Photovoltaic module and preparation method thereof

Abstract

The invention relates to the photovoltaic field, and provides a photovoltaic module and a preparation method of the photovoltaic module, the photovoltaic module comprises a plurality of battery strings, each battery string comprises a plurality of battery pieces, the chamfered edge of the first end battery piece and the chamfered edge of the third end battery piece are oppositely arranged, and the chamfered edge of the third end battery piece is opposite to the chamfered edge of the third end battery piece. The chamfered edge of the second end part battery piece and the chamfered edge of the fourth end part battery piece are oppositely arranged; the edge main grid, adjacent to the second end battery piece, of the first end battery piece and the edge main grid, adjacent to the fourth end battery piece, of the third end battery piece are second main grids, and the edge main grid, adjacent to the first end battery piece, of the second end battery piece and the edge main grid, adjacent to the fourth end battery piece, of the second end battery piece are second main grids. Edge main grids, adjacent to the third end part battery piece, on the fourth end part battery piece are first main grids; and the first main grids of the first end part battery piece and the third end part battery piece are connected with the same middle bus bar, and the second main grids of the second end part battery piece and the fourth end part battery piece are connected with the other adjacent middle bus bar, so that the risk of short circuit of the photovoltaic module can be reduced.

Description

Technical Field

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

[0002] Solar energy is an inexhaustible renewable energy source for mankind. Photovoltaic modules are the core and most important part of solar power generation systems. Their function is to convert solar energy into electrical energy and store it in batteries or drive loads.

[0003] A photovoltaic module consists of multiple cell strings, each of which consists of multiple cells connected in series. Each cell string is connected to a central busbar. Lead wires connected to the ends of the central busbar lead the current collected by the cell grid lines out of the photovoltaic module. The layout of cells in existing photovoltaic modules is limited by space, and there is a risk of short circuits between the lead wires. Summary of the Invention

[0004] In view of this, the present application provides a printing screen and a photovoltaic module to solve the short circuit problem caused by the small lead-out line spacing in the prior art.

[0005] In a first aspect, an embodiment of the present application provides a photovoltaic module, comprising: a first battery string group, comprising a first battery string and a second battery string alternately distributed along a first direction; a second battery string group, comprising a third battery string and a fourth battery string alternately distributed along the first direction; an intermediate bus bar, located between the first battery string group and the second battery string group, a plurality of the intermediate bus bars being spaced apart along the first direction; the first battery string, the second battery string, the third battery string and the fourth battery string respectively comprising a plurality of battery cells spaced apart along the second direction, the battery cells being back-contact batteries or back-contact stacked batteries; the battery cells comprising a first main grid and a second main grid spaced apart along the first direction, the first battery string, the second battery string, the third battery string and the fourth battery string respectively having a first end battery cell, a second end battery cell, a third end battery cell and a fourth end battery cell at one end close to the intermediate bus bar, the The edge main grid on the first end battery cell adjacent to the second end battery cell and the edge main grid on the third end battery cell adjacent to the fourth end battery cell are both the second main grid, the edge main grid on the second end battery cell adjacent to the first end battery cell and the edge main grid on the fourth end battery cell adjacent to the third end battery cell are both the first main grid; the first main grid of the first end battery cell and the first main grid of the third end battery cell are respectively connected to the same intermediate bus bar through welding strips, and the second main grid of the second end battery cell and the second main grid of the fourth end battery cell are respectively connected to another adjacent intermediate bus bar through welding strips; the chamfered edge of the first end battery cell is arranged opposite to the chamfered edge of the third end battery cell, and the chamfered edge of the second end battery cell is arranged opposite to the chamfered edge of the fourth end battery cell; the first direction and the second direction are perpendicular to each other.

[0006] In a possible implementation, the chamfered edges of any two battery cells adjacent to each other along the first direction are arranged in the same direction.

[0007] In a possible implementation, the chamfered edges of the plurality of battery cells in the same battery string are arranged in the same direction.

[0008] In a possible implementation, the chamfer size of the battery cell is A×45°, where A satisfies 1mm≤A≤2mm.

[0009] In a possible implementation, along the first direction, a distance L1 between two adjacent intermediate bus bars is 15 mm to 25 mm.

[0010] In one possible implementation, the welding strip includes a first welding strip and a second welding strip, the first welding strip is used to connect the intermediate bus bar and the first main grid on the first end battery cell, and the second welding strip is used to connect the intermediate bus bar and the first main grid on the third end battery cell; the first welding strip and the second welding strip are staggered in the second direction; and / or, the welding strip includes a third welding strip and a fourth welding strip, the third welding strip is used to connect the intermediate bus bar and the second main grid on the second end battery cell, and the fourth welding strip is used to connect the intermediate bus bar and the second main grid on the fourth end battery cell; the third welding strip and the fourth welding strip are staggered in the second direction.

[0011] In one possible implementation, the photovoltaic module also includes a first edge bus bar and a second edge bus bar relatively distributed along a second direction; the first battery string and the second battery string have a fifth end battery cell and a sixth end battery cell at one end close to the first edge bus bar, respectively, and the second main grid of the fifth end battery cell and the first main grid of the sixth end battery cell are respectively connected to the first edge bus bar through welding strips; the third battery string and the fourth battery string have a seventh end battery cell and an eighth end battery cell at one end close to the second edge bus bar, respectively, and the second main grid of the seventh end battery cell and the first main grid of the eighth end battery cell are respectively connected to the second edge bus bar through welding strips.

[0012] In one possible implementation, the number of battery cells in the first battery string, the second battery string, the third battery string, and the fourth battery string are all even numbers; the edge main grid on the fifth end battery cell adjacent to the sixth end battery cell, and the edge main grid on the seventh end battery cell adjacent to the eighth end battery cell are both the first main grid; the edge main grid on the sixth end battery cell adjacent to the fifth end battery cell, and the edge main grid on the eighth end battery cell adjacent to the seventh end battery cell are both the second main grid.

[0013] In one possible implementation, the number of battery cells in the first battery string, the second battery string, the third battery string, and the fourth battery string are all odd numbers; the edge main grid on the fifth end battery cell adjacent to the sixth end battery cell, and the edge main grid on the seventh end battery cell adjacent to the eighth end battery cell are both the second main grid; the edge main grid on the sixth end battery cell adjacent to the fifth end battery cell, and the edge main grid on the eighth end battery cell adjacent to the seventh end battery cell are both the first main grid.

[0014] In a possible implementation, the sum of the number of the first bus bars and the number of the second bus bars on the solar cell is an even number.

[0015] In a possible implementation, the battery cell is a sliced ​​battery cell, and the battery cell includes a first battery cell and a second battery cell, and a structure of one of the first battery cell and the second battery cell is symmetrical to a structure of the other battery cell after being rotated 180°.

[0016] In a second aspect, an embodiment of the present application provides a method for preparing a photovoltaic module, comprising: providing a cell, wherein the cell is a back-contact cell or a back-contact laminated cell, the cell comprising a first main grid and a second main grid spaced apart along a first direction, the cell also having a chamfered edge; utilizing a plurality of the cell cells to be arranged along a second direction to form a first cell string, a second cell string, a third cell string and a fourth cell string, respectively, the first cell string, the second cell string, the third cell string and the fourth cell string having a first end cell cell, a second end cell cell, a third end cell cell and a fourth end cell cell, respectively, the edge main grid on the first end cell cell adjacent to the second end cell cell, and the edge main grid on the third end cell cell adjacent to the fourth end cell cell Adjacent edge main grids are all the second main grids, the edge main grid on the second end battery cell adjacent to the first end battery cell, and the edge main grid on the fourth end battery cell adjacent to the third end battery cell are all the first main grids, the chamfered edge of the first end battery cell is arranged opposite to the chamfered edge of the third end battery cell, and the chamfered edge of the second end battery cell is arranged opposite to the chamfered edge of the fourth end battery cell; the first main grid of the first end battery cell and the first main grid of the third end battery cell are connected to the same intermediate bus bar, and the second main grid of the second end battery cell and the second main grid of the third end battery cell are connected to another adjacent intermediate bus bar; the second direction is perpendicular to the first direction.

[0017] In one possible implementation, the chamfered edges of multiple battery cells in the same battery string are arranged in the same direction, the sum of the number of the first main grid and the second main grid on the battery cell is an even number, the battery cell is a sliced ​​battery cell, and the battery cell includes a first battery cell and a second battery cell that are rotationally symmetrical; when providing the battery cell, the preparation method of the photovoltaic module includes: providing an original battery cell; cutting along the center line of the original battery cell in the second direction to obtain two sliced ​​battery cells; rotating one of the sliced ​​battery cells 180° to obtain the first battery cell and the second battery cell with the chamfered edges arranged in the same direction.

[0018] In one possible implementation, the number of cells in the first cell string, the second cell string, the third cell string, and the fourth cell string is an odd number; when forming the second cell string, the method for preparing the photovoltaic module includes: arranging a plurality of the first cell cells and a plurality of the second cell cells alternately along the second direction, and connecting adjacent first cell cells and second cell cells via welding ribbons to obtain a prefabricated second cell string; rotating the prefabricated second cell string as a whole by 180° to obtain the second cell string; and / or, when forming the third cell string, the method for preparing the photovoltaic module includes: arranging a plurality of the second cell cells and a plurality of the first cell cells alternately along the second direction, and connecting adjacent first cell cells and second cell cells via welding ribbons to obtain the third cell string.

[0019] In one possible implementation, when forming the first battery string, the method for preparing the photovoltaic module includes: arranging a plurality of the first battery cells and a plurality of the second battery cells alternately along the second direction; connecting adjacent first battery cells and second battery cells through welding ribbons to obtain a prefabricated first battery string, and the welding ribbons in the prefabricated first battery string and the welding ribbons in the prefabricated second battery string are distributed in a mirror image; rotating the prefabricated first battery string as a whole 180° to obtain the first battery string; and / or, when forming the fourth battery string, the method for preparing the photovoltaic module includes: arranging a plurality of the second battery cells and a plurality of the first battery cells alternately along the second direction; connecting adjacent first battery cells and second battery cells through welding ribbons to obtain the fourth battery string, and the welding ribbons in the fourth battery string are distributed in a mirror image with the welding ribbons in the third battery string.

[0020] In the present application, the edge main grid of any end cell near the lead-out position is not electrically connected to the middle bus bar, so that there is enough space between the two adjacent middle bus bars for setting the lead-out line, ensuring that there is a large spacing between the lead-out lines of the two adjacent middle bus bars, thereby avoiding the problem of short circuit caused by contact between the two adjacent lead-out lines. When the chamfered edges of multiple cells in the same cell string are in the same direction, the contact area between the welding strip and the edges of each cell on the same cell string is consistent, which is conducive to reducing the risk of cold welding. Moreover, the pressure on the edges of each cell is more uniform, which is conducive to reducing the fragmentation rate in the string welding or lamination steps, thereby improving the yield rate of the photovoltaic module. In addition, when the chamfered edges of multiple cells in the same cell string are in the same direction, if the photovoltaic module is installed at an angle, the risk of shadows from the edges of adjacent cells blocking each other can be reduced, which is conducive to improving the output power of the photovoltaic module. Furthermore, when the chamfered edges of the first-end cell and the third-end cell are arranged facing each other, and the chamfered edges of the second-end cell and the fourth-end cell are arranged facing each other, the chamfered edges of the first-end cell, the second-end cell, the third-end cell, and the fourth-end cell are all arranged with their chamfered edges facing the lead wires. This can provide more space for the lead wires and further reduce the risk of contact between adjacent lead wires. Furthermore, when arranged in this manner, the aesthetics of the photovoltaic module layout can be improved.

[0021] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 any creative work.

[0023] Figure 1 A circuit diagram of a photovoltaic module provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the layout structure of a photovoltaic module provided in an embodiment of the present application;

[0025] Figure 3 for Figure 1 Schematic diagram of the structure of the battery string in FIG;

[0026] Figure 4 for Figure 3 Schematic diagram of the structure of the battery cell;

[0027] Figure 5 for Figure 2Part I is a schematic structural diagram of the first embodiment;

[0028] Figure 6 A schematic diagram of the layout structure of a photovoltaic module provided in an embodiment of the present application;

[0029] Figure 7 for Figure 6 Part II is a schematic structural diagram of the first embodiment;

[0030] Figure 8 A schematic cross-sectional view of a photovoltaic module according to an embodiment of the present invention;

[0031] Figure 9 for Figure 2 Part I is a schematic structural diagram of the second embodiment;

[0032] Figure 10 A schematic diagram of the structure of an uncut solar cell provided in an embodiment of the present application;

[0033] Figure 11 for Figure 10 Schematic diagram of the structure of the battery cell after slicing;

[0034] Figure 12 for Figure 1 Part I in the third embodiment of the structure diagram;

[0035] Figure 13 for Figure 6 Part II is a schematic structural diagram of the second embodiment;

[0036] Figure 14 for Figure 1 A schematic structural diagram of a battery string in another embodiment;

[0037] Figure 15 A schematic structural diagram of an unsliced ​​solar cell provided in an embodiment of the present application in another embodiment;

[0038] Figure 16 for Figure 15 Schematic diagram of the structure of the battery cell after slicing;

[0039] Figure 17 for Figure 2 A schematic structural diagram of part I in the fourth embodiment;

[0040] Figure 18 for Figure 2 A schematic structural diagram of part I in the fifth embodiment;

[0041] Figure 19 for Figure 6 Part II of FIG. 1 is a schematic structural diagram of the third embodiment;

[0042] Figure 20 for Figure 6 Part II of FIG. 1 is a schematic structural diagram of the fourth embodiment;

[0043] Figure 21 A flow chart of a method for preparing a photovoltaic module provided in an embodiment of the present application;

[0044] Figure 22 A flow chart of a method for preparing a photovoltaic module provided in an embodiment of the present application;

[0045] Figure 23 This is a flow chart of a method for preparing a photovoltaic module provided in an embodiment of the present application.

[0046] Reference numerals:

[0047] 100-battery module;

[0048] 101-first battery string group;

[0049] 102 - second battery string group;

[0050] 200-front plate;

[0051] 300-front encapsulation layer;

[0052] 400-back encapsulation layer;

[0053] 500-back panel;

[0054] 10-first battery string;

[0055] 10'-prefabricated first battery string;

[0056] 20- second battery string;

[0057] 20'-prefabricated second battery string;

[0058] 30-third battery string;

[0059] 40- fourth battery string;

[0060] 1- Middle bus bar;

[0061] 2-battery cell;

[0062] 201 - first end battery cell;

[0063] 202 - second end battery cell;

[0064] 203 - third end battery cell;

[0065] 204 - fourth end battery cell;

[0066] 205 - fifth end battery cell;

[0067] 206 - sixth end battery cell;

[0068] 207-seventh end battery cell;

[0069] 208 - eighth end battery cell;

[0070] 21-first main grid;

[0071] 22- second main grid;

[0072] 23-first battery cell;

[0073] 24-second battery cell;

[0074] 25-third battery cell;

[0075] 26- fourth battery cell;

[0076] 27-fifth battery cell;

[0077] 28-sixth battery cell;

[0078] 29-seventh battery cell;

[0079] 210-eighth battery cell;

[0080] 211- ninth battery cell;

[0081] 212-the tenth battery cell;

[0082] 3- welding strip;

[0083] 31- first welding strip;

[0084] 32- second welding strip;

[0085] 33- third welding strip;

[0086] 34- fourth welding strip;

[0087] 4-first edge bus bar;

[0088] 5- Second edge bus bar. DETAILED DESCRIPTION

[0089] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0090] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0091] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0092] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0093] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.

[0094] In order to solve the problem of short circuit caused by too small lead wire spacing in existing photovoltaic modules, the embodiment of the present application provides a photovoltaic module, such as Figure 1 and Figure 2 As shown, the photovoltaic module includes a battery module 100, which includes a first battery string group 101, a second battery string group 102, and a plurality of intermediate bus bars 1. The first battery string group 101 includes first battery strings 10 and second battery strings 20 alternately distributed along a first direction X; the second battery string group 102 includes third battery strings 30 and fourth battery strings 40 alternately distributed along the first direction X; along the second direction Y, the plurality of intermediate bus bars 1 are located between the first battery string group 101 and the second battery string group 102, and the plurality of intermediate bus bars 1 are spaced apart in the first direction X. The embodiment of the present application does not limit the number of the first battery string 10, the second battery string 20, the third battery string 30, and the fourth battery string 40, and can be specifically designed according to the layout and output power requirements of the photovoltaic module.

[0095] It should be noted that the first direction X and the second direction Y are perpendicular to each other. In the embodiment of the present application, one of the first direction X and the second direction Y is the length direction of the photovoltaic module, and the other is the width direction of the photovoltaic module.

[0096] Combine Figure 2 and Figure 3As shown, the first battery string 10, the second battery string 20, the third battery string 30 and the fourth battery string 40 respectively include multiple battery cells 2 spaced apart along the second direction Y. The multiple battery cells 2 in the same battery string are connected in series via welding ribbons 3. The battery cells 2 are back-contact batteries or back-contact stacked batteries, which can reduce light blocking on the front side and improve battery efficiency. Figure 4 As shown, the backlight surface of the battery cell 2 is provided with a first main grid 21 and a second main grid 22 spaced apart along the first direction X. The polarities of the first main grid 21 and the second main grid 22 are opposite, that is, one of the first main grid 21 and the second main grid 22 is a positive main grid and the other is a negative main grid. The embodiments of the present application are all described by taking the case where the first main grid 21 is a negative pole and the second main grid 22 is a positive pole as an example.

[0097] It should be noted that the drawings provided in this application use lines of different thicknesses to distinguish the first main gate 21 and the second main gate 22. This does not limit the relative width between the first main gate 21 and the second main gate 22. The width of the first main gate 21 and the width of the second main gate 22 can be equal or different.

[0098] like Figure 5 As shown, the first, second, third, and fourth cell strings 10, 20, 30, and 40 each have a first end cell 201, a second end cell 202, a third end cell 203, and a fourth end cell 204 at their ends near the intermediate busbar 1. The first busbar 21 of the first end cell 201 and the first busbar 21 of the third end cell 203 are each connected to the same intermediate busbar 1 via a welding ribbon 3, thereby forming a parallel connection between the first and third cell strings 10 and 30. The second busbar 22 of the second end cell 202 and the second busbar 22 of the fourth end cell 204 are each connected to another adjacent intermediate busbar 1 via a welding ribbon 3, thereby forming a parallel connection between the second and fourth cell strings 20 and 40. The edge busbar on the first end cell 201 adjacent to the second end cell 202 is the second busbar 22, and the edge busbar on the third end cell 203 adjacent to the fourth end cell 204 is the second busbar 22. Meanwhile, the edge busbar on the second end cell 202 adjacent to the first end cell 201 is the first busbar 21, and the edge busbar on the fourth end cell 204 adjacent to the third end cell 203 is the first busbar 21. When this layout is used, the edge busbars of any end cell near the lead-out line position (lead-out lines are not shown in the figure, but the area indicated by the circular dotted line in the figure is the area where lead-out lines can be set) are not electrically connected to the middle busbar 1, so that there is sufficient space between two adjacent middle busbars 1 for setting lead-out lines, ensuring a large spacing between the lead-out lines of the two adjacent middle busbars 1, thereby preventing the two adjacent lead-out lines from contacting each other and causing a short circuit.

[0099] When using the above typesetting method, if Figure 5 As shown, along the first direction X, the spacing L1 between two adjacent intermediate busbars 1 is 15 mm to 25 mm. Optionally, L1 is 15 mm to 18 mm, 18 mm to 20 mm, 20 mm to 22 mm, or 22 mm to 25 mm. Alternatively, L1 is 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, or 25 mm. Other values ​​within the above range are also possible, and this application is not limited thereto. When L1 is 15 mm to 25 mm, it provides more space for the lead wires of two adjacent intermediate busbars 1, reducing the risk of short circuits. Furthermore, the overall length of the intermediate busbars 1 can be reduced, saving material and reducing light obstruction by the intermediate busbars 1, thereby improving the output power of the photovoltaic module. Furthermore, when the spacing between adjacent lead wires is large, the use of insulating material is eliminated, saving material, reducing the production cost and process difficulty of the photovoltaic module, and thus improving the production efficiency of the photovoltaic module.

[0100] In some embodiments, as Figure 5 As shown, the cell 2 has chamfered edges and right-angled edges that are relatively distributed along the second direction Y. The chamfered edge of the first end cell 201 is arranged opposite to the chamfered edge of the third end cell 203, and the chamfered edge of the second end cell 202 is arranged opposite to the chamfered edge of the fourth end cell 204. That is, the chamfered edges of the first end cell 201, the second end cell 202, the third end cell 203, and the fourth end cell 204 are all arranged toward the lead wires, which can provide more space for the lead wires and further reduce the risk of contact between two adjacent lead wires. Moreover, when arranged in this way, the aesthetics of the photovoltaic module layout can also be improved.

[0101] In some embodiments, as Figure 3 and Figure 5 As shown, the chamfered edges of multiple cells 2 in the same cell string are arranged in the same direction. When the chamfered edges of multiple cells 2 in the same cell string are in the same direction, the contact area between the welding ribbon 3 and the edges of each cell 2 on the same cell string is consistent, which helps to reduce the risk of cold soldering. Moreover, the pressure on the edges of each cell 2 is more uniform, which helps to reduce the fragmentation rate in the string soldering or lamination steps, thereby improving the yield rate of the photovoltaic module. In addition, when the chamfered edges of multiple cells 2 in the same cell string are in the same direction, if the photovoltaic module is installed at an angle, the risk of shadows from the edges of adjacent cells 2 blocking each other can be reduced, which helps to increase the output power of the photovoltaic module.

[0102] Since the chamfered edge of the first end battery cell 201 is arranged opposite to the chamfered edge of the third end battery cell 203, and the chamfered edge of the second end battery cell 202 is arranged opposite to the chamfered edge of the fourth end battery cell 204, the following can be obtained: Figure 2 and Figure 5 The photovoltaic module structure shown. That is, the chamfered edges of the cell 2 in the first cell string 10 and the chamfered edges of the cell 2 in the second cell string 20 are arranged in the same direction, and the chamfered edges of the cell 2 in the third cell string 30 and the chamfered edges of the cell 2 in the fourth cell string 40 are arranged in the same direction. That is, the chamfered edges of any two adjacent cell cells 2 along the first direction X are arranged in the same direction. When the chamfered edges of the cell 2 in the first cell string 10 and the chamfered edges of the cell 2 in the second cell string 20 are arranged in the same direction, it facilitates rapid alignment between the first cell string 10 and the second cell string 20, thereby improving the assembly efficiency of the photovoltaic module. Moreover, when the chamfered directions of the cell 2 in the first cell string 10 and the cell 2 in the second cell string 20 are consistent, it can ensure that the edges of the two adjacent cell cells 2 along the first direction X are evenly stressed during the lamination process or when impacted, thereby reducing the risk of hidden cracks or ruptures in the cell 2, and thereby improving the yield rate and service life of the photovoltaic module.

[0103] Similarly, when the chamfered edges of the cells 2 in the third cell string 30 and the chamfered edges of the cells 2 in the fourth cell string 40 are arranged in the same direction, this facilitates quick alignment of the third cell string 30 with the fourth cell string 40, thereby improving the assembly efficiency of the photovoltaic module. Furthermore, when the chamfered directions of the cells 2 in the third cell string 30 and the cells 2 in the fourth cell string 40 are aligned, it can ensure that the edges of two adjacent cell cells 2 along the first direction X are uniformly stressed during the lamination process or when subjected to impact, thereby reducing the risk of hidden cracks or ruptures in the cell cells 2, and thereby improving the yield rate and service life of the photovoltaic module.

[0104] When the chamfered edges of the battery cells 2 in the first battery string 10 are arranged in the same direction as the chamfered edges of the battery cells 2 in the second battery string 20, and the chamfered edges of the battery cells 2 in the third battery string 30 are arranged in the same direction as the chamfered edges of the battery cells 2 in the fourth battery string 40, not only can the assembly efficiency, yield rate and service life of the photovoltaic module be improved, but also the regularity of the layout structure of the photovoltaic module can be improved, and the aesthetic appearance can be improved.

[0105] Moreover, at this time, the chamfered edges of the cell 2 in the first cell string 10 are arranged opposite to the chamfered edges of the cell 2 in the third cell string 30, and the chamfered edges of the cell 2 in the second cell string 20 are arranged opposite to the chamfered edges of the cell 2 in the fourth cell string 40. When the chamfered edges of the cell 2 in the first cell string 10 and the chamfered edges of the cell 2 in the third cell string 30 are arranged opposite to each other, the arrangement of the cell 2 in the first cell string 10 and the arrangement of the cell 2 in the third cell string 30 are symmetrical relative to the middle bus bar 1, which not only improves the aesthetics of the photovoltaic module, but also ensures that during the process of connecting the first end cell 201 and the third end cell 203 to the middle bus bar 1 respectively through the welding ribbon 3, the force applied to the first end cell 201 and the third end cell 203 is more uniform, thereby reducing the risk of cold welding and welding leakage, and also reducing the risk of hidden cracks and ruptures in the first end cell 201 and the third end cell 203.

[0106] Similarly, when the chamfered edges of the battery cells 2 in the second battery string 20 are arranged opposite to the chamfered edges of the battery cells 2 in the fourth battery string 40, the arrangement of the battery cells 2 in the second battery string 20 and the arrangement of the battery cells 2 in the fourth battery string 40 are symmetrical relative to the middle bus 1, which not only improves the aesthetics of the photovoltaic module, but also ensures that in the process of connecting the second end battery cell 202 and the fourth end battery cell 204 to the middle bus 1 through the welding strip 3, the force on the second end battery cell 202 and the fourth end battery cell 204 is more uniform, reducing the risk of cold welding and leaking welding, and also reducing the risk of hidden cracks and ruptures in the second end battery cell 202 and the fourth end battery cell 204.

[0107] When the chamfered edges of the cell 2 in the first cell string 10 are arranged opposite to the chamfered edges of the cell 2 in the third cell string 30, and the chamfered edges of the cell 2 in the second cell string 20 are arranged opposite to the chamfered edges of the cell 2 in the fourth cell string 40, it is beneficial to further improve the yield rate and output power of the photovoltaic module.

[0108] In some embodiments, as Figure 6 As shown, the chamfered edges of multiple cells 2 in the same cell string can also be set in different directions. This can save the rotation process of some cells 2 during the production of photovoltaic modules, which is beneficial to reducing the production difficulty of photovoltaic modules and improving the production efficiency of photovoltaic modules.

[0109] Combine Figure 7As shown, the chamfered edges of any two adjacent cells 2 along the first direction X are arranged in the same direction. This ensures that the edges of the two adjacent cells 2 along the first direction X are uniformly stressed during the lamination process or when subjected to impact, thereby reducing the risk of hidden cracks or ruptures in the cells 2, and thereby improving the yield rate and service life of the photovoltaic module. Furthermore, when the chamfered edges of any two adjacent cells 2 along the first direction X are arranged in the same direction, the chamfered directions of the two adjacent cells 2 along the first direction X in the first cell string 10 and the second cell string 20 are the same, and the chamfered directions of the two adjacent cells 2 along the first direction X in the third cell string 30 and the fourth cell string 40 are the same. This facilitates rapid alignment between the first cell string 10 and the second cell string 20, and also facilitates rapid alignment between the third cell string 30 and the fourth cell string 40, thereby improving the assembly efficiency of the photovoltaic module.

[0110] In some embodiments, as Figure 8 As shown, the photovoltaic module also includes a front panel 200, a front encapsulation layer 300, a back encapsulation layer 400, and a back panel 500. The front panel 200 and the back panel 500 jointly clamp the front encapsulation layer 300, the battery module 100, and the back encapsulation layer 400, and form a photovoltaic module through lamination and encapsulation. Among them, the front encapsulation layer 300 is used to protect the light-facing side of the battery module 100, and the back encapsulation layer 400 is used to protect the backlight side of the battery module 100. At the same time, during the lamination process of the photovoltaic module, the front encapsulation layer 300 and the back encapsulation layer 400 are used to encapsulate and protect the battery module 100 to prevent the external environment from affecting the performance of the battery module 100. At the same time, they can also bond the front panel 200, the back panel 500, and the battery module 100 into a whole.

[0111] The front panel 200 and back panel 500 can be made of a rigid material such as tempered glass, polyethylene terephthalate (PET), or polycarbonate (PC), or a flexible material such as polyvinyl fluoride (PVF), ethylene-tetrafluoroethylene copolymer (ETFE), or polyvinylidene fluoride (PVDF). The front encapsulation layer 300 and the back encapsulation layer 400 are adhesive films, and the adhesive film material can be ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), or polyvinyl butyral (PVB). The front encapsulation layer 300 and the back encapsulation layer 400 can also be EPE film (EVA-POE-EVA co-extruded structure) or EP film (EVA-EP co-extruded structure).

[0112] In some embodiments, the photovoltaic module also includes a junction box (not shown in the figure), which is arranged on the outside of the backboard 500. The junction box contains a diode, and the two ends of the diode are connected in reverse parallel to the battery string through lead wires to avoid exceeding the reverse bias limit of the battery and damaging the photovoltaic module.

[0113] In some embodiments, when the battery cell 2 is a back contact battery, the type of the battery cell 2 can be one of an interdigitated back contact battery (IBC), a heterojunction back contact battery (HBC), and a tunnel oxide back contact battery (TBC).

[0114] An IBC cell, along its thickness, consists of a silicon nitride inversion layer, an N+ front surface field, an N-type base silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride anti-reflection layer, and a silver electrode. IBC cells utilize ion implantation technology to achieve uniform P and N regions with precisely controlled junction depths. The front of the cell is free of grid lines, eliminating current losses from metal electrode shading and maximizing the utilization of incident photons. This improves short-circuit current by approximately 7% compared to conventional solar cells. Due to the back-contact structure, grid line shading is not a concern, allowing for a wider grid line ratio, reducing series resistance and achieving a high fill factor. Optimized surface passivation and light-trapping structures enable a low front-surface recombination rate and surface reflection.

[0115] HBC cells combine the advantages of IBC cells and heterojunction cells. Their front surface passivation layer utilizes hydrogenated amorphous silicon, while N-type and P-type amorphous silicon thin films are deposited on the back surface to form a heterojunction. HBC cells fully utilize the superior surface passivation properties of amorphous silicon. The heterojunction structure formed on the back surface has excellent passivation, enabling both higher short-circuit current and open-circuit voltage, thereby improving photoelectric conversion efficiency.

[0116] For TBC batteries, TBC batteries have the advantages of Topcon's tunneling oxide layer technology and IBC's back-arranged electrodes. The passivation effect and open-circuit voltage are significantly improved, which can achieve higher battery conversion efficiency while being economical. The complete production process of TBC batteries mainly includes depositing tunneling oxide layers and P+ polysilicon, depositing passivation films, and printing electrodes on the back of silicon wafers. On the basis of the TOPCon production process, TBC batteries need to add related processes such as masks, laser grooving, PN area preparation, and etching of the back electrodes. The mask is mainly completed by APCVD or PECVD, the preparation of the PN area is mainly completed by PECVD, the etching mainly uses traditional wet equipment, and the grooving process needs to be completed by laser equipment.

[0117] In some embodiments, when the cell 2 is a back-contact stacked cell, the cell 2 may include a back-contact bottom cell and a perovskite top cell, with the perovskite top cell being electrically connected to the light-facing surface of the back-contact bottom cell. The back-contact bottom cell may be one of the above-mentioned interdigitated back-contact cell, heterojunction back-contact cell, and tunneling oxide back-contact cell, and the perovskite top cell is a thin-film solar cell using a perovskite material as the photoactive layer. The structure of a perovskite cell is mainly composed of the following key parts: a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode. These components work together to enable the perovskite cell to effectively absorb sunlight and convert it into electrical energy. The perovskite material in the perovskite light-absorbing layer has excellent light absorption properties, can absorb a wider spectral range, and effectively convert short-wavelength spectra, so that the perovskite top cell has a high photoelectric conversion efficiency.

[0118] The battery cell 2 is a sliced ​​battery, which can be a two-slice battery, a three-slice battery, a four-slice battery or an eight-slice battery. The embodiments of the present application do not limit this. The following description will take the battery cell 2 being a two-slice battery as an example.

[0119] In some embodiments, as Figure 4As shown, the chamfer size of the battery cell 2 is A×45°, and A satisfies 1mm≤A≤2mm, that is, the chamfer of the battery cell 2 is 45°, and the side length A of the chamfer is 1mm~2mm. Optionally, A is 1mm~1.2mm or 1.2mm~1.4mm or 1.4mm~1.6mm or 1.6mm~1.8mm or 1.8mm~2mm. Optionally, A is 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2mm, or other values ​​within the above range, which is not limited in this application. When A is 1mm~2mm, it can reduce the production difficulty of the battery cell 2, facilitate cutting production, and help improve the yield and production efficiency of the battery cell 2. Moreover, it can also appropriately reduce the edge reflection of the battery cell 2, which is conducive to improving the photoelectric conversion efficiency of the battery cell 2.

[0120] like Figure 5 As shown, the welding strip 3 includes a first welding strip 31, a second welding strip 32, a third welding strip 33 and a fourth welding strip 34. The first welding strip 31 is used to connect the intermediate bus bar 1 and the first main grid 21 on the first end battery cell 201, the second welding strip 32 is used to connect the intermediate bus bar 1 and the first main grid 21 on the third end battery cell 203, the third welding strip 33 is used to connect the intermediate bus bar 1 and the second main grid 22 on the second end battery cell 202, and the fourth welding strip 34 is used to connect the intermediate bus bar 1 and the second main grid 22 on the fourth end battery cell 204.

[0121] In some embodiments, as Figure 5 As shown, the first welding ribbon 31 and the second welding ribbon 32 are aligned in the second direction Y, and / or the third welding ribbon 33 and the fourth welding ribbon 34 are aligned in the second direction Y. When the first welding ribbon 31 and the second welding ribbon 32 are aligned, they are on the same horizontal line, which makes it easier to position them, facilitates the arrangement and welding of the first welding ribbon 31 and the second welding ribbon 32, and helps reduce the difficulty of photovoltaic module production and improves the production efficiency of photovoltaic modules. Similarly, when the third welding ribbon 33 and the fourth welding ribbon 34 are aligned, they are on the same horizontal line, which makes it easier to position them, facilitates the arrangement and welding of the third welding ribbon 33 and the fourth welding ribbon 34, and helps reduce the difficulty of photovoltaic module production and improves the production efficiency of photovoltaic modules. When the first welding ribbon 31 and the second welding ribbon 32 are aligned, and the third welding ribbon 33 and the fourth welding ribbon 34 are aligned, this further reduces the difficulty of photovoltaic module production, improves the production efficiency of photovoltaic modules, and improves the aesthetic appearance of photovoltaic modules.

[0122] In other embodiments, Figure 9As shown, the first welding ribbon 31 and the second welding ribbon 32 are staggered in the second direction Y, and / or the third welding ribbon 33 and the fourth welding ribbon 34 are staggered in the second direction Y. When the first welding ribbon 31 and the second welding ribbon 32 are staggered, the local increase in thickness caused by the first welding ribbon 31 and the second welding ribbon 32 overlapping each other can be avoided, reducing the difficulty of lamination and facilitating the flatness of the battery module 100. Similarly, when the third welding ribbon 33 and the fourth welding ribbon 34 are staggered, the local increase in thickness caused by the third welding ribbon 33 and the fourth welding ribbon 34 overlapping each other can be avoided, reducing the difficulty of lamination and facilitating the flatness of the battery module 100. When the first welding ribbon 31 and the second welding ribbon 32 are staggered, and the third welding ribbon 33 and the fourth welding ribbon 34 are staggered, the difficulty of lamination can be further reduced, improving the production efficiency and structural reliability of the photovoltaic module.

[0123] In some embodiments, as Figure 5 As shown, the photovoltaic module further includes a first edge bus bar 4 extending along the first direction X. The first cell string 10 and the second cell string 20 have a fifth end cell 205 and a sixth end cell 206 at one end close to the first edge bus bar 4, respectively. The second bus bar 22 of the fifth end cell 205 and the first bus bar 21 of the sixth end cell 206 are respectively connected to the first edge bus bar 4 via the welding ribbon 3. That is, the first cell string 10 and the second cell string 20 are connected in series via the first edge bus bar 4. Similarly, as Figure 5 As shown, the photovoltaic module further includes a second edge bus bar 5 extending along a first direction X. The second edge bus bar 5 and the first edge bus bar 4 are arranged opposite each other along a second direction Y. The third cell string 30 and the fourth cell string 40 have a seventh end cell 207 and an eighth end cell 208 at their ends near the second edge bus bar 5, respectively. The second busbar 22 of the seventh end cell 207 and the first busbar 21 of the eighth end cell 208 are connected to the second edge bus bar 5 via welding ribbons 3. In other words, the third cell string 30 and the fourth cell string 40 are connected in series via the second edge bus bar 5.

[0124] In some embodiments, as Figure 4As shown, the spacing L2 between the adjacent first main grid 21 and the second main grid 22 on the same solar cell 2 is 8mm to 9.5mm. Optionally, L2 is 8mm to 8.5mm or 8.5mm to 9mm or 9mm to 9.5mm. Optionally, L2 is 8mm, 8.1mm, 8.2mm, 8.3mm, 8.4mm, 8.5mm, 8.6mm, 8.7mm, 8.8mm, 8.9mm, 9mm, 9.1mm, 9.2mm, 9.3mm, 9.4mm or 9.5mm, or other values ​​within the above range, which is not limited in this application. When L2 is 8mm to 9.5mm, the risk of short circuit caused by diffusion or printing deviation in the metallization process can be reduced, which is beneficial to improving the yield of the solar cell 2 and reducing the production cost of photovoltaic modules. Furthermore, appropriate spacing helps ensure efficient collection of photogenerated carriers and improves the heat dissipation of the cell 2, thereby improving the photoelectric conversion efficiency of the cell 2 and extending the service life of the cell 2. The sum of the number of first busbars 21 and second busbars 22 on the cell 2 is 8 to 30, and the sum can be an odd number or an even number.

[0125] In some embodiments, the sum of the number of first busbars 21 and second busbars 22 is an even number, that is, the number of first busbars 21 and second busbars 22 is equal. Preferably, the sum of the number of first busbars 21 and second busbars 22 is 8 to 16, 16 to 20, 20 to 26, or 26 to 30. Preferably, the sum of the number of first busbars 21 and second busbars 22 is 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30, and may be other values ​​within the above ranges, which are not limited in this application.

[0126] When the chamfered edges of multiple battery cells 2 in the same battery string are arranged in the same direction, such as Figure 3 As shown, when the sum of the number of first busbars 21 and second busbars 22 on a cell 2 is an even number, the cells 2 in the same cell string can include two types of cells: first cells 23 and second cells 24. The first cells 23 and second cells 24 are alternately arranged in the second direction Y. The structure of one of the first cell 23 and the second cell 24 is symmetrical with the structure of the other after rotating 180°. The first cell 23 and the second cell 24 are two halves of the same cell, which can reduce the number of original cells required to prepare a photovoltaic module, thereby reducing the production cost of photovoltaic modules.

[0127] refer to Figure 10 As shown, the original cell has a center line in the second direction X ( Figure 10(shown by the dotted line), the original cell comprises two symmetrical upper and lower parts along the center line. The upper cell and the lower cell are respectively provided with first main grids 21 and second main grids 22 alternately distributed along the first direction X, and the first main grids 21 of the upper cell are aligned with the first main grids 21 of the lower cell along the second direction Y, and the second main grids 22 of the upper cell are aligned with the second main grids 22 of the lower cell along the second direction Y. Cutting along the center line can obtain two halves. Rotating one of the halves 180° can obtain the following: Figure 11 There are two two-pieces with the same chamfer direction, one of which is the first battery cell 23 in this embodiment, and the other is the second battery cell 24 in this embodiment.

[0128] The original battery cell may be a rectangular battery cell or a square battery cell, which is not limited in this application.

[0129] like Figure 5 As shown, in the first embodiment, the sum of the number of first busbars 21 and second busbars 22 on the cell 2 is an even number, and the number of cells 2 in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 is an odd number. Preferably, the number of cells 2 in each cell string is 9, 11, 13, 15, 17, 19, or 21. The number of cells 2 in multiple cell strings should be consistent to ensure the neatness of the photovoltaic module layout.

[0130] In this embodiment, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206, and the edge busbar on the seventh end cell 207 adjacent to the eighth end cell 208 are both second busbars 22, and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205, and the edge busbar on the eighth end cell 208 adjacent to the seventh end cell 207 are both first busbars 21. Because the second busbar 22 on the fifth end cell 205 and the first busbar 21 on the sixth end cell 206 are both connected to the first edge busbar 4, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206 and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205 are both connected to the first edge busbar 4. Since the second main grid 22 on the seventh end battery cell 207 and the first main grid 21 on the eighth end battery cell 208 are both connected to the second edge bus bar 5, the edge main grid on the seventh end battery cell 207 adjacent to the eighth end battery cell 208 and the edge main grid on the eighth end battery cell 208 adjacent to the seventh end battery cell 207 are both connected to the second edge bus bar 5.

[0131] The spacing L3 between the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206 and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205 is 1 mm to 2.5 mm. Optionally, L3 is 1 mm to 1.5 mm, 1.5 mm to 2 mm, or 2 mm to 2.5 mm. Optionally, L3 is 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm, or other values ​​within the above ranges, which are not limited in this application. When L3 is 1 mm to 2.5 mm, the first cell string 10 and the second cell string 20 can maintain an appropriate string spacing, preventing the welding ribbon 3 on the main grid at the edge of the fifth end cell 205 from overlapping with the welding ribbon 3 on the main grid at the edge of the sixth end cell 206 due to too small a spacing. This reduces the risk of stress concentration at the edges of the fifth end cell 205 and the sixth end cell 206, as well as the risk of short circuits caused by overlapping welding ribbons 3 of opposite polarity. Furthermore, an appropriate string spacing also helps increase the overall light-receiving area of ​​the photovoltaic module, thereby increasing the output power of the photovoltaic module.

[0132] Similarly, the spacing L4 between the edge busbar on the seventh end cell 207 adjacent to the eighth end cell 208 and the edge busbar on the eighth end cell 208 adjacent to the seventh end cell 207 is 1 mm to 2.5 mm. Optionally, L4 is 1 mm to 1.5 mm, 1.5 mm to 2 mm, or 2 mm to 2.5 mm. Optionally, L4 is 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm, or other values ​​within the above ranges, which are not limited in this application. When L4 is 1 mm to 2.5 mm, the third cell string 30 and the fourth cell string 40 can maintain an appropriate string spacing, preventing the welding ribbon 3 on the edge busbar of the seventh end cell 207 from overlapping with the welding ribbon 3 on the edge busbar of the eighth end cell 208 due to too small a spacing. This reduces the risk of stress concentration at the edges of the seventh end cell 207 and the eighth end cell 208, as well as the risk of short circuits caused by overlapping welding ribbons 3 of opposite polarity. Furthermore, an appropriate string spacing also helps increase the overall light-receiving area of ​​the photovoltaic module, thereby increasing the output power of the photovoltaic module.

[0133] When L3 is equal to L4, it can ensure that the first battery string 10 and the third battery string 30 are aligned along the second direction Y position, and the second battery string 20 and the fourth battery string 40 are aligned along the second direction Y position, which facilitates the layout and assembly of the photovoltaic module and is also beneficial to improving the aesthetic appearance of the photovoltaic module.

[0134] like Figure 12 As shown, in the second embodiment, the sum of the number of first busbars 21 and second busbars 22 on the cell 2 is an even number, and the number of cells 2 in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 is also an even number. Preferably, the number of cells 2 in each cell string is 8, 10, 12, 14, 16, 18, or 20. The number of cells 2 in multiple cell strings should be consistent to ensure the neatness of the photovoltaic module layout.

[0135] In this embodiment, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206, and the edge busbar on the seventh end cell 207 adjacent to the eighth end cell 208 are both first busbars 21; the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205, and the edge busbar on the eighth end cell 208 adjacent to the seventh end cell 207 are both second busbars 22. Because the second busbar 22 on the fifth end cell 205 and the first busbar 21 on the sixth end cell 206 are both connected to the first edge busbar 4, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206 and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205 are not connected to the first edge busbar 4. Since the second main grid 22 on the seventh end battery cell 207 and the first main grid 21 on the eighth end battery cell 208 are both connected to the second edge bus bar 5, the edge main grid on the seventh end battery cell 207 adjacent to the eighth end battery cell 208 and the edge main grid on the eighth end battery cell 208 adjacent to the seventh end battery cell 207 are not connected to the second edge bus bar 5.

[0136] Among them, when the edge main grid on the fifth end battery cell 205 adjacent to the sixth end battery cell 206 and the edge main grid on the sixth end battery cell 206 adjacent to the fifth end battery cell 205 are not connected to the first edge bus bar 4, the risk of the welding strip 3 on the edge main grid of the fifth end battery cell 205 and the welding strip 3 on the edge main grid of the sixth end battery cell 206 overlapping each other can be reduced, thereby reducing the risk of stress concentration at the edges of the fifth end battery cell 205 and the sixth end battery cell 206, and reducing the risk of short circuit caused by overlapping welding strips 3 with opposite polarity.

[0137] Similarly, when the edge main grid on the seventh end battery cell 207 adjacent to the eighth end battery cell 208 and the edge main grid on the eighth end battery cell 208 adjacent to the seventh end battery cell 207 are not connected to the second edge bus bar 5, the risk of the welding strip 3 on the edge main grid of the seventh end battery cell 207 and the welding strip 3 on the edge main grid of the eighth end battery cell 208 overlapping each other can be reduced, thereby reducing the risk of stress concentration at the edges of the seventh end battery cell 207 and the eighth end battery cell 208, and reducing the risk of short circuit due to overlapping of welding strips 3 with opposite polarity.

[0138] When the chamfered edges of multiple battery cells 2 in the same battery string are arranged in different directions, such as Figure 7 As shown, when the sum of the number of first busbars 21 and second busbars 22 on a cell 2 is an even number, the cells 2 in the same cell string may include two types of cells: a fifth cell 27 and a sixth cell 28. The fifth cell 27 and the sixth cell 28 are alternately arranged in the second direction Y. The fifth cell 27 and the sixth cell 28 are two halves of the same cell. The first busbar 21 of the fifth cell 27 and the second busbar 22 of the sixth cell 28 are aligned in the second direction Y, and the second busbar 22 of the fifth cell 27 and the first busbar 21 of the sixth cell 28 are aligned in the second direction Y. Alternatively, the cells 2 in the same cell string may include two types of cells: a seventh cell 29 and an eighth cell 210. The seventh cell 29 and the eighth cell 210 are alternately arranged in the second direction Y. The seventh cell 29 and the eighth cell 210 are two halves of the same cell. The first main grid 21 of the seventh cell 29 is aligned with the second main grid 22 of the eighth cell 210 along the second direction Y, and the second main grid 22 of the seventh cell 29 is aligned with the first main grid 21 of the eighth cell 210 along the second direction Y.

[0139] like Figure 7 As shown, in the first embodiment, when the number of battery cells 2 in the first battery string 10, the second battery string 20, the third battery string 30, and the fourth battery string 40 is an odd number, the first end battery cell 201 and the second end battery cell 202 are both the sixth battery cell 28, and the third end battery cell 203 and the fourth end battery cell 204 are both the seventh battery cell 29. One of the fifth end battery cell 205 and the sixth end battery cell 206 is the fifth battery cell 27 rotated 180°, and the other is the sixth battery cell 28. One of the seventh end battery cell 207 and the eighth end battery cell 208 is the seventh battery cell 29, and the other is the eighth battery cell 210 rotated 180°. The remaining battery cells in the first battery string 10, the second battery string 20, the third battery string 30, and the fourth battery string 40 are as follows: Figure 7 The order shown is not repeated here.

[0140] In the second embodiment, Figure 13 As shown, when the number of cells 2 in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 is an even number, the first end cell 201 and the second end cell 202 are both the sixth cell 28, the third end cell 203 and the fourth end cell 204 are both the seventh cell 29. The fifth end cell 205 and the sixth end cell 206 are both the fifth cell 27, and the seventh end cell 207 and the eighth end cell 208 are both the eighth cell 210. The remaining cells in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 are Figure 13 The order of arrangement shown is not repeated here. In some embodiments, the sum of the number of the first busbars 21 and the second busbars 22 is an odd number, that is, the number of the first busbars 21 and the second busbars 22 is not equal. Preferably, the sum of the number of the first busbars 21 and the second busbars 22 is 9 to 15, 15 to 21, 21 to 25, or 25 to 29. Preferably, the sum of the number of the first busbars 21 and the second busbars 22 is 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, or 29, and may be other values ​​within the above range, which is not limited in this application.

[0141] When the chamfered edges of multiple battery cells 2 in the same battery string are arranged in the same direction, such as Figure 14 As shown, when the sum of the number of first busbars 21 and second busbars 22 on a cell 2 is an odd number, the cells 2 in the same cell string may include two types of cells, a third cell 25 and a fourth cell 26, with the third cell 25 and the fourth cell 26 being alternately distributed in the second direction Y. The third cell 25 and the fourth cell 26 are two halves of the same cell, which can reduce the number of original cells required to prepare a photovoltaic module, thereby reducing the production cost of the photovoltaic module.

[0142] refer to Figure 15 As shown, the original cell has a center line in the second direction X ( Figure 15 The original cell comprises two symmetrical parts, upper and lower, along the center line. The upper cell and the lower cell are respectively provided with first and second main grids 21 and 22 alternately distributed along the first direction X. The first main grid 21 of the upper cell is aligned with the second main grid 22 of the lower cell along the second direction Y, and the second main grid 22 of the upper cell is aligned with the first main grid 21 of the lower cell along the second direction Y. Cutting along the center line can obtain two halves. Rotating one of the halves by 180° can obtain the following: Figure 16The two bipartite sheets with the same chamfer direction are shown, one of which is the third battery sheet 25 in this embodiment, and the other bipartite sheet is the fourth battery sheet 26 in this embodiment.

[0143] The original battery cell may be a rectangular battery cell or a square battery cell, which is not limited in this application.

[0144] like Figure 17 As shown, in the third embodiment, the sum of the number of first busbars 21 and second busbars 22 on the cell 2 is an odd number, and the number of cells 2 in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 is also an odd number. Preferably, the number of cells 2 in each cell string is 9, 11, 13, 15, 17, 19, or 21. The number of cells 2 in multiple cell strings should be consistent to ensure the neatness of the photovoltaic module layout.

[0145] In this embodiment, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206, and the edge busbar on the seventh end cell 207 adjacent to the eighth end cell 208 are both second busbars 22, and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205, and the edge busbar on the eighth end cell 208 adjacent to the seventh end cell 207 are both first busbars 21. Because the second busbar 22 on the fifth end cell 205 and the first busbar 21 on the sixth end cell 206 are both connected to the first edge busbar 4, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206 and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205 are both connected to the first edge busbar 4. Since the second main grid 22 on the seventh end battery cell 207 and the first main grid 21 on the eighth end battery cell 208 are both connected to the second edge bus bar 5, the edge main grid on the seventh end battery cell 207 adjacent to the eighth end battery cell 208 and the edge main grid on the eighth end battery cell 208 adjacent to the seventh end battery cell 207 are both connected to the second edge bus bar 5.

[0146] The spacing L5 between the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206 and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205 is 1 mm to 2.5 mm. Optionally, L5 is 1 mm to 1.5 mm, 1.5 mm to 2 mm, or 2 mm to 2.5 mm. Optionally, L5 is 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm, or other values ​​within the above ranges, which are not limited in this application. When L5 is 1 mm to 2.5 mm, the first cell string 10 and the second cell string 20 can maintain an appropriate string spacing. This prevents the soldering ribbons 3 on the main grid at the edge of the fifth end cell 205 from overlapping with the soldering ribbons 3 on the main grid at the edge of the sixth end cell 206 due to a spacing that is too small. This reduces the risk of stress concentration at the edges of the fifth end cell 205 and the sixth end cell 206, as well as the risk of short circuits caused by overlapping soldering ribbons 3 of opposite polarity. Furthermore, an appropriate string spacing also helps increase the overall light-receiving area of ​​the photovoltaic module, thereby increasing the output power of the photovoltaic module.

[0147] Similarly, the spacing L6 between the edge busbar on the seventh end cell 207 adjacent to the eighth end cell 208 and the edge busbar on the eighth end cell 208 adjacent to the seventh end cell 207 is 1 mm to 2.5 mm. Optionally, L6 is 1 mm to 1.5 mm, 1.5 mm to 2 mm, or 2 mm to 2.5 mm. Optionally, L6 is 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm, or other values ​​within the above ranges, which are not limited in this application. When L6 is 1 mm to 2.5 mm, the third cell string 30 and the fourth cell string 40 can maintain an appropriate string spacing, preventing the welding ribbon 3 on the edge busbar of the seventh end cell 207 from overlapping with the welding ribbon 3 on the edge busbar of the eighth end cell 208 due to too small a spacing. This reduces the risk of stress concentration at the edges of the seventh end cell 207 and the eighth end cell 208, as well as the risk of short circuits caused by overlapping welding ribbons 3 of opposite polarity. Furthermore, an appropriate string spacing also helps increase the overall light-receiving area of ​​the photovoltaic module, thereby increasing the output power of the photovoltaic module.

[0148] When L5 is equal to L6, it can ensure that the first battery string 10 and the third battery string 30 are aligned along the second direction Y position, and the second battery string 20 and the fourth battery string 40 are aligned along the second direction Y position, which facilitates the layout and assembly of the photovoltaic module and is also beneficial to improving the aesthetics of the appearance of the photovoltaic module.

[0149] like Figure 18 As shown, in the second embodiment, the sum of the number of first busbars 21 and second busbars 22 on the cell 2 is an even number, and the number of cells 2 in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 is also an even number. Preferably, the number of cells 2 in each cell string is 8, 10, 12, 14, 16, 18, or 20. The number of cells 2 in multiple cell strings should be consistent to ensure the neatness of the photovoltaic module layout.

[0150] In this embodiment, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206, and the edge busbar on the seventh end cell 207 adjacent to the eighth end cell 208 are both first busbars 21; the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205, and the edge busbar on the eighth end cell 208 adjacent to the seventh end cell 207 are both second busbars 22. Because the second busbar 22 on the fifth end cell 205 and the first busbar 21 on the sixth end cell 206 are both connected to the first edge busbar 4, the edge busbar on the fifth end cell 205 adjacent to the sixth end cell 206 and the edge busbar on the sixth end cell 206 adjacent to the fifth end cell 205 are not connected to the first edge busbar 4. Since the second main grid 22 on the seventh end battery cell 207 and the first main grid 21 on the eighth end battery cell 208 are both connected to the second edge bus bar 5, the edge main grid on the seventh end battery cell 207 adjacent to the eighth end battery cell 208 and the edge main grid on the eighth end battery cell 208 adjacent to the seventh end battery cell 207 are not connected to the second edge bus bar 5.

[0151] Among them, when the edge main grid on the fifth end battery cell 205 adjacent to the sixth end battery cell 206 and the edge main grid on the sixth end battery cell 206 adjacent to the fifth end battery cell 205 are not connected to the first edge bus bar 4, the risk of the welding strip 3 on the edge main grid of the fifth end battery cell 205 and the welding strip 3 on the edge main grid of the sixth end battery cell 206 overlapping each other can be reduced, thereby reducing the risk of stress concentration at the edges of the fifth end battery cell 205 and the sixth end battery cell 206, and reducing the risk of short circuit caused by overlapping welding strips 3 with opposite polarity.

[0152] Similarly, when the edge main grid on the seventh end battery cell 207 adjacent to the eighth end battery cell 208 and the edge main grid on the eighth end battery cell 208 adjacent to the seventh end battery cell 207 are not connected to the second edge bus bar 5, the risk of the welding strip 3 on the edge main grid of the seventh end battery cell 207 and the welding strip 3 on the edge main grid of the eighth end battery cell 208 overlapping each other can be reduced, thereby reducing the risk of stress concentration at the edges of the seventh end battery cell 207 and the eighth end battery cell 208, and reducing the risk of short circuit due to overlapping of welding strips 3 with opposite polarity.

[0153] When the chamfered edges of multiple battery cells 2 in the same battery string are arranged in different directions, such as Figure 19 As shown, when the sum of the number of first busbars 21 and second busbars 22 on a cell 2 is an odd number, the cell 2 in the same cell string may include two types of cell, a ninth cell 211 and a tenth cell 212, with the ninth cell 211 and the tenth cell 212 being alternately distributed in the second direction Y. The ninth cell 211 and the tenth cell 212 are two halves of the same cell, with the first busbar 21 of the ninth cell 211 aligned with the second busbar 22 of the tenth cell 212, and the second busbar 22 of the ninth cell 211 aligned with the first busbar 21 of the tenth cell 212.

[0154] like Figure 19 As shown, in the first embodiment, when the number of battery cells 2 in the first battery string 10, the second battery string 20, the third battery string 30, and the fourth battery string 40 is an odd number, the first end battery cell 201 and the fifth end battery cell 205 are both the tenth battery cell 212, and the remaining battery cells in the first battery string 10 are the ninth battery cell 211 and the tenth battery cell 212 arranged alternately. The third battery string 30 is obtained by rotating the first battery string 10 by 180°. The fourth end battery cell 204 and the eighth end battery cell 208 are both the ninth battery cell 211, and the remaining battery cells in the fourth battery string 40 are the ninth battery cell 211 and the tenth battery cell 212 arranged alternately. The second battery string 20 is obtained by rotating the fourth battery string 40 by 180°.

[0155] like Figure 20As shown, in the second embodiment, when the number of cells 2 in the first cell string 10, the second cell string 20, the third cell string 30, and the fourth cell string 40 is an even number, the cell 201 at the first end is the tenth cell 212, the cell 205 at the fifth end is the ninth cell 211, and the remaining cells in the first cell string 10 are the ninth cell 211 and the tenth cell 212 arranged alternately. The third cell string 30 is obtained by rotating the first cell string 10 by 180°. The cell 204 at the fourth end is the ninth cell 211, the cell 208 at the eighth end is the tenth cell 212, and the second cell string 20 is obtained by rotating the fourth cell string 40 by 180°.

[0156] The present application also provides a method for preparing a photovoltaic module, which is used to obtain the photovoltaic modules described in the above embodiments. The method specifically includes the following steps:

[0157] Step S1: providing a plurality of battery cells 2 , each battery cell 2 including a first busbar 21 and a second busbar 22 spaced apart along a first direction X, and each battery cell 2 also having chamfered edges.

[0158] In this step, the cell 2 is selected to have chamfered edges, which can effectively reduce the risk of hidden cracks or ruptures at the edges of the cell 2 due to stress concentration, and can also reduce edge reflection losses, which is beneficial to improving the photoelectric conversion efficiency of the cell 2.

[0159] Step S2: Arrange multiple battery cells 2 along the second direction Y to form a first battery string 10, a second battery string 20, a third battery string 30, and a fourth battery string 40, respectively, with the chamfered edges of the multiple battery cells 2 in the same battery string arranged in the same direction;

[0160] The battery strings are arranged so that the chamfered edge of the first end battery cell 201 is arranged opposite to the chamfered edge of the third end battery cell 203, and the chamfered edge of the second end battery cell 202 is arranged opposite to the chamfered edge of the fourth end battery cell 204. The first battery string 10, the second battery string 20, the third battery string 30 and the fourth battery string 40 respectively have the first end battery cell 201, the second end battery cell 202, the third end battery cell 203 and the fourth end battery cell 204. The edge main grid on the first end battery cell 201 adjacent to the second end battery cell 202 and the edge main grid on the third end battery cell 203 adjacent to the fourth end battery cell 204 are both second main grids 22. The edge main grid on the second end battery cell 202 adjacent to the first end battery cell 201 and the edge main grid on the fourth end battery cell 204 adjacent to the third end battery cell 203 are both first main grids 21.

[0161] The first busbar 21 of the first end battery cell 201 and the first busbar 21 of the third end battery cell 203 are connected to the same intermediate busbar 1 , and the second busbar 22 of the second end battery cell 202 and the second busbar 22 of the third end battery cell 203 are connected to another adjacent intermediate busbar 1 .

[0162] In this step, the first battery string 10, the second battery string 20, the third battery string 30 and the fourth battery string 40 are arranged so that the edge main grid of any end battery cell near the lead-out position is not electrically connected to the middle bus bar 1, so that there is enough space between the two adjacent middle bus bars 1 for setting the lead-out line, ensuring that there is a large spacing between the lead-out lines of the two adjacent middle bus bars 1, thereby avoiding the problem of short circuit caused by contact between the two adjacent lead-out lines. Moreover, when the chamfered edges of multiple battery cells 2 in the same battery string are in the same direction, it is helpful to reduce the risk of cold soldering of the welding strip 3. Moreover, the first end battery cell 201, the second end battery cell 202, the third end battery cell 203 and the fourth end battery cell 204 are all arranged with the chamfered edges facing the lead-out line, which can provide more layout space for the lead-out line and further reduce the risk of contact between the two adjacent lead-out lines. Moreover, when arranged in this way, the aesthetics of the photovoltaic module layout can also be improved.

[0163] Below is Figure 2 Taking the photovoltaic assembly shown as an example, that is, taking the cell 2 as a two-piece cell, the sum of the number of the first main grid 21 and the second main grid 22 on the cell 2 is an even number, and the number of cell 2 in the first cell string 10, the second cell string 20, the third cell string 30 and the fourth cell string 40 is an odd number, the chamfered edges of multiple cell cells 2 in the same cell string are arranged in the same direction, the chamfered edges of the cell 2 in the first cell string 10 and the chamfered edges of the cell 2 in the third cell string 30 are arranged opposite to each other, and the chamfered edges of the cell 2 in the second cell string 20 and the chamfered edges of the cell 2 in the fourth cell string 40 are arranged opposite to each other, as an example, the above steps are described in detail.

[0164] In some embodiments, as Figure 21 As shown, for step S1, the method for preparing a photovoltaic module includes:

[0165] Step A1: Providing an original battery cell.

[0166] Step A2: Cutting the original cell along the center line in the second direction to obtain two sliced ​​cell sheets.

[0167] Step A3: Rotate one of the sliced ​​cells by 180° to obtain a first cell 23 and a second cell 24 with chamfered edges arranged in the same direction.

[0168] In the above steps, the original battery cell has a center line in the second direction X ( Figure 10(shown by the dotted line), the original cell comprises an upper and lower portion symmetrically arranged along the centerline. The upper cell and the lower cell are respectively provided with first busbars 21 and second busbars 22 alternately distributed along the first direction X. The first busbars 21 of the upper cell are aligned with the first busbars 21 of the lower cell along the second direction Y, and the second busbars 22 of the upper cell are aligned with the second busbars 22 of the lower cell along the second direction Y. Following the above steps, one original cell can be cut into two usable halves.

[0169] In some embodiments, as Figure 22 As shown, for step S2, when forming the second battery string 20, the preparation method of the photovoltaic module includes:

[0170] Step B1: Alternately arrange a plurality of first battery cells 23 and a plurality of second battery cells 24 along the second direction Y, and connect adjacent first battery cells 23 and second battery cells 24 via welding ribbons 3 to obtain a prefabricated second battery string 20 ′.

[0171] In this step, the plurality of first battery cells 23 and the plurality of second battery cells 24 may be alternately arranged along the second direction Y, and then a welding ribbon 3 may be laid and welded using a string welding machine to connect adjacent first battery cells 23 and second battery cells 24 in series.

[0172] Step B2: Rotate the prefabricated second battery string 20 ′ by 180° to obtain the second battery string 20 .

[0173] In this step, the second battery string 20 ′ may be rotated in a counterclockwise direction or a clockwise direction, so that the obtained second battery string 20 can meet the layout requirements of the photovoltaic module.

[0174] In some embodiments, when forming the third battery string 30, the preparation method of the photovoltaic module includes: arranging multiple second battery cells 24 and multiple first battery cells 23 alternately along the second direction Y, and connecting adjacent first battery cells 23 and second battery cells 24 through welding ribbons 3 to obtain the third battery string 30.

[0175] In this step, the plurality of second battery cells 24 and the plurality of first battery cells 23 may be arranged alternately along the second direction Y. Then, a stringer may be used to lay the welding ribbon 3 and perform welding, so that adjacent first battery cells 23 and second battery cells 24 are sequentially connected in series. Welding may also be performed manually, which is not limited in this embodiment.

[0176] In some embodiments, as Figure 23 As shown, for step S2, when forming the first battery string 10, the preparation method of the photovoltaic module includes:

[0177] Step C1: Alternately arrange the plurality of first battery cells 23 and the plurality of second battery cells 24 along the second direction Y.

[0178] Step C2: Connect the adjacent first battery cells 23 and second battery cells 24 via the welding ribbons 3 to obtain a prefabricated first battery string 10 ′. The welding ribbons 3 in the prefabricated first battery string 10 ′ and the welding ribbons 3 in the prefabricated second battery string 20 ′ are distributed in a mirror image.

[0179] In the above steps, the plurality of first battery cells 23 and the plurality of second battery cells 24 can be alternately arranged along the second direction Y. Then, a stringer is used to lay the welding ribbon 3, and the welding is performed using the mirroring function of the stringer. Adjacent first battery cells 23 and second battery cells 24 are sequentially connected in series, so that the distribution of the welding ribbon 3 in the prefabricated first battery string 10' and the distribution of the welding ribbon 3 in the prefabricated second battery string 20' are mirror images relative to the first direction X. The welding can also be performed manually, which is not limited in this embodiment.

[0180] Step C3: rotating the prefabricated first battery string 10 ′ by 180° as a whole to obtain the first battery string 10 .

[0181] In this step, the first battery string 10 ′ may be rotated in a counterclockwise direction or a clockwise direction, so that the obtained first battery string 10 can meet the layout requirements of the photovoltaic module.

[0182] In some embodiments, when forming the fourth cell string 40, the method for preparing the photovoltaic module includes:

[0183] Step D1: Alternately arrange the plurality of second battery cells 24 and the plurality of first battery cells 23 along the second direction Y.

[0184] Step D2: Connect the adjacent first cell slice 23 and second cell slice 24 via the soldering ribbon 3 to obtain a fourth cell string 40 . The soldering ribbon 3 in the fourth cell string 40 is distributed in a mirror image with the soldering ribbon 3 in the third cell string 30 .

[0185] In the above steps, the plurality of second battery cells 24 and the plurality of first battery cells 23 may be arranged alternately along the second direction Y. Then, a stringer may be used to lay the welding ribbon 3, and the welding may be performed using the mirroring function of the stringer. Adjacent first battery cells 23 and second battery cells 24 may be sequentially connected in series, so that the distribution of the welding ribbon 3 in the fourth battery string 40 and the distribution of the welding ribbon 3 in the third battery string 30 are mirror images relative to the first direction X. Manual welding may also be performed, and this embodiment does not limit this.

[0186] In some embodiments, after step S3, the method for preparing a photovoltaic module further includes:

[0187] Step S4: Connect the second main grid 22 of the fifth end battery cell 205 and the first main grid 21 of the sixth end battery cell 206 to the first edge bus bar 4 through the welding strip 3, and connect the second main grid 22 of the seventh end battery cell 207 and the first main grid 21 of the eighth end battery cell 208 to the second edge bus bar 5 through the welding strip 3.

[0188] In this step, the complete circuit structure of the photovoltaic module is formed by connecting the first cell string 10 and the second cell string 20 to the first edge bus bar 4, and connecting the third cell string 30 and the fourth cell string 40 to the second edge bus bar 5. The number of first cell strings 10, second cell strings 20, third cell strings 30, and fourth cell strings 40 is not limited.

[0189] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A photovoltaic module, characterized in that: include: A first battery string group (101) includes first battery strings (10) and second battery strings (20) alternately distributed along a first direction; A second battery string group (102) comprising third battery strings (30) and fourth battery strings (40) alternately distributed along the first direction; An intermediate bus bar (1) is located between the first battery string group (101) and the second battery string group (102), and a plurality of the intermediate bus bars (1) are arranged at intervals along the first direction; The first battery string (10), the second battery string (20), the third battery string (30), and the fourth battery string (40) respectively include a plurality of battery cells (2) spaced apart and distributed along a second direction, and the battery cells (2) are back-contact batteries or back-contact laminated batteries; The battery cell (2) comprises a first main grid (21) and a second main grid (22) spaced apart along the first direction; the first battery string (10), the second battery string (20), the third battery string (30) and the fourth battery string (40) respectively have a first end battery cell (201), a second end battery cell (202), a third end battery cell (203) and a fourth end battery cell (204) at one end close to the middle busbar (1); the edge main grid on the first end battery cell (201) adjacent to the second end battery cell (202) and the edge main grid on the third end battery cell (203) adjacent to the fourth end battery cell (204) are both the second main grid (22); the edge main grid on the second end battery cell (202) adjacent to the first end battery cell (201) and the edge main grid on the fourth end battery cell (204) adjacent to the third end battery cell (203) are both the first main grid (21); The first main grid (21) of the first end battery cell (201) and the first main grid (21) of the third end battery cell (203) are respectively connected to the same intermediate bus bar (1) via welding strips (3), and the second main grid (22) of the second end battery cell (202) and the second main grid (22) of the fourth end battery cell (204) are respectively connected to another adjacent intermediate bus bar (1) via welding strips (3); The chamfered edge of the first end battery cell (201) is arranged opposite to the chamfered edge of the third end battery cell (203), and the chamfered edge of the second end battery cell (202) is arranged opposite to the chamfered edge of the fourth end battery cell (204); The first direction and the second direction are perpendicular to each other.

2. The photovoltaic module according to claim 1, characterized in that The chamfered edges of any two battery cells (2) adjacent to each other along the first direction are arranged in the same direction.

3. The photovoltaic module according to claim 1, characterized in that The chamfered edges of a plurality of battery sheets (2) in the same battery string are arranged in the same direction.

4. The photovoltaic module according to claim 1, characterized in that The chamfer size of the battery cell (2) is A×45°, and A satisfies 1mm≤A≤2mm.

5. The photovoltaic module according to claim 1, characterized in that Along the first direction, the distance L1 between two adjacent intermediate bus bars (1) is 15 mm to 25 mm.

6. The photovoltaic module according to claim 1, characterized in that The welding strip (3) comprises a first welding strip (31) and a second welding strip (32), wherein the first welding strip (31) is used to connect the intermediate bus bar (1) and the first main grid (21) on the first end battery cell (201), and the second welding strip (32) is used to connect the intermediate bus bar (1) and the first main grid (21) on the third end battery cell (203); The first welding strip (31) and the second welding strip (32) are staggered with each other in the second direction; And / or, the welding strip (3) includes a third welding strip (33) and a fourth welding strip (34), the third welding strip (33) is used to connect the intermediate bus bar (1) and the second main grid (22) on the second end battery cell (202), and the fourth welding strip (34) is used to connect the intermediate bus bar (1) and the second main grid (22) on the fourth end battery cell (204); The third welding strip (33) and the fourth welding strip (34) are staggered with each other in the second direction.

7. The photovoltaic module according to claim 1, characterized in that The photovoltaic assembly further comprises a first edge bus bar (4) and a second edge bus bar (5) which are relatively distributed along a second direction; The first battery string (10) and the second battery string (20) each have a fifth end battery cell (205) and a sixth end battery cell (206) at one end close to the first edge busbar (4), and the second main grid (22) of the fifth end battery cell (205) and the first main grid (21) of the sixth end battery cell (206) are respectively connected to the first edge busbar (4) via welding strips (3); The third battery string (30) and the fourth battery string (40) respectively have a seventh end battery cell (207) and an eighth end battery cell (208) at one end close to the second edge bus bar (5); the second main grid (22) of the seventh end battery cell (207) and the first main grid (21) of the eighth end battery cell (208) are respectively connected to the second edge bus bar (5) via welding strips (3).

8. The photovoltaic module according to claim 7, characterized in that: The number of the battery cells (2) in the first battery string (10), the second battery string (20), the third battery string (30) and the fourth battery string (40) are all even numbers; The edge main grid on the fifth end battery cell (205) adjacent to the sixth end battery cell (206), and the edge main grid on the seventh end battery cell (207) adjacent to the eighth end battery cell (208) are both the first main grid (21); The edge main grid adjacent to the sixth end battery cell (206) and the fifth end battery cell (205), and the edge main grid adjacent to the eighth end battery cell (208) and the seventh end battery cell (207) are both the second main grid (22).

9. The photovoltaic module according to claim 7, characterized in that: The number of the battery cells (2) in the first battery string (10), the second battery string (20), the third battery string (30) and the fourth battery string (40) are all odd numbers; The edge main grid on the fifth end battery cell (205) adjacent to the sixth end battery cell (206), and the edge main grid on the seventh end battery cell (207) adjacent to the eighth end battery cell (208) are both the second main grid (22); The edge main grid on the sixth end cell (206) adjacent to the fifth end cell (205) and the edge main grid on the eighth end cell (208) adjacent to the seventh end cell (207) are both the first main grid (21).

10. The photovoltaic module according to claim 1, characterized in that: The sum of the number of the first main grids (21) and the second main grids (22) on the battery cell (2) is an even number.

11. The photovoltaic module according to claim 10, characterized in that: The battery cell (2) is a sliced ​​battery cell, comprising a first battery cell (23) and a second battery cell (24), wherein the structure of one of the first battery cell (23) and the second battery cell (24) is symmetrical to the structure of the other after being rotated 180 degrees.

12. A method for preparing a photovoltaic module, characterized in that: include: A cell (2) is provided, wherein the cell (2) is a back-contact cell or a back-contact laminated cell, the cell (2) comprises a first main grid (21) and a second main grid (22) spaced apart along a first direction, and the cell (2) further comprises a chamfered edge; A plurality of battery cells (2) are arranged along a second direction to form a first battery string (10), a second battery string (20), a third battery string (30) and a fourth battery string (40), respectively; the first battery string (10), the second battery string (20), the third battery string (30) and the fourth battery string (40) respectively have a first end battery cell (201), a second end battery cell (202), a third end battery cell (203) and a fourth end battery cell (204); an edge main grid adjacent to the second end battery cell (202) on the first end battery cell (201) and the third end battery cell (204) The edge main grids on the cell (203) adjacent to the fourth end cell (204) are all the second main grids (22), the edge main grids on the second end cell (202) adjacent to the first end cell (201), and the edge main grids on the fourth end cell (204) adjacent to the third end cell (203) are all the first main grids (21), the chamfered edge of the first end cell (201) and the chamfered edge of the third end cell (203) are arranged facing each other, and the chamfered edge of the second end cell (202) and the chamfered edge of the fourth end cell (204) are arranged facing each other; Connecting the first main grid (21) of the first end battery cell (201) and the first main grid (21) of the third end battery cell (203) to the same intermediate busbar (1), and connecting the second main grid (22) of the second end battery cell (202) and the second main grid (22) of the third end battery cell (203) to another adjacent intermediate busbar (1); The second direction and the first direction are perpendicular to each other.

13. The method for preparing a photovoltaic module according to claim 12, wherein: The chamfered edges of the plurality of battery cells (2) in the same battery string are arranged in the same direction, the sum of the number of the first main grids (21) and the second main grids (22) on the battery cell (2) is an even number, the battery cell (2) is a sliced ​​battery cell, and the battery cell (2) includes a rotationally symmetrical first battery cell (23) and a second battery cell (24); When providing the cell (2), the method for preparing the photovoltaic module includes: Provide original battery cells; Cutting the original cell along a center line in the second direction to obtain two sliced ​​cell sheets; One of the sliced ​​cells is rotated 180 degrees to obtain the first cell (23) and the second cell (24) with chamfered edges arranged in the same direction.

14. The method for preparing a photovoltaic module according to claim 13, wherein: The number of the battery cells (2) in the first battery string (10), the second battery string (20), the third battery string (30) and the fourth battery string (40) are all odd numbers; When forming the second battery string (20), the preparation method of the photovoltaic module includes: Alternating a plurality of the first battery cells (23) and a plurality of the second battery cells (24) along the second direction, and connecting adjacent first battery cells (23) and second battery cells (24) via welding strips (3) to obtain a prefabricated second battery string (20'); Rotating the prefabricated second battery string (20') as a whole by 180 degrees to obtain the second battery string (20); And / or, when forming the third battery string (30), the method for preparing the photovoltaic module includes: A plurality of the second battery cells (24) and a plurality of the first battery cells (23) are alternately arranged along the second direction, and adjacent first battery cells (23) and second battery cells (24) are connected via welding strips (3) to obtain the third battery string (30).

15. The method for preparing a photovoltaic module according to claim 14, characterized in that: When forming the first battery string (10), the preparation method of the photovoltaic module includes: Alternately arranging a plurality of the first battery cells (23) and a plurality of the second battery cells (24) along the second direction; The adjacent first battery slices (23) and the second battery slices (24) are connected by welding strips (3) to obtain a prefabricated first battery string (10'), wherein the welding strips (3) in the prefabricated first battery string (10') and the welding strips (3) in the prefabricated second battery string (20') are distributed in a mirror image; Rotating the prefabricated first battery string (10') as a whole by 180 degrees to obtain the first battery string (10); And / or, when forming the fourth battery string (40), the method for preparing the photovoltaic module includes: Alternately arranging a plurality of the second battery cells (24) and a plurality of the first battery cells (23) along the second direction; The adjacent first battery slices (23) and the second battery slices (24) are connected via welding strips (3) to obtain the fourth battery string (40), wherein the welding strips (3) in the fourth battery string (40) and the welding strips (3) in the third battery string (30) are distributed in a mirror image.

Images