Photovoltaic cell string structure and photovoltaic module
By setting conductive grooves in the photovoltaic cell string and folding them to the back of the cell to connect with the interconnecting strip, the problem of cell damage when the interconnecting strip is folded is solved, achieving consistency in power generation efficiency between cells and improving the reliability of the module.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JA SOLAR TECH YANGZHOU
- Filing Date
- 2025-04-28
- Publication Date
- 2026-04-24
AI Technical Summary
In existing photovoltaic modules, the interconnect strip is easily damaged when it is folded, resulting in microcracks in the cells and uneven illumination, which affects current mismatch.
Grooves are provided in the photovoltaic cell string for folding conductive components, and the conductive components are folded to the back of the cell and connected to the interconnecting strip. This limits the difference in photoelectric conversion efficiency between different cells and ensures the consistency of power generation efficiency between cells.
This effectively avoids the squeezing damage to the solar cells caused by conductive components, ensures the consistency of power generation efficiency among different solar cells in the solar cell string, and improves the reliability and power generation efficiency of photovoltaic modules.
Smart Images
Figure CN224165052U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic module manufacturing technology, and in particular to a photovoltaic cell string structure and a photovoltaic module. Background Technology
[0002] For existing photovoltaic modules, in order to utilize the interconnect strips placed at both ends of the cell string to conduct current through the conductive components, and to ensure that the interconnect strips can carry a sufficient amount of current, the cross-sectional area of the interconnect strips is generally 1 mm². 2 The above is an overview. With the trend towards high-density packaging of photovoltaic (PV) modules, it is necessary to maximize the proportion of cell area within the module. Current improvement methods involve folding the interconnect strips from both ends of the cell string to the back of the string to reduce the size of the PV module and improve its power generation efficiency. However, this method can damage the cells during the folding process (e.g., causing microcracks), and the interconnect strips' shading of the cells leads to uneven light reception, resulting in current mismatch within the PV module. Utility Model Content
[0003] In view of this, this utility model embodiment provides a photovoltaic cell string structure and a photovoltaic module. A groove is provided on the edge of the first cell away from the second cell for folding the conductive component, which can effectively avoid the conductive component squeezing the cell during folding and avoid the problem of cell cracking. At the same time, since the groove causes a partial loss of the first cell, and there are interconnecting strips on the back of both the first and third cells, the photoelectric conversion efficiency among the first, second, and third cells connected in series in the cell string is limited, ensuring the consistency of power generation efficiency among different cells in the cell string.
[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:
[0005] In a first aspect, this utility model provides a photovoltaic cell string structure, comprising: one or more cell strings and multiple interconnecting strips; each cell string includes: a first cell, multiple second cells, a third cell, and multiple conductive elements for connecting the first cell, the multiple second cells, and the third cell in series; wherein, a groove corresponding to the conductive element is provided on the edge of the first cell away from the second cell, and the recess direction of the groove is consistent with the width direction of the first cell; the conductive element connected to the front electrode of the first cell is folded over to the back of the first cell through the groove and connected to the interconnecting strip located on the back of the first cell; multiple second cells are connected in series between the first cell and the third cell through the multiple conductive elements; the back electrode of the third cell is connected to the interconnecting strip located on the back of the third cell through the conductive element; the photoelectric conversion efficiency of the first cell is greater than that of the third cell, and the photoelectric conversion efficiency of the third cell is greater than that of the second cell.
[0006] Optionally, the difference between the photoelectric conversion efficiency of the first solar cell and the photoelectric conversion efficiency of the third solar cell is greater than 0 and less than 0.1%; and / or, the difference between the photoelectric conversion efficiency of the third solar cell and the photoelectric conversion efficiency of the second solar cell is greater than 0 and less than 0.1%.
[0007] Optionally, the groove depth is 2mm to 5mm; and / or, the width of the groove matches the width of the conductive element; and / or, the shape of the groove is at least one of arc or polygon.
[0008] Optionally, the thickness of the region in the interconnect strip connected to the conductive element is less than the thickness of other regions in the interconnect strip.
[0009] Optionally, an insulating pad is also provided between the interconnecting strip and the first battery cell.
[0010] Optionally, the portion of the conductive element connected to the front electrode of the first battery cell that is folded to the back of the first battery cell is located between the insulating pad and the interconnecting strip.
[0011] Optionally, for the structure of multiple battery strings, the interconnecting band includes: an edge interconnecting band located at the edge of the multiple battery strings and an intermediate interconnecting band located between two battery strings arranged side by side; the cross-sectional area of the region covering the first battery cell in the intermediate interconnecting band is equal to the cross-sectional area of the region covering the third battery cell in the intermediate interconnecting band, and the thickness of the region covering the first battery cell in the intermediate interconnecting band is less than the thickness of the region covering the third battery cell in the intermediate interconnecting band.
[0012] Optionally, the thickness of the insulating pad is 0.1 mm to 0.3 mm.
[0013] Optionally, the thickness of the area in the interconnect strip connected to the conductive element is 0.05 mm to 0.3 mm; and / or, the thickness of other areas in the interconnect strip is 0.15 mm to 0.4 mm.
[0014] Secondly, this utility model provides a photovoltaic module, including: a cover plate, a back plate, an encapsulating film located between the cover plate and the back plate, and a photovoltaic cell string structure as described in any one of the above.
[0015] The technical solution of this utility model has the following beneficial effects:
[0016] A groove is provided at the edge of the first solar cell away from the second solar cell to facilitate folding of the conductive component. This effectively prevents the conductive component from squeezing the solar cell during folding, thus avoiding the problem of cell cracking. Simultaneously, because the groove causes a partial loss of the first solar cell, and because there are interconnecting strips on the back of both the first and third solar cells, the photoelectric conversion efficiency among the first, second, and third solar cells connected in series in the battery string is limited, ensuring the consistency of power generation efficiency among different solar cells in the battery string. Attached Figure Description
[0017] The accompanying drawings are provided to better understand this utility model and do not constitute an undue limitation thereof. Wherein:
[0018] Figure 1 This is a schematic diagram of the front structure of the battery string according to this utility model;
[0019] Figure 2 This is a schematic diagram of the back structure of the battery string according to this utility model;
[0020] Figure 3 It is based on Figure 1 A schematic diagram of the cross-sectional structure of the battery string corresponding to point AA in the middle;
[0021] Figure 4 It is based on Figure 1 A schematic diagram of the cross-sectional structure of the battery string corresponding to the middle BB section;
[0022] Figure 5 This is a schematic diagram of the groove provided on the first battery cell of this utility model;
[0023] Figure 6 This is a structural schematic diagram of the arrangement position of a conductive element and an interconnecting strip according to the present invention;
[0024] Figure 7This is a structural schematic diagram showing the arrangement of another conductive element and interconnecting strip according to the present invention;
[0025] Figure 8 This is a structural diagram showing the interconnection strip arrangement when multiple batteries are connected in series and parallel according to this utility model;
[0026] Figure 9 This is a schematic diagram of the front structure of a battery string in the prior art;
[0027] Figure 10 This is a schematic diagram of the back structure of a battery string in the prior art;
[0028] Figure 11 This is a schematic diagram showing the positional relationship between the cover plate, back plate, and encapsulating film according to an embodiment of the present utility model.
[0029] The attached figures are labeled as follows:
[0030] 1-Battery string; 11-First battery cell; 111-Groove; 12-Second battery cell; 13-Third battery cell; 14-Conductive component; 2-Interconnecting strip; 21-Edge interconnecting strip; 22-Intermediate interconnecting strip; 3-Insulating pad;
[0031] 100 - Cover plate; 200 - Back plate; 300 - Encapsulation film. Detailed Implementation
[0032] To facilitate and clearly describe the technical solution of this utility model, exemplary embodiments of this utility model are described below with reference to the accompanying drawings, including various details of the embodiments of this utility model to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this utility model. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.
[0033] In one embodiment of this utility model, such as Figure 1 and Figure 2As shown, this utility model provides a photovoltaic cell string structure, including: one or more cell strings 1 and multiple interconnecting strips 2; each cell string 1 includes: a first cell 11, multiple second cells 12, a third cell 13, and multiple conductive elements 14 for connecting the first cell 11, the multiple second cells 12, and the third cell 13 in series; wherein, a groove 111 corresponding to the conductive element 14 is provided on the edge of the first cell 11 away from the second cell 12, and the recess direction of the groove 111 is consistent with the width direction of the first cell 11; and the groove 111 is connected to the first cell 11. The conductive element 14 connected to the front electrode is folded over to the back of the first battery cell 11 via the groove 111 and connected to the interconnecting strip 2 located on the back of the first battery cell 11; multiple second battery cells 12 are connected in series between the first battery cell 11 and the third battery cell 13 via multiple conductive elements 14; the back electrode of the third battery cell 13 is connected to the interconnecting strip 2 located on the back of the third battery cell 13 via the conductive element 14; the photoelectric conversion efficiency of the first battery cell 11 is greater than that of the third battery cell 13, and the photoelectric conversion efficiency of the third battery cell 13 is greater than that of the second battery cell 12. Figure 1 A schematic diagram of the front structure of each battery string in this invention is shown. Figure 2 A schematic diagram of the back structure of each battery string is shown.
[0034] It should be noted that this utility model mainly targets bifacial photovoltaic modules. Compared to photovoltaic modules that only generate electricity from the front, the back side of the photovoltaic module in this utility model also affects the power generation efficiency of the cells. Therefore, after folding the interconnecting strip 2, this utility model needs to limit the photoelectric conversion efficiency among the first cell 11, the second cell 12, and the third cell 13 to ensure that the first cell 11, the second cell 12, and the third cell 13 can still guarantee the maximum current even when their back-side shading areas are different. Specifically, since the first cell 11 has a groove 111 for folding the conductive element 14, the first cell 11 has the smallest area compared to the second cell 12 and the third cell 13. Furthermore, the interconnecting strip 2 is also provided on the back side of the first cell 11, which shading part of the back side area of the first cell 11. Therefore, the photoelectric conversion efficiency of the first cell 11 needs to be guaranteed to be the highest. The third solar cell 13 has the second highest photoelectric conversion efficiency. This is because, although the third solar cell 13 does not have a recess 111 (i.e., no area loss), interconnecting strips 2 are still required on its back side to ensure that the current in the battery string 1 is discharged through the interconnecting strips 2 connected to the first solar cell 11 and the third solar cell 13 respectively, forming a complete closed-loop structure. Therefore, the back side of the third solar cell 13 also suffers from shading caused by the interconnecting strips 2. Thus, compared to the second solar cell 12, which has no shading, the third solar cell 13 has a higher photoelectric conversion efficiency, but lower than the photoelectric conversion efficiency of the first solar cell 11, which has an area loss.
[0035] For example, Figure 1 In the diagram, AA and BB indicate the folding direction of the conductive element 14, that is, folding it from the front of the battery string 1 to the back of the battery string 1. This reduces the ineffective volume occupied by the interconnecting strip 2 and does not affect the sunlight absorption efficiency of the front of the battery string 1. To clearly see the structure of the battery string 1 at the groove 111, this utility model uses... Figure 3 and Figure 4 Taking this as an example, the cross-sectional structures of battery string 1 corresponding to point AA and point BB will be explained respectively. (Comparison) Figure 3 and Figure 4 It can be seen that in the area where the groove 111 is not provided, the first battery piece 11 is the same length as the second battery piece 12 and the third battery piece 13. However, in the area where the groove 111 is provided, the length of the first battery piece 11 is shorter than the length of the second battery piece 12 and the third battery piece 13. It is evident that the first battery piece 11 has a partial missing area at its edge due to the groove 111.
[0036] For example, with Figure 5 The groove 111 provided on the first battery cell 11 will be explained in detail using an example. Figure 5 As shown, the multiple grooves 111 are spaced apart, that is, the position of each groove 111 corresponds to a conductive element 14, and is used to fold a conductive element 14. Figure 5 In this designation, H represents the groove depth of the groove 111, i.e., the depth along the recess. In one optional embodiment, the groove depth of the groove 11 is 2mm to 5mm, such as 2mm, 3mm, 4mm, 5mm, etc. To minimize the obstruction of sunlight to the front of the battery cell, the conductive component 14 is usually small in size, with a width between 0.8mm and 4mm and a thickness between 0.1mm and 0.4mm. Therefore, this invention only needs to provide sufficient folding space for the conductive component 14 to ensure that the conductive component 14 does not bulge after folding.
[0037] In order to distinguish it from existing technologies, this utility model uses... Figure 9 and Figure 10 Taking the existing battery string structure as an example, we will explain it. Figure 9 This is a schematic diagram of the front structure of each battery string in the prior art. Figure 10 This is a schematic diagram of the back structure of each battery string in the prior art. (Comparison) Figure 9 , Figure 10 and the aforementioned Figures 1 to 5 It can be seen that the prior art does not provide a groove 111 on the first battery cell 11. Such a design is very likely to cause damage to the battery cell (microcracks, cracks, etc.) during the folding of the busbar. In addition, the prior art does not consider the compatibility between this utility model and multiple battery cells with different shielding areas.
[0038] In a further optional embodiment, the width of the groove 111 in this invention matches the width of the conductive element 14, maximizing the power generation area of the first solar cell 11. Specifically, the shape of the groove 111 is at least one of arc shape and polygon shape. Typically, the conductive element 14 is a circular solder strip, so the shape of the groove 111 can be set to arc shape to avoid gaps between the conductive element 14 and the outer contour of the groove 111, thereby preventing displacement during subsequent photovoltaic module lamination.
[0039] It should be noted that although the photoelectric conversion efficiencies of the first solar cell 11, the second solar cell 12, and the third solar cell 13 are all different, the difference should not be too large. In an optional embodiment, the difference between the photoelectric conversion efficiency of the first solar cell 11 and the third solar cell 13 is greater than 0 and less than 0.1%; the difference between the photoelectric conversion efficiency of the third solar cell 13 and the second solar cell 12 is greater than 0 and less than 0.1%. The specific value of the photoelectric conversion efficiency is matched to the power generation area of each solar cell, and therefore can be specifically set according to actual needs to minimize current mismatch in photovoltaic modules and improve the reliability of photovoltaic modules during practical applications.
[0040] It should also be noted that if the conductive element 14 is only soldered to one side of the interconnect strip 2, the interconnect strip 2 will be thicker in the area in contact with the conductive element 14 compared to other areas (i.e., the conductive element 14 is protruding). Figure 6 As shown, this can lead to the risk of cracking during the stacking of multiple battery strings 1. Therefore, in an optional embodiment of this invention, the thickness of the region in the interconnecting strip 2 connected to the conductive element 14 is less than the thickness of other regions in the interconnecting strip 2, such as... Figure 7 As shown. In other words, this invention thins the area of the interconnecting strip 2 connected to the conductive element 14 to ensure that the portion of the interconnecting strip 2 connected to the conductive element 14 does not protrude. In an optional embodiment, the thickness of the area of the interconnecting strip 2 connected to the conductive element 14 is 0.05mm to 0.3mm, for example, 0.05mm, 0.1mm, 0.2mm, 0.3mm, etc.; the thickness of other areas of the interconnecting strip 2 is 0.15mm to 0.4mm, for example, 0.15mm, 0.2mm, 0.3mm, 0.4mm, etc.
[0041] It is understandable that after the interconnecting strip 2 connects to the conductive part 14 on the front side of the first battery cell 11, it cannot be electrically connected to the conductive part 14 on the back side of the first battery cell 11 to avoid short circuits. Therefore, in an optional embodiment, an insulating pad 3 is also provided between the interconnecting strip 2 and the first battery cell 11. Figure 3 and Figure 4 It can be seen that by setting the insulating pad 3, the part of the conductive part 14 that is folded to the back of the first battery cell 11 connected to the front of the first battery cell 11 can be prevented from being connected to the conductive part 14 connected to the back of the first battery cell 11, thus avoiding the occurrence of a short circuit.
[0042] In a further optional embodiment, the thickness of the insulating pad 3 is 0.1mm to 0.3mm, such as 0.1mm, 0.2mm, 0.3mm, etc. It is understood that if the thickness of the insulating pad 3 is set too thick, it will also cause bulging problems in some areas of the interconnecting strip 2, leading to the risk of cell cracking during the multi-layer battery stacking process, and also resulting in material waste. Conversely, if the thickness of the insulating pad 3 is too thin, it will affect the insulation performance and may pose a risk of short circuit due to current breakdown. Therefore, this invention sets the thickness of the insulating pad 3 to 0.1mm to 0.3mm, which ensures insulation performance while avoiding resource waste.
[0043] In one optional embodiment, the portion of the conductive element 14 connected to the front electrode of the first battery cell 11 that is folded to the back of the first battery cell 11 is located between the insulating pad 3 and the interconnecting strip 2. During the folding process, there are two different scenarios: one is that the conductive element 14 is folded to the back side of the interconnecting strip 2, i.e., from top to bottom, the order is the first battery cell 11, the insulating pad 3, the interconnecting strip 2, and the conductive element 14. The other scenario is that the conductive element 14 is folded between the interconnecting strip 2 and the insulating pad 3, in which case the order from top to bottom is the first battery cell 11, the insulating pad 3, the conductive element 14, and the interconnecting strip 2. In practical applications, different configurations can be selected according to actual needs, and this invention does not impose specific limitations on this.
[0044] It is understandable that when there is only one battery string 1, or multiple battery strings 1 connected in parallel or series, the multiple battery strings 1 are only connected to the two ends of the battery string 1 by the interconnecting strip 2 to form a parallel or series structure. However, when multiple battery strings 1 are connected in a combination of series and parallel, there will be an intermediate interconnecting strip 22 located between two battery strings 1 arranged side by side, such as... Figure 8 As shown. Therefore, in an optional embodiment of this utility model, for the structure of multiple battery strings 1, the interconnecting strip 2 includes: an edge interconnecting strip 21 located at the edge of the multiple battery strings 1 and an intermediate interconnecting strip 22 located between two battery strings 1 arranged side by side; the cross-sectional area of the region covering the first battery cell 11 in the intermediate interconnecting strip 22 is equal to the cross-sectional area of the region covering the third battery cell 13 in the intermediate interconnecting strip 22, and the thickness of the region covering the first battery cell 11 in the intermediate interconnecting strip 22 is less than the thickness of the region covering the third battery cell 13 in the intermediate interconnecting strip 22. This is because, in the process of multi-layer battery cell lamination, in order to ensure that the position of the intermediate interconnecting strip 22 corresponding to the insulating pad 3 is not damaged by excessive thickness due to high pressure on the stacked battery cells, the part of the intermediate interconnecting strip 22 corresponding to the insulating pad 3 is set to be thinner than the part of the intermediate interconnecting strip 22 without the insulating pad 3. For example, with Figure 8For example, each row includes two battery strings 1 arranged horizontally side by side. Edge interconnecting strips 21 are provided at both ends of the two battery strings 1, and a middle interconnecting strip 22 is provided at the connection between the two battery strings 1. For the middle interconnecting strip 22, the part corresponding to the battery string 1 of the first row is directly provided on the back of the third battery cell 13 of the battery string 1 and connected to the conductive part 14 on the back of the third battery cell 13, so there is no insulating pad 3. The part corresponding to the battery string 1 of the second row is connected to the conductive part 14 on the front of the first battery cell 11 of the battery string 1 after being folded to the back. In order to avoid short circuit with the conductive part 14 on the back of the first battery cell 11, an insulating pad 3 is provided in the part of the middle interconnecting strip 22 corresponding to the battery string of the second row. Therefore, the area of the middle interconnecting strip 22 corresponding to the battery string 1 of the first row is actually thinner than the area corresponding to the battery string 1 of the second row (due to the lack of the thickness of the insulating pad 3). Therefore, in order to ensure that the thickness of different regions of the intermediate interconnecting strip 22 is uniform during the lamination process, the portion of the intermediate interconnecting strip 22 corresponding to the insulating pad 3 is thinned in this embodiment of the invention, so that the thickness of the portion corresponding to the insulating pad 3 plus the thickness of the insulating pad 3 can be equal to the thickness of the portion corresponding to the portion without the insulating pad 3.
[0045] It should be noted that for the edge interconnecting strip 21, the conductive element 14 can be folded either to the back side of the interconnecting strip 2 or between the interconnecting strip 2 and the insulating pad 3. However, for the middle interconnecting strip 22, since the middle interconnecting strip 22 needs to connect two battery strings 1 arranged side by side, the conductive element 14 can only be folded between the interconnecting strip 2 and the insulating pad 3. Otherwise, holes would need to be drilled in the interconnecting strip 2 so that the conductive element 14 can pass through the holes and be folded to the back side of the interconnecting strip 2, which would increase the unnecessary manufacturing process. Therefore, this utility model chooses to fold the conductive element 14 between the interconnecting strip 2 and the insulating pad 3 to simplify the manufacturing process.
[0046] In practical applications, to ensure consistent current carrying capacity across multiple interconnecting strips 2, the cross-sectional areas of the intermediate interconnecting strip 22 and the edge interconnecting strip 21 need to be equal. As mentioned earlier, the intermediate interconnecting strip 22 has a thinner thickness corresponding to the insulating pad 3, therefore, the portion of the intermediate interconnecting strip 22 corresponding to the insulating pad 3 is wider than the portion of the edge interconnecting strip 22 corresponding to the insulating pad 3. In this case, to effectively ensure the consistency of power generation efficiency between the first battery cell 11 and the third battery cell 13, in an optional embodiment, for the intermediate interconnecting strip 22 and the edge interconnecting strip 21, the width of the area corresponding to the third battery cell 13 is defined as 2 × the width of the edge interconnecting strip 21 + the gap between the two battery strings 1 arranged side by side. The gap between the two battery strings 1 arranged side by side is actually the gap between the two corresponding third battery cells 13 in the two battery strings 1 arranged side by side. By defining the relationship between the widths of the intermediate interconnecting strip 22 and the edge interconnecting strip 21 as described above, the mixing of multiple battery cells can be effectively avoided.
[0047] In summary, the photovoltaic cell string structure provided in this embodiment of the present invention has a groove 111 for folding the conductive member 14 at the edge of the first cell 11 away from the second cell 12. This effectively avoids the conductive member 14 squeezing the cell during folding, thus preventing cell cracking. Furthermore, because the groove 111 causes a partial loss of the first cell 11, and the interconnecting strip 2 blocks the back of both the first cell 11 and the third cell 13, the photoelectric conversion efficiency among the first cell 11, the second cell 12, and the third cell 13 connected in series in the cell string 1 is limited, ensuring the consistency of power generation efficiency among different cells in the cell string 1.
[0048] In one embodiment of this utility model, a photovoltaic module is also provided, such as... Figure 11 As shown, it includes: a cover plate 100, a back plate 200, an encapsulating film 300 located between the cover plate 100 and the back plate 200, and any of the aforementioned photovoltaic cell string structures.
[0049] It is understandable that the battery string structure provided above can be used in photovoltaic modules and sold as a whole with photovoltaic modules, or it can be sold separately as a single unit.
[0050] The above steps are provided only to help understand the structure, method, and core idea of this utility model. For those skilled in the art, various improvements and modifications can be made to this utility model without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this utility model.
Claims
1. A photovoltaic cell string structure, characterized in that, include: One or more battery strings (1) and multiple interconnecting strips (2); Each of the battery strings (1) includes: a first battery cell (11), a plurality of second battery cells (12), a third battery cell (13), and a plurality of conductive elements (14) for connecting the first battery cell (11), the plurality of second battery cells (12), and the third battery cell (13) in series; wherein, A groove (111) corresponding to the conductive element (14) is provided on the edge of the first battery cell (11) away from the second battery cell (12). The recess direction of the groove (111) is consistent with the width direction of the first battery cell (11). The conductive element (14) connected to the front electrode of the first battery cell (11) is folded over to the back of the first battery cell (11) through the groove (111) and connected to the interconnecting strip (2) located on the back of the first battery cell (11). Multiple second battery cells (12) are connected in series between the first battery cell (11) and the third battery cell (13) via multiple conductive elements (14); The back electrode of the third battery cell (13) is connected to the interconnecting strip (2) located on the back of the third battery cell (13) via the conductive element (14); The photoelectric conversion efficiency of the first battery cell (11) is greater than that of the third battery cell (13), and the photoelectric conversion efficiency of the third battery cell (13) is greater than that of the second battery cell (12).
2. The photovoltaic cell string structure according to claim 1, characterized in that, The difference between the photoelectric conversion efficiency of the first battery cell (11) and the photoelectric conversion efficiency of the third battery cell (13) is greater than 0 and less than 0.1%. And / or, The difference between the photoelectric conversion efficiency of the third solar cell (13) and the photoelectric conversion efficiency of the second solar cell (12) is greater than 0 and less than 0.1%.
3. The photovoltaic cell string structure according to claim 1, characterized in that, The groove (111) has a depth of 2mm to 5mm; And / or, The width of the groove (111) matches the width of the conductive element (14); And / or, The groove (111) is at least one of arc shape and polygon shape.
4. The photovoltaic cell string structure according to claim 1, characterized in that, The thickness of the region in the interconnecting strip (2) connected to the conductive element (14) is less than the thickness of other regions in the interconnecting strip (2).
5. The photovoltaic cell string structure according to claim 1, characterized in that, An insulating pad (3) is also provided between the interconnecting strip (2) and the first battery cell (11).
6. The photovoltaic cell string structure according to claim 5, characterized in that, The portion of the conductive element (14) connected to the front electrode of the first battery cell (11) that is folded to the back of the first battery cell (11) is located between the insulating pad (3) and the interconnecting strip (2).
7. The photovoltaic cell string structure according to claim 1, characterized in that, For the structure of multiple battery strings (1), the interconnecting strip (2) includes: an edge interconnecting strip (21) located at the edge of the multiple battery strings (1) and an intermediate interconnecting strip (22) located between two battery strings (1) arranged side by side; The cross-sectional area of the region covering the first battery cell (11) in the intermediate interconnect strip (22) is equal to the cross-sectional area of the region covering the third battery cell (13) in the intermediate interconnect strip (22). Furthermore, the thickness of the region covering the first battery cell (11) in the intermediate interconnect strip (22) is less than the thickness of the region covering the third battery cell (13) in the intermediate interconnect strip (22).
8. The photovoltaic cell string structure according to claim 6, characterized in that, The thickness of the insulating pad (3) is 0.1mm to 0.3mm.
9. The photovoltaic cell string structure according to claim 4, characterized in that, The thickness of the area in the interconnecting strip (2) connected to the conductive element (14) is 0.05 mm to 0.3 mm; And / or, The thickness of other regions in the interconnecting band (2) is 0.15 mm to 0.4 mm.
10. A photovoltaic module, characterized in that, It includes a cover plate (100), a back plate (200), an encapsulating film (300) located between the cover plate (100) and the back plate (200), and a photovoltaic cell string structure according to any one of claims 1-9.