Photovoltaic module and reflective bus bar thereof

Abstract

The utility model relates to a photovoltaic module and a reflective bus bar thereof. The reflective bus bar comprises a bus bar main body and a first reflective layer. The bus bar body is provided with a first side face facing the battery piece. And the first reflecting layer is connected to the first side surface, and can be used for directly reflecting sunlight to the battery piece and / or reflecting the sunlight to the glass plate and reflecting the sunlight to the battery piece through the glass plate. When sunlight enters the first reflecting layer on the first side face, the first reflecting layer can directly reflect the sunlight to the battery piece and / or indirectly reflect the sunlight to the battery piece, and the sunlight in the area between the reflective bus bar and the battery piece does not directly enter the back plate as in the related technology. And the light is reflected to the battery piece through the first reflecting layer and is absorbed and utilized by the battery piece, so that the utilization rate of the light can be improved, and the output power of the photovoltaic module can be increased.

Description

Technical Field

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

[0002] Busbars, as key components in the manufacturing process of photovoltaic modules, are mainly used to bring out the positive and negative terminals of solar cells for connection to the junction box after encapsulation, enabling the current from the solar cells to be collected and transmitted outwards. To improve light utilization, reflective busbars with reflective properties are increasingly being used.

[0003] In related technologies, the front of the light-emitting busbar is usually provided with a serrated structure. A reflective layer is set on the surface of the serrated structure to play a directional reflection role, reflecting the light incident on the reflective layer to the glass and air interface. Then, through total internal reflection at the glass and air interface, the incident light is reflected to the surface of the adjacent solar cell, thereby generating additional photocurrent and realizing the reuse of the incident light.

[0004] Although the reflective busbars in the relevant technologies utilize the incident light incident on their front side and improve the light utilization rate to a certain extent, some incident light still enters the back panel through the gap between the reflective busbars and the solar cells, resulting in poor utilization. Utility Model Content

[0005] Therefore, it is necessary to overcome the shortcomings of the existing technology and provide a photovoltaic module and its reflective busbar that can improve the utilization rate of incident light, thereby increasing the output power of the photovoltaic module.

[0006] A reflective busbar for a photovoltaic module, the photovoltaic module including a backsheet, solar cells, and a glass plate, wherein the reflective busbar and the solar cells are both located between the backsheet and the glass plate, the reflective busbar being located beside the solar cells, and the reflective busbar comprising:

[0007] A busbar body, the busbar body having a first side facing the battery cell; and

[0008] A first reflective layer is attached to the first side surface. The first reflective layer is used to directly reflect sunlight onto the solar cell and / or reflect sunlight onto the glass plate and then onto the solar cell.

[0009] In one embodiment, the busbar body further has a back side facing the back plate, the first side side is set as a flat surface and is set at an angle to the back side, the angle between the first side side and the back side is α, 0° < α < 45°, or 45° < α < 90°.

[0010] In one embodiment, 10°≤a≤35°, or 55°≤a≤80°.

[0011] In one embodiment, the busbar body has a second side surface located on the side of the busbar body opposite to the first side surface; the reflective busbar also includes a second reflective layer connected to the second side surface, the second reflective layer being able to directly reflect sunlight onto the solar cell and / or reflect sunlight onto the glass plate and then reflect it back to the solar cell.

[0012] In one embodiment, the second side is set as a flat surface and is angled to the back surface, and the angle between the second side and the back surface is β, where 0° < β < 45°, or 45° < β < 90°.

[0013] In one embodiment, the first reflective layer and the second reflective layer are each independently made of aluminum foil, silver, or tin-lead alloy material; the first side and the second side are both polished surfaces; and the thickness of the first reflective layer and the second reflective layer are each independently set to be greater than 0 and less than or equal to 50 μm.

[0014] In one embodiment, the busbar body has a second side surface, which is located on the side of the busbar body opposite to the first side surface; the second side surface is a flat surface and perpendicular to the back surface.

[0015] In one embodiment, the busbar body has a front side facing the glass plate, the front side has at least one serrated portion, the serrated portion has a third side side facing the battery cell, the third side side is set at an angle to the front side and the angle is r, 0° < r < 45°, or 45° < r < 90°.

[0016] In one embodiment, the busbar body further has a back side facing the backplate, and the reflective busbar further includes a welding layer connected to the back side; the welding layer is used to connect with the solder strip of the battery cell.

[0017] A photovoltaic module, the photovoltaic module including the aforementioned reflective busbar.

[0018] In the aforementioned photovoltaic module and its reflective busbar, when sunlight is incident on the first reflective layer on the first side, the first reflective layer can directly reflect sunlight onto the solar cell and / or indirectly reflect sunlight onto the solar cell. The sunlight in the area between the reflective busbar and the solar cell no longer directly incident on the backsheet as in related technologies, but is reflected to the solar cell through the first reflective layer and absorbed and utilized by the solar cell, thereby improving the light utilization rate and increasing the output power of the photovoltaic module. Attached Figure Description

[0019] Figure 1 This is a structural diagram of a reflective busbar according to an embodiment of this application.

[0020] Figure 2 This is a structural diagram of a reflective busbar according to another embodiment of this application.

[0021] Figure 3 This is a structural diagram of a reflective busbar according to another embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the optical path of a photovoltaic cell according to an embodiment of this application when exposed to sunlight.

[0023] Figure 5 This is a schematic diagram of the optical path of a photovoltaic cell under sunlight according to another embodiment of this application.

[0024] 10. Reflective busbar; 11. Busbar body; 111. First side; 112. Second side; 113. Back; 114. Front; 12. First reflective layer; 13. Second reflective layer; 14. Serrated section; 141. Third side; 15. Third reflective layer; 16. Welding layer; 20. Backplate; 30. Battery cell; 40. Glass plate. Detailed Implementation

[0025] 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.

[0026] As described in the background section, in the prior art, some incident light passes through the gap between the reflective busbar and the battery cell and is incident on the back panel, resulting in poor utilization. The inventors have discovered that the reason for this problem is that the side of the reflective busbar facing the adjacent battery cell is perpendicular to the back of the reflective busbar and forms a gap with the battery cell. The incident light passes through this gap and is directly incident on the back panel instead of the battery cell, resulting in light loss.

[0027] Based on the above reasons, the present invention provides a photovoltaic module and its reflective busbar, which can improve the utilization rate of incident light, thereby increasing the output power of the photovoltaic module.

[0028] See Figure 4 or Figure 5 , Figure 4 and Figure 5 The following are schematic diagrams showing the optical path of a photovoltaic cell under sunlight according to two different embodiments of this application. One embodiment of this application provides a photovoltaic module, which includes a reflective busbar 10. For the specific structure of the reflective busbar 10, please refer to [link to relevant documentation]. Figures 1 to 3 In any given configuration, the photovoltaic module also includes a backsheet 20, solar cells 30, and a glass panel 40. Reflective busbars 10 and solar cells 30 are both located between the backsheet 20 and the glass panel 40. The photovoltaic module also includes solder ribbons (not shown in the figure). There are multiple solar cells 30, which are arranged sequentially at intervals along the length of the solder ribbons and connected by the solder ribbons to form a cell string. The number of cell strings is not limited to one; for example, multiple strings can be arranged sequentially along a length perpendicular to the solder ribbons. The reflective busbars 10 are connected to each solder ribbon, serving to collect current and output it outwards. The reflective busbars 10 are specifically arranged beside the solar cells 30. Specifically, the reflective busbar 10 can be arranged in the middle part of the battery string along the arrangement direction of each battery cell 30, so that battery cells 30 are arranged on both the left and right sides of the reflective busbar 10; or it can be arranged at the head or tail end of the battery string along the arrangement direction of each battery cell 30, so that battery cells 30 are arranged on one side of the reflective busbar 10 and battery cells 30 are not arranged on the other side.

[0029] Please refer to the following: Figure 2 , Figure 4 and Figure 5 The reflective busbar 10 includes a busbar body 11 and a first reflective layer 12. The busbar body 11 has a first side surface 111 facing the solar cell 30. The first reflective layer 12 is connected to the first side surface 111 and can be used to directly reflect sunlight onto the solar cell 30 and / or reflect sunlight onto the glass plate 40 and then reflect it back to the solar cell 30.

[0030] In the aforementioned photovoltaic module and its reflective busbar 10, when sunlight is incident on the first reflective layer 12 on the first side 111, the first reflective layer 12 can directly reflect sunlight onto the solar cell 30 and / or indirectly reflect sunlight onto the solar cell 30. The sunlight in the area between the reflective busbar 10 and the solar cell 30 no longer directly incident on the backsheet 20 as in related technologies, but is reflected to the solar cell 30 through the first reflective layer 12 and absorbed and utilized by the solar cell 30, thereby improving the light utilization rate and increasing the output power of the photovoltaic module.

[0031] In some embodiments, the first reflective layer 12 includes, but is not limited to, a film layer made of a metallic material with high reflectivity, such as aluminum foil, silver, or a tin-lead alloy, which can be flexibly selected according to actual needs. In this embodiment, the first reflective layer 12 is specifically made of aluminum foil, for example. Compared with other materials, aluminum foil has a reflectivity of up to 95%, which is higher, and the material cost of aluminum foil is much lower than that of tin-lead alloy. Therefore, using aluminum foil to make the first reflective layer 12 not only reduces material costs but also significantly improves the reflective effect.

[0032] Based on the aforementioned embodiments, the first side surface 111 is polished to achieve a smoothness level of 32 or higher. This reduces the thickness of the first reflective layer 12 disposed on the first side surface 111, thus achieving the required reflection effect and reducing the material cost of the first reflective layer 12.

[0033] In some embodiments, the busbar body 11 is made of metal materials such as copper or aluminum and is used to connect with the solder strip of the battery cell 30 to collect current and output the current outward.

[0034] In some embodiments, the busbar body 11 serves as the main material of the reflective busbar 10, and the first reflective layer 12 is fixedly connected to the first side surface 111. Optionally, the first reflective layer 12 can be, for example, bonded to the first side surface 111, formed on the first side surface 111 using 3D printing technology, deposited on the first side surface 111, or printed on the first side surface 111, etc. In this way, with the first reflective layer 12 fixedly disposed on the first side surface 111, the first incident light incident on the first side surface 111 will be more efficiently reflected directly onto the battery cell 30 for use by the battery cell 30, or it can be reflected onto the glass plate 40 and then reflected by the glass plate 40 onto the battery cell 30 for use by the battery cell 30.

[0035] In some embodiments, the shape of the first reflective layer 12 depends on the shape of the first side surface 111. When the first side surface 111 is flat, the first reflective layer 12 is flat accordingly; when the first side surface 111 is arc-shaped, the first reflective layer 12 is arc-shaped, such as a circular arc or an elliptical arc. Therefore, during the manufacturing process, once the shape of the first side surface 111 is determined, the shape of the first reflective layer 12 can be determined accordingly. Optionally, the first side surface 111 can be set to a flat surface, an arc shape, or other irregular shapes. In this embodiment, the description will be specifically based on the example of the first side surface 111 being flat.

[0036] In some embodiments, the busbar body 11 further comprises a back surface 113 facing the backplate 20. Optionally, the back surface 113 is, for example, on the same plane as the surface of the battery cell 30 facing the backplate 20, or has a height deviation of, for example, within 3 mm along the thickness direction of the battery cell 30. The thickness D1 of the busbar body 11 and the thickness D2 of the battery cell 30 satisfy, for example, the following relationship: D1 / D2 is 1 to 3, specifically, for example, 1, 1.5, 2, 2.5, or 3, etc.

[0037] Furthermore, the first side surface 111 is designed as a flat surface and forms an angle with the back surface 113, with the angle between the first side surface 111 and the back surface 113 being α. Taking sunlight, i.e., incident light, incident on the first side surface 111 in a direction perpendicular to the glass plate 40 as an example, the light path analysis shows that:

[0038] Please see Figure 2 and Figure 4 When 0° < a < 45°, specifically, a is, for example, 1°, 5°, 10°, 15°, 20°, 25°, 35°, or 43°, the first reflective layer 12 can be used to reflect incident light to the glass plate 40 and then from the glass plate 40 to the solar cell 30. Specifically, when a is, for example, between 10° and 35°, light can be more indirectly reflected to the solar cell 30, thus improving light utilization.

[0039] Please see Figure 2 and Figure 5 When 45° < a < 90°, specifically, a is, for example, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°, the first reflective layer 12 can be used to directly reflect the incident light onto the solar cell 30. Specifically, when a is, for example, between 55° and 80°, the light can be reflected more directly onto the solar cell 30, thus improving light utilization.

[0040] Please see Figure 2 and Figure 3 In one embodiment, the busbar body 11 is provided with a second side surface 112. The second side surface 112 is located on the side of the busbar body 11 that is opposite to the first side surface 111.

[0041] For the reflective busbar 10 located in the middle portion of the battery string along the arrangement direction of each battery cell 30, please refer to... Figure 2 , Figure 4 and Figure 5The reflective busbar 10 also includes a second reflective layer 13 connected to the second side surface 112. The second reflective layer 13 can be used to directly reflect sunlight onto the solar cell 30 and / or reflect sunlight onto the glass plate 40 and then back to the solar cell 30. Thus, not only the first side surface 111 of the busbar body 11 can be utilized, but also the second side surface 112 of the busbar body 11. Similar to the function of the first reflective layer 12 on the first side surface 111, the second reflective layer 13 on the second side surface 112 performs the same function, thereby further improving light utilization.

[0042] Specifically, when the second side surface 112 is flat, the second reflective layer 13 is flat; when the second side surface 112 is arc-shaped, the second reflective layer 13 is arc-shaped, such as a circular arc or an elliptical arc.

[0043] In some specific embodiments, the second side surface 112 is set as a flat surface and forms an angle with the back surface 113, the angle between the second side surface 112 and the back surface 113 being β. Where 0° < β < 45°, β specifically includes, for example, 1°, 5°, 10°, 15°, 20°, 25°, 35°, or 43°, etc. The second reflective layer 13 can be used to reflect incident light to the glass plate 40 and then from the glass plate 40 to the solar cell 30, such as... Figure 4 As shown. Alternatively, 45° < β < 90°, where β is, for example, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°, etc., and the second reflective layer 13 can be used to directly reflect the incident light onto the solar cell 30, such as... Figure 5 As shown.

[0044] It should be noted that the relationship between a and β can be flexibly adjusted and set according to actual needs. It can be a=β, in which case the cross-sectional profile of the busbar body 11 along its length direction is set in an isosceles trapezoid shape, which is conducive to mass production. Alternatively, it can be a<β or a>β, both of which can improve the utilization rate of light.

[0045] In one specific embodiment, the first reflective layer 12 and the second reflective layer 13 are each independently made of aluminum foil material, which not only has higher reflectivity but also lower cost. Furthermore, both the first side surface 111 and the second side surface 112 are polished surfaces with a smoothness level of 32 or higher. This allows for a reduction in the thickness of the reflective layer while still achieving a high reflectivity, further reducing material costs. Specifically, the thicknesses of the first reflective layer 12 and the second reflective layer 13 are each independently set to be greater than 0 and less than or equal to 50 μm.

[0046] For the reflective busbars 10 arranged at the head or tail end of the battery string along the arrangement direction of each battery cell 30, please refer to Figure 3 In one embodiment, the second side 112 is a flat surface perpendicular to the back surface 113, i.e., β=90°. When the reflective busbar 10 is located at the beginning or end of the photovoltaic module's cell string, the first side 111 faces the cell 30 and is spaced apart from the cell 30, while the second side 112 is located on the side of the busbar body 11 facing away from the cell 30. In other words, there is no cell 30 spaced apart from the second side 112. In this case, the second side 112 is a flat surface perpendicular to the back surface 113, and there is no need to provide a second reflective layer 13 on the second side 112. Of course, the second side 112 can also be set at other angles with the back surface 113, such as an acute angle or an obtuse angle.

[0047] In one embodiment, the busbar body 11 has a front surface 114 facing the glass plate 40. The front surface 114 has at least one serrated portion 14, and the serrated portion 14 has a third side surface 141 facing the battery cell 30. The third side surface 141 is set at an angle to the front surface 114 and the angle is r, 0° < r < 45°, or 45° < r < 90°.

[0048] The serrated portion 14 and the busbar body 11 are made of the same material, including but not limited to copper, aluminum, and other metal materials. In this embodiment, the serrated portion 14 and the busbar body 11 are integrally formed.

[0049] Based on the aforementioned embodiments, the reflective busbar 10 further includes a third reflective layer 15 disposed on the third side 141. The third reflective layer 15 is made of materials including, but not limited to, aluminum foil, silver, or tin-lead alloy. Specifically, similar to the first reflective layer 12, the third reflective layer 15 is made of aluminum foil, which has a high reflectivity, thereby improving the utilization rate of light.

[0050] Based on the aforementioned embodiment, the serrated portion 14 serves as a carrier for the third reflective layer 15, providing support for it. The third side surface 141 is polished to improve the flatness of the third reflective layer 15, thereby reducing its thickness, for example, to a thickness greater than 0 and less than or equal to 50 μm.

[0051] Please see Figure 2 , Figure 4 and Figure 5For the reflective busbar 10 arranged in the middle portion along the arrangement direction of each battery cell 30 in the battery string, at least two serrated portions 14 are provided. The third side 141 of one serrated portion 14 faces the adjacent battery cell 30, and the third side 141 of the other serrated portion 14 faces the adjacent battery cell 30. Specifically, the serrated portions 14 of the battery cell 30 with the third side 141 facing one side of the reflective busbar 10 are symmetrically arranged with the serrated portions 14 of the battery cell 30 with the third side 141 facing the other side of the reflective busbar 10.

[0052] For the reflective busbars 10 arranged at the head or tail end of the battery string along the arrangement direction of each battery cell 30, please refer to Figure 3 In one embodiment, the serrated portion 14 is provided as at least one, and the third side 141 of each serrated portion 14 faces the battery cell 30 located on one side of the reflective busbar 10.

[0053] The cross-sectional shape of the serrated part 14 along its length direction includes, but is not limited to, a right-angled triangle, an isosceles triangle, or an equilateral triangle. The specific shape can be flexibly adjusted and set according to actual needs, and is not limited here.

[0054] In one embodiment, the busbar body 11 further has a back surface 113 facing the back panel 20. The reflective busbar 10 also includes a welding layer 16 attached to the back surface 113. The welding layer 16 is used to connect to the solder strips of the battery cell 30.

[0055] In some embodiments, the solder layer 16 is solder, mainly composed of an alloy such as tin-lead or tin-lead-silver, and the thickness of the solder layer 16 is 10μm to 50μm, specifically, for example, 10μm, 20μm, 30μm, 40μm or 50μm, etc.

[0056] In some embodiments, the photovoltaic module further includes an encapsulating film disposed between the backsheet 20 and the glass plate 40. The backsheet 20, the solar cells 30, and the glass plate 40 are connected and fixed by the encapsulating film.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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 reflective busbar for a photovoltaic module, the photovoltaic module comprising a backsheet (20), solar cells (30), and a glass plate (40), wherein the reflective busbar (10) and the solar cells (30) are both located between the backsheet (20) and the glass plate (40), and the reflective busbar (10) is located beside the solar cells (30), characterized in that, The reflective busbar (10) includes: The busbar body (11) has a first side surface (111) facing the battery cell (30); and The first reflective layer (12) is connected to the first side surface (111). The first reflective layer (12) can be used to directly reflect sunlight onto the battery cell (30) and / or reflect sunlight onto the glass plate (40) and then reflect it back to the battery cell (30) by the glass plate (40).

2. The reflective busbar according to claim 1, characterized in that, The main body (11) of the busbar also has a back side (113) facing the back plate (20). The first side side (111) is set as a flat surface and is set at an angle to the back side (113). The angle between the first side side (111) and the back side (113) is a, 0° < a < 45°, or 45° < a < 90°.

3. The reflective busbar according to claim 2, characterized in that, 10°≤a≤35°, or 55°≤a≤80°.

4. The reflective busbar according to claim 2, characterized in that, The busbar body (11) has a second side (112), which is located on the side of the busbar body (11) opposite to the first side (111). The reflective busbar (10) also includes a second reflective layer (13) connected to the second side (112). The second reflective layer (13) can be used to directly reflect sunlight onto the battery cell (30) and / or reflect sunlight onto the glass plate (40) and be reflected by the glass plate (40) onto the battery cell (30).

5. The reflective busbar according to claim 4, characterized in that, The second side (112) is set as a flat surface and is set at an angle to the back (113). The angle between the second side (112) and the back (113) is β, 0° < β < 45°, or 45° < β < 90°.

6. The reflective busbar according to claim 4, characterized in that, The first reflective layer (12) and the second reflective layer (13) are each independently made of aluminum foil, silver or tin-lead alloy material; the first side (111) and the second side (112) are both made of polished surface; the thickness of the first reflective layer (12) and the second reflective layer (13) are each independently set to be greater than 0 and less than or equal to 50 μm.

7. The reflective busbar according to claim 2, characterized in that, The busbar body (11) has a second side (112), which is located on the side of the busbar body (11) away from the first side (111); the second side (112) is a flat surface and perpendicular to the back surface (113).

8. The reflective busbar according to claim 1, characterized in that, The busbar body (11) has a front side (114) facing the glass plate (40), and the front side (114) has at least one serrated part (14). The serrated part (14) has a third side side (141) facing the battery cell (30). The third side side (141) is set at an angle to the front side (114) and the angle is r, 0° < r < 45°, or 45° < r < 90°.

9. The reflective busbar according to any one of claims 1 to 8, characterized in that, The busbar body (11) also has a back side (113) facing the back plate (20), and the reflective busbar (10) also includes a welding layer (16) connected to the back side (113); the welding layer (16) is used to connect with the welding strip of the battery cell (30).

10. A photovoltaic module, characterized in that, The photovoltaic module includes a reflective busbar as described in any one of claims 1 to 9.

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