Solar cell, solar cell string and photovoltaic module

Abstract

The utility model discloses a solar cell, a solar cell string and a photovoltaic assembly. The solar cell comprises a first main gate electrode and a second main gate electrode, the first main gate electrode and the second main gate electrode are both arranged on the back face of the solar cell, and the back face of the solar cell is provided with a first welding area and a second welding area which are arranged at intervals; one end of the first main gate electrode is located in the first welding area, the other end of the first main gate electrode and the second welding area are arranged in a spaced mode, one end of the second main gate electrode and the first welding area are arranged in a spaced mode, and the other end of the second main gate electrode is located in the second welding area. In the solar cell, the welding effectiveness between the welding strip and the first main gate electrode and between the welding strip and the second main gate electrode can be improved, and the contact resistance between the first main gate electrode and the welding strip to be welded and between the second main gate electrode and the welding strip to be welded can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a solar cell, a solar cell string and a photovoltaic assembly. Background Art

[0002] The electrodes of solar cells can be divided into main grid electrodes and fine grid electrodes. The fine grid electrodes are connected to the main grid electrodes. The main grid electrodes are usually provided with multiple pads arranged at intervals. The pads are usually used for welding with welding strips. However, there is usually a certain height difference between the pads and the fine grid electrodes, which makes it difficult for the welding strip to fully contact the pads, thereby causing the contact resistance between the welding strip and the main grid electrode to increase or welding failure. Utility Model Content

[0003] Based on this, in order to ensure that the welding strip can be effectively welded to the main grid electrode and improve the contact resistance between the two, it is necessary to provide a solar cell.

[0004] According to some embodiments of the present disclosure, a solar cell is provided, comprising a first main grid electrode and a second main grid electrode, wherein the first main grid electrode and the second main grid electrode are both disposed on the back side of the solar cell, and the back side of the solar cell has a first welding area and a second welding area disposed at intervals;

[0005] One end of the first main gate electrode is located in the first welding area, and the other end of the first main gate electrode is spaced apart from the second welding area. One end of the second main gate electrode is spaced apart from the first welding area, and the other end of the second main gate electrode is located in the second welding area.

[0006] In some embodiments of the present disclosure, the first main gate electrode includes a first welding portion located in the first welding area and a first electrode portion located outside the first welding area, and the first electrode portion is located between the first welding area and the second welding area.

[0007] In some embodiments of the present disclosure, the second main gate electrode includes a second welding portion located in the second welding area and a second electrode portion located outside the second welding area, and the second electrode portion is located between the first welding area and the second welding area.

[0008] In some embodiments of the present disclosure, a plurality of first fine gate electrodes are further included, wherein the first fine gate electrodes are connected to the first electrode portion and an extension direction of the first fine gate electrodes intersects with an extension direction of the first electrode portion.

[0009] In some embodiments of the present disclosure, a plurality of second fine gate electrodes are further included, wherein the second fine gate electrodes are connected to the second electrode portion and an extension direction of the second fine gate electrodes intersects with an extension direction of the second electrode portion.

[0010] In some embodiments of the present disclosure, the first welding area and the second welding area are both in the shape of long strips, and the extension direction of the first welding area is parallel to the extension direction of the second welding area; there are multiple first main gate electrodes, and the multiple first main gate electrodes are arranged in parallel in the welding direction; there are multiple second main gate electrodes, and the multiple second main gate electrodes are arranged in parallel along the extension direction of the first welding area.

[0011] Furthermore, the present disclosure also provides a solar cell string, which includes a connecting welding ribbon and a plurality of solar cells as described in any of the above embodiments, wherein the connecting welding ribbon is welded to two adjacent solar cells.

[0012] In some embodiments of the present disclosure, a plurality of the solar cells are arranged in parallel in sequence, a portion of the connecting welding ribbon is located on the first welding area of ​​one of the solar cells and is welded to the first main grid electrode in the solar cell, and a portion of the connecting welding ribbon is located on the second welding area of ​​another solar cell and is welded to the second main grid electrode in the solar cell.

[0013] In some embodiments of the present disclosure, the solar cell includes a first side and a second side that are relatively arranged, the first welding area is closer to the first side, and the second welding area is closer to the second side; in two adjacent solar cells, the first side of one of the solar cells is adjacent to the second side of the other solar cell.

[0014] In some embodiments of the present disclosure, the first welding area and the second welding area are both in the shape of long strips, and the first welding area and the second welding area both extend along a welding direction, and a plurality of the solar cells are sequentially arranged in parallel in the welding direction.

[0015] In some embodiments of the present disclosure, the solar cell string also includes a first end welding strip and a second end welding strip, the first end welding strip and the second end welding strip are respectively welded to the two outermost solar cells, and the first end welding strip is welded to the first main grid electrode in one of the solar cells, and the second end welding strip is welded to the second main grid electrode in another solar cell.

[0016] Furthermore, the present disclosure also provides a photovoltaic assembly, which includes a bus bar and a solar cell string as described in any of the above embodiments, and a plurality of the solar cell strings are electrically connected through the bus bar.

[0017] In conventional technology, a solder strip is usually arranged along the extension direction of the main gate electrode, which requires a matching solder pad to be arranged on the main gate electrode. However, in order to make up for the height difference between the solder pad and the fine gate electrode, solder paste is usually printed on the solder pad, but the solder will react with the silver in the electrode to form an intermetallic compound, causing the electrode to fall off.

[0018] In the solar cell disclosed in the present invention, protruding ends are respectively provided on the first main grid electrode and the second main grid electrode to serve as the parts to be welded with the welding strip. Specifically, one end of the first main grid electrode is located in the first welding area, and one end of the second main grid electrode is located in the second welding area. The first welding area and the second welding area can serve as welding areas of the welding strip, so that the welding strip can be welded to the ends of the first main grid electrode and the ends of the second main grid electrode without short-circuiting the positive and negative electrodes, so that the welding strip to be welded can be more fully contacted with the first main grid electrode and the second main grid electrode, improve the welding effectiveness between the welding strip and the first main grid electrode and the second main grid electrode, and improve the contact resistance between the first main grid electrode and the second main grid electrode and the welding strip to be welded. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a solar cell;

[0020] Figure 2 It is a structural schematic diagram of a solar cell string;

[0021] Figure 3 A schematic diagram of the structure of a photovoltaic module.

[0022] The reference numerals and their meanings are as follows:

[0023] 10. Solar cell; 11. First cell; 12. Second cell; 13. Third cell; 101. First welding area; 102. Second welding area; 103. First side; 104. Second side; 110. First main grid electrode; 111. First electrode portion; 112. First welding portion; 120. Second main grid electrode; 121. Second electrode portion; 122. Second welding portion; 131. First fine grid electrode; 132. Second fine grid electrode; 200. Connecting welding strip; 210. First end welding strip; 220. Second end welding strip; 300. Bus bar. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively in combination with the embodiments and the effect diagrams. The embodiments provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0025] It should be noted that when an element is referred to as being "fixed" to another element, it may be directly fixed to another original part or there may also be a central element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a central element at the same time. In addition, in the description of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integrated connection; it may be a mechanical connection or an electrical connection; it may be a direct connection, or an indirect connection through an intermediate medium, or it may be internal communication between two elements. It should be understood that it is possible for those skilled in the art to understand the specific meanings of the above terms according to the specific circumstances without causing ambiguity.

[0026] Unless otherwise specified, in the description of the present invention, terms indicating orientation or positional relationship, such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", and "outside", are based on the orientation or positional relationship shown in the drawings of the utility model. They are only for the convenience and simplification of the description of the content of the utility model and to help readers understand the description in conjunction with the drawings. They do not limit or imply a specific orientation that the device or element referred to must have, and therefore should not be understood as a limitation on the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. "Multiple" herein includes a combination of two or more than two items.

[0028] Figure 1 FIG. 1 is a schematic diagram of the structure of a solar cell 10 disclosed in the present invention. Figure 1As shown, the solar cell 10 includes a first main gate electrode 110 and a second main gate electrode 120, both of which are disposed on the back of the solar cell 10, and a first welding area 101 and a second welding area 102 are disposed at intervals on the back of the solar cell 10. One end of the first main gate electrode 110 is located in the first welding area 101, and the other end of the first main gate electrode 110 is spaced from the second welding area 102, and one end of the second main gate electrode 120 is spaced from the first welding area 101, and the other end of the second main gate electrode 120 is located in the second welding area 102.

[0029] Among them, the polarities of the first main gate electrode 110 and the second main gate electrode 120 are different. The first main gate electrode 110 and the second main gate electrode 120 can be the positive electrode or the negative electrode of the solar cell respectively. For example, the first main gate electrode 110 can be the positive electrode of the solar cell, and the second main gate electrode 120 can be the negative electrode of the solar cell.

[0030] In conventional technology, a solder strip is usually arranged along the extension direction of the main gate electrode, which requires a matching solder pad to be arranged on the main gate electrode. In order to make up for the height difference between the solder pad and the fine gate electrode, solder paste is usually printed on the solder pad, but the solder will react with the silver in the electrode to form an intermetallic compound, causing the electrode to fall off.

[0031] In the solar cell 10 of the present disclosure, protruding ends are respectively provided on the first main grid electrode 110 and the second main grid electrode 120 to serve as the portion to be welded with the welding strip. Specifically, one end of the first main grid electrode 110 is located in the first welding area 101, and one end of the second main grid electrode 120 is located in the second welding area 102. The first welding area 101 and the second welding area 102 can serve as welding areas of the welding strip, so that the welding strip can be welded to the ends of the first main grid electrode 110 and the ends of the second main grid electrode 120 without short-circuiting the positive and negative electrodes, so that the welding strip to be welded can be more fully contacted with the first main grid electrode 110 and the second main grid electrode 120, improve the welding effectiveness between the welding strip and the first main grid electrode 110 and the second main grid electrode 120, and improve the contact resistance between the first main grid electrode 110 and the second main grid electrode 120 and the welding strip to be welded.

[0032] Reference Figure 1As shown, in some examples of this embodiment, the first main gate electrode 110 may include a first welding portion 112 located in the first welding area 101 and a first electrode portion 111 located outside the first welding area 101, and the first electrode portion 111 may be disposed between the first welding area 101 and the second welding area 102. Further, the first electrode portion 111 is electrically connected to the first welding portion 112. The first welding portion 112 may be a portion that is directly in contact with and fixedly connected to the welding strip, and the first electrode portion 111 may be a portion that collects photogenerated carriers of the solar cell 10.

[0033] In some examples of this embodiment, the material of the first welding portion 112 may be different from the material of the first electrode portion 111. By setting the first welding portion 112 to be different from the material of the first electrode portion 111, the connection stability between the first main grid electrode 110 and the welding strip can be improved while improving the conductivity of the first main grid electrode 110. For example, the material of the first electrode portion 111 may include silver, and the material of the first welding portion 112 may include solder. Silver can make the first electrode portion 111 have higher conductivity, so that the first main grid electrode 110 has better carrier collection ability, and the solder can provide a stronger welding force to ensure that the welding strip can be more stably welded to the first main grid electrode 110.

[0034] It can be understood that in some other examples, the material of the first welding portion 112 may also be the same as the material of the first electrode portion 111 , for example, both the first welding portion 112 and the first electrode portion 111 may include conductive silver paste.

[0035] Reference Figure 1 As shown, in some examples of this embodiment, the second main gate electrode 120 may include a second welding portion 122 located in the second welding area 102 and a second electrode portion 121 located outside the second welding area 102, and the second electrode portion 121 may be disposed between the first welding area 101 and the second welding area 102. Further, the second electrode portion 121 is electrically connected to the second welding portion 122. The second welding portion 122 may be a portion that is directly in contact with and fixedly connected to the welding strip, and the second electrode portion 121 may be a portion that collects photogenerated carriers of the solar cell 10.

[0036] In some examples of this embodiment, the material of the second welding portion 122 may be different from the material of the second electrode portion 121. By setting the second welding portion 122 to be different from the material of the second electrode portion 121, the connection stability between the second main grid electrode 120 and the welding strip can be improved while improving the conductivity of the second main grid electrode 120. For example, the material of the second electrode portion 121 may include silver, and the material of the second welding portion 122 may include solder. Silver can make the second electrode portion 121 have higher conductivity, so that the second main grid electrode 120 has better carrier collection ability, and the solder can provide a stronger welding force to ensure that the welding strip can be more stably welded to the second main grid electrode 120.

[0037] It can be understood that in some other examples, the material of the second welding portion 122 may also be the same as the material of the second electrode portion 121 . For example, both the second welding portion 122 and the second electrode portion 121 may include conductive silver paste.

[0038] Reference Figure 1 As shown, in some examples of this embodiment, the solar cell 10 further includes a plurality of first fine gate electrodes 131, the first fine gate electrodes 131 are connected to the first electrode portion 111 and the extension direction of the first fine gate electrodes 131 intersects with the extension direction of the first electrode portion 111. The first fine gate electrodes 131 intersecting with the first electrode portion 111 can collect more carriers and gather them in the main gate electrode, thereby improving the carrier collection capability of the solar cell 10. It can be understood that the line width of the first fine gate electrode 131 can be smaller than the line width of the first electrode portion 111.

[0039] In some examples of this embodiment, first fine gate electrodes 131 may be disposed on opposite sides of the first electrode portion 111 .

[0040] Reference Figure 1 As shown, in some examples of this embodiment, the solar cell 10 further includes a plurality of second fine gate electrodes 132, the second fine gate electrodes 132 are connected to the second electrode portion 121, and the extension direction of the second fine gate electrodes 132 intersects with the extension direction of the second electrode portion 121. The second fine gate electrodes 132 intersecting with the second electrode portion 121 can collect more carriers and gather them in the main gate electrode, thereby improving the carrier collection capability of the solar cell 10. It can be understood that the line width of the second fine gate electrode 132 can be smaller than the line width of the second electrode portion 121.

[0041] In some examples of this embodiment, second fine gate electrodes 132 may be disposed on opposite sides of the second electrode portion 121 .

[0042] Further, refer to Figure 1As shown, multiple first fine gate electrodes 131 and multiple second fine gate electrodes 132 can be arranged between adjacent first main gate electrodes 110 and second main gate electrodes 120, and the first fine gate electrode 131 can be located between two adjacent second fine gate electrodes 132, and the second fine gate electrode 132 can also be located between two adjacent first fine gate electrodes 131.

[0043] Reference Figure 1 As shown, in some examples of this embodiment, the first welding area 101 may be in the shape of a long strip, and the extension direction of the first welding area 101 may be parallel to one edge of the solar cell 10. For example, the extension direction of the first welding area 101 may be as follows: Figure 1 Further, the second welding area 102 can be parallel to the first welding area 101 .

[0044] Reference Figure 1 As shown, in some examples of this embodiment, the solar cell 10 may include a first side 103 and a second side 104 that are relatively arranged, the first welding area 101 is arranged closer to the first side 103, and the second welding area 102 is arranged closer to the second side 104, that is, the first welding area 101 can be arranged between the first side 103 and the second welding area 102, and the second welding area 102 can be arranged between the second side 104 and the first welding area 101.

[0045] Reference Figure 1 As shown, in some examples of this embodiment, there may be multiple first main gate electrodes 110, and the multiple first main gate electrodes 110 are sequentially arranged in parallel in the extension direction of the first welding area 101. There may also be multiple second main gate electrodes 120, and the multiple second main gate electrodes 120 are sequentially arranged in parallel in the extension direction of the second welding area 102. Figure 1 In the embodiment, the arrangement direction of the plurality of first main gate electrodes 110 and the arrangement direction of the plurality of second main gate electrodes 120 are both in the horizontal direction.

[0046] Reference Figure 1 As shown, in some examples of this embodiment, the intervals between the plurality of first main gate electrodes 110 are equal, and the intervals between the plurality of second main gate electrodes 120 are equal.

[0047] Reference Figure 1 As shown, in some examples of this embodiment, the first main gate electrode 110 is in a strip shape, and the extension direction of the first main gate electrode 110 can be perpendicular to the extension direction of the first welding area 101. The second main gate electrode 120 can also be in a strip shape, and the extension direction of the second main gate electrode 120 can also be perpendicular to the extension direction of the second welding area 102.

[0048] Reference Figure 1As shown, in some examples of this embodiment, the first main gate electrode 110 can be arranged in parallel with the second main gate electrode 120 .

[0049] Reference Figure 1 As shown, in some examples of this embodiment, the first main gate electrode 110 and the second main gate electrode 120 are alternately arranged. By alternately arranging the first main gate electrode 110 and the second main gate electrode 120, different photogenerated carriers are easier to separate and be led out, which can further improve the extraction efficiency of photogenerated carriers.

[0050] Further, refer to Figure 1 As shown, in some examples of this embodiment, the spacing between the first main gate electrode 110 and two adjacent second main gate electrodes 120 can be equal, and the spacing between the second main gate electrode 120 and two adjacent first main gate electrodes 110 can also be equal.

[0051] It is understandable that Figure 1 In the solar cell 10 shown, the first welding area 101 is arranged above the second welding area 102, but the solar cell 10 can be turned over to change the orientation of the components therein, for example, after turning over 180 degrees, the second welding area 102 can be located above the first welding area 101, but this still does not exceed the above. Figure 1 The scope of the solar cell 10 is shown.

[0052] In traditional technology, in order to prevent the welding strip from short-circuiting the fine grid electrode, it is usually necessary to set an insulating glue on the fine grid electrode, which also leads to a significant increase in the material cost of solar cells. In addition, the insulating glue is prone to deformation during the welding and lamination processes, which may cause insulation failure in severe cases, resulting in poor quality of solar cells. Figure 1 The solar cell 10 can avoid the fine grid electrode to set the first welding area 101 and the second welding area 102, and can also effectively solve the problem and improve the quality of the solar cell 10.

[0053] In addition, conventional solar cells usually require more than three soldering strips, and the thermal expansion coefficients of the soldering strips and silicon are significantly different, which causes the entire cell to warp during the welding process. The present invention only requires two soldering strips that are respectively connected to the first main grid electrode 110 and the second main grid electrode 120, which not only saves soldering strip materials, but also improves the warping problem in conventional technologies.

[0054] In the actual production process, it is usually necessary to connect multiple solar cells 10 into a solar cell string through a welding ribbon. The present disclosure also provides a solar cell string, which may include a connecting welding ribbon 200 and multiple solar cells 10 as in the above embodiment, and the connecting welding ribbon 200 is connected to two adjacent solar cells 10. It can be understood that the first welding area 101 and the second welding area 102 can be provided for the connecting welding ribbon 200, and the connecting welding ribbon 200 provided in the first welding area 101 and the second welding area 102 can be respectively welded to the first main grid electrode 110 and the second main grid electrode 120.

[0055] Figure 2 is a schematic diagram of the structure of a solar cell string, referring to Figure 2 As shown, in this embodiment, a plurality of solar cells 10 are arranged in parallel in sequence, a portion of the connecting welding ribbon 200 is located on the first welding area 101 of one of the solar cells 10 and welded to the first main grid electrode 110 in the solar cell 10, and a portion of the connecting welding ribbon 200 is located on the second welding area 102 of another solar cell 10 and welded to the second main grid electrode 120 in the solar cell 10. By welding the connecting welding ribbon 200 to the first main grid electrode 110 of one solar cell 10 and the second main grid electrode 120 of another solar cell 10, the adjacent solar cells 10 can be connected in series, thereby improving the output voltage of the solar cell string.

[0056] Further, for ease of explanation, Figure 2 Three solar cells 10 are shown, namely a first cell 11, a second cell 12 and a third cell 13. The first cell 11, the second cell 12 and the third cell 13 are arranged in parallel in sequence.

[0057] Reference Figure 2 As shown, in some examples of this embodiment, the first welding area 101 and the second welding area 102 can both be in the shape of long strips, and the extension direction of the first welding area 101 is parallel to the extension direction of the second welding area 102. For example, the first welding area 101 and the second welding area 102 can be connected along the extension direction of the connecting welding strip 200 (i.e., Figure 2 The plurality of solar cells 10 may be arranged in parallel in the extending direction of the connecting ribbon 200. For example, the first cell 11, the second cell 12 and the third cell 13 may be arranged in parallel in the extending direction of the connecting ribbon 200. This can make the arrangement of the plurality of solar cells 10 more regular and facilitate the arrangement of the connecting ribbon 200 between two adjacent solar cells 10.

[0058] Further, refer to Figure 2As shown, in some examples of this embodiment, the solar cell 10 includes a first side 103 and a second side 104 that are arranged opposite to each other, the first welding area 101 is closer to the first side 103, the second welding area 102 is closer to the second side 104, and, in two adjacent solar cells 10, the first side 103 of one solar cell 10 is adjacent to the second side 104 of the other solar cell 10. Wherein, "adjacent" means that the first side 103 and the second side 104 are adjacent in the side-by-side direction of the solar cells 10, so that in two adjacent solar cells 10, the first welding area 101 on one solar cell 10 is closer to the second welding area 102 on the other solar cell 10, thereby reducing the distance between the first welding area 101 and the second welding area 102 as much as possible, thereby reducing the length of the required connecting welding strip 200, and saving materials.

[0059] For example, according to Figure 2 In the orientation shown, in the first battery 11 and the third battery 13, the first side 103 is located above the second side 104, and in the second battery 12, the second side 104 is located above the first side 103. Then the second side 104 of the second battery 12 is adjacent to the first side 103 of the first battery 11 and the first side 103 of the third battery 13, respectively, and the first side 103 of the second battery 12 is adjacent to the second side 104 of the first battery 11 and the second side 104 of the third battery 13, respectively. The first main grid electrode 110 of the first battery 11 and the second main grid electrode 120 of the second battery 12 can be connected by a connecting welding strip 200, and the first main grid electrode 110 of the second battery 12 and the second main grid electrode 120 of the third battery 13 can be connected by another connecting welding strip 200.

[0060] It can be understood that among the plurality of solar cells 10 arranged in parallel, there are two solar cells 10 located at the outermost sides, and the two solar cells 10 respectively have a first main grid electrode 110 and a second main grid electrode 120 that are not connected to the connecting ribbon 200 .

[0061] Reference Figure 2 As shown, in some examples of this embodiment, the solar cell string may also include a first end welding strip 210 and a second end welding strip 220, the first end welding strip 210 and the second end welding strip 220 may be respectively connected to the two outermost solar cells 10, and the first end welding strip 210 is welded to the first main grid electrode 110 in one of the solar cells 10, and the second end welding strip 220 is welded to the second main grid electrode 120 in the other solar cell 10.

[0062] For example, in Figure 2In the embodiment, the second main grid electrode 120 of the first battery 11 can be welded to the first end welding strip 210, and the first main grid electrode 110 of the second battery 12 can be welded to the second end welding strip 220. The first end welding strip 210 and the second end welding strip 220 can lead the two poles of the solar cell 10 to the external circuit and supply power. It can be understood that in other embodiments, the positions of the first end welding strip 210 and the second end welding strip 220 can also be interchanged.

[0063] Furthermore, the present disclosure also provides a photovoltaic module. Figure 3 This is a schematic diagram of the structure of a photovoltaic module. Figure 3 As shown, the photovoltaic assembly may include a bus bar 300 and a plurality of Figure 2 In the solar cell string shown in FIG. 1 , multiple solar cell strings can be electrically connected via a bus bar 300 .

[0064] Furthermore, multiple solar cell strings can be connected in parallel or in series via the bus bar 300. In this embodiment, multiple solar cell strings can be connected in parallel via the bus bar 300. Figure 3 As shown, the two first end welding ribbons 210 in two adjacent solar cell strings can be electrically connected through one bus bar 300, and the two second end welding ribbons 220 can be electrically connected through another bus bar 300, thereby achieving parallel connection between the two adjacent solar cell strings.

[0065] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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.

[0066] The above embodiments only express several implementation methods of the utility model, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A solar cell, characterized in that: Comprising a first main grid electrode (110) and a second main grid electrode (120), the first main grid electrode (110) and the second main grid electrode (120) are both arranged on the back side of the solar cell (10), and the back side of the solar cell (10) has a first welding area (101) and a second welding area (102) arranged at intervals; One end of the first main gate electrode (110) is located in the first welding area (101), and the other end of the first main gate electrode (110) is spaced apart from the second welding area (102); one end of the second main gate electrode (120) is spaced apart from the first welding area (101), and the other end of the second main gate electrode (120) is located in the second welding area (102).

2. The solar cell according to claim 1, characterized in that: The first main gate electrode (110) comprises a first welding portion (112) located in the first welding area (101) and a first electrode portion (111) located outside the first welding area (101), the first electrode portion (111) being located between the first welding area (101) and the second welding area (102); and / or, The second main gate electrode (120) comprises a second welding portion (122) located in the second welding area (102) and a second electrode portion (121) located outside the second welding area (102); the second electrode portion (121) is located between the first welding area (101) and the second welding area (102).

3. The solar cell according to claim 2, characterized in that: It also comprises a plurality of first fine gate electrodes (131), wherein the first fine gate electrodes (131) are connected to the first electrode portion (111), and an extension direction of the first fine gate electrodes (131) intersects with an extension direction of the first electrode portion (111); and / or, It also comprises a plurality of second fine gate electrodes (132), wherein the second fine gate electrodes (132) are connected to the second electrode portion (121), and the extension direction of the second fine gate electrodes (132) intersects with the extension direction of the second electrode portion (121).

4. The solar cell according to any one of claims 1 to 3, characterized in that: The first welding area (101) and the second welding area (102) are both in the shape of long strips, and the extension direction of the first welding area (101) is parallel to the extension direction of the second welding area (102); There are a plurality of first main gate electrodes (110), and the plurality of first main gate electrodes (110) are arranged in parallel along the extension direction of the first welding area (101); there are a plurality of second main gate electrodes (120), and the plurality of second main gate electrodes (120) are arranged in parallel along the extension direction of the first welding area (101).

5. A solar cell string, characterized in that: It comprises a connecting welding strip (200) and a plurality of solar cells (10) according to any one of claims 1 to 4, wherein two adjacent solar cells (10) are respectively welded via the connecting welding strip (200).

6. The solar cell string according to claim 5, characterized in that: A plurality of solar cells (10) are arranged in parallel in sequence, part of the connecting welding strips (200) are located on the first welding area (101) of one of the solar cells (10) and are welded to the first main grid electrode (110) in the solar cell (10), and part of the connecting welding strips (200) are located on the second welding area (102) of another solar cell (10) and are welded to the second main grid electrode (120) in the solar cell (10).

7. The solar cell string according to claim 6, characterized in that: The solar cell (10) comprises a first side (103) and a second side (104) arranged opposite to each other, the first welding area (101) being closer to the first side (103), and the second welding area (102) being closer to the second side (104); In two adjacent solar cells (10), the first side edge (103) of one of the solar cells (10) is adjacent to the second side edge (104) of the other solar cell (10).

8. The solar cell string according to any one of claims 6 to 7, characterized in that: The first welding area (101) and the second welding area (102) are both in the shape of long strips, and the first welding area (101) and the second welding area (102) are both extended along the extension direction of the connecting welding strip (200), and the plurality of solar cells (10) are arranged in sequence in parallel in the extension direction of the connecting welding strip (200).

9. The solar cell string according to any one of claims 6 to 7, characterized in that: The solar cell string further comprises a first end welding strip (210) and a second end welding strip (220), wherein the first end welding strip (210) and the second end welding strip (220) are respectively welded to the two solar cells (10) located at the outermost sides, and the first end welding strip (210) is welded to the first main grid electrode (110) in one of the solar cells (10), and the second end welding strip (220) is welded to the second main grid electrode (120) in another of the solar cells (10).

10. A photovoltaic module, characterized in that: It comprises a bus bar (300) and a solar cell string as claimed in any one of claims 5 to 9, wherein a plurality of solar cell strings are electrically connected via the bus bar (300).

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