Solar cell
By designing the harpoon part and overlapping interval in the main gate and fine gate structure of the solar cell, the problems of dummy welding and hidden cracking during the welding process are solved, and higher welding quality and detection efficiency are achieved.
Patent Information
- Application Number
- CN202420321688.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-21
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2034-02-21
AI Technical Summary
Existing solar cell cells are prone to false welding and hidden cracking during welding.
A solar cell is designed, with the main gate and fine gate structure including a harpoon portion, a closed end and an open end. The harpoon portion overlaps the closed end of the harpoon portion and forms overlapping intervals at the harpoon position to improve welding quality.
Through the improved structural design, the proportion of welding dummy and hidden cracks has been reduced, 0.3% and 0.22% respectively, improving the welding quality and detection efficiency of solar cells.
Smart Images
Figure CN222655669U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of photovoltaic cells, and more specifically, to a solar cell sheet. Background Art
[0002] Solar cells, also known as photovoltaic cells, are semiconductor devices that convert sunlight directly into electrical energy. Solar cell photovoltaic modules include multiple solar cells welded by welding ribbons, where the solar cells are made of polycrystalline silicon wafers through a series of processes.
[0003] The grid line structure of existing solar cells generally includes a plurality of thin grid lines spaced apart laterally and a plurality of main grid lines spaced apart longitudinally and intersecting with the thin grid lines. During the welding process of the welding strips, the solar cells of the existing technology are prone to cold welding and hidden cracking.
[0004] Therefore, there is an urgent need to provide a solar cell that can improve the cold solder joints and hidden cracks during the welding process. Utility Model Content
[0005] In view of this, the utility model provides a solar cell comprising:
[0006] The main grid includes a first section extending along a first direction, two ends of the first section are respectively provided with a harpoon portion, the harpoon portion includes a closed end and an open end extending along the first direction, and a first welding point is provided at the closed end;
[0007] A fine grid extending along a second direction, the second direction intersecting the first direction;
[0008] The fine grid includes a first fine grid, which overlaps with the closed end along a first direction, and includes a plurality of sub-segments along a second direction, with a first interval between adjacent sub-segments, and the first interval overlaps with the closed end.
[0009] Optionally, along the second direction, the length of the first interval is less than or equal to the width of the closed end.
[0010] Optionally, the solar cell sheet further includes a first edge and a second edge arranged opposite to each other along a first direction; along the first direction, a distance between the closed end and the first edge is d1, and 6.5 mm≤d1≤7.5 mm.
[0011] Optionally, along the first direction, a distance between the opening end and the first edge is d2, 0.55 mm≤d2≤1.55 mm.
[0012] Optionally, along the first direction, a distance between the first fine grid and the first welding point is d3, and 0.11 mm≤d3≤0.41 mm.
[0013] Optionally, along the first direction, a distance between adjacent fine grids is d4, and 0.7 mm≤d4≤1.3 mm.
[0014] Optionally, along the first direction, the harpoon portion overlaps with M fine grids, 3≤M≤8.
[0015] Optionally, the fine grid further includes an edge fine grid, and along the first direction, the edge fine grid overlaps with the opening end. Along the second direction, the edge fine grid includes a plurality of edge fine grid sub-segments, and there is a second interval between adjacent edge fine grid sub-segments, and the second interval overlaps with the opening end.
[0016] Optionally, the number of edge fine grids is N, where 1≤N≤3.
[0017] Optionally, a plurality of second welding spots are further arranged on the first section along the first direction, and the second welding spots have the same area as the first welding spots.
[0018] Compared with the prior art, the solar cell provided by the utility model achieves at least the following beneficial effects:
[0019] The utility model provides a solar cell sheet, comprising: a main grid and a fine grid, wherein the main grid comprises a first section extending along a first direction, and two ends of the first section are respectively provided with harpoon parts, which are used to collect current near the edge of the solar cell sheet; a first welding point is provided at a closed end to provide a certain basis for subsequent welding of welding strips; the fine grid comprises a first fine grid, and along the first direction, the first fine grid overlaps with the closed end of the harpoon part, which is convenient for current collection, avoids the darkening phenomenon when the solar cell sheet is tested for EL, and improves the detection efficiency of the solar cell sheet; along the second direction, the first fine grid comprises a plurality of sub-segments, and a first interval is provided between adjacent sub-segments, and a first interval is provided between adjacent sub-segments, and a first interval is provided between adjacent sub-segments. An interval overlaps with the closed end, which can avoid the formation of a small amount of tin-lead alloy between the welding strip and the first fine grid at a position close to the first welding point when welding the welding strip, resulting in a bulge on the solar cell, thereby reducing the risk of hidden cracks in the solar cell; the problem of cold soldering caused by the welding strip having large fluctuations in height due to the inconsistent height between the welding strip and the main grid after the harpoon part and the fine grid are overlapped during the welding process, and the welding strip and the welding point are not tightly fitted, is improved. The cold soldering ratio of a solar cell provided by the utility model is reduced by about 0.3% compared with the solar cell in the prior art, and the hidden crack ratio is reduced by about 0.22% compared with the solar cell in the prior art.
[0020] Of course, any product implementing the present utility model does not necessarily need to achieve all of the above-mentioned technical effects at the same time.
[0021] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.
[0023] Figure 1 This is a schematic diagram of a solar cell provided by the utility model;
[0024] Figure 2 yes Figure 1 The enlarged schematic diagram of point A in the middle;
[0025] Figure 3 yes Figure 1 Schematic diagram of the structure of the main grid and fine grid at A in the middle;
[0026] 100-solar cell, 1-main grid, 11-first section, 12-fish fork portion, 121-closed end, 1211-connecting grid, 1212-extended grid, 122-open end, 2-fine grid, 21-first fine grid, 211-sub-segment, 22-edge fine grid, 221-edge fine grid sub-segment, 3-first edge, 4-second edge, 5-first welding point, 6-first interval, 7-second interval, y-first direction, x-second direction. DETAILED DESCRIPTION
[0027] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention.
[0028] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present invention, its application, or uses.
[0029] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.
[0030] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.
[0031] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0032] In the prior art, the main grid of a solar cell adopts a harpoon design near both ends of the edge, and a thin grid directly penetrates the harpoon and overlaps the main grid. In the direction perpendicular to the solar cell, the height of the thin grid near the welding point is significantly higher than the height between the main grid and the welding point. During the welding process, due to the large fluctuations in the height of the welding strip, the welding strip and the welding point are not tightly fitted, which can easily lead to a cold weld.
[0033] The utility model provides a solar cell sheet which can solve the above problems existing in the prior art.
[0034] Reference Figure 1-Figure 3 The utility model provides a solar cell 100, comprising: a main grid 1, the main grid 1 comprising a first section 11 extending along a first direction y, a harpoon portion 12 is provided at both ends of the first section 11, the harpoon portion 12 comprises a closed end 121 and an open end 122 extending along the first direction y, and a first welding point 5 is provided at the closed end 121;
[0035] A fine grid 2, the fine grid 2 extends along a second direction x, and the second direction x intersects the first direction y;
[0036] The fine grid 2 includes a first fine grid 21 , which overlaps with the closed end 121 along the first direction y. The first fine grid 21 includes a plurality of sub-segments 211 along the second direction x. There are first intervals 6 between adjacent sub-segments 211 , and the first intervals 6 overlap with the closed end 121 .
[0037] Specifically, the utility model provides a solar cell 100, comprising: a main grid 1, the main grid 1 comprising a first section 11 along a first direction y, the two ends of the first section 11 are respectively close to a first edge 3 and a second edge 4, and harpoon portions 12 are respectively arranged at the two ends of the first section 11; the harpoon portions 12 are arranged at both ends of the main grid 1, and when the welding strip is arranged during the welding process, the welding strip can be combed at the open end 122 of the harpoon portion 12 to avoid the welding strip and the fine grid 2 forming an alloy to produce a bulge, thereby reducing the risk of cracks caused by the welding bulge.
[0038] The harpoon portion 12 includes a closed end 121 and an open end 122 extending along the first direction y. Figure 3 The closed end 121 is composed of a small section of a connecting grid 1211 extending along the second direction x and an extended grid 1212 extending along the first direction y and arranged at both ends of the connecting grid 1211 along the second direction x; the open end 122 is composed of two relatively arranged extended grids 1212 extending along the first direction y and away from the connecting grid 1211; the closed end 121 of the harpoon portion 12 is provided with a first welding point 5.
[0039] A fine grid 2, the fine grid 2 extends along a second direction x, and the second direction x intersects the first direction y;
[0040] Among them, the fine grid 2 includes a first fine grid 21, and along the first direction y, the first fine grid 21 overlaps with the closed end 121, which is convenient for current collection, avoids the darkening phenomenon when the solar cell 100 is tested for EL, and improves the detection efficiency of the solar cell 100; along the second direction x, the first fine grid 21 includes a plurality of sub-segments 211, and there is a first interval 6 between adjacent sub-segments 211, and the first interval 6 overlaps with the closed end 121, so as to improve the welding process. The welding strip has large height fluctuations due to the inconsistent height between the harpoon part 12 and the fine grid 2 and the main grid 1, and the phenomenon of cold welding caused by the loose fit between the welding strip and the welding point can also be avoided. A small amount of tin-lead alloy is formed between the welding strip and the first fine grid 21 at a position close to the first welding point 5, and a bulge appears on the solar cell 100, thereby reducing the risk of hidden cracks.
[0041] It should be noted that along the second direction x, the distances between adjacent busbars 1 are equal, that is, the busbars 1 are evenly arranged on the solar cell 100 . Evenly arranging multiple busbars 1 can balance the current collection path and improve the working efficiency of the solar cell 100 .
[0042] It can be understood that the utility model provides a solar cell 100, comprising: a main grid 1 and a fine grid 2, the main grid 1 comprising a first section 11 extending along a first direction y, and a harpoon portion 12 is respectively arranged at both ends of the first section 11, for collecting current at the edge of the solar cell 100; a first welding point 5 is arranged at a closed end 121 to connect the harpoon portion 12 with the first section 11 of the main grid 1; the fine grid 2 comprises a first fine grid 21, along the first direction y, the first fine grid 21 overlaps with the closed end 121 of the harpoon portion 12, to facilitate current collection, avoid darkening when the solar cell 100 is tested for EL, and improve the detection efficiency of the solar cell 100; along the second direction x, the first fine grid 21 comprises There are multiple sub-segments 211, and there is a first interval 6 between adjacent sub-segments 211. The first interval 6 overlaps with the closed end 121, which can avoid the welding strip and the first fine grid 21 forming a small amount of tin-lead alloy at a position close to the first welding point 5, which may cause a bulge on the solar cell 100 and reduce the risk of hidden cracks. The problem of cold welding caused by the uneven height of the welding strip caused by the overlap of the harpoon part 12 and the fine grid 2 with the main grid during welding and the cold welding caused by the loose fit between the welding strip and the welding point is improved. The cold welding ratio of the solar cell 100 provided by the utility model is reduced by about 0.3% compared with the solar cell of the prior art, and the hidden crack ratio is reduced by about 0.22% compared with the solar cell of the prior art.
[0043] Table 1 is a comparison table of the proportion of poor welding of solar cells. The experimental group corresponds to the solar cells of this embodiment, and the control group corresponds to the solar cells of the prior art.
[0044] Table 1 Comparison table of poor welding ratio of solar cells
[0045] Welding deviation Cold soldering Hidden crack other Control group 0.21％ 0.53％ 0.62％ 0.10％ Experimental Group 0.20％ 0.21％ 0.40％ 0.10％
[0046] The utility model provides a solar cell 100, including a main grid 1, the main grid 1 includes a first section 11 extending along a first direction y, and two ends of the first section 11, namely, two ends close to a first edge 3 and a second edge 4 of the solar cell 100, are provided with a harpoon portion 12, and the harpoon portion 12 includes a closed end 121 and an open end 122 that are relatively arranged along the first direction y; the utility model provides a solar cell 100, further including a fine grid 2 arranged along a second direction x, wherein the fine grid 2 includes a first fine grid 21, and along the first direction y, the first fine grid 22 is provided with a first fine grid 21, and the first fine grid 22 is provided with a first fine grid 21. The fine grid 21 overlaps with the closed end 121; along the second direction x, the first fine grid 21 includes a plurality of sub-segments 211, and there is a first interval 6 between adjacent sub-segments 211, and the first interval 6 overlaps with the closed end 121; exemplary, the present application conducts a comparative experiment on the above-mentioned embodiments, as shown in Table 1, a solar cell provided by the present utility model is compared with a solar cell sheet in which the main grid near the edge adopts a harpoon design at both ends, and the auxiliary grid (i.e., the fine grid) directly penetrates the harpoon part and overlaps the main grid, and the welding deviation ratio of the control group (solar cell sheet of the prior art) is The percentage of the welding deviation of the experimental group (a solar cell 100 provided by the present invention) is 0.21%; the percentage of the false welding of the control group (solar cell of the prior art) is 0.53%, and the percentage of the false welding of the experimental group (a solar cell 100 provided by the present invention) is 0.21%; the percentage of the hidden cracks of the control group (solar cell of the prior art) is 0.62%, and the percentage of the hidden cracks of the experimental group (a solar cell 100 provided by the present invention) is 0.40%; the percentage of other (bad phenomena) of the control group (solar cell of the prior art) is 0.10%, and the percentage of other (bad phenomena) of the experimental group (a solar cell 100 provided by the present invention) is 0.10%; it can be seen that the percentage of the welding false welding of the experimental group (a solar cell 100 provided by the present invention) is about 0.3% lower than that of the solar cell of the control group (the prior art), which is a significant improvement; the percentage of the hidden cracks of the experimental group (a solar cell 100 provided by the present invention) is 0.22%, which is also a significant improvement; the welding deviation ratio of the experimental group (a solar cell 100 provided by the utility model) is also improved to a certain extent compared with the solar cell of the control group (existing technology). In summary, the solar cell 100 provided by the utility model is provided with harpoon parts 12 at both ends of the first section 11 extending along the first direction y of the main grid 1, and the first fine grid 21 extending along the second direction x overlaps with the closed end 121 of the harpoon part 12. Along the second direction x, the first fine grid 21 includes a plurality of sub-segments 211, and there is a first interval 6 between adjacent sub-segments 211. The first interval 6 overlaps with the closed end 121, which can effectively improve the phenomenon of cold welding caused by large fluctuations of the welding strip after the harpoon part 12 and the fine grid 2 overlap during welding, and the welding strip and the welding point are not tightly attached; it can also avoid the welding strip and the first fine grid 21 at the position close to the first welding point 5. The formation of a small amount of tin-lead alloy, which causes bulges on the solar cell 100, effectively reduces the risk of hidden cracks. .
[0047] In some optional embodiments, referring to Figure 2 and Figure 3 , along the second direction x, the length of the first interval 6 is less than or equal to the width of the closed end 121.
[0048] It should be noted that the width of the closed end 121 along the second direction x is the distance from the extended gate 1212 at one end of the connecting gate 1211 to the extended gate 1212 at the other end of the connecting gate 1211 along the second direction x.
[0049] Optionally, along the second direction x, the length of the first interval 6 is equal to the width of the closed end 121; Optionally, along the second direction x, the length of the first interval 6 is less than the width of the closed end 121. The utility model only exemplarily shows that along the second direction x, the length of the first interval 6 is equal to the width of the closed end 121 (refer to Figure 3 ), for the second direction x, the case where the length of the first interval 6 is smaller than the width of the closed end 121 is not shown.
[0050] It can be understood that along the second direction x, the length of the first interval 6 is less than or equal to the width of the closed end 121, which can effectively improve the phenomenon of cold soldering caused by the large ups and downs of the soldering ribbon and the loose fit between the soldering ribbon and the soldering point due to the overlap of the harpoon portion 12 and the fine grid 2 during the welding process; it can also avoid the formation of a small amount of tin-lead alloy between the soldering ribbon and the first fine grid 21 at a position close to the first soldering point 5, resulting in a bulge on the solar cell 100, effectively reducing the risk of hidden cracks.
[0051] In some optional embodiments, referring to Figure 1-Figure 2The solar cell 100 further includes a first edge 3 and a second edge 4 disposed opposite to each other along a first direction y; along the first direction y, a distance between the closed end 121 and the first edge 3 is d1, 6.5 mm ≤ d1 ≤ 7.5 mm.
[0052] It should be noted that, along the first direction y, the distance between the closed end 121 of the harpoon portion 12 close to the first edge 3 and the first edge 3 is equal to the distance between the closed end 121 of the harpoon portion 12 close to the second edge 4 and the second edge 4 .
[0053] Optionally, along the first direction y, the distance d1 between the closed end 121 and the first edge 3 can be 6.5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7.0mm, 7.1mm, 7.2mm, 7.3mm, 7.4mm and 7.5mm; when d1<6.5mm, along the first direction y, the distance between the closed end 121 and the first edge 3 is too small. If there is a large warping at the edge of the back panel glass, the pressure applied to the solar cell 100 by the warped portion of the edge of the back panel glass during lamination is relatively large, which is easy to cause cracks; when d1>7.5mm, along the first direction y, the distance between the closed end 121 and the first edge 3 is too small. If the distance is too large, the length of the harpoon portion 12 along the first direction y is relatively large, and the length of the first section 11 of the main grid 1 is relatively short, which affects the transmission of current on the solar cell 100 and reduces the battery efficiency. Therefore, along the first direction y, the distance between the closed end 121 and the first edge 3 is d1, and when 6.5mm≤d1≤7.5mm, the distance between the closed end 121 and the first edge 3 is appropriate, which can not only concentrate the current and speed up the current transmission efficiency, but also avoid cracks caused by the main grid 1 being too close to the first edge 3 or the second edge 4 of the solar cell 100 due to the relatively large pressure applied to the solar cell 100 by the warped edge of the back panel glass during lamination.
[0054] Optionally, along the first direction y, the distance d1 between the closed end 121 and the first edge 3 may also be 6.5 mm≤d1≤6.9 mm, 6.63 mm≤d1≤7.05 mm, 6.95 mm≤d1≤7.25 mm, 7.18 mm≤d1≤7.35 mm, and 7.33 mm≤d1≤7.5 mm.
[0055] In some optional embodiments, referring to Figure 2 , along the first direction y, the distance between the opening end 122 and the first edge 3 is d2, 0.55mm≤d2≤1.55mm.
[0056] It should be noted that, along the first direction y, the distance between the opening end 122 of the harpoon portion 12 close to the first edge 3 and the first edge 3 is equal to the distance between the opening end 122 of the harpoon portion 12 close to the second edge 4 and the second edge 4 .
[0057] Optionally, along the first direction y, the distance d2 between the opening end 122 and the first edge 3 can be 0.55mm, 0.56mm, 0.57mm, 0.58mm, 0.59mm, 0.60mm, 0.62mm, 0.65mm, 0.68mm, 0.70mm, 0.72mm, 0.75mm, 0.78mm, 0.80mm, 0.83mm, 0.85mm, 0.88mm, 0.90mm. , 0.93mm, 0.95mm, 1.00mm, 1.05mm, 1.08mm, 1.13mm, 1.18mm, 1.23mm, 1.25mm, 1.32mm, 1.34mm, 1.36mm, 1.38mm, 1.40mm, 1.42mm, 1.46mm, 1.48mm, 1.50mm, 1.53mm and 1.55mm; when d2<0.55mm, along the first direction y, The distance between the opening end 122 and the first edge 3 is too small, and the distance between the main grid 1 and the edge of the solar cell 100 is too small. For example, if there is a large warping at the edge of the back glass, the pressure applied to the solar cell 100 by the warped portion of the edge of the back glass is relatively large during lamination, which can easily cause cracks. When d2>1.55mm, along the first direction y, the distance between the opening end 122 and the first edge 3 is too large, and the main grid 1 is far away from the edge of the solar cell 100, resulting in dispersed current transmission and reduced current transmission efficiency of the solar cell 100. Therefore, when 0.55mm≤d2≤1.55mm, along the first direction y, the distance between the opening end 122 and the first edge 3 is appropriate, which can not only concentrate the current and speed up the current transmission efficiency, but also avoid cracks caused by the main grid 1 being too close to the first edge 3 or the second edge 4 of the solar cell 100 due to the large pressure applied to the solar cell 100 by the warped portion of the edge of the back glass during lamination.
[0058] Optionally, along the first direction y, the distance d2 between the opening end 122 and the first edge 3 may also be 0.55 mm≤d2≤0.75 mm, 0.65 mm≤d2≤0.80 mm, 0.75 mm≤d2≤1.12 mm, 0.93 mm≤d2≤1.35 mm and 1.25 mm≤d2≤1.55 mm.
[0059] In some optional embodiments, referring to Figure 2 Along the first direction y, the distance between the first fine grid 21 and the first welding point 5 is d3, 0.11mm≤d3≤0.41mm.
[0060] Optionally, along the first direction y, the distance d3 between the first fine grid 21 and the first welding point 5 can be 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.20mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.30mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.40mm and 0.41mm; when d3<0.11mm, along the first direction y, the distance d3 between the first fine grid 21 and the first welding point 5 can be 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.20mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.30mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, 0.40mm and 0.41mm. If the distance between the first welding points 5 is too small, the welding strip is likely to form an alloy with the fine grid 2 during welding to produce a bulge, increasing the risk of cracks caused by the welding bulge; when d3>0.41mm, along the first direction y, the distance between the first fine grid 21 and the first welding point 5 is too large, and the fine grid 2 is unevenly distributed or sparsely arranged, which will affect the solar cell 100's ability to absorb light, reduce the utilization rate of sunlight, and affect the battery efficiency; therefore, when 0.11mm≤d3≤0.41mm, along the first direction y, the distance between the first fine grid 21 and the first welding point 5 is appropriate, which can avoid the welding strip and the fine grid 2 being too close during welding, forming an alloy and causing the welding strip to produce bulges and cracks, and can also make the fine grid 2 evenly distributed, improve the utilization rate of sunlight by the solar cell 100, and improve the battery efficiency.
[0061] Optionally, along the first direction y, the distance d3 between the first fine grid 21 and the first welding point 5 may also be 0.11 mm≤d3≤0.21 mm, 0.18 mm≤d3≤0.29 mm, 0.27 mm≤d3≤0.35 mm, and 0.33 mm≤d3≤0.41 mm.
[0062] In some optional embodiments, referring to Figure 2 Along the first direction y, the distance between adjacent fine grids 2 is d4, 0.7mm≤d4≤1.3mm.
[0063] Optionally, along the first direction y, the distance d4 between adjacent fine grids 2 can specifically be 0.7mm, 0.72mm, 0.75mm, 0.77mm, 0.78mm, 0.8mm, 0.82mm, 0.84mm, 0.86mm, 0.88mm, 0.9mm, 0.93mm, 0.95mm, 0.98mm, 1.0mm, 1.13mm, 1.15mm, 1.2mm, 1.23mm, 1.25mm, and 1.3mm; when d4<0.7mm, along the first direction y, the distance between adjacent fine grids 2 is too small, the fine grids 2 are densely arranged, the number of fine grids 2 is large, and the length of each fine grid 2 needs to be shortened accordingly, resulting in a reduction in the area of the solar cell 100 unit, thereby increasing the total voltage and current. The size is reduced; too dense fine grids 2 will increase the internal resistance of the photovoltaic cell, reduce the electron transmission efficiency, and affect the performance of the solar cell 100; when d4>1.3mm, along the first direction y, the distance between adjacent fine grids 2 is too large, and the fine grids 2 are arranged sparsely, which reduces the light absorption capacity of the surface of the solar cell 100, weakens the utilization rate of sunlight, and affects the efficiency of the solar cell 100; so when 0.7mm≤d4≤1.3mm, along the first direction y, the distance between adjacent fine grids 2 is appropriate, and the fine grids 2 are evenly distributed, which can greatly reduce the total relative power loss of the top layer lateral current and the relative power loss of the fine grid 2 shading, thereby reducing the total power loss caused by the electrode and increasing the square resistance, while reducing the power loss caused by the electrode and improving the efficiency of the solar cell 100.
[0064] Optionally, along the first direction y, the distance d4 between adjacent fine grids 2 may also be 0.7 mm≤d4≤0.85 mm, 0.73 mm≤d4≤0.95 mm, 0.86 mm≤d4≤1.12 mm, 0.96 mm≤d4≤1.21 mm and 1.1 mm≤d4≤1.3 mm.
[0065] In some optional embodiments, referring to Figure 2 , along the first direction y, the harpoon portion 12 overlaps with M fine grids 2, 3≤M≤8.
[0066] It should be noted that along the first direction y, M fine grids 2 overlap with the harpoon portion 12 between the first fine grid 21 and the edge fine grid 22, which is convenient for current collection, ensures normal collection of carriers, and improves the efficiency of the solar cell 100.
[0067] Optionally, along the first direction y, the harpoon portion 12 overlaps with M fine grids 2, where M can specifically be 3, 4, 5, 6, 7 and 8; when M<3, the number of fine grids 2 overlapping with the harpoon portion 12 is small, which affects current collection and reduces the efficiency of the solar cell 100; when M>8, the number of fine grids 2 overlapping with the harpoon portion 12 is large, and the fine grids 2 are densely arranged; therefore, when 3≤M≤8, the number of fine grids 2 overlapping with the harpoon portion 12 is appropriate, which is convenient for current collection and ensures normal collection of carriers.
[0068] In some optional embodiments, referring to Figure 2 and Figure 3 The fine grid 2 also includes an edge fine grid 22. Along the first direction y, the edge fine grid 22 overlaps with the opening end 122. Along the second direction, the edge fine grid 22 includes a plurality of edge fine grid sub-segments 221. There are second intervals 7 between adjacent edge fine grid sub-segments 221, and the second intervals 7 overlap with the opening end 122.
[0069] It should be noted that the width of the opening end 122 along the second direction x is the distance from one extension grid 1212 to another extension grid 1212 of the opening end 122 of the harpoon portion 12 close to the first edge 3 or the second edge 4 along the second direction x.
[0070] Optionally, along the second direction x, the length of the second interval 7 may be equal to the width of the opening end 122; optionally, along the second direction x, the length of the second interval 7 may be less than the width of the opening end 122. The utility model only exemplarily shows that along the second direction x, the length of the second interval 7 is equal to the width of the opening end 121 (refer to Figure 3 ), the case where the second interval 7 is smaller than the width of the opening end 122 along the second direction x is not shown.
[0071] It can be understood that, along the first direction y, the edge fine grid 22 overlaps with the open end 122, which is convenient for current collection, avoids the darkening phenomenon when the solar cell 100 is tested for EL, and improves the detection efficiency of the solar cell 100; along the second direction, the edge fine grid 22 includes a plurality of edge fine grid sub-segments 221, and there is a second interval 7 between adjacent edge fine grid sub-segments 221, and the second interval 7 overlaps with the open end 122, so as to improve the phenomenon of cold soldering caused by the large fluctuation of the welding strip after the harpoon part 12 and the fine grid 2 are overlapped during the welding process, and the welding strip is warped. When welding the welding strip, the welding strip can be combed at the open end of the harpoon part 12 to avoid the welding strip and the harpoon part 12. The fine grid 2 forms a small amount of tin-lead alloy, which causes a bulge on the solar cell 100, thereby reducing the risk of hidden cracks.
[0072] In some optional embodiments, the number of the edge fine grids 22 is N, where 1≤N≤3.
[0073] Optionally, the number N of the edge fine grids 22 can be specifically 1, 2, or 3; when N>3, the number of the edge fine grids 22 is too large, and a large number of fine grids 2 that do not overlap with the harpoon portion 12 in the direction perpendicular to the plane where the solar cell 100 is located will affect the collection of carriers and affect the efficiency of the solar cell 100; when N=0, the fine grids 2 close to the first edge 3 or the second edge 4 penetrate the harpoon portion 12 and overlap the main grid 1, causing a bulge at the overlap between multiple fine grids 2 close to the first edge 3 or the second edge 4 and the main grid 1. During welding, the bulge of the welding strip is likely to cause defects such as cold welding or hidden cracks, so 1≤N≤3, which not only ensures that a certain number of edge fine grids 2 are set to avoid the bulge of the welding strip at the edge, further improves the phenomenon of cold welding, but also ensures that sufficient fine grids 2 penetrate the harpoon portion 12 and overlap the main grid 1, and does not affect the collection of carriers.
[0074] In some optional embodiments, a plurality of second welding spots (not shown in the figure) are further arranged on the first segment 11 along the first direction y, and the second welding spots have the same area as the first welding spots 5 .
[0075] It can be understood that the first welding point 5 is located at the position where the harpoon portion 12 is set on the main grid 1, connecting the first section 11 of the main grid 1 and the harpoon portion 12 to ensure the transmission of current. The second welding point is located on the main grid 1. There are multiple second welding points, which are used to collect current to ensure the transmission effect of current on the solar cell 100. The first welding point 5 and the second welding point have equal areas, so that the welding points on the solar cell 100 are evenly arranged, which enhances the aesthetics and facilitates the subsequent welding with the welding strip, avoiding defects such as cold welding, hidden cracks and welding deviation caused by the warping of the welding strip due to different sizes or heights of the welding points.
[0076] Optionally, the solar cell 100 provided by the present invention may be of various sizes available on the market, such as 158 mm*158 mm, 182 mm*182 mm, and 210 mm*210 mm.
[0077] Optionally, the solar cell 100 provided by the present invention may be a TOPcon cell or a PERC cell.
[0078] It can be seen from the above embodiments that the solar cell 100 provided by the utility model achieves at least the following beneficial effects:
[0079] The utility model provides a solar cell 100, comprising: a main grid 1 and a fine grid 2, wherein the main grid 1 comprises a first section 11 extending along a first direction y, and two ends of the first section 11 are respectively provided with a harpoon portion 12, which is used to collect current at the edge of the solar cell 100; a first welding point 5 is provided at a closed end 121 to provide a certain basis for subsequent welding of a welding strip; the fine grid 2 comprises a first fine grid 21, and along the first direction y, the first fine grid 21 overlaps with the closed end 121 of the harpoon portion 12, which is convenient for current collection, avoids the solar cell 100 from darkening when testing EL, and improves the detection efficiency of the solar cell 100; along the second direction x, the first fine grid 21 comprises a plurality of sub-segments 211 There is a first interval 6 between adjacent sub-segments 211, and the first interval 6 overlaps with the closed end 121, which can avoid the welding strip from forming a small amount of tin-lead alloy with the first fine grid 21 at a position close to the first welding point 5, causing a bulge on the solar cell 100, thereby reducing the risk of hidden cracks; improving the welding process due to the uneven height of the welding strip caused by the overlap of the harpoon part 12 with the fine grid 2 and the main grid 1, and the phenomenon of cold welding caused by the welding strip and the loose fit between the welding strip and the welding point. The cold welding ratio of the solar cell 100 provided by the utility model is reduced by about 0.3% compared with the solar cell of the prior art, and the hidden crack ratio is reduced by about 0.22% compared with the solar cell of the prior art.
[0080] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration rather than for limiting the scope of the present invention.
[0081] It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.
Claims
1. A solar cell, characterized in that: include: A main grid, the main grid comprising a first section extending along a first direction, two ends of the first section are respectively provided with a harpoon portion, the harpoon portion comprises a closed end and an open end extending along the first direction, and a first welding point is provided at the closed end; A fine grid extending along a second direction, wherein the second direction intersects the first direction; The fine grid includes a first fine grid, and along the first direction, the first fine grid overlaps with the closed end. Along the second direction, the first fine grid includes a plurality of sub-segments, and there is a first interval between adjacent sub-segments, and the first interval overlaps with the closed end.
2. The solar cell according to claim 1, characterized in that: Along the second direction, the length of the first interval is less than or equal to the width of the closed end.
3. The solar cell according to claim 1, characterized in that: The solar cell sheet further includes a first edge and a second edge arranged opposite to each other along the first direction; along the first direction, a distance between the closed end and the first edge is d1, and 6.5 mm≤d1≤7.5 mm.
4. The solar cell according to claim 3, characterized in that: Along the first direction, a distance between the opening end and the first edge is d2, and 0.55 mm≤d2≤1.55 mm.
5. The solar cell according to claim 1, characterized in that: Along the first direction, the distance between the first fine grid and the first welding point is d3, and 0.11 mm≤d3≤0.41 mm.
6. The solar cell according to claim 1, characterized in that: Along the first direction, the distance between adjacent fine grids is d4, and 0.7 mm≤d4≤1.3 mm.
7. The solar cell according to claim 1, characterized in that: Along the first direction, the harpoon portion overlaps with M of the fine grids, 3≤M≤8.
8. The solar cell according to claim 1, characterized in that: The fine grid also includes an edge fine grid, which overlaps with the opening end along the first direction, and includes a plurality of edge fine grid sub-segments along the second direction, with a second interval between adjacent edge fine grid sub-segments, and the second interval overlaps with the opening end.
9. The solar cell according to claim 8, characterized in that: The number of the edge fine grids is N, 1≤N≤3.
10. The solar cell according to claim 1, characterized in that: Along the first direction, a plurality of second welding spots are further arranged on the first segment, and the second welding spots have the same area as the first welding spots.