Electrode structure of solar cell, solar cell piece and photovoltaic module

Abstract

The utility model relates to an electrode structure of a solar cell, a solar cell piece and a photovoltaic module, the electrode structure comprises a plurality of auxiliary grids and a plurality of main grid connecting lines, each main grid connecting line comprises a middle connecting section and transition sections connected to two ends of the middle connecting section, and the width of each transition section is gradually increased in the direction away from the middle connecting section. The end, away from the middle connecting section, of at least one transition section is provided with a thickening section, and the total length of the transition section and the thickening section at the same end of the middle connecting section ranges from 11 mm to 15.5 mm. According to the electrode structure of the solar cell, the solar cell piece and the photovoltaic module, the thickened section is led out from the transition section to increase the width of the end part of the main grid connecting line so as to improve the connection stability with the welding strip, and the total length of the transition section and the thickened section connected with the transition section is controlled, so that the silver paste consumed by thickening is reduced, and the production efficiency is improved under the condition of low cost. The probability that the edge of the solar cell is blackened is reduced, and the reliability and the output power of the photovoltaic module are improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to an electrode structure of a solar cell, a solar cell sheet and a photovoltaic module. Background Art

[0002] Recently, renewable energy sources such as photovoltaics have become the dominant energy sources, and crystalline silicon solar cells have always been the protagonists of the market. In the process of preparing solar cells, screen printing is an important process for producing solar cells, which is used to make the electrodes of solar cells. The electrode structure of solar cells is divided into the secondary grid line part and the main grid line part. The mainstream printing method is step-by-step printing, and 0BB (no main grid) is single printing.

[0003] In the related art, in the conventional electrode structure of 0BB screen printing, the silver paste of the secondary grid line must form a good ohmic contact with the silicon wafer to ensure good carrier transmission capability, and the main grid connection line is used to lead out at the edge of the screen printing and connect to the welding tape, so as to use the welding tape to realize the series welding of the solar cell sheet with another solar cell sheet.

[0004] However, when the main grid connection line is connected to the welding strip at the edge of the solar cell, a cold weld is likely to occur between the end of the main grid connection line and the welding strip, and then the edge of the solar cell and the welding strip overlap will have poor contact, which will cause the edges of the solar cells welded together to be black, affecting the reliability and output power of the photovoltaic module. For example, in the series welding of photovoltaic modules, the welding strip connecting one solar cell to another solar cell will form a certain step, so that the positions where the two ends of the welding strip are connected to the main grid connection line are likely to be tense and warped, resulting in poor electrical contact between the welding strip and the main grid connection line, which will cause the edges of the solar cells welded together to be black. In order to reduce this poor contact and reduce the blackening of the edges of solar cells, the material of the welding ribbon is usually improved to increase the flexibility of the welding ribbon so as to reduce the tension of the welding ribbon after welding with the main grid connection line, thereby reducing the probability of the welding ribbon warping and causing poor electrical contact with the main grid connection line. However, welding ribbons with higher flexibility usually rely on the use of precious metals with good ductility (such as gold, silver and other metals), which leads to high costs. Utility Model Content

[0005] Based on this, a solar cell electrode structure, a solar cell sheet and a photovoltaic module are provided to solve the technical problem of how to reduce the probability of edge blackening of string-welded solar cells at low cost to improve the reliability and output power of the photovoltaic module.

[0006] On the one hand, the present application provides an electrode structure for a solar cell, which includes a plurality of sub-grids arranged in parallel at intervals and a plurality of main grid connection lines vertically connected to the sub-grids. The main grid connection lines include an intermediate connection section and tapered sections connected to both ends of the intermediate connection section. The width of the tapered section gradually widens in a direction away from the intermediate connection section, and the minimum width of the tapered section is equal to the width of the intermediate connection section. At least one end of the tapered section away from the intermediate connection section is provided with a thickened section, and the total length of the tapered section and the thickened section at the same end of the intermediate connection section ranges from 11 mm to 15.5 mm.

[0007] In one embodiment, the width of the thickened section is equal to the maximum width of the tapered section, and the length of the thickened section ranges from 10 mm to 15 mm.

[0008] In one embodiment, a small head end is formed at the minimum width of the tapered section, and a large head end is formed at the maximum width of the tapered section. The width of the small head end ranges from 20 μm to 26 μm, and the width of the large head end ranges from 55 μm to 65 μm.

[0009] In one embodiment, the length of the tapered section ranges from 0.5 mm to 1.0 mm.

[0010] In one embodiment, the length of the intermediate connection section ranges from 70 mm to 80 mm.

[0011] In one embodiment, the width of the sub-grid ranges from 0.05 mm to 0.1 mm, the distance between any two adjacent sub-grids is the same, and the number of sub-grids is 85 to 185;

[0012] And / or, the distance between any two adjacent main grid connection lines is the same, and the number of main grid connection lines is 5 to 15.

[0013] In one embodiment, the electrode structure further includes two current collecting bars, one of the current collecting bars is connected to one end of all the main grid connection lines, and the other current collecting bar is connected to the other end of all the main grid connection lines.

[0014] On the other hand, the present application provides a solar cell including the electrode structure as described above.

[0015] On yet another aspect, the present application provides a photovoltaic module, which includes a plurality of solder tapes and the solar cell as described above. One ends of the plurality of solder tapes are electrically connected to the backlight surface of the solar cell, and the other ends are electrically connected to the light-receiving surface of another solar cell.

[0016] In one embodiment, the solder strip is flat and is in electrical contact with the end of the main grid connection line of the electrode structure.

[0017] For the above-mentioned electrode structure of the solar cell, the solar cell chip and the photovoltaic module, the main grid connection line of the electrode structure includes an intermediate connection section and tapered sections connected to both ends of the intermediate connection section. The width of the tapered section gradually becomes wider in the direction away from the intermediate connection section, and the minimum width of the tapered section is equal to the width of the intermediate connection section. Thus, for the electrode structure of the present application, only by leading out a thickened section through the tapered section can the width of the end of the main grid connection line be increased to improve the contact area with the solder strip, and the total length of the tapered section and the thickened section connected thereto is controlled within 11 mm - 15.5 mm. Therefore, while providing sufficient contact area for the solder strip, the silver paste consumed by thickening is reduced. By using the electrode structure of the solar cell of the present application, there is no need to increase the width of the intermediate connection section to save the amount of silver paste used and reduce costs. Based on the increased contact area between the thickened section and the solder strip, it is not easy to have poor soldering when the main grid connection line is connected to the solder strip, effectively improving the connection stability between the main grid connection line and the solder strip, avoiding the blackening phenomenon at the lap joint between the edge of the solar cell chip and the solder strip due to poor contact, and improving the reliability and output power of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the connection structure of the solar cell chip of the photovoltaic module according to an embodiment of the present application.

[0020] Figure 2 It is a schematic diagram of the connection between the electrode structure and the solder strip in the photovoltaic module according to an embodiment of the present application.

[0021] Figure 3 For Figure 2 It is a partially enlarged schematic diagram of the structure of the solar cell chip of the photovoltaic module shown.

[0022] Figure 4 It is a schematic diagram of the structure of the main grid connection line of the solar cell chip in the photovoltaic module according to an embodiment of the present application.

[0023] Figure 5 It is a schematic diagram of the electrode structure of the solar cell chip of the photovoltaic module according to another embodiment of the present application.

[0024] Figure 6 ForFigure 5 In the electrode structure of the solar cell of the shown photovoltaic module, it is a schematic diagram of the connection structure between the main grid connection line and the current collector bar.

[0025] Figure 7 It is a test schematic diagram in which the edge of the solar cell turns black after series soldering of the solar cell with the electrode structure in the related technology.

[0026] Figure 8 It is a test schematic diagram after series soldering of the solar cell with the electrode structure of the embodiment of the present application.

[0027] Explanation of reference numerals:

[0028] 100, photovoltaic module; 10, solar cell; 11, electrode structure; 111, main grid connection line; 112, sub-grid; 113, current collector bar; 1111, intermediate connection section; 1112, tapered section; 1113, thickened section; 20, solder ribbon. Detailed Description of the Invention

[0029] In order to make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the specific embodiments of the present application in detail with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time.

[0031] The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions are only for the purpose of illustration and do not represent the only implementation.

[0032] It should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0033] In an embodiment of the present application, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0034] As shown in Figure 1 and Figure 2 a photovoltaic module 100 provided by an embodiment of the present application includes a plurality of solder tapes 20 and solar cells 10. The number of solar cells 10 can be 2 or more than 2. The solar cells 10 are electrically connected through a plurality of solder tapes 20 to achieve series connection with each other. Specifically, one end of the plurality of solder tapes 20 is electrically connected to the backlight surface of the solar cell 10, and the other end is electrically connected to the light-receiving surface of another solar cell 10. Among them, the backlight surface of the solar cell 10 refers to the back surface of the solar cell 10, that is, the side of the solar cell 10 facing away from the sun when in use; correspondingly, the light-receiving surface of the solar cell 10 refers to the front surface of the solar cell 10, that is, the side of the solar cell 10 facing the sun when in use.

[0035] The solar cell 10 includes an electrode structure 11, and the electrode structure 11 includes a plurality of sub-grids 112 arranged in parallel at intervals and a plurality of main grid connection lines 111 vertically connected to the sub-grids 112. The main grid connection lines 111 are used to connect with each sub-grid 112. The sub-grids 112 are used to collect and transport photo-generated carriers and converge them to the main grid connection lines 111, and continuously export current when exposed to sunlight. In this embodiment, the main grid connection lines 111 electrically lead out the solar cell 10 and are electrically connected to the solder tapes 20. By using the way that the main grid connection lines 111 are vertically connected to the sub-grids 112, no PAD points are required on the surface of the solar cell 10, realizing the 0BB (without main grid) structure design, which is beneficial to reducing the shading area and reducing the series resistance, thereby improving the output power per unit area of the photovoltaic module 100.

[0036] As shown in Figure 3 and Figure 4As shown, in the electrode structure 11 of the embodiment of the present application, the main grid connection line 111 includes an intermediate connection segment 1111 and tapered segments 1112 connected to both ends of the intermediate connection segment 1111. The width of the tapered segment 1112 gradually widens in the direction away from the intermediate connection segment 1111, and the minimum width of the tapered segment 1112 is equal to the width of the intermediate connection segment 1111. A thickened segment 1113 is provided at one end of the tapered segment 1112 away from the intermediate connection segment 1111, so that the width of the end of the main grid connection line 111 is increased by means of the thickened segment 1113. In this way, when the main grid connection line 111 is connected to the solder tape 20, it is not easy to have a false soldering, which is beneficial to the connection stability between the main grid connection line 111 and the solder tape 20, avoiding the blackening phenomenon caused by poor contact at the lap joint between the edge of the solar cell 10 and the solder tape 20, and improving the reliability and the output power per unit area of the photovoltaic module 100.

[0037] It should be noted that the tapered segments 1112 located at both ends of the intermediate connection segment 1111 may both be provided with thickened segments 1113, or only one of the tapered segments 1112 may be provided with a thickened segment 1113. For example, in some embodiments, the intermediate connection segment 1111 is only connected to the thickened segment 1113 through the tapered segment 1112 at one end. In this embodiment, the thickened segment 1113 can still be used to increase the welding area with the solder tape 200.

[0038] The total length of the tapered segment 1112 and the thickened segment 1113 located at the same end of the intermediate connection segment 1111 ranges from 11 mm to 15.5 mm. For example, the total length of the tapered segment 1112 and the thickened segment 1113 located at the same end of the intermediate connection segment 1111 can be 11 mm, 12 mm, 13 mm, 14 mm or 15.5 mm. In this embodiment, by controlling the total length of the tapered segment 1112 and the thickened segment 1113 within the range of 11 mm to 15.5 mm, it is possible to provide sufficient contact area for the solder tape and reduce the silver paste consumed due to thickening. Then, with the electrode structure 11 of the present application, there is no need to increase the width of the intermediate connection segment 1111 to save the amount of silver paste and reduce costs, so that the probability of the edge of the series-connected solar cells turning black can be reduced at low cost.

[0039] It should be noted here that in the electrode structure 11 of the present application, the structural design of the main grid connection line 111 only increases the silver paste consumption of the tapered section 1112 and the widened part of the thickened section 1113. The overall silver paste cost increases little. Compared with the related art where precious metal materials are used to make the solder ribbon 20 to increase the flexibility of the solder ribbon 20 and improve the connection stability between the solder ribbon 20 and the main grid connection line 111, adopting the electrode structure 11 of the present application has the advantage of low cost, which is conducive to reducing the probability of the edge of the series-connected solar cell 10 turning black while maintaining low cost, so as to improve the reliability of the photovoltaic module 100 and the output power per unit area.

[0040] Continuing to combine Figure 3 and Figure 4 As shown, the width of the thickened section 1113 is equal to the maximum width of the tapered section 1112, which is conducive to smoothly connecting the relatively narrow middle connection section 1111 with the relatively wide thickened section 1113 by using the tapered section 1112. This structural form is conducive to manufacturing the main grid connection line 111 by printing silver paste, reducing the process difficulty and improving the processing efficiency. The length of the thickened section 1113 ranges from 10 mm to 15 mm. For example, the length of the thickened section 1113 can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm. In this embodiment, the welding area between the main grid connection line 111 and the solder ribbon 20 is increased by using the thickened section 1113, thereby improving the electrical connection stability.

[0041] In some embodiments, a small head end is formed at the minimum width of the tapered section 1112, and a large head end is formed at the maximum width of the tapered section. The width of the small head end ranges from 20 μm to 26 μm, and the width of the large head end ranges from 55 μm to 65 μm. In this embodiment, the tapered width of the tapered section 1112 is neither too wide to consume a large amount of silver paste nor too narrow to be unfavorable for carrier transmission. Subsequently, this structural setting is conducive to reducing the use of silver paste while maintaining the carrier transmission ability, so as to reduce the cost.

[0042] The width of the small head end of the tapered section 1112 can be 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm or 26 μm. The width of the large head end of the tapered section 1112 can be 55 μm, 56 μm, 57 μm, 58 μm, 59 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm or 65 μm. It can be understood that the small head end is connected to the middle connection section 1111, and the width of the tapered section 1112 gradually increases from the small head end to the large head end, so that while maintaining the carrier transmission ability, the end of the main grid connection line 111 can be widened, which is conducive to increasing the contact area between the main grid connection line 111 and the solder ribbon 20 and reducing the probability of poor contact.

[0043] The main grid connection line 111 can be an integrally formed structure. Specifically, the middle connection section 1111, the tapered section 1112 and the thickened section 1113 of the main grid connection line 111 are all integrally formed, which is conducive to simplifying the processing steps and improving the production efficiency.

[0044] In some embodiments, the solder ribbon 20 is flat. The solder ribbon 20 is in electrical contact with the end of the main grid connection line 111. Since the solder ribbon 20 is flat, the solder ribbon 20 and the end of the main grid connection line 111 can maintain a large-area contact, thereby reducing the probability of poor contact, which is conducive to improving the reliability of the photovoltaic module 100. It should be noted here that the solder ribbon 20 can be integrally formed with the main grid connection line 111. Thus, when performing series soldering on multiple solar cells 10, the solder ribbon 20 can be used to connect with the sub-grid 112 in multiple solar cells 10, improving the series soldering efficiency.

[0045] In some embodiments, the length of the tapered section 1112 ranges from 0.5 mm to 1.0 mm. For example, the length of the tapered section 1112 is 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm. In this embodiment, based on the gradually increasing width of the tapered section 1112, a larger contact area can be provided for the solder ribbon 20, enhancing the connection stability between the main grid connection line 111 and the solder ribbon 20, which is conducive to improving the reliability of the photovoltaic module 100. The tapered section 1112 may only have a part in contact with the solder ribbon 20. Therefore, if the tapered section 1112 is too long, the part that does not need to be in contact with the solder ribbon 20 will be widened, increasing the amount of silver paste used. In this embodiment, setting the length of the tapered section 1112 to range from 0.5 mm to 1.0 mm can not only maintain the stable connection between the main grid connection line 111 and the solder ribbon 20, but also reduce the amount of silver paste, which is conducive to reducing the production cost of the photovoltaic module 100.

[0046] The length of the middle connection section 1111 ranges from 70 mm to 80 mm. For example, the length of the middle connection section 1111 is 70 mm, 71 mm, 72 mm, 73 mm, 74 mm, 75 mm, 76 mm, 77 mm, 78 mm, 79 mm or 80 mm. Controlling the length of the middle connection section 1111 within this range can meet the need to be adapted to connect with an appropriate number of sub-grids 112. For example, the number of sub-grids 112 is from 85 to 185, and the specific number of sub-grids 112 can be 85, 90, 95, 105, 125, 135, 155, 165 or 185. The number of sub-grids 112 is not limited herein.

[0047] In some embodiments, the width of the auxiliary grid 112 ranges from 0.05 mm to 0.1 mm. For example, the width of the auxiliary grid 112 is 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.1 mm.

[0048] Understandably, the distance between any two adjacent auxiliary grids 112 is the same, and the distance between any two adjacent main grid connection lines 111 is the same. In some embodiments, the number of main grid connection lines 111 is from 5 to 15. Specifically, the number of main grid connection lines 111 can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15. The number of main grid connection lines 111 is not limited herein.

[0049] Combined Figure 5 with Figure 6 As shown, in some embodiments, the electrode structure 11 further includes two current guiding bars 113. One current guiding bar 113 is connected to one end of all the main grid connection lines 111, and the other current guiding bar 113 is connected to the other end of all the main grid connection lines 111. In this embodiment, the current guiding bars 113 can be used to further converge the carriers guided by the multiple main grid connection lines 111 so as to connect the carriers to the solder strip 20. Since the current guiding bars 113 are connected to the ends of the main grid connection lines 111, the solder strip 20 can be connected to the current guiding bars 113, thereby increasing the contact area between the two, improving the connection stability, reducing the probability of the edge of the solar cell 10 turning black due to poor contact at the lap joint with the solder strip 20, and improving the reliability and the output power per unit area of the photovoltaic module 100.

[0050] By testing the photovoltaic module 100 of the embodiments of the present application and the photovoltaic modules of the same area in the related art, some of the test results are shown in Table 1 below.

[0051] Table 1

[0052]

[0053] For ease of understanding, the relevant parameters in Table 1 are described below by taking the photovoltaic module 100 as an example.

[0054] In Table 1, Pmax refers to the maximum power of the photovoltaic module 100. Voc refers to the voltage between the positive and negative electrodes of the photovoltaic module 100 when the positive and negative electrodes are not connected to a load, that is, the open-circuit voltage. Isc refers to the current when the positive and negative electrodes of the photovoltaic module 100 are short-circuited, that is, the short-circuit current. FF refers to the fill factor, also called the curve factor. The fill factor is the ratio of the maximum power of the photovoltaic module 100 to the product of the open-circuit voltage and the short-circuit current: FF = Pm / (Isc×Voc). As an important parameter for evaluating the output characteristics of the solar cells used in the photovoltaic module 100, the higher its value, the more rectangular the output characteristics of the solar cells used are, and the higher the photoelectric conversion efficiency of the photovoltaic module 100.

[0055] The test results in Table 1 show that, compared with the electrode structure of the related art, after using the electrode structure 11 in the embodiment of the present application, the fill factor is increased from 83.19% to 83.36%, and then the photoelectric conversion efficiency of the photovoltaic module 100 is improved. In addition, it can be seen from Table 1 that the maximum power of the photovoltaic module 100 is increased by 1.8 W.

[0056] Combined with Figure 7 As shown, in the related art, if the structural improvement design of the main grid connection line 111 in the electrode structure 11 of the present application is not adopted, there is a problem of edge blackening in the series-connected solar cells. Combined with Figure 8 As shown, by improving the electrode structure 11 in the present application, in the obtained photovoltaic module 100, the situation of edge blackening of the solar cells 10 has been improved. Therefore, by using the electrode structure 11 of the present application, the technical problem of edge blackening of the series-connected solar cells 10 is solved, and the photoelectric conversion efficiency of the photovoltaic module 100 is improved.

[0057] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope recorded in this specification.

[0058] The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the inventive concept of the present application, several deformations and improvements can be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An electrode structure (11) of a solar cell, characterized in that, It includes a plurality of sub-grid lines (112) arranged in parallel at intervals and a plurality of main-grid connection lines (111) vertically connected to the sub-grid lines (112). The main-grid connection lines (111) include an intermediate connection section (1111) and tapered sections (1112) connected to both ends of the intermediate connection section (1111). The width of the tapered section (1112) gradually becomes wider in the direction away from the intermediate connection section (1111). The minimum width of the tapered section (1112) is equal to the width of the intermediate connection section (1111). At least one end of the tapered section (1112) away from the intermediate connection section (1111) is provided with a thickened section (1113). The total length of the tapered section (1112) and the thickened section (1113) at the same end of the intermediate connection section (1111) ranges from 11 mm to 15.5 mm.

2. The electrode structure (11) of the solar cell according to claim 1, characterized in that, The width of the thickened section (1113) is equal to the maximum width of the tapered section (1112), and the length of the thickened section (1113) ranges from 10 mm to 15 mm.

3. The electrode structure (11) of the solar cell according to claim 1 or 2, characterized in that, A small-head end is formed at the minimum width of the tapered section (1112), and a large-head end is formed at the maximum width of the tapered section (1112). The width of the small-head end ranges from 20 μm to 26 μm, and the width of the large-head end ranges from 55 μm to 65 μm.

4. The electrode structure (11) of the solar cell according to claim 3, characterized in that, The length of the tapered section (1112) ranges from 0.5 mm to 1.0 mm.

5. The electrode structure (11) of the solar cell according to claim 1, characterized in that, The length of the intermediate connection section (1111) ranges from 70 mm to 80 mm.

6. The electrode structure (11) of the solar cell according to claim 1, characterized in that, The width of the sub-grid line (112) ranges from 0.05 mm to 0.1 mm. The distance between any two adjacent sub-grid lines (112) is the same, and the number of sub-grid lines (112) is from 85 to 185. And / or, the distance between any two adjacent main-grid connection lines (111) is the same, and the number of main-grid connection lines (111) is from 5 to 15.

7. The electrode structure (11) of the solar cell according to claim 1, characterized in that, It further includes two current-collecting bars (113). One current-collecting bar (113) is connected to one end of all the main-grid connection lines (111), and the other current-collecting bar (113) is connected to the other end of all the main-grid connection lines (111).

8. A solar cell (10), characterized in that, It includes the electrode structure (11) according to any one of claims 1 to 7.

9. A photovoltaic module (100), characterized in that, It includes a plurality of solder tapes (20) and the solar cell (10) according to claim 8. One end of each of the plurality of solder tapes (20) is electrically connected to the backlight surface of the solar cell (10), and the other end is electrically connected to the light-receiving surface of another solar cell (10).

10. The photovoltaic module (100) according to claim 9, characterized in that, The solder tape (20) is flat and is in electrical contact with the end of the main-grid connection line (111) of the electrode structure (11).

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