Electrode of solar cell and solar cell

Abstract

The utility model relates to the field of solar cells, particularly provides an electrode of a solar cell and the solar cell, and aims to solve the problem that the shading area loss of an electrode of an existing solar cell is relatively large. In order to achieve the purpose, an electrode of the solar cell comprises a first conductive pattern and a second conductive pattern, grid lines in the first conductive pattern are arranged in the same direction, the first conductive pattern comprises auxiliary grid lines, and the auxiliary grid lines are used for being connected with main grid lines; each grid line in the second conductive pattern is arranged along the same direction, and the second conductive pattern comprises a functional grid line which is crossed with the auxiliary grid line; wherein the first conductive pattern and the second conductive pattern are formed through printing of different screens. According to the scheme, shading loss can be reduced, photoelectric conversion efficiency is improved, slurry cost is saved, and the service life of the screen printing plate can be prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solar cells, and specifically provides an electrode of a solar cell and the solar cell. BACKGROUND

[0002] Currently, the preparation technology of solar cell grid lines mainly relies on traditional printing technology, and the screen used for screen printing is indispensable as one of the five elements of printing. With the continuous improvement of the conversion efficiency of the cell, the grid line needs to have a more optimal aspect ratio to ensure the conductivity and a lower shading area. As an indispensable carrier for printing, the prepared solar cell grid line is required to minimize the loss of shading area and save the paste as much as possible.

[0003] Taking the printing of solar cell grid lines without screen joints as an example, the printing without screen joints can realize a grid line with a more optimal aspect ratio and better uniformity due to the absence of the angle between the steel wire and the screen frame. However, due to the reasons such as the size of the layout and the service life of the screen, the grid line opening may coincide with the steel wire, which affects the ink penetration. Therefore, the screen manufacturer bends the grid line in this part when making the screen. At the same time, the line width of the grid line in this part is intentionally increased by about 10 um to optimize the printing performance when designing the screen due to the influence of the screen joint on the ink penetration. This will cause a loss of shading area, affect the conversion efficiency, and increase the cost of the paste.

[0004] Correspondingly, there is a need in the art for a new electrode of a solar cell and the solar cell to solve the problem of large loss of shading area of the existing electrode of the solar cell. CONTENT OF THE INVENTION

[0005] The present application aims to solve the above technical problems, i.e., to solve the problem of large loss of shading area of the existing electrode of the solar cell.

[0006] In a first aspect, the present application provides an electrode of a solar cell, characterized in that it comprises: a first conductive pattern, each grid line in the first conductive pattern is arranged along the same direction, the first conductive pattern comprises a sub-grid line, the sub-grid line is used to be connected with a main grid line; a second conductive pattern, each grid line in the second conductive pattern is arranged along the same direction, the second conductive pattern comprises a functional grid line which is arranged transversely to the sub-grid line; wherein the first conductive pattern and the second conductive pattern are formed by printing with different screens.

[0007] In the optional technical solution of the above-mentioned electrode of a solar cell, the functional grid line comprises an anti-breaking grid line, both ends of the anti-breaking grid line are connected to adjacent sub-grid lines.

[0008] In the optional technical solution of the above-mentioned electrode of a solar cell, the functional grid line comprises a frame grid line, the frame grid line is connected to the end part on the same side of each sub-grid line.

[0009] In the optional technical solutions for the electrodes of the above-mentioned solar cell, the functional grid line further includes a branched grid line, which is located on at least one side of the sub-grid line and connected to the end of the main grid line.

[0010] In the optional technical solutions for the electrodes of the above-mentioned solar cell, the second conductive pattern further includes the main grid line, which is cross-connected with each of the sub-grid lines.

[0011] In the above-mentioned optional technical solutions for the electrodes of the solar cell, the main grid lines and the functional grid lines are formed by printing with different screen printing plates; or the main grid lines and the functional grid lines are formed by printing with the same screen printing plate.

[0012] In the optional technical solutions for the electrodes of the above-mentioned solar cell, the first conductive pattern is formed by screen printing without mesh; and / or the second conductive pattern is formed by screen printing without mesh.

[0013] In the above-mentioned optional technical solutions for the electrodes of the solar cell, the first conductive pattern is formed by printing on a fully open steel plate; and / or the second conductive pattern is formed by printing on a fully open steel plate.

[0014] In the optional technical solutions for the electrodes of the above-mentioned solar cell, each grid line in the first conductive pattern is a straight line; and / or each grid line in the second conductive pattern is a straight line.

[0015] In another aspect, this application also provides a solar cell, characterized in that the solar cell includes the electrodes of the solar cell described in any of the above embodiments.

[0016] Those skilled in the art will understand that the electrodes of the solar cell of this application include a first conductive pattern and a second conductive pattern. Each grid line in the first conductive pattern is arranged along the same direction, and the first conductive pattern includes sub-grid lines for connecting with the main grid lines. Each grid line in the second conductive pattern is arranged along the same direction, and the second conductive pattern includes functional grid lines that intersect with the sub-grid lines. The first conductive pattern and the second conductive pattern are formed by printing with different screen printing plates.

[0017] When employing the above-mentioned solutions, for example, when forming functional grid lines (such as anti-breakage grid lines, border grid lines, and branched grid lines) and sub-grid lines through screen printing without mesh knots, since the functional grid lines and sub-grid lines of this application are formed by printing on different screens, that is, the functional grid lines and sub-grid lines are formed by step-by-step printing, it is not necessary to design all grid line openings on the same screen, and the grid line openings on each screen are set along the same direction, reducing or avoiding the phenomenon of grid line openings completely overlapping with steel wires. Therefore, the electrodes of the solar cell of this application do not need to increase the linewidth, thereby reducing shading loss, improving photoelectric conversion efficiency, saving paste costs, and also increasing screen life. When forming functional grid lines and sub-grid lines through printing on a fully open steel plate, since the grid line openings of the fully open steel plate do not contain steel wires, but exist in a fully open form (which allows for some breaks), the paste penetration of the screen is smoother, the grid lines are flatter and more uniform, and the grid line width can be made thinner, thereby avoiding the loss of shading area, improving conversion efficiency, and reducing paste costs. Furthermore, if the subgrid lines are printed in a fully open steel plate and the functional grid lines are printed in a fully open steel plate, compared to printing all grid lines in the same screen, multiple overlapping parts can be avoided, thereby improving the overall tension and load-bearing capacity, and thus increasing the screen life. Attached Figure Description

[0018] The following describes possible embodiments of this application with reference to the accompanying drawings, in which:

[0019] Figure 1 This is a schematic diagram of the electrode layout structure of a solar cell in the prior art;

[0020] Figure 2 yes Figure 1 Enlarged view of the anti-breakage grid line in the image;

[0021] Figure 3 yes Figure 1 Enlarged view of the bifurcated grid lines in the image;

[0022] Figure 4 This is a schematic diagram of the layout structure of the sub-grid lines of the electrode of the solar cell of this application;

[0023] Figure 5 This is a schematic diagram of the layout structure of the grid lines, anti-breakage grid lines, and branched grid lines of the electrode of the solar cell of this application;

[0024] Figure 6 yes Figure 5 Enlarged view of the bifurcated grid lines;

[0025] Figure 7 yes Figure 5 Enlarged view of the anti-breakage grid line.

[0026] Explanation of reference numerals in the attached figures:

[0027] 10 - Prior art sub-gate line; 11 - Prior art border gate line; 12 - Prior art anti-breakage gate line; 13 - Prior art branched gate line;

[0028] 20 - Sub-grid line; 30 - Anti-breakage grid line; 40 - Border grid line; 50 - Branching grid line. Detailed Implementation

[0029] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0030] It should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly, and can refer to direct connection or indirect connection through an intermediate medium such as a refrigerant pipe, etc. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] First, it should be noted that the following embodiments are only used to explain the technical principles of this application and are not intended to limit the scope of protection of this application. To better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details.

[0032] Furthermore, it should be noted that in the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] Figures 1 to 3 This is a layout structure of existing solar cell electrodes. Figure 1 The frame grid lines 11, anti-breakage grid lines 12, branch grid lines 13, and sub-grid lines 10 of the solar cell electrode are all printed on a single screen. For screen printing without mesh, due to the size of the printing plate, the frame grid lines 11, anti-breakage grid lines 12, and branch grid lines 13, which are not parallel to the sub-grid lines 10, may have grid openings that overlap with the steel wires, affecting ink penetration. Therefore, the frame grid lines 11, anti-breakage grid lines 12, and branch grid lines 13 are made into a curved state. At the same time, because they pass through the mesh knots multiple times, affecting ink penetration, the line width of the frame grid lines 11, anti-breakage grid lines 12, and branch grid lines 13 is deliberately increased by about 10µm during plate design to optimize printability. However, this will result in a loss of light-blocking area, affecting conversion efficiency and increasing ink costs.

[0034] To address the aforementioned problems, this application provides an electrode for a solar cell, such as... Figures 4 to 7 As shown, the electrode can be either the front electrode or the back electrode of a solar panel. It is formed by screen printing. Specifically, it includes a first conductive pattern and a second conductive pattern. All grid lines in the first conductive pattern are arranged along the same direction. The first conductive pattern includes sub-grid lines 20, which are used to connect with the main grid lines (not shown in the figure). All grid lines in the second conductive pattern are arranged along the same direction. The second conductive pattern includes functional grid lines that intersect with the sub-grid lines 20. The first conductive pattern and the second conductive pattern are formed by screen printing with different screens.

[0035] Specifically, refer to Figure 4 The first conductive pattern may consist only of sub-gate lines 20. Sub-gate lines 20 may include multiple parallel and evenly spaced central sub-gate lines, and edge sub-gate lines evenly spaced from the central sub-gate lines and located on opposite sides of them. The main body of the edge sub-gate lines is parallel to the central sub-gate lines, and both ends of the edge sub-gate lines may be bent towards the central gate lines. All sub-gate lines 20 are arranged in the same direction. Figure 4 The first direction is shown in the diagram. During screen printing, a first conductive pattern can be printed using a first screen, wherein the pattern structure in the first screen may include only the first conductive pattern, that is, only the aforementioned sub-grid lines 20. It should be noted that although the sub-grid lines 20 described above are uniformly spaced, this is not intended to limit the scope of protection of this application. They may also be non-uniformly spaced, and these adjustments do not deviate from the principles of this application and are all within the scope of protection of this application.

[0036] This application allows for the printing of functional grid lines of a second conductive pattern using a second screen, which is a different screen from the first screen. (See reference...) Figure 5 The functional grid line may include a breakage-prevention grid line 30, with both ends of the breakage-prevention grid line 30 connected to adjacent sub-grid lines 20. It is understood that the breakage-prevention grid line 30 connects adjacent sub-grid lines 20 together. When one of the adjacent sub-grid lines 20 breaks, its current can be conducted through the breakage-prevention grid line 30 to the other sub-grid lines 20 and ultimately converge to the main grid line. In other words, its function is to prevent local breakage of sub-grid lines 20 from affecting current collection efficiency. The breakage-prevention grid line 30 can be arranged perpendicularly to the sub-grid lines 20, and multiple spaced-apart breakage-prevention grid lines 30 can be connected between each adjacent sub-grid line 20.

[0037] In one possible implementation, the functional gate line also includes a border gate line 40, which is connected to the ends of each sub-gate line 20 on the same side. Specifically, the border gate line 40 can be located on opposite sides along the length of the sub-gate line 20, with each side of the border gate line 40 connected to the end of each sub-gate line 20. The function of the border gate line 40 is that when any adjacent sub-gate line 20 breaks, its current can be conducted through the border gate line 40 to other sub-gate lines 20 and eventually converge to the main gate line, thus preventing the current collection efficiency from being affected by the breakage of a local sub-gate line 20.

[0038] In one possible implementation, the functional gate line also includes a forked gate line 50, which is located on at least one side of the sub-gate line 20 and connected to the end of the main gate line. For example, the forked gate line 50 is located on opposite sides of the sub-gate line 20, and the forked gate lines 50 on both sides are respectively connected to the two ends of the main gate line. The forked gate line 50 can also be called a harpoon line, that is, it includes two forked first gate lines and second gate lines. The same side of the first gate line and the second gate line can gradually narrow or be parallel to each other. The end of one side of the forked gate line 50 can be connected to the end of the main gate line through a solder pad. It can be understood that the function of the forked gate line 50 is to perform end welding, reducing the microcrack phenomenon in the battery caused by the yield strength of the solder strip during welding.

[0039] The aforementioned anti-breakage grid line 30, border grid line 40, and branching grid line 50 are all arranged along the same direction, for example, along... Figure 5 In the second direction setting, when the above scheme is adopted, for example, when the functional grid lines (anti-breakage grid line 30, border grid line 40 and branch grid line 50) and sub-grid lines 20 are formed by screen printing without mesh knots, since the functional grid lines and sub-grid lines 20 of this application are formed by printing on different screens, that is, the functional grid lines and sub-grid lines 20 are formed by step printing, it is not necessary to design all grid line openings on the same screen, and the grid line openings on each screen are set along the same direction, reducing or avoiding the phenomenon that the grid line openings completely overlap with the steel wires. Thus, each grid line in the first conductive pattern and the second conductive pattern can be designed as a straight line, that is, the border grid line 40, anti-breakage grid line 30 and branch grid line 50 mentioned above are also straight lines. Therefore, the line width will not be increased, the printing quality will be improved, the light-blocking loss caused by the curved design will be reduced, the photoelectric conversion efficiency will be improved, and the paste cost will be saved.

[0040] On the other hand, since the sub-grid line 20 of this application is printed on a screen, the anti-breakage grid line 30, the border grid line 40 and the branch grid line 50 are printed on a screen, and each grid line is designed to be straight, such as the longer border grid line 40 which does not need to be bent and is wider, the tension, strength and load-bearing capacity of the screen can be improved, thereby improving the service life of the screen.

[0041] It should be noted that although the anti-breakage grid line 30, the branching grid line 50 and the border grid line 40 of this application are described as examples of being printed on the same screen, this is not intended to limit the scope of protection of this application. For example, at least one of the anti-breakage grid line 30, the branching grid line 50 and the border grid line 40 among the functional grid lines can also be printed on different screens as the other types of functional grid lines. These adjustments do not deviate from the principle of this application and are all within the scope of protection of this application.

[0042] As one possible implementation, the second conductive pattern of this application also includes a main grid line, which is cross-connected with each sub-grid line 20. Specifically, the main grid line can be arranged perpendicularly to the sub-grid lines 20. The main grid line is used to collect the current of each sub-grid line 20 and then connect each battery cell in series. Since the main grid line, the border grid line 40, the anti-breakage grid line 30, and the branch grid line 50 extend in the same direction, the main grid line and the border grid line 40, the anti-breakage grid line 30, and the branch grid line 50 can be printed in the same screen to save the number of screens while avoiding light loss; however, this is not a limitation, the main grid line and the border grid line 40, the anti-breakage grid line 30, and the branch grid line 50 can also be printed in different screens. When the main grid lines, border grid lines 40, anti-breakage grid lines 30, and branch grid lines 50 are formed by printing on different screens, the main grid lines can be printed first, followed by the sub-grid lines 20 and functional grid lines (border grid lines 40, anti-breakage grid lines 30, and branch grid lines 50) printed in stages. It is understood that the above printing sequence is not fixed. As long as the functional grid lines and main grid lines are formed on different screens from the sub-grid lines 20, those skilled in the art can adjust the printing sequence as needed. These adjustments do not deviate from the principles of this application and are all within the scope of protection of this application.

[0043] It should be noted that although the main grid lines, sub-grid lines 20 and functional grid lines described above in this application are all illustrated by forming them through screen printing without mesh, this is not intended to limit the scope of protection of this application. The main grid lines, sub-grid lines 20 and functional grid lines described above can also be formed by printing through a fully open steel plate, etc. These adjustments to the printing methods do not deviate from the principles of this application and are all within the scope of protection of this application.

[0044] Because the grid lines of a fully open steel plate do not contain steel wires, but exist in a fully open form (allowing for some breaks), the ink penetration through the screen is smoother, and the grid lines are flatter and more uniform. This allows for finer grid line widths, thus avoiding loss of light-blocking area, improving conversion efficiency, and reducing ink costs. Furthermore, printing the secondary grid lines 20, the anti-breakage grid lines 30, the border lines, and the branching grid lines 50 on a single fully open steel plate, compared to printing all grid lines on the same screen, avoids multiple overlapping sections, thereby improving overall tension and load-bearing capacity, and ultimately extending the screen's lifespan.

[0045] It should be noted that for printing on fully open steel plates, the main grid lines can be printed on the same fully open steel plate as the functional grid lines, or they can be printed on different fully open steel plates. This application does not impose any specific restrictions on this.

[0046] Furthermore, it should be noted that although the first conductive pattern of this application is described using only the sub-gate line 20 as an example, this is not intended to limit the scope of protection of this application. As long as each gate line in the first conductive pattern is arranged along the same direction, it may also include other types of gate lines. These types of gate lines can be any existing or future gate lines. These adjustments do not deviate from the principle of this application and are all within the scope of protection of this application.

[0047] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. An electrode for a solar cell, characterized in that, include: A first conductive pattern, wherein each gate line in the first conductive pattern is arranged along the same direction, and the first conductive pattern includes a sub-gate line, which is used to connect with the main gate line; The second conductive pattern, wherein each gate line in the second conductive pattern is arranged along the same direction, and the second conductive pattern includes functional gate lines that intersect with the sub-gate lines; The first conductive pattern and the second conductive pattern are formed by printing with different screen printing plates.

2. The electrode of the solar cell according to claim 1, characterized in that, The functional grid line includes a breakage prevention grid line, the two ends of which are connected to the adjacent sub-grid line.

3. The electrode of the solar cell according to claim 1 or 2, characterized in that, The functional grid line includes a border grid line, which is connected to the end of each of the sub-grid lines on the same side.

4. The electrode of the solar cell according to claim 3, characterized in that, The functional grid line also includes a branched grid line, which is located on at least one side of the sub-grid line and connected to the end of the main grid line.

5. The electrode of the solar cell according to claim 1, characterized in that, The second conductive pattern also includes the main gate line, which is cross-connected with each of the sub-gate lines.

6. The electrode of the solar cell according to claim 5, characterized in that, The main grid lines and the functional grid lines are formed by printing with different screen printing plates; or The main grid lines and the functional grid lines are formed by printing on the same screen.

7. The electrode of the solar cell according to claim 1, characterized in that, The first conductive pattern is formed using screen printing without mesh; and / or The second conductive pattern is formed by screen printing without mesh.

8. The electrode of the solar cell according to claim 1, characterized in that, The first conductive pattern is formed by printing on a fully open steel plate; and / or The second conductive pattern is formed by printing on a fully open steel plate.

9. The electrode of the solar cell according to claim 1, characterized in that, Each gate line in the first conductive pattern is a straight line; and / or Each grid line in the second conductive pattern is a straight line.

10. A solar cell, characterized in that, The solar cell includes the electrodes of the solar cell according to any one of claims 1 to 9.

Images