Solar cell

Abstract

The invention relates to a solar cell, which belongs to the field of solar cells and comprises a cell body, auxiliary grid lines and fine grid lines, a plurality of fine grid lines are uniformly distributed on the front surface of the cell body along a transverse center line, and a plurality of auxiliary grid lines vertically intersected with the fine grid lines are arranged on the front surface of the cell body. A plurality of welding contact points which are arranged at equal intervals and connected with the auxiliary grid lines are arranged on the fine grid lines, and the welding contact points are hollow-out; the fine grid lines comprise a first grid line and a second grid line which are adjacently arranged, and the first grid line and the second grid line are connected through a welding contact. According to the invention, the first grid lines and the second grid lines are spaced, and the welding contacts are hollow, so that the shielding of the main grid lines on the front surface of the cell is reduced, and the shading rate is reduced.

Description

Technical Field

[0001] The invention belongs to the field of solar cells, and in particular relates to a solar cell sheet. Background Art

[0002] Solar cells are an important part of converting solar energy into electrical energy, and solar cell grid lines are an important component in solar cells. The function of solar cell grid lines is to transmit the electrical energy generated in solar cells to the circuit, thereby realizing the power generation function of solar cells.

[0003] The grid lines of solar cells are divided into main grid lines and auxiliary grid lines. The front electrode of a conventional solar cell has 5 main grid lines with a width of about 1 mm. After welding with the welding ribbon, the shading area of ​​the front of the battery accounts for about 3.5% of the total area of ​​the battery. The shading rate is relatively high, which affects the input power of the battery. In addition, the silver paste consumption is high, and the production cost of the battery is high.

[0004] In order to solve the above problems, the present invention provides a new type of solar cell, which not only reduces the shading of the main grid line on the surface of the cell and reduces the shading rate, but also ensures that the battery electrode has good current collection and transmission capabilities. Summary of the invention

[0005] In view of the above problems, the present invention proposes a solar cell, comprising a cell body, auxiliary grid lines, and fine grid lines. The front side of the cell body is evenly distributed with a plurality of fine grid lines along the transverse center line. The front side of the cell body is provided with a plurality of auxiliary grid lines perpendicularly intersecting the fine grid lines. The fine grid lines are provided with a plurality of welding contacts equidistantly arranged and connected to the auxiliary grid lines, and the welding contacts are hollow. The fine grid lines include a first grid line and a second grid line adjacent to each other, and the first grid line and the second grid line are connected via welding contacts.

[0006] Furthermore, the first grid line and the second grid line are spaced 0.2 mm apart.

[0007] Furthermore, the width of the first gate line and the second gate line are both 0.04 mm.

[0008] Furthermore, the welding contact points include circular ring-shaped welding contact points and diamond-shaped welding contact points, and the circular ring-shaped welding contact points and diamond-shaped welding contact points are sequentially and repeatedly arranged on the fine grid lines.

[0009] Furthermore, the hollow shapes of the annular welding contact points and the diamond-shaped welding contact points are consistent with their own shapes.

[0010] Furthermore, the side length of the rhombus-shaped welding contact point is 0.6-1 mm.

[0011] Further, the side length of the hollowed-out shape of the diamond-shaped welding contact point is half of the side length of the diamond-shaped welding contact point.

[0012] Further, the diameter of the circular-ring-shaped welding contact point is 0.4 - 0.5 mm.

[0013] Further, 15 fine grid lines are evenly distributed along the horizontal center line on the front side of the battery cell body.

[0014] Further, the welding contact points are formed on the fine grid lines through a secondary printing process.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1) In the present invention, there is a spacing between the first grid line and the second grid line, and the welding contact points are hollowed out, so the occlusion of the main grid line on the front side of the battery cell is reduced, and the light-shielding rate is lowered.

[0017] 2) In the present invention, the first grid line and the second grid line are connected through the welding contact points, thus ensuring that the battery electrodes have good current collection and transmission capabilities.

[0018] 3) The present invention uses a group of the first grid line and the second grid line to replace a main grid line, reducing the occlusion on the front side of the battery cell, enabling the short-circuit current of the battery and the module to increase correspondingly, and thus improving the experimental efficiency.

[0019] 4) In the present invention, the welding contact points are all hollowed out, which can not only ensure good welding between the fine grid lines and the sub-grid lines, but also reduce the proportion of the light-shielding area and the silver paste used in printing.

[0020] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, the claims, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 Shows a schematic structural diagram according to an embodiment of the present invention;

[0023] Figure 2 Shows Figure 1 A partial enlarged view of A in

[0024] Figure 3 shows Figure 1 a partially enlarged view of B in

[0025] Reference numerals: 1, battery cell body; 11, fine grid lines; 111, first grid line; 112, second grid line; 12, sub-grid lines; 2, circular welding contact points; 3, diamond-shaped welding contact points. Specific embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] Figure 1 shows a schematic structural diagram according to an embodiment of the present invention. As Figure 1 shown, a solar cell includes a battery cell body 1 and sub-grid lines 12, and further includes fine grid lines 11. A plurality of fine grid lines 11 are evenly distributed along the horizontal center line on the front surface of the battery cell body 1. A plurality of sub-grid lines 12 perpendicular to and intersecting the fine grid lines 11 are provided on the front surface of the battery cell body 1. A plurality of welding contact points arranged at equal intervals and connected to the sub-grid lines 12 are provided on the fine grid lines 11, and the welding contact points are in a hollow shape; the fine grid lines 11 include adjacent first grid lines 111 and second grid lines 112, and the first grid lines 111 and the second grid lines 112 are connected through the welding contact points.

[0028] For the solar cell, through the distance between the first grid lines 111 and the second grid lines 112, the blockage of the main grid lines on the front surface of the battery cell is reduced, the light shielding rate is lowered, and good current collection and transmission capabilities of the battery electrodes are ensured through the hollow-shaped welding contact points.

[0029] In some embodiments, the distance between adjacent fine grid lines 11 is 11.933 mm; the blockage of the front surface of the battery cell body 1 is reduced, and the light shielding rate is lowered.

[0030] In some embodiments, 160 sub-grid lines 12 perpendicular to and intersecting the fine grid lines 11 are evenly distributed on the front surface of the battery cell body 1; the 160 sub-grid lines 12 can comprehensively collect the current of the first grid lines 111 and the second grid lines 112 and output it.

[0031] In some embodiments, the width of the auxiliary gate line 12 is 0.025 mm, and the spacing between adjacent auxiliary gate lines 12 is 1.1125 mm; the blocking of the front side of the cell by the auxiliary gate line 12 is reduced, and the light shielding rate is lowered.

[0032] In some embodiments, the spacing between adjacent auxiliary gate lines 12 is 1.1125 mm, the proportion of the light shielding area is reduced, the light receiving area of the cell body 1 is increased, the conversion efficiency of the cell is improved, and the power of the photovoltaic module is further enhanced.

[0033] In some embodiments, the spacing between the first gate line 111 and the second gate line 112 is 0.2 mm; the blocking of the front side of the cell by the main gate line is reduced, and the light shielding rate is lowered.

[0034] In some embodiments, the widths of the first gate line 111 and the second gate line 112 are both 0.04 mm; the blocking of the front side of the cell by the main gate line is reduced, and the light shielding rate is lowered.

[0035] In some embodiments, the first gate line 111 and the second gate line 112 are both perpendicularly intersecting with the auxiliary gate line 12 so that the auxiliary gate line 12 can collect the current generated by the first gate line 111 and the second gate line 112.

[0036] In some embodiments, the solder contact points include an annular solder contact point 2 and a diamond-shaped solder contact point 3, and the annular solder contact point 2 and the diamond-shaped solder contact point 3 are sequentially and repeatedly arranged on the fine gate line 11; the annular solder contact point and the diamond-shaped solder contact point 3 can increase the welding contact area and the height of the welding contact point, can also ensure good welding of the first gate line 111, the second gate line 112 and the auxiliary gate line 12, and can also reduce the proportion of the light shielding area.

[0037] In some embodiments, the hollow shapes of the annular solder contact point 2 and the diamond-shaped solder contact point 3 are both consistent with their own shapes; the light shielding area can be minimized to the greatest extent, and good welding of the first gate line 111, the second gate line 112 and the auxiliary gate line 12 is ensured. Because it is in a hollow shape, the silver paste used for printing is also reduced.

[0038] In some embodiments, the side length of the diamond-shaped solder contact point 3 is 0.6 - 1 mm; the welding area is ensured.

[0039] Figure 2 Shows Figure 1 A partial enlarged view of A in. As Figure 2 As shown, in some embodiments, the side length of the diamond-shaped solder contact point 3 is 0.8 mm; not only the welding quality is ensured, but also the welding height is increased.

[0040] In some embodiments, the side length of the hollow shape of the diamond-shaped welding contact point 3 is 0.4 mm, which reduces the shading area.

[0041] In some embodiments, the side length of the hollow shape of the diamond-shaped welding contact 3 is half of the side length of the diamond-shaped welding contact 3; this not only ensures the welding quality, but also increases the welding height.

[0042] In some embodiments, the diameter of the annular welding contact point 2 is 0.4-0.5 mm, which can increase the contact area of ​​welding and the welding height, and avoid abnormalities when welding the first grid line 111, the second grid line 112 and the auxiliary grid line 12.

[0043] Figure 3 Shows Figure 1 A partial enlarged view of B. Figure 3 As shown, in some embodiments, the diameter of the circular welding contact 2 is 0.45 mm, and the diameter of the hollow shape of the circular welding contact 2 is 0.25 mm; it can increase the contact area of ​​welding and increase the welding height, and can also ensure good welding of the first grid line 111, the second grid line 112 and the auxiliary grid line 12.

[0044] In some embodiments, 15 groups of fine grid lines 11 are evenly distributed along the horizontal center line on the front side of the battery cell body 1; the first grid lines 111 and the second grid lines 112 replace the main grid lines, which not only reduces the shading area of ​​the grid lines on the front side of the battery cell body 1, but also increases the short-circuit current of the battery and the components accordingly, thereby improving the test efficiency.

[0045] In some embodiments, the welding contact points are formed on the fine grid lines 11 through a secondary printing process, which can increase the welding contact area and the welding height.

[0046] The working principle of solar cells is as follows:

[0047] There is a gap between the first grid line 111 and the second grid line 112 and the welding contact point is hollow, which greatly reduces the shielding of the front of the battery cell. Among them, the battery cell body 1 is made, and the first grid line 111, the second grid line 112, and the auxiliary grid line 12 are screen-printed on the front of the battery cell body 1, and then the slurry is printed at equal intervals at the intersection of the first grid line 111, the second grid line 112 and the auxiliary grid line 12 to form a hollow welding contact point, and different patterns can use different screens. The welding contact point can not only increase the welding area, but also reduce the shielding of the main grid line on the front of the battery cell, thereby reducing the shading rate.

[0048] The size of the front side of a conventional battery is 182mm×182mm, with 5 main grid lines each 1mm wide and 160 secondary grid lines each 25μm wide. The main grid lines can be in a hollowed-out form to reduce the silver paste used in printing. However, when welding, a solder tape about 1mm wide will be welded to all areas of the main grid, blocking sunlight. Therefore, the area of sunlight blocked by the main grid lines is 1mm×5×182mm = 910mm 2 ; the area of sunlight blocked by the secondary grid lines 12 and 4 borders is 0.025mm×(160 + 2)×(179.5mm - 1mm×5) + 2×179.5mm×0.02mm = 713.675mm 2 The total area of sunlight blocked on the front side of a conventional five-main-grid battery is 1623.675mm 2 .

[0049] When the number of groups of the fine grid lines 11 is 15, the test data is as follows:

[0050] The size of the front side of the battery cell body 1 is 182mm*182mm. Along the horizontal center line of the front side of the battery cell body 1, 15 first grid lines 111 and 15 second grid lines 112 are evenly distributed. The widths of the first grid lines 111 and the second grid lines 112 are both 0.04mm. The spacing between adjacent fine grid lines 11 is 11.933mm. There are 160 secondary grid lines 12, which are evenly arranged along the vertical center line of the front side of the battery cell body 1. The width of each secondary grid line 12 is 0.025mm and the length is 179.5mm. The spacing between adjacent secondary grid lines 12 is 1.1125mm. At the junctions of the secondary grid lines 12 with the first grid lines 111 and the second grid lines 112, from top to bottom, silver paste is printed at the 13th, 28th, 43rd, 58th, 73rd, 88th, 103rd, 118th, 133rd, and 148th junctions to form welding contact points, and the shapes of the welding contact points are arranged in sequence as circular welding contact points 2 and diamond-shaped welding contact points 3 and repeated. The side length of the diamond-shaped welding contact point 3 is 0.8mm, the side length of the hollowed-out shape of the diamond-shaped welding contact point 3 is 0.4mm, the radius of the circular welding contact point 2 is 0.45mm, and the radius of the hollowed-out shape of the circular welding contact point 2 is 0.25mm.

[0051] The area of sunlight blocked by the 15 first grid lines 111 and the 15 second grid lines 112 is 0.04mm×30×182mm = 218.4mm 2 ; the area of sunlight blocked by the secondary grid lines 12 and 4 borders is 0.025mm×(160 + 2)×(179.5mm - 0.2mm×15) + 0.025mm×2×179.5mm = 723.675mm 2 .

[0054] In addition to the fine grid lines 11, the shading of the diamond-shaped welding contacts 3 and the circular welding contacts 2 to sunlight is (0.8 mm × 0.8 mm - 0.4 mm × 0.4 mm) × 75 + (π × 0.45 2 mm 2 - π × 0.25 2 mm 2 ) × 75 = 45.42 mm 2 , in this test, the total shading area of the fine grid lines 11, the sub-grid lines 12, the circular welding contacts 2, and the diamond-shaped welding contacts 3 is 218.4 mm 2 + 723.675 mm 2 + 45.42 mm 2 = 987.495 mm 2 .

[0055] In this test, the fine grid lines 11, the sub-grid lines 12, the circular welding contacts 2, and the diamond-shaped welding contacts 3 reduce the shading area compared with the pattern of the five main grid lines by 1623.675 mm 2 - 978.495 mm 2 = 636.18 mm 2 .

[0056] The proportion of the reduced shading area in the total area is 6.3618 cm 2 ÷ 259.17 cm 2 = 2.45%

[0057] It can be known from the test data that in this embodiment, on the premise of ensuring good current collection and transmission capabilities of the battery electrodes, the shading rate is reduced.

[0058] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solar cell, comprising a cell body (1) and auxiliary grid lines (12). It is characterized in that it further comprises fine grid lines (11). A plurality of fine grid lines (11) are evenly distributed along the horizontal center line on the front surface of the cell body (1). A plurality of auxiliary grid lines (12) perpendicular to and intersecting with the fine grid lines (11) are provided on the front surface of the cell body (1). A plurality of welding contact points arranged at equal intervals and connected to the auxiliary grid lines (12) are provided on the fine grid lines (11), and the welding contact points are in a hollow shape; the fine grid lines (11) include adjacent first grid lines (111) and second grid lines (112), and the first grid lines (111) and the second grid lines (112) are connected through the welding contact points.

2. The solar cell according to claim 1, It is characterized in that the distance between the first grid line (111) and the second grid line (112) is 0.2 mm.

3. The solar cell according to claim 1, It is characterized in that the widths of the first grid line (111) and the second grid line (112) are both 0.04 mm.

4. The solar cell according to claim 1, It is characterized in that the welding contact points include circular welding contact points (2) and diamond-shaped welding contact points (3), and the circular welding contact points (2) and the diamond-shaped welding contact points (3) are arranged in sequence and repeatedly on the fine grid lines (11).

5. The solar cell according to claim 4, It is characterized in that the hollow shapes of the circular welding contact points (2) and the diamond-shaped welding contact points (3) are the same as their own shapes.

6. The solar cell according to claim 5, It is characterized in that the side length of the diamond-shaped welding contact point (3) is 0.6 - 1 mm.

7. The solar cell according to claim 6, It is characterized in that the side length of the hollow shape of the diamond-shaped welding contact point (3) is half of the side length of the diamond-shaped welding contact point (3).

8. The solar cell according to claim 5, It is characterized in that the diameter of the circular welding contact point (2) is 0.4 - 0.5 mm.

9. The solar cell according to any one of claims 1 - 8, It is characterized in that 15 fine grid lines (11) are evenly distributed along the horizontal center line on the front surface of the cell body (1).

10. The solar cell according to any one of claims 1 - 8, It is characterized in that the welding contact points are formed on the fine grid lines (11) through a secondary printing process.

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