Solar cells and photovoltaic modules

Abstract

The embodiment of the present application provides a kind of solar cell and photovoltaic module, solar cell includes cell body and the electrode structure located at the surface of cell body, electrode structure includes: first fine grid line and second fine grid line with opposite polarity, the first surface of cell body includes multiple fine grid line areas;Multiple fine grid line areas include the first fine grid line area of printing first fine grid line and the second fine grid line area of printing second fine grid line;First flow grid line, first flow grid line is along first connecting line and is electrically connected with multiple first fine grid lines in target area.The embodiment of the present application is electrically connected with first flow grid line by being arranged in the target area of cell body first fine grid line, when solder strip is welded with fine grid line, the position of target area can increase the pulling force with solder strip, so that solder strip is welded more firmly, to improve the stability of solar cell.

Description

Technical Field

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

[0002] Back-contact (BC) cells, due to their unobstructed front side and high conversion efficiency, are gradually becoming the mainstream technology for high-efficiency crystalline silicon cells. However, BC cells have high process complexity and material costs, especially since the silver paste for printing the grid lines accounts for 15%-20% of the cell cost. Therefore, the industry is focusing on "no main grid" and "low silver" strategies, thus developing gridless back-contact cells, which have sub-grids on the back of the cell but no main grid.

[0003] However, in gridless back contact batteries, the sub-grids become the main body of electrical connection. That is, to achieve electrical connection with the battery, it is necessary to make contact with the sub-grids. The sub-grids are relatively thin, and the tension on the solder ribbon is small when they come into contact with the solder ribbon. Moreover, there are many sub-grids, which increases the difficulty of subsequent battery electrical performance calibration or efficiency classification. Utility Model Content

[0004] This application provides a solar cell and a photovoltaic module to solve or alleviate one or more technical problems in the prior art.

[0005] As a first aspect of the embodiments of this application, this application provides a solar cell, including a cell body and an electrode structure located on the surface of the cell body, the electrode structure including: The first surface of the battery cell body includes multiple fine grid lines arranged sequentially along a first direction at a predetermined interval, comprising a first fine grid line area with first fine grid lines printed on it and a second fine grid line area with second fine grid lines printed on it. The first current-guiding grid line, the first surface of the cell body includes at least one target area, the target area includes a target number of fine grid line areas, the first current-guiding grid line is electrically connected to multiple first fine grid lines in the target area along a first connection line; in the target area, a second fine grid line area is printed with multiple second fine grid lines, and a first gap is formed between adjacent second fine grid lines, the first current-guiding grid line passes through the first gap and is electrically connected to the first fine grid lines.

[0006] In one embodiment, the electrode structure further includes a solder strip that is electrically connected to a plurality of first fine grid lines along a first solder strip route, wherein the first solder strip route is collinear with the first connection line.

[0007] In one implementation, in the target region, a first fine grid line region is connected to a plurality of first guide grid lines arranged in sequence.

[0008] In one embodiment, the number of first guide grid lines connected in a first fine grid line region is matched with the number of solder strips.

[0009] In one embodiment, the battery cell body includes multiple segments, each segment having a target area at its end.

[0010] In one implementation, the target number is 1 / 12 to 1 / 3 of the number of fine grid lines in each segment, or the target number is 6 to 20 lines.

[0011] In one embodiment, the electrode structure further includes a second flow guide grid line, which is electrically connected to a plurality of first flow guide grid lines along the edge of the target region.

[0012] In one embodiment, the cell body includes a first target region and a second target region; a second current-guiding grid line in the first target region extends along the edge of the cell body toward the second region and is electrically connected to the second current-guiding grid line in the second target region.

[0013] In one embodiment, the width of the first guide grid line / second guide grid line is 3-10 times the width of the first fine grid line / second fine grid line, or is 100um~300um.

[0014] In one embodiment, a pad is provided along the first strip path on the first fine grid line. The pad includes a main body and two concentrated portions located on both sides of the main body. The two concentrated portions are tapered and gradually narrow from the side of the main body toward the extension direction of the first fine grid line.

[0015] As a second aspect of the present application, the present application provides a photovoltaic module including at least one battery string, wherein the battery string includes at least one solar cell as described in any of the above embodiments.

[0016] This embodiment of the application provides a first current-guiding grid line in the target area of ​​the solar cell body. This increases the tension between the solder ribbon and the fine grid line at the target area during welding, resulting in a stronger weld and improved stability of the solar cell. Furthermore, during solar cell testing, electrical connections can be made at the first current-guiding grid line, eliminating the need for separate connections to multiple fine grid lines, thus reducing the number of electrical connections and improving testing efficiency.

[0017] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0019] Figure 1 A schematic diagram of the electrode structure of a two-segment solar cell provided according to an embodiment of this application is shown.

[0020] Figure 2 Show Figure 1 A magnified structural diagram of region A in the middle. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0022] This application provides a solar cell, which includes a cell body and an electrode structure located on the surface of the cell body. Figure 1 A schematic diagram of the electrode structure of a two-segment solar cell provided according to an embodiment of this application is shown. Figure 2 Show Figure 1 A magnified structural diagram of region A in the middle. (See diagram below.) Figure 1 and Figure 2 As shown, the electrode structure includes a first fine grid line 110 and a second fine grid line 120 with opposite polarities, as well as a first current-guiding grid line 210. It can be understood that the first fine grid line 110 and the second fine grid line 120 are used to draw positive and negative charge carriers from inside the solar cell, respectively, to form a current; then, they are connected in series with other solar cells via solder ribbons to generate electricity.

[0023] The first surface of the solar cell body includes multiple fine grid line regions arranged sequentially along a first direction at predetermined intervals; these multiple fine grid line regions include a first fine grid line region with printed first fine grid lines 110 and a second fine grid line region with printed second fine grid lines 120. Both the first fine grid lines 110 and the second fine grid lines 120 are disposed on the same surface of the solar cell body, i.e., the back side of the solar cell, ensuring unobstructed front side and improving the power generation efficiency of the solar cell. The alternating arrangement of the first and second fine grid line regions ensures a balanced flow rate of positive and negative charge carriers towards the fine grid lines within the solar cell, improving the efficiency of current generation.

[0024] In this embodiment of the application, the electrode structure further includes a first current-guiding grid line 210. The first surface of the battery cell body includes at least one target region 400. The target region 400 includes a target number of fine grid line regions. The first current-guiding grid line 210 is electrically connected to multiple first fine grid lines 110 in the target region 400 along a first connection line. In the target region 400, a second fine grid line region is printed with multiple second fine grid lines 120, and a first gap is formed between adjacent second fine grid lines 120. The first current-guiding grid line 210 passes through the first gap and is electrically connected to the first fine grid lines 110.

[0025] In this embodiment, since the electrodes of the first fine gate line 110 and the second fine gate line 120 are opposite, and the first current-conducting gate line 210 is electrically connected to the first fine gate line 110, it needs to be insulated from the second sub-gate line. By disconnecting the second fine gate line 120 at the position crossed by the first current-conducting gate line 210, it is prevented from extending to the first connection line and crossing the first current-conducting gate line 210, thereby preventing the second fine gate line 120 from being electrically connected to the first current-conducting gate line 210.

[0026] This embodiment of the application provides a first current-guiding grid line 210 in the target area 400 of the solar cell body. This increases the tension between the solder ribbon and the fine grid line at the target area 400 during welding, resulting in a stronger weld and improved stability of the solar cell. Furthermore, during testing of the solar cell, electrical connections can be made at the first current-guiding grid line 210, eliminating the need for separate connections to multiple fine grid lines, thus reducing the number of electrical connections and improving testing efficiency.

[0027] In one embodiment, the electrode structure further includes a solder strip (not shown in the figure), which is electrically connected to a plurality of first fine grid lines 110 along a first solder strip route, and the first solder strip route is collinear with the first connection line.

[0028] The solder ribbon is used to electrically connect to multiple first fine grid lines 110, including first fine grid lines 110 within the target region 400 and first fine grid lines 110 outside the target region 400, to realize the electrical connection of multiple first fine grid lines 110 on the back side of the cell body and collect carriers of the same polarity.

[0029] At the same time, on the second solder strip line, the solder strip is electrically connected to multiple second fine grid lines 120 along the second solder strip line to achieve the collection of carriers of the other polarity.

[0030] The first connecting line is the electrical connection route of the first current guide grid line 210. The first connecting line is collinear with the first welding strip line, so that the welding strip is welded to the first current guide grid line 210 during welding. The first current guide grid line 210 can increase the tension on the welding strip and improve the stability of welding strip.

[0031] Similarly, in the target area 400, a third current guide grid line 220 is provided on the second connecting line that overlaps with the second welding strip line. The third current guide grid line 220 is electrically connected to the second sub-grid line, and the polarity of the third current guide grid line 220 is the same as that of the second sub-grid line.

[0032] In one embodiment, in the target region 400, a first fine grid line region is connected to a plurality of first guide grid lines 210 arranged in sequence.

[0033] A first fine grid region includes multiple first guide grid lines 210 to collect carriers from multiple locations.

[0034] Meanwhile, a second fine grid region includes multiple third guide grid lines 220 to collect carriers from multiple locations.

[0035] In the target region 400, multiple first guide grid lines 210 and multiple third guide grid lines 220 are alternately distributed along the direction of the first fine grid line region or the direction of the second fine grid line region.

[0036] In one embodiment, the number of first guide grid lines 210 connected in a first fine grid line region is adapted to the number of solder strips.

[0037] In a solar cell, multiple solder strips are required to be welded to grid lines to guide current from multiple locations and improve power generation efficiency. Correspondingly, multiple first current-guiding grid lines 210 can be set up, corresponding to the solder strips. That is, at the locations where solder strips need to be welded, first current-guiding grid lines 210 or third current-guiding grid lines 220 are respectively set up. This ensures that during solder strip welding, the first current-guiding grid lines 210 / third current-guiding grid lines 220 can make more stable contact with the solder strips, thereby improving the welding stability of each solder strip and avoiding current loss due to localized poor soldering.

[0038] In one embodiment, the battery cell body includes multiple segments, each segment having a target region 400 at its end.

[0039] For example, such as Figure 1 The two-cell battery comprises a first cell and a second cell distributed front to back. The first cell has a target area 400 at both its beginning and end, and the second cell also has a target area 400 at both its beginning and end. When welding the solder strip to the cell body, the ends of each cell are prone to incomplete welds. Therefore, a target area 400 is set at these locations. A first current-guiding grid line 210 and a third current-guiding grid line 220 are plated into the target area 400 to increase the tensile strength during welding with the solder strip, enhance the welding stability at this location, and avoid incomplete welds.

[0040] In one implementation, the target number is 1 / 12 to 1 / 3 of the number of fine grid lines in each segment, or the target number is 6 to 20 lines.

[0041] The target quantity can be set as the target area 400 based on the location where poor soldering is likely to occur during the welding process. The number of fine grid lines in this target area 400 can be considered as the target quantity.

[0042] Based on welding experience, the target number can be set between 6 and 20, for example, 6, 8, 10, 14, 16, or 20. For example... Figure 1 In the target area 400, there are 14 fine grid line areas. Starting from the outermost fine grid line area at the edge of the cell segment, the 14th fine grid line area is all within the target area 400.

[0043] In one example, when the number of fine grid lines in a cell segment is small, the target number of fine grid lines in the target region 400 can be reduced proportionally. For instance, if the total number of fine grid lines in a cell segment is 48, the number of fine grid lines in the target region 400 should be less than or equal to 16. This is to avoid the target region 400 being too large, where the length of the first current-guiding grid line 210 exceeds 1 / 3 of the length of the first segment. If the length of the first current-guiding grid line 210 in both target regions 400 exceeds 2 / 3 of the length of the first segment, then the length of the first current-guiding grid line 210 becomes too long, which is equivalent to adding a main grid, thus hindering the saving of silver paste usage.

[0044] Therefore, the target number of fine grid line areas in target region 400 can be greater than 1 / 12 and less than 1 / 3 of the number of fine grid line areas in each segment. The target number of fine grid line areas in target region 400 being greater than 1 / 12 of the number of fine grid line areas in each segment can also be based on welding experience, where the reinforcement length during strip welding needs to be greater than 1 / 6 of the total segment length to provide sufficient tensile force for a strong weld.

[0045] In one embodiment, the electrode structure further includes a second flow guide grid line 230, which is electrically connected to a plurality of first flow guide grid lines 210 along the edge of the target region 400.

[0046] The second current-guiding grid line 230 connects multiple first current-guiding grid lines 210 in series, so that during the performance testing of the solar cell, contact with any point of the second current-guiding grid line 230 can achieve electrical connection with multiple first current-guiding grid lines 210, without the need for separate electrical connections with multiple first current-guiding grid lines 210, thus improving the testing efficiency of the solar cell.

[0047] In one embodiment, the battery cell body includes a first target region 400 and a second target region 400; a second flow guide grid line 230 of the first target region 400 extends along the edge of the battery cell body toward the second region and is electrically connected to the second flow guide grid line 230 in the second target region 400.

[0048] The second current-guiding grid lines 230 in the two target regions 400 are electrically connected, so that contact with any point on the second current-guiding grid line 230 will achieve electrical connection with the second current-guiding grid line 230 in both target regions 400. This avoids localized poor soldering that could lead to non-contact of the fine grid lines and cause current loss. Furthermore, the second current-guiding grid lines 230 are routed around the edge of the cell body, so contact with any point on the edge of the cell body will achieve electrical connection, simplifying the electrical connection operation and further improving the testing efficiency of the cell.

[0049] In one embodiment, the width of the first flow guide grid line 210 / the second flow guide grid line 230 is 3-10 times the width of the first fine grid line 110 / the second fine grid line 120, or is 100um~300um.

[0050] The width of the first current-guiding grid line 210 / second current-guiding grid line 230 can be set with reference to the width of the main grid line in a solar cell with a main grid, for example, it can be 100um~300um. The width of the first current-guiding grid line 210 / second current-guiding grid line 230 is greater than the width of the first fine grid line 110 / second fine grid line 120, thereby providing sufficient tension for solder ribbon welding and achieving more stable contact with the solder ribbon.

[0051] In one embodiment, a pad 300 is provided on the first fine grid line along the first solder strip route. The pad 300 includes a main body 310 and two concentrated portions 320 located on both sides of the main body 310. The two concentrated portions 320 are tapered and gradually narrow from the side of the main body 310 toward the extension direction of the first fine grid line.

[0052] The solder ribbon is soldered to the solar cell via soldering to the solder pad 300. The solder in the solder pad 300 acts as a conductor during the soldering process, concentrating the solder within the pad 300 and fixing it to the solder ribbon. The solder pad 300 is made of metal and needs to conduct the charge carriers from the fine grid lines to the solder ribbon. The specially designed concentration section 320 can pre-accumulate charge carriers, thereby increasing the rate at which charge carriers concentrate on the solder ribbon.

[0053] Other configurations of the solar cells in the above embodiments can be derived from various technical solutions now and in the future known to those skilled in the art, and will not be described in detail here.

[0054] This application also provides a photovoltaic module, including at least one battery string, wherein the battery string includes at least one solar cell as described in any of the above embodiments.

[0055] Other components of the photovoltaic modules in the above embodiments can be derived from various technical solutions that are now and will be known to those skilled in the art, and will not be described in detail here.

[0056] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Therefore, they should not be construed as limitations on this application.

[0057] 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 that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0058] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," 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, an electrical connection, or a communication 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0059] 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 above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0060] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. 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 implementations and / or arrangements discussed.

[0061] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A solar cell, characterized by, The battery includes a battery cell body and an electrode structure located on the surface of the battery cell body, the electrode structure comprising: The first surface of the battery cell body includes a first fine grid line and a second fine grid line with opposite polarities, and a plurality of fine grid line regions arranged sequentially along a first direction at a predetermined interval; the plurality of fine grid line regions include a first fine grid line region printed with the first fine grid line and a second fine grid line region printed with the second fine grid line; The first current-guiding grid line, wherein the first surface of the battery cell body includes at least one target area, the target area includes a target number of the fine grid line areas, the first current-guiding grid line is electrically connected to a plurality of the first fine grid lines in the target area along a first connection line; in the target area, a second fine grid line area is printed with a plurality of the second fine grid lines, and a first gap is formed between adjacent second fine grid lines, the first current-guiding grid line passes through the first gap and is electrically connected to the first fine grid lines.

2. The solar cell according to claim 1, characterized in that, The electrode structure also includes a solder strip, which is electrically connected to multiple first fine grid lines along a first solder strip route, and the first solder strip route is collinear with the first connection line.

3. The solar cell according to claim 2, characterized in that, In the target area, a first fine grid line area is connected to multiple first flow guide grid lines arranged in sequence.

4. The solar cell according to claim 3, characterized in that, In a first fine grid line region, the number of connected first flow guide grid lines is matched with the number of solder strips.

5. The solar cell according to claim 1, characterized in that, The battery cell body includes multiple segments, and the target area is provided at the end of each segment.

6. The solar cell according to claim 5, characterized in that, The target number is 1 / 12 to 1 / 3 of the number of fine grid line regions in each segment, or the target number is 6 to 20 lines.

7. The solar cell according to claim 6, characterized in that, The electrode structure further includes a second flow guide grid line, which is electrically connected to a plurality of the first flow guide grid lines along the edge of the target region.

8. The solar cell according to claim 7, characterized in that, The battery cell body includes a first target region and a second target region; the second flow guide grid line in the first target region extends along the edge of the battery cell body toward the second region and is electrically connected to the second flow guide grid line in the second target region.

9. The solar cell according to claim 7, characterized in that, The width of the first flow guide grid line / second flow guide grid line is 3-10 times the width of the first fine grid line / second fine grid line, or 100um~300um.

10. The solar cell according to claim 2, characterized in that, Along the first solder strip route, a solder pad is provided on the first fine grid line. The solder pad includes a main body and two concentrated portions located on both sides of the main body. The two concentrated portions are tapered, gradually narrowing from the side of the main body toward the extension direction of the first fine grid line.

11. A photovoltaic module, characterized in that, It includes at least one battery string, wherein the battery string includes at least one solar cell as described in any one of claims 1 to 10.

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