A back contact photovoltaic module

Abstract

The application discloses a back contact type photovoltaic module and belongs to the technical field of photovoltaic modules. A cell string comprises cell pieces, the cell pieces have oppositely arranged first surfaces and second surfaces, the first surface of each cell piece is provided with first electric connecting members and second electric connecting members which are arranged alternately and spaced apart along a first direction and a second direction, the plurality of cell pieces comprises first cell pieces and second cell pieces, a first film layer is arranged on the side of the first electric connecting members away from the first cell pieces, a second film layer is arranged on the side of the first electric connecting members away from the second cell pieces, the second film layer is provided with a hollow part, the hollow part is arranged correspondingly to the first electric connecting members, a first bus bar is arranged on the side of the second film layer away from the second cell pieces, the first bus bar is electrically connected to the first electric connecting members through the hollow part, the number of layers of the second film layer is greater than or equal to the number of layers of the first film layer, and the thickness of the second film layer is greater than or equal to the thickness of the first film layer.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module technology, specifically to a back-contact photovoltaic module. Background Technology

[0002] Back-contact photovoltaic (PV) modules, as a type of PV module, offer advantages such as high photoelectric conversion efficiency and aesthetically pleasing appearance. A back-contact PV module includes a cell string, which comprises multiple cells arranged sequentially along a first direction. A first solder strip and a second solder strip extend along the first direction and are alternately spaced along a second direction on the back of the cells. This allows at least two adjacent cells to be connected in series or parallel via the first and second solder strips, forming a cell string to collect the charge carriers generated by the cells.

[0003] In related technologies, a busbar extends along a second direction and connects to a first solder strip to collect the charge carriers gathered by the first solder strip. To prevent short circuits in the photovoltaic module, an insulating film is placed between the busbar and the second solder strip to isolate the busbar from the second solder strip and prevent short circuits in the photovoltaic module.

[0004] However, the above-mentioned method of setting an insulating film between the second solder strip and the busbar results in higher process requirements for photovoltaic modules, affecting the manufacturing efficiency of photovoltaic modules. Summary of the Invention

[0005] This application discloses a back-contact photovoltaic module to solve, or at least partially solve, the problem in the prior art where an insulating film is placed between the second solder strip and the busbar to block the second solder strip and the busbar, resulting in high process requirements for the photovoltaic module and affecting the manufacturing efficiency of the photovoltaic module.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows:

[0007] This application discloses a photovoltaic module, comprising a battery string, the battery string including a plurality of battery cells arranged sequentially along a first direction, each battery cell having a first surface and a second surface disposed opposite to each other, the first surface of each battery cell having a first electrical connector and a second electrical connector extending along the first direction and alternately arranged along a second direction, the plurality of battery cells including first battery cells and second battery cells, the second direction intersecting the first direction; a first film layer disposed on the side of the first electrical connector and the second electrical connector away from the first battery cell; a second film layer disposed on the side of the first electrical connector and the second electrical connector away from the second battery cell, the second film layer having a cutout portion corresponding to the first electrical connector; a first busbar disposed on the side of the second film layer away from the second battery cell, the first busbar extending along the second direction, the first busbar being electrically connected to the first electrical connector through the cutout portion; wherein, the number of layers of the second film layer is greater than or equal to the number of layers of the first film layer, and / or, the thickness of the second film layer is greater than or equal to the thickness of the first film layer.

[0008] The photovoltaic module disclosed in this application has a first film layer disposed on the side of the first and second electrical connectors away from the first solar cell, thereby fixing the first and second electrical connectors to the first surface of the first solar cell through the first film layer. A second film layer is disposed on the side of the first and second electrical connectors away from the second solar cell, thereby fixing the first and second electrical connectors to the first surface of the second solar cell through the second film layer.

[0009] Furthermore, the second film layer has perforations corresponding to the first electrical connector. A first busbar is located on the side of the second film layer away from the second solar cell, extending along a second direction. The first busbar is electrically connected to the first electrical connector through the perforations. It can be understood that the second film layer can block the second electrical connector and the first busbar, preventing them from conducting and causing a short circuit in the photovoltaic module.

[0010] Furthermore, the number of layers in the second film layer is greater than or equal to the number of layers in the first film layer, and / or the thickness of the second film layer is greater than or equal to the thickness of the first film layer, so that the second film layer can block the second electrical connector and the first busbar, preventing the second electrical connector and the first busbar from conducting and causing a short circuit in the photovoltaic module. Attached Figure Description

[0011] Figure 1 This diagram illustrates the structure of the photovoltaic module described in the embodiments of this application. Figure 1 ;

[0012] Figure 2 This diagram illustrates the structure of the photovoltaic module described in the embodiments of this application. Figure 2 ;

[0013] Figure 3 This diagram illustrates the structure of the photovoltaic module described in the embodiments of this application. Figure 3 ;

[0014] Figure 4 This diagram illustrates the structure of the photovoltaic module described in the embodiments of this application. Figure 4 ;

[0015] Figure 5 This is a cross-sectional view of the photovoltaic module described in the embodiments of this application;

[0016] Figure 6 This is a partial schematic diagram of the photovoltaic module described in the embodiments of this application. Figure 1 ;

[0017] Figure 7 This is a partial schematic diagram of the photovoltaic module described in the embodiments of this application. Figure 2 ;

[0018] Figure 8 This is a partial schematic diagram of the photovoltaic module described in the embodiments of this application. Figure 3 ;

[0019] Figure 9 This diagram illustrates the structure of the second film layer in the embodiments of this application. Figure 1 ;

[0020] Figure 10 This diagram illustrates the structure of the second film layer in the embodiments of this application. Figure 2 ;

[0021] Figure 11 This diagram illustrates the structure of the second film layer in the embodiments of this application. Figure 3 ;

[0022] Figure 12 This is a cross-sectional view of the second membrane layer in an embodiment of this application;

[0023] Figure 13 This is a schematic diagram showing the structure of the first film layer in the embodiments of this application.

[0024] Figure label:

[0025] 10: Battery string; 11: Battery cell; 111: First battery cell; 112: Second battery cell; 113: Third battery cell; 114: Fourth battery cell; 115: Fifth battery cell; 12: First electrical connector; 13: Second electrical connector; 14: First pad; 141: First sub-pad; 15: Second pad; 151: Second sub-pad;

[0026] 20: First film layer;

[0027] 30: Second film layer; 31: Perforated section; 311: Through hole; 312: Groove; 32: Fixing film; 33: Insulating film;

[0028] 40: First busbar;

[0029] 50: Second busbar;

[0030] 60: Third busbar;

[0031] 70: First adhesive film;

[0032] 80: Front glass;

[0033] 90: Second adhesive film;

[0034] 100: Back panel;

[0035] X: First direction; Y: Second direction. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present invention.

[0037] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0038] This application discloses a back-contact photovoltaic module, which includes a battery string 10, comprising a plurality of battery cells 11 arranged sequentially along a first direction X. Each battery cell 11 has a first surface and a second surface disposed opposite to each other. The first surface of each battery cell 11 is provided with a first electrical connector 12 and a second electrical connector 13 extending along the first direction X and alternately arranged along a second direction Y. The plurality of battery cells 11 includes a first battery cell 111 and a second battery cell 112, with the second direction Y intersecting the first direction X. A first film layer 20 is disposed on the first electrical connectors 12 and 13 away from the first battery cell 111. The second film layer 30 is disposed on the side of the first electrical connector 12 and the second electrical connector 13 away from the second battery cell 112. The second film layer 30 is provided with a hollow portion 31, which is correspondingly disposed with respect to the first electrical connector 12. The first busbar 40 is disposed on the side of the second film layer 30 away from the second battery cell 112. The first busbar 40 extends along the second direction Y and is electrically connected to the first electrical connector 12 through the hollow portion 31. The number of layers of the second film layer 30 is greater than or equal to the number of layers of the first film layer 20, and / or the thickness of the second film layer 30 is greater than or equal to the thickness of the first film layer 20.

[0039] This application discloses a back-contact photovoltaic module, which has the advantages of high photoelectric conversion efficiency and beautiful appearance.

[0040] The back-contact photovoltaic module disclosed in this application has intersecting first direction X and second direction Y. Exemplarily, the first direction X is the length direction of the back-contact photovoltaic module, and the second direction Y is the width direction of the back-contact photovoltaic module. Alternatively, the first direction X is the width direction of the back-contact photovoltaic module, and the second direction Y is the length direction of the back-contact photovoltaic module.

[0041] The following will use the first direction X as the length direction of the back-contact photovoltaic module and the second direction Y as the width direction of the back-contact photovoltaic module.

[0042] like Figure 1 , Figure 2 and Figure 6 As shown, the back-contact photovoltaic module disclosed in this application includes a battery string 10, which includes a plurality of battery cells 11 arranged sequentially along a first direction X. Exemplarily, the plurality of battery cells 11 are arranged at intervals along the first direction X. Alternatively, the plurality of battery cells 11 are arranged sequentially along the first direction X, with a portion of one battery cell 11 stacked on top of another in any two adjacent battery cells 11.

[0043] Along the thickness direction of the photovoltaic module, the solar cell 11 has a first surface and a second surface arranged opposite to each other. The first surface is the light-receiving surface of the solar cell 11 facing the sunlight, i.e., the front surface, and the second surface is the back surface of the solar cell 11 facing away from the sunlight, i.e., the back surface. Alternatively, the first surface is the back surface of the solar cell 11, and the second surface is the light-receiving surface of the solar cell 11.

[0044] The following will use the example of the first surface being the backlight surface of the battery cell 11 and the second surface being the light-receiving surface of the battery cell 11 to illustrate the relevant aspects of this application.

[0045] The first surface of the solar cell 11 is provided with a first fine grid and a second fine grid extending along the second direction Y and spaced apart along the first direction X, so as to collect the charge carriers generated by the solar cell 11 through the first fine grid and the second fine grid. The first surface of the solar cell 11 is also provided with a first electrical connector 12 and a second electrical connector 13 extending along the first direction X and spaced apart alternately along the second direction Y. The first electrical connector 12 is electrically connected to the first fine grid so as to collect the charge carriers collected by the first fine grid through the first electrical connector 12. A first insulating adhesive is provided between the first electrical connector 12 and the second fine grid so as to block the first electrical connector 12 from conducting through the first electrical connector 12 and the second fine grid, thereby preventing the photovoltaic module from short-circuiting. The second electrical connector 13 is electrically connected to the second fine grid to collect the charge carriers collected by the second fine grid. A second insulating adhesive is provided between the second electrical connector 13 and the first fine grid to block the second electrical connector 13 from being connected to the first fine grid, thereby preventing the photovoltaic module from short-circuiting.

[0046] like Figure 6 As shown, the plurality of battery cells 11 includes a first battery cell 111 and a second battery cell 112. It can be understood that the first battery cell 111 is one of the plurality of battery cells 11, the second battery cell 112 is one of the plurality of battery cells 11, and the first battery cell 111 and the second battery cell 112 are different battery cells 11 in a battery string 10. Exemplarily, the first battery cell 111 and the second battery cell 112 are two adjacent battery cells 11 in a battery string 10.

[0047] It should be noted that, in this embodiment, the specific arrangement of the first battery cell 111 and the second battery cell 112 in the battery string 10 is not limited. In practical applications, technicians can set it as needed.

[0048] The first electrical connector 12 and the second electrical connector 13 have opposite conductivity types. If the first electrical connector 12 is a positive electrical connector, then the second electrical connector 13 is a negative electrical connector. If the first electrical connector 12 is a negative electrical connector, then the second electrical connector 13 is a positive electrical connector.

[0049] It should be noted that the first electrical connector 12 and the second electrical connector 13 can be solder strips, or other electrical connectors. In this embodiment, no particular restrictions are placed on the specific types of the first electrical connector 12 and the second electrical connector 13. In practical applications, those skilled in the art can choose according to their needs.

[0050] In this embodiment of the application, a first film layer 20 is provided on the side of the first electrical connector 12 and the second electrical connector 13 away from the first battery cell 111, so as to fix the first electrical connector 12 and the second electrical connector 13 to the first surface of the first battery cell 111, that is, the back side, through the first film layer 20.

[0051] In this embodiment, a second film layer 30 is provided on the side of the first electrical connector 12 and the second electrical connector 13 away from the second solar cell 112, so as to fix the first electrical connector 12 and the second electrical connector 13 to the first surface, i.e., the back surface, of the second solar cell 112 through the second film layer 30. Furthermore, the second film layer 30 has insulating properties, and can block the first busbar 40 and the second electrical connector 13 disposed on the second film layer 30, so as to prevent the first busbar 40 and the second electrical connector 13 from conducting, thus avoiding a short circuit in the photovoltaic module.

[0052] The second film layer 30 has a perforated portion 31, which corresponds to the first electrical connector 12. A first busbar 40 is located on the side of the second film layer 30 away from the second solar cell 112. The first busbar 40 extends along the second direction Y and can be electrically connected to the first electrical connector 12 through the perforated portion 31 to collect the charge carriers gathered by the first electrical connector 12 and transmit the collected charge carriers to an external circuit. Furthermore, the second film layer 30 is insulating, preventing the second electrical connector 13 and the first busbar 40 from conducting and causing a partial short circuit in the photovoltaic module.

[0053] It should be noted that in the embodiments of this application, the number of layers of the second film layer 30 is greater than or equal to the number of layers of the first film layer 20, and / or the thickness of the second film layer 30 is greater than or equal to the thickness of the first film layer 20, so that the second film layer 30 can block the second electrical connector 13 and the second solar cell 112, and prevent the second electrical connector 13 and the second solar cell 112 from conducting, which would cause a short circuit in the photovoltaic module.

[0054] For example, the first film layer 20 includes only a fixing film 32, and the second film layer 30 includes a fixing film 32 and an insulating film 33 stacked sequentially; alternatively, the second film layer 30 is integrally formed by co-extrusion of the fixing film 32 and the insulating film 33. The thickness of the fixing film 32 in the first film layer 20 is the same as the thickness of the fixing film 32 in the second film layer 30. Therefore, in this case, the number of layers in the second film layer 30 is greater than the number of layers in the first film layer 20, and the thickness of the second film layer 30 is greater than the thickness of the first film layer 20.

[0055] For example, the first film layer 20 includes a fixed film 32 and an insulating film 33 stacked sequentially, and the second film layer 30 also includes a fixed film 32 and an insulating film 33 stacked sequentially; alternatively, the second film layer 30 is integrally formed by co-extrusion of the fixed film 32 and the insulating film 33. The thickness of the fixed film 32 in the first film layer 20 is the same as the thickness of the fixed film 32 in the second film layer 30, and the thickness of the insulating film 33 in the first film layer 20 is the same as the thickness of the insulating film 33 in the second film layer 30. Therefore, in this case, the number of layers in the second film layer 30 is equal to the number of layers in the first film layer 20, and the thickness of the second film layer 30 is equal to the thickness of the first film layer 20.

[0056] The photovoltaic module disclosed in this application has a first film layer 20 disposed on the side of the first electrical connector 12 and the second electrical connector 13 away from the first solar cell 111, thereby fixing the first electrical connector 12 and the second electrical connector 13 to the first surface of the first solar cell 111 through the first film layer 20. A second film layer 30 is disposed on the side of the first electrical connector 12 and the second electrical connector 13 away from the second solar cell 112, thereby fixing the first electrical connector 12 and the second electrical connector 30 to the first surface of the second solar cell 112 through the second film layer 30.

[0057] Furthermore, the second film layer 30 is provided with a perforated portion 31, which is correspondingly disposed with the first electrical connector 12. The first busbar 40 is disposed on the side of the second film layer 30 away from the second solar cell 112, and extends along the second direction Y. The first busbar 40 is electrically connected to the first electrical connector 12 through the perforated portion 31. It can be understood that the second film layer 30 can block the second electrical connector 13 and the first busbar 40 to prevent the second electrical connector 13 and the first busbar 40 from conducting, thus avoiding a short circuit in the photovoltaic module.

[0058] Furthermore, the number of layers in the second film layer 30 is greater than or equal to the number of layers in the first film layer 20, and / or the thickness of the second film layer 30 is greater than or equal to the thickness of the first film layer 20, so that the second film layer 30 can block the second electrical connector 13 and the first busbar 40, preventing the second electrical connector 13 and the first busbar 40 from conducting and causing a short circuit in the photovoltaic module.

[0059] In some embodiments, the first film layer 20 includes a fixed film 32; such as Figure 12 As shown, the second film layer 30 includes a fixed film 32 and an insulating film 33 stacked sequentially.

[0060] In one optional implementation, the first film layer 20 in this embodiment only includes a fixing film 32, which fixes the first electrical connector 12 and the second electrical connector 13 to the first surface of the first solar cell 111. The second film layer 30 includes a fixing film 32 and an insulating film 33 stacked sequentially. The fixing film 32 can fix the first electrical connector 12 and the second electrical connector 13 to the first surface of the first solar cell 111, while the insulating film 33 can block the second electrical connector 13 from the first busbar 40, preventing the second electrical connector 13 and the first busbar 40 from conducting and causing a partial short circuit in the photovoltaic module, thus affecting the reliability of the photovoltaic module.

[0061] For example, the fixing film 32 can be an ethylene / vinyl acetate copolymer film (also known as an EVA film, EVA stands for Ethylene Vinyl Acetate Copolymer), a polyolefin elastomer film (also known as a POE film, POE stands for Polyolefin Elastomer), or an EPE co-extruded film. An EPE co-extruded film is a three-layer composite encapsulating film manufactured through a co-extrusion process, consisting of two layers of EVA resin and one layer of POE resin, typically in the form of EVA / POE / EVA. The fixing film 32 can also be a polyvinyl butyral film (also known as a PVB film, PVB stands for Polyvinyl Butyral). Of course, the fixing film 32 can also be other adhesive film layers. In this embodiment, the specific material of the fixing film 32 is not limited; in practical applications, those skilled in the art can choose according to their needs.

[0062] For example, the insulating film 33 can be a polyethylene terephthalate film (also known as a PET film, PET stands for Polyethylene terephthalate), a polyimide film (also known as a PI film, PI stands for Polyimide), an EVA film, a POE film, an EPE co-extruded film, or a PVB film. Of course, the insulating film 33 can also be other insulating film layers. In this embodiment, the specific material of the insulating film 33 is not limited; in practical applications, those skilled in the art can choose according to their needs.

[0063] In some embodiments, such as Figure 12As shown, both the first film layer 20 and the second film layer 30 include a fixed film 32 and an insulating film 33 stacked sequentially.

[0064] As an optional implementation, in this embodiment, both the first film layer 20 and the second film layer 30 can be configured to include a fixed film 32 and an insulating film 33 stacked sequentially. The first film layer 20 fixes the first electrical connector 12 and the second electrical connector 13 to the first surface of the first battery cell 111, and the second film layer 30 fixes the first electrical connector 12 and the second electrical connector 13 to the first surface of the second battery cell 112. Furthermore, the second film layer 30 has a perforated portion 31, through which the first busbar 40 can be electrically connected to the first electrical connector 12, thereby collecting the charge carriers collected by the first electrical connector 12 and transmitting the collected charge carriers to an external circuit.

[0065] In this embodiment, both the first film layer 20 and the second film layer 30 are configured to include a fixed film 32 and an insulating film 33 stacked sequentially, so that the first film layer 20 and the second film layer 30 can use the same structure of film, thereby simplifying the manufacturing process of photovoltaic modules and improving the manufacturing efficiency of photovoltaic modules.

[0066] In some embodiments, such as Figure 6 As shown, the first battery cell 111 and the second battery cell 112 are arranged adjacent to each other; along the first direction X, the second battery cell 112 is located at the outermost position of the battery string 10.

[0067] like Figure 1 As shown, along the first direction X, the first battery cell 111 and the second battery cell 112 are two adjacent battery cells 11 in the battery string 10. The second battery cell 112 is the end battery cell located on the outermost side of the battery string 10, and the first battery cell 111 is the battery cell adjacent to the second battery cell 112.

[0068] In other words, the first busbar 40 in this embodiment is an end busbar, which collects the charge carriers collected by the first electrical connector 12 and transmits the collected charge carriers to the external circuit.

[0069] In some embodiments, such as Figure 3 , Figure 4 and Figure 7As shown, along the first direction X, a row of solar cells 11 includes at least one cell string 10, and each row of solar cells 11 includes N solar cells 11. When N is an odd number, the N solar cells 11 also include a third solar cell 113. Along the first direction X, the third solar cell 113 is the (N+1) / 2th solar cell 11. The second film layer 30 is disposed on the side of the first electrical connector 12 and the second electrical connector 13 away from the third solar cell 113. The photovoltaic module also includes a second busbar 50, which is disposed on the side of the second film layer 30 away from the third solar cell 113. The second busbar 50 extends along the second direction Y and is electrically connected to the first electrical connector 12 or the second electrical connector 13 through a cutout portion 31.

[0070] The back-contact photovoltaic module disclosed in this application includes at least one string of cells 10 in each row of cells 11 along the first direction X. When using integral welding, one row of cells 11 consists of a single string of cells 10. When using conventional welding processes, one row of cells 11 includes at least two strings of cells 10, typically two strings arranged vertically. At least one string of cells 10 is arranged sequentially along the first direction X. Each row of cells 11 includes N cells 11, where N is a positive integer. N can be either odd or even.

[0071] When N is odd, that is, each column of battery cells 11 includes an odd number of battery cells. Along the first direction X, the (N+1) / 2th battery cell 11 among the N battery cells 11 is the third battery cell 113. It can be understood that the third battery cell 113 is the battery cell 11 located in the middle position of the column of battery cells.

[0072] In this embodiment, a second film layer 30 is disposed on the side of the first electrical connector 12 and the second electrical connector 13 away from the third battery cell 113, and a second busbar 50 is disposed on the side of the second film layer 30 away from the third battery cell 113. The second busbar 50 extends along the second direction Y. A cutout portion 31 is provided on the second film layer 30, and the second busbar 50 is electrically connected to one of the first electrical connector 12 or the second electrical connector 13 through the cutout portion 31, so as to collect the charge carriers collected by the first electrical connector 12 or the second electrical connector 13 and transmit the collected charge carriers to an external circuit.

[0073] Furthermore, the second film layer 30 can block the second busbar 50 from being connected to either the second electrical connector 13 or the first electrical connector 12, thereby preventing the second busbar 50 from being connected to the second electrical connector 13 or the first electrical connector 12, which would cause a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module.

[0074] It should be noted that the second busbar 50 in this embodiment is an intermediate busbar, which collects the charge carriers collected by the first electrical connector 12 or the second electrical connector 13 and transmits the collected charge carriers to the external circuit.

[0075] In some embodiments, such as Figure 1 , Figure 2 and Figure 8 As shown, along the first direction X, a row of battery cells 11 includes at least one battery string 10, and each row of battery cells 11 includes N battery cells 11, when N is an even number; the N battery cells 11 include a fourth battery cell 114 and a fifth battery cell 115, and along the first direction X, the fourth battery cell 114 and the fifth battery cell 115 are the N / 2th and (N+2) / 2th battery cells 11, respectively; the second film layer 30 is disposed on the first electrical connector 12 and the second electrical connector 13 away from the fourth battery cell 114 and On one side of the fifth solar cell 115, along the thickness direction of the photovoltaic module, the cutout portion 31 is positioned opposite to the fourth solar cell 114 and the fifth solar cell 115; the photovoltaic module also includes a third busbar 60, which is disposed on the side of the second film layer 30 away from the fourth solar cell 114 and the fifth solar cell 115, and extends along the second direction Y. The third busbar 60 is electrically connected to the first electrical connector 12 or the second electrical connector 13 through the cutout portion 31.

[0076] When N is even, that is, each column of battery cells 11 includes an even number of battery cells. Along the first direction X, the N / 2th and (N+2) / 2nd battery cells 11 are the fourth battery cell 114 and the fifth battery cell 115, respectively. It can be understood that the fourth battery cell 114 and the fifth battery cell 115 are the two battery cells 11 located in the middle position of the column of battery cells 11.

[0077] In this embodiment, a second film layer 30 is provided on the side of the first electrical connector 12 and the second electrical connector 13 away from the fourth battery cell 114, and another second film layer 30 is provided on the side of the first electrical connector 12 and the second electrical connector 13 away from the fifth battery cell 115. The second film layer 30 has a perforated portion 31, which is positioned opposite to the position near the fourth battery cell 114 and the fifth battery cell 115. A third busbar 60 is provided on the side of the second film layer 30 away from the fourth battery cell 114 and the fifth battery cell 115. The third busbar 60 is electrically connected to one of the first electrical connector 12 or the second electrical connector 13 through the perforated portion 31 to collect the charge carriers collected by the first electrical connector 12 or the second electrical connector 13 and transmit the collected charge carriers to an external circuit.

[0078] Furthermore, the second film layer 30 can block the third busbar 60 from being connected to either the second electrical connector 13 or the first electrical connector 12, thereby preventing the third busbar 60 from being connected to the second electrical connector 13 or the first electrical connector 12, which would cause a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module.

[0079] It should be noted that the third bus 60 in this embodiment is an intermediate bus, which collects the charge carriers collected by the first electrical connector 12 or the second electrical connector 13 and transmits the collected charge carriers to the external circuit.

[0080] In some embodiments, such as Figure 1 and Figure 2 As shown, the battery string 10 includes multiple battery strings 10, which are arranged at intervals along the second direction Y; in two adjacent battery strings 10, along the second direction Y, the first film layer 20 in one battery string 10 is correspondingly arranged with the first film layer 20 in the other battery string 10, and the second film layer 30 in one battery string 10 is correspondingly arranged with the second film layer 30 in the other battery string 10.

[0081] The back-contact photovoltaic module disclosed in this application includes multiple cell strings 10, which are arranged at intervals along a second direction Y. In two adjacent cell strings 10 along the second direction Y, the first film layer 20 in one cell string 10 and the first film layer in the other cell 10 are correspondingly arranged, and the second film layer 30 in one cell string 10 and the second film layer 30 in the other cell string 10 are also correspondingly arranged. That is, in two adjacent cell strings 10, the first film layer 20 and the second film layer 30 are arranged in the same position in the cell string 10.

[0082] In this embodiment of the application, along the first direction X, in two adjacent battery strings 10, the positions of the first film layer 20 and the second film layer 30 in the battery string 10 are set to be the same, thereby simplifying the arrangement of the first film layer 20 and the second film layer 30, reducing the processing difficulty of photovoltaic modules, and improving the processing efficiency of photovoltaic modules.

[0083] Furthermore, in the above configuration, along the second direction Y, the busbar can extend from one battery string 10 to another adjacent battery string 10 to collect the charge carriers generated by at least two battery strings 10 and transmit the collected charge carriers to an external circuit.

[0084] In some embodiments, such as Figure 6As shown, along the second direction Y, the distance between two adjacent edges of two adjacent second film layers 30 is M; among two adjacent second battery cells 112, along the second direction Y, the shortest distance between the outermost first electrical connector 12 or second electrical connector 13 of one second battery cell 112 and the outermost first electrical connector 12 or second electrical connector 13 of the other second battery cell 112 is S, satisfying M≤S.

[0085] In this embodiment of the application, along the second direction Y, the distance between two adjacent edges of two adjacent second film layers 30 is M. That is, among two adjacent second film layers 30, along the second direction Y, the edge of one second film layer 30 closest to the other is called the first edge, and the edge of the other second film layer 30 closest to the first film layer 30 is called the second edge. The distance between the first edge and the second edge along the second direction Y is M.

[0086] Along the second direction Y, in two adjacent second battery cells 112, the distance between the first electrical connector 12 or second electrical connector 13 closest to the other second battery cell 112 and the first electrical connector 12 or second electrical connector 13 closest to the first battery cell 112 on the other second battery cell 112 is S. That is, along the second direction Y, in two adjacent second battery cells 112, the shortest distance between the first electrical connector 12 or second electrical connector 13 closest to the outermost point in one second battery cell 112 and the first electrical connector 12 or second electrical connector 13 closest to the outermost point in the other second battery cell 112 is S.

[0087] In this embodiment, M is set to be less than or equal to S. It can be understood that the second film layer 30 can cover all the first electrical connectors 12 and second electrical connectors 13 on the corresponding second solar cell 112, so as to fix the first electrical connectors 12 and second electrical connectors 13 to the first surface of the second solar cell 112 through the second film layer 30. Furthermore, the second film layer 30 can also block the busbar and the second electrical connector 13, preventing the busbar and the second electrical connector 13 from conducting, which could lead to a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module.

[0088] In some embodiments, such as Figure 6 As shown, in the second battery cell 112, along the second direction Y, the distance between adjacent first electrical connector 12 and second electrical connector 13 is A, which satisfies A≥S.

[0089] In this embodiment of the application, in the second battery cell 112, along the second direction Y, the distance between adjacent first electrical connectors 12 and second electrical connectors 13 in the second battery cell 112 is set as A, and A is greater than or equal to S. That is, along the second direction Y, the distance A between two adjacent first electrical connectors 12 and second electrical connectors 13 in the second battery cell 112 is greater than or equal to the shortest distance S between the outermost first electrical connector 12 or second electrical connector 13 in one second battery cell 112 and the outermost first electrical connector 12 or second electrical connector 13 in the other second battery cell 112.

[0090] In this embodiment, by setting A to be greater than or equal to S, the distance between the first electrical connector 12 or the second electrical connector 13 closest to the outermost edge of the second solar cell 112 and the corresponding edge of the second solar cell 112 is smaller. The first electrical connector 12 or the second electrical connector 13 closest to the outermost edge can better collect the charge carriers generated in the edge region of the second solar cell 112, thereby improving the collection efficiency of charge carriers in the edge region of the second solar cell 112 and improving the photoelectric conversion efficiency of the photovoltaic module.

[0091] In some embodiments, such as Figure 6 As shown, along the second direction Y, the length of the second solar cell 112 is L1, and the length of the second film layer 30 is L2, satisfying that L2≤L1; the projection of the second film layer 30 onto the plane of the second solar cell 112 falls within the second solar cell 112.

[0092] In this embodiment, the projection of the second film layer 30 onto the plane of the second battery cell 112 falls within the second battery cell 112. That is, on the plane of the second battery cell 112, the area of ​​the second film layer 30 is less than or equal to the area of ​​the second battery cell 112. Furthermore, along the second direction Y, the length L1 of the second battery cell 112 is greater than or equal to the length L2 of the second film layer 30. It can be understood that along the second direction Y, the length of each second battery cell 112 is greater than or equal to the length of the corresponding second film layer 30.

[0093] With the above configuration, each second film layer 30 can fix the first electrical connector 12 and the second electrical connector 13 on the corresponding second solar cell 112 to the first surface of the second solar cell 112. Furthermore, the second film layer 30 will not extend beyond the second solar cell 112 to avoid excessive length of the second film layer 30 along the second direction Y, which would lead to material waste and excessively high cost of the photovoltaic module.

[0094] Furthermore, if the length of the second film layer 30 is too long along the second direction Y, the second film layer 30 will extend onto the adjacent second solar cell 112 and overlap with the second film layer 30 on the adjacent second solar cell 112, affecting the flatness of the second film layer 30. If the flatness of the second film layer 30 is poor, it will cause the first electrical connector 12 and the second electrical connector 13 to shift, affecting the reliability of the photovoltaic module.

[0095] In some embodiments, such as Figure 6 As shown, along the first direction X, the width of the second battery cell 112 is L4, and the width of the second film layer 30 is L5, satisfying L5≤L4.

[0096] In this embodiment of the application, along the first direction X, the width L4 of the second battery cell 112 is set to be greater than or equal to the width L5 of the second film layer 30. It can be understood that along the first direction X, the width of each second battery cell 112 is greater than or equal to the width of the corresponding second film layer 30.

[0097] With the above configuration, each second film layer 30 can fix the first electrical connector 12 and the second electrical connector 13 on the corresponding second solar cell 112 to the first surface of the second solar cell 112. Furthermore, the second film layer 30 will not extend beyond the second solar cell 112 to avoid excessive width of the second film layer 30 along the first direction X, which would lead to waste of material and excessively high cost of the photovoltaic module.

[0098] Furthermore, if the width of the second film layer 30 along the first direction X is too wide, the second film layer 30 will also extend onto the adjacent second solar cell 112, overlapping with the second film layer 30 on the adjacent second solar cell 112, thereby affecting the flatness of the second film layer 30. If the flatness of the second film layer 30 is poor, it will cause the first electrical connector 12 and the second electrical connector 13 to shift, affecting the reliability of the photovoltaic module.

[0099] like Figure 6As shown, along the second direction Y, the second battery cell 112 has a first side and a second side disposed opposite to each other, and along the first direction X, the second battery cell 112 has a third side and a fourth side disposed opposite to each other. Specifically, along the second direction Y, the distance between the edge of the second film layer 30 near the first side of the second battery cell 112 and the first side of the second battery cell 112 is greater than or equal to 0 mm and less than or equal to 20 mm. For example, along the second direction Y, the distance between the edge of the second film layer 30 near the first side of the second battery cell 112 and the first side of the second battery cell 112 can be 0 mm, 3 mm, 6 mm, 9 mm, 12 mm, 15 mm, 20 mm, etc. Along the second direction Y, the distance between the edge of the second film layer 30 near the second side of the second battery cell 112 and the second side of the second battery cell 112 is greater than or equal to 0 mm and less than or equal to 20 mm. For example, along the second direction Y, the distance between the edge of the second film layer 30 near the second side of the second battery cell 112 and the second side of the second battery cell 112 can be 0mm, 5mm, 8mm, 10mm, 13mm, 15mm, 20mm, etc.

[0100] Wherein, along the first direction X, the distance between the edge of the second film layer 30 near the third side of the second battery cell 112 and the third side of the second battery cell 112 is greater than or equal to 0 mm and less than or equal to 15 mm. For example, along the first direction X, the distance between the edge of the second film layer 30 near the third side of the second battery cell 112 and the third side of the second battery cell 112 can be 0 mm, 3 mm, 6 mm, 9 mm, 12 mm, 15 mm, etc. Along the first direction X, the distance between the edge of the second film layer 30 near the fourth side of the second battery cell 112 and the fourth side of the second battery cell 112 is greater than or equal to 0 mm and less than or equal to 15 mm. For example, along the first direction X, the distance between the edge of the second film layer 30 near the fourth side of the second battery cell 112 and the fourth side of the second battery cell 112 can be 0 mm, 3 mm, 6 mm, 9 mm, 12 mm, 15 mm, etc.

[0101] In some embodiments, such as Figure 6 As shown, a plurality of first pads 14 are provided between the second battery cell 112 and the first electrical connector 12, and the plurality of first pads 14 are spaced apart along the first direction X; the second film layer 30 covers the first pads 14 located on the outermost side along the first direction X.

[0102] In this embodiment of the application, a plurality of first pads 14 are provided between the first electrical connector 12 and the second battery cell 112, so that the first electrical connector 12 is soldered to the second battery cell 112 through the plurality of first pads 14, so that the first electrical connector 12 is connected to the first fine grid, and the charge carriers collected by the first fine grid are collected through the first electrical connector 12.

[0103] For example, two first solder pads 14 may be provided between the first electrical connector 12 and the second battery cell 112, three first solder pads 14 may be provided between the first electrical connector 12 and the second battery cell 112, four first solder pads 14 may be provided between the first electrical connector 12 and the second battery cell 112, or five first solder pads 14 may be provided between the first electrical connector 12 and the second battery cell 112. In this embodiment, the specific number of first solder pads 14 provided between the first electrical connector 12 and the second battery cell 112 is not limited. In practical applications, technicians can set the number of first solder pads 14 as needed.

[0104] In this embodiment, the second film layer 30 can cover the outermost first pad 14 along the first direction X. It can be understood that the second film layer 30 can cover all the first pads 14 between the first electrical connector 12 and the second solar cell 112. By covering all the first pads 14 between the first electrical connector 12 and the second solar cell 112 with the second film layer 30, it is ensured that the second film layer 30 can better fix the first electrical connector 12 to the first surface of the second solar cell 112, preventing the first electrical connector 12 from shifting and affecting the reliability of the photovoltaic module.

[0105] In some embodiments, such as Figure 6 As shown, a plurality of second pads 15 are provided between the second battery cell 112 and the second electrical connector 13, and the plurality of second pads 15 are spaced apart along the first direction X; the second film layer 30 covers the second pads 15 located on the outermost side along the first direction X.

[0106] In this embodiment, a plurality of second pads 15 are provided between the second electrical connector 13 and the second battery cell 112, so that the second electrical connector 13 is soldered to the second battery cell 112 through the plurality of second pads 15, so that the second electrical connector 13 is connected to the second fine grid, and the carriers collected by the second fine grid are collected through the second electrical connector 13.

[0107] For example, two second pads 15 may be provided between the second electrical connector 13 and the second battery cell 112, three second pads 15 may be provided between the second electrical connector 13 and the second battery cell 112, four second pads 15 may be provided between the second electrical connector 13 and the second battery cell 112, or five second pads 15 may be provided between the second electrical connector 13 and the second battery cell 112. In this embodiment, the specific number of second pads 15 provided between the second electrical connector 13 and the second battery cell 112 is not limited. In practical applications, technicians can set the number of second pads 15 as needed.

[0108] In this embodiment, the second film layer 30 can cover the outermost second pad 15 along the first direction X. It can be understood that the second film layer 30 can cover all the second pads 15 between the second electrical connector 13 and the second solar cell 112. By covering all the second pads 15 between the second electrical connector 13 and the second solar cell 112 with the second film layer 30, it is ensured that the second film layer 30 can better fix the second electrical connector 13 to the first surface of the second solar cell 112, preventing the second electrical connector 13 from shifting and affecting the reliability of the photovoltaic module.

[0109] In some embodiments, such as Figure 6 As shown, along the second direction Y, the second battery cell 112 has a first side and a second side that are arranged opposite to each other; the first pad 14 or the second pad 15 closest to the first side is the first sub-pad 141, and the first pad 14 or the second pad 15 closest to the second side is the second sub-pad 151. The distance between the first sub-pad 141 and the second sub-pad 151 is L3, which satisfies L2≥L3; and / or, the projection of the second film layer 30 on the plane where the second battery cell 112 is located covers the first sub-pad 141 and the second sub-pad 151.

[0110] In this embodiment, the battery cell 11 can be a rectangular battery cell or a square battery cell. In this embodiment, the specific shape of the battery cell 11 is not subject to excessive restrictions; in practical applications, those skilled in the art can choose according to their needs.

[0111] The following explanation will use a rectangular solar cell 11 as an example to illustrate this application.

[0112] Along the second direction Y, the second battery cell 112 has a first side and a second side disposed opposite to each other. When the electrical connector closest to the first side is the first electrical connector 12, the pad closest to the first side is the first pad 14. When the electrical connector closest to the first side is the second electrical connector 13, the pad closest to the first side is the second pad 15. When the electrical connector closest to the second side is the first electrical connector 12, the pad closest to the second side is the first pad 14. When the electrical connector closest to the second side is the second electrical connector 13, the pad closest to the second side is the second pad 15.

[0113] In this embodiment, the first pad 14 or the second pad 15 closest to the first side is referred to as the first sub-pad 141, and the first pad 14 or the second pad 15 closest to the second side is referred to as the second sub-pad 151. Along the second direction Y, the distance between the first sub-pad 141 and the second sub-pad 151 is L3, and along the second direction Y, the length of the second film layer 30 is L2, where L2 is greater than or equal to L3. That is, along the second direction Y, the length of the second film layer 30 is greater than the distance between the first sub-pad 141 and the second sub-pad 151. Furthermore, the projection of the second film layer 30 onto the plane of the second solar cell 112 covers the first sub-pad 141 and the second sub-pad 151, ensuring that the second film layer 30 can fix all the first electrical connectors 12 and the second electrical connectors 13 to the first surface of the second solar cell 112, preventing the first electrical connectors 12 or the second electrical connectors 13 from shifting and affecting the reliability of the photovoltaic module.

[0114] In some embodiments, such as Figure 6 As shown, along the first direction X, on the second cell 112, the second film layer 30 covers at least two adjacent first pads 14.

[0115] As an optional implementation, along the first direction X, on the second battery cell 112, the second film layer 30 may cover only two adjacent first pads 14, or the second film layer 30 may cover multiple adjacent first pads 14. In this embodiment, there is no excessive limitation on the number of first pads 14 specifically covered by the second film layer 30; in practical applications, those skilled in the art can set it as needed.

[0116] In this embodiment of the application, along the first direction X, on the second cell 112, the second film layer 30 covers at least two adjacent first pads 14, so that the width of the second film layer 30 along the first direction X is narrower, thereby reducing the amount of material used in the second film layer 30, reducing the cost of the photovoltaic module, and enhancing the market competitiveness of the photovoltaic module.

[0117] In some embodiments, along the first direction X, in two adjacent second cell sheets 112, the second film layer 30 covers at least one first pad 14 on one second cell sheet 112 that is closest to the other second cell sheet 112.

[0118] As an alternative implementation, when there is an even number of cells in a row of cells 11, along the first direction X, in two adjacent second cells 112, the second film layer 30 covers at least one first pad 14 on one second cell 112 that is closest to the other second cell 112.

[0119] It can be understood that the two adjacent second battery cells 112 here are the adjacent fourth battery cell 114 and fifth battery cell 115 mentioned above. The second film layer 30 on the fourth battery cell 114 covers at least one first pad 14 on the fourth battery cell 112 that is closest to the fifth battery cell 115. The second film layer 30 on the fifth battery cell 115 covers at least one first pad 14 on the fifth battery cell 115 that is closest to the fourth battery cell 114.

[0120] By making the width of the second film layer 30 along the first direction X narrower through the above settings, the amount of material used in the second film layer 30 is reduced, the cost of photovoltaic modules is reduced, and the market competitiveness of photovoltaic modules is enhanced.

[0121] In some embodiments, such as Figures 6 to 8 As shown, along the first direction X, the cutout portion 31 is offset from the first pad 14.

[0122] As an optional implementation, the cutout portion 31 and the first pad 14 can be misaligned along the first direction X. This is to prevent welding material from being stacked between the busbar and the first electrical connector 12 during the process of welding the busbar to the first electrical connector 12 through the cutout portion 31. The thickness of this welding material would overlap with the thickness of the first pad 14, resulting in a large thickness difference in the photovoltaic module. This could lead to defects such as fragmentation and microcracks in the second cell 112 during the photovoltaic module lamination process, affecting the process yield of the photovoltaic module.

[0123] In some embodiments, along the first direction X, the cutout portion 31 at least partially overlaps with the first pad 14.

[0124] Of course, in some alternative embodiments, along the first direction X, the cutout portion 31 may also partially overlap with the first pad 14, so that more first pads 14 can be provided between the first electrical connector 12 and the second cell 112, thereby improving the reliability of the welding between the first electrical connector 12 and the second cell 112 and improving the reliability of the photovoltaic module.

[0125] In some embodiments, such as Figure 9 and Figure 10 As shown, the hollow portion 31 includes a through hole 311, which penetrates the second film layer 30.

[0126] In this embodiment, the hollow portion 31 can be set as a through hole 311, which penetrates the second membrane layer 30 so that the busbar can be welded to the first electrical connector 12 through the through hole 311.

[0127] It should be noted that the through hole 311 in this embodiment can be a round hole, a square hole, a rectangular hole, a triangular hole, a polygonal hole, or a hole with other irregular structures. In this embodiment, no excessive restrictions are placed on the specific structure of the through hole 311. In practical applications, those skilled in the art can set it according to their needs.

[0128] It should be noted that, in this embodiment, the number of through holes 311 corresponds to the number of first electrical connectors 12. It can be understood that the number of through holes 311 is the same as the number of first electrical connectors 12.

[0129] Taking a rectangular through hole 311 as an example, the length of the through hole 311 along the second direction Y is greater than or equal to 4mm and less than or equal to 15mm. For example, the length of the through hole 311 along the second direction Y can be 4mm, 6mm, 8mm, 10mm, 12mm, 15mm, etc. The width of the through hole 311 along the first direction X is greater than or equal to 1mm and less than or equal to 12mm. For example, the width of the through hole 311 along the first direction X can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, etc.

[0130] In some embodiments, such as Figure 11 As shown, the hollow portion 31 includes a groove 312. Along the first direction X, the groove 312 is disposed on one side of the second film layer 30 and penetrates the second film layer 30.

[0131] As an alternative implementation, the cutout 31 can be configured as a groove 312, which is located on one side of the second film layer 30 along the first direction X. Furthermore, the groove 312 penetrates the second film layer 30 along the thickness direction of the photovoltaic module, allowing the busbar to be welded to the first electrical connector 12 through the groove 312.

[0132] It should be noted that the groove 312 in this embodiment can be a square groove, a U-shaped groove, an elliptical groove, a semi-circular groove, or other irregularly shaped groove. In this embodiment, the specific structure of the groove is not subject to excessive restrictions. For grooves of different shapes, their maximum length along the first direction X or the second direction Y should not be less than the maximum length of the pad in that direction. In practical applications, technicians can set it as needed.

[0133] It should be noted that, in this embodiment, the number of grooves 312 corresponds to the number of first electrical connectors 12. It can be understood that the number of grooves 312 is the same as the number of first electrical connectors 12.

[0134] Taking a square groove 312 as an example, the length of the groove 312 along the second direction Y is greater than or equal to 4mm and less than or equal to 15mm. For example, the length of the groove 312 along the second direction Y can be 4mm, 6mm, 8mm, 10mm, 12mm, 15mm, etc. The width of the groove 312 along the first direction X is greater than or equal to 1mm and less than or equal to 12mm. For example, the width of the groove 312 along the first direction X can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, etc.

[0135] In some embodiments, such as Figure 6 As shown, along the second direction Y, the width of the cutout portion 31 is greater than or equal to the width of the first electrical connector 12.

[0136] In this embodiment of the application, along the second direction Y, the width of the cutout portion 31 is set to be greater than or equal to the width of the first electrical connector 12, so that the first electrical connector 12 can be exposed in the cutout portion 31, thereby welding the busbar and the first electrical connector 12 together through the cutout portion 31, improving the reliability of the electrical connection between the busbar and the first electrical connector 12.

[0137] In some embodiments, the first surface of the battery cell 11 is provided with a first fine grid and a second fine grid that extend along the second direction Y and are alternately arranged along the first direction X. The first fine grid is electrically connected to the first electrical connector 12, and an insulating adhesive is provided between the first fine grid and the second electrical connector 13. Along the second direction Y, the width of the cutout portion 31 is less than or equal to the width of the insulating adhesive.

[0138] In this embodiment, a first fine grid and a second fine grid extending along the second direction Y and alternately arranged along the first direction X are provided on the first surface of the solar cell 11 to collect the charge carriers generated by the solar cell 11. A first electrical connector 12 is electrically connected to the first fine grid to collect the charge carriers collected by the first fine grid and transmit the collected charge carriers to an external circuit. An insulating adhesive is provided between the first electrical connector 12 and the first fine grid to prevent the first electrical connector 12 from conducting with the first fine grid, thus avoiding a partial short circuit in the photovoltaic module.

[0139] In this embodiment, the width of the cutout portion 31 along the second direction Y is set to be less than the width of the insulating adhesive to avoid the cutout portion 31 being too wide along the second direction Y, which would cause the busbar to conduct with the second electrical connector 13, resulting in a partial short circuit in the photovoltaic module and affecting the reliability of the photovoltaic module.

[0140] In some embodiments, such as Figure 6As shown, the projection of the hollow portion 31 onto the plane where the second battery cell 112 is located is on the side of the first pad 14 or the second pad 15 located on the outermost side along the first direction X, close to the corresponding side of the second battery cell 112.

[0141] As an optional implementation, the cutout portion 31 has a projection onto the plane where the second battery cell 112 is located. This projection is located along the first direction X on the side of the outermost first pad 14 or second pad 15 closest to the corresponding side of the second battery cell 112. That is, along the first direction X, the cutout portion 31 is closer to the corresponding side of the second battery cell 112 than the first pad 14 or second pad 15 closest to the side of the second battery cell 112.

[0142] With the above settings, along the first direction X, the busbar can be positioned closer to the side of the second cell 112 to avoid the hollow part 31 overlapping with the first pad 14 or the second pad 15. The welding material in the hollow part 31 overlaps with the thickness of the first pad 14 or the second pad 15, resulting in a large difference in the thickness of the photovoltaic module. This can cause defects such as fragmentation and microcracks in the second cell 112 during the photovoltaic module lamination process, affecting the process yield of the photovoltaic module.

[0143] In some embodiments, along the first direction X, the projection of the cutout portion 31 onto the plane where the second battery cell 112 is located is between two adjacent first pads 14.

[0144] As an optional implementation, along the first direction X, the projection of the cutout portion 31 onto the plane where the second cell 112 is located is set between two adjacent first pads 14 to avoid the cutout portion 31 overlapping with the first pads 14. The welding material in the cutout portion 31 overlaps with the thickness of the first pads 14, resulting in a large difference in the thickness of the photovoltaic module. This leads to defects such as fragmentation and microcracks in the second cell 112 during the photovoltaic module lamination process, affecting the process yield of the photovoltaic module.

[0145] In some embodiments, such as Figure 6 As shown, along the second direction Y, the length of the hollow part 31 is L6, and the width between two adjacent first electrical connectors 12 and second electrical connectors 13 is L7, satisfying that 1 / 2*L6≤L7.

[0146] In this embodiment, along the second direction Y, the length of the cutout portion 31 is set to L6, and the width between two adjacent first electrical connectors 12 and second electrical connectors 13 is set to L7, where L7 is greater than or equal to twice L6. This is to prevent the cutout portion 31 from extending onto the second electrical connector 13, which could cause the busbar to conduct with the second electrical connector 13, resulting in a partial short circuit in the photovoltaic module and affecting its reliability.

[0147] In some embodiments, such as Figure 6 As shown, along the first direction X, the width of the hollow part 31 is L8, and the width of the first busbar 40 is L9, satisfying L8≥L9.

[0148] When the cutout portion 31 is a rectangular structure, the width of the cutout portion 31 along the first direction X is greater than or equal to 1 mm and less than or equal to 12 mm. For example, the width of the cutout portion 31 along the first direction X can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, etc.

[0149] The width of the first busbar 40 is less than or equal to the width of the cutout portion 31. That is, the width of the first busbar 40 is greater than or equal to 1 mm and less than or equal to 12 mm. For example, the width of the first busbar 40 can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, etc.

[0150] In this embodiment of the application, along the first direction X, the width L8 of the hollow portion 31 is set to be greater than or equal to the width L9 of the first busbar 40, so that the first busbar 40 can be connected to the first electrical connector 12 through the hollow portion 31, thereby improving the reliability of the connection between the first busbar 40 and the first electrical connector 12 and ensuring the reliability of the photovoltaic module.

[0151] It should be noted that in the back-contact photovoltaic module disclosed in this application embodiment, a second adhesive film 90 is provided on the side of the first busbar 40 away from the second film layer 30, and a backplate 100 is provided on the side of the second adhesive film 90 away from the second film layer 30. The backplate 100 is bonded to the back of the second cell 112 through the second adhesive film 90, so as to support the photovoltaic module through the backplate 100 and improve the strength and reliability of the photovoltaic module.

[0152] Furthermore, a first adhesive film 70 is provided on the front side, i.e., the first surface, of the second solar cell 112, and a front glass is provided on the side of the first adhesive film 70 away from the second solar cell 112. The second solar cell 112 is bonded to the front side of the second solar cell 112 through the first adhesive film 70. This protects the photovoltaic module through the front glass, thereby improving the strength and reliability of the photovoltaic module.

[0153] The back panel 100 can be a back glass panel, or it can be other supporting components. In this embodiment, the specific material of the back panel 100 is not subject to excessive restrictions. In practical applications, technicians can select the specific material of the back panel 100 as needed.

[0154] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0155] Although alternative embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make further changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the alternative embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0156] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity from another, and do not necessarily require or imply any such actual relationship or order between these entities. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or terminal device that includes that element.

[0157] The technical solution provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the principle and implementation of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A back-contact photovoltaic module, characterized in that, include: A battery string (10) includes a plurality of battery cells (11) arranged sequentially along a first direction (X). Each battery cell (11) has a first surface and a second surface disposed opposite to each other. The first surface of the battery cell (11) is provided with a first electrical connector (12) and a second electrical connector (13) extending along the first direction (X) and arranged alternately along a second direction (Y). The plurality of battery cells (11) include a first battery cell (111) and a second battery cell (112). The second direction (Y) intersects the first direction (X). A first film layer (20) is disposed on the side of the first electrical connector (12) and the second electrical connector (13) away from the first battery cell (111); The second film layer (30) is disposed on the side of the first electrical connector (12) and the second electrical connector (13) away from the second battery cell (112). The second film layer (30) is provided with a hollow part (31), which is correspondingly disposed to the first electrical connector (12). The first busbar (40) is disposed on the side of the second film layer (30) away from the second battery cell (112). The first busbar (40) extends along the second direction (Y). The first busbar (40) is electrically connected to the first electrical connector (12) through the hollow part (31). Wherein, the number of layers of the second film layer (30) is greater than or equal to the number of layers of the first film layer (20), and / or, the thickness of the second film layer (30) is greater than or equal to the thickness of the first film layer (20).

2. The back-contact photovoltaic module according to claim 1, characterized in that, The first film layer (20) includes a fixed film (32); The second film layer (30) includes a fixed film (32) and an insulating film (33) stacked in sequence.

3. The back-contact photovoltaic module according to claim 1, characterized in that, Both the first film layer (20) and the second film layer (30) include a fixed film (32) and an insulating film (33) stacked in sequence.

4. The back-contact photovoltaic module according to claim 1, characterized in that, The first battery cell (111) and the second battery cell (112) are arranged adjacent to each other; Along the first direction (X), the second battery cell (112) is located at the outermost position of the battery string (10).

5. The back-contact photovoltaic module according to claim 1, characterized in that, Along the first direction, a column of the battery cells (11) includes at least one of the battery strings (10), and each column of the battery cells (11) includes N of the battery cells (11), where N is an odd number. The N battery cells (11) further include a third battery cell (113) along the first direction (X), wherein the third battery cell (113) is the (N+1) / 2th battery cell (11); The second film layer (30) is disposed on the side of the first electrical connector (12) and the second electrical connector (13) away from the third battery cell (113); The photovoltaic module further includes a second busbar (50), which is disposed on the side of the second film layer (30) away from the third cell (113). The second busbar (50) extends along the second direction (Y) and is electrically connected to the first electrical connector (12) or the second electrical connector (13) through the cutout portion (31).

6. The back-contact photovoltaic module according to claim 1, characterized in that, Along the first direction, a column of the battery cells (11) includes at least one of the battery strings (10), and each column of the battery cells (11) includes N of the battery cells (11), where N is an even number. The N battery cells (11) include a fourth battery cell (114) and a fifth battery cell (115), and along the first direction (X), the fourth battery cell (114) and the fifth battery cell (115) are the N / 2 and (N+2) / 2th battery cells (11), respectively; The second film layer (30) is disposed on the side of the first electrical connector (12) and the second electrical connector (13) away from the fourth battery cell (114) and the fifth battery cell (115). Along the thickness direction of the photovoltaic module, the hollow part (31) is positioned opposite to the fourth battery cell (114) and the fifth battery cell (115). The photovoltaic module further includes a third busbar (60), which is disposed on the side of the second film layer (30) away from the fourth cell (114) and the fifth cell (115). The third busbar (60) extends along the second direction (Y) and is electrically connected to the first electrical connector (12) or the second electrical connector (13) through the cutout portion (31).

7. The back-contact photovoltaic module according to any one of claims 1-6, characterized in that, The battery string (10) includes a plurality of battery strings (10) arranged at intervals along the second direction (Y); In two adjacent battery strings (10), along the second direction (Y), the first film layer (20) in one battery string (10) is correspondingly arranged with the first film layer (20) in the other battery string (10), and the second film layer (30) in one battery string (10) is correspondingly arranged with the second film layer (30) in the other battery string (10).

8. The back-contact photovoltaic module according to claim 7, characterized in that, Along the second direction (Y), the distance between two adjacent edges of two adjacent second film layers (30) is M; In two adjacent second battery cells (112), along the second direction (Y), the shortest distance between the outermost first electrical connector (12) or second electrical connector (13) of one second battery cell (112) and the outermost first electrical connector (12) or second electrical connector (13) of the other second battery cell (112) is S, which satisfies M≤S.

9. The back-contact photovoltaic module according to claim 8, characterized in that, In the second battery cell (112), along the second direction (Y), the distance between adjacent first electrical connectors (12) and second electrical connectors (13) is A, which satisfies A≥S.

10. The back-contact photovoltaic module according to claim 1, characterized in that, Along the second direction (Y), the length of the second battery cell (112) is L1, and the length of the second film layer (30) is L2, satisfying that L2≤L1; The projection of the second film layer (30) onto the plane of the second battery cell (112) falls into the second battery cell (112).

11. The back-contact photovoltaic module according to claim 1, characterized in that, Along the first direction (X), the width of the second battery cell (112) is L4, and the width of the second film layer (30) is L5, satisfying L5≤L4.

12. The back-contact photovoltaic module according to claim 1, characterized in that, A plurality of first pads (14) are provided between the second battery cell (112) and the first electrical connector (12), and the plurality of first pads (14) are spaced apart along the first direction (X); The second film layer (30) covers the first pad (14) located on the outermost side along the first direction (X).

13. The back-contact photovoltaic module according to claim 12, characterized in that, A plurality of second pads (15) are provided between the second battery cell (112) and the second electrical connector (13), and the plurality of second pads (15) are spaced apart along the first direction (X); The second film layer (30) covers the second pad (15) located on the outermost side along the first direction (X).

14. The back-contact photovoltaic module according to claim 13, characterized in that, Along the second direction (Y), the second battery cell (112) has a first side and a second side disposed opposite to each other; The first pad (14) or the second pad (15) closest to the first side is the first sub-pad (141), and the first pad (14) or the second pad (15) closest to the second side is the second sub-pad (151). The distance between the first sub-pad (141) and the second sub-pad (151) is L3, which satisfies L2≥L3. And / or, the projection of the second film layer (30) onto the plane where the second battery cell (112) is located covers the first sub-pad (141) and the second sub-pad (151).

15. The back-contact photovoltaic module according to claim 14, characterized in that, Along the first direction (X), on the second battery cell (112), the second film layer (30) covers at least two adjacent first pads (14); Alternatively, along the first direction (X), in two adjacent second battery cells (112), the second film layer (30) covers at least one of the first pads (14) on one second battery cell (112) that is closest to the other second battery cell (112).

16. The back-contact photovoltaic module according to claim 12, characterized in that, Along the first direction (X), the cutout portion (31) is offset from the first pad (14); Alternatively, along the first direction (X), the cutout (31) at least partially overlaps with the first pad (14).

17. The back-contact photovoltaic module according to claim 1, characterized in that, The hollow portion (31) includes a through hole (311) that penetrates the second film layer (30).

18. The back-contact photovoltaic module according to claim 1, characterized in that, The hollow portion (31) includes a groove (312) along the first direction (X). The groove (312) is disposed on one side of the second film layer (30) and penetrates the second film layer (30).

19. The back-contact photovoltaic module according to claim 1, characterized in that, Along the second direction (Y), the width of the cutout (31) is greater than or equal to the width of the first electrical connector (12); And / or, the first surface of the battery cell (11) is provided with a first fine grid and a second fine grid extending along the second direction (Y) and arranged alternately at intervals along the first direction (X), the first fine grid is electrically connected to the first electrical connector (12), and an insulating adhesive is provided between the first fine grid and the second electrical connector (13), and along the second direction (Y), the width of the hollow portion (31) is less than or equal to the width of the insulating adhesive.

20. The back-contact photovoltaic module according to claim 13, characterized in that, The projection of the hollow portion (31) onto the plane where the second battery cell (112) is located is on the side of the first pad (14) or the second pad (15) located on the outermost side along the first direction (X) near the corresponding side of the second battery cell (112). Alternatively, along the first direction (X), the projection of the cutout (31) onto the plane where the second battery cell (112) is located lies between two adjacent first pads (14).

21. The back-contact photovoltaic module according to claim 1, characterized in that, Along the second direction (Y), the length of the hollow part (31) is L6, and the width between two adjacent first electrical connectors (12) and second electrical connectors (13) is L7, satisfying that 1 / 2*L6≤L7.

22. The back-contact photovoltaic module according to claim 1, characterized in that, Along the first direction (X), the width of the hollow part (31) is L8, and the width of the first busbar (40) is L9, satisfying L8≥L9.

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