Electrode structure of back-contact solar cell, battery 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] This application relates to the field of solar cell technology, and in particular to the electrode structure, battery and its assembly, and solar power generation system of back contact solar cells.

Background Art

[0002] A back contact solar cell is a battery that places both the emitter and the base contact electrodes on the back surface (non-light receiving surface) of the battery. There is no shielding by metal electrodes on the light receiving surface of this battery, thereby effectively increasing the short-circuit current of the battery sheet.

[0003] In related technologies, in the design of the back electrode pattern of back contact solar cells, usually, a design is adopted in which the same-polarity main gates are connected by thin gates and are cut off from the different-polarity main gates. For example, the positive thin gate is cut off from the negative main gate electrode, and the negative thin gate is cut off from the positive main gate electrode.

[0004] However, in such a design, since the thin gates are cut off from the different-polarity main gate electrodes, the entire battery area of the back contact solar cell is divided into almost unconnected strip-shaped independent battery areas. In this way, finally, in the EL test diagram of the finished product assembly, black strip-shaped and black block-shaped non-uniformities appear on the battery sheet, causing mismatches in the assembly and reducing the power of the assembly.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This application aims to provide an electrode structure, battery and its assembly, and solar power generation system of back contact solar cells, and to solve the conventional technical problems that black strip-shaped and black block-shaped non-uniformities appear on the battery sheet in the EL test diagram of the finished product assembly of back contact solar cells, causing mismatches in the assembly and reducing the power of the assembly.

Means for Solving the Problems

[0006] The present invention is realized as follows. The electrode structure of the back-contact solar cell of the embodiment of the present invention is used in a back-contact solar cell, the back-contact solar cell includes alternately provided first polarity regions and second polarity regions, and the electrode structure is Several first subgate electrodes for collecting current in the first polarity region and several second subgate electrodes for collecting current in the second polarity region are provided alternately at intervals. A number of first main gate electrodes connected to the first subgate electrode, and a number of second main gate electrodes connected to the second subgate electrode, which are arranged alternately at intervals, and the arrangement direction of the first main gate electrode and the second main gate electrode differs from the arrangement direction of the first subgate electrode and the second subgate electrode, including a number of first main gate electrodes and a number of second main gate electrodes, Here, the first sub-gate electrode includes a first collecting gate line electrode and a first connecting gate line electrode, the first collecting gate line electrode being connected to the first main gate electrode and cut to the second main gate electrode, and the first connecting gate line electrode connecting two adjacent first main gate electrodes by passing through the second main gate electrode between two adjacent first main gate electrodes.

[0007] Furthermore, the number of the first connecting gate wire electrodes is multiple, and the multiple first connecting gate wire electrodes are provided on the back-contact type solar cell at intervals along the alignment direction of the first sub-gate electrode and the second sub-gate electrode.

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

[0009] Furthermore, several first solder joints are provided at intervals on the second main gate electrode, and the position where the first connecting gate wire electrode penetrates the second main gate electrode is located between two adjacent first solder joints.

[0010] Furthermore, the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 10 mm or less.

[0011] Furthermore, the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 5 mm or less.

[0012] Furthermore, the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 3 mm or less.

[0013] Furthermore, the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 1 mm or less.

[0014] Furthermore, the first insulating layer is applied to the position where the first connecting gate wire electrode penetrates the second main gate electrode.

[0015] Furthermore, some of the second sub-gate electrodes include a second collecting gate line electrode and a second connecting gate line electrode, the second collecting gate line electrode being connected to the second main gate electrode and cut to the first main gate electrode, and the second connecting gate line electrode connecting two adjacent second main gate electrodes by passing through the first main gate electrode between two adjacent second main gate electrodes.

[0016] Furthermore, the number of the second connecting gate wire electrodes is multiple, and the multiple second connecting gate wire electrodes are provided on the back-contact type solar cell at intervals along the alignment direction of the first sub-gate electrode and the second sub-gate electrode.

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

[0018] Furthermore, the second connecting gate line electrode and the first connecting gate line electrode equally partition the back contact type solar cell into a plurality of same 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 μm - 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, a plurality of second soldering joints are provided at intervals on the first main gate electrode, and the position where the second connecting gate line electrode penetrates the first main gate electrode is located between two adjacent second soldering joints.

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

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

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

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

[0025] Furthermore, a second insulating layer is coated at the position where the second connecting gate line electrode penetrates the first main gate electrode.

[0026] This application further provides a back-contact type solar cell, the back-contact type solar cell includes the electrode structure of the back-contact type solar cell according to any one of the above, and the electrode structure is provided on the backlight surface of the back-contact type solar cell.

[0027] This application further provides a back-contact type battery assembly, the back-contact type battery assembly includes the above-mentioned back-contact type solar cell.

[0028] This application further provides a solar power generation system, the solar power generation system includes the above-mentioned back-contact type battery assembly.

Effect of the Invention

[0029] In the electrode structure, battery, its assembly and solar power generation system of the back-contact type solar cell according to the embodiment of this application, the first collection gate line electrode is cut off from the second main gate electrode, and the first connection gate line electrode penetrates through the second main gate electrode between two adjacent first main gate electrodes and connects the two adjacent first main gate electrodes, that is, a first separation region is formed in the second main gate electrode, and the first connection gate line electrode penetrates through this first separation region to connect the two adjacent first main gate electrodes.

[0030] In this way, the first connecting gate wire electrode divides the back-contact solar cell into multiple regions in the direction of the arrangement of the first and second sub-gate electrodes. The first connecting gate wire electrode penetrates the second main gate electrode and connects adjacent first main gate electrodes, thereby connecting all first main gate electrodes in parallel to a single whole, making its electrical performance more uniform. For example, the current density of the back-contact solar cell can be made more uniform. Moreover, the second main gate electrodes cut by the first connecting gate wire electrode, and the multiple regions partitioned by the first connecting gate wire electrode, can be connected by a welding ribbon during the subsequent welding process to form the assembly. Finally, the back-contact solar cell after welding becomes a whole with uniform electrical performance. Furthermore, it further improves the EL streaky and blocky blackening phenomenon in the back-contact solar cell when the back-contact battery assembly undergoes EL testing, effectively avoids mismatch in the back-contact battery assembly, and improves the power of the assembly.

[0031] Additional aspects and advantages of the present invention are given in part in the following description, and in part become apparent from the following description or are understood through the practice of the present invention. [Brief explanation of the drawing]

[0032] [Figure 1] This is a schematic diagram of a module for a solar power generation system according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of a module of a back-contact type battery assembly according to an embodiment of the present invention. [Figure 3] This is a schematic diagram of the electrode structure according to an embodiment of the present invention. [Figure 4] This is a schematic diagram of the electrode pattern design for a conventional back-contact solar cell. [Figure 5] This is another schematic diagram of the electrode structure according to the embodiment of the present application. [Figure 6] This is another schematic diagram of the electrode structure according to an embodiment of the present invention. [Figure 7]This is yet another schematic diagram of the electrode structure according to an embodiment of the present invention. [Figure 8] This is an EL test diagram of a back-contact type battery assembly using conventional technology. [Figure 9] This is an EL test diagram of a back-contact type battery assembly according to an embodiment of the present invention. [Modes for carrying out the invention]

[0033] To further clarify the purpose, technical solution, and advantages of this application, the application will be described in more detail below in conjunction with the accompanying drawings and embodiments. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals from beginning to end represent the same or similar elements or elements having the same or similar function. The embodiments described below with reference to the accompanying drawings are illustrative and used solely for the purpose of explaining this application and cannot be used to understand its limitations. Furthermore, it should be understood that the specific embodiments described herein are for interpretation purposes only and not to limit this application.

[0034] In the description of this application, the directions or positional relationships indicated by terms such as "up," "down," "left," "right," "horizontal," and "vertical" are directions or positional relationships shown based on the attached drawings, and are merely for the purpose of facilitating and simplifying the explanation of this application. They do not indicate or suggest that the device or element being referred to must be configured and operated in a specific direction or orientation, and therefore should not be understood as limitations on this application.

[0035] Furthermore, the terms "first" and "second" are used solely for descriptive purposes and should not be understood as indicating or suggesting relative importance, or implicitly indicating the number of technical features being referred to. Thus, features designated as "first" and "second" may explicitly or implicitly include one or more of the aforementioned features. In the descriptions herein, "multiple," "multiple clusters," and "multiple pieces" mean two or more unless otherwise specifically limited.

[0036] The following disclosure provides many different embodiments or examples to realize different structures of the present application. For the sake of brevity of the disclosure, the parts and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. Reference numerals and / or reference letters may be repeated in different examples in this specification, and such redundancies are for the purpose of simplification and clarity and do not themselves indicate relationships between the various embodiments and / or settings discussed. Although various examples of specific processes and materials are provided in this specification, those skilled in the art will be able to recognize the application of other processes and / or usage scenarios of other materials.

[0037] In this invention, a back-contact solar cell is divided into multiple regions in the direction of the arrangement of the first and second sub-gate electrodes by a first connecting gate wire electrode. The first connecting gate wire electrode penetrates the second main gate electrode and connects adjacent first main gate electrodes, thereby connecting all first main gate electrodes in parallel to a single whole, making its electrical performance more uniform. For example, the current density of the back-contact solar cell can be made more uniform. Furthermore, the second main gate electrodes cut by the first connecting gate wire electrode, and the multiple regions partitioned by the first connecting gate wire electrode, can be connected by a welding ribbon during the subsequent welding process to form the assembly. Finally, the back-contact solar cell after welding becomes a whole with uniform electrical performance. Moreover, the EL streaky and blocky blackening phenomenon in the back-contact solar cell when the back-contact battery assembly undergoes EL testing is further improved, effectively avoiding mismatches in the back-contact battery assembly and improving the power of the assembly.

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

[0039] In the back-contact type battery assembly 200, multiple back-contact type solar cells 100 can be connected in series in sequence to form multiple battery strings. Each battery string can achieve a combined current output after being connected in series, parallel, or a combination of series and parallel. For example, connections between each battery sheet can be achieved by welding a welding ribbon, and connections between each battery string can be achieved by busbars. For example, in this application, when forming the assembly, welding strips for achieving connections between each back-contact type solar cell 100 can be welded to both the first main gate electrode 13 and the second main gate electrode 14, thereby forming the back-contact type battery assembly 200.

[0040] The back-contact solar cell 100 in the embodiment of the present application may include a substrate (not shown) and an 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) is provided with alternating first polarity regions and second polarity regions (not shown), the first polarity region having opposite polarity to the second polarity region, for example the first polarity region may be a P-type impurity region and the second polarity region may be an N-type impurity region, or for example the first polarity region may be an N-type impurity region and the second polarity region may be a P-type impurity region, and is not specifically limited here.

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

[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. In other words, 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] The arrangement direction of the first main gate electrode 13 and the second main gate electrode 14 differs from the arrangement direction of the first sub-gate electrode 11 and the second sub-gate electrode 12. For example, as shown in Figure 3, the first sub-gate electrode 11 and the second sub-gate electrode 12 are arranged alternately with spacing along the transverse direction, while the first main gate electrode 13 and the second main gate electrode 14 are arranged alternately with spacing along the vertical direction, and their arrangement directions are 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. In other words, 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 first secondary gate electrodes 11 may include a first collecting gate wire electrode 111 and a first connecting gate wire electrode 112 (i.e., the thick gate wire electrode in Figure 3), the first collecting gate wire electrode 111 being connected to a first main gate electrode 13 and cut to a second main gate electrode 14, the first connecting gate wire electrode 112 being connected to two adjacent first main gate electrodes 13 by penetrating the second main gate electrode 14 between two adjacent first main gate electrodes 13, that is, as shown in Figure 3, a first separation region 140 may be formed in the second main gate electrode 14, and the first connecting gate wire electrode 112 is connected to two adjacent first main gate electrodes 13 by penetrating this first separation region 140. As can be understood, in such a case, the first connecting gate wire 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 battery assembly 200, and solar power generation system 1000 of the embodiment of the present application, the first collection gate wire electrode 111 is cut to the second main gate electrode 14, and the first connecting gate wire electrode 112 is connected to the two adjacent first main gate electrodes 13 by penetrating the second main gate electrode 14 between 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 wire electrode 112 penetrates this first separation region 140 to bring the two adjacent first main gate electrodes 13 adjacent to each other.

[0046] In this way, the first connecting gate wire electrode 112 can divide the back-contact solar cell 100 into multiple regions in the direction of the arrangement of the first sub-gate electrode 11 and the second sub-gate electrode 12 (i.e., the vertical direction in the figure). The first connecting gate wire electrode 112 penetrates the second main gate electrode 14 and connects the adjacent first main gate electrode 13, thereby connecting all the first main gate electrodes 13 in parallel to the whole, making its electrical performance more uniform, for example, making the current density of the back-contact solar cell 100 more uniform. Moreover, the first connecting gate wire electrode 112 The multiple regions demarcated by the second main gate electrode 14, which has been cut, and the first connecting gate wire electrode 112 can be connected by a welding ribbon during the subsequent welding process to form the assembly. Finally, the back-contact solar cell 100 after welding becomes a whole with uniform electrical performance, and further improves the EL streaky and blocky blackening phenomenon in the back-contact solar cell 100 when the back-contact battery assembly 200 undergoes EL testing, effectively avoids mismatch in the back-contact battery assembly 200, and improves the power of the assembly.

[0047] To understand this, in the field of solar cell technology, electroluminescence (EL) testing is typically performed to detect internal defects in solar cells. However, in EL testing, the brightness in the test image is directly proportional to the minority carrier lifetime (or minority carrier diffusion length) and current density of the cell sheet. Areas with defects in the solar cell have a relatively low minority carrier diffusion length, resulting in a relatively darker image. These defects typically include silicon material defects, diffusion defects, printing defects, sintering defects, and single cell anomalies with different conversion efficiencies.

[0048] To make it easier to understand, referring to Figure 4, in the prior art, subgate gates of different polarities are all connected to the same polarity main gate gate and disconnected to the opposite polarity main gate gate. As shown in Figure 4, the positive subgate 2 is connected to the positive main gate 1 and disconnected to the negative main gate 3, and the negative subgate 4 is connected to the negative main gate 3 and disconnected to the positive main gate 1.

[0049] In such cases, the two identical main gate electrodes are equivalent to independent battery regions that are hardly connected. However, back-contact solar cells have some defects. For example, defects in the silicon material itself can cause uneven black streaks or black blocks to appear in the test image when performing subsequent EL testing. For example, the appearance of striped images with distinct light and dark areas can lead to a certain mismatch in the subsequent assembly, resulting in a decrease in the assembly's power.

[0050] However, compared to the electrode design in the prior art shown in Figure 4, in the embodiment of the present application, by providing the first connecting gate wire electrode 112 of the first sub-gate electrode 11 to connect the first main gate electrode 13 adjacent to the second main gate electrode 14 through it, the first main gate electrodes 13 of the same polarity are connected in parallel to form a single whole, thereby forming a whole with uniform electrical performance (for example, uniform current density), which improves the streaky and blocky blackening phenomena in EL images, makes the brightness of each back-contact type solar cell 100 in the EL image more uniform, and further improves the power of the back-contact type battery assembly 200.

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

[0052] As shown in Figure 3, in the embodiment shown in Figure 3, the first sub-gate electrode 11 and the second sub-gate electrode 12 are arranged alternately with a gap in between along the vertical direction, and correspondingly, the first polarity region and the second polarity region are also arranged alternately along the vertical direction. The first main gate electrode 13 and the second main gate electrode 14 may be arranged alternately along the horizontal direction perpendicular to the first sub-gate electrode 11 and the second sub-gate electrode 12.

[0053] In other words, in the embodiment shown in Figure 3, the first connecting gate wire electrode 112 can divide the entire back-contact solar cell 100 into multiple regions along the longitudinal direction, and these longitudinally partitioned regions are connected by a welding ribbon during assembly welding, so that the back-contact solar cell 100 after welding can become a whole with uniform electrical performance.

[0054] For clarity, in the embodiments of this application, the number of first and second sub-gate electrodes 11 and 12 can be determined based on the actual area of ​​the back-contact solar cell 100, the width and distance between the first and second sub-gate electrodes 11 and 12, and is not specifically limited thereto.

[0055] Furthermore, in the embodiments of this application, the first sub-gate electrode 11 and the second sub-gate electrode 12 may be, and are not limited to, aluminum gate wire, silver gate wire, copper gate wire, or silver-clad copper gate wire.

[0056] To make it clear, in the embodiments of the present application, the first sub-gate electrode 11 and the second sub-gate electrode 12 may be selected to be gate wires of the same or different metal types, for example, the first sub-gate electrode 11 and the second sub-gate electrode 12 may both be selected to be aluminum gate wires, or the first sub-gate electrode 11 may be selected to be an aluminum gate wire and the second sub-gate electrode 12 may be selected to be a silver gate wire. Here, if the first sub-gate electrode 11 or the second sub-gate electrode 12 is an aluminum gate wire or a silver gate wire, it may be printed onto the impurity area 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 wire, it may be plated onto the impurity area of ​​the back-contact solar cell 100 by methods such as electroplating or vapor deposition.

[0057] Of course, in the embodiments of this application, the first main gate electrode 13 and the second main gate electrode 14 may be made of gate wires such as copper, silver, aluminum, or silver-clad copper, and are not specifically limited herein.

[0058] To make it clear, in the embodiments of the present application, the back-contact type battery assembly 200 may further include a metal frame, a back plate, solar glass, and an adhesive film (none of which are shown). The adhesive film can be filled between the front surface and the solar glass, the back surface and the back plate and adjacent battery sheets of the back-contact type solar cell 100, and the filler 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, and can be specifically selected according to the circumstances, and is not limited thereto.

[0059] The solar glass may be covered by an adhesive film on the front of the back-contact solar cell 100. The solar glass may be ultra-white glass having high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, the light transmittance of ultra-white glass can reach 92% or more, which can protect the back-contact solar cell 100 without significantly affecting its efficiency. At the same time, the adhesive film can bond the solar glass to the back-contact solar cell 100, and the presence of the adhesive film can provide sealing, insulation, and waterproofing / moisture protection to 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 of several options, and may typically be tempered glass, organic glass, or an aluminum alloy TPT composite adhesive film. Specifically, it can be provided depending on the situation and is not limited thereto. The entire structure consisting of the backplate, back-contact solar cell 100, adhesive film, and solar glass may 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 metal frame can be used to mount the back-contact battery assembly 200 in the required position.

[0061] Furthermore, in this embodiment, the solar power generation system 1000 may be applied to solar power plants, such as ground-based power plants, rooftop power plants, and water-based power plants, or to equipment or devices that generate electricity using sunlight, such as user solar power supplies, solar streetlights, solar-powered automobiles, and solar-powered buildings. Of course, as can be understood, the application scenarios of the solar power generation system 1000 are not limited to these; that is, the solar power generation system 1000 may be applied to any field where it is necessary to generate electricity using sunlight.

[0062] Taking a solar power generation system network as an example, the solar power generation system 1000 may include a solar power generation array, a merging box, and an inverter. The solar power generation array may be a combination of multiple back-contact battery assemblies 200. For example, multiple back-contact battery assemblies 200 can constitute multiple solar power generation arrays. The solar power generation arrays are connected to a merging box, which can merge the current from the solar power generation arrays. The merged current is then converted through an inverter into AC power required by the commercial power grid and accessed by the commercial network to provide solar power.

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

[0064] In this way, the electrical performance of the back-contact type solar cell 100 can be made more uniform by using multiple first connecting gate wire electrodes 112. The multiple regions demarcated by the multiple first connecting gate wire electrodes 112 can be connected by a welding ribbon during the subsequent welding process, resulting in a whole with uniform electrical performance.

[0065] Specifically, as shown in Figure 3, in such embodiments, the first connecting gate wire electrodes 112 are preferably uniformly arranged with spacing along the longitudinal direction. Multiple first connecting gate wire electrodes 112 can equalize electrical performance (e.g., current density), further improve brightness in EL test images, make the brightness of the back-contact solar cell 100 more uniform, and improve EL streaky and blocky blackening phenomena. In this application, the number of first connecting gate wire 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 wire electrodes 112 may be set according to the specific circumstances and is not limited here.

[0066] Note that Figure 3 shows only the two first connecting gate wire electrodes 112 and a portion of the sub-gate electrode and main gate electrode of the electrode structure 10, and this is merely an example for explanation and understanding. In some embodiments, further first sub-gate electrode electrodes 11 and second sub-gate electrode electrodes 12 may be provided in all four directions (up, down, left, and right) in Figure 3, and multiple first main gate electrode electrodes 13 and second main gate electrode electrodes 14 may be provided in the left and right directions. Some first connecting gate wire electrodes 112 may be provided above and below the first connecting gate wire electrodes 112. The specific number of electrodes 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 wire electrode 112 may be 80um-1.5mm.

[0068] In this way, by setting the width of the first connecting gate wire electrode 112 within a reasonable range of 80um-1.5mm, the effect of parallel merging by connecting the first connecting gate wire electrode 112 to two adjacent first main gate electrodes 13 and the effect of equalizing electrical performance can be ensured. At the same time, it is possible to avoid the first connecting gate wire electrode 112 overheating or melting due to being too narrow and unable to withstand the current transmission between the two adjacent first main gate electrodes 13, while simultaneously avoiding the waste of slurry due to being too wide.

[0069] Specifically, in such embodiments, the width of the first connecting gate wire electrode 112 may be any one of the following values: 80um, 100um, 200um, 300um, 400um, 500um, 600um, 700um, 800um, 900um, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or 80um-1.5mm, and is not specifically limited herein.

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

[0071] In this way, by making the width of the first connecting gate wire electrode 112 larger than 1.5 times the width of the first collecting gate wire electrode 111, more uniform reliability of the current density can be ensured.

[0072] Of course, to make it understandable, and to reduce the use of slurry as much as performance allows, the width of the first connecting gate wire electrode 112 may be approximately the same as the width of the first collecting gate wire electrode 111. In such a case, parallel connection between the first main gate electrodes 13 can be achieved by providing multiple first connecting gate wire electrodes 112.

[0073] Example 4 Referring to Figure 3, in some embodiments, the second main gate electrode 14 has several first solder joints 141 spaced apart, and the position where the first connecting gate wire electrode 112 penetrates the second main gate electrode 14 is located between two adjacent first solder joints 141, that is, the first separated region 140 is located between two adjacent first solder joints 141.

[0074] In this way, by providing the first connecting gate wire electrode 112 between two adjacent first solder joints 141, the connection of the two adjacent first main gate electrodes 13 can be realized, thereby achieving parallel connection of the first main gate electrodes 13, while simultaneously ensuring the integrity of the first solder joints 141 and securing the welding function of the second main gate electrode 14.

[0075] Specifically, in such embodiments, some first solder joints 141 may be distributed uniformly at intervals around the second main gate electrode 14, and it is preferable that there is one first connecting gate wire electrode 112 between two adjacent first solder joints 141. In this way, the presence of one first connecting gate wire electrode 112 between two pairs of first solder joints 141 reduces the number of first separation regions 140 between two adjacent first solder joints 141, thereby avoiding any influence on the welding of the second main gate electrode 14.

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

[0077] Furthermore, in such embodiments, it is more preferable that the pitch between two adjacent first solder joints 141 be between 11 mm and 30 mm. By setting the pitch between the first solder joints 141 within this optimal range, it is possible to ensure a sufficient number of first solder joints 141 to avoid welding defects during welding and to ensure the reliability of the welding, while simultaneously avoiding increased costs due to an excessive number of first solder joints 141.

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

[0079] In this way, each first solder joint 141 corresponds to one first connecting gate wire electrode 112, and the reliability of the connection can be ensured by the uniform arrangement of the first connecting gate wire electrodes 112.

[0080] Specifically, in such a case, the first solder joint 141 can be divided into two spaced-apart opposing parts by the first connecting gate wire electrode, preferably with the first connecting gate wire electrode located at the center of the first solder joint 141, and the first connecting gate wire electrode 112 is connected to two adjacent first main gate electrodes 13 passing through the center of the first solder joint 141 to realize a parallel connection of the first main gate electrodes.

[0081] In such cases, the reliability of subsequent welding can be ensured by setting the length of the first solder joint 141 to be longer or the width of the first solder joint 141 to be wider, so that the first solder joint 141 is not blocked by the first connecting gate wire electrode and does not affect the subsequent welding effect.

[0082] Example 5 Furthermore, referring to Figure 3, in some embodiments, the distance between the first connecting gate wire electrode 112 and the centerlines between two adjacent first solder joints 141 is 10 mm or less. In other words, the distance between the first connecting gate wire electrode 112 and the midpoint between two adjacent first solder joints 141 is 10 mm or less.

[0083] In this way, the first connecting gate wire electrode 112 maintains an appropriate distance from the first solder joint 141, thereby avoiding the problem of tack welding occurring during welding to the first solder joint 141 due to the presence of the first connecting gate wire electrode 112, while simultaneously making the electrical performance (e.g., current density) more uniform.

[0084] To make it clear, in some embodiments, during the printing process, the height of the first connecting gate wire electrode 112 is the same as the height of the first solder joint 141, or even slightly higher than the height of the first solder joint 141. The distance between the first connecting gate wire electrode 112 and the first solder joint 141 must not be too small. If it is too small, there will be a certain height difference between the first connecting gate wire electrode 112 and the first solder joint 141, making tack welding more likely during welding. Therefore, if the distance between the first connecting gate wire electrode 112 and the centerlines of two adjacent first solder joints 141 is 10 mm or less, it is possible to effectively avoid the tack welding occurring due to the distance between the first solder joint 141 and the first connecting gate wire electrode 112 being too small, thereby increasing the defect rate.

[0085] Furthermore, in such embodiments, the distance between the first connecting gate wire electrode 112 and the centerlines between two adjacent first solder joints 141 is 5 mm or less.

[0086] In this way, by setting the distance between the first connecting gate wire electrode 112 and the centers 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 connecting gate wire 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 connecting gate wire electrode 112 can be aligned as closely as possible with the center line between the two first solder joints 141, thereby improving the degree of uniformity of electrical performance.

[0088] Example 6 Referring to Figure 5, in some embodiments, the first insulating layer 15 is covered at the position where the first connecting gate wire electrode 112 penetrates the second main gate electrode 14, that is, the first separated region 140 in Figure 3 can be covered with the first insulating layer 15.

[0089] In this way, by covering the region where the second main gate electrode 14 is penetrated by the first connecting gate wire electrode 112 with the first insulating layer 15, it is possible to avoid leakage current caused by the welding ribbon coming into contact with the first connecting gate wire electrode 112 when welding the first solder joint 141.

[0090] Specifically, the size of the first insulating layer 15 may be the same as the size of the first separation region 140 on the second main gate electrode 14, or it may be slightly larger, in order to achieve insulation. In other words, on the second main gate electrode 14, the first insulating layer 15 covers only the region corresponding to the first separation region 140, while the first insulating layer 15 is not provided in other regions, and the first insulating layer 15 may be an insulating adhesive.

[0091] Example 7 Referring to Figure 6, in some embodiments, a few second secondary gate electrodes 12 may include a second collecting gate wire electrode 121 and a second connecting gate wire electrode 122, the second collecting gate wire electrode 121 being connected to a second main gate electrode 14 and cut to the first main gate electrode 13, and the second connecting gate wire electrode 122 connecting two adjacent second main gate electrodes 14 by penetrating the first main gate electrode 13 between two adjacent second main gate electrodes 14. That is, as shown in Figure 6, a second separation region 130 is formed in the first main gate electrode 13, and the second connecting gate wire electrode 122 penetrates this second separation region 130 to connect two adjacent second main gate electrodes 14. As can be understood, in such a case, the second connecting gate wire electrode 122 is insulated and isolated from the first main gate electrode 13 by the second separation region 130.

[0092] In this way, the first connecting gate line electrode 112 and the second connecting gate line electrode 122 can divide the back-contact type solar cell 100 into multiple regions in the direction of the arrangement of the first sub-gate electrode 11 and the second sub-gate electrode 12 (i.e., the vertical direction in Figure 6). The first connecting gate line electrode 112 penetrates the second main gate electrode 14 and connects the adjacent first main gate electrode 13, thereby connecting all the first main gate electrodes 13 in parallel to form one whole, and the second connecting gate line electrode 122 penetrates the first main gate electrode 13 and connects the adjacent second main gate electrode 14. By doing so, all the second main gate electrodes 14 are connected in parallel to the whole, and the multiple regions demarcated by the first connecting gate electrode 112 and the second connecting gate electrode 122 are connected by a welding ribbon during the subsequent welding process to form the assembly, the electrical performance (e.g., current density) of the back-contact solar cell 100 is made more uniform, the EL streaky and blocky blackening phenomenon in the back-contact solar cell 100 when the battery assembly undergoes EL testing is further improved, and the power of the assembly can be further increased.

[0093] In other words, in such embodiments, by providing a second connecting gate wire 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 diagram can be further improved, thereby making the brightness of the back-contact solar cell 100 in the EL test image more uniform and further improving the power of the assembly.

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

[0095] In this way, the electrical performance of the back-contact type solar cell 100 can be made more uniform by using multiple second connecting gate wire electrodes 122, and the multiple regions demarcated by the multiple second connecting gate wire electrodes 122 can be connected by a welding ribbon during the subsequent welding process, resulting in an overall structure with uniform electrical performance.

[0096] Specifically, as shown in Figure 3, in such embodiments, the second connecting gate wire electrodes 122 are preferably uniformly arranged with spacing along the longitudinal direction. Multiple second connecting gate wire electrodes 122 can equalize electrical performance (e.g., current density), further improve brightness in EL test images, make the brightness of the back-contact solar cell 100 more uniform, and improve EL streaky and blocky blackening phenomena. In this application, the number of second connecting gate wire electrodes 122 can be determined according to the size of the back-contact solar cell 100, and the pitch between two adjacent second connecting gate wire electrodes 122 may be set according to the specific circumstances and is not limited here.

[0097] Example 9 In some embodiments, it is preferable that the second connecting gate wire electrode 122 is provided adjacent to the first connecting gate wire electrode 112, with a gap between them.

[0098] In this way, by arranging the second connecting gate wire electrode 122 and the first connecting gate wire electrode 112 adjacent to each other, the positional difference between the first separated region 140 on the second main gate electrode 14 and the second separated region 130 on the first main gate electrode 13 can be reduced, making it easier to fabricate the first main gate electrode 13 and the second main gate electrode 14.

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

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

[0101] Specifically, as shown in Figure 6, the first connecting gate wire electrode 112 and the second connecting gate wire electrode 122 can divide the back-contact solar cell 100 into multiple nearly independent regions in the longitudinal direction, each region corresponding to a single small solar cell, and these multiple regions are connected by a welding ribbon during the subsequent assembly welding process to form a whole with uniform electrical performance and improve the power of the assembly. As can be understood, since both the first main gate electrode 13 and the second main gate electrode 14 are disconnected in multiple stages, the multiple main gate electrodes can be connected by a welding ribbon during subsequent welding.

[0102] Of course, as can be understood, in some embodiments, the first connecting gate wire electrode 112 and the second connecting gate wire electrode 122 are not located adjacent to each other, but may be spaced apart, and are not specifically limited herein.

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

[0104] In this way, by setting the width of the second connecting gate wire electrode 122 within a reasonable range of 80um-1.5mm, the effect of connecting the two adjacent second main gate electrodes 14 and performing parallel merging, as well as the effect of uniformization, can be ensured. At the same time, it is possible to avoid the second connecting gate wire electrode 122 overheating or melting due to being too narrow and unable to withstand the current transmission between the two adjacent second main gate electrodes 14, while simultaneously avoiding the waste of slurry due to being too wide.

[0105] Specifically, in such embodiments, the width of the second connecting gate wire electrode 122 may be any one of the following values: 80um, 100um, 200um, 300um, 400um, 500um, 600um, 700um, 800um, 900um, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or 80um-1.5mm, and is not specifically limited herein.

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

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

[0108] Of course, as can be understood, the width of the second connecting gate wire electrode 122 may be approximately the same as the width of the second collecting gate wire electrode 121, as long as performance allows. In such cases, parallel connection between the second main gate electrodes 14 can be achieved by providing multiple second connecting gate wire electrodes 122.

[0109] Example 11 Referring to Figure 6, in some embodiments, the second main gate electrode 14 has several second solder joints 131 spaced apart, and the position where the second connecting gate wire electrode 122 penetrates the second main gate electrode 14 is between two adjacent second solder joints 131, that is, the second spaced region 130 is located between two adjacent second solder joints 131.

[0110] In this way, by providing the second connecting gate wire electrode 122 between two adjacent second solder joints 131, the connection of the two adjacent second main gate electrodes 14 is realized, thereby achieving parallel connection of the second main gate electrodes 14, while simultaneously ensuring the integrity of the second solder joint 131 and securing the welding function of the first main gate electrode 13.

[0111] Specifically, in such embodiments, some second solder joints 131 may be distributed uniformly at intervals around the first main gate electrode 13, and it is preferable that there is one second connecting gate wire electrode 122 between two adjacent second solder joints 131. In this way, the presence of one second connecting gate wire electrode 122 between two pairs of second solder joints 131 reduces the number of second separation regions 130 between two adjacent second solder joints 131, thereby avoiding any influence on the welding of the second main gate electrode 14.

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

[0113] Furthermore, in such embodiments, it is more preferable that the pitch between two adjacent second solder joints 131 be between 11 mm and 30 mm. By setting the pitch between the second solder joints 131 within this optimal range, it is possible to ensure a sufficient number of second solder joints 131 to avoid welding defects during welding and to ensure the reliability of the welding, while simultaneously avoiding increased costs due to an excessive number of second solder joints 131.

[0114] Of course, in some embodiments, the location where the second connecting gate wire electrode 122 penetrates the first main gate electrode 13 may be located in the second solder joint 131, that is, the second solder joint 131 has a second spaced region 130 for the second connecting gate wire electrode 122 to be drilled.

[0115] In this way, each second solder joint 131 corresponds to one second connecting gate wire electrode 122, and the uniform arrangement of the second connecting gate wire electrodes 122 ensures connection reliability between the second main gate electrodes 14.

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

[0117] In such cases, to avoid the second solder joint 131 being blocked by the second connecting gate wire electrode 122 and affecting the subsequent welding effect, the reliability of the subsequent welding can be ensured by setting the length of the second solder joint 131 to be longer or the width of the second solder joint 131 to be wider.

[0118] Example 12 Furthermore, referring to Figure 6, in some embodiments, the distance between the second connecting gate wire electrode 122 and the centerlines between two adjacent second solder joints 131 is 10 mm or less. In other words, the distance between the second connecting gate wire electrode 122 and the midpoint between two adjacent second solder joints 131 is 10 mm or less.

[0119] In this way, by maintaining the second connecting gate wire electrode 122 at an appropriate distance from the second solder joint 131, it is possible to avoid the problem of tack welding occurring during welding to the second solder joint 131 due to the presence of the second connecting gate wire electrode 122, while simultaneously making the electrical performance (e.g., current density) more uniform.

[0120] To make it clear, in some embodiments, during the printing process, the height of the second connecting gate wire electrode 122 is the same as the height of the second solder joint 131, or even slightly higher than the height of the second solder joint 131. The distance between the second connecting gate wire electrode 122 and the second solder joint 131 must not be too small. If it is too small, there will be a certain height difference between the second connecting gate wire electrode 122 and the second solder joint 131, making tack welding more likely during welding. Therefore, if the distance between the second connecting gate wire electrode 122 and the centerlines of two adjacent second solder joints 131 is 10 mm or less, it is possible to effectively avoid the tack welding occurring due to the distance between the second solder joint 131 and the second connecting gate wire electrode 122 being too small, thereby increasing the defect rate.

[0121] Furthermore, in such embodiments, the distance between the second connecting gate wire electrode 122 and the centerlines between two adjacent second solder joints 131 is 5 mm or less.

[0122] In this way, by setting the distance between the second connecting gate wire electrode 122 and the center of 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 such embodiments, the distance between the second connecting gate wire 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 connecting gate wire electrode 122 can be aligned as closely as possible with the center line between the two second solder joints 131 to improve the degree of uniformity of electrical performance.

[0124] Example 13 Referring to Figure 7, in some embodiments, the second insulating layer 16 is covered at the position where the second connecting gate wire electrode 122 penetrates the first main gate electrode 13, that is, the second separated region 130 in Figure 6 can be covered with the second insulating layer 16.

[0125] In this way, by covering the region where the first main gate electrode 13 is penetrated by the second connecting gate wire electrode 122 with the second insulating layer 16, it is possible to avoid leakage current caused by the welding ribbon coming into contact with the second connecting gate wire electrode 122 when welding the second solder joint 131.

[0126] Specifically, the size of the second insulating layer 16 may be the same as the size of the second separation region 130 on the first main gate electrode 13, or it may be slightly larger, in order to achieve insulation. In other words, on the first main gate electrode 13, the second insulating layer 16 covers only the region corresponding to the second separation region 130, while the second insulating layer 16 is not provided in other regions, 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 a back-contact solar cell 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 a back-contact solar cell with the electrode structure in Figures 6 and 7 of the present application, where each small rectangle in Figures 8 and 9 represents one back-contact solar cell.

[0128] As can be seen from Figure 8, in the conventional technology, when the assembly performs an EL test, the brightness image obtained shows severe black streaks (i.e., black and white stripes with distinct light and dark areas) in the back-contact type solar cell, which easily causes a mismatch in the assembly and further leads to a decrease in the assembly's power. However, in Figure 9, after adopting the electrode structure of the present invention, the electrical performance of the back-contact type solar cell is uniform overall, and in the EL test image, the brightness of each region of the back-contact type solar cell is relatively uniform, and the power of the assembly is improved accordingly.

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

[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 Figure 4, while the present application is an assembly packaged using a back-contact solar cell with the electrode structure shown in Figures 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, in the comparative example, after packaging is complete, the power of the assembly decreases to 98.60% of the power of the back-contact solar cell, and the packaging loss is 1.40%. In the present application, however, the power of the assembly decreases to 98.92% of the power of the back-contact solar cell, and the packaging loss is 1.08%, meaning that the power of the assembly in the present application is 0.32% higher than that of the comparative example. From this, it can be seen that by adopting the technical solution of the present application, the packaging loss during packaging of the assembly can be effectively reduced and the power of the assembly can be improved.

[0132] In this specification, any description referring to terms such as “several examples,” “exemplary examples,” “examples,” “specific examples,” or “several examples” means that the specific features, structures, materials, or characteristics described in connection with such examples are included in at least one example of this application. In this specification, exemplary descriptions of the above terms do not necessarily mean the same examples. The specific features, structures, materials, or characteristics described can be appropriately combined in any one or more examples.

[0133] The above is merely a preferred embodiment of the present application and does not limit it. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application should all be included within the scope of protection.

Claims

1. An electrode structure for a back-contact solar cell, wherein the back-contact solar cell includes alternately arranged first polarity regions and second polarity regions, and the electrode structure is A plurality of first subgate electrodes for collecting current in the first polarity region, and a plurality of second subgate electrodes for collecting current in the second polarity region, are provided alternately at intervals. A plurality of first main gate electrodes connected to the first subgate electrode, which are arranged alternately at intervals, and a plurality of second main gate electrodes connected to the second subgate electrode, wherein the arrangement direction of the first main gate electrode and the second main gate electrode is different from the arrangement direction of the first subgate electrode and the second subgate electrode, Here, the plurality of first sub-gate electrodes include a first collecting gate line electrode and a first connecting gate line electrode, the first collecting gate line electrode is connected to the first main gate electrode and cut to the second main gate electrode, the first connecting gate line electrode connects two adjacent first main gate electrodes by passing through the second main gate electrode between two adjacent first main gate electrodes, thereby connecting all the first main gate electrodes in parallel to form one whole. A first separation region is formed in the second main gate electrode, and the first connecting gate wire electrode penetrates the first separation region to connect two adjacent first main gate electrodes, and the first connecting gate wire electrode is insulated and separated from the second main gate electrode via the first separation region. Each of the multiple second subgate electrodes includes a second collecting gate line electrode and a second connecting gate line electrode, the second collecting gate line electrode being connected to the second main gate electrode and cut to the first main gate electrode, and the second connecting gate line electrode connecting two adjacent second main gate electrodes by passing through the first main gate electrode between two adjacent second main gate electrodes, thereby connecting all the second main gate electrodes in parallel to form one whole. A second separation region is formed in the first main gate electrode, and the second connecting gate wire electrode penetrates the second separation region to connect two adjacent second main gate electrodes, and the second connecting gate wire electrode is insulated and separated from the first main gate electrode via the second separation region. The second main gate electrode is provided with a plurality of first solder joints spaced apart, the position where the first connecting gate wire electrode penetrates the second main gate electrode is located between two adjacent first solder joints, the distance between the first connecting gate wire electrode and the centerlines of the two adjacent first solder joints is 10 mm or less, and / or The first main gate electrode is provided with a plurality of second solder joints at intervals, the position where the second connecting gate wire electrode penetrates the first main gate electrode is located between two adjacent second solder joints, and the distance between the second connecting gate wire electrode and the centerlines of the two adjacent second solder joints is 10 mm or less. The width of the first connecting gate wire electrode is 80 μm - 1.5 mm, and / or The width of the first connecting gate wire electrode is at least 1.5 times the width of the first collecting gate wire electrode. The width of the second connecting gate wire electrode is 80 μm - 1.5 mm, and / or The electrode structure for a back-contact type solar cell is characterized in that the width of the second connecting gate wire electrode is at least 1.5 times the width of the second collection gate wire electrode.

2. The electrode structure for a back-contact solar cell according to claim 1, characterized in that the number of first connecting gate wire electrodes is a plurality, and the plurality of first connecting gate wire electrodes are provided on the back-contact solar cell at intervals along the alignment direction of the first sub-gate electrode and the second sub-gate electrode.

3. The electrode structure of a back-contact type solar cell according to claim 1, characterized in that the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 5 mm or less.

4. The electrode structure of a back-contact type solar cell according to claim 3, characterized in that the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 3 mm or less.

5. The electrode structure for a back-contact type solar cell according to claim 4, characterized in that the distance between the first connecting gate wire electrode and the centerlines of two adjacent first solder joints is 1 mm or less.

6. The electrode structure of a back-contact type solar cell according to claim 1, characterized in that a first insulating layer is provided at the position where the first connecting gate wire electrode penetrates the second main gate electrode.

7. The electrode structure for a back-contact solar cell according to claim 1, characterized in that the number of the second connecting gate wire electrodes is a plurality, and the plurality of the second connecting gate wire electrodes are provided on the back-contact solar cell at intervals along the alignment direction of the first sub-gate electrode and the second sub-gate electrode.

8. The electrode structure of a back-contact type solar cell according to claim 1, characterized in that the second connecting gate wire electrode and the first connecting gate wire electrode are provided adjacent to each other with a gap between them.

9. The electrode structure for a back-contact solar cell according to claim 8, characterized in that the second connecting gate wire electrode and the first connecting gate wire electrode evenly divide the back-contact solar cell into a plurality of identical regions in the arrangement direction of the first sub-gate electrode and the second sub-gate electrode.

10. The electrode structure of a back-contact type solar cell according to claim 1, characterized in that the distance between the second connecting gate wire electrode and the centerlines of two adjacent second solder joints is 5 mm or less.

11. The electrode structure of a back-contact type solar cell according to claim 10, characterized in that the distance between the second connecting gate wire electrode and the centerlines of two adjacent second solder joints is 3 mm or less.

12. The electrode structure of a back-contact type solar cell according to claim 11, characterized in that the distance between the second connecting gate wire electrode and the centerlines of two adjacent second solder joints is 1 mm or less.

13. The electrode structure of a back-contact type solar cell according to claim 1, characterized in that a second insulating layer is provided at the position where the second connecting gate wire electrode penetrates the first main gate electrode.

14. A back-contact solar cell, comprising an electrode structure of a back-contact solar cell according to any one of claims 1 to 13, wherein the electrode structure is provided on the backlight surface of the back-contact solar cell.

15. A back-contact type battery assembly, characterized in that it includes a back-contact type solar cell as described in claim 14.

16. A solar power generation system, characterized by including the back-contact type battery assembly described in claim 15.

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