Solar cell module and photovoltaic system

Abstract

The invention is applicable to the technical field of solar cells, and provides a solar cell module and a photovoltaic system.The solar cell module comprises a first cover plate, a first adhesive film, a cell string, a second adhesive film and a second cover plate, the cell string comprises a plurality of cell pieces, and each cell piece comprises a first surface and a second surface which are oppositely arranged; every two adjacent battery pieces are connected through the corresponding welding strip, and each welding strip comprises a first welding part arranged on the first surface; the plurality of first pre-fixing films are arranged on the first welding part and are fixedly connected with the first surface; each first pre-fixing film comprises a main body part and at least one extension part which is connected with the main body part and extends to the outer side of the edge of the battery piece, the extension parts are connected with the first adhesive film and the second adhesive film, and the extension parts of at least two adjacent first pre-fixing films of the battery string are overlapped and connected in the thickness direction of the battery piece. According to the solar cell module, the fixing effect of the pre-fixing film on the welding strip can be improved, and the reliability of the solar cell module is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a solar cell assembly and a photovoltaic system. Background Art

[0002] A solar cell is a semiconductor device that can convert solar energy into electrical energy. Under light conditions, a photocurrent is generated inside the solar cell, which outputs electrical energy through electrodes. In recent years, the production technology of solar cells has been continuously improved, the production cost has been continuously reduced, and the conversion efficiency has been continuously improved. The application of solar cell power generation has become increasingly widespread and has become an important energy source for power supply.

[0003] In the prior art, in order to reduce the slurry cost of solar cells, busbar-free cells have appeared on the market, that is, fine grid lines are printed on the cells. When the cells form a solar cell module, the fine grid lines of the cells are directly connected with solder strips, and a pre-fixing film is set on the cells, and the pre-fixing film is heated to melt the pre-fixing film and adhere to the surface of the cells, thereby fixing the solder strip on the cells. However, after lamination to form a solar cell module, the pre-fixing film is not set beyond the edge of the cells, and the pre-fixing films on adjacent cells are independent of each other. The pre-fixing film is not fixed firmly, so that the solder strip is not fixed firmly, affecting the reliability of the solar cell module. Summary of the invention

[0004] The invention provides a solar cell assembly, aiming to solve the problem in the prior art that a pre-fixing film of the solar cell assembly is not firmly fixed, resulting in unstable fixing of a welding strip, thus affecting the reliability of the solar cell assembly.

[0005] The present invention is implemented by providing a solar cell assembly, comprising a first cover plate, a first adhesive film, at least one battery string, a second adhesive film and a second cover plate stacked in sequence, wherein the battery string comprises: A plurality of battery cells are arranged at intervals along a first direction, wherein the battery cells include a first surface and a second surface that are arranged opposite to each other; a plurality of welding strips, two adjacent battery cells are connected by the welding strips, the welding strips are extended along the first direction, a plurality of the welding strips are spaced apart along a second direction, the second direction intersects the first direction, and the welding strips include a first welding portion disposed on the first surface; and A plurality of first pre-fixing films, each of which is arranged on the corresponding battery cell, the first pre-fixing film is arranged on the first welding portion and fixedly connected to the first surface, and the second adhesive film covers the first pre-fixing film; the first pre-fixing film includes a main body covering the first surface, and at least one extension portion connected to the main body and extending to the outside of the edge of the battery cell, the extension portion is connected to the first adhesive film and the second adhesive film, and the battery string has at least two adjacent extension portions of the first pre-fixing films overlapping and connected in the thickness direction of the battery cell.

[0006] Preferably, the battery sheet includes a first battery edge and a second battery edge that are arranged opposite to each other along the first direction; The extension portion includes a first extension portion and a second extension portion, the first extension portion and the second extension portion are respectively arranged at opposite ends of the main body along the first direction, the first extension portion covers the edge of the first battery and extends to the outside of the edge of the first battery, the second extension portion covers the edge of the second battery and extends to the outside of the edge of the second battery, and the first extension portion of the first pre-fixed film is overlapped and connected with the second extension portion of the adjacent first pre-fixed film.

[0007] Preferably, the distance between two adjacent battery cells in the battery string is L1, the projection length of the first extension portion in the first direction is S1, the projection length of the second extension portion in the first direction is S2, and the sum of S1 and S2 is greater than L1.

[0008] Preferably, both S1 and S2 are greater than L1 / 2, and both S1 and S2 are smaller than L1.

[0009] Preferably, the extension portions of the first pre-fixed films on two adjacent battery cells are overlapped and connected to form a first overlapping portion, and the thickness of the first overlapping portion is greater than the thickness of the main body portion.

[0010] Preferably, a projection length of the first overlapping portion in the first direction is smaller than a distance between two adjacent battery cells in the battery string.

[0011] Preferably, the first overlapping portion is provided with a cavity structure.

[0012] Preferably, the battery string includes a first battery cell located at its first end, the first battery cell is connected to an edge bus bar, the distance between the first battery cell and the edge bus bar is L2, the first extension portion of the first pre-fixed film on the first battery cell extends toward the edge bus bar, and the projection length of the first extension portion of the first pre-fixed film on the first battery cell in the first direction is less than L2.

[0013] Preferably, the battery string includes a second battery cell located at its second end, the second battery cell is connected to an intermediate bus bar, the distance between the second battery cell and the intermediate bus bar is L3, the second extension portion of the first pre-fixed film on the second battery cell extends toward the intermediate bus bar, and the projection length of the second extension portion of the first pre-fixed film on the second battery cell in the first direction is less than L3.

[0014] Preferably, the battery cell includes a third battery edge and a fourth battery edge arranged opposite to each other along the second direction; the extension portion includes a third extension portion and a fourth extension portion, the third extension portion and the fourth extension portion are respectively connected to the opposite ends of the main body portion along the second direction, the third extension portion covers the third battery edge and extends to the outside of the third battery edge, and the fourth extension portion covers the fourth battery edge and extends to the outside of the fourth battery edge.

[0015] Preferably, the projection lengths of the third extension portion and the fourth extension portion in the second direction are both smaller than the projection lengths of the first extension portion and the second extension portion in the first direction.

[0016] Preferably, the battery cell comprises a first grid line and a second grid line arranged on the first surface, the first grid line and the second grid line are arranged at intervals along the first direction, and the first grid line and the second grid line have opposite polarities; The welding strip includes two first welding portions and a connecting portion connecting the two first welding portions, one first welding portion is connected to the first grid line on one of the battery cells, and the other first welding portion is connected to the second grid line on another of the battery cells.

[0017] Preferably, the first pre-fixed film includes at least one of a PVB film, an EVA film, an EPE film, an EP film and a POE film.

[0018] The present invention also provides a photovoltaic system, comprising the above-mentioned solar cell assembly.

[0019] A solar cell assembly provided by the present invention is provided with a first pre-fixing film on the first surface of a battery cell, and a welding strip is fixed on the first surface by using the first pre-fixing film. The first pre-fixing film is provided to include a main body, and an extension part connected to the main body and extending to the outside of the edge of the battery cell. The first pre-fixing film is fixedly connected to the first surface by using the main body, and is connected to the first adhesive film by using the extension part at the same time, so as to increase the fixing area of ​​the first pre-fixing film and make the first pre-fixing film more firmly fixed. Moreover, since the extension parts of at least two adjacent first pre-fixing films in the battery string are overlapped and connected, the adjacent first pre-fixing films can also play a role of fixing each other, which can further improve the fixing effect of the first pre-fixing film, thereby improving the fixing reliability of the first pre-fixing film to the welding strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic plan view of a solar cell assembly provided by an embodiment of the present invention; Figure 2 A schematic plan view of a cell string of a solar cell assembly provided by an embodiment of the present invention; Figure 3 A schematic plan view of a partial structure of a solar cell assembly provided by an embodiment of the present invention; Figure 4 A schematic plan view of a single cell connection ribbon of a cell string of a solar cell assembly provided by an embodiment of the present invention; Figure 5 A cross-sectional schematic diagram of a welding strip connecting two adjacent battery cells of a battery string of a solar cell assembly provided by an embodiment of the present invention; Figure 6 A schematic cross-sectional view of a solar cell assembly along a first direction provided by an embodiment of the present invention; Figure 7 A schematic cross-sectional view of another solar cell assembly along a first direction provided by an embodiment of the present invention; Figure 8 Another cross-sectional schematic diagram of another solar cell assembly provided by an embodiment of the present invention along a first direction; Fig. 9 A schematic cross-sectional view of a solar cell assembly along a second direction provided by an embodiment of the present invention; Fig.10 A schematic plan view of a solar cell assembly provided by an embodiment of the present invention after being covered with a first pre-fixing film; Fig.11 A cross-sectional schematic diagram of a first solar cell assembly provided by an embodiment of the present invention; Fig.12 A cross-sectional schematic diagram of a second solar cell assembly provided by an embodiment of the present invention; Fig.13 A schematic cross-sectional view of a third solar cell assembly provided by an embodiment of the present invention; Fig.14 A schematic cross-sectional view of a fourth solar cell assembly provided by an embodiment of the present invention; Fig.15 A schematic plan view of a single cell connection ribbon of another solar cell assembly provided by an embodiment of the present invention; Fig.16 Another schematic plan view of a single cell connection ribbon of another solar cell assembly provided by an embodiment of the present invention; Fig.17 A cross-sectional schematic diagram of welding strips connecting adjacent cells of another solar cell assembly provided by an embodiment of the present invention; Fig.18 A cross-sectional schematic diagram of another solar cell assembly provided by an embodiment of the present invention; Fig.19 A schematic cross-sectional view of another solar cell assembly along a first direction provided by an embodiment of the present invention; Fig. 20 A cross-sectional schematic diagram of another solar cell assembly provided by an embodiment of the present invention; Fig.21 A schematic cross-sectional view of another solar cell assembly along a first direction provided by an embodiment of the present invention; Fig. 22 Another schematic plan view of a solar cell assembly provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by the terms "upper", "lower", "back", "front", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use scenarios of other materials.

[0025] A solar cell assembly provided by an embodiment of the present invention is provided with a first pre-fixing film on the first surface of a battery cell, and a welding strip is fixed on the first surface by using the first pre-fixing film. The first pre-fixing film is provided to include a main body, and an extension part connected to the main body and extending to the outside of the edge of the battery cell. The first pre-fixing film is fixedly connected to the first surface by using the main body, and is connected to the first adhesive film by using the extension part at the same time, so that the first pre-fixing film is fixed more firmly; moreover, since the extension parts of at least two adjacent first pre-fixing films in the battery string are overlapped and connected, the adjacent first pre-fixing films are mutually fixed through the connection, which can further improve the fixing effect of the first pre-fixing film, thereby improving the fixing reliability of the first pre-fixing film to the welding strip.

[0026] Embodiment 1 Please refer to Figure 1-Figure 8 The embodiment of the present invention provides a solar cell assembly, comprising a first cover plate 1, a first adhesive film 2, at least one battery string, a second adhesive film 4 and a second cover plate 5, which are stacked in sequence, and the battery string comprises: A plurality of battery cells 31 are sequentially arranged in a spaced relationship along a first direction Y, wherein the battery cells 31 include a first surface 315 and a second surface 316 that are oppositely arranged; A plurality of welding strips 32, two adjacent battery cells 31 are connected by the welding strips 32, the welding strips 32 are extended along the first direction Y, and the plurality of welding strips 32 are arranged at intervals along the second direction X, the second direction X intersects the first direction Y, and the welding strips 32 include a first welding portion 321 arranged on the first surface 315; and A plurality of first pre-fixed films 33, each of which is disposed on a corresponding battery cell 31, the first pre-fixed film 33 is disposed on the first welding portion 321 and fixedly connected to the first surface 315, and the second adhesive film 4 covers the first pre-fixed film 33; the first pre-fixed film 33 includes a main body 336 covering the first surface 315, and at least one extension portion 330 connected to the main body 336 and extending to the outside of the edge of the battery cell 31, the extension portion 330 is connected to the first adhesive film 2 and the second adhesive film 4, and each battery string has at least two adjacent extension portions 330 of the first pre-fixed films 33 overlapping and connected.

[0027] In the embodiment of the present invention, the solar cell assembly includes at least one battery string. When the solar cell assembly includes multiple battery strings, the multiple battery strings can be arranged in multiple rows and columns, and the battery cells 31 in each battery string are connected in series through welding strips 32, and different battery strings can be connected in series or in parallel through bus bars to realize current bus output. Multiple battery strings can form a battery cell array, and are packaged together by the first cover plate 1, the first adhesive film 2, the second adhesive film 4 and the second cover plate 5 to form a solar cell assembly.

[0028] like Figure 1 As shown, as an embodiment of the present invention, the solar cell assembly includes at least one battery string unit 30, and each battery string unit 30 includes: A first battery string 301 and a second battery string 302 are arranged at intervals along a second direction X; The third battery string 303 and the fourth battery string 304 are arranged at intervals along the second direction X, the first battery string 301 and the third battery string 303 are arranged along the first direction Y, and the second battery string 302 and the fourth battery string 304 are arranged along the first direction Y.

[0029] Among them, the first battery string 301 and the second battery string 302 are connected in series, the third battery string 303 and the fourth battery string 304 are connected in series, the first battery string 301 and the third battery string 303 are connected in parallel, and the second battery string 302 and the fourth battery string 304 are connected in parallel. The second battery string 302 of each battery string unit 30 is adjacent to and connected in series with the first battery string 301 of the adjacent battery string unit 30, and the fourth battery string 304 of each battery string unit 30 is adjacent to and connected in series with the third battery string 303 of the adjacent battery string unit 30.

[0030] Specifically, the first battery string 301 and the second battery string 302 of each battery string unit 30 are connected in series at one end through an edge bus bar 306, the third battery string 303 and the fourth battery string 304 are also connected in series through an edge bus bar 306, the first battery string 301 and the third battery string 303 are connected in parallel through an intermediate bus bar 308, the second battery string 302 and the fourth battery string 304 are connected in parallel through an intermediate bus bar 308, the second battery string 302 of the battery string unit 30 is also connected in series with the first battery string 301 of the adjacent battery string unit 30 through the intermediate bus bar 308, and the fourth battery string 304 of each battery string unit 30 is also connected in series with the third battery string 303 of the adjacent battery string unit 30 through the intermediate bus bar 308. Of course, other connection methods can also be used to achieve series-parallel connection between battery strings.

[0031] in, Figure 1 Only three battery string units 30 are illustrated, and the battery string units 30 are sequentially arranged at intervals along the second direction X. Each battery string unit 30 includes the first battery string 301, the second battery string 302, the third battery string 303, and the fourth battery string 304 mentioned above.

[0032] In an embodiment of the present invention, a solar cell assembly is provided by setting a first pre-fixing film 33 on the first surface 315 of a battery cell 31 of a battery string, and fixing a welding strip 32 on the first surface 315 by using the first pre-fixing film 33, and the welding strip 32 is fixed on the first surface 315 without a welding process; at the same time, the first pre-fixing film 33 is configured to include a main body 336, and an extension part 330 connected to the main body 336 and extending to the outside of the battery cell 31. On the premise that the first pre-fixing film 33 is fixedly connected to the first surface 315 by using the main body 336, the extension part 330 is used to connect to the first adhesive film 2 at the same time, so that the first pre-fixing film 33 is fixed more firmly, thereby improving the fixing effect of the first pre-fixing film 33 on the welding strip 32, and the connection of the extension part 330 with the first adhesive film 2 can improve the pre-fixing effect of the first pre-fixing film 33 on the welding strip 32 before lamination.

[0033] At the same time, since the battery string has at least two adjacent extensions 330 of the first pre-fixed films 33 overlapping and connected, the extension 330 of the first pre-fixed film 33 on one battery cell 31 overlaps and connects with the extension 330 of the first pre-fixed film 33 on the adjacent battery cell 31, so that the adjacent first pre-fixed films 33 can also play a role of fixing each other, and the overlapping connection of adjacent first pre-fixed films 33 can enhance the structural strength of the connection between adjacent first pre-fixed films 33, further prevent the first pre-fixed films 33 from moving, improve the fixing effect of the first pre-fixed films 33, and then improve the fixing reliability of the first pre-fixed films 33 to the welding strip 32. Optionally, the extensions 330 of any two adjacent first pre-fixed films 33 in each battery string overlap and connect, which can improve the fixing effect of each first pre-fixed film 33.

[0034] As an embodiment of the present invention, the extension portion 330 is bent relative to the main body portion 336 toward the plane where the second surface 316 is located. Part of the extension portion 330 is located on the side of the plane where the first surface 315 is located, away from the second surface 316, and part of the extension portion 330 is located on the side of the plane where the first surface 315 is located, close to the second surface 316. The extension portion 330 is non-parallel to the first surface 315. The bent extension portion 330 forms a limiting matching structure with the battery cell 31, which can effectively prevent the first pre-fixed film 33 from loosening and shifting, so that the first pre-fixed film 33 is stably fixed on the battery cell 31. At the same time, the extension portion 330 also forms a limiting matching structure with the first adhesive film 2 and the second adhesive film 4, which is beneficial to increase the bonding force between the extension portion 330 and the first adhesive film 2 and the second adhesive film 4, which can effectively prevent the first pre-fixed film 33 from loosening, and greatly improve the fixing reliability of the first pre-fixed film 33 to the welding strip 32.

[0035] In some other embodiments, the extension portion 330 can also be bent relative to the main body portion 336 in a direction away from the plane where the second surface 316 is located. The extension portion 330 is located on the side of the plane where the first surface 315 is located, away from the second surface 316. The extension portion 330 can also form a limiting matching structure with the first adhesive film 2 and the second adhesive film 4, which is beneficial to increase the bonding force between the extension portion 330 and the first adhesive film 2 and the second adhesive film 4, and also improve the fixing reliability of the first pre-fixed film 33 to the welding strip 32.

[0036] In the embodiment of the present invention, one of the first surface 315 and the second surface 316 of the cell 31 is a light-facing surface, and the other is a backlight surface. The cell 31 may be a back-contact solar cell or a double-sided contact solar cell. Specifically, in the case where the cell 31 is a back-contact solar cell, only the first surface 315 of the cell 31 has grid lines. For example, the cell 31 may be an IBC solar cell or an HBC solar cell. In the case where the cell 31 is a double-sided contact cell, both the first surface 315 and the second surface 316 of the cell 31 have grid lines, for example, the cell 31 may be a Topcon solar cell.

[0037] In the embodiment of the present invention, the first cover plate 1 and the second cover plate 5 can both be glass, that is, the solar cell module can be a double-glass module; alternatively, one of the first cover plate 1 and the second cover plate 5 can be glass and the other can be a back plate, that is, the solar cell module can be a single-glass module.

[0038] In the embodiment of the present invention, each battery string includes a plurality of welding strips 32, and the specific number of welding strips 32 of each battery string is not limited, and the specific number of welding strips 32 can be flexibly set according to actual applications. Specifically, each welding strip 32 is extended along the first direction Y, that is, the length direction of the welding strip 32 is the first direction Y, and each welding strip 32 is sequentially spaced along the second direction X.

[0039] In the embodiment of the present invention, the main body 336 completely covers the first surface 315 , that is, the size of the main body 336 is the same as the size of the battery cell 31 , so that the first welding portion 321 of the welding ribbon 32 is fixed on the first surface 315 of the battery cell 31 .

[0040] In the embodiment of the present invention, the number of the first pre-fixed films 33 matches the number of the battery cells 31, and a first pre-fixed film 33 is correspondingly arranged on each battery cell 31, so as to facilitate the fixing of the welding strip 32 on each battery cell 31. Compared with the whole pre-fixed film being laid on the entire battery string, a first pre-fixed film 33 is correspondingly arranged on each battery cell 31 in the present embodiment. When the first pre-fixed film 33 is adsorbed and laid on the battery cell 31, the first pre-fixed film 33 is not easy to bend and deform during the process, which makes it easier for the first pre-fixed film 33 to be adsorbed and laid, and facilitates the laminating process of the first pre-fixed film 33, which can reduce the difficulty of production and processing of the solar cell module. Each first pre-fixed film 33 forms an extension 330 on at least one battery edge of the battery cell 31, and can also form an extension 330 on each battery edge of the battery cell 31. Among them, the extension 330 is specifically the part of the first pre-fixed film 33 that exceeds the edge of the battery cell 31.

[0041] Please refer to Figure 4-Figure 10In the embodiment of the present invention, the battery cell 31 includes a first battery edge 311 and a second battery edge 312 arranged opposite to each other along the first direction Y, and a third battery edge 313 and a fourth battery edge 314 arranged opposite to each other along the second direction X.

[0042] The extension portion 330 may include a first extension portion 331 connected to the main body portion 336 and extending to the outside of the first battery edge 311 along the first direction Y, a second extension portion 332 connected to the main body portion 336 and extending to the outside of the second battery edge 312 along the first direction Y, a third extension portion 333 connected to the main body portion 336 and extending to the outside of the third battery edge 313 along the second direction X, and a fourth extension portion 334 connected to the main body portion 336 and extending to the outside of the fourth battery edge 314 along the second direction X. The extension portion 330 includes at least one of the first extension portion 331, the second extension portion 332, the third extension portion 333, and the fourth extension portion 334.

[0043] Please refer to Figure 4 and Fig.10 , as an embodiment of the present invention, the battery sheet 31 includes a first battery edge 311 and a second battery edge 312 arranged opposite to each other along a first direction Y; The extension portion 330 includes a first extension portion 331 and a second extension portion 332, and the first extension portion 331 and the second extension portion 332 are respectively arranged at the opposite ends of the main body portion 336 along the first direction Y. The first extension portion 331 covers the first battery edge 311 and extends to the outside of the first battery edge 311, and the second extension portion 332 covers the second battery edge 312 and extends to the outside of the second battery edge 312. The first extension portion 331 of the first pre-fixed film 33 overlaps and is connected with the second extension portion 332 of the adjacent first pre-fixed film 33.

[0044] In this embodiment, the welding ribbon 32 extends along the first direction Y, and at least a portion of the welding ribbon 32 extends to the outside of the first battery edge 311, and at least a portion of the welding ribbon 32 extends to the outside of the second battery edge 312 along the first direction Y. The first extension portion 331 is used to wrap around the first battery edge 311 position of the welding ribbon 32, so that the welding ribbon 32 is not easily offset at the first battery edge 311 position; at the same time, the second extension portion 332 wraps around the second battery edge 312 position of the welding ribbon 32, so that the welding ribbon 32 is not easily offset at the second battery edge 312 position, which can greatly improve the fixing stability of the welding ribbon 32 at the first battery edge 311 position and the second battery edge 312 position, and further improve the structural reliability of the solar cell module. Moreover, at least a portion of the area where the soldering strip 32 exceeds the first battery edge 311 is covered and fixed by the first extension portion 331, and at least a portion of the area where the soldering strip 32 exceeds the second battery edge 312 is covered and fixed by the second extension portion 332, so as to prevent the soldering strip 32 from loosening at the first battery edge 311 and the second battery edge 312, thereby improving the fixing effect of the soldering strip 32 at the first battery edge 311 and the second battery edge 312. The first extension portion 331 of the first pre-fixing film 33 overlaps and connects with the second extension portion 332 of the adjacent first pre-fixing film 33, and the adjacent first pre-fixing films 33 are connected to each other to fix each other, thereby further improving the fixing effect of the first pre-fixing film 33 and improving the fixing reliability of the first pre-fixing film 33 to the soldering strip 32.

[0045] As an embodiment of the present invention, the battery cell 31 also includes a third battery edge 313 and a fourth battery edge 314 which are arranged opposite to each other along the second direction X; the extension portion 330 includes a third extension portion 333 and a fourth extension portion 334, the third extension portion 333 and the fourth extension portion 334 are respectively connected to the opposite ends of the main body portion 336 along the second direction X, the third extension portion 333 covers the third battery edge 313 and extends to the outside of the third battery edge 313, and the fourth extension portion 334 covers the fourth battery edge 314 and extends to the outside of the fourth battery edge 314.

[0046] In this embodiment, the first pre-fixed film 33 is connected to the first adhesive film 2 and the second adhesive film 4 respectively by using the third extension part 333 and the fourth extension part 334 distributed along the second direction X, and the bent third extension part 333 and the fourth extension part 334 form a limiting matching structure with the battery cell 31, and at the same time, the first pre-fixed film 33 is limited and fixed in the first direction Y and the second direction X, which can further enhance the fixing effect of the first pre-fixed film 33, further enhance the fixing stability of the welding strip 32, and enhance the reliability of the solar cell module.

[0047] The structures of the extension parts 330 are the same, that is, the structures of the first extension part 331 , the second extension part 332 , the third extension part 333 and the fourth extension part 334 are the same; of course, in some possible embodiments, the structures of the extension parts 330 may also be different.

[0048] As an embodiment of the present invention, the projection lengths of the third extension portion 333 and the fourth extension portion 334 along the second direction X are both smaller than the projection lengths of the first extension portion 331 and the second extension portion 332 along the first direction Y.

[0049] In this embodiment, it can be understood that the projection length of the third extension portion 333 along the second direction X is smaller than the projection length of the first extension portion 331 along the first direction Y, and the projection length of the third extension portion 333 along the second direction X is smaller than the projection length of the second extension portion 332 along the first direction Y; the projection length of the fourth extension portion 334 along the second direction X is smaller than the projection length of the first extension portion 331 along the first direction Y, and the projection length of the fourth extension portion 334 along the second direction X is smaller than the projection length of the second extension portion 332 along the first direction Y. Among them, the projection lengths of the third extension portion 333 and the fourth extension portion 334 along the second direction X can be equal, the projection lengths of the first extension portion 331 and the second extension portion 332 along the first direction Y can be equal, and the projection lengths of the third extension portion 333 and the fourth extension portion 334 along the second direction X are both smaller than the projection lengths of the first extension portion 331 and the second extension portion 332 along the first direction Y, which can reduce the size design of the first pre-fixed film 33 in the second direction X, avoid overlapping of the first pre-fixed films 33 on adjacent battery strings distributed along the second direction X, and help reduce the material usage of the first pre-fixed film 33.

[0050] As an embodiment of the present invention, the first pre-fixing film 33 includes at least one of a PVB film, an EVA film, an EPE film, an EP film, and a POE film.

[0051] The material of the first pre-fixed film 33 may be one of PVB film, EVA film, EPE film, EP film and POE film, or a laminate of at least two of the PVB film, EVA film, EPE film, EP film and POE film. The material of the PVB film is polyvinyl butyral (PVB), the material of the EVA film is ethylene-vinyl acetate copolymer (EVA), the material of the POE film is polyolefin elastomer (POE), the material of the EPE film is EPE (EVA-POE-EVA), and the material of the EP film is EP (EVA-POE). In this embodiment, the first adhesive film 2 and the second adhesive film 4 include at least one of PVB film, EVA film, EPE film, EP film and POE film. In addition, the material of the first pre-fixed film 33 can be the same as or different from the material of the first adhesive film 2 and the second adhesive film 4.

[0052] As an embodiment of the present invention, the spacing L1 between adjacent battery cells 31 of the battery string is 0.3-0.6 mm. The distance from the edge of the first pre-fixing film 33 to the edge of the battery cell 31 is 0.3-0.6 mm, which can achieve good fixation of the first pre-fixing film 33 and help reduce material costs.

[0053] As an embodiment of the present invention, the thickness of the first pre-fixing film 33 is 5-150 micrometers, which can achieve good fixation of the first pre-fixing film 33 and maintain good optical properties of the battery cell 31.

[0054] Embodiment 2 Please refer to Figure 3-Figure 5 As an embodiment of the present invention, the battery cell 31 includes a first gate line 317 and a second gate line 318 disposed on the first surface 315, the first gate line 317 and the second gate line 318 are spaced apart along the first direction Y, and the first gate line 317 and the second gate line 318 have opposite polarities; The welding strip 32 includes two first welding portions 321 and a connecting portion 320 connecting the two first welding portions 321 . One first welding portion 321 is connected to a first grid line 317 on one battery cell 31 , and the other first welding portion 321 is connected to a second grid line 318 on another battery cell 31 .

[0055] In this embodiment, the cell 31 is a back contact solar cell, the first surface 315 is the backlight surface of the cell 31, and the cell 31 is provided with grid lines only on the first surface 315, the number of the first grid lines 317 and the second grid lines 318 are both multiple, and the first grid lines 317 and the second grid lines 318 are alternately arranged on the first surface 315. Among them, one of the first grid lines 317 and the second grid lines 318 is a positive grid line, and the other is a negative grid line.

[0056] In this embodiment, a first welding portion 321 of the welding ribbon 32 is connected to a corresponding first grid line 317 on a battery cell 31 , and another first welding portion 321 of the welding ribbon 32 is connected to a corresponding second grid line 318 on an adjacent battery cell 31 , thereby realizing the series connection of adjacent battery cells 31 .

[0057] As an embodiment of the present invention, the welding strip 32 is arranged to cross the first gate line 317 and the second gate line 318 and is connected to the first gate line 317 or the second gate line 318 .

[0058] In the present embodiment, the welding strip 32 is arranged to intersect with the first grid line 317 and the second grid line 318. Specifically, the second direction X is arranged perpendicular to the first direction Y. The first grid line 317 and the second grid line 318 are arranged parallel and spaced along the first direction Y, that is, the welding strip 32 is arranged perpendicular to the first grid line 317 and the second grid line 318. Of course, in other possible embodiments, the welding strip 32 may not be arranged perpendicular to the first grid line 317 and the second grid line 318, as long as the welding strip 32 is arranged to intersect with the first grid line 317 and the second grid line 318.

[0059] like Figure 4 As shown, in this embodiment, an insulating layer 310 is arranged between the welding strip 32 connected to the first gate line 317 on each battery cell 31 and the second gate line 318, and an insulating layer 310 is also arranged between the welding strip 32 connected to the second gate line 318 on each battery cell 31 and the first gate line 317, so that the welding strip 32 connected to the first gate line 317 on the battery cell 31 and the second gate line 318 are well insulated, and the welding strip 32 connected to the second gate line 318 on the battery cell 31 and the first gate line 317 are well insulated. In this embodiment, the soldering strip 32 is placed on the first surface 315 in sequence, the first welding portion 321 of the soldering strip 32 contacts the corresponding first gate line 317, and the soldering strip 32 is fixed on the first surface 315 using the first pre-fixing film 33, thereby fixing the soldering strip 32 and achieving electrical connection between the soldering strip 32 and the corresponding gate line.

[0060] Embodiment 3 Please refer to Figure 3 and Figure 6 As an embodiment of the present invention, the extension portions 330 of two adjacent first pre-fixation films 33 are overlapped and connected in the thickness direction of the battery cell 31 .

[0061] In this embodiment, in each battery string, the first extension portion 331 and the second extension portion 332 of the first pre-fixed film 33 on two adjacent battery cells 31 are arranged adjacent to each other, and the first extension portion 331 and the second extension portion 332 between two adjacent battery cells 31 are overlapped and connected into one along the thickness direction of the battery cell 31, which can increase the thickness of the overlapping area of ​​the first pre-fixed film 33, which is conducive to further improving the fixing effect of the first pre-fixed film 33.

[0062] As an embodiment of the present invention, the spacing between two adjacent battery cells 31 in the battery string is L1, the projection length of the first extension portion 331 along the first direction Y is S1, the projection length of the second extension portion 332 along the first direction Y is S2, and the sum of S1 and S2 is greater than L1.

[0063] In this embodiment, when the sum of S1 and S2 is greater than L1, the first extension portion 331 and the second extension portion 332 between two adjacent battery cells 31 overlap and connect into one, which is beneficial to further improve the fixing effect of the first pre-fixing film 33 .

[0064] As an embodiment of the present invention, S1 and S2 are both greater than L1 / 2, and S1 and S2 are both less than L1.

[0065] In this embodiment, S1 and S2 are controlled to be greater than L1 / 2, which can ensure the overlapping area between the first extension portion 331 and the second extension portion 332 and improve the fixing effect of the first pre-fixed film 33. At the same time, S1 and S2 are controlled to be less than L1 to avoid the extension portion 330 of the first pre-fixed film 33 from extending onto the adjacent battery cell 31, thereby maintaining the good optical performance of the battery cell 31.

[0066] As an embodiment of the present invention, the extension portions 330 of the first pre-fixed films 33 on two adjacent battery cells 31 overlap and connect to form a first overlapping portion 300 , and a thickness D1 of the first overlapping portion 300 is greater than a thickness D2 of the main portion 336 .

[0067] In this embodiment, when the sum of S1 and S2 is greater than L1, the first extension portion 331 and the second extension portion 332 between two adjacent battery cells 31 overlap to form a first overlapping portion 300. By controlling the thickness of the first overlapping portion 300 to be greater than the thickness of the main body 336, it is beneficial to improve the structural strength of the overlapping position of adjacent first pre-fixed films 33, so that the adjacent first pre-fixed films 33 are firmly connected, which is beneficial to further improve the fixing reliability of the first pre-fixed film 33 and improve the fixing performance of the welding strip 32.

[0068] As an embodiment of the present invention, a projection length of the first overlapping portion 300 in the first direction Y is smaller than a spacing L1 between two adjacent battery cells 31 in the battery string.

[0069] In this embodiment, the projection length of the first overlapping portion 300 in the first direction Y is controlled to be smaller than the spacing L1 between two adjacent battery cells 31 in the battery string to prevent the extension portion 330 of the first pre-fixed film 33 from extending onto the adjacent battery cells 31 and maintain good optical properties of the battery cells 31.

[0070] As an embodiment of the present invention, the first overlapping portion 300 is provided with a cavity structure (not shown).

[0071] In this embodiment, the first overlapping portion 300 is provided with at least one cavity structure, preferably the first overlapping portion 300 is provided with multiple cavity structures, so that the first overlapping portion 300 has a loose structure, and the cavity structure makes the first adhesive film 2 and the second adhesive film 4 more firmly combined with the first overlapping portion 300, which can greatly increase the bonding force between the first overlapping portion 300 and the first adhesive film 2 and the second adhesive film 4, and improve the fixing effect of the first pre-fixed film 33; at the same time, the cavity structure provided in the first overlapping portion 300 can play a buffering role, which can reduce the stress of the first pre-fixed film 33, avoid the breakage of the first pre-fixed film 33, and make the combination between adjacent first pre-fixed films 33 more stable. Among them, the cavity structure can be specifically a hollow cavity or a cavity filled with air.

[0072] Embodiment 4 Please refer to Figure 7 As another embodiment of the present invention, the extension portions 330 of two adjacent first pre-fixed films 33 are connected in the first direction Y.

[0073] In this embodiment, in each battery string, the first extension portion 331 and the second extension portion 332 of the first pre-fixed film 33 on two adjacent battery cells 31 are arranged adjacent to each other, and the end of the first extension portion 331 of the first pre-fixed film 33 on one battery cell 31 and the end of the second extension portion 332 of the first pre-fixed film 33 on another battery cell 31 are just in contact and connected as a whole in the first direction Y, which can also improve the fixing effect of the first pre-fixed film 33. As an embodiment of the present invention, the spacing between two adjacent battery cells 31 in the battery string is L1, the projection length of the first extension portion 331 in the first direction Y is S1, the projection length of the second extension portion 332 in the first direction Y is S2, and the sum of S1 and S2 is equal to L1.

[0074] In this embodiment, the projection length of the first extension portion 331 in the first direction Y is S1, and the projection length of the second extension portion 332 in the first direction Y is S2. The sum of S1 and S2 is equal to L1, which can ensure that the ends of the first extension portion 331 and the second extension portion 332 of the first pre-fixed film 33 on two adjacent battery cells 31 are just in contact and connected as a whole, which can improve the fixing effect of the first pre-fixed film 33, and compared with the overlap of the first extension portion 331 and the second extension portion 332, it is beneficial to reduce the material consumption of the first pre-fixed film 33. As an embodiment of the present invention, S1 and S2 are both equal to L1 / 2, and the sum of S1 and S2 is equal to L1, which can ensure that the ends of the first extension portion 331 and the second extension portion 332 of the first pre-fixed film 33 on two adjacent battery cells 31 are just in contact and connected as one, which can enhance the fixing effect of the first pre-fixed film 33.

[0075] As an embodiment of the present invention, one of S1 and S2 is greater than L1 / 2, and the other is less than L1 / 2, and the sum of S1 and S2 is equal to L1. This can also ensure that the ends of the first extension 331 and the second extension 332 of the first pre-fixed film 33 on two adjacent battery cells 31 are just in contact and connected as a whole, which can enhance the fixing effect of the first pre-fixed film 33.

[0076] Embodiment 5 Please refer to Figure 10-11 As an embodiment of the present invention, the extension portion 330 includes: The first extension portion 3311 is connected to the main body portion 336, and the first extension portion 3311 is bent relative to the main body portion 336 toward the side of the plane where the second surface 316 is located. A portion of the first extension portion 3311 is located on the side of the plane where the first surface 315 is located away from the second surface 316, and a portion of the first extension portion 3311 is located on the side of the plane where the first surface 315 is located close to the second surface 316.

[0077] In the present embodiment, each extension portion 330 is bent from the edge of the battery cell 31 toward the plane close to the second surface 316 to form a first extension portion 3311, and the first extension portion 3311 is used to cover the edge position of the battery cell 31. The first portion of the first extension portion 3311 is located on the side of the plane where the first surface 315 is located away from the second surface 316, and the second portion of the first extension portion 3311 is located on the side of the plane where the first surface 315 is located close to the second surface 316, that is, the first extension portion 3311 is partially located above the plane where the first surface 315 is located, and the first extension portion 3311 is partially located below the plane where the first surface 315 is located. The first extension portion 3311 can better limit the movement of the first pre-fixed film 33, and can increase the bonding force between the extension portion 330 and the first adhesive film 2 and the second adhesive film 4, which can further enhance the fixing effect of the first pre-fixed film 33 on the welding strip 32.

[0078] Please refer to Fig.11 As an embodiment of the present invention, the first extension portion 3311 includes an upper surface 3310 disposed away from the second surface 316, the upper surface 3310 includes a first end disposed close to the battery cell 31, and a second end disposed away from the battery cell 31, and a vertical distance from the first end of the upper surface 3310 to the plane where the second surface 316 is located is greater than a vertical distance from the second end of the upper surface 3310 to the plane where the second surface 316 is located.

[0079] In this embodiment, since the first extension portion 3311 is bent from the first battery edge 311 toward the plane close to the second surface 316, the vertical distance from the first end of the upper surface 3310 to the plane where the second surface 316 is located is greater than the vertical distance from the second end of the upper surface 3310 to the plane where the second surface 316 is located, the upper surface 3310 of the first extension portion 3311 and the main body portion 336 are located in different planes, and the first extension portion 3311 is inclined relative to the second surface 316, which is beneficial to increase the total length design of the extension portion 330, thereby increasing the bonding area between the extension portion 330 and the first adhesive film 2 and the second adhesive film 4, and improving the adhesion force of the extension portion 330.

[0080] As an embodiment of the present invention, the vertical distance from the upper surface 3310 to the plane where the second surface 316 is located gradually decreases from the first end to the second end.

[0081] In this embodiment, the vertical distance from the upper surface 3310 to the plane where the second surface 316 is located gradually decreases from the first end to the second end, which is beneficial to increase the length of the extension portion 330 and increase the fixing effect of the extension portion 330 and the first adhesive film 2 and the second adhesive film 4.

[0082] As an embodiment of the present invention, the upper surface 3310 of the first extension portion 3311 is an inclined surface or a curved surface.

[0083] In this embodiment, the upper surface 3310 of the first extension portion 3311 may be an inclined surface or an arc surface, which is convenient for the processing and shaping of the first extension portion 3311 and can ensure the contact area between the first extension portion 3311 and the second adhesive film 4. The upper surface 3310 of the first extension portion 3311 may also be a wavy surface, that is, the upper surface 3310 of the first extension portion 3311 is a surface with concave and convex surfaces, which can increase the surface roughness of the first extension portion 3311, thereby increasing the bonding force between the first extension portion 3311 and the second adhesive film 4, and further improving the fixing effect of the first pre-fixed film 33.

[0084] As an embodiment of the present invention, the angle C between the upper surface 3310 of the first extension portion 3311 and the plane where the second surface 316 is located is 10-80°. In this embodiment, the angle C between the upper surface 3310 of the first extension portion 3311 and the plane where the second surface 316 is located is set in the range of 10-80°, which can not only improve the fixing effect of the first extension portion 3311, but also avoid the first extension portion 3311 from bending too much, so that the first extension portion 3311 is not easy to break, and the structural reliability of the first pre-fixed film 33 is improved. For example, the angle C between the upper surface 3310 of the first extension portion 3311 and the plane where the second surface 316 is located can be any value of 10°, 20°, 30°, 40°, 50°, 60°, 70°, and 80°.

[0085] As another embodiment of the present invention, the upper surface 3310 of the first extension portion 3311 can also be a non-inclined surface, and the angle between the line between the first end of the upper surface 3310 and the second end of the upper surface 3310 and the plane where the second surface 316 is located is set to 10~80 degrees, which can also increase the fixing effect of the first pre-fixed film 33, ensure the good fixing performance of the first pre-fixed film 33, and make the extension portion 330 not easy to break, ensuring the good structural strength of the first pre-fixed film 33.

[0086] Please refer to Figure 12-14 As an embodiment of the present invention, the battery cell 31 includes several side surfaces connecting the first surface 315 and the second surface 316, and the extension portion 330 surrounds at least a partial area of ​​at least one side surface, which can increase the adhesion between the first pre-fixed film 33 and the battery cell 31, making the first pre-fixed film 33 more firmly fixed and preventing the welding strip 32 from shifting in position.

[0087] As an embodiment of the present invention, the side surface includes a first side surface 3191 connecting the first surface 315 and the second surface 316 and located on the side where the first battery edge 311 is located, and the first extension portion 331 surrounds at least a portion of the first side surface 3191 of the battery cell 31.

[0088] In this embodiment, the first extension portion 331 of the first pre-fixed film 33 surrounds at least a portion of the first side surface 3191 of the battery cell 31, and the second extension portion 332 of the first pre-fixed film 33 surrounds at least a portion of the second side surface 3192 of the battery cell 31, which can increase the adhesion of the first pre-fixed film 33, make the first pre-fixed film 33 more firmly fixed, and prevent the welding strip 32 from shifting in position.

[0089] As an embodiment of the present invention, the battery cell 31 includes a second side surface 3192 connecting the first surface 315 and the second surface 316 and located on the side where the second battery edge 312 is located, and the second extension portion 332 surrounds at least a portion of the second side surface 3192 of the battery cell 31 to further increase the adhesion between the first pre-fixing film 33 and the battery cell 31, thereby improving the fixing effect of the first pre-fixing film 33.

[0090] In addition, the side surface also includes a third side surface connecting the first surface 315 and the second surface 316 and located on the side where the third battery edge 313 is located, and a fourth side surface connecting the first surface 315 and the second surface 316 and located on the side where the fourth battery edge 314 is located. The third extension portion 333 can surround at least a portion of the third side surface of the battery cell 31, and the fourth extension portion 334 surrounds at least a portion of the fourth side surface of the battery cell 31 to further enhance the fixing effect of the first pre-fixed film 33.

[0091] Please refer to Fig.12 The first extension portion 331 only partially surrounds a portion of the first side surface 3191. On the one hand, it can increase the adhesion between the first pre-fixed film 33 and the battery cell 31, and improve the fixing effect of the first pre-fixed film 33. On the other hand, it can avoid the bending angle of the first extension portion 331 being too large, prevent the first extension portion 331 from breaking, and improve the structural stability of the first extension portion 331.

[0092] Please refer to Figure 13-Figure 14 The first extension portion 331 surrounds the entire area of ​​the first side surface 3191, which can greatly improve the adhesion between the first pre-fixed film 33 and the battery cell 31, and can further prevent the first pre-fixed film 33 from loosening; moreover, the soldering ribbon 32 can be fixed to the first side surface 3191 by using the first extension portion 331, which can prevent the soldering ribbon 32 from warping and loosening at the first battery edge 311 away from the second surface 316, and can greatly improve the fixing effect of the soldering ribbon 32 at the first battery edge 311.

[0093] Please refer again Fig.12 As an embodiment of the present invention, the first adhesive film 2 surrounds at least a portion of the side surface, and the first adhesive film 2 includes a filling portion 21 surrounding the side surface, and the filling portion 21 is located between the extension portion 330 and the side surface.

[0094] In this embodiment, the filling portion 21 has a buffering effect on the extension portion 330 of the first pre-fixed film 33, thereby preventing the extension portion 330 from breaking, improving the structural reliability of the first pre-fixed film 33, and further improving the reliability of the solar cell module structure.

[0095] Specifically, the first extension portion 331 does not completely cover the first side surface 3191 of the cell 31, the filling portion 21 of the first adhesive film 2 surrounds a portion of the first side surface 3191, and the filling portion 21 of the first adhesive film 2 is embedded between the first extension portion 3311 of the first extension portion 331 and the first side surface 3191. The filling portion 21 of the first adhesive film 2 can improve the fixing effect of the first pre-fixed film 33, and at the same time, the filling portion 21 has a buffering effect on the first extension portion 331 of the first pre-fixed film 33, which can prevent the first extension portion 331 from breaking, improve the structural reliability of the first pre-fixed film 33, and further improve the reliability of the solar cell module structure. Similarly, the second extension portion 332 does not completely cover the second side surface 3192 of the cell 31, the filling portion 21 of the first adhesive film 2 surrounds the second side surface 3192, and the filling portion 21 of the first adhesive film 2 is embedded between the first extension portion 3311 of the second extension portion 332 and the second side surface 3192, further improving the structural reliability of the first pre-fixed film 33.

[0096] Please refer to Figure 10-Figure 14 As an embodiment of the present invention, the extension portion 330 further includes: The second extension portion 3312 is connected to the first extension portion 3311 . The second extension portion 3312 extends from the first extension portion 3311 in a direction away from the battery cell 31 . The second extension portion 3312 is connected between the first adhesive film 2 and the second adhesive film 4 .

[0097] In this embodiment, the second extension portion 3312 of each extension portion 330 is connected between the first adhesive film 2 and the second adhesive film 4, which can further increase the bonding area between the extension portion 330 and the first adhesive film 2 and the second adhesive film 4, and is conducive to further improving the fixing effect of the first pre-fixed film 33. The second extension portion 3312 can be arranged parallel to the second surface 316 of the battery cell 31, and the second extension portion 3312 can also be arranged non-parallel to the second surface 316 of the battery cell 31.

[0098] As an embodiment of the present invention, the second extension portion 3312 and the first extension portion 3311 are arranged at an angle to each other, that is, the second extension portion 3312 is not parallel or colinear with respect to the first extension portion 3311, and the second extension portion 3312 is bent relative to the first extension portion 3311, which is beneficial to further increase the bonding force between the extension portion 330 and the adhesive film.

[0099] Please refer to Fig.14 As an embodiment of the present invention, the extension portion 330 further includes a third extension portion 3314 connected to the first extension portion 3311 and extending to the second surface 316 , and the third extension portion 3314 surrounds a partial area of ​​the second surface 316 .

[0100] In this embodiment, the extension portion 330 is provided to include a third extension portion 3314 connected to the first extension portion 3311 and extending to the second surface 316. The third extension portion 3314 surrounds the edge portion of the second surface 316. The third extension portion 3314 cooperates with the second surface 316 to surround and fix the extension portion 330 on the battery cell 31, which can further prevent the first pre-fixed film 33 from detaching from the battery cell 31, further play a role in fixing the first pre-fixed film 33, enhance the fixing effect of the first pre-fixed film 33, and further enhance the fixing effect of the welding strip 32; at the same time, the third extension portion 3314 can fix the welding strip 32 on the side surface of the battery cell 31, which can greatly improve the reliability of fixing the welding strip 32 on the battery cell 31.

[0101] Please refer to Figure 6 As an embodiment of the present invention, the thickness D2 of the main body 336 is smaller than the thickness D3 of the battery cell 31 .

[0102] In this embodiment, the first pre-fixed film 33 can be flexibly set according to the thickness of the battery cell 31, and the thickness of the first pre-fixed film 33 before lamination is less than the thickness of the battery cell 31. For example, the thickness of the battery cell 31 is 100-180 microns, and the thickness of the first pre-fixed film 33 before lamination can be 5-150 microns, as long as the thickness of the first pre-fixed film 33 is less than the thickness of the battery cell 31. The thickness of the main body 336 is less than the thickness of the battery cell 31, which is conducive to the first pre-fixed film 33 being bent to form the extension 330 after lamination, which is conducive to increasing the fixing effect of the first pre-fixed film 33, and at the same time, it can avoid the first pre-fixed film 33 being too thick and affecting the performance of the solar cell module.

[0103] As an embodiment of the present invention, at least a portion of the extension portion 330 is provided with a cavity structure (not shown).

[0104] The first extension part 3311 of the extension part 330 may be provided with a cavity structure, the second extension part 3312 of the extension part 330 may be provided with a cavity structure, or both the first extension part 3311 and the second extension part 3312 may be provided with a cavity structure. The cavity structure provided in the extension part 330 can make the first adhesive film 2 and the second adhesive film 4 more firmly bonded to the extension part 330, greatly increase the bonding force between the extension part 330 and the first adhesive film 2 and the second adhesive film 4, and enhance the fixing effect of the first pre-fixed film 33; at the same time, the cavity structure provided in the extension part 330 can play a buffering role, and can also reduce the stress of the extension part 330 and avoid the fracture of the extension part 330. Specifically, the cavity structure can be a hollow cavity or a cavity filled with air.

[0105] As an embodiment of the present invention, the thickness of at least a portion of the first extension portion 3311 is greater than the thickness of the main body portion 336 .

[0106] In this embodiment, the thickness of only a part of the first extension part 3311 may be greater than the thickness of the main body part 336, or the thickness of all the first extension part 3311 may be greater than the thickness of the main body part 336. Since the thickness of at least a part of the first extension part 3311 may be greater than the thickness of the main body part 336, the structural strength of the first extension part 3311 may be further increased, the tensile strength of the first extension part 3311 may be improved, and the first extension part 3311 may be prevented from breaking, which is beneficial to improving the performance of the first pre-fixed film 33; at the same time, the bonding force between the first extension part 3311 and the first adhesive film 2 and the second adhesive film 4 may be increased, and the fixing effect of the first pre-fixed film 33 may be further enhanced.

[0107] Embodiment 6 Please refer to Figure 6-Figure 14 As an embodiment of the present invention, the first pre-fixed film 33 further includes: The protrusion structure 335 is protruded on the extension portion 330 , and the protrusion structure 335 is connected to the first adhesive film 2 and / or the second adhesive film 4 .

[0108] In the embodiment of the present invention, the protruding structure 335 can be arranged on the side of the extension part 330 close to the second surface 316, or on the side of the extension part 330 away from the second surface 316, and the protruding direction on the extension part 330 is not limited, the protruding structure 335 can be protruded toward the first adhesive film 2 or the second adhesive film 4, and the protruding structure 335 can also be protruded toward the battery cell 31. The protruding structure 335 can be in the shape of a long strip, and the cross section of the protruding structure 335 is an arc-shaped protrusion, a sawtooth-shaped protrusion, or other irregular-shaped protrusions.

[0109] Specifically, the protruding structure 335 may include a first protruding structure 3351 protruding on the first extension portion 331, a second protruding structure 3352 protruding on the second extension portion 332, a third protruding structure 3353 protruding on the third extension portion 333, and a fourth protruding structure 3354 protruding on the fourth extension portion 334. It can be understood that the protruding structure 335 may be provided on the first extension portion 331, the second extension portion 332, the third extension portion 333, and the fourth extension portion 334, or only the first extension portion 331, the second extension portion 332, the third extension portion 333, and the fourth extension portion 334. The structures of the protruding structures 335 on each extension portion 330 are the same. Of course, in some other embodiments, the structures of the protruding structures 335 on each extension portion 330 may also be different.

[0110] Please refer to Fig.10In this embodiment, the first pre-fixing film 33 includes a first edge 3301 opposite to the first battery edge 311, a second edge 3302 opposite to the second battery edge 312, a third edge 3303 opposite to the third battery edge 313, and a fourth edge 3304 opposite to the fourth battery edge 314. The first protruding structure 3351 is located between the first battery edge 311 and the first edge 3301 of the first pre-fixing film 33, the second protruding structure 3352 is located between the second battery edge 312 and the second edge 3302 of the first pre-fixing film 33, the third protruding structure 3353 is located between the third battery edge 313 and the third edge 3303 of the first pre-fixing film 33, and the fourth protruding structure 3354 is located between the fourth battery edge 314 and the fourth edge 3304 of the first pre-fixing film 33. Each extension part 330 is connected to the first adhesive film 2 and / or the second adhesive film 4 by means of the protruding structure 335 thereon, and at the same time further enhances the bonding force between the first pre-fixed film 33 and the adhesive film, thereby enhancing the fixing effect of the first pre-fixed film 33; moreover, the protruding structure 335 can reduce the pulling force of the extension part 330, enhance the buffering effect, and prevent the extension part 330 from breaking.

[0111] In this embodiment, the extension portion 330 of the first pre-fixed film 33 is connected to the first adhesive film 2 and / or the second adhesive film 4 using a protruding structure 335, further enhancing the bonding force between the extension portion 330 and the adhesive film and strengthening the fixing effect; moreover, the protruding structure 335 can reduce the tensile force of the extension portion 330, thereby achieving a buffering effect and preventing the extension portion 330 from breaking.

[0112] As an embodiment of the present invention, the protruding structure 335 is disposed on the first extending portion 3311 or the second extending portion 3312 .

[0113] In this embodiment, when the protrusion structure 335 is disposed on the first extension portion 3311 or the second extension portion 3312 , the protrusion structure 335 is disposed protruding relative to the surface of the first extension portion 3311 or the second extension portion 3312 , which is beneficial to increase the bonding force between the first extension portion 3311 or the second extension portion 3312 and the second adhesive film 4 .

[0114] As an embodiment of the present invention, the protruding structure 335 is disposed at the connection between the first extending portion 3311 and the second extending portion 3312 .

[0115] In this embodiment, when the protruding structure 335 is disposed at the connection between the first extension portion 3311 and the second extension portion 3312, the protruding structure 335 is disposed relative to the surface protrusion of the connection between the first extension portion 3311 and the second extension portion 3312, which is conducive to increasing the bonding force between the connection between the first extension portion 3311 and the second extension portion 3312 and the second adhesive film 4, and the existence of the protruding structure 335 is also conducive to increasing the buffering effect of the connection between the first extension portion 3311 and the second extension portion 3312, thereby preventing the connection between the first extension portion 3311 and the second extension portion 3312 from breaking. Among them, the drawings of the present invention only illustrate the situation where the protruding structure 335 is disposed at the connection between the first extension portion 3311 and the second extension portion 3312.

[0116] As an embodiment of the present invention, the surface of each protrusion structure 335 away from the first adhesive film 2 is configured as a wavy surface.

[0117] In this embodiment, the surface of each protrusion structure 335 away from the first adhesive film 2 is set to a wavy surface. The wavy surface can further increase the bonding force between the protrusion structure 335 and the second adhesive film 4, further improve the fixing effect of the first pre-fixing film 33, and thus improve the fixing effect of the welding strip 32.

[0118] Please refer again Fig.10 As an embodiment of the present invention, each protruding structure 335 includes a first side edge 3356 disposed close to the battery cell 31 and a second side edge 3357 disposed away from the battery cell 31, and the first side edge 3356 and the second side edge 3357 are disposed in a concave-convex manner.

[0119] In this embodiment, the first side edge 3356 and the second side edge 3357 of the protruding structure 335 are in a wave shape with concave and convex parts connected, which can further enhance the bonding force between the protruding structure 335 and the first adhesive film 2 and the second adhesive film 4 and further enhance the fixing effect of the first pre-fixed film 33 .

[0120] As an embodiment of the present invention, the length of the first protruding structure 3351 and the second protruding structure 3352 along the second direction X is greater than or equal to the length of the battery cell 31 along the second direction X, which is beneficial to further improve the fixing effect of each welding strip 32.

[0121] As an embodiment of the present invention, the length of the third protruding structure 3353 and the fourth protruding structure 3354 along the first direction Y is greater than or equal to the length of the battery cell 31 along the first direction Y, which can further enhance the fixing effect of the first pre-fixing film 33 .

[0122] As an embodiment of the present invention, the projection lengths of the first protruding structure 3351 and the second protruding structure 3352 along the first direction Y are both 10-200 micrometers.

[0123] In this embodiment, by controlling the projection lengths of the first protruding structure 3351 and the second protruding structure 3352 along the first direction Y to be 10 to 200 microns, a good buffering effect of the first protruding structure 3351 and the second protruding structure 3352 can be ensured, and the breakage of the first extension portion 331 and the second extension portion 332 can be avoided. At the same time, sufficient contact area between the first protruding structure 3351 and the second protruding structure 3352 and the first adhesive film 2 and the second adhesive film 4 can be ensured, ensuring a more appropriate bonding force between the first pre-fixed film 33 and the first adhesive film 2 and the second adhesive film 4; moreover, the first protruding structure 3351 and the second protruding structure 3352 can play a good limiting role on the welding strip 32.

[0124] As an embodiment of the present invention, the second adhesive film 4 forms a groove matching the protrusion structure 335 at a position corresponding to the protrusion structure 335 , and the protrusion structure 335 is embedded in the groove.

[0125] In this embodiment, the protruding structure 335 is embedded in the groove of the second adhesive film 4, so that a concave-convex matching structure is formed between the first pre-fixed film 33 and the second adhesive film 4, which can further prevent the first pre-fixed film 33 from loosening relative to the second adhesive film 4 and improve the fixing effect between the first pre-fixed film 33 and the second adhesive film 4.

[0126] Please refer to Fig.11 As an embodiment of the present invention, a first positioning groove formed by a depression is provided on a side of the first extension portion 331 away from the protruding structure 335, and a first positioning protrusion 22 is formed at a position of the first adhesive film 2 corresponding to the first positioning groove, and the first positioning protrusion 22 is embedded in the first positioning groove.

[0127] In this embodiment, the first adhesive film 2 forms a first positioning protrusion at a position corresponding to the first positioning groove, so that a concave-convex matching structure is formed between the first pre-fixed film 33 and the first adhesive film 2, which can further prevent the first pre-fixed film 33 from loosening relative to the first adhesive film 2 and improve the fixing effect between the first pre-fixed film 33 and the first adhesive film 2.

[0128] As an embodiment of the present invention, the first protruding structure 3351 is disposed on the first extending portion 3311 of the first extension portion 331 , and the sum of the projection lengths of the first protruding structure 3351 and the first extending portion 3311 of the first extension portion 331 along the first direction Y is 30-400 μm.

[0129] In this embodiment, the sum of the projection lengths of the first protruding structure 3351 and the first extension portion 3311 of the first extension portion 331 along the first direction Y is 30 to 400 microns, which can ensure a good fixing effect of the first pre-fixed film 33 and at the same time provide a good fixing limit for the welding strip 32 .

[0130] As an embodiment of the present invention, the second protruding structure 3352 is disposed on the first extending portion 3311 of the second extension portion 332 , and the sum of the projection lengths of the second protruding structure 3352 and the first extending portion 3311 of the second extension portion 332 along the first direction Y is 30-400 μm.

[0131] In this embodiment, the sum of the projection lengths of the second protruding structure 3352 and the first extension portion 3311 of the second extension portion 332 along the first direction Y is 30 to 400 microns, which can ensure a good fixing effect of the first pre-fixed film 33 and at the same time provide a good fixing limit for the welding strip 32.

[0132] Embodiment 7 Please refer to Figure 15-17 As another embodiment of the present invention, the battery cell 31 includes a first grid line 317 disposed on the first surface 315 and a second grid line 318 disposed on the second surface 316, and the polarities of the first grid line 317 and the second grid line 318 are opposite; The welding strip 32 further includes a second welding portion 322 and a connecting portion 320 , wherein the connecting portion 320 connects the first welding portion 321 and the second welding portion 322 . The first welding portion 321 connects the first grid line 317 on one battery cell 31 , and the second welding portion 322 connects the second grid line 318 on another battery cell 31 .

[0133] In this embodiment, the cell 31 is a double-sided contact solar cell, and grid lines are provided on the first surface 315 and the second surface 316 of the cell 31. Specifically, the polarity of each first grid line 317 on the first surface 315 is the same, and the polarity of each second grid line 318 on the second surface 316 is the same, and one of the first grid line 317 and the second grid line 318 is a positive fine grid line, and the other is a negative fine grid line. For example, the first grid line 317 is a positive fine grid line, and the second grid line 318 is a negative fine grid line.

[0134] Among them, the first welding portion 321 of the welding ribbon 32 is located on the first surface 315 of one battery cell 31 and connected to the first grid line 317 of the battery cell 31, and the second welding portion 322 of the welding ribbon 32 is located on the second surface 316 of another battery cell 31 and connected to the second grid line 318 of the battery cell 31, thereby realizing the series connection between adjacent battery cells 31.

[0135] Embodiment 8 Please refer to Figure 17-Figure 19 On the basis of the seventh embodiment, the solar cell assembly further comprises: The second pre-fixing film 36 located on the second surface 316 is disposed on the second welding portion 322 and fixes the second welding portion 322 to the second surface 316 , and the second pre-fixing film 36 does not extend outside the edge of the battery cell 31 .

[0136] In this embodiment, a second pre-fixing film 36 is provided on the second surface 316 of the battery cell 31, and the second welding portion 322 of the welding strip 32 is fixed to the second surface 316 by the second pre-fixing film 36, thereby fixing the welding strip 32; at the same time, the second pre-fixing film 36 does not extend out of the outside of the battery cell 31, that is, the second pre-fixing film 36 does not exceed the edge of the battery cell 31, thereby avoiding the overlap of the extension portion 330 of the first pre-fixing film 33 with the second pre-fixing film 36, thereby reducing material costs.

[0137] The material and thickness of the second pre-fixing film 36 may be the same as or different from the material and thickness of the first pre-fixing film 33 .

[0138] Embodiment 9 Please refer to Fig. 20 and Fig.21 , based on the seventh embodiment, further comprising: The second pre-fixed film 36 is located on the second surface 316, and the second pre-fixed film 36 is arranged on the second welding portion 322 and the second welding portion 322 is fixedly connected to the second surface 316. The second pre-fixed film 36 extends to the outer side of the edge of the battery cell 31 to form at least one extension portion 361, and the extension portion 361 is connected to the first adhesive film 2. The projection area of ​​the extension portion 361 on the plane where the second surface 316 is located does not overlap with the projection area of ​​the extension portion 330 on the plane where the second surface 316 is located.

[0139] In this embodiment, the cell 31 is a double-sided contact solar cell. The first pre-fixed film 33 extends to the outside of the cell 31 to form an extension 330, and the extension 330 is used to improve the fixing stability of the first pre-fixed film 33, thereby improving the reliability of the soldering ribbon 32 fixed on the first surface 315, and the extension 361 is used to improve the fixing stability of the second pre-fixed film 36, thereby improving the reliability of the soldering ribbon 32 fixed on the second surface 316, and further improving the structural reliability of the solar cell assembly.

[0140] In the present embodiment, since the projection area of ​​the extension portion 361 on the plane where the second surface 316 is located does not overlap with the projection area of ​​the extension portion 330 on the plane where the second surface 316 is located, after lamination, the extension portion 361 does not overlap with the extension portion 330; between adjacent battery cells 31 of the battery string, the side edge of the battery cell 31 where the extension portion 330 is set does not have the extension portion 361, and the side edge of the battery cell 31 where the extension portion 361 is set does not have the extension portion 330, so that the extension portion 361 of the second pre-fixed film and the extension portion 330 of the first pre-fixed film are staggered, ensuring that the extension portion 361 and the extension portion 330 do not overlap, avoiding the overlap of the extension portion 361 and the extension portion 330 to generate bubbles, and improving the structural reliability of the solar cell module.

[0141] As an embodiment of the present invention, the first pre-fixing films 33 on two adjacent battery cells 31 can be connected to each other to improve the fixing effect of the first pre-fixing films 33. Of course, the first pre-fixing films 33 on two adjacent battery cells 31 may not be connected; the second pre-fixing films 36 on two adjacent battery cells 31 may be connected to each other to improve the fixing effect of the second pre-fixing films 36. Of course, the second pre-fixing films 36 on two adjacent battery cells 31 may not be connected.

[0142] As an embodiment of the present invention, the first pre-fixed film 33 includes a first extension portion 331 extending from the first battery edge 311 to the outside of the battery cell 31, and the second pre-fixed film 36 includes an extension portion 361 extending from the second battery edge 312 to the outside of the battery cell 31. The first extension portions 331 between adjacent battery cells 31 are arranged adjacent to each other, or the extension portions 361 between adjacent battery cells 31 are arranged adjacent to each other. The first extension portions 331 between the battery cells 31 may overlap or not overlap, and the extension portions 361 between the battery cells 31 may overlap or not overlap.

[0143] Among them, the extension portion 330 of the first pre-fixed film 33 between adjacent battery cells 31 can overlap to form a first overlapping portion 300, and the thickness D1 of the first overlapping portion 300 is greater than the thickness D2 of the main body 336; the extension portion 361 between adjacent battery cells 31 can overlap to form a second overlapping portion 400, and the thickness D4 of the second overlapping portion 400 is greater than the thickness of the second pre-fixed film 36 covering the upper portion of the second surface 316, so that the adjacent first pre-fixed films 33 are fixed and limited to each other, and the adjacent second pre-fixed films 36 are fixed and limited to each other, which can improve the reliability of the first pre-fixed film 33 and the second pre-fixed film 36 fixing the welding strip 32.

[0144] Embodiment 10 Please refer to Figure 1 and Fig. 22 As an embodiment of the present invention, the distance L4 between the first battery string 301 and the second battery string 302 in the battery string unit 30 is greater than the distance L5 between the second battery string 302 and the first battery string 301 of the adjacent battery string unit 30. By increasing the distance between the first battery string 301 and the second battery string 302 in the battery string unit 30, it is convenient to install the corresponding junction box and bypass diode in the battery string unit 30, and it is convenient to assemble the solar cell module. Similarly, the distance between the third battery string 303 and the fourth battery string 304 in the battery string unit 30 is greater than the distance between the fourth battery string 304 and the third battery string 303 of the adjacent battery string unit 30, which is also convenient for installing the junction box and bypass diode, and it is convenient for assembling the solar cell module.

[0145] Please refer to Fig. 22As an embodiment of the present invention, the battery string includes a first battery cell 3101 located at a first end thereof, the first battery cell 3101 is connected to the edge bus bar 306, the spacing between the first battery cell 3101 and the edge bus bar 306 is L2, and the first extension portion 331 of the first pre-fixed film 33 on the first battery cell 3101 extends toward the edge bus bar 306, and the projection length of the first extension portion 331 in the first direction Y is less than L2.

[0146] In this embodiment, the first extension portion 331 of the first pre-fixed film 33 on the first battery cell 3101 extends toward the edge bus bar 306, and the projection length of the first extension portion 331 in the first direction Y is less than L2, which prevents the first extension portion 331 of the first pre-fixed film 33 from completely covering the extended portion of the welding strip 32, thereby ensuring good welding between the welding strip 32 and the edge bus bar 306, and the first extension portion 331 has a good fixing effect on the portion of the welding strip 32 extending out of the edge position of the first battery cell 3101.

[0147] As an embodiment of the present invention, the battery string includes a second battery cell 3102 located at the second end, the second battery cell 3102 is connected to the middle bus bar 308, the distance between the second battery cell 3102 and the middle bus bar 308 is L3, the second extension portion 332 of the first pre-fixed film 33 of the second battery cell 3102 extends toward the middle bus bar 308, and the projection length of the second extension portion 332 in the first direction Y is less than L3.

[0148] In this embodiment, the spacing between the second battery cell 3102 and the intermediate bus bar 308 connected to it is L3, and the projection length of the first extension portion 331 of the first pre-fixed film 33 on the second battery cell 3102 in the first direction Y is less than L3, which prevents the second extension portion 332 of the first pre-fixed film 33 on the second battery cell 3102 from completely covering the protruding portion of the welding ribbon 32, thereby ensuring good welding between the protruding portion of the welding ribbon 32 at the second end of the battery string and the intermediate bus bar 308. At the same time, the second extension portion 332 has a good fixing effect on the portion of the welding ribbon 32 extending out of the edge position of the second battery cell 3102.

[0149] Please refer to Fig. 22 The battery assembly includes at least two battery strings arranged in sequence along the second direction X, and the sum of the projection lengths of the third extension portion 333 and the fourth extension portion 334 along the second direction X is less than the spacing between the two battery strings arranged along the second direction X. The third extension portion 333 and the fourth extension portion 334 can be used to increase the fixing effect of the first pre-fixing film 33, and the first pre-fixing films 33 on two adjacent battery strings along the second direction X are not overlapped, which is beneficial to reducing the cost of the first pre-fixing film 33.

[0150] Among them, the distance between the first battery string 301 and the second battery string 302 in each battery string unit 30 is L4, the fourth extension portion 334 of the first pre-fixed film 33 on the first battery string 301 and the third extension portion 333 of the first pre-fixed film 33 on the second battery string 302 are arranged adjacent to each other, and the projection length of the fourth extension portion 334 of the first pre-fixed film 33 on the first battery string 301 and the third extension portion 333 of the first pre-fixed film 33 on the second battery string 302 along the second direction X is less than L4 / 2.

[0151] In this embodiment, the projection lengths of the fourth extension 334 of the first pre-fixed film 33 on the first battery string 301 and the third extension 333 of the first pre-fixed film 33 on the second battery string 302 along the second direction X are controlled to be less than L4 / 2, which can not only increase the fixing effect of the first pre-fixed film 33, but also prevent the first pre-fixed film 33 on the battery cell 31 of the first battery string 301 from overlapping with the first pre-fixed film 33 on the battery cell 31 of the second battery string 302, thereby reducing the cost of the first pre-fixed film 33.

[0152] Embodiment 11 The embodiment of the present invention further provides a photovoltaic system, which includes the solar cell assembly of the above embodiment. It should be noted that the photovoltaic system and the above solar cell assembly have the same or similar beneficial effects, and the relevant parts between the two can be referenced to each other. In order to avoid repetition, they will not be described here.

[0153] In this embodiment, the photovoltaic system can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple solar photovoltaic components. For example, multiple solar photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0154] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0155] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solar cell module, characterized in that: It comprises a first cover plate, a first adhesive film, at least one battery string, a second adhesive film and a second cover plate which are stacked in sequence, wherein the battery string comprises: A plurality of battery cells are arranged at intervals along a first direction, wherein the battery cells include a first surface and a second surface that are arranged opposite to each other; a plurality of welding strips, two adjacent battery cells are connected by the welding strips, the welding strips are extended along the first direction, a plurality of the welding strips are spaced apart along a second direction, the second direction intersects the first direction, and the welding strips include a first welding portion disposed on the first surface; and A plurality of first pre-fixing films, each of which is arranged on the corresponding battery cell, the first pre-fixing film is arranged on the first welding portion and fixedly connected to the first surface, and the second adhesive film covers the first pre-fixing film; the first pre-fixing film includes a main body covering the first surface, and at least one extension portion connected to the main body and extending to the outside of the edge of the battery cell, the extension portion is connected to the first adhesive film and the second adhesive film, and the battery string has at least two adjacent extension portions of the first pre-fixing films overlapping and connected in the thickness direction of the battery cell.

2. The solar cell assembly according to claim 1, characterized in that: The battery sheet includes a first battery edge and a second battery edge arranged opposite to each other along the first direction; The extension portion includes a first extension portion and a second extension portion, the first extension portion and the second extension portion are respectively arranged at opposite ends of the main body along the first direction, the first extension portion covers the edge of the first battery and extends to the outside of the edge of the first battery, the second extension portion covers the edge of the second battery and extends to the outside of the edge of the second battery, and the first extension portion of the first pre-fixed film is overlapped and connected with the second extension portion of the adjacent first pre-fixed film.

3. The solar cell assembly according to claim 2, characterized in that: The distance between two adjacent battery cells in the battery string is L1, the projection length of the first extension portion in the first direction is S1, the projection length of the second extension portion in the first direction is S2, and the sum of S1 and S2 is greater than L1.

4. The solar cell assembly according to claim 3, characterized in that: Both the S1 and the S2 are greater than L1 / 2, and both the S1 and the S2 are smaller than L1.

5. The solar cell assembly according to claim 1, characterized in that: The extension parts of the first pre-fixing films on two adjacent battery cells are overlapped and connected to form a first overlapping part, and the thickness of the first overlapping part is greater than the thickness of the main body part.

6. The solar cell assembly according to claim 5, characterized in that: A projected length of the first overlapping portion in the first direction is smaller than a distance between two adjacent battery cells in the battery string.

7. The solar cell assembly according to claim 5, characterized in that: The first overlapping portion is provided with a cavity structure.

8. The solar cell assembly according to claim 2, characterized in that: The battery string includes a first battery cell located at a first end thereof, the first battery cell is connected to an edge bus bar, the distance between the first battery cell and the edge bus bar is L2, the first extension portion of the first pre-fixed film on the first battery cell extends toward the edge bus bar, and the projection length of the first extension portion of the first pre-fixed film on the first battery cell in the first direction is less than L2.

9. The solar cell assembly according to claim 8, characterized in that: The battery string includes a second battery cell located at its second end, the second battery cell is connected to an intermediate bus bar, the distance between the second battery cell and the intermediate bus bar is L3, the second extension portion of the first pre-fixed film on the second battery cell extends toward the intermediate bus bar, and the projection length of the second extension portion of the first pre-fixed film on the second battery cell in the first direction is less than L3.

10. The solar cell assembly according to claim 2, characterized in that: The battery cell includes a third battery edge and a fourth battery edge arranged opposite to each other along the second direction; the extension portion includes a third extension portion and a fourth extension portion, the third extension portion and the fourth extension portion are respectively connected to the opposite ends of the main body portion along the second direction, the third extension portion covers the third battery edge and extends to the outside of the third battery edge, and the fourth extension portion covers the fourth battery edge and extends to the outside of the fourth battery edge.

11. The solar cell assembly according to claim 10, characterized in that: Projection lengths of the third extension portion and the fourth extension portion in the second direction are both smaller than projection lengths of the first extension portion and the second extension portion in the first direction.

12. The solar cell assembly according to claim 1, characterized in that: The battery cell comprises a first grid line and a second grid line arranged on the first surface, the first grid line and the second grid line are arranged at intervals along the first direction, and the first grid line and the second grid line have opposite polarities; The welding strip includes two first welding portions and a connecting portion connecting the two first welding portions, one first welding portion is connected to the first grid line on one of the battery cells, and the other first welding portion is connected to the second grid line on another of the battery cells.

13. The solar cell assembly according to claim 1, characterized in that: The first pre-fixed film includes at least one of a PVB film, an EVA film, an EPE film, an EP film, and a POE film.

14. A photovoltaic system, characterized in that: Comprising a solar cell assembly as described in any one of claims 1 to 13.

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