Electrode structure of back-contact solar cell, cell and its assembly, and solar power generation system

Abstract

This application relates to the solar cell technology field and provides an electrode structure for a back-contact solar cell, a cell and its assembly, and a solar power generation system, in which some first sub-gate electrodes of the electrode structure include a first collecting gate line electrode and a first connecting gate line electrode, the first collecting gate line electrode is connected to a first main gate electrode and is disconnected by a second main gate electrode, and the first connecting gate line electrode passes through a second main gate electrode between two adjacent first main gate electrodes to connect two adjacent first main gate electrodes. In this way, the first connecting gate line electrode passes through the second main gate electrode to connect adjacent first main gate electrodes, thereby connecting all the first main gate electrodes in parallel into a single whole and making their electrical performance more uniform. After welding, the back-contact solar cell becomes a single whole with uniform electrical performance. Furthermore, when the assembly is subjected to an EL test, the EL streak and block-like blackening phenomena in the back-contact solar cell are improved, effectively avoiding mismatch in the back-contact cell assembly and improving the power of the assembly.

Description

[Technical Field]

[0001] The present application relates to the field of solar cell technology, and more particularly to an electrode structure of a back-contact solar cell, a cell and its assembly, and a solar power generation system. [Background technology]

[0002] A back-contact solar cell is a cell in which both the emission electrode and the base contact electrode are placed on the back side (non-light-receiving surface) of the cell, and the light-receiving surface of this cell is not shielded by any metal electrodes, thereby effectively increasing the short-circuit current of the cell sheet.

[0003] In the related art, the design of the back electrode pattern of a back-contact solar cell generally employs a design in which a thin gate connects a main gate of the same polarity and is then cut off to a main gate of the opposite polarity, for example, a positive thin gate is cut off to a negative main gate electrode, and a negative thin gate is cut off to a positive main gate electrode.

[0004] However, in this design, the thin gate is cut into the opposite polarity main gate electrode, so the whole cell area of ​​the back-contact solar cell is divided into stripe-like independent cell regions that are almost not connected, and thus the EL test pattern of the finished assembly finally shows black stripes and black block-like unevenness on the cell sheet, which causes assembly mismatch and reduces the power of the assembly. Summary of the Invention [Problem to be solved by the invention]

[0005] This application provides an electrode structure for a back-contact solar cell, a cell and its assembly, and a solar power generation system, and aims to solve the conventional technical problem that in the EL test diagram of the finished assembly of a back-contact solar cell, black streaks and black blocks appear as unevenness on the cell sheet, causing mismatch in the assembly and reducing the power of the assembly. [Means for solving the problem]

[0006] The present invention is realized as follows: An electrode structure of a back-contact solar cell according to an embodiment of the present invention is used in a back-contact solar cell, the back-contact solar cell includes alternating first polarity regions and second polarity regions, and the electrode structure comprises: a number of first sub-gate electrodes for collecting current in the first polarity regions and a number of second sub-gate electrodes for collecting current in the second polarity regions, the first sub-gate electrodes being alternately spaced apart; a number of first main gate electrodes connected to the first sub-gate electrodes and a number of second main gate electrodes connected to the second sub-gate electrodes, which are alternately provided at intervals, and an arrangement direction of the first main gate electrodes and the second main gate electrodes is different from an arrangement direction of the first sub-gate electrodes and the second sub-gate electrodes; Here, some of the first sub-gate electrodes include a first collection gate line electrode and a first connecting gate line electrode, the first collection gate line electrode is connected to the first main gate electrode and is disconnected by the second main gate electrode, and the first connecting gate line electrode connects two adjacent first main gate electrodes by penetrating a second main gate electrode between the two adjacent first main gate electrodes.

[0007] Furthermore, the number of the first connection gate line electrodes is plural, and the plural first connection gate line electrodes are arranged at intervals along the arrangement direction of the first sub-gate electrode and the second sub-gate electrode on the back-contact type solar cell.

[0008] Furthermore, the width of the first connecting gate line electrode is 80 um-1.5 mm; and / or The width of the first connection gate line electrode is at least 1.5 times the width of the first collection gate line electrode.

[0009] Furthermore, the second main gate electrode has a number of first solder joints spaced apart, and the positions at which the first connection gate line electrode penetrates the second main gate electrode are located between two adjacent first solder joints.

[0010] Furthermore, the distance between the first connection gate line electrode and the center line between two adjacent first solder joints is 10 mm or less.

[0011] Furthermore, the distance between the first connection gate line electrode and the center line between two adjacent first solder joints is 5 mm or less.

[0012] Furthermore, the distance between the first connection gate line electrode and the center line between two adjacent first solder joints is 3 mm or less.

[0013] Furthermore, the distance between the first connection gate line electrode and the center line between two adjacent first solder joints is 1 mm or less.

[0014] Furthermore, a first insulating layer covers the position where the first connection gate line electrode penetrates the second main gate electrode.

[0015] Furthermore, some of the second sub-gate electrodes include a second collection gate line electrode and a second connecting gate line electrode, the second collection gate line electrode is connected to the second main gate electrode and is disconnected from the first main gate electrode, and the second connecting gate line electrode penetrates the first main gate electrode between two adjacent second main gate electrodes to connect two adjacent second main gate electrodes.

[0016] Furthermore, the number of the second connection gate line electrodes is plural, and the plural second connection gate line electrodes are arranged at intervals along the arrangement direction of the first sub-gate electrode and the second sub-gate electrode on the back-contact type solar cell.

[0017] Furthermore, the second connection gate line electrode and the first connection gate line electrode are provided adjacent to each other with a gap therebetween.

[0018] Furthermore, the second connection gate line electrode and the first connection gate line electrode equally divide the back-contact solar cell into a plurality of equal regions in the arrangement direction of the first sub-gate electrode and the second sub-gate electrode.

[0019] Furthermore, the width of the second connecting gate line electrode is 80 um-1.5 mm; and / or The width of the second connecting gate line electrode is at least 1.5 times the width of the second collecting gate line electrode.

[0020] Furthermore, the first main gate electrode has a number of second solder joints spaced apart, and the positions at which the second connection gate line electrode penetrates the first main gate electrode are located between two adjacent second solder joints.

[0021] Furthermore, the distance between the second connection gate line electrode and the center line between two adjacent second solder joints is 10 mm or less.

[0022] Furthermore, the distance between the second connection gate line electrode and the center line between two adjacent second solder joints is 5 mm or less.

[0023] Furthermore, the distance between the second connection gate line electrode and the center line between two adjacent second solder joints is 3 mm or less.

[0024] Furthermore, the distance between the second connection gate line electrode and the center line between two adjacent second solder joints is 1 mm or less.

[0025] Furthermore, a second insulating layer covers the position where the second connection gate line electrode penetrates the first main gate electrode.

[0026] The present application further provides a back-contact solar cell, which includes an electrode structure of the back-contact solar cell described in any one of the above, and the electrode structure is provided on a backlight surface of the back-contact solar cell.

[0027] The present application further provides a back-contact cell assembly, which includes the back-contact solar cell described above.

[0028] The present application further provides a solar power generation system, the solar power generation system including the back-contact type cell assembly described above. [Effects of the Invention]

[0029] In the electrode structure of the back-contact solar cell, the cell and its assembly, and the solar power generation system according to the embodiments of the present application, the first collection gate line electrode is cut by the second main gate electrode, and the first connecting gate line electrode penetrates the second main gate electrode between two adjacent first main gate electrodes to connect the two adjacent first main gate electrodes, that is, a first separation region is formed in the second main gate electrode, and the first connecting gate line electrode penetrates this first separation region to connect the two adjacent first main gate electrodes.

[0030] In this way, the first connecting gate line electrode divides the back-contact solar cell into multiple regions in the arrangement direction of the first sub-gate electrodes and the second sub-gate electrodes. The first connecting gate line electrode penetrates the second main gate electrodes and connects adjacent first main gate electrodes, thereby connecting all of the first main gate electrodes in parallel into a whole, thereby making the electrical performance more uniform, for example, the current density of the back-contact solar cell more uniform. Moreover, the second main gate electrodes cut by the first connecting gate line electrode and the multiple regions divided by the first connecting gate line electrode can be connected by welding ribbons in a subsequent welding process to form an assembly. Finally, the back-contact solar cell after welding becomes a whole with uniform electrical performance. Furthermore, when the back-contact cell assembly is subjected to an EL test, the EL streak and block-like blackening phenomena in the back-contact solar cell are further improved, effectively avoiding mismatches in the back-contact cell assembly and improving the power of the assembly.

[0031] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present application. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a schematic diagram of a module of a solar power generation system according to an embodiment of the present application. [Figure 2] 1 is a schematic diagram of a module of a back-contact battery assembly according to an embodiment of the present application. [Figure 3] 1 is a structural schematic diagram of an electrode structure according to an embodiment of the present application; [Figure 4] 1 is a structural schematic diagram of the electrode pattern design of a back-contact solar cell in the prior art; FIG. [Figure 5] FIG. 2 is another structural schematic diagram of an electrode structure according to an embodiment of the present application. [Figure 6] FIG. 10 is another structural schematic diagram of an electrode structure according to an embodiment of the present application. [Figure 7]10 is a schematic diagram of yet another structure of an electrode structure according to an embodiment of the present application. [Figure 8] FIG. 1 is an EL test diagram of a back-contact type battery assembly in the prior art. [Figure 9] FIG. 1 is an EL test diagram of a back-contact type battery assembly according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0033] In order to clarify the objectives, technical solutions, and advantages of the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and examples. Examples of the above-mentioned embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are illustrative and are used only to explain the present application, and the limitations of the present application cannot be understood. Furthermore, it should be understood that the specific examples described herein are only for the purpose of interpreting the present application, and are not intended to limit the present application.

[0034] In the description of this application, the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "horizontal," and "vertical" are orientations or positional relationships shown based on the accompanying drawings, and are intended merely to facilitate and simplify the description of this application, and do not indicate or suggest that the indicated devices or elements must be configured or operated in a specific orientation, and therefore should not be understood as limitations on this application.

[0035] It should be noted that the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or the number of the indicated technical features. Accordingly, a feature qualified as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of this application, "plurality," "multiple blocks," and "plurality" mean two or more unless specifically limited otherwise.

[0036] The following disclosure provides many different embodiments or examples for realizing different structures of the present application. To simplify the disclosure of the present application, specific example components and configurations will be described below. Of course, these are merely examples and are not intended to limit the present application. It should be noted that reference numerals and / or letters may be repeated in different examples herein; such repetition is for the purposes of simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. It should be noted that although various specific process and material examples are provided herein, those skilled in the art may recognize other process applications and / or material usage scenarios.

[0037] In the present application, the back-contact solar cell is divided into multiple regions by the first connecting gate line electrode in the arrangement direction of the first sub-gate electrodes and the second sub-gate electrodes, and the first connecting gate line electrode penetrates the second main gate electrodes and connects adjacent first main gate electrodes, thereby connecting all the first main gate electrodes in parallel into a whole, thereby making the electrical performance more uniform, for example, making the current density of the back-contact solar cell more uniform. Furthermore, the second main gate electrodes cut by the first connecting gate line electrode and the multiple regions divided by the first connecting gate line electrode can be connected by welding ribbons in a subsequent welding process to form an assembly. Finally, the back-contact solar cell after welding becomes a whole with uniform electrical performance. Furthermore, when the back-contact cell assembly is subjected to an EL test, the EL streak and block-like blackening phenomena in the back-contact solar cell are further improved, effectively avoiding mismatches in the back-contact cell assembly and improving the power of the assembly.

[0038] Example 1 Referring to Figures 1 and 2, a solar power generation system 1000 according to an embodiment of the present application may include a back-contact type cell assembly 200 according to an embodiment of the present application, and the back-contact type cell assembly 200 according to an embodiment of the present application may include a plurality of back-contact type solar cells 100 according to an embodiment of the present application.

[0039] The back-contact solar cells 100 in the back-contact battery assembly 200 can be connected in series to form multiple battery strings, and each battery string can be connected in series, in parallel, or in a series-parallel combination to achieve a combined current output. For example, the connections between each battery sheet can be achieved by welding welding ribbons, and the connections between each battery string can be achieved by bus bars. For example, in the present application, when forming the assembly, welding strips can be welded to both the first main gate electrode 13 and the second main gate electrode 14 to achieve connections between each back-contact solar cell 100, thereby forming the back-contact battery assembly 200.

[0040] The back-contact solar cell 100 in the embodiment of the present application may include a substrate (not shown) and the electrode structure 10 in the embodiment of the present application, the substrate may be a silicon wafer, and the back surface of the substrate (i.e., the backlight surface of the back-contact solar cell 100) has alternating first polarity regions and second polarity regions (not shown), the first polarity regions have the opposite polarity to the second polarity regions, for example, the first polarity regions may be P-type impurity regions and the second polarity regions may be N-type impurity regions, or for example, the first polarity regions may be N-type impurity regions and the second polarity regions may be P-type impurity regions, and the specifics are not limited here.

[0041] Referring to FIG. 3, the electrode structure 10 in the embodiment of the present application may be provided on the backlight surface of a back-contact solar cell 100, and the electrode structure 10 may include a number of first sub-gate electrodes 11 and a number of second sub-gate electrodes 12 that are alternately arranged at intervals, and may also include a number of first main gate electrodes 13 and a number of second main gate electrodes 14 that are alternately arranged at intervals.

[0042] The first sub-gate electrode 11 is used to collect current in the first polarity region, and the second sub-gate electrode 12 is used to collect current in the second polarity region, i.e., the first sub-gate electrode 11 may correspond to the first polarity region, and the second sub-gate electrode 12 may correspond to the second polarity region.

[0043] 3, the first sub-gate electrodes 11 and the second sub-gate electrodes 12 are alternately arranged at intervals along the horizontal direction, and the first main gate electrodes 13 and the second main gate electrodes 14 are alternately arranged at intervals along the vertical direction, with their arrangement directions perpendicular to each other. The first main gate electrode 13 is connected to the first sub-gate electrode 11, and the second main gate electrode 14 is connected to the second sub-gate electrode 12. That is, the first main gate electrode 13 may be used to collect the current collected by the first sub-gate electrode 11, and the second main gate electrode 14 may be used to collect the current collected by the second sub-gate electrode 12.

[0044] Here, some of the first sub-gate electrodes 11 may include a first collection gate line electrode 111 and a first connecting gate line electrode 112 (i.e., the thick gate line electrode in FIG. 3 ), the first collection gate line electrode 111 is connected to the first main gate electrode 13 and is disconnected by the second main gate electrode 14, and the first connecting gate line electrode 112 penetrates the second main gate electrode 14 between the two adjacent first main gate electrodes 13 to connect to the two adjacent first main gate electrodes 13, that is, as shown in FIG. 3 , a first separation region 140 may be formed in the second main gate electrode 14, and the first connecting gate line electrode 112 connects the two adjacent first main gate electrodes 13 through this first separation region 140. As can be understood, in such a case, the first connecting gate line electrode 112 is insulated and separated from the second main gate electrode 14 by the first separation region 140.

[0045] In the electrode structure 10, back-contact solar cell 100, back-contact cell assembly 200 and solar power generation system 1000 of the embodiments of the present application, the first collection gate line electrode 111 is cut by the second main gate electrode 14, and the first connecting gate line electrode 112 penetrates the second main gate electrode 14 between two adjacent first main gate electrodes 13 and connects to the two adjacent first main gate electrodes 13, that is, a first separation region 140 is formed in the second main gate electrode 14, and the first connecting gate line electrode 112 penetrates this first separation region 140 to adjoin the two adjacent first main gate electrodes 13.

[0046] In this way, the first connecting gate line electrode 112 can divide the back-contact type solar cell 100 into a plurality of regions in the arrangement direction of the first sub-gate electrodes 11 and the second sub-gate electrodes 12 (i.e., the vertical direction in the figure). The first connecting gate line electrode 112 penetrates the second main gate electrode 14 and connects adjacent first main gate electrodes 13, thereby connecting all of the first main gate electrodes 13 in parallel to one whole, making the electrical performance more uniform. For example, the current density of the back-contact type solar cell 100 can be made more uniform. In addition, the first connecting gate line electrode 112 The regions defined by the second main gate electrode 14 and the first connecting gate line electrode 112 cut by the welding ribbon can be connected by a welding ribbon in a subsequent welding process to form an assembly. Finally, the back-contact solar cell 100 after welding becomes a whole with uniform electrical performance. Furthermore, when the back-contact cell assembly 200 undergoes an EL test, the back-contact solar cell 100 will exhibit improved EL streaks and block-like blackening phenomena, which will effectively avoid mismatching of the back-contact cell assembly 200 and improve the power of the assembly.

[0047] As can be understood, in the solar cell technology field, EL testing, i.e., electroluminescence testing, is commonly performed to detect internal defects in solar cells. However, in the EL testing, the brightness of the test image is directly proportional to the minority carrier lifetime (or minority carrier diffusion length) and current density of the cell sheet. The defective parts of the solar cell have a relatively low minority carrier diffusion length, so the brightness of the displayed image is relatively dark. The defects usually include silicon material defects, diffusion defects, printing defects, sintering defects, and single cell abnormal phenomena with different conversion efficiencies.

[0048] As can be easily understood, referring to FIG. 4, in the prior art, sub-gate electrodes of different polarities are all connected to main gate electrodes of the same polarity and are separated into main gate electrodes of the opposite polarity. As shown in FIG. 4, the positive sub-gate 2 is connected to the positive main gate 1 and is separated into the negative main gate 3, and the negative sub-gate 4 is connected to the negative main gate 3 and is separated into the positive main gate 1.

[0049] In such a case, the two same-sex main gate electrodes are equivalent to independent cell regions with almost no connection between them, but the back-contact solar cell may have some defects, such as defects in the silicon material itself, which may cause uneven black streaks or black blocks to appear in the test image when an EL test is subsequently performed, resulting in a certain mismatch in the subsequently formed assembly and a decrease in the power of the assembly.

[0050] However, compared to the electrode design scheme of the prior art shown in FIG. 4 , in the embodiment of the present application, the first connecting gate line electrode 112 of the first sub-gate electrode 11 is arranged to penetrate the second main gate electrode 14 and connect the adjacent first main gate electrodes 13, so that the first main gate electrodes 13 of the same polarity are connected in parallel to form a whole, thereby forming a whole with uniform electrical performance (e.g., uniform current density), thereby improving the streaky and block-like blackening phenomenon in the EL image, making the brightness of each back-contact solar cell 100 in the EL image more uniform, and further improving the power of the back-contact cell assembly 200.

[0051] Specifically, in the embodiment of the present application, the first polarity region has the opposite polarity to the second polarity region, and the first sub-gate electrode 11 also has the opposite polarity to the second sub-gate electrode 12. For example, the first sub-gate electrode 11 is a positive sub-gate electrode for collecting positive electrode current in the positive electrode region, and the second sub-gate electrode 12 is a negative sub-gate electrode for collecting negative electrode current in the negative electrode region, or the first sub-gate electrode 11 is a negative sub-gate electrode for collecting negative electrode current in the negative electrode region, and the second sub-gate electrode 12 is a positive gate line electrode for collecting positive electrode current in the positive electrode region. Here, the positive sub-gate electrode is provided in a P-type impurity region of the back-contact solar cell 100, and the negative sub-gate electrode is provided in an N-type impurity region of the back-contact solar cell 100.

[0052] 3, in the embodiment shown in FIG. 3, the first sub-gate electrodes 11 and the second sub-gate electrodes 12 are alternately arranged at intervals along the vertical direction, and correspondingly, the first polarity regions and the second polarity regions are alternately arranged along the vertical direction. The first main gate electrodes 13 and the second main gate electrodes 14 may be alternately arranged along the horizontal direction perpendicular to the first sub-gate electrodes 11 and the second sub-gate electrodes 12.

[0053] That is, in the embodiment shown in FIG. 3, the first connecting gate line electrode 112 can divide the entire back-contact solar cell 100 into multiple regions along the vertical direction, and the multiple vertically divided regions are connected by welding ribbons during assembly welding, so that the back-contact solar cell 100 after welding can finally become a whole with uniform electrical performance.

[0054] It should be understood that in the embodiments of the present application, the number of the first sub-gate electrodes 11 and the second sub-gate electrodes 12 can be determined based on the area size of the actual back-contact type solar cell 100, the width and distance of the first sub-gate electrodes 11 and the second sub-gate electrodes 12, and is not specifically limited here.

[0055] Furthermore, in the embodiment of the present application, the first sub-gate electrode 11 and the second sub-gate electrode 12 may be an aluminum gate line, a silver gate line, a copper gate line, or a silver-coated copper gate line, and are not limited here.

[0056] As can be understood, in the present embodiment, the first sub-gate electrode 11 and the second sub-gate electrode 12 can be gate lines of the same or different metal types, for example, the first sub-gate electrode 11 and the second sub-gate electrode 12 can both be aluminum gate lines, or the first sub-gate electrode 11 can be an aluminum gate line and the second sub-gate electrode 12 can be a silver gate line. Here, if the first sub-gate electrode 11 or the second sub-gate electrode 12 is an aluminum gate line or a silver gate line, it can be printed on the impurity region of the back-contact solar cell 100 by screen printing, and if the first sub-gate electrode 11 or the second sub-gate electrode 12 is a copper gate line, it can be plated on the impurity region of the back-contact solar cell 100 by methods such as electroplating or evaporation.

[0057] Of course, in the embodiment of the present application, the first main gate electrode 13 and the second main gate electrode 14 may adopt gate lines such as copper, silver, aluminum, or silver-coated copper, and the specific examples are not limited here.

[0058] As can be understood, in the present embodiment, the back-contact cell assembly 200 may further include a metal frame, a back plate, a solar-powered glass, and an adhesive film (none of which are shown). The adhesive film may be filled between the front and solar-powered glass of the back-contact solar cell 100, the back and back plate, and the adjacent cell sheet. As a filler, the adhesive film may be a transparent colloid with good light transmission and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific adhesive film may be selected according to the actual situation and is not limited herein.

[0059] The solar cell 100 may be covered with an adhesive film on the front surface thereof. The solar cell 100 may be an ultra-white glass having high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, the light transmittance of the ultra-white glass may reach 92% or more, which can protect the back-contact solar cell 100 while minimizing the impact on the efficiency of the back-contact solar cell 100. At the same time, the adhesive film can bond the solar cell 100 to the back-contact solar cell 100, and the presence of the adhesive film can provide hermetic insulation and waterproof / moisture-proofing for the back-contact solar cell 100.

[0060] The backplate can be attached to the adhesive film on the back surface of the back-contact solar cell 100. The backplate can protect and support the back-contact solar cell 100 and has reliable insulation, water repellency, and aging resistance. The backplate can be made of a variety of materials, including tempered glass, organic glass, and an aluminum alloy TPT composite adhesive film. The specific backplate can be provided according to the circumstances and is not limited thereto. The entire assembly consisting of the backplate, back-contact solar cell 100, adhesive film, and solar power generating glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire back-contact battery assembly 200 and can stably support and mount the back-contact battery assembly 200. For example, the back-contact battery assembly 200 can be mounted in a desired position using the metal frame.

[0061] Furthermore, in this embodiment, the solar power generation system 1000 may be applied to a solar power plant, such as a ground power plant, a rooftop power plant, a water power plant, etc., and may also be applied to equipment or devices that generate electricity using sunlight, such as a user solar power supply, a solar road light, a solar automobile, a solar building, etc. Of course, it can be understood that the application scenarios of the solar power generation system 1000 are not limited thereto, that is, the solar power generation system 1000 may be applied to all fields that require the use of sunlight to generate electricity.

[0062] Taking a solar power generation system grid as an example, the solar power generation system 1000 may include a solar power generation array, a junction box, and an inverter. The solar power generation array may be an array combination of a plurality of back-contact type battery assemblies 200. For example, a plurality of back-contact type battery assemblies 200 can constitute a plurality of solar power generation arrays. The solar power generation arrays are connected to a junction box, which can combine the currents generated by the solar power generation arrays. The combined current passes through an inverter to be converted into AC power required by the commercial power grid, and then can be accessed by the commercial power grid to realize solar power supply.

[0063] Example 2 Referring to Figure 3, in some embodiments, the number of first connection gate line electrodes 112 is multiple, and the multiple first connection gate line electrodes 112 are spaced apart along the arrangement direction of the first sub-gate electrodes 11 and the second sub-gate electrodes 12 on the back-contact type solar cell 100 (i.e., the vertical direction in Figure 3).

[0064] In this way, the multiple first connection gate line electrodes 112 can make the electrical performance of the back-contact type solar cell 100 more uniform, and the multiple areas partitioned by the multiple first connection gate line electrodes 112 can be connected by welding ribbons in the subsequent welding process to form a whole with uniform electrical performance.

[0065] 3, in this embodiment, the first connecting gate line electrodes 112 are preferably uniformly spaced apart along the vertical direction, and the use of multiple first connecting gate line electrodes 112 can achieve uniform electrical performance (e.g., current density), improve the brightness of the EL test image, make the brightness of the back-contact solar cell 100 more uniform, and reduce the EL streak and block-like blackening phenomena. In this application, the number of first connecting gate line electrodes 112 can be determined according to the size of the back-contact solar cell 100, and the pitch between two adjacent first connecting gate line electrodes 112 can be set according to specific circumstances and is not limited herein.

[0066] In addition, Figure 3 only shows two first connecting gate line electrodes 112 and some of the sub-gate electrodes and main gate electrodes of the electrode structure 10, which is merely an example for explanation and understanding. In some embodiments, first sub-gate electrodes 11 and second sub-gate electrodes 12 may be further provided in all four directions, i.e., up, down, left, and right, in Figure 3. A plurality of first main gate electrodes 13 and second main gate electrodes 14 may be further provided in the left and right directions. A number of first connecting gate line electrodes 112 may be provided above and below the first connecting gate line electrode 112. The specific number of first connecting gate line electrodes 112 can be determined according to the size of the back-contact type solar cell 100, and is not specifically limited here.

[0067] Example 3 In some embodiments, the width of the first connecting gate line electrode 112 may be 80 um-1.5 mm.

[0068] In this way, by setting the width of the first connection gate line electrode 112 within a reasonable range of 80 um-1.5 mm, the effect of the first connection gate line electrode 112 being connected to two adjacent first main gate electrodes 13 to achieve parallel merging and the effect of uniform electrical performance can be ensured, and it is possible to avoid the first connection gate line electrode 112 being too small to withstand the current transmission between the two adjacent first main gate electrodes 13, which would cause the first connection gate line electrode 112 to overheat or melt down, while at the same time it is possible to avoid the first connection gate line electrode 112 being too wide and causing slurry to be wasted.

[0069] Specifically, in such an embodiment, the width of the first connection gate line electrode 112 may be any one of 80 um, 100 um, 200 um, 300 um, 400 um, 500 um, 600 um, 700 um, 800 um, 900 um, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or 80 um-1.5 mm, and is not specifically limited thereto.

[0070] Furthermore, in some embodiments, the width of the first connecting gate line electrode 112 is preferably greater than 1.5 times the width of the first collecting gate line electrode 111 .

[0071] In this way, by making the width of the first connection gate line electrode 112 larger than 1.5 times the width of the first collection gate line electrode 111, it is possible to ensure more uniform and reliable current density.

[0072] Of course, as can be understood, in order to reduce the use of slurry, as far as performance permits, the width of the first connecting gate line electrode 112 may be approximately the same as the width of the first collecting gate line electrode 111, and in such a case, parallel connection between the first main gate electrodes 13 can be realized by providing multiple first connecting gate line electrodes 112.

[0073] Example 4 Referring to FIG. 3, in some embodiments, the second main gate electrode 14 has a number of first solder joints 141 spaced apart, and the position where the first connection gate line electrode 112 penetrates the second main gate electrode 14 is located between two adjacent first solder joints 141, i.e., the first separation region 140 is located between two adjacent first solder joints 141.

[0074] In this way, by arranging the first connection gate line electrode 112 between two adjacent first solder joints 141, it is possible to connect two adjacent first main gate electrodes 13 and realize parallel connection of the first main gate electrodes 13, while at the same time ensuring the integrity of the first solder joint 141 and ensuring the welding function of the second main gate electrode 14.

[0075] Specifically, in such an embodiment, a number of first solder joints 141 may be distributed at uniform intervals on the second main gate electrode 14, and it is preferable that the number of first connection gate line electrodes 112 between two adjacent first solder joints 141 is one. In this way, by having one first connection gate line electrode 112 between every two first solder joints 141, the number of first separation areas 140 between two adjacent first solder joints 141 can be reduced and the influence on the welding of the second main gate electrode 14 can be avoided.

[0076] In such an embodiment, the distance between two adjacent first solder joints 141 on the second primary gate electrode 14 may be greater than 5 mm, and preferably greater than 9 mm. In some embodiments, for the same size, the distance between two adjacent first solder joints 141 can be greater than 11 mm and less than 45 mm to reduce the use of slurry for the first solder joints 141.

[0077] Furthermore, in such an embodiment, it is more preferable that the pitch between two adjacent first solder joints 141 may be 11 mm or more and 30 mm or less. In this way, by setting the pitch between the first solder joints 141 within this optimum range, it is possible to ensure the number of first solder joints 141 and avoid welding defects during welding, ensuring welding reliability, while also avoiding an increase in costs due to an excessive number of first solder joints 141.

[0078] Of course, in some embodiments, the position where the first connecting gate line electrode 112 penetrates the second main gate electrode 14 may be located at the first solder joint 141, that is, a first separation area 140 is formed at the first solder joint 141 for the first connecting gate line electrode 112 to penetrate.

[0079] In this way, each first solder joint 141 corresponds to one first connection gate line electrode 112, and the first connection gate line electrodes 112 are uniformly arranged, thereby ensuring the reliability of the connection.

[0080] Specifically, in such a case, the first solder joint 141 can be divided into two parts facing each other at a distance by the first connection gate line electrode, and it is preferable that the first connection gate line electrode is located at the center position of the first solder joint 141, and the first connection gate line electrode 112 is connected to two adjacent first main gate electrodes 13 through the center position of the first solder joint 141 to realize parallel connection of the first main gate electrodes.

[0081] In such a case, the reliability of subsequent welding can be ensured by setting the length of the first solder joint 141 long or the width of the first solder joint 141 wide so that the first solder joint 141 is not blocked by the first connection gate line electrode and affects the subsequent welding effect.

[0082] Example 5 3, in some embodiments, the distance between the first connecting gate line electrode 112 and the center line between two adjacent first solder joints 141 is 10 mm or less. That is, the distance between the first connecting gate line electrode 112 and the midpoint between two adjacent first solder joints 141 is 10 mm or less.

[0083] In this way, the first connection gate line electrode 112 can maintain an appropriate distance between itself and the first solder joint 141, thereby avoiding the problem that the presence of the first connection gate line electrode 112 causes temporary welding to occur at the first solder joint 141 during welding, while at the same time making the electrical performance (e.g., current density) more uniform.

[0084] As can be seen, in some embodiments, during the printing process, the height of the first connection gate line electrode 112 is the same as or even slightly higher than the height of the first solder joint 141, and the distance between the first connection gate line electrode 112 and the first solder joint 141 should not be too small; if it is too small, there will be a certain height difference between the first connection gate line electrode 112 and the first solder joint 141, making it easy for tack welding to occur during welding. Therefore, as long as the distance between the first connection gate line electrode 112 and the center line between two adjacent first solder joints 141 is 10 mm or less, it can effectively avoid the occurrence of tack welding and an increase in the defect rate due to the distance between the first solder joint 141 and the first connection gate line electrode 112 being too small.

[0085] Furthermore, in such an embodiment, the distance between the first connecting gate line electrode 112 and the centerline between two adjacent first solder joints 141 is 5 mm or less.

[0086] In this way, by setting the distance between the first connection gate line electrode 112 and the center of the two first solder joints 141 within this preferred range, subsequent welding performance can be improved and electrical performance can be made more uniform.

[0087] In this embodiment, the distance between the first connection gate line electrode 112 and the center line between two adjacent first solder joints 141 is preferably 3 mm or less, and most preferably 1 mm. In this way, the position of the first connection gate line electrode 112 can be aligned as closely as possible with the center line between the two first solder joints 141, thereby improving the uniformity of electrical performance.

[0088] Example 6 Referring to FIG. 5, in some embodiments, a first insulating layer 15 may be coated at the location where the first connecting gate line electrode 112 penetrates the second main gate electrode 14, i.e., the first isolation region 140 in FIG. 3 may be coated with the first insulating layer 15.

[0089] In this way, by covering the area where the second main gate electrode 14 is penetrated by the first connecting gate line electrode 112 with the first insulating layer 15, it is possible to prevent the welding ribbon from coming into contact with the first connecting gate line electrode 112 and causing an electrical leakage when welding the first solder joint 141.

[0090] Specifically, the size of the first insulating layer 15 may be the same as or slightly larger than the size of the first separation region 140 on the second main gate electrode 14 to achieve insulation; that is, on the second main gate electrode 14, only the region corresponding to the first separation region 140 is covered with the first insulating layer 15, while the other regions are not provided with the first insulating layer 15, and the first insulating layer 15 may be an insulating adhesive.

[0091] Example 7 6 , in some embodiments, some of the second sub-gate electrodes 12 may include a second collection gate line electrode 121 and a second connecting gate line electrode 122, where the second collection gate line electrode 121 is connected to the second main gate electrode 14 and is disconnected by the first main gate electrode 13, and the second connecting gate line electrode 122 penetrates the first main gate electrode 13 between two adjacent second main gate electrodes 14 to connect the two adjacent second main gate electrodes 14. That is, as shown in FIG. 6 , a second separation region 130 is formed in the first main gate electrode 13, and the second connecting gate line electrode 122 penetrates the second separation region 130 to connect the two adjacent second main gate electrodes 14. As can be understood, in such a case, the second connecting gate line electrode 122 is insulated and separated from the first main gate electrode 13 by the second separation region 130.

[0092] In this way, the back-contact type solar cell 100 can be divided into a plurality of regions in the arrangement direction of the first sub-gate electrodes 11 and the second sub-gate electrodes 12 (i.e., the vertical direction in FIG. 6) by the first connecting gate line electrode 112 and the second connecting gate line electrode 122. The first connecting gate line electrode 112 penetrates the second main gate electrodes 14 and connects adjacent first main gate electrodes 13, thereby connecting all the first main gate electrodes 13 in parallel to one whole. The second connecting gate line electrode 122 penetrates the first main gate electrodes 13 and connects adjacent second main gate electrodes 14. By doing so, all the second main gate electrodes 14 are connected in parallel to one whole, and the multiple regions defined by the first connecting gate line electrodes 112 and the second connecting gate line electrodes 122 are connected by welding ribbons in the subsequent welding process to form an assembly, which further makes the electrical performance (e.g., current density) of the back-contact solar cell 100 more uniform, and further improves the EL streak and block-like blackening phenomenon in the back-contact solar cell 100 when the cell assembly undergoes EL testing, thereby further improving the power of the assembly.

[0093] That is, in this embodiment, by providing the second connecting gate line electrode 122, the degree of uniformity of the electrical performance of the back-contact solar cell 100 can be further improved, and the situation of uneven brightness in the EL test image can be further improved, so that the brightness of the back-contact solar cell 100 in the EL test image can be more uniform, and the power of the assembly can be further improved.

[0094] Example 8 Referring to Figure 6, similar to the first connecting gate line electrode 112, in some embodiments, the number of second connecting gate line electrodes 122 is multiple, and the multiple second connecting gate line electrodes 122 are spaced apart along the arrangement direction of the first sub-gate electrode 11 and the second sub-gate electrode 12 on the back-contact type solar cell 100.

[0095] In this way, the multiple second connection gate line electrodes 122 can make the electrical performance of the back-contact type solar cell 100 more uniform, and the multiple areas partitioned by the multiple second connection gate line electrodes 122 can be connected by welding ribbons in the subsequent welding process to form a whole with uniform electrical performance.

[0096] 3, in this embodiment, the second connection gate line electrodes 122 are preferably uniformly spaced apart along the vertical direction, and the use of multiple second connection gate line electrodes 122 can achieve uniform electrical performance (e.g., current density), improve the brightness of the EL test image, make the brightness of the back-contact solar cell 100 more uniform, and reduce the EL streak and block-like blackening phenomena. In this application, the number of second connection gate line electrodes 122 can be determined according to the size of the back-contact solar cell 100, and the pitch between two adjacent second connection gate line electrodes 122 can be set according to specific circumstances and is not limited herein.

[0097] Example 9 In some embodiments, the second connecting gate line electrode 122 is preferably disposed adjacent to and spaced apart from the first connecting gate line electrode 112 .

[0098] In this way, by arranging the second connection gate line electrode 122 and the first connection gate line electrode 112 adjacent to each other, the difference in position between the first separation region 140 on the second main gate electrode 14 and the second separation region 130 on the first main gate electrode 13 is reduced, making it easier to fabricate the first main gate electrode 13 and the second main gate electrode 14.

[0099] Furthermore, in such an embodiment, the second connecting gate line electrode 122 and the first connecting gate line electrode 112 evenly divide the back-contact solar cell 100 into multiple equal regions in the arrangement direction of the first sub-gate electrode 11 and the second sub-gate electrode 12.

[0100] In this way, the first connecting gate line electrode 112 and the second connecting gate line electrode 122 can divide the back-contact solar cell 100 into equal regions, and the electrical performance within each equal region is relatively uniform, thereby making the overall electrical performance formed after connecting each region by welding more uniform and further improving the power of the assembly.

[0101] 6, the first connecting gate line electrode 112 and the second connecting gate line electrode 122 can divide the back-contact solar cell 100 into multiple approximately independent regions in the vertical direction, each of which corresponds to a small solar cell. The multiple regions are then connected by welding ribbons in the subsequent assembly welding process to form a whole with uniform electrical performance and improve the power of the assembly. As can be seen, because the first main gate electrode 13 and the second main gate electrode 14 are both interrupted in multiple stages, the multiple main gate electrodes can be connected by welding ribbons in the subsequent welding.

[0102] Of course, it can be understood that in some embodiments, the first connecting gate line electrode 112 and the second connecting gate line electrode 122 may not be adjacently arranged, but may be spaced apart, and this is not specifically limited here.

[0103] Example 10 In some embodiments, the width of the second connecting gate line electrode 122 may be 80 um-1.5 mm.

[0104] In this way, by setting the width of the second connection gate line electrode 122 within a reasonable range of 80 um-1.5 mm, the effect of the second connection gate line electrode 122 connecting two adjacent second main gate electrodes 14 to achieve parallel merging and uniformity is ensured, and it is possible to avoid the second connection gate line electrode 122 being too small to withstand the current transmission between the two adjacent second main gate electrodes 14, which would cause the second connection gate line electrode 122 to overheat and even melt down, while at the same time it is possible to avoid the second connection gate line electrode 122 being too wide and causing slurry to be wasted.

[0105] Specifically, in such an embodiment, the width of the second connection gate line electrode 122 may be any one of 80 um, 100 um, 200 um, 300 um, 400 um, 500 um, 600 um, 700 um, 800 um, 900 um, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, or 80 um-1.5 mm, and is not specifically limited thereto.

[0106] Furthermore, in some embodiments, the width of the second connecting gate line electrode 122 is preferably greater than 1.5 times the width of the second collecting gate line electrode 121 .

[0107] In this way, by making the width of the second connection gate line electrode 122 larger than 1.5 times the width of the second collection gate line electrode 121, two adjacent second main gate electrodes 14 are connected in parallel, thereby ensuring more uniform and reliable current density.

[0108] Of course, as can be understood, as long as performance permits, the width of the second connection gate line electrode 122 may be approximately the same as the width of the second collection gate line electrode 121, and in such a case, parallel connection between the second main gate electrodes 14 can be realized by providing multiple second connection gate line electrodes 122.

[0109] Example 11 Referring to FIG. 6, in some embodiments, the second main gate electrode 14 has a number of second solder joints 131 spaced apart, and the position where the second connection gate line electrode 122 penetrates the second main gate electrode 14 is between two adjacent second solder joints 131, i.e., the second separation region 130 is located between two adjacent second solder joints 131.

[0110] In this way, by arranging the second connection gate line electrode 122 between two adjacent second solder joints 131, it is possible to connect two adjacent second main gate electrodes 14 and realize parallel connection of the second main gate electrodes 14, while at the same time ensuring the integrity of the second solder joint 131 and ensuring the welding function of the first main gate electrode 13.

[0111] Specifically, in such an embodiment, a number of second solder joints 131 may be distributed at uniform intervals on the first main gate electrode 13, and it is preferable that the number of second connection gate line electrodes 122 between two adjacent second solder joints 131 is one. In this way, by having one second connection gate line electrode 122 between every two second solder joints 131, the number of second separation areas 130 between two adjacent second solder joints 131 can be reduced and the influence on the welding of the second main gate electrode 14 can be avoided.

[0112] In such an embodiment, the distance between two adjacent second solder joints 131 on the second primary gate electrode 14 may be greater than 5 mm, and preferably greater than 9 mm. In some embodiments, for the same size, the distance between two adjacent second solder joints 131 can be greater than 11 mm and less than 45 mm to reduce the use of slurry for the second solder joints 131.

[0113] Furthermore, in such an embodiment, it is more preferable that the pitch between two adjacent second solder joints 131 may be 11 mm or more and 30 mm or less. In this way, by setting the pitch between the second solder joints 131 within this optimum range, it is possible to ensure the number of second solder joints 131 and avoid welding defects during welding, ensuring the reliability of welding, while also avoiding an increase in costs due to an excessive number of second solder joints 131.

[0114] Of course, in some embodiments, the position where the second connecting gate line electrode 122 penetrates the first main gate electrode 13 may be located at the second solder joint 131, that is, a second separation area 130 is formed at the second solder joint 131 for the second connecting gate line electrode 122 to penetrate.

[0115] In this way, each second solder joint 131 corresponds to one second connection gate line electrode 122, and by uniformly arranging the second connection gate line electrodes 122, connection reliability between the second main gate electrodes 14 can be ensured.

[0116] Specifically, in such a case, the second solder joint 131 can be divided into two parts spaced apart and facing each other by the second connection gate line electrode 122, and it is preferable that the second connection gate line electrode 122 is located at the center position of the second solder joint 131, and the second connection gate line electrode 122 passes through the center position of the second solder joint 131 to connect two adjacent second main gate electrodes 14, thereby realizing parallel connection of the second main gate electrodes 14.

[0117] In such a case, in order to avoid the second solder joint 131 being blocked by the second connection gate line electrode 122 and affecting the subsequent welding effect, the length of the second solder joint 131 can be set long or the width of the second solder joint 131 can be set wide, thereby ensuring the reliability of the subsequent welding.

[0118] Example 12 6, in some embodiments, the distance between the second connection gate line electrode 122 and the center line between two adjacent second solder joints 131 is 10 mm or less. That is, the distance between the second connection gate line electrode 122 and the midpoint between two adjacent second solder joints 131 is 10 mm or less.

[0119] In this way, by keeping the second connection gate line electrode 122 at an appropriate distance from the second solder joint 131, it is possible to avoid the problem of temporary welding occurring at the second solder joint 131 due to the presence of the second connection gate line electrode 122, while at the same time making the electrical performance (e.g., current density) more uniform.

[0120] As can be seen, in some embodiments, during the printing process, the height of the second connection gate line electrode 122 is the same as or even slightly higher than the height of the second solder joint 131, and the distance between the second connection gate line electrode 122 and the second solder joint 131 should not be too small; if it is too small, there will be a certain height difference between the second connection gate line electrode 122 and the second solder joint 131, making it easy for tack welding to occur during welding. Therefore, as long as the distance between the second connection gate line electrode 122 and the center line between two adjacent second solder joints 131 is 10 mm or less, it can effectively avoid the occurrence of tack welding and an increase in the defect rate due to the distance between the second solder joint 131 and the second connection gate line electrode 122 being too small.

[0121] Furthermore, in such an embodiment, the distance between the second connecting gate line electrode 122 and the centerline between two adjacent second solder joints 131 is 5 mm or less.

[0122] In this way, by setting the distance between the second connection gate line electrode 122 and the center between the two second solder joints 131 within this preferred range, subsequent welding performance can be improved and electrical performance can be made more uniform.

[0123] In this embodiment, the distance between the second connection gate line electrode 122 and the center line between two adjacent second solder joints 131 is preferably 3 mm or less, and most preferably 1 mm. In this way, the position of the second connection gate line electrode 122 can be aligned as closely as possible with the center line between the two second solder joints 131 to improve the uniformity of electrical performance.

[0124] Example 13 Referring to FIG. 7, in some embodiments, a second insulating layer 16 may be coated at the location where the second connecting gate line electrode 122 penetrates the first main gate electrode 13, i.e., the second isolation region 130 in FIG. 6 may be coated with the second insulating layer 16.

[0125] In this way, by covering the area where the first main gate electrode 13 is penetrated by the second connecting gate line electrode 122 with the second insulating layer 16, it is possible to prevent the welding ribbon from coming into contact with the second connecting gate line electrode 122 when welding the second solder joint 131, thereby preventing leakage of electricity.

[0126] Specifically, the size of the second insulating layer 16 may be the same as or slightly larger than the size of the second separation region 130 on the first main gate electrode 13 to achieve insulation; that is, on the first main gate electrode 13, only the region corresponding to the second separation region 130 is covered with the second insulating layer 16, while the other regions are not provided with the second insulating layer 16, and the second insulating layer 16 may be an insulating adhesive.

[0127] Finally, referring to Figures 8 and 9, Figure 8 is an EL test image of an assembly formed using back-contact solar cells designed with the electrode pattern in Figure 4 of the prior art, and Figure 9 is an EL test image of an assembly formed using back-contact solar cells with the electrode structures in Figures 6 and 7 of the present application, and each small rectangle in Figures 8 and 9 represents one back-contact solar cell.

[0128] As can be seen from Figure 8, in the prior art, the back-contact solar cell exhibits severe black streaks (i.e., black and white stripes with distinct light and dark areas) in the brightness image obtained when the assembly is subjected to an EL test, which makes it easy for the assembly to mismatch and further reduces the power of the assembly. However, as can be seen from Figure 9, after adopting the electrode structure of the present application, the back-contact solar cell as a whole has uniform electrical performance, and in the EL test image, the brightness of each region of the back-contact solar cell is relatively uniform, and the power of the assembly is also improved accordingly.

[0129] Table 1 below is a comparison table of performance tests of an assembly formed using a back-contact solar cell with the electrode pattern in FIG. 4 and an assembly formed using a back-contact solar cell with the electrode structure of the present application.

[0130] [Table 1]

[0131] Comparative Example 1 in Table 1 is an assembly packaged using a back-contact solar cell with the electrode pattern shown in FIG. 4, while the present application is an assembly packaged using back-contact solar cells with the electrode structures shown in FIGS. 6 and 7 of the present application. Here, the CTM value represents the ratio of the power of the assembly after packaging to the power of the back-contact solar cell before packaging, and the gain is the difference between the CTM value of the present application and the CTM value of the comparative example. As can be seen from Table 1, after packaging was completed in the comparative example, the power of the assembly was reduced to 98.60% of the power of the back-contact solar cell, resulting in a packaging loss of 1.40%. In contrast, in the present application, the power of the assembly was reduced to 98.92% of the power of the back-contact solar cell, resulting in a packaging loss of 1.08%, resulting in a power increase of 0.32% compared to the comparative example. This demonstrates that the technical solution of the present application can effectively reduce packaging loss during assembly packaging and improve the power of the assembly.

[0132] In the description herein, references to terms such as "some embodiments," "exemplary embodiments," "examples," "specific examples," or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the description herein, references to the above-mentioned exemplary terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics can be combined in any suitable manner in any one or more embodiments or examples.

[0133] It should be noted that the above is merely a preferred embodiment of the present application and does not limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. 1. An electrode structure for a back-contact solar cell, the back-contact solar cell including alternating first polarity regions and second polarity regions, the electrode structure comprising: a number of first sub-gate electrodes for collecting current in the first polarity regions and a number of second sub-gate electrodes for collecting current in the second polarity regions, the first sub-gate electrodes being alternately spaced apart; a number of first main gate electrodes connected to the first sub-gate electrodes and a number of second main gate electrodes connected to the second sub-gate electrodes, which are alternately provided at intervals, and the arrangement direction of the first main gate electrodes and the second main gate electrodes is different from the arrangement direction of the first sub-gate electrodes and the second sub-gate electrodes; wherein some of the first sub-gate electrodes include a first collection gate line electrode and a first connecting gate line electrode, the first collection gate line electrode is connected to the first main gate electrode and is cut off by the second main gate electrode, the first connecting gate line electrode penetrates the second main gate electrode between two adjacent first main gate electrodes to connect two adjacent first main gate electrodes, thereby connecting all the first main gate electrodes in parallel into one whole; An electrode structure of a back-contact solar cell, characterized in that a first separation region is formed in the second main gate electrode, the first connecting gate line electrode connects two adjacent first main gate electrodes by drilling the first separation region, and the first connecting gate line electrode is insulated and isolated from the second main gate electrode via the first separation region.

2. 2. The electrode structure of a back-contact solar cell according to claim 1, wherein the number of the first connection gate line electrodes is plural, and the plural first connection gate line electrodes are arranged at intervals on the back-contact solar cell along the arrangement direction of the first sub-gate electrode and the second sub-gate electrode.

3. The width of the first connecting gate line electrode is 80 um-1.5 mm; and / or 2. The electrode structure of a back-contact solar cell according to claim 1, wherein the width of the first connecting gate line electrode is at least 1.5 times the width of the first collecting gate line electrode.

4. 2. The electrode structure of a back-contact solar cell according to claim 1, wherein the second main gate electrode has a number of first solder joints spaced apart, and the positions at which the first connection gate line electrode penetrates the second main gate electrode are located between two adjacent first solder joints.

5. 5. The electrode structure of a back-contact solar cell according to claim 4, wherein the distance between the first connecting gate line electrode and the center line between two adjacent first solder joints is 10 mm or less.

6. 6. The electrode structure of a back-contact solar cell according to claim 5, wherein the distance between the first connecting gate line electrode and the center line between two adjacent first solder joints is 5 mm or less.

7. 7. The electrode structure of a back-contact solar cell according to claim 6, wherein the distance between the first connecting gate line electrode and the center line between two adjacent first solder joints is 3 mm or less.

8. 8. The electrode structure of a back-contact solar cell according to claim 7, wherein the distance between the first connecting gate line electrode and the center line between two adjacent first solder joints is 1 mm or less.

9. 2. The electrode structure of a back-contact solar cell according to claim 1, wherein a first insulating layer is coated at a position where the first connection gate line electrode penetrates the second main gate electrode.

10. 2. The electrode structure of a back-contact solar cell according to claim 1, wherein some of the second sub-gate electrodes include a second collection gate line electrode and a second connecting gate line electrode, the second collection gate line electrode is connected to the second main gate electrode and is cut off by the first main gate electrode, and the second connecting gate line electrode penetrates the first main gate electrode between two adjacent second main gate electrodes to connect two adjacent second main gate electrodes.

11. 11. The electrode structure of a back-contact solar cell as described in claim 10, characterized in that the number of the second connection gate line electrodes is plural, and the plural second connection gate line electrodes are arranged at intervals on the back-contact solar cell along the arrangement direction of the first sub-gate electrode and the second sub-gate electrode.

12. 11. The electrode structure of a back-contact solar cell according to claim 10, wherein the second connection gate line electrode and the first connection gate line electrode are provided adjacent to each other with a gap therebetween.

13. 13. The electrode structure of a back-contact solar cell according to claim 12, wherein the second connection gate line electrode and the first connection gate line electrode equally divide the back-contact solar cell into a plurality of equal regions in the arrangement direction of the first sub-gate electrode and the second sub-gate electrode.

14. The width of the second connecting gate line electrode is 80 um-1.5 mm; and / or 11. The electrode structure of a back-contact solar cell according to claim 10, wherein the width of the second connecting gate line electrode is at least 1.5 times the width of the second collecting gate line electrode.

15. 11. The electrode structure of a back-contact solar cell according to claim 10, wherein the first main gate electrode has a number of second solder joints spaced apart, and the positions at which the second connection gate line electrode penetrates the first main gate electrode are located between two adjacent second solder joints.

16. 16. The electrode structure of a back-contact solar cell according to claim 15, wherein the distance between the second connecting gate line electrode and the center line between two adjacent second solder joints is 10 mm or less.

17. 17. The electrode structure of a back-contact solar cell of claim 16, wherein the distance between the second connecting gate line electrode and the center line between two adjacent second solder joints is 5 mm or less.

18. 18. The electrode structure of a back contact solar cell of claim 17, wherein the distance between the second connecting gate line electrode and the center line between two adjacent second solder joints is 3 mm or less.

19. 20. The electrode structure of a back contact solar cell of claim 18, wherein the distance between the second connecting gate line electrode and the center line between two adjacent second solder joints is 1 mm or less.

20. 11. The electrode structure of a back-contact solar cell according to claim 10, wherein a second insulating layer is coated at a position where the second connection gate line electrode penetrates the first main gate electrode.

21. A back-contact solar cell comprising an electrode structure of a back-contact solar cell according to any one of claims 1 to 20, wherein the electrode structure is provided on a backlight surface of the back-contact solar cell.

22. 22. A back-contact cell assembly comprising the back-contact solar cell of claim 21.

23. 23. A solar power generation system comprising the back-contacted cell assembly of claim 22.

Images