Photovoltaic cell without main grid and photovoltaic module
By setting connecting grid lines and fine grid lines on the surface of gridless photovoltaic cells, the problem of poor conductivity in the edge area of photovoltaic cells is solved, and conductivity and current collection efficiency are improved at low cost.
Patent Information
- Application Number
- CN202520327820.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2035-02-26
AI Technical Summary
Existing gridless photovoltaic cells have poor conductivity in the edge region, resulting in black edges during module EL testing, and existing solutions increase manufacturing costs.
Several fine grid lines are set on the surface of the gridless photovoltaic cell, and connecting grid lines are set at the start end, end end and interconnection end. The connecting grid lines are connected to at least two fine grid lines to ensure stable connection between the solder strip and the fine grid lines. By increasing the number of connecting grid lines at the start end and end end of the current flow, the conductivity of the edge area is improved.
While ensuring low manufacturing costs, the conductivity of the photovoltaic cell edge region was improved, the disconnection between the solder strip and the fine grid line was avoided, and the current collection efficiency was enhanced.
Smart Images
Figure CN223928728U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic cells, and in particular to a gridless photovoltaic cell and photovoltaic module. Background Technology
[0002] Existing 0BB (busbarless) photovoltaic cells retain only the sub-busbar, reducing the use of metal electrodes to decrease the shading area on the light-receiving surface, improve the photoelectric conversion efficiency, and simultaneously reduce the amount of silver paste used in the photovoltaic cell. In existing busbarless photovoltaic cells, after removing the main busbar, solder ribbons are used to collect the photocurrent gathered by the sub-busbar. Currently, increasing the number of solder ribbons shortens the current transmission path in the sub-busbar, reduces series resistance, and thus increases module power. To ensure a stable connection between the solder ribbons and the busbarless photovoltaic cell during low-temperature soldering, current methods use a film coating on the solder ribbons. However, existing methods suffer from poor conductivity at the edges of the photovoltaic cell due to a 2-4 mm gap between the starting position of the solder ribbon and the edge of the busbarless photovoltaic cell, or because the film is not firmly fixed to the solder ribbon at the edge. This results in black edges appearing during module EL testing.
[0003] Therefore, how to provide a gridless photovoltaic cell that solves the problem of poor conductivity in the edge region of a photovoltaic cell while ensuring low manufacturing cost is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0004] In view of this, the purpose of this utility model is to provide a gridless photovoltaic cell and photovoltaic module, which solves the problem that the edge area of the photovoltaic cell has poor conductivity and black edges appear during the EL test of the module.
[0005] To solve the above-mentioned technical problems, this utility model provides a gridless photovoltaic cell, wherein a plurality of fine grid lines are provided on the surface of the gridless photovoltaic cell, the plurality of fine grid lines are arranged at intervals along a first direction and extend along a second direction;
[0006] The gridless photovoltaic cell has a first surface and a second surface opposite to each other, and a current-charging start end is formed on the first surface along the first direction, and a current-charging end end is formed on the second surface along the first direction.
[0007] Both the end of the first surface away from the starting end of the busbar along the first direction and the end of the second surface away from the ending end of the busbar along the first direction are interconnecting ends;
[0008] The starting end, the ending end, and the interconnection end are each provided with a connecting grid line at the corresponding position of the solder strip, and each connecting grid line is connected to at least two fine grid lines.
[0009] The number of connecting grid lines set at the starting end and the ending end of the busbar corresponding to the laying position of a solder strip is not less than the number of connecting grid lines set at the interconnecting end corresponding to the laying position of the same solder strip.
[0010] Optionally, the number of connecting grid lines set at the starting end and the ending end of the busbar corresponding to the laying position of a solder strip is greater than the number of connecting grid lines set at the interconnecting end corresponding to the laying position of the same solder strip.
[0011] Optionally, two connecting grid lines are provided at the starting end of the busbar corresponding to the laying position of each welding strip, and two connecting grid lines are provided at the ending end of the busbar corresponding to the laying position of each welding strip.
[0012] At each location where a solder strip is laid, a single connecting grid line is provided at the interconnection end.
[0013] Optionally, at the starting point of the busbar corresponding to the laying position of each solder strip, the spacing between the two connecting grid lines is 0.2 mm to 1 mm;
[0014] At the location where each solder strip is laid, the spacing between the two connecting grid lines at the bus termination point is 0.2 mm to 1 mm.
[0015] Optionally, at the location where each solder strip is laid, corresponding to the starting and ending points of the busbar, the outermost fine grid line between the two connecting grid lines is interrupted.
[0016] Optionally, the length of the connecting grid line is 1.5 mm to 15 mm.
[0017] Optionally, at the starting end of the busbar, corresponding to the laying position of each welding strip, two connecting grid lines are provided.
[0018] At each location where a welding strip is laid, two connecting grid lines are provided at the bus termination end.
[0019] At each location where a solder strip is laid, two connecting grid lines are provided at the interconnection end.
[0020] Optionally, at the intersection of the thin grid line and the connecting grid line, a thickened sub-grid line with a gradually changing width along the second direction is provided.
[0021] Optionally, along the first direction, the length of the thickened sub-gate line located on the outer side is greater than the length of the thickened sub-gate line located on the inner side.
[0022] This utility model also provides a photovoltaic module, which includes a battery layer formed by multiple busbarless photovoltaic cell strings connected by a common flow.
[0023] The gridless photovoltaic cell string includes a solder strip, a carrier film, and multiple gridless photovoltaic cells arranged in sequence as described above.
[0024] The welding strip is disposed on the surface of the gridless photovoltaic cell, and the carrier film is laid on the outside of the welding strip;
[0025] In each pair of adjacent gridless photovoltaic cells, a first cell and a second cell are defined, and the solder strip on the first surface of the first cell extends to the second surface of the second cell through the gap between the first cell and the second cell.
[0026] As can be seen, the gridless photovoltaic cell provided by this utility model has a plurality of fine grid lines on its surface, which are spaced apart along a first direction and extend along a second direction. The gridless photovoltaic cell has a first surface and a second surface opposite to each other, and a current-charging start end is formed on the first surface along the first direction, and a current-charging end end is formed on the second surface along the first direction. The end of the first surface away from the current-charging start end along the first direction and the end of the second surface away from the current-charging end along the first direction are both interconnect ends. Connecting grid lines are provided at the current-charging start end, the current-charging end and the interconnect ends at the positions corresponding to the solder strip laying positions, and each connecting grid line connects at least two fine grid lines. The number of connecting grid lines provided at the current-charging start end and the current-charging end at the position corresponding to the position of a solder strip is not less than the number of connecting grid lines provided at the interconnect ends at the same position corresponding to the position of the same solder strip. This invention addresses the issue of poor conductivity in the edge region of photovoltaic cells by setting a busbar start end, a busbar end, and an interconnection end. At each location corresponding to the solder ribbon laying position, a connecting grid line is provided that simultaneously connects at least two fine grid lines. This connecting grid line enables the transmission of photocurrent collected by the fine grid lines at the edge of the gridless photovoltaic cell to other fine grid lines via the connecting grid line when the connection between the fine grid lines and the solder ribbon is broken. Furthermore, considering that the conductivity of the solder ribbon is worse at the start and end ends compared to the interconnection end, by ensuring that the number of connecting grid lines at the busbar start and end ends is no less than the number at the interconnection end, the poor conductivity in the edge region of the photovoltaic cell can be improved while maintaining a lower manufacturing cost.
[0027] In addition, this utility model also provides a photovoltaic module, which also has the above-mentioned beneficial effects. Attached Figure Description
[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0029] Figure 1 A schematic diagram of a gridless photovoltaic cell provided in an embodiment of this utility model;
[0030] Figure 2 A schematic diagram of a whole-cell gridless photovoltaic cell provided for an embodiment of this utility model;
[0031] Figure 3 This is a schematic diagram of another gridless photovoltaic cell provided in an embodiment of the present invention;
[0032] Figure 4 This is a partially enlarged schematic diagram of the connecting grid lines in a gridless photovoltaic cell provided as an embodiment of the present invention;
[0033] Figure 5 A schematic diagram of the structure of the first surface of a gridless photovoltaic cell provided in an embodiment of this utility model;
[0034] Figure 6 A partially enlarged schematic diagram of the connecting grid lines in another gridless photovoltaic cell provided in this embodiment of the present invention;
[0035] Figure 7 A schematic diagram of the structure of the second surface of a gridless photovoltaic cell provided in an embodiment of this utility model;
[0036] Figure 8 A schematic diagram of a gridless photovoltaic cell string in a photovoltaic module provided by an embodiment of this utility model;
[0037] Figures 1 to 8 The reference numerals in the attached figures are explained as follows:
[0038] 1-Full-cell gridless photovoltaic cell; 2-Spindle; 3-Connecting grid line at the start of the current collection; 4-Connecting grid line at the end of the current collection; 5-Connecting grid line at the interconnection point; 10-Gridless photovoltaic cell; 11-First surface; 12-Start of current collection; 13-Interconnection point; 14-Second surface; 15-End of current collection; 20-Fine grid line; 21-Thickened sub-grid line; 30-Connecting grid line. Detailed Implementation
[0039] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0040] Example 1:
[0041] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a gridless photovoltaic cell provided in an embodiment of the present invention. The gridless photovoltaic cell 10 has a plurality of fine grid lines 20 on its surface, which are spaced apart along a first direction and extend along a second direction.
[0042] The gridless photovoltaic cell 10 has a first surface 11 and a second surface 14 facing each other, and a busbar start end 12 is formed on the first surface 11 along a first direction, and a busbar end 15 is formed on the second surface 14 along the first direction.
[0043] The end of the first surface 11 away from the bus start end 12 along the first direction, and the end of the second surface 14 away from the bus end 15 along the first direction, are both interconnect ends 13.
[0044] At the starting end 12, the ending end 15, and the interconnection end 13, corresponding to the position where the solder strip is laid, a connecting grid line 30 is provided, and each connecting grid line 30 is connected to at least two thin grid lines 20.
[0045] The number of connecting grid lines 30 set at the starting end 12 and the ending end 15 corresponding to the laying position of a solder strip is not less than the number of connecting grid lines 30 set at the same laying position of the interconnection end 13.
[0046] It should be noted that in this embodiment, all the fine grid lines 20 are arranged in parallel, that is, the first direction in which the fine grid lines 20 are spaced apart is perpendicular to the second direction in which the fine grid lines 20 extend. In this embodiment, one end of the first surface 11 of a gridless photovoltaic cell along the first direction is set as the current-collecting start end 12. The current-collecting start end 12 set here is the starting end when laying the solder ribbon. The other end of the first surface 11 of the gridless photovoltaic cell, opposite to the current-collecting start end 12 along the first direction, is set as the interconnect end 13. It can be foreseen that when laying the solder ribbon, the starting end of the solder ribbon is set at the current-collecting start end 12 of the first surface 11 of the gridless photovoltaic cell, extends along the first direction until it exceeds the interconnect end 13 of the first surface 11 of the gridless photovoltaic cell, and is laid on the surface of another adjacent gridless photovoltaic cell. At this time, because the solder strip does not extend to the edge contour of the gridless photovoltaic cell at the current collection start end 12, there is a gap between it and the edge contour of the gridless photovoltaic cell. Specifically, the starting position of the solder strip is generally set to be about 2 mm to 4 mm away from the edge of the gridless photovoltaic cell; or at both ends of the gridless photovoltaic cell along the first direction, there is a problem of the fine grid lines 20 near the edge detaching from the solder strip. Both of these issues result in the photocurrent collected by the fine grid lines 20 near the edge of the gridless photovoltaic cell not being effectively collected by the solder strip, which in turn leads to poor conductivity in the edge area of the gridless photovoltaic cell. Furthermore, the current collection start end 12 located on the first surface 11 of the gridless photovoltaic cell... The conductivity stability at point 2 is lower than that at interconnection point 13. Therefore, in this embodiment, the connecting grid line 30 can transfer the photocurrent collected by the fine grid line 20 at the point of disconnection to the inner fine grid line 20 and be collected by the solder ribbon when the fine grid line 20 is disconnected from the solder ribbon. This avoids the problem of poor conductivity at the edge. Furthermore, the number of connecting grid lines 30 at the current collection start point 12 of the first surface 11 of the gridless photovoltaic cell 10 is not less than the number of connecting grid lines 30 at the interconnection point 13 of the first surface 11 of the gridless photovoltaic cell 10. This ensures that the improvement rate of conductivity of the gridless photovoltaic cell 10 is increased when the manufacturing cost is limited. Accordingly, the second surface 14 of the target gridless photovoltaic cell is described. When laying the solder strip, the solder strip extends from the first surface 11 of the adjacent gridless photovoltaic cell and reaches the interconnection end 13 of the second surface 14 of the target gridless photovoltaic cell, and ends at the bus termination end 15 of the second surface 14 of the target gridless photovoltaic cell. At this time, while ensuring the manufacturing cost, the number of connecting grid lines 30 at the bus termination end 15 of the second surface 14 of the gridless photovoltaic cell is not less than the number of connecting grid lines 30 at the interconnection end 13 of the second surface 14 of the gridless photovoltaic cell, which can enhance the improvement effect on the conductivity of the cell edge area.In this embodiment, the first surface 11 and the second surface 14 of the gridless photovoltaic cell 10 both include a middle region and an edge region along the first direction. In this embodiment, a connecting grid line 30 is provided at the edge region, and multiple thin grid lines 20 in the edge region are connected at the same time.
[0047] In this embodiment, the specific extension direction of the connecting grid line 30 is not limited, as long as it can connect multiple fine grid lines 20. For example, the connecting grid line 30 can be set to extend along a first direction, that is, the connecting grid line 30 is perpendicular to the fine grid line 20, or the connecting grid line 30 can be set to only intersect with multiple fine grid lines 20. To further reduce the amount of material used when setting the connecting grid line 30, the connecting grid line 30 can be set perpendicular to the fine grid line 20. In addition, when preparing a half-cell gridless photovoltaic cell, the whole gridless photovoltaic cell 1 is cut into pieces, and the whole gridless photovoltaic cell 1 can be referred to as Figure 2 , Figure 2 This is a schematic diagram of a whole-cell gridless photovoltaic cell provided by an embodiment of the present invention. The connecting grid lines 30 also need to be positioned in the middle of the whole-cell gridless photovoltaic cell 1. The connecting grid lines 30 positioned in this middle location serve as connecting grid lines 30 at one edge of each half-cell gridless photovoltaic cell after slicing. Therefore, the extension length of the connecting grid lines 30 positioned in the middle of the whole-cell gridless photovoltaic cell 1 should be twice the length of the connecting grid lines 30 located at the edges of the half-cell gridless photovoltaic cell. Correspondingly, when the whole-cell gridless photovoltaic cell 1 needs to be sliced into multiple half-cell gridless photovoltaic cells, connecting grid lines 30 need to be provided at each cutting point to ensure that each half-cell gridless photovoltaic cell has connecting grid lines 30 at both edges along the first direction after slicing. In this embodiment, the fine grid lines 20 and connecting grid lines 30 can be printed simultaneously and can use the same high-purity silver paste.
[0048] Furthermore, in order to ensure that the poor conductivity of the edges of the gridless photovoltaic cells is improved, the length of the connecting grid line 30 can be set to 1.5 mm to 15 mm.
[0049] In this embodiment, the length of the connecting grid line 30 is set to 1.5 mm to 15 mm. This ensures that the conductivity of areas with poor conductivity at the edge of the gridless photovoltaic cell can be improved by setting the connecting grid line 30, further avoiding the problem that the photocurrent collected by the fine grid line 20 cannot be transmitted to the solder ribbon. In this embodiment, the width of the connecting grid line 30 can be set to between 0.015 mm and 0.055 mm.
[0050] Furthermore, in a feasible embodiment, to ensure the stability of the connection between the fine grid lines 20 at the edge of the gridless photovoltaic cell and the solder ribbon, reference can be made to... Figure 3 , Figure 3This is a schematic diagram of another gridless photovoltaic cell provided in an embodiment of the present invention. Two connecting grid lines 30 can be provided at each position where the aforementioned busbar initiation end 12 corresponds to the laying position of each solder strip;
[0051] At each location where a welding strip is laid, there are two connecting grid lines 30 at the bus termination end 15.
[0052] Two connecting grid lines 30 are provided at each position where the solder strip is laid on the interconnection terminal 13.
[0053] In this embodiment, two connecting grid lines 30 are provided at the starting end 12, the ending end 15, and the interconnection end 13 of the gridless photovoltaic cell 10, that is, at both ends of the gridless photovoltaic cell 10 along the first direction, corresponding to the positions where the solder ribbon is laid. This further improves the stability of the connection between the fine grid lines 20 at the starting end 12, the ending end 15, and the interconnection end 13 and the solder ribbon, while ensuring the material cost of laying the connecting grid lines 30. The connecting grid lines 30 provided in this embodiment can refer to... Figure 4 , Figure 4 This is a partially enlarged schematic diagram of the connecting grid lines in a gridless photovoltaic cell provided by an embodiment of the present invention. The structure, in which two connecting grid lines 30 are provided at each location, is as follows: Figure 4 As shown in the figure. In this embodiment, it can be further configured such that, at the location where the interconnecting end 13 corresponds to the laying position of each solder strip, the outermost fine grid line 20 between the two connecting grid lines 30 is interrupted.
[0054] Furthermore, in order to avoid the occurrence of broken grid lines at the intersection of the fine grid line 20 and the connecting grid line 30, a thickened sub-grid line 21 with a gradually changing width along the second direction can be provided at the intersection of the fine grid line 20 and the connecting grid line 30.
[0055] It should be noted that, in this embodiment, at the intersection of the thin gate line 20 and the connecting gate line 30, a thickened sub-gate line 21 with a gradually decreasing width is provided along the extension direction of the thin gate line 20. Specifically, in this embodiment, the width of the thin gate line 20 can be set to gradually decrease in the second direction away from the connecting gate line 30 until it is reduced to the width value of the non-thickened part of the thin gate line 20. In this embodiment, the length of the thickened sub-gate line 21 along the second direction can be set to 0.5 mm to 2 mm, and the width along the first direction can be set to 0.025 mm to 0.055 mm.
[0056] Furthermore, in order to avoid the solder strip from shifting and overlapping into the non-thickened area of the fine grid line 20 during installation, the length of the thickened sub-grid line 21 located on the outer side along the first direction can be set to be greater than the length of the thickened sub-grid line 21 located on the inner side.
[0057] It should be noted that, in this embodiment, the thickened sub-grid line 21 at the intersection of the fine grid line 20 and the connecting grid line 30 can also prevent grid breakage when the solder strip is welded to the fine grid line 20. In this embodiment, the length of the thickened sub-grid line 21 along the second direction on the outer fine grid line 20 is greater than the length of the thickened sub-grid line 21 along the second direction on the inner fine grid line 20. When the solder strip deviates, even if the solder strip deviates more near the edge, it can still be laid on the thickened sub-grid line 21. This reduces the risk of grid breakage at the weld between the solder strip and the fine grid line 20 while ensuring the grid line manufacturing cost.
[0058] The gridless photovoltaic cell provided in this embodiment of the present invention has a plurality of fine grid lines 20 on its surface, which are spaced apart along a first direction and extend along a second direction. The gridless photovoltaic cell 10 has opposing first and second surfaces 11, with a current-charging start end 12 formed on the first surface 11 along the first direction, and a current-charging end 15 formed on the second surface 14 along the first direction. At the end of the first surface 11 away from the current-charging start end 12 along the first direction, a current-charging end 15 is formed... The end of the second surface 14 along the first direction away from the bus termination end 15 is an interconnect end 13. The bus start end 12, the bus termination end 15 and the interconnect end 13 are each provided with a connecting grid line 30 at the position where the solder strip is laid, and each connecting grid line 30 is connected to at least two thin grid lines 20. The number of connecting grid lines 30 provided at the position where the bus start end 12 and the bus termination end 15 are laid for a solder strip is not less than the number of connecting grid lines 30 provided at the position where the interconnect end 13 is laid for the same solder strip. This invention addresses the issue of poor conductivity in the edge region of photovoltaic cells by setting a busbar start end 12, a busbar end 15, and an interconnection end 13. At each location corresponding to the solder ribbon laying position, a connecting grid line 30 is provided that simultaneously connects at least two fine grid lines 20. This allows the photocurrent collected by the fine grid lines 20 at the edge of the gridless photovoltaic cell to be transmitted to other fine grid lines 20 via the connecting grid line 30 when the connection between the fine grid lines 20 and the solder ribbon is broken. This solves the problem of poor conductivity in the edge region of photovoltaic cells. Furthermore, considering that the conductivity between the solder ribbon and the cell is worse at the start and end ends compared to the interconnection end 13, by ensuring that the number of connecting grid lines 30 at the busbar start end 12 and the busbar end 15 is not less than the number of connecting grid lines 30 at the interconnection end 13, the poor conductivity in the edge region of photovoltaic cells can be improved while maintaining a lower manufacturing cost.
[0059] Furthermore, by setting the length of the connecting grid line 30 to 1.5 mm to 15 mm, this embodiment of the invention can effectively improve the conductivity stability of the area with poor conductivity at the edge of the gridless photovoltaic cell 10, avoiding the problem that the photocurrent collected by the fine grid line 20 cannot be transmitted to the solder ribbon. In this embodiment, two connecting grid lines 30 are set at both ends of the gridless photovoltaic cell 10 along the first direction, corresponding to the position where the solder ribbon is laid, further improving the stability of the connection between the fine grid line 20 and the solder ribbon. By setting a thickened sub-grid line 21 with a gradually changing width along the extension direction of the fine grid line 20 at the intersection of the fine grid line 20 and the connecting grid line 30, the problem of grid breakage at the intersection of the fine grid line 20 and the connecting grid line 30 can be avoided. By setting the length of the thickened sub-grid line 21 located on the outer side to be greater than the length of the thickened sub-grid line 21 located on the inner side along the spacing direction of the fine grid line 20, the risk of grid breakage at the welding point between the solder ribbon and the fine grid line 20 can be reduced while ensuring the grid line manufacturing cost.
[0060] Example 2:
[0061] Please refer to Figure 1 , Figure 5 This is a schematic diagram of the structure of the first surface of a gridless photovoltaic cell provided in an embodiment of the present invention. The gridless photovoltaic cell differs from Embodiment 1 described above in that:
[0062] The number of connecting grid lines 30 set at the above-mentioned bus start end 12 and bus end end 15 corresponding to the laying position of a solder strip is greater than the number of connecting grid lines 30 set at the interconnect end 13 corresponding to the laying position of the same solder strip.
[0063] It should be noted that in this embodiment, the number of connecting grid lines 30 at the start end 12 and the end end 15 corresponding to the same solder strip is greater than the number of connecting grid lines 30 at the interconnect end 13. This increases the amount of material used in areas where the fine grid lines 20 are at high risk of disconnection from the solder strip, while ensuring sufficient material for the limited fabrication of the connecting grid lines 30. This improves the effective utilization rate of the connecting grid lines 30, reducing fabrication costs while more effectively improving the poor conductivity at the edges of the gridless photovoltaic cell 10. This embodiment does not limit the specific number of connecting grid lines 30 at the start end 12 and the end end 15, or at the interconnect end 13. The number can be set according to actual conductivity stability requirements, as long as the number of connecting grid lines 30 at the start end 12 and the end end 15 corresponding to the same solder strip is greater than the number of connecting grid lines 30 at the interconnect end 13.
[0064] Furthermore, in order to further reduce the amount of slurry used in the preparation of the connecting grid line 30, two connecting grid lines 30 can be provided at each laying position of each welding strip at the above-mentioned busbar start end 12, and two connecting grid lines 30 can be provided at each laying position of each welding strip at the busbar end 15.
[0065] At each location where the interconnection terminal 13 is laid, a single connecting grid line 30 is provided.
[0066] In this embodiment, two connecting grid lines 30 are provided at the solder ribbon laying positions at both the starting end 12 and the ending end 15, ensuring a stable connection between the solder ribbon and the fine grid line 20. Meanwhile, only one connecting grid line 30 is provided at the solder ribbon laying position at the interconnection end 13. This improves the conductivity of the edge region of the gridless photovoltaic cell 10 while maintaining manufacturing costs. The structure of providing two connecting grid lines 30 at each location in this embodiment can be referenced. Figure 4 , Figure 4 This is a partially enlarged schematic diagram of the connecting grid lines in a gridless photovoltaic cell provided as an embodiment of the present invention. The structure in this embodiment, where one connecting grid line 30 is provided at each location, can be referenced from [the present invention]. Figure 6 , Figure 6 This is a partially enlarged schematic diagram of the connecting grid lines in another gridless photovoltaic cell provided as an embodiment of the present invention. The structure of the second surface of the gridless photovoltaic cell in this embodiment can be referenced from... Figure 7 , Figure 7 This is a schematic diagram of the structure of the second surface of a gridless photovoltaic cell provided in an embodiment of the present invention.
[0067] Furthermore, in order to ensure that the connecting grid line 30 provided at each solder strip corresponding to the bus start end 12 and the bus end end 15 can effectively improve the conductive connection efficiency and avoid the resistance of the fine grid line 20 at the disconnection point being too large and affecting the current collection efficiency, the spacing between the two connecting grid lines 30 provided at the laying position of each solder strip corresponding to the bus start end 12 can be set to 0.2 mm to 1 mm.
[0068] At the location where each solder strip is laid, the distance between the two connecting grid lines 30 at the bus termination end 15 is 0.2 mm to 1 mm.
[0069] In this embodiment, at the bus start end 12 and bus end end 15, the spacing between the two connecting grid lines 30 corresponding to each solder strip is 0.2 mm to 1 mm. This allows the fine grid line 20 that is disconnected from the solder strip to be connected to the nearest adjacent fine grid line 20, and then connected to the solder strip through the adjacent fine grid line 20. This reduces the change in the original connection path between the fine grid line 20 and the solder strip, and improves the ease of fabrication of the connecting grid lines 30. In this embodiment, the contact surface between the solder strip and the gridless photovoltaic cell 10 is not limited. However, it should be noted that when the spacing between the two connecting lines is set to 0.2 mm, and the width formed by the contact surface between the solder strip and the gridless photovoltaic cell 10 along the second direction reaches 0.2 mm, the solder strip can simultaneously cover the two connecting grid lines 30. This improves the conductivity of the connection between the solder strip and the grid line without damaging the grid line during soldering.
[0070] Furthermore, in order to reduce the stress when welding the solder strip to the gridless photovoltaic cell 10, the two connecting grid lines 30 at the location of each solder strip at the above-mentioned busbar start end 12 and busbar end end 15 can be interrupted at least at the outermost fine grid line 20.
[0071] It should be noted that in this embodiment, two connecting grid lines 30 are provided at both the starting end 12 and the ending end 15. By ensuring that at least the outermost fine grid line 20 between the two connecting grid lines 30 is interrupted (i.e., the outermost fine grid line 20 does not contact the solder strip), the stress during welding of the solder strip to the gridless photovoltaic cell 10 can be reduced, thus improving the stability of the solder strip welding. This embodiment does not limit the specific number of fine grid lines 20 interrupted between the two connecting grid lines 30 at the starting end 12 and the ending end 15. For example, two fine grid lines 20 can be provided interrupted between the two connecting grid lines 30, starting from the outermost fine grid line 20; or three fine grid lines 20 can be provided interrupted between the two connecting grid lines 30.
[0072] The gridless photovoltaic cell provided by this utility model embodiment, corresponding to the same solder strip, has a greater number of connecting grid lines 30 set at the start end 12 and the end end 15 than the number of connecting grid lines 30 set at the interconnect end 13. Under the premise of ensuring the limited material for the preparation of connecting grid lines 30, the effective utilization rate of connecting grid lines 30 is improved. While reducing the preparation cost, the problem of poor conductivity at the edge of the gridless photovoltaic cell 10 is more effectively improved.
[0073] Furthermore, this embodiment of the invention provides two connecting grid lines 30 at the solder ribbon laying positions corresponding to the starting end 12 and the ending end 15 of the busbar, while providing only one connecting grid line 30 at the solder ribbon laying position corresponding to the interconnection end 13. This significantly improves the conductivity of the edge region of the gridless photovoltaic cell 10 while ensuring manufacturing costs. Setting the spacing between the two connecting grid lines 30 corresponding to each solder ribbon to 0.2 mm to 1 mm reduces the alteration of the original fine grid line 20 and the solder ribbon's conductive path, improving the ease of fabrication of the connecting grid lines 30. By interrupting at least the outermost fine grid line 20 between the two connecting grid lines 30 at each location, the stress during solder ribbon welding to the gridless photovoltaic cell 10 is reduced, improving the stability of the solder ribbon welding.
[0074] In one feasible embodiment, the above-mentioned grid-free photovoltaic cell may specifically include:
[0075] The surface of the gridless photovoltaic cell is provided with several fine grid lines, which are arranged at intervals along a first direction and extend along a second direction perpendicular to the first direction.
[0076] A gridless photovoltaic cell has a first surface and a second surface opposite to each other, and a busbar start end is formed on the first surface along a first direction, and a busbar termination end is formed on the second surface along the first direction.
[0077] Both the end of the first surface away from the start of the bus and the end of the second surface away from the end of the bus in the first direction are interconnection terminals.
[0078] At the starting end, ending end and interconnection end of the bus, a connecting grid line is provided at the corresponding position of the solder strip, and each connecting grid line is connected to at least two thin grid lines.
[0079] At the starting end of the bus, two connecting grid lines are installed at the laying position of each welding strip. At the ending end of the bus, two connecting grid lines are installed at the laying position of each welding strip. At the interconnection end, a single connecting grid line is installed at the laying position of each welding strip.
[0080] At the starting end of the bus, corresponding to the laying position of each welding strip, the spacing between the two connecting grid lines is 0.2 mm to 1 mm. At the ending end of the bus, corresponding to the laying position of each welding strip, the spacing between the two connecting grid lines is 0.2 mm to 1 mm.
[0081] At the starting and ending points of the busbar, corresponding to the laying position of each solder strip, the two connecting grid lines shall be interrupted at least at the outermost fine grid line.
[0082] The length of the connecting grid wire is 1.5 mm to 15 mm;
[0083] At the intersection of the fine grid line and the connecting grid line, a thickened sub-grid line with a gradually changing width along the second direction is provided; along the first direction, the length of the thickened sub-grid line on the outer side is greater than the length of the thickened sub-grid line on the inner side.
[0084] The following describes a photovoltaic module provided by an embodiment of the present invention. The photovoltaic module described below can be referred to in correspondence with the gridless photovoltaic cell described above.
[0085] The photovoltaic module provided in this embodiment of the utility model includes a battery layer formed by multiple busbarless photovoltaic cell strings connected by a common flow.
[0086] The gridless photovoltaic cell string includes a solder ribbon 2, a carrier film, and multiple gridless photovoltaic cells 10 arranged sequentially as described above;
[0087] The welding ribbon 2 is placed on the surface of the gridless photovoltaic cell 10, and the carrier film is laid on the outside of the welding ribbon 2;
[0088] In each pair of adjacent gridless photovoltaic cells 10, a first cell and a second cell are divided, and the solder strip on the first surface of the first cell extends to the second surface of the second cell through the gap between the first cell and the second cell.
[0089] It should be noted that the gridless photovoltaic cell string in this embodiment can refer to... Figure 8 , Figure 8 This is a schematic diagram of a gridless photovoltaic cell string in a photovoltaic module provided by an embodiment of the present invention. In this embodiment, the photovoltaic module may further include a front encapsulating film and a front cover plate located on the front side of the cell layer, and a back encapsulating film and a back plate located on the back side of the cell layer. In this embodiment, in two adjacent gridless photovoltaic cells 10, a solder ribbon 2 is laid on the first surface of one of the cells. The starting end of the solder ribbon 2 is located at the current-carrying start end of the cell, and the solder ribbon extends to the second surface of the adjacent cell. Specifically, the ending end of the solder ribbon is located at the current-carrying end of the adjacent cell, to complete the current-carrying connection between the two adjacent cells. In this embodiment, the connecting grid line 3 at the current-carrying start end, the connecting grid line 4 at the current-carrying end, and the connecting grid line 5 at the interconnection end are as follows... Figure 8 As shown in the image.
[0090] The photovoltaic module provided in this embodiment includes a battery layer formed by multiple gridless photovoltaic cell strings connected by a busbar. The gridless photovoltaic cell string includes a solder ribbon 2, a carrier film, and multiple gridless photovoltaic cells 10 arranged sequentially as described above. The solder ribbon 2 is disposed on the surface of the gridless photovoltaic cell 10, and the carrier film is laid on the outside of the solder ribbon 2. In each pair of adjacent gridless photovoltaic cells 10, a first cell and a second cell are divided. The solder ribbon 2 at the first surface of the first cell extends to the second surface of the second cell through the gap between the first cell and the second cell. The gridless photovoltaic cell 10 has a plurality of fine grid lines on its surface, which are spaced apart along a first direction and extend along a second direction. The gridless photovoltaic cell has a first surface and a second surface, with a current-charging start end formed on the first surface along the first direction and a current-charging end formed on the second surface along the first direction. The end of the first surface away from the current-charging start end and the end of the second surface away from the current-charging end along the first direction are both interconnect ends. The current-charging start end, the current-charging end, and the interconnect end are all provided with connecting grid lines at the positions where the solder strips are laid, and each connecting grid line connects at least two fine grid lines. The number of connecting grid lines provided at the current-charging start end and the current-charging end corresponding to the position where a solder strip is laid is not less than the number of connecting grid lines provided at the interconnect end corresponding to the position where the same solder strip is laid. This invention addresses the issue of poor conductivity in the edge region of photovoltaic cells by setting a busbar start end, a busbar end, and an interconnection end. At each location corresponding to the placement of the solder ribbon 2, a connecting grid line is provided that simultaneously connects at least two fine grid lines. This connecting grid line enables the transmission of photocurrent collected by the fine grid lines at the edge of the gridless photovoltaic cell to other fine grid lines via the connecting grid line when the connection is broken, and then to the solder ribbon 2. Furthermore, considering the problem that the conductivity of the solder ribbon 2 is worse at the start and end ends compared to the interconnection end, by ensuring that the number of connecting grid lines at the busbar start and end ends is no less than the number at the interconnection end, the poor conductivity in the edge region of the photovoltaic cell can be improved while maintaining a lower manufacturing cost.
[0091] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0092] Furthermore, it should be noted that in this document, relationships such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion.
[0093] The present invention provides a detailed description of a gridless photovoltaic cell and photovoltaic module. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the structure and core idea of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A gridless photovoltaic cell, characterized by, The surface of the main-grid-free photovoltaic cell is provided with a plurality of fine grid lines, which are arranged at intervals along a first direction and extend along a second direction; The main-grid-free photovoltaic cell is formed with opposite first and second surfaces, and a busbar starting end is formed on the first surface along the first direction, and a busbar ending end is formed on the second surface along the first direction; An end of the first surface away from the busbar starting end along the first direction and an end of the second surface away from the busbar ending end along the first direction are both interconnection ends; The busbar starting end, the busbar ending end and the interconnection end are each provided with a connection grid line at a position corresponding to the laying position of a solder strip, and each connection grid line is connected to at least two fine grid lines; The number of connection grid lines provided at a position corresponding to the laying position of a solder strip at the busbar starting end and the busbar ending end is not less than the number of connection grid lines provided at a position corresponding to the laying position of the same solder strip at the interconnection end.
2. The gridless photovoltaic cell of claim 1, wherein, The number of connection grid lines provided at a position corresponding to the laying position of a solder strip at the busbar starting end and the busbar ending end is greater than the number of connection grid lines provided at a position corresponding to the laying position of the same solder strip at the interconnection end.
3. The gridless photovoltaic cell of claim 2, wherein, The busbar starting end is provided with two connection grid lines at a position corresponding to the laying position of each solder strip, and the busbar ending end is provided with two connection grid lines at a position corresponding to the laying position of each solder strip; The interconnection end is provided with a single connection grid line at a position corresponding to the laying position of each solder strip.
4. The gridless photovoltaic cell of claim 3, wherein, The spacing between the two connection grid lines provided at a position corresponding to the laying position of each solder strip at the busbar starting end is 0.2-1 mm; The spacing between the two connection grid lines provided at a position corresponding to the laying position of each solder strip at the busbar ending end is 0.2-1 mm.
5. The gridless photovoltaic cell of claim 3, wherein, Between the two connection grid lines provided at a position corresponding to the laying position of each solder strip at the busbar starting end and the busbar ending end, at least the outermost fine grid line is interrupted.
6. The gridless photovoltaic cell of claim 1, wherein, The length of the connection grid line is 1.5-15 mm.
7. The gridless photovoltaic cell of claim 1, wherein, The busbar starting end is provided with two connection grid lines at a position corresponding to the laying position of each solder strip; The busbar ending end is provided with two connection grid lines at a position corresponding to the laying position of each solder strip; The interconnection end is provided with two connection grid lines at a position corresponding to the laying position of each solder strip.
8. The gridless photovoltaic cell of claim 1, wherein, At the intersection of the fine grid line and the connection grid line, a thickened sub-grid line with a width gradually changing along the second direction is provided.
9. The gridless photovoltaic cell of claim 8, wherein, Along the first direction, the length of the thickened sub-grid line on the outside is greater than the length of the thickened sub-grid line on the inside.
10. A photovoltaic module, characterized by, The photovoltaic module comprises a cell layer formed by a plurality of main-grid-free photovoltaic cell strings connected by busbars; The main-grid-free photovoltaic cell string comprises a solder strip, a carrier film, and a plurality of main-grid-free photovoltaic cells arranged in sequence as claimed in any one of claims 1-9; The solder strip is arranged on the surface of the main-grid-free photovoltaic cell, and the carrier film is laid on the outside of the solder strip; In each of two adjacent ones of the free-grid photovoltaic cells, a first cell piece and a second cell piece are defined, and a ribbon at the first surface of the first cell piece extends through a gap between the first cell piece and the second cell piece to the second surface of the second cell piece.