Photovoltaic module

Abstract

The application relates to a photovoltaic module. The photovoltaic module comprises a plurality of cell pieces, the plurality of cell pieces are connected in series, the cell pieces are provided with pattern electrodes, a plurality of interconnection strips are used for connecting the cell pieces in series, and a solder fusion structure is used for electrically connecting the interconnection strips and the pattern electrodes; wherein the circumferential surface of at least one interconnection strip is provided with at least one first area which is not covered by the solder fusion structure. The light utilization rate of the cell pieces can be improved, and the power generation efficiency of the photovoltaic module is improved.

Description

Technical Field

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

[0002] With the development of photovoltaic technology, photovoltaic modules are being used more and more widely. To conduct current collected by the main and secondary grids on the solar cells, or to connect multiple solar cells in series, interconnecting strips are usually welded to the surface of the solar cells. These interconnecting strips are electrically connected to the main and secondary grids, thereby enabling current conduction or connecting multiple solar cells in series.

[0003] However, the light utilization rate of the solar cells in related technologies is low. Utility Model Content

[0004] Based on this, the present application provides a photovoltaic module that can improve the light utilization rate of the solar cells and improve the power generation efficiency of the photovoltaic module.

[0005] On one hand, this application provides a photovoltaic module, characterized in that it includes:

[0006] Multiple solar cells are connected in series, and patterned electrodes are provided on the solar cells.

[0007] Multiple interconnecting strips, used for series connection of solar cells; and

[0008] The solder fusion structure connects the interconnecting strips to the patterned electrodes via the solder fusion structure.

[0009] In this embodiment, at least one interconnecting strip has at least one first area on its periphery that is not covered by the solder fusion structure.

[0010] In one implementation, at least one interconnecting strip includes at least one welded connection segment;

[0011] The welded connection section is the section on the interconnecting strip corresponding to the solder fusion structure; the orthographic projection of the welded connection section on the solar cell overlaps with the orthographic projection of the solder fusion structure on the solar cell;

[0012] The first area is located on the periphery of the welded joint section.

[0013] In one implementation, the first region on at least one welded joint segment is constructed as a continuous region;

[0014] Along the extension direction of the welded joint, the size of the first region is equal to the size of the welded joint.

[0015] In one implementation, the interconnecting strip includes a conductive substrate, which includes at least one of a copper conductive substrate, an aluminum conductive substrate, an alloy conductive substrate, or a copper-aluminum composite substrate.

[0016] And / or, the interconnecting strip includes a conductive substrate and a reflective layer, the reflective layer at least covering the first region.

[0017] In one implementation, the reflective layer wraps around the surface of the interconnect strip.

[0018] In one implementation, the reflective layer comprises a metallic material with a reflectivity greater than 70%, and / or the reflective layer comprises a metallic material with a melting point higher than that of the solder weld structure, preferably silver or aluminum.

[0019] In one implementation, the first region has a first roughness, and the surface of the solder welded structure has a second roughness, wherein the first roughness is less than the second roughness.

[0020] In one implementation, the first roughness Ra < 0.6 μm, preferably Ra ≤ 0.4 μm.

[0021] In one implementation, a first region on at least one interconnecting strip is constructed as a continuous region along the extension direction of the interconnecting strip.

[0022] In one implementation, the reflectivity of the first region is greater than or equal to 70%.

[0023] In one implementation, the patterned electrode includes multiple pad groups, each pad group includes multiple pads, and the multiple pads in each pad group are arranged at intervals along the extension direction of the interconnect strip; the interconnect strip is electrically connected to the pads through a solder welding structure.

[0024] In at least one pad group, the first region includes the section connecting the welded joint segments connected by the welded fusion structures on at least two adjacent pads.

[0025] In one implementation, in each pad group, the first region includes the section between the welded joint segments connected by the welded fusion structures on any adjacent pads.

[0026] In one implementation, the patterned electrode includes a plurality of first grid lines arranged along the extension direction of the interconnect strip, the extension direction of the first grid lines being perpendicular to the extension direction of the interconnect strip;

[0027] Multiple pads include a first pad, which is disposed on a first gate line;

[0028] The solder fusion structure includes a first solder fusion structure, and the first pad is electrically connected to the interconnect strip through the first solder fusion structure.

[0029] In one implementation, on a plane parallel to the thickness direction of the battery cell and parallel to the extension direction of the interconnect strip, the interconnect strip has a first orthographic projection, and at least one first solder fusion structure has a second orthographic projection. The second orthographic projection includes a first sub-projection and a second sub-projection, the first sub-projection overlaps with the first orthographic projection, and the second sub-projection is located outside the first orthographic projection.

[0030] Along the thickness direction of the solar cell, the ratio A of the size of the first sub-projection to the size of the first orthographic projection is less than or equal to 0.93, preferably less than or equal to 0.5.

[0031] In one implementation, any first solder fusion structure has a second orthographic projection on a plane parallel to the thickness direction of the battery cell and parallel to the extension direction of the interconnect strip.

[0032] In one implementation, the orthographic projection of the first solder weld structure onto the solar cell has a first dimension along a direction perpendicular to the extension direction of the interconnect strip, and the orthographic projection of the interconnect strip onto the solar cell has a second dimension, wherein the ratio of the first dimension to the second dimension is less than or equal to 1.1.

[0033] In one implementation, the multiple pads also include a second pad, the area of ​​which is larger than that of the first pad;

[0034] The solder welding structure also includes a second solder welding structure, through which the interconnecting strip is electrically connected to the second pad; the area of ​​the second solder welding structure projected onto the cell is larger than the area of ​​the first solder welding structure projected onto the cell.

[0035] In one implementation, along the extension direction of the interconnect strip, the first region includes the periphery of the interconnect strip between the second pad and the adjacent first pad.

[0036] In one implementation, on a plane parallel to the thickness direction of the battery cell and parallel to the extension direction of the interconnect strip, the interconnect strip has a first orthographic projection, and at least one second solder fusion structure has a second orthographic projection. The second orthographic projection includes a first sub-projection and a second sub-projection, the first sub-projection overlaps with the first orthographic projection, and the second sub-projection is located outside the first orthographic projection.

[0037] Along the thickness direction of the solar cell, the ratio A of the size of the first sub-projection to the size of the first orthographic projection is less than or equal to 0.93.

[0038] In one implementation, along the thickness direction of the solar cell, the ratio A of the size of the first sub-projection to the size of the first orthographic projection is greater than or equal to 0.25 and less than or equal to 0.5.

[0039] In one implementation, at least a portion of the second solder fusion structure is connected on the side of the interconnect strip away from the cell.

[0040] In one implementation, the cross-sectional shape of the interconnecting strip includes a circle along the extension direction perpendicular to the interconnecting strip.

[0041] In one implementation, the interconnecting strip includes two first sidewalls facing each other along a direction perpendicular to the extension direction of the interconnecting strip;

[0042] The two first sidewalls are inclined along a direction perpendicular to the battery cell, and the first region is located on the first sidewalls.

[0043] In one implementation, the end of the first sidewall facing the solder fusion structure overlaps with the solder fusion structure in a direction perpendicular to the extension of the interconnect strip.

[0044] In one implementation, the cross-sectional shape of the interconnecting strip along the extension direction perpendicular to the interconnecting strip includes any one of triangle, trapezoid, and pentagon.

[0045] In one implementation, the patterned electrode further includes a second gate line, which intersects the first gate line at the first pad and is electrically connected to the second pad.

[0046] The solder fusion structure includes a third solder fusion structure, through which the interconnecting strip is electrically connected to the second gate line.

[0047] In one implementation, at least one interconnecting strip includes at least one non-welded connection segment, the orthographic projection of the non-welded connection segment onto the solar cell being located outside the orthographic projection of the solder fusion structure onto the solar cell, and at least a portion of the first region being located within the non-welded connection segment.

[0048] In one implementation, at least one interconnecting strip:

[0049] At least one non-welded connection segment includes a first non-welded connection segment located between the same interconnect strip connected to the same cell and any two adjacent solder fusion structures.

[0050] In one implementation, the solder fusion structure is formed by soldering with solder paste, preferably tin paste.

[0051] The photovoltaic module provided in this application embodiment features patterned electrodes on the solar cells. These patterned electrodes allow for the collection of photocurrent, improving the collection efficiency. Multiple solar cells are connected in series via interconnecting strips, facilitating the outward transmission of the photocurrent collected by the patterned electrodes. The interconnecting strips are connected to the patterned electrodes via solder fusion structures, and at least one interconnecting strip has at least one first region on its peripheral surface that is not covered by the solder fusion structure. Because this first region is not covered by the solder fusion structure, the surface roughness of the first region is reduced after the interconnecting strip is welded, compared to the method in related technologies where solder covers the entire solder strip surface. This allows the first region to reflect light, reusing it on the surface of the solar cells and improving the light utilization rate of the solar cells. This ultimately improves the power generation efficiency of the photovoltaic module. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of a photovoltaic module provided in some embodiments of this application.

[0053] Figure 2 This is a schematic diagram of a structure in which solar cells and interconnecting strips cooperate in a photovoltaic module according to some embodiments of this application.

[0054] Figure 3 This is a top view of a photovoltaic module provided in some embodiments of this application.

[0055] Figure 4 This is another top view of the photovoltaic module provided in some embodiments of this application.

[0056] Figure 5 This is a side view of the solar cells, solder welding structure, and interconnect strips in a photovoltaic module provided in some embodiments of this application.

[0057] Figure 6 This is a schematic diagram of another structure for the cooperation between solar cells and interconnecting strips in a photovoltaic module provided in some embodiments of this application.

[0058] Figure 7 This is yet another top view of a photovoltaic module provided in some embodiments of this application.

[0059] Figure 8 yes Figure 7 A magnified view of a portion of point A in the middle.

[0060] Figure 9 This is an optical path analysis diagram of light reflected from the surface of the interconnect strip exposed on the solder fusion structure in a photovoltaic module provided in some embodiments of this application.

[0061] Figure 10This is another structural schematic diagram of the photovoltaic module in which the solar cells and interconnecting strips cooperate, provided in some embodiments of this application.

[0062] Figure 11 This is another structural schematic diagram of the photovoltaic module in which the solar cells and interconnecting strips cooperate, provided in some embodiments of this application.

[0063] Figure 12 This is another structural schematic diagram of the photovoltaic module in which the solar cells and interconnecting strips cooperate, provided in some embodiments of this application.

[0064] Explanation of reference numerals in the attached figures:

[0065] 10 - Solar cell; 20 - Interconnect strip; 30 - Solder welding structure; 40 - Adhesive film; 60 - Tin-lead solder;

[0066] 11-Patterned electrode; 21-Conductive substrate; 22-Reflective layer; 23-First sidewall; 24-Welded connection section; 25-Non-welded connection section; 26-First connection section; 27-Second connection section; 28-Black area; 31-First solder fusion structure; 32-Second solder fusion structure;

[0067] 111 - Pad; 112 - First gate line; 113 - Second gate line;

[0068] 111a - First pad; 111b - Second pad. Detailed Implementation

[0069] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0070] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms 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.

[0071] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0072] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0073] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0074] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0075] Figure 1 This is a schematic diagram of a photovoltaic module provided in some embodiments of this application.

[0076] In some examples, refer to Figure 1 As shown, some examples of embodiments of this application provide a photovoltaic module. The photovoltaic module may include a plurality of solar cells 10.

[0077] In some examples, the solar cell 10 may have a thickness direction (e.g., Figure 1 Two surfaces opposite each other (in the direction shown by the z-axis).

[0078] In some examples, of the two surfaces opposite each other along the thickness direction of the solar cell 10, one surface can be the light-facing surface, and the other surface can be the backlight surface.

[0079] In some examples, the light-facing side can be referred to as the front of the solar cell. The back-facing side can be referred to as the back of the solar cell.

[0080] In some examples, the solar cell 10 may include a silicon-based cell. It is understood that the type of solar cell 10 is shown only as a specific example and is not intended to limit the specific type of solar cell 10.

[0081] In some examples, multiple solar cells 10 can be electrically connected in series to form the photoelectric conversion body of a photovoltaic module.

[0082] In some examples, the solar cell 10 may be provided with a patterned electrode 11. The patterned electrode 11 can form an ohmic contact with the solar cell 10, thereby collecting the photocurrent generated by the photoelectric conversion of the solar cell 10. Specifically, in some embodiments, the patterned electrode 11 may include grid lines.

[0083] In some examples, the patterned electrode 11 can be printed onto the battery cell 10 by screen printing.

[0084] In some examples, each of the multiple battery cells 10 may be provided with patterned electrodes 11.

[0085] In some examples, the patterned electrode 11 may be disposed on at least one surface of the cell 10 in the thickness direction.

[0086] In some examples, the patterned electrode 11 may be disposed on the light-facing side of the solar cell 10, that is, the patterned electrode 11 may include a front patterned electrode. In other examples, the patterned electrode 11 may be disposed on the back-facing side of the solar cell 10, that is, the patterned electrode 11 may include a back patterned electrode.

[0087] In some examples of embodiments of this application, by providing patterned electrodes 11 on the battery cell 10, the photocurrent generated by the battery cell 10 can be collected through the patterned electrodes 11, which can reduce the transmission path of the photocurrent and thus reduce the loss of current during transmission.

[0088] In some examples, refer to Figure 1 As shown, a photovoltaic module may include multiple interconnecting strips 20. The interconnecting strips 20 can be used for series connection of solar cells 10. In some examples of embodiments of this application, multiple solar cells 10 can be connected in series via interconnecting strips 20.

[0089] In some examples, the arrangement direction of multiple interconnecting strips 20 may intersect with the extension direction of the interconnecting strips 20. It can be understood that the interconnecting strips 20 can be used for series connection of battery cells 10, so the interconnecting strips 20 have a longitudinal extension direction, and therefore the extension direction of the interconnecting strips 20 refers to the length direction of the interconnecting strips 20.

[0090] In some examples, the arrangement direction of multiple interconnecting strips 20 can be perpendicular to the extension direction of the interconnecting strips 20.

[0091] In some examples, the interconnecting strip 20 can be electrically connected to the patterned electrode 11, thereby connecting adjacent solar cells 10 in series.

[0092] In some examples, the interconnecting strip 20 can be electrically connected to the patterned electrode 11 by welding.

[0093] In some examples, the surface of interconnect strip 20 is not coated with solder before soldering. The solder layer thickness on the surface of the interconnect strip is typically in the micrometer range, such as 8 μm, 10 μm, 11 μm, 12 μm, 15 μm, or 18 μm. Specifically, in some embodiments, the solder may include tin-lead solder. In some examples, when soldering interconnect strip 20, solder can be printed on patterned electrode 11, and the interconnect strip 20 and patterned electrode 11 can be soldered together.

[0094] Figure 2 This is a schematic diagram of a structure in which solar cells and interconnecting strips cooperate in a photovoltaic module according to some embodiments of this application.

[0095] In some examples, refer to Figure 2 As shown, the photovoltaic module may include multiple solder fusion structures 30. The interconnect strip 20 can be electrically connected to the patterned electrode 11 through the solder fusion structures 30.

[0096] In some examples, the solder fusion structure 30 can be formed by melting solder. Specifically, in some embodiments, the solder fusion structure 30 can be formed by melting solder and interconnect strip 20; in other embodiments, the solder fusion structure 30 can be formed by melting solder and pattern electrode 11; and in still other embodiments, the solder fusion structure 30 can be formed by melting solder, interconnect strip 20 and pattern electrode.

[0097] In some examples, the solder weld structure 30 may be made of a conductive material. For example, the solder may be solder paste.

[0098] It is understood that in some examples of embodiments of this application, the specific type of solder fusion structure 30 is shown only as a specific example and is not intended to limit the specific material of the solder fusion structure 30.

[0099] Figure 3 This is a top view of a photovoltaic module provided in some embodiments of this application.

[0100] In some examples, refer to Figure 3 As shown, the peripheral surface of the interconnect strip 20 may have at least one first area (not labeled) not covered by the solder fusion structure 30. It is understood that when the solder fusion structure 30 is soldered to the interconnect strip 20 after being melted with solder paste or solder, the solder fusion structure 30 typically accumulates between the interconnect strip 20 and the pattern electrode 11 under the influence of interfacial tension. In other words, the solder fusion structure 30 between the interconnect strip 20 and the pattern electrode 11 typically does not form a cavity to create the first area.

[0101] In some examples of embodiments of this application, at least one first region not covered by the solder fusion structure 30 is provided on the circumferential surface of the interconnect strip 20. Thus, since the first region is not covered by the solder fusion structure, after the interconnect strip welding is completed, the surface roughness of the first region is reduced compared to the method of wrapping the entire solder strip surface in related technologies. The first region can reflect light, allowing the light to be reflected back to the surface of the solar cell for reuse, thereby improving the light utilization rate of the solar cell. This improves the power generation efficiency of the photovoltaic module.

[0102] In some examples, refer to Figure 3 As shown, in the extending direction of the interconnect strip 20, at least one interconnect strip 20 includes at least one non-welded connection segment 25. Here, taking the non-welded connection segment 25 on the front side of the battery cell 10 as an example, the non-welded connection segment 25 refers to the section below the interconnect strip 20 where the solder welding structure 30 is not provided. In other words, the non-welded connection segment 25 is the section that is not connected to the battery cell through the solder welding structure 30, and the non-welded connection segment 25 is not in direct contact with the solder welding structure 30.

[0103] It is understood that at least one interconnecting strip 20 may also include a welded connection segment 24. Here, the welded connection segment 24 on the front side of the battery cell 10 is used as an example. The welded connection segment 24 refers to the section below the interconnecting strip 20 where a solder fusion structure 30 is provided. For example, the welded connection segment 24 is electrically connected to the patterned electrode 11 through the solder fusion structure 30.

[0104] It is also understandable that Figure 3 In the embodiment shown, the extension direction of the interconnecting strip 20 is the x-axis direction. In some embodiments, the x-axis direction can be the length direction of the interconnecting strip 20.

[0105] In some examples, the non-welded connection segment 25 may be located between two adjacent welded connection segments 24.

[0106] In some examples, the orthographic projection of the non-welded connection segment 25 on the cell 10 is outside the orthographic projection of the solder weld structure 30 on the cell 10.

[0107] In some examples, the size of the interconnect strip 20 along the extension direction of the interconnect strip 20 can be larger than the size of the solder fusion structure 30, so that the orthographic projection of the non-welded connection segment 25 on the cell 10 can be outside the orthographic projection of the solder fusion structure 30 on the cell 10.

[0108] The photovoltaic module provided in this application embodiment has patterned electrodes 11 on the solar cells 10. This allows for the collection of photocurrent by the patterned electrodes 11, improving the collection efficiency. Multiple solar cells 10 are connected in series by multiple interconnecting strips 20, facilitating the outward transmission of the photocurrent collected by the patterned electrodes 11. The interconnecting strips 20 are connected to the patterned electrodes 11 via solder fusion structures 30. At least one interconnecting strip 20 includes at least one non-soldering connection segment 25, the orthographic projection of which onto the solar cell 10 is outside the orthographic projection of which onto the solar cell 10. Thus, along the extension direction of the interconnecting strip 20, there is no solder fusion structure 30 between the non-soldering connection segment 25 and the solar cell 10, reducing the material used for the solder fusion structure 30 and lowering the manufacturing cost of the photovoltaic module.

[0109] In some examples, refer to Figure 3 As shown, on at least one interconnect strip 20, at least one non-welded connection segment 25 may include a first non-welded connection segment. The first non-welded connection segment is a segment connected on the same interconnect strip 20 of the same solar cell 10 between sections connecting two adjacent solder fusion structures 30. In other words, on the same interconnect strip 20 of the same solar cell 10, the non-welded connection segment 25 located between sections connecting two adjacent solder fusion structures 30 is defined as the first non-welded connection segment.

[0110] When hot spot problems occur during photovoltaic module hot spot testing or use, the local temperature of the cell 10 will rise (sometimes reaching or exceeding the melting point of the solder fusion structure 30). At this time, the solder fusion structure 30 will be activated and produce a "metal adsorption effect". That is, the solder fusion structure 30 and the surrounding metal pattern electrodes, such as Ag electrodes, will undergo an alloying reaction. Some metal pattern electrodes and tin in the solder fusion structure will undergo an alloying reaction to form brittle intermetallic compounds, such as Ag3Sn. This will greatly reduce the adhesion performance of the metal pattern electrodes on the surface of the cell 10. After cooling, the metal pattern electrodes are easy to detach from the cell 10 and form a broken grid. The "metal adsorption effect" usually increases with the increase of the volume or content of the solder fusion structure. In some examples of the embodiments of this application, a first non-welded connection segment 25 is set, that is, two adjacent solder fusion structures 30 are spaced apart. Under the premise of satisfying the electrical connection between the interconnect strip and the battery cell, the volume and amount of the solder fusion structure 30 are reduced, the synergistic effect when two adjacent solder fusion structures 30 are combined into one is reduced, the degree of alloying of the patterned electrode is reduced, and the risk of failure after the photovoltaic module has hot spot problem is reduced to a certain extent, and the anti-hot spot performance of the photovoltaic module is improved.

[0111] In some examples, the non-welded connection segment 25 may have multiple first non-welded connection segments.

[0112] In some examples, at least one interconnecting strip 20 has a non-welded connection segment 25 connecting any two adjacent solder fusion structures 30.

[0113] In some examples, non-welded connection segments 25 are connected between any two adjacent solder fusion structures 30 on any interconnecting strip 20.

[0114] In some examples, at least one non-welded connection segment 25 on at least one interconnecting strip 20 may include a second non-welded connection segment. Wherein, the second non-welded connection segment may be located at the end of the interconnecting strip 20 along its extension direction; in other words, on the same interconnecting strip 20 of the same cell 10, the non-welded connection segment 25 located at the end of the interconnecting strip 20 in its extension direction is defined as the second non-welded connection segment.

[0115] In this way, the pulling of the interconnect strip 20 on the battery cell due to thermal expansion at the end can be reduced, the stress on the battery cell 10 can be reduced, and the risk of the battery cell 10 breaking can be reduced.

[0116] In some examples, the second non-welded connection segment is located outside the orthogonal projection of the patterned electrode 11 onto the battery cell (10). During welding, the solder melts into a liquid state when heated, which tends to reduce the surface energy. If a patterned electrode is not provided between the interconnect strip and the battery cell, the solder cannot be evenly distributed through the wetting electrode, but tends to accumulate and pile up at the edge, which can easily lead to microcracks in the battery cell 10.

[0117] In some examples, at least one non-welded connection segment 25 on at least one interconnecting strip 20 may include a third non-welded connection segment. The third non-welded connection segment extends to and is flush with one side edge of the cell 10. Along the extension direction of the interconnecting strip 20, the third non-welded connection segment may be located at the edge where the current cell 10 is adjacent to another cell 10, and the interconnecting strip 20 connects from the front side of the current cell 10 to the back side of the adjacent cell 10.

[0118] In some examples, at least a portion of the third non-welded connection near the edge has its orthographic projection on the cell outside the orthographic projection of the patterned electrode 11 on the cell.

[0119] It is understandable that during welding, the solder melts into a liquid state when heated, which tends to reduce the surface energy. If there is no patterned electrode between the interconnect strip and the cell, the solder cannot be evenly distributed through the wetting electrode, but tends to accumulate and pile up at the edge, which can easily lead to microcracks in the cell.

[0120] When the interconnecting strip 20 connects from the front of the current battery cell 10 to the back of the adjacent battery cell 10, the height of the interconnecting strip 20 at the edge of the current battery cell 10 decreases along the thickness direction of the battery cell 10 because it extends towards the back of the adjacent battery cell 10. In some examples of embodiments of this application, this part of the interconnecting strip 20 is set as a third non-welded connection segment. That is, there is no solder fusion structure 30 between the interconnecting strip 20 and the battery cell 10 at the edge of the battery cell 10. Thus, when soldering the interconnecting strip 20 and the patterned electrode 11, the molten solder has fluidity. Since no solder is provided between the third non-welded connection segment set at the edge of the battery cell 10 and the battery cell 10, there is no situation where solder flows along the interconnecting strip 20 towards the back of the adjacent battery cell 10 at the edge of the battery cell 10. Therefore, it can avoid the solder fusion structure 30 from piling up due to solder accumulation on the back of adjacent solar cells 10, which would cause microcracks in the solar cells 10 and protect the solar cells 10.

[0121] In some examples, the interconnect strip 20 has a flattened structure in the section connecting the front of the current cell 10 to the back of the adjacent cell 10. At least a portion of the third non-welded connection section near the edge is flattened. In the direction of interconnect strip extension, at least a portion of the third non-welded connection section near the edge has a gradient with the interconnect strip 20 in the cell thickness direction. No solder is provided between the third non-welded connection section and the cell 10. Therefore, there is no situation where solder flows and accumulates along the interconnect strip 20 at the flattened structure of the third non-welded connection section, reducing the risk of microcracks at the edge of the cell.

[0122] In some examples, the interconnect strip 20 may include a fourth segment (not labeled in the figure). The segment of the interconnect strip 20 located between two connected solar cells 10 is constructed as the fourth segment, and no solder is provided on the fourth segment. In this way, solder can be prevented from flowing along the slope of the interconnect strip 20 from the front of the solar cell 10 to the back of the adjacent solar cell 10, thus preventing solder accumulation on the back of the adjacent solar cell 10 and the resulting high solder weld structure 30, which could cause microcracks in the solar cell 10, thereby protecting the solar cell 10.

[0123] In some examples, at least one interconnecting strip 20 includes a first non-welded connection segment, a second non-welded connection segment, a third non-welded connection segment, and a fourth segment.

[0124] In some examples of embodiments of this application, the first non-welded connection segment is disposed between any two adjacent solder fusion structures 30 connected to the same battery cell and the same interconnect strip 20, which are connected to the welded connection segments 24. That is, on the same battery cell 10, at least two solder fusion structures 30 can be disposed at intervals along the extension direction of the interconnect strip 20.

[0125] In some examples, along the extension direction of the interconnecting strip 20, the first non-welded connection segment may be located between the welded connection segments 24 where the two solder fusion structures 30 are connected.

[0126] In some examples, on the same cell 10, any two adjacent solder fusion structures 30 can be spaced apart along the extension direction of the interconnect strip 20.

[0127] In some examples, if two adjacent solder fusion structures 30 are connected together by solder along the extension direction of the interconnect strip 20, then these two solder fusion structures 30 can be considered as one solder fusion structure 30.

[0128] In some examples, in related technologies, tin-lead solder 60 is coated on the surface of the interconnect strip 20, and the tin-lead solder 60 melts during the lamination process to form a weld. This results in tin-lead solder 60 being present in the extension direction of the interconnect strip 20. Furthermore, the tin-lead solder 60 extends beyond the orthogonal projection of the interconnect strip 20 onto the solar cell along the width direction of the interconnect strip 20, which may obstruct the light-receiving surface of the solar cell.

[0129] In some examples of embodiments of this application, at least two solder fusion structures 30 on the same solar cell 10 are spaced apart along the extension direction of the interconnect strip 20. This reduces the amount of solder fusion structures 30 used, lowering the manufacturing cost of the photovoltaic module. Furthermore, the interconnect strip 20 between the spaced-apart solder fusion structures 30 does not have a solder fusion structure 30. In other words, compared to the related art where the interconnect strip 20 has tin-lead solder 60 along its extension direction, the spaced-apart position between the two solder fusion structures 30 reduces the shading of the solder fusion structures 30 on the light-receiving area of ​​the solar cell 10 in the width direction of the interconnect strip 20, increasing the light-receiving area of ​​the solar cell 10 and thus improving the light utilization rate of the solar cell 10. This improves the photoelectric conversion efficiency of the photovoltaic module.

[0130] Figure 4 This is another top view of the photovoltaic module provided in some embodiments of this application.

[0131] In some examples, at least one solder weld structure 30 is provided on at least one interconnecting strip 20 on the same cell 10.

[0132] In some examples, at least one interconnect strip 20 may include at least one welded connection segment 24. The welded connection segment 24 may be electrically connected to the patterned electrode 11 via a solder fusion structure 30. In other words, the welded connection segment 24 may be a segment on the interconnect strip corresponding to the solder fusion structure 30.

[0133] In some examples, the welded connection segment 24 can be the section where the orthographic projection of the interconnect strip 20 on the solar cell 10 overlaps with the orthographic projection of the solder fusion structure 30 on the solar cell 10. In other words, the orthographic projection of the welded connection segment 24 on the solar cell 10 overlaps with the orthographic projection of the solder fusion structure 30 on the solar cell 10. In some examples, the overlap can mean that the portion of the orthographic projection of the welded connection segment 24 on the solar cell 10 and the orthographic projection of the solder fusion structure 30 on the solar cell 10 has the same dimension along the extension direction of the interconnect strip 20.

[0134] In some examples, on the same cell 10, one of the multiple interconnect strips 20 can be provided with a solder fusion structure 30.

[0135] In some examples, on the same cell 10, one of the multiple interconnect strips 20 can be provided with multiple solder fusion structures 30.

[0136] In some examples, on the same cell 10, some of the interconnecting bars 20 can be provided with a solder fusion structure 30.

[0137] In some examples, on the same cell 10, some of the interconnecting strips 20 can be provided with multiple solder fusion structures 30.

[0138] In some examples, on the same cell 10, any one of the multiple interconnect strips 20 can be provided with a solder fusion structure 30.

[0139] In some examples, on the same cell 10, any one of the multiple interconnect strips 20 can be provided with multiple solder fusion structures 30.

[0140] In some examples, along the extension direction of the interconnect strip 20, the orthographic projection of the end of the interconnect strip 20 on the cell 10 is outside the orthographic projection of the solder fusion structure 30 on the cell 10.

[0141] In some examples, along the extension direction of the interconnect strip 20, the orthographic projection of the end of the interconnect strip 20 onto the cell 10 may exceed the orthographic projection of the solder fusion structure 30 onto the cell 10.

[0142] In some examples, when a solder fusion structure 30 and an interconnect strip 20 are provided on the solar cell 10, the solder fusion structure 30 can be arranged along the extension direction of the interconnect strip 20. Along the extension direction of the interconnect strip 20, the length of the solder fusion structure 30 can be less than the length of the interconnect strip 20, so that the projection of at least one end of the interconnect strip 20 onto the solar cell 10 is outside the projection of the solder fusion structure 30 onto the solar cell 10. It should be noted that the interconnect strip 20 has two ends, namely the two ends along its length direction, which can be defined as the beginning end and the end end. At least one end refers to at least one of the beginning end and the end end.

[0143] In some examples of embodiments of this application, at least one solder fusion structure 30 is provided on at least one interconnect strip 20 on the same solar cell 10, and the projection of the end of the interconnect strip 20 on the solar cell 10 is positioned outside the projection of the solder fusion structure 30 on the solar cell 10 along the extending direction of the interconnect strip 20. This reduces the amount of solder fusion structure 30 used, thereby lowering the production and processing costs of photovoltaic modules.

[0144] Furthermore, the projection of the end of the interconnect strip 20 onto the solar cell 10 is positioned outside the projection of the solder fusion structure 30 onto the solar cell 10. Thus, the end of the interconnect strip 20 is not connected to the solar cell 10 via the solder fusion structure 30. When the photovoltaic module is subjected to external impact, the end of the interconnect strip 20 can shift relative to the solar cell 10 within a preset range, thereby buffering and dispersing the external impact force, reducing the impact intensity on the solar cell 10, and thus reducing the risk of microcracks or fragmentation of the solar cell 10, extending the service life of the photovoltaic module.

[0145] It is understood that when the interconnecting strip 20 connects from the front of the current battery cell 10 to the back of the adjacent battery cell 10, the height of the interconnecting strip 20 at the edge of the current battery cell 10 decreases along the thickness direction of the battery cell 10 because it extends towards the back of the adjacent battery cell 10. In some embodiments of this application, this part of the interconnecting strip 20 is set as a second non-welded connection segment. That is, there is no solder fusion structure 30 between the interconnecting strip 20 and the battery cell 10 at the edge of the battery cell 10. Thus, when soldering the interconnecting strip 20 and the patterned electrode 11, the solder is in a molten state and has fluidity, and there is no situation where the solder flows along the interconnecting strip 20 towards the back of the adjacent battery cell 10 at the edge of the battery cell 10. Therefore, it is possible to avoid the solder fusion structure 30 that eventually forms due to solder accumulation on the back of the adjacent battery cell 10, which could cause microcracks in the electrode sheet 10 and protect the battery cell 10.

[0146] In some examples, refer to Figure 2 and Figure 4 As shown, at least two solder fusion structures 30 are spaced apart on the same solar cell 10 along the extension direction of the interconnect strip 20. That is, at least two solder fusion structures 30 can be provided along the extension direction of the interconnect strip 20.

[0147] In some examples, refer to Figure 4 As shown, at least one welded joint segment 24 has at least one first area on its peripheral surface that is not covered by the solder fusion structure 30. That is, at least one of the multiple solder fusion structures 30 does not cover the peripheral surface of the interconnect strip 20. This reduces the amount of solder in the welded joint segment and reduces the risk of grid breakage due to solder-electrode metal alloying at elevated temperatures, because at hot spot test temperatures, the larger the solder volume and content, the greater the adsorption force on the metal grid lines.

[0148] In some examples, the first region may be located on the side of the interconnect strip 20 opposite to the battery cell 10.

[0149] In some examples, the interconnecting strips 20 placed on the solar cell 10 have a symmetrical structure, with the upper symmetrical portion of the interconnecting strip 20 located on the side facing away from the solar cell 10. The first region is located on this side of the interconnecting strip 20. This side of the interconnecting strip 20 facing away from the solar cell 10 is the main reflective area. This arrangement enhances the reflective effect of the interconnecting strip 20 and improves the photoelectric conversion efficiency.

[0150] In some examples, taking the interconnecting strip 20 located on the front side of the battery cell 10 as an example, the first region may be located at the top of the interconnecting strip 20 away from the battery cell 10. Alternatively, the first region may extend from the top of the interconnecting strip 20 away from the battery cell 10 around the circumference of the interconnecting strip 20 towards the battery cell 10.

[0151] In some examples, in a solder weld structure 30, a first region may be exposed at least a portion of the solder weld structure 30. That is, along the length of the interconnect strip, a solder weld structure 30 may have a portion that does not cover the side of the interconnect strip 20 away from the cell 10, while another portion covers the side of the interconnect strip 20 away from the cell 10.

[0152] In some examples, the first region on at least one welded joint 24 can be constructed as a continuous region. In other words, the first region corresponding to at least one welded joint 24 is a monolithic segment.

[0153] In some examples, the size of the first region along the extension direction of the welded joint 24 may be equal to the size of the welded joint 24.

[0154] In some examples, at least one first region on the interconnecting strip 20 is constructed as a continuous region along the extension direction of the interconnecting strip 20.

[0155] During hot spot testing of photovoltaic modules, the local temperature of the cell 10 rises (sometimes reaching or exceeding the melting point of the solder fusion structure 30). At this time, the alloying process between the solder fusion structure 30 and the Ag electrode is accelerated. The brittle Ag3Sn phase generated by the alloying reaction of some Ag electrodes or Ag grid lines significantly reduces the adhesion of the grid lines to the surface of the cell 10. After the hot spot test, the grid line electrodes are prone to detach from the cell 10, forming broken grids. In some examples of embodiments of this application, by reducing the amount of solder fusion structure 30, the degree of grid line electrode alloying can be reduced, which can, to some extent, reduce the risk of photovoltaic module failure after hot spot testing.

[0156] In addition, during the use of photovoltaic modules, when hot spot effect occurs, the local temperature of the cell 10 will rise (sometimes reaching or exceeding the melting point of the solder fusion structure 30); in this embodiment, by reducing the amount of solder fusion structure 30, the degree of grid motor alloying can be reduced, thereby improving the hot spot resistance of the photovoltaic module.

[0157] In some examples, the solar cell 10 may include a light-facing surface. The light-facing surface may be one of the surfaces along the thickness direction of the solar cell 10. In some examples, the light-facing surface may also be referred to as the front side of the solar cell.

[0158] In some examples, the solar cell 10 may include a backlight surface. The backlight surface may be another surface along the thickness direction of the solar cell 10. Along the thickness direction of the solar cell 10, the light-facing surface may be disposed opposite to the backlight surface. In some examples, the backlight surface may also be referred to as the back side of the solar cell.

[0159] In some examples, at least the light-facing surface of the solar cell 10 may be provided with patterned electrodes 11.

[0160] In some examples, the light-facing surface of the solar cell 10 may be provided with patterned electrodes 11. For example, the solar cell 10 may include a tunnel oxide passivated contact (TOPCon) cell.

[0161] In some examples, the interconnecting strip 20 can connect the patterned electrodes 11 of adjacent cells 10 in series.

[0162] In some examples, the interconnecting strip 20 may include a first connecting segment 26, which may be electrically connected to the patterned electrode 11 of one of two adjacent battery cells 10.

[0163] In some examples, the interconnecting strip 20 may include a second connecting segment 27. The second connecting segment 27 may be connected to the first connecting segment 26. The second connecting segment 27 may be electrically connected to the patterned electrode 11 of another of two adjacent solar cells 10.

[0164] In some examples, the back surface of the solar cell 10 may be provided with patterned electrodes 11. For example, the solar cell 10 may include a back contact (BC) cell.

[0165] In some examples, patterned electrodes 11 may be provided on both the light-facing and back-facing surfaces of the solar cell 10.

[0166] In some examples, two adjacent solar cells 10 may be of the same type. The patterned electrodes 11 on the light-facing and back-facing sides of the solar cells 10 may be arranged in the same, similar, or identical manner.

[0167] In some examples, the types of two adjacent solar cells 10 may be different. The patterned electrodes 11 on the light-facing and back-facing sides of the solar cell 10 may be arranged differently.

[0168] In some examples of embodiments of this application, the patterned electrode 11 is at least disposed on the light-facing surface of the solar cell 10. Thus, the portion of the interconnect strip 20 exposed in the solder fusion structure 30 can reflect light, improving the light utilization rate of the solar cell 10. This enhances the photoelectric conversion efficiency of the photovoltaic module.

[0169] In some examples, patterned electrodes 11 may be provided on both the light-facing side and the backlighting side, and the conductivity of the patterned electrodes 11 on at least one side of at least a portion of the multiple battery cells 10 may be the same.

[0170] In some examples, at least a portion of the battery cells 10 may have the same conductive polarity on the patterned electrodes 11 facing the light-emitting surface.

[0171] In some examples, the conductive polarity of the patterned electrodes 11 on the back surface of at least a portion of the multiple solar cells 10 may be the same.

[0172] In some examples, the conductive polarity of the patterned electrodes 11 on the light-facing surface of all the multiple solar cells 10 can be the same.

[0173] In some examples, the conductive polarity of the patterned electrodes 11 on the back surface of all the multiple solar cells 10 can be the same.

[0174] In some examples, at least a portion of the multiple battery cells 10 may be TOPCon batteries.

[0175] In some examples, all of the multiple battery cells 10 may be TOPCon batteries.

[0176] It is understood that in some examples of embodiments of this application, when patterned electrodes 11 are provided on both the front and back sides of the battery cell 10, the conductivity of the front patterned electrode and the conductivity of the back patterned electrode may be opposite.

[0177] In some examples of embodiments of this application, patterned electrodes 11 are provided on both the light-facing and back-facing surfaces of the solar cell 10. This can improve the bifaciality of the solar cell 10, enhance its back-side power generation capability, and increase power generation under the same installation conditions. Furthermore, it facilitates the production and processing of the solar cell 10, thereby reducing the processing and production costs of photovoltaic modules.

[0178] Figure 5 This is a side view of the solar cells, solder welding structure, and interconnect strips in a photovoltaic module provided in some embodiments of this application.

[0179] In some examples, refer to Figure 5 As shown, a photovoltaic module may include an encapsulant film 40. The encapsulant film 40 may cover the interconnect strip 20 and the solar cell 10.

[0180] In some examples, a portion of the adhesive film 40 may be filled between the interconnect strip 20 and the battery cell 10.

[0181] In some examples, the adhesive film 40 may fill at least part of the non-welded connection section 25 between the battery cell 10.

[0182] In some examples, the adhesive film 40 may fill the space between all non-welded joints 25 and the battery cell 10.

[0183] In some examples, film 40 may include ethylene-vinyl acetate copolymer (EVA).

[0184] In some examples, the film 40 may include a polyolefin elastomer (POE).

[0185] It is understood that in some examples of the embodiments of this application, the specific type of adhesive film 40 is only shown as a specific example and is not intended to limit the specific type of adhesive film 40.

[0186] In some examples of embodiments of this application, an adhesive film 40 is provided, which covers the interconnect strip 20 and the solar cell 10, with a portion of the adhesive film 40 located between the non-welded connection section 25 and the solar cell 10. In this way, the adhesive film 40 can support the non-welded connection section 25 of the solar cell 10, preventing the interconnect strip 20 from directly pressing on the solar cell 10 and thus protecting it. Furthermore, the adhesive film 40 can form a continuous adhesive layer on the non-welded connection section 25, enhancing the mechanical anchoring of the interconnect strip 20 to the solar cell interface, improving the peel strength of the interconnect strip 20, and extending the service life of the photovoltaic module.

[0187] In some examples, the solder weld structure 30 can be formed by soldering with solder paste.

[0188] In some examples, the solder weld structure 30 may be formed by solder paste.

[0189] In some examples, solder paste can be applied to the patterned electrode 11 during the specific setup, and the interconnect strip 20 can be placed on the solder paste. Then, through melting and soldering, a solder weld structure 30 is formed.

[0190] In some examples, the solder paste may include a lead-free alloy. The solder paste can melt and wet the interconnect strip 20 and the patterned electrode 11 during reflow soldering at 180°C-220°C to form a metallized solder weld structure 30.

[0191] In some examples of embodiments of this application, the solder fusion structure 30 is formed by soldering with solder paste. In this way, the interconnect strip 20 and the pattern electrode 11 can be electrically connected using the lower soldering temperature of the solder paste. This avoids the influence of high temperature on the interconnect strip 20, maintains the integrity of the appearance of the interconnect strip 20 and the smoothness of the surface of the interconnect strip 20 exposed outside the solder fusion structure 30, thereby improving the reflectivity of the surface of the interconnect strip 20 exposed outside the solder fusion structure 30 to light, improving the light utilization rate of the solar cell 10, and improving the photoelectric conversion efficiency of the photovoltaic module.

[0192] In addition, the solder paste has a lower soldering temperature. Compared with the method of soldering by wrapping tin-lead solder on the surface of the interconnect strip in related technologies, the lower soldering temperature can reduce the thermal stress on the cell 10, reduce the breakage rate of the cell 10, and improve the yield of photovoltaic modules.

[0193] In some examples, the solder fusion structure 30 is formed by soldering with solder paste. This makes it easier to expose the side of the interconnect strip 20 away from the solar cell 10 outside the solder fusion structure 30, and to allow the exposed surface of the interconnect strip 20 to reflect and reuse light, which helps to improve the light utilization rate of the solar cell 10.

[0194] In some examples, the first region may have a first roughness.

[0195] In some examples, the surface of the interconnecting strip 20 may have a first roughness.

[0196] In some examples, the surface of the solder weld structure 30 may have a second roughness.

[0197] In some examples, the first roughness can be smaller than the second roughness.

[0198] In some examples, the first roughness and the second roughness can be defined as the arithmetic mean of the absolute values ​​of the surface profile height deviations within the sampling length. It mathematically quantifies the microscopic unevenness of the surface; the smaller the value, the smoother the surface.

[0199] In some examples, the initial roughness of the surface of the interconnecting strip 20 can be measured using the following methods:

[0200] The battery with the welded interconnect strip 20 is placed on the test platform. The diamond probe is adjusted to make contact with the interconnect strip 20, ensuring that the probe's movement direction is consistent with the extension direction of the interconnect strip 20. The probe traverses the interconnect strip 20 at a speed of 0.6 mm / s. The length traversed by the probe can be 4 mm. During the 4 mm traversal, the first surface roughness Ra data of the interconnect strip 20 is exported. In some examples of embodiments of this application, the testing instrument model is ACCRETECH-SURTCOM-480A-22.

[0201] In some examples, the interconnect strip 20 is used as a copper conductive substrate for testing. The first roughness Ra of the surface of the copper conductive substrate at multiple test points can be 0.251μm, 0.215μm, and 0.287μm, respectively.

[0202] In some examples, taking the silver-plated interconnect strip 20 as an example, the first roughness Ra at multiple test points can be 0.092um, 0.062um, 0.076um, 0.114um, 0.117um, 0.177um, 0.166um, 0.238um, 0.322um, and 0.331um, respectively.

[0203] In some examples, related technologies involve wrapping tin-lead solder around the surface of the interconnect strip and then bonding the interconnect strip using a lamination process. The surface roughness of the bonded interconnect strip is typically greater than 0.6 μm.

[0204] In some examples, the power output of modules composed of two adjacent solar cells is compared and tested. A standard light source is provided using a solar simulator, and the power output of two adjacent solar cells is measured. Electrical parameter measuring equipment is used to accurately determine the current and voltage of the photovoltaic module, thereby calculating the power.

[0205] In some examples of embodiments of this application, the power of interconnect strip 20, which is a silver-plated interconnect strip, is compared with that of interconnect strips coated with tin-lead solder in related technologies, as shown in the table below:

[0206] Power comparison of small components Pmax / W Isc / A Voc / V FF Interconnect strips coated with tin-lead solder - Ra=0.6um 5.33 5.071 1.47 71.37 Ag interconnect strip Ra=0.1um 5.36 5.087 1.47 71.59 Difference 0.03 0.016 0.00 0.23 Improvement rate / % 0.56% 0.31% -0.07% 0.32%

[0207] It can be seen that in a small module composed of two solar cells, the power of the module can be significantly improved by reducing the surface roughness of the interconnecting strip.

[0208] In some examples, the initial roughness Ra can be less than 0.6 μm. This allows light to be reflected by the smooth interconnect strips 20, improving the light utilization rate of the solar cell 10 and increasing the output power of the photovoltaic module.

[0209] In some examples, the first roughness Ra can be less than or equal to 0.4 μm.

[0210] In some examples, the first roughness Ra can be less than or equal to 0.39 μm.

[0211] In some examples, the first roughness Ra can be less than or equal to 0.3 μm.

[0212] In some examples, the first roughness Ra can be less than or equal to 0.2 μm.

[0213] In some examples, the first roughness Ra can be less than or equal to 0.15 μm.

[0214] In some examples, the first roughness Ra can be less than or equal to 0.1 μm.

[0215] In some examples of embodiments of this application, the roughness of the first region is set to a first roughness, and the roughness of the surface of the solder fusion structure 30 is set to a second roughness; and the first roughness is less than the second roughness. This improves the smoothness of the first region, thereby improving the interconnect strip 20. This allows the interconnect strip 20 to reflect more light onto the surface of the solar cell 10 for utilization, improving the light utilization rate of the solar cell 10 and enhancing the photoelectric conversion efficiency of the photovoltaic module.

[0216] Furthermore, in some examples of embodiments of this application, the surface roughness of the interconnect strip 20 is set to a first roughness. The first roughness is less than the second roughness of the surface of the solder fusion structure 30. In this way, the surface of the interconnect strip 20 in contact with the solder fusion structure 30 can be a relatively smooth surface, which can reduce the porosity of the connection between the solder fusion structure 30 and the interconnect strip 20, reduce the resistance between the solder fusion structure 30 and the interconnect strip 20, reduce the loss of photocurrent, and facilitate the collection and transmission of photocurrent.

[0217] In some examples, the reflectivity of the first region can be greater than or equal to 70%.

[0218] In some examples, the reflectivity of the first region can be greater than 70%.

[0219] In some examples, the reflectivity of the first region can be equal to 70%.

[0220] In some examples, the reflectivity of the surface of the interconnect strip 20 can be greater than or equal to 70%.

[0221] In some examples, the reflectance of the first region or the surface of the interconnect strip 20 can be measured using an ultraviolet spectrophotometer. In the embodiments of this application, the wavelength range for testing can be 300 nm to 1200 nm.

[0222] In some examples, the interconnect strip 20 can be placed on the sample holder of a UV spectrophotometer for measurement. The intensity of the reflected light from the interconnect strip 20 is measured and compared with the intensity of the reflected light from a standard sample to calculate the reflectivity of the surface of the interconnect strip 20.

[0223] It is understood that in some examples of the embodiments of this application, the surface roughness of the interconnect strip 20 can be set according to the specific material of the interconnect strip 20. For example, for silver, a material with high reflectivity, a higher first roughness Ra will result in higher reflectivity. For aluminum, a material with low reflectivity, the first roughness Ra of the surface of the interconnect strip 20 can be set to be lower.

[0224] It should be noted that the numerical values ​​and ranges involved in the embodiments of this application are approximate values. Due to the influence of the manufacturing process, there may be a certain range of errors, which can be considered negligible by those skilled in the art.

[0225] In some examples, the first region can be micro- or nano-polished to improve the reflectivity of the surface of the interconnect strip 20.

[0226] In some examples of embodiments of this application, the reflectivity of the first region is set to be greater than or equal to 70%. Thus, the interconnect strip 20 exposed on the surface of the solder fusion structure 30 can reflect light onto the surface of the solar cell 10 for reuse, thereby increasing the short-circuit current of the photovoltaic module and improving its photoelectric conversion efficiency.

[0227] In some examples, the interconnect strip 20 can be a conductive substrate 21. That is, the surface of the interconnect strip 20 may not be covered with solder. For example, the surface of the interconnect strip 20 may not be covered with tin-lead solder.

[0228] In some examples, the conductive substrate 21 may include at least one of a copper conductive substrate 21, an aluminum conductive substrate 21, an alloy conductive substrate 21, or a copper-aluminum composite substrate.

[0229] In some examples of embodiments of this application, the conductive substrate 21 is directly used as the interconnect strip 20. This, compared to interconnect strips formed by coating the surface of the conductive substrate 21 with tin-lead solder in related technologies, simplifies the manufacturing process of the interconnect strip 20 by eliminating the need for tin-lead solder coating, thus saving on the manufacturing cost of the photovoltaic module. Furthermore, the amount of solder fusion structure 30 can be controlled, making it easier to reduce its usage and further saving on the manufacturing cost of the photovoltaic module. On the other hand, the surface of the conductive substrate 21 can reflect light to the surface of the solar cell 10, improving the light utilization rate of the solar cell 10. This can increase the short-circuit current of the photovoltaic module and improve its photoelectric conversion efficiency.

[0230] Figure 6 This is a schematic diagram of another structure for the cooperation between solar cells and interconnecting strips in a photovoltaic module provided in some embodiments of this application.

[0231] In some examples, refer to Figure 6 As shown, the interconnect strip 20 may include a reflective layer 22. The reflective layer 22 may at least wrap around the conductive substrate 21 on the side opposite to the battery cell 10.

[0232] In some examples, at least a portion of the reflective layer 22 may be exposed to the solder weld structure 30.

[0233] In some examples, the reflective layer 22 may be wrapped around the surface of the conductive substrate 21.

[0234] In some examples, the conductive substrate 21 can be a copper strip. The conductive substrate 21 can be used for current transmission.

[0235] In some examples of embodiments of this application, a reflective layer 22 is provided, which at least covers the first region and is at least partially exposed to the solder fusion structure 30. Thus, the incident light can be reflected by the reflective layer 22, allowing the solar cell 10 to utilize the light irradiated by the reflective layer 22, thereby improving the light utilization rate of the solar cell 10.

[0236] Furthermore, in some examples of embodiments of this application, by providing a reflective layer 22, the reflective layer 22 reduces the heat absorption of the interconnect strips 20, thereby improving the output power of the photovoltaic module in high-temperature environments. Moreover, the reflective layer 22 can isolate the conductive substrate 21 from the environment, reducing the corrosion rate of the conductive substrate 21 by salt spray and extending the damp heat aging period of the photovoltaic module.

[0237] In some examples, the reflective layer 22 intersects the thickness direction of the solar cell 10. That is, the reflective layer 22 can have a certain angle with the thickness direction of the solar cell 10. This increases the amount of light reflected by the reflective layer 22 onto the solar cell 10, thereby improving the light utilization efficiency of the solar cell 10.

[0238] In some examples, the reflective layer 22 may include a metallic material with a reflectivity greater than 70%.

[0239] In some examples, the reflective layer 22 may include a metallic material with a melting point higher than that of the solder weld structure 30.

[0240] In some examples, the reflective layer 22 may include either silver or aluminum.

[0241] In some examples, the reflective layer 22 may be an electroplated silver layer or an aluminum layer.

[0242] It is understood that in some examples of the embodiments of this application, the material and arrangement of the reflective layer 22 are shown only as specific examples and are not intended to limit the specific material and arrangement of the reflective layer 22. In other instances, the reflective layer 22 may also be made of other types of materials.

[0243] In some examples of embodiments of this application, a metal material with a reflectivity greater than 70% or a metal material with a melting point higher than that of the solder fusion structure 30 is used as the reflective layer 22. This ensures, on the one hand, the reflectivity of the reflective layer 22, thereby improving the light utilization rate of the solar cell 10 and the photoelectric conversion efficiency of the photovoltaic module. On the other hand, since the melting point of the reflective layer 22 is higher than that of the solder fusion structure 30, the melting of the solder fusion structure 30 will not affect the reflective layer 22 when the interconnecting strip 20 and the patterned electrode 11 are welded together. This ensures the integrity of the reflective layer 22's morphology and its smooth surface, guaranteeing effective light reflection after the photovoltaic module welding is completed. This further improves the light utilization rate of the solar cell 10.

[0244] Figure 7 This is yet another top view of a photovoltaic module provided in some embodiments of this application. Figure 8 yes Figure 7 A magnified view of a portion of point A in the middle.

[0245] In some examples, refer to Figure 7 and Figure 8 As shown, the patterned electrode 11 may include a plurality of pads 111. The plurality of pads 111 may be arranged at intervals along the extension direction of the interconnect strip 20.

[0246] In some examples, the interconnect strip 20 can be electrically connected to the pad 111 via the solder fusion structure 30.

[0247] It is understood that in some examples of the embodiments of this application, the way in which the solder welding structure 30 electrically connects the interconnect strip 20 to the pad 111 may be the same as, similar to or similar to the way in which the solder welding structure 30 electrically connects the interconnect strip 20 to the pattern electrode 11 in the foregoing embodiments of this application. For details, please refer to the detailed description of the foregoing embodiments of this application. The embodiments of this application will not repeat the details.

[0248] In some examples, a first non-welded connection segment is provided between at least two adjacent pads 111. That is, the projection of the interconnect strip 20 between at least two adjacent pads 111 onto the cell 10 can be outside the projection of the solder fusion structure 30 onto the cell 10. In other words, in some examples of the embodiments of this application, at least some of the interconnect strips 20 between adjacent pads 111 can be suspended, or supported by the adhesive film 40 described in detail in the foregoing embodiments of this application. In this way, the interconnect strips 20 between at least some of the adjacent pads 111 can form a stress buffer structure. In the case of thermal expansion of the photovoltaic module, the interconnect strips 20 located between adjacent pads 111 and whose projection on the cell 10 is outside the solder fusion structure 30 can release stress through deformation, which can block the transmission of thermal stress to the cell 10 and reduce the risk of cell 10 breakage.

[0249] In some examples, the projection of the interconnect strip 20 between adjacent pads 111 onto the cell 10 may be outside the projection of the solder weld structure 30 onto the cell 10.

[0250] In some examples of embodiments of this application, a patterned electrode 11 is formed by setting multiple pads 111. The multiple pads 111 are arranged at intervals along the extension direction of the interconnect strip 20, and the interconnect strip 20 is electrically connected to the pads 111 through a solder fusion structure 30. Furthermore, the interconnect strip 20 between at least two adjacent pads 111 is a first non-welded connection segment. This reduces the amount of solder fusion structure 30 used, saving on the production and processing costs of the photovoltaic module. It also reduces the shading of the surface of the cell 10 by the solder fusion structure 30, increasing the light-receiving area of ​​the cell 10 and improving the light utilization rate of the cell 10.

[0251] In some examples, in each of the pad groups, the first non-welded connection segment is connected between the welded connection segments connected by the solder fusion structure (30) on any adjacent pad (111).

[0252] In some examples of embodiments of this application, taking a 16BB, 210R-66 type photovoltaic module (210R means the size of a single cell is 210mm * 182mm; a single module consists of 66 single cells) as an example, while keeping the number and size of the solder pads, the size of the interconnect strips, the conductive substrate, the reflective layer (silver), etc., consistent, the following configurations are used: Configuration 1: On any cell of the same type, the solder fusion structure 30 connected to adjacent solder pads 111 is connected by a first non-soldering connection segment; Configuration 2: Interconnect strips coated with tin-lead solder are used to connect to the cells. The solder consumption per module in Configuration 1 is 13.2g, and in Configuration 2 it is 46g. The module power of Configuration 1 is 4W higher than that of Configuration 2, while maintaining the same reliability. Thus, the spaced solder fusion structure 30 configuration of this application has the advantages of saving on the processing and production costs of photovoltaic modules and increasing module power.

[0253] The inventors discovered that charge carriers are collected by patterned electrodes and transported to the interconnect strips through solder fusion structures. During the transport process, the transport path of charge carriers follows the principle of proximity, that is, most charge carriers are directly transported upward in the vertical direction to the interconnect strips. Therefore, the solder fusion structures located at non-pad locations provide little help for charge carrier collection and transport. Removing this part of the solder fusion structure has little impact on charge carrier transport, even if the spacing of the solder fusion structure has little effect, and can increase the light-receiving area and increase the component power.

[0254] In addition, the adhesive film 40 can fill the gap between at least two adjacent pads 111, so that the adhesive film 40 can support the interconnect strip 20. The adhesive film 40 can form a mechanical buffer structure. In the event of thermal expansion, the deformation of the adhesive film 40 can absorb the stress formed by thermal expansion, which can prevent the interconnect strip 20 from pulling the battery cell 10 in the entire extension direction of the interconnect strip 20, and can effectively protect the battery cell 10.

[0255] In some examples, a first non-soldering connection segment can be provided between any two adjacent pads 111. In this way, since the solder fusion structure 30 on any two adjacent pads 111 is broken, the molten solder fusion structure 30 will not gather towards the pads 111 during the soldering process, reducing the possibility of solder agglomeration due to agglomeration, and avoiding the situation where the pattern electrode 11 breaks due to the solder fusion structure absorbing silver; thus ensuring the effectiveness of the pattern electrode 11 in collecting charge carriers.

[0256] In some examples, refer to Figure 7 and Figure 8 As shown, the patterned electrode 11 may include a plurality of first gate lines 112.

[0257] In some examples, multiple first grid lines 112 may be arranged at intervals along the extension direction of the interconnecting strip 20.

[0258] In some examples, the first grid line 112 may be a sub-grid of the cell 10.

[0259] In some examples, the first grid line 112 may extend along the arrangement direction of the plurality of interconnecting strips 20.

[0260] In some examples, the extension direction of the first grid line 112 may be perpendicular to the extension direction of the interconnecting strip 20.

[0261] In some examples, pad 111 may include a first pad 111a. The first pad 111a may be located on the first gate line 112.

[0262] In some examples, refer to Figure 8 As shown, the solder fusion structure 30 may include a first solder fusion structure 31. The first solder fusion structure 31 can be used to electrically connect the interconnect strip 20 to the first pad 111a.

[0263] In some examples, the arrangement of the first solder fusion structure 31 may be the same as, similar to or similar to the arrangement of the solder fusion structure 30 in the foregoing embodiments of this application. For details, please refer to the detailed description of the foregoing embodiments of this application. The embodiments of this application will not repeat the details.

[0264] It is understood that in some examples of the embodiments of this application, the arrangement of the first gate line 112 and the first pad 111a may be the same as, similar to or similar to that in the related art. For details, please refer to the detailed description of the foregoing embodiments of this application. The embodiments of this application will not repeat the details here.

[0265] In some examples of embodiments of this application, multiple first grid lines 112 are provided and arranged at intervals along the extension direction of the interconnect strip 20. In this way, the photocurrent generated by the solar cell 10 can be collected through multiple first grid lines 112, which can improve the collection efficiency of the photocurrent and reduce the transmission path and loss of the photocurrent.

[0266] A first pad 111a is provided on the first gate line 112. A first solder welding structure 31 is used to electrically connect the interconnect strip 20 to the first pad 111a. In this way, the stability of the electrical connection between the interconnect strip 20 and the first gate line 112 can be improved, and the photocurrent collected on the first gate line 112 can be transferred to the interconnect strip 20.

[0267] Figure 9 This is an optical path analysis diagram of light reflected from the surface of the interconnect strip exposed on the solder fusion structure in a photovoltaic module provided in some embodiments of this application.

[0268] In some examples, refer to Figure 9 As shown, the cylindrical interconnecting strip 20 is used as a specific example for illustration.

[0269] In some examples, in a plane parallel to the thickness direction of the cell 10 and parallel to the extension direction of the interconnecting strip 20 (e.g. Figure 9 On a plane that coincides with the dashed line i and is perpendicular to the paper, the interconnecting strip 20 can have a first orthographic projection.

[0270] In some examples, at least one first solder weld structure 31 may have a second orthographic projection on a plane perpendicular to the thickness direction of the cell 10 and parallel to the extension direction of the interconnect strip 20.

[0271] In some examples, the second orthographic projection may include the first sub-projection. The first sub-projection may overlap with the first orthographic projection.

[0272] In some examples, the second orthographic projection may include a second sub-projection, which may be located outside the first orthographic projection. The second sub-projection may be located on the side of the first orthographic projection facing the solar cell 10.

[0273] In some examples, refer to Figure 9 As shown, experiments demonstrate that the cylindrical interconnect strip 20 has a partial black area 28 on the side facing away from the solar cell 10. After the black area 28 reflects light, the light is difficult to reflect back onto the solar cell 10 for use. Experiments show that the angle corresponding to the arc length occupied by the black area 28 on the surface of the interconnect strip 20 is approximately 42°.

[0274] In some examples, along the thickness direction of the cell 10, there are 21° black areas 28 on both sides of the diameter of the interconnect strip 20.

[0275] It is understandable that this is to ensure that the interconnect strip 20, exposed on the surface of the solder fusion structure 30, can reflect light onto the surface of the solar cell 10 for utilization. (Refer to...) Figure 9 As shown, the coverage area of ​​the interconnect strip 20 of the solder fusion structure 30 must be located at least below the extreme position of the black area 28.

[0276] In some examples, refer to Figure 9 As shown, the extreme position of black zone 28 is used as the analysis point for analysis.

[0277] In some examples, along the thickness direction of the solar cell 10, the size of the first sub-projection can be d1. The size of the second sub-projection can be d2. (See reference...) Figure 9 As shown, the ratio of d1 to d2 can be the ratio of d1 to a diameter of the cylindrical interconnect strip 20 that is parallel to the thickness direction of the cell 10.

[0278] In some examples, refer to Figure 9As shown, in triangle ABC, point C is analyzed as the extreme position of black zone 28. Triangle ABC is a right triangle. sin(90-α / 2) is the ratio of the dimension d1 of the second sub-projection in triangle ABC to the hypotenuse of the triangle. It can be seen that the hypotenuse of the triangle coincides with the diameter of the interconnect strip 20 passing through the extreme point C of black zone 28, and the hypotenuse is larger than the diameter of the interconnect strip 20. That is, the denominator of sin(90-α / 2) is larger than that of the ratio of d1 to d2; the value of sin(90-α / 2) is smaller than that of the ratio of d1 to d2, thereby ensuring that at least part of the surface located below the extreme point C of black zone 28 is exposed outside the solder fusion structure 30. Therefore, in some examples of embodiments of this application, the ratio A of the dimension of the first sub-projection to the dimension of the first orthographic projection can be set to less than 0.93. In this way, it can be ensured that there is at least a partially exposed surface that can reflect light to the solar cell 10 for utilization, thereby improving the light utilization rate of the solar cell 10.

[0279] In some examples, this is to improve the light utilization efficiency of solar cell 10. (See reference...) Figure 9 As shown, along the thickness direction of the solar cell 10, the ratio of the dimension d1 of the first sub-projection to the dimension d2 of the first orthographic projection can be greater than or equal to 0.25 and less than 0.93. Thus, the interconnecting strip 20, located on a side parallel to the surface of the solar cell 10 with a diameter x opposite to the solar cell 10, can be completely exposed to the solder welding structure 30. In other words, with... Figure 9 Taking the orientation in the middle as an example, the surface of the interconnect strip 20 above the diameter x is completely exposed to the solder fusion structure 30. This allows the interconnect strip 20 to have the maximum reflective surface, which can improve the light utilization rate of the solar cell 10.

[0280] In some examples, the ratio of the size d1 of the first sub-projection to the size d2 of the first orthographic projection along the thickness direction of the cell 10 can be less than or equal to 0.5.

[0281] In some examples, any first solder fusion structure 31 may have a second orthographic projection on a plane parallel to the thickness direction of the cell 10 and parallel to the extension direction of the interconnect strip 20.

[0282] In some examples, the cross-sectional shape of the interconnecting strip 20 may include a circle along the extension direction perpendicular to the interconnecting strip 20. That is, in some examples of embodiments of this application, the interconnecting strip 20 may be a cylindrical interconnecting strip 20.

[0283] It should be noted that in this embodiment, the cross-sectional shape of the interconnecting strip 20 is circular. Here, "circular" not only includes an absolute circle but can also be approximately circular. Those skilled in the art will understand that due to limitations in processing technology and conditions, the cross-sectional shape of the interconnecting strip 20 may have certain errors, which are negligible to those skilled in the art.

[0284] In some examples of embodiments of this application, the cross-sectional shape of the interconnect strip 20 is set to circular. This ensures that the peripheral wall of the interconnect strip 20 intersects the thickness direction of the solar cell 10. The curved surface can reflect light onto the surface of the solar cell 10, improving the light utilization rate of the photovoltaic module. Furthermore, the circular interconnect strip 20 is isotropic, so the orientation of the interconnect strip when placed on the solar cell does not need to be considered, reducing manufacturing complexity and improving production efficiency. During the welding process of the interconnect strip 20, even if the interconnect strip 20 rolls slightly, it will not affect the reflective effect and will not damage the solar cell 10, effectively protecting the solar cell 10.

[0285] In some examples, for ease of illustration, a plane parallel to the thickness direction of the battery cell 10 and perpendicular to the extension direction of the interconnect strip 20 can be defined as the first plane. For example, refer to Figure 9 As shown, the first plane can refer to Figure 11 The paper in the middle.

[0286] In some examples, the cross-section of the interconnecting strip 20 in the first plane may have a first tangent point and a vertex. It can be understood that the vertex may be the point on the cross-section of the interconnecting strip 20 in the first plane that is farthest from the battery cell 10.

[0287] In some examples, the tangent line passing through the first tangent point can be parallel to the thickness direction of the solar cell 10.

[0288] In some examples, the first solder weld structure 31 covering the arc segment of the interconnect strip 20 located on the side away from the first tangent point from the cell 10 may have a first arc length.

[0289] In some examples, the arc segment of the interconnect strip 20 located between the first tangent point and the vertex has a second arc length. The ratio of the first arc length to the second arc length is less than 6.9:9. In this way, it can be ensured that a portion of the surface below the extreme position C of the black area 28 can be exposed to the solder weld structure 30, thereby allowing light to be reflected onto the surface of the solar cell 10 for utilization.

[0290] In some examples, refer to Figure 9As shown, it can be understood that the diameter with a 45° angle between the interconnect strip 20 and the plane parallel to the solar cell 10 is a limiting point for the change in the light reflection path. Light reflected from the surface at angles greater than 45° travels away from the surface of the solar cell 10 and strikes the encapsulation glass layer of the photovoltaic module (e.g., Figure 9 (As indicated by the middle arrow a), the reflected light is totally reflected by the encapsulating glass layer to the surface of the solar cell 10 for utilization. At angles below 45°, the reflected light can directly strike the surface of the solar cell 10 for utilization (e.g., ...). Figure 9 (The direction indicated by the middle arrow b). Therefore, in some examples of embodiments of this application, the ratio of the first arc length to the second arc length can be less than 0.5. In this way, at least part of the surface below 45° can be exposed, which can improve the reflectivity of the interconnecting strip to light and improve the light utilization efficiency of the battery cell 10.

[0291] In some examples, the first solder fusion structure 31 covers the side of the interconnect strip 20 located near the first cut point of the solar cell 10. In this way, the surface of the interconnect strip 20 on the side of the first cut point away from the solar cell 10 can be exposed, thereby increasing the area of ​​the interconnect strip 20 surface that reflects light and improving the light utilization rate of the solar cell 10.

[0292] In some examples, refer to Figure 8 As shown, along a direction perpendicular to the extension direction of the interconnect strip 20 (e.g., the arrangement direction of the plurality of interconnect strips 20 described in detail in the foregoing embodiments of this application). The orthographic projection of the first solder fusion structure 31 on the battery cell 10 may have a first dimension d3. The orthographic projection of the interconnect strip 20 on the battery cell 10 may have a second dimension d4.

[0293] In some examples, the ratio of the second dimension d4 to the first dimension d3 can be less than or equal to 1.1. This reduces the amount of the first solder weld structure 31 used and minimizes its obstruction of the first gate line 112, keeping the first gate line 112 clean and exposed. This does not affect the current-collecting function of the first gate line 112 and avoids optical obstruction, ensuring effective current collection by the first gate line 112.

[0294] In some examples, since the first solder fusion structure 31 is printed on the first pad 111a, the amount of the first solder fusion structure 31 used is greatly reduced compared to wrapping the solder around the surface of the interconnect strip 20. This allows the first solder fusion structure 31 to be concentrated at the position where the interconnect strip 20 contacts the first gate line 112, reducing the outward expansion of the first solder fusion structure 31 along the direction of the first gate line 112. In other words, it reduces the coverage and obstruction of the first gate line 112 by the first solder fusion structure 31, keeping the first gate line 112 clean and exposed, without affecting the current collection function of the first gate line 112, and without causing optical obstruction to the first gate line 112, thus ensuring effective current collection by the first gate line 112.

[0295] Furthermore, since the amount of solder used in the first solder fusion structure 31 is significantly reduced compared to wrapping the solder around the surface of the interconnect strip 20, the local temperature of the cell 30 rises during hot spot testing of the photovoltaic module (sometimes reaching or exceeding the melting point of the first solder fusion structure 31). At this time, the alloying process between the solder and the first grid line 112 is accelerated. Excessive Ag electrodes or the brittle Ag3Sn phase generated by the alloying reaction of the first grid line 112 significantly reduces the adhesion of the first grid line 112 to the surface of the cell 30. After the hot spot test, the first grid line 112 easily detaches from the cell 30, forming a broken grid. By reducing the amount of solder used, the alloying degree of the first grid line 112 can be reduced, which can, to some extent, reduce the risk of photovoltaic module failure after undergoing hot spot testing.

[0296] In some examples, refer to Figure 7 As shown, pad 111 may include a second pad 111b. The area of ​​the second pad 111b may be larger than the area of ​​the first pad 111a.

[0297] In some examples, refer to Figure 8 As shown, the solder fusion structure 30 may include a second solder fusion structure 32. The second solder fusion structure 32 can be used to electrically connect the interconnect strip 20 to the second pad 111b.

[0298] In some examples, the area of ​​the second solder fusion structure 32 projected onto the solar cell 10 can be larger than the area of ​​the first solder fusion structure 31 projected onto the solar cell 10. Thus, the second solder fusion structure 32 can increase the connection strength between the interconnect strip 20 and the solar cell 10, thereby improving the tensile strength of the interconnect strip 20.

[0299] It is understood that in some examples of the embodiments of this application, the arrangement of the second solder fusion structure 32 may be the same as, similar to or similar to the arrangement of the solder fusion structure 30 in the foregoing embodiments of this application. For details, please refer to the detailed description of the foregoing embodiments of this application. The embodiments of this application will not repeat this description further.

[0300] In some examples, refer to Figure 8 As shown, along the extension direction of the interconnect strip 20, the interconnect strip 20 between the second pad 111b and the adjacent first pad 111a is a non-welded connection segment 25. That is, in some examples of the embodiments of this application, along the extension direction of the interconnect strip 20, the first solder fusion structure 31 and the adjacent second solder fusion structure 32 can be arranged at intervals.

[0301] In some examples, the solder fusion structures 30 can be arranged at intervals along the extension direction of the interconnect strip 20, with adjacent solder fusion structures 30 spaced apart. In this way, the interconnect strip 20 between adjacent solder fusion structures 30 can be fully exposed, which can increase the reflective area of ​​the interconnect strip 20, improve the light utilization rate of the photovoltaic module, and improve the photoelectric conversion efficiency of the photovoltaic module.

[0302] In some examples, the interconnect strip 20 may have a first orthographic projection on a plane parallel to the thickness direction of the cell 10 and parallel to the extension direction of the interconnect strip 20.

[0303] In some examples, at least one second solder weld structure 32 has a second orthographic projection. The second orthographic projection may include a first sub-projection and a second sub-projection.

[0304] In some examples, the first sub-projection may overlap with the first orthographic projection. The second sub-projection may be located outside the first orthographic projection.

[0305] In some examples, along the thickness direction of the cell 10, the ratio A of the size of the first sub-projection to the size of the first orthographic projection can be less than or equal to 0.93.

[0306] In some examples, along the thickness direction of the cell 10, the ratio A of the size of the first sub-projection to the size of the first orthographic projection can be greater than or equal to 0.25 and less than or equal to 0.5.

[0307] It is understood that in some examples of the embodiments of this application, on a plane parallel to the thickness direction of the battery cell 10 and parallel to the extension direction of the interconnect strip 20, the second orthographic projection of the second solder fusion structure 32 may be the same as, similar to or similar to the second orthographic projection of the first solder fusion structure 31. The specific arrangement of the second solder fusion structure 32 can be referred to the detailed description of the first solder fusion structure 31 in the foregoing embodiments of this application, and will not be repeated in the embodiments of this application.

[0308] In some examples, at least a portion of the second solder fusion structure 32 can be connected on the side of the interconnect strip 20 away from the battery cell 10. That is, in some examples of the embodiments of this application, at least a portion of the second solder fusion structure 32 can wrap around the interconnect strip 20. In this way, the connection strength between the interconnect strip 20 and the battery cell 10 can be improved, and the peel strength of the interconnect strip 20 can be improved.

[0309] In some examples, the patterned electrode 11 may include a second gate line 113. The second gate line 113 may intersect the first gate line 112 at the first pad 111a.

[0310] In some examples, the second gate line 113 can be the main gate.

[0311] In some examples, the extension direction of the second gate line 113 may be the same as, similar to or approximate to the extension direction of the first gate line 112.

[0312] In some examples, the solder fusion structure 30 may include a third solder fusion structure. The third solder fusion structure may be used to electrically connect the interconnect strip 20 to the second gate line 113.

[0313] In some examples, the configuration of the third solder fusion structure may be the same as, similar to or similar to the first solder fusion structure 31 or the second solder fusion structure 32. For details, please refer to the detailed description of the first solder fusion structure 31 or the second solder fusion structure 32 in the foregoing embodiments of this application. The embodiments of this application will not repeat the details.

[0314] In some examples, after the interconnect strip 20 is peeled off from the cell 10, it can be seen that the third solder weld structure is clustered at the intersection of the first grid line 112, the second grid line 113, and the interconnect strip 20. The third solder weld structure extends outward a small distance along the direction of the first grid line 112, and has little impact on the current collection of the first grid line 112.

[0315] Figure 10 This is another structural schematic diagram of the photovoltaic module in which the solar cells and interconnecting strips cooperate, provided in some embodiments of this application. Figure 11 This is another structural schematic diagram of the photovoltaic module in which the solar cells and interconnecting strips cooperate, provided in some embodiments of this application. Figure 12 This is another structural schematic diagram of the photovoltaic module in which the solar cells and interconnecting strips cooperate, provided in some embodiments of this application.

[0316] In some examples, refer to Figures 10-12 As shown, the interconnecting strip 20 may include two first sidewalls 23 that are opposite each other along a direction perpendicular to the extension of the interconnecting strip 20.

[0317] In some examples, the two first sidewalls 23 are inclined in a direction perpendicular to the distance from the battery cell 10.

[0318] In some examples, the cross-sectional shape of the interconnecting strip 20 can be conical or quasi-conical along the direction perpendicular to the extension of the interconnecting strip 20.

[0319] In some examples of embodiments of this application, the interconnecting strip 20 includes two first sidewalls 23 facing each other along a direction perpendicular to the extension direction of the interconnecting strip 20; and the two first sidewalls 23 are inclined in a direction perpendicular to the battery cell 10. In this way, light can be reflected onto the surface of the battery cell 10 through the two first sidewalls 23 for utilization, thereby improving the light utilization rate of the battery cell 10.

[0320] In some examples, refer to Figures 10-12 As shown, the end of the first sidewall 23 facing the solder fusion structure 30 overlaps with the solder fusion structure 30 in a direction perpendicular to the extension of the interconnect strip 20.

[0321] In some examples, that is, the end of the first sidewall 23 facing the solder weld structure 30 may extend into the solder weld structure 30. Alternatively, a portion of the solder weld structure 30 may rise onto the first sidewall 23 under interfacial tension.

[0322] In some examples, the cross-sectional shape of the interconnect strip 20 may include any one of a triangle, trapezoid, and pentagon, along the thickness direction of the battery cell 10 and perpendicular to the extension direction of the interconnect strip 20.

[0323] In some examples, refer to Figure 12 As shown, when the cross-sectional shape of the interconnecting strip 20 is pentagonal, the pentagonal cross-section may include a first straight side (not labeled in the figure), a second straight side (not labeled in the figure), and a third straight side (not labeled in the figure); the first straight side may be parallel or approximately parallel to the surface of the solar cell 10. The second straight side may be connected to one end of the first straight side, and the third straight side may be connected to the other end of the first straight side opposite to the second straight side. The second and third straight sides may be parallel or approximately parallel to the thickness direction of the solar cell 10.

[0324] In some examples, the pentagonal cross-section may include a first hypotenuse and a second hypotenuse, the first hypotenuse may be connected to the end of the second straight side away from the battery cell, and the second hypotenuse may be connected to the end of the third straight side away from the battery cell.

[0325] In some examples, the first hypotenuse can be connected to the second hypotenuse.

[0326] In some examples of embodiments of this application, the cross-sectional shape of the interconnect strip 20 is set to any one of a triangle, trapezoid, and pentagon along the thickness direction of the solar cell 10 and perpendicular to the extension direction of the interconnect strip 20. In this way, the first sidewall 23 can be inclined relative to the thickness direction of the solar cell 10, facilitating the reflection of light from the first sidewall 23 onto the surface of the solar cell 10 for utilization. This improves the reflectivity of the interconnect strip 20, enhances the light utilization rate of the photovoltaic module, and thus improves the photoelectric conversion efficiency of the photovoltaic module.

[0327] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0328] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A photovoltaic module, characterized in that, include: Multiple battery cells (10) are connected in series, and each battery cell (10) is provided with a patterned electrode. Multiple interconnecting strips (20) for connecting the battery cells (10) in series; and The solder fusion structure (30) is used to electrically connect the interconnecting strip (20) to the patterned electrode (11) through the solder fusion structure (30); Among them, at least one of the interconnecting strips (20) has at least one first area not covered by the solder welding structure (30) on its peripheral surface.

2. The photovoltaic module according to claim 1, characterized in that, At least one of the interconnecting strips (20) includes at least one welded connection segment (24); The welding connection segment (24) is the section on the interconnecting strip (20) corresponding to the solder fusion structure (30); the orthographic projection of the welding connection segment on the battery cell (10) overlaps with the orthographic projection of the solder fusion structure (30) on the battery cell (10); The first region is located on the circumference of the welded joint section.

3. The photovoltaic module according to claim 2, characterized in that, The first region on at least one of the welded joint segments (24) is constructed as a continuous region; Along the extension direction of the welded connection segment (24), the size of the first region is equal to the size of the welded connection segment (24).

4. The photovoltaic module according to claim 1, characterized in that, The interconnecting strip (20) includes a conductive substrate (21), which includes at least one of a copper conductive substrate (21), an aluminum conductive substrate (21), or an alloy conductive substrate (21). And / or, the interconnecting strip (20) includes a conductive substrate (21) and a reflective layer (22), the reflective layer (22) at least covering the first region.

5. The photovoltaic module according to claim 4, characterized in that, The reflective layer (22) is wrapped around the surface of the interconnect strip (20).

6. The photovoltaic module according to claim 5, characterized in that, The reflective layer (22) comprises a metallic material with a reflectivity greater than 70%, and / or the reflective layer (22) comprises a metallic material with a melting point higher than that of the solder fusion structure (30).

7. The photovoltaic module according to claim 1, characterized in that, The first region has a first roughness, and the surface of the solder fusion structure (30) has a second roughness, wherein the first roughness is less than the second roughness.

8. The photovoltaic module according to claim 7, characterized in that, The first roughness Ra < 0.6 μm.

9. The photovoltaic module according to claim 1, characterized in that, At least one of the first regions on the interconnecting strip (20) is constructed as a continuous region along the extension direction of the interconnecting strip (20).

10. The photovoltaic module according to claim 9, characterized in that, The reflectivity of the first region is greater than or equal to 70%.

11. The photovoltaic module according to claim 2, characterized in that, The patterned electrode (11) includes multiple pad groups, each pad group includes multiple pads (111), and the multiple pads (111) in each pad group are arranged at intervals along the extension direction of the interconnect strip (20); the interconnect strip (20) is electrically connected to the pads (111) through the solder welding structure (30); In at least one of the pad groups, the first region includes the section connecting the welded joint segments (24) to which the solder fusion structures (30) on at least two adjacent pads (111) are connected.

12. The photovoltaic module according to claim 11, characterized in that, In each of the pad groups, the first region includes the section between the welded connection segments connected by the solder fusion structure (30) on any adjacent pad (111).

13. The photovoltaic module according to claim 11, characterized in that, The patterned electrode (11) includes a plurality of first gate lines (112) arranged along the extension direction of the interconnect strip (20), the extension direction of the first gate lines (112) being perpendicular to the extension direction of the interconnect strip (20); The plurality of pads (111) includes a first pad (111a), which is disposed on the first gate line (112); The solder welding structure (30) includes a first solder welding structure (31), and the first pad (111a) is electrically connected to the interconnecting strip (20) through the first solder welding structure (31).

14. The photovoltaic module according to claim 13, characterized in that, On a plane parallel to the thickness direction of the battery cell (10) and parallel to the extension direction of the interconnect strip (20), the interconnect strip (20) has a first orthographic projection, and at least one of the first solder fusion structures (31) has a second orthographic projection. The second orthographic projection includes a first sub-projection and a second sub-projection. The first sub-projection overlaps with the first orthographic projection, and the second sub-projection is located outside the first orthographic projection. Along the thickness direction of the battery cell (10), the ratio A of the size of the first sub-projection to the size of the first orthographic projection is less than or equal to 0.

93.

15. The photovoltaic module according to claim 14, characterized in that, On a plane parallel to the thickness direction of the battery cell (10) and parallel to the extension direction of the interconnect strip (20), any one of the first solder welding structures has the second orthographic projection.

16. The photovoltaic module according to claim 14, characterized in that, Along a direction perpendicular to the extension direction of the interconnect strip (20), the orthographic projection of the first solder fusion structure (31) on the battery cell (10) has a first dimension, and the orthographic projection of the interconnect strip (20) on the battery cell (10) has a second dimension, the ratio of the first dimension to the second dimension being less than or equal to 1.

1.

17. The photovoltaic module according to any one of claims 14-16, characterized in that, The plurality of pads (111) further includes a second pad (111b), the area of ​​which is larger than the area of ​​the first pad (111a); The solder welding structure (30) further includes a second solder welding structure (32), and the interconnecting strip (20) is electrically connected to the second pad (111b) through the second solder welding structure (32); the area of ​​the second solder welding structure (32) projected onto the battery cell (10) is greater than the area of ​​the first solder welding structure (31) projected onto the battery cell (10).

18. The photovoltaic module according to claim 17, characterized in that, Along the extension direction of the interconnect strip (20), the first region includes the circumferential surface of the interconnect strip (20) between the second pad (111b) and the adjacent first pad (111a).

19. The photovoltaic module according to claim 17, characterized in that, On a plane parallel to the thickness direction of the battery cell (10) and parallel to the extension direction of the interconnect strip (20), the interconnect strip (20) has a first orthographic projection, and at least one of the second solder fusion structures has a second orthographic projection. The second orthographic projection includes a first sub-projection and a second sub-projection, the first sub-projection overlaps with the first orthographic projection, and the second sub-projection is located outside the first orthographic projection. Along the thickness direction of the battery cell (10), the ratio A of the size of the first sub-projection to the size of the first orthographic projection is less than or equal to 0.

93.

20. The photovoltaic module according to claim 19, characterized in that, Along the thickness direction of the battery cell (10), the ratio A of the size of the first sub-projection to the size of the first orthographic projection is greater than or equal to 0.25 and less than or equal to 0.

5.

21. The photovoltaic module according to claim 19, characterized in that, At least a portion of the second solder fusion structure (32) is connected to the side of the interconnect strip (20) away from the battery cell (10).

22. The photovoltaic module according to claim 11, characterized in that, Along the extension direction perpendicular to the interconnecting strip (20), the cross-sectional shape of the interconnecting strip (20) includes a circle.

23. The photovoltaic module according to claim 11, characterized in that, The interconnecting strip (20) includes two first sidewalls (23) that are opposite each other along a direction perpendicular to the extension of the interconnecting strip (20); The two first sidewalls (23) are inclined in a direction perpendicular to the battery cell (10), and the first region is located on the first sidewall (23).

24. The photovoltaic module according to claim 23, characterized in that, The first sidewall (23) overlaps with the solder fusion structure (30) at one end facing the solder fusion structure (30) in the extension direction perpendicular to the interconnect strip (20).

25. The photovoltaic module according to claim 23, characterized in that, Along the extension direction perpendicular to the interconnecting strip (20), the cross-sectional shape of the interconnecting strip (20) includes any one of triangle, trapezoid and pentagon.

26. The photovoltaic module according to claim 19, characterized in that, The patterned electrode (11) further includes a second gate line (113), which intersects with the first gate line (112) at the first pad (111a) and is electrically connected to the second pad; The solder welding structure (30) includes a third solder welding structure, and the interconnecting strip (20) is electrically connected to the second gate line (113) through the third solder welding structure.

27. The photovoltaic module according to any one of claims 1-10, characterized in that, At least one of the interconnecting strips (20) includes at least one non-welded connection segment (25), the non-welded connection segment (25) having an orthographic projection on the cell (10) located outside the orthographic projection of the solder fusion structure (30) on the cell, and at least a portion of the first region being located in the non-welded connection segment (25).

28. The photovoltaic module according to claim 27, characterized in that, On at least one of the interconnecting strips (20): At least one of the non-welded connection segments (25) includes a first non-welded connection segment located between the same interconnect strip (20) connected to the same cell (10) and any two adjacent solder fusion structures (30).

29. The photovoltaic module according to any one of claims 1-10, characterized in that, The solder fusion structure (30) is formed by soldering solder paste.

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