Solar cell, cell assembly and photovoltaic system

Abstract

The utility model provides a solar cell, a cell assembly and a photovoltaic system. According to the solar cell, a first surface of a cell substrate comprises a middle grid line area and a side grid line area; the fine grids comprise continuous fine grids arranged in the middle grid line area and discontinuous fine grids arranged in the side grid line areas, the continuous fine grids are continuously arranged in the second direction, the discontinuous fine grids are separated from the main grids with opposite conduction types at the two ends of the second direction, and the discontinuous fine grids are conductively connected with the main grids with the same conduction type; thus, according to the solar cell, the main grids are arranged in the side grid line areas on the two sides of the middle grid line area, so that when the solar cell in the cell module is connected with the welding strip, the main grids arranged in the side grid line areas can provide pulling force for the welding strip, the phenomenon of pseudo soldering of the welding strip is reduced, and the mechanical stability of the cell module is improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to a solar cell, a battery module and a photovoltaic system. Background Technology

[0002] Because gridless solar cells do not have a main grid, they can reduce shading losses from the grid lines, thereby improving photoelectric conversion efficiency.

[0003] However, in existing gridless solar cells, the welding pull of the solder strips connected to the gridless solar cell is relatively weak, which easily leads to the phenomenon of incomplete soldering.

[0004] Therefore, how to improve the tensile strength of the solder strips in battery modules and reduce the phenomenon of incomplete soldering has become an urgent problem to be solved. Utility Model Content

[0005] This invention provides a solar cell, a battery module, and a photovoltaic system to solve the technical problem of how to reduce the phenomenon of poor soldering of solder strips in battery modules.

[0006] This utility model is implemented as follows: This utility model provides a solar cell, a battery module, and a photovoltaic system. A solar cell includes: a battery substrate having a first surface and a second surface, the first surface including a central grid region and side grid regions disposed on both sides of the central grid region in a first direction; a plurality of main grids arranged along a second direction and extending along the first direction, the main grids being disposed in the side grid regions and avoiding the central grid region, the second direction intersecting the first direction; and a plurality of fine grids arranged along the first direction and extending along the second direction, the fine grids including continuous fine grids disposed in the central grid region and discontinuous fine grids disposed in the side grid regions, the continuous fine grids being arranged along the first direction and extending along the second direction. The two-directional continuous arrangement includes: the intermittent fine gates are spaced apart from the main gates along the second direction, with the portions of the intermittent fine gates having the same conductivity type as the main gates; and multiple busbars are disposed on both sides of the first surface in the second direction and extend along the first direction. The busbars are conductively connected to the continuous fine gates having the same conductivity type as the continuous fine gates, and the portions of the busbars having the same conductivity type as the continuous fine gates are spaced apart. The portions of the busbars having the same conductivity type as the continuous fine gates are conductively connected to the intermittent fine gates, and the portions of the busbars having the opposite conductivity type are spaced apart by the intermittent fine gates.

[0007] Furthermore, the solar cell also includes a first axis of symmetry extending along the second direction, and the side grid line region includes a first side grid line region and a second side grid line region; the main grid disposed in the first side grid line region and the main grid disposed in the second side grid line region are symmetrical about the first axis of symmetry.

[0008] Furthermore, the length of the main gate in the first direction is 1 mm to 55 mm.

[0009] Furthermore, the main grid is provided with at least one first solder joint.

[0010] Furthermore, the first surface includes two first edges extending along the second direction and disposed opposite to each other; in the first direction, the distance between the first edge and the first solder point closest to the first edge is 5 mm to 25 mm.

[0011] Furthermore, in the first direction, the distance between two adjacent first solder joints is a first distance; when there are multiple first distances, the ratio of any two first distances is 0.8 to 1.2.

[0012] Furthermore, the main grid includes a bent section connecting the end of the first solder joint, the extension direction of which intersects the first direction.

[0013] Furthermore, the first surface also includes edge regions disposed on both sides of the first surface in a second direction, the edge regions having at least one second solder joint, the second solder joints being arranged along the first direction, the second solder joints being conductively connected to the portion of the fine gate having the same conductivity type as themselves, and the second solder joints being spaced apart from the fine gate having the opposite conductivity type as themselves.

[0014] Furthermore, the first surface includes two first edges extending along the second direction and disposed opposite to each other; in one of the edge regions, the first and / or last second solder joint in the first direction is an edge second solder joint, and the edge second solder joint is connected to a first grid line at one end near the first edge.

[0015] Furthermore, in the first direction, the distance between two adjacent second solder points is 5 mm to 260 mm.

[0016] Furthermore, in one of the said edge regions, the line connecting the center points of each of the second solder joints is a first straight line segment, which is parallel to the first direction.

[0017] Furthermore, the busbar is electrically connected to all the second solder joints that have the same conductivity type.

[0018] This utility model embodiment also provides a battery assembly, which includes the solar cell described above.

[0019] This utility model embodiment also provides a photovoltaic system, which includes the battery module as described above.

[0020] Thus, in this embodiment of the solar cell, by placing the main grid in the side grid regions on both sides of the central grid region, the main grid in the side grid regions can provide tension to the solder ribbon when the solar cell is connected to the solder ribbon in the cell module, thereby reducing the phenomenon of poor soldering and improving the mechanical stability of the cell module. Furthermore, by setting the main grid to avoid the central grid region, and the central grid region having a continuous fine grid, the main grid avoids partially shading the central grid region of the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a photovoltaic system module provided in one embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of a battery assembly provided in one embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of a solar cell provided in one embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of a solar cell provided in another embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of a solar cell provided in another embodiment of the present invention;

[0027] Figure 6 This is a partial structural schematic diagram of a solar cell provided in one embodiment of the present invention;

[0028] Figure 7 This is a partial structural diagram of a solar cell with a bent section in another embodiment of the present invention.

[0029] Key component symbols: 1000, Photovoltaic system; 1001, Battery module; 100, Solar cell; 10, First surface; 11, Middle grid area; 12, Side grid area; 20, Main grid; 40, Busbar; 50, First axis of symmetry; 60, Second solder joint; 70, First grid line; 80, First straight segment; 13, Edge area; 21, First solder joint; 22, Bend segment; 31, Continuous fine grid; 32, Discontinuous fine grid; 101, First edge; 121, First side grid area; 122, Second side grid area. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as limiting the present utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0031] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "top", "bottom", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0035] Please see Figure 1 and Figure 2 The photovoltaic system 1000 in this embodiment of the present invention may include the battery module 1001 in this embodiment of the present invention. The battery module 1001 in this embodiment of the present invention may include a plurality of solar cells 100 in this embodiment of the present invention. The plurality of solar cells 100 may be connected in series to form a battery string. The battery strings in the battery module 1001 may be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between the battery strings may be achieved by a bus bar.

[0036] Specifically, the battery module 1001 can be a double-glass module or a single-glass module; the battery module 1001 can be a 54-pane, 60-pane, 72-pane, or other types. No specific limitation is made on the specific form of the battery module 1001.

[0037] In this embodiment, the photovoltaic system 1000 can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy for power generation, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 1000 are not limited to these; that is, the photovoltaic system 1000 can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system 1000 may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules 1001. For example, multiple battery modules 1001 can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0038] The accompanying drawings provided in this utility model are schematic diagrams, and some elements are not shown in the drawings. The purpose is to clearly describe the technical solution and highlight the key points of the utility model. It is not intended to limit the technical solution to exclude these unshown elements. That is to say, the drawings are only examples and do not represent a limitation on the specific form of the solar cell 100.

[0039] like Figures 3 to 7 As shown, the solar cell 100 in this embodiment of the present invention includes: a cell substrate, a plurality of main grids 20, a plurality of fine grids, and a plurality of busbars 40. The cell substrate has a first surface 10 and a second surface. The first surface 10 includes a central grid region 11 and side grid regions 12 disposed on both sides of the central grid region 11 in a first direction. The plurality of main grids 20 are arranged along a second direction and extend along a first direction. The main grids 20 are disposed in the side grid regions 12 and avoid the central grid region 11. The second direction intersects the first direction. The plurality of fine grids are arranged along the first direction and extend along the second direction. The fine grids include continuous fine grids 31 disposed in the central grid region 11 and discontinuous fine grids 32 disposed in the side grid regions 12. The continuous fine grids 31 are continuously disposed from the second direction. The discontinuous fine grids 32 are spaced apart from the main grids 20 with opposite conductivity types along the second direction. The discontinuous fine grids 32 are electrically connected to the portion of the main grids 20 with the same conductivity type.

[0040] Multiple busbars 40 are disposed on both sides of the first surface 10 in the second direction and extend along the first direction. The busbars 40 are electrically connected to continuous fine gates 31 of the same conductivity type. The busbars 40 are spaced apart from continuous fine gates 31 of opposite conductivity type. The busbars 40 are electrically connected to intermittent fine gates 32 of the same conductivity type.

[0041] Thus, in this embodiment of the present invention, the solar cell 100, by setting the main grid 20 on the side grid regions 12 on both sides of the central grid region 11, allows the main grid 20 located in the side grid regions 12 to provide tension to the solder ribbon when the solar cell 100 in the battery module 1001 is connected to the solder ribbon, thereby reducing the phenomenon of poor soldering and improving the mechanical stability of the battery module 1001. Moreover, by setting the main grid 20 to avoid the central grid region 11, and the central grid region 11 having a continuous fine grid 31, the main grid 20 is prevented from partially shading the central grid region 11 of the solar cell 100, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0042] Understandably, while existing grid-less solar cells can reduce shading losses, they also lead to insufficient tension in the solder ribbons, resulting in incomplete soldering.

[0043] Therefore, in the solar cell 100 of this utility model embodiment, by setting the main grid 20 on the side grid line regions 12 on both sides of the middle grid line region 11, and by setting the main grid 20 to avoid the middle grid line region 11, and by providing the middle grid line region 11 with a continuous fine grid 31, the solar cell 100 can improve the photoelectric conversion efficiency, thereby increasing the tension of the solder ribbon connected to the solar cell 100 in the battery module 1001, and thus improving the stability of the battery module 1001.

[0044] Specifically, the battery substrate is the main body of the solar cell 100. Exemplarily, the battery substrate may include a silicon substrate, and may also include a dielectric layer, a doped layer, a passivation layer, etc., which can be configured according to actual conditions. A first surface 10 and a second surface are arranged opposite to each other, with the first surface 10 being the backlight surface of the battery substrate and the second surface being the light-facing surface. The backlight surface of the battery substrate refers to the side of the battery substrate that faces away from sunlight when the battery module 1001 is naturally installed. The light-facing surface of the battery substrate refers to the side of the battery substrate that faces sunlight when the battery module 1001 is naturally installed.

[0045] The solar cell 100 in this invention can be a back contact cell, such as an IBC cell (Interdigitated Back Contact), an ABC cell (All Back Contact), an HPBC cell (Hybrid Passivated Back Contact), an HBC cell (Hetero Junction Back Contact), a TBC cell (Tandem Back Contact), etc.

[0046] The solar cell 100 in this invention can also be a PERC cell (Passivated Emitter and Rear Cell), a TOPcon cell (Tunnel Oxide Passivated Contact), an HJT cell (Heterojunction with Intrinsic Thin Layer), a perovskite tandem cell, a flexible cell, or a non-silicon solar cell 100, etc. No limitation is made here.

[0047] In this embodiment of the invention, the solar cell 100 is used as a back-contact battery for illustration.

[0048] like Figures 3 to 6As shown, the first surface 10 further includes a central gate line region 11 and side gate line regions 12. There are two side gate line regions 12, namely a first side gate line region 121 and a second side gate line region 122, which are located on both sides of the central gate line region 11 in the first direction.

[0049] Specifically, the main grids 20 of the solar cell 100 are all located in the side grid line regions 12 on both sides, and the main grids 20 are arranged to avoid the middle grid line region 11. In other words, the main grids 20 are not located in the middle grid line region 11.

[0050] Furthermore, the length of the main grid 20 in the first direction is from 1 mm to 55 mm, for example, 1 mm, 2 mm, 3 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, and 55 mm. In this way, the main grid 20 can provide sufficient tension for the solder ribbon while avoiding excessive shading of the solar cell 100 due to its excessive length, thus affecting the photoelectric conversion efficiency of the solar cell 100.

[0051] Understandably, the length of the main grid 20 cannot be too short. If the main grid 20 is too short, it will not be able to provide sufficient tension for the solder ribbon during solar cell welding. Furthermore, the length of the main grid 20 cannot be too long either. If the main grid 20 is too long, it will cause excessive shading of the solar cell 100, thereby affecting the photoelectric conversion efficiency of the solar cell 100.

[0052] Furthermore, the main gate 20 is perpendicular to the fine gate, thereby enabling the collection of current from each fine gate in the side gate line region 12.

[0053] Specifically, the fine grid of the solar cell 100 includes a continuous fine grid 31 disposed in the intermediate grid line region 11 and a discontinuous fine grid 32 disposed in the side grid line region 12. The continuous fine grid 31 is disposed continuously in the second direction. By disposing of the continuous fine grid 31 in the intermediate grid line region 11, the carriers in the doped layer corresponding to the intermediate grid line region 11 can be fully collected, thereby improving the photoelectric conversion efficiency of the solar cell 100. Moreover, by disposing of the fine grid 32 in the side grid line region 12, the carriers in the doped layer corresponding to the side grid line region 12 can be fully collected, and the fine grid in the side grid line region 12 can be disconnected from the heterogeneous main grid 20 in the side grid line region 12, avoiding leakage caused by direct contact between the positive and negative grid lines.

[0054] Furthermore, in the side grid line region 12, two adjacent discontinuous fine grids 32 in the second direction are spaced apart. The main grid 20 with the opposite conductivity type can be separated at the interval between the two adjacent discontinuous fine grids 32 in the second direction to achieve insulation between the fine grid and the opposite main grid 20. Insulation can be achieved by spacing, without the need for additional insulating components, thereby reducing the manufacturing cost and complexity of the solar cell 100.

[0055] Furthermore, in the side grid line region 12, each discontinuous fine grid 32 is electrically connected to the adjacent same-polarity main grid 20. In this way, the discontinuous fine grid 32 and the main grid 20 can be arranged in close proximity, thereby reducing the current transmission path between the discontinuous fine grid 32 and the main grid 20, and thus improving the cell efficiency of the solar cell 100.

[0056] It is understandable that one or more discontinuous fine gates 32 can be electrically connected to a main gate 20.

[0057] Specifically, the solar cell 100 further includes busbars 40, which are disposed on both sides of the first surface 10 in the second direction and extend along the first direction. In this embodiment of the invention, two busbars 40 with different conductivity types are provided, respectively located on both sides of the first surface 10 in the second direction.

[0058] Furthermore, the busbar 40 is electrically connected to the continuous fine grid 31 with the same conductivity type, and the busbar 40 is electrically connected to the partially discontinuous fine grid 32 with the same conductivity type. Thus, when the continuous fine grid 31 or the discontinuous fine grid 32 breaks, the current can bypass the break point through the busbar 40, allowing the current to continue to flow. This avoids the inability to transmit or collect current in parts of the solar cell 100 due to grid line breakage, reducing the degradation of the electrical performance of the solar cell 100 and thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0059] It is understood that both the busbar 40 and the main grid 20 are grid lines in the solar cell 100 that function to collect fine grid current. Specifically, the busbar 40 and the main grid 20 can be grid lines with the same structure, but their placement and size are different. Specifically, the busbar 40 is located on both sides of the first surface 10 in the second direction.

[0060] like Figure 4As shown, in one possible embodiment, the solar cell 100 further includes a first axis of symmetry 50 extending along a second direction, and the side grid region 12 includes a first side grid region 121 and a second side grid region 122; the main grid 20 disposed in the first side grid region 121 and the main grid 20 disposed in the second side grid region 122 are symmetrical about the first axis of symmetry 50. This allows the main grid 20 to be uniformly distributed in the first direction, thereby reducing uneven stress distribution of the solar cell 100 during the welding process with the solder strip, and thus reducing the risk of microcracks and fragmentation of the solar cell 100 in the battery module 1001.

[0061] Specifically, the first axis of symmetry 50 is an axis of symmetry of the solar cell 100, which can divide the solar cell 100 into two identical parts in the first direction.

[0062] It is understood that the main gate 20 located in the first side gate line region 121 and the main gate 20 located in the second side gate line region 122 are symmetrical about the first axis of symmetry 50. This means that the main gate 20 located in the first side gate line region 121 and the main gate 20 located in the second side gate line region 122 are arranged in a mirror image with the first axis of symmetry 50 as the axis of symmetry, and the main gate 20 located in the first side gate line region 121 and the main gate 20 located in the second side gate line region 122 are correspondingly arranged.

[0063] Furthermore, in the first direction, the two main gates 20 that are symmetrical about the first axis of symmetry 50 have the same polarity.

[0064] Furthermore, in the first direction, the two main gates 20 that are symmetrical about the first axis of symmetry 50 are not connected.

[0065] In one possible implementation, the main grid 20 is provided with at least one first solder joint 21. Thus, by providing the first solder joint 21 in the main grid 20, the welding pull between the main grid 20 and the solder strip can be increased when the solar cell 100 is connected to the solder strip, thereby further reducing the phenomenon of poor soldering of the solder strip and improving the mechanical stability of the battery module 1001.

[0066] Furthermore, the number of first solder points 21 in each main busbar 20 is between 1 and 5. It is understandable that if the number of first solder points 21 in the main busbar 20 is too large, the overall length of the main busbar 20 will be too long, thus increasing the shading of the solar cell 100 by the main busbar 20 and affecting the photoelectric conversion efficiency of the cell module 1001. If the number of first solder points 21 in the main busbar 20 is too small, the welding pull reliability of the cell module 1001 will be insufficient, increasing the risk of poor solder joints.

[0067] The table below shows the relationship between the number of first solder joints 21 in the main busbar 20 and the photoelectric conversion efficiency of the battery module 1001, as well as the weld pull reliability of the battery module 1001. We can clearly see that when the number of first solder joints 21 in each main busbar 20 is between 1 and 5, the photoelectric conversion efficiency of the battery module 1001 can be improved while reducing the risk of incomplete soldering and ensuring the weld pull reliability of the battery module 1001.

[0068]

[0069] Furthermore, the first solder joint 21 can be square, circular, rectangular, wedge-shaped, or other shapes. The dimension of the first solder joint 21 in the first direction can be from 300μm to 3000μm, for example, 300μm, 500μm, 800μm, 1000μm, 1500μm, 2000μm, 2500μm, or 3000μm. The dimension of the first solder joint 21 in the second direction can also be from 300μm to 3000μm, for example, 300μm, 500μm, 800μm, 1000μm, 1500μm, 2000μm, 2500μm, or 3000μm.

[0070] Specifically, the solar cell 100 can be formed by dividing the entire solar cell 100 into two, three, four, five, or other equal parts. No specific division ratio is specified here.

[0071] like Figures 3 to 6 As shown, in one possible implementation, when the main gate 20 has multiple first solder joints 21, the distance between two adjacent first solder joints 21 in the first direction is a first distance D1; when there are multiple first distances D1, the ratio of any two first distances D1 is 0.8 to 1.2. This ensures that the current collected by each first solder joint 21 is relatively balanced, preventing uneven distribution of the first solder joints 21 from causing excessive current in some first solder joints, resulting in uneven heating and increased line resistance.

[0072] It is understandable that when there are multiple first solder points 21 in the main grid 20, the spacing between adjacent first solder points 21 can be set to be relatively uniform. Therefore, setting the ratio of any two first spacings D1 to 0.8 to 1.2, for example, 0.8, 0.9, 1.0, 1.1, 1.2, can improve the cell efficiency of the solar cell 100 and reduce the heat loss of the solar cell 100.

[0073] In one possible implementation, when there are multiple first solder joints 21 in the main grid 20, the multiple first solder joints 21 include test solder joints, the area of ​​which is larger than the area of ​​the other first solder joints 21. Thus, by setting up test solder joints, a user can contact the test solder joints with a detection device to complete the testing of the solar cell 100.

[0074] like Figure 3 and Figure 4 As shown, in one possible implementation, the first surface 10 includes two first edges 101 extending along a second direction and disposed opposite to each other; in the first direction, the distance t between the first edge 101 and the first solder point 21 closest to the first edge 101 is 5 mm to 25 mm, for example, 5 mm, 8 mm, 10 mm, 15 mm, 20 mm, or 25 mm. This avoids the first solder point 21 being too close to the edge of the solar cell 100, thereby reducing stress concentration at the edge of the solar cell 100 and preventing bending of the cell due to excessive stress at the edge, thus reducing the risk of microcracks and fragmentation of the solar cell 100. Furthermore, in the battery module 1001, insufficient solder strip tension due to excessive stress at the edge of the solar cell 100 can be avoided, reducing defects in the battery module 1001.

[0075] Specifically, the first edge 101 is the boundary line of the first surface 10 of the solar cell 100. The first edge 101 extends along a second direction.

[0076] It is understandable that the stress is more concentrated at the edge of the solar cell 100, and the setting of the first solder point 21 will further increase the stress at the edge of the solar cell 100. Therefore, in this embodiment of the present invention, by setting the distance t from the first edge 101 to the first solder point 21 closest to the first edge 101 to be 5mm to 25mm, each first solder point 21 can be kept away from the edge of the solar cell 100 where the stress is more concentrated, thereby reducing the stress concentration at the edge of the solar cell 100, thereby reducing the risk of microcracks and fragmentation of the solar cell 100 and reducing the defects of the battery module 1001.

[0077] like Figure 3 and Figure 7As shown, in one possible implementation, the main grid 20 includes a bent section 22 connecting the end of the first solder joint 21, the extension direction of the bent section 22 intersecting the first direction. This allows the bent section 22 to disperse the welding stress of the first solder joint 21 and the nearby solder strips and grid lines when the solar cell 100 is connected to the solder strips, preventing deformation of the solder strips and grid lines, reducing grid line breakage and cell warping of the solar cell 100, improving the stability of the solar cell 100, and thus improving the efficiency of the battery module 1001.

[0078] Specifically, a bent segment 22 is connected to at least one end of the first solder joint 21. For example, a bent segment 22 may be provided on one segment of the first solder joint 21 in the first direction; or a bent segment 22 may be provided on both ends of the first solder joint 21 in the first direction, without limitation.

[0079] For example, in the battery module 1001, the solder ribbon is connected to the first solder joint 21 and extends along a first direction, applying stress to the solar cell 100. The bending section 22 extends in a direction intersecting the first direction. When the solder ribbon applies stress to the solar cell 100, the bending section 22 can disperse the stress generated by the solder ribbon, thereby reducing damage to the solar cell 100 caused by the stress. This avoids incomplete soldering or deformation of the main grid 20 by the solder ribbon, thus reducing warping of the solar cell 100, improving the structural stability of the solar cell 100, and ultimately increasing the efficiency of the battery module 1001.

[0080] In one possible implementation, in the side grid line region 12, the first solder joint 21 is electrically connected to at least two discontinuous fine grids 32. This increases the current collection path between the first solder joint 21 and the fine grids, and when one of the discontinuous fine grids 32 electrically connected to the first solder joint 21 breaks, the remaining discontinuous fine grids 32 connected to the first solder joint 21 can still maintain current transmission with the first solder joint 21, thereby reducing the power loss of the solar cell 100.

[0081] like Figure 4 and Figure 5 As shown, in one possible embodiment, the first surface 10 further includes edge regions 13 disposed on both sides of the first surface 10 in a second direction. Each edge region 13 has at least one second solder point 60, which are arranged along the first direction. Each second solder point 60 is conductively connected to a portion of the fine grid with the same conductivity type, and is spaced apart from fine grids with the opposite conductivity type. Thus, by providing multiple second solder points 60 in the edge regions 13, the welding pull force in the edge regions 13 can be dispersed when the solar cell 100 is welded to the solder strip, thereby reducing the risk of poor solder joints and grid line breakage, and ultimately improving the stability of the battery module 1001.

[0082] It is understandable that when the solar cell 100 is connected to the solder strip, the solder joints in the edge region 13 of the solar cell 100 will be subjected to a large welding pull force because the solar cell 100 will warp towards the grid line surface. Therefore, by setting multiple second solder joints 60 arranged at intervals along the first direction in the edge region 13, the welding pull force in the edge region 13 is distributed to each second solder joint 60, thereby reducing the risk of poor soldering of the solder strip and grid line breakage, and thus improving the stability of the battery module 1001.

[0083] When there are multiple second solder points 60 in an edge region 13, the multiple second solder points 60 are arranged at intervals along the first direction.

[0084] Specifically, the edge region 13 of the first surface 10 in the solar cell 100 is the portion of the two side edges of the first surface 10 in the second direction. The edge region 13 overlaps with both the middle grid line region 11 and the side grid line region 12.

[0085] Furthermore, the second solder point 60 is conductively connected to at least two fine grids. This increases the current collection path between the second solder point 60 and the fine grids, and when one of the fine grids conductively connected to the second solder point 60 breaks, the remaining fine grids connected to the second solder point 60 can still maintain current transmission with the first solder point 21, thereby reducing the power loss of the solar cell 100.

[0086] It is understood that the second solder joint 60 can be located in the middle gate line region 11 or in the side gate line region 12. The second solder joint 60 located in the middle gate line region 11 is electrically connected to at least two continuous fine gates 31, and the second solder joint 60 located in the side gate line region 12 is electrically connected to at least two discontinuous fine gates 32.

[0087] Furthermore, a second solder joint 60 is also provided in the intermediate gate line region 11. This is to prevent the fine gates from conductively connecting with the second solder joint 60 in the intermediate gate line region 11, which has a conductivity type opposite to its own, thus avoiding current loss. In this embodiment of the invention, not all the fine gates in the intermediate gate line region 11 are continuous fine gates 31. Instead, near the second solder joint 60 in the intermediate gate line region 11, there are intermittent fine gates 32 with a conductivity type opposite to that of the second solder joint 60. Furthermore, the continuous fine gates 31 in the intermediate gate line region 11 are also conductively connected to the bus gate line 40 with the same conductivity type.

[0088] Furthermore, the second solder joint 60 can be square, circular, rectangular, wedge-shaped, or similar shapes. The dimensions of the second solder joint 60 in the first direction can be from 300μm to 3000μm, for example, 300μm, 500μm, 800μm, 1000μm, 1500μm, 2000μm, 2500μm, or 3000μm. The dimensions of the first solder joint 21 in the second direction can also be from 300μm to 3000μm, for example, 300μm, 500μm, 800μm, 1000μm, 1500μm, 2000μm, 2500μm, or 3000μm.

[0089] Furthermore, when there are multiple second solder points 60 in an edge region 13, the distance between two adjacent second solder points 60 in the first direction is a second distance k, and the ratio of any two second distances k is between 0.8 and 1.2, for example, 0.8, 0.9, 1.0, 1.1, and 1.2. This ensures that the current collected by each second solder point 60 is relatively balanced, preventing uneven distribution of the second solder points 60 from causing excessive current in some second solder points, resulting in uneven heating and increased line resistance.

[0090] Furthermore, when there are multiple second solder joints 60 in an edge region 13, the spacing between two adjacent second solder joints 60 in the first direction is from 5 mm to 260 mm. For example, it can be 5 mm, 10 mm, 20 mm, 50 mm, 80 mm, 100 mm, 120 mm, 150 mm, 180 mm, 200 mm, 250 mm, or 260 mm. In this way, while ensuring that the second solder joints 60 can absorb current well, the total cost of the second solder joints 60 can be avoided from being too high.

[0091] Furthermore, in the second direction, the two opposing second solder points 60 have different electrical conductivity types.

[0092] Furthermore, when there are multiple second solder points 60 in an edge region 13, in the second direction, the distance between two adjacent second solder points 60 is greater than 70mm, for example, 80mm, 90mm, 100mm, or 150mm.

[0093] Furthermore, in an edge region 13, the line connecting the center points of each of the second solder points 60 is a first straight line segment 80, which is parallel to a first direction. This reduces the welding complexity when welding the solar cell 100 to the solder strip and improves the welding efficiency of the battery module 1001.

[0094] Specifically, the center point of the second solder joint 60 is the geometric center of the second solder joint 60.

[0095] like Figure 5As shown, it can be understood that in an edge region 13, the line connecting the center points of each second solder point 60 is a first straight line segment 80, which is parallel to the first direction, allowing each second solder point 60 to be collinearly arranged in the first direction. When the user connects the solder strip to the second solder point 60 from the first direction, the solder strip only needs to be welded along a single axis, without the need for adjustments to direction, angle, or trajectory, thereby reducing welding difficulty and improving the welding efficiency of the battery assembly 1001.

[0096] In one possible implementation, the first surface 10 includes two first edges 101 extending along a second direction and disposed opposite to each other; in an edge region 13, the first and / or last second solder joint 60 in the first direction is an edge second solder joint 60, and the end of the edge second solder joint 60 near the first edge 101 is connected to a first grid line 70. Thus, when the solar cell 100 is connected to the solder strip, the welding stability between the edge second solder joint 60 and the solder strip can be increased, reducing the phenomenon of incomplete soldering of the solder strip, thereby reducing defects in the battery module 1001.

[0097] It is understood that the edge second solder point 60 is the first and / or last second solder point 60 in the edge region 13, and therefore the edge second solder point 60 is relatively close to the edge of the solar cell. The stress is more concentrated at the edge of the solar cell 100, so the tensile strength of the second solder point 60 and the solder strip 200 is insufficient, and it is easy to have a cold solder joint. Therefore, in this embodiment of the present invention, the solar cell 100 has a first grid line 70 connected to the end of the edge second solder point 60 near the first edge 101. The first grid line 70 can disperse the stress of the solder strip on the edge second solder point 60, which can increase the welding stability between the edge second solder point 60 and the solder strip, reduce the cold solder joint phenomenon of the solder strip, and thus reduce the defects of the battery module 1001.

[0098] In one possible implementation, the busbar 40 is electrically connected to all the second solder joints 60 of the same conductivity type. Thus, when a break occurs in the grid, current can bypass the break point through the second solder joints 60 and be transmitted to the busbar 40, allowing current to continue to flow. This avoids the inability of localized current transmission or accumulation in the solar cell 100 due to grid breakage, reducing the degradation of the solar cell 100's electrical performance and the risk of hot spots, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0099] Furthermore, in the second direction, the busbar 40 and the second solder joint 60, which have the same conductivity type, are arranged adjacent to each other. This allows for a close proximity arrangement between the busbar 40 and the second solder joint 60, thereby reducing the current transmission path between them and improving the cell efficiency of the solar cell 100.

[0100] The battery module 1001 provided by this utility model may include the solar cell 100 described in any of the above-mentioned claims. In the battery module 1001, the solar cell 100 may be welded with 10 to 30 solder strips, for example, 10, 15, 20, 25, or 30 strips. The specific number of solder strips welded to the solar cell 100 can be selected according to actual needs. It is understood that when the number of solder strips welded to the solar cell 100 is too small, the transmission distance between the grid and the solder strips will be too long, resulting in an excessively large additional series resistance of the solar cell 100, thereby reducing the photoelectric conversion efficiency of the solar cell 100. When the number of solder strips welded to the solar cell 100 is too large, the spacing between the solder strips will be too small, thereby increasing the risk of short circuits in the battery module 1001 and also increasing the total cost of the solder strips.

[0101] Therefore, setting the number of solder ribbons welded to the solar cell 100 to 10 to 30 can reduce the total cost of the solder ribbons while avoiding reducing the photoelectric conversion efficiency of the solar cell 100, thereby reducing the manufacturing cost of the battery module 1001.

[0102] It is understood that in such an embodiment, the battery assembly 1001 may also include a frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back surfaces of the solar cells 100, the photovoltaic glass, adjacent solar cells 100, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0103] Photovoltaic glass can be applied to the encapsulating film on the front side of the solar cell 100. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell 100 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell 100 together, providing sealing, insulation, and waterproofing / moisture protection for the solar cell 100.

[0104] The backsheet can be attached to the adhesive film on the back side of the solar cell 100. The backsheet provides protection and support for the solar cell 100, and possesses reliable insulation, water resistance, and aging resistance. Multiple options are available for the backsheet, typically including tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice is determined based on the specific circumstances and is not limited here. The backsheet, solar cell 100, adhesive film, and photovoltaic glass can be integrated into a frame. The frame serves as the main external support structure for the entire battery module 1001, providing stable support and installation for the battery module 1001. For example, the battery module 1001 can be installed at the desired location via the frame.

[0105] In the description of this specification, references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do 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 one or more embodiments or examples.

[0106] Furthermore, the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A solar cell, characterized in that, include: A battery substrate has a first surface and a second surface opposite to each other. The first surface includes a central grid line region and side grid line regions disposed on both sides of the central grid line region in a first direction. Multiple main gates are arranged along a second direction and extend along a first direction. The main gates are located in the side gate line area and avoid the middle gate line area. The second direction intersects the first direction. Multiple fine gates are arranged along a first direction and extend along a second direction. The fine gates include continuous fine gates in the middle gate line region and discontinuous fine gates in the side gate line region. The continuous fine gates are continuously arranged along the second direction. The discontinuous fine gates are spaced apart from the main gates with opposite conductivity types along the second direction. The portions of the discontinuous fine gates with the same conductivity type as themselves are conductively connected to the main gates. Multiple busbars are disposed on both sides of the first surface in the second direction and extend along the first direction. The busbars are conductively connected to the continuous fine gates with the same conductivity type. The busbars are spaced apart from the continuous fine gates with the opposite conductivity type. The portions of the busbars with the same conductivity type are conductively connected to the discontinuous fine gates. The portions of the busbars with the opposite conductivity type are spaced apart by the discontinuous fine gates.

2. The solar cell according to claim 1, characterized in that, It also includes a first axis of symmetry extending along the second direction, and the side gate line region includes a first side gate line region and a second side gate line region; The main gate located in the first side gate line region is symmetrical to the main gate located in the second side gate line region about the first axis of symmetry.

3. The solar cell according to claim 1, characterized in that, The length of the main gate in the first direction is 1 mm to 55 mm.

4. The solar cell according to claim 1, characterized in that, The main grid has at least one first solder joint.

5. The solar cell according to claim 4, characterized in that, The first surface includes two first edges extending along the second direction and disposed opposite to each other; In the first direction, the distance from the first edge to the first solder point closest to the first edge is 5 mm to 25 mm.

6. The solar cell according to claim 4, characterized in that, In the first direction, the distance between two adjacent first solder joints is the first distance; When there are multiple first spacings, the ratio of any two first spacings is between 0.8 and 1.

2.

7. The solar cell according to claim 4, characterized in that, The main grid includes a bent section connecting the end of the first solder joint, and the extending direction of the bent section intersects the first direction.

8. The solar cell according to claim 1, characterized in that, The first surface further includes edge regions disposed on both sides of the first surface in a second direction. The edge regions are provided with at least one second solder joint. The second solder joints are arranged along the first direction. The second solder joints are conductively connected to the portion of the fine gate that has the same conductivity type as themselves. The second solder joints are spaced apart from the fine gate that has the opposite conductivity type as themselves.

9. The solar cell according to claim 8, characterized in that, The first surface includes two first edges extending along the second direction and disposed opposite to each other; In one of the edge regions, the first and / or last second solder joints in the first direction are edge second solder joints, and the edge second solder joints are connected to a first grid line at one end near the first edge.

10. The solar cell according to claim 8, characterized in that, In the first direction, the distance between two adjacent second solder points is 5 mm to 260 mm.

11. The solar cell according to claim 8, characterized in that, In one of the edge regions, the line connecting the center points of each of the second solder joints is a first straight line segment, which is parallel to the first direction.

12. The solar cell according to claim 8, characterized in that, The busbar is electrically connected to all the second solder joints that have the same conductivity type.

13. A battery assembly, characterized in that, The battery assembly includes a solar cell as described in any one of claims 1 to 12.

14. A photovoltaic system, characterized in that, The photovoltaic system includes the battery module as described in claim 13.

Images