Photovoltaic module

Abstract

The photovoltaic module comprises battery pieces and a welding strip, the multiple battery pieces are arranged in the first direction, projections of every two adjacent battery pieces in the second direction have an overlapping area, every two adjacent battery pieces are connected through the welding strip, each battery piece comprises a first surface and a second surface in the second direction, a first main grid is arranged on the first surface, and a second main grid is arranged on the second surface. The first surface is provided with a first main grid, the first main grid comprises a first flow guide part, the second surface is provided with a second main grid, the second main grid comprises a second flow guide part, the projection area of the first flow guide part is smaller than that of the second flow guide part in the second direction, and the projection of the first flow guide part is located in the projection of the welding strip corresponding to the first flow guide part. According to the design, the shading area of the first diversion part is reduced so as to improve the photoelectric conversion efficiency of the photovoltaic module, the second diversion part is arranged on the second surface of the battery piece, the area of the second diversion part is larger than that of the first diversion part, and the possibility of shading loss of the battery piece caused by the second diversion part is reduced while the current collection capacity of the second diversion part is improved.

Description

Technical Field

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

[0002] Photovoltaic modules are used to convert received solar energy into electrical energy. Currently, the photoelectric efficiency of photovoltaic modules is low, which affects the reliability of photovoltaic modules. Summary of the invention

[0003] In view of this, the present application provides a photovoltaic module to help solve the problem of low photoelectric conversion efficiency of photovoltaic modules in the prior art.

[0004] An embodiment of the present application provides a photovoltaic module, including a battery cell and a welding strip, wherein the plurality of battery cells are arranged along a first direction, and the projections of two adjacent battery cells along a second direction have an overlapping area, and the two adjacent battery cells are connected by a welding strip, wherein the battery cell includes a first surface and a second surface along the second direction, a first main grid is arranged on the first surface, the first main grid includes a first guide portion, and a second main grid is arranged on the second surface, the second main grid includes a second guide portion, and along the second direction, a projection area of ​​the first guide portion is smaller than a projection area of ​​the second guide portion, and the projection of the first guide portion is located within the projection of the corresponding welding strip.

[0005] In a possible embodiment, the first main grid includes a first main body portion, the first main body portion is connected to the welding strip, the first guide portion is connected to at least one end of the first main body portion, the projection shape of the first guide portion along the second direction is an "I" shape, and the setting direction of the first guide portion is the same as the setting direction of the first main body portion.

[0006] In a possible implementation manner, the first guide portion is connected to two ends of the first main body portion, and the first guide portion and the first main body portion are connected to the same welding strip.

[0007] In a possible implementation manner, along the second direction, a projection of at least a portion of the structure of the second guide portion is located outside a projection of the corresponding welding strip.

[0008] In a possible embodiment, the second main grid includes a second main body portion, the second main body portion is connected to the welding strip, and the second guide portion is connected to at least one end of the second main body portion, wherein the second guide portion includes a first guide segment and a second guide segment connected to each other, and the distance between the first guide segment and the second guide segment gradually increases in a direction away from the second main body portion.

[0009] In a possible implementation manner, the maximum distance between the first guide segment and the second guide segment is W1, the width of the welding strip is W2, and W1 and W2 satisfy: W1>W2.

[0010] In a possible implementation, the photovoltaic assembly includes a buffer, and along the second direction, the buffer is located between two adjacent solar cells.

[0011] In a possible implementation, along the second direction, a projection area of ​​the buffer is larger than an area of ​​an overlapping region of projections of two adjacent battery cells.

[0012] In a possible implementation manner, the length of the buffer component is the same as the length of the battery cell, and the thickness D of the buffer component satisfies: 50 μm≤D≤200 μm.

[0013] In a possible embodiment, the two adjacent battery cells are respectively a first battery cell and a second battery cell, and the buffer is arranged on a side of the welding strip facing the second surface of the first battery cell, and / or the buffer is arranged on a side of the welding strip facing the first surface of the second battery cell.

[0014] The embodiment of the present application provides a photovoltaic module, including a cell and a welding strip, wherein a plurality of cells are arranged along a first direction, and the projections of two adjacent cells along a second direction have an overlapping area, and the two adjacent cells are connected by a welding strip, wherein the cell includes a first surface and a second surface along the second direction, a first main grid is arranged on the first surface, and the first main grid includes a first guide portion, and a second main grid is arranged on the second surface, and the second main grid includes a second guide portion, and along the second direction, the projection area of ​​the first guide portion is smaller than the projection area of ​​the second guide portion, and the projection of the first guide portion is located within the projection of the welding strip corresponding thereto. By reducing the area of ​​the first guide portion on the first surface, the light shielding area of ​​the first guide portion is reduced, and the projection of the first guide portion is located within the projection of the welding strip corresponding thereto, so that the first guide portion will not block the area of ​​the cell other than the welding strip, thereby increasing the area of ​​the first surface of the cell that receives light, thereby improving the photoelectric conversion efficiency of the photovoltaic module. The area of ​​the second guide portion is larger than that of the first guide portion. The second guide portion is arranged on the second surface of the battery cell, which increases the current collection capacity of the second guide portion while reducing the possibility of the second guide portion causing shading loss to the battery cell. On the other hand, when the battery cell is serially welded, since the projection of the first guide portion is located within the projection of the corresponding welding strip, the welding strip can be welded to the entire first guide portion, that is, the entire first guide portion can be alloyed with the welding strip, so that the current collected by the first guide portion is directly transmitted to the welding strip, which reduces the current transmission path, reduces the current transmission loss, and also improves the photoelectric conversion efficiency of the photovoltaic module.

[0015] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 A schematic diagram of a photovoltaic module in one embodiment of the present application; Figure 2 This is a schematic diagram of connecting battery cells through welding ribbons in one embodiment of the present application; Figure 3 A schematic diagram of a first surface of a battery cell in an embodiment of the present application; Figure 4 A schematic diagram of the second surface of a battery cell in one embodiment of the present application; Figure 5 for Figure 3 A magnified view of part I; Figure 6 for Figure 4 Enlarged view of part II; Figure 7 This is a partial schematic diagram of the connection between the battery cell and the welding ribbon in one embodiment of the present application; Figure 8 A schematic diagram of a battery cell and a buffer member in an embodiment of the present application; Fig. 9 This is a schematic diagram of another embodiment of the present application in which battery cells are connected via welding ribbons.

[0018] Reference numerals: 1000-PV panels; 100-battery layer; 10-battery cell; 10a-first surface; 10b- second surface; 11- first main grid; 111- first guide portion; 112- first main body; 12- second main grid; 121- second guide portion; 1211-first diversion section; 1211a-first end; 1212- second diversion section; 1212a-second end; 122- second main body; 13- buffer; 20-welding strip; 200-cover plate; 300-first adhesive film layer; 400- second adhesive film layer; 500-back panel; W1-the maximum distance between the first guide section and the second guide section; W2-Width of the solder strip. DETAILED DESCRIPTION

[0019] 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.

[0020] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0021] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" 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 other meanings.

[0022] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0023] like Figure 1As shown, an embodiment of the present application provides a photovoltaic module 1000. The photovoltaic module 1000 may include a cover plate 200, a first adhesive film layer 300, a battery layer 100, a second adhesive film layer 400 and a back plate 500. The cover plate 200, the first adhesive film layer 300, the battery layer 100, the second adhesive film layer 400 and the back plate 500 are arranged along the thickness direction of the photovoltaic module 1000 and laminated together. Among them, the cover plate 200 may be a glass cover plate, and the glass cover plate has a high light transmittance. The first adhesive film layer 300 bonds the cover plate 200 and the battery layer 100 together to encapsulate and protect the battery layer 100. The material of the first adhesive film layer 300 may be one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE) and polyvinyl butyral (PVB). Combined Figure 2 As shown, the battery layer 100 includes at least one battery string, and the battery string includes a plurality of electrically connected battery cells 10, and the battery cells 10 can convert solar energy into electrical energy. The second adhesive film layer 400 connects the battery layer 100 with the back plate 500, and it also plays a role in encapsulating and protecting the battery layer 100. The material of the second adhesive film layer 400 can be one or more of the above-mentioned EVA, POE, and PVB. The material of the back plate 500 can be glass, or the back plate 500 can also be composed of a plurality of polymer film layers.

[0024] The battery cell may be a two-piece, a three-piece, a four-piece or an eight-piece obtained by cutting a whole battery, that is, the battery cell may be a sliced ​​battery.

[0025] The types of the above-mentioned cells include but are not limited to Passivated Emitter and Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Heterojunction with Intrinsic Thin-film (HJT), Perovskite cells, etc.

[0026] For PERC cells, along the thickness direction, PERC cells include 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, and the back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back, replacing the full aluminum back field, enhancing the internal back reflection of light in the silicon base, reducing the recombination rate on the back, and increasing the efficiency of the cell by 0.5%-1%.

[0027] For TOPCon cells, along the thickness direction, TOPCon cells include metal silver electrodes, front surface silicon nitride passivation layers, boron-doped emitters, N-type base silicon layers, diffused doping layers, ultra-thin silicon oxide, doped polysilicon, silicon nitride, and metal silver electrodes. The back of the cell is composed of an ultra-thin silicon oxide layer (1nm~2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure can block the recombination of minority carrier holes and increase the open circuit voltage and short circuit current of the cell. The ultra-thin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking the recombination of minority carrier holes. The good passivation effect of ultra-thin silicon oxide and heavily doped silicon film causes the energy band on the silicon wafer surface to bend, thereby forming a field passivation effect, greatly increasing the probability of electron tunneling, and reducing the contact resistance, which increases the open circuit voltage and short circuit current of the cell, thereby improving the cell conversion efficiency.

[0028] For HJT cells, along the thickness direction, the HJT cells 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.

[0029] For perovskite cells, along the thickness direction, the perovskite cell includes substrate material, conductive film, electron transport layer (titanium dioxide), perovskite absorption layer (hole transport layer), and 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 low loss, so they can generate higher photoelectric voltage and current, making perovskite show higher photoelectric conversion efficiency.

[0030] The surface of the above-mentioned cell may be provided with grid lines, wherein the grid lines may include intersecting (usually mutually perpendicular) main grids and fine grids, and the main grids and fine grids are usually formed by printing and sintering metal paste (such as silver paste). The fine grids can be used to collect and conduct current on the cell, and the main grids can be used to collect current on the fine grids for convergence. In order to improve the power generation efficiency of photovoltaic modules and reduce costs, the cell may be a multi-busbar (MBB) cell, that is, multiple main grids are printed on the surface of the cell. The multi-busbar technology can reduce the number of fine grids and reduce costs by increasing the number of main grids. At the same time, it can also shorten the current conduction path between the main grid and the fine grid to reduce power loss and thus increase the power of the cell.

[0031] like Figure 2As shown, in the embodiment of the present application, a plurality of the above-mentioned cells 10 are arranged along the first direction X, and the projections of two adjacent cells 10 along the second direction Z have an overlapping area, the area of ​​the overlapping area is smaller than the area of ​​the cell 10, the first direction X may be the width direction of the cell 10, and the second direction Z may be the thickness direction of the cell 10. Specifically, along the second direction Z, one of the two adjacent cells 10 is stacked on one side of the other, and the projections of the ends of the two cells 10 overlap, that is, the ends of the two adjacent cells 10 are stacked together, so that the plurality of cells 10 are arranged in an imbricate manner, thereby reducing the spacing between the cells 10, increasing the arrangement density of the cells 10 in the photovoltaic module 1000, and thereby increasing the power of the photovoltaic module 1000.

[0032] Among them, the battery cell 10 includes a first surface 10a and a second surface 10b along the second direction Z. The first surface 10a can be the light-receiving surface of the battery cell 10, that is, the surface that can be directly illuminated by sunlight, and the second surface 10b can be the backlight surface of the battery cell 10, that is, the surface that is not directly illuminated by sunlight. Both the first surface 10a and the second surface 10b can receive sunlight and convert light energy into electrical energy.

[0033] Please also refer to Figure 3 and Figure 4 A first main grid 11 is disposed on the first surface 10a, and a second main grid 12 is disposed on the second surface 10b. The first main grid 11 and the second main grid 12 can be arranged at intervals along a third direction Y, and the third direction Y can be the length direction of the battery cell 10. Two adjacent battery cells 10 are connected by a welding strip 20, and the welding strip 20 is arranged in a one-to-one correspondence with the first main grid 11 and the second main grid 12. Specifically, one welding strip 20 can be connected to the first main grid 11 of one battery cell 10 and the second main grid 12 of another battery cell 10 to achieve electrical connection between the two battery cells 10.

[0034] The first main grid 11 includes a first current guide portion 111, and the second main grid 12 includes a second current guide portion 121. Both the first current guide portion 111 and the second current guide portion 121 can be arranged at the edge of the battery cell 10, and both are used to collect the current at the edge of the battery cell 10. Along the second direction Z, the projection area of ​​the first current guide portion 111 is smaller than the projection area of ​​the second current guide portion 121, and the projection of the first current guide portion 111 is located within the projection of the corresponding welding strip 20.

[0035] By reducing the area of ​​the first guide portion 111 on the first surface 10a, the light shielding area of ​​the first guide portion 111 is reduced. At the same time, the projection of the first guide portion 111 is located within the projection of the corresponding welding strip 20, that is, the welding strip 20 can completely cover the first guide portion 111, so that the first guide portion 111 will not block the area of ​​the battery cell 10 outside the welding strip 20, thereby increasing the area of ​​the first surface 10a of the battery cell 10 that receives light, thereby improving the photoelectric conversion efficiency of the photovoltaic module 1000. The area of ​​the second guide portion 121 is larger than that of the first guide portion 111. The second guide portion 121 is arranged on the second surface 10b of the battery cell 10, which increases the current collection capacity of the second guide portion 121 while reducing the possibility of the second guide portion 121 causing light shielding loss to the battery cell 10. On the other hand, when the battery cells 10 are serially welded, since the projection of the first guide portion 111 is located within the projection of the corresponding welding strip 20, the welding strip 20 can be welded to the entire first guide portion 111, that is, the entire first guide portion 111 can be alloyed with the welding strip 20, so that the current collected by the first guide portion 111 is directly transmitted to the welding strip 20, which reduces the current transmission path, reduces the current transmission loss, and also improves the photoelectric conversion efficiency of the photovoltaic module 1000.

[0036] like Figure 2 , Figure 3 as well as Figure 5 As shown, in a possible embodiment, the first main grid 11 includes a first main body 112, the first main body 112 is connected to the welding strip 20, the first guide portion 111 is connected to at least one end of the first main body 112, the projection shape of the first guide portion 111 along the second direction Z is an "I" shape, and the setting direction of the first guide portion 111 is the same as the setting direction of the first main body 112.

[0037] The first main body 112 and the first guide portion 111 are both arranged along the first direction X, and the projections of the first main body 112 and the first guide portion 111 along the second direction Z are both in the shape of a letter "I". The first main body 112 also serves to collect current. Along the first direction X, the first guide portion 111 can be connected to one end or both ends of the first main body 112. The first guide portion 111 and the first main body 112 can be integrally formed. Specifically, the first guide portion 111 and the first main body 112 are both formed by printing and sintering metal paste.

[0038] The first guide portion 111 is designed to be in the shape of a letter "I" so as to reduce the light shielding area of ​​the first guide portion 111 while realizing the current collection function of the first guide portion 111, thereby increasing the area of ​​the first surface 10a of the cell 10 receiving light, so as to improve the photoelectric conversion efficiency of the photovoltaic module 1000. At the same time, the shape of the first guide portion 111 is the same as that of the first main body portion 112, and the setting direction of the first guide portion 111 is the same as that of the first main body portion 112, thereby improving the stability of the structure of the first main grid 11, reducing the possibility of stress concentration at the connection between the first guide portion 111 and the first main body portion 112, and facilitating the printing of metal paste, thereby simplifying the production process of the photovoltaic module 1000.

[0039] In some embodiments, the width of the first guide portion 111 may be the same as the width of the first main body portion 112 to facilitate the preparation of the first main gate 11 .

[0040] In some embodiments, the width of the first guide portion 111 can be greater than the width of the first main body portion 112. By increasing the width of the first guide portion 111, the area of ​​the first guide portion 111 for collecting current is increased, that is, the current collection ability of the first guide portion 111 is enhanced, thereby improving the first main grid 11 The current collection ability of the edge of the battery cell 10 is improved, thereby improving the photoelectric conversion efficiency of the photovoltaic module 1000.

[0041] like Figure 2 , Figure 3 as well as Figure 5 As shown, in a possible implementation manner, the first guide portion 111 is connected to two ends of the first main body portion 112 , and the first guide portion 111 and the first main body portion 112 are connected to the same welding strip 20 .

[0042] The first guide portion 111 is connected to both ends of the first main body 112 along the first direction X, so that the first main grid 11 has a linear structure. The welding strip 20 is connected to the first main body 112 and the first guide portion 111 by welding. Specifically, the welding strip 20, the first main body 112 and the first guide portion 111 can be connected together by high-temperature welding. During the welding process, the metal (such as metal tin) in the welding strip 20 and the metal (such as metal silver) in the first guide portion 111 and the first main body 112 undergo an alloying reaction, that is, the welding strip 20, the first guide portion 111 and the first main body 112 are alloyed, so that the current collected by the first guide portion 111 can be directly transmitted to the welding strip 20 without passing through the first main body 112 to be transmitted to the welding strip 20, thereby reducing the current transmission path, reducing the current transmission loss, and improving the photoelectric conversion efficiency of the photovoltaic module 1000. At the same time, since the first guide portion 111 has an "I"-shaped structure, the first guide portion 111 and the welding strip 20 can form a relatively stable connection structure, reducing the possibility of stress concentration on the battery cell 10 at the position of the first guide portion 111 causing hidden cracks or fragments in the battery cell 10.

[0043] like Figure 2 and Figure 4 As shown, in a possible implementation manner, along the second direction Z, a projection of at least a portion of the structure of the second guide portion 121 is located outside a projection of the corresponding welding strip 20 .

[0044] Along the second direction Z, the projection of the entire structure of the second guide portion 121 is located outside the projection of the corresponding welding strip 20, or the projection of a portion of the structure of the second guide portion 121 is located outside the projection of the corresponding welding strip 20. This design ensures that when the battery cell 10 is being serially soldered, a portion of the structure or the entire structure of the second guide portion 121 will not be connected to the welding strip 20, so that the welding strip 20 is in a movable state at the edge of the battery cell 10 (i.e., the position where the second guide portion 121 is set). In other words, the edge of the battery cell 10 is not fixed by the welding strip 20, thereby reducing the possibility of stress concentration at the edge of the battery cell 10 during lamination, testing, transportation, etc., thereby reducing the possibility of hidden cracks or fragments in the battery cell 10, and improving the overall reliability of the photovoltaic module 1000.

[0045] like Figure 2 , Figure 4 as well as Figure 6As shown, in a possible embodiment, the second main grid 12 includes a second main body 122, the second main body 122 is connected to the welding strip 20, and the second guide portion 121 is connected to at least one end of the second main body 122, wherein the second guide portion 121 includes a first guide segment 1211 and a second guide segment 1212 connected to each other, and the distance between the first guide segment 1211 and the second guide segment 1212 gradually increases in the direction away from the second main body 122.

[0046] The second guide portion 121 can be connected to at least one end of the second main body 122 along the first direction X. The setting direction of the second main body 122 is different from the setting direction of the first guide section 1211 and the setting direction of the second guide section 1212, so that the second main body 122, the first guide section 1211 and the second guide section 1212 can be connected to form a structure similar to a "Y" shape. Among them, the first guide section 1211 and the second guide section 1212 extend toward the edge of the battery cell 10 in different directions respectively, and the distance between the first guide section 1211 and the second guide section 1212 gradually increases in the direction away from the second main body 122, so that the two can be connected to form a harpoon structure similar to a "V" shape or a "U" shape.

[0047] By providing the first guide section 1211 and the second guide section 1212, the second guide section 121 can more effectively collect the current at the edge of the battery cell 10, thereby increasing the ability of the second main grid 12 to collect current at the edge of the battery cell 10, improving the performance of the battery cell 10, and further improving the photoelectric conversion efficiency of the photovoltaic module 1000.

[0048] In some embodiments, the width of the first guide segment 1211 and the width of the second guide segment 1212 are the same as the width of the second main body 122 to facilitate the preparation of the second main grid 12 .

[0049] In some embodiments, the width of the first guide segment 1211 and the width of the second guide segment 1212 are greater than the width of the second main body 122. By increasing the width of the first guide segment 1211 and the second guide segment 1212, the area of ​​the second guide portion 121 for collecting current is increased, that is, the current collection ability of the second guide portion 121 is enhanced, thereby improving the second main grid 12 The current collection ability of the edge of the battery cell 10 is improved, thereby improving the photoelectric conversion efficiency of the photovoltaic module 1000.

[0050] In some embodiments, the first main grid includes a first main body, a first guide portion and a third guide portion. Along the second direction, the first guide portion and the third guide portion are respectively connected to the two ends of the first main body. The structures of the first main body and the first guide portion have been described above and will not be repeated here. The structure of the third guide portion is the same as the structure of the second guide portion described above, that is, one end of the first main body has an "I"-shaped guide portion, and the other end of the first main body has a "V"-shaped or "U"-shaped guide portion.

[0051] In some embodiments, the second main grid includes a second main body, a second guide portion and a fourth guide portion. Along the second direction, the second guide portion and the fourth guide portion are respectively located at both ends of the second main body. The structures of the second main body and the second guide portion have been described above and will not be repeated here. The structure of the fourth guide portion is the same as the structure of the first guide portion described above, that is, one end of the second main body has an "I"-shaped guide portion, and the other end of the second main body has a "V"-shaped or "U"-shaped guide portion.

[0052] like Figure 6 and Figure 7 As shown, in a possible implementation manner, the maximum distance between the first guide segment 1211 and the second guide segment 1212 is W1, the width of the welding strip 20 is W2, and W1 and W2 satisfy: W1>W2.

[0053] The first guide section 1211 has a first end 1211a at one end away from the second main body 122, and the second guide section 1212 has a second end 1212a at one end away from the second main body 122. The first section and the second end 1212a are located at the edge of the battery cell 10. When the welding ribbon 20 is connected to the second main grid 12, the welding ribbon 20 can be located between the first end 1211a and the second end 1212a. Since the width W2 of the welding ribbon 20 is less than the maximum distance W1 between the first guide section 1211 and the second guide section 1212, there is a certain interval between the welding ribbon 20 and the first end 1211a and the second end 1212a, that is, along the second direction Z, the projections of the first end 1211a and the second end 1212a are located outside the projection of the welding ribbon 20. Since there is a certain interval between the welding strip 20 and the first end 1211a of the first guide section 1211 and the second end 1212a of the second guide section 1212, it is avoided that the first end 1211a and the second end 1212a are melted at high temperature and alloyed with the welding strip 20 during the welding process of the welding strip 20, that is, the welding strip 20 will not be connected to the first end 1211a and the second end 1212a, so that the edge of the battery cell 10 is not fixed by the welding strip 20, thereby reducing the possibility of stress concentration at the edge of the battery cell 10 causing hidden cracks or even breakage of the battery cell 10, thereby improving the overall reliability of the photovoltaic module 1000.

[0054] In some embodiments, the minimum distance between the first guide section and the second guide section is W3, the width of the welding strip is W2, and W3 and W2 satisfy: W3>W2. This design further increases the interval between the first guide section and the welding strip and the interval between the second guide section and the welding strip, avoiding the first guide section and the second guide section from being melted at high temperature and alloyed with the welding strip during the welding process, so that the edge of the battery cell is not fixed by the welding strip, thereby reducing the possibility of stress concentration at the edge of the battery cell causing hidden cracks or even fragmentation of the battery cell, thereby improving the overall reliability of the photovoltaic module.

[0055] In some embodiments, two adjacent cells are respectively a first cell and a second cell, and the welding tape is welded to the first main body and the first guide portion of the first main grid of the first cell, and is welded to the second main body of the second main grid of the second cell, and the projection of the second guide portion of the second main grid is located outside the projection of the corresponding welding tape, so the welding tape is not welded to the second guide portion. The first guide portion of the first surface of the cell is welded to the welding tape, so that the current collected by the first guide portion is directly transmitted to the welding tape, which reduces the transmission path of the current, reduces the transmission loss of the current, and improves the photoelectric conversion efficiency of the photovoltaic module. The second guide portion of the second surface of the cell is not welded to the welding tape, so that the edge of the second surface of the cell is not fixed by the welding tape, which reduces the possibility of stress concentration at the edge of the cell during lamination, testing, handling, etc., thereby reducing the possibility of hidden cracks or even fragments of the cell, thereby improving the overall reliability of the photovoltaic module.

[0056] like Figure 2 As shown, in a possible implementation, the photovoltaic assembly 1000 includes a buffer 13 , and along the second direction Z, the buffer 13 is located between two adjacent solar cells 10 .

[0057] The buffer member 13 plays a buffering role. The buffer member 13 can be located at the overlapping position of two adjacent battery cells 10 to avoid hard contact between the two adjacent battery cells 10, thereby reducing the possibility of stress concentration at the overlapping position of the two adjacent battery cells 10, thereby reducing the possibility of hidden cracks or fragments in the battery cells 10 during lamination and subsequent use, thereby improving the reliability of the photovoltaic module 1000.

[0058] In some embodiments, the buffer may include one or more of ethylene vinyl acetate (EVA), polyolefin elastomer (POE), and polyvinyl butyral (PVB).

[0059] like Figure 2As shown, in a possible implementation manner, along the second direction Z, the projected area of ​​the buffer 13 is larger than the area of ​​the overlapping region of the projections of two adjacent battery cells 10, that is, the buffer 13 can extend from the overlapping position of the adjacent battery cells 10. By increasing the effective area of ​​the buffer 13, the buffer 13 plays a reliable buffering role between the battery cells 10, reducing the possibility of stress concentration at the overlapping position of two adjacent battery cells 10, thereby reducing the possibility of hidden cracks or fragments in the battery cells 10.

[0060] like Figure 8 As shown, in a possible implementation manner, the length of the buffer 13 is the same as the length of the battery cell 10 , which increases the effective area of ​​the buffer 13 to improve the reliability of the buffer 13 .

[0061] The thickness D of the buffer 13 (i.e., the size of the buffer 13 along the second direction Z) satisfies: 50μm≤D≤200μm, for example, D can be 50μm, 60μm, 80μm, 100μm, 120μm, 140μm, 160μm, 180μm or 200μm, and of course, it can also be other values ​​within the above range. If the thickness of the buffer 13 is too small, for example, D<50μm, the buffering effect of the buffer 13 is weakened, and the risk of stress concentration at the overlapping position of two adjacent battery cells 10 is increased, resulting in an increase in the risk of hidden cracks and fragments of the battery cells 10, thereby affecting the reliability of the photovoltaic module 1000. If the thickness of the buffer 13 is too large, for example, D>200μm, the thickness of the battery string increases, that is, the thickness of the photovoltaic module 1000 increases, thereby affecting the mechanical properties and reliability of the photovoltaic module 1000. Therefore, setting the thickness of the buffer 13 to 50 μm ≤ D ≤ 200 μm can improve the buffering effect of the buffer 13 while keeping the thickness of the photovoltaic module 1000 within a reasonable range, thereby ensuring the overall stability and reliability of the photovoltaic module 1000 .

[0062] like Figure 2 and Fig. 9 As shown, in a possible embodiment, two adjacent battery cells 10 are respectively a first battery cell and a second battery cell, and the buffer 13 is arranged on the side of the second surface 10b of the welding strip 20 facing the first battery cell, and / or the buffer 13 is arranged on the side of the first surface 10a of the welding strip 20 facing the second battery cell.

[0063] As mentioned above, the battery cell 10 is a sliced ​​battery. Specifically, the first battery cell and the second battery cell can be obtained by dividing the whole battery cell into two equal parts, three equal parts or four equal parts. Along the second direction Z, the buffer 13 can be arranged on one side of the welding strip 20. Specifically, as Figure 2As shown, when the buffer 13 is disposed on the side of the solder strip 20 facing the second surface 10b of the first battery cell, along the second direction Z, the upper end surface of the buffer 13 is connected to the second surface 10b of the first battery cell, and the lower end surface of the buffer 13 is connected to the solder strip 20 connected to the first surface 10a of the second battery cell. Figures 3 to 6 As shown, the buffer member 13 can cover the second guide portion 121 of the second surface 10b of the first battery cell, so that the welding ribbon 20 is welded to the second main body 122 of the second main grid 12, but not to the second guide portion 121 of the second main grid 12. At the same time, the welding ribbon 20 can be welded to the first main body 112 and the first guide portion 111 of the first main grid 11 of the first battery cell.

[0064] like Fig. 9 As shown, when the buffer 13 is disposed on the side of the solder strip 20 facing the first surface 10a of the second battery cell, along the second direction Z, the upper end surface of the buffer 13 is connected to the solder strip 20 connected to the second surface 10b of the first battery cell, and the lower end surface of the buffer 13 is connected to the first surface 10a of the second battery cell. Figures 3 to 6 As shown, the welding ribbon 20 can cover the first guide portion 111 of the first surface 10a of the second battery cell, so that the welding ribbon 20 is welded to the first main body portion 112 of the first main grid 11 but not to the first guide portion 111. At the same time, the welding ribbon 20 can be welded to the second main body portion 122 of the second main grid 12 of the first battery cell but not to the second guide portion 121 of the second main grid 12.

[0065] The buffer 13 is arranged on one side of the welding strip 20 to avoid hard contact between two adjacent battery cells 10, thereby reducing the possibility of stress concentration at the overlapping position of the two adjacent battery cells 10. At the same time, it also reduces the possibility of the buffer 13 interfering with the connection between the welding strip 20 and the main grid, so as to improve the reliability of the photovoltaic module 1000.

[0066] In other embodiments, the buffer components may be disposed on both sides of the welding strip along the second direction to further improve the buffering effect of the buffer components and reduce the possibility of stress concentration occurring at the overlapping position of two adjacent battery cells.

[0067] When preparing a photovoltaic module, a buffer may be provided on the first surface and / or the second surface of the cell in advance, and then adjacent cells are connected by welding ribbons through a stringing machine to form a cell string. Alternatively, adjacent cells may be connected by welding ribbons through a stringing machine to form a cell string, and then a buffer may be provided on the side of the welding ribbon facing the first surface and / or the second surface of the cell.

[0068] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A photovoltaic module, characterized in that: include: Battery cells, wherein a plurality of the battery cells are arranged along a first direction, and projections of two adjacent battery cells along a second direction have an overlapping area; A welding strip, through which two adjacent battery cells are connected; The battery cell includes a first surface and a second surface along the second direction, a first main grid is arranged on the first surface, the first main grid includes a first guide portion, and a second main grid is arranged on the second surface, the second main grid includes a second guide portion; along the second direction, a projection area of ​​the first guide portion is smaller than a projection area of ​​the second guide portion, and the projection of the first guide portion is located within the projection of the corresponding welding strip.

2. The photovoltaic module according to claim 1, characterized in that: The first main grid includes a first main body portion, the first main body portion is connected to the welding strip, and the first guide portion is connected to at least one end of the first main body portion; The projection shape of the first guide portion along the second direction is an "I" shape, and the setting direction of the first guide portion is the same as the setting direction of the first main body portion. 3 . The photovoltaic module according to claim 2 , wherein the first guide portion is connected to two ends of the first main body portion, and the first guide portion and the first main body portion are connected to the same welding strip.

4. The photovoltaic module according to claim 1, characterized in that: Along the second direction, a projection of at least a portion of the structure of the second guide portion is located outside a projection of the corresponding welding strip.

5. The photovoltaic module according to claim 3, characterized in that: The second main grid includes a second main body portion, the second main body portion is connected to the welding strip, and the second guide portion is connected to at least one end of the second main body portion; The second guide portion includes a first guide segment and a second guide segment connected to each other, and the distance between the first guide segment and the second guide segment gradually increases in a direction away from the second main body portion.

6. The photovoltaic module according to claim 5, characterized in that: The maximum distance between the first guide segment and the second guide segment is W1, the width of the welding strip is W2, and W1 and W2 satisfy: W1>W2.

7. The photovoltaic module according to any one of claims 1 to 6, characterized in that: The photovoltaic assembly includes a buffer component, and along the second direction, the buffer component is located between two adjacent solar cells.

8. The photovoltaic module according to claim 7, characterized in that: Along the second direction, the projection area of ​​the buffer is larger than the area of ​​the overlapping region of the projections of two adjacent battery cells.

9. The photovoltaic module according to claim 8, characterized in that: The length of the buffer member is the same as the length of the battery cell, and the thickness D of the buffer member satisfies: 50 μm≤D≤200 μm.

10. The photovoltaic module according to claim 9, characterized in that: The two adjacent battery cells are respectively a first battery cell and a second battery cell; The buffer is disposed on a side of the soldering ribbon facing the second surface of the first battery cell, and / or the buffer is disposed on a side of the soldering ribbon facing the first surface of the second battery cell.

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