Solar cell, photovoltaic module and metal screen

Abstract

The application relates to a solar cell, a photovoltaic module and a metal screen. By arranging a fine grid reinforcing portion and a main grid reinforcing portion on the solar cell, at least part of the main grid reinforcing portion overlaps the fine grid reinforcing portion, the electrical connection between the main grid line and the fine grid line is strengthened, the welding tension is effectively strengthened, the welding reliability of the extremely narrow fine grid line is ensured, the possibility of broken grid is reduced, the current generated on the fine grid line can be more efficiently gathered on the main grid line, and the collection capacity of the entire solar cell to the photo-generated current is improved. Since at least part of the main grid reinforcing portion overlaps the broken area, the main grid reinforcing portion can connect the two adjacent fine grid lines, the process of additionally connecting the two adjacent fine grid lines is saved, the production process is greatly simplified, the production cycle is effectively shortened, and the production efficiency is improved. Meanwhile, since the two adjacent fine grid lines do not need additional connection, the influence of the additional connection on the light-shielding performance can be avoided, and the power generation efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to solar cells, photovoltaic modules and metal mesh printing plates. Background Technology

[0002] In recent years, photovoltaic cell printing technology has shown a steady development trend. This development is largely due to the continuous improvement of screen printing technology, which has provided strong support for the refinement of printed grid lines. With the help of increasingly advanced screen printing technology, the width of printed grid lines can be continuously reduced, and the grid lines are becoming finer. This optimizes the structure of photovoltaic cell electrodes and, to a certain extent, helps to improve the performance indicators of the cell, such as photoelectric conversion efficiency.

[0003] As the grid lines become thinner, their mechanical strength is relatively weakened, making them prone to breakage during welding. Breakage disrupts the normal current conduction path, increasing the series resistance of the cell and consequently reducing its photoelectric conversion efficiency. Utility Model Content

[0004] Therefore, it is necessary to provide a solar cell, photovoltaic module, and metal mesh to address the problem of broken grid lines in existing grids.

[0005] A solar cell includes a cell body and an electrode assembly disposed on the cell body, the electrode assembly comprising:

[0006] At least one main gate structure, the main gate structure including a main gate line and at least one main gate reinforcement connected to the main gate line;

[0007] At least two fine grid groups arranged along a first direction, each fine grid group including a plurality of fine grid lines arranged along a second direction, the fine grid lines being connected to the main grid reinforcement portion; in two adjacent fine grid groups, the fine grid lines of one fine grid group are opposite to the fine grid lines of the other fine grid group, and there is a break zone between the two opposite fine grid lines;

[0008] At least one fine grid reinforcement portion is connected to the main grid reinforcement portion;

[0009] Wherein, in the thickness direction of the battery body, at least a portion of the main grid reinforcement overlaps with the break area, and at least a portion of the main grid reinforcement overlaps with the fine grid reinforcement; the first direction is the length direction of the fine grid line, the second direction is the length direction of the main grid line, and any two of the first direction, the second direction, and the thickness direction of the battery body intersect.

[0010] In one embodiment, the main grid reinforcement is provided with a hollow portion, which penetrates the main grid reinforcement along the thickness direction of the battery body.

[0011] In one embodiment, the dimension of the main gate reinforcement along the second direction is greater than the dimension of the fine gate line along the second direction.

[0012] In one embodiment, the orthographic projection of the main grid line on the battery body is located outside the orthographic projection of the main grid reinforcement on the battery body;

[0013] Alternatively, in the thickness direction of the battery body, at least a portion of the main grid reinforcement overlaps with the main grid line.

[0014] In one embodiment, at least a portion of the fine grid lines overlaps with the fine grid reinforcement in the thickness direction of the battery body.

[0015] In one embodiment, the main gate reinforcement includes a first reinforcement section and a second reinforcement section distributed along the first direction;

[0016] In the thickness direction of the battery body, at least a portion of the first reinforcing segment overlaps with the break area, and at least a portion of the second reinforcing segment overlaps with at least a portion of the fine grid reinforcing portion.

[0017] In one embodiment, at least a portion of the fine grid reinforcement overlaps with the break region in the thickness direction of the battery body.

[0018] In one embodiment, the solar cell further includes a connecting portion connected to the main grid reinforcement portion; the connecting portion is connected to the fine grid lines;

[0019] The connecting portion and the main gate reinforcement portion are distributed along the first direction.

[0020] In one embodiment, the connecting portion is provided at both ends of the main gate reinforcement portion along the first direction;

[0021] And / or, the dimension of the connecting portion along the second direction is greater than the dimension of the main gate reinforcement portion along the second direction.

[0022] In one embodiment, the projection of the main grid reinforcement onto the battery body includes at least one of polygon, circle, semicircle, ellipse and semi-ellipse.

[0023] And / or, the projection of the fine grid reinforcement on the battery body includes at least one of polygon, circle, semicircle, ellipse and semi-ellipse.

[0024] In one embodiment, a passivation layer is provided on the surface of the battery body;

[0025] The fine gate reinforcement is connected to the side of the main gate reinforcement that is away from the passivation layer.

[0026] In one embodiment, the main gate structure includes a plurality of main gate reinforcement portions distributed along the second direction, and the plurality of main gate reinforcement portions are connected one-to-one with a plurality of fine gate lines in the fine gate group;

[0027] The electrode assembly includes a plurality of fine gate reinforcement portions distributed along the second direction, and the plurality of fine gate reinforcement portions are one-to-one opposite to the plurality of fine gate lines in the fine gate group.

[0028] In one embodiment, the electrode assembly includes a plurality of main gate structures distributed along the first direction, and the main gate structures are connected between any two adjacent fine gate groups.

[0029] A photovoltaic module, comprising a solar cell as described above.

[0030] A metal mesh plate, comprising:

[0031] The main grid screen includes a first printing area and a first reinforcing printing area, wherein the first printing area is used to print the main grid lines and the first reinforcing printing area is used to print the main grid reinforcement.

[0032] The fine grid printing plate includes a second reinforced printing area, a non-printing area, and a plurality of second printing areas distributed along a first direction. The non-printing area is located between two adjacent second printing areas distributed along the first direction. The second printing areas are used to print fine grid lines, and the second reinforced printing area is used to print fine grid reinforcement portions.

[0033] In the thickness direction of the battery body, at least a portion of the first reinforced printed area overlaps with the non-printed area.

[0034] The aforementioned solar cells, photovoltaic modules, and metal mesh panels. By incorporating fine grid reinforcements and main grid reinforcements on the solar cells, the area and thickness of the welding region are increased, reducing the risk of desoldering due to thermal stress or mechanical vibration. In the thickness direction of the cell body, at least a portion of the main grid reinforcement overlaps with the fine grid reinforcement; that is, the orthographic projection of the fine grid reinforcement onto the cell body lies within the orthographic projection of the main grid reinforcement onto the cell body. The paste thickness in the overlapping area is greater, strengthening the electrical connection between the main grid lines and the fine grid lines, effectively enhancing welding tensile strength, ensuring the welding reliability of the extremely narrow fine grid lines, reducing the possibility of grid breakage, and allowing the current generated on the fine grid lines to be more efficiently concentrated on the main grid lines. This, in turn, improves the overall solar cell's ability to collect photocurrent, contributing to increased cell output power and photoelectric conversion efficiency. Meanwhile, during production, transportation, installation, and use, the main grid reinforcement and fine grid reinforcement locally reinforce the main grid lines and fine grid lines, enhancing their resistance to external forces and reducing the risk of mechanical damage such as breakage or breakage. This improves the overall structural integrity and durability of the solar cell. In the thickness direction of the cell body, since at least part of the main grid reinforcement overlaps with the break area (i.e., the orthographic projection of the break area onto the cell body lies within the orthographic projection of the main grid reinforcement), adjacent fine grid lines can be connected via the main grid reinforcement. This eliminates the need for additional connection processing between adjacent fine grid lines, greatly simplifying the production process, effectively shortening the production cycle, and improving production efficiency. Furthermore, since no additional connection is required between adjacent fine grid lines, the impact of additional connections on shading performance is avoided, thus improving power generation efficiency. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the electrode assembly in the solar cell provided in the first embodiment of this application.

[0037] Figure 2 for Figure 1 A partial schematic diagram of the electrode assembly shown.

[0038] Figure 3 for Figure 1 A schematic diagram of the main grid line and main grid reinforcement in the electrode assembly shown.

[0039] Figure 4 for Figure 1 A schematic diagram of the fine grid lines and fine grid reinforcement in the electrode assembly shown.

[0040] Figure 5 for Figure 4 A partial schematic diagram of the fine grid lines and fine grid reinforcement in the electrode assembly shown.

[0041] Figure 6 This is a partial schematic diagram of the main grid line and the main grid reinforcement in the electrode assembly provided in the second embodiment of this application.

[0042] Figure 7 This is a partial schematic diagram of the main grid line and the main grid reinforcement in the electrode assembly provided in the third embodiment of this application.

[0043] Figure 8 This is a schematic diagram of a solar cell provided in the fourth embodiment of this application.

[0044] Figure 9 for Figure 8 A partial schematic diagram of the electrode assembly shown.

[0045] Figure 10 for Figure 8 A schematic diagram of the main grid line and main grid reinforcement in the electrode assembly shown.

[0046] Figure 11 for Figure 10 A partial schematic diagram of the main grid line and main grid reinforcement in the electrode assembly shown.

[0047] Figure 12 for Figure 8 A partial schematic diagram of the fine grid lines and fine grid reinforcement in the electrode assembly shown.

[0048] Figure 13 This is a schematic diagram of the electrode assembly in a solar cell provided in the fifth embodiment of this application.

[0049] Figure 14 This is a partial cross-sectional view of a solar cell provided in an embodiment of this application.

[0050] Reference numerals: 110, main grid line; 120, main grid reinforcement; 121, first reinforcement section; 122, second reinforcement section; 125, hollow section; 130, connecting section; 210, fine grid line; 220, fine grid reinforcement; 230, disconnection area; 310, battery body; 320, passivation layer. Detailed Implementation

[0051] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0052] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0053] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0055] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0057] Electrode printing is a crucial step in the manufacturing process of solar cells, as its quality directly impacts various aspects such as photoelectric conversion efficiency, performance, and production efficiency. With continuous technological advancements and increasingly stringent performance requirements for solar cells, stencil printing technology has gradually demonstrated its unique advantages and is gaining more attention within the industry. Compared to conventional screen printing, stencil printing offers significant characteristics and advantages. Firstly, stencil printing can achieve finer grid linewidths, reaching extremely narrow lines such as 8µm, approximately 10µm narrower than those produced by conventional screen printing. Narrower grid linewidths allow for more precise electrode design, helping to reduce shading area and improve the cell's light absorption and utilization efficiency, thus potentially positively impacting photoelectric conversion efficiency. Secondly, stencil printing also improves production efficiency, increasing it by more than 0.15%. For large-scale solar cell production, this effectively reduces production costs and enhances production efficiency.

[0058] The inventors of this application discovered that, in order to enhance the lifespan of the stencil printing plate, the fine grid design must contain breaks. While this design extends the plate's lifespan to some extent, it introduces new problems, namely, the need for additional fine grid connection designs. These additional connections inevitably increase the light-blocking area, thus obstructing the light that the battery could otherwise receive, resulting in a decrease in the battery's current output and affecting its overall power generation performance. Furthermore, with the achievement of narrower fine grid linewidths in stencil printing, the reduced linewidth weakens the structural strength of the fine grid during subsequent welding processes, making it prone to weld breaks. Welded grid breaks directly damage the conductive path of the electrodes, leading to a severe decline in the battery's electrical performance, affecting normal battery use and product yield.

[0059] Based on this, one embodiment of this application provides a solar cell that can solve the above-mentioned technical problems. The solar cell provided by one embodiment of this application will now be described in detail with reference to the accompanying drawings.

[0060] See Figure 2 , Figure 9 or Figure 13 As shown, an embodiment of this application provides a solar cell including a cell body and an electrode assembly disposed on the cell body. The electrode assembly includes at least one main grid structure, at least two fine grid groups arranged along a first direction, and at least one fine grid reinforcement 220. The main grid structure includes main grid lines 110 and at least one main grid reinforcement 120 connected to the main grid lines 110. The fine grid groups include a plurality of fine grid lines 210 arranged along a second direction, and the fine grid lines 210 are connected to the main grid reinforcement 120. In two adjacent fine grid groups, the fine grid lines 210 of one fine grid group are opposite to the fine grid lines 210 of the other fine grid group, and there is a break region 230 between the two opposite fine grid lines 210. The fine grid reinforcement 220 is connected to the main grid reinforcement 120. In the thickness direction of the cell body, at least a portion of the main grid reinforcement 120 overlaps with the break region 230, and at least a portion of the main grid reinforcement 120 overlaps with the fine grid reinforcement 220. The first direction is the length direction of the fine grid line 210, which is the X direction in the diagram; the second direction is the length direction of the main grid line 110, which is the Y direction in the diagram; and the thickness direction of the battery body is... Figure 14 The Z-direction; any two of the first direction, the second direction, and the thickness direction of the battery body intersect. For example, in Figure 2 In the embodiment shown, the first direction is the left-right direction, the second direction is the up-down direction, and the thickness direction of the battery body is the direction perpendicular to the paper surface.

[0061] By incorporating the fine grid reinforcement 220 and the main grid reinforcement 120, the area and thickness of the welding region are increased, reducing the risk of desoldering due to thermal stress or mechanical vibration. In the thickness direction of the cell body, at least a portion of the main grid reinforcement 120 overlaps with the fine grid reinforcement 220; that is, the orthographic projection of the fine grid reinforcement 220 onto the cell body lies within the orthographic projection of the main grid reinforcement 120 onto the cell body. The paste thickness in the overlapping area is greater, strengthening the electrical connection between the main grid line 110 and the fine grid line 210, effectively enhancing welding pull, ensuring the welding reliability of the extremely narrow fine grid line 210, reducing the possibility of grid breakage, and allowing the current generated on the fine grid line 210 to be more efficiently concentrated onto the main grid line 110. This, in turn, improves the overall solar cell's ability to collect photocurrent, contributing to increased cell output power and photoelectric conversion efficiency. Meanwhile, during production, transportation, installation and use, the main grid reinforcement 120 and the fine grid reinforcement 220 locally reinforce the main grid line 110 and the fine grid line 210, enhancing their ability to resist external damage and reducing the risk of mechanical damage such as breakage or damage to the main grid line 110 and the fine grid line 210, thereby improving the overall structural integrity and durability of the solar cell.

[0062] In the thickness direction of the battery body, since at least a portion of the main grid reinforcement 120 overlaps with the break region 230, that is, the orthographic projection of the break region 230 on the battery body is within the orthographic projection of the main grid reinforcement 120 on the battery body, adjacent two fine grid lines 210 can be connected through the main grid reinforcement 120. This eliminates the need for additional connection processing of adjacent two fine grid lines 210, greatly simplifying the production process, effectively shortening the production cycle, and improving production efficiency. At the same time, since no additional connection is required between adjacent two fine grid lines 210, the impact of additional connection on shading performance can also be avoided, thus improving power generation efficiency.

[0063] See Figure 13 As shown, in one embodiment, a perforated portion 125 is provided on the main grid reinforcement portion 120, and the perforated portion 125 penetrates the main grid reinforcement portion 120 along the thickness direction of the battery body. In the embodiment shown in the figure, the perforated portion 125 is a perforated groove. By providing a perforated groove, the metal region recombination is reduced, the series resistance is reduced, the battery efficiency is improved, and the amount of paste used can also be reduced. In some embodiments, multiple perforated grooves can be provided, for example, in the attached figure. Figure 13 In the illustrated embodiment, there are four perforated slots. Understandably, the number of perforated slots can be set according to actual needs.

[0064] See Figure 13As shown, in one embodiment, the dimension of the main grid reinforcement 120 along the second direction Y is greater than the dimension of the fine grid line 210 along the second direction Y. That is, the width of the main grid reinforcement 120 is greater than the width of the fine grid line 210. The wider and exposed main grid reinforcement 120 can provide a wider and smoother conduction path for current, which helps to improve the overall current collection efficiency of the cell and increase the output power of the cell.

[0065] See Figure 3 and Figure 7 As shown, in one embodiment, the orthographic projection of the main grid line 110 onto the battery body is outside the orthographic projection of the main grid reinforcement 120 onto the battery body. For example, in Figure 7 In the embodiment shown, the main grid line 110 and the main grid reinforcement 120 are arranged in a T-shape, which allows the current generated on the numerous fine grid lines 210 to be more efficiently gathered into the main grid reinforcement 120 and then transmitted to the main grid line 110. This effectively reduces the loss in the current collection process, improves the current collection efficiency of the entire cell, and helps to improve the output power of the cell.

[0066] See Figure 9 and Figure 11 As shown, at least a portion of the main grid reinforcement 120 overlaps with the main grid line 110 in the thickness direction of the battery body. For example, in Figure 11 In the embodiment shown, the main grid reinforcement 120 and the main grid line 110 are arranged in a cross shape, which helps to distribute the current collected from the fine grid line 210 to the main grid line 110 more evenly, avoiding problems such as current disturbance, local congestion or excessive resistance during transmission, effectively ensuring the stability of current conduction, which is conducive to improving the photoelectric conversion efficiency of the battery, and enabling the battery to perform better when working.

[0067] See Figure 2 and Figure 5 As shown, in one embodiment, at least a portion of the fine grid line 210 overlaps with the fine grid reinforcement portion 220 in the thickness direction of the battery body; that is, the fine grid line 210 is connected to the fine grid reinforcement portion 220. This allows for more efficient collection of current generated from the battery's active region, enabling the current to converge more quickly and comprehensively onto subsequent current collection channels such as the main grid line 110, thereby improving the overall current collection efficiency of the battery and contributing to increased output power and photoelectric conversion efficiency.

[0068] See Figure 2 and Figure 5As shown, in one embodiment, the main grid reinforcement 120 includes a first reinforcement segment 121 and a second reinforcement segment 122 distributed along a first direction X. In the thickness direction of the battery body, at least a portion of the first reinforcement segment 121 overlaps with the break region 230, and at least a portion of the second reinforcement segment 122 overlaps with at least a portion of the fine grid reinforcement 220. The first reinforcement segment 121 connects two adjacent fine grid lines 210, avoiding current interruption or local current blockage caused by grid breakage, and effectively ensuring the integrity of the current conduction path inside the battery. The overlap of the second reinforcement segment with the fine grid reinforcement 220 results in a larger paste thickness in the overlapping area, strengthening the electrical connection between the main grid line 110 and the fine grid line 210, and effectively enhancing the welding pull force.

[0069] See Figure 9 and Figure 12 As shown, in one embodiment, the fine grid reinforcement 220 is disposed in the break region 230, that is, at least a portion of the break region 230 overlaps with the fine grid reinforcement 220 in the thickness direction of the battery body. Thus, the fine grid reinforcement 220 constructs a new current path, allowing current to continue smoothly transmitting to the main grid line 110, effectively restoring the continuity of current conduction, minimizing current loss due to grid breakage, thereby improving the photoelectric conversion efficiency and output power of the battery.

[0070] See Figure 2 or Figure 13 As shown, in one embodiment, the solar cell further includes a connecting portion 130 connected to the main grid reinforcement portion 120; the connecting portion 130 is connected to the fine grid lines 210; the connecting portion 130 and the main grid reinforcement portion 120 are distributed along a first direction X. Connecting the fine grid lines 210 and the main grid reinforcement portion 120 through the connecting portion 130 reduces the requirements for printing precision in the solar cell, making it easier to achieve uniform and continuous printing, reducing electrode performance degradation caused by printing deviations or breakpoints, and improving production efficiency and product yield. Simultaneously, the connecting portion 130 can more evenly collect and distribute the current on the fine grid lines 210 to the main grid reinforcement portion 120. This avoids situations where the local current is too large or too small due to uneven current collection on the fine grid lines 210, resulting in a more balanced current distribution throughout the cell and improving the overall performance and stability of the cell.

[0071] See Figure 13As shown, in one embodiment, connecting portions 130 are provided at both ends of the main grid reinforcement 120 along the first direction X. Thus, the main grid reinforcement 120 can collect current from the fine grid lines 210 more comprehensively through the connecting portions 130 at both ends, improving the current collection efficiency of the solar cell and reducing current loss during transmission through the fine grid lines 210, thereby contributing to improved overall solar cell performance. Simultaneously, the connecting portions 130 at both ends can act as current shunting and converging points, preventing current concentration at one end of the main grid reinforcement 120, thereby making the current distribution across the entire main grid reinforcement 120 more uniform, which is beneficial for improving the power generation efficiency and stability of the solar cell.

[0072] See Figure 13 As shown, the dimension of the connecting portion 130 along the second direction Y is larger than the dimension of the main grid reinforcement portion 120 along the second direction Y. When current is collected from the fine grid lines 210 to the main grid reinforcement portion 120, the connecting portion 130 can reduce the obstruction in the current transmission process, reduce resistance loss, and enable the current to be transmitted more efficiently, thereby improving the fill factor and conversion efficiency of the solar cell.

[0073] In one embodiment, the projection of the main grid reinforcement 120 onto the battery body includes at least one of a polygon, a circle, a semicircle, an ellipse, and a semi-ellipse. See also... Figure 7 As shown, in one embodiment, the projection of the main grid reinforcement 120 onto the battery body is rectangular, which can provide a more stable and uniform current transmission path. (See also...) Figure 6 As shown, in another embodiment, the projection of the main grid reinforcement 120 onto the battery body is a pentagon.

[0074] In one embodiment, the projection of the fine grid reinforcement 220 onto the battery body includes at least one of a polygon, a circle, a semicircle, an ellipse, and a semi-ellipse. See also... Figure 12 As shown, the projection of the fine grid reinforcement 220 onto the battery body is rectangular. (See reference...) Figure 5 As shown, in other embodiments, the projection of the fine grid reinforcement 220 onto the battery body is a heptagon.

[0075] See Figure 14As shown, in one embodiment, a passivation layer 320 is provided on the surface of the battery body 310. The passivation layer 320 can effectively reduce surface recombination and metal-to-metal contact recombination, thereby improving battery conversion efficiency. The fine grid reinforcement 220 is connected to the side of the main grid reinforcement 120 opposite to the passivation layer 320. In some embodiments, the main grid structure is formed using non-burn-through paste printing, such as silver paste composed of silver powder, glass powder, organic carrier, etc., or aluminum paste composed of aluminum powder, binder, etc. The fine grid lines 210 and the fine grid reinforcement 220 are formed using burn-through paste printing, such as high-temperature silver paste containing a high proportion of silver powder and a special glass powder system, or a composite paste containing metals such as silver and aluminum.

[0076] By providing the fine grid reinforcement 220 on the side of the main grid reinforcement 120 away from the passivation layer 320, and having an overlapping area between the fine grid reinforcement 220 and the main grid reinforcement 120 in the thickness direction Z of the cell body 310, it is possible to prevent the paste of the fine grid lines 210 from burning through the passivation layer 320, such as the silicon nitride film, thereby improving the open-circuit voltage of the cell, ensuring the electrical performance and conversion efficiency of the cell, and also ensuring welding performance. In some embodiments, the solar cell can be a tunnel oxide passivated contact cell (TOPCon), a passivated emitter and back surface passivated contact cell (PERC), or a heterojunction cell (HJT).

[0077] In some embodiments, the size of the fine gate reinforcement portion 220 along the second direction Y ranges from 20 μm to 80 μm, and the size of the fine gate reinforcement portion 220 along the first direction X ranges from 400 μm to 1600 μm. In some embodiments, the size of the fine gate reinforcement portion 220 along the second direction Y, i.e., the width, can be 35 μm, and the size of the fine gate reinforcement portion 220 along the first direction X, i.e., the length, can be 800 μm. In other embodiments, the width of the fine gate reinforcement portion 220 can also be 20 μm, 50 μm, 60 μm, 80 μm, etc., and the length of the fine gate reinforcement portion 220 can be 400 μm, 600 μm, 1000 μm, 1600 μm, etc., which can be set according to actual needs.

[0078] In some embodiments, the size of the main gate reinforcement portion 120 along the second direction Y ranges from 20 μm to 80 μm, and the size of the main gate reinforcement portion 120 along the first direction X ranges from 400 μm to 1600 μm. In some embodiments, the size of the main gate reinforcement portion 120 along the second direction Y, i.e., the width, can be 30 μm, and the size of the main gate reinforcement portion 120 along the first direction X, i.e., the length, can be 600 μm. In other embodiments, the width of the main gate reinforcement portion 120 can also be 20 μm, 50 μm, 60 μm, 80 μm, etc., and the length of the main gate reinforcement portion 120 can be 400 μm, 600 μm, 1000 μm, 1600 μm, etc., which can be set according to actual needs.

[0079] In some embodiments, the dimension of the connecting portion 130 along the first direction X ranges from 10 μm to 40 μm, and the dimension of the connecting portion 130 along the second direction Y ranges from 10 μm to 160 μm. In some embodiments, the dimension of the connecting portion 130 along the first direction X, i.e., the width dimension, can be 10 μm to 20 μm, and the dimension of the connecting portion 130 along the second direction Y, i.e., the length dimension, can be 60 μm to 100 μm. In other embodiments, the width dimension of the connecting portion 130 can also be 10 μm, 20 μm, 40 μm, etc., and the length dimension of the connecting portion 130 can be 10 μm, 60 μm, 100 μm, 160 μm, etc., which can be set according to actual needs.

[0080] See Figure 1 As shown, in one embodiment, the main grid structure includes multiple main grid reinforcement sections 120 distributed along the second direction Y, with each main grid reinforcement section 120 connected one-to-one with a multiple fine grid line 210 in the fine grid group; the electrode assembly includes multiple fine grid reinforcement sections 220 distributed along the second direction Y, with each fine grid reinforcement section 220 connected one-to-one with a multiple fine grid line 210 in the fine grid group. That is, for a single fine grid group, the number of fine grid lines 210 is the same as the number of main grid reinforcement sections 120, and the number of fine grid lines 210 is the same as the number of fine grid reinforcement sections 220. Thus, each main grid reinforcement section 120 can efficiently receive the current collected by its corresponding fine grid line 210, avoiding incomplete collection and losses during current transmission from the fine grid line 210 to the main grid due to loose connections or unreasonable structures, thereby significantly improving the overall current collection efficiency of the solar cell and contributing to increased cell output power.

[0081] In other embodiments, a main gate reinforcement may also be provided on the same main gate line. The main gate reinforcement is used to connect at least two fine gate lines distributed along the second direction. That is, the size of the main gate reinforcement along the second direction is greater than the spacing between two adjacent fine gate lines distributed along the second direction.

[0082] See Figure 1 As shown, in one embodiment, the electrode assembly includes multiple main grid structures distributed along a first direction X, with a main grid structure connecting any two adjacent fine grid groups. This design ensures that the current collected by the fine grid lines 210 in each region is collected promptly by the corresponding main grid structure, preventing excessive current loss due to long-distance transmission within the fine grid. This improves the battery's efficiency in collecting photogenerated carriers, helps increase the battery's short-circuit current, and enhances output power.

[0083] Furthermore, one embodiment of this application also provides a photovoltaic module (not shown), including the solar cell of any of the above embodiments. By strengthening the electrical connection between the main grid line and the fine grid line, the welding pull is effectively strengthened, ensuring the welding reliability of the extremely narrow fine grid line, reducing the possibility of grid breakage, and allowing the current generated on the fine grid line to be more efficiently concentrated on the main grid line, improving the photovoltaic module's ability to collect photocurrent and helping to improve photoelectric conversion efficiency. By connecting two adjacent fine grid lines through the main grid reinforcement section, the process of additional connection processing for two adjacent fine grid lines is eliminated, greatly simplifying the production process, effectively shortening the production cycle, and improving production efficiency. At the same time, since no additional connection is required between two adjacent fine grid lines, the impact of additional connection on shading performance can also be avoided, improving power generation efficiency.

[0084] Understandably, this photovoltaic module also includes an encapsulation layer. The encapsulation layer is used to encapsulate and fix the solar cells, isolating them from the external environment and preventing moisture, oxygen, and other substances from entering and causing corrosion, oxidation, or other damage to the cells. It also buffers external stress and enhances the overall mechanical strength of the photovoltaic module, ensuring that the module can operate normally and maintain structural stability under different working conditions. The encapsulation layer can be made of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), etc.

[0085] The photovoltaic module also includes a cover plate, such as a glass cover plate, to protect components such as the cells from external environmental corrosion. At the same time, because the glass cover plate needs to have good light transmittance, it allows sunlight to pass through to the maximum extent possible and reach the solar cells, ensuring that the cells can fully absorb light energy for photoelectric conversion.

[0086] An embodiment of this application also provides a metal mesh screen (not shown), including a main grid screen and a fine grid screen; the main grid screen includes a first printing area and a first reinforcing printing area, the first printing area being used to print main grid lines, and the first reinforcing printing area being used to print main grid reinforcement portions; the fine grid screen includes a second reinforcing printing area, a non-printing area, and a plurality of second printing areas distributed along a first direction, the non-printing area being located between two adjacent second printing areas distributed along the first direction; the second printing area is used to print fine grid lines, and the second reinforcing printing area is used to print fine grid reinforcement portions; wherein, in the thickness direction of the battery body, at least a portion of the first reinforcing printing area overlaps with the non-printing area.

[0087] The electrode structure printed using this metal screen printing plate has a larger paste thickness in the overlapping area due to the overlap of the main grid reinforcement and the fine grid reinforcement in the thickness direction of the cell body. This strengthens the electrical connection between the main grid lines and the fine grid lines, effectively enhancing the welding tensile strength. This allows the current generated on the fine grid lines to be more efficiently concentrated on the main grid lines, thereby improving the solar cell's ability to collect photocurrent and contributing to increased output power and photoelectric conversion efficiency. Furthermore, because the first reinforcing printing area overlaps with the non-printed area, adjacent fine grid lines can be connected through the printed main grid reinforcement, eliminating the need for additional connection processing between adjacent fine grid lines. This greatly simplifies the production process, effectively shortens the production cycle, and improves production efficiency. In some embodiments, the metal screen printing plate can be a steel mesh screen.

[0088] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A solar cell, characterized in that, The solar cell includes a cell body and an electrode assembly disposed on the cell body, the electrode assembly including: At least one main gate structure, the main gate structure including a main gate line (110) and at least one main gate reinforcement (120) connected to the main gate line (110). At least two fine grid groups are arranged along a first direction, each fine grid group including a plurality of fine grid lines (210) arranged along a second direction, the fine grid lines (210) being connected to the main grid reinforcement (120); in two adjacent fine grid groups, the fine grid lines (210) of one fine grid group are opposite to the fine grid lines (210) of the other fine grid group, and there is a break zone (230) between the two opposite fine grid lines (210). At least one fine grid reinforcement (220) is connected to the main grid reinforcement (120); In the thickness direction of the battery body, at least a portion of the main grid reinforcement (120) overlaps with the break region (230), and at least a portion of the main grid reinforcement (120) overlaps with the fine grid reinforcement (220); the first direction is the length direction of the fine grid line (210), the second direction is the length direction of the main grid line (110), and any two of the first direction, the second direction, and the thickness direction of the battery body intersect.

2. The solar cell according to claim 1, characterized in that, The main grid reinforcement (120) is provided with a hollow part (125), and the hollow part (125) penetrates the main grid reinforcement (120) along the thickness direction of the battery body.

3. The solar cell according to claim 1, characterized in that, The dimension of the main gate reinforcement (120) along the second direction is greater than the dimension of the fine gate line (210) along the second direction.

4. The solar cell according to claim 1, characterized in that, The orthographic projection of the main grid line (110) on the battery body is located outside the orthographic projection of the main grid reinforcement (120) on the battery body; Alternatively, in the thickness direction of the battery body, at least a portion of the main grid reinforcement (120) overlaps with the main grid line (110).

5. The solar cell according to claim 1, characterized in that, In the thickness direction of the battery body, at least a portion of the fine grid line (210) overlaps with the fine grid reinforcement portion (220).

6. The solar cell according to claim 5, characterized in that, The main gate reinforcement (120) includes a first reinforcement section (121) and a second reinforcement section (122) distributed along the first direction; In the thickness direction of the battery body, at least a portion of the first reinforcing segment (121) overlaps with the break region (230), and at least a portion of the second reinforcing segment (122) overlaps with at least a portion of the fine grid reinforcing portion (220).

7. The solar cell according to claim 1, characterized in that, In the thickness direction of the battery body, at least a portion of the fine grid reinforcement (220) overlaps with the disconnection region (230).

8. The solar cell according to any one of claims 1 to 7, characterized in that, The solar cell also includes a connecting portion (130) connected to the main grid reinforcement portion (120); the connecting portion (130) is connected to the fine grid line (210). The connecting portion (130) and the main gate reinforcement portion (120) are distributed along the first direction.

9. The solar cell according to claim 8, characterized in that, Along the first direction, the connecting portion (130) is provided at both ends of the main gate reinforcement portion (120). And / or, the dimension of the connecting portion (130) along the second direction is greater than the dimension of the main gate reinforcement portion (120) along the second direction.

10. The solar cell according to any one of claims 1 to 7, characterized in that, The projection of the main grid reinforcement (120) onto the battery body includes at least one of polygon, ellipse and semi-ellipse; And / or, the projection of the fine grid reinforcement (220) onto the battery body includes at least one of polygon, ellipse and semi-ellipse.

11. The solar cell according to any one of claims 1 to 7, characterized in that, A passivation layer (320) is provided on the surface of the battery body (310). The fine gate reinforcement (220) is connected to the side of the main gate reinforcement (120) away from the passivation layer (320).

12. The solar cell according to any one of claims 1 to 7, characterized in that, The main gate structure includes a plurality of main gate reinforcement portions (120) distributed along the second direction, and the plurality of main gate reinforcement portions (120) are connected one-to-one with the plurality of fine gate lines (210) in the fine gate group; The electrode assembly includes a plurality of fine gate reinforcement portions (220) distributed along the second direction, with each of the fine gate reinforcement portions (220) being opposite to a plurality of fine gate lines (210) in the fine gate group.

13. The solar cell according to any one of claims 1 to 7, characterized in that, The electrode assembly includes a plurality of main gate structures distributed along the first direction, and the main gate structures are connected between any two adjacent fine gate groups.

14. A photovoltaic module, characterized in that, Including the solar cell as described in any one of claims 1 to 13.

15. A metal mesh printing plate, characterized in that, include: The main grid screen includes a first printing area and a first reinforcing printing area, wherein the first printing area is used to print the main grid lines and the first reinforcing printing area is used to print the main grid reinforcement. The fine grid plate includes a second reinforced printing area, a non-printing area, and a plurality of second printing areas distributed along a first direction, wherein the non-printing area is located between two adjacent second printing areas distributed along the first direction; The second printing area is used to print fine grid lines, and the second reinforcing printing area is used to print fine grid reinforcement. In the thickness direction of the battery body, at least a portion of the first reinforced printed area overlaps with the non-printed area.

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