Solar cell without main grid and solar cell pack

Abstract

The utility model relates to a main-grid-free solar cell, the main-grid-free solar cell comprises a solar cell piece body and an electrode arranged on the solar cell piece body, the electrode comprises a plurality of first thin grid lines, and the first thin grid lines are arranged in parallel; the first thin grid lines are arranged in parallel, the second thin grid lines are arranged in parallel, the second thin grid lines are not parallel to the first thin grid lines, and the first thin grid lines and the second thin grid lines are interwoven to form a plurality of grids; the bonding pads are electrically connected with the first fine grid lines and the second fine grid lines, and at least two grids are arranged between every two bonding pads which are closest to each other. The situation that the light current cannot be collected almost does not occur, and badness caused by breakage of the thin grid lines is not likely to occur; meanwhile, the consumed silver paste is reduced, and the cost is saved.

Description

Technical Field

[0001] The present application relates to the field of new energy, and in particular to solar cells. Background Art

[0002] At present, the crystalline silicon solar cells produced on a large scale generally include: a battery body, a main grid line and a fine grid line arranged on the battery body, a welding pad arranged on the main grid line, and a welding strip welded to the main grid line and the welding pad. The welding pad has a large area, a strong bonding force with the battery body, and provides a higher welding tension; the main grid line is used to collect current, and its width is higher than the fine grid line. The width of the main grid line is also lower than the welding pad, so as to effectively increase the light-receiving area on the front of the component and improve the photoelectric conversion efficiency. The main grid line has a low bonding force with the battery body. During the production and transportation of solar cells, it may be pulled out of shape or even pulled off from the battery body by the welding strip, thereby causing the fine grid line connected to the main grid line to break, causing the electrical connection between the main grid line and the fine grid line to be disconnected, resulting in the photocurrent cannot be collected normally, thereby affecting the electrical performance of the component and reducing the power.

[0003] At present, with the fierce market competition, the cost of batteries has shown a continuous downward trend, the amount of silver paste used in the grid lines is getting lower and lower, the mechanical strength is also decreasing, and the probability of adverse conditions caused by the breakage of fine grid lines is getting higher and higher. Utility Model Content

[0004] The embodiments of the present application provide a busbar-free solar cell and a solar cell group to solve the technical problem that the fine grid lines are prone to breakage and thus cause adverse conditions.

[0005] In a first aspect, an embodiment of the present application provides a busbar-less solar cell, the busbar-less solar cell comprising a solar cell body, and an electrode disposed on the solar cell body, the electrode comprising:

[0006] A plurality of first thin gate lines, wherein the first thin gate lines are arranged parallel to each other;

[0007] a plurality of second fine grid lines, wherein the second fine grid lines are arranged in parallel with each other and are not parallel to the first fine grid lines, and the first fine grid lines and the second fine grid lines are interwoven with each other to form a plurality of grids;

[0008] A plurality of pads are provided, wherein the pads are electrically connected to the first fine gate line and the second fine gate line, and the two pads closest to each other are at least separated by two grids.

[0009] In some embodiments of the present application, the pads are distributed in a rectangular array.

[0010] In some embodiments of the present application, the pads are all arranged at the intersection of the first fine gate line and the second fine gate line.

[0011] In some embodiments of the present application, the first thin gate line and the second thin gate line are perpendicular to each other; and / or,

[0012] The spacing between adjacent first thin gate lines is equal to the spacing between adjacent second thin gate lines.

[0013] In some embodiments of the present application, the lateral angle between the first fine grid lines and the rectangular array of the pads is 45°.

[0014] In some embodiments of the present application, the lateral angle between the first fine gate lines and the rectangular array formed by the pads is an angle in arctan1 / n, where n is an integer not less than 2.

[0015] In some embodiments of the present application, the width of the first fine grid line is 0.02-0.03 mm; and / or,

[0016] The width of the second thin grid line is 0.02-0.03 mm.

[0017] In some embodiments of the present application, the spacing between adjacent first fine grid lines is 1.1-1.6 mm; and / or,

[0018] The spacing between adjacent second fine grid lines is 1.1-1.6 mm.

[0019] In some embodiments of the present application, the spacing between adjacent pads is 3.1-4.3 mm.

[0020] In a second aspect, an embodiment of the present application provides a solar cell group, the solar cell group comprising:

[0021] Several busbar-free solar cells, wherein the busbar-free solar cells are the busbar-free solar cells described in the first aspect;

[0022] A plurality of soldering strips, all the soldering pads are soldered to the soldering strips, and in a rectangular array of the soldering pads, the soldering pads in each horizontal row are soldered to the same soldering strip, or the soldering pads in each vertical column are soldered to the same soldering strip.

[0023] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0024] The busbar-free solar cell provided in the embodiment of the present application abandons the busbar line, adds fine grid lines, and interweaves the first fine grid lines and the second fine grid lines to form a plurality of grids. Even if multiple breakpoints appear on the first fine grid lines and the second fine grid lines, the photocurrent can still be transmitted to the pad on the grid, and there is almost no situation where the photocurrent cannot be collected, and it is not easy to cause defects due to the breakage of the fine grid lines. At the same time, the consumption of silver paste is reduced, which has the advantage of cost saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 A schematic diagram of the structure of a busbar-free solar cell provided in Example 1 of the present application;

[0028] Figure 2 A schematic diagram of the structure of a busbar-free solar cell provided in Example 2 of the present application;

[0029] Figure 3 This is a schematic diagram of the structure of an existing solar cell in the art provided in this application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] Unless otherwise specified, the terms used herein should be understood as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. In the event of a conflict, this specification takes precedence.

[0032] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0033] Existing solar cells have a technical problem that thin grid lines are prone to breakage, leading to adverse conditions.

[0034] The technical solution provided by the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0035] In the first aspect, the present application embodiment provides a busbar-free solar cell. Figure 1 , Figure 2 The busbar-free solar cell comprises a solar cell body 1 and an electrode arranged on the solar cell body 1, wherein the electrode comprises:

[0036] A plurality of first thin gate lines 2, wherein the first thin gate lines 2 are arranged parallel to each other;

[0037] a plurality of second thin grid lines 3, wherein the second thin grid lines 3 are arranged in parallel with each other, and the second thin grid lines 3 are not parallel to the first thin grid lines 2, and the first thin grid lines 2 and the second thin grid lines 3 are interwoven with each other to form a plurality of grids;

[0038] A plurality of pads 4 are provided, wherein the pads 4 are electrically connected to the first fine grid lines 2 and the second fine grid lines 3 , and the two pads 4 closest to each other are at least spaced apart by two grids.

[0039] The existing solar cell structure in the field is as follows Figure 3 As shown. Current solar cells generally include: a battery body 01, a main grid line 02 and a thin grid line 03 arranged on the battery body 01, a PAD pad 04 arranged on the main grid line 02, and a welding strip welded to the main grid line 02 and the PAD pad 04. The main grid line 02 and the thin grid line 03 are usually perpendicular, and the main grid lines 02 are connected by the thin grid lines 03. The main grid line 02 has a low bonding force with the battery body 01. During the production and transportation of solar cells, it may be pulled from the battery body 01 by the welding strip to be deformed or even pulled off, thereby causing the thin grid line 03 connected to the main grid line 02 to break. When two breakpoints 05 appear simultaneously on a thin grid line 03 connecting two adjacent main grid lines 02, a section of the thin grid line 03 between the two breakpoints 05 is no longer electrically connected to the main grid line 02. It should be noted that the adjacent main grid lines 02 are all subjected to the tension of the welding strip, and the tension is transmitted to the two ends of the thin grid lines 03 respectively, so the probability of two breakpoints 05 appearing on a thin grid line 03 at the same time is not very low. The electrical connection between the main grid line 02 and the thin grid line 03 is disconnected, resulting in the inability to collect the photocurrent normally, which in turn affects the electrical performance of the component and reduces the power.

[0040] Compared with the existing solar cell, the present application abandons the main grid line, adds fine grid lines, and makes the first fine grid line 2 and the second fine grid line 3 interweave to form a plurality of grids. At the same time, the present application limits the two closest pads 4 to be at least two grids apart, so that the two pads 4 will not be connected only by a section of fine grid line, and there will be no situation where the photocurrent cannot be collected normally due to two breakpoints between the two pads 4. Even if there are multiple breakpoints on the first fine grid line 2 and the second fine grid line 3, the photocurrent can still be transmitted to the pad 4 on the grid, and there will be almost no situation where the photocurrent cannot be collected. Even in the case of a small probability, the multiple breakpoints that appear just block all current paths, and there will be almost no major impact, because of the characteristics of the grid structure itself, the larger the area of ​​the area where the electrical connection is disconnected, the more breakpoints are required to appear at a specific position. Obviously, as the area of ​​the area where the electrical connection is disconnected increases, the probability of its occurrence will be significantly reduced. Therefore, even if the electrical connection is disconnected in the present application, in most cases it will only affect a small area.

[0041] At the same time, in the art, the main grid lines consume much more silver paste than the fine grid lines. Even if the present application adds a large number of fine grid lines after abandoning the main grid lines, the consumed silver paste is still reduced. Therefore, the present application also has the advantage of reducing costs.

[0042] The present application abandons the main grid lines, increases fine grid lines, and interweaves the first fine grid lines 2 and the second fine grid lines 3 to form a plurality of grids. Even if multiple breakpoints appear on the first fine grid lines 2 and the second fine grid lines 3, the photocurrent can still be transmitted to the pad 4 on the grid. There is almost no possibility that the photocurrent cannot be collected, and it is not easy to cause defects due to the breakage of the fine grid lines. At the same time, the consumption of silver paste is reduced, which has the advantage of cost saving.

[0043] In some embodiments of the present application, the pads 4 are distributed in a rectangular array.

[0044] The array distribution can make the pad 4 collect the photocurrent uniformly, so that the overall circuit works more stably. The rectangular array distribution is easy to implement in terms of technology, and other forms of array distribution can also be used according to actual process requirements.

[0045] In some embodiments of the present application, the pads 4 are all arranged at the intersections of the first thin gate lines 2 and the second thin gate lines 3 .

[0046] The pad 4 is arranged at the intersection of the first thin grid line 2 and the second thin grid line 3, that is, the pad 4 can collect photocurrent in four directions, and even if three directions are disconnected electrically, the collection of photocurrent is not affected. Therefore, arranging the pad 4 at the intersection of the first thin grid line 2 and the second thin grid line 3 is conducive to more stable collection of photocurrent.

[0047] In some embodiments of the present application, the first thin gate lines 2 and the second thin gate lines 3 are perpendicular to each other; and / or,

[0048] The spacing between adjacent first thin gate lines 2 is equal to the spacing between adjacent second thin gate lines 3 .

[0049] The spacing between adjacent first thin gate lines 2 is equal to the spacing between adjacent second thin gate lines 3 , so that the distribution of the thin gate lines can be more uniform and the overall circuit can work more stably.

[0050] In some embodiments of the present application, the pads 4 are distributed in a square array, and the lateral angle between the first fine grid lines 2 and the square array of the pads 4 is 45°. Figure 1 The advantage of this distribution method is that it is easy to find reference points when printing and easy to implement in terms of technology.

[0051] In some embodiments of the present application, the pads 4 are distributed in a square array, and the lateral angle between the first fine grid lines 2 and the rectangular array of the pads 4 is an angle in arctan1 / n, where n is an integer not less than 2.

[0052] Please refer to Figure 2 , Figure 2 In the case of n=1, the lateral angle between the rectangular array formed by the first fine gate lines 2 and the pads 4 is arctan1 / 2.

[0053] Generally speaking, solar cells are connected in series to form a solar cell group through welding ribbons. Each welding ribbon is usually welded to a whole row or column of welding pads 4. When the welding process is implemented, the main grid lines or thin grid lines on the welded rows or columns are also connected to the welding ribbons.

[0054] Figure 1 The structure shown is easy to implement in terms of process, but it is easy to observe that there is an intersection of the first fine grid line 2 and the second fine grid line 3 on the row or column welded with the welding ribbon, and the four segments of fine grid lines forming the intersection will be affected by its tension, which increases the probability of the fine grid line being broken by the tension of the welding ribbon.

[0055] and Figure 2The structure shown is slightly more difficult to implement in terms of process, but it is also relatively easy to find clear reference points, and the row or column where the welding ribbon is welded is only connected to a single section of the fine grid line, and is not connected to the intersection of the first fine grid line 2 and the second fine grid line 3. Only one section of the fine grid line will be affected by its tension, which reduces the probability of the fine grid line breaking due to the tension of the welding ribbon.

[0056] In some embodiments of the present application, the width of the first thin grid line 2 is 0.02-0.03 mm; and / or,

[0057] The width of the second thin grid line 3 is 0.02-0.03 mm.

[0058] As an example, the width of the first thin gate line 2 may be 0.02 mm, 0.022 mm, 0.025 mm, 0.027 mm, or 0.03 mm.

[0059] As an example, the width of the second thin gate line 3 may be 0.02 mm, 0.022 mm, 0.025 mm, 0.027 mm, or 0.03 mm.

[0060] In some embodiments of the present application, the spacing between adjacent first fine grid lines 2 is 1.1-1.6 mm; and / or,

[0061] The interval between adjacent second thin grid lines 3 is 1.1-1.6 mm.

[0062] As an example, the interval between adjacent first thin gate lines 2 may be 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or 1.6 mm.

[0063] As an example, the interval between adjacent second thin grid lines 3 may be 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or 1.6 mm.

[0064] In some embodiments of the present application, the distance between adjacent pads 4 is 2.4-3.6 mm.

[0065] As an example, the spacing between adjacent pads 4 may be 2.4 mm, 2.6 mm, 2.8 mm, 3.3 mm, or 3.6 mm.

[0066] In a second aspect, an embodiment of the present application provides a solar cell group, the solar cell group comprising:

[0067] Several busbar-free solar cells, wherein the busbar-free solar cells are the busbar-free solar cells described in the first aspect;

[0068] A plurality of soldering strips, all the soldering pads 4 are soldered to the soldering strips, and in a rectangular array of the soldering pads 4, each horizontal row of the soldering pads 4 is soldered to the same soldering strip, or each vertical column of the soldering pads 4 is soldered to the same soldering strip.

[0069] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.

[0070] Example 1

[0071] This embodiment provides a busbar-free solar cell. Figure 1 The busbar-free solar cell comprises a solar cell body 1 and an electrode arranged on the solar cell body 1, wherein the electrode comprises:

[0072] A plurality of first thin gate lines 2, wherein the first thin gate lines 2 are arranged parallel to each other;

[0073] a plurality of second thin grid lines 3, wherein the second thin grid lines 3 are arranged in parallel with each other, and the second thin grid lines 3 are not parallel to the first thin grid lines 2, and the first thin grid lines 2 and the second thin grid lines 3 are interwoven with each other to form a plurality of grids;

[0074] A plurality of pads 4 are provided, wherein the pads 4 are electrically connected to the first fine grid lines 2 and the second fine grid lines 3 , and the two pads 4 closest to each other are at least spaced apart by two grids.

[0075] The pads 4 are all arranged at the intersections of the first thin gate lines 2 and the second thin gate lines 3 .

[0076] The pads 4 are distributed in a rectangular array.

[0077] The first thin gate lines 2 and the second thin gate lines 3 are perpendicular to each other.

[0078] The spacing between adjacent first thin gate lines 2 is equal to the spacing between adjacent second thin gate lines 3 .

[0079] The lateral angle of the rectangular array formed by the first fine gate lines 2 and the pads 4 is 45°.

[0080] The width of the first thin grid line 2 is 0.02-0.03 mm, and the width of the second thin grid line 3 is 0.02-0.03 mm.

[0081] The spacing between adjacent first thin grid lines 2 is 1.1-1.6 mm, and the spacing between adjacent second thin grid lines 3 is 1.1-1.6 mm.

[0082] The distance between adjacent pads 4 is 3.1-4.3 mm.

[0083] Example 2

[0084] This embodiment provides a busbar-free solar cell. Figure 2 The busbar-free solar cell comprises a solar cell body 1 and an electrode arranged on the solar cell body 1, wherein the electrode comprises:

[0085] A plurality of first thin gate lines 2, wherein the first thin gate lines 2 are arranged parallel to each other;

[0086] a plurality of second thin grid lines 3, wherein the second thin grid lines 3 are arranged in parallel with each other, and the second thin grid lines 3 are not parallel to the first thin grid lines 2, and the first thin grid lines 2 and the second thin grid lines 3 are interwoven with each other to form a plurality of grids;

[0087] A plurality of pads 4 are provided, wherein the pads 4 are electrically connected to the first fine grid lines 2 and the second fine grid lines 3 , and the two pads 4 closest to each other are at least spaced apart by two grids.

[0088] The pads 4 are all arranged at the intersections of the first thin gate lines 2 and the second thin gate lines 3 .

[0089] The pads 4 are distributed in a rectangular array.

[0090] The first thin gate lines 2 and the second thin gate lines 3 are perpendicular to each other.

[0091] The spacing between adjacent first thin gate lines 2 is equal to the spacing between adjacent second thin gate lines 3 .

[0092] The lateral angle between the rectangular array formed by the first fine gate lines 2 and the pads 4 is arctan1 / 2.

[0093] The width of the first thin grid line 2 is 0.02-0.03 mm, and the width of the second thin grid line 3 is 0.02-0.03 mm.

[0094] The spacing between adjacent first thin grid lines 2 is 1.1-1.6 mm, and the spacing between adjacent second thin grid lines 3 is 1.1-1.6 mm.

[0095] The distance between adjacent pads 4 is 2.4-3.6 mm.

[0096] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0097] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present application specification, the terms "including", "comprising", etc. refer to "including but not limited to". Moreover, the terms "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. For the association relationship of more than three associated objects described by "and / or", it means that any one of these three associated objects can exist alone, or any at least two of them exist at the same time. For example, for A, and / or B, and / or C, it can be represented that any one of A, B, and C exists alone, or any two of them exist at the same time, or three of them exist at the same time. In this article, "at least one" refers to one or more, and "multiple" refers to two or more. "At least one", "the following at least one (individual)" or similar expressions refer to any combination of these items, including any combination of single (individual) or plural (individual). For example, "at least one (individual) of a, b, or c", or "at least one (individual) of a, b, and c", can all represent: a, b, c, ab (i.e. a and b), ac, bc, or abc, wherein a, b, and c can be single or multiple, respectively.

[0098] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A busbar-free solar cell, characterized in that: The busbar-free solar cell comprises a solar cell body and an electrode disposed on the solar cell body, wherein the electrode comprises: A plurality of first thin gate lines, wherein the first thin gate lines are arranged parallel to each other; a plurality of second fine grid lines, wherein the second fine grid lines are arranged in parallel with each other and are not parallel to the first fine grid lines, and the first fine grid lines and the second fine grid lines are interwoven with each other to form a plurality of grids; A plurality of pads are provided, wherein the pads are electrically connected to the first fine gate line and the second fine gate line, and the two pads closest to each other are at least separated by two grids.

2. The busbar-free solar cell according to claim 1, characterized in that: The pads are distributed in a rectangular array.

3. The busbar-free solar cell according to claim 2, characterized in that: The pads are all arranged at intersections of the first thin gate lines and the second thin gate lines.

4. The busbar-free solar cell according to claim 3, characterized in that: The first thin gate lines and the second thin gate lines are perpendicular to each other; and / or, The spacing between adjacent first thin gate lines is equal to the spacing between adjacent second thin gate lines.

5. The busbar-free solar cell according to claim 4, characterized in that: The lateral angle between the rectangular array formed by the first fine gate lines and the pads is 45°.

6. The busbar-free solar cell according to claim 4, characterized in that: The lateral angle between the first fine gate lines and the rectangular array formed by the pads is an angle in arctan1 / n, where n is an integer not less than 2.

7. The busbar-free solar cell according to claim 1, characterized in that: The width of the first fine grid line is 0.02-0.03 mm; and / or, The width of the second thin grid line is 0.02-0.03 mm.

8. The busbar-free solar cell according to claim 1, characterized in that: The spacing between adjacent first fine grid lines is 1.1-1.6 mm; and / or, The spacing between adjacent second fine grid lines is 1.1-1.6 mm.

9. The busbar-free solar cell according to claim 1, characterized in that: The distance between adjacent pads is 3.1-4.3 mm.

10. A solar cell group, characterized in that: The solar cell array comprises: A plurality of busbar-free solar cells, wherein the busbar-free solar cells are the busbar-free solar cells according to any one of claims 2 to 9; A plurality of soldering strips, all the soldering pads are soldered to the soldering strips, and in a rectangular array of the soldering pads, the soldering pads in each horizontal row are soldered to the same soldering strip, or the soldering pads in each vertical column are soldered to the same soldering strip.

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