Solar cell, cell assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a solar cell, a cell module and a photovoltaic system. The battery string comprises a plurality of battery pieces, a plurality of main grids are arranged on the battery pieces, extend in the first direction and are alternately arranged in the second direction, a forked structure is arranged on the battery pieces, open rectangles are formed in the ends of the main grids, and a plurality of welding strips are arranged on the battery pieces, extend in the first direction and are arranged at intervals in the second direction. The welding strip covers the main grid and at least part of the first branch structure and is conductively connected with the first main grid and the second main grid, and the end part of the welding strip is positioned in the open rectangle. Therefore, the welding strip can be connected with the main grid to lead out the current of the main grid, and meanwhile, the end part of the welding strip is arranged in the open rectangle, so that short circuit caused by short circuit between the end part of the welding strip and other parts during free movement is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a solar cell, a battery assembly and a photovoltaic system. Background Art

[0002] Solar cell power generation is a sustainable source of clean energy, utilizing the photovoltaic effect of semiconductor pn junctions to convert sunlight into electrical energy. Solar cells excite electrons by absorbing photons, and these electrons are then channeled through a built-in electric field to generate an electric current. At this point, the grid lines can collect and transmit current, thereby converting light energy into electrical energy. However, in the related art, stress concentration is prone to occur at the connection point between the grid lines and the welding ribbons. This often results in the welding ribbons being disconnected from the grid lines during the installation of the welding ribbons or during lamination processes. Furthermore, after the welding ribbons are connected to the grid lines, the ends are often in a free-moving state. When the ends of the welding ribbons are free-moving, they can short-circuit with other components, causing a short circuit. Utility Model Content

[0003] The present application provides a solar cell, a battery module and a photovoltaic system, aiming to solve the problem of stress concentration and short circuit at the end of the welding ribbon at the connection position between the grid line and the welding ribbon.

[0004] The solar cell provided by the present application includes a cell string, a plurality of main grids, a bifurcated structure and a plurality of welding strips, wherein the cell string includes a plurality of cell slices, the plurality of cell slices are distributed along a first direction, a plurality of main grids are arranged on the cell slices, the main grids include a plurality of first main grids and a plurality of second main grids, the first main grids and the second main grids extend along the first direction and are alternately arranged along the second direction, the first main grids and the second main grids are opposite in polarity, the bifurcated structure is arranged on the cell slice, the bifurcated structure includes a first bifurcated structure and a second bifurcated structure, the first bifurcated structure is arranged at an end of the first main grid and / or the second bifurcated structure is arranged at an end of the second main grid, the first bifurcated structure and the second bifurcated structure are arranged The fork structures are each formed with an open rectangle, and several of the welding strips are arranged on the battery cell, and the welding strips extend along the first direction and are arranged at intervals along the second direction. The welding strips cover or partially cover the first main grid and the second main grid, and are conductively connected to the first main grid and the second main grid. There is at least one welding strip covering or partially covering the first main grid and at least part of the first forked structure, and is electrically connected to the first main grid and the first forked structure. There is at least one welding strip covering or partially covering the second main grid and at least part of the second forked structure, and is electrically connected to the second main grid and the second forked structure, wherein the end of the welding strip is at least partially arranged inside the open rectangle.

[0005] Furthermore, the battery cell includes a first battery cell and a second battery cell, the first busbar of the first battery cell and the second busbar of the second battery cell are arranged in a one-to-one correspondence, and the welding ribbon includes a first welding ribbon and a second welding ribbon, the first welding ribbon connects the first busbar and the first bifurcated structure of the first battery cell and the second busbar and the second bifurcated structure of the second battery cell, and the second welding ribbon connects the first busbar and the first bifurcated structure of the second battery cell to the component to be connected;

[0006] Wherein, the two ends of the first welding strip are respectively arranged in the opening rectangle of the first forked structure and the opening rectangle of the second forked structure.

[0007] Furthermore, the component to be connected is the second main grid or bus bar of another adjacent first battery cell.

[0008] Furthermore, the bifurcated structure includes a first straight segment, a second straight segment, a third straight segment, and a fourth straight segment, wherein the first straight segment and the second straight segment are connected to the busbar and are arranged opposite to each other along the second direction, the third straight segment is connected to an end of the first straight segment away from the second straight segment and extends along the first direction, and the fourth straight segment is connected to an end of the second straight segment away from the first straight segment and extends along the first direction;

[0009] The first straight line segment, the second straight line segment, the third straight line segment, and the fourth straight line segment together define the open rectangle.

[0010] Furthermore, the length of the first straight line segment or the second straight line segment along the second direction is greater than the length of the third straight line segment or the fourth straight line segment along the first direction.

[0011] Furthermore, the battery cell includes a plurality of fine grids, and the fine grids include a plurality of first fine grids and a plurality of second fine grids, the first fine grids and the second fine grids extend along the second direction and are alternately arranged along the first direction, the first fine grids and the second fine grids have opposite polarities, the first fine grids are connected to the first main grid and disconnected at the second main grid, and the second fine grids are connected to the second main grid and disconnected at the first main grid.

[0012] Furthermore, there is at least one first fine gate electrically connected to the first bifurcated structure and avoiding the second bifurcated structure, and there is at least one second fine gate electrically connected to the second bifurcated structure and avoiding the first bifurcated structure.

[0013] Furthermore, the length of the first fine gate connected to the first bifurcated structure is shorter than the length of the first fine gate connected to the first main gate;

[0014] The length of the second fine gate extending to connect the second bifurcated structure is shorter than the length of the second fine gate extending to connect the second main gate.

[0015] Furthermore, the width of the first bifurcated structure along the second direction is smaller than the distance between adjacent second main grids;

[0016] A width of the second bifurcated structure along the second direction is smaller than a distance between adjacent first main gates.

[0017] Furthermore, the solar cell further includes a pad structure, and the pad structure is arranged in the bifurcated structure.

[0018] The battery assembly provided in the embodiments of the present application includes the solar cell described in any one of the above embodiments.

[0019] The photovoltaic system provided in the embodiments of the present application includes the battery assembly described in the above embodiments.

[0020] In the solar cell, battery assembly and photovoltaic system of the embodiment of the present application, the solar cell includes a battery string, a plurality of main grids, a bifurcated structure and a plurality of welding strips, the battery string includes a plurality of battery slices, the plurality of battery slices are distributed along a first direction, the plurality of main grids are arranged on the battery slices, the main grids include a plurality of first main grids and a plurality of second main grids, the first main grids and the second main grids extend along the first direction and are alternately arranged along the second direction, the first main grids and the second main grids are opposite in nature, the bifurcated structure is arranged on the battery slice, the bifurcated structure includes a first bifurcated structure and a second bifurcated structure, the first bifurcated structure is arranged at the end of the first main grid and / or the second bifurcated structure is arranged at the end of the first main grid. At the end of the second main grid, the first bifurcated structure and the second bifurcated structure are each formed with an open rectangle. Several welding ribbons are disposed on the cell, extending along a first direction and spaced apart along a second direction. The welding ribbons cover or partially cover the first and second main grids and are electrically connected to the first and second main grids. At least one welding ribbon covers or partially covers the first main grid and at least a portion of the first bifurcated structure and is electrically connected to the first main grid and the first bifurcated structure. At least one welding ribbon covers or partially covers the second main grid and at least a portion of the second bifurcated structure and is electrically connected to the second main grid and the second bifurcated structure. The ends of the welding ribbons are located within the open rectangle. In this way, the welding ribbons can connect to the main grid to conduct current from the main grid. At the same time, the ends of the welding ribbons are disposed within the open rectangle to prevent the ends of the welding ribbons from shorting with other components when they are free to move, thereby preventing a short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of a solar cell according to an embodiment of the present application;

[0022] Figure 2is another structural schematic diagram of a solar cell according to an embodiment of the present application;

[0023] Figure 3 This is a partial structural diagram of a solar cell according to an embodiment of the present application;

[0024] Figure 4 is another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0025] Figure 5 This is another partial structural diagram of a solar cell according to an embodiment of the present application;

[0026] Figure 6 This is another partial structural diagram of a solar cell according to an embodiment of the present application;

[0027] Figure 7 is a schematic structural diagram of a battery assembly according to an embodiment of the present application;

[0028] Figure 8 It is a structural diagram of a photovoltaic system according to an embodiment of the present application.

[0029] Description of main component symbols:

[0030] Solar cell 100, cell string 10, cell 20, first cell 21, second cell 22, first main grid 30, first fine grid 31, second main grid 40, second fine grid 41, welding ribbon 50, first welding ribbon 51, second welding ribbon 52, to-be-connected part 60, bus bar 61, bifurcated structure 70, first bifurcated structure 71, second bifurcated structure 72, open rectangle 73, first straight line segment 74, second straight line segment 75, third straight line segment 76, fourth straight line segment 77, welding pad structure 80, cell assembly 200, photovoltaic system 300. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. 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 with 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. In addition, it should be understood that the specific embodiments described herein are merely used to explain the present application and are not intended to limit the present application.

[0032] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be understood as limitations on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0035] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0036] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art will appreciate the application of other processes and / or the use scenarios of other materials.

[0037] Currently, solar cells are semiconductor devices that convert sunlight into electrical energy. Solar cells utilize the photovoltaic effect, absorbing photons to excite electrons, and then channel these electrons through a built-in electric field to generate an electric current. Grid lines collect and transmit the generated current, thereby converting light energy into electrical energy. However, in related technologies, stress concentration is prone to occur at the connection point between the grid lines and the welding ribbons. This often leads to disconnection between the welding ribbons and the grid lines during the installation of the welding ribbons or lamination processes. Furthermore, after the welding ribbons are connected to the grid lines, their ends are often free to move. When the ends of the welding ribbons are free to move, they can short-circuit with other components, causing a short circuit.

[0038] Example 1

[0039] See also Figures 1 to 4In the solar cell 100 of the embodiment of the present application, the solar cell 100 includes a cell string 10, a plurality of main grids, a bifurcated structure 70 and a plurality of welding ribbons 50. The cell string 10 includes a plurality of cell sheets 20, and the plurality of cell sheets 20 are distributed along a first direction. The plurality of main grids are arranged on the cell sheets 20. The main grids include a plurality of first main grids 30 and a plurality of second main grids 40. The first main grids 30 and the second main grids 40 extend along the first direction and are alternately arranged along the second direction. The first main grids 30 and the second main grids 40 have opposite polarities. The bifurcated structure 70 is arranged on the cell sheet 20. The bifurcated structure 70 includes a first bifurcated structure 71 and a second bifurcated structure 72. The first bifurcated structure 71 is arranged at the end of the first main grid 30 and / or the second bifurcated structure 72 is arranged at the end of the second main grid 40. The first bifurcated structure 71 and the second bifurcated structure 72 are both formed with an open rectangle 73, and a number of welding strips 50 are arranged on the battery cell 20, and the welding strips 50 extend along the first direction and are arranged at intervals along the second direction. The welding strips 50 cover or partially cover the first main grid 30 and the second main grid 40, and are conductively connected to the first main grid 30 and the second main grid 40. There is at least one welding strip 50 that covers or partially covers the first main grid 30 and at least part of the first bifurcated structure 71, and is electrically connected to the first main grid 30 and the first bifurcated structure 71. There is at least one welding strip 50 that covers or partially covers the second main grid 40 and at least part of the second bifurcated structure 72, and is electrically connected to the second main grid 40 and the second bifurcated structure 72, wherein the end of the welding strip 50 is at least partially arranged inside the open rectangle 73.

[0040] In the solar cell 100 of the embodiment of the present application, the solar cell 100 includes a cell string 10, a plurality of main grids, a bifurcated structure 70 and a plurality of welding strips 50, the cell string 10 includes a plurality of cell sheets 20, the plurality of cell sheets 20 are distributed and arranged along a first direction, a plurality of main grids are arranged on the cell sheets 20, the main grids include a plurality of first main grids 30 and a plurality of second main grids 40, the first main grids 30 and the second main grids 40 extend along the first direction and are alternately arranged along the second direction, the first main grids 30 and the second main grids 40 have opposite polarities, the bifurcated structure 70 is arranged on the cell sheet 20, the bifurcated structure 70 includes a first bifurcated structure 71 and a second bifurcated structure 72, the first bifurcated structure 71 is arranged at the end of the first main grid 30 and / or the second bifurcated structure 72 is arranged at the end of the second main grid 40 The first bifurcated structure 71 and the second bifurcated structure 72 are each formed with an open rectangular shape 73. Several welding ribbons 50 are disposed on the cell 20. The welding ribbons 50 extend along the first direction and are spaced apart along the second direction. The welding ribbons 50 cover or partially cover the first busbar 30 and the second busbar 40 and are electrically connected to the first busbar 30 and the second busbar 40. At least one welding ribbon 50 covers or partially covers the first busbar 30 and at least a portion of the first bifurcated structure 71 and is electrically connected to the first busbar 30 and the first bifurcated structure 71. At least one welding ribbon 50 covers or partially covers the second busbar 40 and at least a portion of the second bifurcated structure 72 and is electrically connected to the second busbar 40 and the second bifurcated structure 72. The ends of the welding ribbons 50 are at least partially disposed within the open rectangular shape 73. In this way, the welding ribbons 50 can connect to the busbars to conduct current from the busbars. At the same time, the ends of the welding ribbons 50 are disposed within the open rectangular shape 73 to prevent the ends of the welding ribbons 50 from shorting with other components when they are free to move, thereby preventing a short circuit.

[0041] Specifically, multiple battery cells 20 are distributed along a first direction and can be interconnected to form a battery string 10. Furthermore, a first busbar 30 and a second busbar 40 are provided on the battery cells 20. In the second direction of the battery cells 20, the first busbar 30, the second busbar 40, the first busbar 30, the second busbar 40, and so on are arranged in sequence from top to bottom. This fully utilizes the space provided by the battery cells 20 in the second direction. Furthermore, the first busbar 30 and the second busbar 40 extend fully in the first direction, maximizing the space on the surface of the battery cells 20.

[0042] Furthermore, the first busbar 30 and the second busbar 40 have opposite polarities. The specific polarities represented by "first" and "second" are not limited here; they are simply used to distinguish between busbars of different polarities. In other words, the first busbar 30 can be either positive or negative, and the second busbar 40 can be either positive or negative. However, when the first busbar 30 is positive, the second busbar 40 is negative; and when the first busbar 30 is negative, the second busbar 40 is positive. Distinguishing between different polarities facilitates connections between different battery cells 20.

[0043] Furthermore, a bifurcated structure 70 is provided at the ends of both the first busbar 30 and the second busbar 40. The bifurcated structure 70 can form an open rectangular shape 73. Alternatively, a bifurcated structure 70 is provided at the end of the first busbar 30, while no bifurcated structure 70 is provided at the end of the second busbar 40. Alternatively, no bifurcated structure 70 is provided at the end of the first busbar 30, while a bifurcated structure 70 is provided at the end of the second busbar 40. The bifurcated structure 70 can be provided at one or both ends of the busbar.

[0044] Exemplarily, a bifurcated structure 70 is only provided at one end of the main grid. For example, a bifurcated structure 70 is only provided at the left end of the first main grid 30, but not at the right end; a bifurcated structure 70 is only provided at the right end of the second main grid 40, but not at the left end. Of course, in other embodiments, a bifurcated structure 70 can be provided at both ends of the main grid, so that the structure of the battery string 10 after welding is more stable. At the same time, bifurcated structures 70 are provided at both ends of the main grid, and the arrangement of the bifurcated structures 70 of each battery cell 20 is the same, so that the production process of the battery cells 20, especially the battery string 10, is simplified. However, if a bifurcated structure 70 is provided only at one end of the main grid, it is necessary to design and produce battery cells 20 with two arrangements of bifurcated structures 70. In the embodiment of the present application, the specific arrangement of the main grid and the bifurcated structure 70 is not limited to meet various needs.

[0045] In some embodiments, a welding ribbon 50 is also provided on the cell 20. The welding ribbon 50 is similar to the distribution of the main grid, extending along the first direction and arranged at intervals along the second direction. At the same time, the welding ribbon 50 covers or partially covers the first main grid 30 and the second main grid 40, and is electrically connected to the first main grid 30 and the second main grid 40. In other words, the welding ribbon 50 is electrically connected to the main grid to transmit the current collected by the main grid from the cell 20. In some cases, if the performance requirements of the cell string 10 are high, the welding ribbon 50 can be made to completely cover the first main grid 30 and the second main grid 40 to ensure that the contact area between the welding ribbon 50 and the grid line is large enough, thereby reducing resistance and loss, increasing the circuit current carrying capacity, improving the performance of the cell string 10, and avoiding the risk of desoldering. In other cases, if the performance requirements of the cell string 10 are low, the welding ribbon 50 can be made to partially cover the first main grid 30 and the second main grid 40 to save costs and reduce production costs.

[0046] In addition, the welding strip 50 covers or partially covers the main grid and the bifurcated structure 70. Depending on the degree of coverage of the welding strip 50, battery cells 20 with different welding strengths and resistances can be obtained to meet different needs. At the same time, the bifurcated structure 70 is formed with an open rectangle 73, and the end of the welding strip 50 is located inside the open rectangle 73. The force points at the ends of the welding strip 50 are concentrated in the open rectangle 73 formed by the bifurcated structure 70, reducing the force on the main grid, increasing the structural strength of the battery string 10, and reducing the problem of disconnection between the welding strip 50 and the main grid when setting the welding strip 50 or laminating. Moreover, even after the welding strip 50 is disconnected from the main grid, the range of movement of the welding strip 50 is limited to the open rectangle 73 formed by the bifurcated structure 70, reducing the possibility of short circuit.

[0047] It is understood that after the soldering ribbon 50 connects the battery cells 20 to form the battery string 10, the soldering ribbon 50 at the predetermined position needs to be cut. At this time, the cut ends of the soldering ribbon 50 can be confined within the opening rectangle 73 to avoid short circuits with fine grids of different polarities.

[0048] Example 2

[0049] See also Figures 1 to 3 In some optional embodiments, the battery cell 20 includes a first battery cell 21 and a second battery cell 22. The first busbar 30 of the first battery cell 21 and the second busbar 40 of the second battery cell 22 are arranged in a one-to-one correspondence. The welding ribbon 50 includes a first welding ribbon 51 and a second welding ribbon 52. The first welding ribbon 51 connects the first busbar 30 and the first bifurcated structure 71 of the first battery cell 21 and the second busbar 40 and the second bifurcated structure 72 of the second battery cell 22. The second welding ribbon 52 connects the first busbar 30 and the first bifurcated structure 71 of the second battery cell 22 to the to-be-connected member 60.

[0050] The two ends of the first welding strip 51 are respectively disposed within the opening rectangle 73 of the first bifurcated structure 71 and the opening rectangle 73 of the second bifurcated structure 72 .

[0051] Specifically, if the cell 20 is divided into multiple regions of equal size from top to bottom along the second direction, such as Region 1, Region 2, Region 3, Region 4, ..., the first busbar 30 and first bifurcated structure 71 of the first cell 21 can be located in odd-numbered regions (e.g., Region 1, Region 3, ...) of the first cell 21. Since the first busbar 30 of the first cell 21 and the second busbar 40 of the second cell 22 are arranged in a one-to-one correspondence, the second busbar 40 and second bifurcated structure 72 of the second cell 22 should be located in odd-numbered regions (e.g., Region 1, Region 3, ...) of the second cell 22. This makes it easier for the first welding ribbon 51 to connect the first busbar 30 and first bifurcated structure 71 of the first cell 21 and the second busbar 40 and second bifurcated structure 72 of the second cell 22, simplifying the operation steps. Furthermore, since the first busbar 30 and the second busbar 40 have opposite polarities, the first cell 21 and the second cell 22 can be connected in series via the welding ribbon 50 to form a cell string 10.

[0052] Furthermore, the first main grid 30 and the first bifurcated structure 71 of the second battery cell 22 can be located in even-numbered areas (such as area 2, area 4, etc.), and the second welding ribbon 52 connects the first main grid 30 and the first bifurcated structure 71 of the second battery cell 22 and the part to be connected 60. Similarly, the second main grid 40 and the second bifurcated structure 72 of the first battery cell 21 can also be located in even-numbered areas (such as area 2, area 4, etc.), and the second welding ribbon 52 can connect the second main grid 40 and the second bifurcated structure 72 of the first battery cell 21 and the part to be connected 60. The part to be connected 60 can be another battery cell 20, or it can be other external circuits, etc. This application does not limit the part to be connected 60 to meet various needs.

[0053] Furthermore, because the first welding ribbon 51 connects the first busbar 30 and the first bifurcated structure 71 of the first cell 21 and the second busbar 40 and the second bifurcated structure 72 of the second cell 22, and the ends of the welding ribbon 50 are disposed within the open rectangle 73 formed by the bifurcated structure 70, the two ends of the first welding ribbon 51 are respectively disposed within the open rectangle 73 of the first bifurcated structure 71 and the open rectangle 73 of the second bifurcated structure 72. Similarly, the two ends of the second welding ribbon 52 are respectively disposed within the open rectangle 73 of the first bifurcated structure 71 of the second cell 22 and on the component to be connected 60; alternatively, the two ends of the second welding ribbon 52 are respectively disposed within the open rectangle 73 of the second bifurcated structure 72 of the first cell 21 and on the component to be connected 60.

[0054] In the embodiment of the present application, the type of the connecting member 60 is not limited to meet various needs.

[0055] Example 3

[0056] See also Figure 3 In some optional embodiments, the component to be connected 60 is the second main grid 40 or bus bar 61 of another adjacent first battery cell 21 .

[0057] Specifically, the first main grid 30 on the second battery cell 22 can be connected to the second main grid 40 of another adjacent first battery cell 21 through the second welding ribbon 52, so that more battery cells 20 are connected in series on the battery string 10, thereby increasing the performance of the battery string 10. Similarly, the second main grid 40 on the first battery cell 21 can also be connected to the first main grid 30 of another adjacent second battery cell 22 through the second welding ribbon 52, thereby increasing the performance of the battery string 10. Of course, the first main grid 30 on the second battery cell 22 can also be connected to the bus bar 61 through the second welding ribbon 52; or the second main grid 40 of the first battery cell 21 can be connected to the bus bar 61 through the second welding ribbon 52. In this way, the current on the battery string 10 can be converged through the welding ribbon 50 and then through the bus bar 61, thereby connecting to the external circuit (for example, a battery, a power grid, etc.). This application does not limit the circuit connected to the bus bar 61 to meet various needs.

[0058] Example 4

[0059] See also Figure 1 、 Figure 2 and Figure 4 as well as Figure 5 In some optional embodiments, the bifurcated structure 70 includes a first straight segment 74, a second straight segment 75, a third straight segment 76, and a fourth straight segment 77. The first straight segment 74 and the second straight segment 75 are connected to the main grid and are arranged opposite to each other along the second direction. The third straight segment 76 is connected to an end of the first straight segment 74 away from the second straight segment 75 and extends along the first direction. The fourth straight segment 77 is connected to an end of the second straight segment 75 away from the first straight segment 74 and extends along the first direction.

[0060] The first straight line segment 74 , the second straight line segment 75 , the third straight line segment 76 and the fourth straight line segment 77 together define an opening rectangle 73 .

[0061] For example, the end of the main grid is connected to one end of the first straight segment 74 and one end of the second straight segment 75 of the bifurcated structure 70, and the first straight segment 74 and the second straight segment 75 extend in opposite directions along the second direction, that is, one of the first straight segment 74 and the second straight segment 75 extends upward and the other extends downward (for example, the first straight segment 74 extends upward along the second direction, and the second straight segment 75 extends downward along the second direction; or, the second straight segment 75 extends upward along the second direction, and the first straight segment 74 extends downward along the second direction). The first straight segment 74 and the second straight segment 75 are perpendicular to the main grid line, and one end of the first straight segment 74 and the second straight segment 75 is connected to one end of the main grid. The position where the three are connected will serve as a welding point to connect the welding ribbon 50 to ensure stable force during welding.

[0062] At the same time, the other end of the first straight segment 74 is connected to one end of the third straight segment 76, and the other end of the second straight segment 75 is connected to one end of the fourth straight segment 77, and the third straight segment 76 and the fourth straight segment 77 of the bifurcated structure 70 extend along the first direction away from the main grid, and the third straight segment 76 and the fourth straight segment 77 remain parallel to the main grid line. In this way, the first straight segment 74, the second straight segment 75, the third straight segment 76 and the fourth straight segment 77 can jointly limit the opening rectangle 73, so that the end of the welding ribbon 50 is welded within the opening rectangle 73, limiting the position of the end of the welding ribbon 50, and preventing the end of the welding ribbon 50 from moving freely after being desoldered and directly or indirectly connected to other main grids of opposite polarity on the same battery cell 20 to cause a short circuit. It should be noted that the above example is only used to illustrate the positional relationship between the straight segments, and does not limit the specific position and size of the straight segments to meet various needs.

[0063] In some embodiments, the first and second straight segments 74, 75 may not be perpendicular to the busbar. This is not a limitation in the embodiments of the present application, as it can meet various requirements. For example, the first and second straight segments 74, 75 may extend along a direction within the angle between the second direction and the first direction, so that after extension, the first and second straight segments 74, 75 form a certain angle, such as an acute angle, with the opposite side of the connected busbar. In this way, when the first and second straight segments 74, 75, as well as the third and fourth straight segments 76, 77, form a certain area (this area can be a triangle or trapezoidal area; the third and fourth straight segments 76, 77 may not be provided when forming a triangle), the bifurcated structure 70 can further reduce the spatial position occupied by the cell 20 in the second direction, allowing the fine grid connected to the bifurcated structure 70 to extend longer, thereby improving the photoelectric conversion efficiency of the cell 20. Of course, the first and second straight segments 74, 75 can also be connected together to form an obtuse angle; or form a single straight segment, extending along a direction within the angle between the second direction and the first direction, and not perpendicular to the busbar.

[0064] Example 5

[0065] See also Figure 1 、 Figure 4 and Figure 5 In some optional embodiments, the length of the first straight line segment 74 or the second straight line segment 75 along the second direction is greater than the length of the third straight line segment 76 or the fourth straight line segment 77 along the first direction.

[0066] In this way, after the welding ribbon 50 is cut, the distance between the outermost edge of the welding ribbon 50 and the position of the first welding point is equal to the length of the third straight line segment 76 along the first direction. At this time, it can be ensured that the free end of the welding ribbon 50 is set within the opening rectangle 73. Even if the free end of the welding ribbon 50 is bent, it will not exceed the length of the first straight line segment 74 or the second straight line segment 75 along the second direction.

[0067] Specifically, since the first and second straight segments 74 and 75 extend in the second direction, and the third and fourth straight segments 76 and 77 extend in the first direction, and the length of the first or second straight segment 74 and 75 in the second direction is greater than the length of the third or fourth straight segment 76 and 77 in the first direction, the open rectangle 73 formed by the bifurcated structure 70 has sufficient space for welding the welding ribbon 50 while reducing the impact on the length of the busbar, allowing the busbar to be arranged longer in the first direction. This can enhance the welding strength of the battery string 10 while ensuring the performance of the battery cell 20.

[0068] Example 6

[0069] See also Figures 1 to 3 In some optional embodiments, the battery cell 20 includes a plurality of fine grids, which include a plurality of first fine grids 31 and a plurality of second fine grids 41. The first fine grids 31 and the second fine grids 41 extend along the second direction and are alternately arranged along the first direction. The first fine grids 31 and the second fine grids 41 have opposite polarities. The first fine grid 31 is connected to the first main grid 30 and is disconnected at the second main grid 40. The second fine grid 41 is connected to the second main grid 40 and is disconnected at the first main grid 30.

[0070] Specifically, on the cell 20, a busbar extending in the first direction is connected to a plurality of fine grids extending in the second direction. For example, a first busbar 30 is connected to a plurality of first fine grids 41, and the plurality of first fine grids 31 may be perpendicular to the first busbar 30. In other words, a first busbar 30 may have a plurality of first fine grids 31 connected perpendicularly to the first busbar 30. Similarly, a second busbar 40 may have a plurality of second fine grids 41 connected perpendicularly to the second busbar 40.

[0071] Furthermore, in the region between adjacent first and second busbars 30 and 40, first fine gates 31 and second fine gates 41 are alternately arranged along the first direction. For example, in the region between the first and second busbars 30 and 40, the arrangement may be in the order of first fine gate 31, second fine gate 41, first fine gate 31, second fine gate 41, and so on, from left to right. One end of the first fine gate 31 is electrically connected to the first busbar 30, and the other end extends along the second direction toward the second busbar 40, stopping close to the second busbar 40 while maintaining a certain safety distance. Alternatively, the first fine gate 31 extends to the insulating layer of the second busbar 40 and stops. Similarly, one end of the second fine gate 41 is electrically connected to the second busbar 40, and the other end extends along the second direction toward the first busbar 30, stopping close to the first busbar 30 while maintaining a certain safety distance. Alternatively, the second fine gate 41 extends to the insulating layer of the first busbar 30 and stops. The insulating layer can be made of a variety of materials, such as polymers, glass, or ceramics, and can also be made of different types of insulating materials, such as gas insulation, liquid insulation, or solid insulation. The present embodiment does not limit the material and type of the insulating layer between the fine grid and the profiled main grid to meet various needs.

[0072] Furthermore, both the first busbar 30 and the second busbar 40 are connected to thin gates of the same polarity. For example, the first busbar 30 and the first thin gate 31 have the same polarity, and the first thin gate 31 can be installed on both sides of the first busbar 30. For example, the first thin gate 31 can be arranged to penetrate the first busbar 30 and be electrically connected to the first busbar 30 in the middle. The lengths of the first thin gates 31 on both sides of the first busbar 30 can be the same or different. Similarly, the second busbar 40 and the second thin gate 41 have the same polarity, and the second busbar 40 can also be provided with the second thin gate 41. The second thin gate 41 can also penetrate the second busbar 40 and be electrically connected to the second busbar 40 in the middle. The lengths of the second thin gates 41 on both sides of the second busbar 40 can be the same or different. In this way, the connection of multiple thin gates of the same polarity to the busbar increases the photoelectric conversion efficiency. Furthermore, the number of first thin gates 31 connected to the first busbar 30 can be the same, and the number of second thin gates 41 connected to the second busbar 40 can be equal. The above-mentioned through-going fine gates can simplify the process flow. Of course, in other requirements, the fine gates on both sides of the main gate can be not through-going, but can extend from the main gate along the second direction to both sides. This is not limited in the embodiments of this application to meet various requirements.

[0073] Example 7

[0074] See also Figure 2 and Figure 6In some optional embodiments, there is at least one first fine gate 31 electrically connected to the first bifurcated structure 71 and avoiding the second bifurcated structure 72 , and there is at least one second fine gate 41 electrically connected to the second bifurcated structure 72 and avoiding the first bifurcated structure 71 .

[0075] Specifically, a fine gate is also provided on the bifurcated structure 70 connected to the main gate, and the fine gate has the same polarity as the main gate connected to the bifurcated structure 70. In other words, the connection path of the fine gate can be the first main gate 30 connected to the first bifurcated structure 71 connected to the first fine gate 31, and the three have the same polarity; or, the second main gate 40 connected to the second bifurcated structure 72 connected to the second fine gate 41, and the three also have the same polarity. There can be only one fine gate connected to a bifurcated structure 70, or there can be multiple fine gates. There is at least one first fine gate 31 connected to the first bifurcated structure 71 connected to the first main gate 30, and the first fine gate 31 connected to the first bifurcated structure 71 extends along the second direction toward the second bifurcated structure 72 connected to the second main gate 40, and stops at a position close to the second bifurcated structure 72 and leaving a certain safety distance. At the same time, there is at least one second fine grid 41 connected to the second bifurcated structure 72 and the second main grid 40. The second fine grid 41 connected to the second bifurcated structure 72 extends along the second direction toward the first bifurcated structure 71 connected to the first main grid 30, and stops at a position close to the first bifurcated structure 71 and leaving a certain safe distance. In this way, the space in the battery cell 20 can be fully utilized to install more fine grids, thereby ensuring the performance of the battery cell 20.

[0076] Example 8

[0077] See also Figure 1 、 Figure 4 and Figure 6 In some optional embodiments, the length of the first fine gate 31 connected to the first bifurcated structure 71 is shorter than the length of the first fine gate 31 connected to the first main gate 30 ;

[0078] The length of the second fine gate 41 connected to the second bifurcated structure 72 is shorter than the length of the second fine gate 41 connected to the second main gate 40 .

[0079] Specifically, because the open rectangle 73 formed by the bifurcated structure 70 occupies a certain position in the second direction, it occupies the extension space of the fine grid connected to the bifurcated structure 70 in the second direction, resulting in the length of the fine grid connected to the bifurcated structure 70 being shorter than the fine grid directly connected to the main grid. In other words, the distance between the first bifurcated structure 71 and the second main grid 40 adjacent in the second direction is shorter than the distance between the first main grid 30 and the second main grid 40 connected to the first bifurcated structure 71 in the second direction, resulting in the fine grid connected to the bifurcated structure 70 having less extension space than the fine grid directly connected to the main grid.

[0080] For example, there is at least one first fine grid 31 connected to the first bifurcated structure 71 and the first main grid 30. The first fine grid 31 connected to the first bifurcated structure 71 extends along the second direction toward the second main grid 40, and stops at a position close to the second main grid 40 and a certain safety distance. At the same time, there is at least one second fine grid 41 connected to the second bifurcated structure 72 and the second main grid 40. The second fine grid 41 connected to the second bifurcated structure 72 extends along the first direction toward the first main grid 30, and stops at a position close to the first main grid 30 and a certain safety distance. This allows the space in the cell 20 to be fully utilized to install more fine grids, thereby ensuring the performance of the cell 20.

[0081] Embodiment 9

[0082] See also Figure 2 and Figure 6 In some optional embodiments, the width of the first bifurcated structure along the second direction is smaller than the distance between adjacent second main grids;

[0083] The width of the second bifurcated structure along the second direction is smaller than the distance between adjacent first main grids.

[0084] In this way, a short circuit caused by the connection between the bifurcated structure 70 and the opposite-sex main grid can be avoided, thereby ensuring the performance of the battery cell 20 .

[0085] Specifically, the bifurcated structure 70 includes a first straight segment 74 and a second straight segment 75 in the second direction. The first straight segment 74 and the second straight segment 75 extend in opposite directions in the second direction and have the same extension length. The total extension length of the first straight segment 74 and the second straight segment 75 should be less than the distance between the adjacent first busbar 30 and the second busbar 40. For example, the second straight segment 75 of the first bifurcated structure 71 extends along the second direction toward the adjacent second busbar 40, and the extension length is less than half of the distance between the adjacent first busbar 30 and the second busbar 40. The first straight segment 74 of the second bifurcated structure 72 extends along the second direction toward the adjacent first busbar 30, and the extension length is less than half of the distance between the adjacent first busbar 30 and the second busbar 40. In the embodiments of the present application, only the total length of the first and second straight segments 74 and 75 of the bifurcated structure 70 in the second direction must be less than the distance between the adjacent first busbar 30 and the second busbar 40. The specific extension lengths of the first and second straight segments 74 and 75 are not limited to meet various requirements.

[0086] Example 10

[0087] See also Figure 1 、 Figure 3 and Figure 5 In some optional embodiments, the solar cell 100 further includes a pad structure 80 , which is disposed within the bifurcated structure 70 .

[0088] Specifically, a soldering pad structure 80 is provided within the open rectangular portion 73 formed by the bifurcated structure 70. The end of the soldering ribbon 50 can be soldered to the soldering pad within the open rectangular portion 73. This provides a stable soldering surface for the soldering ribbon 50, which is then tightly bonded to the soldering pad through welding, forming a secure connection. The combined use of the soldering pad and soldering ribbon 50 can enhance the post-weld bonding strength of the different cell cells 20, improve the reliability of the battery string 10, and further reduce stress-induced short circuits caused by the soldering ribbon 50 becoming loose and detached.

[0089] Example 11

[0090] See also Figure 1 and Figure 7 The battery assembly 200 provided in the embodiment of the present application includes the solar cell 100 of any one of the above embodiments.

[0091] It is understood that in such an embodiment, the battery assembly 200 may further include a frame, a backplane, photovoltaic glass, and an adhesive film. The adhesive film may be filled between the front and back surfaces of the battery cells 20 and between the photovoltaic glass and adjacent battery cells 20. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be EVA film or POE film. The specific selection can be based on actual conditions and is not limited here.

[0092] Photovoltaic glass can cover the adhesive film on the front of the cell 20. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, ultra-clear glass can have a light transmittance of over 92%, protecting the cell 20 while minimizing the impact on its efficiency. The adhesive film also bonds the photovoltaic glass and cell 20 together, providing sealing, insulation, and waterproofing of the cell 20.

[0093] The backsheet can be attached to the film on the back of the cell 20. The backsheet can protect and support the cell 20 and has reliable insulation, water resistance, and aging resistance. There are multiple options for the backsheet, typically tempered glass, organic glass, aluminum alloy TPT composite film, etc. The specific configuration can be based on the specific situation and is not limited here. The entire structure consisting of the backsheet, cell 20, film, and photovoltaic glass can be placed on a frame. The frame serves as the main external support structure for the entire battery assembly 200 and can provide stable support and installation for the battery assembly 200. For example, the battery assembly 200 can be installed in the desired location via the frame.

[0094] Example 12

[0095] See also Figure 1、 Figure 7 and Figure 8 The photovoltaic system 300 provided in the embodiment of the present application includes the solar cell 100 of the above embodiment.

[0096] In the solar cell 100, the battery assembly 200 and the photovoltaic system 300 of the embodiment of the present application, the solar cell 100 includes a battery string 10, a plurality of main grids, a bifurcated structure 70 and a plurality of welding strips 50, the battery string 10 includes a plurality of battery cells 20, the plurality of battery cells 20 are distributed along a first direction, the plurality of main grids are arranged on the battery cells 20, the main grids include a plurality of first main grids 30 and a plurality of second main grids 40, the first main grids 30 and the second main grids 40 extend along the first direction and are alternately arranged along the second direction, the first main grids 30 and the second main grids 40 have opposite polarities, the bifurcated structure 70 is arranged on the battery cell 20, the bifurcated structure 70 includes a first bifurcated structure 71 and a second bifurcated structure 72, the first bifurcated structure 71 is arranged at the end of the first main grid 30 and / or the second bifurcated structure 72 is arranged at the end of the first main grid 30 The ends of the second busbar 40, the first bifurcated structure 71, and the second bifurcated structure 72 are each formed with an open rectangular shape 73. Several welding ribbons 50 are disposed on the cell 20. The welding ribbons 50 extend along a first direction and are spaced apart along a second direction. The welding ribbons 50 cover or partially cover the first busbar 30 and the second busbar 40 and are electrically connected to the first busbar 30 and the second busbar 40. At least one welding ribbon 50 covers or partially covers the first busbar 30 and at least a portion of the first bifurcated structure 71 and is electrically connected to the first busbar 30 and the first bifurcated structure 71. At least one welding ribbon 50 covers or partially covers the second busbar 40 and at least a portion of the second bifurcated structure 72 and is electrically connected to the second busbar 40 and the second bifurcated structure 72. The ends of the welding ribbons 50 are at least partially disposed within the open rectangular shape 73. In this manner, the welding ribbons 50 can connect to the busbar to conduct current from the busbar. Furthermore, the ends of the welding ribbons 50 are disposed within the open rectangular shape 73 to prevent the ends of the welding ribbons 50 from shorting to other components when they are free to move, thereby preventing them from causing a short circuit.

[0097] In this embodiment, the photovoltaic system 300 can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of the photovoltaic system 300 are not limited to this, that is, the photovoltaic system 300 can be applied to all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system 300 may include a photovoltaic array, a junction box, and an inverter. The photovoltaic array can be an array combination of multiple battery modules 200. For example, multiple battery modules 200 can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box, which can combine the current generated by the photovoltaic array. The combined current flows through the inverter to convert it into the alternating current required by the mains power grid and then connects to the mains power network to achieve solar power supply.

[0098] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0099] In addition, the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A solar cell, characterized in that: include: A battery string includes a plurality of battery cells, wherein the plurality of battery cells are distributed along a first direction; A plurality of main grids are provided on the battery cell, wherein the main grids include a plurality of first main grids and a plurality of second main grids, wherein the first main grids and the second main grids extend along the first direction and are alternately provided along the second direction, and the first main grids and the second main grids have opposite polarities; a bifurcated structure provided on the battery cell, the bifurcated structure including a first bifurcated structure and a second bifurcated structure, the first bifurcated structure being provided at an end of the first main grid and / or the second bifurcated structure being provided at an end of the second main grid, and both the first bifurcated structure and the second bifurcated structure being formed into an open rectangle; A plurality of welding strips are provided on the solar cell, the welding strips extend along the first direction and are arranged at intervals along the second direction, the welding strips cover or partially cover the first busbar and the second busbar, and are conductively connected to the first busbar and the second busbar; There is at least one welding ribbon covering or partially covering the first busbar and at least part of the first bifurcated structure, and electrically connected to the first busbar and the first bifurcated structure; there is at least one welding ribbon covering or partially covering the second busbar and at least part of the second bifurcated structure, and electrically connected to the second busbar and the second bifurcated structure; Wherein, the end portion of the welding strip is at least partially arranged inside the opening rectangle.

2. The solar cell according to claim 1, wherein The battery cell includes a first battery cell and a second battery cell, the first busbar of the first battery cell and the second busbar of the second battery cell are arranged in a one-to-one correspondence, the welding ribbon includes a first welding ribbon and a second welding ribbon, the first welding ribbon connects the first busbar and the first bifurcated structure of the first battery cell and the second busbar and the second bifurcated structure of the second battery cell, and the second welding ribbon connects the first busbar and the first bifurcated structure of the second battery cell to a component to be connected; Wherein, the two ends of the first welding strip are respectively arranged in the opening rectangle of the first forked structure and the opening rectangle of the second forked structure.

3. The solar cell according to claim 2, wherein The component to be connected is the second main grid or bus bar of another adjacent first battery cell.

4. The solar cell according to claim 1, wherein The bifurcated structure includes a first straight segment, a second straight segment, a third straight segment, and a fourth straight segment, wherein the first straight segment and the second straight segment are connected to the main grid and are arranged opposite to each other along the second direction, the third straight segment is connected to an end of the first straight segment away from the second straight segment and extends along the first direction, and the fourth straight segment is connected to an end of the second straight segment away from the first straight segment and extends along the first direction; The first straight line segment, the second straight line segment, the third straight line segment, and the fourth straight line segment together define the open rectangle.

5. The solar cell according to claim 4, wherein A length of the first straight line segment or the second straight line segment along the second direction is greater than a length of the third straight line segment or the fourth straight line segment along the first direction.

6. The solar cell according to claim 1, wherein The battery cell includes a plurality of fine grids, which include a plurality of first fine grids and a plurality of second fine grids. The first fine grids and the second fine grids extend along the second direction and are alternately arranged along the first direction. The first fine grids and the second fine grids have opposite polarities. The first fine grids are connected to the first main grid and disconnected at the second main grid. The second fine grids are connected to the second main grid and disconnected at the first main grid.

7. The solar cell according to claim 6, characterized in that There is at least one first fine gate electrically connected to the first bifurcated structure and avoiding the second bifurcated structure, and there is at least one second fine gate electrically connected to the second bifurcated structure and avoiding the first bifurcated structure.

8. The solar cell according to claim 7, characterized in that The length of the first fine gate extending to connect the first bifurcated structure is shorter than the length of the first fine gate extending to connect the first main gate; The length of the second fine gate extending to connect the second bifurcated structure is shorter than the length of the second fine gate extending to connect the second main gate.

9. The solar cell according to claim 7, wherein: The width of the first bifurcated structure along the second direction is smaller than the distance between adjacent second main grids; A width of the second bifurcated structure along the second direction is smaller than a distance between adjacent first main gates.

10. The solar cell according to claim 1, wherein The solar cell further includes a pad structure, and the pad structure is disposed in the bifurcated structure.

11. A battery assembly, characterized in that: The solar cell comprises the solar cell according to any one of claims 1 to 10.

12. A photovoltaic system, characterized in that: Comprising the battery assembly as claimed in claim 11.

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