Photovoltaic laminated piece, photovoltaic laminated piece preparation method and photovoltaic module

Abstract

The invention discloses a photovoltaic laminated piece, a preparation method of the photovoltaic laminated piece and a photovoltaic module, which are applied to the photovoltaic field, in the photovoltaic laminated piece, a front adhesive film and a front cover plate are pre-compounded, and a back adhesive film and a back plate are pre-compounded; the front adhesive film comprises a front low-gram-weight adhesive film part and a front strip film part which is positioned on the surface of the front low-gram-weight adhesive film part and corresponds to a preset position; and / or, the back adhesive film comprises a back low-gram-weight adhesive film part and a back strip film part which is located on the surface of the back low-gram-weight adhesive film part and corresponds to a preset position, and the preset position is arranged at the peripheral edge of the photovoltaic laminated piece, and / or between the battery pieces, and / or between the battery strings, and / or at the corresponding bus bar. The front adhesive film and / or the back adhesive film are / is composed of the strip film and the low-gram-weight adhesive film, the thicknesses of the adhesive films at different positions are set in a differentiated mode, on one hand, bubbles generated due to adhesive shortage in the assembly can be reduced, on the other hand, short circuit of the welding strip and the bus bar can be avoided, and the yield of the assembly is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaics, in particular to a photovoltaic laminate, a photovoltaic laminate preparation method and a photovoltaic module. BACKGROUND

[0002] With the development of photovoltaic technology, there is a higher demand for reducing the grammage of the adhesive film in the photovoltaic module to reduce the preparation cost of the photovoltaic module. However, when the adhesive film in the cell photovoltaic module is thinned to a certain extent, bubbles will be generated due to lack of adhesive between the cell strings and / or between the cell pieces, resulting in defects in the module due to the thinning of the adhesive film. In addition, due to the thickness of the adhesive film not meeting the requirements, short circuit of the welding strip or busbar in the photovoltaic module occurs, resulting in damage to the module.

[0003] Therefore, how to provide a thin film by setting the original adhesive film in the photovoltaic module, reduce the thickness of the adhesive film in the photovoltaic module, and at the same time avoid further defects in the photovoltaic module, is a technical problem that technicians in the field need to solve. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a photovoltaic laminate, a photovoltaic laminate preparation method and a photovoltaic module, which solve the problem that in the prior art, when the adhesive film in the cell photovoltaic module is thinned to a certain extent, bubbles will be generated due to lack of adhesive between the cell strings and / or between the cell pieces, and due to the thickness of the adhesive film not meeting the requirements, short circuit of the welding strip or busbar in the photovoltaic module occurs, resulting in damage to the module.

[0005] To solve the above technical problems, the present application provides a photovoltaic laminate, comprising:

[0006] a front cover, a front adhesive film, a photovoltaic cell, a back adhesive film and a back plate arranged in layers;

[0007] The front adhesive film is pre-combined with the front cover, and the back adhesive film is pre-combined with the back plate;

[0008] The front adhesive film comprises a front low-grammage adhesive film part, and a front strip film part arranged on the surface of the front low-grammage adhesive film part, corresponding to the four peripheral edges of the photovoltaic laminate, and / or between the cell pieces in the photovoltaic laminate, and / or between the cell strings in the photovoltaic laminate, and / or at the front busbar in the photovoltaic laminate; and / or, the back adhesive film comprises a back low-grammage adhesive film part, and a back strip film part arranged on the surface of the back low-grammage adhesive film part, corresponding to the four peripheral edges of the photovoltaic laminate, and / or between the cell pieces in the photovoltaic laminate, and / or between the cell strings in the photovoltaic laminate, and / or at the back busbar in the photovoltaic laminate.

[0009] Optionally, the front strip film part is located between the front low-grammage film part and the front cover plate.

[0010] Optionally, the back strip film part is located between the back low-grammage film part and the back plate.

[0011] Optionally, a textured pattern is formed on the side surface of the front low-grammage film part facing away from the front cover plate.

[0012] Optionally, a textured pattern is formed on the side surface of the back low-grammage film part facing away from the back plate.

[0013] Optionally, a front overlap part in the front strip film part is formed at a position corresponding to the bus bar lead-out hole; the front overlap part is an overlap part formed by multiple sub-strip film parts in the front strip film part converging at the same position.

[0014] Optionally, a back overlap part in the back strip film part is formed at a position corresponding to the bus bar lead-out hole; the back overlap part is an overlap part formed by multiple sub-strip film parts in the back strip film part converging at the same position.

[0015] Optionally, the back strip film part is a white strip film.

[0016] The white strip film comprises an adhesive layer facing the back plate and a reflective layer facing away from the back plate.

[0017] Optionally, the width of the front strip film part and / or the back strip film part is 5-20 mm.

[0018] Optionally, the photovoltaic cell is a back-contact photovoltaic cell.

[0019] The front cover plate is a front glass, and the back plate is a back glass.

[0020] The front film is pre-combined with the front glass, and the front film comprises the front low-grammage film part and the front strip film part.

[0021] The back film is pre-combined with the back glass, and the back film comprises a back low-grammage film part and a white strip film.

[0022] The application also provides a photovoltaic laminate preparation method, comprising:

[0023] Laying a front film on the surface of a front cover plate, and pre-combining the front cover plate and the front film;

[0024] Laying a back film on the surface of a back plate, and pre-combining the back plate and the back film;

[0025] Laying a solder strip and a photovoltaic cell on a side of the front adhesive film away from the front cover plate, laying the back adhesive film pre-composited with the back plate on a side of the photovoltaic cell away from the front cover plate, to obtain a photovoltaic laminate;

[0026] The front adhesive film comprises a front low-grammage adhesive film part, and a front strip film part arranged on a surface of the front low-grammage adhesive film part and corresponding to a periphery of the photovoltaic laminate, and / or a space between cell pieces in the photovoltaic laminate, and / or a space between cell strings in the photovoltaic laminate, and / or a front busbar in the photovoltaic laminate; and / or, the back adhesive film comprises a back low-grammage adhesive film part, and a back strip film part arranged on a surface of the back low-grammage adhesive film part and corresponding to a periphery of the photovoltaic laminate, and / or a space between cell pieces in the photovoltaic laminate, and / or a space between cell strings in the photovoltaic laminate, and / or a back busbar in the photovoltaic laminate.

[0027] Optionally, the laying the front adhesive film on the surface of the front cover plate and pre-compositing the front cover plate and the front adhesive film comprise:

[0028] laying the front strip film part and the front low-grammage adhesive film part on the surface of the front cover plate in sequence, and pre-compositing the front cover plate, the front strip film part and the front low-grammage adhesive film part;

[0029] The laying the back adhesive film on the surface of the back plate and pre-compositing the back plate and the back adhesive film comprise:

[0030] laying the back strip film part and the back low-grammage adhesive film part on the surface of the back plate in sequence, and pre-compositing the back plate, the back strip film part and the back low-grammage adhesive film part.

[0031] The application further provides a photovoltaic module, comprising:

[0032] The photovoltaic laminate as described above after the lamination process.

[0033] It can be seen that the photovoltaic laminated piece provided by the application comprises a front cover plate, a front adhesive film, a photovoltaic cell, a back adhesive film and a back plate which are laminated, the front adhesive film is pre-combined with the front cover plate, the back adhesive film is pre-combined with the back plate, the front adhesive film comprises a front low-grammage adhesive film part and a front strip film part arranged on the surface of the front low-grammage adhesive film part and corresponding to the four peripheral edges of the photovoltaic laminated piece, and / or the intercell gaps in the photovoltaic laminated piece, and / or the inter-string gaps in the photovoltaic laminated piece, and / or the front bus bars in the photovoltaic laminated piece; and / or the back adhesive film comprises a back low-grammage adhesive film part and a back strip film part arranged on the surface of the back low-grammage adhesive film part and corresponding to the four peripheral edges of the photovoltaic laminated piece, and / or the intercell gaps in the photovoltaic laminated piece, and / or the inter-string gaps in the photovoltaic laminated piece, and / or the back bus bars in the photovoltaic laminated piece. The front adhesive film and / or the back adhesive film are composed of a strip film and a low-grammage adhesive film, and the strip film is arranged corresponding to the four peripheral edges of the photovoltaic laminated piece, and / or the intercell gaps in the photovoltaic laminated piece, and / or the inter-string gaps in the photovoltaic laminated piece, and / or the front bus bars in the photovoltaic laminated piece, and the thickness of the adhesive film at different positions is thickened correspondingly, which can reduce the bubbles caused by the lack of adhesive in the assembly, and on the other hand, the thickened adhesive film corresponding to the solder strip and the bus bar can avoid the short circuit of the solder strip and the bus bar, thereby improving the yield of the assembly.

[0034] In addition, the application also provides a photovoltaic laminated piece preparation method and a photovoltaic assembly, which also have the above beneficial effects. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute the embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0036] Figure 1 A structural schematic diagram of a photovoltaic laminated piece provided by an embodiment of the application;

[0037] Figure 2 A structural schematic diagram of a front cover plate in a photovoltaic laminated piece provided by an embodiment of the application;

[0038] Figure 3 A structural schematic diagram of a front cover plate provided by an embodiment of the application, on which a front strip film part is laid;

[0039] Figure 4 A structural schematic diagram of a front cover plate provided by an embodiment of the application, on which a front strip film part and a front low-grammage adhesive film part are laid;

[0040] Figure 5 An example diagram of a strip film part corresponding to the inter-string laying strip film part of a cell string in a photovoltaic cell is provided for an embodiment of the present application.

[0041] Figure 6 An example diagram of a strip film part corresponding to the inter-cell laying strip film part of a cell in a photovoltaic cell is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0043] Embodiment 1:

[0044] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a photovoltaic laminate is provided for an embodiment of the present application. The photovoltaic laminate can include:

[0045] A front cover, a front adhesive film, a photovoltaic cell, a back adhesive film and a back plate are laminated.

[0046] The front adhesive film is pre-combined with the front cover, and the back adhesive film is pre-combined with the back plate.

[0047] The front adhesive film includes a front low-grammage adhesive film part, and a front strip film part located on the surface of the front low-grammage adhesive film part, corresponding to the four peripheral edges of the photovoltaic laminate, and / or the inter-cell of the photovoltaic laminate, and / or the inter-string of the photovoltaic laminate, and / or the front bus bar of the photovoltaic laminate; and / or, the back adhesive film includes a back low-grammage adhesive film part, and a back strip film part located on the surface of the back low-grammage adhesive film part, corresponding to the four peripheral edges of the photovoltaic laminate, and / or the inter-cell of the photovoltaic laminate, and / or the inter-string of the photovoltaic laminate, and / or the back bus bar of the photovoltaic laminate.

[0048] It needs to be explained that in a general photovoltaic module, the front cover, the front adhesive film, the photovoltaic cell, the back adhesive film and the back plate are arranged in the laminated module. In this embodiment, by pre-combining the front adhesive film with the front cover and pre-combining the back adhesive film with the back plate, the offset of the adhesive film during lamination can be avoided, and the yield of the module can be improved. It needs to be further explained that in this embodiment, the front adhesive film and / or the back adhesive film can be set as the improved adhesive film structure in this application, that is, in this embodiment, only one of the front adhesive film and the back adhesive film is improved as the improved adhesive film, which can improve the above-mentioned defects existing in the photovoltaic stack, or in this embodiment, the front adhesive film can be improved first, that is, the front adhesive film comprises a front low weight adhesive film part and a front strip film part, which is arranged corresponding to the four peripheral edges of the photovoltaic stack, and / or the inter-cell of the photovoltaic stack, and / or the inter-string of the photovoltaic stack, and / or the front bus bar of the photovoltaic stack. At this time, the front strip film part can be arranged corresponding to any one of the four peripheral edges of the photovoltaic stack, the inter-cell of the photovoltaic stack, the inter-string of the photovoltaic stack and the front bus bar of the photovoltaic stack, but in order to ensure the effect of arranging the front strip film part, the front strip film part can be preferably arranged corresponding to the four peripheral edges of the photovoltaic stack, the inter-cell of the photovoltaic stack, the inter-string of the photovoltaic stack and the front bus bar of the photovoltaic stack. Further, in this embodiment, the back adhesive film can be preferably arranged corresponding to the back low weight adhesive film part and the back strip film part, and the back strip film part can be preferably arranged corresponding to the four peripheral edges of the photovoltaic stack, the inter-cell of the photovoltaic stack, the inter-string of the photovoltaic stack and the back bus bar of the photovoltaic stack.

[0049] The specific structure of the front adhesive film is not limited in this embodiment, as long as the front low weight adhesive film part and the front strip film part can be stably connected. In this embodiment, the front low weight adhesive film part and the front strip film part can be integrally formed, or the front low weight adhesive film part and the front strip film part can be independently prepared and connected by pre-combining the front adhesive film with the front cover. Correspondingly, the back low weight adhesive film part and the back strip film part included in the back adhesive film in this embodiment can be fixed according to the above-mentioned front low weight adhesive film part and the front strip film part.

[0050] In the embodiment, the front side tape film part, the front side low weight adhesive film part and the front side cover plate can be pre-combined by low temperature laminating treatment, and the back side tape film part, the back side low weight adhesive film part and the back plate can be pre-combined. In the embodiment, the pre-combination can also be achieved by hot plate hot pressing, hot roller and other methods. In the process of manufacturing the cell string, the white film can be used to improve the optical utilization rate between the cells and to shield the solder strip to improve the appearance of the laminated assembly. Specifically, in the embodiment, when the tape film part is pre-combined by low temperature laminating treatment using a laminating machine, the time for vacuumizing is as short as possible to prevent the tape film part from being deviated due to vacuumizing. The tape film part is pre-combined by using the laminating machine, and only the bottom plate heating and silicone plate pressing functions are used. In the embodiment, the white film can be provided on the surface of the back plate corresponding to the positions of the four peripheral edges, the positions of the bus bars and the positions between the cell strings as the back side tape film part. At this time, the width of the white film can be adjusted to improve the optical gain on the front side of the photovoltaic module and reduce the optical shielding on the back side. In a feasible embodiment, to avoid the tape film part from shielding the photovoltaic cell, the width of the tape film part corresponding to the positions between the cell pieces in the photovoltaic stack and the width of the tape film part corresponding to the positions between the cell strings in the photovoltaic stack can be less than the width of the tape film part at other positions.

[0051] Further, to slow down the raised step formed in the adhesive film due to the laid tape film part and to avoid the tape film from being deviated during the laminating process, the accuracy of the tape film filling the gap is reduced, the above-mentioned front side tape film part can be arranged between the front side low weight adhesive film part and the front side cover plate.

[0052] And / or, the back side tape film part is arranged between the back side low weight adhesive film part and the back plate.

[0053] It should be noted that in the embodiment, the above-mentioned front side tape film part can be arranged between the front side low weight adhesive film part and the front side cover plate, and the back side tape film part can be arranged between the back side low weight adhesive film part and the back plate. The low weight adhesive film part can be arranged on the tape film part to pre-fix the tape film part. In addition, by arranging the low weight adhesive film part on the tape film part, the raised step in the adhesive film due to the laid tape film part can be slowed down, and the local extrusion of the photovoltaic cell can be avoided to cause the cell piece to be broken. In the embodiment, after the pre-combination treatment, the adhesive film at the step formed due to the laid tape film part is extruded outward, so that the L-shaped corner of the raised part is changed to a more gentle transition, and the local extrusion of the adhesive film can be avoided to cause the cell piece to be broken.

[0054] Further, to improve the fixing effect of the adhesive film on the cell piece and to avoid the cell piece from being deviated, the above-mentioned front side low weight adhesive film part can be provided with a texture pattern on the side surface away from the front side cover plate.

[0055] And / or, the back side low weight adhesive film part can be provided with a texture pattern on the side surface away from the back plate.

[0056] It needs to be explained. In this embodiment, the low grammage adhesive film part is arranged close to the surface of the photovoltaic cell, and a texture pattern is formed on the surface of the low grammage adhesive film part. The friction between the surface of the low grammage adhesive film part and the photovoltaic cell can be improved, and the fixing and packaging effect of the low grammage adhesive film on the photovoltaic cell can be improved. In this embodiment, the surface of the low grammage adhesive film close to the photovoltaic cell is provided with a texture pattern, which can be in the shape of a grid or other protrusions. The texture pattern can limit the battery string and the battery sheet, and reduce the lamination deviation.

[0057] The photovoltaic laminate provided by the embodiment of the present application comprises a front cover plate, a front adhesive film, a photovoltaic cell, a back adhesive film and a back plate arranged in layers. The front adhesive film is pre-combined with the front cover plate, and the back adhesive film is pre-combined with the back plate. The front adhesive film comprises a front low-grammage adhesive film part and a front strip film part arranged on the surface of the front low-grammage adhesive film part and corresponding to the four peripheral edges of the photovoltaic laminate, and / or the inter-sheet gaps in the photovoltaic laminate, and / or the inter-string gaps in the photovoltaic laminate, and / or the front bus bars in the photovoltaic laminate. Alternatively, the back adhesive film comprises a back low-grammage adhesive film part and a back strip film part arranged on the surface of the back low-grammage adhesive film part and corresponding to the four peripheral edges of the photovoltaic laminate, and / or the inter-sheet gaps in the photovoltaic laminate, and / or the inter-string gaps in the photovoltaic laminate, and / or the back bus bars in the photovoltaic laminate. The front adhesive film and / or the back adhesive film is composed of a strip film and a low-grammage adhesive film, and the strip film corresponds to the four peripheral edges of the photovoltaic laminate, and / or the inter-sheet gaps in the photovoltaic laminate, and / or the inter-string gaps in the photovoltaic laminate, and / or the front bus bars in the photovoltaic laminate. The thickness of the adhesive film at different positions is thickened correspondingly. On the one hand, the bubbles caused by lack of adhesive in the assembly can be reduced. On the other hand, the thickened adhesive film at the solder strip and the bus bar can avoid short circuit of the solder strip and the bus bar, and improve the yield of the assembly.

[0058] In addition, the front strip film part is arranged between the front low-grammage adhesive film part and the front cover plate, and / or the back strip film part is arranged between the back low-grammage adhesive film part and the back plate, which can slow down the protruding step formed by the strip film part in the adhesive film, and avoid deviation of the strip film during lamination. The surface of the front low-grammage adhesive film part away from the front cover plate is provided with a texture pattern, and / or the surface of the back low-grammage adhesive film part away from the back plate is provided with a texture pattern, which can improve the fixing effect of the adhesive film on the battery sheet and avoid deviation of the battery sheet.

[0059] Embodiment 2:

[0060] Please refer to Figure 3 , Figure 3 The structure diagram of the front cover plate on which the front strip film part is arranged in a photovoltaic laminate provided by the embodiment of the present application. Compared with the above-mentioned embodiment 1, the difference is that:

[0061] The front face overlapping portion in the front face strip film portion is formed at a position corresponding to the bus bar lead-out hole; the front face overlapping portion is an overlapping portion formed by the plurality of sub strip film portions intersecting at the same position in the front face strip film portion;

[0062] And / or, the back face overlapping portion in the back face strip film portion is formed at a position corresponding to the bus bar lead-out hole; the back face overlapping portion is an overlapping portion formed by the plurality of sub strip film portions intersecting at the same position in the back face strip film portion.

[0063] It should be noted that, in order to facilitate the laying of the strip film portion and reduce the complexity of cutting and preparing the strip film portion, the strip film portion corresponding to the laying of the photovoltaic laminate can be overlapped at the intersection, that is, the strip film portion includes a plurality of independently prepared sub strip film portions, and the plurality of sub strip film portions intersect at the same position to form an overlapping portion, the height of the overlapping portion protrudes from other positions in the adhesive film, in order to avoid the occurrence of cell fragments in the photovoltaic cell during lamination, the overlapping portion can be arranged at a position corresponding to the bus bar lead-out hole, which can alleviate the problem of cell fragment caused by the local extrusion of the overlapping portion to the photovoltaic cell.

[0064] Further, in order to improve the photoelectric conversion efficiency of the photovoltaic module, the back face strip film portion can be a white strip film;

[0065] The white strip film includes an adhesive layer facing the back plate and a reflective layer facing away from the back plate.

[0066] It needs to be explained that in the embodiment, the white strip film is arranged on the back surface to reflect the light from the gap between the battery pieces and / or the gap between the battery strings and / or the gap at the four edges of the photovoltaic cell to the surface of the battery piece, thereby improving the light utilization rate. In the embodiment, the white strip film can be an EVA film. In the embodiment, the back surface film can only include the white strip film, and the white strip film can be pre-combined with the back plate. It needs to be further explained that in the embodiment, the white strip film is arranged on the back surface, and the width of the white strip film between the battery strings in the photovoltaic stack can be 3-10 mm, the width of the white strip film corresponding to the long edge of the four edges of the rectangular photovoltaic cell can be 10-25 mm, the width of the white strip film corresponding to the short edge of the four edges of the rectangular photovoltaic cell can be 15-35 mm, and the width of the white strip film corresponding to the bus bar can be 8-15 mm. The specific width of the strip film is selected based on the fact that the module does not leak light and does not block the light receiving surface of the back surface battery string. In addition, in the embodiment, the battery string can be arranged in a whole string during the string manufacturing process, and the inter-piece white film is pasted between the battery pieces and the head and tail of the battery string, and the welding band is placed to complete the battery string manufacturing process through high-temperature welding or low-temperature film coating. The inter-piece white film has a double-layer structure, one layer close to the battery piece is a transparent EVA layer with adhesion after heating, and the other layer away from the battery piece is a white EVA with high reflectivity. The battery piece is placed on a bottom plate at 90-140°C, and the inter-piece white film cut in advance is placed between the battery pieces of the battery string by the suction cup, and the inter-piece white film is adhered to the battery piece by heating the bottom plate. Further, in the embodiment, the width of the white strip film at the edge can be greater than the width of the white strip film between the strings or between the pieces to balance the light blocking rate and the reflection efficiency.

[0067] Further, in order to ensure that the strip film part fills the gap in the photovoltaic stack, the width of the front strip film part and / or the back strip film part can be 5-20 mm.

[0068] In the embodiment, by setting the width of the strip film part to 5-20 mm, the strip film part can fill the gap and avoid bubbles while avoiding blocking the light receiving of the photovoltaic cell, thereby ensuring the photoelectric conversion efficiency of the photovoltaic stack.

[0069] Further, in order to improve the adaptability of the photovoltaic stack, the photovoltaic cell can be a back contact photovoltaic cell.

[0070] The front cover plate is a front glass, and the back plate is a back glass.

[0071] The front film is pre-combined with the front glass, and the front film includes a front low-gram film part and a front strip film part.

[0072] The back adhesive film is pre-combined with the back glass, and the back adhesive film includes a back low-grammage adhesive film part and a white strip film.

[0073] It should be noted that, in the embodiment, the battery is set as a back contact double-glass battery, the front adhesive film is set as including a front low-grammage adhesive film part and a front strip film part, and the back adhesive film is set as including a back low-grammage adhesive film part and a white strip film, so as to solve the problem of bubbles after lamination due to the thinning of the front adhesive film without a solder strip in the back contact double-glass battery, and improve the adaptability between the improved adhesive film and other structures in the photovoltaic layer stack in the embodiment. The back contact double-glass battery mentioned in the embodiment includes a combination of back contact battery technology and traditional PERC battery technology, TOPCon battery technology and heterojunction battery technology, and HPBC battery, HBC battery and TBC battery are obtained. In the embodiment, the front adhesive film can be further thinned compared with other conventional batteries due to the absence of metal grid lines and solder strips on the front of the back contact cell, but when the adhesive film is thinned to a certain extent, the inter-string of the battery string and the edge of the photovoltaic cell will produce bubbles after lamination due to lack of adhesive, resulting in that the thickness of the adhesive film cannot reach the expected value.

[0074] At present, the double-glass assembly can improve the front optical reflection by grid coating on the back glass and gap film between the back glasses. Considering the printing accuracy of the grid coating glass, the coating width cannot be too narrow, which affects the double-sided rate of the assembly, and the degree of tempering of the glass will be reduced after the coating process. In addition, in order to reduce the transmission loss of the solder strip, the back contact battery assembly usually selects a large-diameter round wire or a high-thickness flat solder strip. When the back adhesive film is too low, the solder strip is easy to penetrate the gap film and contact after lamination, resulting in short circuit of the assembly. At the same time, the gap film process is complicated and a new film equipment needs to be added, which cannot be used in large quantities in the back contact assembly.

[0075] The photovoltaic layer stack provided by the embodiment of the application can alleviate the problem of cell chip fragments caused by the local extrusion of the overlapping part to the photovoltaic cell by setting the overlapping part corresponding to the busbar lead-out hole. In addition, the white strip film at the back strip film part can reflect the light irradiated on the back strip film part to the surface of the cell chip after reflection, thereby improving the light utilization rate. By setting the width of the strip film part to 5-20 mm, the strip film part can fill the gap and avoid the formation of bubble structure, while avoiding blocking the light collection of the photovoltaic cell and ensuring the photoelectric conversion efficiency of the photovoltaic layer stack. By setting the battery as a back contact double-glass battery, the front adhesive film as including a front low-grammage adhesive film part and a front strip film part, and the back adhesive film as including a back low-grammage adhesive film part and a white strip film, the photovoltaic layer stack can be adapted to the back contact double-glass battery.

[0076] In a feasible embodiment, the photovoltaic layer stack can specifically include the following structure:

[0077] The front glass, the front adhesive film, the back contact photovoltaic cell, the back adhesive film and the back glass are arranged in a stack.

[0078] The front adhesive film is pre-combined with the front glass, and the back adhesive film is pre-combined with the back glass.

[0079] The front adhesive film comprises a front low-grammage adhesive film part, and a front strip film part arranged on a surface of the front low-grammage adhesive film part and corresponding to a periphery edge of the photovoltaic stack, and / or a space between cell pieces in the photovoltaic stack, and / or a space between cell strings in the photovoltaic stack, and / or a front busbar in the photovoltaic stack; the front strip film part is arranged between the front low-grammage adhesive film part and the front glass; a textured pattern is formed on a surface of the front low-grammage adhesive film part away from the front glass; a front overlap part in the front strip film part is formed at a position corresponding to a busbar lead-out hole; the front overlap part is an overlap part formed by a plurality of sub-strip film parts in the front strip film part at the same position.

[0080] The back adhesive film comprises a back low-grammage adhesive film part, and a white strip film arranged on a surface of the back low-grammage adhesive film part and corresponding to a periphery edge of the photovoltaic stack, and / or a space between cell pieces in the photovoltaic stack, and / or a space between cell strings in the photovoltaic stack, and / or a back busbar in the photovoltaic stack; the white strip film is arranged between the back low-grammage adhesive film part and the back glass; a textured pattern is formed on a surface of the back low-grammage adhesive film part away from the back glass; a back overlap part in the white strip film is formed at a position corresponding to a busbar lead-out hole; the back overlap part is an overlap part formed by a plurality of sub-strip film parts in the white strip film at the same position.

[0081] The white strip film comprises an adhesive layer close to the back glass, and a reflective layer away from the back glass.

[0082] The width of the front strip film part is 5-20 mm.

[0083] A photovoltaic stack preparation method provided by an embodiment of the present application is described below, and the photovoltaic stack preparation method described below can be correspondingly referred to the photovoltaic stack described above.

[0084] The photovoltaic stack preparation method provided by the embodiment of the present application can comprise:

[0085] S101: laying a front adhesive film on a surface of a front cover plate, and pre-combining the front cover plate and the front adhesive film;

[0086] S102: laying a back adhesive film on a surface of a back plate, and pre-combining the back plate and the back adhesive film;

[0087] S103: Laying the solder strip and the photovoltaic cell on the side of the front adhesive film away from the front cover plate, laying the back adhesive film pre-combined with the back plate on the side of the photovoltaic cell away from the front cover plate, and obtaining a photovoltaic laminated assembly;

[0088] The front adhesive film comprises a front low-grammage adhesive film part, and a front strip film part arranged on the surface of the front low-grammage adhesive film part and corresponding to the four peripheral edges of the photovoltaic laminated assembly, and / or the inter-cell piece of the photovoltaic laminated assembly, and / or the inter-string piece of the photovoltaic laminated assembly, and / or the front bus bar of the photovoltaic laminated assembly; and / or the back adhesive film comprises a back low-grammage adhesive film part, and a back strip film part arranged on the surface of the back low-grammage adhesive film part and corresponding to the four peripheral edges of the photovoltaic laminated assembly, and / or the inter-cell piece of the photovoltaic laminated assembly, and / or the inter-string piece of the photovoltaic laminated assembly, and / or the back bus bar of the photovoltaic laminated assembly.

[0089] The photovoltaic laminated assembly preparation method provided in the embodiment comprises the following steps: laying the front strip film part and the front low-grammage adhesive film part on the surface of the front cover plate in sequence, and pre-combining the front low-grammage adhesive film part, the front strip film part, and the front cover plate by low-temperature lamination by using a laminating machine, so as to prevent the front strip film part from deviating in the process and causing a lack of glue type bubble after lamination, and also to avoid the step caused by the high-grammage front strip film part and the breakage and other defects caused by lamination. The back strip film part and the back low-grammage adhesive film part are laid on the surface of the back plate, and the back strip film part and the back low-grammage adhesive film part are pre-combined with the back plate by low-temperature lamination, so as to prevent the back strip film part from deviating and causing light leakage due to vacuumization in the lamination process, reduce the reflection of front light, and also prevent the appearance of the front of the assembly from being affected. In the embodiment, the cell pieces can be arranged in a whole string, the white film is pasted between the pieces in the arranged cell string and at the head and tail of the cell string by low-temperature heating, then the solder strip is placed, and the cell string is completed by high-temperature welding or low-temperature film coating. The cell string is laid on the front cover plate pre-combined with the front strip film part and the front low-grammage adhesive film part, the back plate pre-combined with the back strip film part and the back low-grammage adhesive film part is laid after the bus bar welding is completed, and the photovoltaic laminated assembly is prepared.

[0090] Further, in order to prevent the strip film part from deviating in the pre-combination process, the above step of laying the front adhesive film on the surface of the front cover plate and pre-combining the front cover plate and the front adhesive film comprises the following steps:

[0091] The front strip film part and the front low-grammage adhesive film part are laid on the surface of the front cover plate in sequence, and the front cover plate, the front strip film part, and the front low-grammage adhesive film part are pre-combined.

[0092] The back adhesive film is laid on the surface of the back plate, and the back plate and the back adhesive film are pre-combined, comprising the following steps:

[0093] The back strip film part and the back low-grammage adhesive film part are laid on the surface of the back plate in sequence, and the back plate, the back strip film part, and the back low-grammage adhesive film part are pre-combined.

[0094] In the embodiment, by arranging the front side strip film part between the front side low weight adhesive film part and the front side cover plate and the back side strip film part between the back side low weight adhesive film part and the back plate, the low weight adhesive film part can be used to cover the strip film part to form pre-fixing of the strip film part, and the shift of the strip film part during pre-combination and lamination processing can be avoided.

[0095] Specifically, in the embodiment, the front side strip film part with high weight is laid between the battery strings corresponding to the front side glass, then the front side low weight adhesive film part is laid on the front side strip film part, and the three are pre-combined by low temperature lamination of the laminator. The white strip film is laid between the battery strings corresponding to the back side glass, and the whole conventional back side packaging adhesive film is laid on the upper side of the white strip film, and the three are pre-combined by low temperature lamination of the laminator. The battery pieces are arranged in a whole string, the white film is laid between the battery pieces under low temperature condition, and the battery string is completed by high temperature welding or low temperature film coating after the welding strip is placed. The prepared battery string is laid on the front side glass with pre-combined front side strip film part and front side low weight adhesive film part, the back side glass with pre-combined white strip film and conventional back side packaging adhesive film is covered after the busbar welding is completed, and the assembly is completed after lamination.

[0096] Specifically, the parameters of the low temperature lamination of the laminator can be set as follows: the vacuum extraction time is 15 s, and the lamination temperature is set to 70°C. The specific material of the front side strip film part can be set to be consistent with the front side low weight adhesive film part, or the strip film part can be set to be POE, EVA, EPE or the like.

[0097] Specifically, after the strip film part and the low weight adhesive film part are placed on the glass, high temperature cloth, release film and other release materials are laid to prevent the adhesive film from adhering to the laminator during lamination. After the glass and the low weight adhesive film part are cooled, the high temperature cloth, release film and other materials are removed to complete the pre-combination processing. The surface of the high temperature cloth and the release film can be a smooth surface, a grid stripe surface or a surface provided with a protruding structure, and the surface of the combined adhesive film can be a smooth surface, a grid stripe surface, a surface with a local concave structure, wherein the smooth surface can increase the vacuum suction force, the grid stripe can increase the friction force, and the local concave structure can limit the movement of the battery string and reduce the shift of the battery string caused by process transportation. In one embodiment, after the strip film and the adhesive film are placed on the glass, hot pressing is performed by using a hot plate with a temperature of 90-120°C for 5-20 s to complete the pre-combination of the glass and the adhesive film. The high temperature cloth is pasted on the surface of the hot plate, and the hot plate can be quickly separated from the adhesive film after heating. In another embodiment, after the strip film and the adhesive film are placed on the glass, hot rolling is performed by using a hot roller with a temperature of 90-120°C, and auxiliary rollers can be arranged before and after the hot roller to improve the pre-combination effect of the glass and the adhesive film.

[0098] The photovoltaic laminated piece is obtained by the photovoltaic laminated piece preparation method, the front adhesive film comprises a front low-grammage adhesive film part and a front strip film part arranged on the surface of the front low-grammage adhesive film part and corresponding to the four edges of the photovoltaic laminated piece, and / or the inter-cell part of the photovoltaic laminated piece, and / or the inter-string part of the photovoltaic laminated piece, and / or the front busbar of the photovoltaic laminated piece; and / or the back adhesive film comprises a back low-grammage adhesive film part and a back strip film part arranged on the surface of the back low-grammage adhesive film part and corresponding to the four edges of the photovoltaic laminated piece, and / or the inter-cell part of the photovoltaic laminated piece, and / or the inter-string part of the photovoltaic laminated piece, and / or the back busbar of the photovoltaic laminated piece. The front adhesive film and / or the back adhesive film are composed of the strip film and the low-grammage adhesive film, the strip film is arranged corresponding to the four edges of the photovoltaic laminated piece, and / or the inter-cell part of the photovoltaic laminated piece, and / or the inter-string part of the photovoltaic laminated piece, and / or the front busbar of the photovoltaic laminated piece, and the thickness of the adhesive film at different positions is thickened, which can reduce the bubbles caused by the lack of adhesive in the assembly, and the thickened adhesive film corresponding to the solder strip and the busbar can avoid the short circuit of the solder strip and the busbar, thereby improving the yield of the assembly.

[0099] In addition, the front strip film part is arranged between the front low-grammage adhesive film part and the front cover plate, and the back strip film part is arranged between the back low-grammage adhesive film part and the back plate, so that the low-grammage adhesive film part covers the strip film part to pre-fix the strip film part, thereby avoiding the deviation of the strip film part during the pre-combination and the lamination.

[0100] The photovoltaic assembly provided by the embodiment of the present application can comprise the photovoltaic laminated piece after the lamination.

[0101] The photovoltaic assembly provided by the embodiment of the present application can comprise the photovoltaic laminated piece after the lamination.

[0102] The photovoltaic laminate in the embodiment includes at least a front cover, a front adhesive film, a photovoltaic cell, a back adhesive film and a back plate arranged in a stack; the front adhesive film is pre-combined with the front cover, and the back adhesive film is pre-combined with the back plate; the front adhesive film includes a front low-grammage adhesive film part, and a front strip film part arranged on the surface of the front low-grammage adhesive film part, corresponding to the four edges of the photovoltaic laminate, and / or the inter-cell of the photovoltaic laminate, and / or the inter-string of the photovoltaic laminate, and / or the front busbar of the photovoltaic laminate; and / or, the back adhesive film includes a back low-grammage adhesive film part, and a back strip film part arranged on the surface of the back low-grammage adhesive film part, corresponding to the four edges of the photovoltaic laminate, and / or the inter-cell of the photovoltaic laminate, and / or the inter-string of the photovoltaic laminate, and / or the back busbar of the photovoltaic laminate.

[0103] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0104] In addition, it should also be noted that, in this document, relationships such as first and second are intended to distinguish one entity or operation from another, and do not necessarily require or imply any actual such relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device.

[0105] The above describes in detail the photovoltaic laminate, the photovoltaic laminate preparation method and the photovoltaic module provided by the application. The principles and implementation manners of the application are described by using specific examples. The above embodiment is only used to help understand the method of the application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range can be changed. In summary, the content of the specification should not be understood as a limitation of the application.

Claims

1. A photovoltaic cascade, characterized in that, include: A front cover plate, a front adhesive film, photovoltaic cells, a back adhesive film, and a back sheet are stacked together; The front adhesive film is pre-laminated with the front cover plate, and the back adhesive film is pre-laminated with the back plate; The front encapsulant film includes a front low-weight encapsulant film portion and a front strip film portion located on the surface of the front low-weight encapsulant film portion, corresponding to the four edges of the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or at the front busbar in the photovoltaic stack; and / or, the back encapsulant film includes a back low-weight encapsulant film portion and a back strip film portion located on the surface of the back low-weight encapsulant film portion, corresponding to the four edges of the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or at the back busbar in the photovoltaic stack.

2. The photovoltaic laminate according to claim 1, characterized in that, The front strip film portion is located between the front low-weight adhesive film portion and the front cover plate; And / or, the back strip film portion is located between the back low-weight adhesive film portion and the back plate.

3. The photovoltaic laminate according to claim 2, characterized in that, The low-weight adhesive film portion on the front side has a textured pattern formed on the side surface facing away from the front cover plate; And / or, the low-weight adhesive film portion on the back side has a textured pattern formed on the side surface facing away from the back plate.

4. The photovoltaic laminate according to claim 1, characterized in that, The front overlapping portion of the front strip membrane is formed at the position corresponding to the busbar outlet hole; the front overlapping portion is the overlapping portion formed by the convergence of multiple sub-strip membrane portions at the same location in the front strip membrane portion. And / or, the back overlap portion in the back strip film portion is formed at the position corresponding to the busbar outlet hole; the back overlap portion is the overlap portion formed by multiple sub-strip film portions converging at the same location in the back strip film portion.

5. The photovoltaic laminate according to claim 1, characterized in that, The back strip film portion is white strip film; The white strip film includes an adhesive layer facing the back panel and a reflective layer facing away from the back panel.

6. The photovoltaic laminate according to claim 1, characterized in that, The width of the front strip and / or the back strip is 5 mm to 20 mm.

7. The photovoltaic laminate according to claim 1, characterized in that, The photovoltaic cell is a back-contact photovoltaic cell; The front cover is front glass, and the back panel is back glass; The front adhesive film is pre-laminated with the front glass, and the front adhesive film includes the front low-weight adhesive film portion and the front strip film portion; The back adhesive film is pre-laminated with the back glass, and the back adhesive film includes a low-weight back adhesive film portion and a white strip film.

8. A method for fabricating a photovoltaic laminate, characterized in that, include: A front adhesive film is laid on the surface of the front cover plate, and the front cover plate and the front adhesive film are pre-composite. A backing film is laid on the surface of the back panel, and the back panel and the backing film are pre-composite. A welding strip and a photovoltaic cell are laid on the side of the front adhesive film facing away from the front cover plate. The back adhesive film, which is pre-composite with the back plate, is laid on the side of the photovoltaic cell facing away from the front cover plate to obtain a photovoltaic laminate. The front encapsulant film includes a front low-weight encapsulant film portion and a front strip film portion located on the surface of the front low-weight encapsulant film portion, corresponding to the four edges of the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or at the front busbar in the photovoltaic stack; and / or, the back encapsulant film includes a back low-weight encapsulant film portion and a back strip film portion located on the surface of the back low-weight encapsulant film portion, corresponding to the four edges of the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or between the solar cells in the photovoltaic stack, and / or at the back busbar in the photovoltaic stack.

9. The method for fabricating photovoltaic laminates according to claim 8, characterized in that, The step of laying a front adhesive film on the surface of the front cover plate and pre-compositing the front cover plate and the front adhesive film includes: The front strip film portion and the front low-weight adhesive film portion are sequentially laid on the surface of the front cover plate, and the front cover plate, the front strip film portion and the front low-weight adhesive film portion are pre-composite treated. The step of laying a backing film on the surface of the back panel and pre-compositing the back panel and the backing film includes: The back strip film portion and the back low-weight adhesive film portion are sequentially laid on the surface of the back plate, and the back plate, the back strip film portion and the back low-weight adhesive film portion are pre-composite.

10. A photovoltaic module, characterized in that, include: A photovoltaic laminate as described in any one of claims 1 to 7 that has undergone lamination processing.

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