Photovoltaic module

Abstract

This utility model discloses a photovoltaic module, which includes multiple solar cells and multiple solder strips. The solder strips are disposed on the solar cells, including edge solder strips and intermediate solder strips. The edge solder strips are disposed along a second direction in the edge region of the solar cells, and the intermediate solder strips are disposed along the second direction in the middle region of the solar cells. The intermediate solder strips have the same cross-sectional shape along a first direction, while the edge solder strips have different cross-sectional shapes along the first direction. By setting edge and intermediate solder strips of different specifications on the solar cells, the stiffness distribution of the solder strips can be optimized. When the photovoltaic module is subjected to external mechanical loads, the stress at the connection between the solder strips and the solar cells can be effectively dispersed, reducing stress concentration. Simultaneously, the different specifications of the edge and intermediate solder strips can adapt to the differentiated deformation of different regions of the solar cells, further reducing the risk of solar cell breakage, extending the service life of the photovoltaic module, and improving the reliability of the photovoltaic module.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic module technology, and in particular to a photovoltaic module. Background Technology

[0002] In existing technologies, photovoltaic modules consist of multiple solar cells, which are usually connected in series using solder ribbons of the same specifications. When a photovoltaic module is subjected to external mechanical loads, the stress cannot be effectively dispersed because the stiffness of the solder ribbons is the same at all points. This leads to stress concentration at the connection between the solar cells and the solder ribbons, making the solar cells prone to breakage and reducing the service life of the photovoltaic module. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the purpose of this invention is to provide a photovoltaic module that can reduce the risk of cell breakage.

[0004] According to an embodiment of the present invention, a photovoltaic module includes: a plurality of solar cells and a plurality of solder ribbons; the plurality of solder ribbons are disposed on the solar cells, the plurality of solder ribbons extend along a first direction and are arranged along a second direction, the plurality of solder ribbons connect adjacent solar cells along the first direction, the first direction and the second direction are different, the plurality of solder ribbons include edge solder ribbons and middle solder ribbons, the edge solder ribbons are disposed along the second direction in the edge region of the solar cells, the middle solder ribbons are disposed along the second direction in the middle region of the solar cells, and the middle solder ribbons are disposed on the side of the edge solder ribbons away from the corresponding edge of the solar cells along the second direction; wherein, the cross-sectional shape of the middle solder ribbons along the first direction is the same, and the cross-sectional shape of the edge solder ribbons along the first direction is different.

[0005] According to the photovoltaic module of this utility model embodiment, by setting edge solder strips and middle solder strips of different specifications on the solar cell, the stiffness distribution of the solder strips can be optimized. When the photovoltaic module is subjected to external mechanical loads, the stress at the connection between the solder strip and the solar cell can be effectively dispersed, reducing stress concentration. At the same time, the edge solder strips and middle solder strips of different specifications can adapt to the differentiated deformation of different areas of the solar cell, further reducing the risk of solar cell breakage, extending the service life of the photovoltaic module, and improving the reliability of the photovoltaic module.

[0006] In some embodiments, the edge solder strip includes: a first connecting segment and a second connecting segment, one end of the first connecting segment being electrically connected to one of the adjacent solar cells; the first connecting segment and the second connecting segment being connected at their adjacent ends, the second connecting segment being electrically connected at its end away from the first connecting segment to the other of the adjacent solar cells, and at least a portion of the first connecting segment having a different cross-sectional shape than the second connecting segment.

[0007] In some embodiments, the projection of the first connecting segment along the thickness direction of the battery cell is located on one of the adjacent battery cells, and the projection of at least a portion of the second connecting segment away from the first connecting segment along the thickness direction of the battery cell is located on the other of the adjacent battery cells, with the ends of the first connecting segment and the second connecting segment away from each other located on different sides of the thickness direction of the adjacent battery cells.

[0008] In some embodiments, the edge strip further includes a third connecting segment connected between the first connecting segment and the second connecting segment, the third connecting segment being located between adjacent solar cells along the first direction.

[0009] In some embodiments, at least a portion of the cross-sectional shape of the end of the first connecting segment connected to the second connecting segment is the same as the cross-sectional shape of the second connecting segment.

[0010] In some embodiments, at least a portion of the cross-sectional shape of the first connecting segment is circular; and / or, the cross-sectional shape of the second connecting segment is non-circular; and / or, the cross-sectional shape of the intermediate weld strip is circular.

[0011] In some embodiments, the cross-sectional shape of the second connecting segment is rectangular or oblong.

[0012] In some embodiments, the first connecting segment and the second connecting segment transition smoothly along the first direction.

[0013] In some embodiments, the cross-sectional area of ​​the intermediate solder strip is larger than the cross-sectional area of ​​the edge solder strip.

[0014] In some embodiments, the diameter of the intermediate welding strip is φ, wherein φ satisfies: 0.24mm≤φ≤0.27mm.

[0015] In some embodiments, the battery cell includes a plurality of grid lines, the edge solder strip and the middle solder strip are electrically connected to the corresponding grid lines respectively, the height of the edge solder strip and the corresponding grid line on the surface of the battery cell adjacent to the edge solder strip after being electrically connected is H1, and the height of the middle solder strip and the corresponding grid line on the surface of the battery cell adjacent to the middle solder strip after being electrically connected is H2, wherein H1 and H2 satisfy: H1≤H2.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a photovoltaic module according to an embodiment of the present utility model; Figure 2 This is a partial schematic diagram of a photovoltaic module according to another perspective of an embodiment of the present utility model.

[0018] Figure label: 100. Photovoltaic modules; 10. Solar cell; 11. First surface; 12. Second surface; 13. First solar cell; 14. Second solar cell; 20. Welding strip; 21. Edge welding strip; 211. First connecting section; 212. Second connecting section; 213. Third connecting section; 22. Middle welding strip; A. First direction; B. Second direction. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Figures 1-2 A photovoltaic module 100 according to an embodiment of the present utility model is described. The photovoltaic module 100 includes: a plurality of solar cells 10 and a plurality of solder strips 20.

[0020] Specifically, such as Figure 1 and Figure 2 As shown, multiple solder ribbons 20 are disposed on the solar cell 10. These ribbons extend along a first direction A and are arranged along a second direction B. The ribbons 20 connect adjacent solar cells 10 along the first direction A. The first direction A and the second direction B are different. Each solder ribbon 20 includes edge solder ribbons 21 and intermediate solder ribbons 22. The edge solder ribbons 21 are disposed along the second direction B in the edge region of the solar cell 10, and the intermediate solder ribbons 22 are disposed along the second direction B in the middle region of the solar cell 10. The intermediate solder ribbons 22 are located on the side of the edge solder ribbons 21 away from the corresponding edge of the solar cell 10 along the second direction B. The intermediate solder ribbons 22 have the same cross-sectional shape along the first direction A, while the edge solder ribbons 21 have different cross-sectional shapes along the first direction A. In this embodiment, the first direction A is the length direction of the photovoltaic module 100, and the second direction B is the width direction of the photovoltaic module 100. The first direction A and the second direction B are perpendicular to each other.

[0021] It should be noted that the phrase "the edge corresponding to the solar cell 10" in the statement "the intermediate solder strip 22 is located on the side of the edge solder strip 21 away from the corresponding edge of the solar cell 10 along the second direction B" refers to the edge of the solar cell 10 corresponding to the edge solder strip 21. For example, for... Figure 2In the middle, the leftmost edge solder strip 21, whose "corresponding edge of the battery cell 10" refers to the left edge of the battery cell 10. Similarly, the rightmost edge solder strip 21, whose "corresponding edge of the battery cell 10" refers to the right edge of the battery cell 10.

[0022] Additionally, "the cross-section of the solder strip along the first direction A" refers to... Figure 2 The cross-section obtained after cutting the weld strip along the second direction B.

[0023] Multiple battery cells 10 are arranged along a first direction A and connected in series by multiple solder strips 20. All solder strips 20 extend along the first direction A and are spaced apart along a second direction B. Each solder strip 20 includes edge solder strips 21 and intermediate solder strips 22. Optionally, there are two edge solder strips 21, each adjacent to one of the two edges of the battery cell 10 along the second direction B. Multiple intermediate solder strips 22 are spaced apart along the second direction B, and all intermediate solder strips 22 have the same cross-sectional shape along the first direction A. The edge solder strips 21 have slightly different cross-sectional shapes along the first direction A. The specifications and rigidity of the intermediate solder strips 22 and edge solder strips 21 are different. Optionally, each edge solder strip 21 includes at least a portion of a circular cross-sectional segment and a portion of a rectangular or oblong cross-sectional segment, which are sequentially connected along the first direction A. The irregularly shaped edge solder strip 21 can be made to have an overall height lower than that of the middle solder strip 22, or by reducing the height of the portion of the edge solder strip 21 that contacts the edge of the solar cell 10 along the first direction A. This increases the contact area between the edge of the solar cell 10 and the corresponding edge solder strip 21 along the first direction A, reduces the overall height of the edge solder strip 21 after it is set with the solar cell 10, reduces the stress at the overlap between the edge area of ​​the solar cell 10 and the solder strip 20, and optimizes the structure of the photovoltaic module 100. Optionally, at least a portion of the solder strip segment with a circular cross-sectional shape is the first connecting segment 211 as described below, and the solder strip segment with a rectangular or oblong cross-sectional shape is the second connecting segment 212.

[0024] According to the photovoltaic module 100 of this utility model embodiment, by setting edge solder strips 21 and middle solder strips 22 of different specifications on the cell 10, the stiffness distribution of the solder strips 20 can be optimized. When the photovoltaic module 100 is subjected to external mechanical loads, the stress at the connection between the solder strips 20 and the cell 10 is effectively dispersed, reducing stress concentration. At the same time, the edge solder strips 21 and middle solder strips 22 of different specifications can adapt to the differentiated deformation of different areas of the cell 10, further reducing the risk of cell breakage, extending the service life of the photovoltaic module 100, and improving the reliability of the photovoltaic module 100.

[0025] According to some embodiments of this utility model, such as Figure 1As shown, the edge welding strip 21 includes: a first connecting segment 211 and a second connecting segment 212, one end of the first connecting segment 211 being electrically connected to one of the adjacent battery cells 10; the first connecting segment 211 and the second connecting segment 212 being connected at their adjacent ends, and the second connecting segment 212 being electrically connected at its end away from the first connecting segment 211 to the other of the adjacent battery cells 10, and at least a portion of the first connecting segment 211 having a different cross-sectional shape than the second connecting segment 212.

[0026] It should be noted that the "connection" in "the first connecting segment 211 and the second connecting segment 212 are connected at their adjacent ends" can be either a direct connection or an indirect connection.

[0027] Two adjacent battery cells 10 along the first direction A are connected in series by an edge solder strip 21 and a middle solder strip 22. The edge solder strip 21 includes a first connecting segment 211 and a second connecting segment 212 extending along the first direction A. The first connecting segment 211 and the second connecting segment 212 are connected at their adjacent ends along the first direction A. The other ends of the first connecting segment 211 and the second connecting segment 212, which are far apart from each other along the first direction A, are electrically connected to the two adjacent battery cells 10 respectively. The cross-sectional shape of the end of the first connecting segment 211 that is far apart from the second connecting segment 212 along the first direction A is different from the cross-sectional shape of the second connecting segment 212.

[0028] Optionally, the battery cell 10 includes a first battery cell 13 and a second battery cell 14 adjacent to each other along the first direction A. The first connecting segment 211 and the second connecting segment 212 are connected at their adjacent ends along the first direction A. The other end of the first connecting segment 211 away from the second connecting segment 212 is electrically connected to the first battery cell 13. The other end of the second connecting segment 212 away from the first connecting segment 211 is electrically connected to the second battery cell 14. The intermediate solder strip 22 is electrically connected to the first battery cell 13 and the second battery cell 14 at both ends along the first direction A, thereby realizing the series connection between the first battery cell 13 and the second battery cell 14.

[0029] Therefore, by connecting the first connecting segment 211 and the second connecting segment 212 at their adjacent ends and at their far ends to two adjacent solar cells 10, it is convenient to realize the series connection of adjacent solar cells 10. At the same time, by designing that at least part of the first connecting segment 211 has a different cross-sectional shape than the second connecting segment 212, the first connecting segment 211 and the second connecting segment 212 have different stiffnesses, which effectively disperses stress, thereby reducing stress concentration at the connection between the edge welding strip 21 and the solar cell 10, reducing the risk of microcracks or breakage of the solar cell 10, and extending the service life of the photovoltaic module 100.

[0030] According to some embodiments of this utility model, such as Figure 1As shown, the projection of the first connecting segment 211 along the thickness direction of the battery cell 10 is located on one of the adjacent battery cells 10, and the projection of at least a portion of the second connecting segment 212 away from the first connecting segment 211 along the thickness direction of the battery cell 10 is located on the other of the adjacent battery cells 10. The ends of the first connecting segment 211 and the second connecting segment 212 away from each other are located on different sides of the thickness direction of the adjacent battery cells 10.

[0031] In this embodiment, the battery cell 10 includes a first surface 11 and a second surface 12. The first surface 11 and the second surface 12 are respectively disposed on both sides of the battery cell 10 along the thickness direction. The projection of the first connecting segment 211 along the thickness direction of the battery cell 10 is located on the first battery cell 13. At least a portion of the second connecting segment 212 away from the first connecting segment 211 is located on the second battery cell 14 along the thickness direction of the battery cell 10. The first connecting segment 211 is located on the first surface 11 of the first battery cell 13, and the other end of the second connecting segment 212 away from the first connecting segment 211 is located on the second surface 12 of the second battery cell 14.

[0032] Therefore, by placing the ends of the first connecting segment 211 and the second connecting segment 212 away from each other on different sides of the thickness direction of the adjacent solar cells 10, the edge welding strip 21 can collect the current in the edge regions of the two adjacent solar cells 10 along the thickness direction, thereby improving the current collection efficiency of the photovoltaic module 100.

[0033] According to some embodiments of this utility model, such as Figure 1 As shown, the edge welding strip 21 also includes a third connecting segment 213, which is connected between the first connecting segment 211 and the second connecting segment 212, and is located between adjacent battery cells 10 along the first direction A.

[0034] The third connecting segment 213 is connected at both ends along the first direction A to the adjacent ends of the first connecting segment 211 and the second connecting segment 212, respectively. The end of the third connecting segment 213 connected to the first connecting segment 211 is located on the first surface 11 of the first battery cell 13, and the other end of the third connecting segment 213 connected to the second connecting segment 212 is located on the second surface 12 of the second battery cell 14. That is, one end of the third connecting segment 213 is connected to the end of the first connecting segment 211 adjacent to the end of the second connecting segment 212, and the other end of the third connecting segment 213 extends obliquely along the first direction A from the first connecting segment 211 toward the second connecting segment 212 and along the thickness direction of the battery cell 10 from the first surface 11 toward the second surface 12, and is connected to the end of the second connecting segment 212 adjacent to the end of the first connecting segment 211.

[0035] Therefore, by setting the third connecting segment 213, it is convenient to connect the first connecting segment 211 and the second connecting segment 212, thereby facilitating the edge solder strip 21 to collect the current in the edge regions on both sides of the adjacent two battery cells 10 along the thickness direction, and improving the reliability of the connection between the first connecting segment 211 and the second connecting segment 212.

[0036] According to some embodiments of the present invention, at least a portion of the cross-sectional shape of one end of the first connecting segment 211 connected to the second connecting segment 212 is the same as the cross-sectional shape of the second connecting segment 212.

[0037] Furthermore, at least a portion of the cross-sectional shape of the first connecting segment 211 is circular. That is, the cross-sectional shape of the end of the first connecting segment 211 away from the second connecting segment 212 along the first direction A is circular. As a result, the tensile strength and bending resistance of the end of the first connecting segment 211 away from the second connecting segment 212 along the first direction A of the edge weld strip 21 can be improved.

[0038] Optionally, the cross-sectional shape of the second connecting segment 212 is non-circular. Because the cross-sectional shape of the second connecting segment 212 differs from the cross-sectional shape of the end of the first connecting segment 211 away from the second connecting segment 212 along the first direction A, the stiffness of the first connecting segment 211 and the second connecting segment 212 are different. This optimizes the stiffness distribution of the edge solder strip 21, effectively dispersing the stress at the connection between the edge solder strip 21 and the solar cell 10 when the photovoltaic module 100 is subjected to external mechanical loads, reducing the risk of breakage in the edge region of the solar cell 10, extending the service life of the solar cell 10, and improving the reliability of the photovoltaic module 100.

[0039] Optionally, the cross-sectional shape of the intermediate weld strip 22 is circular. This can improve the tensile strength and bending resistance of the intermediate weld strip 22, while also facilitating its processing and manufacturing.

[0040] Optionally, when at least a portion of the cross-sectional shape of the first connecting segment 211 is circular, the cross-sectional shape of the second connecting segment 212 is non-circular, and the cross-sectional shape of the intermediate solder strip 22 is circular, the diameter of the circular portion of the first connecting segment 211 is the same as the diameter of the intermediate solder strip 22. This can improve the production efficiency of the photovoltaic module 100 and improve the consistency of the photovoltaic module 100.

[0041] Optionally, the cross-sectional shape of the edge solder strip 21 is circular, and the cross-sectional shape of the middle solder strip 22 is also circular. In this case, the diameter of the edge solder strip 21 is smaller than the diameter of the middle solder strip 22. This reduces the height and stiffness of the edge region of the solar cell 10, allowing the solar cell 10 to better adapt to deformation under mechanical or thermal stress, avoiding stress concentration, effectively reducing microcracks and fractures in the edge region of the solar cell 10, improving the integrity and stability of the solar cell 10, and enhancing the reliability of the photovoltaic module 100.

[0042] Optionally, at least a portion of the cross-sectional shape of the first connecting segment 211 is triangular, and the cross-sectional shape of the intermediate solder strip 22 is also triangular. This allows more incident light to be reflected back to the surface of the solar cell 10, reducing optical loss and improving light utilization, thereby increasing the output power of the photovoltaic module 100. Simultaneously, it reduces the risk of poor soldering of the solder strip 20 and improves the stability of the soldering process.

[0043] According to some embodiments of this utility model, the cross-sectional shape of the second connecting segment 212 is rectangular or oblong. In this case, at least a portion of the cross-sectional shape of the end where the first connecting segment 211 connects to the second connecting segment 212 is rectangular or oblong can increase the contact area between at least a portion of the end where the first connecting segment 211 connects to the second connecting segment 212 and between the second connecting segment 212 and the battery cell 10, thereby improving welding strength, reducing the risk of stress concentration, preventing the battery cell 10 from breaking, reducing the risk of incomplete welding of the edge welding strip 21 during welding, and facilitating the positioning of the edge welding strip 21, reducing the risk of displacement of the edge welding strip 21 during welding, and ensuring welding yield.

[0044] According to some embodiments of this utility model, the first connecting segment 211 and the second connecting segment 212 smoothly transition along the first direction A. That is, the two ends of the third connecting segment 213 smoothly transition with the first connecting segment 211 and the second connecting segment 212 respectively along the first direction A. This ensures a uniform change in mechanical properties between the first connecting segment 211 and the second connecting segment 212, improving the reliability of the edge welding strip 21.

[0045] It is understandable that "the first connecting segment 211 and the second connecting segment 212 smoothly transition along the first direction A" means that the cross-sectional area of ​​the first connecting segment 211 and the second connecting segment 212 along the first direction A gradually changes.

[0046] According to some embodiments of the present invention, the cross-sectional area of ​​the intermediate weld strip 22 is larger than the cross-sectional area of ​​the edge weld strip 21.

[0047] When the cross-sectional area of ​​the edge solder strip 21 is smaller than that of the middle solder strip 22, the stiffness of the edge solder strip 21 is less than that of the middle solder strip 22. Therefore, by designing the cross-sectional area of ​​the middle solder strip 22 to be larger than that of the edge solder strip 21, the stiffness distribution of the solder strip 20 is optimized, effectively reducing the risk of stress concentration in the edge region of the solar cell 10. This allows the solder strip 20 to adapt to the differentiated deformation of different regions of the solar cell 10, reducing the risk of cracks or breakage of the solar cell 10 due to stress concentration. Simultaneously, it reduces the shading area of ​​the edge solder strip 21 on the solar cell 10, reducing light energy loss, increasing the output power of the photovoltaic module 100, and saving production costs.

[0048] According to some embodiments of this utility model, the diameter of the intermediate welding strip 22 is φ, and φ satisfies: 0.24mm≤φ≤0.27mm.

[0049] When the diameter of the intermediate solder strip 22 is less than 0.24 mm, the small diameter may result in lower structural strength, making it prone to breakage or incomplete soldering. Simultaneously, the excessive resistance of the intermediate solder strip 22 reduces the output power of the photovoltaic module 100. Conversely, when the diameter of the intermediate solder strip 22 is greater than 0.27 mm, the excessive diameter may increase the shading area of ​​the intermediate solder strip 22 on the solar cell 10, increasing production costs. For example, φ=0.25 mm.

[0050] Therefore, by limiting the diameter range of the intermediate solder strip 22, while ensuring that the intermediate solder strip 22 has high structural strength, the shading area of ​​the intermediate solder strip 22 on the solar cell 10 can be reduced, the resistance of the intermediate solder strip 22 can be reduced, the output power of the photovoltaic module 100 can be effectively improved, and the production cost can be reduced.

[0051] Optionally, when the cross-sectional shape of the edge weld strip 21 is circular and the cross-sectional shape of the middle weld strip 22 is circular, the diameter of the edge weld strip 21 is 0.22mm-0.24mm.

[0052] According to some embodiments of the present invention, the battery cell 10 includes a plurality of grid lines. The edge solder strip 21 and the middle solder strip 22 are electrically connected to the corresponding grid lines respectively. After the edge solder strip 21 and the corresponding grid line are electrically connected, the height of the surface of the battery cell 10 on the side adjacent to the edge solder strip 21 is H1. After the middle solder strip 22 and the corresponding grid line are electrically connected, the height of the surface of the battery cell 10 on the side adjacent to the middle solder strip 22 is H2. H1 and H2 satisfy: H1≤H2.

[0053] The solar cell 10 also includes a solar cell body, with multiple grid lines disposed on both sides of the solar cell body along the thickness direction of the solar cell 10. Edge solder strips 21 and intermediate solder strips 22 are respectively disposed on the side of the corresponding grid line away from the solar cell body along the thickness direction of the solar cell 10. Edge solder strips 21 and intermediate solder strips 22 respectively collect the current on the corresponding grid line. When at least a portion of the cross-sectional shape of the first connecting segment 211 of the edge grid line is circular, the cross-sectional shape of the second connecting segment 212 is non-circular, and the cross-sectional shape of the intermediate solder strip 22 is circular, along the thickness direction of the battery cell 10, the distance between the portion of the first connecting segment 211 with a circular cross-sectional shape and the corresponding side surface of the battery cell body is less than or equal to the distance between the intermediate solder strip 22 and the corresponding side surface of the battery cell body; the portion of the first connecting segment 211 with the same cross-sectional shape as the second connecting segment 212 and the distance between the second connecting segment 212 and the corresponding side surface of the battery cell body is less than the distance between the intermediate solder strip 22 and the corresponding side surface of the battery cell body; when the cross-sectional shape of the edge solder strip 21 is circular and the cross-sectional shape of the intermediate solder strip 22 is circular, along the thickness direction of the battery cell 10, the distance between the edge solder strip 21 and the corresponding side surface of the battery cell body is less than the distance between the intermediate solder strip 22 and the corresponding side surface of the battery cell body.

[0054] Therefore, by optimizing the height of the edge solder strip 21 and the middle solder strip 22 relative to the surface of the corresponding cell 10, the electrical connection effect is ensured. When the photovoltaic module 100 is subjected to external mechanical loads, stress concentration at the connection between the edge solder strip 21 and the corresponding grid line can be avoided, stress can be dispersed, the risk of cell breakage or microcracks in the cell 10 can be reduced, the service life of the photovoltaic module 100 can be effectively extended, and the reliability of the photovoltaic module 100 can be improved.

[0055] Optionally, along the thickness direction of the solar cell 10, edge solder strips 21 and middle solder strips 22 are respectively provided with solder joints between them and the corresponding grid lines. The cross-sectional shape of the solder joints is elliptical, with uniform size, moderate length and width, smooth surface without pores or cracks, and full solder filling, which can ensure good electrical connection and mechanical strength. In order to reduce the thermal stress generated during the welding process, the solar cell 10 is preheated to reach a certain temperature level before welding. After welding, a slow cooling process is adopted to allow the welding area to cool slowly, reduce the internal stress of the solder joints, improve the mechanical strength and reliability of the solder joints, and improve the stability of the photovoltaic module 100.

[0056] Optionally, considering the mechanical strength and electrical performance of the solar cell 10, suitable edge solder strips 21 and middle solder strips 22 are selected for matching, and the solder strips 20 are subjected to performance tests, including mechanical performance tests (such as tensile strength, elongation, etc.), electrical performance tests (such as resistivity, etc.) and environmental performance tests (such as resistance to damp heat, resistance to salt spray, etc.), to ensure that the materials and surface treatment of the solder strips 20 meet the manufacturing standards and performance requirements of the photovoltaic module 100.

[0057] Compared with traditional photovoltaic modules, the photovoltaic module 100 using the edge solder strip 21 and the middle solder strip 22 in this application has a cell breakage rate of about 0.06% in mechanical load and thermal cycling tests, which significantly improves the reliability and stability of the photovoltaic module 100. In long-term operation, the photovoltaic module 100 can better resist various environmental stresses, such as mechanical load, temperature changes, humidity, etc., reduce maintenance and replacement costs, and extend the service life of the photovoltaic module 100.

[0058] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 utility model.

[0059] In the description of this utility model, "first feature" and "second feature" may include one or more of the features. In the description of this utility model, "multiple" means two or more. In the description of this utility model, "above" or "below" the second feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. In the description of this utility model, "above," "over," and "on top" of the second feature includes the first feature 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.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0061] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A photovoltaic module, characterized by, include: Multiple battery cells; Multiple solder strips are disposed on the battery cell, extending along a first direction and arranged along a second direction. The multiple solder strips connect adjacent battery cells along the first direction. The first direction and the second direction are different. The multiple solder strips include edge solder strips and middle solder strips. The edge solder strips are disposed along the second direction in the edge region of the battery cell, and the middle solder strips are disposed along the second direction in the middle region of the battery cell. The middle solder strips are disposed on the side of the edge solder strips away from the corresponding edge of the battery cell along the second direction. Wherein, the cross-sectional shape of the middle weld strips along the first direction is the same, while the cross-sectional shape of the edge weld strips along the first direction is different.

2. The photovoltaic module of claim 1, wherein, The edge solder strip includes: A first connecting segment, one end of which is electrically connected to one of the adjacent battery cells; A second connecting segment is formed where the first connecting segment and the second connecting segment are connected at their adjacent ends, and the end of the second connecting segment away from the first connecting segment is electrically connected to another of the adjacent battery cells. At least a portion of the first connecting segment has a different cross-sectional shape than the second connecting segment.

3. The photovoltaic module of claim 2, wherein, The projection of the first connecting segment along the thickness direction of the battery cell is located on one of the adjacent battery cells, and the projection of at least a portion of the second connecting segment away from the first connecting segment along the thickness direction of the battery cell is located on the other of the adjacent battery cells, with the ends of the first connecting segment and the second connecting segment away from each other located on different sides of the thickness direction of the adjacent battery cells.

4. The photovoltaic module according to claim 2, characterized in that, The edge solder strip also includes: A third connecting segment is connected between the first connecting segment and the second connecting segment, and the third connecting segment is located between adjacent battery cells along the first direction.

5. The photovoltaic module of claim 2, wherein, At least a portion of the cross-sectional shape of the end where the first connecting segment connects to the second connecting segment is the same as the cross-sectional shape of the second connecting segment.

6. The photovoltaic module of claim 2, wherein, At least a portion of the cross-sectional shape of the first connecting segment is circular; and / or, The cross-sectional shape of the second connecting segment is non-circular; and / or, The cross-sectional shape of the intermediate welding strip is circular.

7. The photovoltaic module of claim 2, wherein, The cross-sectional shape of the second connecting segment is rectangular or oblong.

8. The photovoltaic module of claim 2, wherein, The first connecting segment and the second connecting segment transition smoothly along the first direction.

9. The photovoltaic module of claim 1, wherein, The cross-sectional area of ​​the intermediate weld strip is larger than that of the edge weld strip.

10. The photovoltaic module of claim 1, wherein, The diameter of the intermediate welding strip is φ, and φ satisfies: 0.24mm≤φ≤0.27mm.

11. The photovoltaic module of claim 1, wherein, The battery cell includes multiple grid lines. The edge solder strip and the middle solder strip are electrically connected to the corresponding grid lines. After the edge solder strip and the corresponding grid line are electrically connected, the height of the surface of the battery cell adjacent to the edge solder strip is H1. After the middle solder strip and the corresponding grid line are electrically connected, the height of the surface of the battery cell adjacent to the middle solder strip is H2. H1 and H2 satisfy: H1≤H2.

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