Solar cell, cell string, 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 string, a cell module and a photovoltaic system. The solar cell comprises a cell substrate, a first fine grid, a second fine grid, a confluence structure and a first bending structure, the confluence structure is arranged on the cell substrate, at least part of the first fine grid is connected with the confluence structure, and the first bending structure is connected with the first fine grid and the confluence structure. The first bending structure extends along the first direction and is at least partially bent towards the second direction, and the width of the contact part of the confluence structure and the first bending structure in the second direction is greater than the width of the first fine grid in the second direction. Therefore, the first fine grid and the confluence structure are connected through the first bending structure, so that the confluence structure has a certain movement margin on the plane of the cell substrate. And the width of the contact part of the first bending structure and the confluence structure in the second direction is greater than that of the first fine grid in the second direction, so that the connection stability is further improved.

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 string, a battery assembly and a photovoltaic system. Background Art

[0002] At present, solar cells are semiconductor devices that directly convert sunlight energy into electrical energy. Solar cells use the photovoltaic effect to excite electrons by absorbing photons, and then conduct these electrons to generate current through a built-in electric field. At this time, the grid line 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 position between the grid line and the pad, and the grid line is often broken at this point when setting the welding strip or laminating. Utility Model Content

[0003] The embodiments of the present application provide a solar cell, a cell string, a cell assembly and a photovoltaic system, which are intended to solve the problem that fine grids and pads of photovoltaic cells are easily disconnected during the preparation and use of the photovoltaic cells.

[0004] An embodiment of the present application provides a solar cell, which includes a cell substrate, a first fine grid, a second fine grid, a bus structure and a first bending structure, wherein the first fine grid is arranged on the cell substrate, the first fine grid extends along a first direction, the second fine grid is arranged on the cell substrate, the first fine grid and the second fine grid are arranged along a second direction, the bus structure is arranged on the cell substrate, the first fine grid is at least partially connected to the bus structure, the first bending structure connects the first fine grid and the bus structure, the first bending structure extends along the first direction and is at least partially bent in the second direction, and the width of the contact portion between the bus structure and the first bending structure in the second direction is greater than the width of the first fine grid in the second direction.

[0005] In the solar cell according to the embodiment of the present application, the solar cell includes a cell substrate, a first fine grid, a second fine grid, a busbar structure, and a first bending structure. The first fine grid is disposed on the cell substrate and extends along a first direction. The second fine grid is disposed on the cell substrate, and the first fine grid and the second fine grid are arranged along a second direction. The busbar structure is disposed on the cell substrate, and at least a part of the first fine grid is connected to the busbar structure. The first bending structure connects the first fine grid and the busbar structure, extends along the first direction and is at least partially bent in the second direction. The width of the contact portion between the busbar structure and the first bending structure in the second direction is greater than the width of the first fine grid in the second direction. Thus, the first fine grid and the busbar structure are connected by the first bending structure, so that the busbar structure has a certain movement margin on the plane of the cell substrate. The first bending structure can elastically change when the solder ribbon is connected to the busbar structure to ensure stable connection. At the same time, the width of the contact portion between the first bending structure and the busbar structure in the second direction is greater than the width of the first fine grid in the second direction, further improving the connection stability and avoiding stress concentration from breaking the first fine grid.

[0006] Further, the maximum bending distance of the first bending structure relative to the first fine grid in the second direction is 100 μm - 400 μm.

[0007] Further, the height of the first bending structure in a third direction, where the third direction is perpendicular to both the first direction and the second direction, is 35 μm - 200 μm.

[0008] Further, the solar cell further includes a second fine grid and a third fine grid disposed on the cell substrate. The second fine grid, the first fine grid, and the third fine grid all extend along the first direction and are arranged along the second direction. In the second direction, the second fine grid and the third fine grid are adjacent to the first fine grid.

[0009] The first bending structure includes a first bending section and a second bending section. The first bending section is bent relative to the first fine grid in a direction close to the second fine grid, and the second bending section is bent relative to the first fine grid in a direction close to the third fine grid.

[0010] Further, the maximum bending distance of the first bending section relative to the first fine grid in the second direction is less than the distance between the first fine grid and the second fine grid.

[0011] The maximum bending distance of the second bending section relative to the first fine grid in the second direction is less than the distance between the first fine grid and the third fine grid.

[0012] Further, the plurality of first bending segments and the plurality of second bending segments are alternately arranged along the first direction.

[0013] Further, the first bending structure is wavy.

[0014] Further, the solar cell further includes main grid lines disposed on the cell substrate, the current collecting structure is formed on the main grid lines, and a plurality of the main grid lines extend along the second direction and are distributed along the first direction;

[0015] The first fine grid is connected to the main grid line or the current collecting structure;

[0016] The second fine grid and the third fine grid are disconnected at the main grid line.

[0017] Further, the solar cell further includes a second bending structure, the second bending structure connects the main grid line and the current collecting structure, and the second bending structure extends along the second direction and is at least partially bent toward the first direction.

[0018] Further, the maximum bending distance of the second bending structure relative to the main grid line in the first direction is 100 μm - 400 μm;

[0019] The height of the second bending structure in the third direction is 35 μm - 200 μm, where the third direction is perpendicular to both the first direction and the second direction.

[0020] The battery string provided by the embodiment of the present application includes the solar cell as described in any one of the above embodiments.

[0021] The battery module provided by the embodiment of the present application includes the battery string as described in the above embodiment.

[0022] The photovoltaic system provided by the embodiment of the present application includes the battery module as described in the above embodiment.

[0023] In the solar cell, cell string, solar module, and photovoltaic system according to the embodiments of the present application, the solar cell includes a cell substrate, a first fine grid, a second fine grid, a busbar structure, and a first bending structure. The first fine grid is disposed on the cell substrate and extends along a first direction. The second fine grid is disposed on the cell substrate, and the first fine grid and the second fine grid are arranged along a second direction. The busbar structure is disposed on the cell substrate, and at least a part of the first fine grid is connected to the busbar structure. The first bending structure connects the first fine grid and the busbar structure, extends along the first direction, and is at least partially bent toward the second direction. The width of the contact portion between the busbar structure and the first bending structure in the second direction is greater than the width of the first fine grid in the second direction. In this way, the first fine grid and the busbar structure are connected by the first bending structure, so that the busbar structure has a certain margin of movement on the plane of the cell substrate. The first bending structure can elastically change when the solder ribbon is connected to the busbar structure to ensure stable connection. At the same time, the width of the contact portion between the first bending structure and the busbar structure in the second direction is greater than the width of the first fine grid in the second direction, further improving the connection stability and avoiding stress concentration from breaking the first fine grid. Description of the Drawings

[0024] Figure 1 is a partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0025] Figure 2 is another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0026] Figure 3 is yet another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0027] Figure 4 is still another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0028] Figure 5 is still another partial structural schematic diagram of a solar cell according to an embodiment of the present application;

[0029] Figure 6 is a module structural schematic diagram of a cell string according to an embodiment of the present application;

[0030] Figure 7 is a module structural schematic diagram of a solar module according to an embodiment of the present application;

[0031] Figure 8 is a module structural schematic diagram of a photovoltaic system according to an embodiment of the present application.

[0032] Main Element Symbol Description:

[0033] Solar cell 100, cell substrate 10, first fine grid 20, second fine grid 30, third fine grid 40, busbar structure 50, first bending structure 60, first bending section 61, second bending section 62, main grid line 70, second bending structure 80, battery string 200, battery module 300, photovoltaic system 400. Detailed implementation manners

[0034] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0037] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection or a communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0038] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0040] In the related art, solar cells utilize the photovoltaic effect to excite electrons by absorbing photons, and conduct these electrons to generate current through a built-in electric field. However, stress concentration is prone to occur at the connection position between the grid line and the pad, and the grid line is often broken at this point when the welding strip is set or the lamination process is performed. In the embodiment of the present application, the first fine grid and the bus structure are connected by a first bending structure, so that the bus structure has a certain movement margin on the plane of the battery cell substrate, and the first bending structure can change elastically when the welding strip is connected to the bus structure to ensure a stable connection; at the same time, the width of the contact portion of the first bending structure with the bus structure in the second direction is greater than the width of the first fine grid in the second direction, which further improves the connection stability and avoids stress concentration from breaking the first fine grid.

[0041] Embodiment 1

[0042] See also Figure 1 , Figure 2 and Figure 3, a solar cell 100 provided by an embodiment of the present application, the solar cell 100 includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50, and a first bending structure 60. The first fine grid 20 is disposed on the cell substrate 10 and extends along a first direction. The second fine grid 30 is disposed on the cell substrate 10. The first fine grid 20 and the second fine grid 30 are disposed along a second direction. The busbar structure 50 is disposed on the cell substrate 10. At least a part of the first fine grid 20 is connected to the busbar structure 50. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50. The first bending structure 60 extends along the first direction and is at least partially bent toward the second direction. The width of the contact portion between the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction.

[0043] In the solar cell 100 of the embodiment of the present application, the solar cell 100 includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50, and a first bending structure 60. The first fine grid 20 is disposed on the cell substrate 10 and extends along a first direction. The second fine grid 30 is disposed on the cell substrate 10. The first fine grid 20 and the second fine grid 30 are disposed along a second direction. The busbar structure 50 is disposed on the cell substrate 10. At least a part of the first fine grid 20 is connected to the busbar structure 50. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50. The first bending structure 60 extends along the first direction and is at least partially bent toward the second direction. The width of the contact portion between the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. Thus, the first fine grid 20 and the busbar structure 50 are connected by the first bending structure 60, so that the busbar structure 50 has a certain movement margin on the plane of the cell substrate 10. The first bending structure 60 can elastically change when the solder strip is connected to the busbar structure 50 to ensure stable connection. At the same time, the width of the contact portion between the first bending structure 60 and the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, further improving the connection stability and avoiding stress concentration from breaking the first fine grid 20.

[0044] Specifically, the first fine grid 20 and the busbar structure 50 are connected by the first bending structure 60, so that the busbar structure 50 has a certain movement margin on the plane of the cell substrate 10. That is to say, when the busbar structure 50 moves slightly relative to the cell substrate 10, it can pull the first bending structure 60 to elastically change and move slightly to avoid breaking the connection between the first fine grid 20 and the busbar structure 50 during the process preparation, thereby improving the connection stability.

[0045] Further, in the second direction, the width of the bus bar structure 50 is greater than the widths of the first bending structure 60 and the first fine grid 20. Since the first bending structure 60 bends downward in the second direction relative to the first fine grid 20, that is to say, the first bending structure 60 has a certain slope relative to the first fine grid 20. In this way, the width of the contact portion between the bus bar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. The first bending structure 60 and the bus bar structure 50 have a larger connection area, which can improve the connection stability between the first bending structure 60 and the bus bar structure 50, eliminate the problem of stress concentration, and avoid the first fine grid 20 being broken by stress concentration.

[0046] It can be understood that when the first fine grid 20, the bus bar structure 50, and the first bending structure 60 are arranged on the battery substrate 10, the relative positions of the first fine grid 20, the bus bar structure 50, and the first bending structure 60 and the battery substrate 10 do not change. However, during the connection process between the bus bar structure 50 and the solder strip, stress concentration often occurs, causing a relative movement tendency of the bus bar structure 50 relative to the first fine grid 20. At this time, at least part of the first bending structure 60 has a slope with the first fine grid 20 and is connected to the bus bar structure 50, and can move slightly with the bus bar structure 50. In this way, the slight movement distance of the first bending structure 60 relative to the battery substrate 10 is very small, and the problem of stress concentration can be eliminated. At the same time, the first bending structure 60 and the bus bar structure 50 have a larger connection area, which can effectively reduce the tensile pressure and further avoid the problem of stress concentration.

[0047] Furthermore, during the welding and lamination processes of the battery substrate 10, the first bending structure 60 effectively disperses stress, reduces the risk of fine grid fracture, thereby improving the overall reliability and service life of the solar cell 100. It not only improves the mechanical performance of the solar cell 100, but also improves the electrical performance of the solar cell 100, ensuring higher power generation efficiency and longer service life.

[0048] In the embodiment of the present application, the polarities of the first fine grid 20 and the second fine grid 30 are not limited, and the polarities of the first fine grid 20 and the second fine grid 30 are opposite to each other to meet different requirements. Exemplarily, the first fine grid 20 is a positive grid line, the second fine grid 30 is a negative grid line, the first fine grid 20 can be connected to the bus bar structure 50, and the bus bar structure 50 can be connected to the solder strip to connect to an external load, thereby realizing the power generation operation. The solder strip can be connected to multiple bus bar structures 50, thereby converging the currents of multiple first fine grids 20. Of course, it can also be that the first fine grid 20 is a negative grid line and the second fine grid 30 is a positive grid line.

[0049] It can be understood that the "first" and "second" in the first fine grid 20 and the second fine grid 30 are relative concepts, indicating that the two grid lines are different.

[0050] In addition, in the embodiments of the present application, the specific material type of the first bending structure 60 is not limited to meet different requirements. In one example, the first bending structure 60 may be a part of the busbar structure 50. That is to say, when the busbar structure 50 is prepared on the battery substrate 10, the first bending structure 60 is prepared at the same time, and the first bending structure 60 is made of the same material as the busbar structure 50. When the busbar structure 50 is solder paste, the first bending structure 60 can be made of solder paste, further increasing the connection stability between the first bending structure 60 and the busbar structure 50. In another example, the first bending structure 60 may be a part of the first fine grid 20. That is to say, when the first fine grid 20 is prepared on the battery substrate 10, the first bending structure 60 is prepared at the same time, and the first bending structure 60 is made of the same material as the first fine grid 20.

[0051] In this embodiment, the solar cell 100 may be a main-gridless cell. The fine grid directly conducts the current to the solder strip through the busbar structure 50, and the solder strip conducts the current to an external load to perform the power generation operation.

[0052] In addition, in the embodiments of the present application, the corresponding relationship between the first fine grid 20 and the first bending structure 60 is not limited. For example, some of the first fine grids 20 are not connected to the busbar structure 50, so the first bending structure 60 is not provided at the end of this part of the first fine grid 20 to meet different requirements.

[0053] In some embodiments, the first bending structure 60 may be selectively provided at the ends of some of the first fine grids 20, and the first bending structure 60 is not provided at the ends of the other part of the first fine grids 20. In other embodiments, the first bending structure 60 may be provided at one end of the first fine grid 20, and not provided at the other end. In still other embodiments, the first bending structure 60 may be provided at both ends of all of the first fine grids 20.

[0054] Embodiment 2

[0055] Please refer to Figure 1 and Figure 2, in some alternative embodiments, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction is 100 μm - 400 μm. For example, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm.

[0056] In this way, setting the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 within this range can not only ensure that the busbar structure 50 has a margin of movement to avoid disconnection between the busbar structure 50 and the first bending structure 60, but also prevent the first bending structure 60 from affecting other fine grids.

[0057] Exemplarily, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction can be 200 μm, which can not only ensure that the busbar structure 50 has sufficient movement margin to avoid disconnection between the busbar structure 50 and the first bending structure 60 due to stress or external force, but also effectively prevent the first bending structure 60 from interfering with or affecting adjacent fine grids.

[0058] Furthermore, during the process of process preparation, the solder tape needs to be welded to the busbar structure 50, so that the solder tape connects multiple first fine grids 20 to achieve current convergence. However, during the connection process between the solder tape and the busbar structure 50, the problem of stress concentration often occurs, and even leads to the problem of fracture or disconnection at the connection between the first fine grid 20 and the busbar structure 50. The busbar structure 50 of the embodiment of the present application can be connected to the first fine grid 20 through the first bending structure 60, ensuring the flexibility and adaptability of the busbar structure 50 on the battery substrate 10 and improving the connection stability between the first fine grid 20 and the busbar structure 50. In this way, by reasonably controlling the bending distance of the first bending structure 60, the mechanical strength and flexibility of the connection part with the busbar structure 50 can be better balanced, thereby improving the reliability during the welding and use processes and extending the service life of the solar cell 100.

[0059] Of course, the distance between the first fine grid 20 and the second fine grid 30 should be greater than the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction to avoid the problem of short circuit.

[0060] Embodiment III

[0061] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the height of the first bending structure 60 in the third direction is 35 μm - 200 μm, where the third direction is perpendicular to both the first direction and the second direction. For example, the height of the first bending structure 60 in the third direction can be 35 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm.

[0062] In this way, by setting the height of the first bending structure 60 relative to the battery cell substrate 10 in the third direction within this range, the stable connection between the first fine grid 20 and the busbar structure 50 can be ensured, and the influence of the too-high height of the first bending structure 60 on the thickness of the battery module 300 can be avoided.

[0063] Exemplarily, the height of the first bending structure 60 in the third direction can be 80 μm. By setting the first bending structure 60 at this height, the connection stability between the first fine grid 20 and the busbar structure 50 can be ensured, and the influence of the too-high height of the first bending structure 60 on the overall thickness of the battery module 300 can be avoided.

[0064] Furthermore, the height of the first fine grid 20 in the third direction can also be 35 μm - 200 μm. The heights of the first fine grid 20 and the first bending structure 60 in the third direction can be the same to ensure the connection stability between the first fine grid 20 and the first bending structure 60. In this embodiment, the heights of the first fine grid 20 and the first bending structure 60 in the third direction can both be 80 μm, which can minimize the influence on the thickness of the battery module 300 while ensuring the mechanical connection reliability, and contribute to optimizing the overall performance and appearance of the battery module 300.

[0065] Embodiment Four

[0066] Please refer to Figure 1 and Figure 2 In some alternative embodiments, the solar cell 100 further includes a second fine grid 30 and a third fine grid 40 disposed on the battery cell substrate 10. The second fine grid 30, the first fine grid 20, and the third fine grid 40 all extend along the first direction and are arranged along the second direction. In the second direction, the second fine grid 30 and the third fine grid 40 are adjacent to the first fine grid 20;

[0067] The first bending structure 60 includes a first bending segment 61 and a second bending segment 62. The first bending segment 61 bends relative to the first fine grid 20 in a direction approaching the second fine grid 30, and the second bending segment 62 bends relative to the first fine grid 20 in a direction approaching the third fine grid 40.

[0068] In this way, the second fine grid 30 and the third fine grid 40 are respectively arranged on both sides of the first fine grid 20. The segment of the first bending structure 60 that approaches the second fine grid 30 relative to the first fine grid 20 is the first bending segment 61, and the segment that approaches the third fine grid 40 relative to the first fine grid 20 is the second bending segment 62. At the same time, the first bending segment 61 and the second bending segment 62 can be alternately connected. In this way, without increasing the maximum bending distance in the second direction, the movement margin of the first bending structure 60 on the plane of the battery substrate 10 can be improved, ensuring the stable connection between the busbar structure 50 and the first fine grid 20.

[0069] In this embodiment, the second fine grid 30 and the third fine grid 40 can be respectively arranged on both sides of the first fine grid 20 and are adjacent to each other. The first bending structure 60 is composed of a first bending segment 61 and a second bending segment 62. Among them, the first bending segment 61 bends relative to the first fine grid 20 in a direction approaching the second fine grid 30, and the second bending segment 62 bends relative to the first fine grid 20 in a direction approaching the third fine grid 40. Dividing the first bending structure 60 into the first bending segment 61 and the second bending segment 62 can increase the bending length of the first bending structure 60 and avoid affecting other fine grids.

[0070] In an example, the first fine grid 20 is a positive electrode fine grid. At this time, both the second fine grid 30 and the third fine grid 40 are negative electrode fine grids. In this way, the positive electrode fine grid and the negative electrode fine grid can be alternately arranged along the second direction. In addition, the first fine grid 20, the second fine grid 30, and the third fine grid 40 only define the relative positional relationship. For example, please refer to Figure 1 ., the number of the first fine grid 20, the second fine grid 30, and the third fine grid 40 is multiple. In such a case, the second fine grid 30 is above the first first fine grid 20, and the fine grid below the first first fine grid 20 is the third fine grid 40, and this fine grid is also the second fine grid 30 of the second first fine grid 20, and so on, forming a form of alternately arranging one positive electrode fine grid and one negative electrode fine grid.

[0071] Embodiment Five

[0072] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, the maximum bending distance of the first bending segment 61 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the second fine grid 30;

[0073] The maximum bending distance of the second bending section 62 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the third fine grid 40.

[0074] In this way, the first bending structure 60 is connected between the first fine grid 20 and the busbar structure 50. At the same time, the maximum bending distances of the first bending section 61 and the second bending section 62 are less than the distances from other fine grids, which can prevent the first bending section 61 and the second bending section 62 from being short-circuited with other fine grids and improve the connection stability between the first fine grid 20 and the busbar structure 50.

[0075] Specifically, the maximum bending distance of the first bending section 61 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the second fine grid 30; the maximum bending distance of the second bending section 62 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the third fine grid 40. In this way, not only the possibility of short-circuit between the bending section and other fine grids is avoided, but also the connection stability between the first fine grid 20 and the busbar structure 50 is enhanced, and the range of the movement margin of the busbar structure 50 is increased, which helps to improve the structural reliability and electrical conductivity of the overall solar cell.

[0076] Of course, in other embodiments, insulating glue can be provided between the first bending structure 60 and the second fine grid 30, and at the same time, insulating glue can be provided between the first bending structure 60 and the third fine grid 40. In this way, the first fine grid 20 can be prevented from being short-circuited with other fine grids through the first bending structure 60.

[0077] Embodiment Six

[0078] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, a plurality of first bending sections 61 and a plurality of second bending sections 62 are alternately arranged along the first direction.

[0079] In this way, a plurality of first bending sections 61 and a plurality of second bending sections 62 are alternately arranged along the first direction, which increases the movement margin of the busbar structure 50 while avoiding short-circuiting with other fine grids, thereby ensuring stable connection between the first fine grid 20 and the busbar structure 50.

[0080] Exemplarily, the number of the first bending segments 61 and the second bending segments 62 is two each. When the first fine grid 20 approaches the bus bar structure 50, the first of the first bending segments 61 is connected to the first of the second bending segments 62, the first of the second bending segments 62 is then connected to the second of the first bending segments 61, the second of the first bending segments 61 is then connected to the second of the second bending segments 62, and the second of the second bending segments 62 is finally connected to the bus bar structure 50. In this way, the multiple first bending segments 61 and second bending segments 62 are alternately distributed in the first direction, which not only significantly increases the movement margin of the bus bar structure 50 on the plane of the cell substrate 10, but also effectively disperses the stress during the welding and heat treatment processes. This alternating arrangement further improves the connection stability between the first fine grid 20 and the bus bar structure 50, ensures the durability and conductivity of the cell during actual use, reduces the risk of fracture caused by stress concentration, and improves the overall reliability and service life of the solar cell 100.

[0081] Embodiment VII

[0082] Please refer to Figure 1 and Figure 2 , in some alternative embodiments, the first bending structure 60 is wavy.

[0083] In this way, the first bending structure 60 can be bent up and down in a wavy shape, increasing the movement margin of the bus bar structure 50 without increasing the maximum bending distance, thereby ensuring the stable connection between the first fine grid 20 and the bus bar structure 50.

[0084] Specifically, the first bending structure 60 is wavy, that is to say, the connection positions of the first bending segments 61 and the second bending segments 62 can be rounded to avoid the problem of stress concentration caused by sudden changes at the connection positions of the first bending segments 61 and the second bending segments 62.

[0085] Furthermore, the first bending segments 61 and the second bending segments 62 themselves are also arc-shaped, significantly increasing the movement margin of the bus bar structure 50 without increasing the maximum bending distance. This wavy structure can better buffer the stress changes generated during the welding and heat treatment processes, avoid fractures between the first bending segments 61 and the second bending segments 62 or within the bodies of the first bending segments 61 and the second bending segments 62, and thus effectively ensure the connection stability between the first fine grid 20 and the bus bar structure 50.

[0086] Embodiment VIII

[0087] Please refer to Figure 3 and Figure 4 , in some alternative embodiments, the solar cell 100 further includes main grid lines 70 disposed on the cell substrate 10, the bus bar structure 50 is formed on the main grid lines 70, and the multiple main grid lines 70 extend along the second direction and are distributed along the first direction;

[0088] The first fine grid 20 is connected to the main grid line 70 or the bus bar structure 50;

[0089] The second fine grid 30 and the third fine grid 40 are disconnected at the main grid line 70.

[0090] In this way, the first fine grid 20 can be connected to the main grid line 70 through the first bending structure 60 and the bus bar structure 50, so as to conduct the collected current to the external load through the main grid line 70 and the solder strip, thereby realizing the power generation action.

[0091] Specifically, the polarities of the second fine grid 30 and the third fine grid 40 can be the same. Therefore, it is necessary to disconnect at the position of the main grid line 70 to avoid short - circuiting with the main grid line 70. The main grid line 70 can connect and collect the current on multiple first fine grids 20. At the same time, the bus bar structure 50 is formed on the main grid line 70, and part of the first fine grids 20 can be connected to the bus bar structure 50 through the first bending structure 60, thereby converging the current of all the first fine grids 20 on the main grid line 70. The solder strip can be connected to the bus bar structure 50 by welding and extend along the direction of the main grid line 70, thereby conducting the current of the main grid line 70 to the external load.

[0092] It can be understood that there is another main grid connected to the second fine grid 30 and the third fine grid 40, and the first fine grid 20 is disconnected here. Other bus bar components and solder strips can also be provided on this main grid. In addition, in the embodiments of the present application, the shape of the bus bar structure 50 is not limited either to meet different requirements.

[0093] Of course, in some embodiments, the polarities of the second fine grid 30 and the third fine grid 40 are the same, and the polarity of the first fine grid 20 is the same as that of the main grid line 70. An insulating adhesive can be provided between the second fine grid 30 and the third fine grid 40 and the main grid line 70 to avoid short - circuit problems.

[0094] Embodiment Nine

[0095] Please refer to Figure 3 and Figure 4 , in some alternative embodiments, the solar cell 100 further includes a second bending structure 80. The second bending structure 80 connects the main grid line 70 and the bus bar structure 50, and the second bending structure 80 extends along the second direction and is at least partially bent towards the first direction.

[0096] In this way, the main grid line 70 is connected to the busbar structure 50 through the second bending structure 80, so that the busbar structure 50 has a certain movement margin on the plane of the cell substrate 10. The second bending structure 80 can elastically change when the solder tape is connected to the busbar structure 50 to ensure stable connection. At the same time, the width of the contact part between the second bending structure 80 and the busbar structure 50 in the first direction is greater than the width of the main grid line 70 in the first direction, further improving the connection stability and avoiding the main grid line 70 being pulled off due to stress concentration.

[0097] In this embodiment, a second bending structure 80 is also formed between the main grid line 70 and the busbar structure 50, further increasing the movement margin of the busbar structure 50 on the plane of the cell substrate 10. That is to say, when the busbar structure 50 moves slightly relative to the cell substrate 10, it can pull the second bending structure 80 to elastically change and move slightly to avoid breaking the connection between the main grid line 70 and the busbar structure 50 during the process preparation, improving the connection stability.

[0098] Further, in the first direction, the width of the busbar structure 50 is greater than the widths of the second bending structure 80 and the main grid line 70. Since the second bending structure 80 bends left and right relative to the main grid line 70 in the first direction, that is to say, the second bending structure 80 has a certain slope relative to the main grid line 70. In this way, the width of the contact part between the busbar structure 50 and the second bending structure 80 in the first direction is greater than the width of the main grid line 70 in the first direction. The second bending structure 80 and the busbar structure 50 have a larger connection area, which can improve the connection stability between the second bending structure 80 and the busbar structure 50, eliminate the problem of stress concentration, and avoid the main grid line 70 being pulled off due to stress concentration.

[0099] Please refer to Figure 5 , in some embodiments, the second bending structure 80 can be wavy.

[0100] In addition, in the embodiments of the present application, the corresponding relationship between the main grid line 70 and the second bending structure 80 is not limited to meet different requirements. In some embodiments, the second bending structure 80 can be selectively provided at the ends of some of the main grid lines 70, and the ends of the other part of the main grid lines 70 are not provided with the second bending structure 80. In other embodiments, the second bending structure 80 can be provided at one end of the main grid line 70 and not provided at the other end. In still other embodiments, the second bending structure 80 can be provided at both ends of all of the main grid lines 70.

[0101] Embodiment Ten

[0102] Please refer to Figures 3 to 5 , in some alternative embodiments, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction is 100 μm - 400 μm;

[0103] The height of the second bending structure 80 in the third direction is 35 μm - 200 μm, where the third direction is perpendicular to both the first direction and the second direction at the same time.

[0104] In this way, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction is set within this range, which can not only ensure that the busbar structure 50 has a margin of movement to avoid disconnection between the busbar structure 50 and the second bending structure 80, but also prevent the second bending structure 80 from affecting other fine grid lines. At the same time, the height of the second bending structure 80 relative to the cell substrate 10 in the third direction is set within this range, which can not only ensure the stable connection between the main grid line 70 and the busbar structure 50, but also prevent the height of the second bending structure 80 from being too high to affect the thickness of the battery module 300.

[0105] For example, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm.

[0106] Again, for example, the height of the second bending structure 80 in the third direction can be 35 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm.

[0107] Exemplarily, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction can be 300 μm. At the same time, the height of the second bending structure 80 in the third direction can be 100 μm. In this way, it can be ensured that the busbar structure 50 has sufficient movement margin on the plane of the cell substrate 10. Effectively avoid the problem of disconnection between the busbar structure 50 and the second bending structure 80 caused by stress concentration. In addition, proper control of the bending distance can also prevent the second bending structure 80 from interfering with or affecting the normal functions of other fine grid lines or the main grid line. At the same time, the height of the second bending structure 80 in the third direction is controlled within a reasonable range, which can not only ensure the connection stability between the main grid line 70 and the busbar structure 50, but also prevent the height of the bending structure from being too high, thus affecting the overall thickness and structural integrity of the battery module 300.

[0108] Example XI

[0109] Please refer to Figure 1 and Figure 6 , the battery string 200 provided by the embodiment of the present application includes the solar cell 100 as described in any one of the above embodiments.

[0110] In the solar cell 100 and the battery string 200 of the embodiment of the present application, the solar cell 100 includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50, and a first bending structure 60. The first fine grid 20 is disposed on the cell substrate 10 and extends along a first direction. The second fine grid 30 is disposed on the cell substrate 10. The first fine grid 20 and the second fine grid 30 are disposed along a second direction. The busbar structure 50 is disposed on the cell substrate 10. At least a part of the first fine grid 20 is connected to the busbar structure 50. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50. The first bending structure 60 extends along the first direction and is at least partially bent toward the second direction. The width of the contact portion of the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. In this way, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain margin of movement on the plane of the cell substrate 10. The first bending structure 60 can elastically change when the solder tape is connected to the busbar structure 50 to ensure stable connection. At the same time, the width of the contact portion of the first bending structure 60 and the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, further improving the connection stability and avoiding the first fine grid 20 being broken due to stress concentration.

[0111] It can be understood that in the battery string 200, the battery string 200 may include two serially connected cells, three serially connected cells, or other more numbers of cells. Specifically, the number of cells to be connected in series can be determined according to the actual use situation. In addition, in the embodiment of the present application, the size and type of the cells are not limited either. The specifications and sizes of adjacent cells can be the same or different to meet different requirements.

[0112] Example XII

[0113] Please refer to Figure 1 and Figure 7 , the battery module 300 provided by the embodiment of the present application includes the battery string 200 as described in the above embodiment.

[0114] In the solar cell 100, cell string 200, and solar cell module 300 according to the embodiments of the present application, the solar cell 100 includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50, and a first bending structure 60. The first fine grid 20 is disposed on the cell substrate 10 and extends along a first direction. The second fine grid 30 is disposed on the cell substrate 10, and the first fine grid 20 and the second fine grid 30 are arranged along a second direction. The busbar structure 50 is disposed on the cell substrate 10, and at least a part of the first fine grid 20 is connected to the busbar structure 50. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50, and the first bending structure 60 extends along the first direction and is at least partially bent toward the second direction. The width of the contact portion between the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. Thus, the first fine grid 20 and the busbar structure 50 are connected by the first bending structure 60, so that the busbar structure 50 has a certain margin of movement on the plane of the cell substrate 10, and the first bending structure 60 can elastically change when the solder ribbon is connected to the busbar structure 50 to ensure stable connection. At the same time, the width of the contact portion between the first bending structure 60 and the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, further improving the connection stability and avoiding the first fine grid 20 being broken due to stress concentration.

[0115] It can be understood that in such an embodiment, the solar cell module 300 may further include a frame, a backsheet, a photovoltaic glass, and an encapsulant film. The encapsulant film may be filled between the front and back surfaces of the cell substrate 10, the photovoltaic glass, adjacent cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulant film may be an EVA encapsulant film or a POE encapsulant film, and specific selection can be made according to actual situations and is not limited herein.

[0116] The photovoltaic glass may cover the encapsulant film on the front surface of the cell substrate 10. The photovoltaic glass may be ultra-clear glass, which has a high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, the light transmittance of the ultra-clear glass can reach more than 92%, and it can protect the cell as much as possible without affecting the efficiency of the cell. At the same time, the encapsulant film can bond the photovoltaic glass and the cell together, and the presence of the encapsulant film can seal and insulate the cell and prevent water and moisture.

[0117] The backsheet can be attached to the adhesive film on the back of the cell substrate 10. The backsheet can protect and support the cell, and has reliable insulation, water resistance and aging resistance. There are multiple choices for the backsheet, which can usually be tempered glass, plexiglass, aluminum alloy TPT composite film, etc., and can be specifically set according to specific circumstances, which is not limited here. The whole composed of the backsheet, the cell, the adhesive film and the photovoltaic glass can be arranged on the frame. The frame is the main external support structure of the entire battery module 300, and can stably support and install the battery module 300. For example, the battery module 300 can be installed at the required installation position through the frame.

[0118] Embodiment Thirteen

[0119] Please refer to Figure 1 and Figure 8 , the photovoltaic system 400 provided by the embodiment of the present application includes the battery module 300 as described in the above embodiment.

[0120] In the solar cell 100, the battery string 200, the battery module 300 and the photovoltaic system 400 of the embodiment of the present application, the solar cell 100 includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50 and a first bending structure 60. The first fine grid 20 is arranged on the cell substrate 10 and extends along a first direction. The second fine grid 30 is arranged on the cell substrate 10, and the first fine grid 20 and the second fine grid 30 are arranged along a second direction. The busbar structure 50 is arranged on the cell substrate 10, and at least part of the first fine grid 20 is connected to the busbar structure 50. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50. The first bending structure 60 extends along the first direction and is at least partially bent toward the second direction. The width of the contact part between the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. In this way, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain margin of movement on the plane of the cell substrate 10. The first bending structure 60 can elastically change when the solder ribbon is connected to the busbar structure 50 to ensure stable connection; at the same time, the width of the contact part between the first bending structure 60 and the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, further improving the connection stability and avoiding breaking the first fine grid 20 due to stress concentration.

[0121] In this embodiment, the photovoltaic system 400 can be applied in a photovoltaic power station, such as a ground power station, a rooftop power station, a water surface power station, etc., or can also be applied to devices or apparatuses that use solar energy for power generation, such as a user solar power supply, a solar street lamp, a solar vehicle, a solar building, and so on. Of course, it can be understood that the application scenarios of the photovoltaic system 400 are not limited thereto, that is to say, the photovoltaic system 400 can be applied in all fields that require solar power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system 400 can include a photovoltaic array, a busbar box, and an inverter. The photovoltaic array can be an array combination of multiple battery modules 300. For example, multiple battery modules 300 can form multiple photovoltaic arrays. The photovoltaic arrays are connected to the busbar box, and the busbar box can aggregate the current generated by the photovoltaic arrays. The aggregated current flows through the inverter and is converted into alternating current required by the commercial power grid and then connected to the commercial power grid to achieve solar power supply.

[0122] In the description of this specification, the descriptions referring to terms such as "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0123] In addition, the above are only the preferred embodiments of the present application and are not used to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A solar cell, characterized in that: include: Battery cell substrate; A first fine grid is disposed on the battery cell substrate, and the first fine grid extends along a first direction; A second fine grid is arranged on the battery cell substrate, wherein the first fine grid and the second fine grid are arranged along a second direction; A bus structure is provided on the battery cell substrate, wherein at least part of the first fine grid is connected to the bus structure; A first bending structure, wherein the first bending structure connects the first fine grid and the bus structure, the first bending structure extends along the first direction and is at least partially bent toward the second direction, and a width of a contact portion between the bus structure and the first bending structure in the second direction is greater than a width of the first fine grid in the second direction.

2. The solar cell according to claim 1, characterized in that A maximum bending distance of the first bending structure relative to the first fine grid in the second direction is 100 μm-400 μm.

3. The solar cell according to claim 1, characterized in that The height of the first bending structure in the third direction is 35 μm-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction.

4. The solar cell according to claim 1, characterized in that The solar cell further comprises a second fine grid and a third fine grid arranged on the cell substrate, wherein the second fine grid, the first fine grid and the third fine grid all extend along the first direction and are arranged along the second direction, and in the second direction, the second fine grid and the third fine grid are adjacent to the first fine grid; The first bending structure includes a first bending section and a second bending section. The first bending section bends relative to the first fine grid toward the second fine grid, and the second bending section bends relative to the first fine grid toward the third fine grid.

5. The solar cell according to claim 4, characterized in that: The maximum bending distance of the first bending section relative to the first fine grid in the second direction is smaller than the distance between the first fine grid and the second fine grid; A maximum bending distance of the second bending section relative to the first fine grid in the second direction is smaller than a distance between the first fine grid and the third fine grid.

6. The solar cell according to claim 4, characterized in that: The plurality of first bending segments and the plurality of second bending segments are alternately arranged along the first direction.

7. The solar cell according to claim 4, characterized in that: The first bending structure is in a wave shape.

8. The solar cell according to claim 4, characterized in that: The solar cell further comprises a main grid line arranged on the cell substrate, the busbar structure is formed on the main grid line, and a plurality of the main grid lines extend along the second direction and are distributed along the first direction; The first fine grid is connected to the main grid line or the bus structure; The second fine gate and the third fine gate are disconnected at the main gate line.

9. The solar cell according to claim 8, characterized in that The solar cell further includes a second bending structure, the second bending structure connecting the main grid line and the bus structure, and the second bending structure extending along the second direction and at least partially bending toward the first direction.

10. The solar cell according to claim 9, characterized in that: The maximum bending distance of the second bending structure relative to the main grid line in the first direction is 100 μm-400 μm; A height of the second bending structure in a third direction is 35 μm-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction.

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

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

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

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