Photovoltaic cell piece and string group thereof

Abstract

The utility model relates to the photovoltaic field, and specifically discloses a photovoltaic cell and a string group thereof. The utility model relates to a photovoltaic cell. The photovoltaic cell is provided with a negative grid line and a positive grid line, the cathode grid line is at least partially connected with cathode interconnection strips, the cathode interconnection strips are gathered on a cathode welding strip, and the cathode welding strip is at least connected with a first welding strip; the positive grid lines are at least partially connected with positive interconnection strips, the positive interconnection strips are gathered on a positive welding strip, and the positive welding strip is at least connected with a second welding strip. According to the invention, the positions of the cells and the distance between the cells are easy to change.

Description

Technical Field

[0001] The present application relates to the field of photovoltaics, and in particular to a photovoltaic cell and a string thereof. Background Art

[0002] Currently, solar cells are mostly connected via interconnecting bars welded to the main grid. With the development of multi-busbar technology, the number of interconnecting bars between solar cells has increased. When applied to photovoltaic curtain walls, the spacing between the crystalline silicon cells of photovoltaic modules in the curtain wall is relatively large due to the building's light transmittance requirements. Using multiple interconnecting bars to connect multi-busbar cells can cause obstruction and affect indoor lighting. Furthermore, to meet the requirements of curtain wall pattern design and other irregular photovoltaic product designs, the solar cell placement method needs to be more flexible. However, the method of connecting solar cells using multiple interconnecting bars does not easily change the cell position and spacing. Utility Model Content

[0003] The present application aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present application is to provide a photovoltaic cell and a string thereof.

[0004] In a first aspect of the present application, a photovoltaic cell is provided, wherein the photovoltaic cell is provided with a negative pole grid line and a positive pole grid line;

[0005] The negative electrode grid lines are at least partially connected to negative electrode interconnecting bars, the negative electrode interconnecting bars are gathered on a negative electrode welding strip, and the negative electrode welding strip is connected to at least one first welding strip;

[0006] The positive electrode grid lines are at least partially connected to positive electrode interconnection bars, the positive electrode interconnection bars are gathered on a positive electrode welding strip, and at least one second welding strip is connected to the positive electrode welding strip.

[0007] In a first aspect, the present application combines the negative interconnecting strips on the negative electrode welding ribbon and the positive interconnecting strips on the positive electrode welding ribbon, then provides a first welding ribbon for connection on the negative electrode welding ribbon and a second welding ribbon for connection on the positive electrode welding ribbon. Adjacent photovoltaic cells are connected by the first and second welding ribbons, replacing the solution in the related art where photovoltaic cells are connected by interconnecting strips. Therefore, the welding workload for connecting adjacent photovoltaic cells is reduced. When applied to photovoltaic curtain walls, this can reduce light obstruction in the building interior and improve the aesthetics. Furthermore, the shape and size of the negative electrode welding ribbon, the positive electrode welding ribbon, the first welding ribbon, and the second welding ribbon can be flexibly configured, making it easy to change the position of the cells and the distance between the cells.

[0008] According to an embodiment of the present application, in a photovoltaic cell, the angle between the direction of the negative electrode welding ribbon and the direction of the second welding ribbon is non-zero. As a result, the second welding ribbon can extend in any direction outside the negative electrode welding ribbon, facilitating connection.

[0009] According to an embodiment of the present application, in a photovoltaic cell, the angle between the direction of the positive electrode welding ribbon and the direction of the second welding ribbon is non-zero. As a result, the second welding ribbon can extend in any direction outside the positive electrode welding ribbon, facilitating connection.

[0010] According to an embodiment of the present application, in a photovoltaic cell, the negative electrode welding ribbon and the positive electrode welding ribbon are arranged in parallel, thereby being used to connect interconnection strips extending to the same length.

[0011] According to an embodiment of the present application, in the photovoltaic cell, the angle between the direction of the negative electrode welding strip and the direction of the second welding strip is 90°.

[0012] According to an embodiment of the present application, the angle between the direction of the positive electrode welding strip and the direction of the second welding strip is 90°.

[0013] According to an embodiment of the present application, in a photovoltaic cell, the cross-sections of the negative electrode welding ribbon, the positive electrode welding ribbon, the first welding ribbon, and the second welding ribbon are independently arc-shaped or strip-shaped. This satisfies the requirement for connecting interconnecting ribbons of different lengths and facilitates the formation of patterns of various shapes.

[0014] According to an embodiment of the present application, in the photovoltaic cell, the cross-sectional areas of the negative electrode welding strip, the positive electrode welding strip, the first welding strip and the second welding strip are independently 0.5 mm 2 ~3mm 2 Therefore, the large cross-sectional area of ​​the soldering ribbon is suitable for long-distance connection and reduces circuit loss.

[0015] According to an embodiment of the present application, the photovoltaic cell satisfies at least one of the following characteristics: (a) the cross-section of the negative electrode welding ribbon is rectangular, the thickness of the negative electrode welding ribbon is 0.25mm to 0.5mm, and / or the width of the negative electrode welding ribbon is 2mm to 5mm; (b) the cross-section of the positive electrode welding ribbon is rectangular, the thickness of the positive electrode welding ribbon is 0.25mm to 0.5mm, and / or the width of the positive electrode welding ribbon is 2mm to 5mm; (c) the cross-section of the first welding ribbon is rectangular, the thickness of the first welding ribbon is 0.25mm to 0.5mm, and / or the width of the first welding ribbon is 2mm to 5mm; (d) the cross-section of the second welding ribbon is rectangular, the thickness of the second welding ribbon is 0.25mm to 0.5mm, and / or the width of the second welding ribbon is 2mm to 5mm. Thus, low resistance and easy welding are achieved.

[0016] According to an embodiment of the present application, in a photovoltaic cell, the negative electrode soldering ribbon, the positive electrode soldering ribbon, the first soldering ribbon, and the second soldering ribbon are independently tin-lead soldering ribbon, indium-tin soldering ribbon, tin-bismuth soldering ribbon, tin-lead-silver soldering ribbon, or tin soldering ribbon, thereby having good electrical conductivity and welding performance.

[0017] According to an embodiment of the present application, the photovoltaic cell further includes a bypass diode, the cathode of which is connected to the negative electrode welding ribbon, and the anode of which is connected to the positive electrode welding ribbon. This allows each cell to be connected to a separate bypass diode, so that if one cell fails, the operation of other cells will not be affected.

[0018] A second aspect of the present application provides a photovoltaic cell string comprising the photovoltaic cell described in the first aspect. This significantly reduces the number of interconnecting strips between the photovoltaic cell strings, allowing for more diverse cell patterns. This photovoltaic cell string can be used in fields such as photovoltaic curtain walls and photovoltaic lighting, offering advantages such as high light transmittance, low circuit loss, and diverse patterns.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 It is a schematic diagram of the structure of a photovoltaic cell;

[0022] Figure 2 It is a schematic diagram of the structure of the interconnection of photovoltaic cells in the related art;

[0023] Figure 3 It is another structural diagram of the interconnection of photovoltaic cells in the related art;

[0024] Figure 4 is a schematic structural diagram of a photovoltaic cell in some embodiments;

[0025] Figure 5 is a schematic diagram of the interconnection structure of photovoltaic cells in some embodiments;

[0026] Figure 6 is a schematic diagram of the structure of interconnected photovoltaic cells in other embodiments;

[0027] Figure 7 is a schematic diagram of the structure of interconnected photovoltaic cells in some other embodiments;

[0028] Figure 8It is a schematic diagram of the structure of interconnected photovoltaic cells in some further embodiments.

[0029] Reference numerals: 101 - photovoltaic cell; 102 - positive electrode grid line; 103 - negative electrode interconnection bar; 104 - positive electrode interconnection bar; 201 - negative electrode welding strip; 202 - positive electrode welding strip; 203 - first welding strip; 204 - second welding strip; 300 - bypass diode. DETAILED DESCRIPTION

[0030] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0031] At present, the structural diagram of photovoltaic cells can be seen in Figure 1 The photovoltaic cell 101 includes a positive grid line 102 and a negative grid line. The positive grid line 102 of the photovoltaic cell 101 is connected to a positive interconnection bar 104, and the negative grid line of the photovoltaic cell 101 is connected to a negative interconnection bar 103. Figure 2 ,from Figure 2 It can be seen that the two photovoltaic cells are interconnected by each interconnection bar. Specifically, the negative interconnection bar 103 of the photovoltaic cell is connected to the positive interconnection bar 104 of the other photovoltaic cell. Figure 3 ,from Figure 3 It can be seen that at the same height, two adjacent photovoltaic cells are interconnected by each interconnection bar. Specifically, the negative interconnection bar 103 of a photovoltaic cell is connected to the positive interconnection bar 104 of another photovoltaic cell, while at different heights, they are connected by welding strips.

[0032] As can be seen from the above, the number of interconnecting strips between cells is currently high. Furthermore, when the spacing between crystalline silicon cells in curtain wall assemblies is large, using multiple interconnecting strips to connect multiple busbar cells can cause obstruction and affect indoor lighting. The interconnection methods used in related technologies for photovoltaic curtain walls require multiple interconnecting strips to connect the cells, making it difficult to change the position of the cells or the distance between them.

[0033] Accordingly, in a first aspect of the present application, a photovoltaic cell is provided, wherein the photovoltaic cell is provided with a negative pole grid line and a positive pole grid line;

[0034] The negative electrode grid lines are at least partially connected to negative electrode interconnecting bars, all of the negative electrode interconnecting bars are gathered on a negative electrode welding strip, and at least one first welding strip is connected to the negative electrode welding strip;

[0035] The positive electrode grid lines are at least partially connected to positive electrode interconnection bars, and all the positive electrode interconnection bars are gathered on a positive electrode welding strip, and at least one second welding strip is connected to the positive electrode welding strip.

[0036] Thus, in the first aspect of the present application, all negative interconnecting strips are gathered on the negative electrode welding strip, and all positive interconnecting strips are gathered on the positive electrode welding strip. A first welding strip is then provided on the negative electrode welding strip, and a second welding strip is provided on the positive electrode welding strip. Adjacent photovoltaic cells are connected by the first welding strip and the second welding strip, thereby replacing the scheme in the related art where photovoltaic cells are connected by each interconnecting strip. Due to the simplification of the first welding strip and the second welding strip, the welding workload for connecting adjacent photovoltaic cells is reduced. When applied to photovoltaic curtain walls, it can reduce light obstruction in the building interior and improve the aesthetics. In addition, the shape and size of the negative electrode welding strip, the positive electrode welding strip, the first welding strip, and the second welding strip can be flexibly set, making it easy to change the position of the cells and the distance between the cells.

[0037] It is worth noting that the above at least partially includes all and part, and those skilled in the art can arrange according to demand.For example, each positive electrode grid line can be connected to a positive interconnection bar respectively, half of the positive electrode grid lines are connected with the positive interconnection bar, or 3 / 4 of the positive electrode grid lines are connected with the positive interconnection bar.The same is true for the setting of the negative electrode grid line and the negative electrode interconnection bar.In addition, in this application, the interconnection bar refers to the welding rod directly connected to the grid line, and the welding strip (positive electrode welding strip, negative electrode welding strip, first welding strip, second welding strip) refers to the welding rod / strip that is not directly connected to the grid line.

[0038] Furthermore, the photovoltaic cell may include a polycrystalline silicon photovoltaic cell, a monocrystalline silicon photovoltaic cell or an amorphous silicon photovoltaic cell.

[0039] As an example, see Figure 4 , Figure 4 The schematic diagram of the structure of a photovoltaic cell in some embodiments includes a photovoltaic cell 101. Each positive grid line 102 at the top of the photovoltaic cell 101 is connected to a positive interconnection bar 104. All positive interconnection bars 104 converge on a vertical positive welding ribbon 202, on which a transverse second welding ribbon 204 is provided. Similarly, each negative grid line at the bottom of the photovoltaic cell 101 is connected to a negative interconnection bar 103. All negative interconnection bars 103 converge on a transverse negative welding ribbon 201, on which a transverse first welding ribbon 203 is provided. As a result, when connecting multiple such photovoltaic cells, the connection is made by relying on the first welding ribbon 203 and the second welding ribbon 204, greatly reducing the number of interconnection bars.

[0040] In this application, the sizes and shapes of the positive electrode ribbon 202, negative electrode ribbon 201, first ribbon 203, and second ribbon 204 are relatively flexible, allowing for the formation of a variety of patterns. In some embodiments, the angle between the direction of the negative electrode ribbon 201 and the direction of the first ribbon 203 is non-zero; the angle between the direction of the positive electrode ribbon 202 and the direction of the second ribbon 204 is also non-zero. This allows the positive electrode ribbon 202 and the negative electrode ribbon 201 to extend outward, facilitating connection, thanks to the first and second ribbons 203, 204.

[0041] In some embodiments, the negative electrode welding ribbon 201 and the positive electrode welding ribbon 202 are arranged in parallel, and the angle between the direction of the negative electrode welding ribbon 201 and the direction of the first welding ribbon 203 is 90 degrees; the angle between the direction of the positive electrode welding ribbon 202 and the direction of the second welding ribbon 204 is also 90 degrees. In this way, a relatively regular connection of crystalline silicon photovoltaic cells is achieved. As an example, Figure 5 This is a schematic diagram of the interconnection structure of some photovoltaic cells. It can be seen that the positive electrode welding ribbon 202 and the negative electrode welding ribbon 201 are arranged in parallel, the first welding ribbon 203 is perpendicular to the negative electrode welding ribbon 201, and the second welding ribbon 204 is perpendicular to the positive electrode welding ribbon 202. Adjacent photovoltaic cells are connected by the positive electrode welding ribbon 202 and the negative electrode welding ribbon 201. As another example, see Figure 7 , the positive electrode welding strip 202 and the negative electrode welding strip 201 are also arranged in parallel, the first welding strip 203 is perpendicular to the negative electrode welding strip 201, and the second welding strip 204 is perpendicular to the positive electrode welding strip 202. Thus, a different interconnection structure is obtained.

[0042] In some embodiments, the cross-sections of the positive electrode welding strip 202, the negative electrode welding strip 201, the first welding strip 203, and the second welding strip 204 are independently arc-shaped or strip-shaped. Thus, different patterns are obtained. As an example, see Figure 8 In this structure, the positive electrode welding strip 202 and the negative electrode welding strip 201 are both arc-shaped, the first welding strip 203 and the second welding strip 204 are long strips, and adjacent photovoltaic cells are connected by the first welding strip 203 and the second welding strip 204, and the resulting interconnection structure is flower-shaped.

[0043] It can be understood that the resistance of a conductor is inversely proportional to its cross-sectional area. Increasing the cross-sectional area can reduce the resistance. Based on this, the cross-sectional areas of the negative electrode welding strip 201, the positive electrode welding strip 202, the first welding strip 203, and the second welding strip 204 can be appropriately increased to optimize the circuit loss.

[0044] In some embodiments, in the photovoltaic cell, the cross-sectional areas of the negative electrode welding strip 201, the positive electrode welding strip 202, the first welding strip 203 and the second welding strip 204 are independently 0.5 mm 2 ~3mm 2, for example, 0.5mm 2 , 1mm 2 , 2mm 2 , 3mm 2 Thus, the large cross-sectional area of ​​the welding strip is suitable for long-distance connection and reduces circuit loss. The cross-sectional area of ​​the negative electrode welding strip 201, the positive electrode welding strip 202, the first welding strip 203 and the second welding strip 204 are independently 0.5mm 2 ~3mm 2 , which means that the cross-sectional area of ​​the negative electrode welding strip 201 is 0.5mm 2 ~3mm 2 The cross-sectional area of ​​the positive electrode welding strip 202 is 0.5 mm 2 ~3mm 2 The cross-sectional area of ​​the first welding strip 203 is 0.5 mm 2 ~3mm 2 The cross-sectional area of ​​the second welding strip 204 is 0.5 mm 2 ~3mm 2 Any value in , the four do not affect each other.

[0045] In some embodiments, the cross-section of the negative electrode welding ribbon 201 is rectangular, and the thickness of the negative electrode welding ribbon 201 is 0.25 mm to 0.5 mm, for example, 0.25 mm, 0.35 mm, 0.4 mm, 0.5 mm, etc.; further, the width of the negative electrode welding ribbon 201 is 2 mm to 5 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, etc., respectively. Thus, low resistance and easy welding are achieved.

[0046] In other embodiments, the cross-section of the positive electrode welding ribbon 202 is rectangular, and the thickness of the positive electrode welding ribbon 202 is 0.25 mm to 0.5 mm, for example, 0.25 mm, 0.35 mm, 0.4 mm, 0.5 mm, etc.; further, the width of the positive electrode welding ribbon is 2 mm to 5 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, etc., respectively. Thus, low resistance and easy welding are achieved.

[0047] In some other embodiments, the cross-section of the first welding ribbon 203 is rectangular, and the thickness of the first welding ribbon 203 is 0.25 mm to 0.5 mm, for example, 0.25 mm, 0.35 mm, 0.4 mm, 0.5 mm, etc.; further, the width of the first welding ribbon 203 is 2 mm to 5 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, etc., thereby achieving low resistance and easy welding.

[0048] In some other embodiments, the cross-section of the second welding ribbon 204 is rectangular, and the thickness of the second welding ribbon 204 is 0.25 mm to 0.5 mm, for example, 0.25 mm, 0.35 mm, 0.4 mm, 0.5 mm, etc.; further, the width of the second welding ribbon 204 is 2 mm to 5 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm, etc., thereby achieving low resistance and easy welding.

[0049] For example, taking a 16BB cell as an example, the conventional connection method uses a 0.25mm diameter solder strip with a cross-sectional area of ​​0.785mm. 2 In this application, the negative electrode welding strip 201, the positive electrode welding strip 202, the first welding strip 203 and the second welding strip 204 are all long strips with a rectangular cross section, a width of 3mm and a thickness of 0.35mm, corresponding to a cross-sectional area of ​​1.05mm. 2 As a result, the cross-sectional area is increased, and when the distance between the battery cells is increased, the circuit resistance of the present application is smaller and the circuit loss is reduced.

[0050] In this field, soldering ribbons typically use copper substrates with coatings, including tin-lead, indium-tin, tin-bismuth, tin-lead-silver, and tin. In some embodiments, the negative electrode soldering ribbon 201, the positive electrode soldering ribbon 202, the first soldering ribbon 203, and the second soldering ribbon 204 are each independently tin-lead, indium-tin, tin-bismuth, tin-lead-silver, or tin. This provides excellent electrical conductivity and soldering performance.

[0051] In some embodiments, the photovoltaic cell further includes a bypass diode 300, which is connected in parallel with the photovoltaic cell. Specifically, the cathode of the bypass diode 300 is connected to the negative electrode welding ribbon 201, and the anode of the bypass diode 300 is connected to the positive electrode welding ribbon 202. Thus, through the design of the negative electrode welding ribbon 201 and the positive electrode welding ribbon 202, the bypass diode 300 can be connected to a single cell. When the cell fails due to problems such as obstruction or hidden cracks, the bypass diode 300 is turned on without affecting the use of other cells in the circuit, thereby maximizing the power of the module. Figure 6 It can be seen that each photovoltaic cell can be connected to a bypass diode 300. If the photovoltaic cell fails, it will not affect the operation of other photovoltaic cells.

[0052] The second aspect of the present application provides a photovoltaic cell string group, including the photovoltaic cell group described in the first aspect. As a result, the number of interconnecting strips between the photovoltaic cell strings is greatly reduced, and the patterns formed by the cells are more diverse. It can be applied to fields such as photovoltaic curtain walls and photovoltaic lamps, and has the advantages of high light transmittance, low circuit loss, and diversified patterns. For example, when applied to photovoltaic curtain walls, due to the simplification of the first welding strip and the second welding strip, the welding workload of connecting adjacent photovoltaic cells is reduced, and the slippage and interlacing of the interconnecting strips during lamination is reduced, which can reduce the light blocking in the building interior and improve the aesthetics.

[0053] The photovoltaic cell string of the second aspect is formed by welding the photovoltaic cells of the first aspect to each other, for example, Figures 5 to 8 As can be seen from the figure, the photovoltaic cell strings shown in the figure can be formed in various patterns, including rectangular, irregular, and flower-shaped. Furthermore, the photovoltaic cell string of the second aspect can also be formed by welding the photovoltaic cell of the first aspect with other photovoltaic cells. Any cell string that includes the photovoltaic cell of the first aspect falls within the scope of the photovoltaic cell string of the second aspect.

[0054] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "an example" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0055] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A photovoltaic cell, characterized in that: The photovoltaic cell sheet is provided with a negative pole grid line and a positive pole grid line; The negative electrode grid line is at least partially connected to a negative electrode interconnection bar, the negative electrode interconnection bar is gathered on a negative electrode welding strip, and at least one first welding strip is connected to the negative electrode welding strip; The positive electrode grid lines are at least partially connected to positive electrode interconnection bars, the positive electrode interconnection bars are gathered on positive electrode welding strips, and at least one second welding strip is connected to the positive electrode welding strips.

2. The photovoltaic cell according to claim 1, characterized in that: The angle between the direction in which the negative electrode welding strip is located and the direction in which the first welding strip is located is a non-zero angle; or / and The angle between the direction in which the positive electrode welding strip is located and the direction in which the second welding strip is located is a non-zero angle.

3. The photovoltaic cell according to claim 1, characterized in that: The negative electrode welding strip and the positive electrode welding strip are arranged in parallel.

4. The photovoltaic cell according to claim 1 or 2, characterized in that: The angle between the direction of the negative electrode welding strip and the direction of the first welding strip is 90°; or / and The angle between the direction of the positive electrode welding strip and the direction of the second welding strip is 90°.

5. The photovoltaic cell according to claim 1 or 2, characterized in that: The cross-sections of the negative electrode welding strip, the positive electrode welding strip, the first welding strip and the second welding strip are independently arc-shaped or strip-shaped.

6. The photovoltaic cell according to claim 1, characterized in that: The cross-sectional areas of the negative electrode welding strip, the positive electrode welding strip, the first welding strip and the second welding strip are independently 0.5 mm 2 ~3mm 2 .

7. The photovoltaic cell according to claim 1 or 6, characterized in that: The photovoltaic cell satisfies at least one of the following characteristics: (a) the cross-section of the negative electrode welding strip is rectangular, the thickness of the negative electrode welding strip is 0.25 mm to 0.5 mm, and / or the width of the negative electrode welding strip is 2 mm to 5 mm; (b) the cross-section of the positive electrode welding strip is rectangular, the thickness of the positive electrode welding strip is 0.25 mm to 0.5 mm, and / or the width of the positive electrode welding strip is 2 mm to 5 mm; (c) the cross-section of the first welding strip is rectangular, the thickness of the first welding strip is 0.25 mm to 0.5 mm, and / or the width of the first welding strip is 2 mm to 5 mm; (d) The cross section of the second welding strip is rectangular, the thickness of the second welding strip is 0.25 mm to 0.5 mm, and / or the width of the second welding strip is 2 mm to 5 mm.

8. The photovoltaic cell according to claim 1, characterized in that: The negative electrode welding strip, the positive electrode welding strip, the first welding strip and the second welding strip are independently tin-lead welding strips, indium-tin welding strips, tin-bismuth welding strips, tin-lead-silver welding strips or tin welding strips.

9. The photovoltaic cell according to claim 1, characterized in that: Also includes: A bypass diode, wherein the cathode of the bypass diode is connected to the cathode welding strip, and the anode of the bypass diode is connected to the anode welding strip.

10. The photovoltaic cell according to claim 1, characterized in that: The photovoltaic cell sheet includes a polycrystalline silicon photovoltaic cell sheet, a monocrystalline silicon photovoltaic cell sheet or an amorphous silicon photovoltaic cell sheet.

11. A photovoltaic cell string group, characterized in that: A photovoltaic cell comprising the photovoltaic cell according to any one of claims 1 to 10.

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