Solar cell modules and photovoltaic systems

Abstract

This application relates to the field of solar cell technology and provides a solar cell module and photovoltaic system, including: a first cell string and a second cell string; the first cell string includes a first end cell closest to the second cell string; an intermediate busbar, connecting the first and second cell strings in parallel, disposed on the back side of the first end cell; a first solder strip, electrically connecting the first end cell and the intermediate busbar; a first pre-fixing film, disposed on the side of the first solder strip away from the first end cell; an insulating layer, disposed between the intermediate busbar and the first end cell, partially overlapping with the first pre-fixing film; the first solder strip includes a first part and a second part, the first part having the first pre-fixing film and the insulating layer; the second part having an insulating layer on the side away from the first end cell and not having the first pre-fixing film; the length of the first part is greater than the length of the second part. This improves the pre-fixing effect of the solder strip, thereby improving the reliability of the solar cell module.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and in particular relates to a solar cell module and photovoltaic system. Background Technology

[0002] A solar cell is a semiconductor device that converts solar energy into electrical energy. Under sunlight, a photocurrent is generated inside the solar cell, which outputs electrical energy through electrodes. In recent years, solar cell manufacturing technology has continuously improved, production costs have been decreasing, and conversion efficiency has been increasing. Solar cell power generation is becoming increasingly widespread and is an important energy source for electricity supply.

[0003] In the prior art, solar cell modules consist of multiple cells connected by solder ribbons. However, the solder ribbons are prone to misalignment, which affects the reliability of solar cell modules. Summary of the Invention

[0004] This application provides a solar cell module and photovoltaic system, which aims to improve the pre-fixation effect of the solder strip, thereby improving the reliability of the solar cell module.

[0005] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, a back-contact solar cell is provided, comprising: a first battery string and a second battery string arranged along a first direction; the first battery string including a first end cell closest to the second battery string; an intermediate busbar connecting the first battery string and the second battery string in parallel and disposed on the back side of the first end cell; a first solder strip electrically connecting the first end cell and the intermediate busbar and extending along the first direction; a first pre-fixed film disposed on the side of the first solder strip away from the first end cell; an insulating layer disposed between the intermediate busbar and the first end cell and partially overlapping the first pre-fixed film; the first solder strip including a first portion and a second portion, the first portion having the first pre-fixed film and the insulating layer on the side away from the first end cell; the second portion having the insulating layer but not the first pre-fixed film on the side away from the first end cell; and the length of the first portion being greater than the length of the second portion along the first direction.

[0006] In some embodiments, the length of the first portion along the first direction is 2mm to 30mm.

[0007] In some embodiments, the length of the second part along the first direction is 0.2 mm to 5 mm.

[0008] In some embodiments, the solar cell module further includes a second pre-fixed film; the first cell string further includes a second end cell furthest from the second cell string; The second end cell is provided with a second solder strip extending along the first direction; The second pre-fixed film is disposed on the side of the second welding strip opposite to the second end battery cell.

[0009] In some embodiments, the second end cell includes a first region near the intermediate busbar and a second region away from the intermediate busbar; the second pre-fixed film is disposed in the first region and avoids the second region.

[0010] In some embodiments, the length of the second region along the first direction is greater than 2 mm.

[0011] In some embodiments, the second pre-fixed film completely covers the second end battery cell.

[0012] In some embodiments, the solar cell module further includes a third pre-fixed film; along the first direction, the first cell string further includes a plurality of intermediate cells located between the first end cell and the second end cell; the plurality of intermediate cells are provided with a third solder strip extending along the first direction; the third pre-fixed film is disposed on the side of the third solder strip opposite to the plurality of intermediate cells.

[0013] In some embodiments, the first end cell overlaps with the adjacent middle cell portion.

[0014] In some embodiments, the first solder strip further includes a third portion; the third portion has the first pre-fixed film on the side opposite to the first end battery cell and does not have the insulating layer.

[0015] In some embodiments, the second battery string includes a third end battery piece closest to the first battery string; the third end battery piece partially overlaps with the first end battery piece.

[0016] In some embodiments, along the first direction, the overlap length between the third end battery cell and the first end battery cell is 0.1 mm to 5 mm.

[0017] In some embodiments, along the first direction, the overlap length between the third end battery cell and the first end battery cell is 0.6 mm to 1.2 mm.

[0018] In some embodiments, the first pre-fixed film includes at least one of PVB film, EVA film, EPE film, EP film and POE film.

[0019] Secondly, the present invention provides a photovoltaic system, which includes the solar cell module described above.

[0020] The beneficial effects of this invention are as follows: In the solar cell module and photovoltaic system of this application embodiment, since the first part has a first pre-fixing film and an insulating layer on the side away from the first end cell; that is, the length of the first part is the overlap length of the first insulating layer and the first pre-fixing film, and the second part has an insulating layer but no first pre-fixing film on the side away from the first end cell; that is, the length of the second part is the overlap length of the insulating layer and the first solder ribbon in direct contact; the length of the first part is greater than the length of the second part, which can ensure that the pre-fixing of the first solder ribbon is completed during the pre-fixing film covering stage as much as possible. The first solder ribbon not covered by the first pre-fixing film is then pre-fixed by the insulating layer. The probability of the first solder ribbon shifting in the two steps is small, which can improve the reliability of the solar cell module. Attached Figure Description

[0021] Figure 1 This is a partial structural schematic diagram of a solar cell module provided in an embodiment of this application; Figure 2 This is a partial structural schematic diagram of a solar cell module provided in another embodiment of this application; Figure 3 This is a partial structural schematic diagram of a solar cell module provided in another embodiment of this application; Figure 4 This is a partial structural schematic diagram of a solar cell module provided in another embodiment of this application; Figure 5 This is a partial structural schematic diagram of a solar cell module provided in another embodiment of this application.

[0022] Key component symbols: Solar cell module 10; First cell string 11; Second cell string 12; First end cell 13; Middle busbar 14; Insulating layer 15; First pre-fixing film 16; First solder ribbon 17; First section 171; Second section 172; Third section 173; Second end cell 18; First region 181; Second region 182; Third end cell 19; Second pre-fixing film 20; Second solder ribbon 21; Middle cell 22; Third pre-fixing film 23; Third solder ribbon 24; Third cell string 25; Fourth cell string 26; Edge busbar 27. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein 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 this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0024] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0029] According to one aspect of this application, a solar cell module 10 is provided, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 ,as well as Figure 5 As shown, it includes: a first battery string 11 and a second battery string 12, arranged along a first direction; the first battery string 11 includes a first end battery piece 13 closest to the second battery string 12; The intermediate busbar 14, which connects the first battery string 11 and the second battery string 12 in parallel, is located on the back of the first end battery cell 13. The first welding strip 17 electrically connects the first end battery cell 13 and the intermediate busbar 14, and extends along the first direction; The first pre-fixing film 16 is disposed on the side of the first welding strip 17 away from the first end battery cell 13; Insulating layer 15; disposed between the intermediate busbar 14 and the first end battery cell 13, and partially overlapping with the first pre-fixed film 16; The first solder strip 17 includes a first part 171 and a second part 172. The first part 171 is provided with the first pre-fixing film 16 and the insulating layer 15 on the side away from the first end battery sheet 13. The second part 172 is provided with the insulating layer 15 on the side away from the first end battery sheet 13, but is not provided with the first pre-fixing film 16. Along the first direction, the length L1 of the first part 171 is greater than the length L2 of the second part 172.

[0030] In the solar cell module 10 and photovoltaic system of this application embodiment, since the first part 171 is provided with a first pre-fixing film 16 and an insulating layer 15 on the side away from the first end cell 13; that is, the length of the first part 171 is the overlap length of the first insulating layer 15 and the pre-fixing film, and the second part 172 is provided with an insulating layer 15 but not with the first pre-fixing film 16 on the side away from the first end cell 13; that is, the length of the second part 172 is the overlap length of the direct contact between the insulating layer 15 and the first solder ribbon 17, the length of the first part 171 is greater than the length of the second part 172, which can ensure that the pre-fixation of the first solder ribbon 17 is completed during the pre-fixing film covering stage as much as possible. The first solder ribbon 17 not covered by the first pre-fixing film 16 is then pre-fixed by the insulating layer 15. The probability of the first solder ribbon 17 shifting in the two steps is small, which can improve the reliability of the solar cell module 10.

[0031] In this embodiment of the invention, the solar cell module 10 includes at least one cell string. When the solar cell module 10 includes multiple cell strings, the multiple cell strings can be arranged in multiple rows and columns. The cells within each cell string are connected in series by solder strips. Different cell strings can be connected in series or parallel by busbars to achieve current collection and output. Multiple cell strings can form a cell array and are encapsulated together by a cover plate and an encapsulating film to form the solar cell module 10.

[0032] In this embodiment of the invention, the first battery string 11 includes the first end battery closest to the second battery string 12. It is understood that the battery string may include two battery cells arranged in the first direction and connected in series, three battery cells connected in series, or a greater number of battery cells. The specific number of battery cells to be connected in series can be determined according to the actual usage, and the present invention does not limit this. Furthermore, the grid lines on the battery cells are not shown in the drawings. The grid lines on the battery cells can be arranged according to the actual situation; for example, they can be battery cells with main grids or battery cells without main grids.

[0033] In this embodiment of the invention, the intermediate busbar 14, which connects the first battery string 11 and the second battery string 12 in parallel, is located on the back side of the first end battery cell 13. As an embodiment of the invention, the solar cell module 10 includes the first battery string 11 and the second battery string 12 overlapping along a first direction; and the third battery string 25 and the fourth battery string 26 overlapping along the first direction; wherein the first battery string 11 and the third battery string 25 are arranged along a second direction; and the second battery string 12 and the fourth battery string 26 are arranged along the second direction.

[0034] Specifically, one end of the first battery string 11 and the second battery string 12 are connected in parallel through the intermediate bus bar 14, and one end of the third battery string 25 and the fourth battery string 26 are connected in parallel through the intermediate bus bar 14; one end of the first battery string 11 and the third battery string 25 are connected in series through the edge bus bar 27, and one end of the second battery string 12 and the fourth battery string 26 are connected in series through the edge bus bar 27. Of course, other connection methods can also be used to achieve the series and parallel connection between the battery strings, which is not limited here.

[0035] In this embodiment of the invention, the first solder strip 17 electrically connects the first end battery cell 13 and the intermediate busbar 14, extends along the first direction, and is spaced apart along the second direction.

[0036] The first solder strip 17 is one of tin-plated copper solder strip, bismuth-plated copper solder strip, silver-plated copper solder strip, indium-plated copper solder strip, or tin-lead alloy copper solder strip. This application does not specifically limit the shape or composition of the first solder strip 17, and adjustments can be made flexibly according to actual circumstances.

[0037] In this embodiment of the invention, the first pre-fixed film 16 is disposed on the side of the first welding strip 17 away from the first end battery cell 13.

[0038] Specifically, after the first welding ribbon 17 is laid on the first end battery cell 13, a first pre-fixing film 16 is attached to the back of the first end battery cell 13 using an automatic film applicator. Then, the first pre-fixing film 16 is adsorbed by an adsorption block, placed on the first end battery cell 13, and heated. During heating, pressure is applied to the first pre-fixing film 16 by the adsorption block, causing it to slightly melt and then solidify, thus bonding it to the back of the first end battery cell 13, thereby fixing the first welding ribbon 17 to the first end battery cell 13. Furthermore, the temperature is maintained within the range of 50℃-150℃ during the laying of the first pre-fixing film 16 to allow it to slightly melt and then solidify, bonding it to the back of the first end battery cell 13.

[0039] It should be noted that the first pre-fixing film 16 does not completely cover the first solder strip 17. Within the coverage area of ​​the insulating layer 15, the first solder strip 17 includes a first part 171 away from the intermediate busbar 14 and a second part 172 close to the intermediate busbar 14. The first part 171 and the second part 172 are arranged along the first direction. The first part 171 is provided with the first pre-fixing film 16 and the insulating layer 15 on the side away from the first end battery cell 13. The second part 172 is provided with the insulating layer 15 on the side away from the first end battery cell 13 and is not provided with the first pre-fixing film 16.

[0040] More specifically, the first end cell 13 includes a third region away from the intermediate busbar 14 and a fourth region close to the intermediate busbar 14; the third and fourth regions are arranged along a first direction, and the first pre-fixing film 16 is disposed in the third region, avoiding the fourth region; that is, the third region is covered by the first pre-fixing film 16, and the fourth region is not covered by the first pre-fixing film 16. More specifically, the first pre-fixing film 16 completely covers the third region, and the fourth region is not covered by the first pre-fixing film 16; the first part 171 of the first solder ribbon 17 is disposed in the third region, and the second part 172 of the second solder ribbon 21 is disposed in the fourth region.

[0041] It should be noted that the pre-fixing film can fix the solder ribbons on each battery cell individually. In this case, the pre-fixing film is a sheet-like film layer structure corresponding to the size of a battery cell. That is, the first pre-fixing film 16 is a sheet-like film layer structure corresponding to the size of a first end battery cell 13. Of course, the pre-fixing film can also fix the solder ribbons on multiple battery cells at the same time. In this case, the pre-fixing film is a continuous film layer structure, and the specific length can be cut as needed. That is, the first pre-fixing film 16 is a continuous film layer structure, covering the first end battery cell 13 and also covering the other battery cells in the first battery string 11.

[0042] In this embodiment of the invention, the insulating layer 15 is disposed between the intermediate busbar 14 and the first end battery cell 13, and partially overlaps with the first pre-fixing film 16. Specifically, the insulating layer 15 extends along the second direction, and the lower surface of the insulating layer 15 has an end region and a non-end region. The end region of the lower surface of the insulating layer 15 partially overlaps with the first pre-fixing film 16. The overlap is such that the insulating layer 15 is located on the side of the first pre-fixing film 16 away from the first end battery cell 13, the non-end region of the lower surface of the insulating layer 15 contacts the back edge region of the first end battery cell 13, and the upper surface of the insulating layer 15 carries the intermediate busbar 14.

[0043] The insulating layer 15 can be made of at least one of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and ethylene-vinyl acetate copolymer (EVA).

[0044] In some embodiments of this application, the length L1 of the first part 171 along the first direction is greater than 2 mm. That is, the length of the first part 171 along the first direction is any value of 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm or 2 mm to 30 mm, and is not limited herein.

[0045] Thus, along the first direction, the length L1 of the first portion 171 is within a suitable range, ensuring that the overlap length between the insulating layer 15 and the first pre-fixing film 16 at the first portion 171 is sufficiently long. This allows the first pre-fixing film 16 and the insulating layer 15 to also provide mutual fixation, further preventing the first pre-fixing film 16 from moving and improving its fixing effect, thereby enhancing the reliability of the first pre-fixing film 16 in fixing the first solder ribbon 17. On the other hand, it also avoids the waste of insulating layer 15 material due to excessive overlap length, reducing the component manufacturing cost.

[0046] In some embodiments of this application, the length L2 of the second part 172 along the first direction is 0.2mm to 5mm. For example, it can be any value between 0.2mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm or 0.2mm to 5mm, and is not limited herein.

[0047] Thus, the length L2 of the second part 172 is within a suitable range, which can avoid the second part 172 being too short, resulting in most of the solder strip ends having excessively thick film layers, which can easily cause microcracks at the solder strip ends. It can also avoid the second part 172 being too long, resulting in the insulation layer 15 and the first pre-fixed film 16 overlapping too shortly, so that the first pre-fixed film 16 and the insulation layer 15 cannot play a mutual fixing role, which would affect the reliability of the component.

[0048] In some embodiments of this application, the solar cell module 10 further includes a second pre-fixed film 20; the first battery string 11 further includes a second end battery cell 18 furthest from the second battery string 12; the second end battery cell 18 is provided with a second solder strip 21 extending in a first direction; the second solder strip 21 is electrically connected to the second end battery cell 18 and the edge busbar, and the second pre-fixed film 20 is disposed on the side of the second solder strip 21 away from the second end battery cell 18 and is fixedly connected to the surface of the second end battery cell 18.

[0049] Specifically, the second pre-fixing film 20 covers at least a portion of the length of the second welding strip 21. The method of laying the second pre-fixing film 20 can refer to the method of laying the first pre-fixing film 16 described above, and will not be repeated here.

[0050] The edge busbar extends along the second direction and is located on the outer side or back side of the second end cell 18. The second solder strip 21 is one of tin-plated copper solder strip, bismuth-plated copper solder strip, silver-plated copper solder strip, indium-plated copper solder strip, or tin-lead alloy copper solder strip. In this application, the shape and composition of the second solder strip 21 can be the same as or different from the first solder strip 17, and can be flexibly adjusted according to actual conditions; no specific limitation is made here.

[0051] Thus, the second pre-fixing film 20 can pre-fix the second solder strip 21 on the second end cell 18, thereby achieving a pre-fixing effect on the second solder strip 21 on the second end cell 18, preventing the second solder strip 21 on the second end cell 18 from shifting, and improving the reliability of the solar cell module 10.

[0052] In some embodiments of this application, the second end battery cell 18 includes a first region 181 near the intermediate busbar 14 and a second region 182 away from the intermediate busbar 14; the second pre-fixed film 20 is disposed in the first region 181 and avoids the second region 182.

[0053] In other words, the second pre-fixing film 20 does not completely cover the second end battery cell 18. The first region 181 is covered by the second pre-fixing film 20, while the second region 182 is not covered by the second pre-fixing film 20. The pre-fixing film can fix the solder ribbons on each battery cell individually. In this case, the pre-fixing film is a sheet-like film layer structure corresponding to the size of one battery cell. That is, the second pre-fixing film 20 is a sheet-like film layer structure corresponding to the size of one second end battery cell 18. Of course, the pre-fixing film can also fix the solder ribbons on multiple battery cells simultaneously. In this case, the pre-fixing film is a continuous film layer structure, and the specific length can be cut as needed. That is, the second pre-fixing film 20 is a continuous film layer structure, covering the second end battery cell 18 and also covering the other battery cells in the first battery string 1111.

[0054] In this way, the pre-fixed films on both sides of the battery string are set in the same way, eliminating the need to distinguish between different pre-fixed film rolls at different ends, which simplifies the battery manufacturing process.

[0055] In some embodiments of this application, the length of the second region 182 along the first direction is greater than 2 mm. For example, the length of the second region 182 along the first direction can be any value of 2.1 mm, 2.3 mm, 2.5 mm, 2.7 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, or greater than 2 mm, and is not limited herein. The lengths of the second region 182 and the fourth region are the same along the first direction; however, the lengths of the fourth region and the second region 182 can also be different, and are not limited herein.

[0056] Thus, along the first direction, the length of the second region 182 is within a suitable range, which can simplify the battery manufacturing process, save the amount of the second pre-fixed film 20 used, and reduce the module manufacturing cost; and the pre-fixation of the larger length of the second welding strip 21 has a better pre-fixation effect, which can improve the reliability of the solar cell module 10.

[0057] In some embodiments of this application, the second pre-fixed film 20 completely covers the second end battery cell 18.

[0058] In this way, all areas of the second solder strip 21 on the second end cell 18 can be pre-fixed, which further improves the pre-fixation effect of the second solder strip 21 and can further improve the reliability of the solar cell module 10.

[0059] In some embodiments of this application, the solar cell module 10 further includes a third pre-fixed film 23; along the first direction, the first cell string 11 further includes a plurality of intermediate cell sheets 22 located between the first end cell sheet 13 and the second end cell sheet 18; the plurality of intermediate cell sheets 22 are provided with a third solder strip 24 extending along the first direction; the third pre-fixed film 23 is disposed on the side of the third solder strip 24 away from the plurality of intermediate cell sheets 22.

[0060] Specifically, the third pre-fixing film 23 covers at least a portion of the third welding strip 24. The method of laying the third pre-fixing film 23 can refer to the method of laying the first pre-fixing film 16 described above, and will not be repeated here.

[0061] It should be noted that the third pre-fixing film 23 may overlap with the first pre-fixing film 16, and / or, the third pre-fixing film 23 may overlap with the second pre-fixing film 20. Specifically, the third pre-fixing film 23 may overlap with the first pre-fixing film 16, but the third pre-fixing film 23 and the second pre-fixing film 20 may not overlap; or the third pre-fixing film 23 may not overlap with the first pre-fixing film 16, but the third pre-fixing film 23 may overlap with the second pre-fixing film 20. In this way, adjacent third pre-fixing films 23 and first pre-fixing films 16 can also play a mutual fixing role, which can improve the fixing effect of the first pre-fixing film 16 and the third pre-fixing film 23. The third pre-fixing film 23 may be a single film layer, that is, multiple intermediate battery cells correspond to one whole third pre-fixing film 23, or each intermediate battery cell may correspond to one third pre-fixing film 23, which is not limited here.

[0062] Of course, the third pre-fixed film 23 can also be non-overlapping with the first pre-fixed film 16, and the third pre-fixed film 23 can be non-overlapping with the second pre-fixed film 20. This reduces the amount of pre-fixed film used, lowering the manufacturing cost of the battery module. In this case, the third pre-fixed film 23, the first pre-fixed film 16, and the second pre-fixed film 20 can be a single, integrated film layer, meaning they belong to different regions of this integrated layer. This eliminates the need to lay a separate pre-fixed film for each battery cell, reducing the pre-fixed film laying time and improving battery manufacturing efficiency.

[0063] The third solder strip 24 is one of tin-plated copper solder strip, bismuth-plated copper solder strip, silver-plated copper solder strip, indium-plated copper solder strip, or tin-lead alloy copper solder strip. The shape and composition of the third solder strip 24 in this application can be the same as or different from the first solder strip 17; no specific limitations are made here, and adjustments can be made flexibly according to actual circumstances.

[0064] Thus, the third pre-fixing film 23 can pre-fix the third solder strip 24 of the intermediate cell 22, thereby achieving a pre-fixing effect on the third solder strip 24 on the intermediate cell 22, preventing the third solder strip 24 on the intermediate cell 22 from shifting, and improving the reliability of the solar cell module 10.

[0065] In some embodiments of this application, the first end battery cell 13 partially overlaps with the adjacent intermediate battery cell 22; and / or, two adjacent intermediate battery cells 22 partially overlap; and / or, the second end battery cell 18 partially overlaps with the adjacent intermediate battery cell 22. Specifically, the first end battery cell 13 partially overlaps with the adjacent intermediate battery cell 22; and two adjacent intermediate battery cells 22 partially overlap, and the second end battery cell 18 partially overlaps with the adjacent intermediate battery cell 22; or, the first end battery cell 13 partially overlaps with the adjacent intermediate battery cell 22; and two adjacent intermediate battery cells 22 do not overlap, and the second end battery cell 18 partially overlaps with the adjacent intermediate battery cell 22; or, the first end battery cell 13 partially overlaps with the adjacent intermediate battery cell 22; and two adjacent intermediate battery cells 22 partially overlap, and the second end battery cell 18 does not overlap with the adjacent intermediate battery cell 22; of course, the first end battery cell 13 can also overlap with the adjacent intermediate battery cell 22, which can be set according to needs.

[0066] Understandably, the overlap between the first end cell 13 and the adjacent middle cell 22 can eliminate the conventional gaps between cells, allowing more cells to be arranged per unit area, effectively increasing the light-receiving area and improving the output power of the module.

[0067] In some embodiments of this application, the first solder ribbon 17 further includes a third portion 173; the third portion 173 has the first pre-fixing film 16 on the side opposite to the first end battery cell 13, and does not have the insulating layer 15. This allows for pre-fixation of all areas of the first solder ribbon 17, improving the reliability of the battery assembly.

[0068] Specifically, along the first direction, the first solder strip 17 includes a third part 173, a first part 171, and a second part 172 arranged sequentially, all integrally formed. At this time, the third part 173 has the first pre-fixing film 16 but no insulating layer 15. The first part 171 has the first pre-fixing film 16 and the insulating layer 15, while the second part 172 does not have the first pre-fixing film 16 but has the insulating layer 15.

[0069] In some embodiments of this application, the second battery string 12 includes a third end battery piece 19 closest to the first battery string 11; the third end battery piece 19 partially overlaps with the first end battery piece 13. That is, two battery strings adjacent in the first direction are arranged in an overlapping manner.

[0070] Specifically, the partial overlap between the third end battery cell 19 and the first end battery cell 13 means that the third end battery cell and the first end battery cell 13 partially overlap in a direction perpendicular to the surface of the battery cell. The overlap can be such that the edge region of the third end battery cell 19 is superimposed on the edge region of the first end battery cell 13 to form a stacked structure, or the edge region of the third end battery cell 19 is superimposed on the edge region of the first end battery cell 13 to form a stacked structure.

[0071] Thus, the overlapping design of the third end cell 19 and the first end cell 13 can eliminate the conventional gaps between the cell strings, allowing more cells to be arranged per unit area, effectively increasing the light-receiving area and improving the output power of the module.

[0072] It should be noted that the solar cell module 10 also includes a fourth pre-fixed film and a fourth solder strip. The fourth solder strip is electrically connected to the third end cell 19 and the intermediate busbar 14 and extends along the first direction. The fourth pre-fixed film is disposed on the side of the fourth solder strip away from the third end cell 19. The fourth pre-fixed film and the insulating layer 15 may partially overlap or not overlap. If there is a gap between the fourth pre-fixed film and the insulating layer 15, the fourth solder strip can be directly led out from the gap to the intermediate busbar 14.

[0073] The second battery string 12 also includes a fourth end battery piece and a plurality of intermediate battery pieces 22 located between the third end battery piece 19 and the fourth end battery piece. The structure and setting method of the pre-fixed film of the fourth end battery piece can be the same as the structure and setting method of the pre-fixed film of the second end battery piece 18 in the first battery string 11. The structure and setting method of the pre-fixed film of the plurality of intermediate battery pieces 22 in the second battery string 12 is the same as the structure and setting method of the pre-fixed film on the plurality of intermediate battery pieces 22 in the first battery string 11. For details, please refer to the above description, which will not be repeated here.

[0074] In some embodiments of this application, the overlap length W1 between the third end battery piece 19 and the first end battery piece 13 is 0.1mm to 5mm. For example, it can be any value between 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm or 0.1mm to 5mm, and is not limited herein.

[0075] Thus, the overlap length W1 between the third end cell 19 and the first end cell 13 is within a suitable range. If the overlap length is less than 0.1 mm, the near-zero gap hard contact makes the cell edge a stress concentration point. Under the thermal stress of lamination and the mechanical stress during use, the probability of microcracks will increase. If the overlap length is greater than 5 mm, it will directly reduce the effective surface area of ​​the cell exposed to sunlight, affecting power generation efficiency. Therefore, setting the overlap length W1 between 0.1 mm and 5 mm avoids excessive stress at the cell edge, reducing the risk of microcracks and breakage, and also improves power generation efficiency.

[0076] Preferably, along the first direction, the overlap length W1 between the third end battery piece 19 and the first end battery piece 13 is 0.6 mm to 1.2 mm. For example, it can be any value between 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm or 0.6 mm to 1.2 mm, and is not limited herein.

[0077] This can further reduce the risk of microcracks and fragmentation, and improve power generation efficiency.

[0078] In some embodiments of this application, at least a portion of the first solder strip 17 extends into a folded section near the edge of the first battery string 11. The folded section folds towards the first end battery cell 13 and contacts the intermediate busbar 14.

[0079] It should be noted that the first end cell 13 has two opposing edges, one of which is close to the adjacent intermediate cell 22. The other edge is close to the edge of the first cell string 11. The folded section and the first solder strip 17 are vertically positioned along the thickness of the first end cell 13.

[0080] The insulating layer 15 and the intermediate busbar 14 are stacked and extend along the second direction. The insulating layer 15 and the intermediate busbar 14 are placed between the folded sections of the first solder strip 17. The side of the insulating layer 15 facing away from the first end battery cell 13 is in contact with the side of the intermediate busbar 14 facing the first end battery cell 13. The side of the insulating layer 15 facing the first end battery cell 13 is in contact with the first solder strip 17. The side of the intermediate busbar 14 facing away from the first end battery cell 13 is in contact with the folded section.

[0081] In the specific processing, the folding section extends beyond the edge of the first battery string 11 before folding. Welding between the folding section and the intermediate busbar 14 is performed on the side of the first battery string 11. After welding, the folding section is folded again. When welding the folding section and the intermediate busbar 14 on the side of the first battery string 11, the extension of the folding section beyond the edge of the first battery string 11 provides more space for the welding operation, avoiding potential obstacles encountered when operating in the narrow space inside the first battery string 11. This allows for more precise welding and improves welding quality. Simultaneously, it avoids affecting the first end battery cell 13 during welding, such as causing thermal damage or microcracks, which would reduce the lifespan and stability of the battery assembly.

[0082] In some embodiments of this application, the first pre-fixing film 16 includes at least one of PVB film, EVA film, EPE film, EP film, and POE film. And / or, the second pre-fixing film 20 includes at least one of PVB film, EVA film, EPE film, EP film, and POE film. And / or, the third pre-fixing film 23 includes at least one of PVB film, EVA film, EPE film, EP film, and POE film. The PVB film is made of polyvinyl butyral (PVB), the EVA film is made of ethylene-vinyl acetate copolymer (EVA), the POE film is made of polyolefin elastomer (POE), the EPE film is made of EPE (EVA-POE-EVA), and the EP film is made of EP (EVA-POE). Thus, the above materials have high light transmittance, allowing for pre-fixation of the solder ribbon without affecting the light-receiving effect of the solar cell.

[0083] The materials used to prepare the third pre-fixed membrane 23, the second pre-fixed membrane 20, and the first pre-fixed membrane 16 can be the same or different, and this is not restricted here.

[0084] In one embodiment of the present invention, the thickness of the first pre-fixed film 16 is 5 to 150 micrometers. For example, it can be any value between 5 micrometers, 50 micrometers, 100 micrometers, 150 micrometers, or 5 to 150 micrometers, and is not limited herein. This achieves good fixation of the first pre-fixed film 16 while maintaining good optical performance of the solar cell. The thicknesses of the second pre-fixed film 20 and the third pre-fixed film 23 can be the same as or different from those of the first pre-fixed film 16.

[0085] It is understood that in such embodiments, the solar cell module 10 may further include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back of the solar cells, the photovoltaic glass, and adjacent solar cells. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0086] Photovoltaic glass can be applied to the encapsulating film on the front of the solar cell. This photovoltaic glass can be ultra-clear glass, which boasts high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell together, providing sealing, insulation, and waterproofing / moisture protection for the cell.

[0087] The backsheet can be attached to the adhesive film on the back of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, adhesive film, and photovoltaic glass together form a single unit mounted on a metal frame. The metal frame serves as the main external support structure for the entire solar cell module 10, providing stable support and installation for the solar cell module 10. For example, the solar cell module 10 can be installed at the desired location using the metal frame.

[0088] The photovoltaic system of this application embodiment includes the solar cell module 10 described above.

[0089] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple solar cell modules 10. For example, multiple solar cell modules 10 can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0090] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A solar cell module, characterized in that, include: A first battery string and a second battery string are arranged along a first direction; the first battery string includes a first end cell closest to the second battery string. The intermediate busbar, which connects the first battery string and the second battery string in parallel, is located on the back of the first end battery cell; The first solder strip electrically connects the first end battery cell and the intermediate busbar, and extends along the first direction; A first pre-fixing film is disposed on the side of the first welding strip opposite to the first end battery cell; Insulating layer; It is located between the intermediate busbar and the first end battery cell, and overlaps with the first pre-fixed film portion; The first solder strip includes a first part and a second part. The first part has the first pre-fixing film and the insulating layer on the side opposite to the first end battery cell. The second part has the insulating layer on the side opposite to the first end battery cell but does not have the first pre-fixing film. Along the first direction, the length of the first part is greater than the length of the second part.

2. The solar cell module according to claim 1, characterized in that, Along the first direction, the length of the first part is 2mm to 30mm.

3. The solar cell module according to claim 1, characterized in that, Along the first direction, the length of the second part is 0.2mm to 5mm.

4. The solar cell module according to claim 1, characterized in that, The solar cell module also includes a second pre-fixed film; The first battery string also includes a second end battery cell that is furthest from the second battery string; The second end cell is provided with a second solder strip extending along the first direction; The second pre-fixed film is disposed on the side of the second welding strip opposite to the second end battery cell.

5. The solar cell module according to claim 4, characterized in that, The second end cell includes a first region near the intermediate busbar and a second region away from the intermediate busbar; the second pre-fixed film is disposed in the first region, avoiding the second region.

6. The solar cell module according to claim 5, characterized in that, Along the first direction, the length of the second region is greater than 2 mm.

7. The solar cell module according to claim 4, characterized in that, The second pre-fixed film completely covers the second end battery cell.

8. The solar cell module according to claim 1, characterized in that, The solar cell module also includes a third pre-fixed film; Along the first direction, the first battery string also includes a plurality of intermediate battery cells located between the first end battery cell and the second end battery cell; A third solder strip extending along the first direction is provided on several of the intermediate battery cells; The third pre-fixed film is disposed on the side of the third welding strip opposite to the plurality of intermediate battery cells.

9. The solar cell module according to claim 8, characterized in that, The first end cell overlaps with the adjacent middle cell.

10. The solar cell module according to claim 1, characterized in that, The first solder strip also includes a third part; the third part has the first pre-fixed film on the side opposite to the first end battery cell, and does not have the insulating layer.

11. The solar cell module according to claim 1, characterized in that, The second battery string includes a third end battery cell closest to the first battery string; the third end battery cell partially overlaps with the first end battery cell.

12. The solar cell module according to claim 11, characterized in that, Along the first direction, the overlap length between the third end battery cell and the first end battery cell is 0.1 mm to 5 mm.

13. The solar cell module according to claim 12, characterized in that, Along the first direction, the overlap length between the third end battery cell and the first end battery cell is 0.6 mm to 1.2 mm.

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

15. A photovoltaic system, characterized in that, Includes the solar cell module as described in any one of claims 1-14.

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