Manufacturing method of photovoltaic module

Abstract

The embodiment of the invention relates to the technical field of photovoltaic, and provides a manufacturing method of a photovoltaic module, which is at least beneficial to improving the reliability of the photovoltaic module. The manufacturing method comprises the steps that 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, the second adhesive film layer is located on the first adhesive film layer, the second adhesive film layer is provided with a plurality of hollowed-out parts arranged in the first direction, and the hollowed-out parts and the first adhesive film layer define a containing groove; the thickness of the first adhesive film layer is greater than that of the second adhesive film layer; battery pieces are laid, the multiple battery pieces are in one-to-one correspondence with the containing grooves, and the adjacent battery pieces are sequentially connected through interconnection parts; laying a third adhesive film layer and a second cover plate on the battery piece to form a to-be-laminated piece; and laminating the to-be-laminated piece.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a method for manufacturing a photovoltaic module. Background Art

[0002] At present, global energy consumption is increasing rapidly, traditional fossil energy is becoming increasingly depleted, and energy and environmental issues have gradually become two major issues of global concern. Under the pressure of environmental pollution and sustainable development, major countries have listed the solar photovoltaic industry as a key area of ​​renewable energy development and utilization.

[0003] In order to obtain photovoltaic modules with suitable current, voltage and output power, in the solar photovoltaic industry, solar cells need to be connected in series and formed into photovoltaic modules through processes such as stacking, lamination and packaging before they can become practical application products with power output. In the manufacturing process of crystalline silicon photovoltaic modules, the cells are first welded into battery strings with welding ribbons, and then multiple battery strings are arranged neatly. Next, the bus bars are welded to the welding ribbons extending from the ends of multiple battery strings. The bus bars can then collect the current into the junction box to provide power to the outside world.

[0004] However, the battery cells are prone to hidden cracks or fragments during the string welding process, and due to the different thermal expansion coefficients of the welding ribbon and the battery cells, the battery cells are prone to warping after string welding, which leads to low reliability of photovoltaic modules. Summary of the invention

[0005] The embodiment of the present application provides a method for manufacturing a photovoltaic module, which is at least beneficial to improving the reliability of the photovoltaic module.

[0006] According to some embodiments of the present application, on the one hand, the embodiments of the present application provide a method for manufacturing a photovoltaic module, including: laying a first film layer and a second film layer on a first cover plate, the first film layer covering the surface of the first cover plate, the second film layer being located on the first film layer, the second film layer having a plurality of hollow portions arranged along a first direction, the hollow portions and the first film layer forming a receiving groove, the thickness of the first film layer being greater than the thickness of the second film layer; laying battery cells, arranging a plurality of battery cells to correspond to the receiving grooves one by one, and connecting adjacent battery cells in sequence through interconnecting portions; laying a third film layer and a second cover plate on the battery cells to form a laminated component; and laminating the laminated component.

[0007] In some embodiments, laying out the battery cell includes: placing the battery cell in a receiving groove, laying out the interconnection portion on a surface of the battery cell away from the first adhesive film layer, and then fixing the interconnection 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 laying the battery cells includes: placing the first end of the battery cell close to the first side in the accommodating groove, placing the second end of the battery cell close to the second side on the second adhesive film layer, along the first direction, the first end of an adjacent battery cell is located below the second end of another battery cell, and the interconnection portion is located between the first end of one battery cell and the second end of another battery cell.

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

[0010] In some embodiments, laying a sub-film layer on the first film layer also includes: arranging multiple sub-film layers arranged along a first direction in the same receiving groove, and the thicknesses of the multiple sub-film layers increase sequentially in a direction from the first side to the second side.

[0011] In some embodiments, after laying the battery cell and before laying the third film layer and the second cover plate on the battery cell, it also includes: laying a fourth film layer on the surface of the first end of the battery cell away from the first film layer, and the thickness of the fourth film layer is equal to the thickness of the second film layer.

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

[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 laying the first adhesive film layer and the second adhesive film layer on the first cover plate and before laying the battery cell, the method includes: locally heating the first cover plate, the first adhesive film layer and the second adhesive film layer to make the first adhesive film layer and the first cover plate bonded and fixed to each other, and the first adhesive film layer and the second adhesive film layer bonded and fixed to each other.

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

[0016] In some embodiments, after laying the battery cells, the method further includes: performing a pre-fixation process, at least heating the second adhesive film layer, so that the second adhesive film layer is melted and then bonded and fixed to the side wall of the battery cell.

[0017] The technical solution provided by the embodiments of the present application has at least the following advantages:

[0018] In the manufacturing method of the photovoltaic module provided by the embodiment of the present application, the first adhesive film layer is first covered on the first cover plate, and the second adhesive film layer with multiple hollow parts is arranged on the first adhesive film layer, so that the hollow parts and the first adhesive film layer form a receiving groove, and in the subsequent step of laying the battery cells, the receiving groove surrounded by the first adhesive film layer and the second adhesive film layer can play a role in fixing the relative position of the battery cells; after further laying the battery cells in the receiving groove, the third adhesive film layer and the second cover plate are laid to form a laminated part; after laminating the laminated part, the photovoltaic module is obtained. Through the manufacturing method of the photovoltaic module provided by the embodiment of the present application, it is not necessary to weld multiple battery cells into a battery string before lamination, which can avoid the problem of battery cell warping caused by the string welding process, and omitting the string welding step can also help reduce the risk of hidden cracks or fragments of the battery cells, thereby helping to improve the reliability of the photovoltaic module; at the same time, after omitting the string welding step, string welding equipment is not required, which is also conducive to reducing the manufacturing cost of the photovoltaic module and improving production efficiency. In addition, the thickness of the first film layer is greater than that of the second film layer. The thicker thickness of the first film layer is beneficial for the first film layer to wrap the front side of the battery cell, thereby protecting the battery cell; the thinner thickness of the second film layer can save the material usage cost of the second film layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present application or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A flowchart corresponding to the method for manufacturing a photovoltaic module provided in an embodiment of the present application;

[0021] Figures 2 to 6 A schematic structural diagram corresponding to each step of the first method for manufacturing a photovoltaic module provided in an embodiment of the present application;

[0022] Figures 7 to 11 A schematic structural diagram corresponding to each step of the second method for manufacturing a photovoltaic module provided in an embodiment of the present application;

[0023] Fig.12 A schematic diagram of a structure corresponding to a step of laying battery cells provided in an embodiment of the present application;

[0024] Fig.13 A structural schematic diagram corresponding to the step of laying a fourth adhesive film layer provided in an embodiment of the present application. DETAILED DESCRIPTION

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

[0026] In the manufacturing method of the photovoltaic module provided by the embodiment of the present application, the first adhesive film layer is first covered on the first cover plate, and the second adhesive film layer with multiple hollow parts is arranged on the first adhesive film layer, so that the hollow parts and the first adhesive film layer form a receiving groove, and in the subsequent step of laying the battery cells, the receiving groove surrounded by the first adhesive film layer and the second adhesive film layer can play a role in fixing the relative position of the battery cells; after further laying the battery cells in the receiving groove, the third adhesive film layer and the second cover plate are laid to form a laminated part; after laminating the laminated part, the photovoltaic module is obtained. Through the manufacturing method of the photovoltaic module provided by the embodiment of the present application, it is not necessary to weld multiple battery cells into a battery string before lamination, which can avoid the problem of battery cell warping caused by the string welding process, and omitting the string welding step can also help reduce the risk of hidden cracks or fragments of the battery cells, thereby helping to improve the reliability of the photovoltaic module; at the same time, after omitting the string welding step, string welding equipment is not required, which is also conducive to reducing the manufacturing cost of the photovoltaic module and improving production efficiency. In addition, the thickness of the first film layer is greater than that of the second film layer. The thicker thickness of the first film layer is beneficial for the first film layer to wrap the front side of the battery cell, thereby protecting the battery cell; the thinner thickness of the second film layer can save the material usage cost of the second film layer.

[0027] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood 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 the present application, “plurality” means more than two, unless otherwise clearly and specifically defined.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the description of the embodiments of the present application, technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0032] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0033] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layer are magnified 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 a third component may be present between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as "substantially" 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 partial edge of the entire surface.

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

[0035] The terms used in the description of various embodiments herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of various embodiments described and the appended claims, "components" are also intended to include plural forms unless the context clearly indicates otherwise.

[0036] The following will describe the various embodiments of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present application, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed in the present application can be implemented.

[0037] Figure 1 A flowchart corresponding to the method for manufacturing a photovoltaic module provided in an embodiment of the present application; Figures 2 to 6 The schematic diagram of the structure corresponding to each step of the first method for manufacturing a photovoltaic module provided in the embodiment of the present application, wherein: Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA1 direction; Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure along direction AA1.

[0038] refer to Figures 1 to 6 The first method for manufacturing a photovoltaic module provided in an embodiment of the present application includes:

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

[0040] Step S12: Combine with reference Figure 4 and Figure 5 , laying out the battery cells 130 , aligning the plurality of battery cells 130 with the receiving grooves 131 one by one, and sequentially connecting the adjacent battery cells 130 through the interconnection portions 140 .

[0041] In this embodiment, the grid lines of different polarities on the battery cell 130 are all on the back side of the battery cell 130, that is, the battery cell 130 is a BC battery (Back Contact), and the interconnection part 140 is a welding strip. In this way, the steps of laying the battery cell 103 include: placing the battery cell 130 in the receiving groove 131, the front side of the battery cell 130 is in contact with the first adhesive film layer 121, laying the interconnection part 140 on the surface of the battery cell 130 away from the first adhesive film layer 121 (that is, the back side), and then fixing the interconnection part 140 on 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 superimpose TOPCon (Tunnel Oxide Passivated Contact) technology and IBC technology, or HBC batteries that superimpose HIT / HJT (Heterojunction Technology) technology and IBC technology. Of course, other types of back contact batteries can also be used.

[0043] The type of the cell 130 may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell or a multi-compound solar cell. The multi-compound solar cell may specifically 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 a laminated component.

[0045] Step S14: performing lamination processing on the laminated parts.

[0046] In the manufacturing method of the photovoltaic module provided in the embodiment of the present application, the first adhesive film layer 121 is first covered on the first cover plate 111, and the second adhesive film layer 122 having a plurality of hollow portions is arranged 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 cell 130, the receiving groove 131 surrounded by the first adhesive film layer 121 and the second adhesive film layer 122 can play a role in fixing the relative position of the battery cell 130, and can prevent the battery cell 130 from moving during the laying of the interconnection portion 140, thereby improving the stability of the interconnection portion 140 connecting adjacent battery cells 130; after further laying the battery cell 130 in the receiving groove 131, the third adhesive film layer 123 and the second cover plate 112 are laid on the battery cell 130 to form a laminated component; after laminating the laminated component, the photovoltaic module is obtained. By using the manufacturing method of the photovoltaic module provided in the embodiment of the present application, it is not necessary to weld the multiple battery cells 130 into a battery string before lamination, which can avoid the problem of battery cell warping caused by the string welding process. In addition, omitting the string welding step can also help reduce the risk of hidden cracks or fragments of the battery cells 130, thereby helping to improve the reliability of the photovoltaic module. At the same time, after omitting the string welding step, the string welding equipment is not required, which can also help to reduce the manufacturing cost of the photovoltaic module and improve production efficiency. In addition, the thickness of the first film layer 121 is greater than that of the second film layer 122. The thicker thickness of the first film layer 121 is beneficial for the first film layer 121 to wrap the front side of the battery cell 130, thereby protecting the battery cell 130. Since the second film layer 122 is located between adjacent battery cells 130, it only needs to limit the movement of the battery cell 130 on the surface of the first film layer 121. The thinner thickness of the second film layer 122 can save the material cost of the second film layer 122, and at the same time, it can also avoid the problem that the second film layer 122 lifts up the interconnection portion 140, resulting in the battery cell 130 and the interconnection portion 140 being unable to contact each other.

[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-white glass, which has high light transmittance and transparency, and is conducive to improving the light absorption efficiency of the photovoltaic module.

[0048] In some embodiments, the surface of the first cover plate 111 facing the first adhesive film layer 121 may have a concave-convex structure, and the concave-convex structure may increase the utilization rate of incident light, thereby facilitating the improvement of the light conversion efficiency of the photovoltaic module.

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

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

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

[0052] refer to Figure 4 The size of the hollow portion may be larger than the size of the battery cell 130 , and correspondingly, the size of the receiving groove 131 is larger than the size of the battery cell 130 . Thus, 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 side wall of the battery cell 130 and the inner wall of the receiving groove 131 is 0-2 mm, for example, 0 mm, 0.5 mm, 0.7 mm, 1 mm, 1.5 mm, 1.8 mm or 2 mm. In other words, the size of the receiving groove 131 is slightly larger than the size of the battery cell 130, which is conducive to the battery cell 130 being able to smoothly enter the receiving groove 131, and at the same time, it can also avoid the problem of misalignment of the layout of the battery cell 130 caused by the excessive activity space of the battery cell 130 in 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 film layer 121 , and the second adhesive film layer 122 may be fixed.

[0055] For example, the first cover plate 111 , the first adhesive film layer 121 and the second adhesive film layer 122 may be locally heated to bond the first adhesive film layer 121 to the first cover plate 111 and to bond the first adhesive film layer 121 to the second adhesive film layer 122 . That is to say, after laying the first adhesive film layer 121 and the second adhesive film layer 122 on the first cover plate 111 and before laying the battery cell 130, the first cover plate 111, the first adhesive film layer 121 and the second adhesive film layer 122 are first locally heated to partially melt the first adhesive film layer 121 and the second adhesive film layer 122, so that the first adhesive film layer 121 and the second adhesive film layer 122 are firmly bonded and fixed to each other, and the first adhesive film layer 121 and the first cover plate 111 are also bonded and fixed to each other. 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 arrangement position of the battery cell 130 in the subsequent placement of the battery cell 130.

[0056] The temperature of the local heating treatment may be greater than the melting temperature of the first adhesive film layer 121, and the difference between the temperature of the local heating treatment and the melting temperature of the first adhesive film layer 121 is less than or equal to 10°C; and / or, the temperature of the local heating treatment is greater than the melting temperature of the second adhesive film layer 122, and the difference between the temperature of the local heating treatment and the melting temperature of the second adhesive film layer 122 is less than or equal to 10°C. When the difference between the melting temperatures of the first adhesive film layer 121 and the second adhesive film layer 122 is greater than 10°C, the temperature of the local heating treatment may be determined according to the one with the higher melting temperature of the first adhesive film layer 121 and the second adhesive film layer 122. When the difference between the temperature of the local heating treatment and the melting temperature of the first adhesive film layer 121 and / or the melting temperature of the second adhesive film layer 122 is within an appropriate range, the first adhesive film layer 121 and the second adhesive film layer 122 may be partially melted to produce a certain bonding effect, and at the same time, the problem of local collapse or deformation due to excessive melting will not be caused.

[0057] The local heating process may adopt one or more of an infrared heating process, a microwave heating process, a hot air heating process or a laser heating process.

[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 coating an adhesive layer between the first cover plate 111 and the first adhesive film layer 121 in step S11, so that the relative positions between the first cover plate 111 and the first adhesive film layer 121 are fixed; similarly, coating an adhesive layer between the first adhesive film layer 121 and the second adhesive film layer 122, so that the relative positions between the first adhesive film layer 121 and the second adhesive film layer 122 are fixed. The adhesive layer can be glue or light-curing glue.

[0059] In some other embodiments, the relative positions of the first cover plate 111, the first film layer 121 and the second film layer 122 may be fixed by, in step S11, after laying the first film layer 121 on the first cover plate 111, the first cover plate 111 and the second film layer 122 may be subjected to full-surface heating treatment so that the first film layer 121 and the first cover plate 111 are bonded to each other as a whole, and then the second film layer 122 is placed on the first film layer 121. The second film layer 122 and the first film layer 121 may be fixed by local heating treatment or coating an adhesive layer.

[0060] The whole surface heating treatment may adopt one or more of a lamination process, an infrared heating process, a microwave heating process, a hot air heating process, a hot roller heating process or a laser heating process.

[0061] In some embodiments, the ratio of the thickness of the second adhesive film layer 122 to the thickness of the battery cell 130 is 0.5 to 0.8, for example, it can be 0.5, 0.6, 0.7 or 0.8. The second adhesive film layer 122 is located between adjacent battery cells 130. In order to avoid the second adhesive film layer 122 being too high to cause the interconnection portion 140 to be lifted up and unable to contact the battery cell 130, the thickness of the second adhesive film layer 122 needs to be less than the thickness of the battery cell 130. At the same time, the second adhesive film layer 122 also needs to fill the gap between adjacent battery cells 130. The thickness of the second adhesive film layer 122 cannot be too small to avoid the problem of bubbles between adjacent battery cells 130. Therefore, the ratio of the thickness of the second adhesive film 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 may be 90 μm to 180 μm, for example, 90 μm, 100 μm, 120 μm, 150 μm or 180 μm.

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

[0064] In some embodiments, the interconnection 140 may be a low-temperature solder strip, that is, the melting point of the tinned layer on the surface of the solder strip is 135° C. to 150° C. In this way, the interconnection 140 may be alloyed with the grid lines on the cell 130 in the subsequent lamination process, so as to improve the carrier transmission efficiency between the interconnection 140 and the cell 130, thereby improving the efficiency of the photovoltaic module.

[0065] After step S12 , the method further includes: laying bus bars, where the bus bars are used to connect ends of the interconnection parts 140 to conduct current on the interconnection parts 140 .

[0066] In the drawings provided in the embodiments of the present application, a battery string including three battery cells 130 is taken 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 may also be 4, 5, 6 or 8, etc. In some embodiments, multiple battery strings may also be connected in series or in parallel through a bus bar.

[0067] In some embodiments, after step S12 , the process further includes: performing a pre-fixing process, where the pre-fixing process 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 film layer 122 so that the second adhesive film layer 122 is melted and then bonded and fixed to the side wall of the battery cell 130. After laying the battery cell 130, the second adhesive film layer 122 is heated so that the second adhesive film layer 122 is melted and then bonded and fixed to the side wall of the battery cell 130, which can fix the relative position of the battery cell 130 on the one hand; on the other hand, the second adhesive film layer 122 pre-fills the gap between adjacent battery cells 130, which can avoid the problem of bubbles between the battery cells 130 in the subsequent lamination process.

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

[0070] In other embodiments, before step S12, it includes: before placing the battery cell 130 in the receiving groove 131, an adhesive layer can be coated on the bottom surface of the receiving groove 131 (i.e., the surface of the first adhesive film layer 121) so that the battery cell 130 is fixed in the receiving groove 131 through 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, organic glass or aluminum alloy. The material of the third film layer 123 can be one or more of ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film or polyvinyl butyral (PVB) film.

[0072] In some embodiments, the thickness of the third adhesive film layer 123 is greater than that of the first adhesive film layer 121. Since the third adhesive film layer 123 is located on the back side of the battery cell 130, a plurality of interconnecting portions 140 are provided on the back side of the battery cell 130, which causes the back side of the battery cell 130 to be more uneven than the front side. The greater thickness of the third adhesive film layer 123 is beneficial for the third adhesive film layer 123 to wrap the back side of the battery cell 130, thereby protecting the battery cell 130.

[0073] In some embodiments, the melting index of the material of the third film layer 123 is greater than the melting index of the material of the first film layer 121. Since the back side of the battery cell 130 is more uneven than the front side, the greater fluidity of the third film layer 123 can be more conducive to the third film layer 123 wrapping the interconnection portion 140, thereby avoiding the problem of bubbles generated between the battery cell 130 and the third film layer 123.

[0074] Figures 7 to 11 The schematic diagram of the structure corresponding to each step of the second method for manufacturing a photovoltaic module provided in the embodiment of the present application, wherein: Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure along the BB1 ​​direction, Fig.10 for Fig. 9 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 the embodiment of the present application includes:

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

[0077] Step S12: Combine with reference Fig. 9 and Fig.10 , laying out the battery cells 230 , aligning the plurality of battery cells 230 with the receiving grooves 231 one by one, and sequentially connecting the adjacent battery cells 230 through interconnecting portions (not shown in the figure).

[0078] In this embodiment, the grid lines of different polarities on the battery cell 130 are respectively located on the front and back sides of the battery cell 130. The battery cell 230 is laid with the first cover plate 111 having two opposite sides along the first direction X, namely the first side and the second side, including: placing the first end of the battery cell 230 close to the first side in the receiving groove 231, placing the second end of the battery cell 230 close to the second side on the second adhesive film layer 222, 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 a plurality of battery cells 230 form a battery string with a shingled structure.

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

[0080] The type of the cell 230 may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell or a multi-compound solar cell. The multi-compound solar cell may specifically 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 Fig.11 , a third adhesive film layer 223 and a second cover plate 212 are laid on the battery cell 230 to form a laminated component.

[0082] Step S14: performing lamination processing on the laminated parts.

[0083] In the manufacturing method of the photovoltaic module provided in the embodiment of the present application, the first cover plate 211 is first covered with a first adhesive film layer 221, and a second adhesive film layer 222 having a plurality of hollow portions is arranged 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 play a role in fixing 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 then stacks it on the first end of another battery cell 230, so as to facilitate the formation of a battery string stacked in a shingled manner. There is no gap between the battery cells 230, which can make full use of the available area on the surface of the photovoltaic module, reduce the line loss of the traditional metal grid line, and greatly improve the conversion efficiency of the photovoltaic module. After further laying the cell 230 in the receiving groove 231, the third adhesive film layer 223 and the second cover plate 212 are laid to form a laminated part; the laminated part is laminated to obtain a photovoltaic module. Through the manufacturing method of the photovoltaic module provided by the embodiment of the present application, it is not necessary to weld multiple cell pieces 230 into a cell string before lamination, which can avoid the problem of cell warping caused by the string welding process, and omitting the string welding step can also help reduce the risk of hidden cracks or fragments of the cell 230, which is beneficial to improve the reliability of the photovoltaic module; at the same time, after omitting the string welding step, string welding equipment is not required, which is also beneficial to reduce the manufacturing cost of the photovoltaic module and improve production efficiency. In addition, the thickness of the first adhesive film layer 221 is greater than that of the second adhesive film layer 222. The thicker thickness of the first adhesive film layer 221 is beneficial for the first adhesive film layer 221 to wrap the surface of the battery cell 230 facing the first adhesive film layer 221, thereby protecting the battery cell 230. Since the second adhesive film layer 222 is located at the overlapping part of adjacent battery cells 230, the thinner thickness of the second adhesive film layer 122 can save the material usage cost of the second adhesive film layer 122, and at the same time, it can also avoid the problem that the second adhesive film layer 122 lifts the second end of the battery cell 230, resulting in the second end of the battery cell 230 being unable to contact the first end of another 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-white glass, which has high light transmittance and transparency, and is conducive to improving the light absorption efficiency of the photovoltaic module.

[0085] In some embodiments, the surface of the first cover plate 211 facing the first adhesive film layer 221 may have a concave-convex structure, and the concave-convex structure may increase the utilization rate of incident light, thereby facilitating the improvement of the light conversion efficiency of the photovoltaic module.

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

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

[0088] In some embodiments, the melt index of the material of the second adhesive film layer 222 may be greater than the melt index of the material of the first adhesive film layer 221. Thus, at the same melting temperature, the fluidity of the second adhesive film layer 222 is greater than the fluidity of the first adhesive film layer 221. In the subsequent lamination process, the greater fluidity of the second adhesive film layer 222 is conducive to filling the gap between the battery cell 230 and the first adhesive film layer 221 to avoid the problem of bubbles.

[0089] In some embodiments, along the first direction X, the width of the second end of the battery cell 230 beyond the second adhesive film 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, etc. The width of the second end of the battery cell 230 beyond the second adhesive film layer 222 corresponds to the overlapping width with the first end of another battery cell 230. The overlapping width between adjacent battery cells 230 needs to be within an appropriate range to avoid excessive shielding of the surface of the battery cell 230 caused by the overlap, thereby avoiding affecting the light absorption area and light conversion efficiency of the battery cell 230.

[0090] refer to Fig. 9 In some embodiments, along the direction perpendicular to the first direction X, the distance between any side wall of the battery cell 130 and the inner wall of the receiving groove 131 is 0-2 mm, for example, 0, 0.5 mm, 0.7 mm, 1 mm, 1.5 mm, 1.8 mm or 2 mm. In other words, the size of the receiving groove 131 along the direction perpendicular to the first direction X is slightly larger than the size of the battery cell 130, which is conducive to the battery cell 130 being able to smoothly enter the receiving groove 131, and at the same time, it can also avoid the problem of misalignment of the layout of the battery cell 130 caused by the excessive activity space of the battery cell 130 in 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 film layer 121, and the second adhesive film layer 122 may be fixed. The fixing method may refer to the fixing method in the aforementioned embodiment and will not be repeated here.

[0092] In some embodiments, the ratio of the thickness of the second adhesive film 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 film layer 222 is located below the second end of the battery cell 230. To avoid the second end of the battery cell 230 being lifted up and unable to contact the first end of another battery cell 230 due to the high height of the second adhesive film layer 222, the thickness of the second adhesive film layer 222 needs to be less than the thickness of the battery cell 230. At the same time, the second adhesive film layer 222 also needs to fill the gap between the battery cell 230 and the first adhesive film layer 221. The thickness of the second adhesive film layer 222 cannot be too small to avoid the problem of bubbles between the battery cell 230 and the first adhesive film layer 221. Therefore, the ratio of the thickness of the second adhesive film 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 may be 90 μm to 180 μm, for example, 90 μm, 100 μm, 120 μm, 150 μm or 180 μm.

[0094] In some embodiments, the interconnection 140 may be a conductive adhesive or a solder layer. The surface of the solder layer may have a tinned layer, and the melting point of the tinned layer may be 135° C. to 150° C. In this way, the interconnection may be alloyed with the grid line on the cell 130 in the subsequent lamination process, so as to improve the carrier transmission efficiency between the interconnection and the cell 230, thereby improving the efficiency of the photovoltaic module.

[0095] After step S12, the process further includes: laying bus bars, which are used to connect the battery cells 130 at the ends to derive the current in the battery string.

[0096] Fig.12 A structural schematic diagram corresponding to the steps of laying battery cells provided in an embodiment of the present application.

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

[0098] Continue to refer Fig.12 In some embodiments, laying a sub-adhesive film layer 224 on the first adhesive film layer 221 includes: arranging multiple sub-adhesive film layers 224 arranged along the first direction X in the same receiving groove 231, and the thickness of the multiple sub-adhesive film layers 224 increases in sequence in the direction from the first side to the second side. In this way, the slope formed by the multiple sub-adhesive film layers 224 is the same as the inclination angle of the battery cell 230.

[0099] In some embodiments, the angle at which the battery cell 230 is inclined relative to the surface of the first adhesive film layer 221 may be greater than 0° and less than or equal to 0.1°, for example, 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, polyethylene octene co-elastomer (POE) film or polyvinyl butyral (PVB) film.

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

[0102] Fig.13 A structural schematic diagram corresponding to the step of laying a fourth adhesive film layer provided in an embodiment of the present application.

[0103] refer to Fig.13In some embodiments, after laying the battery cell 230, before laying the third adhesive film layer 223 and the second cover plate 212 on the battery cell 230, the method further includes: laying the fourth adhesive film layer 225 on the surface of the first end of the battery cell 230 away from the first adhesive film layer 221, and the thickness of the fourth adhesive film layer 225 is equal to the thickness of the second adhesive film layer 222. Since the battery cells 230 are stacked obliquely relative to the surface of the first adhesive film layer 221 to form a shingled structure, there is a gap between the surface of the first end of the battery cell 230 away from the first adhesive film layer 221 and the third adhesive film layer 223. Before laying the third adhesive film layer 223 and the second cover plate 212 on the battery cell 230, laying the fourth adhesive film layer 225 is beneficial to fill the gap between the first end of the battery cell 230 and the third adhesive film layer 223 in the subsequent lamination process, thereby avoiding the problem of bubbles.

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

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

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

[0107] In some embodiments, after step S12 , the battery cell 230 may be pre-fixed. The method of the pre-fixed treatment may refer to the method of pre-fixed treatment of the battery cell 130 in the aforementioned embodiment, which will not be described in detail here.

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

[0109] In the manufacturing method of the photovoltaic module provided by the embodiment of the present application, the first adhesive film layer is first covered on the first cover plate, and the second adhesive film layer with multiple hollow parts is arranged on the first adhesive film layer, so that the hollow parts and the first adhesive film layer form a receiving groove, and in the subsequent step of laying the battery cells, the receiving groove surrounded by the first adhesive film layer and the second adhesive film layer can play a role in fixing the relative position of the battery cells; after further laying the battery cells in the receiving groove, the third adhesive film layer and the second cover plate are laid to form a laminated part; after laminating the laminated part, the photovoltaic module is obtained. Through the manufacturing method of the photovoltaic module provided by the embodiment of the present application, it is not necessary to weld multiple battery cells into a battery string before lamination, which can avoid the problem of battery cell warping caused by the string welding process, and omitting the string welding step can also help reduce the risk of hidden cracks or fragments of the battery cells, thereby helping to improve the reliability of the photovoltaic module; at the same time, after omitting the string welding step, string welding equipment is not required, which is also conducive to reducing the manufacturing cost of the photovoltaic module and improving production efficiency. In addition, the thickness of the first film layer is greater than that of the second film layer. The thicker thickness of the first film layer is beneficial for the first film layer to wrap the front side of the battery cell, thereby protecting the battery cell; the thinner thickness of the second film layer can save the material usage cost of the second film layer.

[0110] Correspondingly, another embodiment of the present application further provides a photovoltaic module, which can be formed by the preparation method of the photovoltaic module in the above embodiment. The photovoltaic module includes: a battery string, the battery string is composed of a plurality of battery cells, and adjacent battery cells are connected by interconnection parts; a film layer, the film layer wraps the surface of the battery string; and a cover plate, the cover plate is located on the surface of the film layer away from the battery string.

[0111] The film layer is formed by melting and mixing at least the first film layer, the second film layer and the third film layer in the above embodiment. Since the first film layer, the second film layer and the third film layer are melted with each other after the lamination process, there may be no obvious dividing line between the first film layer, the second film layer and the third film layer.

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

[0113] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present application. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application, and therefore the scope of protection of the present application shall be subject to the scope defined in the claims.

Claims

1. A method for manufacturing a photovoltaic module, characterized in that: include: Laying a first adhesive film layer and a second adhesive film layer on the first cover plate, wherein the first adhesive film layer covers the surface of the first cover plate, the second adhesive film layer is located on the first adhesive film layer, the second adhesive film layer has a plurality of hollow portions arranged along a first direction, the hollow portions and the first adhesive film layer form a receiving groove, and the thickness of the first adhesive film layer is greater than the thickness of the second adhesive film layer; Laying out the battery cells, arranging the battery cells to correspond to the receiving grooves one by one, and sequentially connecting the adjacent battery cells through interconnection parts; Laying a third adhesive film layer and a second cover plate on the battery sheet to form a laminated component; The to-be-laminated member is subjected to a lamination process.

2. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: Laying the battery cell includes: placing the battery cell in the receiving groove, laying the interconnection part on the surface of the battery cell away from the first adhesive film layer, and then fixing the interconnection part to the surface of the battery cell.

3. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: The first cover plate includes a first side and a second side opposite to each other along the first direction, and the battery sheet is laid thereon, including: The first end of the battery cell close to the first side is placed in the receiving groove, and the second end of the battery cell close to the second side is placed on the second adhesive film layer. Along the first direction, the first end of one adjacent battery cell is located below the second end of another adjacent battery cell, and the interconnection portion is located between the first end of one battery cell and the second end of the other battery cell.

4. The method for manufacturing a photovoltaic module according to claim 3, characterized in that: Before laying the battery sheet, the method further includes: Laying a sub-adhesive film layer on the first adhesive film layer, the sub-adhesive film layer is located in the receiving groove, the distance between the sub-adhesive film layer and the second adhesive film layer on the first side is greater than the distance between the sub-adhesive film layer and the second adhesive film layer on the second side, and the thickness of the sub-adhesive film layer is less than the thickness of the second adhesive film layer; After laying the battery cell, a surface of the sub-adhesive film layer away from the first adhesive film layer is in contact with the battery cell.

5. The method for manufacturing a photovoltaic module according to claim 4, characterized in that: Laying a sub-adhesive film layer on the first adhesive film layer also includes: arranging a plurality of the sub-adhesive film layers arranged along the first direction in the same receiving groove, and the thicknesses of the plurality of the sub-adhesive film layers increase sequentially in the direction from the first side to the second side.

6. The method for manufacturing a photovoltaic module according to claim 3, characterized in that: After laying the battery cell and before laying the third adhesive film layer and the second cover plate on the battery cell, the method further includes: A fourth adhesive film layer is laid on a 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.

7. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: The ratio of the thickness of the second adhesive film layer to the thickness of the battery cell is 0.5 to 0.

8.

8. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: After laying the first adhesive film layer and the second adhesive film layer on the first cover plate and before laying the battery cell, the method includes: locally heating the first cover plate, the first adhesive film layer and the second adhesive film layer to make the first adhesive film layer and the first cover plate bonded and fixed to each other, and to make the first adhesive film layer and the second adhesive film layer bonded and fixed to each other.

9. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: The melt index of the material of the second adhesive film layer is greater than the melt index of the material of the first adhesive film layer.

10. The method for manufacturing a photovoltaic module according to claim 1, characterized in that: After laying the battery sheets, the method further includes: A pre-fixation process is performed to at least heat the second adhesive film layer so that the second adhesive film layer is melted and then bonded and fixed to the side wall of the battery cell.

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