Solar cell and photovoltaic module

Abstract

The utility model discloses a solar cell and a photovoltaic assembly, which are applied to the field of photovoltaic technology. According to the utility model, the auxiliary bonding pads are added between the adjacent bonding pads at the two ends of the main grid line, so that the distance between the adjacent bonding pads at the two ends of the main grid line is reduced, the contact area with a welding strip can be increased, and the problem of pseudo soldering caused by overlarge distance between the bonding pads can be solved; and the stress at the two ends of the assembly end is larger, the contact area with the welding strip can be increased by increasing the areas of the bonding pads at the two ends of the main grid line, the deviation of the welding strip can be avoided, and the cold solder joint of the assembly can be improved. Meanwhile, the auxiliary bonding pad with a small area can play an auxiliary role between the adjacent bonding pads, and the consumption of slurry can be reduced by reducing the area of the auxiliary bonding pad.

Description

Technical Field

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

[0002] In the production and application of solar cells, multiple solar cells are typically welded together to output high power. Conventional SMBB (Super Multi-Busbar) bifacial cells have multiple main grid lines and sub-grid lines on both the front and back. The sub-grid lines collect the charge carriers generated in the solar cell, and because they are connected to the main grid lines, they transport the charge carriers to the main grid lines, where they then output current. Each main grid line on the surface of the solar cell has multiple solder pads (collectively called pads) for welding. During the module welding process, solder ribbons are used to weld all the pads together from multiple cells to form electrical contacts, allowing multiple cells to be connected in series or parallel to output high-power current. However, in traditional solar cells, the spacing between the pads on the main grid lines is too large, which can lead to poor soldering at the module end. Furthermore, in traditional solar cells, the main grid lines and sub-grid lines usually use different pastes; if they do not make good contact, it will affect the module's power output. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a solar cell and a photovoltaic module for improving module solder joint defects and increasing module power.

[0004] To solve the above-mentioned technical problems, this utility model provides a solar cell, comprising: a solar cell; the surface of the solar cell is provided with a plurality of main grid lines and a plurality of sub-grid lines; the main grid lines extend along a first direction and are arranged sequentially along a second direction; the sub-grid lines extend along the second direction and are arranged sequentially along the first direction;

[0005] Both ends of the main grid line are provided with a harpoon structure; a first pad is provided at the intersection of the main grid line and the harpoon structure; a second pad is provided on the main grid line between the two first pads; an auxiliary pad is provided between the first pad and the adjacent second pad; the area of ​​the first pad is larger than the area of ​​the second pad, and the area of ​​the second pad is larger than the area of ​​the auxiliary pad.

[0006] The distance between two adjacent second pads is greater than the distance between the first pad and the adjacent auxiliary pad; the distance between two adjacent second pads is greater than the distance between the auxiliary pad and the adjacent second pad.

[0007] Optionally, both the main grid line and the harpoon structure are connected to the secondary grid line; at least a portion of the secondary grid line connected to the harpoon structure penetrates the interior of the harpoon structure, and the main grid line extends into the interior of the harpoon structure and connects to the secondary grid line inside the harpoon structure.

[0008] Optionally, the sub-grid line that is close to the opening of the harpoon structure and connected to the harpoon structure does not penetrate the interior of the harpoon structure;

[0009] The sub-grid line, which is opposite to the opening of the harpoon structure and connected to the harpoon structure, penetrates the interior of the harpoon structure.

[0010] Optionally, the number of the sub-grid lines near the opening of the harpoon structure and connected to the harpoon structure is 2 to 4, including the values ​​at both ends.

[0011] Optionally, the distance between the first pad and the adjacent auxiliary pad is equal to the distance between the auxiliary pad and the adjacent second pad;

[0012] And / or, along the direction toward both ends of the main gate line, the distance between two adjacent second pads gradually decreases.

[0013] Optionally, the first pad is rectangular in shape, with the two corners closest to the harpoon structure being right angles and the two corners away from the harpoon structure being rounded.

[0014] And / or, the auxiliary pad is rhomboid in shape;

[0015] And / or, the second pad is rectangular in shape and has rounded corners.

[0016] Optionally, the length of the first pad along the first direction is 0.6mm to 1mm, including the values ​​at both ends; the length of the first pad along the second direction is 1mm to 1.5mm, including the values ​​at both ends.

[0017] And / or, the length of the auxiliary pad along the first direction is 0.03mm to 0.08mm, including the values ​​at both ends; the length of the auxiliary pad along the second direction is 0.6mm to 1.2mm, including the values ​​at both ends;

[0018] And / or, the length of the second pad along the first direction is 0.5mm to 0.8mm, including the values ​​at both ends; the length of the second pad along the second direction is 0.6mm to 1mm, including the values ​​at both ends.

[0019] Optionally, the surface of the battery cell includes a front side and a back side; the number of pads on the front side of the battery cell is the same as the number of pads on the back side of the battery cell; the pads include a first pad, an auxiliary pad, and a second pad; in the first direction, there is a gap between the pads on the front side of the battery cell and the corresponding pads on the back side of the battery cell.

[0020] Optionally, in the first direction, the distance between the pads on the front side of the battery cell and the corresponding pads on the back side of the battery cell is greater than or equal to 1 mm.

[0021] To solve the above-mentioned technical problems, this utility model also provides a photovoltaic module, including the above-mentioned solar cell.

[0022] As can be seen, the solar cell provided by this utility model increases the contact area with the solder ribbon by adding auxiliary solder pads between adjacent solder pads at both ends of the main grid line, thereby solving the problem of cold solder joints caused by excessive solder pad spacing. Furthermore, the module ends experience greater force; increasing the area of ​​the solder pads at both ends of the main grid line increases the contact area with the solder ribbon and prevents solder ribbon misalignment, thus improving cold solder joints. Simultaneously, a smaller auxiliary solder pad can provide auxiliary support between adjacent solder pads, and reducing the area of ​​the auxiliary solder pads also reduces paste consumption. This utility model also provides a photovoltaic module with the above-mentioned beneficial effects. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 A schematic diagram of a battery cell graphic structure provided for an embodiment of this utility model;

[0025] Figure 2 A schematic diagram of the internal structure of a harpoon structure provided in an embodiment of this utility model;

[0026] Figure 3 A schematic diagram of a first pad structure provided in an embodiment of this utility model;

[0027] Figure 4 A schematic diagram of an auxiliary pad structure provided for an embodiment of this utility model;

[0028] Figure 5A schematic diagram of a second pad structure provided in an embodiment of this utility model;

[0029] Figure 6 A side view of a battery cell provided for an embodiment of this utility model;

[0030] Figure 7 A schematic diagram of the spacing between each pad provided for an embodiment of this utility model;

[0031] Figure 8 This is a schematic diagram of the pad distribution provided for an embodiment of the present utility model.

[0032] The annotations in the attached figures are explained as follows:

[0033] 101-Harpoon structure; 102-First pad; 103-Second pad; 104-Main busbar; 105-Sub-busbar; 106-Auxiliary pad; 21-Pad on the front of the cell; 22-Pad on the back of the cell. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] Please refer to Figure 1 The present invention provides a solar cell that may include: a solar cell; a plurality of main grid lines 104 and a plurality of sub-grid lines 105 are disposed on the surface of the solar cell; the main grid lines 104 extend along a first direction and are arranged sequentially along a second direction; the sub-grid lines 105 extend along the second direction and are arranged sequentially along the first direction.

[0036] Both ends of the main gate line 104 are provided with a harpoon structure 101; a first pad 102 is provided at the intersection of the main gate line 104 and the harpoon structure 101; a second pad 103 is provided on the main gate line 104 between the two first pads 102; an auxiliary pad 106 is provided between the first pad 102 and the adjacent second pad 103; the area of ​​the first pad 102 is larger than the area of ​​the second pad 103, and the area of ​​the second pad 103 is larger than the area of ​​the auxiliary pad 106.

[0037] The distance between two adjacent second pads 103 is greater than the distance between the first pad 102 and the adjacent auxiliary pad 106; the distance between two adjacent second pads 103 is greater than the distance between the auxiliary pad 106 and the adjacent second pad 103.

[0038] Furthermore, in this embodiment, the distance between the first pad 102 and the adjacent auxiliary pad 106 can be equal to the distance between the auxiliary pad 106 and the adjacent second pad 103. It should be noted that the auxiliary pad is positioned in the middle of the first pad 102 and the second pad 103 at the beginning and end, in order to reduce the distance between the first pad 102 and the second pad 103 at the beginning and end, increase the contact area with the solder ribbon, and thus reduce cold solder joints.

[0039] Furthermore, in this embodiment, the distance between two adjacent second pads 103 can gradually decrease along the direction towards both ends of the main grid line 104. It should be noted that because the forces at both ends of the component are greater during soldering, a smaller spacing between pads near the ends can increase the contact area with the solder ribbon and reduce the risk of poor soldering.

[0040] Furthermore, in this embodiment, both the main gate line 104 and the harpoon structure 101 are connected to the sub-gate lines 105. At least a portion of the sub-gate lines 105 connected to the harpoon structure 101 can penetrate the interior of the harpoon structure 101, and the main gate line 104 extends into the interior of the harpoon structure 101, connecting with the sub-gate lines 105 inside the harpoon structure 101. It should be noted that by extending the main gate line 104 into the interior of the harpoon structure 101 and connecting all the sub-gate lines 105, the contact area between the main gate line 104 and the sub-gate lines 105 can be increased, thereby increasing the current collection of the sub-gate lines 105 inside the harpoon structure 101 and thus improving the component power.

[0041] This embodiment does not limit the specific arrangement of the sub-grid lines 105 inside the harpoon structure 101, and may include, but is not limited to, the following: Figure 2 As shown, the sub-gate line 105 near the opening of the harpoon structure 101 and connected to the harpoon structure 101 does not penetrate the interior of the harpoon structure 101; the sub-gate line 105 away from the opening of the harpoon structure 101 and connected to the harpoon structure 101 penetrates the interior of the harpoon structure 101. It should be noted that in this embodiment, by disconnecting part of the sub-gate line 105 at the opening of the harpoon structure 101, microcracks in the component soldering can be avoided.

[0042] This embodiment does not limit the number of secondary gate lines 105 disconnected at the opening of the harpoon structure 101. For example, the number of secondary gate lines 105 near the opening of the harpoon structure 101 and connected to the harpoon structure 101 can be 2 to 4, including the values ​​at both ends. This embodiment does not limit the specific size of the main gate line 104. For example, the length of the main gate line 104 along the second direction can be 15μm to 45μm, including the values ​​at both ends. In the first direction, it is sufficient to ensure that the main gate line 104 can extend into the interior of the harpoon structure 101 and connect with all the secondary gate lines 105 inside the harpoon structure 101.

[0043] This embodiment does not limit the specific shape of the first pad 102, and may include, but is not limited to, the following: Figure 3 As shown, the first pad 102 is rectangular in shape, with two right angles on the side closest to the harpoon structure 101 and two rounded corners on the side away from the harpoon structure 101. It should be noted that in this embodiment, the contact end between the first pad 102 and the harpoon structure 101 is set at a right angle, which can improve the contact between the first pad 102 and the harpoon structure 101.

[0044] This embodiment does not limit the specific shape of the auxiliary pad 106, and may include, but is not limited to, the shape of the auxiliary pad 106. Figure 4 As shown, the auxiliary pad 106 is rhomboid in shape. It should be noted that in this embodiment, the auxiliary pad 106 is rhomboid in shape to ensure increased contact while making the component more aesthetically pleasing.

[0045] This embodiment does not limit the specific shape of the second pad 103, and may include, but is not limited to, the following: Figure 5 As shown, the second pad 103 is rectangular in shape and has rounded corners.

[0046] This embodiment does not limit the specific size of the first solder pad. For example, the length of the first solder pad 102 along the first direction can be 0.6mm to 1mm, including the values ​​at both ends; the length of the first solder pad 102 along the second direction can be 1mm to 1.5mm, including the values ​​at both ends. It should be noted that in this embodiment, the length of the first solder pad along the second direction has a certain tolerance for solder line offset.

[0047] This embodiment does not limit the specific size of the auxiliary pad 106. For example, the length of the auxiliary pad 106 along the first direction can be 0.03mm to 0.08mm, including the values ​​at both ends; the length of the auxiliary pad 106 along the second direction can be 0.6mm to 1.2mm, including the values ​​at both ends. It should be noted that in this embodiment, the length of the auxiliary pad 106 along the second direction has a certain tolerance for solder line offset. Furthermore, it should be noted that when the shape of the auxiliary pad 106 is rhomboid, the length of the auxiliary pad 106 along the second direction can be the long diagonal length, and correspondingly, the length of the auxiliary pad 106 along the first direction can be the short diagonal length.

[0048] This embodiment does not limit the specific size of the second solder pad. For example, the length of the second solder pad 103 along the first direction can be 0.5mm to 0.8mm, including the values ​​at both ends; the length of the second solder pad 103 along the second direction can be 0.6mm to 1mm, including the values ​​at both ends. It should be noted that in this embodiment, the length of the second solder pad along the second direction has a certain tolerance for solder line offset.

[0049] This embodiment can be a bifacial solar cell, meaning the cell surface can include a front and a back side; the number of pads 21 on the front side of the cell can be the same as the number of pads 22 on the back side; the pads can include a first pad 102, an auxiliary pad 106, and a second pad 103; in a first direction, the pads 21 on the front side of the cell can have a distance D between them and the corresponding pads 22 on the back side, such as... Figure 6 As shown. It should be noted that if the pads on the front and back of the solar cell overlap, the overall height of the overlapping area will be relatively high, which can easily lead to microcracks and fragmentation. In this embodiment, the two corresponding pads on the front and back of the solar cell are spaced apart in the first direction, which can reduce the overall height of the solar cell and thus avoid microcrack fragmentation.

[0050] This embodiment does not limit the specific spacing between the two corresponding pads on the front and back of the battery cell in the first direction. For example, in the first direction, the spacing D between the pad 21 on the front of the battery cell and the corresponding pad 22 on the back of the battery cell may be greater than or equal to 1 mm.

[0051] This embodiment does not limit the specific spacing between the pads on the front side of the battery cell, as long as the spacing D between the pad 21 on the front side of the battery cell and the corresponding pad 22 on the back side of the battery cell is greater than or equal to 1mm. For example, it can be as follows: Figure 7 As shown, five second pads 103 are provided on the surface of the main grid line 104 between the two first pads 102; in the first direction, the distance d1 between the first first pad 102 on the front side of the cell and the first edge of the cell is 3.86mm~7.86mm, including the values ​​at both ends;

[0052] And / or, the spacing d2 between the first auxiliary pad 106 and the first first pad 102 is 5.94mm to 9.94mm, including the values ​​at both ends;

[0053] And / or, the spacing d3 between the first second pad 103 and the first auxiliary pad 106 is 5.91mm to 9.91mm, including the values ​​at both ends;

[0054] And / or, the spacing d4 between the second second pad 103 and the first second pad 103 is 12.85mm to 17.85mm, including the values ​​at both ends;

[0055] And / or, the spacing d5 between the third second pad 103 and the second second pad 103 is 13.75mm to 17.75mm, including the values ​​at both ends;

[0056] And / or, the spacing d6 between the fourth second pad 103 and the third second pad 103 is 13.79mm~17.79mm, including the values ​​at both ends;

[0057] And / or, the spacing d7 between the fifth second pad 103 and the fourth second pad 103 is 12.07mm~16.07mm, including the values ​​at both ends;

[0058] And / or, the spacing d8 between the second auxiliary pad 106 and the fifth second pad 103 is 5.37mm to 9.37mm, including the values ​​at both ends;

[0059] And / or, the spacing d9 between the second first pad 102 and the second auxiliary pad 106 is 6.45mm to 10.45mm, including the values ​​at both ends;

[0060] And / or, the distance d10 between the second edge of the battery cell and the second first pad 102 is 4mm to 8mm, including the values ​​at both ends.

[0061] This embodiment does not limit the specific spacing between the pads on the back of the battery cell, as long as the spacing D between the pad 21 on the front of the battery cell and the corresponding pad 22 on the back of the battery cell is greater than or equal to 1mm. For example, it can be as follows: Figure 7 As shown, the distance d1 between the first first pad 102 on the back of the battery cell and the first edge of the battery cell is 5.86mm to 9.86mm, including the values ​​at both ends;

[0062] And / or, the spacing d2 between the first auxiliary pad 106 and the first first pad 102 is 6.44mm to 10.44mm, including the values ​​at both ends;

[0063] And / or, the spacing d3 between the first second pad 103 and the first auxiliary pad 106 is 5.36mm to 9.36mm, including the values ​​at both ends;

[0064] And / or, the spacing d4 between the second second pad 103 and the first second pad 103 is 13.7mm to 17.7mm, including the values ​​at both ends;

[0065] And / or, the spacing d5 between the third second pad 103 and the second second pad 103 is 10.25mm to 14.25mm, including the values ​​at both ends;

[0066] And / or, the spacing d6 between the fourth second pad 103 and the third second pad 103 is 11.89mm~15.89mm, including the values ​​at both ends;

[0067] And / or, the spacing d7 between the fifth second pad 103 and the fourth second pad 103 is 13.64mm~17.64mm, including the values ​​at both ends;

[0068] And / or, the spacing d8 between the second auxiliary pad 106 and the fifth second pad 103 is 5.92mm to 9.92mm, including the values ​​at both ends;

[0069] And / or, the spacing d9 between the second first pad 102 and the second auxiliary pad 106 is 4.98mm to 8.98mm, including the values ​​at both ends;

[0070] And / or, the distance d10 between the second edge of the battery cell and the second first pad 102 is 6.97mm to 10.97mm, including the values ​​at both ends.

[0071] Based on the above embodiments, this invention increases the contact area with the solder ribbon by adding auxiliary pads between adjacent pads at both ends of the main busbar, thereby solving the problem of cold solder joints caused by excessive pad spacing. Furthermore, since the module ends experience greater force, increasing the area of ​​the pads at both ends of the main busbar increases the contact area with the solder ribbon and prevents solder ribbon misalignment, thus improving the module's cold solder joint performance. Simultaneously, smaller auxiliary pads can provide auxiliary support between adjacent pads, and reducing the area of ​​the auxiliary pads also reduces paste consumption.

[0072] The photovoltaic module provided in this embodiment may include the aforementioned solar cell.

[0073] Based on the above embodiments, since the present invention uses the aforementioned solar cell, it also has the aforementioned beneficial effects.

[0074] To make this utility model easier to understand, the embodiments of this utility model provide a method such as... Figure 1 The solar cell shown has several main grid lines 104 and several sub-grid lines 105 on its surface. Each main grid line 104 includes nine pads, and the nine pads are constructed using... Figure 8 The distribution pattern shown ( Figure 8 (This is a schematic diagram after removing the sub-gate line 105 and the harpoon structure 101), where the first pad 102 at both ends is a large pad, and its appearance is as follows. Figure 3 The rounded-corner rectangle shown has the following dimensions: length 1.2mm, width 0.6mm, and rounded corner diameter 0.3mm. The five second pads 103 between the first and last pads 102 are small pads, and their appearance is as follows... Figure 4 The rounded rectangle shown has the following dimensions: length 0.8mm, width 0.5mm. There is an auxiliary pad 106 between the first pad 102 at both ends and between the adjacent first and second pads 103. Its appearance is as follows... Figure 5The rhombus shown has the following dimensions: long diagonal 1.2mm, short diagonal 0.35mm. In this embodiment, different welding machines are used to perform EL (Electroluminescence) testing on the aforementioned half-cell solar cells, cell strings formed by connecting multiple half-cell solar cells in series, finished modules, and half-cell solar cells without auxiliary pads 106, cell strings formed by connecting multiple half-cell solar cells in series, and finished modules. This testing process includes:

[0075] 1. Finished solar cells are first cut into half-cells before the stringing machine. Then, the cut half-cells are connected in series on the stringing machine using welding ribbon, with 11 half-cells forming a string. Each string is tested by an EL tester after the stringing machine to count the proportion of poor welds in half-cells and single strings.

[0076] 2. Each set of 12 strings is arranged in a fixed layout and then laminated and packaged to form a single component. The single component is then subjected to finished product EL testing, and the proportion of poor solder joints is statistically analyzed.

[0077] Component EL testing: A forward bias voltage is applied to the battery string and module using a string EL tester (test voltage 15V~25V) and a finished product EL tester (test voltage 40V~60V) to inject non-equilibrium carriers. A high-resolution CCD (Charge Coupled Device) camera is used to capture EL images of the battery string and module under near-infrared light to identify and locate poor EL defects.

[0078] The comparative data of different welding machines are shown in Table 1.

[0079] Table 1 Comparison data of different welding machines

[0080]

[0081] According to the comparison data in Table 1, the addition of auxiliary pad 106 significantly improved the problem of poor soldering at the component end.

[0082] Furthermore, the spacing between each pad on the front and back of the aforementioned battery cell is designed as follows: Figure 7As shown, the front side spacing is: d1=5.86mm, d2=7.94mm, d3=7.91mm, d4=15.85mm, d5=15.75mm, d6=15.79mm, d7=14.07mm, d8=7.37mm, d9=8.45mm, d10=6mm; the back side spacing is: d1=7.86mm, d2=8.44mm, d3=7.36mm, d4=15.70mm, d5=12.25mm, d6=13.89mm, d7=15.64mm, d8=7.92mm, d9=6.98mm, d10=8.97mm. Using the above spacing ensures that the spacing between pads in close proximity on both the front and back sides is greater than 1mm.

[0083] Furthermore, the design incorporates five sub-grid lines 105 within the front-side harpoon structure 101 of the battery cell, with the two sub-grid lines 105 at the opening being disconnected. Additionally, the design incorporates eight sub-grid lines 105 within the front-side harpoon structure 101 of the battery cell, with the two sub-grid lines 105 at the opening being disconnected. Simultaneously, as... Figure 2 As shown, the main grid line 104 on the front and back of the battery cell is designed to extend into the harpoon structure 101 and connect to the sub-grid line 105 inside the harpoon structure 101, which can increase the current collection of the sub-grid line 105 inside the harpoon structure 101. After conducting experiments on the battery cell of this embodiment, it was verified that the improved component power can be greater than 1W.

[0084] The present invention has provided a detailed description of a solar cell and photovoltaic module. For those skilled in the art, based on the ideas of the embodiments of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A solar cell, characterized in that, include: Battery cells; The surface of the battery cell is provided with multiple main grid lines and multiple sub-grid lines; the main grid lines extend along a first direction and are arranged sequentially along a second direction; the sub-grid lines extend along the second direction and are arranged sequentially along the first direction. Both ends of the main grid line are provided with a harpoon structure; a first pad is provided at the intersection of the main grid line and the harpoon structure; a second pad is provided on the main grid line between the two first pads; an auxiliary pad is provided between the first pad and the adjacent second pad; the area of ​​the first pad is larger than the area of ​​the second pad, and the area of ​​the second pad is larger than the area of ​​the auxiliary pad. The distance between two adjacent second pads is greater than the distance between the first pad and the adjacent auxiliary pad; the distance between two adjacent second pads is greater than the distance between the auxiliary pad and the adjacent second pad.

2. The solar cell according to claim 1, characterized in that, Both the main grid line and the harpoon structure are connected to the sub-grid line; at least a portion of the sub-grid line connected to the harpoon structure penetrates the interior of the harpoon structure, and the main grid line extends into the interior of the harpoon structure and connects with the sub-grid line inside the harpoon structure.

3. The solar cell according to claim 2, characterized in that, The sub-grid line that is close to the opening of the harpoon structure and connected to the harpoon structure does not penetrate the interior of the harpoon structure. The sub-grid line, which is opposite to the opening of the harpoon structure and connected to the harpoon structure, penetrates the interior of the harpoon structure.

4. The solar cell according to claim 3, characterized in that, The number of the sub-grid lines near the opening of the harpoon structure and connected to the harpoon structure is 2 to 4, including the values ​​at both ends.

5. The solar cell according to claim 1, characterized in that, The distance between the first pad and the adjacent auxiliary pad is equal to the distance between the auxiliary pad and the adjacent second pad; And / or, along the direction toward both ends of the main gate line, the distance between two adjacent second pads gradually decreases.

6. The solar cell according to claim 1, characterized in that, The first pad is rectangular in shape, with the two corners closest to the harpoon structure being right angles and the two corners away from the harpoon structure being rounded. And / or, the auxiliary pad is rhomboid in shape; And / or, the second pad is rectangular in shape and has rounded corners.

7. The solar cell according to claim 1, characterized in that, The length of the first pad along the first direction is 0.6mm to 1mm, including the values ​​at both ends; the length of the first pad along the second direction is 1mm to 1.5mm, including the values ​​at both ends. And / or, the length of the auxiliary pad along the first direction is 0.03mm to 0.08mm, including the values ​​at both ends; the length of the auxiliary pad along the second direction is 0.6mm to 1.2mm, including the values ​​at both ends; And / or, the length of the second pad along the first direction is 0.5mm to 0.8mm, including the values ​​at both ends; the length of the second pad along the second direction is 0.6mm to 1mm, including the values ​​at both ends.

8. The solar cell according to any one of claims 1 to 7, characterized in that, The surface of the solar cell includes a front side and a back side; the number of pads on the front side of the solar cell is the same as the number of pads on the back side of the solar cell; the pads include a first pad, an auxiliary pad, and a second pad; in the first direction, there is a gap between the pads on the front side of the solar cell and the corresponding pads on the back side of the solar cell.

9. The solar cell according to claim 8, characterized in that, In the first direction, the distance between the pads on the front side of the battery cell and the corresponding pads on the back side of the battery cell is greater than or equal to 1 mm.

10. A photovoltaic module, characterized in that, include: The solar cell according to any one of claims 1 to 9.

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