Solar cell, cell string, cell assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a solar cell, a cell string, a cell module and a photovoltaic system. The solar battery comprises a battery piece, a plurality of main grids and a plurality of fine grids, the main grids and the fine grids are arranged on the battery piece, the main grids extend in the first direction and are alternately arranged in the second direction, the fine grids and the main grids are arranged in a crossed mode, transition sections which gradually change in the first direction are formed at the ends of the main grids, and the transition sections avoid hollow-out areas. The fine grid passes through the hollow area and is connected with the transition section. Therefore, the transition section and the hollow area formed at the end part of the main grid can save main grid slurry, and meanwhile, the transition section can relieve stress concentration. In addition, the fine grid can burn through the passivation layer in the hollow area so as to be electrically connected with the doping layer, it is guaranteed that current generated in the area can be collected, and the power generation efficiency is improved.

Description

Technical Field

[0001] The present application belongs to the field of solar cell technology, and in particular relates to a solar cell, a cell string, a cell assembly and a photovoltaic system. Background Art

[0002] Solar cell power generation is a sustainable source of clean energy, utilizing the photovoltaic effect of semiconductor pn junctions to convert sunlight into electrical energy. In related technologies, a solar cell is a semiconductor device that directly converts sunlight energy into electrical energy, with metal grid lines used to collect and transmit current. However, in related technologies, the main grid lines are prepared first, followed by the fine grid lines. The main grid lines are placed between the fine grid lines and the doped layer to block the fine grid lines and the doped layer, preventing the current generated by the doped layer in this area from being extracted, reducing power generation efficiency. Utility Model Content

[0003] The present application provides a solar cell, a cell string, a cell assembly and a photovoltaic system, which aim to solve the problem that the current generated by the doped layer shielded by the main grid cannot be extracted.

[0004] The solar cell provided in the present application includes a cell sheet, a plurality of main grids and a plurality of fine grids, the plurality of main grids are arranged on the cell sheet, the main grids include a plurality of first main grids and a plurality of second main grids, the first main grid and the second main grid extend along a first direction and are alternately arranged along a second direction, the first main grid and the second main grid have opposite polarities, a plurality of fine grids are arranged on the cell sheet, the fine grids include a plurality of first fine grids and a plurality of second fine grids, the first fine grid and the second fine grid have opposite polarities, the first fine grid is arranged to cross the first main grid and is disconnected at the second main grid, the second fine grid is arranged to cross the second main grid and is disconnected at the first main grid, a first gradient section that gradually changes along the first direction is formed at the end of the first main grid, the first gradient section avoids the first hollow area, the first fine grid passes through the first hollow area and is connected to the first gradient section.

[0005] Furthermore, a second gradient section that gradually changes along the first direction is formed at the end of the second main grid, the second gradient section avoids the second hollow area, and the second fine grid passes through the second hollow area and connects to the second gradient section.

[0006] Furthermore, the first gradual transition section and / or the second gradual transition section is in a trapezoidal shape, an inverted V shape, or an inverted trapezoidal shape.

[0007] Furthermore, when the first transition section is trapezoidal, the first hollow areas are located on both sides of the first transition section along the second direction; and / or

[0008] When the second gradient section is trapezoidal, the second hollow areas are located on both sides of the second gradient section along the second direction.

[0009] Furthermore, when the first transition section is in an inverted V shape or an inverted trapezoidal shape, the first hollow area is located inside the first transition section along the second direction; and / or

[0010] When the second transition section is in an inverted V shape or an inverted trapezoidal shape, the second hollow area is located inside the second transition section along the second direction.

[0011] Furthermore, the cell further includes a first doping layer and a second doping layer, the first doping layer and the second doping layer extend along the second direction and are alternately arranged along the first direction.

[0012] Furthermore, the first fine gate is arranged in the first doping layer, the second fine gate is arranged in the second doping layer, the first fine gate and the second fine gate extend along the second direction, and are alternately arranged along the first direction.

[0013] Furthermore, the first fine gate disposed in the first gradient section passes through the first hollow region to be electrically connected to the first doped layer;

[0014] The second fine gate disposed in the second gradient section passes through the second hollow region to be electrically connected to the second doped layer.

[0015] The battery string provided in the embodiments of the present application includes the solar cell described in any one of the above embodiments.

[0016] The battery assembly provided in the embodiments of the present application includes the battery string described in the above embodiments.

[0017] The photovoltaic system provided in the embodiments of the present application includes the battery assembly described in the above embodiments.

[0018] In the solar cell, cell string, cell assembly, and photovoltaic system of the embodiments of the present application, the solar cell includes a cell, a plurality of busbars, and a plurality of fine grids. The plurality of busbars are arranged on the cell, and the busbars include a plurality of first busbars and a plurality of second busbars. The first busbars and the second busbars extend along a first direction and are alternately arranged along a second direction. The first busbars and the second busbars have opposite polarities. The plurality of fine grids are arranged on the cell, and the fine grids include a plurality of first fine grids and a plurality of second fine grids. The first fine grids and the second fine grids have opposite polarities. The first fine grids are arranged to intersect with the first busbar and are disconnected at the second busbar. The second fine grids are arranged to intersect with the second busbar and are disconnected at the first busbar. A first gradient segment that gradually changes along the first direction is formed at the end of the first busbar. The first gradient segment avoids the first hollow area. The first fine grid passes through the first hollow area and connects to the first gradient segment. In this way, the first gradient segment and the first hollow area formed at the end of the first busbar can save busbar paste, and the first gradient segment can relieve stress concentration. In addition, the first fine grid can burn through the passivation layer in the first hollow area to electrically connect the doped layer, ensuring that the current generated in the area can be collected, thereby improving the power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a solar cell according to an embodiment of the present application;

[0020] Figure 2 is another structural schematic diagram of a solar cell according to an embodiment of the present application;

[0021] Figure 3 is a schematic diagram of a partial cross-sectional structure of a solar cell according to an embodiment of the present application;

[0022] Figure 4 1 is a schematic diagram of a partial structure of a solar cell according to an embodiment of the present application;

[0023] Figure 5 This is another partial structural diagram of a solar cell according to an embodiment of the present application;

[0024] Figure 6 is another partial structural diagram of a solar cell according to an embodiment of the present application;

[0025] Figure 7 This is a schematic structural diagram of a battery string according to an embodiment of the present application;

[0026] Figure 8 is a schematic structural diagram of a battery assembly according to an embodiment of the present application;

[0027] Figure 9 It is a structural diagram of a photovoltaic system according to an embodiment of the present application.

[0028] Description of main component symbols:

[0029] Solar cell 100, battery cell 10, first main grid 20, first fine grid 21, first gradient section 22, first hollow area 23, second main grid 30, second fine grid 31, second gradient section 32, second hollow area 33, doped layer 40, first doped layer 41, second doped layer 42, passivation layer 50, battery string 200, battery assembly 300, photovoltaic system 400. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are merely used to explain the present application and are not intended to limit the present application.

[0031] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They 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, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0032] 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 the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0034] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0035] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art will appreciate the application of other processes and / or the use scenarios of other materials.

[0036] In related technologies, the main grid lines are prepared first, followed by the fine grid lines. The main grid lines are placed between the fine grid lines and the doped layer to block the fine grid lines and the doped layer, preventing the current generated by the doped layer in this area from being extracted, thereby reducing power generation efficiency. In the embodiments of the present application, the gradient section and hollow area formed at the end of the main grid can save main grid slurry, while the gradient section can relieve stress concentration. In addition, the fine grid can burn through the passivation layer in the hollow area to electrically connect to the doped layer, ensuring that the current generated in this area can be collected, thereby improving power generation efficiency.

[0037] Example 1

[0038] See also Figures 1 to 3In the solar cell 100 of the embodiment of the present application, the solar cell 100 includes a cell 10, several busbars, and several fine grids. The several busbars are arranged on the cell 10. The busbars include several first busbars 20 and several second busbars 30. The first busbars 20 and the second busbars 30 extend along a first direction and are alternately arranged along a second direction. The first busbars 20 and the second busbars 30 have opposite polarities. The several fine grids are arranged on the cell 10. The fine grids include several first fine grids 21 and several second fine grids 31. The first fine grids 21 and the second fine grids 31 have opposite polarities. The first fine grids 21 are arranged to cross the first busbar 20 and are disconnected at the second busbar 30. The second fine grids 31 are arranged to cross the second busbar 30 and are disconnected at the first busbar 20. A first gradient section 22 that gradually changes along the first direction is formed at the end of the first busbar 20. The first gradient section 22 avoids the first hollow area 23. The first fine grid 21 passes through the first hollow area 23 and connects to the first gradient section 22.

[0039] In the solar cell 100 of the embodiment of the present application, the solar cell 100 includes a cell 10, several main grids and several fine grids. The several main grids are arranged on the cell 10, and the main grids include several first main grids 20 and several second main grids 30. The first main grids 20 and the second main grids 30 extend along the first direction and are alternately arranged along the second direction. The first main grids 20 and the second main grids 30 have opposite polarities. The several fine grids are arranged on the cell 10, and the fine grids include several first fine grids 21 and several second fine grids 31. The first fine grids 21 and the second fine grids 31 have opposite polarities. The first fine grids 21 are arranged to cross the first main grid 20 and are disconnected at the second main grid 30. The second fine grids 31 are arranged to cross the second main grid 30 and are disconnected at the first main grid 20. A first gradient section 22 that gradually changes along the first direction is formed at the end of the first main grid 20. The first gradient section 22 avoids the first hollow area 23. The first fine grid 21 passes through the first hollow area 23 and is connected to the first gradient section 22. In this way, the first tapered section 22 and first hollowed region 23 formed at the end of the first busbar 20 can save busbar paste, while the first tapered section 22 can also alleviate stress concentration. Furthermore, the first fine grid 21 can burn through the passivation layer 50 in the first hollowed region 23 to electrically connect to the doped layer 40, ensuring that the current generated in this region can be collected, thereby improving power generation efficiency.

[0040] Specifically, the first busbars 20 and the second busbars 30 are alternately arranged along the second direction on the cell 10. That is, the first busbars 20, the second busbars 30, the first busbars 20, the second busbars 30, and so on are arranged in sequence from top to bottom along the second direction of the cell 10. This fully utilizes the space on the cell 10 in the second direction. Furthermore, the first busbars 20 and the second busbars 30 fully extend in the first direction, maximizing the space on the surface of the cell 10.

[0041] Furthermore, the first busbar 20 and the second busbar 30 have opposite polarities. The specific polarities represented by "first" and "second" are not limited here; "first" and "second" are simply used to distinguish between busbars of two different polarities. That is, the first busbar 20 can be either positive or negative, and the second busbar 30 can be either positive or negative. However, when the polarity of the first busbar 20 is positive, the polarity of the second busbar 30 is negative; and when the polarity of the first busbar 20 is negative, the polarity of the second busbar 30 is positive. Distinguishing between different polarities facilitates connection to different battery cells 10 or external circuits, and also facilitates the extraction of the current generated by the doped layer 40.

[0042] Furthermore, both the first busbar 20 and the second busbar 30 are connected to a plurality of fine grids of the same polarity. For example, the first busbar 20 and the first fine grid 21 have the same polarity, and the first busbar 20 is connected to a plurality of first fine grids 21 on both sides; the second busbar 30 and the second fine grid 31 have the same polarity, and the second busbar 30 is connected to a plurality of second fine grids 31 on both sides. The first fine grids 21 can be arranged to cross-connect with the first busbar 20, with the center electrically connected to the first busbar 20. The lengths of the first fine grids 21 on both sides of the first busbar 20 can be the same or different. Similarly, the second busbar 30 can also be provided with second fine grids 31. The second fine grids 31 can also cross-connect with the second busbar 30, with the center electrically connected to the second busbar 30. The lengths of the second fine grids 31 on both sides of the second busbar 30 can be the same or different. In this way, the connection of multiple fine grids of the same polarity to the busbar facilitates the extraction of current generated in the doped layer 40, thereby increasing the photoelectric conversion efficiency of the cell 10. Furthermore, the number of first fine grids 21 on either side of the first busbar 20 can be equal, and the number of second fine grids 31 on either side of the second busbar 30 can also be equal. In this way, the fine grids arranged crosswise with the busbars can simplify the process flow while facilitating the extraction of the current generated in the majority of the doped layer 40 of the cell 10. Of course, in other applications, the fine grids on either side of the busbar can extend independently from the busbar in the second direction. The specific connection method between the busbars and the fine grids is not limited in the embodiments of this application to meet various requirements.

[0043] In the solar cell 100 in the embodiment of the present application, the main grid end is further formed with a gradient section that gradually changes along the first direction, and the gradient section avoids the hollow area. That is to say, the two sides of the main grid end gradually shrink and become thinner inward to form a gradient section; or, the main grid end gradually splits to both sides, so that the main grid end forms a gradient section that splits from the inside to the two sides, but the width of the main grid end in the second direction remains unchanged, but the inside of the main grid end is hollow. The gradient section is set to leave more areas on the surface of the battery cell 10 (such as on both sides of the gradient section or inside the gradient section), and the left area is set as a hollow area. It should be noted that the above description of the shrinkage and splitting of the gradient section at the main grid end is to facilitate readers to understand the gradient section and the hollow area under the concept of the traditional main grid. In actual production, there is no further processing of the arranged and formed main grid to shrink or split it to form a gradient section, but the gradient section of the desired shape is directly formed in the production arrangement. Of course, if the arranged and formed main grid needs to be provided with a gradient section, it can be further processed by a similar shrinking and splitting method as described above. The embodiment of the present application does not limit the formation principle and process of the gradient section to meet various needs.

[0044] For example, a first gradient segment 22 is formed at the end of the first busbar 20, gradually changing directionally. The first gradient segment 22 avoids the first hollow region 23, and the first fine grid 21 passes through the first hollow region 23 and connects to the first gradient segment 22. In this way, the first gradient segment 22 and the first hollow region 23 formed at the end of the first busbar 20 can save busbar paste, while the first gradient segment 22 can also alleviate stress concentration. Furthermore, the first fine grid 21 can burn through the passivation layer 50 in the first hollow region 23 to electrically connect to the first doped layer 41, ensuring that the current generated in the doped layer 40 in the first hollow region 23 can be collected, thereby improving the power generation efficiency of the solar cell 100. It should be noted that the gradient segments can be provided only at the ends of the busbar, or they can be provided at intervals in the middle section of the busbar extending along the first direction, with the areas left free of the gradient segments being hollowed out, and the fine grid electrically connected to the doped layer 40 in the hollow region. The embodiments of this application do not limit the location of the gradient segments on the busbar or the number of gradient segments, to meet various needs.

[0045] Example 2

[0046] See also Figures 1 to 3 In some optional embodiments, a second gradient section 32 that gradients along the first direction is formed at the end of the second main grid 30 , the second gradient section 32 avoids the second hollow area 33 , and the second fine grid 31 passes through the second hollow area 33 and connects to the second gradient section 32 .

[0047] In this way, the second tapered section 32 and second hollowed region 33 formed at the end of the second busbar 30 can save busbar paste, while the second tapered section 32 can also alleviate stress concentration. Furthermore, the second fine grid 31 can burn through the passivation layer 50 in the second hollowed region 33 to electrically connect to the second doped layer 42, ensuring that the current generated in the doped layer 40 in the second hollowed region 33 can be collected, thereby improving the power generation efficiency of the solar cell 100.

[0048] Specifically, like the first main grid 20, the end of the second main grid 30 also has a second gradient section 32 that gradually changes along the first direction, and the second gradient section 32 avoids the second hollow area 33. The second fine grid 31 passes through the second hollow area 33 and connects to the second gradient section 32. In this way, the second gradient section 32 and the second hollow area 33 formed at the end of the second main grid 30 can further save main grid paste, while the second gradient section 32 can further alleviate stress concentration. In addition, the fine grid can burn through the passivation layer 50 in the hollow area to electrically connect to the doped layer 40, further ensuring that the current generated in the doped layer 40 in this area can be collected, thereby improving the power generation efficiency of the solar cell 100.

[0049] Example 3

[0050] See also Figures 4 to 6 The first gradual transition section 22 and / or the second gradual transition section 32 are trapezoidal, inverted V-shaped, or inverted trapezoidal.

[0051] In this way, the gradient segments of different shapes make the shape of the hollow area and the positional relationship between the hollow area and the gradient segment diverse, so as to meet various needs.

[0052] Specifically, the first gradient section 22 at the end of the first main grid 20 and the second gradient section 32 at the end of the second main grid 30 can have the same shape, such as a trapezoid, an inverted V-shape, or an inverted trapezoid. Of course, the first gradient section 22 and the second gradient section 32 can also have different shapes. For example, the first gradient section 22 is trapezoidal and the second gradient section 32 is inverted V-shape or an inverted trapezoid; or, the first gradient section 22 is inverted V-shape and the second gradient section 32 is trapezoidal or an inverted trapezoid; or, the first gradient section 22 is inverted trapezoidal and the second gradient section 32 is inverted V-shape or a trapezoid. Of course, the first gradient section 22 and the second gradient section 32 can also have other shapes, such as M-shape, W-shape, and T-shape, and can be regular or irregular. The embodiment of the present application does not limit the shape of the first gradient section 22 and the second gradient section 32 formed after the main grid end is gradually transformed, so as to meet various needs.

[0053] Example 4

[0054] See also Figures 4 to 6 In some optional embodiments, when the first transition section 22 is trapezoidal, the first hollow areas 23 are located on both sides of the first transition section 22 along the second direction; and / or

[0055] When the second transition section 32 is trapezoidal, the second hollow areas 33 are located on both sides of the second transition section 32 along the second direction.

[0056] In this way, the fine gate can be electrically connected to the doped layer 40 in the hollow region, and conduct the current generated by the doped layer 40 in the hollow region.

[0057] Specifically, the ends of the first busbar 20 shrink inward and taper along both sides of the second direction, forming a trapezoidal first gradient segment 22. After the ends of the first busbar 20 shrink and taper, the vacant spaces on both sides form first hollow regions 23. Therefore, the first hollow regions 23 can be located on both sides of the first gradient segment 22 along the second direction.

[0058] Similarly, the ends of the second main grid 30 on both sides in the second direction shrink inward and become thinner, forming a trapezoidal second gradient section 32. After the ends of the second main grid 30 shrink and become thinner, the vacant spaces on both sides form second hollow areas 33. Therefore, the second hollow areas 33 are located on both sides of the second gradient section 32 along the second direction.

[0059] Furthermore, when the first transition section 22 and the second transition section 32 have other shapes (such as an inverted V-shape or an inverted trapezoid), the hollow areas may not be located on both sides of the transition section ends, but may be located inside the transition sections. In other words, the first transition section 22 may be trapezoidal, so that the first hollow areas 23 can be located on both sides of the first transition section 22 along the second direction, while the second transition section 32 may be in an inverted V-shape or an inverted trapezoid, so that the second hollow areas 33 are not located on both sides of the second transition section 32 along the second direction; or, the first transition section 22 may be in an inverted V-shape or an inverted trapezoid, so that the first hollow areas 23 are not located on both sides of the first transition section 22 along the second direction, while the second transition section 32 may be trapezoidal, so that the second hollow areas 33 can be located on both sides of the second transition section 32 along the second direction. The embodiments of the present application do not limit the positional relationship between the transition sections and the hollow areas to meet various needs.

[0060] Example 5

[0061] See also Figures 4 to 6 In some optional embodiments, when the first transition section 22 is in an inverted V-shape or an inverted trapezoidal shape, the first hollow area 23 is located inside the first transition section 22 along the second direction; and / or

[0062] When the second transition section 32 is in an inverted V shape or an inverted trapezoidal shape, the second hollow area 33 is located inside the second transition section 32 along the second direction.

[0063] In this way, the arrangement of the gradient segments and the hollow regions in different positional relationships can enable the fine gates arranged in various ways to be electrically connected to the doped layer 40 in the hollow region, thereby conducting the current generated by the doped layer 40 in the hollow region.

[0064] Specifically, the middle of the end of the first gradient section 22 can be split into an inverted V-shape or an inverted trapezoidal shape on both sides along the second direction. After the split, a corresponding space is left in the middle of the end of the first gradient section 22 to form a first hollow area 23, while the gradient section at the end of the first main grid 20 does not become wider on both sides along the second direction. In this way, the first hollow area 23 can be located inside the first gradient section 22 along the second direction. Similarly, the middle of the end of the second gradient section 32 can be split into an inverted V-shape or an inverted trapezoidal shape on both sides along the second direction. After the split, a corresponding space is left in the middle of the end of the second gradient section 32 to form a second hollow area 33, while the gradient section at the end of the second main grid 30 does not become wider on both sides along the second direction. In this way, the second hollow area 33 can also be located inside the second gradient section 32 along the second direction; alternatively, when the first gradient section 22 is in an inverted V-shape or an inverted trapezoidal shape, so that the first hollow area 23 is located inside the first gradient section 22 along the second direction, the second gradient section 32 can be in a trapezoidal shape, so that the second hollow area 33 is not located inside the second gradient section 32 along the second direction; alternatively, when the first gradient section 22 is in a trapezoidal shape, so that the first hollow area 23 is not located inside the first gradient section 22 along the second direction, the second gradient section 32 can be in an inverted V-shape or an inverted trapezoidal shape, so that the second hollow area 33 is located inside the second gradient section 32 along the second direction. The embodiments of the present application do not limit the positional relationship between the gradient section and the hollow area to meet various needs.

[0065] Example 6

[0066] See also Figure 1 and Figure 2 The cell 10 further includes a first doping layer 41 and a second doping layer 42 . The first doping layer 41 and the second doping layer 42 extend along the second direction and are alternately arranged along the first direction.

[0067] In this way, the fine gates of different polarities can guide the currents generated by the different doping layers 40 to flow in different directions, so that the solar cell 100 has both positive and negative polarities.

[0068] Specifically, the first doped layer 41 and the second doped layer 42 can be arranged in the order of first doped layer 41, second doped layer 42, first doped layer 41, second doped layer 42, ... in the first direction. This fully utilizes the space provided by the cell 10 in the first direction. Furthermore, the first doped layer 41 and the second doped layer 42 extend fully in the second direction, maximizing the space on the surface of the cell 10 and enabling the solar cell 100 to generate more current under sunlight.

[0069] Example 7

[0070] See also Figure 2 、 Figure 4 、 Figure 5and Figure 6 In some optional embodiments, the first fine gate 21 is disposed in the first doping layer 41 , the second fine gate 31 is disposed in the second doping layer 42 , the first fine gate 21 and the second fine gate 31 extend along the second direction and are alternately disposed along the first direction.

[0071] In this way, the current generated by the first doping layer 41 and the second doping layer 42 can be transmitted to the first busbar 20 and the second busbar 30 through the first fine gate 21 and the second fine gate 31 , and then led out of the solar cell 10 .

[0072] Specifically, the first fine gate 21 is disposed in the first doped layer 41, and the second fine gate 31 is disposed in the second doped layer 42. Furthermore, in the region between the adjacent first and second main gates 20 and 30, the first and second fine gates 21 and 31 are alternately distributed along the first direction, similar to the first and second doped layers 41 and 42. For example, in the region between the first and second main gates 20 and 30, the order of distribution from left to right may be first fine gate 21, second fine gate 31, first fine gate 21, second fine gate 31, and so on. This allows the current generated in the first doped layer 41 to be conducted through the first fine gate 21, and the current generated in the second doped layer 42 to be conducted through the second fine gate 31.

[0073] Furthermore, the fine grid at the edge of the battery cell 10 along the first direction is connected to the gradient section of the main grid, and the passivation layer 50 in the hollow area formed by the avoidance of the gradient section of the main grid can be burned through, thereby electrically connecting the doped layer 40 and extracting the current generated in the doped layer 40 at this location, thereby improving the performance of the battery cell 10.

[0074] Exemplarily, the first fine gate 21 is disposed in the first doped layer 41. One end of the first fine gate 21 maintains a safe distance from the second main gate 30, while the other end extends along the second direction toward the first main gate 20, simultaneously conducting current from the first doped layer 41. When the first gradient section 22 is trapezoidal, first hollow regions 23 are provided on both sides of the first gradient section 22 in the second direction. The first fine gate 21 extends along the second direction toward the first main gate 20, first passing through the first hollow region 23, burning through the passivation layer 50 in the first hollow region 23, and connecting to the doped layer 40 in the first hollow region 23, and then connecting to the first main gate 20. In this way, the first fine gate 21 can conduct current generated in the first doped layer 41 and the doped layer 40 below the hollow region. When the first gradient section 22 is in an inverted V-shape or an inverted trapezoidal shape, a first hollow region 23 is provided within the first gradient section 22 along the second direction. The first fine gate 21 extends along the second direction toward the first main gate 20, connecting to the first main gate 20, then extending to the first hollow region 23, burning through the passivation layer 50 in the first hollow region 23, and connecting to the doped layer 40 in the first hollow region 23. In this way, current generated below the first doped layer 41 and the first hollow region 23 can be conducted to the first main gate 20 through the first fine gate 21. Similarly, the second fine gate 31, second doped layer 42, second hollow region 33, and second gradient are also arranged as in the above embodiment.

[0075] Furthermore, the first fine grid 21 and the second fine grid 31 extend along the second direction. That is, one end of the first fine grid 21 is electrically connected to the first main grid 20, and the other end extends along the second direction toward the second main grid 30, stopping at a position close to the second main grid 30 while leaving a certain safety distance. Similarly, one end of the second fine grid 31 is electrically connected to the second main grid 30, and the other end extends along the second direction toward the first main grid 20, stopping at a position close to the first main grid 20 while leaving a certain safety distance.

[0076] It is understood that the description of the extension direction of the fine grid in the above embodiment is for the convenience of the reader, and the fine grid does not necessarily have to extend from the busbar of the same polarity to the busbar of the opposite polarity, or from the busbar of the opposite polarity to the busbar of the same polarity. Instead, there are more extension methods, such as extending from the middle of the two polarity busbars to both sides, or directly arranging the formed fine grid on the battery cell 10. The embodiments of the present application do not limit the specific extension method and arrangement process of the fine grid to meet various needs.

[0077] Example 8

[0078] See also Figure 2 and Figure 3 In some optional embodiments, the first fine gate 21 provided in the first gradient section 22 passes through the first hollow region 23 to electrically connect to the first doped layer 41 ;

[0079] The second fine gate 31 disposed in the second gradient section 32 passes through the second hollow region 33 to be electrically connected to the second doped layer 42 .

[0080] In this way, the current generated by the doped layer 40 below the hollow region can be extracted, thereby improving the performance of the solar cell 100 .

[0081] Specifically, when the first transition section 22 is trapezoidal, first hollow regions 23 are provided on both sides of the first transition section 22 along the second direction. The first fine gate 21 extends along the second direction toward the first busbar 20, first passing through the first hollow region 23, burning through the passivation layer 50 in the first hollow region 23, connecting to the doped layer 40 below the first hollow region 23, and finally connecting to the first busbar 20. In this way, the first fine gate 21 can conduct the current generated by the first doped layer 41 and the doped layer 40 below the hollow region. When the first transition section 22 is in an inverted V-shape or an inverted trapezoidal shape, the first hollow region 23 is provided within the first transition section 22 along the second direction. The first fine gate 21 extends along the second direction toward the first busbar 20 until it connects to the first busbar 20, then extends to the first hollow region 23, burning through the passivation layer 50 in the first hollow region 23, and connecting to the doped layer 40 below the first hollow region 23. Thus, the current generated under the first doped layer 41 and the first hollow region 23 can be conducted to the first main gate 20 through the first fine gate 21. Similarly, the second fine gate 31, the second doped layer 42, the second hollow region 33 and the second gradient are also arranged as in the above embodiment.

[0082] Example 9

[0083] See also Figure 1 and Figure 7 The cell string 200 provided in the embodiment of the present application includes the solar cell 100 of any one of the above embodiments.

[0084] In the embodiment of the present application, the battery string 200 can be a shape in which a plurality of sheet-shaped solar cells 100 are connected in series in sequence and are connected by welding strips and bus bars. It is understandable that in the battery string 200, the battery string 200 may include two battery cells 10 connected in series, three battery cells 10 connected in series, or other larger numbers of battery cells 10. The specific number of battery cells 10 that need to be connected in series can be determined based on actual usage. In addition, in the embodiment of the present application, there is no limitation on the size and type of the solar cell 100. The specifications and sizes of adjacent battery cells 10 can be the same or different to meet different needs.

[0085] In the embodiments of this application, the specific connection method for adjacent battery cells 10 is not limited to meet different needs. In one embodiment, the edges of two adjacent battery cells 10 are at least partially stacked together; in another embodiment, the two adjacent battery cells 10 can be spaced apart. The spacing between two adjacent battery cells 10 is within an appropriate range to avoid the limited operating space and increased welding difficulty caused by too small a spacing, and to avoid the waste of component space and increased costs caused by too large a spacing.

[0086] Example 10

[0087] See also Figure 1 、 Figure 7 and Figure 8 The battery assembly 300 provided in the embodiment of the present application includes the battery string 200 of the above embodiment.

[0088] In this embodiment, the battery assembly 300 may further include a frame, a backsheet, photovoltaic glass, and an adhesive film. The adhesive film may be filled between the front and back surfaces of the back-contact battery, the photovoltaic glass, adjacent cells 10, etc., and may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be EVA film or POE film. The specific choice may be based on actual conditions and is not limited here.

[0089] Photovoltaic glass can cover the adhesive film on the front of the back-contact cell. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, ultra-clear glass can have a light transmittance of over 92%, protecting the back-contact cell while minimizing its efficiency. The adhesive film also bonds the photovoltaic glass and the back-contact cell together, providing a sealed insulation, waterproofing, and moisture-proofing.

[0090] The backsheet can be attached to the film on the back of the back-contact cell. The backsheet protects and supports the back-contact cell, offering reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, organic glass, and aluminum alloy TPT composite film. The specific configuration depends on the specific situation and is not limited here. The entire assembly consisting of the backsheet, back-contact cell, film, and photovoltaic glass can be mounted on a frame. The frame serves as the primary external support structure for the entire battery assembly 300 and provides stable support and installation for the battery assembly 300. For example, the frame allows the battery assembly 300 to be installed in the desired location.

[0091] Example 11

[0092] See also Figure 1 、 Figure 7 、 Figure 8 and Figure 9 The photovoltaic system 400 provided in the embodiment of the present application includes the battery assembly 300 of the above embodiment.

[0093] In the solar cell 100, the cell string 200, the cell assembly 300 and the photovoltaic system 400 of the embodiment of the present application, the solar cell 100 includes a cell 10, a plurality of main grids and a plurality of fine grids, wherein the plurality of main grids are arranged on the cell 10, the main grids include a plurality of first main grids 20 and a plurality of second main grids 30, the first main grids 20 and the second main grids 30 extend along a first direction and are alternately arranged along a second direction, the first main grids 20 and the second main grids 30 have opposite polarities, and the plurality of fine grids are arranged on the cell 10, the fine grids including It includes a plurality of first fine grids 21 and a plurality of second fine grids 31. The first fine grids 21 and the second fine grids 31 have opposite polarities. The first fine grid 21 is arranged to cross the first main grid 20 and is disconnected at the second main grid 30. The second fine grid 31 is arranged to cross the second main grid 30 and is disconnected at the first main grid 20. A first gradient section 22 that gradually changes along the first direction is formed at the end of the first main grid 20. The first gradient section 22 avoids the first hollow area 23. The first fine grid 21 passes through the first hollow area 23 and is connected to the first gradient section 22. In this way, the first gradient section 22 and the first hollow area 23 formed at the end of the first main grid 20 can save main grid slurry, and the first gradient section 22 can relieve stress concentration. In addition, the first fine grid 21 can burn through the passivation layer 50 of the first hollow area 23 to electrically connect to the doping layer 40, ensuring that the current generated in this area can be collected, thereby improving the power generation efficiency.

[0094] In this embodiment, the photovoltaic system 400 can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water-surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of the photovoltaic system 400 are not limited to this. In other words, the photovoltaic system 400 can be applied to all fields that require solar power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system 400 may include a photovoltaic array, a junction box, and an inverter. The photovoltaic array can be an array combination of multiple battery assemblies 300. For example, multiple battery assemblies 300 can form multiple photovoltaic arrays. The photovoltaic array is connected to a junction box, which can combine the current generated by the photovoltaic array. The combined current flows through the inverter to convert it into the alternating current required by the mains power grid and then connects to the mains power network to achieve solar power supply.

[0095] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative use of the above terms does 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 any one or more embodiments or examples.

[0096] In addition, the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A solar cell, characterized in that: include: Battery cells; A plurality of main grids are provided on the battery cell, wherein the main grids include a plurality of first main grids and a plurality of second main grids, wherein the first main grids and the second main grids extend along a first direction and are alternately provided along a second direction, and the first main grids and the second main grids have opposite polarities; A plurality of fine grids are provided on the cell, the fine grids including a plurality of first fine grids and a plurality of second fine grids, the first fine grids and the second fine grids are opposite in polarity, the first fine grids are arranged to cross the first main grid and are disconnected at the second main grid, the second fine grids are arranged to cross the second main grid and are disconnected at the first main grid; A first gradient section is formed at the end of the first main grid and gradually changes along the first direction. The first gradient section avoids the first hollow area. The first fine grid passes through the first hollow area and connects to the first gradient section.

2. The solar cell according to claim 1, characterized in that A second gradient section that gradually changes along the first direction is formed at the end of the second main grid, the second gradient section avoids the second hollow area, and the second fine grid passes through the second hollow area and connects to the second gradient section.

3. The solar cell according to claim 2, characterized in that The first gradual transition section and / or the second gradual transition section are in a trapezoidal shape, an inverted V shape, or an inverted trapezoidal shape.

4. The solar cell according to claim 3, characterized in that When the first transition section is trapezoidal, the first hollow areas are located on both sides of the first transition section along the second direction; and / or When the second gradient section is trapezoidal, the second hollow areas are located on both sides of the second gradient section along the second direction.

5. The solar cell according to claim 3, characterized in that When the first transition section is in an inverted V shape or an inverted trapezoidal shape, the first hollow area is located inside the first transition section along the second direction; and / or When the second transition section is in an inverted V shape or an inverted trapezoidal shape, the second hollow area is located inside the second transition section along the second direction.

6. The solar cell according to claim 2, characterized in that The cell further includes a first doping layer and a second doping layer, wherein the first doping layer and the second doping layer extend along the second direction and are alternately arranged along the first direction.

7. The solar cell according to claim 6, characterized in that The first fine gate is disposed in the first doping layer, the second fine gate is disposed in the second doping layer, the first fine gate and the second fine gate extend along the second direction and are alternately disposed along the first direction.

8. The solar cell according to claim 7, characterized in that The first fine gate disposed in the first gradient section passes through the first hollow region to be electrically connected to the first doped layer; The second fine gate disposed in the second gradient section passes through the second hollow region to be electrically connected to the second doped layer.

9. A battery string, characterized in that: The solar cell comprises the solar cell according to any one of claims 1 to 8.

10. A battery assembly, characterized in that: Comprising the battery string as claimed in claim 9.

11. A photovoltaic system, characterized in that: Comprising the battery assembly as claimed in claim 10.

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