Solar cell electrode, solar cell, and photovoltaic module

Abstract

A solar cell electrode, a solar cell, and a photovoltaic module. The solar cell electrode comprises: a plurality of grid lines, which are arranged in parallel at intervals in a first direction, wherein at least some of the grid lines each comprise first connecting portions and second connecting portions; the first connecting portions are connected to the second connecting portions; the second connecting portions are adapted to connect to a solder ribbon; and the cross-sectional area of each second connecting portion in the first direction is larger than the cross-sectional area of each first connecting portion in the first direction. By means of providing the second connecting portions to facilitate an operation of connecting the solder ribbon to the grid lines, the connection reliability between the grid lines and the solder ribbon can be improved; and by using a relatively thin finger structure, the grid lines can meet the requirements for use and for connection to the solder ribbon, so that the amount of usage of slurry required for preparing the grid lines can be greatly reduced, and the portions of a surface of a cell that are shielded by the grid lines can be also reduced, thereby helping to realize cost reduction and efficiency improvement of the solar cell.

Description

Solar cell electrodes, solar cells and photovoltaic modules

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 25, 2023, with application number 202322305448.1 and invention name “Solar cell electrode, solar cell and photovoltaic module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of photovoltaic technology, and specifically relates to a solar cell electrode, a solar cell and a photovoltaic module. Background Art

[0003] As a new energy source, efficient use of solar energy helps to alleviate energy and environmental pressures. As the core component of solar power stations, solar cells can convert solar energy into electrical energy using the photoelectric effect. With the continuous development of solar cell technology, cost reduction and efficiency improvement of solar cells have received widespread attention.

[0004] In related technologies, the electrode structure of a solar cell is mainly composed of multiple main grid lines and several fine grid lines. The main grid lines and the fine grid lines are vertically cross-connected. The fine grid lines are used to collect the current generated by the conversion of the battery cells, and the main grid lines are used to collect the current on the fine grid lines. After the main grid lines are welded to the welding strips through the welding pads, the current collected by the main grid lines is led out to the outside of the solar cell through the welding strips.

[0005] However, the electrode structure used in related technologies requires a large amount of silver paste to manufacture the grid lines, increasing the manufacturing cost of the battery. In addition, the large number of main grid lines and fine grid lines obstructs the battery surface, affecting the battery's conversion efficiency. In addition, in solar cells using a main grid electrode structure, the soldering ribbon is welded to the pads set on the main grid lines. If there is a biased soldering or a cold solder joint, it is easy to cause the fine grid lines to break after rework. Therefore, the soldering accuracy of the soldering ribbon is required to be high.

[0006] Summary of the Invention

[0007] The present application aims to provide a solar cell electrode, a solar cell and a photovoltaic module, which can solve the problems of large silver paste consumption required for manufacturing grid lines using the electrode structure in the related technology and the grid lines blocking the surface of the battery. At the same time, it also facilitates the connection operation between the welding strip and the grid line and improves the connection reliability between the grid line and the welding strip.

[0008] In order to solve the above technical problems, this application is implemented as follows:

[0009] In a first aspect, an embodiment of the present application provides a solar cell electrode, comprising: a plurality of grid lines, the plurality of grid lines being arranged in parallel and spaced apart along a first direction;

[0010] At least part of the gate line includes a first connection part and a second connection part, the first connection part and the second connection part are connected to each other, and the second connection part is suitable for connecting to a welding strip; wherein the cross-sectional area of ​​the second connection part along the first direction is larger than the cross-sectional area of ​​the first connection part along the first direction.

[0011] Optionally, the gate line includes a plurality of the first connection parts and a plurality of the second connection parts;

[0012] The plurality of first connection portions are arranged at intervals along a second direction, the second direction being perpendicular to the first direction; the second connection portion is embedded between two adjacent first connection portions, and the two adjacent first connection portions are connected through the second connection portion.

[0013] Optionally, the gate line includes the first connecting portion and a plurality of the second connecting portions;

[0014] The first connection portion extends along a second direction to form a gate line body, and the second direction is perpendicular to the first direction; a plurality of second connection portions are arranged on the gate line body at intervals, and the second connection portions are connected to the gate line body.

[0015] Optionally, each of the plurality of gate lines includes the first connecting portion and the second connecting portion.

[0016] Optionally, the gate lines provided with the first connecting portion and the second connecting portion among the plurality of gate lines are first gate lines, and the gate lines other than the first gate lines among the plurality of gate lines are second gate lines, and the first gate lines and the second gate lines are alternately arranged in parallel along the first direction.

[0017] Optionally, along the first direction, the number of second gate lines between two adjacent first gate lines is N, satisfying: 0≤N≤3.

[0018] Optionally, the second gate line includes the first connecting portion, the first connecting portion extends along a second direction, and the second direction is perpendicular to the first direction.

[0019] Optionally, the maximum width of the first connection portion along the first direction is W1 μm, and the maximum width of the second connection portion along the first direction is W2 μm, satisfying: 1.5≤W2 / W1≤5.

[0020] Optionally, a maximum length of the second connection portion along the extension direction of the gate line is L μm, satisfying: 100≤L≤300.

[0021] Optionally, a third direction is defined to be perpendicular to the first direction and the extension direction of the gate line. Along the third direction, the maximum height of the gate line at the first connection portion is H1 μm, and the maximum height of the gate line at the second connection portion is H2 μm, satisfying: 1.1≤H2 / H1≤3.

[0022] Optionally, the first connecting portion and the second connecting portion are separately formed structures.

[0023] Optionally, the weldability of the second connection portion is better than that of the first connection portion.

[0024] In a second aspect, an embodiment of the present application provides a solar cell, comprising a cell substrate, wherein the front and / or back side of the cell substrate is provided with the solar cell electrode described in the first aspect.

[0025] In a third aspect, an embodiment of the present application provides a photovoltaic module comprising the above-mentioned solar cell.

[0026] In an embodiment of the present application, the solar cell electrode includes a plurality of grid lines arranged in parallel and spaced apart, and at least some of the grid lines include a first connecting portion and a second connecting portion. The cross-sectional area of ​​the second connecting portion is set to be larger than the cross-sectional area of ​​the first connecting portion so that the second connecting portion can be used to connect to the welding ribbon, which not only facilitates the connection operation between the welding ribbon and the grid line, but also improves the connection reliability between the grid line and the welding ribbon. In addition, the grid line in the present application can adopt a relatively thin fine grid structure to meet the requirements of use and connection with the welding ribbon. In this way, the amount of slurry required to prepare the grid line can be greatly reduced, and the grid line can reduce the obstruction of the battery surface, thereby helping to reduce the cost and improve the efficiency of solar cells.

[0027] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] FIG1 is a top view of a solar cell electrode according to an embodiment of the present application;

[0030] FIG2 is a cross-sectional view of a grid line of a solar cell electrode according to an embodiment of the present application;

[0031] FIG3 is a schematic diagram of a forming structure of the gate line in FIG2 according to an embodiment of the present application;

[0032] FIG4 is a cross-sectional view of a grid line of another solar cell electrode according to an embodiment of the present application;

[0033] FIG5 is a schematic diagram of a forming structure of the gate line in FIG4 according to an embodiment of the present application;

[0034] FIG6 is a schematic diagram of another solar cell electrode according to an embodiment of the present application;

[0035] FIG7 is a schematic diagram of another solar cell electrode according to an embodiment of the present application;

[0036] FIG8 is a top view of a grid line of a solar cell electrode according to an embodiment of the present application;

[0037] FIG9 is a test result of the connection strength between the grid lines and the soldering ribbons in the solar cell electrodes according to an embodiment of the present application;

[0038] FIG10 is a test result of the connection strength between the grid line and the welding ribbon in a conventional solar cell electrode;

[0039] FIG. 11 is a schematic diagram of a partial structure of an electrode structure of a solar cell according to a comparative example.

[0040] Reference numerals:

[0041] 100: gate line; 101: first connection part; 102: second connection part; 100a: gate line body; 110: first gate line; 120: second gate line; 200: battery substrate; X: first direction; Y: second direction; Z: third direction. Specific embodiments

[0042] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein 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 exemplary and are only used to explain the present application and are not to be construed as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. Throughout the description of this application, unless otherwise specified, "plurality" means two or more. Furthermore, "and / or" in the specification and claims refers to at least one of the connected entities, and the character " / " generally indicates an "or" relationship between the connected entities.

[0044] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0046] Before explaining the solar cell electrodes, solar cells, and photovoltaic modules provided in the embodiments of the present application, the application scenarios of the solar cell electrodes, solar cells, and photovoltaic modules provided in the embodiments of the present application are specifically described:

[0047] Typically, a solar cell includes multiple cells, and electrodes are formed on the front and back of each cell. In related art, there are two main structures of electrodes formed on the surface of the cell: one is a main grid electrode structure, and the other is a main grid electrode-free structure.

[0048] The main grid electrode structure includes a main grid line and fine grid lines. The main grid line and fine grid lines are connected perpendicularly. The fine grid lines are used to collect the current generated by the cell conversion, and the main grid lines are used to collect the current on the fine grid lines. At the same time, there are welding pads on the main grid lines. Welding ribbons are used to weld to the welding pads to connect multiple cell cells in series to form a battery string. The current collected by the main grid lines in each cell is then transmitted to the outside of the battery via the welding ribbons.

[0049] However, the use of this main grid electrode structure requires a large amount of paste consumption during the printing and manufacturing of the grid lines, resulting in high production costs. In addition, the grid lines block a large amount of light on the surface of the cell, affecting the conversion efficiency of the cell and reducing the power generation of the cell. For example, in a 182mm half-cell cell, using the electrode structure in the related art, the paste consumption required for printing the grid lines is 100mg, and the grid lines block the light area on the cell surface of 513mm. 2 .

[0050] In addition, in solar cells with a main grid electrode structure, the welding ribbon is welded and fixed to the welding pad set on the main grid line. If there is biased welding or cold welding, it is easy to cause the fine grid line to break after rework. Therefore, the welding accuracy of the welding ribbon is required to be high.

[0051] Another main grid electrode structure without a main grid electrode is adopted, in which only fine grid lines are printed on the surface of the battery cell. In order to achieve the connection between the fine grid lines and the welding ribbons, it is usually necessary to use specific laminating equipment to lay the welding ribbons on the preset adhesive film to make a welding ribbon mesh. Then, the adhesive film with the welding ribbon mesh is laid on the surface of the battery cell, and the ohmic connection between the welding ribbons and the fine grid lines is achieved through lamination and bonding.

[0052] However, although the use of this main grid electrode structure reduces the slurry consumption required for printing the grid lines, the cost of producing the solder ribbon mesh is very high, and specific laminating equipment is required to laminate and fix the solder ribbon. It is basically incompatible with the current large-scale mass-produced string soldering equipment, which increases production difficulty and equipment costs.

[0053] The present application provides a solar cell electrode, a solar cell and a photovoltaic module. By optimizing the solar cell electrode structure, the consumption of paste for printing grid lines can be reduced and the shading area of ​​the cell surface can be reduced. At the same time, it also facilitates the connection operation between the welding strip and the grid lines.

[0054] The solar cell electrode, solar cell and photovoltaic module provided in the embodiments of the present application are described in detail below with reference to specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0055] As shown in Figure 1, according to some embodiments of the present application, the solar cell electrode includes: a plurality of grid lines 100, and the plurality of grid lines 100 are arranged in parallel and spaced apart along a first direction X; at least part of the grid lines 100 include a first connection portion 101 and a second connection portion 102, the first connection portion 101 and the second connection portion 102 are connected to each other, and the second connection portion 102 is suitable for connection to a welding ribbon; wherein the cross-sectional area of ​​the second connection portion 102 along the first direction X is greater than the cross-sectional area of ​​the first connection portion 101 along the first direction X.

[0056] In an embodiment of the present application, the solar cell electrode includes a plurality of grid lines 100 arranged in parallel and spaced apart, and at least some of the grid lines 100 include a first connecting portion 101 and a second connecting portion 102. The cross-sectional area of ​​the second connecting portion 102 is set to be larger than the cross-sectional area of ​​the first connecting portion 101, so that the second connecting portion 102 can be used to connect to the welding ribbon, which not only facilitates the connection operation between the welding ribbon and the grid line 100, but also improves the connection reliability between the grid line 100 and the welding ribbon. In addition, the grid line 100 in the present application can adopt a relatively thin fine grid structure to meet the requirements of use and connection with the welding ribbon. In this way, the amount of slurry required to prepare the grid line 100 can be greatly reduced, and the obstruction of the grid line 100 on the cell surface can be reduced, thereby helping to reduce the cost and improve the efficiency of solar cells.

[0057] It should be noted that the cross-sectional shape of the second connecting portion 102 can be square, rectangular, circular, elliptical, trapezoidal, etc., and can also be any other shape formed by a combination of straight lines and / or curves. This application does not impose any restrictions on this.

[0058] The electrode in the embodiment of the present application can be applied to a solar cell. In actual use, a screen printing process can be used to print a paste on the surface of a cell of the solar cell to form a plurality of grid lines 100 .

[0059] The solar cell may include one of a HIT cell, a HJT cell, a HDT cell, a PERC cell, a PERL cell, a PERT cell or a TOPCON cell.

[0060] Of course, the electrodes in the embodiments of the present application can also be used in other types of solar cells. Those skilled in the art can select application scenarios according to actual needs, and the present application does not limit this.

[0061] Specifically, a plurality of gate lines 100 are arranged in parallel and spaced apart along a first direction X. Among the plurality of gate lines 100, some gate lines 100 may include a first connecting portion 101 and a second connecting portion 102 connected to each other, wherein a cross-sectional area of ​​the second connecting portion 102 along the first direction X is larger than a cross-sectional area of ​​the first connecting portion 101 along the first direction X. By providing the second connecting portion 102 with a relatively large cross-sectional area in some gate lines 100, so that the second connecting portion 102 can be used for connection with the soldering ribbon, the actual connection operation is facilitated and the connection strength between the gate line 100 and the soldering ribbon is increased.

[0062] In specific applications, multiple grid lines 100 can be arranged on the surface of the battery substrate 200. The first connecting portion 101 in the grid lines 100 is ohmically connected to the surface of the battery substrate 200. The first connecting portion 101 can then be used to collect the current generated by the photoelectric conversion of the battery substrate 200. The second connecting portion 102 can be used to connect to the welding ribbon, so that the current collected by the first connecting portion 101 is collected by the second connecting portion 102 and then transferred to the welding ribbon, which then outputs the current to the outside of the battery.

[0063] Compared with the conventional main grid electrode structure, the electrode structure in the embodiment of the present application can significantly reduce the amount of slurry required to prepare the grid line 100, and can reduce the shielding of the grid line 100 on the cell surface, thereby improving the conversion efficiency of the solar cell.

[0064] In addition, by adopting the electrode structure in the embodiment of the present application, during the connection process between the gate line 100 and the welding ribbon, the second connecting portion 102 with a relatively large cross-sectional area is used to contact the welding ribbon, which facilitates the welding operation between the gate line 100 and the welding ribbon, reduces the welding difficulty, and can effectively reduce the risk of biased welding and broken grid.

[0065] Furthermore, compared to conventional busbar-less electrode structures, the electrode structure of the present embodiment facilitates the welding and fixing of the gate line 100 to the welding ribbon due to the provision of the second connection portion 102 in the gate line 100 for connecting to the welding ribbon. This allows the welding operation to be performed using conventional string welding equipment without the need for additional production equipment, significantly reducing production complexity and costs.

[0066] In some embodiments, among the plurality of gate lines 100, the gate line 100 including the first connecting portion 101 and the second connecting portion 102 is referred to as the first gate line 110, and the gate lines 100 other than the first gate line 110 are referred to as the second gate lines 120. The second gate lines 120 do not require a dedicated connection point with the soldering ribbon and can therefore be relatively thin. This helps reduce the amount of paste used and reduces obstruction of the battery surface while meeting the performance requirements of the gate lines 100.

[0067] The second gate line 120 may be configured to have the same or similar structure as the first connection portion 101 , or may be configured to have other structures according to actual needs, and this application does not impose any limitation thereto.

[0068] In some embodiments, the first connection portion 101 and the second connection portion 102 can be made of the same paste or different pastes. For example, at least one of the first connection portion 101 and the second connection portion 102 can be made of silver paste, or copper paste coated with silver paste.

[0069] Optionally, the weldability of the second connection portion 102 is better than the weldability of the first connection portion 101 .

[0070] Specifically, the first connection part 101 and the second connection part 102 can be made of different slurries, wherein the welding performance of the slurry used in the second connection part 102 is stronger than the welding performance of the slurry used in the first connection part 101, so that the weldability of the second connection part 102 is better than the weldability of the first connection part 101, so that the second connection part 102 can be better welded and fixed to the welding strip.

[0071] Among them, the weldability of the gate line 100 can be evaluated by the welding ability of the gate line 100 and the welding strip. For example, using the same welding process, the first connecting part 101 and the second connecting part 102 are respectively welded to the same welding strip, and the welding process difficulty, welding strength and other performance indicators between the two are compared to evaluate the weldability.

[0072] It should be noted that the weldability of the gate line 100 may also be tested using other detection methods, which may be configured according to actual needs and are not limited in this application.

[0073] It should be noted that the specific slurry for preparing the gate line 100 can be selected according to actual needs, and the embodiment of the present application does not limit this.

[0074] Optionally, the first connecting portion 101 and the second connecting portion 102 are separate molded structures.

[0075] In the embodiment of the present application, the first connecting portion 101 and the second connecting portion 102 are formed in stages on the surface of the battery substrate 200 and connected to each other, thereby utilizing the first connecting portion 101 to collect current and utilizing the second connecting portion 102 to connect to the welding ribbon. This facilitates the use of different molding processes to manufacture the first connecting portion 101 and the second connecting portion 102, thereby meeting the different processing and usage requirements of the first connecting portion 101 and the second connecting portion 102, and facilitating actual processing and manufacturing.

[0076] In some embodiments, the gate line 100 can be formed by screen printing, using a printing screen with a preset pattern structure to print the gate line 100 on the surface of the battery substrate 200. Specifically, a first slurry and a first screen can be used to print the first connecting portion 101 on the surface of the battery substrate 200. Then, a second slurry and a second screen can be used to print the second connecting portion 102 on the surface of the battery substrate 200. The position of the second connecting portion 102 is made to correspond to the position of the first connecting portion 101, so that the gate line 100 can be formed by the first connecting portion 101 and the second connecting portion 102.

[0077] The specific structures of the first and second screens can be designed based on the specific structures of the solar cell electrodes. The first and second slurries can be made of the same material or different materials. Those skilled in the art can select the appropriate slurry type and printing screen structure based on actual needs, and this embodiment of the present application does not limit this.

[0078] Optionally, as shown in Figures 2 and 3, the gate line 100 includes a plurality of first connection portions 101 and a plurality of second connection portions 102; the plurality of first connection portions 101 are arranged at intervals along the second direction Y, and the second direction Y is perpendicular to the first direction X; the second connection portion 102 is embedded between two adjacent first connection portions 101, and the two adjacent first connection portions 101 are connected through the second connection portion 102.

[0079] In the embodiment of the present application, the first connecting portions 101 in the gate line 100 are arranged at intervals along the second direction Y, and the second connecting portion 102 is embedded between two adjacent first connecting portions 101. The first connecting portions 101 and the second connecting portions 102 are sequentially connected to form a complete gate line 100. In this way, while satisfying the current collection function of the first connecting portions 101 and the connection function of the second connecting portions 102, the slurry consumption required for preparing the first connecting portions 101 can be reduced, thereby reducing processing costs.

[0080] Specifically, the arrangement direction of the plurality of gate lines 100 is set as the first direction X, and the extension direction of each gate line 100 is set as the second direction Y. The first direction X is perpendicular to the second direction Y.

[0081] In a specific application, as shown in Figures 2 and 3, for the same gate line 100, during the preparation process, a plurality of first connecting portions 101 can be formed on the surface of the battery substrate 200, spaced apart along the second direction Y, with a gap between two adjacent first connecting portions 101. Then, the gaps are further processed to form second connecting portions 102, with the ends of the second connecting portions 102 respectively connected to two adjacent first connecting portions 101. Thus, a gate line 100 can be formed by sequentially connecting the plurality of first connecting portions 101 and the plurality of second connecting portions 102.

[0082] Optionally, as shown in Figures 4 and 5, the gate line 100 includes a first connecting portion 101 and multiple second connecting portions 102; the first connecting portion 101 extends along the second direction Y to form a gate line body 100a, and the second direction Y is perpendicular to the first direction X; multiple second connecting portions 102 are arranged at intervals on the gate line body 100a, and the second connecting portions 102 are connected to the gate line body 100a.

[0083] In the embodiment of the present application, a first connecting portion 101 extending continuously along the second direction Y is provided to form a grid line main body 100a by the first connecting portion 101, and then a plurality of second connecting portions 102 are spaced apart on the grid line main body 100a to form a grid line 100. In this way, the use of a continuous structure of the first connecting portion 101 helps to reduce the design complexity of the printing screen required for processing the first connecting portion 101, thereby facilitating actual preparation and processing.

[0084] In a specific application, as shown in Figures 4 and 5, for the same gate line 100, during the preparation process, a first connection portion 101 of a corresponding length can be directly processed according to the designed length of the gate line 100, and then a plurality of second connection portions 102 arranged at intervals can be formed on the first connection portion 101, so that the second connection portion 102 at least partially covers the first connection portion 101. A gate line 100 can be formed by the first connection portion 101 of a continuous structure and a plurality of second connection portions 102.

[0085] It can be understood that since the second connection part 102 of the embodiment of the present application partially covers the surface of the first connection part 101, the precision requirement for the processing position during processing is relatively low, which reduces the processing difficulty and facilitates the actual processing operation.

[0086] Optionally, as shown in FIG. 1 , each of the plurality of gate lines 100 includes a first connection portion 101 and a second connection portion 102 .

[0087] In the embodiment of the present application, each of the plurality of grid lines 100 includes a first connecting portion 101 and a second connecting portion 102, and the grid lines 100 are formed by interconnecting the first connecting portion 101 and the second connecting portion 102. In this way, in actual use, each grid line 100 can be connected to the welding ribbon through the second connecting portion 102, thereby ensuring that each grid line 100 can be stably connected to the welding ribbon, thereby improving the connection strength and reliability between the solar cell electrode and the welding ribbon.

[0088] It is understood that, compared to conventional busbar-type structures using pads, the electrode structure of the present embodiment not only ensures a stable connection between all gate lines 100 and the soldering ribbon, but also reduces the number of steps and material loss required to prepare the pads. Furthermore, compared to conventional busbar-type structures using pads connected to the soldering ribbon, the force applied to the multiple second connecting portions 102 connected to the soldering ribbon in the present embodiment is more uniform, avoiding the problem of localized stress concentration.

[0089] 6 and 7 , the gate lines 100 having the first connecting portion 101 and the second connecting portion 102 among the plurality of gate lines 100 are first gate lines 110 , and the gate lines 100 other than the first gate lines 110 among the plurality of gate lines 100 are second gate lines 120 , and the first gate lines 110 and the second gate lines 120 are alternately arranged in parallel along the first direction X.

[0090] In an embodiment of the present application, first gate lines 110 and second gate lines 120 are arranged alternately and in parallel along a first direction X. By connecting a plurality of first gate lines 110 to a soldering ribbon, the connection requirements with the soldering ribbon can be met, and no special structure for connecting to the soldering ribbon is required in the second gate lines 120. This helps to reduce the amount of slurry required to prepare the gate lines 100 and reduce processing costs.

[0091] Specifically, among the plurality of gate lines 100, first gate lines 110 are arranged along the first direction X, and a preset number of second gate lines 120 are arranged between every two adjacent first gate lines 110. The second gate lines 120 can adopt a relatively thin gate line 100 structure, without the need for a soldering ribbon connection structure similar to the second connecting portion 102.

[0092] In a specific application, when connecting the gate line 100 to the welding tape, the welding tape is welded and fixed to the second connecting portion 102 in the first gate line 110, and the welding tape is directly overlapped and contacted with the second gate line 120. In this way, the connection requirements between the entire electrode structure and the welding tape can be met, and the amount of slurry used to prepare the gate line 100 can be reduced.

[0093] Optionally, as shown in FIG. 6 , the second gate line 120 includes a first connection portion 101 , and the first connection portion 101 extends along a second direction Y, where the second direction Y is perpendicular to the first direction X.

[0094] In the embodiment of the present application, by arranging the first connecting portion 101 along the second direction Y to form the second gate line 120, the second gate line 120 can be simultaneously processed while the first connecting portion 101 of the first gate line 110 is being processed, thereby facilitating actual processing and manufacturing. Furthermore, by using the first connecting portion 101 with a relatively small cross-sectional area to form the second gate line 120, while meeting the performance requirements of the second gate line 120, the amount of slurry required to prepare the second gate line 120 can be reduced, thereby reducing processing costs.

[0095] Of course, the second gate line 120 may also adopt other structures, and those skilled in the art may configure them according to actual needs, and the embodiments of the present application do not limit this.

[0096] Optionally, as shown in FIG6 and FIG7 , along the first direction X, the number of the second gate lines 120 between two adjacent first gate lines 110 is N, satisfying: 0≤N≤3.

[0097] In the embodiment of the present application, by setting the number of second gate lines 120 between two adjacent first gate lines 110, while meeting the use requirements of the entire electrode structure and the connection requirements with the welding strip, it helps to reduce the amount of slurry required for preparing the gate lines 100.

[0098] It is understandable that if all the gate lines 100 are provided with the second connecting portion 102, a good connection between each gate line 100 and the welding strip can be achieved, but this structure requires relatively more slurry; and if the number of second gate lines 120 between two adjacent first gate lines 110 is too large, the connection point between the welding strip and the gate line 100 will be too large, which will affect the connection stability between the gate line 100 and the welding strip.

[0099] Therefore, in the embodiment of the present application, by reasonably setting the number range of the second gate lines 120 between two adjacent first gate lines 110, the amount of slurry required for preparing the gate lines 100 is reduced while ensuring the connection performance between the gate lines 100 and the soldering tape.

[0100] Optionally, as shown in FIG8 , the maximum width of the first connection portion 101 along the first direction X is W1 μm, and the maximum width of the second connection portion 102 along the first direction X is W2 μm, satisfying: 1.5≤W2 / W1≤5.

[0101] In the embodiment of the present application, by setting a reasonable range of the ratio W2 / W1 of the maximum width W2 of the second connecting portion 102 along the first direction X to the maximum width W1 of the first connecting portion 101 along the first direction X in the gate line 100, a good connection between the second connecting portion 102 and the soldering ribbon can be achieved by utilizing the larger width, thereby facilitating the actual soldering ribbon connection operation. At the same time, by controlling the upper limit of the ratio range of W2 / W1, the second connecting portion 102 is prevented from being too wide, thereby increasing the amount of slurry used.

[0102] It is understood that by setting the maximum width W2 of the second connection portion 102 along the first direction X to be greater than the maximum width W1 of the first connection portion 101 along the first direction X, the second connection portion 102 can be better connected to the solder ribbon. However, if the width of the second connection portion 102 is too wide, unnecessary slurry waste will be caused.

[0103] To this end, in the embodiment of the present application, by setting a reasonable range of the ratio W2 / W1 between the maximum width W2 of the second connecting portion 102 in the gate line 100 and the maximum width W1 of the first connecting portion 101, it can not only meet the connection requirements between the gate line 100 and the welding strip, but also reduce the amount of slurry required to prepare the gate line 100.

[0104] In some embodiments, the ratio W2 / W1 between the maximum width W2 of the second connection portion 102 along the first direction X and the maximum width W1 of the first connection portion 101 along the first direction X can be set to any value such as 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5, or a range between any two values.

[0105] In a specific application, the width of the first connection portion 101 and the width of the gate line 100 at the second connection portion 102 are measured along the second direction Y, and at least three width values ​​are measured respectively, and the maximum value of the at least three width values ​​is taken as the final measurement value.

[0106] It should be noted that when measuring the width of the first connecting portion 101 and the second connecting portion 102, the measuring tools and methods used should be consistent to reduce equipment errors and human errors. Of course, the specific measuring methods and tools can be selected according to actual needs and are not limited in this embodiment of the present application.

[0107] 8 , the maximum length of the second connection portion 102 along the extension direction of the gate line 100 is L μm, satisfying: 100≤L≤300. The extension direction of the gate line 100 is parallel to the second direction Y.

[0108] In an embodiment of the present application, a reasonable value range of the maximum length L of the second connecting portion 102 along the second direction Y is set so as to reduce the amount of slurry required to prepare the second connecting portion 102 while ensuring that the gate line 100 can be stably connected to the soldering ribbon through the second connecting portion 102.

[0109] In some embodiments, the maximum length L of the second connection portion 102 along the second direction Y can be set to any value such as 100μm, 120μm, 150μm, 170μm, 190μm, 200μm, 210μm, 250μm, 28μm, 300μm, or a range between any two values.

[0110] Optionally, as shown in Figures 2 and 4, a third direction Z is defined as being perpendicular to the first direction X and the extension direction of the gate line 100. Along the third direction Z, the maximum height of the gate line 100 at the first connection portion 101 is H1μm, and the maximum height of the gate line 100 at the second connection portion 102 is H2μm, satisfying: 1.1≤H2 / H1≤3.

[0111] In an embodiment of the present application, by setting a reasonable range of the ratio H2 / H1 between the maximum height H2 of the gate line 100 at the second connection portion 102 and the maximum height H1 of the gate line 100 at the first connection portion 101, the connection requirements between the gate line 100 and the welding strip can be met, and the amount of slurry required to prepare the gate line 100 can be reduced.

[0112] It is understood that by setting the maximum height H2 of the gate line 100 at the second connection portion 102 to be greater than the maximum height H1 of the gate line 100 at the first connection portion 101, the relatively high second connection portion 102 facilitates the connection operation with the soldering ribbon. However, if the height H2 of the gate line 100 at the second connection portion 102 is too high, it will not only cause slurry waste, but also cause interference with other components during installation and use.

[0113] In some embodiments, the ratio H2 / H1 can be set to any value such as 1.1, 1.2, 1.5, 1.8, 2.0, 2.3, 2.5, 2.6, 2.8, 3, or a range between any two values.

[0114] In a specific application, along the third direction Z, the height of the gate line 100 at the first connection portion 101 and the height of the gate line 100 at the second connection portion 102 are measured respectively, and at least three height values ​​are measured respectively, and the maximum value of the at least three height values ​​is taken as the final measurement value.

[0115] It should be noted that when measuring the height of different parts of the grid line 100, the measuring tools and measuring methods used should be consistent to reduce equipment errors and human errors. Of course, specific measuring methods and measuring tools can be selected according to actual needs, and the embodiments of the present application do not limit this.

[0116] In some embodiments, solar cells were prepared using conventional busbar electrode structures and the electrode structure of the present application, and relevant performance data of the cells were tested and compared:

[0117] The comparative example is a solar cell printed with a conventional busbar electrode structure. The front of the solar cell is printed with 60 cross-shaped fine grid lines and 25 busbars, and the back is printed with 100 fine grid lines and 25 busbars. The busbars are soldered to the solder ribbon via pads, with five pads provided for each busbar. As shown in Figure 11, Figure 11 shows a partial structural schematic diagram of the electrode structure of the solar cell of the comparative example.

[0118] Among them, the embodiment is a solar cell printed with the electrode structure of the embodiment of the present application, the front of the solar cell is printed with 60 parallel grid lines 100 and each grid line 100 is provided with 25 second connection parts 102, and the back is printed with 100 parallel grid lines 100 and each grid line 100 is provided with 25 second connection parts 102, and each grid line 100 is formed by multiple first connection parts 101 and multiple second connection parts 102 alternately connected in sequence, and the second connection part 102 is embedded between two adjacent first connection parts 101.

[0119] By calculating the silver paste consumption for printing the grid lines 100 and the light-receiving area of ​​the solar cell in the comparative example and the embodiment, the specific results are shown in Table 1:

[0120] Table 1

[0121] According to the contents of Table 1 above, compared with the comparative example, the electrode structure in the embodiment of the present application can save 13.9 mg of silver paste required for printing the grid lines 100. At the same time, the light receiving area of ​​each solar cell surface can be increased by 0.58%.

[0122] Furthermore, the electrical performance of the two solar cells was tested, and the test results are shown in Table 2:

[0123] Table 2

[0124] As can be seen from Table 2, the short-circuit current (Isc) of the solar cell of the embodiment of the present application can be increased by 0.0337A compared with the solar cell of the comparative example, the open-circuit voltage (Uoc) is basically the same, the fill factor (FF) is reduced by 0.31%, and the efficiency (Eff) is increased by 0.005%.

[0125] It can be understood that the use of the solar cell electrode of the embodiment of the present application can not only reduce the silver paste consumption of the printed grid line 100, but also reduce the shading of the grid line 100 on the cell surface, thereby increasing the light-receiving area of ​​the cell, thereby improving the short-circuit current and conversion efficiency.

[0126] Furthermore, the two solar cells in the above embodiment were used to weld the grid lines 100 on the surface of the cells to the welding ribbons, and the connection strength between the welding ribbons and the grid lines 100 was tested using a tensile testing machine. The test results are shown in Figures 9 and 10.

[0127] FIG10 shows the test results of the connection strength between the grid lines and the welding strips in conventional solar cell electrodes. As shown in FIG10 , the bonding strength between the welding strips and the grid lines 100 is intermittently distributed, with the bonding strength at the welding points being much greater than the bonding strength at other locations. This results in an uneven distribution of bonding strength between the welding strips and the grid lines 100, resulting in stress concentration points, which can easily cause local damage to the solar cell during use.

[0128] FIG9 shows the test results of the connection strength between the grid lines and the soldering ribbon in the solar cell electrodes of the present invention. As shown in FIG9, the bonding force between the soldering ribbon and the grid lines 100 fluctuates within a certain range, that is, the bonding force distribution between the soldering ribbon and the grid lines 100 is relatively uniform. This helps eliminate stress concentration points and improves the connection stability between the soldering ribbon and the grid lines 100.

[0129] Optionally, an embodiment of the present application further provides a solar cell, comprising a cell substrate 200 , wherein the front and / or back surface of the cell substrate 200 is provided with the solar cell electrodes in the above embodiment.

[0130] In an embodiment of the present application, the solar cell electrode includes a plurality of grid lines 100 arranged in parallel and spaced apart, and at least some of the grid lines 100 include a first connecting portion 101 and a second connecting portion 102. The cross-sectional area of ​​the second connecting portion 102 is set to be larger than the cross-sectional area of ​​the first connecting portion 101, so that the second connecting portion 102 can be used to connect to the welding ribbon, which not only facilitates the connection operation between the welding ribbon and the grid line 100, but also improves the connection reliability between the grid line 100 and the welding ribbon. In addition, the grid line 100 in the present application can adopt a relatively thin fine grid structure to meet the requirements of use and connection with the welding ribbon. In this way, the amount of slurry required to prepare the grid line 100 can be greatly reduced, and the obstruction of the grid line 100 on the cell surface can be reduced, thereby helping to reduce the cost and improve the efficiency of solar cells.

[0131] Specifically, a solar cell includes a front side and a back side, and the solar cell electrodes described in the above embodiments may be provided on at least one of the front side and the back side of the solar cell. The electrode structures on the front side and the back side of the solar cell may be the same or different. Those skilled in the art may configure these structures based on actual needs, and the embodiments of the present application are not limited thereto.

[0132] It should be noted that the solar cell electrode provided on the surface of the battery substrate 200 may include the solar cell electrode in any of the above embodiments. The specific structure of the solar cell electrode can be found in the above content and will not be described in detail in the embodiments of this application.

[0133] Optionally, an embodiment of the present application further provides a photovoltaic assembly, comprising the solar cell in the above embodiment.

[0134] In an embodiment of the present application, the solar cell electrode includes a plurality of grid lines 100 arranged in parallel and spaced apart, and at least some of the grid lines 100 include a first connecting portion 101 and a second connecting portion 102. The cross-sectional area of ​​the second connecting portion 102 is set to be larger than the cross-sectional area of ​​the first connecting portion 101, so that the second connecting portion 102 can be used to connect to the welding ribbon, which not only facilitates the connection operation between the welding ribbon and the grid line 100, but also improves the connection reliability between the grid line 100 and the welding ribbon. In addition, the grid line 100 in the present application can adopt a relatively thin fine grid structure to meet the requirements of use and connection with the welding ribbon. In this way, the amount of slurry required to prepare the grid line 100 can be greatly reduced, and the obstruction of the grid line 100 on the cell surface can be reduced, thereby helping to reduce the cost and improve the efficiency of solar cells.

[0135] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0136] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A solar cell electrode, characterized in that: include: A plurality of grid lines, wherein the plurality of grid lines are arranged in parallel and at intervals along a first direction; At least part of the gate lines include a first connection portion and a second connection portion, the first connection portion and the second connection portion are interconnected, and the second connection portion is suitable for connecting to a welding strip; wherein a cross-sectional area of ​​the second connection portion along the first direction is greater than a cross-sectional area of ​​the first connection portion along the first direction.

2. The solar cell electrode according to claim 1, characterized in that: The gate line includes a plurality of the first connection parts and a plurality of the second connection parts; A plurality of the first connection parts are arranged at intervals along a second direction, and the second direction is perpendicular to the first direction; the second connection part is embedded between two adjacent first connection parts, and the two adjacent first connection parts are connected through the second connection part.

3. The solar cell electrode according to claim 1, characterized in that: The gate line includes the first connection portion and a plurality of the second connection portions; The first connection portion extends along a second direction to form a gate line body, and the second direction is perpendicular to the first direction; a plurality of second connection portions are arranged on the gate line body at intervals, and the second connection portions are connected to the gate line body.

4. The solar cell electrode according to claim 1, characterized in that: Each of the plurality of gate lines includes the first connection portion and the second connection portion.

5. The solar cell electrode according to claim 1, characterized in that: The gate lines provided with the first connection portion and the second connection portion among the plurality of gate lines are first gate lines, the gate lines other than the first gate lines among the plurality of gate lines are second gate lines, and the first gate lines and the second gate lines are alternately arranged in parallel along the first direction.

6. The solar cell electrode according to claim 5, characterized in that: Along the first direction, the number of second gate lines between two adjacent first gate lines is N, satisfying: 0≤N≤3.

7. The solar cell electrode according to claim 5, characterized in that: The second gate line includes the first connection portion, the first connection portion extends along a second direction, and the second direction is perpendicular to the first direction.

8. The solar cell electrode according to any one of claims 1 to 7, characterized in that: The maximum width of the first connection portion along the first direction is W1 μm, and the maximum width of the second connection portion along the first direction is W2 μm, satisfying: 1.5≤W2 / W1≤5.

9. The solar cell electrode according to any one of claims 1 to 7, characterized in that: The maximum length of the second connection portion along the extending direction of the gate line is L μm, satisfying: 100≤L≤300.

10. The solar cell electrode according to any one of claims 1 to 7, characterized in that: A third direction is defined to be perpendicular to the first direction and the extension direction of the gate line. Along the third direction, the maximum height of the gate line at the first connection portion is H1 μm, and the maximum height of the gate line at the second connection portion is H2 μm, satisfying: 1.1≤H2 / H1≤3.

11. The solar cell electrode according to claim 1, characterized in that: The first connecting portion and the second connecting portion are separately formed structures.

12. The solar cell electrode according to claim 11, characterized in that: The weldability of the second connection portion is better than the weldability of the first connection portion.

13. A solar cell, characterized in that: The invention comprises a battery substrate, wherein the front side and / or the back side of the battery substrate is provided with the solar cell electrode as claimed in any one of claims 1 to 12.

14. A photovoltaic module, characterized in that: Comprising the solar cell as claimed in claim 13.

Images