Manufacturing methods of photovoltaic modules

Abstract

This application relates to the field of photovoltaic technology and provides a method for manufacturing photovoltaic modules, which at least helps to improve the reliability of photovoltaic modules. The manufacturing method includes: laying a first adhesive film layer and a second adhesive film layer on a first cover plate, the first adhesive film layer covering the surface of the first cover plate, the second adhesive film layer being located on the first adhesive film layer, the second adhesive film layer having a plurality of hollow portions arranged along a first direction, the hollow portions and the first adhesive film layer forming a receiving groove, the thickness of the first adhesive film layer being greater than the thickness of the second adhesive film layer; laying solar cells, with a plurality of solar cells corresponding one-to-one with the receiving groove, and connecting adjacent solar cells sequentially through interconnection portions; laying a third adhesive film layer and a second cover plate on the solar cells to form a laminate; and performing a lamination process on the laminate.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a method for manufacturing a photovoltaic module. Background Technology

[0002] With global energy consumption rapidly increasing and traditional fossil fuels becoming increasingly depleted, energy and environmental issues have gradually become two major global concerns. Driven by pressure to address environmental pollution and achieve sustainable development, major countries have prioritized the solar photovoltaic industry in their renewable energy development and utilization efforts.

[0003] In order to obtain photovoltaic modules with suitable current, voltage and output power, the solar photovoltaic industry needs to connect solar cells in series and go through processes such as stacking, lamination and encapsulation to form photovoltaic modules before they can become practical power output products. In the manufacturing process of crystalline silicon photovoltaic modules, the cells are first connected in series with solder ribbons to form cell strings. Then, multiple cell strings are arranged neatly. Next, the busbar is welded to the solder ribbons extending from the ends of multiple cell strings. The busbar can then collect the current into the junction box to provide power to the outside.

[0004] However, the stringing process is prone to risks such as microcracks or fragmentation of the solar cells. Furthermore, due to the difference in thermal expansion coefficients between the solder strip and the solar cells, the solar cells are prone to warping after stringing, which leads to lower reliability of the photovoltaic modules. Summary of the Invention

[0005] This application provides a method for manufacturing a photovoltaic module, which at least helps to improve the reliability of the photovoltaic module.

[0006] According to some embodiments of this application, one aspect of this application provides a method for manufacturing a photovoltaic module, comprising: laying a first adhesive film layer and a second adhesive film layer on a first cover plate, the first adhesive film layer covering the surface of the first cover plate, the second adhesive film layer being located on the first adhesive film layer, the second adhesive film layer having a plurality of hollow portions arranged along a first direction, the hollow portions and the first adhesive film layer forming a receiving groove, the thickness of the first adhesive film layer being greater than the thickness of the second adhesive film layer; laying solar cells, with a plurality of solar cells corresponding one-to-one with the receiving groove, and connecting adjacent solar cells sequentially through interconnection portions; laying a third adhesive film layer and a second cover plate on the solar cells to form a laminate; and performing a lamination process on the laminate.

[0007] In some embodiments, laying the battery cell includes: placing the battery cell in a receiving groove, laying an interconnect portion on the surface of the battery cell away from the first adhesive layer, and then fixing the interconnect portion to the surface of the battery cell.

[0008] In some embodiments, the first cover plate includes a first side and a second side opposite to each other along a first direction, and a battery sheet is laid thereon, including: placing the first end of the battery sheet near the first side in a receiving groove, placing the second end of the battery sheet near the second side on a second adhesive layer, wherein along the first direction, the first end of an adjacent battery sheet is located below the second end of another battery sheet, and an interconnection portion is located between the first end of one battery sheet and the second end of another battery sheet.

[0009] In some embodiments, before laying the battery cell, the method further includes: laying a sub-film layer on the first film layer, the sub-film layer being located in a receiving groove, the distance between the sub-film layer and the second film layer on the first side being greater than the distance between the sub-film layer and the second film layer on the second side, and the thickness of the sub-film layer being less than the thickness of the second film layer; after laying the battery cell, the surface of the sub-film layer away from the first film layer is in contact with the battery cell.

[0010] In some embodiments, laying a sub-adhesive film layer on the first adhesive film layer further includes: providing a plurality of sub-adhesive film layers arranged in a first direction in the same receiving groove, wherein the thickness of the plurality of sub-adhesive film layers increases sequentially in the direction from the first side to the second side.

[0011] In some embodiments, after the battery cell is laid and before the third adhesive film layer and the second cover plate are laid on the battery cell, the method further includes laying a fourth adhesive film layer on the surface of the first end of the battery cell away from the first adhesive film layer, wherein the thickness of the fourth adhesive film layer is equal to the thickness of the second adhesive film layer.

[0012] In some embodiments, the thickness of the second adhesive layer is 0.5 to 0.8 times the thickness of the battery cell.

[0013] In some embodiments, an adhesive layer is coated between the first adhesive film layer and the second adhesive film layer.

[0014] In some embodiments, after the first adhesive film layer and the second adhesive film layer are laid on the first cover plate, and before the battery cell is laid, the method includes: performing localized heat treatment on the first cover plate, the first adhesive film layer and the second adhesive film layer to bond and fix the first adhesive film layer to the first cover plate and to bond and fix the first adhesive film layer to the second adhesive film layer.

[0015] In some embodiments, the melt index of the material of the second adhesive layer is greater than the melt index of the material of the first adhesive layer.

[0016] In some embodiments, after laying the battery cell, the process further includes: performing a pre-fixing treatment, at least heating the second adhesive film layer so that the second adhesive film layer melts and adheres to the sidewall of the battery cell.

[0017] The technical solution provided in this application has at least the following advantages:

[0018] In the photovoltaic module manufacturing method provided in this application embodiment, a first adhesive film layer is first covered on a first cover plate, and a second adhesive film layer with multiple perforations is provided on the first adhesive film layer so that the perforations and the first adhesive film layer form a receiving groove. In the subsequent step of laying the battery cells, the receiving groove formed by the first and second adhesive film layers can fix the relative position of the battery cells. After laying the battery cells in the receiving groove, a third adhesive film layer and a second cover plate are laid to form a component to be laminated. After laminating the component to be laminated, a photovoltaic module is obtained. The photovoltaic module manufacturing method provided in this application embodiment eliminates the need to weld multiple battery cells into a battery string before lamination, which can avoid the problem of battery cell warping caused by the stringing process. Moreover, omitting the stringing step can also help reduce the risk of microcracks or fragmentation of the battery cells, thereby improving the reliability of the photovoltaic module. At the same time, omitting the stringing step eliminates the need for stringing equipment, which can also help reduce the manufacturing cost of photovoltaic modules and improve production efficiency. In addition, the thickness of the first adhesive layer is greater than that of the second adhesive layer. The thicker thickness of the first adhesive layer is beneficial for the first adhesive layer to wrap the front of the battery cell, thereby protecting the battery cell; the thinner thickness of the second adhesive layer can save on the material cost of the second adhesive layer. Attached Figure Description

[0019] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart corresponding to the manufacturing method of the photovoltaic module provided in the embodiments of this application;

[0021] Figures 2 to 6 A schematic diagram of the structure corresponding to each step of the manufacturing method of the first photovoltaic module provided in the embodiments of this application;

[0022] Figures 7 to 11 A schematic diagram of the structure corresponding to each step of the second photovoltaic module manufacturing method provided in the embodiments of this application;

[0023] Figure 12 This is a structural schematic diagram corresponding to a step of laying battery cells provided in an embodiment of this application;

[0024] Figure 13 This is a structural schematic diagram corresponding to a step of laying a fourth adhesive film layer provided in an embodiment of this application. Detailed Implementation

[0025] As can be seen from the background technology, the reliability of photovoltaic modules needs to be improved.

[0026] In the photovoltaic module manufacturing method provided in this application embodiment, a first adhesive film layer is first covered on a first cover plate, and a second adhesive film layer with multiple perforations is provided on the first adhesive film layer so that the perforations and the first adhesive film layer form a receiving groove. In the subsequent step of laying the battery cells, the receiving groove formed by the first and second adhesive film layers can fix the relative position of the battery cells. After laying the battery cells in the receiving groove, a third adhesive film layer and a second cover plate are laid to form a component to be laminated. After laminating the component to be laminated, a photovoltaic module is obtained. The photovoltaic module manufacturing method provided in this application embodiment eliminates the need to weld multiple battery cells into a battery string before lamination, which can avoid the problem of battery cell warping caused by the stringing process. Moreover, omitting the stringing step can also help reduce the risk of microcracks or fragmentation of the battery cells, thereby improving the reliability of the photovoltaic module. At the same time, omitting the stringing step eliminates the need for stringing equipment, which can also help reduce the manufacturing cost of photovoltaic modules and improve production efficiency. In addition, the thickness of the first adhesive layer is greater than that of the second adhesive layer. The thicker thickness of the first adhesive layer is beneficial for the first adhesive layer to wrap the front of the battery cell, thereby protecting the battery cell; the thinner thickness of the second adhesive layer can save on the material cost of the second adhesive layer.

[0027] In the description of the embodiments of this application, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0028] In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0031] In the description of the embodiments of this application, technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0032] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0033] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0034] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included.

[0035] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0036] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0037] Figure 1 A flowchart corresponding to the manufacturing method of the photovoltaic module provided in the embodiments of this application; Figures 2 to 6 The diagram shows the structural details of each step in the manufacturing method of the first photovoltaic module provided in this application embodiment. Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure along the AA1 direction; Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure along the AA1 direction.

[0038] refer to Figures 1 to 6 The first method for manufacturing a photovoltaic module provided in this application includes:

[0039] Step S11: Refer to the reference Figure 2 and Figure 3 A first adhesive film layer 121 and a second adhesive film layer 122 are laid on the first cover plate 111. The first adhesive film layer 121 covers the surface of the first cover plate 111, and the second adhesive film layer 122 is located on the first adhesive film layer 121. The second adhesive film layer 122 has a plurality of hollow portions arranged along the first direction X. The hollow portions and the first adhesive film layer 121 form a receiving groove 131. The thickness of the first adhesive film layer 121 is greater than the thickness of the second adhesive film layer 122.

[0040] Step S12: Refer to the reference Figure 4 and Figure 5 The battery cells 130 are laid out, and the multiple battery cells 130 are matched one-to-one with the receiving grooves 131. The adjacent battery cells 130 are connected sequentially through the interconnection section 140.

[0041] In this embodiment, the grid lines of different polarities on the battery cell 130 are all located on the back side of the battery cell 130, that is, the battery cell 130 is a BC battery (Back Contact battery), and the interconnection portion 140 is a solder ribbon. Thus, the step of laying the battery cell 103 includes: placing the battery cell 130 in the receiving groove 131, with the front side of the battery cell 130 in contact with the first adhesive film layer 121, laying the interconnection portion 140 on the surface of the battery cell 130 away from the first adhesive film layer 121 (i.e., the back side), and then fixing the interconnection portion 140 to the surface of the battery cell 130, so that multiple battery cells 130 are connected in series to form a battery string.

[0042] BC batteries include IBC batteries (Interdigitated Back Contact), HPBC batteries (Hybrid Passivated Back Contact), TBC batteries that combine TOPCon (TunnelOxide Passivated Contact) technology and IBC technology, or HBC batteries that combine HIT / HJT (Heterojunction Technology) technology and IBC technology. Of course, other types of back contact batteries are also possible.

[0043] The type of solar cell 130 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0044] Step S13: Reference Figure 6 A third adhesive film layer 123 and a second cover plate 112 are laid on the battery cell 130 to form the laminate to be laminated.

[0045] Step S14: Perform lamination on the component to be laminated.

[0046] In the photovoltaic module manufacturing method provided in this application embodiment, a first adhesive film layer 121 is first covered on a first cover plate 111, and a second adhesive film layer 122 with multiple hollow portions is provided on the first adhesive film layer 121 so that the hollow portions and the first adhesive film layer 121 form a receiving groove 131. In the subsequent step of laying the battery cells 130, the receiving groove 131 formed by the first adhesive film layer 121 and the second adhesive film layer 122 can fix the relative position of the battery cells 130, and can prevent the battery cells 130 from moving during the laying of the interconnection part 140, thereby improving the stability of the interconnection part 140 connecting adjacent battery cells 130. After laying the battery cells 130 in the receiving groove 131, a third adhesive film layer 123 and a second cover plate 112 are laid on the battery cells 130 to form a laminate. After laminating the laminate, a photovoltaic module is obtained. The photovoltaic module manufacturing method provided in this application eliminates the need to weld multiple cells 130 into a cell string before lamination, thus avoiding cell warping caused by the stringing process. Furthermore, omitting the stringing step can reduce the risk of microcracks or fragmentation of the cells 130, thereby improving the reliability of the photovoltaic module. At the same time, omitting the stringing step eliminates the need for stringing equipment, which also helps to reduce the manufacturing cost of the photovoltaic module and improve production efficiency. Furthermore, the thickness of the first adhesive layer 121 is greater than the thickness of the second adhesive layer 122. The greater thickness of the first adhesive layer 121 is beneficial for the first adhesive layer 121 to wrap the front of the battery cell 130, thereby protecting the battery cell 130. Since the second adhesive layer 122 is located between adjacent battery cells 130, its function is to limit the movement of the battery cell 130 on the surface of the first adhesive layer 121. The thinner thickness of the second adhesive layer 122 can save on the material cost of the second adhesive layer 122, and at the same time, it can also avoid the problem that the second adhesive layer 122 will lift up the interconnection part 140, causing the battery cell 130 and the interconnection part 140 to be unable to contact.

[0047] In step S11, the material of the first cover plate 111 can be one or more of tempered glass, inorganic glass, or organic glass. For example, the material of the first cover plate 111 can be ultra-clear glass, which has high light transmittance and transparency, and is beneficial to improving the light absorption efficiency of photovoltaic modules.

[0048] In some embodiments, the surface of the first cover plate 111 facing the first adhesive film layer 121 may have an uneven structure, which may increase the utilization rate of incident light, thereby improving the light conversion efficiency of the photovoltaic module.

[0049] In step S11, the material of the first adhesive layer 121 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film. The material of the second adhesive layer 122 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0050] In some embodiments, the material of the first adhesive layer 121 and the material of the second adhesive layer 122 may be the same or different.

[0051] In some embodiments, the melt index of the material of the second adhesive layer 122 may be greater than that of the material of the first adhesive layer 121. Thus, at the same melting temperature, the fluidity of the second adhesive layer 122 is greater than that of the first adhesive layer 121. In subsequent lamination processes, the greater fluidity of the second adhesive layer 122 is beneficial for filling the gaps between adjacent battery cells 130 to avoid the problem of air bubbles.

[0052] refer to Figure 4 The size of the hollow part can be larger than the size of the battery cell 130. Correspondingly, the size of the receiving groove 131 is larger than the size of the battery cell 130. In this way, during the process of laying the battery cell 130 in step 12, the battery cell 130 can smoothly enter the receiving groove 131.

[0053] In some embodiments, the gap width between any sidewall of the battery cell 130 and the inner wall of the receiving groove 131 is 0 to 2 mm, for example, it can be 0 mm, 0.5 mm, 0.7 mm, 1 mm, 1.5 mm, 1.8 mm, or 2 mm. That is, the size of the receiving groove 131 is slightly larger than the size of the battery cell 130. This facilitates the smooth entry of the battery cell 130 into the receiving groove 131, and at the same time avoids the problem of misalignment of the battery cell 130 due to excessive space for movement within the receiving groove 131.

[0054] In some embodiments, after step S11 and before step S12, the relative positions of the first cover plate 111, the first adhesive layer 121, and the second adhesive layer 122 can be fixed.

[0055] For example, the first cover plate 111, the first adhesive layer 121 and the second adhesive layer 122 can be locally heated to bond the first adhesive layer 121 to the first cover plate 111 and to bond the first adhesive layer 121 to the second adhesive layer 122. In other words, after the first adhesive film layer 121 and the second adhesive film layer 122 are laid on the first cover plate 111 and before the battery cell 130 is laid, the first cover plate 111, the first adhesive film layer 121 and the second adhesive film layer 122 are subjected to local heating treatment so that the first adhesive film layer 121 and the second adhesive film layer 122 are locally melted, thereby making the first adhesive film layer 121 and the second adhesive film layer 122 firmly bonded together. At the same time, the first adhesive film layer 121 is also bonded to the first cover plate 111. In this way, relative displacement between the first cover plate 111 and the first adhesive film layer 121 and between the first adhesive film layer 121 and the second adhesive film layer 122 can be avoided, which is beneficial to improving the accuracy of the battery cell 130 arrangement position during the subsequent placement of the battery cell 130.

[0056] The temperature of the localized heating treatment can be higher than the melting temperature of the first adhesive layer 121, and the difference between the two melting temperatures is less than or equal to 10°C; and / or, the temperature of the localized heating treatment can be higher than the melting temperature of the second adhesive layer 122, and the difference between the two melting temperatures is less than or equal to 10°C. When the difference between the melting temperatures of the first adhesive layer 121 and the second adhesive layer 122 is greater than 10°C, the temperature of the localized heating treatment can be determined based on the higher melting temperature of the first adhesive layer 121 and the second adhesive layer 122. When the temperature of the localized heating treatment is within an appropriate range from the melting temperatures of the first adhesive layer 121 and / or the second adhesive layer 122, localized melting of the first adhesive layer 121 and the second adhesive layer 122 can occur to produce a certain bonding effect, while avoiding localized collapse or deformation due to excessive melting.

[0057] Localized heating treatment can employ one or more of the following processes: infrared heating, microwave heating, hot air heating, or laser heating.

[0058] In other embodiments, the relative positions of the first cover plate 111, the first adhesive film layer 121, and the second adhesive film layer 122 can be fixed by applying an adhesive layer between the first cover plate 111 and the first adhesive film layer 121 in step S11, thereby fixing their relative positions. Similarly, an adhesive layer can also be applied between the first adhesive film layer 121 and the second adhesive film layer 122 to fix their relative positions. The adhesive layer can be glue or a UV-curable adhesive, etc.

[0059] In some other embodiments, the relative positions of the first cover plate 111, the first adhesive layer 121, and the second adhesive layer 122 can be fixed by the following steps: In step S11, after the first adhesive layer 121 is laid on the first cover plate 111, the first cover plate 111 and the second adhesive layer 122 can be subjected to full-surface heat treatment to bond the first adhesive layer 121 to the first cover plate 111 as a whole. Then, the second adhesive layer 122 is placed on the first adhesive layer 121. The second adhesive layer 122 can be fixed to the first adhesive layer 121 by local heat treatment or by coating an adhesive layer.

[0060] The entire surface can be heated using one or more of the following processes: lamination, infrared heating, microwave heating, hot air heating, hot roller heating, or laser heating.

[0061] In some embodiments, the thickness ratio of the second adhesive layer 122 to the thickness of the battery cell 130 is 0.5 to 0.8, for example, 0.5, 0.6, 0.7, or 0.8. The second adhesive layer 122 is located between adjacent battery cells 130. To prevent the interconnect portion 140 from being unable to contact the battery cell 130 after being lifted due to the excessive height of the second adhesive layer 122, the thickness of the second adhesive layer 122 needs to be less than the thickness of the battery cell 130. Simultaneously, the second adhesive layer 122 also needs to fill the gaps between adjacent battery cells 130. The thickness of the second adhesive layer 122 cannot be too small to avoid air bubbles forming between adjacent battery cells 130. Therefore, the thickness ratio of the second adhesive layer 122 to the thickness of the battery cell 130 needs to be within an appropriate range.

[0062] The thickness of the second adhesive film layer 122 can be 90μm to 180μm, for example, it can be 90μm, 100μm, 120μm, 150μm or 180μm.

[0063] In some embodiments, in step S12, the interconnection portion 140 can be fixed to the surface of the battery cell 130 by means of conductive adhesive, light-curing adhesive or insulating film bonding.

[0064] In some embodiments, the interconnect portion 140 can be a low-temperature solder strip, i.e., the tin plating layer on the surface of the solder strip has a melting point of 135°C to 150°C. In this way, during the subsequent lamination process, the interconnect portion 140 can be alloyed with the grid lines on the cell 130, which is beneficial to improving the carrier transport efficiency between the interconnect portion 140 and the cell 130, thereby improving the efficiency of the photovoltaic module.

[0065] After step S12, the method further includes laying a busbar, which is used to connect the ends of the interconnection section 140 to conduct current through the interconnection section 140.

[0066] In the accompanying drawings provided in this application, a battery string comprising three battery cells 130 is used as an example, which does not constitute a limitation on the number of battery cells 130 in the battery string. In some embodiments, the number of battery cells in the battery string can also be four, five, six, or eight, etc. In some embodiments, multiple battery strings can also be connected in series or in parallel through busbars.

[0067] In some embodiments, after step S12, a pre-fixing process is further included, which is used to fix the relative position of the battery cell 130 and the receiving groove 131.

[0068] In one example, the pre-fixing process includes heating at least the second adhesive layer 122 to melt it and bond it to the sidewall of the battery cell 130. Heating the second adhesive layer 122 after laying the battery cell 130 melts it and bonds it to the sidewall of the battery cell 130. This serves two purposes: firstly, it fixes the relative positions of the battery cells 130; secondly, the second adhesive layer 122 pre-fills the gaps between adjacent battery cells 130, preventing air bubbles from forming between the battery cells 130 during subsequent lamination.

[0069] In another example, the pre-fixation process includes heating the first adhesive layer 121 and the second adhesive layer 122 so that the first adhesive layer 121 melts and is bonded and fixed to the battery cell 130; at the same time, the second adhesive layer 122 melts and is bonded and fixed to the side wall of the battery cell 130, thereby improving the stability of the battery cell 130 fixation.

[0070] In some other embodiments, before step S12, an adhesive layer may be applied to the bottom surface of the receiving groove 131 (i.e. the surface of the first adhesive film layer 121) before placing the battery cell 130 into the receiving groove 131, so that the battery cell 130 is fixed in the receiving groove 131 by the adhesive layer.

[0071] In step S13, the material of the second cover plate 112 can be one or more of tempered glass, inorganic glass, plexiglass, or aluminum alloy. The material of the third adhesive layer 123 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0072] In some embodiments, the thickness of the third adhesive layer 123 is greater than the thickness of the first adhesive layer 121. Since the third adhesive layer 123 is located on the back side of the battery cell 130, and the back side of the battery cell 130 is provided with a plurality of interconnecting portions 140, the back side of the battery cell 130 is more uneven than the front side. The greater thickness of the third adhesive layer 123 is beneficial for the third adhesive layer 123 to wrap the back side of the battery cell 130, so as to protect the battery cell 130.

[0073] In some embodiments, the melt index of the material of the third adhesive layer 123 is greater than that of the material of the first adhesive layer 121. Since the back side of the battery cell 130 is less smooth than the front side, the greater fluidity of the third adhesive layer 123 can better wrap the interconnect portion 140, thereby avoiding the problem of air bubbles between the battery cell 130 and the third adhesive layer 123.

[0074] Figures 7 to 11 The diagram shows the structural steps corresponding to each step of the second photovoltaic module manufacturing method provided in this application embodiment. Figure 8 for Figure 7 A schematic diagram of the cross-sectional structure along the BB1 ​​direction. Figure 10 for Figure 9 A schematic diagram of the cross-sectional structure along the BB1 ​​direction.

[0075] refer to Figure 1 as well as Figures 7 to 11 The second method for manufacturing a photovoltaic module provided in this application includes:

[0076] Step S11: Refer to the reference Figure 7 and Figure 8 A first adhesive film layer 221 and a second adhesive film layer 222 are laid on the first cover plate 211. The first adhesive film layer 221 covers the surface of the first cover plate 211, and the second adhesive film layer 222 is located on the first adhesive film layer 221. The second adhesive film layer 222 has a plurality of hollow parts arranged along the first direction X. The hollow parts and the first adhesive film layer 221 form a receiving groove 231. The thickness of the first adhesive film layer 221 is greater than the thickness of the second adhesive film layer 222.

[0077] Step S12: Refer to the reference Figure 9 and Figure 10 The battery cells 230 are laid out, and the multiple battery cells 230 are matched one-to-one with the receiving grooves 231. The adjacent battery cells 230 are connected sequentially through the interconnection part (not shown in the figure).

[0078] In this embodiment, the grid lines of different polarities on the battery cell 130 are located on the front and back sides of the battery cell 130, respectively. The battery cell 230 is laid with the first cover plate 111 on opposite sides along the first direction X as the first side and the second side, respectively. This includes: placing the first end of the battery cell 230 near the first side in the receiving groove 231, placing the second end of the battery cell 230 near the second side on the second adhesive layer 222, and along the first direction X, the first end of an adjacent battery cell 230 is located below the second end of another battery cell 230, and the interconnection portion is located between the first end of one battery cell 230 and the second end of another battery cell 230, so that multiple battery cells 230 form a shingled battery string.

[0079] In this embodiment, the solar cell 230 can be any one of PERC (Passivated Emitter and Rear Cell), PERT (Passivated Emitter and Rear Totally-diffused cell), TOPCon (Tunnel Oxide Passivated Contact), or HIT / HJT (Heterojunction Technology) cells.

[0080] The type of solar cell 230 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0081] Step S13: Reference Figure 11 A third adhesive film layer 223 and a second cover plate 212 are laid on the battery cell 230 to form the laminate to be laminated.

[0082] Step S14: Perform lamination on the component to be laminated.

[0083] In the photovoltaic module manufacturing method provided in this application embodiment, a first adhesive film layer 221 is first covered on a first cover plate 211, and a second adhesive film layer 222 with multiple hollow portions is provided on the first adhesive film layer 221 so that the hollow portions and the first adhesive film layer 221 form a receiving groove 231. In the subsequent step of laying the battery cell 230, the first end of the battery cell 230 is located in the receiving groove 231, and the second end of the battery cell 230 is located on the second adhesive film layer 222. On the one hand, the receiving groove 231 can fix the first end of the battery cell 230; on the other hand, the second adhesive film layer 222 raises the second end of the battery cell 230 and stacks it on the first end of another battery cell 230, which is conducive to forming a stacked battery string in a shingled manner. There are no gaps between the battery cells 230, which can make full use of the usable area of ​​the photovoltaic module surface, reduce the line loss of traditional metal grid lines, and significantly improve the conversion efficiency of the photovoltaic module. After further laying the solar cells 230 in the receiving groove 231, a third adhesive film layer 223 and a second cover plate 212 are laid to form a component to be laminated; after laminating the component to be laminated, a photovoltaic module is obtained. The photovoltaic module manufacturing method provided in this application embodiment eliminates the need to weld multiple solar cells 230 into a string before lamination, avoiding the problem of solar cell warping caused by the stringing process. Furthermore, omitting the stringing step also helps reduce the risk of microcracks or fragmentation of the solar cells 230, thus improving the reliability of the photovoltaic module. Simultaneously, eliminating the stringing step eliminates the need for stringing equipment, further reducing the manufacturing cost of the photovoltaic module and improving production efficiency. Furthermore, the thickness of the first adhesive layer 221 is greater than the thickness of the second adhesive layer 222. The greater thickness of the first adhesive layer 221 is beneficial for the first adhesive layer 221 to wrap the surface of the battery cell 230 facing the first adhesive layer 221, thereby protecting the battery cell 230. Since the second adhesive layer 222 is located at the overlapping area of ​​adjacent battery cells 230, the thinner thickness of the second adhesive layer 222 can save on the material cost of the second adhesive layer 222. At the same time, it can also avoid the problem that the second end of the battery cell 230 cannot contact the first end of the other battery cell 230 because the second adhesive layer 122 lifts up the second end of the battery cell 230.

[0084] In step S11, the material of the first cover plate 211 can be one or more of tempered glass, inorganic glass, or organic glass. For example, the material of the first cover plate 211 can be ultra-clear glass, which has high light transmittance and transparency, and is beneficial to improving the light absorption efficiency of photovoltaic modules.

[0085] In some embodiments, the surface of the first cover plate 211 facing the first adhesive film layer 221 may have an uneven structure, which may increase the utilization rate of incident light, thereby improving the light conversion efficiency of the photovoltaic module.

[0086] In step S11, the material of the first adhesive layer 221 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film. The material of the second adhesive layer 222 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0087] In some embodiments, the material of the first adhesive layer 221 may be the same as or different from the material of the second adhesive layer 122.

[0088] In some embodiments, the melt index of the material of the second adhesive layer 222 can be greater than that of the material of the first adhesive layer 221. Thus, at the same melting temperature, the flowability of the second adhesive layer 222 is greater than that of the first adhesive layer 221. In subsequent lamination processes, the greater flowability of the second adhesive layer 222 is beneficial for filling the gap between the battery cell 230 and the first adhesive layer 221 to avoid the formation of air bubbles.

[0089] In some embodiments, along the first direction X, the width of the second end of the solar cell 230 extending beyond the second adhesive layer 222 is greater than 0 and less than or equal to 0.5 mm, for example, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. The width of the second end of the solar cell 230 extending beyond the second adhesive layer 222 corresponds to the overlap width with the first end of another solar cell 230. The overlap width between adjacent solar cells 230 needs to be within an appropriate range to avoid excessive shading of the surface of the solar cell 230 caused by overlap, thereby avoiding affecting the light absorption area and light conversion efficiency of the solar cell 230.

[0090] refer to Figure 9 In some embodiments, the distance between any sidewall of the battery cell 130 and the inner wall of the receiving groove 131 along the direction perpendicular to the first X is 0 to 2 mm, for example, it can be 0, 0.5 mm, 0.7 mm, 1 mm, 1.5 mm, 1.8 mm, or 2 mm. That is, the size of the receiving groove 131 along the direction perpendicular to the first X is slightly larger than the size of the battery cell 130. This facilitates the smooth entry of the battery cell 130 into the receiving groove 131, and at the same time avoids the problem of misalignment of the battery cell 130 due to excessive space for movement within the receiving groove 131.

[0091] In some embodiments, after step S11 and before step S12, the relative positions of the first cover plate 111, the first adhesive layer 121 and the second adhesive layer 122 can be fixed. The fixing method can refer to the fixing method in the foregoing embodiments, and will not be repeated here.

[0092] In some embodiments, the thickness ratio of the second adhesive layer 222 to the thickness of the battery cell 130 is 0.5 to 0.8, for example, 0.5, 0.6, 0.7, or 0.8. The second adhesive layer 222 is located below the second end of the battery cell 230. To prevent the second end of the battery cell 230 from being unable to contact the first end of the other battery cell 230 due to the height of the second adhesive layer 222 being too high, the thickness of the second adhesive layer 222 needs to be less than the thickness of the battery cell 230. Simultaneously, the second adhesive layer 222 also needs to fill the gap between the battery cell 230 and the first adhesive layer 221. The thickness of the second adhesive layer 222 cannot be too small to avoid air bubbles forming between the battery cell 230 and the first adhesive layer 221. Therefore, the thickness ratio of the second adhesive layer 222 to the thickness of the battery cell 230 needs to be within an appropriate range.

[0093] The thickness of the second adhesive film layer 222 can be 90μm to 180μm, for example, it can be 90μm, 100μm, 120μm, 150μm or 180μm.

[0094] In some embodiments, the interconnect portion 140 may be a conductive adhesive or a solder layer. The surface of the solder layer may have a tin plating layer with a melting point of 135°C to 150°C. In this way, the interconnect portion may be alloyed with the grid lines on the cell 130 during subsequent lamination, which is beneficial to improving the carrier transport efficiency between the interconnect portion and the cell 230, thereby improving the efficiency of the photovoltaic module.

[0095] After step S12, the method further includes laying a busbar for connecting the battery cells 130 located at the ends to draw current from the battery string.

[0096] Figure 12 This is a structural schematic diagram corresponding to a step of laying battery cells provided in an embodiment of this application.

[0097] refer to Figure 12In some embodiments, before laying the battery cell 230, the method further includes: laying a sub-adhesive film layer 224 on the first adhesive film layer 221, the sub-adhesive film layer 224 being located in the receiving groove 231, the distance between the sub-adhesive film layer 224 and the second adhesive film layer 222 on the first side being greater than the distance between the sub-adhesive film layer 224 and the second adhesive film layer 222 on the second side, and the thickness of the sub-adhesive film layer 224 being less than the thickness of the second adhesive film layer 222; after laying the battery cell 230, the surface of the sub-adhesive film layer 224 away from the first adhesive film layer 221 is in contact with the battery cell 230. In other words, the sub-adhesive layer 224 is located on the side of the receiving groove 231 near the second end of the battery cell 230. Thus, when the battery cell 230 is placed in the receiving groove 231, the gap between the battery cell 230 and the first adhesive layer 221 is filled by the sub-adhesive layer 224. On the one hand, the sub-adhesive layer 224 can support the battery cell 230; on the other hand, in the subsequent lamination process, the sub-adhesive layer 224 can fill the gap between the battery cell 230 and the first adhesive layer 221 more quickly, avoiding the problem of air bubbles.

[0098] Continue to refer to Figure 12 In some embodiments, a sub-film layer 224 is laid on the first adhesive film layer 221, including: a plurality of sub-film layers 224 arranged along a first direction X within the same receiving groove 231, and the thickness of the plurality of sub-film layers 224 increasing sequentially in the direction from the first side to the second side. Thus, the slope formed by the plurality of sub-film layers 224 is the same as the tilt angle of the battery cell 230.

[0099] In some embodiments, the angle at which the battery cell 230 is tilted relative to the surface of the first adhesive film layer 221 can be greater than 0° and less than or equal to 0.1°, for example, it can be 0.02°, 0.05°, 0.08° or 0.1°.

[0100] The material of the sub-film layer 224 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0101] In some embodiments, the materials of the second adhesive layer 222 and the sub-adhesive layer 224 may be the same or different.

[0102] Figure 13 This is a structural schematic diagram corresponding to a step of laying a fourth adhesive film layer provided in an embodiment of this application.

[0103] refer to Figure 13In some embodiments, after laying the battery cell 230 and before laying the third adhesive layer 223 and the second cover plate 212 on the battery cell 230, a fourth adhesive layer 225 is laid on the surface of the battery cell 230 away from the first adhesive layer 221, the thickness of the fourth adhesive layer 225 being equal to the thickness of the second adhesive layer 222. Since the battery cells 230 are stacked at an angle relative to the surface of the first adhesive layer 221 to form a shingled structure, there is a gap between the surface of the battery cell 230 away from the first adhesive layer 221 and the third adhesive layer 223. Laying the fourth adhesive layer 225 before laying the third adhesive layer 223 and the second cover plate 212 on the battery cell 230 facilitates filling the gap between the first end of the battery cell 230 and the third adhesive layer 223 during subsequent lamination processes, thereby avoiding the problem of air bubbles.

[0104] The material of the fourth film layer 225 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0105] In some embodiments, the material of the fourth adhesive layer 225 may be the same as or different from the material of the third adhesive layer 223.

[0106] In some embodiments, the melt index of the material of the fourth adhesive layer 225 is greater than that of the material of the third adhesive layer 223. This makes it easier for the fourth adhesive layer 225 to fill the gap between the battery cell 230 and the third adhesive layer 223 more quickly during the subsequent lamination process.

[0107] In some embodiments, after step S12, the battery cell 230 can be pre-fixed. The pre-fixing method can refer to the pre-fixing method of the battery cell 130 in the foregoing embodiments, and will not be repeated here.

[0108] In step S13, the material of the second cover plate 212 can be one or more of tempered glass, inorganic glass, plexiglass, or aluminum alloy. The material of the third adhesive layer 223 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0109] In the photovoltaic module manufacturing method provided in this application embodiment, a first adhesive film layer is first covered on a first cover plate, and a second adhesive film layer with multiple perforations is provided on the first adhesive film layer so that the perforations and the first adhesive film layer form a receiving groove. In the subsequent step of laying the battery cells, the receiving groove formed by the first and second adhesive film layers can fix the relative position of the battery cells. After laying the battery cells in the receiving groove, a third adhesive film layer and a second cover plate are laid to form a component to be laminated. After laminating the component to be laminated, a photovoltaic module is obtained. The photovoltaic module manufacturing method provided in this application embodiment eliminates the need to weld multiple battery cells into a battery string before lamination, which can avoid the problem of battery cell warping caused by the stringing process. Moreover, omitting the stringing step can also help reduce the risk of microcracks or fragmentation of the battery cells, thereby improving the reliability of the photovoltaic module. At the same time, omitting the stringing step eliminates the need for stringing equipment, which can also help reduce the manufacturing cost of photovoltaic modules and improve production efficiency. In addition, the thickness of the first adhesive layer is greater than that of the second adhesive layer. The thicker thickness of the first adhesive layer is beneficial for the first adhesive layer to wrap the front of the battery cell, thereby protecting the battery cell; the thinner thickness of the second adhesive layer can save on the material cost of the second adhesive layer.

[0110] Accordingly, another embodiment of this application also provides a photovoltaic module, which can be formed using the photovoltaic module manufacturing method described in the above embodiments. The photovoltaic module includes: a cell string, which is composed of multiple cells connected to adjacent cells via interconnections; an encapsulating film layer that covers the surface of the cell string; and a cover plate located on the surface of the encapsulating film layer away from the cell string.

[0111] The adhesive film layer is formed by melting and mixing the first adhesive film layer, the second adhesive film layer and the third adhesive film layer in the above embodiments. Since the first adhesive film layer, the second adhesive film layer and the third adhesive film layer are melted together after lamination, there may be no obvious boundary between the first adhesive film layer, the second adhesive film layer and the third adhesive film layer.

[0112] The cover plate includes a first cover plate and a second cover plate. Both the first cover plate and the second cover plate can be one or more of tempered glass, inorganic glass, or plexiglass. In this case, the photovoltaic module is a double-glass module, meaning that both sides of the photovoltaic module can be used to absorb sunlight to improve the light conversion efficiency of the photovoltaic module. Alternatively, the first cover plate can be one or more of tempered glass, inorganic glass, or plexiglass, and the second cover plate can be an aluminum alloy cover plate, meaning that the second cover plate is not light-transmitting. In this case, the photovoltaic module is a single-glass module, and only one side of the photovoltaic module is used to absorb sunlight.

[0113] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for manufacturing a photovoltaic module, characterized in that, include: A first adhesive film layer and a second adhesive film layer are laid on a first cover plate. The first adhesive film layer covers the surface of the first cover plate, and the second adhesive film layer is located on the first adhesive film layer. The second adhesive film layer has a plurality of perforations arranged along a first direction. The perforations and the first adhesive film layer form a receiving groove. The thickness of the first adhesive film layer is greater than the thickness of the second adhesive film layer. The melt flow index of the material of the second adhesive film layer is greater than the melt flow index of the material of the first adhesive film layer. The first cover plate, the first adhesive film layer, and the second adhesive film layer are subjected to local heat treatment to bond and fix the first adhesive film layer to the first cover plate and to bond and fix the first adhesive film layer to the second adhesive film layer; the difference between the temperature of the local heat treatment and the higher of the melting temperature of the first adhesive film or the second adhesive film is less than or equal to 10°C. The battery cells are laid out, with each battery cell corresponding to a receiving groove, and adjacent battery cells are sequentially connected by interconnecting parts. The first cover plate includes a first side and a second side opposite to each other along the first direction. Laying out the battery cells includes: placing the first end of the battery cell near the first side in the receiving groove, and placing the second end of the battery cell near the second side on the second adhesive layer. Along the first direction, the first end of an adjacent battery cell is located below the second end of another battery cell. The interconnecting part is located between the first end of one battery cell and the second end of another battery cell. The surface of the interconnecting part has a welding layer with a melting point of 135°C to 150°C. The interconnecting part is fixed to the surface of the battery cell by means of conductive adhesive, light-curing adhesive, or insulating film bonding. Pre-fixing treatment is performed, at least by heating the second adhesive film layer so that the second adhesive film layer melts and adheres to the side wall of the battery cell. A third adhesive film layer and a second cover plate are laid on the battery cell to form the laminate to be laminated; The component to be laminated is subjected to a lamination process to weld the battery cell to the interconnection portion.

2. The method for manufacturing a photovoltaic module according to claim 1, characterized in that, Before laying the solar cells, the procedure also includes: A sub-film layer is laid on the first film layer, the sub-film layer is located in the receiving groove, the distance between the sub-film layer and the second film layer on the first side is greater than the distance between the sub-film layer and the second film layer on the second side, and the thickness of the sub-film layer is less than the thickness of the second film layer. After the battery cell is laid, the surface of the sub-film layer away from the first film layer comes into contact with the battery cell.

3. The method for manufacturing a photovoltaic module according to claim 2, characterized in that, Laying a sub-film layer on the first film layer further includes: setting a plurality of the sub-film layers arranged along the first direction in the same receiving groove, wherein the thickness of the plurality of sub-film layers increases sequentially in the direction from the first side to the second side.

4. The method for manufacturing a photovoltaic module according to claim 1, characterized in that, After the battery cell is laid, and before the third adhesive film layer and the second cover plate are laid on the battery cell, the method further includes: A fourth adhesive film layer is laid on the surface of the first end of the battery cell away from the first adhesive film layer, and the thickness of the fourth adhesive film layer is equal to the thickness of the second adhesive film layer.

5. The method for manufacturing a photovoltaic module according to claim 1, characterized in that, The thickness of the second adhesive film layer is 0.5 to 0.8 times the thickness of the battery cell.

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