A solar cell module and a photovoltaic system

Abstract

The present invention is applicable to the technical field of solar cell, and provides a solar cell module and a photovoltaic system. The solar cell module includes a first cover plate, a first encapsulant film, a cell string, a second encapsulant film and a second cover plate. The cell string includes: a plurality of solar cells, each solar cell including a first surface, a second surface and a side surface; a plurality of solder ribbons, adjacent two solar cells being connected by the solder ribbons, the solder ribbons including a first welding portion disposed on the first surface; a plurality of first pre-fixing films, each first pre-fixing film including a main body portion and at least one extension portion connected to the main body portion and extending outside the edge of the solar cell, the extension portion being bent relative to the main body portion towards the plane where the second surface is located, the extension portion being connected to the first encapsulant film and the second encapsulant film, and the first encapsulant film including a filling portion located between the side surface and the extension portion. The solar cell module of the present invention can improve the fixing effect of the first pre-fixing film on the solder ribbons and improve the reliability of the solar cell module.

Description

Technical Field

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

[0002] A solar cell is a semiconductor device that can convert solar energy into electrical energy. Under illumination conditions, a photocurrent is generated inside the solar cell, and electrical energy is output through electrodes. In recent years, the production technology of solar cells has been continuously improved, the production cost has been continuously reduced, the conversion efficiency has been continuously increased, and 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 paste cost of solar cells, main-grid-free cell wafers have emerged on the market, that is, fine grid lines are printed on the cell wafers. When the cell wafers are assembled into a solar cell module, the fine grid lines of the cell wafers are directly connected by solder tapes. A pre-fixing film is provided on the cell wafer, and the pre-fixing film is heated to melt and bond to the surface of the cell wafer, so as to fix the solder tape on the cell wafer, and the connection between the cell wafers forms a battery string. However, after laminating to form a solar cell module, the pre-fixing film does not extend beyond the edge of the cell wafer, resulting in unstable fixation of the pre-fixing film, and thus unstable fixation of the solder tape, affecting the reliability of the solar cell module. Summary of the Invention

[0004] The present invention provides a solar cell module, aiming to solve the problem that in the prior art, the pre-fixing film of the solar cell module is not stably fixed, resulting in unstable fixation of the solder tape and affecting the reliability of the solar cell module.

[0005] The present invention is implemented as follows. A solar cell module is provided, which includes a first cover plate, a first encapsulant film, at least one battery string, a second encapsulant film, and a second cover plate that are sequentially stacked. The battery string includes:

[0006] A plurality of cell wafers spaced along a first direction. The cell wafer includes a first surface and a second surface arranged oppositely, and a side surface connecting the first surface and the second surface;

[0007] A plurality of solder tapes. Adjacent two of the cell wafers are connected by the solder tape. The solder tape extends along the first direction. A plurality of the solder tapes are spaced along a second direction. The second direction intersects the first direction. The solder tape includes a first welding portion disposed on the first surface; and

[0008] A plurality of first pre-fixing films, each of the first pre-fixing films is disposed on a corresponding solar cell, the first pre-fixing film is disposed 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 portion covering the first surface, and at least one extension portion connected to the main body portion and extending outside the edge of the solar cell, the extension portion is bent relative to the main body portion in a direction close to the plane where the second surface is located, the extension portion is connected to the first adhesive film and the second adhesive film, and the first adhesive film includes a filling portion located between the side surface and the extension portion, and the filling portion surrounds at least a part of the region of the side surface.

[0009] Preferably, the solar cell includes a first grid line and a second grid line disposed on the first surface, the first grid line and the second grid line are spaced apart along the first direction, and the polarities of the first grid line and the second grid line are opposite;

[0010] The solder ribbon 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 solar cell, and the other first welding portion is connected to the second grid line on the other solar cell.

[0011] Preferably, the solar cell includes a first grid line disposed on the first surface and a second grid line disposed on the second surface, and the polarities of the first grid line and the second grid line are opposite;

[0012] The solder ribbon further includes a second welding portion and a connecting portion, the connecting portion connects the first welding portion and the second welding portion, the first welding portion is connected to the first grid line on one solar cell, and the second welding portion is connected to the second grid line on the other solar cell.

[0013] Preferably, the solar cell includes a first cell edge and a second cell edge disposed opposite to each other along the first direction;

[0014] The extension portion includes a first extension portion and a second extension portion, the first extension portion and the second extension portion are respectively disposed at opposite ends of the main body portion along the first direction, the first extension portion covers the first cell edge and extends outside the first cell edge, and the second extension portion covers the second cell edge and extends outside the second cell edge.

[0015] Preferably, the cell includes a third cell edge and a fourth cell edge that are oppositely disposed along the second direction; the epitaxial portion includes a third epitaxial portion and a fourth epitaxial portion, the third epitaxial portion and the fourth epitaxial portion are respectively connected to opposite ends of the main body portion along the second direction, the third epitaxial portion covers the third cell edge and extends to the outside of the third cell edge, and the fourth epitaxial portion covers the fourth cell edge and extends to the outside of the fourth cell edge.

[0016] Preferably, the epitaxial portion includes:

[0017] A first extension portion connected to the main body portion, and the first extension portion is bent relative to the main body portion toward the plane where the second surface is located.

[0018] Preferably, the epitaxial portion further includes:

[0019] A second extension portion connected to the first extension portion, the second extension portion extends away from the cell from the first extension portion, and the second extension portion is connected between the first adhesive film and the second adhesive film.

[0020] Preferably, the second extension portion and the first extension portion are disposed at an angle to each other.

[0021] Preferably, the epitaxial portion surrounds a partial area of the side surface.

[0022] Preferably, the side surface includes a first side surface connecting the first surface and the second surface and located on the side where the first cell edge is located, and a second side surface connecting the first surface and the second surface and located on the side where the second cell edge is located. The first epitaxial portion surrounds a partial area of the first side surface, and the second epitaxial portion surrounds a partial area of the second side surface.

[0023] Preferably, the first extension portion includes an upper surface disposed away from the plane where the second surface is located. The upper surface includes a first end close to the cell and a second end away from the cell. The perpendicular distance from the first end of the upper surface to the plane where the second surface is located is greater than the perpendicular distance from the second end of the upper surface to the plane where the second surface is located.

[0024] Preferably, the perpendicular distance from the upper surface to the plane where the second surface is located gradually decreases from the first end to the second end.

[0025] Preferably, the upper surface of the first extension portion is an inclined surface or a curved surface.

[0026] Preferably, the angle between the inclined surface and the plane where the second surface is located is 10 to 80°.

[0027] Preferably, at least a partial region of the outer extension portion is provided with a cavity structure.

[0028] Preferably, the thickness of the main body portion is less than the thickness of the battery cell.

[0029] Preferably, the first pre-fixing film further comprises:

[0030] A convex structure protruding on the outer extension portion, and the convex structure is connected to the first adhesive film and / or the second adhesive film.

[0031] Preferably, the convex structure is disposed on the surface of the outer extension portion close to the second adhesive film, and the convex structure is embedded in the second adhesive film.

[0032] Preferably, the convex structure is disposed on the surface of the outer extension portion close to the first adhesive film, and the convex structure is embedded in the first adhesive film.

[0033] Preferably, the convex structure is simultaneously disposed on the surface of the outer extension portion close to the second adhesive film and the surface of the outer extension portion close to the first adhesive film. The convex structure on the surface of the outer extension portion close to the second adhesive film is embedded in the second adhesive film, and the convex structure on the surface of the outer extension portion close to the first adhesive film is embedded in the first adhesive film.

[0034] The present invention also provides a photovoltaic system, including the above-mentioned solar cell module.

[0035] A solar cell module provided by the present invention fixes a solder ribbon on a first surface by arranging a first pre-fixing film on the first surface of a cell. The first pre-fixing film is arranged to include a main body portion and an extension portion connected to the main body portion and extending outside the cell. On the premise that the first pre-fixing film is fixedly connected to the first surface by using the main body portion, the extension portion is simultaneously connected to a first encapsulant film, increasing the fixing area of the first pre-fixing film and making the first pre-fixing film more stable, thereby improving the fixing effect of the first pre-fixing film on the solder ribbon. Moreover, the extension portion is bent towards the plane where the second surface is located relative to the main body portion, so that the extension portion forms a limiting fit with the cell, which is beneficial to increasing the bonding force between the extension portion and the cell, and the cell can block the movement of the extension portion. At the same time, the bent extension portion also forms a limiting fit with the first encapsulant film and a second encapsulant film, which is beneficial to increasing the bonding force between the extension portion and the first encapsulant film and the second encapsulant film, and can well prevent the first pre-fixing film from loosening, greatly improving the fixing reliability of the first pre-fixing film, and further improving the fixing effect of the first pre-fixing film on the solder ribbon. In addition, the first encapsulant film is provided with a filling portion located between the side surface of the cell and the extension portion. The filling portion of the first encapsulant film has a buffering effect on the extension portion of the first pre-fixing film, which can avoid breaking of the extension portion, improve the structural reliability of the first pre-fixing film, and further improve the structural reliability of the solar cell module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a plan view of a solar cell module provided by an embodiment of the present invention;

[0037] Figure 2 is a plan view of a cell string of a solar cell module provided by an embodiment of the present invention;

[0038] Figure 3 is a partial structure plan view of a solar cell module provided by an embodiment of the present invention;

[0039] Figure 4 is a plan view of a single cell of a cell string of a solar cell module provided by an embodiment of the present invention connecting a solder ribbon;

[0040] Figure 5 is a cross-sectional view of adjacent two cells of a cell string of a solar cell module provided by an embodiment of the present invention connecting a solder ribbon;

[0041] Figure 6 is a cross-sectional view of a solar cell module provided by an embodiment of the present invention along a first direction;

[0042] Figure 7 is another cross-sectional view of a solar cell module provided by an embodiment of the present invention along a first direction;

[0043] Figure 8 A schematic cross-sectional view of a solar cell module provided by an embodiment of the present invention in a second direction;

[0044] Figure 9 A schematic plan view of a solar cell module provided by an embodiment of the present invention after a cell is covered with a first pre-fixing film;

[0045] Figure 10 A schematic cross-sectional view of a first solar cell module provided by an embodiment of the present invention;

[0046] Figure 11 A schematic cross-sectional view of a second solar cell module provided by an embodiment of the present invention;

[0047] Figure 12 A schematic cross-sectional view of another solar cell module provided by an embodiment of the present invention;

[0048] Figure 13 A schematic plan view of a single cell of another solar cell module provided by an embodiment of the present invention connected to a welding strip;

[0049] Figure 14 Another schematic plan view of a single cell of another solar cell module provided by an embodiment of the present invention connected to a welding strip;

[0050] Figure 15 A schematic cross-sectional view of adjacent cells of another solar cell module provided by an embodiment of the present invention connected to a welding strip;

[0051] Figure 16 A schematic cross-sectional view of another solar cell module provided by an embodiment of the present invention;

[0052] Figure 17 Another schematic cross-sectional view of another solar cell module provided by an embodiment of the present invention;

[0053] Figure 18 A schematic cross-sectional view of yet another solar cell module provided by an embodiment of the present invention;

[0054] Figure 19 Another schematic cross-sectional view of yet another solar cell module provided by an embodiment of the present invention;

[0055] Figure 20 Another schematic plan view of a solar cell module provided by an embodiment of the present invention. Detailed implementation manners

[0056] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as a limitation to 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.

[0057] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "back", "front", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is 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 should not be construed as a limitation to the present invention.

[0058] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the first feature has a lower horizontal height than the second feature.

[0059] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. This 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.

[0060] An embodiment of the present invention provides a solar cell module. By providing a first pre-fixing film on the first surface of the cell, the first welding portion of the solder ribbon is fixed on the first surface by using the first pre-fixing film. The first pre-fixing film is configured to include a main body portion and an extension portion connected to the main body portion and extending outside the cell. On the premise that the first pre-fixing film is fixedly connected to the first surface by using the main body portion, the extension portion is simultaneously connected to the first encapsulant film, increasing the fixing area of the first pre-fixing film and making the fixing of the first pre-fixing film more stable. Moreover, the extension portion is bent relative to the main body portion in a direction close to the plane where the second surface is located, so that the extension portion forms a limiting fit with the cell, which is beneficial to increasing the bonding force between the extension portion and the cell. And the bent extension portion forms a limiting fit with the first encapsulant film and the second encapsulant film, which is beneficial to increasing the bonding force between the extension portion and the first encapsulant film and the second encapsulant film, and can well prevent the first pre-fixing film from loosening, greatly improving the fixing reliability of the first pre-fixing film, and further improving the fixing effect of the first pre-fixing film on the solder ribbon.

[0061] Embodiment 1

[0062] Please refer to Figures 1 - 10 , an embodiment of the present invention provides a solar cell module, including a first cover plate 1, a first encapsulant film 2, at least one cell string, a second encapsulant film 4, and a second cover plate 5 that are sequentially stacked. The cell string includes:

[0063] A plurality of cells 31 sequentially arranged at intervals along the first direction Y. The cell 31 includes a first surface 315 and a second surface 316 that are oppositely arranged, and a side surface 319 connecting the first surface 315 and the second surface 316;

[0064] A plurality of solder ribbons 32. Adjacent two cells 31 are connected by the solder ribbons 32. The solder ribbons 32 extend along the first direction Y. The plurality of solder ribbons 32 are arranged at intervals along the second direction X. The second direction X intersects the first direction Y. The solder ribbon 32 includes a first welding portion 321 disposed on the first surface 315; and

[0065] A plurality of first pre-fixing films 33. Each first pre-fixing film 33 is disposed on the corresponding cell 31. Each first pre-fixing film 33 is disposed on the first welding portion 321 and fixedly connected to the first surface 315. The second encapsulant film 4 covers the first pre-fixing film 33. The first pre-fixing film 33 includes a main body portion 336 covering the first surface 315 and at least one extension portion 330 connected to the main body portion 336 and extending outside the edge of the cell 31. The extension portion 330 is bent relative to the main body portion 336 in a direction close to the plane where the second surface 316 is located, and the extension portion 330 is connected to the first encapsulant film 2 and the second encapsulant film 4. The first encapsulant film 2 includes a filling portion 21 located between the side surface 319 and the extension portion 330, and the filling portion 21 surrounds at least a partial area of the side surface 319.

[0066] In an embodiment of the present invention, the solar cell module includes at least one battery string. When the solar cell module includes a plurality of battery strings, the plurality of battery strings can be arranged in multiple rows and multiple columns. The solar cells 31 within each battery string are connected in series by solder tapes 32. The different battery strings can be connected in series or in parallel through busbars to achieve current collection and output. The plurality of battery strings can form a solar cell array and are encapsulated together with a first cover plate 1, a first encapsulant film 2, a second encapsulant film 4, and a second cover plate 5 to form a solar cell module.

[0067] As Figure 1 shown, as an embodiment of the present invention, the solar cell module includes at least one battery string unit 30, and each battery string unit 30 includes:

[0068] a first battery string 301 and a second battery string 302 that are spaced apart along a second direction X;

[0069] a third battery string 303 and a fourth battery string 304 that are spaced apart along the second direction X. The first battery string 301 and the third battery string 303 are arranged along a first direction Y, and the second battery string 302 and the fourth battery string 304 are arranged along the first direction Y.

[0070] Wherein, 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 an 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 an adjacent battery string unit 30.

[0071] Specifically, one end of the first battery string 301 and the second battery string 302 of each battery string unit 30 is connected in series through an edge busbar 306, and the third battery string 303 and the fourth battery string 304 are also connected in series through an edge busbar 306. The first battery string 301 and the third battery string 303 are connected in parallel through an intermediate busbar 308, and the second battery string 302 and the fourth battery string 304 are connected in parallel through an intermediate busbar 308. The second battery string 302 of the battery string unit 30 is connected in series with the first battery string 301 of an adjacent battery string unit 30 through the intermediate busbar 308 as well. The fourth battery string 304 of each battery string unit 30 is connected in series with the third battery string 303 of an adjacent battery string unit 30 through the intermediate busbar 308 as well. Of course, other connection methods can also be used to achieve the series and parallel connections between the battery strings.

[0072] Wherein, Figure 1Only three battery string units 30 are schematically shown, and the battery string units 30 are arranged at intervals in sequence along the second direction X. Each battery string unit 30 includes the above-mentioned first battery string 301, second battery string 302, third battery string 303, and fourth battery string 304.

[0073] In an embodiment of the present invention, a provided solar cell module fixes a welding tape 32 on a first surface 315 by arranging a first pre-fixing film 33 on the first surface 315 of a battery chip 31 of a battery string, and the welding tape 32 does not need to be fixed on the first surface 315 by a welding process; meanwhile, the first pre-fixing film 33 is arranged to include a main body portion 336 and an extension portion 330 connected to and extending outside the battery chip 31. On the premise that the first pre-fixing film 33 is fixedly connected to the first surface 315 by using the main body portion 336, the extension portion 330 is simultaneously connected to the first adhesive film 2, 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 tape 32, and by connecting the extension portion 330 to the first adhesive film 2, the pre-fixing effect of the first pre-fixing film 33 on the welding tape 32 before lamination can be improved.

[0074] Meanwhile, the extension portion 330 is bent relative to the main body portion 336 in a direction close to the plane of the second surface 316. The bent extension portion 330 forms a limiting and matching structure with the battery chip 31, which can well prevent the first pre-fixing film 33 from loosening and shifting, so that the first pre-fixing film 33 is stably fixed on the battery chip 31. At the same time, the extension portion 330 also forms a limiting and matching structure with the first adhesive film 2 and the second adhesive film 4, which is beneficial to increasing the bonding force between the extension portion 330 and the first adhesive film 2 and the second adhesive film 4, and can well prevent the first pre-fixing film 33 from loosening, greatly improving the fixing reliability of the first pre-fixing film 33 on the welding tape 32.

[0075] Please refer to Figures 9 - 11 , in an embodiment of the present invention, the first adhesive film 2 is provided with a filling portion 21 located between the side surface 319 and the extension portion 330, and the filling portion 21 wraps at least a part of the area of the side surface 319. Since the filling portion 21 is arranged between the side surface 319 and the extension portion 330, the filling portion 21 of the first adhesive film 2 has a buffering effect on the extension portion 330 of the first pre-fixing film 33, which can avoid the bending angle of the extension portion 330 being too large, so that the bending angle of the extension portion 330 relative to the main body portion 336 is less than 90 degrees, which can avoid the extension portion 330 from being broken, improve the structural reliability of the first pre-fixing film 33, and further improve the structural reliability of the solar cell module.

[0076] In an 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 can be a back-contact solar cell or a double-sided contact solar cell. Specifically, when 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 can be an IBC solar cell or an HBC solar cell. When 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 can be a Topcon solar cell.

[0077] In an embodiment of the present invention, both the first cover plate 1 and the second cover plate 5 can 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 is glass, and the other is a backplane, that is, the solar cell module can be a single-glass module.

[0078] In an embodiment of the present invention, each cell string includes a plurality of solder tapes 32, and the specific number of solder tapes 32 in each cell string is not limited, and the specific number of solder tapes 32 can be flexibly set according to actual applications. Specifically, each solder tape 32 extends along the first direction Y, that is, the length direction of the solder tape 32 is the first direction Y, and the solder tapes 32 are arranged at intervals in sequence along the second direction X.

[0079] In an embodiment of the present invention, the main body portion 336 completely covers the first surface 315, that is, the size of the main body portion 336 is the same as the size of the cell 31, so that the first welding portion 321 of the solder tape 32 is fixed on the first surface 315 of the cell 31, and the extension portion 330 extends beyond the cell edge of the cell 31 to be connected to the first adhesive film 2 and the second adhesive film 4.

[0080] In an embodiment of the present invention, the number of the first pre-fixing films 33 is adapted to the number of the cells 31, and one first pre-fixing film 33 is correspondingly arranged on each cell 31, which is convenient for fixing the solder tapes 32 on each cell 31 and is also convenient for performing the film covering process of the first pre-fixing film 33. Each first pre-fixing film 33 forms an extension portion 330 at at least one cell edge of the corresponding cell 31, or an extension portion 330 can be formed at each cell edge of the cell 31. Among them, the extension portion 330 is specifically the part of the first pre-fixing film 33 that extends beyond the edge of the cell 31.

[0081] Please refer to Figures 4 - 9 In an embodiment of the present invention, the cell 31 includes a first cell edge 311 and a second cell edge 312 that are oppositely arranged along the first direction Y, and a third cell edge 313 and a fourth cell edge 314 that are oppositely arranged along the second direction X.

[0082] Among them, the extension part 330 may include a first extension part 331 connected to the main body part 336 and extending along the first direction Y to the outside of the first battery edge 311, a second extension part 332 connected to the main body part 336 and extending along the first direction Y to the outside of the second battery edge 312, a third extension part 333 connected to the main body part 336 and extending along the second direction X to the outside of the third battery edge 313, and a fourth extension part 334 connected to the main body part 336 and extending along the second direction X to the outside of the fourth battery edge 314. Among them, the extension part 330 includes at least one of the first extension part 331, the second extension part 332, the third extension part 333, and the fourth extension part 334.

[0083] Please refer to FIG. 6 - Figure 9 , as an embodiment of the present invention, the battery cell 31 includes a first battery edge 311 and a second battery edge 312 oppositely arranged along the first direction Y;

[0084] The extension part 330 includes a first extension part 331 and a second extension part 332. The first extension part 331 and the second extension part 332 are respectively arranged at opposite ends of the main body part 336 along the first direction Y. The first extension part 331 covers the first battery edge 311 and extends to the outside of the first battery edge 311, and the second extension part 332 covers the second battery edge 312 and extends to the outside of the second battery edge 312.

[0085] In this embodiment, the welding ribbon 32 extends along the first direction Y. At least a part of the welding ribbons 32 extend to the outside of the first battery edge 311, and at least a part of the welding ribbons 32 extend along the first direction Y to the outside of the second battery edge 312. The first extension part 331 is used to cover the position of the first battery edge 311 of the welding ribbon 32 extending to the outside of the first battery edge 311, and the first extension part 331 wraps around the position of the first battery edge 311 of the welding ribbon 32, so that the welding ribbon 32 is not prone to position deviation at the position of the first battery edge 311; at the same time, the second extension part 332 is used to cover the position of the second battery edge 312 of the welding ribbon 32 extending to the outside of the second battery edge 312, and the second extension part 332 wraps around the position of the second battery edge 312 of the welding ribbon 32, so that the welding ribbon 32 is not prone to position deviation at the position of the second battery edge 312, which can greatly improve the fixing stability of the welding ribbon 32 at the positions of the first battery edge 311 and the second battery edge 312, and further improve the structural reliability of the solar cell module. Moreover, at least a part of the area where the welding ribbon 32 extends beyond the first battery edge 311 is covered and fixed by the first extension part 331, and at least a part of the area where the welding ribbon 32 extends beyond the second battery edge 312 is covered and fixed by the second extension part 332, avoiding the loosening of the welding ribbon 32 at the positions of the first battery edge 311 and the second battery edge 312, thereby improving the fixing effect of the welding ribbon 32 at the positions of the first battery edge 311 and the second battery edge 312.

[0086] As an embodiment of the present invention, the cell 31 further includes a third cell edge 313 and a fourth cell edge 314 disposed opposite to each other along the second direction X; the epitaxial portion 330 includes a third epitaxial portion 333 and a fourth epitaxial portion 334, and the third epitaxial portion 333 and the fourth epitaxial portion 334 are respectively connected to opposite ends of the main body portion 336 along the second direction X. The third epitaxial portion 333 covers the third cell edge 313 and extends to the outside of the third cell edge 313, and the fourth epitaxial portion 334 covers the fourth cell edge 314 and extends to the outside of the fourth cell edge 314.

[0087] In this embodiment, the first pre-fixing film 33 is respectively connected to the first adhesive film 2 and the second adhesive film 4 by using the third epitaxial portion 333 and the fourth epitaxial portion 334 distributed along the second direction X. The bent third epitaxial portion 333 and the fourth epitaxial portion 334 form a limiting and fitting structure with the cell 31, and at the same time, the first pre-fixing film 33 is limited and fixed in the first direction Y and the second direction X, which can further improve the fixing effect of the first pre-fixing film 33, further improve the fixing stability of the solder strip 32, and improve the reliability of the solar cell module.

[0088] Among them, the structures of the epitaxial portions 330 are the same, that is, the structures of the first epitaxial portion 331, the second epitaxial portion 332, the third epitaxial portion 333 and the fourth epitaxial portion 334 are the same; of course, in some possible embodiments, the structures of the epitaxial portions 330 may also be different.

[0089] 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.

[0090] Among them, the first pre-fixing film 33 may be one of a PVB film, an EVA film, an EPE film, an EP film and a POE film, or may be a laminate of at least two of a PVB film, an EVA film, an EPE film, an EP film and a 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).

[0091] In this embodiment, the first adhesive film 2 and the second adhesive film 4 include at least one of a PVB film, an EVA film, an EPE film, an EP film and a POE film. In addition, the material of the first pre-fixing film 33 may be the same as or different from the materials of the first adhesive film 2 and the second adhesive film 4.

[0092] As an embodiment of the present invention, the spacing L1 between adjacent solar cells 31 of the solar cell string is 0.3 to 0.6 mm. The distance from the edge of the first pre-fixing film 33 to the edge of the solar cell 31 is 0.3 to 0.6 mm, which can not only achieve good fixation of the first pre-fixing film 33, but also help reduce the material cost.

[0093] As an embodiment of the present invention, the thickness of the first pre-fixing film 33 is 5 to 150 μm, which can not only achieve good fixation of the first pre-fixing film 33, but also maintain good optical performance of the solar cell 31.

[0094] Embodiment 2

[0095] Please refer to Figures 3 - 5 , as an embodiment of the present invention, the solar cell 31 includes a first grid line 317 and a second grid line 318 disposed on the first surface 315. The first grid line 317 and the second grid line 318 are spaced apart along the first direction Y, and the polarities of the first grid line 317 and the second grid line 318 are opposite;

[0096] The welding ribbon 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 the first grid line 317 on one solar cell 31, and the other first welding portion 321 is connected to the second grid line 318 on another solar cell 31.

[0097] In this embodiment, the solar cell 31 is a back-contact solar cell, the first surface 315 is the backlight surface of the solar cell 31, and grid lines are only disposed on the first surface 315 of the solar cell 31. The numbers of the first grid line 317 and the second grid line 318 are both multiple, and the first grid line 317 and the second grid line 318 are alternately disposed on the first surface 315. Among them, one of the first grid line 317 and the second grid line 318 is a positive grid line, and the other is a negative grid line.

[0098] In this embodiment, one first welding portion 321 of the welding ribbon 32 is connected to the corresponding first grid line 317 on one solar cell 31, and the other first welding portion 321 of the welding ribbon 32 is connected to the corresponding second grid line 318 on the adjacent solar cell 31, realizing the series connection of adjacent solar cells 31.

[0099] As an embodiment of the present invention, the welding ribbon 32 is disposed crosswise with the first grid line 317 and the second grid line 318 and is connected to the first grid line 317 or the second grid line 318.

[0100] In this embodiment, the welding ribbon 32 intersects with the first grid line 317 and the second grid line 318. Specifically, the second direction X is perpendicular to the first direction Y. The first grid line 317 and the second grid line 318 are arranged in parallel at intervals along the first direction Y, that is, the welding ribbon 32 is arranged perpendicular to the first grid line 317 and the second grid line 318. Of course, in other possible embodiments, the welding ribbon 32 may not be perpendicular to the first grid line 317 and the second grid line 318, as long as it is ensured that the welding ribbon 32 intersects with the first grid line 317 and the second grid line 318.

[0101] As Figure 4 shown, in this embodiment, an insulating layer 310 is provided between the welding ribbon 32 connected to the first grid line 317 and the second grid line 318 on each cell 31, and an insulating layer 310 is also provided between the welding ribbon 32 connected to the second grid line 318 and the first grid line 317 on each cell 31, so as to keep good insulation between the welding ribbon 32 connected to the first grid line 317 and the second grid line 318 on the cell 31, and keep good insulation between the welding ribbon 32 connected to the second grid line 318 and the first grid line 317 on the cell 31.

[0102] In this embodiment, the welding ribbon 32 is sequentially placed on the first surface 315. The first welding portion 321 of the welding ribbon 32 contacts the corresponding first grid line 317, and the welding ribbon 32 is fixed on the first surface 315 by using the first pre-fixing film 33, so as to realize the fixation of the welding ribbon 32 and realize the electrical connection between the welding ribbon 32 and the corresponding grid line. Of course, in some other embodiments, the cell 31 may not be provided with grid lines, and the welding ribbon 32 may directly contact the doped polysilicon layer on the cell 31 to realize current collection.

[0103] Embodiment III

[0104] Please refer to Figures 9 - 11 , as an embodiment of the present invention, the epitaxial portion 330 includes:

[0105] A first extension portion 3311 connected to the main body portion 336, and the first extension portion 3311 is bent relative to the main body portion 336 toward the plane where the second surface 316 is located.

[0106] In this embodiment, each extension part 330 is bent from the edge of the battery cell 31 towards the plane where the second surface 316 is located to form a first extension part 3311, and the first extension part 3311 is used to cover the edge position of the battery cell 31. The first extension part 3311 includes a first part 3315 above the plane G where the first surface 315 is located and a second part 3316 below the plane G where the first surface 315 is located. It can be understood that the first extension part 3311 is divided into the first part 3315 and the second part 3316 by the plane G where the first surface 315 is located. The first part 3315 of the first extension part 3311 is the part of the first extension part 3311 above the plane G where the first surface 315 is located, and the second part 3316 of the first extension part 3311 is the part of the first extension part 3311 below the plane G where the first surface 315 is located, that is, part of the first extension part 3311 is above the plane G where the first surface 315 is located, and part of the first extension part 3311 is below the plane G where the first surface 315 is located, so that the first extension part 3311 can better restrict the movement of the first pre-fixing film 33, and can increase the bonding force between the extension part 330 and the first adhesive film 2 and the second adhesive film 4, and can further improve the fixing effect of the first pre-fixing film 33 on the welding tape 32.

[0107] Please refer to Figure 10 , as an embodiment of the present invention, the first extension part 3311 includes an upper surface 3310 arranged away from the second surface 316. The upper surface 3310 includes a first end close to the battery cell 31 and a second end far from the battery cell 31. 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.

[0108] In this embodiment, since the first extension part 3311 is bent towards the plane where the second surface 316 is located, and 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 part 3311 and the main body part 336 are located in different planes, and the first extension part 3311 is inclined relative to the second surface 316, which is beneficial to increasing the total length design of the extension part 330, thereby increasing the bonding area between the extension part 330 and the first adhesive film 2 and the second adhesive film 4, and improving the adhesion of the extension part 330.

[0109] 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 direction.

[0110] In this embodiment, in the direction from the first end to the second end, the vertical distance from the upper surface 3310 to the plane where the second surface 316 is located gradually decreases in the direction from the first end to the second end, which is conducive to increasing the length of the extension portion 330 and enhancing the fixing effect between the extension portion 330, the first adhesive film 2, and the second adhesive film 4.

[0111] 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.

[0112] In this embodiment, the upper surface 3310 of the first extension portion 3311 can be an inclined surface or a curved surface, which is convenient for the processing and forming 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 can also be a wavy surface, that is, the upper surface 3310 of the first extension portion 3311 is a surface with concave and convex connections, 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 enhancing the fixing effect of the first pre-fixing film 33.

[0113] As an embodiment of the present invention, the upper surface 3310 of the first extension portion 3311 is an inclined surface, and the angle C between the inclined surface and the plane where the second surface 316 is located is 10° to 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 within the range of 10° to 80°, which can not only improve the fixing effect of the first extension portion 3311 but also prevent the first extension portion 3311 from being bent at too large an angle, making the first extension portion 3311 not easily break and enhancing the structural reliability of the first pre-fixing film 33. For example, the angle between the inclined surface and the plane where the second surface 316 is located can be any value among 10°, 20°, 30°, 40°, 50°, 60°, 70°, and 80°. In addition, 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 also be other angles, as long as 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 an acute angle.

[0114] 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 connection line between the first end and the second end of the upper surface 3310 and the plane where the second surface 316 is located is 10° to 80 degrees, which can also increase the fixing effect of the first pre-fixing film 33, ensure the good fixing performance of the first pre-fixing film 33, and prevent the extension portion 330 from being easily broken, ensuring the good structural strength of the first pre-fixing film 33.

[0115] Please refer to Figure 9 and Figure 11, as an embodiment of the present invention, the outer extension portion 330 wraps around a partial area of the side surface 319, which can increase the adhesion between the first pre-fixing film 33 and the battery cell 31, make the fixing of the first pre-fixing film 33 more stable, and prevent the position deviation of the welding tape 32.

[0116] As an embodiment of the present invention, the side surface 319 includes a first side surface 3191 that connects the first surface 315 and the second surface 316 and is located on the side where the first battery edge 311 is located, and the first outer extension portion 331 wraps around a partial area of the first side surface 3191 of the battery cell 31.

[0117] In this embodiment, the first outer extension portion 331 of the first pre-fixing film 33 wraps around a partial area of the first side surface 3191 of the battery cell 31, which can increase the adhesion of the first pre-fixing film 33, make the fixing of the first pre-fixing film 33 more stable, and prevent the position deviation of the welding tape 32; moreover, a filling portion 21 is provided between the first side surface 3191 and the first outer extension portion 331, and the filling portion 21 plays a buffering role for the first outer extension portion 331, which can avoid too large a bending angle of the first outer extension portion 331 and avoid breakage of the first outer extension portion 331.

[0118] As an embodiment of the present invention, the battery cell 31 includes a second side surface 3192 that connects the first surface 315 and the second surface 316 and is located on the side where the second battery edge 312 is located, and the second outer extension portion 332 wraps around a partial area 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 and improve the fixing effect of the first pre-fixing film 33; moreover, a filling portion 21 is provided between the second side surface 3192 and the second outer extension portion 332, and the filling portion 21 plays a buffering role for the second outer extension portion 332, which can avoid too large a bending angle of the second outer extension portion 332 and avoid breakage of the second outer extension portion 332.

[0119] Please refer to Figure 8 and Figure 10, the side surface 319 further includes a third side surface 3193 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 3194 connecting the first surface 315 and the second surface 316 and located on the side where the fourth battery edge 314 is located. A filling portion 21 is provided between the third side surface 3193 and the third extension portion 333, and a filling portion 21 is provided between the fourth side surface 3194 and the fourth extension portion 334, which can prevent the bending angles of the third extension portion 333 and the fourth extension portion 334 from being too large and avoid breakage of the third extension portion 333 and the fourth extension portion 334. The third extension portion 333 can wrap around a partial area of the third side surface 3193 of the battery cell 31, and the fourth extension portion 334 can wrap around a partial area of the fourth side surface 3194 of the battery cell 31 to further improve the fixing effect of the first pre-fixing film 33.

[0120] Please refer to Figure 11 , the first extension portion 331 only partially wraps around a partial area of the first side surface 3191. On the one hand, it can increase the adhesion between the first pre-fixing film 33 and the battery cell 31 and improve the fixing effect of the first pre-fixing film 33. On the other hand, it can prevent the bending angle of the first extension portion 331 from being too large, prevent breakage of the first extension portion 331, and improve the structural stability of the first extension portion 331.

[0121] Specifically, the first extension portion 331 does not completely cover the first side surface 3191 of the battery cell 31. The filling portion 21 of the first adhesive film 2 wraps around a partial area 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-fixing film 33. At the same time, the filling portion 21 has a buffering effect on the first extension portion 331 of the first pre-fixing film 33, which can avoid breakage of the first extension portion 331, improve the structural reliability of the first pre-fixing film 33, and further improve the structural reliability of the solar cell module. Similarly, the second extension portion 332 does not completely cover the second side surface 3192 of the battery cell 31. The filling portion 21 of the first adhesive film 2 wraps around 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-fixing film 33.

[0122] Please refer to Figures 9 - 11 , as an embodiment of the present invention, the extension portion 330 further includes:

[0123] A second extension portion 3312 connected to the first extension portion 3311, and the second extension portion 3312 extends away from the battery cell 31 from the first extension portion 3311, and the second extension portion 3312 is connected between the first adhesive film 2 and the second adhesive film 4.

[0124] 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, facilitating further improvement of the fixing effect of the first pre-fixing film 33. Among them, the second extension portion 3312 can be arranged parallel to the second surface 316 of the battery cell 31, or the second extension portion 3312 can be arranged non-parallel to the second surface 316 of the battery cell 31.

[0125] 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 non-parallel or non-collinear with respect to the first extension portion 3311, and the second extension portion 3312 is bent with respect to the first extension portion 3311, which is beneficial to further increasing the bonding force between the extension portion 330 and the adhesive film.

[0126] Please refer to Figure 12 , as an embodiment of the present invention, the thickness D2 of the main body portion 336 is less than the thickness D3 of the battery cell 31.

[0127] In this embodiment, the first pre-fixing film 33 can be flexibly set according to the thickness of the battery cell 31, and the thickness of the first pre-fixing film 33 before lamination is less than the thickness of the battery cell 31. For example, when the thickness of the battery cell 31 is 100 - 180 microns, the thickness of the first pre-fixing film 33 before lamination can be 5 - 150 microns, as long as the thickness of the first pre-fixing film 33 is less than the thickness of the battery cell 31. Among them, the thickness of the first pre-fixing film 33 being less than the thickness of the battery cell 31 is beneficial for the first pre-fixing film 33 to be bent relatively to form the extension portion 330 after lamination, which is beneficial to increasing the fixing effect of the first pre-fixing film 33. The thickness of the main body portion 336 being less than the thickness of the battery cell 31 can prevent the optical performance of the battery cell 31 from being affected by the excessive thickness of the main body portion 336.

[0128] As an embodiment of the present invention, at least a part of the extension portion 330 is provided with a cavity structure (not shown).

[0129] Among them, the cavity structure may be provided in the first extension portion 3311 of the outer extension portion 330, or may be provided in the second extension portion 3312 of the outer extension portion 330, or may be provided in both the first extension portion 3311 and the second extension portion 3312. The cavity structure provided in the outer extension portion 330 can make the first adhesive film 2 and the second adhesive film 4 bind more firmly to the outer extension portion 330, greatly increasing the binding force between the outer extension portion 330 and the first adhesive film 2 and the second adhesive film 4, and improving the fixing effect of the first pre-fixed film 33; at the same time, the cavity structure provided in the outer extension portion 330 can play a buffering role, and can also reduce the stress of the outer extension portion 330 and avoid the fracture of the outer extension portion 330. Among them, the cavity structure may specifically be a hollow cavity or a cavity filled with air.

[0130] As an embodiment of the present invention, the thickness of at least a part of the first extension portion 3311 is greater than the thickness of the main body portion 336.

[0131] In this embodiment, it may be that only a part of the first extension portion 3311 has a thickness greater than the thickness of the main body portion 336, or it may be that the thickness of all regions of the first extension portion 3311 is greater than the thickness of the main body portion 336. Since the thickness of at least a part of the first extension portion 3311 can be greater than the thickness of the main body portion 336, the structural strength of the first extension portion 3311 can be further increased, the tensile resistance of the first extension portion 3311 can be improved, the fracture of the first extension portion 3311 can be avoided, and it is beneficial to improve the performance of the first pre-fixed film 33; at the same time, the binding force between the first extension portion 3311 and the first adhesive film 2 and the second adhesive film 4 can be increased, and the fixing effect of the first pre-fixed film 33 can be further enhanced.

[0132] Embodiment Four

[0133] Please refer to Figures 6 - 12 , as an embodiment of the present invention, the first pre-fixed film 33 further includes:

[0134] A convex structure 335 protruding from the outer extension portion 330, and the convex structure 335 is connected to the first adhesive film 2 and / or the second adhesive film 4.

[0135] In the embodiment of the present invention, the convex structure 335 can be disposed on one side of the extension portion 330 close to the second surface 316, or can be disposed on the side of the extension portion 330 facing away from the second surface 316, and the convex direction on the extension portion 330 is not limited. The convex structure 335 can protrude towards the first adhesive film 2 or the second adhesive film 4. In addition, the convex structure 335 can also protrude towards the battery cell 31. Among them, the convex structure 335 can be strip-shaped, and the cross section of the convex structure 335 is an arc-shaped protrusion, a serrated protrusion or other irregular-shaped protrusions. The convex structure 335 is disposed on the surface of the extension portion 330 close to the second adhesive film 4, and the convex structure 335 is embedded in the second adhesive film 4, or the convex structure 335 is disposed on the surface of the extension portion 330 close to the first adhesive film 2, and the convex structure 335 is embedded in the first adhesive film 2, or the convex structure 335 is simultaneously disposed on the surface of the extension portion 330 close to the second adhesive film 4 and the surface of the extension portion 330 close to the first adhesive film 2. The convex structure 335 on the surface of the extension portion 330 close to the second adhesive film 4 is embedded in the second adhesive film 4, and the convex structure 335 on the surface of the extension portion 330 close to the first adhesive film 2 is embedded in the first adhesive film 2.

[0136] Specifically, the convex structure 335 can include a first convex structure 3351 protruding on the first extension portion 331, a second convex structure 3352 protruding on the second extension portion 332, a third convex structure 3353 protruding on the third extension portion 333, and a fourth convex structure 3354 protruding on the fourth extension portion 334. It can be understood that the convex structure 335 can be disposed on each of the first extension portion 331, the second extension portion 332, the third extension portion 333, and the fourth extension portion 334, or only one of the first extension portion 331, the second extension portion 332, the third extension portion 333, and the fourth extension portion 334 can be provided with the convex structure 335. Among them, the structures of the convex structures 335 on each extension portion 330 are the same. Of course, in some other embodiments, the structures of the convex structures 335 on each extension portion 330 can also be different.

[0137] Please refer to Figure 9, in 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 convex structure 3351 is located between the first battery edge 311 and the first edge 3301 of the first pre-fixing film 33, the second convex structure 3352 is located between the second battery edge 312 and the second edge 3302 of the first pre-fixing film 33, the third convex 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 convex 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 using the convex structure 335 thereon, while further enhancing the bonding force between the first pre-fixing film 33 and the adhesive film, and enhancing the fixing effect of the first pre-fixing film 33; moreover, the convex structure 335 can reduce the tensile force of the extension part 330, improve the buffering effect, and prevent the extension part 330 from breaking.

[0138] As an embodiment of the present invention, the convex structure 335 is arranged on the first extension part 3311 or the second extension part 3312.

[0139] In this embodiment, when the convex structure 335 is arranged on the first extension part 3311 or the second extension part 3312, the convex structure 335 protrudes from the surface of the first extension part 3311 or the second extension part 3312, which is beneficial to increasing the bonding force between the position of the first extension part 3311 or the second extension part 3312 and the second adhesive film 4.

[0140] As an embodiment of the present invention, the convex structure 335 is arranged at the connection of the first extension part 3311 and the second extension part 3312.

[0141] In this embodiment, when the convex structure 335 is arranged at the connection of the first extension part 3311 and the second extension part 3312, the convex structure 335 protrudes from the surface at the connection of the first extension part 3311 and the second extension part 3312, which is beneficial to increasing the bonding force between the connection of the first extension part 3311 and the second extension part 3312 and the second adhesive film 4, and the existence of the convex structure 335 is also beneficial to increasing the buffering effect at the connection of the first extension part 3311 and the second extension part 3312, and avoiding breakage at the connection of the first extension part 3311 and the second extension part 3312. Among them, only the situation where the convex structure 335 is arranged at the connection of the first extension part 3311 and the second extension part 3312 is schematically shown in the drawings of the present invention.

[0142] As an embodiment of the present invention, the distance from the edge of the battery cell 31 to the convex structure 335 is less than the distance from the edge of the battery cell 31 to the edge of the corresponding epitaxial portion 330, so that the convex structure 335 is located between the edge of the battery cell 31 and the edge of the epitaxial portion 330, which is conducive to improving the bonding force between the first pre-fixing film 33 and the adhesive film and enhancing the fixing effect. Moreover, the convex structure 335 can reduce the pulling force of the epitaxial portion 330, improve the buffering effect, and prevent the epitaxial portion 330 from breaking.

[0143] As an embodiment of the present invention, the surface of each convex structure 335 away from the first adhesive film 2 is set as a wavy surface.

[0144] In this embodiment, the surface of each convex structure 335 away from the first adhesive film 2 is set as a wavy surface. The wavy surface can further increase the bonding force between the convex 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.

[0145] Among them, the surfaces of the first convex structure 3351, the second convex structure 3352, the third convex structure 3353 and the fourth convex structure 3354 away from the first adhesive film 2 are all set as wavy surfaces, which further improves the fixing effect of the first pre-fixing film 33.

[0146] Please refer to again Figure 9 , as an embodiment of the present invention, each convex structure 335 includes a first side edge 3356 close to the battery cell 31 and a second side edge 3357 far from the battery cell 31, and the first side edge 3356 and the second side edge 3357 are arranged in an uneven connection.

[0147] In this embodiment, the first side edge 3356 and the second side edge 3357 of the convex structure 335 are in a wavy shape of uneven connection, which can further improve the bonding force between the convex structure 335 and the first adhesive film 2 and the second adhesive film 4, and further improve the fixing effect of the first pre-fixing film 33.

[0148] As an embodiment of the present invention, the length of the first convex structure 3351 and the second convex structure 3352 in the second direction X is greater than or equal to the length of the battery cell 31 in the second direction X, which is conducive to further improving the fixing effect of each welding strip 32.

[0149] As an embodiment of the present invention, the length of the third convex structure 3353 and the fourth convex structure 3354 in the first direction Y is greater than or equal to the length of the battery cell 31 in the first direction Y, which can further improve the fixing effect of the first pre-fixing film 33.

[0150] As an embodiment of the present invention, the projected lengths of the first convex structure 3351 and the second convex structure 3352 along the first direction Y are both 10 to 200 micrometers.

[0151] In this embodiment, by controlling the projected lengths of the first convex structure 3351 and the second convex structure 3352 along the first direction Y to be both 10 to 200 micrometers, a good buffering effect of the first convex structure 3351 and the second convex structure 3352 can be ensured, the breakage of the first epitaxial portion 331 and the second epitaxial portion 332 can be avoided, and at the same time, a sufficient contact area between the first convex structure 3351 and the second convex structure 3352 and the first adhesive film 2 and the second adhesive film 4 can be ensured, so as to ensure a suitable bonding force between the first pre-fixed film 33 and the first adhesive film 2 and the second adhesive film 4; moreover, the first convex structure 3351 and the second convex structure 3352 can play a good limiting role on the welding strip 32.

[0152] As an embodiment of the present invention, at the position of the second adhesive film 4 corresponding to the convex structure 335, a groove matching the convex structure 335 is formed, and the convex structure 335 is embedded in the groove.

[0153] In this embodiment, the convex 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.

[0154] Please refer to Figure 10 , as an embodiment of the present invention, on the surface of the first epitaxial portion 331 facing away from the convex structure 335, a first positioning groove (not labeled) formed by a depression is provided, a first positioning protrusion 22 is formed at the 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.

[0155] In this embodiment, the first positioning protrusion 22 is formed at the position of the first adhesive film 2 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.

[0156] As an embodiment of the present invention, the first convex structure 3351 is provided on the first extension portion 3311 of the first epitaxial portion 331, and the sum of the projected lengths of the first convex structure 3351 and the first extension portion 3311 of the first epitaxial portion 331 along the first direction Y is 30 to 400 micrometers.

[0157] In this embodiment, the sum of the projection lengths of the first protrusion structure 3351 and the first extension portion 3311 of the first extension portion 331 in the first direction Y is 30 to 400 microns, which can ensure a good fixing effect of the first pre-fixing film 33, and at the same time is beneficial to well fixing and limiting the solder tape 32 extending outside the edge 311 of the first battery.

[0158] As an embodiment of the present invention, the second protrusion structure 3352 is disposed on the first extension portion 3311 of the second extension portion 332, and the sum of the projection lengths of the second protrusion structure 3352 and the first extension portion 3311 of the second extension portion 332 in the first direction Y is 30 to 400 microns.

[0159] In this embodiment, the sum of the projection lengths of the second protrusion structure 3352 and the first extension portion 3311 of the second extension portion 332 in the first direction Y is 30 to 400 microns, which can ensure a good fixing effect of the first pre-fixing film 33, and at the same time plays a good role in fixing and limiting the solder tape 32 extending outside the edge 312 of the second battery.

[0160] Embodiment Five

[0161] Please refer to again Figure 6 , as an embodiment of the present invention, the distance between two adjacent solar cells 31 in the solar cell string is L1, the projection length of the first extension portion 331 of the first pre-fixing film 33 in the first direction Y is S1, and the projection length of the second extension portion 332 of the first pre-fixing film 33 in the first direction Y is S2, and the sum of S1 and S2 is less than L1.

[0162] In this embodiment, the sum of S1 and S2 is less than L1, which can prevent the first extension portion 331 and the second extension portion 332 of the first pre-fixing film 33 of two adjacent solar cells 31 from overlapping, and can reduce the material cost of the first pre-fixing film 33.

[0163] As an embodiment of the present invention, the distance between two adjacent solar cells 31 in the solar cell string is L1, and the projection lengths of the first extension portion 331 and the second extension portion 332 of the first pre-fixing film 33 in the first direction Y are both less than L1 / 2, which can further ensure that the first pre-fixing films 33 on two adjacent solar cells 31 in the adjacent solar cell strings do not overlap, which can not only improve the fixing effect of the first pre-fixing film 33, but also reduce the material cost of the first pre-fixing film 33.

[0164] Embodiment Six

[0165] Please refer to Figure 3 and Figure 12 , as an embodiment of the present invention, the extension portions 330 of the first pre-fixing films 33 on at least two adjacent solar cells 31 in each solar cell string are connected.

[0166] In this embodiment, since at least two adjacent first pre-fixing films 33 on the battery cells 31 are connected, the extending portions 330 of the first pre-fixing film 33 on one battery cell 31 and the extending portions 330 of the first pre-fixing film 33 on the adjacent battery cell 31 are connected into one body, so that the adjacent first pre-fixing films 33 can also play a role in fixing each other, which can further prevent the first pre-fixing film 33 from moving and improve the fixing effect of the first pre-fixing film 33.

[0167] As an embodiment of the present invention, the distance between two adjacent battery cells 31 in the battery string is L1, the projection length of the first extending portion 331 in the first direction Y is S1, and the projection length of the second extending portion 332 in the first direction Y is S2, and the sum of S1 and S2 is greater than or equal to L1.

[0168] In this embodiment, in each battery string, the first extending portion 331 and the second extending portion 332 of the first pre-fixing film 33 on two adjacent battery cells 31 are arranged adjacent to each other. When the sum of S1 and S2 is greater than L1, the first extending portion 331 and the second extending portion 332 between two adjacent battery cells 31 intersect and are connected into one body, which is beneficial to further improving the fixing effect of the first pre-fixing film 33; when the sum of S1 and S2 is equal to L1, the first extending portion 331 and the second extending portion 332 of the first pre-fixing film 33 on two adjacent battery cells 31 are connected end to end into one body, which can also improve the fixing effect of the first pre-fixing film 33.

[0169] As an embodiment of the present invention, the distance between two adjacent battery cells 31 in each battery string is L1, and the projection lengths of the first extending portion 331 and the second extending portion 332 of the first pre-fixing film 33 on each battery string in the first direction Y are greater than or equal to L1 / 2.

[0170] In this embodiment, the projection lengths of the first extending portion 331 and the second extending portion 332 of the first pre-fixing film 33 on the battery cells 31 in each battery string in the first direction Y are greater than or equal to L1 / 2, so that the first pre-fixing films 33 on the adjacent battery cells 31 in the battery string can be connected, which is beneficial to improving the pre-fixing effect of the first pre-fixing film 33 in the battery string, making the fixing effect of the solder tape 32 in the whole battery string better, and improving the connection reliability of the battery string.

[0171] As an embodiment of the present invention, the extending portions 330 of two adjacent first pre-fixing films 33 are overlapped and connected 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 portion 336.

[0172] In this embodiment, when the sum of S1 and S2 is greater than L1, the first epitaxial portion 331 and the second epitaxial portion 332 between two adjacent solar cells 31 overlap to form a first overlapping portion 300. By controlling the thickness of the first overlapping portion 300 to be greater than that of the main body portion 336, it is beneficial to improve the structural strength of the overlapping position of the adjacent first pre-fixing films 33, stably connect the adjacent first pre-fixing films 33, further improve the fixing reliability of the first pre-fixing films 33, and enhance the fixing performance of the solder tape 32.

[0173] As an embodiment of the present invention, the first overlapping portion 300 is provided with a cavity structure (not shown).

[0174] In this embodiment, since the first overlapping portion 300 is provided with a cavity structure, the first overlapping portion 300 has a loose structure, so that the first adhesive film 2, the second adhesive film 4 and the first overlapping portion 300 are more firmly combined, 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-fixing film 33. At the same time, the cavity structure provided in the first overlapping portion 300 can play a buffering role, reduce the stress of the first pre-fixing film 33, avoid the fracture of the first pre-fixing film 33, and make the combination between the adjacent first pre-fixing films 33 more stable. Among them, the cavity structure can specifically be a hollow cavity or a cavity filled with air.

[0175] Embodiment Seven

[0176] Please refer to Figures 13 - 15 , as another embodiment of the present invention, the solar cell 31 includes a first grid line 317 provided on the first surface 315 and a second grid line 318 provided on the second surface 316, and the polarities of the first grid line 317 and the second grid line 318 are opposite;

[0177] The solder tape 32 further includes a second welding portion 322 and a connecting portion 320. 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 solar cell 31, and the second welding portion 322 connects the second grid line 318 on another solar cell 31.

[0178] In this embodiment, the solar cell 31 is a double-sided contact solar cell, and grid lines are provided on both the first surface 315 and the second surface 316 of the solar cell 31. Specifically, the polarities of the first grid lines 317 on the first surface 315 are the same, the polarities of the second grid lines 318 on the second surface 316 are 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.

[0179] Among them, the first welding portion 321 of the welding ribbon 32 is located on the first surface 315 of a cell 31 and is connected to the first grid line 317 of the cell 31. The second welding portion 322 of the welding ribbon 32 is located on the second surface 316 of another cell 31 and is connected to the second grid line 318 of the cell 31, realizing the series connection between adjacent cells 31.

[0180] Embodiment Eight

[0181] Please refer to Figures 15 - 17 , on the basis of Embodiment Seven, the solar cell module further includes:

[0182] A second pre-fixing film 36 located on the second surface 316. The second pre-fixing film 36 is disposed on the second welding portion 322 and fixedly connects the second welding portion 322 to the second surface 316, and the second pre-fixing film 36 does not extend beyond the edge of the cell 31.

[0183] In this embodiment, by providing the second pre-fixing film 36 on the second surface 316 of the cell 31, the second welding portion 322 of the welding ribbon 32 is fixed on the second surface 316 by using the second pre-fixing film 36, thereby realizing the fixation of the welding ribbon 32. At the same time, the second pre-fixing film 36 does not extend beyond the outside of the cell 31, that is, the second pre-fixing film 36 does not exceed the edge of the cell 31, avoiding the overlapping of the extension portion 330 of the first pre-fixing film 33 and the second pre-fixing film 36.

[0184] Among them, the material and thickness of the second pre-fixing film 36 may be the same as or different from those of the first pre-fixing film 33.

[0185] Embodiment Nine

[0186] Please refer to Figure 18 and Figure 19 , on the basis of Embodiment Seven, it further includes:

[0187] A second pre-fixing film 36 located on the second surface 316. The second pre-fixing film 36 is disposed on the second welding portion 322 and fixedly connects the second welding portion 322 to the second surface 316. The second pre-fixing film 36 extends to the outside of the edge of the cell 31 to form at least one extension portion 361. The extension portion 361 is connected to the first adhesive film 2, and 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.

[0188] In this embodiment, the solar cell 31 is a double-sided contact solar cell. The first pre-fixing film 33 extends outward from the position of the first cell edge 311 to form an extension part 330 outside the solar cell 31. The extension part 330 is used to improve the fixing stability of the first pre-fixing film 33, thereby improving the reliability of the solder strip 32 fixed on the first surface 315. The extension part 361 is used to improve the fixing stability of the second pre-fixing film 36, thereby improving the reliability of the solder strip 32 fixed on the second surface 316, and further improving the structural reliability of the solar cell module.

[0189] In this embodiment, since the projection area of the extension part 361 on the plane where the second surface 316 is located does not overlap with the projection area of the extension part 330 on the plane where the second surface 316 is located, it is avoided that the extension part 361 of the second pre-fixing film 36 overlaps with the extension part 330 of the first pre-fixing film 33 after lamination; one side edge of the solar cell 31 provided with the extension part 330 does not have the extension part 361, and one side edge of the solar cell 31 provided with the extension part 361 does not have the extension part 330, realizing the dislocation arrangement of the extension part 361 of the second pre-fixing film 36 and the extension part 330 of the first pre-fixing film 33, ensuring that the extension part 361 and the extension part 330 do not overlap, and avoiding the generation of bubbles due to the overlap of the extension part 361 and the extension part 330.

[0190] As an embodiment of the present invention, the first pre-fixing films 33 on two adjacent solar cells 31 can be connected to each other to improve the fixing effect of the first pre-fixing film 33. Of course, the first pre-fixing films 33 on two adjacent solar cells 31 can also not be connected; the second pre-fixing films 36 on two adjacent solar cells 31 can be connected to each other or not be connected. Of course, the second pre-fixing films 36 on two adjacent solar cells 31 can also not be connected.

[0191] As an embodiment of the present invention, the first pre-fixing film 33 includes a first extension part 331 extending outward from the position of the first cell edge 311 to the outside of the solar cell 31, and the second pre-fixing film 36 includes an extension part 361 extending outward from the position of the second cell edge 312 to the outside of the solar cell 31. The first extension parts 331 between adjacent solar cells 31 are arranged adjacent to each other or the extension parts 361 between adjacent solar cells 31 are arranged adjacent to each other. Among them, the first extension parts 331 between the solar cells 31 can overlap or not overlap, and the extension parts 361 between the solar cells 31 can overlap or not overlap.

[0192] Among them, the extension parts 330 of the first pre-fixing films 33 between adjacent solar cells 31 can overlap to form a first overlapping part 300, and the thickness D1 of the first overlapping part 300 is greater than the thickness D2 of the main body part 336; the extension parts 361 between adjacent solar cells 31 can overlap to form a second overlapping part 400, and the thickness D4 of the second overlapping part 400 is greater than the thickness of the part of the second pre-fixing film 36 covering the second surface 316, so that adjacent first pre-fixing films 33 are fixed and limited to each other, and adjacent second pre-fixing films 36 are fixed and limited to each other, which can improve the reliability of the first pre-fixing film 33 and the second pre-fixing film 36 in fixing the welding strip 32.

[0193] Embodiment Ten

[0194] Please refer to Figure 1 and Figure 20 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, which is convenient for the assembly of 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 beneficial to the installation of the junction box and bypass diode and convenient for the assembly of the solar cell module.

[0195] Please refer to Figure 6 and Figure 20 As an embodiment of the present invention, the battery string includes a first solar cell 3101 at its first end. The first solar cell 3101 is connected to the edge bus bar 306. The distance between the first solar cell 3101 and the edge bus bar 306 is L2. The first extension part 331 of the first pre-fixing film 33 on the first solar cell 3101 extends towards the edge bus bar 306, and the projection length of the first extension part 331 in the first direction Y is less than L2.

[0196] In this embodiment, the first extension part 331 of the first pre-fixing film 33 on the first solar cell 3101 extends towards the edge bus bar 306, and the projection length of the first extension part 331 in the first direction Y is less than L2, which avoids the first extension part 331 of the first pre-fixing film 33 completely covering the extended part of the welding strip 32, can ensure good welding between the welding strip 32 and the edge bus bar 306, and the first extension part 331 has a good fixing effect on the part of the welding strip 32 extending out of the edge of the first solar cell 3101.

[0197] As an embodiment of the present invention, the battery string includes a second cell 3102 located at the second end. The second cell 3102 is connected to an intermediate bus bar 308. The distance between the second cell 3102 and the intermediate bus bar 308 is L3. The second extension portion 332 of the first pre-fixing film 33 of the second cell 3102 extends towards the intermediate bus bar 308, and the projection length of the second extension portion 332 in the first direction Y is less than L3.

[0198] In this embodiment, the distance between the second cell 3102 and the intermediate bus bar 308 connected thereto is L3, and the projection length of the second extension portion 332 of the first pre-fixing film 33 on the second cell 3102 in the first direction Y is less than L3, which avoids the second extension portion 332 of the first pre-fixing film 33 on the second cell 3102 completely covering the protruding part of the solder strip 32, ensuring good welding between the protruding part of the solder strip 32 at the second end of the battery string and the intermediate bus bar 308, and the second extension portion 332 has a good fixing effect on the part of the solder strip 32 extending out of the edge position of the second cell 3102.

[0199] Please refer to Figure 8 and Figure 20 As an embodiment of the present invention, 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-fixing film 33 on the first battery string 301 is adjacent to the third extension portion 333 of the first pre-fixing film 33 on the second battery string 302, and the projection lengths of the fourth extension portion 334 of the first pre-fixing film 33 on the first battery string 301 and the third extension portion 333 of the first pre-fixing film 33 on the second battery string 302 in the second direction X are less than L4 / 2.

[0200] In this embodiment, by controlling the projection lengths of the fourth extension portion 334 of the first pre-fixing film 33 on the first battery string 301 and the third extension portion 333 of the first pre-fixing film 33 on the second battery string 302 in the second direction X to be less than L4 / 2, not only can the fixing effect of the first pre-fixing film 33 be increased, but also the first pre-fixing film 33 of the cell 31 of the first battery string 301 does not overlap with the first pre-fixing film 33 of the cell 31 of the second battery string 302, which is beneficial to reducing the cost of the first pre-fixing film 33.

[0201] Embodiment XI

[0202] The embodiment of the present invention further provides a photovoltaic system, which includes the solar cell module of any of the above embodiments. It should be noted that this photovoltaic system has the same or similar beneficial effects as the above solar cell module, and the relevant parts between the two can be mutually referred to. To avoid repetition, it will not be elaborated here.

[0203] In this embodiment, the photovoltaic system can be applied in a photovoltaic power station, such as a ground power station, a rooftop power station, a water surface power station, etc., or can also be applied to equipment or devices that use solar energy for power generation, such as a user solar power supply, a solar street lamp, a solar car, a solar building, and so on. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be applied in all fields that require solar power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a busbar box, and an inverter. The photovoltaic array can be an array combination of multiple solar photovoltaic modules. For example, multiple solar photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to the busbar box, and the busbar box can collect the current generated by the photovoltaic arrays. After the collected current flows through the inverter and is converted into alternating current required by the mains power grid, it is connected to the mains network to achieve solar power supply.

[0204] In the description of this specification, the description with reference to terms such as "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0205] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle 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 includes 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, and the battery string includes: A plurality of solar cells arranged at intervals along a first direction, and each solar cell includes a first surface and a second surface which are oppositely arranged, and a side surface connecting the first surface and the second surface; A plurality of welding tapes, adjacent two of the solar cells are connected by the welding tapes, the welding tapes extend along the first direction, and a plurality of the welding tapes are arranged at intervals along a second direction, the second direction intersects with the first direction, and the welding tape includes a first welding portion disposed on the first surface; and A plurality of first pre-fixing films, each of the first pre-fixing films is disposed on a corresponding solar cell, the first pre-fixing film is disposed 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 portion covering the first surface and at least one extension portion connected to the main body portion and extending outside the edge of the solar cell, the extension portion is bent in a direction close to the plane where the second surface is located relative to the main body portion, the extension portion is connected to the first adhesive film and the second adhesive film, and the first adhesive film includes a filling portion located between the side surface and the extension portion, and the filling portion surrounds at least a part of the side surface; the extension portion includes a first extension portion and a second extension portion, the first extension portion and the second extension portion are respectively disposed at opposite ends of the main body portion along the first direction, the first extension portions of the first pre-fixing films on adjacent two of the solar cells are adjacent to the second extension portions, and the first extension portion and the second extension portion are both bent in a direction close to the plane where the second surface is located.

2. The solar cell module according to claim 1, wherein, The solar cell includes a first grid line and a second grid line disposed on the first surface, the first grid line and the second grid line are arranged at intervals along the first direction, and the polarities of the first grid line and the second grid line are opposite; The welding tape includes two of the first welding portions and a connecting portion connecting the two first welding portions, one of the first welding portions is connected to the first grid line on one of the solar cells, and the other first welding portion is connected to the second grid line on the other solar cell.

3. The solar cell module according to claim 1, wherein The solar cell includes a first grid line disposed on the first surface and a second grid line disposed on the second surface, and the polarities of the first grid line and the second grid line are opposite; The welding tape further includes a second welding portion and a connecting portion, the connecting portion connects the first welding portion and the second welding portion, the first welding portion is connected to the first grid line on one of the solar cells, and the second welding portion is connected to the second grid line on the other solar cell.

4. The solar cell module according to claim 1, wherein, The solar cell includes a first cell edge and a second cell edge which are oppositely arranged along the first direction; The first extension portion covers the first cell edge and extends outside the first cell edge, and the second extension portion covers the second cell edge and extends outside the second cell edge.

5. The solar cell module according to claim 1 or 4, characterized in that, The cell includes a third cell edge and a fourth cell edge oppositely arranged along the second direction; the epitaxial part includes a third epitaxial part and a fourth epitaxial part, the third epitaxial part and the fourth epitaxial part are respectively connected to opposite ends of the main body part along the second direction, the third epitaxial part covers the third cell edge and extends to the outside of the third cell edge, and the fourth epitaxial part covers the fourth cell edge and extends to the outside of the fourth cell edge.

6. The solar cell module according to claim 1, wherein, The epitaxial part includes: A first extension part connected to the main body part, and the first extension part is bent relative to the main body part towards the plane where the second surface is located.

7. The solar cell module according to claim 6, characterized in that, The epitaxial part further includes: A second extension part connected to the first extension part, and the second extension part extends away from the cell in a direction away from the first extension part, and the second extension part is connected between the first adhesive film and the second adhesive film.

8. The solar cell module according to claim 7, wherein The second extension part and the first extension part are arranged at an angle to each other.

9. The solar cell module according to claim 4, wherein, The epitaxial part surrounds a partial area of the side surface.

10. The solar cell module according to claim 9, wherein, The side surface includes a first side surface connecting the first surface and the second surface and located on the side where the first cell edge is located, and a second side surface connecting the first surface and the second surface and located on the side where the second cell edge is located. The first epitaxial part surrounds a partial area of the first side surface, and the second epitaxial part surrounds a partial area of the second side surface.

11. The solar cell module according to claim 6, wherein, The first extension part includes an upper surface arranged away from the plane where the second surface is located. The upper surface includes a first end close to the cell and a second end away from the cell. The perpendicular distance from the first end of the upper surface to the plane where the second surface is located is greater than the perpendicular distance from the second end of the upper surface to the plane where the second surface is located.

12. The solar cell module according to claim 11, wherein, The perpendicular distance from the upper surface to the plane where the second surface is located gradually decreases from the first end to the second end.

13. The solar cell module according to claim 11, characterized in that, The upper surface of the first extension part is an inclined surface or a curved surface.

14. The solar cell module according to claim 13, wherein, The angle between the inclined surface and the plane where the second surface is located is 10° to 80°.

15. The solar cell module according to claim 1, characterized in that, At least a partial area of the epitaxial part is provided with a cavity structure.

16. The solar cell module according to claim 1, wherein The thickness of the main body part is less than the thickness of the cell.

17. The solar cell module according to claim 1, wherein, The first pre-fixing film further includes: A convex structure protruding on the epitaxial part, and the convex structure is connected to the first adhesive film and / or the second adhesive film.

18. The solar cell module according to claim 17, wherein The convex structure is arranged on the surface of the epitaxial part close to the second adhesive film, and the convex structure is embedded in the second adhesive film.

19. The solar cell module according to claim 17, wherein, The convex structure is arranged on the surface of the epitaxial part close to the first adhesive film, and the convex structure is embedded in the first adhesive film.

20. The solar cell module according to claim 17, wherein The convex structure is simultaneously arranged on the surface of the epitaxial part close to the second adhesive film and the surface of the epitaxial part close to the first adhesive film. The convex structure on the surface of the epitaxial part close to the second adhesive film is embedded in the second adhesive film, and the convex structure on the surface of the epitaxial part close to the first adhesive film is embedded in the first adhesive film.

21. A photovoltaic system, characterized in that, It includes the solar cell module according to any one of claims 1 to 20.

Images