Solar cell, screen printing plate, solder strip and photovoltaic module

Abstract

The embodiment of the invention provides a solar cell, a screen printing plate, a welding strip and a photovoltaic module. The solar cell comprises a cell piece and an electrode grid line structure arranged on the surface of the cell piece. The electrode grid line structure comprises a plurality of auxiliary grids, the auxiliary grids extend from the first end of the battery piece to the second end of the battery piece, and the second end is the end opposite to the first end; the width of the auxiliary grid is gradually increased from the first end to the second end. According to the embodiment of the invention, the auxiliary gate is designed to be of a gradual change structure, so that the width of the auxiliary gate is gradually increased, and the auxiliary gate for transmitting the carriers is gradually widened along with the accumulation of the carriers, so that the auxiliary gate has enough width for transmitting the carriers, the loss of the carriers is avoided, and the loss of the power of the battery is further avoided.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a solar cell, a screen, a welding ribbon and a photovoltaic module. Background Art

[0002] With the development of solar cell technology, there are increasingly higher requirements for improving battery power generation efficiency and saving material costs.

[0003] The busbar-less battery reduces the amount of silver paste used and achieves cost reduction by eliminating the busbars on the front and / or back of the solar cell. The busbar-less battery grid structure includes multiple sub-grids, and the welding strips are welded on the sub-grids. In order to avoid large shading that affects the power generation efficiency of the battery, the diameter of the welding strip welded on the sub-grid is relatively small. Along the transmission direction of the current in the welding strip, as the carriers continue to accumulate, the current gradually increases. If the diameter of the welding strip is narrow, it is easy to cause current loss, which will reduce the power generation efficiency of the battery.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a solar cell, a screen, a welding strip and a photovoltaic module to solve or alleviate one or more of the technical problems mentioned above.

[0006] As a first aspect of an embodiment of the present application, an embodiment of the present application provides a solar cell, including a cell and an electrode grid line structure arranged on a surface of the cell; the electrode grid line structure includes: A plurality of auxiliary grids are provided, wherein the auxiliary grids extend from a first end of the battery cell to a second end of the battery cell, wherein the second end is an end opposite to the first end; and the width of the auxiliary grids gradually widens from the first end toward the second end.

[0007] In one embodiment, the distance between adjacent sub-grids at the second end is 2-6 mm.

[0008] In one embodiment, the width of the auxiliary grid gradually widens from the first end toward the second end, including: the width of the auxiliary grid linearly widens from the first end toward the second end relative to the axial length of the auxiliary grid.

[0009] In one embodiment, the width of the secondary grid at the first end is 5-15 um; the width of the secondary grid at the second end is 30-40 um.

[0010] As a second aspect of an embodiment of the present application, an embodiment of the present application provides a printed screen for preparing a solar cell of any implementation aspect of the above-mentioned embodiments; the printed screen includes a screen body, the screen body includes a plurality of strip holes, and the plurality of strip holes correspond to a plurality of sub-grids in the solar cell; the strip holes extend from the first end of the screen body to the second end of the screen body, and the width of the strip holes gradually widens from the first end toward the second end.

[0011] As a third aspect of an embodiment of the present application, an embodiment of the present application provides a solder strip, comprising a strip-shaped solder strip body, wherein the width of the solder strip body gradually widens in a direction extending from a first position toward a second position.

[0012] In one embodiment, the length of the solder strip body is adapted to the length of the battery cell.

[0013] In one embodiment, the welding strip body includes a plurality of segments, each segment includes a first position and a second position; and the length of the segment is adapted to the length of the battery cell.

[0014] In one embodiment, the thickness of the welding strip body gradually increases from the first position toward the second position, and increases linearly relative to the axial length of the welding strip body.

[0015] In one embodiment, the radial cross-section of the welding ribbon body includes any one of a semicircle, a rectangle and a triangle.

[0016] As a fourth aspect of the embodiments of the present application, the embodiments of the present application provide a photovoltaic component, including multiple solar cells of any implementation aspect of the above embodiments; the multiple solar cells are connected in series, and the second end of the solar cell is adjacent to the first end of the adjacent solar cell.

[0017] In one implementation, a plurality of solar cells are connected in series via a welding ribbon in any one of the above embodiments.

[0018] In one embodiment, the welding strip is welded to the secondary grid of the solar cell, one welding strip is welded to one secondary grid, or welding strips are welded to multiple secondary grids at a preset number of intervals.

[0019] In one embodiment, the width, thickness, diameter or radial cross-sectional area of ​​the welding ribbon is determined according to the power value on the secondary grid in the solar cell.

[0020] In the embodiment of the present application, the sub-gate is designed as a gradient structure so that the width of the sub-gate increases from narrow to wide. As carriers accumulate, the sub-gate for transmitting carriers gradually becomes wider, thereby having sufficient width to transmit carriers, avoiding carrier loss and further avoiding battery power loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0022] Figure 1 A schematic structural diagram of a solar cell provided in one embodiment of the present application is shown.

[0023] Figure 2 A schematic structural diagram of a welding strip provided in one embodiment of the present application is shown.

[0024] Figure 3 A schematic structural diagram of a welding strip provided in another embodiment of the present application is shown.

[0025] Figure 4 A schematic structural diagram of a photovoltaic assembly provided in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0029] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0030] An embodiment of the present application provides a solar cell, including a cell and an electrode grid structure arranged on a surface of the cell. Figure 1 The schematic diagram of the electrode grid line structure of the solar cell of the embodiment of the present application is shown; Figure 1 As shown, the electrode grid line structure includes a plurality of sub-grids 200 .

[0031] A solar cell provided in an embodiment of the present application is a main grid-free cell, and the electrode grid line only includes a sub-grid 200, that is, a fine grid. In a main grid-free cell, a welding strip is stacked on the sub-grid 200 to reduce the shading area of ​​the main grid or the welding strip stacked on the main grid. In order to further reduce the shading area, the width of the welding strip is less than or equal to the width of the sub-grid 200. The width of the sub-grid 200 and the width of the welding strip are as narrow as possible to take into account the shading factor and the current loss caused during the current transmission process. In a solar cell, the carriers inside it gradually accumulate, and the current gradually increases, so a welding strip with a certain width is required to avoid current loss.

[0032] In the solar cell provided in the embodiment of the present application, the auxiliary grid 200 located on the surface of the battery cell 100 extends from the first end 101 of the battery cell 100 to the second end 102 of the battery cell 100, and the second end 102 is an end opposite to the first end 101; the width of the auxiliary grid 200 gradually widens from the first end 101 toward the second end 102.

[0033] like Figure 1As shown, a plurality of auxiliary grids 200 are disposed on the surface of the cell 100 . The auxiliary grids 200 may be distributed in parallel and extend from the first end 101 to the second end 102 of the cell 100 . Each auxiliary grid 200 gradually widens from the first end 101 toward the second end 102 .

[0034] In some other examples, among the auxiliary grids 200 on the surface of the battery cell 100, at least one auxiliary grid 200 may gradually widen from the first end 101 toward the second end 102, and the remaining auxiliary grids 200 have the same width in the process of extending from the first end 101 to the second end 102; it can be understood that this implementation scheme is also within the protection scope of the embodiments of the present application.

[0035] For example, the secondary grid 200 on the surface of the solar cell 100 may include a first secondary grid 200 with the same width and a second secondary grid 200 with a gradually varying width, and the first secondary grid 200 and the second secondary grid 200 are alternately arranged according to a preset rule.

[0036] In one example, the solar cell includes a front grid line located on the front of the cell 100 and a back grid line located on the back of the cell 100, based on the fact that the grid line on the back of the cell 100 has less shading effect than the back of the cell 100; the electrode grid line structure of the solar cell can be that the secondary grid 200 in the front grid line is a secondary grid 200 with a gradient; and the secondary grid 200 in the back grid line is a secondary grid 200 with the same width. It can be understood that the electrode grid line structure of the solar cell can also be that the number of secondary grids 200 with a gradient structure in the secondary grid 200 in the front grid line is greater than the number of secondary grids 200 with a gradient structure in the back grid line.

[0037] In the embodiment of the present application, the sub-gate 200 is designed as a gradient structure so that the width of the sub-gate 200 increases from narrow to wide. As the carriers accumulate, the sub-gate 200 for transmitting the carriers gradually becomes wider, thereby having sufficient width to transmit the carriers, avoiding the loss of carriers, and further avoiding the loss of battery power.

[0038] In one embodiment, the distance between adjacent secondary grids 200 at the second end 102 is 2-6 mm.

[0039] In the electrode grid line structure of the embodiment of the present application, the sub-grid 200 gradually becomes wider, so there is no need to increase the number of sub-grids 200 in order to avoid carrier loss.

[0040] In a cell 100 with higher power generation efficiency, a larger number of auxiliary grids 200 may be provided. In this scenario, the number of auxiliary grids 200 should not be too large, so that the spacing between adjacent auxiliary grids 200 at the second end 102, i.e., the wider end of the auxiliary grid 200, should not be less than 2 mm. If the spacing is too small, it is easy to cause a short circuit in the solder strip, which blocks light and affects light absorption.

[0041] Based on the fact that the spacing between adjacent sub-grids 200 at the second end 102 cannot be less than 2 mm, the gradient rate of the sub-grid 200 gradually widening from the first end 101 toward the second end 102 can also be limited. Too large a gradient rate can easily cause the width of the sub-grid 200 at the second end 102 to be too wide, which is too redundant for current transmission and leads to waste of materials.

[0042] Based on the conventional size of the battery cell 100 and the quantity requirement of the auxiliary grids 200 , the interval between adjacent auxiliary grids 200 at the second end 102 is less than or equal to 6 mm.

[0043] The interval between adjacent secondary grids 200 at the second end 102 may be 2 mm, 3 mm, 3.8 mm, 5.6 mm or 6 mm.

[0044] The spacing between adjacent secondary grids 200 at the first end 101 may be 2-6.6 mm. The secondary grid 200 is narrower at the first end 101, and the spacing between adjacent secondary grids 200 at the first end 101 is wider than that at the second end 102. However, since the secondary grid 200 itself is narrower, the spacing between the two ends is not much different.

[0045] In one embodiment, the width of the auxiliary grid 200 gradually widens from the first end 101 toward the second end 102 , including: the width of the auxiliary grid 200 linearly widens from the first end 101 toward the second end 102 relative to the axial length of the auxiliary grid 200 .

[0046] The width of the auxiliary gate 200 gradually widens from the first end 101 toward the second end 102 , and may be widened in a step-like manner or linearly. In the case of linear widening, at least one side of the auxiliary gate 200 is an inclined oblique line.

[0047] The width of the auxiliary grid 200 linearly widens from the first end 101 toward the second end 102 , which can facilitate smooth current transmission and further improve the power generation efficiency of the solar cell.

[0048] In one embodiment, the width of the secondary gate 200 at the first end 101 is 5-15 um; the width of the secondary gate 200 at the second end 102 is 30-40 um.

[0049] By limiting the width of the secondary grid 200 at the first end 101 and the width of the secondary grid 200 at the second end 102, the gradient rate of the secondary grid 200 when gradually widening can also be limited to prevent the secondary grid 200 from being infinitely widened or rapidly widened.

[0050] When the width of the auxiliary gate 200 is gradually changed, the width of the auxiliary gate 200 at the first end 101 can be smaller than that of a conventional auxiliary gate 200 with the same width; the width of the auxiliary gate 200 at the second end 102 is larger than that of a conventional auxiliary gate 200 with the same width to meet the transmission of the gradually accumulated current.

[0051] The width of the secondary grid 200 at the first end 101 and the width of the secondary grid 200 at the second end 102 can be determined by testing the current value of the battery cell 100 at the first end 101 and the current value at the second end 102 and then combining the number of the secondary grids 200 .

[0052] An embodiment of the present application also provides a printed screen for preparing a solar cell of any of the above embodiments; the printed screen includes a screen body, the screen body includes a plurality of strip holes, and the plurality of strip holes correspond to a plurality of sub-grids in the solar cell; the strip holes extend from the first end of the screen body to the second end of the screen body, and the width of the strip holes gradually widens from the first end toward the second end.

[0053] The length and width of the screen are adapted to the length and width of the cell. When the screen is pressed on the surface of the cell, silver paste or other electrode materials that can be used to prepare the secondary grid are injected toward the strip-shaped holes, and these materials are injected into the surface of the cell through the holes to form the secondary grid. The shape of the holes is set in a one-to-one correspondence with the shape of the secondary grid. The shape of the holes is set based on the shape of the secondary grid to be formed.

[0054] In the printing screen provided in the embodiment of the present application, the width of the holes in the screen body gradually widens from the first end toward the second end; so that the secondary grid made on the surface of the battery cell gradually widens from the first end toward the second end. The first end of the screen body is set corresponding to the first end of the battery cell, and the second end of the screen body is set corresponding to the second end of the battery cell. In one example, an identifier can be set on the screen body to determine which end of the screen body is the first end and which end is the second end.

[0055] The present application also provides a welding strip, such as Figure 2 and Figure 3 As shown, the strip-shaped solder strip body 300 is included, and the width of the solder strip body 300 gradually widens in the direction extending from the first position 301 toward the second position 302 .

[0056] The soldering ribbon body 300 is generally in a strip shape to connect adjacent solar cells. The first position 301 and the second position 302 are both position nodes on the soldering ribbon body 300 .

[0057] The welding strip provided in the embodiment of the present application is used to realize welding of the solar cell in the above embodiment. The width of the welding strip body 300 gradually widens in the direction extending from the first position 301 toward the second position 302, so that the width of the welding strip body 300 is adapted to the width of the secondary grid on the battery cell.

[0058] In one embodiment, the length of the welding ribbon body 300 is adapted to the length of the battery cell.

[0059] The strip-shaped welding strip body 300 can be a section of welding strip, and a section of welding strip is correspondingly attached to the secondary grid on the surface of the solar cell, and the head and tail ends are left exposed; the adjacent solar cells are then connected head to tail through the welding strip to achieve series welding of the solar cells.

[0060] When the strip-shaped solder strip body 300 is a segment of solder strip, the length of the segment of solder strip is adapted to the length of the battery cell, so that the solder strip is attached to the secondary grid of the battery cell with the head end and the tail end exposed.

[0061] In one embodiment, Figure 3 As shown, the solder strip body 300 includes a plurality of segments, each of which includes a first position 301 and a second position 302; the length of the segment is adapted to the length of the battery cell.

[0062] The strip-shaped soldering tape body 300 may also be rolled up, and a roll of the soldering tape body 300 includes a plurality of sections. The soldering tape obtained by cutting out a section is equivalent to the sections of the soldering tape in the above example.

[0063] During the string welding process of the solar cells, at least segments are continuously pulled out, one segment is correspondingly attached to the secondary grid of a solar cell, and then the welding strip is welded to the secondary grid.

[0064] In a roll of welding tape, the first positions 301 and the second positions 302 in multiple segments are alternately arranged, such as: the first position 301 of the first segment, the second position 302 of the first segment, the first position 301 of the second segment, the second position 302 of the second segment, the first position 301 of the third segment, the second position 302 of the third segment...; wherein the first position 301 is arranged close to the first end of the battery cell, and the second position 302 is arranged close to the second end of the battery cell.

[0065] In the plurality of sections, the first position 301 and the second position 302 may be positions with equal spacing, and the second position 302 may be a position with the widest width in the section, or a preset marking position in the welding strip body 300 .

[0066] In one embodiment, the thickness of the welding strip body 300 gradually increases from the first position 301 toward the second position 302 , and increases linearly with respect to the axial length of the welding strip body 300 .

[0067] The width of the auxiliary grid is narrower, so the amount of soldering tape required for welding is also less. Therefore, welding can be achieved through thinner soldering tape, which saves the amount of soldering tape and further reduces the shading area of ​​the soldering tape.

[0068] In one implementation, the thickness of the soldering ribbon body 300 at the first position 301 is 5-10 um; the thickness of the soldering ribbon body 300 at the second position 302 is 20-30 um.

[0069] By limiting the thickness of the solder strip body 300 at the first position 301 and the thickness of the solder strip body 300 at the second position 302, the gradient rate of the solder strip body 300 when gradually widening can also be limited to prevent the solder strip body 300 from widening infinitely or rapidly.

[0070] In one embodiment, the radial cross-section of the welding ribbon body 300 includes any one of a semicircular shape, a rectangular shape, and a triangular shape.

[0071] At the position where the width of the auxiliary grid is narrower, the radial cross-section of the welding strip body 300 is set in a semicircular or triangular shape, and the narrower side is attached to the auxiliary grid, for example, the auxiliary grid is attached at the vertex of the triangle, so that it can be ensured that the welding strip body 300 can cover the auxiliary grid and be firmly welded to the auxiliary grid, while reducing the shading area.

[0072] At the position where the width of the auxiliary grid is wider, the radial cross-section of the welding strip body 300 is semicircular, rectangular or triangular, and the wider side is attached to the auxiliary grid, for example, the auxiliary grid is attached to the side of the triangle or the diameter side of the semicircle, or the radial cross-section of the welding strip body 300 is rectangular, and the auxiliary grid can be attached to the long side; so that the welding strip body 300 and the auxiliary grid can be firmly welded, while reducing the amount of solder of the welding strip body 300.

[0073] In the welding ribbon body 300 corresponding to one secondary grid, the radial cross-sections at different positions can be different, so that the structure of the welding ribbon body 300 can make the solar cell have better welding firmness and minimize light shielding.

[0074] The present application embodiment provides a photovoltaic module, such as Figure 4 As shown, it includes a plurality of solar cells 800 according to any one of the above embodiments; the plurality of solar cells 800 are connected in series, and the second end of a solar cell 800 is adjacent to the first end of an adjacent solar cell 800.

[0075] Multiple solar cells 800 are connected in series to collect the current of multiple solar cells 800, so as to increase the power generation of the photovoltaic module and meet the power demand of the user. The series connection between adjacent solar cells 800 enables the current collected by the solar cells 800 to be greater.

[0076] In one implementation, a plurality of solar cells 800 are connected in series via the welding ribbon 400 of any one of the above embodiments.

[0077] In one embodiment, the welding ribbon 400 is welded to the auxiliary grid 200 of the solar cell 800 , one welding ribbon 400 is welded to one auxiliary grid 200 , or the welding ribbon 400 is welded to multiple auxiliary grids 200 at a preset number of intervals.

[0078] In one implementation, the width, thickness, diameter or radial cross-sectional area of ​​the welding ribbon 400 is determined according to the power value on the secondary grid 200 in the solar cell 800 .

[0079] In one example, the shape of the welding ribbon 400, such as the width of the first position 301 and / or the width of the second position 302 of the welding ribbon body 300, and the shape of the radial cross section of the welding ribbon 400 can be determined according to the arrangement of the auxiliary grid 200 in the solar cell 800. Then, based on the shape of the welding ribbon 400, it is determined whether the width, thickness, diameter or radial cross-sectional area of ​​the welding ribbon 400 needs to be determined according to the power value on the auxiliary grid 200 in the solar cell 800; and then the width, thickness, diameter or radial cross-sectional area of ​​the welding ribbon 400 is calculated and determined.

[0080] In one example, the determined width of the welding ribbon 400 may be an average width of a corresponding radial cross section. For example, if the radial cross section of the welding ribbon 400 is a triangle, the average width is half of the base of the triangle.

[0081] In one example, the width of the cell is 182 mm, and the length of a half-cell cell is 105 mm. When the spacing between adjacent auxiliary grids 200 is 2 mm, the number of auxiliary grids 200 is 92; for example, the width of the welding strip 400 is 0.15 mm; the power loss generated by the welding strip 400 itself is 7.5 W; when the spacing between adjacent auxiliary grids 200 is 6 mm, the number of auxiliary grids 200 is 32; the width of the welding strip 400 is still 0.15 mm, the power loss generated by the welding strip 400 itself is 20 W, which is obviously too high. The diameter or width of the corresponding welding strip 400 needs to be increased, such as 0.20 mm, 0.22 mm, etc. When the width of the welding strip 400 is 0.22 mm, the power loss generated by the welding strip 400 can be reduced to 9 W.

[0082] The power loss calculation formula of the welding ribbon 400 is as follows:

[0083] In the formula, P 1: Power loss value generated by the welding strip 400 itself; I : The current in a single welding strip 400; : Line resistance; a : Length of solder strip 400.

[0084] In addition, the number of auxiliary grids 200 and the number of welding strips 400 superimposed on the auxiliary grid 200 are related to the width of the welding strips 400. In specific applications, corresponding parameter values ​​can be selected based on the balance between the number of auxiliary grids 200, the number of welding strips 400 superimposed on the auxiliary grid 200, and the width of the welding strips 400.

[0085] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0086] For the convenience of description, the orientation or position relationship indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, vertical, horizontal" and "top, bottom" is usually based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. Unless otherwise stated, these directional words 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 cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0087] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0088] Unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.

[0089] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0090] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0091] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A solar cell, characterized in that: The invention comprises a battery cell and an electrode grid line structure arranged on the surface of the battery cell; the electrode grid line structure comprises: A plurality of auxiliary grids, wherein the auxiliary grids extend from a first end of the battery cell to a second end of the battery cell, wherein the second end is an end opposite to the first end; and the width of the auxiliary grids gradually widens from the first end toward the second end.

2. The solar cell according to claim 1, characterized in that The distance between adjacent sub-grids at the second end is 2-6 mm.

3. The solar cell according to claim 1, characterized in that The width of the auxiliary grid gradually widens from the first end toward the second end, including: the width of the auxiliary grid linearly widens from the first end toward the second end relative to the axial length of the auxiliary grid.

4. The solar cell according to claim 1, characterized in that The width of the secondary grid at the first end is 5-15 um; the width of the secondary grid at the second end is 30-40 um.

5. A printing screen, characterized in that: Used to prepare the solar cell as described in any one of claims 1 to 4; the printed screen includes a screen body, the screen body includes a plurality of strip holes, and the plurality of strip holes correspond to a plurality of sub-grids in the solar cell; the strip holes extend from the first end of the screen body to the second end of the screen body, and the width of the strip holes gradually widens from the first end toward the second end.

6. A welding strip, characterized in that: It comprises a strip-shaped welding strip body, wherein the width of the welding strip body gradually widens in a direction extending from a first position toward a second position.

7. The welding strip according to claim 6, characterized in that: The length of the welding strip body is adapted to the length of the battery cell.

8. The welding strip according to claim 6, characterized in that: The welding strip body includes a plurality of segments, each of which includes a first position and a second position; and the length of the segment is adapted to the length of the battery cell.

9. The welding strip according to claim 6, characterized in that: The thickness of the welding strip body gradually increases from the first position toward the second position, and increases linearly relative to the axial length of the welding strip body.

10. The welding strip according to any one of claims 8 to 9, characterized in that: The radial cross section of the welding strip body includes any one of a semicircle, a rectangle and a triangle.

11. A photovoltaic module, characterized in that: The invention comprises a plurality of solar cells according to any one of claims 1 to 4; the plurality of solar cells are connected in series, and the second end of the solar cell is adjacent to the first end of the adjacent solar cell.

12. The photovoltaic module according to claim 11, characterized in that: A plurality of the solar cells are connected in series via the welding ribbon according to any one of claims 6 to 10.

13. The photovoltaic module according to claim 12, characterized in that: The welding strip is welded on the auxiliary grid of the solar cell. One welding strip is welded on one auxiliary grid, or the welding strips are welded on multiple auxiliary grids at a preset number of intervals.

14. The photovoltaic module according to claim 12, characterized in that: The width, thickness, diameter or radial cross-sectional area of ​​the welding strip is determined according to the power value on the secondary grid in the solar cell.

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