Battery sheet and photovoltaic module

Abstract

This application relates to a solar cell and a photovoltaic module. The solar cell includes a substrate, a welding reinforcement, and adhesive dots. A main grid and a sub-grid are disposed on the substrate, intersecting each other. The welding reinforcement is located at the intersection of the main grid and the sub-grid and is used for welding to solder ribbons. The adhesive dots are disposed on the main grid and are staggered from the welding reinforcement in the extending direction of the main grid. The adhesive dots are used for bonding to the solder ribbons. This solar cell can improve the power output of a photovoltaic module.

Description

Technical Field

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

[0002] In the photovoltaic industry, single solar cells cannot be used directly as power sources due to their fragility and poor resistance to aging. Multiple solar cells need to be connected in series and parallel to form a solar cell string, and then arranged, stacked, and packaged to form a photovoltaic module before it can be used for a long time.

[0003] With continuous innovation in solar cell technology, adhesive bonding has emerged as a method for metallized interconnection between solder ribbons and the main grid. The main process involves printing adhesive onto the main grid of the solar cell, then thermally welding the solder ribbon to the main grid and bonding it with the adhesive, thus fixing the solder ribbon to the main grid. Adhesive bonding enhances the connection stability between the solder ribbon and the main grid, preventing cold solder joints. However, research has found that photovoltaic modules using adhesive bonding are prone to shadowing at the solder ribbon location after TC (Temperature Cycle Test) testing, leading to power degradation and affecting module performance. Utility Model Content

[0004] Therefore, it is necessary to provide a solar cell and a photovoltaic module to address the issue of how to improve the power output of photovoltaic modules.

[0005] In a first aspect, this application provides a battery cell, comprising:

[0006] A substrate having a main gate and a sub-gate disposed thereon, the main gate and the sub-gate being intersected;

[0007] A welding reinforcement is provided at the intersection of the main grid and the sub-grid, and the welding reinforcement is used for welding with a welding strip;

[0008] Adhesive dots are disposed on the main grid and are offset from the weld reinforcement in the extension direction of the main grid. The adhesive dots are used to bond with the weld strip.

[0009] The technical solution will be further explained below:

[0010] In one embodiment, there are multiple main gates, all of which are spaced apart along a first direction of the substrate, and each main gate extends along a second direction of the substrate, wherein the first direction is perpendicular to the second direction.

[0011] The number of sub-gates is multiple, all of which are arranged at intervals along the second direction, and each sub-gate extends along the first direction;

[0012] The number of welding reinforcements is multiple, and each welding reinforcement is arranged in a one-to-one correspondence at the intersection position of each main grid and each sub-grid;

[0013] Each of the main grids is provided with multiple adhesive dots, and at least one welding reinforcement is provided between two adjacent adhesive dots on each main grid.

[0014] In one embodiment, each of the sub-grids includes multiple sub-grid segments, which are spaced apart along the first direction. The main grid passes through the gap between two adjacent sub-grid segments. The welded reinforcement spans across the main grid, and its two ends are respectively connected to two adjacent sub-grid segments.

[0015] In one embodiment, all welded reinforcements on each of the main grids include at least one reinforcing member and at least one ordinary member, the width of the reinforcing member being greater than the width of the ordinary member.

[0016] In one embodiment, the number of reinforcement members and the number of ordinary members on each main grid are both multiple, and at least one ordinary member is disposed between two adjacent reinforcement members.

[0017] In one embodiment, the welded reinforcement covers the sub-gate.

[0018] In one embodiment, the width of the welded reinforcement gradually decreases from the middle of the welded reinforcement toward both ends of the welded reinforcement.

[0019] In one embodiment, the length of the welded reinforcement ranges from 0.5 mm to 1.0 mm, and the width of the welded reinforcement ranges from 0.02 mm to 0.1 mm.

[0020] In one embodiment, the length of the adhesive dot is 1.0mm-1.5mm; the width of the adhesive dot is 0.2mm-0.8mm.

[0021] Secondly, this application also provides a photovoltaic module, including the aforementioned solar cells.

[0022] In the aforementioned solar cells and photovoltaic modules, welding reinforcements are placed at the intersection of the main busbar and the sub-busbar. These reinforcements, welded to the solder strip, enhance the welding effect between the solder strip and the main busbar, ensuring current flow between them and thus improving the current collection capacity of the solder strip. Simultaneously, adhesive dots are placed on the main busbar, bonding with the solder strip and strengthening the connection between them, preventing the solder strip from being easily pulled off and further enhancing its current collection capacity. Furthermore, by staggering the adhesive dots and welding reinforcements, the adhesive dots are prevented from covering the solder strip and the reinforcement, thus avoiding interference with current flow and preventing shadows in the photovoltaic module during EL testing. This ensures the power output of the photovoltaic module and improves its performance. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Furthermore, the accompanying drawings are not drawn to a 1:1 scale, and the relative dimensions of the various components are shown as examples only and not necessarily to scale. In the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the structure of a battery cell according to one embodiment.

[0027] Figure 2 This is a magnified view of part A of the battery cell shown in Figure 1.

[0028] Figure 3 for Figure 2 The image shows a magnified view of part B.

[0029] Explanation of reference numerals in the attached figures:

[0030] 10. Substrate; 11. Main gate; 12. Sub-gate; 121. Sub-gate segment; 20. Welding reinforcement; 21. Reinforcing member; 22. General component; 30. Adhesive dot. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0037] As described in the background section, currently, photovoltaic modules using adhesive bonding processes, after undergoing TC (Temperature Cycle Test), are prone to exhibiting shadows at the solder ribbon locations during EL (Electroluminescent) testing, resulting in power degradation and impacting module performance. The inventors of this application, through inventive research, discovered the cause: Currently, during adhesive printing on the solar cells, the screen printing pattern and cell pattern are not fully considered to have a one-to-one correspondence. After printing, some adhesive dots 30 are distributed at the solder joints between the main grid 11 and the solder ribbon. After the solder ribbon is subsequently welded to the main grid 11, a structure of paste + adhesive + solder ribbon appears. Due to the insulating nature of the adhesive, current transmission at the solder joints weakens. After TC testing, the photovoltaic module experiences thermal shock, causing stress reactions between the solder ribbon and the cell, further weakening the current collection capacity at the solder joints. This results in noticeable shadows during EL testing, indicating power degradation and affecting module performance.

[0038] Based on this, one embodiment of this application provides a battery cell, see [link to relevant documentation]. Figure 1 as well as Figure 2 One embodiment of the battery cell includes a substrate 10, a welding reinforcement 20, and adhesive dots 30.

[0039] The substrate 10 has a main gate 11 and a secondary gate 12, which are arranged intersecting each other. The secondary gate 12 is used to collect current on the substrate 10, and the main gate 11 is used to summarize the current collected by the secondary gate 12 and transfer it to the solder ribbon. For example, the main gate 11 and the secondary gate 12 are arranged perpendicularly.

[0040] A welding reinforcement 20 is disposed at the intersection of the main grid 11 and the secondary grid 12, and is used for welding with the welding strip. For example, the welding reinforcement 20 (commonly known as a centipede leg) can be printed at the intersection of the main grid 11 and the secondary grid 12 using the same paste as the main grid 11. The welding reinforcement 20 increases the contact area between the main grid 11 and the welding strip, thereby enhancing the welding effect between the welding strip and the main grid 11.

[0041] Adhesive dots 30 are disposed on the main gate 11, and the adhesive dots 30 are staggered with the welding reinforcement 20, that is, the positions of the adhesive dots 30 and the welding reinforcement 20 do not coincide. The adhesive dots 30 are used to bond with the solder ribbon. Exemplarily, the adhesive tape is printed on the substrate 10 by thermosetting adhesive through a printing screen. The bonding of the adhesive dots 30 with the solder ribbon can enhance the connection stability between the solder ribbon and the main gate 11.

[0042] In the aforementioned solar cell, a welding reinforcement 20 is provided at the intersection of the main busbar 11 and the sub-busbar 12. The welding reinforcement 20, when welded to the solder strip, enhances the welding effect between the solder strip and the main busbar 11, ensuring current flow between them and thus improving the current collection capacity of the solder strip. Simultaneously, adhesive dots 30 are provided on the main busbar 11, bonding with the solder strip and strengthening the connection stability between them, preventing the solder strip from being easily pulled off and further enhancing its current collection capacity. Furthermore, by staggering the adhesive dots 30 and the welding reinforcement 20, the adhesive dots 30 are prevented from covering the area between the welding reinforcement 20 and the solder strip, thus avoiding interference with current flow and preventing shadows from appearing on the photovoltaic module during EL testing. This ensures the power output of the photovoltaic module and improves its performance.

[0043] See Figure 1 In one embodiment, there are multiple main gates 11, all of which are spaced apart along a first direction of the substrate 10, and each main gate 11 extends along a second direction of the substrate 10. There are also multiple sub-gates 12, all of which are spaced apart along the second direction, and each sub-gate 12 extends along the first direction. The first direction is perpendicular to the second direction. For example, Figure 1 The straight arrow X in the diagram represents the first direction, and the straight arrow Y represents the second direction. Increasing the number of main grids 11 and sub-grids 12 can improve the current collection capability of the solar cells, thereby further increasing the power of the photovoltaic module.

[0044] Furthermore, there are multiple welding reinforcements 20, and each welding reinforcement 20 is set at the intersection of each main grid 11 and each sub-grid 12. In this way, the number of welding points between the welding strip and the main grid 11 can be increased, thereby shortening the path length of current from the main grid 11 to the welding strip, thereby reducing current loss and increasing the power of the photovoltaic module.

[0045] Furthermore, each main grid 11 is provided with multiple adhesive dots 30, and at least one welded reinforcement 20 is provided between two adjacent adhesive dots 30 on each main grid 11. This increases the bonding points between the solder strip and the main grid 11, thereby further improving the connection stability between the solder strip and the main grid 11.

[0046] See Figure 3 Each sub-grid 12 includes multiple sub-grid segments 121, which are arranged at intervals along the first direction. In other words, the sub-grid 12 has a discontinuous structure, thereby saving the paste required for printing the sub-grid 12 and reducing costs.

[0047] Furthermore, the main gate 11 is inserted between two adjacent sub-gate segments 121, and the welded reinforcement 20 is arranged across the main gate 11. The two ends of the welded reinforcement 20 are respectively connected to the two adjacent sub-gate segments 121, thereby realizing the metallized interconnection between the main gate 11 and the sub-gate 12 and ensuring the current transmission between the main gate 11 and the sub-gate 12.

[0048] See Figure 2 Each main grid 11 has at least one reinforcing member 21 and at least one ordinary member 22 among all the welded reinforcements. The width of the reinforcing member 21 is greater than the width of the ordinary member 22. Therefore, the contact area between the reinforcing member 21 and the welding strip is larger, which further improves the connection stability between the welding strip and the main grid 11 and the current flow capacity.

[0049] Furthermore, each main grid 11 has multiple reinforcing members 21 and multiple ordinary members 22, and at least one ordinary member 22 is provided between two adjacent reinforcing members 21. For example, one, two, three or more ordinary members 22 may be provided between two adjacent reinforcing members 21, so that the main grid 11 and the solder strip are reinforced at regular intervals by a reinforcing member 21, which further improves the connection stability between the solder strip and the main grid 11 and the current flow capacity.

[0050] In some embodiments, the welding reinforcement 20 covers the sub-gate 12. This makes the height of the welding reinforcement 20 higher than the height of the sub-gate 12. Microscopically, a height difference is formed between the welding reinforcement 20 and the sub-gate 12, which to some extent can prevent the adhesive dots 30 from flowing and overflowing onto the welding reinforcement 20 before curing, thereby preventing the adhesive dots 30 from affecting the current flow between the solder strip and the welding reinforcement 20.

[0051] See Figure 3 The width of the welding reinforcement 20 gradually decreases from the middle of the welding reinforcement 20 towards both ends. That is, the welding reinforcement 20 has a structure that is wider in the middle and narrower at both ends. Since the welding strip is generally welded to the middle of the welding reinforcement 20, by making the welding reinforcement 20 wider in the middle and narrower at both ends, it is possible to ensure a stable connection between the welding strip and the welding reinforcement 20, while saving printing paste for the welding reinforcement 20, thereby saving costs.

[0052] Understandably, in some embodiments, the shape of the weld reinforcement 20 may also be a wider rectangle, ellipse, triangle or other polygon, without limitation.

[0053] See Figure 3 For example, in some embodiments, the length L of the welding reinforcement 20 ranges from 0.5mm to 1.0mm, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, etc. The width D of the welding reinforcement 20 ranges from 0.02mm to 0.1mm, such as 0.02mm, 0.035mm, 0.045mm, 0.065mm, 0.075mm, 0.09mm, 0.1mm, etc. Specifically, if the size of the welding reinforcement 20 is too small, it is easy to have a poor connection with the welding strip, affecting the current collection capacity of the welding strip. If the size of the welding reinforcement 20 is too large, too much slurry will be consumed, resulting in high cost. By configuring the length L of the welding reinforcement 20 to be 0.5mm-1.0mm and the width D of the welding reinforcement 20 to be in the range of 0.02mm-0.1mm, it is possible to control costs while ensuring a stable connection between the welding reinforcement 20 and the welding strip.

[0054] For example, in some embodiments, the length M of the adhesive dot 30 is 1.0mm-1.5mm; for example, it can be 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc. The width N of the adhesive dot 30 is 0.2mm-0.8mm; for example, it can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, etc. Specifically, if the size of the adhesive dot 30 is too small, it will easily affect the bonding stability with the solder ribbon; if the size of the adhesive dot 30 is too large, more adhesive will be consumed, resulting in higher costs, and the adhesive will easily overflow onto the welding reinforcement 20, affecting the connection between the welding reinforcement 20 and the solder ribbon. By configuring the length M of the adhesive dot 30 to be 1.0mm-1.5mm and the width N of the adhesive dot 30 to be 0.2mm-0.8mm, it is possible to ensure a stable connection between the adhesive dot 30 and the solder ribbon while preventing adhesive from overflowing onto the welding reinforcement 20.

[0055] This application also provides a photovoltaic module in one embodiment. Specifically, the photovoltaic module of one embodiment includes the solar cells of any of the above embodiments. Exemplarily, in one embodiment, the number of solar cells is multiple, and the multiple solar cells are connected in series or in parallel by solder strips.

[0056] In the aforementioned photovoltaic module, the solar cells incorporate welding reinforcements 20 at the intersection of the main busbar 11 and the sub-busbar 12. The welding reinforcements 20, when welded to the solder strip, enhance the welding effect between the solder strip and the main busbar 11, ensuring current flow between them and thus improving the current collection capacity of the solder strip. Simultaneously, adhesive dots 30 are placed on the main busbar 11, bonding with the solder strip and strengthening the connection between them, preventing the solder strip from being easily pulled off and further enhancing its current collection capacity. Furthermore, by staggering the adhesive dots 30 with the welding reinforcements 20, the adhesive dots 30 are prevented from covering the area between the welding reinforcements 20 and the solder strip, thus avoiding interference with current flow and preventing shadows in the photovoltaic module during EL testing. This ensures the power output of the photovoltaic module and improves its performance.

[0057] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A type of battery cell, characterized in that, include: A substrate (10) is provided with a main gate (11) and a sub-gate (12), the main gate (11) and the sub-gate (12) being disposed intersecting each other; A welding reinforcement (20) is provided at the intersection of the main grid (11) and the sub-grid (12), and the welding reinforcement (20) is used for welding with the welding strip; Adhesive dots (30) are disposed on the main grid (11) and are staggered from the welding reinforcement (20) in the extension direction of the main grid. The adhesive dots (30) are used to bond with the welding strip.

2. The battery cell according to claim 1, characterized in that: The number of main gates (11) is multiple, and all the main gates (11) are arranged at intervals along a first direction of the substrate (10). Each main gate (11) extends along a second direction of the substrate (10), and the first direction is perpendicular to the second direction. The number of sub-gates (12) is multiple, and all the sub-gates (12) are arranged at intervals along the second direction, with each sub-gate (12) extending along the first direction; The number of the welding reinforcements (20) is multiple, and each welding reinforcement (20) is arranged in a one-to-one correspondence at the intersection position of each main grid (11) and each sub-grid (12); Each of the main grids (11) is provided with a plurality of adhesive dots (30), and at least one of the welding reinforcements (20) is provided between two adjacent adhesive dots (30) on each of the main grids (11).

3. The battery cell according to claim 2, characterized in that, Each of the sub-grids (12) includes multiple sub-grid segments (121), which are arranged at intervals along the first direction. The main grid (11) passes through the interval between two adjacent sub-grid segments (121). The welded reinforcement (20) is arranged across the main grid (11), and the two ends of the welded reinforcement (20) are respectively connected to two adjacent sub-grid segments (121).

4. The battery cell according to claim 2, characterized in that, Each of the welded reinforcements (20) on each of the main grids (11) includes at least one reinforcement (21) and at least one ordinary member (22), the width of the reinforcement (21) being greater than the width of the ordinary member (22).

5. The battery cell according to claim 4, characterized in that, The number of reinforcement members (21) on each main grid (11) is multiple and the number of ordinary members (22) is also multiple, and at least one ordinary member (22) is provided between two adjacent reinforcement members (21).

6. The battery cell according to claim 1, characterized in that, The welded reinforcement (20) covers the sub-gate (12).

7. The battery cell according to claim 1, characterized in that, The width of the welded reinforcement (20) gradually decreases from the middle of the welded reinforcement (20) toward both ends of the welded reinforcement (20).

8. The battery cell according to claim 1, characterized in that, The length of the welded reinforcement (20) ranges from 0.5mm to 1.0mm; the width of the welded reinforcement (20) ranges from 0.02mm to 0.1mm.

9. The battery cell according to claim 1, characterized in that, The length of the adhesive dot (30) is 1.0mm-1.5mm; the width of the adhesive dot (30) is 0.2mm-0.8mm.

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

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