Grid line electrode of photovoltaic cell, photovoltaic cell and photovoltaic module

Abstract

The utility model relates to the technical field of photovoltaic cells, and specifically discloses a grid line electrode of a photovoltaic cell, a photovoltaic cell, and a photovoltaic module. The grid line electrode of the photovoltaic cell includes a main grid line and a thin grid line; the thin grid line includes a first widening section, a connecting section, and a second widening section, and the two ends of the connecting section are respectively connected to the first widening section and the second widening section; the line widths of the first widening section and the second widening section are both greater than the line width of the connecting section, and the two edges of the main grid line are respectively overlapped with the first widening section and the second widening section, so that the connecting section is located within the two edges of the main grid line. The grid line electrode of the photovoltaic cell can reduce the cost of the metal slurry used to make the thin grid line, and can also greatly increase the welding resistance of the thin grid line, effectively avoid the risk of grid breakage during welding, and greatly improve the welding yield of the photovoltaic module.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, and in particular to a grid line electrode of a photovoltaic cell, a photovoltaic cell and a photovoltaic component. Background Art

[0002] In recent years, in order to meet people's demand for cost reduction and efficiency improvement of photovoltaic products, the fine grid lines used in photovoltaic cells have been gradually refined, and the solder resistance of the metal slurry used to make the fine grid lines has also deteriorated; therefore, in the process of manufacturing photovoltaic modules, since the welding ribbon is welded at the junction of the main grid line and the auxiliary grid line (or fine grid line), the welding ribbon can easily melt the fine grid line of the photovoltaic cell, which in turn brings challenges to the welding yield of photovoltaic modules.

[0003] In order to reduce the risk of grid breakage during welding, publication number CN208256683U discloses a front electrode structure of a multi-busbar battery and a solar cell, wherein the secondary grid line is composed of a straight segment and a deformed segment, the deformed segment is arranged at the intersection of the secondary grid line and the main grid line, and the width of the deformed segment gradually widens from the end of the straight segment to the main grid line; thus, the problem of secondary grid line welding breakage during the welding process of the multi-busbar battery is improved by widening the deformed segment. However, when the welding strip is offset by a large distance, the welding strip will contact the position where the width of the deformed segment is smaller, which will still increase the risk of grid breakage during welding.

[0004] In addition, in order to reduce the risk of grid breakage during welding, the publication number CN216084903U also discloses a solar cell grid line structure and a photovoltaic module, wherein the main grid and the auxiliary grid are overlapped, and the auxiliary grid is provided with two support parts, which are respectively located on the left and right sides of the overlap. When the welding boundary of the photovoltaic welding strip is located on the support part, the risk of grid breakage during welding can be reduced. However, the existing solar cell grid line structure defines that: the distance from the welding boundary to the main grid is greater than the distance from the welding boundary to the edge of the support part close to the main grid; that is, there is a spacing between the edge of the main grid and the support part, and the main grid and the support part do not overlap. Within this spacing, the main grid and the unwidened auxiliary grid are overlapped. The applicant found based on the analysis of the sample pieces of the photovoltaic module welding grid breakage that the welding grid breakage is mainly caused by the offset of the welding strip and the failure to weld in the middle of the main grid. Therefore, if the edge of the welding strip of the existing solar cell grid line structure is offset to the spacing position between the main grid and the support part (that is, offset to the position of the auxiliary grid overlapped with the main grid), there will still be a risk of grid breakage during welding. Utility Model Content

[0005] The utility model aims to overcome the deficiencies of the prior art and provide a grid line electrode of a photovoltaic cell, a photovoltaic cell and a photovoltaic module.

[0006] Based on this, the utility model discloses a grid line electrode of a photovoltaic cell, including a main grid line and a thin grid line;

[0007] The thin grid line comprises a first widening section, a connecting section and a second widening section, and two ends of the connecting section are respectively connected to the first widening section and the second widening section;

[0008] The line widths of the first widening section and the second widening section are both greater than the line width of the connecting section, and two edges of the main grid line are overlapped with the first widening section and the second widening section respectively, so that the connecting section is located within two edges of the main grid line.

[0009] Preferably, the line width of the first widening section is consistent with the line width of the second widening section, and the line widths of the first widening section and the second widening section at various positions are consistent;

[0010] The line width d1 of the first widening section and the line length L1 of the second widening section are both 25-35 μm, and the line length L1 are both 400-600 μm.

[0011] Preferably, the line width d2 of the connecting segment is 11-16 μm, and the line length L2 is 30-50 μm.

[0012] Further preferably, the total projected area S of the first widening section, the connecting section and the second widening section is less than 0.03 mm 2 .

[0013] Further preferably, the first widening section, the connecting section and the second widening section are an integrally connected structure.

[0014] Preferably, the grid line electrode of a photovoltaic cell of the utility model further includes a transition section; the first widening section and the connecting section as well as the second widening section and the connecting section are connected via the transition section.

[0015] Further preferably, the line width of the transition section gradually increases from one end to the other end thereof, the wide end of the transition section is connected to the first widening section or the second widening section, and the narrow end of the transition section is connected to the connecting section.

[0016] More preferably, the line width of the wide end of the transition section is consistent with the line width of the first widening section or the second widening section, and the line width of the narrow end of the transition section is consistent with the line width of the connecting section;

[0017] The transition section connected to both ends of the connection section is also located within the two edges of the main grid line; the line length L3 of the transition section is 5-15 μm.

[0018] The utility model also discloses a photovoltaic cell, including a semiconductor silicon wafer and a gate electrode arranged on the semiconductor silicon wafer, wherein the gate electrode includes at least one gate electrode of a photovoltaic cell described above in the utility model, and a welding strip is provided at the overlap between the main gate line and the first widening section and the second widening section.

[0019] The utility model also discloses a photovoltaic assembly, comprising a photovoltaic front plate, a photovoltaic cell and a photovoltaic back plate stacked in sequence from top to bottom, wherein the photovoltaic cell is a photovoltaic cell described above in the utility model.

[0020] Compared with the prior art, the utility model has at least the following beneficial effects:

[0021] In the grid line electrode of the photovoltaic cell of the utility model, the line widths of the first widening section and the second widening section of the thin grid line are made larger than the line width of its connecting section, so as to increase the line widths of the first widening section and the second widening section, so as to increase the welding resistance at the first widening section and the second widening section of the thin grid line, so as to avoid the risk of grid breakage due to welding at the first widening section and the second widening section; at the same time, since the line width of the connecting section in the middle of the thin grid line is relatively small, the metal paste required for making the connecting section can also be saved, thereby reducing the cost; moreover, the two edges of the main grid line are overlapped with the first widening section and the second widening section respectively, so that the connecting section is located within the two edges of the main grid line, that is, the connecting section in the middle of the thin grid line is covered by the main grid line, so that the connecting section has the presence of the main grid line, and even if the connecting section does not use a larger line width, the high welding resistance of the connecting section can be ensured to effectively avoid the risk of grid breakage due to welding.

[0022] Therefore, the grid line electrode of the photovoltaic cell of the present invention can reduce the cost of metal paste used to make fine grid lines while greatly increasing the welding resistance of the fine grid lines, effectively avoiding the risk of grid breakage during welding, and greatly improving the welding yield of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the local structure of welding the grid line electrode and the welding strip of a photovoltaic cell of this embodiment.

[0024] Figure 2 for Figure 1 A partial enlarged view of the part marked with number A.

[0025] Figure 3 It is a schematic structural diagram of a grid line electrode of a photovoltaic cell according to this embodiment.

[0026] Description of the reference numerals: main grid line 1; left edge 11; right edge 12; thin grid line 2; first widening section 21; connecting section 22; second widening section 23; transition section 24; welding strip 3. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] Example

[0029] A grid electrode of a photovoltaic cell of this embodiment, see Figure 1-3 , including a main grid line 1 and a thin grid line 2. In practice, the thin grid line 2 is arranged horizontally on the photovoltaic cell to collect the current generated by the photovoltaic cell, and the main grid line 1 is arranged vertically on the photovoltaic cell to collect the current of each thin grid line 2, and the welding strip 3 is welded at the overlap of the main grid line 1 and the thin grid line 2 (such as Figure 1 As shown), to serve as a connecting conductor.

[0030] In this embodiment, see Figure 2 The fine grid line 2 includes a first widening section 21, a connecting section 22 and a second widening section 23. Figure 2 As shown, the left end of the connecting section 22 is connected to the first widening section 21, and the right end of the connecting section 22 is connected to the second widening section 23; moreover, the line width of the first widening section 21 is greater than the line width of the connecting section 22, and the line width of the second widening section 23 is also greater than the line width of the connecting section 22, so that the wire grid line presents a shape in which the line width of the middle connecting section 22 is small, and the line widths of the first widening section 21 and the second widening section 23 at the left and right ends are large. In this way, by increasing the line width of the first widening section 21 and the second widening section 23, the welding resistance of the first widening section 21 and the second widening section 23 of the fine grid line 2 is increased, avoiding the risk of welding and breaking the grid at the left and right ends of the fine grid line 2. The line width of the connecting section 22 in the middle of the fine grid line 2 is small, so it can also save the metal paste required for making the connecting section 22, reducing costs.

[0031] Further, if Figure 2 As shown, the left edge 11 of the main grid line 1 overlaps with the first widening section 21, and the right edge 12 of the main grid line 1 overlaps with the second widening section 23; in this way, the main grid line 1 and the thin grid line 2 in the grid line electrode of the photovoltaic cell of this embodiment are overlapped. At this time, the connecting section 22 is completely located within the left edge 11 and the right edge 12 of the main grid line 1, that is, the connecting section 22 in the middle of the thin grid line 2 is completely covered by the main grid line 1. In this way, the connecting section 22 has the existence of the main grid line 1, and even if the connecting section 22 does not use a larger line width, the high welding resistance of the connecting section 22 can be ensured to effectively avoid the risk of welding broken grid.

[0032] Therefore, the grid line electrode of the photovoltaic cell of this embodiment can not only reduce the cost of the metal paste used to make the fine grid line 2, but also greatly increase the welding resistance of the fine grid line 2, effectively avoid the risk of grid breakage during welding, and greatly improve the welding yield of the photovoltaic module.

[0033] In practice, the line width of the connecting segment 22 is the same as the line width of the existing thin gate line that has not been widened. Specifically, the line width d2 of the connecting segment 22 is 11-16 μm (such as 14 μm), and the line length L2 of the connecting segment 22 is 30-50 μm (such as Figure 3Thus, the cost of raw materials for making the connecting section 22 is reduced, and the connecting section 22 is ensured to be located between the left edge 11 and the left edge 12 of the main grid line 1.

[0034] Preferably, the line width of each position of the first widening section 21 is kept consistent, and the line width of each position of the second widening section 23 is also kept consistent; moreover, the line width of the first widening section 21 is consistent with the line width of the second widening section 23. In this way, it is ensured that each position of the first widening section 21 and the second widening section 23 has high solder resistance.

[0035] Specifically, Figure 3 As shown, the line width d1 of the first widening section 21 and the second widening section 23 are both 25-35 μm (such as 30 μm), and the line length L1 of the first widening section 21 and the second widening section 23 are both 400-600 μm (such as 457 μm). In this way, the line width of the first widening section 21 and the second widening section 23 is increased, and the first widening section 21 and the second widening section 23 are ensured to have a longer line length, so as to further improve the welding resistance of the fine grid line 2 to prevent the risk of grid breakage due to welding.

[0036] Furthermore, in the grid electrode of the photovoltaic cell of this embodiment, the total projected area S of the first widening section 21, the connecting section 22 and the second widening section 23 is smaller than 0.03 mm 2 (such as 0.0294mm 2 ). However, the total projection area of ​​the deformation segment of the secondary grid line in the prior art such as CN208256683U is usually larger than 0.03mm 2 (such as 0.037mm 2 Thus, while improving the solder resistance of the fine grid lines 2, the consumption of metal paste (such as silver paste) and the cost of raw materials required for manufacturing the fine grid lines 2 not only do not increase, but decrease.

[0037] In addition, to ensure smooth transition connection between the first widening section 21 and the connecting section 22, and between the second widening section 23 and the connecting section 22, and to improve the overall printing performance of the fine grid line 2. Figure 2-3 The grid line electrode of the photovoltaic cell of this embodiment also includes a transition section 24, the first widening section 21 and the connecting section 22 are connected by a transition section 24, and the second widening section 23 and the connecting section 22 are also connected by another transition section 24; the first widening section 21, the transition section 24, the connecting section 22 and the second widening section 23 are preferably an integrally connected structure to simplify the structure and reduce the manufacturing cost.

[0038] Specifically, the line width of the transition section 24 gradually increases from one end to the other end, the wide end of the transition section 24 (i.e., the end of the transition section 24 with a larger line width) is connected to the first widening section 21 or the second widening section 23, and the narrow end of the transition section 24 (i.e., the end of the transition section 24 with a smaller line width) is connected to the connecting section 22.

[0039] Furthermore, the line width of the wide end of the transition section 24 is consistent with the line width of the first widening section 21 or the second widening section 23, and the line width of the narrow end of the transition section 24 is consistent with the line width of the connecting section 22; so as to further ensure smooth transition connection between the first widening section 21 and the connecting section 22, and between the second widening section 23 and the connecting section 22, and further improve its printability. Preferably, the transition section 24 connected to the left and right ends of the connecting section 22 is also located within the left edge 11 and the right edge 12 of the main grid line 1 (such as Figure 2 As shown in FIG. 2 ), the solder resistance of the fine grid line 2 is further improved. Figure 3 As shown, the line length L3 of the transition section 24 is 5-15 μm (eg, 8 μm), so that the line length L3 of the transition section 24 is kept small to reduce the consumption of metal paste and further reduce the raw material cost of the fine gate line 2 .

[0040] A photovoltaic cell of the present embodiment comprises a semiconductor silicon wafer and a gate electrode arranged on the semiconductor silicon wafer, wherein the gate electrode comprises at least one gate electrode of the photovoltaic cell of the present embodiment described above, and a welding strip 3 (such as Figure 1 shown).

[0041] A photovoltaic module of the present embodiment includes a photovoltaic front panel, a photovoltaic cell and a photovoltaic back panel stacked in sequence from top to bottom, and the photovoltaic cell is a photovoltaic cell described above in the present embodiment.

[0042] In practice, in order to ensure the packaging effect of photovoltaic modules, a packaging adhesive layer is also set between the photovoltaic front panel and the photovoltaic cell, and between the photovoltaic cell and the photovoltaic back panel.

[0043] Although the preferred embodiments of the utility model embodiments have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the utility model embodiments.

[0044] The technical solution provided by the utility model is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. At the same time, for general technicians in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

Claims

1. A grid line electrode of a photovoltaic cell, characterized in that: Including main grid lines and fine grid lines; The thin grid line comprises a first widening section, a connecting section and a second widening section, and two ends of the connecting section are respectively connected to the first widening section and the second widening section; The line widths of the first widening section and the second widening section are both greater than the line width of the connecting section, and two edges of the main grid line are overlapped with the first widening section and the second widening section respectively, so that the connecting section is located within two edges of the main grid line.

2. A grid line electrode for a photovoltaic cell according to claim 1, characterized in that: The line width of the first widening section is consistent with the line width of the second widening section, and the line widths of the first widening section and the second widening section at each position are consistent; The line width d1 of the first widening section and the line length L1 of the second widening section are both 25-35 μm, and the line length L1 are both 400-600 μm.

3. A grid line electrode for a photovoltaic cell according to claim 1, characterized in that: The line width d2 of the connecting section is 11-16 μm, and the line length L2 is 30-50 μm.

4. A grid line electrode for a photovoltaic cell according to any one of claims 1 to 3, characterized in that: The total projected area S of the first widening section, the connecting section and the second widening section is less than 0.03 mm 2 .

5. A grid line electrode for a photovoltaic cell according to any one of claims 1 to 3, characterized in that: The first widening section, the connecting section and the second widening section are an integrally connected structure.

6. The grid line electrode of a photovoltaic cell according to claim 1, characterized in that: It also includes a transition section; the first widening section and the connecting section as well as the second widening section and the connecting section are connected via the transition section.

7. A grid line electrode for a photovoltaic cell according to claim 6, characterized in that: The line width of the transition section gradually increases from one end to the other end, the wide end of the transition section is connected to the first widening section or the second widening section, and the narrow end of the transition section is connected to the connecting section.

8. A grid line electrode for a photovoltaic cell according to claim 7, characterized in that: The line width of the wide end of the transition section is consistent with the line width of the first widening section or the second widening section, and the line width of the narrow end of the transition section is consistent with the line width of the connecting section; The transition section connected to both ends of the connection section is also located within the two edges of the main grid line; the line length L3 of the transition section is 5-15 μm.

9. A photovoltaic cell, comprising a semiconductor silicon wafer and a gate electrode arranged on the semiconductor silicon wafer, characterized in that: The grid line electrode comprises at least one grid line electrode of a photovoltaic cell according to any one of claims 1 to 8, and a welding strip is provided at the overlap between the main grid line and the first widening section and the second widening section.

10. A photovoltaic module, comprising a photovoltaic front panel, a photovoltaic cell and a photovoltaic back panel stacked in sequence from top to bottom, characterized in that: The photovoltaic cell is a photovoltaic cell as claimed in claim 9.

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