Solar cells, battery modules and photovoltaic systems

Abstract

This application relates to the field of solar cell technology and provides a solar cell, a cell module, and a photovoltaic system. The solar cell includes a cell substrate; a main grid structure is disposed on the cell substrate and includes pads and a main grid segment connected to the pads. The main grid segment includes at least two sequentially connected conductive parts, and the width values ​​of the multiple conductive parts decrease along the direction away from the pads. By connecting the main grid segment to the pads and setting the width values ​​of the at least two sequentially connected conductive parts on each main grid segment to decrease sequentially along the direction away from the pads, the printing area of ​​the main grid can be reduced, thereby reducing the amount of paste used in the main grid.

Description

Technical Field

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

[0002] The material cost of the main grid is one of the important components of the production cost of solar cells. For example, in traditional crystalline silicon solar cells, the cost of silver paste, which is used as the main grid material, accounts for 10%-15% of the cost of non-silicon materials. As the size of the solar cell increases, the material cost of the main grid may further increase. Therefore, those skilled in the art usually reduce the material cost of the main grid by reducing the amount of main grid paste used.

[0003] Therefore, how to reduce the amount of slurry used in the main grid has become an urgent problem to be solved. Utility Model Content

[0004] This application provides a solar cell, a battery module, and a photovoltaic system, aiming to solve the problem of how to reduce the amount of paste used in the main grid.

[0005] The solar cell provided in this application includes: Battery substrate; A main grid structure is disposed on the battery substrate and includes a pad and a main grid segment connected to the pad. The main grid segment includes at least two sequentially connected conductive portions, and the width values ​​of the multiple conductive portions decrease along the direction away from the pad.

[0006] Specifically, the width of the first end of the conductive portion is equal to the width of its last end.

[0007] More specifically, the width difference between two adjacent conductive portions is greater than 0 mm and less than or equal to 0.74 mm.

[0008] More specifically, the width of the conductive portion connected to the pad is 0.2 mm to 1.5 mm.

[0009] More specifically, the width of the conductive portion furthest from the pad is 0.02 mm to 0.1 mm.

[0010] More specifically, the length d1 of the main gate segment is 3mm to 12mm.

[0011] More specifically, the difference in length d2 between two adjacent conductive parts is 0 mm to 10 mm.

[0012] Specifically, the width of the conductive portion decreases from the beginning to the end.

[0013] In one specific embodiment, the main gate structure includes two main gate segments, and the first ends of the two main gate segments are respectively connected to the two ends of the pad. In one specific embodiment, the center lines of each pair of adjacent conductive portions are collinear.

[0014] The battery assembly provided in this application includes any of the aforementioned solar cells.

[0015] The photovoltaic system provided in this application includes the battery modules described above.

[0016] The beneficial effect of this application is that by connecting the main gate segment to the pad and setting the width value of at least two sequentially connected conductive parts on each main gate segment to decrease successively along the direction away from the pad, the printing area of ​​the main gate can be reduced, thereby reducing the amount of paste used in the main gate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a photovoltaic system according to one embodiment of this application; Figure 2 This is a schematic diagram of the structure of a battery assembly according to one embodiment of this application; Figure 3 This is a schematic diagram of the structure of a solar cell according to one embodiment of this application; Figure 4 This is a partial structural schematic diagram of a solar cell according to an embodiment of this application; Figure 5 This is one of the enlarged views of the main gate structure according to an embodiment of this application; Figure 6 This is a second enlarged view of the main gate structure according to one embodiment of this application; Figure 7 This is a third enlarged view of the main gate structure according to one embodiment of this application; Figure 8 This is an enlarged view of the conductive part according to one embodiment of this application.

[0018] Explanation of key component symbols: 1, photovoltaic system; 10, battery module; 100, solar cell; 1000, battery substrate; 1001. Main gate; 1002. Main gate structure; 1003. Main gate segment; 1004, Conductive part; 1004a, First conductive part; 1004b, Second conductive part; 1004c, Third conductive part; 1004d, Fourth conductive part; 1004e, Fifth conductive part; 1004f, Sixth conductive part; 1004g, Seventh conductive part; 1004h, Eighth conductive part; 1005, Pad. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0020] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0024] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0025] Please refer to Figure 1 and Figure 2 This application provides a solar cell 100, which includes a cell substrate 1000 and a plurality of main grids 1001 disposed on the cell substrate 1000, with the plurality of main grids 1001 arranged at intervals. Each main grid 1001 includes a plurality of main grid structures 1002 connected end-to-end. It should be noted that the arrangement direction of the plurality of main grids 1001 is perpendicular to the arrangement direction of the plurality of main grid structures 1002.

[0026] Specifically, such as Figure 3 and Figure 4 As shown, each main gate structure 1002 includes a pad 1005 and a main gate segment 1003 connected to the pad 1005. Specifically, the first end of the main gate segment 1003 is connected to the pad 1005. The number of main gate structures 1002 matches the number of pads 1005. Specifically, the number of main gate structures 1002 is equal to the number of pads 1005 (see below for details). In this specific embodiment, when two adjacent main gate structures 1002 are connected end-to-end, the last end of the main gate segment 1003 in one main gate structure 1002 is connected to the other end of the pad 1005 in the adjacent main gate structure 1002. It should be noted that the other end here refers to the other end of the pad 1005 in the adjacent main gate structure 1002 that is away from the main gate segment 1003. It should also be noted that the first end of the main gate segment 1003 is the end closer to the pad 1005, while the last end of the main gate segment 1003 is the end farther away from the pad 1005.

[0027] More specifically, see reference Figure 5Each main grid segment 1003 includes at least two sequentially connected conductive portions 1004 (i.e., adjacent conductive portions 1004 are connected end-to-end), and the width of the plurality of conductive portions 1004 decreases along the direction away from the pad 1005. By adopting the aforementioned arrangement, the printing area of ​​the main grid 1001 on the battery substrate 1000 can be reduced, thereby reducing the amount of paste used in the main grid 1001. It should be noted that the paste for the main grid 1001 can be silver paste, but is not limited to silver paste; it can also be copper paste, aluminum paste, etc. No specific limitations are made here.

[0028] It should be noted that the width values ​​of the multiple conductive parts 1004 decrease along the direction of the principle pad 1005, and can be successively decreased at equal intervals, such as... Figure 6 As shown, it can also be a successive, non-equidistant decrease.

[0029] In one specific embodiment, the width of the beginning end of each conductive portion 1004 can be equal to the width of its end. By using conductive portions 1004 with equal width at both ends, the current can be evenly distributed within the conductive portion 1004, thereby reducing the amount of loss during current transmission within the conductive portion 1004 and thus improving the fill factor of the conductive portion 1004.

[0030] Of course, for reference Figure 7 The width of the beginning of each conductive portion 1004 can be unequal to the width of its end. For example, the width of the conductive portion 1004 decreases from the beginning to the end. By using conductive portions 1004 with unequal widths at the beginning and end, the amount of paste used in the main gate 1001 can be further reduced (compared to conductive portions 1004 with equal widths at the beginning and end). It should be noted that the width of the conductive part 1004 decreases from the beginning to the end, which can be either a successive equal-distance decrease or a successive non-equal-distance decrease.

[0031] exist Figure 8 In the specific embodiment shown, each main gate segment 1003 includes eight conductive portions 1004 connected sequentially or end-to-end. It should be noted that the end closest to the pad 1005 is the starting end of the conductive portion 1004, or, among the two ends of the conductive portion 1004, the end closest to the adjacent conductive portion 1004 with the larger width value is the starting end. Clearly, the conductive portion 1004 connected to the pad 1005 has the largest width value, while the conductive portion 1004 furthest from the pad 1005 has the smallest width value. Along the width direction of the main gate 1001, the conductive portion 1004 closest to the pad 1005 is formed by seven inward retractions to become the conductive portion 1004 furthest from the pad 1005. In other specific embodiments, the number of conductive portions 1004 in each main gate segment 1003 can also be other numbers. No specific limitations are imposed here.

[0032] In some specific embodiments, the width difference between two adjacent conductive portions 1004 can be greater than 0 mm and less than or equal to 0.74 mm. For example, the width difference between two adjacent conductive portions 1004 can be 0.1 mm, 0.2 mm, 0.4 mm, 0.7 mm, and 0.74 mm, etc. Using the aforementioned values ​​for the width difference between two adjacent conductive portions 1004 can ensure that the resistance loss and light-shielding loss of the main gate 1001 are balanced. Moreover, it can also ensure the current transmission speed in the main gate 1001.

[0033] For ease of description and understanding, the eight conductive portions 1004 extending from the closest to the pad 1005 to the furthest from the pad 1005 will be named the first conductive portion 1004a, the second conductive portion 1004b, the third conductive portion 1004c, the fourth conductive portion 1004d, the fifth conductive portion 1004e, the sixth conductive portion 1004f, the seventh conductive portion 1004g, and the eighth conductive portion 1004h, respectively. Obviously, referring to the foregoing, the first conductive portion 1004a is recessed inward along the width direction to form the second conductive portion 1004b, and the second conductive portion... After part 1004b is recessed in the width direction, it forms a third conductive part 1004c. After part 1004c is recessed in the width direction, it forms a fourth conductive part 1004d. After part 1004d is recessed in the width direction, it forms a fifth conductive part 1004e. After part 1004e is recessed in the width direction, it forms a sixth conductive part 1004f. After part 1004f is recessed in the width direction, it forms a seventh conductive part 1004g. After part 1004g is recessed in the width direction, it forms an eighth conductive part 1004h. The width differences between the first conductive portion 1004a and the second conductive portion 1004b, the second conductive portion 1004b and the third conductive portion 1004c, the third conductive portion 1004c and the fourth conductive portion 1004d, the fourth conductive portion 1004d and the fifth conductive portion 1004e, the fifth conductive portion 1004e and the sixth conductive portion 1004f, the sixth conductive portion 1004f and the seventh conductive portion 1004g, and the seventh conductive portion 1004g and the eighth conductive portion 1004h can all be the same or all different. Of course, they can also be partially the same (when the width differences between two adjacent conductive portions 1004 in the eight conductive portions 1004 are partially the same and the other part is different, the number of conductive portions 1004 is less than eight segments). The aforementioned width difference can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, and 0.74mm, etc. No specific restrictions are imposed here.

[0034] In some specific embodiments, the width of the conductive portion 1004 connected to the pad 1005 can be from 0.2 mm to 1.5 mm. That is, the width of the conductive portion 1004 with the largest width among the plurality of conductive portions 1004 can be from 0.2 mm to 1.5 mm. For example, the width of the conductive portion 1004 with the largest width among the plurality of conductive portions 1004 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, and 1.5 mm, etc.

[0035] In this way, by increasing the width of the main gate 1001, a larger contact area can be provided for the solder (e.g., solder paste), thereby forming a stronger mechanical interlock structure between the solder and the main gate 1001. Simultaneously, the resistance during current transmission within the main gate 1001 can be reduced, thus improving the fill factor of the main gate 1001. In some specific embodiments, the width of the conductive portion 1004 furthest from the pad 1005 can be 0.02 mm to 0.1 mm. That is, the width of the conductive portion 1004 with the smallest width among the plurality of conductive portions 1004 can be 0.02 mm to 0.1 mm. For example, the width of the conductive portion 1004 with the smallest width among the plurality of conductive portions 1004 can be 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, and 0.1 mm, etc.

[0036] In this way, while ensuring the mechanical strength and conductivity of the main gate 1001, the resistance value during the current transmission process within the main gate 1001 is prevented from becoming too high.

[0037] In some specific embodiments, the length of the main gate segment 1003 can be 3mm to 12mm, that is, the sum of the lengths of the plurality of conductive parts 1004 is 3mm to 12mm. For example, the length d1 of the main gate segment 1003 can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm and 12mm, etc.

[0038] Increasing the length of the main grid 1001 reduces the lateral transmission distance of current from the fine grid to the main grid 1001, thereby reducing resistance loss during the aforementioned transmission process. Furthermore, a longer main grid 1001 can cover a wider surface area of ​​the solar cell 100, thus reducing the difference in current density between the edge and center regions of the solar cell 100, and improving the uniformity of current collection. However, increasing the length of the main grid 1001 not only leads to a linear increase in resistance but also reduces the effective light-receiving area of ​​the solar cell 100.

[0039] In some specific embodiments, the length difference d2 between two adjacent conductive portions 1004 can be 0 mm to 10 mm. For example, the length difference between two adjacent conductive portions 1004 can be 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, and 10 mm, etc. Referring to the foregoing, the length differences between the first conductive portion 1004a and the second conductive portion 1004b, the second conductive portion 1004b and the third conductive portion 1004c, the third conductive portion 1004c and the fourth conductive portion 1004d, the fourth conductive portion 1004d and the fifth conductive portion 1004e, the fifth conductive portion 1004e and the sixth conductive portion 1004f, the sixth conductive portion 1004f and the seventh conductive portion 1004g, and the seventh conductive portion 1004g and the eighth conductive portion 1004h can all be the same or all different. Of course, they can also be partially the same (or partially different).

[0040] Thus, by setting the length difference between two adjacent conductive portions 1004 to be proportional to the current density gradient, it is easier to balance the resistance loss and shading loss of the main gate segment 1003. The current density gradient of the conductive portion 1004 is obtained through electroluminescence imaging or laser scanning technology.

[0041] In some specific embodiments, along the extending direction of the main gate 1001, the center lines of every two adjacent conductive portions 1004 are collinear to ensure the symmetry of the current flow path within the main gate 1001 and the uniformity of the current distribution. Furthermore, this also ensures the uniformity of stress distribution on the main gate 1001, thereby improving the mechanical strength of the main gate 1001. That is, along the extending direction of the main gate 1001, the main gate segments 1003 are symmetrically arranged. Specifically, along the extending direction of the main gate 1001, the center line of the first conductive portion 1004a is collinear with the center line of the second conductive portion 1004b, the center line of the second conductive portion 1004b is collinear with the center line of the third conductive portion 1004c, the center line of the third conductive portion 1004c is collinear with the center line of the fourth conductive portion 1004d, the center line of the fourth conductive portion 1004d is collinear with the center line of the fifth conductive portion 1004e, the center line of the fifth conductive portion 1004e is collinear with the center line of the sixth conductive portion 1004f, and the center line of the sixth conductive portion 1004f is collinear with the center line of the sixth conductive portion 1004f. The center line of part 1004f is collinear with the center line of the seventh conductive part 1004g, and the center line of the seventh conductive part 1004g is collinear with the center line of the eighth conductive part 1004h. That is, the center lines of the first conductive part 1004a, the second conductive part 1004b, the third conductive part 1004c, the fourth conductive part 1004d, the fifth conductive part 1004e, the sixth conductive part 1004f, the seventh conductive part 1004g, and the eighth conductive part 1004h are collinear with each other.

[0042] In some specific embodiments, the shape of the pad 1005 can be triangular, rectangular, trapezoidal, circular, elliptical, or polygonal. For example, when the pad 1005 is triangular, it can guide sunlight to the surface of the solar cell through multi-angle reflection, thereby reducing reflection loss. When the pad 1005 is rectangular, the symmetrical structure of the rectangular pad 1005 makes the current distribution between the pad 1005 and the main grid 1001 more uniform. At the same time, the right-angled structure of the rectangular pad 1005 is suitable for withstanding the mechanical stress generated during the transportation or installation of the battery module, and the geometric stability of the rectangular pad 1005 makes it less prone to deformation under long-term thermal cycling conditions. When the pad 1005 is trapezoidal, the shape of the trapezoidal... The geometric characteristics of the pad 1005 enable it to form a unique mechanical interlocking structure during the soldering process, thereby significantly improving soldering reliability. When the pad 1005 is circular, or when it is nearly circular, this structure maximizes the utilization of the contact area between the solder ribbon and the pad 1005, and the mechanical stress distribution between them is uniform. Compared to trapezoidal or rectangular pads 1005, this avoids cold solder joints caused by poor contact. When the pad 1005 is polygonal, it helps to accurately match solder ribbons of different wire diameters by adjusting the side length and angle of the pad 1005, thereby optimizing the problem of solder ribbon misalignment and avoiding cold solder joints or over-soldering caused by misalignment between the solder ribbon and the pad 1005. Preferably, the pad 1005 can be a regular octagon, which not only reduces the amount of solder used (compared to circular pads 1005), but also provides sufficient contact area for the solder (compared to rectangular pads 1005).

[0043] In some specific embodiments, the main gate structure 1002 includes two main gate segments 1003, and the first ends of the two main gate segments 1003 are respectively connected to the two ends of the pads 1005. Obviously, the two main gate segments 1003 are symmetrically arranged about the pads 1005. Referring to the foregoing, each main gate 1001 includes a plurality of main gate structures 1005 connected end-to-end, that is, the first and last ends of each pair of adjacent main gate structures 1002 are connected. It can be understood that the first and last ends of the main gate structure 1002 are respectively the last ends of two main gate segments 1003, that is, the first and last ends of two adjacent main gate structures 1002 are connected to the last ends of the corresponding main gate segments 1003 of the adjacent main gate structure 1002 through the last end of the main gate segment 1003 in one main gate structure 1002.

[0044] In summary, the main gate segment 1003 has a gradually changing (meaning the width of the conductive part 1004 decreases successively along the direction away from the pad 1005) tower structure. Therefore, the width of the main gate structure 1002 changes in a pattern of first increasing and then decreasing. Since each main gate 1001 includes several main gate structures 1002 connected end to end, the width of each main gate 1001 changes cyclically according to the pattern of first increasing and then decreasing.

[0045] In some specific embodiments, the solar cell 100 includes a cell substrate 1000 and a main grid structure 1002 as described in the previous embodiments. The difference from the previous embodiments is that the solar cell 100 also includes fine grids. The main grid structure 1002 and the fine grids overlap each other, and both are disposed on the cell substrate 1000. Furthermore, there are multiple fine grids, which are arranged at intervals along the extension direction of the main grids 1001 (the arrangement direction of the multiple fine grids intersects with the arrangement direction of several main grids 1001 in the main grid structure 1002), and the multiple fine grids intersect with several main grids 1001.

[0046] The battery assembly 10 of this application includes the solar cell 100 of any of the above-mentioned embodiments.

[0047] In this embodiment of the battery module 10, multiple solar cells 100 in the battery module 10 can be connected in series to form a battery string, thereby realizing the series current collection and output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0048] It is understood that in such an embodiment, the battery module 10 may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back of the solar cell 100, the photovoltaic glass, adjacent cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0049] Photovoltaic glass can be applied to the encapsulating film on the front side of the solar cell 100. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell 100 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell 100 together, providing sealing, insulation, and waterproofing / moisture protection for the solar cell 100.

[0050] The backsheet can be attached to the encapsulant film on the back of the solar cell 100. The backsheet provides protection and support for the solar cell 100, and possesses reliable insulation, water resistance, and aging resistance. Multiple options are available for the backsheet, typically tempered glass, acrylic glass, aluminum alloy TPT composite encapsulant film, etc., and the specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell 100, encapsulant film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module 10, providing stable support and installation for the battery module 10. For example, the battery module 10 can be installed at the desired location using the metal frame.

[0051] The photovoltaic system 1 of this application includes the battery module 10 described above.

[0052] The photovoltaic system 1 described in this application can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that generate electricity using solar energy, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 1 are not limited to these; that is, the photovoltaic system 1 can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system 1 may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules 10. For example, multiple battery modules 10 can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0053] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A solar cell, characterized by, include: Battery substrate; A main grid structure is disposed on the battery substrate and includes a pad and a main grid segment connected to the pad. The main grid segment includes at least two sequentially connected conductive portions, and the width values ​​of the multiple conductive portions decrease along the direction away from the pad.

2. The solar cell according to claim 1, characterized in that, The width of the first end of the conductive part is equal to the width of its last end.

3. The solar cell according to claim 2, characterized in that, The width difference between two adjacent conductive parts is greater than 0 mm and less than or equal to 0.74 mm.

4. The solar cell of claim 2, wherein, The width of the conductive part connected to the pad is 0.2mm to 1.5mm.

5. The solar cell of claim 2, wherein The width of the conductive portion furthest from the pad is 0.02 mm to 0.1 mm.

6. The solar cell of claim 2, wherein, The length d1 of the main gate segment is 3mm to 12mm.

7. The solar cell according to claim 6, characterized in that, The difference in length d2 between two adjacent conductive parts is 0 mm to 10 mm.

8. The solar cell according to claim 1, characterized in that, The width of the conductive part decreases from the beginning to the end.

9. The solar cell according to any one of claims 1-8, characterized in that, Each of the main gate structures includes two main gate segments, and the first ends of the two main gate segments are respectively connected to the two ends of the pad.

10. A battery assembly, characterized in that, Includes the solar cell according to any one of claims 1-9.

11. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 10.

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