the first glass layer 8 and the battery cell 2 .

[0051] In an illustrative embodiment, Figure 3 As shown, the photovoltaic module includes a sequence (such as Figure 3 The first glass layer 8 (such as back glass), the first adhesive film layer 7 (such as UV cut-off adhesive film, UV is ultraviolet), the battery layer (including battery cells 2 arranged in an array, and a battery string 1 formed by connecting the battery cells 2 in series), the second adhesive film layer 6 (such as a transparent adhesive film) and the second glass layer 5 (such as front glass) are stacked from bottom to top. In detail, the multiple battery cells 2 in the battery layer are arranged in a row array and / or a column array at intervals, and form at least two battery strings 1. Among them, the first adhesive film layer 7 is used to limit the position of the first reflective film 3 relative to the first gap.

[0052] In the layer structure of the photovoltaic module of the above embodiment, the first adhesive film layer 7 (such as UV cut-off adhesive film, UV is ultraviolet light) is a part independent of the first reflective film 3, and the surface of the first light reflecting layer 31 of the first reflective film 3 does not have an insulating layer.

[0053] On this basis, the function of the first adhesive film layer 7 is to absorb the UV band energy of the ultraviolet rays in the sunlight and convert it into heat energy, thereby reducing the damage to the back material (such as the back glass) caused by the ultraviolet rays penetrating the photovoltaic module, so as to extend the service life of the back material and maintain the structural strength of the photovoltaic module. Although the first adhesive film layer 7 has a certain electrical isolation effect, it cannot be regarded as or replace the insulating layer set on the reflective layer of the reflective film in the prior art.

[0054] According to the embodiments of the present utility model, Figure 3 As shown, the thickness of the first reflective film 3 is less than the thickness of the first adhesive film layer 7. In this way, the first adhesive film layer 7 has a greater thickness than the first reflective film 3 (including the first light reflecting layer 31), which is beneficial to prevent the first light reflecting layer 31 from deforming during lamination or other processes and piercing the adhesive film layer 7, resulting in a short circuit between adjacent interconnection strips 9.

[0055] In such an embodiment, based on the structural differences between the first gap between the photovoltaic modules in the battery string 1 and the second gap between the battery cells 2, the first reflective film 3 is specifically designed. The battery cells 2 adjacent to the first gap in the photovoltaic module are encapsulated by the glue film. Moreover, since the first gap is misaligned with the interconnection bars 9 of the photovoltaic module, it is not easy for the interconnection bars to pierce the glue film (i.e., the first glue film layer 7). Therefore, the first reflective film 3 located at this first gap does not need to consider insulation too much, that is, there is no need to provide an insulating layer on the surface of the first light reflection layer 31. In this way, since the first light reflection layer 31 is not covered by the insulating layer, it has a better light reflection effect and also saves the materials required for setting the insulating layer. Further, in the back-contact battery (i.e., BC battery), the power gain brought by the first reflective film 3 is positively correlated with the gap width (i.e., the larger the gap, the greater the power gain). Since the gap between the battery cells between the battery strings is larger than the gap between the battery cells within the battery string, the first reflective film 3 provided at this first gap can provide a better light reflection effect within a wider gap. Therefore, the first reflective film 3 can also improve the power gain of the back-contact battery.

[0056] Further, configuring the width of the first reflective film 3 (including the first light reflection layer 31) to be greater than the width of the first gap can make the projection of the first gap be completely covered by the projection of the first reflective film 3 in the positive projection along the thickness direction of the photovoltaic module (such as the up-down direction shown Figure 3 ), to prevent light leakage, which is beneficial to reflecting as much light passing through the first gap as possible to the light-receiving surface of the battery cell 2. And configuring the width of the first reflective film 3 to be less than the width of the adjacent two interconnection bars 2 is suitable for compensating for the accuracy deviation (currently, the accuracy of the adopted welding equipment (such as a welding machine) is approximately ±0.2 mm) during the welding of the interconnection bars 9 to the battery cell 2, to prevent the first reflective film 3 (including the first light reflection layer 31) from being connected to the interconnection bars 9.

[0057] According to an embodiment of the present invention, as shown in Figure 2 and Figure 3 shown, the first reflective film 3 includes a first adhesive layer 34, a first substrate layer 33, a first microstructure layer 32, and a first light reflection layer 31 that are stacked from bottom to top. The first reflective film 3 is adhered to the surface of the first glass layer 8 facing the battery string 1 through the first adhesive layer 34.

[0058] In a schematic embodiment, as shown in Figure 2As shown, the elastic modulus of the first substrate layer 33 is preferably configured to be greater than that of the first microstructure layer 32. Among them, the first microstructure layer 32 serves as the main support structure of the first light reflection layer 31 and is suitable for withstanding various mechanical stresses applied externally. The first substrate layer 33 with a higher elastic modulus has a stronger anti-deformation ability, which is conducive to distributing the mechanical stress received more evenly on other layer structures of the first reflective film 3; while the first microstructure layer 32 with a smaller elastic modulus is suitable for maintaining the shape of the first light reflection layer 31 (such as the shape and / or cross-sectional shape of the body structure), so that the first light reflection layer 31 can maintain an effective reflection of the incident light.

[0059] In a schematic embodiment, as Figure 2 shown, the first microstructure layer 32 includes but is not limited to being configured as a triangular prism structure (i.e., the cross-section is substantially triangular as Figure 2 shown). Specifically, the plurality of juxtaposed microstructures in the first microstructure layer 32 are configured such that the cross-section along the width direction of the first reflective film 3 (such as the left-right direction as Figure 2 shown) includes but is not limited to being configured as an isosceles triangle. Among them, the angle of the apex angle formed by this cross-section includes but is not limited to any angle in the range of 45° to 150°. It should be understood that the embodiments of the present invention are not limited thereto.

[0060] For example, the microstructure can also be configured as a triangular prism structure with rounded corners, a frustum structure, a cube structure, or any other body structure suitable for setting the first light reflection layer 31 and reflecting the incident light passing through the first gap at a certain angle.

[0061] In a schematic embodiment, as Figure 2 shown, the first substrate layer 33 is also cut to be substantially flush with the side of the first adhesive layer 34. In this way, during the manufacturing process of the first reflective film 3, the first reflective film 3 can be obtained only by cutting a large-sized film layer, which is conducive to simplifying the manufacturing process of the first reflective film 3.

[0062] In a schematic embodiment, as Figure 2 and Figure 3 shown, the first light reflection layer 31 includes but is not limited to being made of a metal material (such as aluminum). Further, the light-reflecting surface of the first light reflection layer 31 (such as the upper surface as Figure 2 shown) faces the first gap, and in the orthographic projection along the thickness direction of the photovoltaic module (such as the up-down direction as Figure 3 shown), the projection of the first gap and the first reflective film 3 coincide, so that the first reflective film 3 can effectively reflect the light passing through the first gap. It should be understood that the embodiments of the present invention are not limited thereto.

[0063] For example, the first light reflection layer 31 can also be made of a non-metallic material, specifically, at least one of titanium dioxide nanoparticles, silicon dioxide nanoparticles, barium sulfate, and aluminum oxide nanoparticles.

[0064] In such an embodiment, the first light reflection layer 31 made of a non-metallic material is beneficial to further improving the insulation of the first reflective film 3. Even if the first reflective film 3 is pierced through the first adhesive film layer 7 due to the manufacturing process of the photovoltaic module (such as lamination process) and is connected to the battery cell 2, it will not form an electrical connection with the electrodes (such as the sub-grid) on the battery cell 2. In this way, the risk of short circuit and leakage between adjacent battery strings 1 can be more effectively avoided.

[0065] According to an embodiment of the present invention, as Figure 3 shown, the width of the first reflective film 3 is 5 to 8 millimeters.

[0066] In a schematic embodiment, as Figure 3 shown, the width of the first reflective film 3 (i.e., d1) can be configured to any value between 6 millimeters and 8 millimeters. Further, the length of the first reflective film 3 (such as Figure 1 the distance between the left end and the right end of the first reflective film 3 shown) is preferably configured to be less than or equal to the length of the battery string 1 (such as Figure 1 the distance between the left edge of the battery cell 2 at the left end and the right edge of the battery cell 2 at the right end shown). It should be understood that the embodiments of the present invention are not limited thereto.

[0067] For example, currently, the distance between adjacent battery strings is generally greater than 3 millimeters. In response to different numbers of main grids (i.e., BB) configured on the battery cell 2, the width of the first reflective film 3 can also be configured to 4 millimeters, 4.5 millimeters, 5 millimeters, 5.5 millimeters, 6 millimeters, 6.5 millimeters, 7 millimeters, 7.5 millimeters, 8 millimeters, 8.5 millimeters, 9 millimeters, 9.5 millimeters, 10 millimeters, or any other width suitable for reflecting at least a part of the light passing through the first gap to the light-receiving surface of the battery cell 2.

[0068] Figure 4 is Figure 1 a cross-sectional schematic view of the second reflective film of the schematic embodiment shown.

[0069] According to an embodiment of the present invention, as Figure 1 and Figure 4 shown, the photovoltaic module further includes a second reflective film 4. The second reflective film 4 is disposed at a second gap between two adjacent battery cells 2 of the same battery string 1. The second reflective film 4 includes an insulating layer 41, a second light reflection layer 42, a second microstructure layer 45, and a second substrate layer 43 that are sequentially stacked. Among them, the light-reflecting surface of the second light reflection layer 42 faces the second gap.

[0070] According to an embodiment of the present utility model, as Figure 1 and Figure 4 shown, in the orthographic projection of the first surface, the projection parts of the first reflective film 3 and the second reflective film 4 overlap. And in the overlapping part, the second adhesive layer 44 of the second reflective film 4 is disposed on the first light reflection layer 31 of the first reflective film 3.

[0071] In a schematic embodiment, as Figure 1 shown, the battery cells 2 are arranged in a row form (sequentially arranged in the left - right direction as shown in Figure 1 shown) to form a battery string 1, and the formed battery string 1 is further arranged in a column form (sequentially arranged in the up - down direction as shown in Figure 1 shown) to form a battery cell layer. For this reason, the first reflective film 3 disposed between adjacent battery strings 1 and the second reflective film 4 disposed between adjacent battery cells 2 will form an overlapping part, so that light leakage caused by the formation of pores between the first reflective film 3 and / or the second reflective film 4 and the battery cells 2 can be prevented.

[0072] On this basis, since the second reflective film 4 has an insulating layer 41, for this reason, the second reflective film 4 can be disposed on the first reflective film 3 in its overlapping part, that is, the second adhesive layer 44 is bonded to the first light reflection layer 31. That is to say, when the first reflective film 3 and the second reflective film 4 are arranged, the first reflective film 3 can be first bonded to the first glass layer 8 (i.e., the back glass), and then the second reflective film 4 is bonded to the first glass layer 8 (i.e., the back glass).

[0073] In such an embodiment, a part of the second reflective film 4 is located on the first reflective film 3. Since the second reflective film 4 has an insulating layer 41, for this reason, it is beneficial to improve the insulation effect of the first reflective film 3. In addition, since a part of the second reflective film 4 is adhesively bonded to the first reflective film 3, for this reason, it also has the effect of restricting the offset of the first reflective film 3, which is beneficial to preventing the position offset of the first reflective film 3 relative to the first glass layer 8 when the first adhesive film layer 7 is formed.

[0074] Figure 5 is Figure 1 a partial cross - sectional view of the second gap part of the schematic embodiment shown.

[0075] According to an embodiment of the present utility model, as Figure 4 and Figure 5 shown, the second reflective film 4 further includes a second adhesive layer 44, which is disposed on the surface of the second base layer 43 facing away from the second micro - structure layer 45. The second reflective film 4 is adhesively bonded to the surface of the first glass layer 8 facing the battery cells 2 through the second adhesive layer 44.

[0076] In a schematic embodiment, as Figure 4 and Figure 5As shown, the second reflective film 4 includes a second adhesive layer 44, a second substrate layer 43, a second microstructure layer 45, a second light reflecting layer 42 and an insulating layer 41 stacked from bottom to top. The second reflective film 4 is bonded to the surface of the second glass layer 8 facing the battery string 1 through the second adhesive layer 44.

[0077] In such an embodiment, based on the characteristics of adjacent cells 2 arranged in the same cell string 1, that is, adjacent cells 2 in the same cell string 1 are connected by interconnection bars 2, and the interconnection bars 2 respond to the lamination process in the photovoltaic module manufacturing process, it is easy to form Figure 5 In response to this feature, the second reflective film 4, in addition to the second adhesive layer 44, the second substrate layer 43, the second microstructure layer 45 and the second light reflecting layer 42, needs to be provided with a corresponding insulating layer 41 on the second light reflecting layer 42, so as to prevent the short circuit caused by the arched deformation part formed by the interconnection strip 9 during the lamination process of the photovoltaic module and / or the second light reflecting layer 42 of the second reflective film 4 piercing the first adhesive film layer 7.

[0078] In view of this, in the embodiment of the utility model, by arranging different layer structures for the first reflective film 3 arranged between the battery cells 2 of different battery strings 1 and the second reflective film 4 arranged between the battery cells 2 of the same battery string 1, the first reflective film 3 located between different battery strings 1 can have a better reflective effect to enhance the power gain of the first reflective film 3 to the photovoltaic module; and the second reflective film 4 located between the same battery string 1 can have a better insulation effect to reduce the occurrence of short circuit and leakage between the battery cells.

[0079] In an illustrative embodiment, Figure 4 As shown, the elastic modulus of the second substrate layer 43 is preferably configured to be greater than the elastic modulus of the second microstructure layer 45. Further, the second microstructure layer 45 includes but is not limited to being configured as a triangular prism structure (i.e., as shown in FIG. Figure 4 The cross section shown is roughly triangular. In detail, the plurality of parallel microstructures in the second microstructure layer 45 are arranged along the width direction of the second reflective film 4 (eg Figure 4 The cross section of the device (in the left and right directions shown) includes but is not limited to being configured as an isosceles triangle. The vertex angle formed by the cross section includes but is not limited to any angle between 45° and 150°. It should be understood that the embodiments of the present utility model are not limited thereto.

[0080] For example, the microstructure may also be configured as a triangular prism structure with rounded corners, a terrace structure, a cubic structure, or other arbitrary structures suitable for setting the second light reflecting layer 42 and making the incident light passing through the second gap reflect at a certain angle.

[0081] In an illustrative embodiment,Figure 4 As shown, the second substrate layer 43 is also substantially flush with the side cut of the second adhesive layer 44.

[0082] In a schematic embodiment, as Figure 4 and Figure 5 shown, the second light reflection layer 42 includes, but is not limited to, being made of a metal material (such as aluminum). Further, the light-reflecting surface of the second light reflection layer 42 (such as Figure 2 the upper surface shown) faces the first gap, and in the orthographic projection along the thickness direction of the photovoltaic module (such as Figure 3 the up-down direction shown), the projection of the first gap and the second light-reflecting film 4 coincide, so that the second light-reflecting film 4 can effectively reflect the light passing through the first gap. It should be understood that the embodiments of the present invention are not limited thereto.

[0083] For example, the second light reflection layer 42 can also be made of a non-metal material, specifically, at least one of titanium dioxide nanometer, silicon dioxide nanometer, barium sulfate, and aluminum oxide nanometer.

[0084] Based on the above structural arrangement, the second light-reflecting film 4 has a similar structure and / or layer structure and / or shape design to the foregoing first light-reflecting film 3, and also has similar technical effects, which will not be elaborated here.

[0085] According to the embodiments of the present invention, as Figure 2 and Figure 4 shown, the first light reflection layer 31 includes a plurality of first light reflection portions arranged side by side in the width direction, and the lower angle formed by adjacent first light reflection portions is 100° - 125°. And / or, the second light reflection layer 42 includes a plurality of second light reflection portions arranged side by side in the width direction, and the lower angle formed by adjacent second light reflection portions is 100° - 125°.

[0086] Referring to the foregoing embodiment as Figure 2 shown, the microstructures with a substantially isosceles triangle cross-section provided on the first microstructure layer 32 have been described. The first light reflection layer 31 is formed on the first microstructures arranged periodically in the width direction (such as Figure 2 the left-right direction shown), thereby forming a plurality of side-by-side first light reflection portions.

[0087] Continuing to refer to Figure 2 shown, the first light reflection portion can be regarded as either the peak structure formed by the first light reflection layer 31 adapting to the shape of the microstructure or the valley structure formed between adjacent peak structures. Based on Figure 2 the embodiment shown, the angles between adjacent peak structures and valley structures are all the same, that is, 100° ≤ α1 ≤ 125°. In a preferred embodiment, α1 can be configured as 120°.

[0088] Similarly, referring to Figure 4 shown in Figure 4 , the second light reflection layer 42 can also adopt a design similar to that of the first light reflection layer 31, that is, 100° ≤ α2 ≤ 125°. In a preferred embodiment, α2 can be configured to 120°.

[0089] In some embodiments, α1 can be configured to be the same as α2 (i.e., α1 = α2); in other embodiments, α1 can be configured to be different from α2 (i.e., α1 ≠ α2), and specifically, it should be appropriate to meet the required light reflection requirements.

[0090] According to the embodiments of the present invention, as Figure 5 shown in Figure 5 , the width of the second reflective film 4 is greater than the width of the second gap.

[0091] In a schematic embodiment, as Figure 5 shown in Figure 5 , the width of the second reflective film 4 (including the second light reflection layer 42) (i.e., as Figure 5 shown in Figure 5 as w2) is configured to be greater than the width of the second gap (i.e., as Figure 5 shown in Figure 5 as d3), that is, w2 > d3. In this way, in the orthographic projection along the thickness direction of the photovoltaic module (such as the up and down direction shown in Figure 5 ), the projection of the second gap can be completely covered by the projection of the second reflective film 4, so as to prevent light leakage, which is beneficial to reflect as much light passing through the second gap as possible to the light-receiving surface of the battery cell 2.

[0092] In a schematic embodiment, as Figure 5 shown in Figure 5 , the width of the second reflective film 4 is 3 to 6 millimeters.

[0093] In a schematic embodiment, as Figure 5 shown in Figure 5 , the width of the second reflective film 4 (i.e., d1) can be configured to any value between 3 millimeters and 6 millimeters. In a preferred embodiment, the width of the second reflective film 4 can be configured to any value between 4 millimeters and 5 millimeters. Further, the length of the second reflective film 4 (such as the distance between the upper end and the lower end of the second reflective film 4 shown in Figure 1 ) includes but is not limited to being configured to be approximately the same as the length of the first side of the battery cell 2 (such as the long side shown in Figure 1 ), or slightly shorter than the length of the first side. It should be understood that the embodiments of the present invention are not limited thereto.

[0094] ​​​​​​For example, currently, the spacing between adjacent solar cells in the same string of solar cells is generally greater than 1 mm. In response to the spacing between the solar cells 2, the width of the second reflective film 4 can also be configured to be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, or any other width suitable for being disposed at the second gap.

[0095] In a schematic embodiment, the materials and manufacturing processes used for the respective layer structures of the first reflective film 3 and the second reflective film 4 are similar.

[0096] For example, the first adhesive layer 34 and the second adhesive layer 44 include, but are not limited to, any one of EVA, POE, LDPE (low-density polyethylene), and other gum-like materials suitable for being adhered to the first glass layer 8 (i.e., the back glass).

[0097] For another example, the first substrate layer 34 and the second substrate layer 43 include, but are not limited to, any one of PI, PEEK, PBI, and PPS.

[0098] Still for another example, the first microstructure layer 32 and the second microstructure layer 45 include, but are not limited to, any one of UV-cured acrylic, epoxy acrylic, phenolic epoxy resin, etc.

[0099] For yet another example, the first light reflection layer 31 and the second light reflection layer 42 are formed on the microstructure layer (i.e., the first microstructure layer 32 or the second microstructure layer 45) by, but not limited to, vacuum coating or chemical vapor deposition (i.e., Chemical Vapor Deposition, CVD).

[0100] It should be noted here that any materials and processes in the art capable of preparing the respective layer structures of the first reflective film 3 and the second reflective film 4 can be selected and applied, and will not be specifically elaborated.

[0101] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only for reference to the drawings and are not used to limit the protection scope of the present invention. Throughout the drawings, the same elements are denoted by the same or similar reference numerals. When it may cause confusion in the understanding of the present invention, the conventional structures or configurations will be omitted.

[0102] The embodiments of the present utility model have been described above. However, these embodiments are merely for illustrative purposes and not for limiting the scope of the present utility model. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present utility model is defined by the appended claims and their equivalents. Without departing from the scope of the present utility model, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present utility model.

Claims

1. A photovoltaic module, characterized in that: The invention comprises a battery cell layer and a first reflective film (3), wherein the battery cell layer comprises at least two battery strings (1), each of the battery strings (1) comprises at least two battery cells (2) and an interconnection bar (9) for connecting two adjacent battery cells (2) in series, the battery cell (2) comprises a first surface and a second surface opposite to the first surface, and the interconnection bars (9) are all arranged on the second surface of the battery cell (2); The first reflective film (3) comprises a first light reflecting layer (31), a first microstructure layer (32) and a first substrate layer (33) which are stacked in sequence; The first reflective film (3) is arranged at a first gap between two adjacent battery strings (1); the reflective surface of the first light reflecting layer (31) is arranged facing the first gap; the width of the first reflective film (3) is greater than the width of the first gap and less than the distance between two interconnecting strips (9) located at the edges of the two battery strings (1) facing each other in the two adjacent battery strings (1).

2. The photovoltaic module according to claim 1, characterized in that: The width of the first reflective film (3) is 5 to 8 millimeters.

3. The photovoltaic module according to claim 1, characterized in that: It also comprises a first glass layer (8) which is stacked on the backlight surface of the battery cell layer, and a first adhesive film layer (7) is arranged between the first glass layer (8) and the battery cell (2).

4. The photovoltaic module according to claim 3, characterized in that: The thickness of the first reflective film (3) is smaller than the thickness of the first adhesive film layer (7).

5. The photovoltaic module according to claim 3, characterized in that: The first reflective film (3) further comprises a first adhesive layer (34) disposed on a surface of the first substrate layer (33) that is opposite to the first microstructure layer (32); the first reflective film (3) is bonded to a surface of the first glass layer (8) that faces the battery string (1) via the first adhesive layer (34).

6. The photovoltaic module according to any one of claims 3 to 5, characterized in that: It also comprises a second reflective film (4), wherein the second reflective film (4) is arranged at a second gap between two adjacent battery sheets (2) of the same battery string (1); The second reflective film (4) comprises an insulating layer (41), a second light reflecting layer (42), a second microstructure layer (45) and a second substrate layer (43) which are stacked in sequence; Wherein, the second light reflecting layer (42) is arranged facing the second gap.

7. The photovoltaic module according to claim 6, characterized in that: The second reflective film (4) further comprises a second adhesive layer (44) disposed on a surface of the second substrate layer (43) that is opposite to the second microstructure layer (45); the second reflective film (4) is bonded to a surface of the first glass layer (8) that faces the cell sheet (2) via the second adhesive layer (44).

8. The photovoltaic module according to claim 6, characterized in that: The width of the second reflective film (4) is greater than the width of the second gap.

9. The photovoltaic module according to claim 6, characterized in that: The first light reflecting layer (31) comprises a plurality of first light reflecting portions arranged side by side along the width direction, and the angle formed by adjacent first light reflecting portions is 100-125°; And / or, the second light reflecting layer (42) comprises a plurality of second light reflecting portions arranged side by side along the width direction, and the angle formed by adjacent second light reflecting portions is 100-125°.

10. The photovoltaic module according to claim 7, characterized in that: In the orthographic projection of the first surface, the projections of the first reflective film (3) and the second reflective film (4) partially overlap, and in the overlapping portion, the second adhesive layer (44) of the second reflective film (4) is arranged on the first light reflecting layer (31) of the first reflective film (3).

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