Photovoltaic module and production method thereof

Abstract

The invention relates to a photovoltaic module and a production method of the photovoltaic module, and a whole battery piece can be cut into four split battery pieces, including two edge pieces with chamfers and two middle pieces without chamfers; the photovoltaic module comprises a plurality of battery strings, each battery string comprises a plurality of first battery sections and a second battery section, each first battery section sequentially comprises an edge piece, a middle piece, a middle piece and an edge piece, the second battery section comprises two edge pieces and three middle pieces, or the second battery section comprises three edge pieces and two middle pieces. In the invention, the battery string is provided with the edge pieces and the middle pieces, so that waste caused by the fact that the middle pieces are not used can be reduced when the battery string is assembled. The number of the edge pieces and the number of the middle pieces in one battery string are only one, so that the using number of the edge pieces and the using number of the middle pieces in one battery string are balanced, and when the battery strings are assembled, the remaining number of the edge pieces and the remaining number of the middle pieces are small.

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 producing the photovoltaic module. Background Art

[0002] Photovoltaic modules can directly convert solar radiation energy into electrical energy, mainly based on the photovoltaic effect of crystalline silicon. That is, when the photons of sunlight are absorbed by semiconductor crystalline silicon, electron-hole pairs are generated. When these electron-hole pairs reach the pn junction composed of p-type crystalline silicon and n-type crystalline silicon, they are separated to both sides of the pn junction by the junction electric field. When an external load is connected, photocurrent is formed and electrical energy is output.

[0003] Photovoltaic modules include cell strings, which are formed by connecting sliced ​​cells in series. Sliced ​​cells are cut from whole cells. The sliced ​​cells cut from whole cells include chamfered edge cells and non-chamfered middle cells. Currently, when assembling cell strings, only chamfered edge cells are used, resulting in wasted middle cells. Summary of the Invention

[0004] The present application provides a photovoltaic module and a method for producing the photovoltaic module, which are used to reduce the waste of sliced ​​solar cells.

[0005] In a photovoltaic module provided by an embodiment of the present application, a whole cell can be cut into four sliced ​​cells, including two edge slices with chamfers and two middle slices without chamfers;

[0006] The photovoltaic assembly includes multiple battery strings, each of which includes multiple first battery segments and one second battery segment. Each of the first battery segments includes the edge sheet, the middle sheet, the middle sheet, and the edge sheet in sequence. The second battery segment includes two edge sheets and three middle sheets, or the second battery segment includes three edge sheets and two middle sheets.

[0007] In one possible design, the second battery segment is located at the head or tail of the battery string.

[0008] In one possible design, the first battery segment includes four sliced ​​battery cells cut from a whole battery cell; the second battery segment includes four sliced ​​battery cells cut from a whole battery cell and a single sliced ​​battery cell.

[0009] In a possible design, a single sliced ​​battery cell in the second battery segment is the edge cell and is located at one end of the second battery segment.

[0010] In a possible design, a single slice of the battery cell in the second battery segment is the middle slice, and is located inside the second battery segment.

[0011] In a possible design, four battery strings are connected in parallel to form a battery string group, and the four second battery segments in a battery string group include four separate sliced ​​battery cells, namely, two edge cells and two middle cells.

[0012] In one possible design, the chamfers of the edge pieces in the photovoltaic module are all located upstream of the current flow direction in the battery string; or, the chamfers of the edge pieces in the photovoltaic module are all located downstream of the current flow direction in the battery string.

[0013] An embodiment of the present application provides a method for producing a photovoltaic module, which is used to produce the photovoltaic module described above. The method for producing the photovoltaic module includes:

[0014] Cutting the entire cell into four sliced ​​cells, including two edge slices with chamfers and two middle slices without chamfers;

[0015] Selecting four of the split battery cells, and arranging them into a first battery segment in the order of the edge cell, the middle cell, the middle cell, and the edge cell;

[0016] Selecting two edge sheets and three middle sheets, or three edge sheets and two middle sheets, and arranging them into a second battery segment;

[0017] A plurality of the first battery segments and one of the second battery segments are connected to form a battery string.

[0018] In one possible design, after the step of cutting the whole cell into four separate cells, the photovoltaic module production method further comprises:

[0019] One of the edge pieces is rotated 180°.

[0020] In a possible design, after the step of rotating one of the edge sheets by 180°, the photovoltaic module production method further comprises:

[0021] The four sliced ​​battery cells cut from the whole battery cell are arranged in sequence to form the first battery segment.

[0022] In the present application, a battery string contains both edge slices and middle slices, thereby reducing waste caused by unused middle slices when the battery strings are connected in series. The number of first battery segments and second battery segments in a battery string is n, and the number of sliced ​​battery slices in a battery string is N=4n+1. When the number of edge slices is 2n, the number of middle slices is 2n+1, and when the number of edge slices is 2n+1, the number of middle slices is 2n. That is, the number of edge slices and middle slices in a battery string differs by only one, making the number of edge slices and middle slices used in a battery string more balanced. When the battery strings are connected in series, the number of leftover edge slices and middle slices is relatively small, which reduces the storage pressure on the remaining sliced ​​battery slices.

[0023] 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

[0024] Figure 1 This is a schematic structural diagram of a photovoltaic module provided in this application in a specific embodiment;

[0025] Figure 2 A schematic diagram of the structure for cutting a whole battery cell;

[0026] Figure 3 for Figure 1 A schematic structural diagram of a battery string in a specific embodiment;

[0027] Figure 4 for Figure 1 A schematic structural diagram of a battery string in a specific embodiment;

[0028] Figure 5 for Figure 1 A schematic structural diagram of a battery string in a specific embodiment;

[0029] Figure 6 for Figure 1 A schematic structural diagram of a battery string in a specific embodiment;

[0030] Figure 7 for Figure 1 A schematic structural diagram of a battery string in another specific embodiment;

[0031] Figure 8 for Figure 1 A schematic structural diagram of a battery string in another specific embodiment;

[0032] Figure 9 for Figure 1 A schematic structural diagram of a battery string in another specific embodiment;

[0033] Figure 10 for Figure 1 A schematic structural diagram of a battery string in another specific embodiment;

[0034] Figure 11 for Figure 1 A schematic structural diagram of a battery string in another specific embodiment;

[0035] Figure 12 for Figure 1 A schematic structural diagram of a battery string in another specific embodiment;

[0036] Figure 13 This is a schematic diagram of the structure of the photovoltaic module provided in this application;

[0037] Figure 14 This is a flow chart of the method for producing a photovoltaic module provided in this application.

[0038] Reference numerals:

[0039] 1-battery string;

[0040] 11-battery string;

[0041] 111-first battery segment;

[0042] 112 - second battery segment;

[0043] 113-sliced ​​battery cells;

[0044] 113a-edge piece;

[0045] 113b-middle piece;

[0046] 12-bus bar;

[0047] 13-jumper wire;

[0048] 2-front packaging structure;

[0049] 3-front film layer;

[0050] 4-back film layer;

[0051] 5-Back side packaging structure.

[0052] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0053] 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.

[0054] 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.

[0055] 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.

[0056] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0057] 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.

[0058] An embodiment of the present application provides a photovoltaic module, comprising a plurality of cell strings 11. The plurality of cell strings 11 are connected in parallel via a bus bar 12 to form a cell string group 1. The cell string groups 1 are connected in series via the bus bar 12 and a jumper 13. For example, the photovoltaic module may include three cell string groups 1 connected in series, each cell string group 1 including four cell strings 11 connected in parallel. It is understood that the photovoltaic module may also include other numbers of cell string groups 1, and the cell string groups 1 may also include other numbers of cell strings 11.

[0059] Specifically, the battery string 11 includes individual battery cells 113 and welding ribbons. The welding ribbons connect adjacent battery cells to connect the individual battery cells 113 in the battery string 11 in series. For battery cells at the head or tail of the battery string 11, the welding ribbons connected to the cells are connected to the busbar 12 to achieve parallel connection between the battery strings 11.

[0060] The types of the sliced ​​cells 113 include, but are not limited to, Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact Cell (TOPCON), Heterojunction with Intrinsic Thin-layer (HIT), Back Contact Cell (BC), Perovskite Solar Cells (PSC), etc. It is understandable that the present application does not specifically limit the types of the sliced ​​cells 113 in the photovoltaic module.

[0061] For TOPCon cells, along their thickness, they consist of a metallic silver electrode, a front-surface silicon nitride passivation layer, a boron-doped emitter, an N-type base silicon layer, a diffused doped layer, ultra-thin silicon oxide, doped polysilicon, silicon nitride, and a metallic silver electrode. The back of the cell is composed of an ultra-thin silicon oxide layer (1nm to 2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivated contact structure. This structure can block minority carrier-hole recombination, thereby increasing the cell's open-circuit voltage and short-circuit current. The ultra-thin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking minority carrier-hole recombination. The excellent passivation effect of the ultra-thin silicon oxide and heavily doped silicon film causes the energy bands on the silicon wafer to bend, thereby forming a field passivation effect. This significantly increases the probability of electron tunneling, reduces contact resistance, and increases the cell's open-circuit voltage and short-circuit current, thereby improving the cell's conversion efficiency.

[0062] For HIT batteries, along their thickness direction, the HIT batteries include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0063] For PERC cells, along the thickness direction, the PERC cell includes the front surface metal silver electrode, the front surface silicon nitride passivation layer, the phosphorus layer emitter, the P-type base silicon layer, the local aluminum back field, the metal aluminum back electrode, the back passivation layer (Al2O3 / SiN x PERC cells use a passivation film to passivate the back surface, replacing the all-aluminum back surface field. This enhances the internal back reflection of light in the silicon substrate, reduces the recombination rate on the back surface, and increases the efficiency of the cell by 0.5%-1%.

[0064] For a PSC cell, along its thickness, the perovskite cell consists of a substrate material, a conductive film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with minimal loss. This can generate a high photogenerated voltage and current, making the perovskite exhibit a high photoelectric conversion efficiency.

[0065] For BC cells, the emitter, surface field and metal electrode are all set on the back of the cell and cross-distributed. The front of the cell uses SiN x / SiO x The double-layer anti-reflection passivation film removes metal electrode obstruction from the front of the cell, allowing the cell to receive more incident light, reducing optical loss and improving photoelectric conversion efficiency.

[0066] In addition, the type of the split cell 113 can also be a stacked cell, which includes a top cell, an intermediate connecting layer, and a bottom cell, wherein the intermediate connecting layer is connected between the bottom cell and the top cell. The top cell can be one of a perovskite cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell, or a gallium arsenide solar cell, and the bottom cell can be one of a PERC cell, a TOPCON cell, a HIT cell, or a BC cell. The intermediate connecting layer can be selected from a transparent material with a high refractive index, such as a transparent conductive metal oxide film (ITO). An effective intermediate connecting layer needs to have high light transmittance to reduce reflection and absorption of light at the connecting layer interface, as well as good conductivity to reduce the impact of series resistance on device performance.

[0067] like Figure 2 As shown, a whole cell can be cut into four sliced ​​cells 113, including two edge slices 113a with chamfers and two middle slices 113b without chamfers. The edge slice 113a has fewer cutting edges than the middle slice 113b, so the damage caused to the edge slice 113a by cutting is less than the damage caused to the middle slice 113b. In addition, the chamfers on the edge slice 113a can alleviate the stress concentration on the sliced ​​cell 113, making it less likely for microcracks or splits to occur on the sliced ​​cell 113. In addition, because the edge slice 113a has chamfers, the light-receiving area of ​​the edge slice 113a is smaller than the light-receiving area of ​​the middle slice 113b, and there may be a small voltage difference between the edge slice 113a and the middle slice 113b.

[0068] like Figure 3As shown, the battery string 11 includes multiple first battery segments 111 and one second battery segment 112. Each first battery segment 111 includes, in sequence, an edge sheet 113a, a middle sheet 113b, a middle sheet 113b, and an edge sheet 113a. The second battery segment 112 includes two edge sheets 113a and three middle sheets 113b, or alternatively, the second battery segment 112 includes three edge sheets 113a and two middle sheets 113b. For example, if a battery string 11 has 17 split battery cells 113, the battery string 11 may include three first battery segments 111 and one second battery segment 112.

[0069] First, the battery string 11 contains both edge slices 113a and middle slices 113b, thereby reducing waste caused by unused middle slices 113b when the battery strings 11 are connected in series. Second, the number of first battery segments 111 and second battery segments 112 in a battery string 11 is n, and the number of sliced ​​battery slices 113 in a battery string 11 is N=4n+1. When the number of edge slices 113a is 2n, the number of middle slices 113b is 2n+1. When the number of edge slices 113a is 2n+1, the number of middle slices 113b is 2n. That is, the number of edge slices 113a and middle slices 113b in a battery string 11 differs by only one. This makes the number of edge slices 113a and middle slices 113b used in a battery string 11 relatively balanced. When the battery strings 11 are connected in series, the number of remaining edge slices 113a and middle slices 113b is relatively small, which reduces the storage pressure on the remaining sliced ​​battery slices 113. In addition, since the number of segmented battery cells 113 in different battery strings 11 is equal, and the number of edge cells 113a in different battery strings 11 differs by at most one, and the number of middle cells 113b in different battery strings 11 differs by at most one, the voltages of different battery strings 11 are relatively close.

[0070] Optionally, a battery string 11 is composed of multiple sliced ​​battery cells 113 cut from n whole battery cells and a single sliced ​​battery cell 113, and the single sliced ​​battery cell 113 belongs to the second battery segment 112. It is understandable that a battery string 11 can also be composed of more than n sliced ​​battery cells 113 cut from whole battery cells.

[0071] Furthermore, the arrangement order of the multiple sliced ​​battery cells 113 after a whole battery cell is cut is: edge piece 113a, middle piece 113b, middle piece 113b and edge piece 113a. Since the first battery segment 111 also includes edge piece 113a, middle piece 113b, middle piece 113b and edge piece 113a in sequence, the multiple sliced ​​battery cells 113 after a whole battery cell is cut can directly form the first battery segment 111, that is, the first battery segment 111 includes four sliced ​​battery cells 113 cut from a whole battery cell, which facilitates the stringing of the battery string 11.

[0072] It is understandable that the split battery cells 113 constituting the first battery segment 111 may not come from the same whole battery cell.

[0073] The second battery segment 112 includes four sliced ​​battery cells 113 cut from a whole battery cell and a single sliced ​​battery cell 113. This allows the four sliced ​​battery cells 113 cut from a whole battery cell to be directly used to form the second battery segment 112, thereby facilitating the assembly of the battery string 11. It is understood that the sliced ​​battery cells 113 that form the second battery segment 112 can be from at least two whole battery cells.

[0074] Furthermore, the four second battery segments 112 in a battery string group 1 include four separate slice battery cells 113, which are two edge slices 113a and two middle slices 113b. This makes the number of slice battery cells 113 in a battery string group 1 4N, of which the number of edge slices 113a is 8n+2, and the number of middle slices 113b is 8n+2. That is, the number of edge slices 113a and the number of middle slices 113b in a battery string group 1 are equal, so that the battery string group 1 uses a more balanced number of edge slices 113a and middle slices 113b. When the battery strings 11 are grouped, the number of edge slices 113a and middle slices 113b left is relatively small, and the storage pressure on the remaining slice battery cells 113 is relatively small.

[0075] Optionally, a battery string 1 is composed of multiple sliced ​​battery cells 113 cut from 4n+1 whole battery cells, so that when the sliced ​​battery cells 113 are not damaged, no individual sliced ​​battery cells 113 are left after assembling a battery string 1. It is understandable that a battery string 1 can also be composed of more than 4n+1 sliced ​​battery cells 113 cut from whole battery cells.

[0076] In a specific embodiment, the second battery segment 112 is located at the head or tail of the battery string 11. When stringing, n-1 first battery segments 111 can be arranged first, and then the second battery segment 112 can be placed at one end of the n-1 first battery segments 111, thereby facilitating the stringing of the battery strings 11. Alternatively, when stringing, n first battery segments 111 can be arranged first, and then a single cell 113 can be placed in a first battery segment 111 at the head or tail, thereby converting the first battery segment 111 into the second battery segment 112, thereby facilitating the stringing of the battery strings 11.

[0077] Specifically, such as Figures 3 to 6As shown, a single sliced ​​cell 113 in the second cell segment 112 is an edge piece 113a (the red sliced ​​cell 113 in the figure shows a single sliced ​​cell 113 in the second cell segment 112), and is located at one end of the second cell segment 112. On the one hand, it is convenient to place a single sliced ​​cell 113 into the second cell segment 112. On the other hand, the edge piece 113a is located at the head or tail of the cell string 11. The chamfer on the edge piece 113a can reduce the probability of the sliced ​​cell 113 located at the head or tail of the cell string 11 from breaking, thereby improving the service life of the photovoltaic module.

[0078] Optional, such as Figure 3 As shown, the second battery segment 112 is located at the head of the battery string 11, and a single cell 113 in the second battery segment 112 is located in the second battery segment 112 near the head of the battery string 11; Figure 4 As shown, the second battery segment 112 is located at the tail of the battery string 11, and a single cell 113 in the second battery segment 112 is located in the second battery segment 112 near the head of the battery string 11; Figure 5 As shown, the second battery segment 112 is located at the head of the battery string 11, and a single cell 113 in the second battery segment 112 is located in the second battery segment 112 near the tail of the battery string 11; Figure 6 As shown, the second battery segment 112 is located at the tail of the battery string 11 , and a single split battery cell 113 in the second battery segment 112 is located in the second battery segment 112 near the tail of the battery string 11 .

[0079] Specifically, such as Figure 7 and Figure 8 As shown, a single sliced ​​cell 113 in the second cell segment 112 is the middle cell 113b and is located inside the second cell segment 112, so that the sliced ​​cell 113 at the head and tail of the cell string 11 are edge cells 113a. The chamfers on the edge cells 113a reduce the probability of the sliced ​​cell 113 at the head or tail of the cell string 11 breaking, thereby improving the service life of the photovoltaic module.

[0080] Optional, such as Figure 7 As shown, the second battery segment 112 is located at the head of the battery string 11, and a single slice battery cell 113 in the second battery segment 112 is located at the position of the second slice battery cell 113 from the head of the battery string 11 in the second battery segment 112; Figure 8As shown, the second battery segment 112 is located at the tail of the battery string 11, and the single cell 113 in the second battery segment 112 is located at the position of the second cell 113 from the tail of the battery string 11 in the second battery segment 112. It is understandable that the single cell 113 in the second battery segment 112 can also be located at the position of the third or fourth cell 113 from the head or tail of the battery string 11 in the second battery segment 112.

[0081] Specifically, such as Figures 9 to 12 As shown, the single split battery cell 113 in the second battery segment 112 is the middle cell 113 b and is located at one end of the second battery segment 112 .

[0082] Optional, such as Figure 9 As shown, the second battery segment 112 is located at the head of the battery string 11, and a single cell 113 in the second battery segment 112 is located in the second battery segment 112 near the tail of the battery string 11; Figure 10 As shown, the second battery segment 112 is located at the tail of the battery string 11, and a single cell 113 in the second battery segment 112 is located in the second battery segment 112 near the head of the battery string 11; Figure 11 As shown, the second battery segment 112 is located at the head of the battery string 11, and a single cell 113 in the second battery segment 112 is located in the second battery segment 112 near the head of the battery string 11; Figure 12 As shown, the second battery segment 112 is located at the tail of the battery string 11 , and a single split battery cell 113 in the second battery segment 112 is located in the second battery segment 112 near the tail of the battery string 11 .

[0083] In a specific embodiment, Figure 1 As shown, multiple battery string groups 1 are arranged along a first direction X, and the battery cells 113 within the battery string 11 are arranged along a second direction Y. The four battery strings 11 in the battery string group 1 are arranged in an array along the first direction X and the second direction Y, respectively, that is, the four battery strings 11 are arranged in two rows and two columns.

[0084] One end of the battery string 11 along the second direction Y is the head of the battery string 11, and the other end is the tail of the battery string 11. In this application, the end of the battery string 11 close to the left side of the figure is the head of the battery string 11, and the end of the battery string 11 close to the right side of the figure is the tail of the battery string 11.

[0085] Optionally, the second battery segments 112 in the multiple battery strings 11 distributed along the first direction X are all located at the head of the battery string 11, and the individual slices 113 in the multiple second battery segments 112 are all edge slices 113a (or middle slices 113b), and the edge slices 113a (or middle slices 113b) are in the same position in the second battery segments 112, so that the arrangement consistency of the photovoltaic modules is high.

[0086] Optionally, the second battery segments 112 in the multiple battery strings 11 distributed along the first direction X are all located at the tail end of the battery string 11, and the individual sliced ​​battery cells 113 in the multiple second battery segments 112 are all intermediate slices 113b (or edge slices 113a), and the intermediate slices 113b (or edge slices 113a) are in the same position in the second battery segments 112, so that the arrangement consistency of the photovoltaic modules is high.

[0087] Optionally, one of the second battery segments 112 in the two battery strings 11 distributed along the second direction X is located at the head of the battery string 11, and the other is located at the tail of the battery string 11, and a separate slice battery cell 113 in the two second battery segments 112 is an edge slice 113a and the other is a middle slice 113b.

[0088] In the above embodiments, the chamfers of the edge pieces 113a in the photovoltaic module are all located upstream of the current flow direction in the battery string 11, or the chamfers of the edge pieces 113a in the photovoltaic module are all located downstream of the current flow direction in the battery string 11, so that relevant personnel can judge the current direction by observing the chamfer position of the edge piece 113a, which is convenient for the maintenance of the photovoltaic module.

[0089] In the above embodiments, Figure 13 As shown, taking the sliced ​​cell 113 as a back-contact cell as an example, the photovoltaic module includes: a front encapsulation structure 2, a front film layer 3, a cell string 1, a back film layer 4, and a back encapsulation structure 5. The front encapsulation structure 2, the front film layer 3, the back film layer 4, and the back encapsulation structure 5 encapsulate the cell string 1 to ensure high mechanical strength of the back-contact photovoltaic module, reduce the impact of hail, wind, mechanical vibration, etc. on the back-contact photovoltaic module, and improve the sealing of the back-contact photovoltaic module, enhancing its corrosion resistance and safety.

[0090] Specifically, the front encapsulation structure 2 and the back encapsulation structure 5 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). These materials have high light transmittance, can improve the photoelectric conversion efficiency of the back-contact photovoltaic module, and ensure the power of the back-contact photovoltaic module. The front film layer 3 and the back film layer 4 can be one of the materials such as ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyvinyl butyral (PVB), EVA-POE-EVA co-extruded film (EPE), and EVA-POE co-extruded film (EP).

[0091] The present application also provides a method for producing a photovoltaic module, which is used to produce the above-mentioned photovoltaic module. Figure 2 and Figure 14 As shown, the production method of the photovoltaic module includes:

[0092] S1: Cutting the entire cell into four separate cells 113, including two edge cells 113a with chamfers and two middle cells 113b without chamfers.

[0093] In this step, the cell 113 can be cut into pieces by mechanical cutting, laser cutting, etc. For example, when cutting the whole cell by laser, the cell can be first grooved and scribed by the grooving laser of the laser dicing machine, and then the cell can be split by the laser dicing machine based on the division process.

[0094] S2: Select four split battery cells 113 and arrange them into a first battery segment 111 in the order of edge cell 113 a , middle cell 113 b , middle cell 113 b and edge cell 113 a .

[0095] In this step, the four split battery cells 113 may come from the same whole battery cell or from multiple whole battery cells. Preferably, the four split battery cells 113 come from the same whole battery cell.

[0096] S3: Select two edge sheets 113 a and three middle sheets 113 b , or three edge sheets 113 a and two middle sheets 113 b , and arrange them into a second battery segment 112 .

[0097] In this step, when the number of edge sheets 113a in the second battery segment 112 is greater than the number of middle sheets 113b, as shown in FIG. Figure 3 and Figure 4 As shown, the arrangement order of the split battery cells 113 in the second battery segment 112 may be: edge cell 113a-edge cell 113a-middle cell 113b-middle cell 113b-edge cell 113a; Figure 5 and Figure 6 As shown, the arrangement order of the split battery cells 113 in the second battery segment 112 may be: edge cell 113 a - middle cell 113 b - middle cell 113 b - edge cell 113 a - edge cell 113 a .

[0098] When the number of the middle sheets 113b in the second battery segment 112 is greater than the number of the edge sheets 113a, as shown in FIG. Figure 7 and Figure 8 As shown, the arrangement order of the split battery cells 113 in the second battery segment 112 may be: edge cell 113a-middle cell 113b-middle cell 113b-middle cell 113b-edge cell 113a; Figure 9 and Figure 12 As shown, the arrangement order of the split battery cells 113 in the second battery segment 112 may be: edge cell 113a-middle cell 113b-middle cell 113b-edge cell 113a-middle cell 113b; Figure 10 and Figure 11 As shown, the arrangement order of the split battery cells 113 in the second battery segment 112 may be: middle cell 113 b - edge cell 113 a - middle cell 113 b - middle cell 113 b - edge cell 113 a .

[0099] Preferably, the five sliced ​​battery cells 113 in the second battery segment 112 are composed of four sliced ​​battery cells 113 cut from a whole battery cell and one separate sliced ​​battery cell 113. When the separate sliced ​​battery cell 113 is an edge cell 113a, the number of edge cells 113a in the second battery segment 112 is greater than the number of middle cells 113b; and when the separate sliced ​​battery cell 113 is a middle cell 113b, the number of middle cells 113b in the second battery segment 112 is greater than the number of edge cells 113a.

[0100] S4 : Connecting a plurality of first battery segments 111 and one second battery segment 112 into a battery string 11 .

[0101] In this step, adjacent cell segments 113 are connected to form a cell string 11 via welding ribbons. Optionally, the cell segments 113 within the first battery segment 111 and the second battery segment 112 are connected first, and then multiple first battery segments 111 and one second battery segment 112 are connected. Alternatively, the cell segments 113 within multiple first battery segments 111 and one second battery segment 112 are connected together. In this case, the first battery segment 111 and the second battery segment 112 only represent the order in which the cell segments 113 are arranged, and do not represent the connection relationship between the cell segments 113.

[0102] S5: Connecting multiple battery strings 11 into a battery string group 1, and connecting the multiple battery string groups 1 in series.

[0103] In this step, multiple battery strings 11 are connected in parallel to form a battery string group 1 through a bus bar 12 , and multiple battery string groups 1 are connected in series through the bus bar 12 and the jumper 13 .

[0104] Preferably, Figure 1 As shown, when four battery strings 11 are connected into a battery string group 1, the second battery segments 112 in two of the battery strings 11 include more edge sheets 113a than middle sheets 113b, and the second battery segments 112 in the other two battery strings 11 include more middle sheets 113b than edge sheets 113a, so that the number of edge sheets 113a and the number of middle sheets 113b in the battery string group 1 are consistent, thereby making the number of remaining edge sheets 113a and middle sheets 113b relatively small, and reducing the storage pressure on the remaining segmented battery cells 113.

[0105] Preferably, Figure 1 As shown, when four battery strings 11 are connected to form a battery string group 1, the four battery strings 11 are arranged in two rows and two columns, so that the second battery segments 112 in the two battery strings 11 distributed along the first direction X contain the same number of edge pieces 113a and the same number of middle pieces 113b.

[0106] Preferably, Figure 1 As shown, when three battery string groups 1 are connected in series, the three battery string groups 1 are distributed along the first direction X, so that the second battery segments 112 in all battery strings 11 distributed along the first direction X contain the same number of edge pieces 113a and the same number of middle pieces 113b, thereby improving the consistency of the photovoltaic module arrangement.

[0107] Further, such as Figure 2 As shown, in step S1: after the whole cell is cut into four sliced ​​cell pieces 113, the production method of the photovoltaic module further includes: rotating one of the edge pieces 113a by 180° so that the chamfers of the edge piece 113a are all facing the same direction, thereby facilitating the arrangement of the first cell segment 111 and the second cell segment.

[0108] Furthermore, in the step: after rotating one of the edge pieces 113a by 180°, the production method of the photovoltaic module also includes: arranging the four sliced ​​cell pieces 113 cut from a whole cell piece into a first cell segment 111 in sequence, thereby simplifying the arranging process, improving the efficiency of arranging the cells, and reducing the time required for arranging the cells.

[0109] 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: A whole battery sheet can be cut into four split battery sheets (113), including two edge sheets (113a) with chamfers and two middle sheets (113b) without chamfers. The photovoltaic module includes a plurality of cell strings (11), the cell strings (11) include a plurality of first cell segments (111) and a second cell segment (112), each of the first cell segments (111) includes the edge sheet (113a), the middle sheet (113b), the middle sheet (113b) and the edge sheet (113a) in sequence, the second cell segment (112) includes two edge sheets (113a) and three middle sheets (113b), or the second cell segment (112) includes three edge sheets (113a) and two middle sheets (113b).

2. The photovoltaic module according to claim 1, characterized in that The second battery segment (112) is located at the head or tail of the battery string (11).

3. The photovoltaic module according to claim 1, characterized in that The first battery segment (111) includes four split battery slices (113) cut from a whole battery slice; The second battery segment (112) includes four sliced ​​battery cells (113) cut from a whole battery cell and a single sliced ​​battery cell (113).

4. The photovoltaic module according to claim 3, characterized in that A single piece of the split battery sheet (113) in the second battery segment (112) is the edge sheet (113a) and is located at one end of the second battery segment (112).

5. The photovoltaic module according to claim 3, characterized in that: A single piece of the split battery sheet (113) in the second battery segment (112) is the middle sheet (113b) and is located inside the second battery segment (112).

6. The photovoltaic module according to claim 3, characterized in that Four battery strings (11) are connected in parallel to form a battery string group (1); the four second battery segments (112) in a battery string group (1) include four separate sliced ​​battery sheets (113), which are two edge sheets (113a) and two middle sheets (113b).

7. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The chamfers of the edge pieces (113a) in the photovoltaic module are all located upstream of the current flow direction in the battery string (11); Alternatively, the chamfers of the edge pieces (113a) in the photovoltaic module are all located downstream in the direction of current flow in the battery string (11).

8. A method for producing a photovoltaic module, characterized in that: Used for producing the photovoltaic module according to any one of claims 1 to 7, the production method of the photovoltaic module comprising: Cutting the entire battery cell into four split battery cells (113), including two edge cells (113a) with chamfers and two middle cells (113b) without chamfers; Selecting four of the split battery sheets (113), and arranging them into a first battery segment (111) in the order of the edge sheet (113a), the middle sheet (113b), the middle sheet (113b), and the edge sheet (113a); Selecting two edge sheets (113a) and three middle sheets (113b), or three edge sheets (113a) and two middle sheets (113b), and arranging them into a second battery segment (112); A plurality of the first battery segments (111) and one second battery segment (112) are connected to form a battery string (11).

9. The method for producing a photovoltaic module according to claim 8, characterized in that: After the step of cutting the whole cell into four separate cell slices (113), the photovoltaic module production method further comprises: One of the edge pieces (113a) is rotated 180°.

10. The method for producing a photovoltaic module according to claim 9, characterized in that: After the step of rotating one of the edge sheets (113a) by 180°, the photovoltaic module production method further comprises: The four split battery sheets (113) cut from a whole battery sheet are sequentially arranged to form the first battery segment (111).

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